A major factor influencing life-history strategies of endotherms is body size. Larger endotherms live longer, develop more slowly, breed later and less frequently, and have fewer offspring per attempt at breeding. The classical evolutionary explanation for this pattern is that smaller animals experience greater extrinsic mortality, which favors early reproduction at high intensity. This leads to a short lifespan and early senescence by three suggested mechanisms. First, detrimental late-acting mutations cannot be removed because of the low force of selection upon older animals (mutation accumulation). Second, genes that promote early reproduction will be favored in small animals, even if they have later detrimental effects (antagonistic pleiotropy). Third, small animals may be forced to reduce their investment in longevity assurance mechanisms (LAMs) in favor of investment in reproduction (the disposable soma theory, DST). The DST hinges on three premises: that LAMs exist, that such LAMs are energetically expensive and that the supply of energy is limited. By contrast, the heat dissipation limit (HDL) theory provides a different conceptual perspective on the evolution of life histories in relation to body size. We suggest that rather than being limited, energy supplies in the environment are often unlimited, particularly when animals are breeding, and that animals are instead constrained by their maximum capacity to dissipate body heat, generated as a by-product of their metabolism. Because heat loss is fundamentally a surface-based phenomenon, the low surface-to-volume ratio of larger animals generates significant problems for dissipating the body heat associated with reproductive effort, which then limits their current reproductive investment. We suggest that this is the primary reason why fecundity declines as animal size increases. Because large animals are constrained by their capacity for heat dissipation, they have low reproductive rates. Consequently, only those large animals living in habitats with low extrinsic mortality could survive leading to the familiar patterns of life-history trade-offs and their links to extrinsic mortality rates. The HDL theory provides a novel mechanism underpinning the evolution of life history and ageing in endotherms, and makes a number of testable predictions that directly contrast with the predictions arising from the DST.

Ethanolic and aqueous extracts from seven plant species used in Turkish traditional medicine were evaluated for in vivo anti-inflammatory and antinociceptive activities; Helleborus orientalis Lam. roots and herbs, Juglans regia L. leaves, Laurocerasus officinalis Roemer leaves, Nerium oleander L. dried and fresh flowers and leaves, Rhododendron ponticum L. leaves, Rubus hirtus Walds. et Kit aerial parts and Rubus sanctus Schreber aerial parts and roots. All the plant extracts, except the aqueous extract of Rubus hirtus, were shown to possess significant antinociceptive activity in varying degrees against p-benzoquinone-induced abdominal contractions in mice. However, only the ethanolic extracts of Helleborus orientalis roots, Juglans regia leaves, Laurocerasus officinalis leaves, Nerium oleander dried and fresh flowers, and Rhododendron ponticum leaves exhibited potent anti-inflammatory activity against carrageenan-induced hind paw edema model in mice without inducing any gastric damage. Results of the present study confirmed the folkloric claim that all the selected materials to possess potent antinociceptive and anti-inflammatory activity.

OBJECTIVE

To assess the clinical effectiveness and cost-effectiveness of adefovirdipivoxil (ADV) and pegylated interferon alfa-2a (PEG) for the treatment of adults with chronic hepatitis B infection (CHB).

METHODS

Electronic databases for the period from 1995-6 to April 2005. Websites of the relevant organisations.

METHODS

Searches were made for studies of clinical effectiveness, cost-effectiveness, quality of life, resource use/costs and epidemiology/natural history. Randomised controlled trials (RCTs) were included that compared PEG and ADV with currently licensed treatments for CHB, including non-pegylated ('standard') interferon alfa (IFN), lamivudine (LAM), and best supportive care. The trials were reviewed in a narrative synthesis but meta-analysis was not undertaken owing to heterogeneity in the interventions and comparators evaluated. A model was developed to estimate the cost-effectiveness (cost-utility) of PEG and of ADV compared with IFN, LAM and best supportive care in a UK cohort of adults with CHB. The perspective of the cost-effectiveness analysis was that of the NHS and personal social services. A Markov state transition model was constructed, informed by a systematic search of the literature to identify source material on the natural history, epidemiology and treatment of CHB. Interventions were evaluated against their closest comparator (for PEG this is IFN, and for ADV this is LAM). In addition, the cost-effectiveness of sequential treatment scenarios was modelled.

RESULTS

A total of 1086 references to clinical effectiveness studies were identified, of which seven fully published RCTs and one systematic review met the inclusion criteria. Four of the RCTs evaluated the effectiveness of ADV and three reported results for PEG. In addition, a conference abstract was included reporting interim results from an on-going Phase II RCT of ADV in combination with LAM. The published trials were of good quality, although details of randomisation and allocation of concealment were poorly reported. ADV was significantly more effective than placebo. Response rates were in the range 21-51% compared with 0%, respectively. For patients resistant to LAM, response rates were significantly higher for those treated with ADV in addition to on-going LAM (35-85%) than those who continued on LAM with placebo (0-11%). Significant alanine aminotransferase (ALT) reductions to normal levels were observed in all studies. For treatment-naive patients, seroconversion rates were 12-14% for ADV compared with 6% for placebo (statistically significant), rates were higher for LAM-resistant patients who received ADV in addition to on-going LAM (8%) than those who continued on LAM with placebo (2%) (no significance value was reported), and rates were higher for LAM-resistant patients who switched to ADV than those who continued on LAM with placebo (11 versus 0%, respectively; not statistically significant). HBsAg loss or seroconversion was observed in less than 5% of patients taking ADV. Two ADV studies reported changes in liver histology. In general, histological improvement and necroinflammatory activity/fibrosis scores were significantly better in ADV groups than in placebo groups. Dose discontinuations for safety reasons were low for patients receiving ADV. With the exception of headache, the most commonly reported adverse events were often seen in the placebo groups in similar proportions to the ADV groups, with different trials reporting conflicting results. PEG/LAM dual therapy and PEG monotherapy were similar in effect on HBV DNA and ALT levels, and both were significantly superior to LAM monotherapy. Response rates were higher for HBeAg-negative patients than for HBeAg-positive patients. HBeAg seroconversion rates at follow-up were significantly higher for PEG monotherapy patients than for those receiving either a combination of PEG and LAM or LAM monotherapy (32, 27 and 19%, respectively). For the comparison between PEG and IFN-2a, there was a significant difference in the combined outcome of ALT normalisation, HBV DNA response and HBeAg seroconversion at follow-up (24 versus 12%, respectively). Changes in liver histology were reported by two studies. There was no statistically significant difference in histological improvement between the PEG monotherapy groups, the LAM monotherapy groups and the dual therapy groups. Two PEG trials reported small percentages (up to 5%) of HBsAg loss or seroconversion among patients receiving PEG either as monotherapy or in combination with LAM, but no HBsAg loss or seroconversion was reported in those receiving LAM monotherapy. Health-related quality of life (HRQoL) scores, as measured by the Short Form with 36 Items, decreased during treatment, but returned to at least baseline levels at follow-up (based on unpublished data). For HBeAg-positive patients, there were no significant differences in scores between treatment groups. Dose discontinuations for safety reasons were significantly higher for patients receiving PEG than for patients receiving LAM monotherapy. The most commonly reported adverse events in the PEG studies were headache, pyrexia, fatigue, myalgia and alopecia. Only one fully published economic evaluation was identified, reporting a US cost-effectiveness study of ADV as salvage therapy for chronic hepatitis B with LAM resistance. A Markov model was used to estimate cost-effectiveness of interferon alfa (6-12 months), LAM and LAM followed by ADV when resistance occurs. ADV generated the most (undiscounted) life-years, but at highest costs, with an incremental cost-effectiveness ratio (ICER) of US$14,204 per life-year gained. Using our model, incremental cost per QALY estimates (baseline cohort of all patients) were: 5994 pounds for IFN compared with best supportive care, 6119 pounds for PEG compared with IFN, 3685 pounds for LAM compared with best supportive care, and 16,569 pounds for ADV compared with LAM. Incremental cost per QALY estimates (HBeAg-positive patients only) were: 7936 pounds for IFN (24 weeks) compared with best supportive care, 16,166 pounds for PEG (48 weeks) compared with IFN (24 weeks), 3489 pounds for LAM compared with best supportive care, and 15,289 pounds for ADV compared with LAM. Incremental cost per QALY estimates (HBeAg-negative patients only) were: 3922 pounds for IFN (48 weeks) compared with best supportive care, 2162 pounds for PEG (48 weeks) compared with IFN (24 weeks), 4131 pounds for LAM compared with best supportive care, and 18,620 pounds for ADV compared with LAM. For the sequential treatment strategies, incremental cost per QALY estimates ranged from 3604 pounds (IFN followed by LAM versus IFN alone) to 11,402 pounds (IFN followed by LAM with adefovir salvage versus IFN followed by LAM). In all of these cases, the ICERs are well within the range that would conventionally be regarded as being cost-effective. The probabilistic sensitivity analysis found that LAM is a cost-effective option at lower willingness-to-pay thresholds for health outcomes, but as the threshold is increased adefovir is increasingly likely to be the optimal intervention. Where a willingness-to-pay threshold of above 10,000 pounds per QALY is employed, PEG is highly likely to be the optimal intervention compared with IFN (based on a cohort of HBeAg-positive and -negative patients). Interferon alfa (non-pegylated or pegylated) followed by LAM would be the optimal strategy at lower willingness-to-pay thresholds. As the threshold increases, the sequential treatment strategy of PEG followed by LAM with adefovir added as salvage therapy is increasingly likely to be the optimal intervention.

CONCLUSIONS

ADV and PEG are associated with significant improvements in a number of biochemical, virological and histological outcomes in both HBeAg-positive and -negative patients. For a small proportion of patients this is associated with resolution of infection. For another proportion it leads to remission and a reduced risk of progressing to cirrhosis, hepatocellular carcinoma, liver transplant and death. For others who do not respond or who relapse, retreatment with another agent is necessary. The results of our cost-effectiveness analysis demonstrate that incremental costs per QALY for a range of comparisons were between 5994 pounds and 16,569 pounds and within the range considered by NHS decision-makers to represent good value for money. When subjected to sensitivity analysis, most costs per QALY estimates remained under 30,000 pounds. Further RCT evidence of the effectiveness of anti-viral treatment is required, particularly for subgroups of patients with different genotypes, patients with cirrhosis, patients from different ethnic groups, patients with co-infections (e.g. HIV, HCV) and co-morbidities, liver transplant patients and children and adolescents.

Lysosomal alpha-mannosidase (LAM: EC 3.2.1.24) belongs to the sequence-based glycoside hydrolase family 38 (GH38). Two other mammalian GH38 members, Golgi alpha-mannosidase II (GIIAM) and cytosolic alpha-mannosidase, are expressed in all tissues. In humans, cattle, cat and guinea pig, lack of lysosomal alpha-mannosidase activity causes the autosomal recessive disease alpha-mannosidosis. Here, we describe the three-dimensional structure of bovine lysosomal alpha-mannosidase (bLAM) at 2.7A resolution and confirm the solution state dimer by electron microscopy. We present the first structure of a mammalian GH38 enzyme that offers indications for the signal areas for mannose phosphorylation, suggests a previously undetected mechanism of low-pH activation and provides a template for further biochemical studies of the family 38 glycoside hydrolases as well as lysosomal transport. Furthermore, it provides a basis for understanding the human form of alpha-mannosidosis at the atomic level. The atomic coordinates and structure factors have been deposited in the Protein Data Bank (accession codes 1o7d and r1o7dsf).

OBJECTIVE

The objective of the study was to correlate the presence of major levator ani muscle (LAM) injuries on magnetic resonance imaging (MRI) with fecal incontinence (FI), pelvic organ prolapse (POP), and urinary incontinence (UI) in primiparous women 6-12 months postpartum.

METHODS

A published scoring system was used to characterize LAM injuries on MRI dichotomously (MRI negative, no/mild vs MRI positive, major).

RESULTS

Major LAM injuries were observed in 17 of 89 (19.1%) women who delivered vaginally with external anal sphincter (EAS) injuries, 3 of 88 (3.5%) who delivered vaginally without EAS injury, and 0 of 29 (0%) who delivered by cesarean section before labor (P=.0005). Among women with EAS injuries, those with major LAM injuries trended toward more FI, 35.3% vs 16.7% (P=.10) and POP, 35.3% vs 15.5% (P=.09), but not UI (P=1.0).

CONCLUSIONS

These data support the growing body of literature suggesting that both EAS and LAM are important for fecal continence and that multiple injuries contribute to pelvic floor dysfunction.

Maintenance of cell-wall integrity in Mycobacterium tuberculosis is essential and is the target of several antitubercular drugs. For example, ethambutol targets arabinogalactan and lipoarabinomannan (LAM) biosynthesis through the inhibition of several arabinofuranosyltransferases. Apart from their role in cell-wall integrity, mycobacterial LAMs also exhibit important immunomodulatory activities. Here we report the isolation and detailed structural characterization of a unique LAM molecule derived from Mycobacterium smegmatis deficient in the arabinofuranosyltransferase AftC (AftC-LAM). This mutant LAM expresses a severely truncated arabinan domain completely devoid of 3,5-Araf-branching residues, revealing an intrinsic involvement of AftC in the biosynthesis of LAM. Furthermore, we found that ethambutol efficiently inhibits biosynthesis of the AftC-LAM arabinan core, unambiguously demonstrating the involvement of the arabinofuranosyltransferase EmbC in early stages of LAM-arabinan biosynthesis. Finally, we demonstrate that AftC-LAM exhibits an enhanced proinflammatory activity, which is due to its ability to activate Toll-like receptor 2 (TLR2). Overall, our efforts further describe the mechanism of action of an important antitubercular drug, ethambutol, and demonstrate a role for specific arabinofuranosyltransferases in LAM biosynthesis. In addition, the availability of sufficient amounts of chemically defined wild-type and isogenic truncated LAMs paves the way for further investigations of the structure-function relationship of TLR2 activation by mycobacterial lipoglycans.

Recently, a combination of spoligotyping and bioinformatics was proposed as a potential tool for defining major circulating clades of tuberculosis bacilli. In the present study, we attempted to validate the above mentioned classification using a new high-throughput marker, named mycobacterial interspersed repetitive units (MIRUs). Using 12 MIRU loci and spoligotyping, we performed data mining of results on clinical isolates of the Mycobacterium tuberculosis complex representative of global mycobacterial allelic diversity. Knowledge rules permitting automatic labeling of major M. tuberculosis families were defined. Using this strategy, MIRU 24 appeared to be most appropriate for classifying our dataset. The Bovis family was shown to be perfectly classified by a maximum of 3 MIRUs, followed by Africanum and East African Indian (EAI) families by 4 MIRUs, the Beijing family by 6 MIRUs, Haarlem and X families by 8 MIRUs, the T family by 9, and the Latin-American and Mediterranean (LAM) family by 10 MIRUs. Considering the hierarchy of family divergence, our results corroborate a recent suggestion that EAI is the ancestral family followed by Africanum and Bovis. On the other hand, T, X, LAM and Haarlem families appear to be of more recent evolution. These results indicate that data mining of MIRUs is a valuable new tool for analyzing the evolutionary dynamics of the M. tuberculosis complex, and for monitoring an infectious disease such as tuberculosis.

BACKGROUND

A rapid diagnostic test for active tuberculosis (TB) at the clinical point-of-care could expedite case detection and accelerate TB treatment initiation. We assessed the diagnostic accuracy of a rapid urine lipoarabinomannan (LAM) test for TB screening among HIV-infected adults in a TB-endemic setting.

METHODS

We prospectively enrolled newly-diagnosed HIV-infected adults (≥18 years) at 4 outpatient clinics in Durban from Oct 2011-May 2012, excluding those on TB therapy. A physician evaluated all participants and offered CD4 cell count testing. Trained study nurses collected a sputum sample for acid-fast bacilli smear microscopy (AFB) and mycobacterial culture, and performed urine LAM testing using Determine™ TB LAM in the clinic. The presence of a band regardless of intensity on the urine LAM test was considered positive. We defined as the gold standard for active pulmonary TB a positive sputum culture for Mycobacterium tuberculosis. Diagnostic accuracy of urine LAM was assessed, alone and in combination with smear microscopy, and stratified by CD4 cell count.

RESULTS

Among 342 newly-diagnosed HIV-infected participants, 190 (56%) were male, mean age was 35.6 years, and median CD4 was 182/mm3. Sixty participants had culture-positive pulmonary TB, resulting in an estimated prevalence of 17.5% (95% CI 13.7-22.0%). Forty-five (13.2%) participants were urine LAM positive. Mean time from urine specimen collection to LAM test result was 40 minutes (95% CI 34-46 minutes). Urine LAM test sensitivity was 28.3% (95% CI 17.5-41.4) overall, and 37.5% (95% CI 21.1-56.3) for those with CD4 count <100/mm3, while specificity was 90.1% (95% CI 86.0-93.3) overall, and 86.9% (95% CI 75.8-94.2) for those with CD4 < 100/mm3. When combined with sputum AFB (either test positive), sensitivity increased to 38.3% (95% CI 26.0-51.8), but specificity decreased to 85.8% (95% CI 81.1-89.7).

CONCLUSIONS

In this prospective, clinic-based study with trained nurses, a rapid urine LAM test had low sensitivity for TB screening among newly-diagnosed HIV-infected adults, but improved sensitivity when combined with sputum smear microscopy.

CD14 is a signaling receptor for both gram-negative bacterial lipopolysaccharide (LPS) and mycobacterial lipoarabinomannan (LAM) that lacks terminal mannosyl units (AraLAM). In contrast, terminally mannosylated LAM (ManLAM) binds the macrophage mannose receptor (MMRc), although the ability of the MMRc to serve as a signaling receptor has not been previously reported. We compared the abilities of AraLAM and ManLAM to induce distinct responses in two monocytic cell populations, freshly isolated human peripheral blood monocytes (PBM) and monocyte-derived macrophages (MDM). The responses examined were chemotaxis and transient changes in free cytosolic calcium ([Ca2+]in). We found that AraLAM but not ManLAM was chemotactic for both PBM and MDM. Migration of these cells in vitro to AraLAM was specifically blocked by an anti-CD14 monoclonal antibody, suggesting that CD14 mediates the chemotactic response to AraLAM. Subsequently, we found that AraLAM induced a transient rise in [Ca2+]in levels within a subpopulation of PBM but not MDM. This response was blocked by anti-CD14 antibodies. In contrast, ManLAM induced a transient rise in [Ca2+]in levels within a subpopulation of MDM but not PBM. This response was blocked by either anti-CD14 or anti-MMRc antibodies. These data suggest that the MMRc can serve as a signaling receptor and that coligation of both CD14 and the MMRc is required to elicit a specific response. Thus, one response to LAM (chemotaxis) can be elicited solely by engaging CD14, whereas a different response (changes in [Ca2+]in levels) depends on both the differentiation state of the cells and concomitant engagement of CD14 and the MMRc.

Correlations were made between clinical and follow-up data and histopathologic findings in 105 women (mean age +/- standard deviation, 38.3 +/- 9.0 years) with pulmonary lymphangioleiomyomatosis (LAM). The actuarial survival (to pulmonary transplantation or death) of the patients from the time of lung biopsy was 85.1% and 71.0% after 5 and 10 years respectively. The histologic severity of LAM, graded as a LAM histologic score (LHS), was determined on the basis of semiquantitative estimation of the percentage of tissue involvement by the two major features of LAM: the cystic lesions and the infiltration by abnormal smooth muscle cells (LAM cells) in each case: LHS-1, <25%; LHS-2, 25% to 50%; and LHS-3, >50%. Analysis using the Kaplan-Meier method revealed significant differences in survival for patients with LHS-1, -2, and -3 (p = 0.01). The 5-and 10-year survivals were 100% and 100% for LHS-1, 81.2% and 74.4% for LHS-2, and 62.8% and 52.4% for LHS-3. Increased degrees of accumulation of hemosiderin in macrophages also were associated with higher LHS scores (p = 0.029) and a worse prognosis (p = 0.0012). Thus, the current study suggests that the LHS may provide a basis for determining the prognosis of LAM.

Tuberous sclerosis complex (TSC) is an autosomal-dominant disorder characterized by the formation of hamartomatous lesions in multiple organ systems. It is the second most common neurocutaneous syndrome after neurofibromatosis type 1 and has been recognized since the late 1800s. Although the disease has complete penetrance, there is also high phenotypic variability: some patients have obvious signs at birth, while others remain undiagnosed for many years. In addition to skin lesions, TSC patients develop numerous brain lesions, angiomyolipoma (AMLs), lymphangiomyomatosis (LAM) in the lungs, cardiac rhabdomyomas, skeletal lesions, and vascular anomalies, all of which are well seen with medical imaging. Our knowledge of TSC genetics and pathophysiology has expanded dramatically in recent years: two genetic loci were discovered in the 1990s and recent elucidation of TSC's interaction with the mTOR pathway has changed how we manage the disease. Meanwhile, medical imaging is playing an increasingly important role in the diagnosis, management, and treatment of TSC. We provide an update on the genetics and pathophysiology of TSC, review its clinical manifestations, and explore the breadth of imaging features in each organ system, from prenatal detection of cardiac rhabdomyomas to monitoring rapamycin therapy to treatment of AMLs by interventional radiology.

Hepatitis B virus (HBV) infection is a major public health problem, and HBV-related acute-on-chronic liver failure (ACLF) has an extremely poor prognosis. There is no standard approach for managing ACLF. Nucleos(t)ide analogue has been proven effective in suppressing viral replication, improving histology and biochemical, and decreasing the inflammatory response in patients with chronic hepatitis B. This study was designed to evaluate the short-term and long-term efficacy of nucleoside analogue treatment of patients with HBV-related ACLF. One hundred and six consecutive subjects were recruited from 2,308 patients with elevated alanine aminotransferase activity. Forty-two patients were treated with 0.5 mg entecavir (ETV) daily (ETV group); 30 patients received 100 mg lamivudine (LAM) daily (LAM group); 34 patients did not take any nucleos(t)ide analogues (non-NAs group). All eligible patients were given standard medical treatment. All the patients were followed up until death or until October 2010. The HBV DNA levels and the short-term and long-term efficacy of the drugs were evaluated. After 3 weeks of nucleoside analogue treatment and/or supportive therapy, HBV DNA levels were decreased when compared with the baseline level in the ETV group (7.04 ± 1.58 log(10) IU/mL vs. 4.03 ± 2.04 log(10) IU/mL, P = 0.001), the LAM group (7.25 ± 0.89 log(10) IU/mL vs. 4.33 ± 2.48 log(10) IU/mL, P = 0.01), and the non-NAs group (5.73 ± 0.96 log(10) IU/mL vs. 4.21 ± 1.47 log(10) IU/mL, P = 0.01). The ETV and LAM groups showed a similar accumulative mortality in the first 3 months of treatment (33.3% vs. 40%, χ(2) = 0.568, P = 0.374). The non-NAs group had a significantly high mortality, compared with the ETV group (64.7% vs. 33.3%, χ(2) = 7.163, P = 0.007), the LAM group (64.7% vs. 40%, χ(2) = 3.906, P = 0.042), and the nucleoside analogue group (ETV group + LAM group) (64.7% vs. 36.2%, χ(2) = 7.443, P = 0.006). All the 56 patients survived were followed up to October 2010. The median follow-up period was 7.3 months. Recurrence was observed in a total of 6 patients (10.72%), of whom 4 patients (33.33%) were from the non-NAs group, 2 (11.11%) from the LAM group after cessation LAM therapy by patients himself, and 0 from the ETV group (P = 0.003). Nucleoside analogue may improve the short-term and long-term prognosis of patients with HBV-related ACLF.

Recommendations regarding key aspects related to the diagnosis and pharmacological treatment of lymphangioleiomyomatosis (LAM) were recently published. We now provide additional recommendations regarding four specific questions related to the diagnosis of LAM and management of pneumothoraces in patients with LAM.

Systematic reviews were performed and then discussed by a multidisciplinary panel. For each intervention, the panel considered its confidence in the estimated effects, the balance of desirable (i.e., benefits) and undesirable (i.e., harms and burdens) consequences, patient values and preferences, cost, and feasibility. Evidence-based recommendations were then formulated, written, and graded using the GRADE (Grading of Recommendations, Assessment, Development, and Evaluation) approach.

For women who have cystic changes on high-resolution computed tomography of the chest characteristic of LAM, but who have no additional confirmatory features of LAM (i.e., clinical, radiologic, or serologic), the guideline panel made conditional recommendations against making a clinical diagnosis of LAM on the basis of the high-resolution computed tomography findings alone and for considering transbronchial lung biopsy as a diagnostic tool. The guideline panel also made conditional recommendations for offering pleurodesis after an initial pneumothorax rather than postponing the procedure until the first recurrence and against pleurodesis being used as a reason to exclude patients from lung transplantation.

Evidence-based recommendations for the diagnosis and treatment of patients with LAM are provided. Frequent reassessment and updating will be needed.

Lymphangioleiomyomatosis (LAM) is a destructive lung disease of women associated with the metastasis of tuberin-null cells with hyperactive mammalian target of rapamycin complex 1 (mTORC1) activity. Clinical trials with the mTORC1 inhibitor rapamycin have revealed partial efficacy but are not curative. Pregnancy appears to exacerbate LAM, suggesting that estrogen (E2) may play a role in the unique features of LAM. Using a LAM patient-derived cell line (bearing biallelic Tuberin inactivation), we demonstrate that E2 stimulates a robust and biphasic activation of ERK2 and transcription of the late response-gene Fra1 associated with epithelial-to-mesenchymal transition. In a carefully orchestrated collaboration, activated mTORC1/S6K1 signaling enhances the efficiency of Fra1 translation of Fra1 mRNA transcribed by the E2-ERK2 pathway, through the phosphorylation of the S6K1-dependent eukaryotic translation initiation factor 4B. Our results indicate that targeting the E2-ERK pathway in combination with the mTORC1 pathway may be an effective combination therapy for LAM.

OBJECTIVE

To evaluate antiviral prophylaxis against hepatitis B virus (HBV) following liver transplantation.

METHODS

Systematic review and meta-analysis. Clinical trials and comparative cohort studies comparing the use of hepatitis B immunoglobulin (HBIg), antivirals, or both following liver transplantation for HBV infection were included. The primary outcome was reappearance of hepatitis B surface antigen (HBsAg). Other outcomes included all-cause and HBV-related mortality, HB-related active liver disease, and reappearance of HBV DNA after transplantation. Relative risks (RR) with 95% confidence intervals (CIs) are reported.

RESULTS

Twenty studies (22 comparisons) were included. Ten studies compared HBIg to combination treatment, 9 compared antivirals to combination treatment, and 3 compared lamivudine (LAM) to HBIg. Combination treatment reduced HBsAg reappearance (RR 0.28; 95% CI 0.12-0.66), and was superior to HBIg alone in all other outcome measures. Combination treatment was significantly better than antivirals in preventing reappearance of HBsAg (RR 0.31; 95% CI 0.22-0.44), even when low-dose HBIg was given. No significant difference was found between HBIg and LAM monotherapy for all measured outcomes. Major limitations with regard to comparability of the study groups in non-randomized trials were revealed.

CONCLUSIONS

Combination treatment with HBIg and LAM reduced HBV recurrence following liver transplantation, compared with HBIg or LAM alone, and reduced mortality compared with HBIg alone.

The C-type lectin dendritic cell (DC)-specific intercellular adhesion molecule 3-grabbing nonintegrin (DC-SIGN) is the major receptor on DCs for mycobacteria of the Mycobacterium tuberculosis complex. Recently, we have shown that although the mannose caps of the mycobacterial surface glycolipid lipoarabinomannan (ManLAM) are essential for the binding to DC-SIGN, genetic removal of these caps did not diminish the interaction of whole mycobacteria with DC-SIGN and DCs. Here we investigated the role of the structurally related glycolipids phosphatidylinositol mannosides (PIMs) as possible ligands for DC-SIGN. In a binding assay with both synthetic and natural PIMs, DC-SIGN exhibited a high affinity for hexamannosylated PIM(6), which contains terminal alpha(1-->2)-linked mannosyl residues identical to the mannose cap on ManLAM, but not for di- and tetramannosylated PIM(2) and PIM(4), respectively. To determine the role of PIM(6) in the binding of whole mycobacteria to DC-SIGN, a mutant strain of M. bovis bacillus Calmette-Guérin deficient in the production of PIM(6) (Delta pimE) was created, as well as a double knockout deficient in the production of both PIM(6) and the mannose caps on LAM (Delta pimE Delta capA). Compared to the wild-type strain, both mutant strains bound similarly well to DC-SIGN and DCs. Furthermore, the wild-type and mutant strains induced comparable levels of interleukin-10 and interleukin-12p40 when used to stimulate DCs. Hence, we conclude that, like ManLAM, PIM(6) represents a bona fide DC-SIGN ligand but that other, as-yet-unknown, ligands dominate in the interaction between mycobacteria and DCs.

Mycobacterium tuberculosis (Mtb), the causative agent of tuberculosis (TB), infects one-third of the world's population and causes 1.5 million deaths each year. The cell envelopes of mycobacteria comprise a wealth of unique glycolipids, including trehalose-6,6'-dimycolate (TDM), lipoarabinomannan (LAM), lipomannan (LM), and phosphatidylinositol (PI) mannosides (PIMs). These lipids are important modulators of the host immune responses during infection and in some cases have been used as adjuvants [e.g., complete Freund's adjuvant (CFA)]. Despite this abundant basic knowledge, the identities of the host immune receptors for mycobacterial lipids have long been elusive. Here we review and summarize our current state of knowledge regarding innate immune receptors for mycobacteria, focusing particularly on immunoreceptor tyrosine-based activation motif (ITAM)-coupled C-type lectin receptors (CLRs), which have been shown to recognize mycobacteria-derived glycolipids.

The leaves of Moringa oleifera Lam (Moringaceae) are used by the Indians in their herbal medicine as a hypocholesterolemic agent in obese patients. The scientific basis for their use in hypercholesterolemia was therefore examined. It was found that administration of the crude leaf extract of Moringa oleifera along with high-fat diet decreased the high-fat diet-induced increases in serum, liver, and kidney cholesterol levels by 14.35% (115-103.2 mg/100 ml of serum), 6.40% (9.4-8.8 mg/g wet weight) and 11.09% (1.09-0.97 mg/g wet weight) respectively. The effect on the serum cholesterol was statistically significant. No significant effect on serum total protein was observed. However, the crude extract increased serum albumin by 15.22% (46-53 g/l). This value was also found to be statistically significant. It was concluded that the leaves of Moringa oleifera have definite hypocholesterolemic activity and that there is valid pharmacological basis for employing them for this purpose in India.

Lymphangioleiomyomatosis (LAM) is a slowly progressive lung disease that is associated with mutations in tuberous sclerosis complex genes, infiltration of the pulmonary parenchyma and lymphatics with neoplastic smooth muscle cells, extensive tissue remodeling and architectural distortion of the lung, and tumors of the chest and abdomen, including lymphangiomyomas and angiomyolipomas. LAM occurs in women in the general population and in patients of both genders with tuberous sclerosis. Overt clinical manifestations of LAM occur almost exclusively in females, however, and include progressive dyspnea on exertion, recurrent pneumothorax, and chylous effusions. The molecular basis of LAM has been extensively characterized over the past decade, resulting in the development of a targeted therapy. This article reviews emerging approaches to the diagnosis and treatment of LAM.

The mammalian/mechanistic target of rapamycin complex 1 (mTORC1) signaling pathway is hyperactivated in a variety of cancers and disorders, including lymphangioleiomyomatosis (LAM) and tuberous sclerosis complex (TSC), which are characterized by mutations in tumor suppressors TSC1 or TSC2. The concern with the use of mTORC1 inhibitors, such as rapamycin or its analogs (rapalogs), is that they cause upregulation of autophagy and suppress the negative feedback loop to Akt, which promotes cell survival, causing the therapy to be only partially effective, and relapse occurs upon cessation of treatment. In this study, we investigate the use of rapamycin in combination with resveratrol, a naturally occurring polyphenol, in TSC2-deficient cells. We tested whether such combination would prevent rapamycin-induced upregulation of autophagy and shift the cell fate toward apoptosis. We found that this combination treatment blocked rapamycin-induced upregulation of autophagy and restored inhibition of Akt. Interestingly, the combination of rapamycin and resveratrol selectively promoted apoptosis of TSC2-deficient cells. Thus, the addition of resveratrol to rapamycin treatment may be a promising option for selective and targeted therapy for diseases with TSC loss and mTORC1 hyperactivation.

OBJECTIVE

To assess the performance indicators of visual inspection with acetic acid (VIA) and visual inspection with Lugol's iodine (VILI) in four Latin American centres participating in the ongoing Latin AMerican Screening (LAMS) study, in settings with moderate incidence of cervical disease and with poorly to moderately well-organized cervical cancer screening.

METHODS

Three Brazilian centres (São Paulo, Campinas and Porto Alegre) and one Argentine centre (Buenos Aires) recruited a total of 11,834 healthy women to undergo VIA, VILI, conventional Pap smear and Hybrid Capture II (HCII).

METHODS

Women who had a positive result from any of these tests were subjected to colposcopy and biopsies (if necessary), and women with high-grade cervical intraepithelial neoplasia (CIN) were properly treated. To control for verification bias, 5% of women with normal tests were referred for colposcopy, as were 20% of HCII-negative women.

RESULTS

Data on VIA (n=11,834), VILI (n=2994), conventional Pap smear (n=10,138) and HCII (n=4195) were available for test comparisons, calculating sensitivity, specificity, and positive and negative predictive values. Overall test positivity was 11.6% for VIA, 23.0% for VILI, 2.2% for Pap smear (LSIL threshold), 1.1% for Pap smear (HSIL threshold) and 17.1% for HCII. VIA was positive in 61.8% of the women with CIN 1, 57.0% of those with CIN 2, 35.0% of women with CIN 3 and in 21 of 28 (75%) of women with cancer. Approximately 10% of women with no detectable disease had an abnormal VIA. Regarding VILI, 83.3% of women diagnosed with CIN 1 and 62.5% of those with CIN 3 had an abnormal test. VILI failed to detect one of three cases of cancer. Both the sensitivity, specificity and positive predictive value of VIA and VILI in detecting CIN 2 or CIN 3 could be significantly improved depending on the combination with Pap smear or HCII (sensitivity up to 100.0% and specificity up to 99.8%).

CONCLUSIONS

The LAMS study failed to reproduce the performance figures obtained with VIA and VILI (as stand-alone tests) in some other settings, where the prevalence of cervical disease was higher. However, a combined use of VIA or VILI with the Pap test or HCII allowed specific detection of cervical abnormalities.

Sweetpotato (Ipomoea batatas Lam.) is an important industrial crop and source of food that contains useful components, including antioxidants such as carotenoids. β-Carotene hydroxylase (CHY-β) is a key regulatory enzyme in the beta-beta-branch of carotenoid biosynthesis and it catalyzes hydroxylation into both β-carotene to β-cryptoxanthin and β-cryptoxanthin to zeaxanthin. To increase the β-carotene content of sweetpotato through the inhibition of further hydroxylation of β-carotene, the effects of silencing CHY-β in the carotenoid biosynthetic pathway were evaluated. A partial cDNA encoding CHY-β was cloned from the storage roots of orange-fleshed sweetpotato (cv. Shinhwangmi) to generate an RNA interference-IbCHY-β construct. This construct was introduced into cultured cells of white-fleshed sweetpotato (cv. Yulmi). Reverse transcription-polymerase chain reaction analysis confirmed the successful suppression of IbCHY-β gene expression in transgenic cultured cells. The expression level of phytoene synthase and lycopene β-cyclase increased, whereas the expression of other genes showed no detectable change. Down-regulation of IbCHY-β gene expression changed the composition and levels of carotenoids between non-transgenic (NT) and transgenic cells. In transgenic line #7, the total carotenoid content reached a maximum of 117 μg/g dry weight, of which β-carotene measured 34.43 μg/g dry weight. In addition, IbCHY-β-silenced calli showed elevated β-cryptoxanthin and zeaxanthin contents as well as high transcript level P450 gene. The 2,2-diphenyl-1-picrylhydrazyl radical scavenging activity (DPPH) in transgenic cells was more than twice that in NT cells. RNA-IbCHY-β calli increased abscisic acid (ABA) content, which was accompanied by enhanced tolerance to salt stress. In addition, the production of reactive oxygen species measured by 3,3'-diaminobenzidine (DAB) staining was significantly decreased in transgenic cultured cells under salt stress. Taken together, the present results indicate that down-regulation of IbCHY-β increased β-carotene contents and total carotenoids in transgenic plant cells and enhanced their antioxidant capacity.

BACKGROUND

The objectives of this curricular innovation project were to implement a flipped classroom curriculum for the gynaecologic oncology topics of the obstetrics and gynaecology medical student clerkship, and to evaluate student satisfaction with the change.

METHODS

Four short online videos on the topics of endometrial hyperplasia, cervical dysplasia, evaluation of an adnexal mass, and ovarian cancer were created, and students were instructed to view them prior to a class-time active learning session. The Learning Activity Management System (lams) open-source online platform was used to create an active learning class-time activity that consisted of a coached discussion of cases. Student satisfaction with the two aspects of the flipped curriculum was obtained. In addition, lecture assessment for the gynaecologic oncology topics and aggregate student performance on the gynaecological oncology questions of the US National Board of Medical Examiners (NBME) Subject Examination were compared before and after implementation of the curriculum.

RESULTS

Eighty-nine students rotated on the clerkship during the pilot period of analysis. Seventy-one students (80%) viewed the videos prior to the class session, and 84 (94%) attended the session. Student satisfaction was very high for both parts of the curriculum. There was no significant difference in aggregate student performance on the gynaecological oncology questions of the NBME Subject Examination. The flipped classroom curriculum demonstrates a promising platform for using technology to make better use of students' time

CONCLUSIONS

Our implementation of the flipped classroom curriculum for the gynaecologic oncology topics successfully demonstrates a promising platform for using technology to make better use of our students' time, and for increasing their satisfaction with the necessary didactic learning of the clerkship.

BACKGROUND

The genus Mycobacterium includes a number of medically important pathogens. The cell walls of these bacteria have many unique features, including the abundance of various inositol lipids, such as phosphatidylinositol mannosides (PIMs), lipomannan (LM), and lipoarabinomannan (LAM). The biosynthesis of these lipids is believed to be prime drug targets, and has been clarified in detail over the past several years.

METHODS

Here we summarize our current understanding of the inositol lipid metabolism in mycobacteria. We will highlight unsolved issues and future directions especially in the context of metabolic regulation.

CONCLUSIONS

Inositol is a building block of phosphatidylinositol (PI), which is further elaborated to become PIMs, LM and LAM. d-myo-inositol 3-phosphate is an intermediate of the de novo inositol synthesis, but it is also the starting substrate for mycothiol synthesis. Controlling the level of d-myo-inositol 3-phosphate appears to be important for maintaining the steady state levels of mycothiol and inositol lipids. Several additional control mechanisms must exist to control the complex biosynthetic pathways of PI, PIMs, LM and LAM. These may include regulatory proteins such as a lipoprotein LpqW, and spatial separation of enzymes, such as the amphipathic PimA mannosyltransferase and later enzymes in the PIMs/LM biosynthetic pathway. Finally, we discuss mechanisms that underlie control of LM/LAM glycan polymer elongation.

CONCLUSIONS

Mycobacteria have evolved a complex network of inositol metabolism. Clarifying its metabolism will not only provide better understanding of bacterial pathogenesis, but also understanding of the evolution and general functions of inositol lipids in nature.