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Publication
Journal: Developmental Biology
December/28/2005
Abstract
To elucidate the function of metazoan B-type lamins during development, new null mutations of the Drosophila B-type lamin gene, lamDm(0), were analyzed in parallel with the misg(sz18) mutation, a lamDm(0) allele reported previously. Although in all these mutants, lamin Dm(0) protein was undetectable in neuroblasts and imaginal disc cells from the second instar larval stage onward, cells continued to proliferate. In contrast to the embryonic lethality of another Drosophila lamDm(0) allele, lam(PM15), reported previously, lethality did not occur until late pupal stages. Chromosomal structure and the overall nuclear shape remained normal even at these late pupal stages, although obviously abnormal nuclear pore complex distribution was observed concomitant with the loss of lamin Dm(0) protein. Compensating expression of lamin C was not induced in the absence of lamin Dm(0). Thus, no lamin-containing nuclear structures were found in proliferating larval neuroblasts. We did find that developmental abnormalities appeared in specific organs during the late pupal stage, preceding lethality. Surprisingly, coordinated size increase (hypertrophy) of the ventriculus was observed accompanied by cell division and muscle layer formation. Hypertrophy of the ventriculus correlated with a decrease in ecdysteroid hormone receptor B1 (EcRB1) protein, and furthermore could be suppressed by a heat-inducible EcRB1 transgene. In contrast, both gonadal and CNS tissues exhibited underdevelopment.
Publication
Journal: Planta
January/12/2014
Abstract
The root of the water fern Azolla is a compact higher-plant organ, advantageous for studies of cell division, cell differentiation, and morphogenesis. The cell complement of A. filiculoides Lam. and A. pinnata R.Br. roots is described, and the lineages of the cell types, all derived ultimately from a tetrahedral apical cell, are characterised in terms of sites and planes of cell division within the formative zone, where the initial cells of the cell files are generated. Subsequent proliferation of the initial cells is highly specific, each cell type having its own programme of divisions prior to terminal differentiation. Both formative and proliferative divisions (but especially the former) occur in regular sequences. Two enantiomorphic forms of root develop, with the dispositions of certain types of cell correlating with the direction, dextrorse or sinistrorse, of the cell-division sequence in the apical cells. Root growth is determinate, the apical cell dividing about 55 times, and its cell-cycle duration decreasing from an initial 10 h to about 4 h during the major phase of root development. Sites of proliferation progress acropetally during aging, but do not penetrate into the zone of formative divisions. The detailed portrait of root development that was obtained is discussed with respect to genetic and epigenetic influences; quantal and non-quantal cell cycles; variation in cell-cycle durations; relationships between cell expansion and cell division: the role of the apical cell; and the limitation of the total number of mitotic cycles during root formation.
Publication
Journal: Food and Chemical Toxicology
September/14/2008
Abstract
Initiation of acetaminophen (APAP) toxicities is believed to be promoted by oxidative stress during the event of overdosage. The aim of the present study was to evaluate the hepatoprotective action of Moringa oleifera Lam (MO), an Asian plant of high medicinal value, against a single high dose of APAP. Groups of five male Sprague-Dawley rats were pre-administered with MO (200 and 800 mg/kg) prior to a single dose of APAP (3g/kg body weight; p.o). Silymarin was used as an established hepatoprotective drug against APAP induced liver injury. The hepatoprotective activity of MO extract was observed following significant histopathological analysis and reduction of the level of alanine aminotransferase (ALT), aspartate aminotransferase (AST) and alkaline phosphatase (ALP) in groups pretreated with MO compared to those treated with APAP alone. Meanwhile, the level of glutathione (GSH) was found to be restored in MO-treated animals compared to the groups treated with APAP alone. These observations were comparable to the group pretreated with silymarin prior to APAP administration. Group that was treated with APAP alone exhibited high level of transaminases and ALP activities besides reduction in the GSH level. The histological hepatocellular deterioration was also evidenced. The results from the present study suggested that the leaves of MO can prevent hepatic injuries from APAP induced through preventing the decline of glutathione level.
Publication
Journal: Journal of Ethnopharmacology
September/25/2014
Abstract
BACKGROUND
Traditional medicine plays a critical role in treatment of chronic debilitating and life threatening conditions and diseases. Cancer is one such condition whose therapeutic intervention is commonly through inexpensive traditional herbal remedies. Increasingly industrialised societies are developing drugs and chemotherapeutics from these traditional herbal plants. Plant biogeography determines the abundance and availability of medicinal plants which in turn determine their use by local communities. The present study was carried out in Kakamega County of Kenya to identify and document medicinal plants used for treatment and management of cancer states by communities living adjacent to Kakamega Tropical rainforest of Kakamega County, Kenya.
METHODS
An ethnobotanical survey was done using semi-structured questionnaires administered to 32 randomly selected herbalists from Kakamega County.
CONCLUSIONS
Sixty five (65) plants of 59 genera and 32 families were identified as candidates in therapeutic intervention against cancer states. Most commonly cited plant species were Spathodea campanulata P. Beauv. ssp. nilotica (Seem), Microglossa pyrifolia (Lam.) Kuntze, Harungana madagascariensis Lam. ex poir, Prunus africana (Hook. f.) kalkman, Cyphostemma serpens (A. Rich), Catharanthus roseus (L.) G. Don and Aloe volkensii Engl. The following were documented for the first time; Aeschynomene abyssinica (A. Rich.) Vatke, Synsepalum cerasiferum (welw.) T. D penn., Albizia coriaria Welw. ex Oliv., Aloe volkensii Engl. Bridelia micrantha (Hochst.) Baill, Croton macrostachyus Delile, Cyphostemma serpens (A. Rich), Dicliptera laxata C.B. Clarke, Ekebergia capensis Sparrm., Gardenia volkensii K. schum. ssp. volkensii, Glycine wightii (wight & Arn.), Ocimum gratissimum Suave, Olea hotcsh spp. hochstetteri, Pavetta abyssinica Fresen., Phyllanthus fischeri Pax, Psydrax schimperiana (A. Rich), Rhus vulgaris Meikle, Senna didymobotyra (Fresen.) Irwin and Barneby, Solanecio nandensis (S. Moore) C. Jeffrey, Solanum mauritianum Scop, Spathodea campanulata P. Beauv. ssp. nilotica (Seem), Spermacoce princea (K. Schum.) Verdc., Tabernaemontana stapfiana Britten, Tragia brevipes Pax and Zanthoxylum gilletii (De Wild.) P.G.Waterman. The most frequently used plant parts were fresh or dried leaves and stem barks. Administration to patients was almost exclusively oral, with the exceptions being topical application especially for breast cancer and skin sarcomas.
CONCLUSIONS
This study identified diverse medicinal plants used in therapeutic and management intervention against cancer by communities living adjacent to Kakamega Tropical Rainforest. The primary mode of administration was oral.
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Journal: European Journal of Radiology
September/27/2012
Abstract
BACKGROUND
Since Birt-Hogg-Dubé syndrome (BHDS) and lymphangioleiomyomatosis (LAM) share some clinical manifestations (multiple pulmonary cysts with pneumothorax, renal tumors, and sometimes skin lesions), the differential diagnosis of the two diseases becomes problem especially in female patients. This study aims to quantify pulmonary cysts in computed tomography (CT) of females with BHDS and those with LAM and also to identify the independent parameters for differentiating the two diseases.
METHODS
Fourteen patients with BHDS and 52 with LAM were studied. In CT scans, lung fields were defined as areas with fewer than -200 Hounsfield units (HU) and pulmonary cysts as areas consisting of 10 or more consecutive pixels with fewer than -960 HU. The extent, number, size and circularity of cysts were calculated by using hand-made software and compared between the two diseases. Moreover, the lung fields were divided into six zones and analyzed for the distribution of cysts. Finally, a stepwise discriminant analysis employing quantitative measurements of cysts and clinical features was performed.
RESULTS
The two diseases were significantly different in all quantitative measurements of cysts. Stepwise discriminant analysis accepted the following four variables: the family history of pneumothorax within the second degree relatives, lower-medial zone predominance of cysts, diffusing capacity and mean size of cysts in this order.
CONCLUSIONS
The quantitative characteristics of pulmonary cysts are significantly different between BHDS and LAM. The independent parameters for differentiating the two diseases are the family history of pneumothorax, zonal predominance of cysts, diffusing capacity and size of cysts.
Publication
Journal: Journal of Clinical Microbiology
November/27/2018
Abstract
The only currently commercialized point-of-care assay for tuberculosis (TB) that measures lipoarabinomannan (LAM) in urine (Alere LF-LAM) has insufficient sensitivity. We evaluated the potential of 100 novel monoclonal antibody pairs targeting a variety of LAM epitopes on a sensitive electrochemiluminescence platform to improve the diagnostic accuracy. In the screening, many antibody pairs showed high reactivity to purified LAM but performed poorly at detecting urinary LAM in clinical samples, suggesting differences in antigen structure and immunoreactivity of the different LAM sources. The 12 best antibody pairs from the screening were tested in a retrospective case-control study with urine samples from 75 adults with presumptive TB. The best antibody pair reached femtomolar analytical sensitivity for LAM detection and an overall clinical sensitivity of 93% (confidence interval [CI], 80% to 97%) and specificity of 97% (CI, 85% to 100%). Importantly, in HIV-negative subjects positive for TB by sputum smear microscopy, the test achieved a sensitivity of 80% (CI, 55% to 93%). This compares to an overall sensitivity of 33% (CI, 20% to 48%) of the Alere LF-LAM and a sensitivity of 13% (CI, 4% to 38%) in HIV-negative subjects in the same sample set. The capture antibody targets a unique 5-methylthio-d-xylofuranose (MTX)-dependent epitope in LAM that is specific to the Mycobacterium tuberculosis complex and shows no cross-reactivity with fast-growing mycobacteria or other bacteria. The present study provides evidence that improved assay methods and reagents lead to increased diagnostic accuracy. The results of this work have informed the development of a sensitive and specific novel LAM point-of-care assay with the aim to meet the WHO's performance target for TB diagnosis.
Publication
Journal: Liver Transplantation
July/5/2010
Abstract
Orthotopic liver transplantation (OLT) recipients without hepatitis B virus (HBV) infection who receive liver grafts from antibody to hepatitis B core antigen-positive [HBcAb(+)], hepatitis B surface antigen-negative [HBsAg(-)] donors have an increased risk of developing de novo hepatitis B infection. We compared the 2 most commonly employed prophylactic regimens-lamivudine (LAM) monotherapy and hepatitis B immunoglobulin (HBIG)+LAM combination therapy-to determine the relative efficacies of these 2 protocols in preventing de novo hepatitis B infection. A comprehensive search of the Cochrane Database of Systematic Reviews, MEDLINE (1966 to June 2009), and bibliographies of retrieved trials was conducted. Eligible studies included OLT recipients who received HBcAb(+) liver grafts and were treated prophylactically with either LAM monotherapy or HBIG+LAM combination therapy. 13 studies were identified as meeting the eligibility criteria. The rates of de novo hepatitis B infection, mortality, and mortality due to de novo hepatitis B infection were assessed. The incidence of de novo hepatitis B infection was 2.7% (n = 73) in patients receiving LAM-only prophylaxis versus 3.6% (n = 110) in patients receiving HBIG+LAM combination therapy. In the HBIG+LAM group, the dose and duration of HBIG therapy were highly variable. The median follow-up time for the LAM monotherapy group was 25.4 months with a range of 14.78 to 27.6 months, whereas the median follow-up time for the LAM+HBIG group was 31.1 months with a range of 15.3 to 38.5 months. The risk of developing de novo hepatitis B infection based on the pretransplant recipient HBV serology in each treatment group could not be calculated because of incomplete data and the limited number of de novo hepatitis B infection cases in the series reviewed. In conclusion, on the basis of these findings, we conclude that published studies have not shown HBIG+LAM combination therapy to be more effective than LAM-only treatment. Nucleoside analogue monotherapy should therefore be considered when one is treating HBV(-) patients who have received liver allografts from HBcAb(+) donors.
Publication
Journal: American Journal of Respiratory Cell and Molecular Biology
April/30/2003
Abstract
Pulmonary lymphangioleiomyomatosis (LAM) is characterized by abnormal smooth muscle-like cell proliferation leading to tissue destruction and cyst formation. We demonstrate that serum response factor (SRF), a critical smooth muscle transcription factor, is overexpressed in LAM cells. To determine whether abnormal SRF levels might have a pathogenic role in LAM, we transfected SRF into mouse lung fibroblasts and performed a cDNA array analysis. High SRF level upregulated the expression of matrix metalloproteinase (MMP)-2 and MMP-14, two MMPs previously shown to be increased in LAM. In addition, SRF down-regulated tissue inhibitor of metalloproteinase (TIMP)-3, one of their inhibitors. TIMP-3 inhibition was further confirmed by reverse transcriptase/polymerase chain reaction, immunoblotting, and immunostaining of human lung fibroblasts transfected with SRF fused to DsRed2 (a red variant of green fluorescent protein). To determine the in vivo significance of our findings, we immunostained 12 LAM cases for TIMP-3. In eight of them, TIMP-3 was ubiquitously present in normal lung parenchyma, but it was absent in LAM lesions. In the remaining cases, including two out of five normal control lungs, the antibody immunoreacted exclusively with elastin, probably due to suboptimal tissue processing. Because timp-3-null mice develop spontaneous emphysema, our findings suggest that SRF-mediated TIMP-3 inhibition might contribute to the tissue damage seen in LAM.
Publication
Journal: Journal of Biological Chemistry
January/30/2000
Abstract
Mannosylated lipoarabinomannans are multifaceted molecules. They have been shown to exert an immunosuppressive role in the immunopathogenesis of tuberculosis. They are also described as antigens of host double negative alphabeta T-cells. Delimitation of ManLAMs epitopes require knowledge of the precise structure of these molecules. The two major functional domains (the cap motifs and the phosphatidylinositol anchor) of the parietal and cellular ManLAMs of Mycobacterium tuberculosis H37Rv were investigated here. Using capillary electrophoresis, we established that parietal and cellular ManLAMs share the same capping motifs, mono-, di-, and trimannosyl units with the same relative abundance. By (31)P NMR analysis of the native LAMs in Me(2)SO-d(6), the major acyl-form of both parietal and cellular H37Rv ManLAM anchors, typified by the P3 phosphorus resonance, comprised a diacylglycerol unit. Three other acyl-forms were characterized in the cellular ManLAMs. Comparative analysis of the cellular Mycobacterium bovis BCG and M. tuberculosis ManLAM acyl-forms revealed the presence of the same populations, but with different relative abundance. The biological importance of the H37Rv ManLAM acyl-form characterization is discussed, particularly concerning the molecular mechanisms of binding of ManLAMs to the CD1 proteins involved in the presentation of ManLAMs to T-cell receptors.
Publication
Journal: Plant Physiology
June/28/2010
Abstract
When root tissue of sweet potato (Ipomoea batatas Lam.) was sliced, acid invertase activity, initially absent in freshly sliced tissue, appeared after a 3- to 6-hour lag phase, rapidly reached a maximum in 18 hours, and thereafter decreased. The increase in invertase activity was accompanied by a decrease in sucrose content of the root tissue. Alkaline invertase activity was present in fresh root tissue, but changed little after wounding. Acid invertase in wounded tissue and alkaline invertase in fresh tissue were purified and their properties were investigated. The acid invertase was a ss-fructofuranosidase and was unaffected by substrate or by any of the cations and several metabolites. The alkaline invertase was more specific for sucrose, was inhibited by glucose and glucose 6-phosphate, and displayed non-Michaelis-Menten kinetics.
Publication
Journal: Biochemistry
May/2/2006
Abstract
Lysine 2,3-aminomutase (LAM) catalyzes the interconversion of l-lysine and l-beta-lysine by a free radical mechanism. The 5'-deoxyadenosyl radical derived from the reductive cleavage of S-adenosyl-l-methionine (SAM) initiates substrate-radical formation. The [4Fe-4S](1+) cluster in LAM is the one-electron source in the reductive cleavage of SAM, which is directly ligated to the unique iron site in the cluster. We here report the midpoint reduction potentials of the [4Fe-4S](2+/1+) couple in the presence of SAM, S-adenosyl-l-homocysteine (SAH), or 5'-{N-[(3S)-3-aminocarboxypropyl]-N-methylamino}-5'-deoxyadenosine (azaSAM) as measured by spectroelectrochemistry. The reduction potentials are -430 +/- 2 mV in the presence of SAM, -460 +/- 3 mV in the presence of SAH, and -497 +/- 10 mV in the presence of azaSAM. In the absence of SAM or an analogue and the presence of dithiothreitol, dihydrolipoate, or cysteine as ligands to the unique iron, the midpoint potentials are -479 +/- 5, -516 +/- 5, and -484 +/- 3 mV, respectively. LAM is a member of the radical SAM superfamily of enzymes, in which the CxxxCxxC motif donates three thiolate ligands to iron in the [4Fe-4S] cluster and SAM donates the alpha-amino and alpha-carboxylate groups of the methionyl moiety as ligands to the fourth iron. The results show the reduction potentials in the midrange for ferredoxin-like [4Fe-4S] clusters. They show that SAM elevates the reduction potential by 86 mV relative to that of dihydrolipoate as the cluster ligand. This difference accounts for the SAM-dependent reduction of the [4Fe-4S](2+) cluster by dithionite reported earlier. Analogues of SAM have a weakened capacity to raise the potential. We conclude that the midpoint reduction potential of the cluster ligated to SAM is 1.2 V less negative than the half-wave potential for the one-electron reductive cleavage of simple alkylsulfonium ions in aqueous solution. The energetic barrier in the reductive cleavage of SAM may be overcome through the use of binding energy.
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Publication
Journal: Journal of Biological Chemistry
November/19/2003
Abstract
Although Mycobacterium kansasii has emerged as an important pathogen frequently encountered in immunocompromised patients, little is known about the mechanisms of M. kansasii pathogenicity. Lipoarabinomannan (LAM), a major mycobacterial cell wall lipoglycan, is an important virulence factor for many mycobacteria, as it modulates the host immune response. Therefore, the detailed structures of the of M. kansasii LAM (KanLAM), as well as of its biosynthetic precursor lipomannan (KanLM), were determined in a clinical strain isolated from a human immunodeficiency virus-positive patient. Structural analyses revealed that these lipoglycans possess important differences as compared with those from other mycobacterial species. KanLAM carries a mannooligosaccharide cap but is devoid of the inositol phosphate cap present in Mycobacterium smegmatis. Characterization of the mannan core of KanLM and KanLAM demonstrated the following occurrences: 1) alpha1,2-oligo-mannopyranosyl side chains, contrasting with the single mannopyranosyl residues substituting the mannan core in all the other structures reported so far; and 2) 5-methylthiopentose residues that were described to substitute the arabinan moiety from Mycobacterium tuberculosis LAM. With respect to the arabinan domain of KanLAM, succinyl groups were found to substitute the C-3 position on 5-arabinofuranosyl residues, reported to be linked to the C-2 of the 3,5-arabinofuranose in Mycobacterium bovis bacillus calmette-guerin LAM. Because M. kansasii has been reported to induce apoptosis, we examined the possibility of the M. kansasii lipoglycans to induce apoptosis of THP-1 cells. Our results indicate that, in contrast to KanLAM, KanLM was a potent apoptosis-inducing factor. This work underlines the diversity of LAM structures among various pathogenic mycobacterial species and also provides evidence of LM being a potential virulence factor in M. kansasii infections by inducing apoptosis.
Publication
Journal: Journal of Clinical Microbiology
July/25/2000
Abstract
The rising incidence of tuberculosis worldwide means an increasing burden on diagnostic facilities, so tests simpler than Ziehl-Neelsen staining are needed. Such tests should be objective, reproducible, and have at least as good a detection limit as 10(4) bacteria/ml. A capture enzyme-linked immunosorbent assay (ELISA) was developed for detection of lipoarabinomannan (LAM) in human sputum samples. As a capture antibody, we used a murine monoclonal antibody against LAM, with rabbit antiserum against Mycobacterium tuberculosis as a source of detector antibodies. The sensitivity of the capture ELISA was evaluated by using purified LAM and M. tuberculosis whole cells. We were able to detect 1 ng of purified LAM/ml and 10(4) M. tuberculosis whole cells/ml. LAM could also be detected in culture filtrate of a 3-week-old culture of M. tuberculosis. The culture filtrate contained approximately 100 microgram of LAM/ml. The detection limit in sputum pretreated with N-acetyl-L-cysteine and proteinase K was 10(4) M. tuberculosis whole cells per ml. Thirty-one (91%) of 34 sputum samples from 18 Vietnamese patients with tuberculosis (32 smear positive and 2 smear negative) were positive in the LAM detection assay. In contrast, none of the 25 sputum samples from 21 nontuberculous patients was positive. This specific and sensitive assay for the detection of LAM in sputum is potentially useful for the diagnosis of tuberculosis.
Publication
Journal: Journal of Chemical Ecology
March/22/2004
Abstract
Centarea maculosa Lam. (spotted knapweed) is one of the most destructive invasive weeds in the western United States, particularly in pastures and rangelands. One of the components that may contribute to its invasiveness is the naturally produced, root-secreted allelochemical (-)-catechin. This compound has been shown to have broad-spectrum phytotoxic activity, possibly assisting C. maculosa in displacing native plant communities. As a recently characterized phytochemical, little is known about the specific effect of (-)-catechin on either C. maculosa or other plant species. We have found that, in vitro, C. maculosa begins to secrete phytotoxic levels of (-)-catechin within 2-3 weeks of seedling emergence. Furthermore, (-)-catechin concentrations consistent with those naturally secreted by C. maculosa were sufficient to inhibit germination in all species tested, including C. maculosa. These concentrations were also often either phytotoxic or growth inhibitory to seedlings in a range of plant species, while having no negative effects on the growth of C. maculosa seedlings. However, our results also indicate that different levels of resistance and susceptibility to (-)-catechin exist in plant populations, suggesting that the capability of C. maculosa to invade an area through allelochemistry may be dependent on the age and species composition of plants in that area.
Publication
Journal: Bipolar Disorders
February/16/2012
Abstract
OBJECTIVE
To compare attention-deficit hyperactivity disorder (ADHD), bipolar spectrum disorders (BPSDs), and comorbidity in the Longitudinal Assessment of Manic Symptoms (LAMS) study.
METHODS
Children ages 6-12 were recruited at first visit to clinics associated with four universities. A BPSD diagnosis required that the patient exhibit episodes. Four hypotheses were tested: (i) children with BPSD + ADHD would have a younger age of mood symptom onset than those with BPSD but no ADHD; (ii) children with BPSD + ADHD would have more severe ADHD and BPSD symptoms than those with only one disorder; (iii) global functioning would be more impaired in children with ADHD + BPSD than in children with either diagnosis alone; and (iv) the ADHD + BPSD group would have more additional diagnoses.
RESULTS
Of 707 children, 421 had ADHD alone, 45 had BPSD alone, 117 had both ADHD and BPSD, and 124 had neither. Comorbidity (16.5%) was slightly less than expected by chance (17.5%). Age of mood symptom onset was not different between the BPSD + ADHD group and the BPSD-alone group. Symptom severity increased and global functioning decreased with comorbidity. Comorbidity with other disorders was highest for the ADHD + BPSD group, but higher for the ADHD-alone than the BPSD-alone group. Children with BPSD were four times as likely to be hospitalized (22%) as children with ADHD alone.
CONCLUSIONS
The high rate of BPSD in ADHD reported by some authors may be better explained as a high rate of both disorders in child outpatient settings rather than ADHD being a risk factor for BPSD. Co-occurrence of the two disorders is associated with poorer global functioning, greater symptom severity, and more additional comorbidity than for either single disorder.
Publication
Journal: Biochemistry
September/19/2001
Abstract
An allylic analogue of the 5'-deoxyadenosyl radical has been characterized at the active site of lysine 2,3-aminomutase (LAM) by electron paramagnetic resonance (EPR) spectroscopy. The anhydroadenosyl radical, 5'-deoxy-3',4'-anhydroadenosine-5'-yl, is a surrogate of the less stable 5'-deoxyadenosyl radical, which has never been observed but has been postulated to be a radical intermediate in the catalytic cycles of a number of enzymes. An earlier communication [Magnusson, O.Th., Reed, G. H., and Frey, P. A. (1999) J. Am. Chem. Soc. 121, 9764-9765] included the initial spectroscopic identification at 77 K of the radical, which is formed upon replacement of S-adenosylmethionine by S-3',4'-anhydroadenosylmethionine as a coenzyme for LAM. The electron paramagnetic resonance spectrum of the radical changes dramatically between 77 and 4.5 K. This unusual temperature dependence is attributed to a spin-spin interaction between the radical and thermally populated, higher spin states of the [4Fe-4S]+2 center, which is diamagnetic at 4.5 K. The EPR spectra of the radical at 4.5 K have been analyzed using isotopic substitutions and simulations. Analysis of the nuclear hyperfine splitting shows that the unpaired spin is distributed equally between C5'- and C3'- as expected for an allylic radical. Hyperfine splitting from the beta-proton at C-2'(H) shows that the dihedral angle to the p(z)-orbital at C-3' is approximately 37 degrees. This conformation is in good agreement with a structural model of the radical. The rate of formation of the allylic radical shows that it is kinetically competent as an intermediate. Measurements of 2H kinetic isotope effects indicate that with lysine as the substrate, the rate-limiting steps follow initial reductive cleavage of the coenzyme analogue.
Publication
Journal: Environmental Pollution
June/28/2006
Abstract
Concentrations of As and other trace elements and their association were examined in groundwater (n = 25) and human hair (n = 59) collected at Gia Lam District and Thanh Tri District, suburban areas of Hanoi, Vietnam, in September 2001. Concentrations of As in the groundwater ranged from <0.10 to 330 microg/l, with about 40% of these exceeding WHO drinking water guideline of 10 microg/l. Also, 76% and 12% of groundwater samples had higher concentrations of Mn and Ba than WHO drinking water guidelines, respectively. Arsenic concentrations in hair of residents in Gia Lam and Thanh Tri Districts (range 0.088-2.77 microg/g dry wt.) were lower than those in other As-contaminated areas of the world, but were higher than those of people in non-contaminated areas. Concentrations of As and Mn in hair of some individuals from the Gia Lam and Thanh Tri Districts exceeded the level associated with their toxicity and, therefore, a potential health risk of As and Mn is a concern for the people consuming the contaminated water in this area. Cumulative As exposure was estimated to be lower than the threshold levels at the present, which might explain the absence of manifestations of chronic As poisoning and arsenicosis in the residents of Gia Lam and Thanh Tri Districts. To our knowledge, this study revealed for the first time that the residents are exposed not only to As but also Mn and Ba from groundwater in the Red River Delta, Vietnam.
Publication
Journal: PLoS ONE
August/1/2012
Abstract
BACKGROUND
Tuberculosis is the most common cause of death among patients with HIV infection living in tuberculosis endemic countries, but many cases are not diagnosed pre-mortem. We assessed the test characteristics of urinary lipoarabinomannan (LAM) and predictors of mortality among HIV-associated tuberculosis suspects in Tanzania.
METHODS
We prospectively enrolled hospitalized HIV-infected patients in Dar es Salaam, with ≥2 weeks of cough or fever, or weight loss. Subjects gave 2 mLs of urine to test for LAM using a commercially available ELISA, ≥2 sputum specimens for concentrated AFB smear and solid media culture, and 40 mLs of blood for culture.
RESULTS
Among 212 evaluable subjects, 143 (68%) were female; mean age was 36 years; and the median CD4 count 86 cells/mm(3). 69 subjects (33%) had culture confirmation of tuberculosis and 65 (31%) were LAM positive. For 69 cases of sputum or blood culture-confirmed tuberculosis, LAM sensitivity was 65% and specificity 86% compared to 36% and 98% for sputum smear. LAM test characteristics were not different in patients with bacteremia but showed higher sensitivity and lower specificity with decreasing CD4 cell count. Two month mortality was 64 (53%) of 121 with outcomes available. In multivariate analysis there was significant association of mortality with absence of anti-retroviral therapy (p = 0.004) and a trend toward association with a positive urine LAM (p = 0.16). Among culture-negative patients mortality was 9 (75%) of 12 in LAM positive patients and 27 (38%) of 71 in LAM negative patients (p = 0.02).
CONCLUSIONS
Urine LAM is more sensitive than sputum smear and has utility for the rapid diagnosis of culture-confirmed tuberculosis in this high-risk population. Mortality data raise the possibility that urine LAM may also be a marker for culture-negative tuberculosis.
Publication
Journal: Clinical and Vaccine Immunology
May/2/2011
Abstract
A simple serodiagnostic test based on the Mycobacterium leprae-specific phenolic glycolipid I(PGL-I), for individuals with leprosy is nearly universally positive in leprosy patients with high bacillary loads but cannot be used as a stand-alone diagnostic test for the entire spectrum of the disease process. For patients with early infection with no detectable acid-fast bacilli in lesions or with low or no antibody titer to PGL-I, as in those at the tuberculoid end of the disease spectrum, this diagnostic approach has limited usefulness. To identify additional M. leprae antigens that might enhance the serological detection of these individuals, we have examined the reactivity patterns of patient sera to PGL-I, lipoarabinomannan (LAM), and six recombinant M. leprae proteins (ML1877, ML0841, ML2028, ML2038, ML0380, and ML0050) by Western blot analysis and enzyme-linked immunosorbent assay (ELISA). Overall, the responses to ML2028 (Ag85B) and ML2038 (bacterioferritin) were consistently high in both multibacillary and paucibacillary groups and weak or absent in endemic controls, while responses to other antigens showed considerable variability, from strongly positive to completely negative. This analysis has given a clearer understanding of some of the differences in the antibody responses between individuals at opposite ends of the disease spectrum, as well as illustrating the heterogeneity of antibody responses toward protein, carbohydrate, and glycolipid antigens within a clinical group. Correlating these response patterns with a particular disease state could allow for a more critical assessment of the form of disease within the leprosy spectrum and could lead to better patient management.
Publication
Journal: Clinical and Experimental Immunology
March/2/1998
Abstract
Immunoenzymatic assays were developed for the measurement of antibodies against mycobacterial lipoarabinomannan (LAM), a cell-free proteic extract (CFX) of Mycobacterium leprae, and the 38-kD protein antigen of M. tuberculosis. Sera from 108 leprosy patients, belonging to all clinical-immunological forms of the spectrum, and 81 patients with localized or disseminated tuberculosis (TB) were tested for antibodies of the four IgG subclasses. Standard calibration curves were used to allow comparisons between results of different isotypes and specificities. Mean concentrations of total IgG antibodies were higher in the overall leprosy population than in TB patients. In leprosy, levels of anti-CFX increased from tuberculoid toward lepromatous forms, with a clear switch from IgG1 to IgG2 subclass predominance. A similar IgG1 to IgG2 conversion was observed in anti-LAM antibodies, although total levels of anti-LAM were similar in patients with tuberculoid and lepromatous forms. In TB, antibodies against polysaccharide and protein antigens were both predominantly of IgG1 subclass, whatever the patient's clinical status, although lower in disseminated forms, probably due to concomitant HIV infection. A hypergammaglobulinaemia was also found in most leprosy and TB patients. In TB this was due to increased IgG1 and IgG3, especially in HIV co-infected patients. Based on the current knowledge of the influence of T cell-secreted cytokines on human immunoglobulin isotype expression, these results do not fit with a putative role of Th1 (such as found in TB and tuberculoid leprosy (TT)) and Th2 (such as found in leprosy lepromatous (LL) leprosy) environment in the isotypy of antibody responses in mycobacterial infections. Nor do variations of isotypy according to pathological conditions seem to be related to the biochemical nature of antigens, since antibodies to LAM and protein antigens had comparable evolutions of their subclass distribution. Other factors are to be investigated in order to understand better the significance and possible roles of antibodies in mycobacterial diseases.
Publication
Journal: PLoS Pathogens
April/25/2016
Abstract
Mycobacterium tuberculosis (Mtb) virulence is decreased by genetic deletion of the lipoprotein LprG, but the function of LprG remains unclear. We report that LprG expressed in Mtb binds to lipoglycans, such as lipoarabinomannan (LAM), that mediate Mtb immune evasion. Lipoglycan binding to LprG was dependent on both insertion of lipoglycan acyl chains into a hydrophobic pocket on LprG and a novel contribution of lipoglycan polysaccharide components outside of this pocket. An lprG null mutant (Mtb ΔlprG) had lower levels of surface-exposed LAM, revealing a novel role for LprG in determining the distribution of components in the Mtb cell envelope. Furthermore, this mutant failed to inhibit phagosome-lysosome fusion, an immune evasion strategy mediated by LAM. We propose that LprG binding to LAM facilitates its transfer from the plasma membrane into the cell envelope, increasing surface-exposed LAM, enhancing cell envelope integrity, allowing inhibition of phagosome-lysosome fusion and enhancing Mtb survival in macrophages.
Publication
Journal: Respirology
September/18/2007
Abstract
OBJECTIVE
To evaluate the characteristics and prognostic factors of Japanese patients with lymphangioleiomyomatosis (LAM).
METHODS
A nationwide survey to identify patients with LAM was conducted by questionnaire. Survival probability was estimated using the Kaplan-Meier method, and the prognostic factors were analysed by Cox regression.
RESULTS
Data were collected on 173 patients with pulmonary LAM. The major presenting features were pneumothorax (43%) and exertional dyspnoea (37%). The survival probabilities for patients presenting with exertional dyspnoea (Group A) were 85%, 60% and 47% after 5, 10 and 15 years, respectively, and for patients presenting with pneumothorax (Group B) were 95%, 89% and 89%, respectively. Although the age at symptom onset was higher among patients in Group A than in Group B, Cox regression revealed that the presenting feature was a prognostic factor independent of age at symptom onset (Group A/B hazard ratio = 5.732, P < 0.01). In the subgroup of patients whose initial FEV(1) was >1000 mL, or FEV(1)/FVC >40%, or %DL(CO) >40%, the rate of deterioration in these tests was greater in Group A than in Group B (P < 0.01 for FEV(1), P < 0.05 for FEV(1)/FVC and %DL(CO)).
CONCLUSIONS
There are two possible subgroups of LAM patients. One subgroup that presented with pneumothorax, had onset of symptoms at a younger age and a more favourable prognosis; the other presented with exertional dyspnoea, had onset of symptoms at an older age and a poorer prognosis.
Publication
Journal: Molecules
October/21/2012
Abstract
The aim of the study was to investigate the in vitro antioxidant properties Moringa oleifera Lam. (MO) extracts and its curative role in acetaminophen (APAP)-induced toxic liver injury in rats caused by oxidative damage. The total phenolic content and antioxidant properties of hydroethanolic extracts of different MO edible parts were investigated by employing an established in vitro biological assay. In the antihepatotoxic study, either flowers or leaves extract (200 mg/kg or 400 mg/kg, i.p) were administered an hour after APAP administration, respectively. N-Acetylcysteine was used as the positive control against APAP-induced hepatotoxicity. The levels of liver markers such as alanine aminotransferase (ALT) and the levels of oxidative damage markers including malondialdehyde (MDA), 4-hydroxynonenal (4-HNE) protein adduct, reduced glutathione (GSH), superoxide dismutase (SOD) and catalase (CAT) were analysed and compared between experimental groups. Among MO edible parts the flower extracts contain the highest total phenolic content and antioxidant capacity, followed by leaves extract. The oxidative marker MDA, as well as 4-HNE protein adduct levels were elevated and GSH, SOD and CAT were significantly decreased in groups treated with hepatotoxin. The biochemical liver tissue oxidative markers measured in the rats treated with MO flowers and leaves hydroethanolic extracts showed a significant (p < 0.05) reduction in the severity of the liver damage. The results of this study strongly indicate the therapeutic properties of MO hydroethanolic extracts against acute liver injury and thereby scientifically support its traditional use.
Publication
Journal: Journal of Ethnopharmacology
December/26/2011
Abstract
OBJECTIVE
This study aimed to identify wild plants collected for medical purposes by the local people of Maden County, located in the Eastern Anatolia Region of Turkey, and to establish the uses and local names of these plants.
METHODS
Field study was carried out over a period of approximately 2 years (2008-2010). During this period, 131 vascular plant specimens were collected. Demographic characteristics of participants, local plant names, utilized parts and preparation methods of the plants were investigated and recorded. In the scope of the study, the plant species were collected; herbarium materials were prepared; and the specimens were entitled. The Zazas are of the major ethnic group in the region. In addition, the relative importance value of the species was determined and informant consensus factor (FIC) was calculated for the medicinal plants included in the study.
RESULTS
A total of 88 medical plants belonging to 41 families were identified in the region. 4 plants out of 88 were recorded to be used for curative purposes for the first time. It was determined that the local names of four different kinds of plants used in Maden were same as the different kinds of plants used in different regions. The most encountered medicinal plant families were Urticaceae (>21%), Rosaceae and Lamiaceae (>17% of use-reports), Asteraceae (>13%), Fabaceae (>8%), Brassicaceae (>7%), Poaceae (>4%); the most common preparations were decoction and infusion. Mentha spicata L. subsp. spicata, Rosa canina L. and Urtica dioica L. was the plants most used by the local people. Anthemis wiedemanniana Fisch. and Mey., Bunium paucifolium DC. var. brevipes (Freyn & Sint.) Hedge & Lam., Tchihatchewia isatidea Boiss., Thymus haussknechtii Velen. were found to be the endemic plants used for medical purposes in Maden, Turkey. The medicinal uses of Bunium paucifolium DC. var. brevipes (Freyn & Sint.) Hedge & Lam., Hippophae rhamnoides L. subsp. caucasica Roussi, Gladiolus atroviolaceus Boiss., Ixiolirion tataricum (Pallas) Herbert subsp. montanum (Labill.) Takht. were recorded for the first time.
CONCLUSIONS
Herbal treatment has become a tradition for the residents of the study region. These plants, which are used in the treatment of many diseases. Comparison of the data obtained in this study from the plants growing in Maden with the experimental data obtained in the previous laboratory studies proved most of the ethnobotanical usages. Literature review showed that curative plants of Maden are used in different parts of the world in the treatment of the same or similar diseases. If a plant is used to treat the same disease in different places across the world then its pharmacologic effect could be accepted. It would be beneficial to conduct pharmacologic studies on such plants. These plants, used in the treatment of many different diseases, are in this region at abundant amounts. Drying enabled local people to use medicinal plants during all seasons of the year. This study identified not only the wild plants collected for medical purposes by local people of Maden County in the Eastern Anatolia Region, but also the uses and local names of these plants. It is tried to generate a source for persons studying in ethnobotany, pharmacology and chemistry sciences by comparing knowledge gained from traditionally used herbs with previous laboratory studies.
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