A change in the formulation of the levothyroxine preparation Synthroid (Flint) in 1982 prompted us to reevaluate the replacement dose of this drug in 19 patients with hypothyroidism. The dose was titrated monthly until thyrotropin levels became normal. The mean replacement dose (+/- SD) was 112 +/- 19 micrograms per day, significantly less (P less than 0.001) than the dose of an earlier formulation--169 +/- 66 micrograms per day--used in a similar study (Stock JM, et al. N Engl J Med 1974; 290:529-33). The fractional gastrointestinal absorption of a tablet of the current formulation is 81 percent, considerably higher than the earlier estimate of 48 percent. Using high-performance liquid chromatographic analysis, we found that the current tablet contains the amount of thyroxine stated by the manufacturer. By measuring the bioavailability of the earlier type of tablet in five patients, we inferred that the strength of the previous tablet had been overestimated. In the present study, the thyrotropin levels of patients on replacement therapy returned to normal when serum triiodothyronine concentrations were not significantly different from those of controls (122 vs. 115 ng per deciliter [1.87 vs. 1.77 nmol per liter]), but when serum thyroxine levels were significantly above those of controls (11.3 vs. 8.7 micrograms per deciliter [145 vs. 112 nmol per liter], P less than 0.001). These findings suggest the possibility that in humans, serum triiodothyronine may play a more important part than serum thyroxine in regulating the serum thyrotropin concentration.

We used T1 oligonucleotide maps, in conjunction with available nucleotide sequences of appropriate C-type viruses, to identify regions of the viral genome that distinguish two biological classes of mink cell focus-forming (MCF) viruses described previously by Cloyd et al. (J. Exp. Med. 151:542-522, 1980). We found that leukemogenic MCF viruses from thymus differed from non-leukemogenic MCFs isolated from nonthymic neoplasms in nucleotide sequences encoding Prp15E and the U3 portion of the long terminal repeat (LTR). The thymic isolates possessed recombinant Prp15E genes, with the 5' to mid portion derived from their ecotropic parents and the extreme 3' portion invariably derived from their nonecotropic parents. These viruses probably derived the entire U3 portion of their LTRs from their nonecotropic parents. The nonthymic MCFs appeared to inherit their entire Prp15E coding region from their nonecotropic parents. We failed to detect consistent differences in gp70-coding sequences between the two groups of MCFs, but this may simply reflect limitations of the data. The studies presented here, in conjunction with studies from a number of labs indicating a role for MCF gp70 in leukemogenesis, indicate that three genetic elements, gp70, p15E, and the U3 portion of the LTR, may all play a role in determining the leukemogenic phenotype of type C viruses of high-leukemic inbred mice.

A new technique for the detection of antibodies bound to proteins blotted onto nitrocellulose paper was developed. The method is rapid, sensitive, and does not require radioactive probes. Proteins transferred to nitrocellulose paper are first reacted with primary antibody followed by reaction with an alkaline phosphatase conjugated second antibody. The phosphatase activity is then visualized using an agar gel impregnated with the histochemical phosphatase stain 5-bromo-4-chloro-3-indolyl phosphate (BCIP) (J. P. Horwitz, J. Chua, M. Noel, J. T. Donatti, and J. Freisler (1966) J. Med. Chem. 9, 447; Sigma Chemical Co., Technical bulletin No. 710-EP (1978]. Antigen-antibody complexes give rise to sharp, permanent blue stained bands both on the nitrocellulose paper and in the agar overlay gel. This procedure allows detection of bands containing less than 20 ng of protein.

Intramuscular injection of an adeno-associated virus (AAV) vector has resulted in vector dose-dependent, stable expression of canine factor IX (cF.IX) in hemophilia B dogs with an F.IX missense mutation (Herzog et al., Nat. Med. 1999;5:56-63). The use of a species-specific transgene allowed us to study risks and characteristics of antibody formation against the therapeutic transgene product. We analyzed seven dogs that had been injected at a single time point at multiple intramuscular sites with varying vector doses (dose per kilogram, dose per animal, dose per site). Comparison of individual animals suggests an increased likelihood of inhibitory anti-cF.IX (inhibitor) development with increased vector doses, with dose per site showing the strongest correlation with the risk of inhibitor formation. In six of seven animals, such immune responses were either absent or transient, and therefore did not prevent sustained systemic expression of cF.IX. Transient inhibitory/neutralizing anti-cF.IX responses occurred at vector doses of 2 x 10(12)/site, whereas a 6-fold higher dose resulted in a longer lasting, higher titer inhibitor. Anti-cF.IX was efficiently blocked in an eighth animal that was injected with a high vector dose per site, but in addition received transient immune suppression. Inhibitor formation was characterized by synthesis of two IgG subclasses and in vitro proliferation of lymphocytes to cF.IX antigen, indicating a helper T cell-dependent mechanism. Anti-cF.IX formation is likely influenced by the extent of local antigen presentation and may be avoided by limited vector doses or by transient immune modulation.

Vaccination of mice with heat shock proteins isolated from tumor cells induces immunity to subsequent challenge with those tumor cells the heat shock protein was isolated from but not with other tumor cells (Udono, H., and P.K. Srivastava. 1994. J. Immunol. 152:5398-5403). The specificity of this immune response is caused by tumor-derived peptides bound to the heat shock proteins (Udono., H., and P.K. Srivastava. 1993. J. Exp. Med. 178:1391-1396). Our experiments show that a single immunization with the heat shock protein gp96 isolated from beta-galactosidase (beta-gal) expressing P815 cells (of DBA/2 origin) induces cytotoxic T lymphocytes (CTLs) specific for beta-gal, in addition to minor H antigens expressed by these cells. CTLs can be induced in mice that are major histocompatibility complex (MHC) identical to the gp96 donor cells (H-2d) as well as in mice with a different MHC (H-2b). Thus gp96 is able to induce "cross priming" (Matzinger, P., and M.J. Bevan. 1977. Cell. Immunol. 33:92-100), indicating that gp96-associated peptides are not limited to the MHC class I ligands of the gp96 donor cell. Our data confirm the notion that samples of all cellular antigens presentable by MHC class I molecules are represented by peptides associated with gp96 molecules of that cell, even if the fitting MHC molecule is not expressed. In addition, we extend previous reports on the in vivo immunogenicity of peptides associated gp96 molecules to two new groups of antigens, minor H antigens, and proteins expressed in the cytosol.

Numerous studies have suggested that iron (Fe) chelators such as desferrioxamine (DFO) may be useful antitumor agents (Blatt and Stitely, Cancer Res 47:1749, 1987; Becton and Bryles, Cancer Res 48:7189, 1988). Recent work with several analogues of the lipophilic Fe chelator, pyridoxal isonicotinoyl hydrazone (PIH), indicate that some of these ligands are considerably more efficient than DFO both in terms of their Fe chelation efficacy and at preventing 3H-thymidine incorporation by neuroblastoma (NB) cells (Richardson and Ponka, J Lab Clin Med 124:660, 1994). Considering this fact, the present study was designed to test the antiproliferative effect of a wide range of PIH analogues to identify the most active compounds. A total of 36 ligands have been examined that were synthesized by condensation of three types of aromatic aldehydes (pyridoxal, salicylaldehyde, and 2-hydroxy-1-naphthyladehyde) with a range of acid hydrazides. The effects of these chelators were assessed using the human NB cell line, SK-N-MC. Although PIH was far more effective than DFO at preventing Fe uptake from transferrin, it was less effective than DFO at preventing cellular proliferation (DFO ID50 = 22 mumol/L; PIH ID50 = 75 mumol/L). In contrast, 14 PIH analogues were far more efficient than DFO at preventing proliferation (ID50 = 1 to 7 mumol/L) and may have potential as antitumor agents. The most effective compounds were those hydrazones derived from 2-hydroxy-1-naphthylaldehyde. Most of the PIH analogues were considerably more effective than DFO at both preventing 59Fe uptake from 59Fe-transferrin and in mobilizing 59Fe from prelabeled NB cells. In addition, a linear relationship between Fe chelation efficacy and antiproliferative activity was found only for hydrazones derived from salicylaldehyde. Apart from gallium (Ga) nitrate having an antiproliferative effect by itself, this metal potentiated the antiproliferative effect of PIH but not that of DFO. Spectrophotometric studies showed that PIH could chelate Ga, and it can be suggested that, like the PIH-Fe complex that donates Fe to reticulocytes (Ponka et al, Biochim Biophys Acta 718:151, 1982), the PIH-Ga complex may efficiently bestow Ga to NB cells. The results suggest that analogues of PIH deserve further vigorous investigation because they may be useful therapeutic agents for the treatment of cancer.

OBJECTIVE

The Canadian Primary Care Sentinel Surveillance Network (CPCSSN) is Canada's first national chronic disease surveillance system based on electronic health record (EHR) data. The purpose of this study was to develop and validate case definitions and case-finding algorithms used to identify 8 common chronic conditions in primary care: chronic obstructive pulmonary disease (COPD), dementia, depression, diabetes, hypertension, osteoarthritis, parkinsonism, and epilepsy.

METHODS

Using a cross-sectional data validation study design, regional and local CPCSSN networks from British Columbia, Alberta (2), Ontario, Nova Scotia, and Newfoundland participated in validating EHR case-finding algorithms. A random sample of EHR charts were reviewed, oversampling for patients older than 60 years and for those with epilepsy or parkinsonism. Charts were reviewed by trained research assistants and residents who were blinded to the algorithmic diagnosis. Sensitivity, specificity, and positive and negative predictive values (PPVs, NPVs) were calculated.

RESULTS

We obtained data from 1,920 charts from 4 different EHR systems (Wolf, Med Access, Nightingale, and PS Suite). For the total sample, sensitivity ranged from 78% (osteoarthritis) to more than 95% (diabetes, epilepsy, and parkinsonism); specificity was greater than 94% for all diseases; PPV ranged from 72% (dementia) to 93% (hypertension); NPV ranged from 86% (hypertension) to greater than 99% (diabetes, dementia, epilepsy, and parkinsonism).

CONCLUSIONS

The CPCSSN diagnostic algorithms showed excellent sensitivity and specificity for hypertension, diabetes, epilepsy, and parkinsonism and acceptable values for the other conditions. CPCSSN data are appropriate for use in public health surveillance, primary care, and health services research, as well as to inform policy for these diseases.

BACKGROUND

Advanced paternal age (APA) is a reported risk factor for schizophrenia in the offspring. We performed a meta-analysis of this association, considering the effect of gender and study design.

METHODS

We identified articles by searching Pub Med, PsychInfo, ISI, and EMBASE, and the reference lists of identified studies. Previously unpublished data from the Northern Finland 1966 Birth Cohort (NFBC 1966) study were also included.

RESULTS

There were 6 cohort studies and 6 case-control studies that met the inclusion criteria. In both study designs, there was a significant increase in risk of schizophrenia in the offspring of older fathers (≥30) compared to a reference paternal age of 25-29, with no gender differences. The relative risk (RR) in the oldest fathers (≥50) was 1.66 [95% confidence interval (95% CI): 1.46-1.89, P < 0.01]. A significant increase in risk was also found for younger fathers (<25) in males (RR = 1.08, 95% CI: 1.02-1.14, P = 0.01) but not females (RR = 1.04, 95% CI: 0.97-1.14, P = 0.28). The population attributable risk percentage (PAR%) was 10% for paternal age ≥30 and 5% for paternal age <25.

CONCLUSIONS

Both APA (≥30) and younger paternal age (<25) increase the risk of schizophrenia; younger paternal age may be associated with an increased risk in males but not females. This risk factor increases the risk of schizophrenia as much as any single candidate gene of risk. The mechanism of these associations is not known and may differ for older and younger fathers.

The lymphocyte glycoprotein CD4 is constitutively internalized and recycled in nonlymphoid cells, but is excluded from the endocytic pathway in lymphocytic cells (Pelchen-Matthews, A., J. E. Armes, G. Griffiths, and M. Marsh. 1991. J. Exp. Med. 173: 575-587). Inhibition of CD4 endocytosis is dependent on CD4 expressing an intact cytoplasmic domain and is only observed in cells where CD4 can interact with the protein tyrosine kinase p56lck, a member of the src gene family. We have expressed p56lck, p60c-src, or chimeras of the two proteins in CD4-transfected NIH-3T3 or HeLa cells. Immunoprecipitation of CD4 and in vitro kinase assays showed that p56lck and the lck/src chimera, which contains the NH2 terminus of p56lck, can associate with CD4. In contrast, p60c-src and the src/lck chimera, which has the NH2 terminus of p60c-src, do not associate with CD4. Endocytosis assays using radioiodinated anti-CD4 monoclonal antibodies demonstrated that coexpression of CD4 with p56lck, but not with p60c-src, inhibited CD4 endocytosis, and that the extent of the inhibition depended directly on the relative levels of CD4 and p56lck expressed. The uptake of mutant CD4 molecules which cannot interact with p56lck was not affected. Measurement of the fluid-phase endocytosis of HRP or the internalization of transferrin indicated that the effect of p56lck was specific for CD4, and did not extend to other receptor-mediated or fluid-phase endocytic processes. Immunogold labeling of CD4 at the cell surface and observation by electron microscopy demonstrated directly that p56lck inhibits CD4 endocytosis by preventing its entry into coated pits.

Recently, passive immunization of human immunodeficiency virus (HIV)-infected individuals with monoclonal antibodies (MAbs) 2G12, 2F5, and 4E10 provided evidence of the in vivo activity of 2G12 but raised concerns about the function of the two membrane-proximal external region (MPER)-specific MAbs (A. Trkola, H. Kuster, P. Rusert, B. Joos, M. Fischer, C. Leemann, A. Manrique, M. Huber, M. Rehr, A. Oxenius, R. Weber, G. Stiegler, B. Vcelar, H. Katinger, L. Aceto, and H. F. Gunthard, Nat. Med. 11:615-622, 2005). In the light of MPER-targeting vaccines under development, we performed an in-depth analysis of the emergence of mutations conferring resistance to these three MAbs to further elucidate their activity. Clonal analysis of the MPER of plasma virus samples derived during antibody treatment confirmed that no changes in this region had occurred in vivo. Sequence analysis of the 2G12 epitope relevant N-glycosylation sites of viruses derived from 13 patients during the trial supported the phenotypic evaluation, demonstrating that mutations in these sites are associated with resistance. In vitro selection experiments with isolates of four of these individuals corroborated the in vivo finding that virus strains rapidly escape 2G12 pressure. Notably, in vitro resistance mutations differed, in most cases, from those found in vivo. Importantly, in vitro selection with 2F5 and 4E10 demonstrated that resistance to these MAbs can be difficult to achieve and can lead to selection of variants with impaired infectivity. This remarkable vulnerability of the virus to interference within the MPER calls for a further evaluation of the safety and efficacy of MPER-targeting therapeutic and vaccination strategies.

Calculations of the RF magnetic (B(1)) field as a function of frequency between 64 and 345 MHz were performed for a head model in an idealized birdcage coil. Absorbed power (P(abs)) and SNR were calculated at each frequency with three different methods of defining excitation pulse amplitude: maintaining 90 degrees flip angle at the coil center (center alpha = pi/2), maximizing FID amplitude (Max. A(FID)), and maximizing total signal amplitude in a reconstructed image (Max. A(image)). For center alpha = pi/2 and Max. A(image), SNR increases linearly with increasing field strength until 260 MHz, where it begins to increase at a greater rate. For these two methods, P(abs) increases continually, but at a lower rate at higher field strengths. Above 215 MHz in MRI of the human head, the use of FID amplitude to set B(1) excitation pulses may result in apparent decreases in SNR and power requirements with increasing static field strength. Magn Reson Med 45:684-691, 2001.

To assess the yield of diagnostic exome sequencing (DES) and to characterize the molecular findings in characterized and novel disease genes in patients with epilepsy.

In an unselected sample of 1,131 patients referred for DES, overall results were compared between patients with and without epilepsy. DES results were examined based on age of onset and epilepsy diagnosis.

Positive/likely positive results were identified in 112/293 (38.2%) epilepsy patients compared with 210/732 (28.7%) patients without epilepsy (P = 0.004). The diagnostic yield in characterized disease genes among patients with epilepsy was 33.4% (105/314). KCNQ2, MECP2, FOXG1, IQSEC2, KMT2A, and STXBP1 were most commonly affected by de novo alterations. Patients with epileptic encephalopathies had the highest rate of positive findings (43.4%). A likely positive novel genetic etiology was proposed in 14/200 (7%) patients with epilepsy; this frequency was highest in patients with epileptic encephalopathies (17%). Three genes (COQ4, DNM1, and PURA) were initially reported as likely positive novel disease genes and were subsequently corroborated in independent peer-reviewed publications.

DES with analysis and interpretation of both characterized and novel genetic etiologies is a useful diagnostic tool in epilepsy, particularly in severe early-onset epilepsy. The reporting on novel genetic etiologies may further increase the diagnostic yield.Genet Med 18 9, 898-905.

We describe a sensitive, reliable and reproducible method, based on three multiplex PCR assays, for the rapid detection of seven common alpha-thalassaemia deletions and one alpha-globin gene triplication. The new assay detects the alpha0 deletions - -SEA, - (alpha)20.5, - -MED, - -FIL and - -THAI in the first multiplex PCR, the second multiplex detects the -alpha3.7 deletion and alphaalphaalphaanti3.7 variant, the third multiplex detects the -alpha4.2 deletion. This simple multiplex method should greatly facilitate the genetic screening and molecular diagnosis of these determinants in populations where alpha-thalassaemias are prevalent.

OBJECTIVE

The purpose of the study was to investigate speech understanding in quiet and noise in subjects bilaterally implanted with multi-channel cochlear implants.

METHODS

Nine adults bilaterally implanted with MED-EL implants were included in the study. The subjects were tested in three conditions: with both implants, with the right implant only, and with the left implant only. Speech tests included monosyllables in quiet and sentences in noise (10 dB signal to noise ratio). Speech was presented from the front, and noise was presented from either 90 degrees or 270 degrees azimuth.

RESULTS

All subjects reported benefit from bilateral stimulation. Speech scores for all subjects were higher with bilateral than with unilateral stimulation. The average score across subjects for sentence understanding was 31.1 percentage points higher with both cochlear implants compared with the cochlear implant ipsilateral to the noise, and 10.7 percentage points higher with both cochlear implants compared with the cochlear implant contralateral to the noise. The average score for recognition of monosyllabic words was 18.7 percentage points higher with both cochlear implants than with one cochlear implant. All of these differences in average scores were significant at the 5% level.

CONCLUSIONS

Bilateral cochlear implantation provides a significant benefit in speech understanding in both quiet and noise.

Autoimmune mediated destruction of beta cells of the islets of Langerhans leads to insulin-dependent diabetes mellitus (IDDM). Rat insulin promoter (RIP) lymphocytic choriomeningitis virus (LCMV) transgenic mice that express the nucleoprotein (NP) or glycoprotein (GP) of LCMV under control of the RIP in their beta cells develop IDDM after infection with LCMV and serve as a model for virus-induced IDDM. Recently, Kagi et al. (Kagi, D., B. Odermatt, P. Ohashi, R.M. Zinkernagel, and H. Hengartner, 1996, J. Exp. Med. 183:2143-2149) showed, using RIP LCMV perforin-deficient mice, that IDDM does not occur in the absence of perforin. They concluded that perforin-mediated killing by cytotoxic T lymphocytes (CTLs) is the main factor needed for beta cell injury and destruction. Here we provide evidence that killing of beta cells is more complex and multifactorial. By the use of our RIP LCMV model, we show that in perforin competent but interferon-gamma (IFN-gamma)-deficient mice, beta cell injury is limited and IDDM does not occur. For these studies, double transgenic mice were generated that were genetically deficient in the production of IFN-gamma and express LCMV NP or GP in their beta cells. In such mice, IDDM was aborted despite the generation of LCMV-specific antiself CTLs that displayed normal cytolytic activity in vitro and in vivo and entered the pancreas. However, mononuclear infiltration into the islets did not occur, and upregulation of class I and II molecules usually found in islets of RIP LCMV single transgenic mice after LCMV infection preceding the onset of clinical IDDM was not present in these bigenic mice. Our findings indicate that in addition to perforin, beta cell destruction, development of insulitis, and IDDM also depend on the cytokine INF-gamma, presumably through enhancement of major histocompatibility complex expression and antigen presentation.

Epstein-Barr virus (EBV)-associated posttransplant lymphoproliferative disease (PTLD) is an uncommon but potentially fatal complication of immunosuppression in solid-organ transplant recipients. A semiquantitative DNA polymerase chain reaction assay was developed to amplify a unique 269-bp region of the EBNA-1 gene in peripheral blood lymphocytes (PBL) using the primers described by Telenti et al (J Clin Microbiol 28:2187, 1990). Serial samples were studied from 23 transplant recipients, 12 of whom were diagnosed with PTLD. The majority of transplant recipients who were EBV seropositive at the time of transplant surgery and who did not develop PTLD (5 of 7, 71%) exhibited less than a 10-fold increase in the levels of EBV-infected PBL over the 0.1 to 5 EBV genomes/10(6) PBL observed in immunocompetent EBV seropositive controls. Transplant recipients who were seronegative at the time of transplantation and who underwent a primary EBV infection but did not develop PTLD exhibited a reduced capacity to control viremia because the levels of EBV-infected PBL were up to 400 times greater than the 1.0 to 50 EBV genomes/10(6) PBL observed in individuals undergoing acute infectious mononucleosis (Rocci et al: N Engl J Med 296:132, 1977). However, all transplant recipients who developed PTLD exhibited a marked elevation of EBV-infected PBL independent of their serologic state at the time of transplantation. Six of the 10 transplant recipients with PTLD exhibited>> or = 300,000 EBV genomes/10(5) PBL, two exhibited 10,000 to 50,000 EBV-infected genomes/10(5) PBL, and one each exhibited 2,500 and 500 EBV genomes/10(5) PBL. However, the latter two samples were obtained 4 to 5 weeks after the diagnosis of PTLD and may reflect a decrease in viral load resulting from immunomodulation. Marked decreases in the levels of EBV nuclear antigen-1 (EBNA-1), EBNA-2, and EBNA-LP antibodies correlated with the increase in EBV-infected PBL. Hence, a quantitative difference in circulating EBV viral load and EBNA antibody levels is evident between transplant recipients with and without PTLD and may be useful as a noninvasive prognostic marker with which to monitor and/or predict the development of PTLD.

We established a new congenic model of hypertension, the mRen(2). Lewis rat and assessed the intracellular expression of angiotensin peptides and receptors in the kidney. The congenic strain was established from the backcross of the (mRen2)27 transgenic rat that expresses the mouse renin 2 gene onto the Lewis strain. The 20-wk-old male congenic rats were markedly hypertensive compared with the Lewis controls (systolic blood pressure: 195 +/- 2 vs. 107 +/- 2 mmHg, P < 0.01). Although plasma ANG II levels were not different between strains, circulating levels of ANG-(1-7) were 270% higher and ANG I concentrations were 40% lower in the mRen2. Lewis rats. In contrast, both cortical (CORT) and medullary (MED) ANG II concentrations were 60% higher in the mRen2. Lewis rats, whereas tissue ANG I was 66 and 84% lower in CORT and MED. For both strains, MED ANG II, ANG I, and ANG-(1-7) were significantly higher than CORT levels. Intracellular ANG II binding distinguished nuclear (NUC) and plasma membrane (PM) receptor using the ANG II radioligand 125I-sarthran. Isolated CORT nuclei exhibited a high density (Bmax >200 fmol/mg protein) and affinity for the sarthran ligand (KD<0.5 nM); the majority of these sites (>95%) were the AT1 receptor subtype. CORT ANG II receptor Bmax and KD values in nuclei were 75 and 50% lower, respectively, for the mRen2. Lewis vs. the Lewis rats. In the MED, the PM receptor density (Lewis: 50 +/- 4 vs. mRen2. Lewis: 21 +/- 5 fmol/mg protein) and affinity (Lewis: 0.31 +/- 0.1 vs. 0.69 +/- 0.1 nM) were lower in the mRen2. Lewis rats. In summary, the hypertensive mRen2. Lewis rats exhibit higher ANG II in both CORT and MED regions of the kidney. Evaluation of intracellular ANG II receptors revealed lower CORT NUC and MED PM AT1 sites in the mRen2. Lewis. The downregulation of AT1 sites in the mRen2. Lewis rats may reflect a compensatory response to dampen the elevated levels of intrarenal ANG II.

The sodium channel Nav1.6, encoded by the gene SCN8A, is one of the major voltage-gated channels in human brain. The sequences of sodium channels have been highly conserved during evolution, and minor changes in biophysical properties can have a major impact in vivo. Insight into the role of Nav1.6 has come from analysis of spontaneous and induced mutations of mouse Scn8a during the past 18 years. Only within the past year has the role of SCN8A in human disease become apparent from whole exome and genome sequences of patients with sporadic disease. Unique features of Nav1.6 include its contribution to persistent current, resurgent current, repetitive neuronal firing, and subcellular localization at the axon initial segment (AIS) and nodes of Ranvier. Loss of Nav1.6 activity results in reduced neuronal excitability, while gain-of-function mutations can increase neuronal excitability. Mouse Scn8a (med) mutants exhibit movement disorders including ataxia, tremor and dystonia. Thus far, more than ten human de novo mutations have been identified in patients with two types of disorders, epileptic encephalopathy and intellectual disability. We review these human mutations as well as the unique features of Nav1.6 that contribute to its role in determining neuronal excitability in vivo. A supplemental figure illustrating the positions of amino acid residues within the four domains and 24 transmembrane segments of Nav1.6 is provided to facilitate the location of novel mutations within the channel protein.

BACKGROUND

The aim of this paper is to highlight emerging data on occupational attributable risk in asthma. Despite well documented outbreaks of disease and the recognition of numerous specific causal agents, occupational exposures previously had been relegated a fairly minor role relative to other causes of adult onset asthma. In recent years there has been a growing recognition of the potential importance of asthma induced by work-related exposures

METHODS

We searched Pub Med from June 1999 through December 2007. We identified six longitudinal general population-based studies; three case-control studies and eight cross-sectional analyses from seven general population-based samples. For an integrated analysis we added ten estimates prior to 1999 included in a previous review.

RESULTS

The longitudinal studies indicate that 16.3% of all adult-onset asthma is caused by occupational exposures. In an overall synthesis of all included studies the overall median PAR value was 17.6%.

CONCLUSIONS

Clinicians should consider the occupational history when evaluating patients in working age who have asthma. At a societal level, these findings underscore the need for further preventive action to reduce the occupational exposures to asthma-causing agents.

OBJECTIVE

The microendoscopic discectomy (MED) technique was initially developed in 1997 to treat herniated lumbar disc disease. Since then, thousands of cases have been successfully performed at more than 500 institutions. This article discusses the technical aspects of this procedure and presents a consecutive case series.

METHODS

A total of 150 consecutive patients underwent MED. MED is performed by a muscle-splitting approach using a series of tubular dilators with consecutively increasing diameters. A tubular retractor is then inserted over the final dilator, and a specially designed endoscope is placed inside the tubular retractor. The microdiscectomy is performed endoscopically while the surgeon views the procedure on a video monitor.

RESULTS

Clinical outcomes were determined using a modified MacNab criteria, which revealed that 77% of patients had excellent, 17% had good, 3% had fair, and 3% had poor outcomes. The average hospital stay was 7.7 hours. The average return to work period was 17 days. Complications primarily included dural tears, which occurred in 8 patients (5%) and were seen early on in the patient series. Complication rates diminished as the surgeon's experience with this technique increased.

CONCLUSIONS

MED for lumbar herniated disc disease can be performed safely and effectively, resulting in a shortened hospital stay and faster return to work; however, there is a learning curve to this procedure.

Cartilage oligomeric matrix protein (COMP) belongs to the thrombospondin family and is a homopentamer primarily expressed in cartilage. Mutations in the COMP gene result in the autosomal dominant chondrodysplasias pseudoachondroplasia (PSACH) and some types of multiple epiphyseal dysplasia (MED), which are characterized by mild to severe short-limb dwarfism and early-onset osteoarthritis. We have generated COMP-null mice to study the role of COMP in vivo. These mice show no anatomical, histological, or ultrastructural abnormalities and show none of the clinical signs of PSACH or MED. Northern blot analysis and immunohistochemical analysis of cartilage indicate that the lack of COMP is not compensated for by any other member of the thrombospondin family. The results also show that the phenotype in PSACH/MED cartilage disorders is not caused by the reduced amount of COMP.

BACKGROUND

During the last century, the management of blunt force trauma to the spleen has changed from observation and expectant management in the early part of the 1900s to mainly operative intervention, to the current practice of selective operative and nonoperative management. These issues were first addressed by the Eastern Association for the Surgery of Trauma (EAST) in the Practice Management Guidelines for Non-operative Management of Blunt Injury to the Liver and Spleen published online in 2003. Since that time, a large volume of literature on these topics has been published requiring a reevaluation of the current EAST guideline.

METHODS

The National Library of Medicine and the National Institute of Health MEDLINE database was searched using Pub Med (www.pubmed.gov). The search was designed to identify English-language citations published after 1996 (the last year included in the previous guideline) using the keywords splenic injury and blunt abdominal trauma.

RESULTS

One hundred seventy-six articles were reviewed, of which 125 were used to create the current practice management guideline for the selective nonoperative management of blunt splenic injury.

CONCLUSIONS

There has been a plethora of literature regarding nonoperative management of blunt splenic injuries published since the original EAST practice management guideline was written. Nonoperative management of blunt splenic injuries is now the treatment modality of choice in hemodynamically stable patients, irrespective of the grade of injury, patient age, or the presence of associated injuries. Its use is associated with a low overall morbidity and mortality when applied to an appropriate patient population. Nonoperative management of blunt splenic injuries should only be considered in an environment that provides capabilities for monitoring, serial clinical evaluations, and has an operating room available for urgent laparotomy. Patients presenting with hemodynamic instability and peritonitis still warrant emergent operative intervention. Intravenous contrast enhanced computed tomographic scan is the diagnostic modality of choice for evaluating blunt splenic injuries. Repeat imaging should be guided by a patient's clinical status. Adjunctive therapies like angiography with embolization are increasingly important adjuncts to nonoperative management of splenic injuries. Despite the explosion of literature on this topic, many questions regarding nonoperative management of blunt splenic injuries remain without conclusive answers in the literature.

In order to identify molecular changes associated with the transmission of avian influenza A H5N1 and H9N2 viruses to humans, the internal genes from these viruses were compared to sequences from other avian and human influenza A isolates. Phylogenetically, each of the internal genes of all sixteen of the human H5N1 and both of the H9N2 isolates were closely related to one another and fell into a distinct clade separate from clades formed by the same genes of other avian and human viruses. All six internal genes were most closely related to those of avian isolates circulating in Asia, indicating that reassortment with human strains had not occurred for any of these 18 isolates. Amino acids previously identified as host-specific residues were predominantly avian in the human isolates although most of the proteins also contained residues observed previously only in sequences of human influenza viruses. For the majority of the nonglycoprotein genes, three distinct subgroups could be distinguished on bootstrap analyses of the nucleotide sequences, suggesting multiple introductions of avian virus strains capable of infecting humans. The shared nonglycoprotein gene constellations of the human H5N1 and H9N2 isolates and their detection in avian isolates only since 1997 when the first human infections were detected suggest that this particular gene combination may confer the ability to infect humans and cause disease. J. Med. Virol. 66:107-114, 2002. Published 2002 Wiley-Liss, Inc.

Mesenchymal stem cells (MSCs) are multipotent progenitor cells exerting immunomodulatory effects on cells of the innate and adaptive immune system. It has been shown that an inflammatory milieu is required for the activation of MSC-mediated immunomodulation, and interferon-γ (IFN-γ) plays an important role in this process. We determined the influence of IFN-γ on human adipose-derived stem cells (ASCs) and human amniotic mesenchymal stromal cells (hAMSCs). We further evaluated the effect of MSCs on stimulated T-cells and peripheral blood mononuclear cells (PBMCs) in a cell-contact independent setting. On IFN-γ treatment, ASCs and hAMSCs possessed significantly higher antiproliferative properties and showed surface characteristics of nonprofessional antigen presenting cells (HLA-DR(+)CD40(med+)CD54(high)) with a possible regulatory phenotype (PD-L1(+)PD-L2(+)). The effect of ASCs and hAMSCs on cytokine secretion and T-cell activation was dependent on stimulation method and cellular context. Although ASCs and hAMSCs highly inhibited cytokine secretion of stimulated PBMCs, this was not observed in the case of purified T-cells. The presence of ASCs even favored the secretion of pro-inflammatory cytokines including IFN-γ by T-cells, although T-cell proliferation was efficiently inhibited. Further, ASCs enhanced the number of CD69(+) T-cells independent of the stimuli and cellular context. Interestingly, ASCs significantly suppressed CD25 expression on phytohemagglutinin stimulated PBMCs but had no effect on αCD3/αCD28 stimulated cells. Depending on the stimulation method and cellular context, immune cells create a specific cytokine milieu in vitro, thus differently influencing MSCs and, in turn, affecting their action on immune cells.