Discovery and verification of amyotrophic lateral sclerosis biomarkers by proteomics

Recent studies using mass spectrometry have discovered candidate biomarkers for amyotrophic lateral sclerosis (ALS). However, those studies utilized small numbers of ALS and control subjects. Additional studies using larger subject cohorts are required to verify these candidate biomarkers. Cerebrospinal fluid (CSF) samples from 100 patients with ALS, 100 disease control, and 41 healthy control subjects were examined by mass spectrometry. Sixty‐one mass spectral peaks exhibited altered levels between ALS and controls. Mass peaks for cystatin C and transthyretin were reduced in ALS, whereas mass peaks for posttranslational modified transthyretin and C‐reactive protein (CRP) were increased. CRP levels were 5.84 ± 1.01 ng/ml for controls and 11.24 ± 1.52 ng/ml for ALS subjects, as determined by enzyme‐linked immunoassay. This study verified prior mass spectrometry results for cystatin C and transthyretin in ALS. CRP levels were increased in the CSF of ALS patients, and cystatin C level correlated with survival in patients with limb‐onset disease. Our biomarker panel predicted ALS with an overall accuracy of 82%. Muscle Nerve 42: 104–111, 2010     

Beneficial effect of recombinant rC1rC2 collagenases on human islet function: Efficacy of low‐dose enzymes on pancreas digestion and yield

A high number of human islets can be isolated by using modern purified tissue dissociation enzymes; however, this requires the use of >20 Wunsch units (WU)/g of pancreas for digestion. Attempts to reduce this dose have resulted in pancreas underdigestion and poor islet recovery but improved islet function. In this study, we achieved a high number of functional islets using a low dose of recombinant collagenase enzyme mixture (RCEM‐1200 WU rC2 and 10 million collagen‐degrading activity [CDA] U of rC1 containing about 209 mg of collagenase to digest a 100‐g pancreas). The collagenase dose used in these isolations is about 42% of the natural collagenase enzyme mixture (NCEM) dose commonly used to digest a 100‐g pancreas. Low‐dose RCEM was efficient in digesting entire pancreases to obtain higher yield (5535 ± 830 and 2582 ± 925 islet equivalent/g, P < .05) and less undigested tissue (16.7 ± 5% and 37.8 ± 3%, P < .05) compared with low‐dose NCEM (12WU/g). Additionally, low‐dose RCEM islets retained better morphology (confirmed with scanning electron microscopy) and higher in vitro basal insulin release (2391 ± 1342 and 1778 ± 978 μU/mL; P < .05) compared with standard‐dose NCEM. Nude mouse bioassay demonstrated better islet function for low‐dose RCEM (area under the curve [AUC] 24 968) compared with low‐dose (AUC–38 225) or standard‐dose NCEM (AUC–38 685), P < .05. This is the first report indicating that islet function can be improved by using low‐dose rC1rC2 (RCEM).     

KOCH'S OR CROHN'S?

Abdominal tuberculosis is not uncommon in the UK, especially in Asian immigrants. It resembles Crohn's disease clinically and radiologically, and it may be difficult to differentiate between them, even at laparotomy or histology. The distinction is important, however, for proper management of the two conditions. Every effort must be made to exclude abdominal tuberculosis before the patient is diagnosed as having Crohn's disease and is treated with steroids.     

Effect of conversion from mycophenolate mofetil to enteric-coated mycophenolate sodium on maximum tolerated dose and gastrointestinal symptoms following kidney transplantation

Despite the potential tolerability advantage of enteric-coated mycophenolate sodium (EC-MPS), no prospective, randomized trial has evaluated whether conversion from mycophenolate mofetil (MMF) to EC-MPS permits mycophenolic acid dose to be increased or gastrointestinal side-effects to be ameliorated. In a randomized, multicenter, open-label trial, kidney transplant recipients experiencing gastrointestinal side-effects either remained on MMF or switched to an equimolar dose of EC-MPS, adjusted 2 weeks subsequently to target the highest tolerated dose up to 1440 mg/day (EC-MPS) or 2000 mg/day (MMF). Patients were followed up to 12 weeks postrandomization. One hundred and thirty-four patients were randomized. The primary efficacy endpoint, the proportion of patients receiving a higher mycophenolic acid (MPA) dose at week 12 than at randomization, was significantly greater in the EC-MPS arm (32/68, 47.1%) than the MMF arm (10/61, 16.4%; P  < 0.001). At the final visit, 50.0% (34/68) of EC-MPS patients were receiving the maximum recommended dose versus 26.2% (16/61) of MMF patients ( P  = 0.007). Kidney transplant patients receiving reduced-dose MMF because of gastrointestinal side-effects can tolerate a significant increase in MPA dose after conversion to EC-MPS. Patient-reported gastrointestinal outcomes with higher doses of EC-MPS remained at least as good as in MMF-treated controls.     

Dimethyltryptamine and other hallucinogenic tryptamines exhibit substrate behavior at the serotonin uptake transporter and the vesicle monoamine transporter

N,N-dimethyltryptamine (DMT) is a potent plant hallucinogen that has also been found in human tissues. When ingested, DMT and related N,N-dialkyltryptamines produce an intense hallucinogenic state. Behavioral effects are mediated through various neurochemical mechanisms including activity at sigma-1 and serotonin receptors, modification of monoamine uptake and release, and competition for metabolic enzymes. To further clarify the pharmacology of hallucinogenic tryptamines, we synthesized DMT, N-methyl-N-isopropyltryptamine (MIPT), N,N-dipropyltryptamine (DPT), and N,N-diisopropyltryptamine. We then tested the abilities of these N,N-dialkyltryptamines to inhibit [³H]5-HT uptake via the plasma membrane serotonin transporter (SERT) in human platelets and via the vesicle monoamine transporter (VMAT2) in Sf9 cells expressing the rat VMAT2. The tryptamines were also tested as inhibitors of [³H]paroxetine binding to the SERT and [³H]dihydrotetrabenazine binding to VMAT2. Our results show that DMT, MIPT, DPT, and DIPT inhibit [³H]5-HT transport at the SERT with K _I values of 4.00 ± 0.70, 8.88 ± 4.7, 0.594 ± 0.12, and 2.32 ± 0.46 μM, respectively. At VMAT2, the tryptamines inhibited [³H]5-HT transport with K _I values of 93 ± 6.8, 20 ± 4.3, 19 ± 2.3, and 19 ± 3.1 μM, respectively. On the other hand, the tryptamines were very poor inhibitors of [³H]paroxetine binding to SERT and of [³H]dihydrotetrabenazine binding to VMAT2, resulting in high binding-to-uptake ratios. High binding-to-uptake ratios support the hypothesis that the tryptamines are transporter substrates, not uptake blockers, at both SERT and VMAT2, and also indicate that there are separate substrate and inhibitor binding sites within these transporters. The transporters may allow the accumulation of tryptamines within neurons to reach relatively high levels for sigma-1 receptor activation and to function as releasable transmitters.     

Renal Transplantation: Experience at a Single Centre

Background

Renal transplantation program in the Armed Forces commenced in Feb 1991 and till date 245 patients have undergone renal transplantation at INHS Asvini. We describe our protocols for donor and recipient evaluation and immunosuppression. Methods: 245 patients received renal transplants during this period, 243 (99.2%) being from live donors. Most of them were started on triple immunosuppression comprising of cyclosporine, azathioprine and prednisolone. Newer drugs like mycophenolate, tacrolimus and sirolimus were administered in a select population.

Result

69 (28.1%) of them had at least one episode of acute rejection, most of which were steroid responsive and 13 (18.8%) of them required either anti CD3 monoclonal or anti-thymocyte globulin (ATG). Complete recovery with normal renal function occurred in 54 (78.2%) cases and 15 (21.7%) recovered with residual dysfunction with maximum serum creatinine being 2.1mg/dl. There were three (1.2%) cases of accelerated rejection during the first week of transplantation and one had graft rupture. All three lost their grafts. There were eight (3.2%) cases of acute tubular necrosis, who recovered completely within 8–14 days. Immediate infections included wound sepsis, lower respiratory tract infection, disseminated candidiasis and disseminated aspergillosis. Late infections included pulmonary tuberculosis, disseminated tuberculosis, cytomegalovirus infection and recurrent urinary tract infection. 28 (11.4%) patients developed post transplant diabetes mellitus. At the end of one year and five years, graft and patient survival were 97.2%, 93%, 80.9% and 85.7% respectively.

Conclusion

Our outcomes show that the transplantation is a viable mode of renal replacement therapy in patients of end stage kidney disease with a near normal rehabilitation.Key Words: Kidney, Transplantation, Immunosuppression, Complications     

Household Water Purification: Low-Cost Interventions

Numerous studies have shown that improving the microbiological quality of household water by point-of-use treatment reduces diarrhoea and other waterborne diseases. The most promising and accessible of the technologies for household water treatment are filtration with ceramic filters, chlorination with storage in an improvised vessel, solar disinfection in clear bottles by the combined action of UV radiation and heat, thermal disinfection (pasteurization) in opaque vessels with sunlight from solar cookers or reflectors and combination systems employing chemical coagulation-flocculation, sedimentation, filtration and chlorination. However each of these technologies have limitations and effectiveness can be increased by use of two or more treatment systems in succession for improved treatment and the creation of multiple barriers. In particular those treatments that provide no residual disinfectant, such as boiling, solar treatment, UV disinfection with lamps and filtration could be followed by chlorination to provide a multibarrier approach. Water purifiers based on multiple interventions such as filtration/ultra filtration/activated carbon adsorption / UV rays disinfection are available in the market which can be used to purify the water at point of use. Water purifiers based on single interventions like candle filters, resins filters or ultraviolet lamp can be used in most places being supplied water after purification. Troops on operational move can purify water by fabric/resins filtration and chlorine disinfection or by flocculent-disinfectant.Key Words: Household water purification, Low-cost interventions, Effectiveness