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Biomedical subjects

M Adler

Publications and source records attributed to M Adler.

At least 91 records · Page 5Linked to original sources
PubMed1997

Identification of a recombinant synaptobrevin-thioredoxin fusion protein by capillary zone electrophoresis using laser-induced fluorescence detection.

Capillary zone electrophoresis (CZE) was utilized to identify a synaptobrevin-thioredoxin fusion protein (TSB-51). TSB-51 is a substrate for cleavage by botulinum toxin B at the Q(76)-F(77) site. TSB-51 was derivatized with a fluorophore, CBQCA [3-(4-carboxy-benzoyl)-2-quinoline-carboxaldehyde], for 4 h at room temperature. Optimal conditions for CZE separation of the TSB-51-CBQCA complex were determined: buffer (sodium borate), pH (9.0), applied voltage (25 kV), temperature (25 degrees C) and forward polarity. SDS-PAGE showed that TSB-51 had a molecular mass of approximately 19 kDa. The protein was transferred to PVDF membrane and sequenced by the Edman degradation method verifying the first twelve amino acids as SDKIIHLTDDSF. TSB-51 was also collected during CZE separation and subsequently sequenced yielding the first three amino acids as SDK. This CZE-LIF method coupled with the CBQCA derivatization, fraction collection and Edman sequencing allowed for identification of the recombinant protein, a fast separation run time and utilization of small volumes of peptide (1.5 ng protein/23.6 nl injection). This method will be used for monitoring the endopeptidase activity of botulinum toxin B on TSB-51.

Amino Acid Sequence↗
PubMed1997

Fluorometric polymerase chain reaction (PCR) enzyme-linked immunosorbent assay for quantification of immuno-PCR products in microplates.

Immuno-polymerase chain reaction (immuno-PCR) allows the detection of protein amounts as low as a few hundred molecules. This enhanced sensitivity is useful for a variety of applications in analytical and biomedical sciences. Application of this technique as a routine method requires the rapid quantification of the PCR products, preferably as an automated readout by microplate-based assays. Here, three methods are compared for detecting such amplified products, i. e., direct staining with a fluorescent intercalating dye, an enzymatic assay utilizing doubly hapten-labeled products, and gel electrophoresis. The enzymatic assay, carried out with either chromogenic or fluorogenic substrate for enzymatic signal amplification, was found to be the most sensitive method. The optimized assay was tested in direct immuno-PCR assays for detecting immunoglobulins (IgG) from mouse and rabbit as well as in a sandwich immuno-PCR assay for detecting recombinant hepatitis B surface antigen (rec. HBsAg). Sensitivity limits were found to be as low as 15 fg (10(-19) mol) IgG, representing a 1000-fold enhancement compared to enzyme-linked immunosorbent assay detection, and about 70 fg (2 x 10(-18) mol) rec. HBsAg, improving the detection limit of currently available methods by a factor of about 700. The well-reproducible enzymatic amplification signal further enhances the sensitivity of immuno-PCR and should render the method suitable for routine laboratories.

Animals↗
PubMed1997

Cefdinir versus amoxicillin/clavulanic acid in the treatment of suppurative acute otitis media in children.

An investigator-blinded, randomized, multicenter study was conducted to compare the efficacy and safety of cefdinir and amoxicillin/clavulanate (amoxicillin/CA) in the treatment of pediatric patients with acute suppurative otitis media. Patients 6 months to 12 years of age were randomized in a 1:1:1 ratio to receive cefdinir 14 mg/kg once-daily, cefdinir 7 mg/kg b.i.d., or amoxicillin/CA 13.3 mg/kg t.i.d. Test-of-cure was determined 11 to 16 days post therapy. Of the 752 patients who entered the study, 665 (88%) completed treatment and 595 (79%) were evaluable. Response rates in the three treatment groups were similar. Overall rates of adverse events were statistically lower in the cefdinir once-daily group than in the amoxicillin/CA group. Diarrhea was the most common adverse event in all treatment groups. Cefdinir given either once-daily or twice-daily is a safe and effective treatment for pediatric patients with acute suppurative otitis media.

Amoxicillin↗
PubMed1997

Detection of fastidious mycobacteria in human intestines by the polymerase chain reaction.

The aim of this study was to determine whether difficult-to-grow mycobacteria are present in human intestines. Intestinal tissue samples were subjected to both mycobacterial culture and a polymerase chain reaction (PCR) assay. After detection by PCR, species identity was determined by hybridizing the amplified 16S rRNA gene fragments with species-specific oligonucleotides. Intestinal biopsies from 63 patients with noninflammatory bowel diseases (n = 22), Crohn's disease (n = 31), or ulcerative colitis (n = 10) were analyzed. Culture and PCR revealed mycobacteria in four (6%) and 25 (40%) samples, respectively. Samples positive by PCR were negative with all probes specific to nine common cultivable species but were positive with Mycobacterium genavense-specific probe in 68% of cases. Mycobacterial isolates were identified as Mycobacterium gordonae and Mycobacterium chelonae. Findings were similar in Crohn's disease samples compared to non-Chron's disease samples. This study shows that difficult-to-grow mycobacteria can be detected by PCR in large and similar proportions of inflamed intestinal tissue from patients with inflammatory bowel disease and intestinal tissue that appears normal from patients with noninflammatory bowel disease.

Adolescent↗
PubMed1997

Efficacy of certain quinolines as pharmacological antagonists in botulinum neurotoxin poisoning.

Various 4- and 8-aminoquinolines, which are effective antimalarial agents, were examined as potential pretreatment compounds for prolongation of the time to 50% block of nerve-elicited muscle twitches in isolated mouse diaphragms exposed to botulinum type A neurotoxin. The 4-aminoquinolines (chloroquine, amodiaquine) and quinacrine, an acridine derivative similar to chloroquine, prolonged the time required for botulinum type A neurotoxin to block neuromuscular transmission by more than 3-fold; 8-aminoquinolines (primaquine and WR242511) had no antibotulinum type A neurotoxin activity. Pyrimethamine, an antimalarial drug lacking the quinoline ring structure, was also ineffective. Rank order potencies based on equimolar effective concentrations for the test compounds were quinacrine > amodiaquine > chloroquine > quinine or quinidine. Maximum protection from botulinum type A neurotoxin-induced neuromuscular block was achieved when muscles were exposed to drug prior to or simultaneously with the toxin. A delay of more than 20 min abolished the protective ability of the antimalarial agents, presumably owing to the release of the toxin from endosomes in quantities sufficient to initiate neuromuscular block. All of the test compounds except quinine and quinidine depressed muscle contractions when concentrations exceeded 20 microM. In addition, amodiaquine at 50 microM induced muscle contracture. A combination of agents at low concentrations that act at different steps of botulinum type A neurotoxin poisoning potentiated the prolongation of time to 50% block in an approximately additive fashion. Thus N,N,N',N'-tetrakis(2-pyridylmethyl)ethylenediamine (2 microM) and quinacrine (5 microM), when administered in combination, produced up to a 4-fold increase in time to 50% block. A similar level of protection with quinacrine alone required a 4-fold increase in the aminoquinoline concentration. Although the mechanism of protection by these antimalarial agents is probably through the raising of endosomal pH, the possibility that some of these drugs could also act by inhibiting toxin-induced channel formation cannot be ruled out.

Aminoquinolines↗
PubMed1997

Structural features of aminoquinolines necessary for antagonist activity against botulinum neurotoxin.

Certain aminoquinoline antimalarial compounds, such as chloroquine, antagonize the paralytic actions of botulinum neurotoxins (BoNT). These studies have been extended to determine the critical structural groups necessary for synthetic aminoquinolines to have antagonist activity against BoNT. Isolated mouse hemidiaphragms were maintained at 36 degrees C and indirectly stimulated; the resulting isometric twitch tensions were recorded as a measure of synaptic function. The muscles were exposed to the test compounds before being treated with a challenge concentration of BoNT (typically 0.2 nM of serotype A). The time to onset of 50% muscle paralysis due to BoNT was used to assess quantitatively the efficacy of the test compounds, which were then ranked on the basis of the concentrations necessary to delay paralysis by a specified time increment. Of the compounds tested, those having a 7-chloro-4-aminoquinoline configuration, similar to chloroquine (or the structurally similar 6-chloro-9-amino acridine group in quinacrine), were most effective. Truncation of the alkyl-amino-alkyl group from chloroquine and conversion of the 4-amino nitrogen to a primary amine did not significantly alter its effectiveness as a BoNT antagonist. However, the 6-chloro- or 8-chloro- isomers of chloroquine were essentially ineffective. These results suggest that aminoquinolines antagonize the paralytic actions of BoNT through interaction with a selective, stereospecific site that is not well correlated with antimalarial activity.

Aminoquinolines↗
PubMed1997

Protection by the heavy metal chelator N,N,N',N'-tetrakis (2-pyridylmethyl)ethylenediamine (TPEN) against the lethal action of botulinum neurotoxin A and B.

The ability of N,N,N',N'-tetrakis (2-pyridylmethyl)-ethyenediamine (TPEN) to protect against botulinum neurotoxin (BoNT) A and B was examined in vivo in mice. To determine the protective efficacy of TPEN, mice were injected i.p. with TPEN as a single bolus or as multiple injections 30 min before and 0, 2, 4 and 6 hr following i.v. challenges with BoNT-A or -B. TPEN treatment did not alter the 24 hr lethality of BoNT but did produce a significant delay in the time to death. For a moderate dose of serotype A (20 LD50), five divided doses of TPEN prolonged the time to death from 7.8 +/- 0.4 hr to 9.9 +/- 0.5 hr. For serotype B, examined under comparable conditions, the prolongation of the time to death was from 6.1 +/- 0.2 hr to 9.4 +/- 0.6 hr. The range of TPEN doses that could be examined in vivo was limited by its acute toxicity. Although low doses of TPEN (< or = 10 mg/kg) were well tolerated, higher doses (> or = 30 mg/kg) led to ataxia, loss of coordination, convulsions and death in 20.3 min or less. In clonal NG108-15 cells, TPEN was found to produce cytotoxicity as revealed by increases in the secretion of the marker enzyme lactate dehydrogenase (LDH), and enhanced reactivity with the vital dye trypan blue. From LDH concentration-response data determined 24 hr after addition of TPEN, the threshold concentration for observing cytotoxicity was 10 microM and the IC50 was 19.8 microM. At the highest TPEN concentration tested (100 microM), cytotoxicity was detected 8 hr after TPEN addition and increased in severity over a 3 day period. The cytotoxicity in NG108-15 cells appears to be distinct from the rapid-onset toxicity observed in whole animals. These results suggest that TPEN may be of potential benefit in delaying the lethal actions of BoNT-A and -B, but its use is limited by its initial and delayed toxicity. Since the therapeutic and toxic actions of TPEN are both related to zinc chelation, the use of TPEN would need to be restricted to low doses as part of a combination therapy.

Animals↗
PubMed1997

Diuretic requirements after therapeutic paracentesis in non-azotemic patients with cirrhosis. A randomized double-blind trial of spironolactone versus placebo.

BACKGROUND/AIMS: Diuretic requirements after mobilization of ascites by paracentesis have never been assessed in cirrhosis. It is also unknown whether diuretics increase the incidence of postparacentesis circulatory dysfunction. The aim of this study was to investigate these features and to assess whether measurement of plasma renin activity and aldosterone prior to paracentesis predicts diuretic response after this procedure. METHODS: Thirty-six patients with non-azotemic cirrhosis and ascites treated by total paracentesis plus i.v. albumin were randomly assigned to receive placebo (n=17) or spironolactone 225 mg/day (n=19) immediately after paracentesis and followed-up for 4 weeks. RESULTS: Five patients (three in the placebo and two in the spironolactone group) abandoned the treatment prior to ascites recurrence or the end of the study due to complications or lack of compliance. The analysis was performed in the remaining 31 patients. Ascites recurrence was more common in the placebo group (13 cases, 93%) than in the spironolactone group (3 cases, 18%) (p<0.0001) and occurred within the first 2 weeks of follow-up in more than 50% of patients. Patients developing ascites in the spironolactone group had higher levels of renin (14.1, 20.6, 32.4 ng/ml per h) and aldosterone (120, 149, 288 ng/dl) than those who did not develop ascites (renin: 2.0+/-2.1 ng/ml per h; range 0.1-6.8; aldosterone: 43+/-38 ng/dl; range 4-116). Three patients in the placebo group and two in the spironolactone group developed postparacentesis circulatory dysfunction (defined as an increase in renin at the third day after paracentesis greater than 50% over baseline levels up to a value higher than 4 ng/ml per h). CONCLUSIONS: Patients with cirrhosis treated by paracentesis should receive diuretics immediately after this procedure to prevent early recurrence of ascites. The administration of 225 mg/day of spironolactone is a good empiric treatment for non-azotemic patients with cirrhosis, because it is effective in most cases and does not increase the incidence of postparacentesis circulatory dysfunction. The determination of plasma levels of renin or aldosterone prior to paracentesis predicts the efficacy of spironolactone in the prevention of ascites recurrence.

Aldosterone↗
PubMed1997

Prognostic evaluation of patients with parenchymal cirrhosis. Proposal of a new simple score.

BACKGROUND/AIMS: The current shortage of organs makes it desirable to establish the prognosis of patients with cirrhosis in order to assess priority for liver transplantation. METHODS: We compared the utility of two exogenous tests (aminopyrine breath test and lidocaine metabolization test), two clinical parameters (encephalopathy, ascites), 18 endogenous tests and five scores (Pugh, Merkel, Orrego, Adler, Pignon) for predicting 1-year mortality in patients with parenchymal cirrhosis. Retrospective (n=49 out of 63 patients) and prospective (n=38 out of 46 patients) series were included. Univariate, multivariate, receiver operator curves and survival curves were employed. RESULTS: We found that endogenous tests were more discriminant than exogenous tests. The best parameters of the univariate analysis (encephalopathy, bilirubin, alkaline phosphatase, cholinesterase and bile acids) and their 25th and 75th percentiles were included in an additive new score which turned out to be superior to the five other scores. Prospectively, the sensitivity of our new score compared to the Pugh score was 82% versus 95% (NS) and the specificity was 89% versus 56% (p<0.01). CONCLUSIONS: Our new simple score appears to be very powerful for predicting prognosis at 1 year for patients with cirrhosis and should be evaluated in other centers.

Adult↗
PubMed1997

BEACOPP: an intensified chemotherapy regimen in advanced Hodgkin's disease. The German Hodgkin's Lymphoma Study Group.

PURPOSE: At present, treatment results for patients with advanced-stage Hodgkin's disease remain unsatisfactory. Standard chemotherapy M(C)OPP (nitrogen mustard (cyclophosphamide). vincristine, procabazine, and prednisone). ABVD (adriamycine, bleomycine, vinblastine, and dacarbacine) or M(C)OPP/ABVD +/- radiotherapy fail to achieve long-term complete remission in 35% to 50% of these patients. The BEACOPP (bleomycin, etoposide, adriamycine, cyclophosphamide, vincristine, procarbazine, and prednisone) regimen was developed to improve treatment results by dose intensification achieved by reduced duration of treatment (time intensification) and addition of etoposide. PATIENTS AND METHODS: Thirty untreated patients with advanced Hodgkin's disease stage IIB IV according to the Ann Arbor classification were treated with the time intensified BEACOPP regimen. Each patient was scheduled to receive eight cycles of chemotherapy with consolidating radiotherapy to sites of initial bulk disease and to residual tumor remaining after chemotherapy. RESULTS: All patients were evaluable for assessment of toxicity, treatment response, freedom from treatment failure (FFTF) and survival (SV). Of 30 treated patients, 29 patients received the intended eight cycles of BEACOPP. One patient in clinical CR, terminated the chemotherapy at his own request after six cycles and is at this time, 48 months after the end of treatment, in complete remission. Toxicity was tolerable with WHO grade 3/4 leucopenia in 28% of chemotherapy cycles and one severe (WHO grade 3) infection. No treatment-related death occurred. Cycles could generally be given on schedule. Complete remission (CR) was achieved in all but two patients (93%). At present, only one patient has relapsed. At a median follow-up of 40 months, FFTF-rate is 89% (lower confidence limit: 80%). One patient died due to progressive disease. CONCLUSION: The BEACOPP regimen is feasible at moderate hematopoeitic toxicity. With a FFTF-rate of 89% at a median follow-up of 40 months, the treatment results are very encouraging. A prospective randomised trial has been initiated to compare the BEACOPP regimen with the standard COPP/ABVD regimen in advanced-stage Hodgkin's disease.

Adult↗
PubMed1997

Delayed administration of Vipera xanthina palaestinae antivenin.

INTRODUCTION: Vipera xanthina palaestinae is the most widely distributed venomous snake in Israel, accounting for most envenomations. A specific equine antivenin is efficacious against both systemic and local manifestations if given within hours. This study sought to determine if delayed vipera xanthina palaestinae antivenin can be effective. METHODS: Patients who had been bitten by vipera xanthina palaestinae during 1991-1995 were evaluated. Those who continued to deteriorate beyond 24 h post envenomation, in spite of treatment or because of delayed diagnosis, were given vipera xanthina palaestinae antivenin. RESULTS: Ten patients were included in the study. Vipera xanthina palaestinae was identified in seven and diagnosis was considered probable in three patients. On admission, eight patients had local signs and seven patients had mild to severe systemic manifestations. The local signs were remarkable and progressive in all patients. In five, systemic signs and laboratory abnormalities were delayed as well. The time range for delayed antivenin administration was 1-6 days after envenomation. Following antivenin administration, progression of local signs ceased in all patients and swelling regressed within 24 h. In nine patients this occurred within 6 h. CONCLUSION: Vipera xanthina palaestinae antivenin administration should be considered in patients with envenomations complicated by marked and progressive local signs, delayed systemic signs and laboratory abnormalities more than 24 h after envenomation.

Adolescent↗
PubMed1997

[Digestive and extra-digestive complications of nonsteroidal anti-inflammatory drugs. Preventive and curative strategies].

The authors review the digestive ulceration risk factors and the criteria for selecting a non steroidal antiinflammatory (NSAI), included the most recent drugs, such as selective anti-cyclo-oxygenases 2. They actualize the preventive strategies and insist on the values of misoprostol and of slow acting anti-rheumatic drugs. In the case of digestive ulcerations, they plead for the immediate stop of the NSAI and its replacement if necessary by corticosteroids, for the prescription of a proton pump inhibitor (PPI) or mesalazine according to the localisation of the lesion, finally for the eradication within 8 days of Helicobacter pylori.

Anti-Inflammatory Agents↗
PubMed1997

[How to follow treated and untreated chronic hepatitis B and C].

Viral hepatitis B and C are important causes of chronic liver disease, cirrhosis and hepatocellular carcinoma. Indications for the treatment of these two forms of chronic viral hepatitis are outlined as well as the practical modalities for the follow-up.

Aftercare↗
PubMed1996

Localization of transforming growth factor-beta 1 precursor and latent TGF-beta 1 binding protein in colorectal adenomas.

Transforming growth factor-beta 1 (TGF-beta 1) is a multifunctional cytokine and is thought to be involved in colorectal tumorigenesis as a regulator of cell growth and differentiation. This role is mainly supported by in vitro studies while its role in vivo remains unclear. The aim of the present study was to investigate whether the TGF-beta 1 precursor (beta 1-LAP) and the latent TGF-beta 1 binding protein (LTBP) are expressed in colorectal adenomas, the presumed precursors of most of colorectal adenocarcinomas. TGF-beta 1 precursor and LTBP were examined in 35 adenomas and 10 normal colonic mucosa specimens by immunohistochemistry, using specific polyclonal antibodies. In normal colonic mucosa, beta 1-LAP was moderately expressed in epithelial crypt cells and in the stromal cells in the lamina propria. In adenomas, beta 1-LAP was localized in epithelial cells with an heterogeneous pattern and was also present in stromal cells around the adenomatous glands. LTBP was not detected in epithelial cells but was observed in stromal cells and in the extracellular matrix (ECM). beta 1-LAP expression in epithelial cells did not correlate with the grade of dysplasia, while LTBP localized in stromal cells and ECM appeared to be closely associated with areas of higher grade of dysplasia. This study is the first demonstration of both beta 1-LAP and LTBP in colorectal adenomas with different dysplasia grades. Our results suggest that TGF-beta 1 might be involved in the mechanisms controlling in vivo colorectal tumorigenesis and support a role for the stromal-associated TGF-beta 1.

Adenomatous Polyps↗
PubMed1996

No Mycobacterium paratuberculosis found in Crohn's disease using polymerase chain reaction.

M. paratuberculosis has been considered as a putative causative factor of Crohn's disease. However, its detection in diseased tissue samples using the polymerase chain reaction yielded conflicting results. We validated this technique for the detection of mycobacteria (any species) and M. paratuberculosis before applying it to 72 intestinal biopsies from patients with Crohn's disease (N = 36), ulcerative colitis (N = 13), and control subjects (N = 23). Possible polymerase chain reaction inhibitors were detected by spiking template DNA with the equivalent of two M. paratuberculosis genomes. Mycobacteria were found in 17/36 (47%), 6/13 (46%), and 13/23 (57%) tissue samples of Crohn's disease, ulcerative colitis, and controls, respectively. No M. paratuberculosis were detected in any sample. It is concluded that mycobacteria are present with a similar frequency in the intestinal tissues or luminal inclusions of patients with inflammatory bowel disease and of those unaffected by the disease. Our data do not support a role for M. paratuberculosis in Crohn's disease.

Adult↗