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Biomedical subjects

L H Bernstein

Publications and source records attributed to L H Bernstein.

At least 91 records · Page 5Linked to original sources
PubMed1982

Metronidazole therapy for perineal Crohn's disease: a follow-up study.

The present study of metronidazole in perineal Crohn's disease includes 26 patients, and is composed of 17 of 21 patients who were previously reported and 9 additional consecutive patients. The course of these patients was evaluated to determine if the drug could be reduced or stopped, whether or not it continued to be effective for prolonged periods, and what long-term side effects were encountered. Dosage reduction was associated with exacerbation of disease activity in all patients, but in all, the perineal manifestations of disease healed promptly when the full dosage of metronidazole was reinstituted. The drug could be successfully discontinued in only 28% of those in whom cessation was attempted; in those patients whose perineal disease worsened with cessation of therapy, rapid healing was achieved if the drug was reintroduced. Sixteen patients received metronidazole for at least 12 mo including 7 for 18-36 mo. Eight of these 16 patients, including 4 on and 4 off the drug, remain healed; the other 8 patients had advanced healing. The only major side effect observed was paresthesias. These occurred in 50% of the patients and developed in the patients at a mean of 6.5 mo after the onset of treatment. They appeared to be dose related and nonprogressive but tended to persist for prolonged periods even after discontinuance of the drug.

Adult↗
PubMed1982

Reserve bilirubin binding capacity measured by absorbance deviation at saturation of primary albumin binding sites.

The reserve bilirubin binding capacity (RBBC) of neonatal serum can be measured by adding to it increments of bilirubin and noting the absorbance change at 484 nm. A 25 mg/dl bilirubin solution is added, in 5 mul increments, to 50 mul of neonatal serum in 2 ml phosphate buffer (200 mmol/L, pH 7.4). With each such addition there is a constant increase in absorbance at 484 nm until all of the albumin primary binding sites are occupied; then the increase becomes nonlinear. RBBC measurements using the proposed method and Sephadex adsorption were performed on 54 pairs of serum samples from 25 premature, jaundiced newborns. The measurements of RBBC by the proposed method warrant further improvement and verification by other laboratories and may be useful in the management of hyperbilirubinemia in the newborn.

Bilirubin↗
PubMed1981

Small-intestine involvement in Waldenstrom's macroglobulinemia. Case report and review of the literature.

A patient presented with a three-year history of diarrhea and was found to have a monoclonal gammopathy (IgM lambda) and a malabsorption syndrome with dilatation of the small bowel. Small-intestinal biopsy revealed a homogeneous eosinophilic granular material between the epithelial cells. On electron microscopy this material was shown to consist of an electron-opaque background mixed wit radiolucent lipid sheres. Immunofluorescent studies showed the accellular material to consist entirely of IgM-reactive material. The patient's course and a review of the literature is presented.

Biopsy↗
PubMed1980

Healing of perineal Crohn's disease with metronidazole.

The effect of metronidazole was studied in 21 consecutive patients with chronic unremitting perineal Crohn's disease. Drainage, erythema, and induration diminished dramatically in all patients, and complete healing was obtained in 10 of 18 patients maintained on therapy. Five others have shown advanced healing; in 2 patients the inflammation is improved, but healing is minimal. Side effects of metallic taste, dark urine, and mild gastrointestinal upset occurred in many patients. However, the dosage had to be decreased in only 4 patients and the drug discontinued in 1 patient, all because of peripheral neuropathy that proved to be reversible. In 2 other patients, metronidazole was discontinued because of poor compliance. If further experience corroborates this prompt and striking response in patients with extreme, disabling, and otherwise unmanageable disease, metronidazole will play an important role in the therapy of perineal Crohn's disease.

Adult↗
PubMed1979

The effect of bacterially produced vitamin B12 analogues (cobamides) on the in vitro absorption of cyanocabalamin.

An incubation system containing rat jejunoileum was used to determine whether analogues of cyanocabalamin (CNCbl) inhibited the in vitro absorption of CNCbl. The naturally occurring analogues "pseudo B12," "factor A," and the nonnaturally occurring analogue desdemethyl B12, were produced by guided biosynthesis with Propionibacterium arabinosum. Factor B was produced by acid cleavage of cyanocabalamin. Inhibition of Co57-CNBbl uptake was demonstrated for cold CNCbl and for desdemethyl B12, although statistical significance was achieved only for cold CNCbl at 40X and 100X the molar quantity of the radiolabeled CNCbl. However, a trend towards progressive inhibition of specific CNCbl binding was shown as increasing concentrations of CNCbl or desdemethyl B12 were used. No inhibition of specific CNCbl binding could be demonstrated for any of the naturally occurring cobamides tested.

Animals↗
PubMed1979

Rapid and accurate diagnosis of acute cholecystitis with 99mTc-HIDA cholescintigraphy.

Technetium-99m dimethyl acetanilide iminodiacetic acid (HIDA) cholescintigraphy was performed on 90 patients with suspected acute cholecystitis. Visualization of the gallbladder established patency of the cystic duct and excluded the diagnosis of acute cholecystitis in 50 of 52 patients. Nonvisualization of the gallbladder with visualization of the common bile duct was diagnostic of acute cholecystitis in 38 patients, all subsequently proven at surgery. The observed accuracy of this procedure is 98% and specificity is 100%. The false negative rate is 5% and false positive rate is zero. Technetium-99m-HIDA has many advantages which make it the procedure of choice in evaluating a patient for suspected acute cholecystitis. It is a rapid, simple, safe examination which provides functional as well as anatomic information about the hepatobiliary system in individuals with a serum bilirubin level up to 8 mg/100 ml.

Acetates↗
PubMed1978

Substrate inhibition of the mitochondrial and cytoplasmic malate dehydrogenases.

The mechanism that leads to an inhibition of enzyme activity in the presence of high concentrations of substrate was investigated with the two malate dehydrogenase isoenzymes obtained from pig heart. The inhibition is promoted by an abortive binary complex formed by the enzymes and the enol form of of oxalacelate. Neither the oxidized coenzyme nor the reduced coenzyme appears to be involved in the formation of this complex. These results suggest that the mechanism of substrate inhibition that occurs with the pig heart malate dehydrogenases is different from that observed with the lactate dehydrogenases from chicken hearts. The inhibition constants for oxalacetate are 2.0 mM with the mitochondrial enzyme and 4.5 mM with the cytoplasmic enzyme. Since the in vivo concentration of oxalacetate is reported to be about 10 micrometer, these data suggest that the substrate inhibition that is exhibited by the malate dehydrogenases may not be of any significance in vivo.

Animals↗
PubMed1978

Studies on the mechanism of the malate dehydrogenase reaction.

The stereospecificity of the chicken heart mitochondrial malate dehydrogenase as well as the ability of this enzyme to form various abortive complexes has been further investigated. The enzyme was found to be specific for the A-hydrogen of NADH. Complex formation of the enzyme with oxalacetate and oxidized coenzymes is pH-dependent and is promoted at alkaline pH values. The enol form of oxalacetate appears to be the species that participates in the formation of the complexes. The binding of L-malate, D-malate, or hydroxymalonate to the enzyme. NADH complex is also pH-dependent, and involves a group on the enzyme with a pK of 7.5. The binding of L-malate is promoted at alkaline pH values, whereas the binding of D-malate and hydroxymalonate is favored at acidic pH values. These results indicate that L-malate and enol-oxalacetate preferentially or exclusively bind to the nonprotonated form of the enzyme, whereas keto-oxalactate, hydroxymalonate, and D-malate only bind to the protonated form of the enzyme. Based on this conclusion, a detailed chemical mechanism for the malate dehydrogenase reaction has been postulated and a schematic illustration of the transition state of the enzyme is presented.

Animals↗
PubMed1978

Spontaneous pneumoperitoneum with Pneumatosis cystoides intestinalis in a patient with mixed connective tissue disease.

Pneumatosis cystoides intestinalis (PCI), a disorder in which gas filled cysts develop within the bowel wall, has been associated with collagen vascular disease, usually progressive systemic sclerosis (PSS). We have extended the spectrum of collagen vascular disease associated with PCI by this report of a patient with mixed connective tissue disease (MCTD) who developed PCI and recurrent spontaneous pneumoperitoneum (SP). Possible pathogenetic mechanisms are reviewed and the management of the asymptomatic patient with pneumoperitoneum, PCI and collagen vascular disease is discussed.

Collagen Diseases↗
PubMed1977

Colonoscopic polypectomy in children.

Three children, 30 to 36 months of age, had solitary juvenile polyps in the sigmoid colon and rectal bleeding of varying severity, In all three patients, the polyps were removed without the use of general anesthesia through a standard 100-cm colonoscope used to examine adult patients. No untoward effects were encountered. Colonoscopic polypectomy is an effective therapeutic procedure and obviates the need for either anxious waiting in the mildly symptomatic patient or colotomy and polypectomy in the child with profuse rectal bleeding.

Child, Preschool↗
PubMed1977

Vascular occlusion and stricture of the sigmoid colon secondary to trauma from a pneumatic hammer.

A patient with stricture of the descending colon secondary to use of a pneumatic hammer is presented. Barium enema and angiographic studies suggested that the etiology was a traumatic vascular injury. Barium granulomata, found in the resected specimen, were presumably due to barium having entered the devitalized tissues during an air contrast study performed during an acute ischemic colitis. The mechanisms of traumatic strictures of the colon are discussed.

Accidents, Occupational↗
PubMed1977

Production of vitamin B 12 analogues in patients with small-bowel bacterial overgrowth.

We investigated the presence of vitamin B 12 analogues (cobamides) and the bacterial conversion of 57Co-B12 (vitamin B12 cyanocobalamin, [57Co]-CN-Cbl) into cobamides in the intestinal contents of four patients with bacterial overgrowth. The (57Co)-CN-Cbl bound to intrinsic factor was given orally. Jejunal contents were aspirated for 24 h and cultured aerobically and anaerobically. The CN-Cbl and cobamides were separated by electrophoresis and chromatography and identified by bioautography. Radioactivity of cobamide zones from duplicate chromatograms showed bacterial conversion of (57Co)-cn-cbl into cobamides. Cobamides ([Ade]CNCBA, [2-Me Ade] CNCba, [CN]2Cbi and factor E) were found in the intestinal contents in three of the four patients, and in two of three patients cobamides represented more than 25% of the administered CN-Cbl. Thus bacterial production of cobamides, both de novo and from ingested CN-Cbl bound to intrinsic factor, occurs in humans with bacterial overgrowth states and results in a significant loss of vitamin B12 to the host.

Anemia, Megaloblastic↗
PubMed1977

Automated kinetic determination of lactate dehydrogenase isoenzymes in serum.

A steady-state kinetic method has been revised for measuring lactate dehydrogenase isoenzyme activities, which relates the inhibition of heart-type isoenzyme activity to the overall isoenzyme composition of the enzyme subunits. The method depends on the pH-dependent formation of an inhibitory ternary complex by the heart-type isoenzyme with NAD+ and pyruvate (if the reaction is measured by NADH oxidation). A preincubation step in the previous method is eliminated. The isoenzymes are measured by measuring the reduction of pyruvate in two different concentrations, which favor either the total or fractional activity, depending on the concentrations of pyruvate and the percentage of heart-type subunits. The method has been adapted to a centrifugal analyzer, which has speeded automated isoenzyme determinations, with an accuracy comparable to that for electrophoretic methods.

Centrifugation↗