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Biomedical subjects

S Cohen

Publications and source records attributed to S Cohen.

At least 343 records · Page 19Linked to original sources
PubMed1994

Reengineering along departmental product flowlines.

This article describes how a medical records department responded to relocating, upgrading a departmental computer system, incorporating severity of illness abstracting, and implementing continuous quality improvement techniques by reengineering along department flowlines over a five-year period. Areas of the department that were restructured were storage and retrieval, record completion, and data collection and reporting functions.

Abstracting and Indexing↗
PubMed1994

Spinal anesthesia with meperidine: will epinephrine prolong its duration?

Meperidine (Demerol) has local anesthetic properties separate from its opioid receptor agonist effect. Unlike morphine, meperidine is structurally similar to local anesthetics. Therefore, it is not surprising that it possesses some characteristics of local anesthetics. If meperidine acts like a local anesthetic, binding to the same receptor sites and inhibiting nerve conduction, then drugs that alter the action and duration of local anesthetics may have a similar effect on it. This double-blinded investigation used low-dose meperidine as the sole intrathecal agent to determine the effect of epinephrine on the duration of sensory blockade. Thirty male ASA physical status I through III patients between the ages of 58-81 years who were scheduled for transurethral resection of the prostate or of bladder tumors were randomly assigned to receive meperidine with or without epinephrine. A continuous spinal technique was utilized, and meperidine 0.5 mg/kg was administered after ascertaining the proper position of the catheter. Fourteen of the patients received epinephrine, and 16 patients did not. There were no statistically significant differences between the two groups in terms of age, height, weight, and ASA physical status. No statistically significant prolongation of the sensory blockade was observed with the addition of epinephrine. There were no statistically significant differences between the two groups with regard to onset time or the incidence of complications. The occurrence of a full motor block in the group that did not receive epinephrine was statistically significant.

Aged↗
PubMed1994

Agreement between histopathological results in clinically diagnosed cases of indeterminate leprosy in São Paulo, Brazil.

Histopathological slides from skin biopsies of fifty-seven self-reporting patients diagnosed as indeterminate leprosy by the Leprosy Control Programme in São Paulo, were sent to three independent histopathologists. Agreement between the reports were based on the following diagnosis: "indeterminate leprosy", "suggestive leprosy" or "no leprosy". A great variation was observed in the interpretation of the histopathological examination. The three pathologists reported "indeterminate leprosy" respectively in 7.0%, 54.4% and 84.2%, of the cases studied. A kappa index of agreement between any two pathologists ranged from 0.08 to 0.32, showing poor agreement between observers. Agreement improved by pooling together the reports "suggestive leprosy" and "indeterminate leprosy". The three pathologists agreed in the results of 24 biopsies of the 27 classified as leprosy by any one of the three observers. Eight cases were considered as "no leprosy" by all pathologists. Higher agreement indices were obtained for positive and negative proportionate concordance between any two examiners. The implications of the variation in the diagnosis of indeterminate leprosy and early leprosy are discussed in the context of public health and case-management.

Brazil↗
PubMed1994

Malignancy-induced secondary achalasia.

Secondary achalasia refers to the development of clinical, radiographic, and manometric findings of achalasia as a result of (i.e., secondary to) another underlying disorder. A variety of malignancies have been associated with secondary achalasia. Adenocarcinoma of the esophagogastric junction accounts for the majority of cases of malignancy-induced achalasia, however, noncontiguous tumors may also cause this disorder. Although rare, malignancy-induced achalasia will occasionally be encountered by gastroenterologists and gastrointestinal radiologists who see patients with dysphagia and/or achalasia. Since treatment is aimed at the underlying neoplasm, it is important to recognize this disorder. Three clinical features suggest the possibility of malignancy as a cause of achalasia: 1) short duration of dysphagia (< 1 year); 2) significant weight loss (> 15 pounds); and 3) age > 55 years. The presence of any of these should at least raise a suspicion of malignancy. Diagnosis may not be evident on routine esophagrams and endoscopy, and requires clinical suspicion for further evaluation with thoraco-abdominal CT scanning and endoscopic ultrasonography.

Adolescent↗
PubMed1994

Healing of NSAID-induced gastric ulcers with a synthetic prostaglandin analog (enprostil).

OBJECTIVE: Conventional ulcer therapy has not been proven effective in healing gastric ulcers caused by nonsteroidal anti-inflammatory drugs (NSAIDs) if the NSAIDs are continued. Our objective in this study was to determine whether a prostaglandin analog is an effective treatment for such NSAID-induced lesions. METHODS: To make this determination, we conducted a 9-wk double-blind trial comparing placebo with enprostil 35 micrograms twice daily and three times daily. Use of antacids was not allowed. Three centers entered 145 patients with chronic inflammatory arthritis and osteoarthritis, mean age 63 yr, who required continuous fixed-dose NSAID therapy within the range of therapeutic dosage. The minimum entrance criterion was the presence of either four gastric erosions or one gastric ulcer. Two pretreatment endoscopies within a 2-wk interval were performed to establish the presence of stable baseline gastric lesions. Endoscopy was repeated at wk 6 and 9 during treatment. All groups were similar with regard to age distribution, sex, weight, height, smoking usage, and alcohol consumption. RESULTS: The ulcer healing rates were 14%, 57%, and 68% at 6 wk and 19%, 68%, and 74% at 9 wk for the groups receiving placebo, enprostil twice daily, and enprostil three times daily, respectively (p < 0.01). Complete mucosal healing of all erosions and ulcers at 9 wk occurred in 59% of enprostil-treated patients and in 10% of placebo-treated patients. Additional gastric erosions and gastric ulcers developed in 16% of placebo patients and 4% of the enprostil patients. Eighteen percent of enprostil patients withdrew early from the study due to adverse experiences, such as diarrhea and abdominal pain. CONCLUSION: We concluded that during continued NSAID therapy 1) enprostil 35 micrograms (taken either twice daily or three times daily) heals NSAID-induced gastric ulcers and erosions and protects the mucosa from further NSAID-induced gastric injury; 2) gastric ulcers and erosions rarely heal spontaneously, and 3) enprostil results in a high incidence of diarrhea.

Aged↗
PubMed1994

In vitro activity of readily available household materials against HIV-1: is bleach enough?

This report describes experiments assessing the effectiveness against HIV of potential disinfecting agents that are commonly available to IDU when they are sharing syringes. We exposed cell-free HIV, HIV-infected cells, and HIV-infected blood containing known quantities of HIV to household cleaning agents, alcohols, peroxide, and highly acidic materials for 1 min, in order to examine the effects of these materials on the infectivity of the HIV. Undiluted liquid laundry bleach and dilute liquid dish detergent reduced the number of culturable HIV to an undetectable level under the experimental conditions used. Diluted bleach was not completely effective. Other potential disinfecting agents, including ethanol, isopropyl alcohol, and hydrogen peroxide, were unable to disinfect high numbers of HIV-infected cells or infected blood. Liquid dish detergent warrants further study as a possible acceptable alternative to bleach. Our data provide support for recommendations to IDU that they disinfect shared syringes every time between users with full-strength liquid laundry bleach to reduce their risk of acquiring or transmitting HIV. When bleach is not available, liquid dish detergent or other available disinfecting agents such as rubbing alcohol, hydrogen peroxide, or high alcohol content beverages are more effective than water at disinfecting HIV, recognizing that these materials are less effective than bleach. Although these materials are effective, they should not be viewed as a substitute for decreased sharing of injection equipment by IDU, or increased availability of sterile needles and syringes.

1-Propanol↗
PubMed1994

Efficacy of a dentifrice containing potassium nitrate, soluble pyrophosphate, PVM/MA copolymer, and sodium fluoride on dentinal hypersensitivity: a twelve-week clinical study.

The effect on dentinal hypersensitivity from the use of a dentifrice containing 5.0% potassium nitrate, 1.3% soluble pyrophosphate, 1.5% PVM/MA copolymer, and 0.243% sodium fluoride in a silica base over a twelve-week period was compared to a matching placebo dentifrice without potassium nitrate. A total of sixty-seven subjects were entered into the study, and stratified into two balanced groups according to their baseline mean thermal (threshold) temperature (Thermodontic Stimulator) and baseline mean tactile (Yeaple Probe) sensitivity scores. The two groups were randomly assigned to use either the potassium nitrate/copolymer/pyrophosphate dentifrice or the placebo dentifrice. The two groups were well balanced with regard to their mean baseline thermal and tactile sensitivity scores, sex and age. Subjects were instructed to brush their teeth twice daily (morning and evening) for one minute with their assigned dentifrice and a commercially available soft-bristled toothbrush. Dentinal hypersensitivity examinations, which included tactile sensitivity, threshold thermal sensitivity, pain thermal sensitivity, air blast, and a visual analog scale were conducted at baseline, six weeks, and twelve weeks. All examinations were conducted by the same dental examiner. After six weeks' use of their assigned products, those subjects in the potassium nitrate/copolymer/pyrophosphate dentifrice group demonstrated statistically significant improvements (p < 0.01), as compared to the placebo dentifrice, in the following parameters: 1) tactile; 2) thermal (threshold and pain); and 3) air blast. After twelve weeks' use of their assigned products, those subjects in the potassium nitrate/copolymer/pyrophosphate dentifrice group again demonstrated statistically significant improvements (p < 0.01), in tactile, thermal (threshold and pain) and air blast sensitivity, as compared to the placebo dentifrice. It was concluded from this study that a dentifrice containing 5.0% potassium nitrate, 1.3% soluble pyrophosphate, 1.5% PVM/MA copolymer, and 0.243% sodium fluoride in a silica base is a clinically effective treatment for reducing dentinal hypersensitivity.

Adult↗
PubMed1994

Anticalculus efficacy of a dentifrice containing potassium nitrate, soluble pyrophosphate, PVM/MA copolymer, and sodium fluoride in a silica base: a twelve-week clinical study.

A randomized, two-compartment calculus clinical study of twelve-weeks duration was conducted among a group of calculus-forming subjects in the St. Louis area. The purpose of this parallel and double-blind clinical study was to compare the effect of a dentifrice containing 5.0% potassium nitrate, 1.3% soluble pyrophosphate, 1.5% PVM/MA copolymer and 0.243% sodium fluoride in a silica base, to that of a placebo dentifrice, with regard to supragingival calculus formation. The study examiner, using the Volpe-Manhold Calculus Index, selected a panel of calculus-prone men and women who had completed a one-month placebo regimen. The Volpe-Manhold Calculus Index scores and the number of completely calculus-free sites were recorded. One-hundred and fifteen subjects were entered into the study. After an oral soft and hard tissue examination, the subjects were given a complete oral prophylaxis and randomly assigned to use either the placebo or test dentifrice for a 12-week home-use period. They were prohibited from using any other means of oral hygiene during the study. After completing 12 weeks of twice-daily brushing at home using their assigned toothpaste and a standard soft-bristled toothbrush, subjects were again assessed for supragingival calculus deposits and calculus-free sites. The dentifrice containing 5.0% potassium nitrate, 1.3% soluble pyrophosphate, 1.5% PVM/MA copolymer and 0.243% sodium fluoride in a silica base, inhibited supragingival calculus formation by 54.4%, as compared to a 0.243% sodium fluoride silica-based placebo dentifrice. The mean Volpe-Manhold Calculus Index scores were compared statistically and the difference indicated statistical significance at probability of 0.01 by means of an analysis of covariance (ANCOVA). The number of calculus-free sites, a second parameter of efficacy, also was compared and demonstrated an absolute difference of 32.6% in favor of the group using the dentifrice containing potassium nitrate, soluble pyrophosphate and PVM/MA copolymer compared to a placebo dentifrice (37.8% vs 5.2%, respectively). An analysis of covariance indicated that this improvement showed statistical significance at a probability of 0.01.

Adult↗
PubMed1993

N-glycosylation of human acetylcholinesterase: effects on activity, stability and biosynthesis.

The role of N-glycosylation in the function of human acetylcholinesterase (HuAChE) was examined by site-directed mutagenesis (Asn to Gln substitution) of the three potential N-glycosylation sites Asn-265, Asn-350 and Asn-464. Analysis of HuAChE mutants, defective in a single or multiple N-glycosylation sites, by expression in transiently or stably transfected human embryonal 293 kidney cells suggests the following. (a) All three AChE glycosylation signals are utilized, but not all the secreted molecules are fully glycosylated. (b) Glycosylation at all sites is important for effective biosynthesis and secretion; extracellular AChE levels in mutants defective in one, two or all three sites amounted to 20-30%, 2-4% and about 0.5% of wild-type level respectively. (c) Some glycosylation mutants display impaired stability, as reflected by increased susceptibility to heat inactivation; substitution of Asn-464 has the most pronounced effect on thermostability. (d) Abrogation of N-glycosylation has no detectable effect on the enzyme activity of HuAChE; all glycosylation mutants, including the triple mutant, hydrolyse acetylthiocholine efficiently, displaying Km, kcat. and kcat./Km values similar to those of the wild-type enzyme. (e) In most mutants, inhibition profiles with edrophonium and bisquaternary ammonium ligands are identical with those of wild-type enzyme; the Asn-350 mutants, however, exhibit a slight decrease in their affinity towards these ligands. (f) Elimination of oligosaccharide side chains has no detectable effect on the surface-related 'peripheral-site' functions; like the wild-type enzyme, all mutants were inhibited by propidium and by increased concentrations of acetylthiocholine.

Acetylcholinesterase↗
PubMed1993

The mechanism of epipodophyllotoxin-induced thymocyte apoptosis: possible role of a novel Ca(2+)-independent protein kinase.

The epipodophyllotoxins, etoposide (VP-16) and teniposide (VM-26), inhibit topoisomerase II activity by stabilization of the cleavable complex between the enzyme and DNA and formation of protein-bound double-stranded DNA breaks. While it is thought that these agents are cytotoxic by preventing cells from completing the S phase or undergoing mitosis, recent evidence suggests that these agents are also potent inducers of programmed cell death or apoptosis in both normal and malignant cells. We have examined the intracellular pathway leading to epipodophyllotoxin-induced apoptosis in normal mouse thymocytes. Epipodophyllotoxin-induced apoptosis may proceed via a mechanism that is independent of inhibition of topoisomerase activity per se because novobiocin and coumermycin, which inhibit the ATPase subunit of topoisomerase II, were relatively inefficient inducers of apoptosis in these cells, under conditions where strong apoptosis by the epipodophyllotoxins and dexamethasone could be observed. In addition, camptothecin, which inhibits topoisomerase I by stabilization of the cleavable complex between that enzyme and DNA, was also a poor inducer of apoptosis in these cells. Our data suggest that epipodophyllotoxin-induced mouse thymocyte apoptosis, like that induced by dexamethasone, proceeds via a mechanism that involves protein kinase C (PKC) or a similar enzyme. Apoptosis induced by VM-26 or by dexamethasone was inhibited by 1-(5-isoquinolinylsulfonyl)-2- methylpiperazine dihydrochloride (H7), an inhibitor of both PKC and cAMP-dependent protein kinases, but was relatively unaffected by N-(2-guanidinoethyl)-5-isoquinolinesulfonamide (HA1004), a more specific inhibitor of cAMP-dependent protein kinases. A more specific inhibitor of PKC, sangivamycin, also inhibited both VM-26-induced and dexamethasone-induced apoptosis. Both VM-26- and dexamethasone-induced apoptosis were unaffected by EGTA, a calcium (Ca2+) chelator, under conditions that inhibited apoptosis induced by the Ca2+ ionophore A23187. Moreover, while strong increases in intracellular Ca2+ were observed in thymocytes treated with A23187, we failed to detect increases in intracellular Ca2+ in cells induced to apoptose with either VM-26 or dexamethasone within the first 2 hr of culture. These results suggest that in mouse thymocytes there are at least two intracellular pathways leading to apoptosis: one, utilized by glucocorticoid and the epipodophyllotoxins, that proceeds in the absence of detectable increases in intracellular Ca2+ and possibly requires a novel Ca(2+)-independent PKC-like enzyme and another, utilized by Ca2+ ionophores, that is at least partially dependent on increased intracellular Ca2+.

Animals↗
PubMed1993

[Massive obesity and anesthesia].

Obese subjects are at a high risk of cardiovascular, respiratory and thromboembolic diseases. Anaesthetists in charge of these patients must take this risk into account, along with technical problems such as difficult venous punctures and intubations. The supine position alone creates situations that can be catastrophic for the respiratory and cardiac functions. In addition, obesity may modify the pharmacokinetics of the often liposoluble drugs used in anaesthesia. From the preoperative to the postoperative phases the anaesthetist's intervention must be envisaged.

Anesthesia, Endotracheal↗
PubMed1993

Induction by EGF and interferon-gamma of tyrosine phosphorylated DNA binding proteins in mouse liver nuclei.

Intraperitoneal injection of epidermal growth factor (EGF) into mice resulted in the appearance in liver nuclei of three tyrosine phosphorylated proteins (84, 91, and 92 kilodaltons) within minutes after administration of EGF. Administration of interferon-gamma (IFN-gamma) resulted in the appearance in liver nuclei of two tyrosine phosphorylated proteins (84 and 91 kilodaltons). The 84- and 91-kilodalton proteins detected after either EGF or IFN-gamma administration were identified as the IFN-gamma activation factors (GAF). Furthermore, gel shift analysis revealed that these GAF proteins, detected after either EGF or IFN-gamma administration, specifically bound to the sis-inducible element of the c-fos promoter. Thus, GAF proteins participate in nuclear signaling in both IFN-gamma and EGF pathways.

Animals↗
PubMed1993

Dissection of the human acetylcholinesterase active center determinants of substrate specificity. Identification of residues constituting the anionic site, the hydrophobic site, and the acyl pocket.

Substrate specificity determinants of human acetylcholinesterase (HuAChE) were identified by combination of molecular modeling and kinetic studies with enzymes mutated in residues Trp-86, Trp-286, Phe-295, Phe-297, Tyr-337, and Phe-338. The substitution of Trp-86 by alanine resulted in a 660-fold decrease in affinity for acetythiocholine but had no effect on affinity for the isosteric uncharged substrate (3,3-dimethylbutylthioacetate). The results demonstrate that residue Trp-86 is the anionic site which binds, through cation-pi interactions, the quaternary ammonium of choline, and that of active center inhibitors such as edrophonium. The results also suggest that in the non-covalent complex, charged and uncharged substrates with a common acyl moiety (acetyl) bind to different molecular environments. The hydrophobic site for the alcoholic portion of the covalent adduct (tetrahedral intermediate) includes residues Trp-86, Tyr-337, and Phe-338, which operate through nonpolar and/or stacking interactions, depending on the substrate. Substrates containing choline but differing in the acyl moiety (acetyl, propyl, and butyryl) revealed that residues Phe-295 and Phe-297 determine substrate specificity of the acyl pocket for the covalent adducts. Phe-295 also determines substrate specificity in the non-covalent enzyme substrate complex and thus, the HuAChE F295A mutant exhibits over 130-fold increase in the apparent bimolecular rate constant for butyrylthiocholine compared with wild type enzyme. Reactivity toward specific butyrylcholinesterase inhibitors is similarly dependent on the nature of residues at positions 295 and 297. Amino acid Trp-286 at the rim of the active site "gorge" and Trp-86, in the active center, are essential elements in the mechanism of inhibition by propidium, a peripheral anionic site ligand. Molecular modeling and kinetic data suggest that a cross-talk between Trp-286 and Trp-86 can result in reorientation of Trp-86 which may then interfere with stabilization of substrate enzyme complexes. It is proposed that the conformational flexibility of aromatic residues generates a plasticity in the active center that contributes to the high efficiency of AChE and its ability to respond to external stimuli.

Acetylcholinesterase↗
PubMed1993

[Koro syndrome--clinical and cultural aspects].

Koro syndrome is a triad which includes a deep-seated fear that the penis will shrink, disappear into the abdomen, and that death will follow. The patient experiences profound anxiety and performs preventive manoeuvres, such as pulling his penis outward. The disorder is considered culture-related, and is endemic in South-East Asia and China, where it occurs in epidemic and sporadic forms. Sporadic cases appear in the western hemisphere, often in association with an underlying psychiatric or organic disorder, usually of the central nervous system. 6 cases of koro have been published from Israel.

Adult↗