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Biomedical subjects

J H Lewis

Publications and source records attributed to J H Lewis.

At least 55 records · Page 3Linked to original sources
PubMed1995

Hepatotoxicity of drugs used in the treatment of gastrointestinal disorders.

Hepatic injury from agents in this category is rare. For example, only a handful of cases of H2-receptor antagonist-related liver injury have been reported despite the hundreds of millions of doses prescribed since the introduction of these drugs more than 15 years ago. Hepatotoxicity from sulfasalazine is uncommon but may be fatal. Injury from other agents used to treat inflammatory bowel disease also may be seen, including veno-occlusive disease from azathioprine. Of increasing importance is the toxicity from alternative health supplements, such as herbal remedies, that may cause acute, sometimes fatal, hepatic necrosis.

Animals↗
PubMed1995

Chemical- and toxin-induced hepatotoxicity.

Hepatic injury due to chemicals or natural toxins may occur from occupational, household, or environmental exposure. The liver may dominate the syndrome of toxicity from such agents as carbon tetrachloride, poison mushrooms, and toxic alkaloids, or may be only one facet of more generalized toxicity. The entire histologic spectrum of injury, from fulminant acute disease to chronic vascular injury to hepatic neoplasia, is seen with agents in this category.

Environmental Pollutants↗
PubMed1994

A multistate outbreak of Escherichia coli O157:H7-associated bloody diarrhea and hemolytic uremic syndrome from hamburgers. The Washington experience.

OBJECTIVE: To determine the source of and describe a large outbreak of Escherichia coli O157:H7 infections in Washington State. DESIGN: Case-control study; environmental investigation; provider-based surveillance for E coli O157:H7 infections. SETTING: Chain of fast-food restaurants, hospitals, physician offices, local laboratories, and local health departments. PARTICIPANTS: Patients with diarrhea and neighborhood controls. A case was defined as diarrhea with culture-confirmed E coli O157:H7 infection or postdiarrheal hemolytic uremic syndrome (HUS) occurring from December 1, 1992, through February 28, 1993, in a Washington State resident. Controls were age- and neighborhood-matched friends of the first 16 case patients. INTERVENTIONS: Announcement to the public; recall of implicated hamburger lots. MAIN OUTCOME MEASURE: Abatement of outbreak due to E coli O157:H7. RESULTS: Infection was associated with eating at a fast-food chain (chain A) in the 10 days before symptoms began. Twelve (75%) of 16 case patients but no controls had eaten at chain A (matched odds ratio undefined; lower 95% confidence interval, 3.5; P < .001). In total, 501 cases were reported, including 151 hospitalizations (31%), 45 cases of HUS (9%), and three deaths. Forty-eight patients (10%) had secondary infections. Of the remaining 453 patients (90%), 398 (86%) reported eating at a Washington chain A restaurant; 92% of them reported eating a regular hamburger. The pulsed-field gel electrophoresis pattern of the E coli O157:H7 strains isolated from all regular hamburger lots of a single production date shipped to Washington was identical to that of the strains isolated from patients. Ten (63%) of 16 regular hamburgers cooked according to chain A policy had internal temperatures below 60 degrees C. Public health action removed more than 250,000 potentially contaminated hamburgers, preventing an estimated 800 cases. CONCLUSIONS: This E coli O157:H7 outbreak, the largest reported, resulted from errors in meat processing and cooking. Public health surveillance through state-mandated reporting of E coli O157:H7 infection as is carried out in Washington State was critical for prompt outbreak recognition and control. Measures should be developed to reduce meat contamination. Consumers and food service workers should be educated about cooking hamburger meat thoroughly.

Adolescent↗
PubMed1994

Siphonaptera of North America north of Mexico: Vermipsyllidae and Rhopalopsyllidae.

The six species of Chaetopsylla Kohaut, 1903, two species of Polygenis Jordan, 1939, and one species of Rhopalopsyllus Baker, 1905 known to occur in North America north of Mexico are reviewed with respect to their host preferences and distribution. Keys are provided for the species, and their salient characters are illustrated.

Animals↗
PubMed1994

Siphonaptera of North America north of Mexico: Ischnopsyllidae.

The four genera and 11 species of bat fleas known to occur in North America north of Mexico are reviewed with respect to their distribution and host preferences. All are found on hosts belonging to the bat family Vespertilionidae except Sternopsylla distincta (Rothschild, 1903) and Hormopsylla trux Jordan, 1950, which parasitize species of Molossidae. Keys are provided for the genera and species and their diagnostic characters are illustrated.

Animals↗
PubMed1994

Siphonaptera of North America north of Mexico: Hystrichopsyllidae s. str.

The three species of Atyphloceras Jordan & Rothschild, 1915 and the four species of Hystrichopsylla Taschenberg, 1880 known to occur in North America north of Mexico are reviewed with respect to their host preferences and distribution. Keys are provided for the species, and their diagnostic characters are illustrated.

Animals↗
PubMed1993

Hepatitis viral markers in patients undergoing primary liver transplants.

The purpose of the study was to determine the prevalence in liver transplant (OLTx) patients of the hepatitis markers (anti-A, anti-B, anti-C, anti-D and HBsAg) and the interrelationships between markers and patients' sexes, ages, dates of transplant, clinicopathological diagnoses, and short-term survivals. Slightly more than half of the patients were male. Anti-A and anti-B were about evenly distributed between male and female. Anti-C, anti-D, and HBsAg were far more common in males. Age and year of transplant showed only a moderate increase in anti-A with increasing age. Anti-A was found in 57% of all patients, anti-B in 18%, anti-C in 17%, and HBsAg in 17%. Anti-D was tested only in patients who were positive for anti-B or HBsAg and occurred in 21 (11%) of 185. The poorest short-term survival occurred in males who showed both anti-A and HBsAg.

Adult↗
PubMed1992

Incidence, prevalence, and clinical course of hepatitis C following liver transplantation.

Hepatitis C virus (HCV) is the agent responsible for posttransfusion hepatitis. The incidence, timing, and clinical course of HCV positive hepatitis in liver transplant recipients are unknown. Three hundred and seventeen donor-recipient liver transplant pairs were grouped on the basis of their pretransplant HCV antibody status. The biopsy findings were examined. Four distinct groups were identified on the basis of HCV serology: group I, both were negative; group II, donor was negative and recipient was positive; group III, donor was positive and recipient was negative; group IV, both were positive. The prevalence of anti-HCV positivity in recipients was 13.6%. The rate of seroconversion was 9.2%. Histologic hepatitis not ascribable to any specific cause other than non-A, non-B (NANB) hepatitis occurred in 13.8%. The incidence of histologic chronic active hepatitis was 1.6%, and none progressed to cirrhosis. The concordance rate for a positive anti-HCV serology and NANB hepatitis was 2.8%. Of the 35 patients (group II and IV) with positive anti-HCV serology pretransplant, only 17 were positive posttransplantation. Based on these data it can be concluded that posttransplant NANB hepatitis occurred in 13.8% of liver recipients. Twenty percent of these were anti-HCV positive. Progression to histologic chronic active hepatitis occurs over a period of 1-5 years in 1.6% of cases.

Adolescent↗
PubMed1992

Clinical trial of a simplified vacuum erection device for impotence treatment.

Thirty-one men participated in a clinical trial of a simplified vacuum erection device (Catalyst) in which the pump and penile cylinder have been combined to facilitate the pumping required to induce a vacuum. Of the 28 men who completed the three-month trial, 26 (93%) reported overall satisfaction with the device and an intention to continue its use, and 2 men were unable to maintain a satisfactory erection. Episodes of mild bruising or development of petechiae occurred in 9 men. None of the complications required treatment or prevented safe use of the device. Our experience with this new vacuum device indicates a high degree of patient satisfaction and minimal complications. On average, patients rated ease of use high at all follow-up visits.

Adult↗
PubMed1992

Comparative hematology: studies on guinea-pigs (Cavia porcellus).

1. Guinea-pig blood clots rapidly and the clots retract in glass tubes. The prothrombin time is long and the activated partial thromboplastin time short compared to human. The Russel viper venom time is similar to human. 2. Factors VII and X assay at levels far below and factors V, VIII and XII assay far above human levels. Other coagulation factors (fibrinogen, II, IX, XI, Fletcher and Fitzgerald) assay within or close to the human range. 3. The thromboplastin generation test results for guinea-pigs and humans are similar. 4. Platelets are numerous and small. They aggregate with ADP, arachidonic acid and pig plasma, variably with ristocetin and poorly with bovine collagen or thrombin. On electron microscopy, platelets appear small with many dark granules (dense bodies). There is an open canicular system. Glycogen particles are sparse. Microtubules are occasionally seen, mitochondria are rare and alpha-granules are not readily distinguished from dark granules. 5. Ristocetin cofactor is very low, assaying at < 16% of human (< 0.16 U/ml). 6. Leukocyte counts are variable (6300-17,000 per microliters) and differential counts show neutrophils slightly lower and lymphocytes slightly higher than average human counts. 7. Guinea-pig erythrocyte parameters fall within human ranges. 8. Protein electrophoresis shows total protein and albumin to be slightly lower than human. 9. Antithrombin III, Protein C and alpha 2-antiplasmin assay within the human range and plasminogen at very low levels. 10. Bleeding times are consistently about 4 min.

Animals↗
PubMed1992

Hepatitis C testing. Comparison of Ortho's EIA and RIBA II tests in 1,182 patients undergoing primary liver transplantation.

Plasma samples from 1,182 patients undergoing primary liver transplantation were tested for anti-hepatitis C (HCV) virus by two methods: Ortho HCV ELISA Test System (EIA) and Chiron RIBA HCV Test System (RIBA II). The EIA results, 0 or +, were recorded first, followed by RIBA results, N = negative, P = positive, or I = indeterminate. Concordant results--0N, + P, + I--were found in 1,076 (91%), and discordant results were found in 106 (9%). The EIA optical density did not relate to concordant or discordant results. Band patterns were described by stating the band position (1, 2, 3, or 4) and inserting a dash (-) if no band was visualized. Most + P samples fell into two patterns: 47% showed all four bands, pattern 1234, and 15% showed the two-band pattern, 34. When the EIA was negative, 0P, the opposite was seen: 8% showed the 1234 pattern and 81% showed the 34 pattern. There were 226 samples that formed bands (+ P, 149; 0P, 31; + I, 15; 0I, 31). The frequency of bands was as follows: 4, 32%; 3, 31%; 2, 19%; and 1, 18%. Band 2 and the EIA test detected antibodies to the same c100-3 fragment and showed 74% concordance. No explanation is apparent for the lower concordance rate here than that between the EIA test and bands 3 = 96% or 4 = 88%. The EIA and RIBA II tests, together with positive liver function tests and abnormal tissue pathologic findings, provide a basis for the diagnosis of HCV.

Antigens, Viral↗
PubMed1992

Esophageal and small bowel obstruction from guar gum-containing "diet pills": analysis of 26 cases reported to the Food and Drug Administration.

Twenty-six domestic reports of suspected adverse reactions from the guar gum-containing diet pill, Cal-Ban 3000 (filed with the FDA) were reviewed. There were 18 instances of esophageal obstruction, seven instances of small bowel obstruction, and one individual who was reported to have died after ingestion of Cal-Ban 3000, but for whom insufficient details were provided to assess causation. There were 14 women and 11 men (mean age 46.3 yr; range 17 to 67 yr) for whom sufficient information was available. Preexisting esophageal or gastric disorders were present in 50% of those with esophageal obstruction, including peptic stricture, pyrosis, hiatal hernia, esophagitis, gastric stapling procedure, Schatzki ring, and muscular dystrophy. Fourteen of these 18 patients with esophageal obstruction were treated successfully by endoscopy, although the tenacious gel-like consistency of the material was often difficult to remove. Two patients required rigid esophagoscopy when flexible endoscopy was unsuccessful. This resulted in the death of one patient who developed a pulmonary embolism after surgical repair of an intraoperative esophageal tear. For the seven patients with small bowel obstruction, no specific predisposing factors were mentioned. One individual required exploratory laparotomy, and inspissated tablets were found in the ileum. These cases, spontaneously reported to the FDA, are very similar to those reported in the literature. The water-holding capacity and gel-forming tendency of guar gum permits it to swell in size 10- to 20-fold, and may lead to luminal obstruction, especially when an anatomic predisposition exists. Such products have been banned in Australia, and Cal-Ban 3000 has recently been removed from the market in the United States. However, unsuspecting patients who are still in possession of the product should be apprised of the potential complications that may arise with its use.

Adverse Drug Reaction Reporting Systems↗
PubMed1991

Agreement between two measures of drug use in a low-prevalence population.

The present study examined the agreement between two measures of prevalence of drug use in the community: self-report and specific pharmacological analyses of urine samples. The data were collected in the context of a random community survey of health practices and attitudes. A random 20% of the households participating in the health study were targeted for biochemical assay. Compliance with urine delivery was relatively high at 79%. Urine samples were screened qualitatively for cannabinoids and benzodiazepines using the enzyme multiplied immunoassay technique (EMIT) (Syva Diagnostics, Palo Alto, CA). Screening for pharmaceuticals used a standard thin-layer chromatography (TLC) technique. Agreement between the self-report and biochemical assay estimates of prevalence was statistically significant (p less than .05). While self-report of substance use is not a perfect measure of consumption, it remains a relatively economical and reasonably accurate method of obtaining estimates of substance use in community samples.

Adolescent↗