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Biomedical subjects

J H Lewis

Publications and source records attributed to J H Lewis.

At least 19 recordsLinked to original sources

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

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

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

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

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

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

A 22-year-old man with thyroid cancer and cholestatic liver disease.

The diagnosis of PSC in association with ulcerative colitis was delayed in this case by the interim development of papillary carcinoma of the thyroid that produced a rapidly enlarging neck mass. The presence of chronic cholestasis, pruritus, and hepatosplenomegaly, along with a liver biopsy with histologic changes consistent with PSC, were not immediately appreciated because of the concern for the patient's thyroid cancer. In all other respects, the clinical features of PSC in this case are characteristic of the disease, with the somewhat unusual feature of intra-abdominal lymphadenopathy. Whether or not the papillary thyroid carcinoma is a coincidental finding rather than an associated disease entity, such as ulcerative colitis, remains open to speculation. In any event, the finding of papillary thyroid carcinoma or any other extrahepatic malignancy in association with PSC is rare, but assumes an added dimension for patients with PSC because the presence of malignancy may affect their suitability for future liver transplant.

Adult

Idiopathic gastric acid hypersecretion: treatment implications for refractory acid/peptic disorders.

Although in most patients with duodenal ulcer disease the ulcer heals after 8 weeks of treatment with standard doses of H2 blockers or other agents, in about 10% the ulcer does not heal. These patients are considered 'refractory' to treatment. Reasons often cited for non-healing include poor patient compliance, cigarette smoking, and non-steroidal anti-inflammatory drug (NSAID) use. Gastric acid hypersecretion also appears to be an important factor in non-healing with standard doses of antisecretory agents. We have defined idiopathic gastric acid hypersecretion as a basal acid output of greater than 10 mmol/h in the absence of an elevated fasting serum gastrin level (or a negative secretin test if gastrin level greater than 100 pg/ml) to exclude persons with Zollinger-Ellison syndrome. Among the acid/peptic-related disorders in which idiopathic gastric acid hypersecretion should be considered are refractory duodenal ulcer, refractory gastro-oesophageal reflux disease (especially patients with oesophagitis), postbleeding duodenal ulcer, and certain rare disorders such as hereditary angioedema. Some children with atypical abdominal pain may also be hypersecretors of gastric acid. Once identified, patients with refractory duodenal ulcer or gastro-oesophageal reflux disease are treated with incremental doses of ranitidine titrated against the level of gastric acid secretion that remains during therapy. Ranitidine was selected to avoid the dose-related antiandrogenic effects and potential hepatic cytochrome P450 system-related drug interactions that may occur with cimetidine. In most cases of refractory duodenal ulcer, doubling the standard dose of ranitidine (to 300 mg b.d.) is sufficient to achieve symptomatic relief and mucosal healing. Higher doses appear to be necessary for refractory oesophagitis. To date, no side effects have been associated with high doses of ranitidine (up to 1800 mg/day) for periods of longer than 6 months. Idiopathic gastric acid hypersecretion is an important factor in explaining why not all patients respond to a 'standard' ulcer-healing dose of H2 blocker, and it provides a rationale for use of higher-dose therapy as a safe and effective alternative to omeprazole or to combination drug therapy in refractory acid/peptic disease.

Adult

Safety profile of long-term H2-antagonist therapy.

The safety profile of low-dose maintenance therapy with H2-antagonists for duodenal ulcer disease suggests that these agents can be given safely for several years and probably much longer. Because information regarding the use of these compounds for more than 10 years in large numbers of patients is lacking, the safety of these drugs should continue to be monitored. The safety profiles of famotidine and nizatidine will require several additional years of postmarking surveillance data to match the depth of our knowledge regarding cimetidine and ranitidine. Compared to a surgical approach to ulcer disease, continuous H2-blocker maintenance therapy is cost-effective and is associated with significantly less morbidity. Patients with a history of bleeding or other ulcer complication should be encouraged to remain on maintenance therapy if they do not undergo surgery. The need for extended maintenance therapy also applied to individuals with frequent symptomatic ulcer relapses, reflux oesophagitis, and a range of less common disorders. Currently, H2-blockers and sucralfate are the only agents approved by the Food and Drug Administration for maintenance therapy of duodenal ulcer disease. Experience with omeprazole is still limited, and its long-term safety profile must await the completion of controlled trials of maintenance therapy. Given the apparent long-term safety of the H2-blockers for maintenance therapy, any new agent must prove to be equally safe in the clinical arena, a task that may be indeed formidable.

Duodenal Ulcer

Clinical evaluation of autotransfusion during liver transplantation.

The clinical suitability of intraoperative autotransfusion was evaluated in 25 patients undergoing orthotopic liver transplantation using a Cell Saver #4 (Haemonetics) with acid-citrate-dextrose anticoagulation. In the first 14 patients (phase 1), biochemical, hematologic, coagulation, and semiquantitative bacteriologic studies were performed from the collected blood, processed blood, and patients' blood before and after 500 mL of autotransfusion. The acid-citrate-dextrose solution produced adequate anticoagulation, and the system effectively removed most of the potassium, red blood cell fragments, plasma free hemoglobin, bilirubin, coagulation factors, platelets, and fibrin degradation products. Autotransfusion (500 mL) did not alter coagulation, electrolyte balance, and hematologic findings in recipients except for a clinically insignificant increase in plasma free hemoglobin. Seventeen of 56 samples of the collected blood or processed blood were positive for coagulase (-) Staphylococcus (occasional or rare), but blood cultures before and after autotransfusion were negative in all patients. In the next 11 patients (phase 2), a quantitative bacteriologic study was performed from the collected blood, processed blood, skin, bile duct stump, peritoneal cavity, and room air using a mock reservoir. The processed blood was not transfused. All blood cultures from the patients were sterile. However, coagulase (-) Staphylococcus or Bacillus sp was seen in two cultures from skin, three from the processed blood, and three from air, suggesting that room air and skin were the sources of contamination. When the patients of the two phases of study were compared, postoperative blood cultures were all sterile, and renal function was similar. Therefore, autotransfusion appears to be clinically acceptable during liver transplantation.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult

Hyaluronan as a propellant for epithelial movement: the development of semicircular canals in the inner ear of Xenopus.

The membranous labyrinth of the inner ear, with its three semicircular canals, originates from a simple spheroidal otic vesicle. The process is easily observed in Xenopus. The vesicle develops three dorsal outpocketings; from the two opposite faces of each outpocketing pillars of tissue are protruded into the lumen; and these paired 'axial protrusions' eventually meet and fuse, to form a column of tissue spanning the lumen of the outpocketing like the hub of a wheel, with a tube of epithelium forming the semicircular canal around the periphery. Each axial protrusion consists of epithelium encasing a core of largely cell-free extracellular matrix that stains strongly with alcian blue. In sections, at least 60% of the stainable material is removed by treatment with Streptomyces hyaluronidase. When Streptomyces hyaluronidase is microinjected into the core of a protrusion in vivo, the protrusion collapses and the corresponding semicircular canal fails to form. Hyaluronan (hyaluronic acid) in the core of the protrusion therefore seems to be essential in driving the extension of the protrusion. Autoradiography with tritiated glucosamine indicates that the hyaluronan-rich matrix is synthesised by the epithelium covering the tip of the protrusion; the basal lamina here appears to be discontinuous. These findings indicate that the epithelium of the axial protrusion propels itself into the lumen of the otocyst by localised synthesis of hyaluronan. Hyaluronan may be used in a similar way in the development of other organs, such as the heart and the secondary palate.

Animals

Diagnostic yield of a positive fecal occult blood test found on digital rectal examination. Does the finger count?

The value of a positive fecal occult blood test (FOBT) found at the time of digital rectal examination is disputed. To determine the significance of a positive FOBT obtained in this manner, the records of 270 patients who underwent colonoscopy for any positive FOBT were retrospectively reviewed. Occult blood was found in 144 patients at the time of digital rectal examination and in 126 individuals after they submitted three spontaneously passed stool specimens. Of the patients with a positive FOBT on rectal examination, 77% were hospitalized at the time compared with only 17% of those with positive FOBTs from spontaneously passed stools. The frequency of colonic abnormalities was similar with both stool collection methods in inpatients and outpatients. No statistically significant differences in neoplastic polyp or colon cancer detection rates, nor in the finding of hemorrhoids or other anorectal abnormalities, were apparent. Therefore, the belief that a positive FOBT found at the time of digital examination can or should be discounted as a false positive (because of the presence of hemorrhoids or other lesions prone to trauma at the time of digital examination) was not substantiated by this study.

Aged

Gastric acid hypersecretion in refractory gastroesophageal reflux disease.

We prospectively evaluated gastric acid output (mEq/h), gastric volume output (ml/h), ambulatory 24-h esophageal pH monitoring, and the endoscopic appearance of the esophagus in 23 patients undergoing treatment of chronic long-standing pyrosis. Twelve of these 23 individuals (52%) remained symptomatic after 3 mo of standard antisecretory treatment with ranitidine, 150 mg twice daily. When compared with initial responders, those patients who did not experience complete symptomatic relief on therapy had significantly higher basal acid output (p less than 0.001), basal volume output (p less than 0.02), and basal upright (but not supine) reflux time (p less than 0.05). Nine of the 12 patients who did not respond to initial treatment had gastric acid hypersecretion (basal acid output greater than 10 mEq/h), and 10 of the 12 had Barrett's epithelium compared with only 1 patient in the initial-responder group (p less than 0.001). All 12 nonresponders were treated for an additional 3 mo with increased doses of ranitidine (mean, 1280 mg/day; range, 600-1800 mg/day), and complete disappearance of pyrosis occurred in 10 of the 12, although no significant endoscopic regression was observed in the extent of the underlying columnar mucosa in those with Barrett's esophagus over the 6-mo duration of the study. A significant correlation was shown between the daily ranitidine dose required to eliminate symptoms and the pretreatment basal acid output (r = 0.81, p less than 0.001); gastric acid output had to be almost totally suppressed (i.e., less than 1 mEq/h) for pyrosis to disappear completely. No side effects occurred with any of these high doses of ranitidine. We conclude that a subgroup of patients with long-standing symptomatic gastroesophageal reflux disease who do not respond to standard ulcer-healing doses of histamine2-receptor antagonists are hypersecretors of basal gastric acid and require increased acid-suppressive therapy. Many of these individuals also have underlying Barrett's epithelium.

Adolescent

Histopathologic analysis of suspected amiodarone hepatotoxicity.

This analysis of the morphology of suspected amiodarone (AD) liver disease is based on a study of liver specimens from 17 individuals. Changes similar to alcoholic liver injury were commonly seen. Steatosis, both macrovesicular and microvesicular, was the most frequent histopathologic feature. Ballooning of hepatocytes, Mallory bodies, and fibrosis were also common. Other changes included nuclear unrest, acidophilic bodies, foam cells, glycogenated nuclei, and portal inflammation. Characteristic lamellar lysosomal inclusion bodies representing phospholipidosis were found in two of 14 specimens studied ultrastructurally. These changes of pseudoalcoholic hepatitis and/or phospholipidosis were present in liver specimens from asymptomatic, anicteric patients with mild elevations in serum aminotransferase or alkaline phosphatase values with or without hepatomegaly, as well as in patients with clinically overt symptoms of hepatotoxicity. Phospholipidosis appears to be a generalized systemic effect of cationic amphophilic compounds, such as AD. The cytotoxic pseudoalcoholic changes appear to be an independent phenomenon in susceptible patients, whom we speculate may have been unable or less able to metabolize AD through normal pathways. The true incidence of hepatic injury from AD remains to be determined from prospective evaluations of pretreatment and follow-up liver biopsies.

Adolescent

Patient acceptance of and satisfaction with an external negative pressure device for impotence.

Patient acceptance of and satisfaction with an external negative pressure device as a treatment for impotence were retrospectively analyzed among 100 men. The over-all satisfaction rate was 68%. Reasons for dissatisfaction with and discontinuing the use of the device included premature loss of penile tumescence and rigidity, pain or discomfort either during application of suction or during intercourse and inconvenience. Negative pressure therapy is an effective treatment for impotence of various etiologies and should be among treatment options offered to the impotent patient.

Consumer Behavior

A statewide outbreak of Escherichia coli O157:H7 infections in Washington State.

In November 1986, a statewide outbreak of Escherichia coli O157:H7 infections in Washington State was identified after a physician in an eastern Washington community hospitalized three patients with hemorrhagic colitis which progressed to thrombotic thrombocytopenic purpura. Epidemiologic investigation identified 37 cases in this community and linked the illnesses to a local restaurant which had served ground beef that was the suspected initial vehicle of transmission. The plasmid profile and toxin production pattern (Shiga-like toxin II alone) of the outbreak strain provided a unique strain marker. E. coli O157:H7 infections caused by this strain were simultaneously seen in other parts of the state among nursing home residents and in patients with the hemolytic-uremic syndrome, and an increase in sporadic cases of hemorrhagic colitis was noted at a Seattle health maintenance organization. It is suspected that a contaminated product, probably ground beef distributed statewide, was the common source. Tracing of this meat led to farms where rectal swabs from six (1%) of 539 cattle tested yielded E. coli O157:H7, although the plasmids and toxin production patterns of these isolates differed from the human outbreak strain. Introduction of a single strain of E. coli O157:H7 has the potential to cause widespread concurrent outbreaks. Such outbreaks are likely to escape recognition until heightened screening and surveillance for E. coli O157:H7 is established.

Adolescent