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Biomedical subjects

D Simon

Publications and source records attributed to D Simon.

At least 37 records · Page 2Linked to original sources
PubMed1992

Direct, simplified, and sensitive assay of angiotensin II in plasma extracts performed with a high-affinity monoclonal antibody.

A very simple, fast, and sensitive RIA of angiotensin (Ang) II has been developed, based on a monoclonal antibody with high affinity and specificity, making possible the direct measurement of circulating Ang II in human plasma after solid-phase extraction. The purified monoclonal antibody 4D8 has an association constant of 1.3 x 10(11) L/mol with Ang II and a cross-reactivity of < 1% for Ang I. The assay can detect as little as 0.8 fmol of Ang II in 2 mL of plasma and is not influenced by the presence of Ang I. Analytical recoveries between 112% and 116% were obtained for Ang II added to human plasma at physiological concentrations. Comparison of the RIA with a reversed-phase, high-performance liquid chromatographic method followed by RIA to measure Ang II in human plasma samples from normal and hypertensive subjects--and from normotensive subjects before and after an acute inhibition of angiotensin-converting enzyme with captopril (50 mg)--showed a high degree of correlation (r2 = 0.93) between the two methods.

Angiotensin II↗
PubMed1992

The quality assurance committee in a general hospital: its use in improvement of the medical record.

A twice-yearly audit of a sample of medical records from each department of a general hospital was initiated by a quality assurance committee and pursued for 8 years. Missing entries that were considered obligatory for good medical performance of each service were identified, and the results (expressed as percent of missing entries of the total) were communicated in graphic form to the specific departments and the senior staff of the hospital. This approach led to an improvement in the medical records (decrease of missing entries), which may reflect a higher quality of medical care. Thus, a sequential audit of medical records by a quality assurance committee may constitute a simple and effective method of monitoring and improving physicians' knowledge and performance.

Hospitals, District↗
PubMed1992

Detection of HIV-1 protein and nucleic acid in enterochromaffin cells of HIV-1-seropositive patients.

Diarrhea contributes significantly to the morbidity and mortality of patients with the acquired immunodeficiency syndrome (AIDS). Up to 50% of AIDS patients have diarrhea, and an etiologic agent for this cannot be identified in all of them. Recent evidence suggests that enterochromaffin cells may be infected by the human immunodeficiency virus type 1 (HIV-1) and may contribute to the unexplained diarrhea. To test this hypothesis further, endoscopic biopsies of duodena from 22 HIV-1 seropositive patients [17 with diarrhea (> 500 g/day and > 3 bowel movements/day), five without diarrhea] and from 15 normal controls (no HIV risk factors) without diarrhea were studied. Formalin-fixed and paraffin-embedded 5-microns sections were examined by immunocytochemistry, using a monoclonal antibody to the HIV-1 gp41 protein, and by in situ hybridization with a full-length biotinylated HIV-1 DNA probe. Positive staining for gp41 was detected in crypt cells, consistent with the location, size, and morphology of enterochromaffin cells, in 11 of 17 HIV-1-seropositive patients with diarrhea, and in none of five without diarrhea. Nucleic acid hybridization staining was performed in five of the 11 patients who had positive gp41 staining; all showed HIV nucleic acid sequences in similar cells. All three of the five patients with positive staining for HIV nucleic acid sequences had diarrhea for which no etiologic agent for diarrhea could be found, and one each had cryptosporidia or microsporidia. No staining was observed in any of the samples from normal control tissues. These results suggest that HIV-1 may infect enterochromaffin cells and possibly alter their function. This, in turn, may contribute to the diarrhea associated with AIDS.

Adult↗
PubMed1992

Treatment options for AIDS-related esophageal and diarrheal disorders.

Gastrointestinal involvement is extremely common in the acquired immunodeficiency syndrome (AIDS), and the vast majority of such afflicted patients manifest disease in the esophagus, or in the small and/or large intestine. A great deal of interest is currently under way to discover the most efficient therapies for the various disorders complicating AIDS, and therapeutic recommendations change frequently. This paper will review the current treatment options of AIDS-related esophageal and diarrheal disorders.

Acquired Immunodeficiency Syndrome↗
PubMed1992

Blastocystis hominis in hospital employees.

Several reports have appeared that either support or deny the importance of the protozoan Blastocystis hominis as an intestinal pathogen in humans. In this report, we describe the clinical characteristics of B. hominis and its response to therapy in hospital employees found to have the parasite on routine screening of stools. During the study, 49 patients with B. hominis were identified, and 413 stools were examined from these patients. Twenty-nine patients were asymptomatic (59%), and 20 had symptoms of bloating, flatulence, soft/loose stools, or constipation. Of these 20 patients, 10 had symptoms that correlated with the presence or absence of B. hominis, four had symptoms that were independent of B. homonis, and six had other intestinal parasites that could account for their symptoms. Nineteen percent of patients without treatment had eradication of B. hominis from stool on follow-up examination. Metronidazole did not increase this rate. Iodoquinol treatment eradicated the organism in 41% of patients (p less than 0.05), and resulted in the reduction or eradication of the parasite in 62%, as determined by follow-up examination.

Adolescent↗
PubMed1992

Acute symptomatic hernia.

Acute symptomatic hernia is a clinical entity characterized by the coexistence of acute incarceration of an abdominal wall hernia together with an acute abdominal disease. Thirteen such cases are described. Increased awareness of this entity, both pre- and intraoperatively, is probably the basis for the improved rate of correct diagnosis (60%) and the decreased mortality (7%).

Adolescent↗
PubMed1992

Medical management of AIDS patients. Gastrointestinal manifestations.

Gastrointestinal manifestations of AIDS are common. Opportunistic infections and tumors may affect any portion of the GI tract from oral cavity to anus. Esophageal involvement may result from Candida, CMV, HSV, HIV, and tumors. Biliary tract and pancreatic disease may cause abdominal pain. Diarrhea occurs in over 50% of AIDS patients and is multifactorial.

Abdominal Pain↗
PubMed1991

Chromosome abnormalities in peripheral blood cells of hepatitis B virus chronic carriers.

Cytogenetic analysis of metaphase chromosome spreads from peripheral blood cells of hepatitis B virus (HBV) chronic carriers and HBV-negative individuals of the same ethnic origin revealed a significantly higher incidence of chromosome breaks and other mitotic aberrations in the HBV chronic carriers. The highest incidence of chromosome breaks was found in chronic carriers who evidenced circulating HBV. Such an association between HBV and these genetic lesions assumes importance in light of the known correlation between HBV chronic carrier status and the high risk of hepatocellular carcinogenesis, where a mutagenic effect of HBV cannot be excluded.

Carcinoma, Hepatocellular↗
PubMed1991

Effect of octreotide on refractory AIDS-associated diarrhea. A prospective, multicenter clinical trial.

OBJECTIVE: To determine the efficacy and safety of octreotide for treatment of refractory, profuse diarrhea in patients with the acquired immunodeficiency syndrome (AIDS). DESIGN: A prospective, open-label study. SETTING: Inpatient metabolic units of four university medical centers. PATIENTS: Fifty-one patients infected with human immunodeficiency virus (HIV) who had uncontrolled diarrhea (greater than or equal to 500-mL liquid stool per day) despite treatment with maximally tolerable doses of antidiarrheal medications. INTERVENTION: After initial baseline studies, patients received octreotide, 50 micrograms every 8 hours for 48 hours. If stool volume was not reduced to less than 250 mL/d, the dose of octreotide was increased stepwise to 100, 250, and 500 micrograms. MAIN RESULTS: Fifty men and one woman (mean age, 36.3 +/- 1.1 years) entered and completed the 28-day protocol (14 days of inpatient therapy and 14 days of outpatient therapy). Stool frequency and volume decreased significantly (6.5 +/- 0.5 stools per day on day 0 compared with 3.8 +/- 0.3 stools per day on day 21 [P less than 0.001] and 1604 +/- 180 mL/d on day 0 compared with 1084 +/- 162 mL/d on day 14 [P less than 0.001], respectively). Twenty-one patients (41.2%) were considered to be partial or complete responders (reduction in daily stool volume by greater than or equal to 50% of initial collections or reduction to less than or equal to 250 mL/d). Of the 21 responders, 14 (67%) had no identifiable pathogens at initial screening compared with 9 of 30 (30%) nonresponders (P less than 0.01). CONCLUSION: Patients with AIDS-associated refractory watery diarrhea, especially those without identifiable pathogens, may respond favorably to subcutaneously administered octreotide. This drug deserves further study in a randomized, placebo-controlled trial.

Acquired Immunodeficiency Syndrome↗
PubMed1991

Electrotransformation of Streptococcus pyogenes with plasmid and linear DNA.

Electrotransformation was used to introduce both plasmid and linear DNA into Streptococcus pyogenes. The method was optimized using strain NZ131, for which transformation frequencies up to 10(7) per micrograms of plasmid DNA were obtained. A linear fragment of DNA, containing the streptokinase gene (ska) in which an internal fragment had been replaced with an erythromycin resistance gene (erm), was transformed into strain NZ131 with a frequency of 10(3) per micrograms DNA. The introduction of linear DNA into S. pyogenes by electrotransformation should be useful for future genetic analyses as well as targeted gene replacement.

Blotting, Southern↗
PubMed1991

[Management of radiation-induced injuries of the intestine].

Radiation-induced injury of the intestine (RII) is a chronic iatrogenic disorder which often necessitates complex surgical intervention. We describe our experience with the surgical management of 9 patients with RII, 8 of whom suffered injuries of the small bowel and 1 of the rectosigmoid. There were 3 deaths, 2 from postoperative complications of ongoing RII and 1 from recurrence of the original tumor. 3 of the survivors continued to suffer from complications attributed to active RII, while only 3 remained symptom-free during follow-up. Our study emphasizes the fundamental role of good nutritional support during the perioperative period in these patients. It also indicates the desirability of using nonirradiated bowel for the anastomosis, and of a bypass procedure instead of resection and primary anastomosis in cases of radiation-induced frozen pelvis. Creating a barrier between the peritoneal cavity and the lower pelvis by an omental flap or other means, should be considered in patients operated on for pelvic cancer who might need adjuvant radiotherapy. This procedure shields the bowel from the radiation field, thus hopefully reducing the incidence of RII.

Humans↗
PubMed1991

Light microscopic diagnosis of human microsporidiosis and variable response to octreotide.

Microsporida are protozoan parasites that have recently been identified as a cause of human disease in immunocompromised patients. Because of their small size, they have been recognized primarily by electron microscopy. This has limited the study of their prevalence, incidence, and association with large-volume diarrhea. The present report describes two cases of Enterocytozoon bieneusi infection of the small intestine in patients with intractable diarrhea in whom the diagnosis was made by light microscopy and confirmed by electron microscopy. Both patients were treated with octreotide, and one had a good response.

Acquired Immunodeficiency Syndrome↗
PubMed1991

Pax: a murine multigene family of paired box-containing genes.

A murine multigene family has been identified that shares a conserved sequence motif, the paired box, with developmental control and tissue-specific genes of Drosophila. To date five murine paired box-containing genes (Pax genes) have been described and one, Pax-1, has been associated with the developmental mutant phenotype undulated. Here we describe the paired boxes of three novel Pax genes, Pax-4, Pax-5, and Pax-6. Comparison of the eight murine paired domains of the mouse, the five Drosophila paired domains, and the three human paired domains shows that they fall into six distinct classes: class I comprises Pox meso, Pax-1, and HuP48; class II paired, gooseberry-proximal, gooseberry-distal, Pax-3, Pax-7, HuP1, and HuP2; class III Pax-2, Pax-5, and Pax-8; class IV Pax-4; class V Pox neuro; and class VI Pax-6. Pax-1 and the human gene HuP48 have identical paired domains, as do Pax-3 and HuP2 as well as Pax-7 and HuP1, and are likely to represent homologous genes in mouse and man. Identical intron-exon structure and extensive sequence homology of their paired boxes suggest that several Pax genes represent paralogs. The chromosomal location of all novel Pax genes and of Pax-3 and Pax-7 has been determined and reveals that they are not clustered.

Amino Acid Sequence↗
PubMed1991

Pulmonary aspiration during emergency endoscopy in patients with upper gastrointestinal hemorrhage.

OBJECTIVE: To evaluate the frequency and significance of aspiration and its clinical importance in patients with upper GI bleeding undergoing esophagogastroduodenoscopy in the ICU. DESIGN: Thirty consecutive patients with active and severe upper GI bleeding were studied. SETTING: ICU. PATIENTS: Ranged in age from 20 to 78 yr with an equal number of males and females. INTERVENTIONS: All patients had continuous pulse oximetry monitoring and had chest radiographs obtained less than 12 hr before endoscopy and less than 4 hr after endoscopy. MEASUREMENTS: Six (20%) of 30 patients developed new lung infiltrates after esophagogastroduodenoscopy. In this group of patients, preendoscopy chest radiographs were obtained after less than 4 hr. In five of these patients, infiltrates were accompanied by fever and/or leukocytosis and oxygen desaturation to less than 90% during the esophagogastroduodenoscopy. CONCLUSION: Clinically significant aspiration pneumonia frequently complicates esophagogastroduodenoscopy in upper GI bleeding patients and is an important mechanism of esophagogastroduodenoscopy-induced hypoxia.

Adult↗
PubMed1991

Eradication of methicillin-resistant Staphylococcus aureus vaginitis with mupirocin.

We report the case of a 54-year-old, quadriplegic woman with a methicillin-resistant Staphylococcus aureus (MRSA) vaginal infection. After failing a five-day course of intravenous vancomycin therapy, the patient was treated for ten days with mupirocin ointment applied intravaginally twice daily, which resulted in eradication of the infection. This report details a novel approach in treating MRSA vaginal infections.

Administration, Intravaginal↗