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Biomedical subjects

J Chiu

Publications and source records attributed to J Chiu.

At least 55 records · Page 3Linked to original sources
PubMed1990

A controlled trial of early adjunctive treatment with corticosteroids for Pneumocystis carinii pneumonia in the acquired immunodeficiency syndrome. California Collaborative Treatment Group.

BACKGROUND: Pneumocystis carinii pneumonia remains a common cause of serious morbidity and mortality in patients with the acquired immunodeficiency syndrome (AIDS). The extensive lung injury that accompanies pneumocystis-associated respiratory failure and the reports of clinical benefit from the use of adjunctive corticosteroids provided the rationale for this prospective multicenter trial. METHODS: A total of 333 patients with AIDS and pneumocystis pneumonia received standard treatment and were randomly assigned to receive either corticosteroids (beginning with the equivalent of 40 mg of prednisone twice daily) or no additional therapy. The primary end points in this unblinded trial were the occurrence of respiratory failure (hypoxemia ratio [partial pressure of arterial oxygen divided by fraction of inspired oxygen] less than 75, intubation, or death), death, and dose-limiting toxicity of the initial standard therapy. RESULTS: Of the patients with confirmed or presumed pneumocystis pneumonia (n = 225 and n = 26, respectively), those assigned to treatment with corticosteroids had a lower cumulative risk at 31 days of respiratory failure (0.14 vs. 0.30, P = 0.004) and of death (0.11 vs. 0.23, P = 0.009), as well as a lower risk of death within 84 days (0.16 vs. 0.26, P = 0.026). The frequency of dose-limiting toxicity of the standard therapy was similar in the two treatment groups. Intention-to-treat analyses of the entire cohort confirmed these findings. Clinical benefit could not be demonstrated, however, for patients with mild disease (hypoxemia ratio, greater than 350), equivalent to a partial pressure of oxygen greater than 75 torr on room air. The patients assigned to corticosteroid treatment had an excess of localized herpetic lesions (26 percent vs. 15 percent, P = 0.04) but not of other infections or of neoplasms. CONCLUSIONS: Early adjunctive treatment with corticosteroids reduces the risks of respiratory failure and death in patients with AIDS and moderate-to-severe pneumocystis pneumonia. Because the adverse effects are few, corticosteroids should be included as part of the initial treatment for persons with AIDS who have moderate-to-severe pneumocystis pneumonia.

Acquired Immunodeficiency Syndrome↗
PubMed1990

Treatment of disseminated Mycobacterium avium complex infection in AIDS with amikacin, ethambutol, rifampin, and ciprofloxacin. California Collaborative Treatment Group.

OBJECTIVE: To determine the efficacy of combination drug therapy for disseminated Mycobacterium avium complex infection in patients with the acquired immunodeficiency syndrome (AIDS). DESIGN: Prospective, nonrandomized, before-after comparison. SETTING: Outpatient clinics at three university medical centers. PATIENTS: Seventeen patients with at least two consecutive blood cultures positive for M. avium complex who had not been previously treated with antituberculous medications. Fifteen of the seventeen patients completed at least 4 weeks of treatment. INTERVENTION: Patients received daily intravenous amikacin (7.5 mg/kg body weight) for the first 4 weeks plus the following oral medications for at least 12 weeks: ciprofloxacin, 750 mg twice daily; ethambutol, 1000 mg daily; and rifampin, 600 mg daily. MEASUREMENTS AND MAIN RESULTS: The baseline geometric mean colony count from blood cultures decreased from 537/mL to 14/mL (P less than 0.001) after 4 weeks of therapy. The microbiologic suppression was sustained while on treatment and was associated with a decrease in systemic symptoms related to M. avium complex infection. Premature withdrawal from treatment (less than 12 weeks) occurred in 7 of 17 patients. The commonest reasons for early withdrawal were gastrointestinal intolerance and hepatic toxicity. CONCLUSIONS: Mycobacterial load and systemic symptoms in patients with AIDS and disseminated M. avium complex infection can be effectively reduced by a regimen containing amikacin, ethambutol, rifampin, and ciprofloxacin.

Acquired Immunodeficiency Syndrome↗
PubMed1989

Persistent Cryptococcus neoformans infection of the prostate after successful treatment of meningitis. California Collaborative Treatment Group.

STUDY OBJECTIVE: To assess the frequency of persistent Cryptococcus neoformans infection in patients with the acquired immunodeficiency syndrome (AIDS) after receiving apparently adequate treatment for meningitis. DESIGN: Blood, urine, and cerebrospinal fluid were cultured at the conclusion of primary therapy to assess the adequacy of treatment. SETTING: Outpatient clinics at three medical centers. PATIENTS: Patients had C. neoformans grown in culture from cerebrospinal fluid. Primary therapy consisted of either 2.0 g of amphotericin B alone; 6 weeks of combination therapy with flucytosine; or, if flucytosine was poorly tolerated, an adjusted minimum total amphotericin B dose. To meet criteria for adequate treatment of meningitis all patients had two sequential cerebrospinal fluid samples which were culture negative. MEASUREMENTS AND MAIN RESULTS: Nine of forty-one patients grew C. neoformans from urine after completion of primary treatment, but none had urinary symptoms. Fungi were visualized in expressed prostatic secretions in 4 of these patients. One patient refused further treatment and developed cryptococcemia within 5 weeks. Three patients received additional amphotericin B; all had persistent funguria without systemic relapse. Six patients received fluconazole; 4 became urine culture negative, and 2 had systemic relapse. CONCLUSION: The persistence of urinary C. neoformans after adequate therapy for meningitis suggests that the urinary tract (probably the prostate) is a sequestered reservoir of infection from which systemic relapse may occur.

Acquired Immunodeficiency Syndrome↗
PubMed1989

Microleakage of core materials for complete cast gold crowns.

This study evaluated the microleakage patterns of complete cast-gold crowns cemented onto teeth rebuilt with pin-retained cores made from cast gold, amalgam, composite resin, and silver-reinforced glass ionomer by using three different cements (zinc phosphate, glass ionomer, and resin cement). Crowns cemented onto unrebuilt tooth preparations with zinc phosphate cement served as controls. The cemented specimens were thermocycled between 4 degrees and 50 degrees C in waterbaths. They were then embedded in epoxy resin and sectioned. The extent of marginal microleakage was evaluated with a stereomicroscope and scored. The findings indicated that the type of luting agent used appeared to affect microleakage more than the core material. No significant differences in the degree of microleakage were found under crowns cemented onto teeth rebuilt with the four core materials when cemented with the same luting cement.

Composite Resins↗
PubMed1988

Listeriosis: an uncommon opportunistic infection in patients with acquired immunodeficiency syndrome. A report of five cases and a review of the literature.

Between January 1985 and March 1986, five cases of listeriosis were reported in Los Angeles County in patients with the acquired immunodeficiency syndrome (AIDS). All patients were homosexual men with no other risk factors for AIDS. Two patients had sepsis only, two patients had sepsis and meningitis, and one patient had sepsis and signs of meningitis. Sixty percent of the cases (three patients) had a prior or concurrent gastrointestinal illness. Eighty percent of the cases (four patients) also had no prior history of antibiotic administration. Both of these findings may have predisposed these AIDS patients to be at increased risk for listeriosis. Although listeriosis is an infrequent illness in AIDS patients, people with AIDS or human immunodeficiency virus infection should probably refrain from ingesting food items associated with listeriosis. These food items include improperly pasteurized dairy products, and raw fruits and vegetables not properly washed.

Acquired Immunodeficiency Syndrome↗
PubMed1988

Calcium and the production of interferon by human peripheral blood mononuclear cells.

We have studied the ability of human peripheral blood mononuclear cells (PBMC) to produce interferon-alpha (IFN-alpha) and IFN-gamma in the presence of pharmacologic agents known to influence calcium transport or calcium-dependent processes. We have found that the production of human (Hu) IFN-gamma is affected significantly by alterations in calcium flux; however, this influence is dependent upon the nature of the compound used to induce IFN. Inhibitors of protein kinase C decreased yields of IFN-gamma but inhibition of calmodulin did not. The presence of vitamin D3 reduced IFN-gamma titers when PHA and IL-2 were used to induce IFN, but not when ionomycin was used as the inducer. The production of IFN-gamma by PBMC was reduced by diminished concentrations in extracellular calcium but not extracellular magnesium. In contrast, neither the presence of any of the pharmacological agents tested above nor the reduction of the calcium concentration influenced the production of HuIFN-alpha by PBMC.

3-Pyridinecarboxylic acid, 1,4-dihydro-2,6-dimethy↗
PubMed1987

Reversal of the effects of cyclosporin A on the production of human interferon-gamma.

Previous reports have documented that cyclosporin A (CsA) can inhibit the production of interferon-gamma (HuIFN-gamma) and interleukin-2 (IL-2). In this report we have extended these earlier findings and have demonstrated that the defect in the production of HuIFN-gamma persists even after the CsA is removed and is associated with altered synthesis of other lymphokines, mainly a cytotoxin and leukocyte migration inhibition factor. In the presence of recombinant exogenous IL-2, the effect of CsA on the synthesis of HuIFN-gamma can be reversed depending on the concentrations of both the IL-2 and CsA. In addition, the presence of the calcium ionophore A23187 partially reverses the inhibitory effect of CsA by synergistically enhancing the synthesis of HuIFN-gamma.

Calcimycin↗
PubMed1987

Optimal conditions for the induction of human mononuclear leukocytes by complexed polyinosinic-polycytidylic acid.

We have defined the optimal circumstances for the induction of human interferon alpha (Hu IFN alpha) in peripheral blood mononuclear cells (PBMC) using complexed polyinosinic-polycytidylic acids (poly rIrC). We have found that a poly rIrC concentration of only 0.1 microgram m/ml or 100 fold less than commonly used in fibroblasts produced maximal yields. Similarly, we have found that the optimal concentration of DEAE-D was 250 micrograms m/ml. Only a minimum exposure period of 30 minutes to the poly rIrC-DEAE-D mixture was found necessary, but the temperature of this incubation was not found to be a critical variant. Finally, we found that addition of exogenous calcium to the inducing solution failed to influence the ultimate titers of the IFN produced.

Calcium↗
PubMed1982

The incidence of Salmonella species and serotypes in young whole chicken carcasses in 1979 as compared with 1967.

A survey was conducted to determine the incidence of salmonellae in processed, ready-to-market, whole young chickens. Carcasses from 15 federally inspected chickens eviscerating plants were analyzed using a carcass washing technique for determining the presence of salmonellae. The results obtained during the 1979 incidence survey were compared to results obtained in an identical 1967 Salmonella survey. In the 1967 study, salmonellae were isolated from 171 ot the 597 (28.6%) whole chickens tetrathionate broth rinsings analysed. In the 1979 study, 222 of 601 (36.9%) of similarly analysed chicken samples were positive. Percentile positive findings from individual plants range from 7.5 to 73.7% in 1967 and from 2.5 to 87.5% in 1979.

Animals↗
PubMed1972

Chemical and histochemical studies of glomerular sialoprotein in nephrotoxic nephritis in rats.

Glomerular sialoprotein (GSP) in nephrotoxic nephritis (NTN) rats was studied by chemical and histochemical methods at 1 to 2 hours, 48 hours, 10 days and 16 days after the induction of the disease by intravenous injection of rabbit antiserum to whole rat glomeruli. Histochemically, GSP was demonstrated by the CI and AB 8 GX stains. After the specimen was taken for histologic studies, the glomeruli from the kidneys of each rat were isolated by differential seiving and centrifugation. Quantitative determination of the glomerular sialic acid content from each rat was done using a combination of the chromatographic method of Svennerholm and the thiobarbituric acid assay of Warren. In normal rats the GSP is seen on the epithelial aspect of the glomerular basement membrane (GBM). Within 1 to 2 hours after induction of NTN, disruptuin of the normal membranous distribution of GSP and its dispersion into the mesangial space or the epithelial cytoplasm was noted. Reduction in the amount of staining was also observed after 48 hours. These changes increased in severity as the histologic lesions progressed. A quantitative decrease in glomerular sialic acid became apparent 10 days after the onset of NTN and was still observed at 16 days. Since GSP is situated at the filtration barrier site and is considered a major component of the glomerular antigenic structure, its changes in NTN suggest that it may play an important role in the pathogenesis of this disease and in the alteration of GBM permeability.

Animals↗