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Biomedical subjects

L O Gentry

Publications and source records attributed to L O Gentry.

104 records · Page 6Linked to original sources

Pneumocystis carinii pneumonia. Problems in diagnosis and therapy in 24 cases.

Twenty-four instances of Pneumocystis carinii pneumonia were recognized in 23 patients at the Stanford University Hospitals between 1962 and 1970. The affected persons could be broadly characterized as "compromised" hosts. All but one were receiving immunosuppressive drug therapy for such underlying disease as hematopoietic malignant disease, collagen vascular disorder, and organ transplant rejection. The one patient not receiving immunosuppressant medication had congenital dysgammaglobulinemia and suffered two discrete bouts of pneumocystis pneumonia. Most of the patients were concomitantly infected with other "opportunistic" pathogens. Open lung biopsy remained the most reliable method of antemortem diagnosis of pneumocystis infection during this eight-year period. It resulted in little morbidity. Unfortunately, direct examination of appropriately stained sputum specimens for cysts was almost uniformly nonproductive. The majority of patients received specific antipneumocystis drug treatment (pentamidine isethionate or pyrimethamine and sulfadiazine). "Cure" was achieved when institution of therapy was prompt and duration of therapy approached the empirically recommended two-week course. The fact that pneumocystis pneumonia can be controlled if recognized early is compelling reason to pursue diagnosis of pneumocystosis in an appropriate clinical setting, namely, in patients with impaired host defenses who have pulmonary infection unresponsive to conventional therapy. There is hope that a noninvasive (serological) technique will be developed shortly to simplify identification of this not uncommon cause of diffuse interstitial pneumonitis.

Adolescent↗

False-positive anti-Toxoplasma fluorescent-antibody tests in patients with antinuclear antibodies.

The indirect fluorescent-antibody (IFA) method for diagnosis of toxoplasmosis is widely used and is considered to be as specific as the Sabin-Feldman dye test. After observing a patient with systemic lupus erythematosus (SLE) who had a positive toxoplasma IFA test but a negative dye test, we studied sera with high titers of antinuclear antibodies from 16 SLE patients and from 2 with rheumatoid arthritis for Toxoplasma antibodies in the immunoglobulin G and M (IgG and IgM) IFA tests and the dye test. Results of these tests were compared with titers of antinuclear antibodies, precipitating antibodies to single-strand deoxyribonucleic acid (DNA), and binding antibodies by use of DNA labeled with (3)H-actinomycin D. Of 18 patients, 11 had IgG and 4 had IgM IFA Toxoplasma antibodies; only 2 had antibodies detectable in the dye test. The immunofluorescence patterns in the Toxoplasma IFA test were indistinguishable from those obtained in patients with toxoplasmosis without antinuclear antibodies. Absorption of SLE sera with DNA did not result in a decrease in Toxoplasma IFA titers. When SLE sera were absorbed with live T. gondii, a marked drop in IgG IFA titer was observed as well as a decrease in titers of antinuclear antibodies and (3)H-DNA binding. Treatment of Toxoplasma cells with deoxyribonuclease and ribonuclease did not decrease their fluorescence. These results suggest that T. gondii nuclear antigens can absorb antinuclear antibodies but do not have exposed substrates for deoxyribonuclease. Tests in which organisms containing "nuclear" antigens for IFA detection of antibodies to these organisms are used may result in "false-positives" with sera containing antinuclear antibodies.

Absorption↗

Antimicrobial activity, pharmacokinetics, therapeutic indications and adverse reactions of ceftazidime.

Ceftazidime is an aminothiazolyl cephalosporin with potent activity against gram-negative bacteria including multiresistant strains of Pseudomonas aeruginosa. It has limited activity against gram-negative anaerobes, is less active against some gram-positive cocci than other newer beta-lactam compounds and is inactive against Streptococcus faecalis and methicillin-resistant Staphylococcus aureus. Ceftazidime is stable against common plasmid and chromosomally mediated beta-lactamase produced by Enterobacteriaceae and Pseudomonas sp. Its pharmacokinetic properties are similar to those of moxalactam and ceftizoxime, and it has a half-life of 1.9 hours. Excretion is by glomerular filtration. It is not metabolized. Ceftazidime penetrates into most body tissue and fluids, including cerebrospinal fluid, and produces therapeutic levels against most of the pathogenic gram-negative bacteria, including P. aeruginosa. Ceftazidime accumulates during renal failure, but is removed by hemodialysis and peritoneal dialysis. As a single agent it has been shown effectively to treat meningitis; urinary tract infections; gram-negative pneumonia; bone, joint and skin infections; and obstetric and gynecologic infections due to susceptible organisms. When combined with an agent that is effective against gram-positive organisms, it is also beneficial in the treatment of infections in seriously ill neonates. Different investigators have used ceftazidime alone or in combination with other agents in the successful treatment of infections in immunosuppressed patients. Adverse reactions have been few and are mostly reversible laboratory findings. The effects of ceftazidime on prothrombin synthesis and platelet function have been minimal, and no drug-induced clinical bleeding has been reported.

Adult↗

Controlled comparative trial of bacampicillin and amoxicillin in therapy of bacterial infections of the lower respiratory tract.

In this study the efficacy of bacampicillin and amoxicillin in treatment of bacterial lower respiratory tract infection were compared. Thirty-eight patients were treated with bacampicillin (800 mg twice a day), and 39 were treated with amoxicillin (500 mg three times a day). Conditions treated included pneumonia, exacerbation of chronic bronchitis, and bronchiectasis. The two groups were roughly comparable in terms of demographic factors and clinical diagnosis. The most common pathogens were Streptococcus pneumoniae and Hemophilus influenzae; isolates of S. pneumoniae were somewhat more prevalent in the group treated with bacampicillin. All patients in both groups were either cured or improved clinically. The offending pathogen was eliminated except for two strains of H. influenzae in the group treated with amoxicillin. There were mild adverse effects, including two cases of diarrhea, in four patients treated with amoxicillin. Two patients treated with bacampicillin had mild adverse effects; no diarrhea was encountered. Minor abnormalities of laboratory test results that possibly were related to therapy were encountered in eight of the patients treated with bacampicillin and three of the patients treated with amoxicillin.

Amoxicillin↗

Clinical evaluation of single-dose oral bacampicillin or ampicillin in therapy of uncomplicated gonorrhea.

Two hundred twenty-eight patients with uncomplicated gonorrhea who returned for follow-up cultures were evaluated for determination of the efficacy of three different regimens of single-dose oral treatment. The regimens included 2.4 g of bacampicillin plus 1.0 g of probenecid, 1.6 g of bacampicillin plus 1.0 g of probenecid, and 3.5 g of ampicillin plus 1.0 g of probenecid. All three regimens were highly effective in the treatment of urogenital and rectal gonorrhea but often failed cure pharyngeal gonorrhea. The highest rate of adverse reactions was reported for patients treated with 2.4 g of bacampicillin plus probenecid. The efficacies of a single oral dose of 1.6 g of bacampicillin (molar equivalent, 1.1 g of ampicillin) plus probenecid and of 3.5 g of ampicillin plus probenecid in the treatment of uncomplicated gonorrhea were equivalent as were the frequencies of adverse reactions to these two regimens.

Ampicillin↗

Subacute bacterial endocarditis due to Actinobacillus actinomycetemcomitans.

Sixteen documented cases of Actinobacillus actinomycetemcomitans endocarditis have been reported in the past 15 years. The characteristic granular growth and the fastidious nature and slow-growing character of this organism decrease the yield of positive blood cultures. Two recently observed cases of subacute endocarditis due to Actinobacillus are reported, one in a patient who required surgical intervention for complications of his disease and the other case associated with an aortic prosthetic valve. The first patient had late embolic complications which are commonly seen with Actinobacillus endocarditis. A review of the literature; including a synoptic table with clinical failures, treatment, and outcome is presented. Unless special care is taken to isolate these slow growing organisms, these cases will be misclassified as culture negative endocarditis.

Actinobacillus↗

A randomized study of tobramycin plus ticarcillin, tobramycin plus cephalothin and ticarcillin, or tobramycin plus mezlocillin in the treatment of infection in neutropenic patients with malignancies.

Two hundred twenty-five patients with 358 febrile episodes were treated with tobramycin and ticarcillin (TT), tobramycin and mezlocillin (TM), or tobramycin, ticarcillin and cephalothin (TTC). There were no statistically significant differences in the response rates for patients who were proven to have infection (67% with TT, 69% with TTC and 53% with TM). Patients were more often cured of their infection if their neutrophil count rose during therapy. In this study, the addition of cephalothin to TT did not increase the frequency of azotemia (10% and 12%, respectively). Although mezlocillin has a broader spectrum of activity in vitro than ticarcillin, it was not more efficacious when combined with tobramycin than ticarcillin plus tobramycin for the treatment of infections in neutropenic patients.

Adult↗

Prescribing considerations in fluoroquinolone therapy.

Comparative trials have shown that the new oral fluoroquinolones are as effective as parenteral cephalosporins and other broad-spectrum agents in treating infections of the urinary tract, lower respiratory tract, and skin and skin structure caused by most gram-negative and selected gram-positive pathogens. The agents are also effective in the treatment of prostatitis and osteomyelitis. Sequential parenteral to oral therapy has also proved useful, even in patients who are severely ill and are in intensive care units. This allows patients to be transferred out of intensive care earlier, reduces hospital stay and pharmacy costs, and improves quality of life. Because of the high bioavailability (> 95%) of ofloxacin, oral and parenteral doses are identical.

Anti-Infective Agents↗