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Biomedical subjects

G G Jackson

Publications and source records attributed to G G Jackson.

At least 55 records · Page 3Linked to original sources
PubMed1979

Comparative in vitro activity of azlocillin, ampicillin, mezlocillin, piperacillin, and ticarcillin, alone and in combination with an aminoglycoside.

The in vitro activities of the newer semisynthetic penicillins azlocillin, mezlocillin, and piperacillin were compared with those of ampicillin and ticarcillin by using 290 clinical laboratory isolates. Piperacillin and mezlocillin were the most active against Escherichia coli, Proteus mirabilis, Klebsiella spp., and Enterobacter spp. When Pseudomonas aeruginosa was tested, piperacillin and azlocillin were more active than either mezlocillin or ticarcillin. Streptococcus pneumoniae and Haemophilus influenzae species were highly susceptible to all of the penicillins tested. Ticarcillin had relatively poor activity against enterococci. The rate of bacterial killing with multiples of the minimal inhibitory concentration of azlocillin, ampicillin, or ticarcillin was tested for E. coli, P. mirabilis, P. aeruginosa, and Klebsiella spp. Increasing concentrations increased the bactericidal effect. The effect of combining azlocillin, ampicillin, or ticarcillin with an aminoglycoside was studied by using both killing curves and checkerboards. The isobolograms constructed from the checkerboards showed a synergistic pattern for the organisms tested, which included E. coli, P. aeruginosa, Klebsiella spp., P. mirabilis, and enterococci. However, the rate of killing was increased by the combination only for P. aeruginosa and enterococci.

Aminoglycosides↗
PubMed1978

Clinical manifestations of infections with herpesviruses after kidney transplantation: a prospective study of various syndromes.

Herpesviruses infections occur commonly following kidney transplantation and immunosuppression, and contribute substantially to morbidity in the transplant recipient. In this prospective study, stomatitis, mononucleosis, hepatitis, or interstitial pneumonia occurred in 24 of 30 patients (80%) as a result of reactivation of latent herpesvirus infections, but the majority of these syndromes were self-limited and the infections were often asymptomatic. Rejection occurred significantly more frequently in CMV-infected patients, but a distinct causal relationship cannot be deduced.

Burkitt Lymphoma↗
PubMed1978

Netilmicin: clinical efficacy, tolerance, and toxicity.

Netilmicin, a new aminoglycoside antibiotic, has increased in vitro bactericidal activity against many strains of Enterobacteriaceae as compared to other aminoglycosides. It is a poor substrate for some of the common gentamicin-inactivating enzymes, and it has minimal toxicity in experimental animals. In 27 hospitalized patients, clinical cure was achieved in all, and the initial infecting organism persisted in only one. Therapeutic serum and urine levels were easily obtained in most patients. No ototoxicity was observed in two patients whose treatment required inordinately high serum levels and in whom other risk factors were present. Ototoxicity in 1 of 21 patients studied was unilateral, partially reversible, and not associated with high serum levels. Although nephrotoxicity occurred in 4 of 25 patients (16%), other host factors could have accounted for the toxicity in two patients. A new observation, not noted with other aminoglycoside antibiotics, was the elevation of serum alkaline phosphatase in 43% of the patients studied.

Adolescent↗
PubMed1978

Search for latent cytomegalovirus in renal allografts.

Cytomegalovirus (CMV) infection is common after renal transplantation, and cytomegaloviruria occurs in about two-thirds of the recipients. These observations suggest that the allografts may be a site of latent infection with CMV and its reactivation may be the source of viruria. To investigate this possibility, 130 kidney specimens from 85 persons were cultured, and simultaneous explants were made of 63 of them from 50 people. No CMV was received from 33 normal kidney or cadaver donors or from 19 allograft recipients who had no evidence of posttransplantation infection with CMV. The experiment included 37 primary organ explants that yielded no evidence of latent virus. Among 33 allograft recipients with posttransplantation CMV infection, overt infectious virus was isolated from 6 of 57 allograft biopsies. All six positive specimens were from four patients, all of whom had viruria simultaneously. Organ explants from 20 of the recipients with demonstrated postoperative CMV infection, including 13 viruric patients, failed to unmask any latent CMV. Thus, allograft kidneys were infrequently infected with CMV (6%), even in patients with viruria (24%). The kidney parenchyma appears to be an uncommon site of latent CMV infection and may not be the usual source of virus in patients with viruria.

Cytomegalovirus↗
PubMed1978

Methods for the clinical evaluation of antibiotics in urinary tract infections.

Antibiotic treatment of urinary tract infections is less than completely successful. Factors involved in the outcome are complex and include host, bacterial and drug factors. Eradication of the bacterial strain from the urine after the discontinuation of drug administration is a critical index in the clinical evaluation. Categorical reports of in vitro bacterial susceptibility correlate poorly with clinical results. Achievement of a bacterial inhibitory concentration of drug in the urine is essential for cure and probably more important than the plasma concentration. The conditions associated with cure and failure in 368 episodes of infection were examined. Distribution of the patients into groups designated "anatomical normal", "systemic nephropathy" and "uronephropathy" showed each of these host factors to have a significant primary effect. In the latter two, but not in the former, the drug susceptibility of the infecting bacterial strain and whether or not it was E. coli or another species of gram-negative bacillus were additional significant factors. When antibiotic treatment was assessed in host comparable episodes a significant rank order of the effectiveness of drugs could be made according to their class action. Bactericidal inhibitors of protein synthesis were best; drugs used primarily as urinary antiseptics were the least effective.

Anti-Bacterial Agents↗
PubMed1977

Actinobacillus actinomycetemcomitans endocarditis in a patient with a prosthetic aortic valve.

Bacterial endocarditis caused by Actinobacillus actinomycetemcomitans is a rare disease. A 48-year-old man who had a Starr-Edwards aortic valve prosthesis inserted in 1972 was admitted for evaluation of confusion, headaches, anorexia, weight loss, diarrhea and weakness. Six blood cultures yielded gram-negative organisms which were subsequently identified as A. actinomycetemcomitans. Treatment with ampicillin and gentamicin resulted in cure which has been maintained after an observation period of eleven months. This represents the second report of A. actinomycetemcomitans endocarditis in a patient with a prosthetic valve.

Actinobacillus Infections↗
PubMed1977

Prospective study of prevalence, incidence, and source of herpesvirus infections in patients with renal allografts.

The prevalence, incidence, and source of infections with different types of herpesviruses were determined prospectively for 25 persons undergoing hemodialysis, 30 allograft recipients, and 16 kidney donors. The prevalence of prior infections with cytomegalovirus (CMV), herpes simplex virus (HSV), and Epstein-Barr virus (EBV) was high (72%-100%) and was similar for healthy persons and those with renal failure. The incidence of infections in patients undergoing hemodialysis was no greater than that before dialysis. In allograft recipients, the incidence of infection with CMV was 73%; HSV, 57%; EBV, 30%; and varicella-zoster virus (clinical), 7%. Ninety-seven percent of the patients developed an infection with one or more herpesviruses. Transfusions, hemodialysis, the allograft, and hospital environment were not significant sources in transmission. Uremia and splenectomy were unimportant in the reactivation of infection. Immunosuppressive drugs possibly algmented by a graft rejection response account for the high incidence of recrudescent infections with CMV and HSV.

Adult↗
PubMed1977

High-pressure liquid chromatographic assay of netilmicin in plasma.

A high-pressure liquid chromatographic method for the quantitative determination of netilmicin in plasma was developed. The procedures involve acetonitrile protein precipitation, methylene chloride extraction, and dansylation to form the fluorescent dansyl derivative of netilmicin, which is extracted into ethyl acetate and chromatographed on a reverse-phase column with aqueous acetonitrile as the mobile phase. A good linear relationship between peak height measurements and netilmicin concentrations was found. This method is sensitive and reproducible; a netilmicin concentration as low as 0.5 mug/ml can be measured with only 0.1 ml of plasma sample. The results of assays of plasma or serum samples by this high-pressure liquid chromatographic method correlate well with those obtained by microbiological assays.

Chromatography, High Pressure Liquid↗
PubMed1976

Effect of a topical interferon inducer on rhinovirus infections in volunteers.

Six controlled trials of a topical interferon inducer, N',N'-diotadecyl-N',N'-bis-(2-hydroxyethyl) propanediamine (CP 20961), against rhinovirus infection in volunteers were reviewed. Controls were the drug vehicle (which consisted of a mixture of polysorbate-80 in gylcerol and saline), saline only, and oral lactose. Multiple doses of the inducer given before challenge in any of three regimens reduced the symptomatic response to viral infection. Treatment with three doses of drug the day before challenge enhanced the interferon response to virus; four days of treatment with either the drug or its vehicle before challenge produced a refractoriness to further interferon induction. Both the drug and its vehicle were capable of inducing nasal interferon. When interferon was present at the time of viral inoculation, symptoms were reduced with or without an increase in the interferon response to infection. The rates of infection and illness were increased after a single dose of drug and decreased after a single dose of the vehicle alone.

Administration, Intranasal↗
PubMed1976

A perspective from controlled investigations of chemotherapy for viral respiratory infections.

Failure to translate discoveries about the etiology of viral respiratory infections into effective vaccines has stimulated research into antiviral chemotherapy. Volunteers whose antibody status before challenge is known and who have been exposed to a known dose of virus at a defined time provide an objective system for controlled observation of antiviral chemotherapy. A perspective on experience with drugs of five different categories of mechanisms of action is presented. Prophylactic and possibly therapeutic control of influenza and rhinovirus infections is possible. Field trials have confirmed that some regimens have beneficial effects and have shown the clinical restrictions of others. Chemotherapy is enhanced by immunoprophylaxis, and vice versa. If the potential of antiviral chemotherapy for clinical use is to be realized, complex virologic problems (some related to drugs and others unrelated) must be overcome. The groundwork is laid for new directions and new successes in the prevention and treatment of viral respiratory diseases with antiviral drugs.

Amantadine↗
PubMed1976

Efficacy of cinoxacin in urinary tract infections.

Cinoxacin, a new synthetic antibacterial agent with in vitro activity against all species of Enterobacteriaceae, was used in the treatment of urinary tract infections in 20 patients. The dose of cinoxacin was 250 mg orally every 6 h for 10 days. The etiological agents were Escherichia coli in fifteen, Klebsiella-Enterobacter in five, Proteus mirabilis in two, and Providencia in one. The minimal inhibitory concentration for these organisms ranged from 2 to 64 mug/ml. Eleven of the 20 patients had renal involvement by defined criteria, whereas the remaining nine were considered to have bladder bacilluria. The initial strain was eradicated during and immediately after treatment in 19 of 20 cases. At 6 weeks, 65% had sterile urine. Bactericidal urine levels of cinoxacin were obtained in all patients. No significant hematological, renal, hepatic, or gastroenterologic toxicity was noted. Cinoxacin appears to be a safe and useful drug in the treatment of urinary tract infections caused by Enterobacteriaceae.

Adult↗