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Biomedical subjects

J D Connor

Publications and source records attributed to J D Connor.

At least 73 records · Page 4Linked to original sources
PubMed1987

Ribavirin disposition in high-risk patients for acquired immunodeficiency syndrome.

Ribavirin is a broad-spectrum antiviral drug that has in vitro activity against human immunodeficiency virus. To determine the kinetics of ribavirin, 17 symptom-free homosexual men with lymphadenopathy were studied. Single doses of ribavirin, 600, 1200, or 2400 mg, were given orally or intravenously. The plasma ribavirin concentration-time profiles were well fitted by a three-compartment open model. Ribavirin followed linear kinetics over the dose range studied. The mean 1-hour postinfusion concentrations after intravenous ribavirin, 600, 1200, and 2400 mg, were 8.0, 19.7, and 37.1 mumol/L, respectively. The mean +/- SD plasma beta-phase half-life, terminal-phase (gamma) half-life, and volume of distribution at steady state were 2.0 +/- 1.1 hours, 35.5 +/- 14.0 hours, and 647 +/- 258 L, respectively. The mean ribavirin renal clearance and total body clearance were 99 +/- 30 and 283 +/- 37 ml/min, respectively. After an oral dose of 600, 1200, and 2400 mg, the mean peak plasma ribavirin concentrations (which occurred 1.5 hours after administration) were 5.1, 9.9, and 12.6 mumol/L, respectively. The mean absorption half-life and bioavailability of ribavirin were 0.5 hour and 45%. Ribavirin had no plasma protein binding and the drug accumulated within red blood cells. In conclusion, ribavirin is incompletely absorbed from the gastrointestinal tract, its renal excretion accounts for approximately one third of the drug's elimination, and drug accumulation (greater than threefold) will result with repetitive dosing at the 6- to 8-hour dosing interval currently used.

AIDS-Related Complex↗
PubMed1987

Pharmacokinetics of acyclovir suspension in infants and children.

Eighteen children from 3 weeks to 6.9 years of age were given an oral acyclovir suspension for herpes simplex or varicella-zoster virus infections. Thirteen patients who were 6 months to 6.9 years old received 600 mg/m2 per dose, and three infants and two children less than 2 years old were given 300 mg/m2 per dose. The drug was given four times a day, except to one infant who was treated with three doses a day. Among the 13 children who received the 600-mg/m2 dose, the maximum concentration in plasma (Cmax) was 0.99 +/- 0.38 microgram/ml (mean +/- standard deviation), the time to maximum concentration (Tmax) was 3.0 +/- 0.86 h, the area under the curve (AUC) was 5.56 +/- 2.17 micrograms.h/ml, and the elimination half-life (t1/2) was 2.59 +/- 0.78 h. The three infants less than 2 months of age who received the 300-mg/m2 dose had a Cmax of 1.88 +/- 1.11 micrograms/ml, a Tmax of 4.10 +/- 0.48 h, an AUC of 6.54 +/- 4.32 micrograms.h/ml, and a t1/2 of 3.26 +/- 0.33 h. The acyclovir suspension was well tolerated by young children. No adverse effects requiring discontinuation of the drug occurred.

Acyclovir↗
PubMed1987

Environmental exposure of primary care personnel to ribavirin aerosol when supervising treatment of infants with respiratory syncytial virus infections.

The potential exposure to ribavirin aerosol in the environment was assessed in nurses caring for infants and children with severe lower respiratory tract infections due to respiratory syncytial virus. Ribavirin aerosol was administered via a ventilator, oxygen tent, or oxygen hood. Participants worked directly with infants receiving ribavirin for 20.0 to 35.0 h over a 3-day period. No toxic or adverse effects of ribavirin aerosol were observed in any of the 19 nurses studied, and ribavirin was not detected in erythrocytes, plasma, or urine collected after the potential exposure period.

Adult↗
PubMed1987

Peroxidase-antiperoxidase assay for rapid detection of respiratory syncytial virus in nasal epithelial specimens from infants and children.

A peroxidase-antiperoxidase (PAP) assay for the rapid detection of respiratory syncytial virus was compared with the indirect immunofluorescence method and with viral culture. Nasal epithelial specimens from 147 infants and children with acute respiratory infections were obtained and evaluated for the presence of respiratory syncytial virus antigens. Sensitivity, specificity, and accuracy by PAP were 91.7, 84.8, and 87.1%, respectively, and 87.0, 88.5, and 88.0%, respectively, by immunofluorescence compared with viral culture. The PAP assay was found to be as accurate as the indirect immunofluorescence method and more convenient to perform, since the color reaction and cell morphology were more easily observable by light microscopy. A new specimen collection method is reported; gentle scraping of the superficial nasal mucosa by the Rhino-probe method provided sufficient numbers of epithelial cells to perform multiple assays.

Adolescent↗
PubMed1987

Assessment of dietary intake of lysine and arginine in patients with herpes simplex.

In this study, dietary intake of the amino acids lysine and arginine did not differ significantly between normal controls and patients with herpes virus. Both groups of subjects consumed significantly more lysine than arginine on a daily basis. Those results are not surprising given the American population's preference for high lysine foods, such as meat and dairy products, as opposed to foods high in arginine, such as legumes, whole grains, and nuts. The mean daily intakes of lysine and arginine for the 16 subjects studied were 8.11 gm +/- 2.28 and 6.32 gm +/- 1.74, respectively. The standard deviations of the mean intakes indicate that there is a large variability in the intake of both amino acids and the ratios of the two amino acids in individual diets. This information is important, considering the conflicting results obtained previously by researchers investigating the efficacy of lysine therapy for herpes infections. The extent of the variability in total amino acid intake or ratio of lysine to arginine in the diet cannot be determined from previous studies. More important, the possible effects of these ranges on the interpretation of study results remain unknown. In order for future studies to accurately determine the effects of supplemental lysine in the treatment of herpes infections, close monitoring of dietary intake is essential.

Arginine↗
PubMed1985

Uptake of [125I]iododeoxycytidine by cells infected with herpes simplex virus: a rapid screening test for resistance to acyclovir.

A rapid screening test for resistance to acyclovir, mediated by a lack of thymidine kinase (TK) activity in herpes simplex virus (HSV), was developed by utilizing the uptake of [125I]iododeoxycytidine (IdC) by infected Vero cells. Cells infected with TK+ virus demonstrate uptake of IdC within 3 hr of infection. The assay can detect as few as 690 pfu of virus. Cells infected with TK virus have an uptake of IdC similar to that of uninfected cells, whereas cells infected with TK+ generally have an uptake greater than 10 times that of uninfected cells if tested when obvious viral cytopathic effect is present. All 19 clinical HSV isolates tested were correctly identified as TK+. Of 17 blinded HSV isolates tested, all six TK- isolates were correctly identified. A single strain with an ID50 of 3.4 micrograms/ml and an altered TK substrate specificity was incorrectly classified as TK+. The assay is a useful, rapid screening test for viral TK activity.

Acyclovir↗
PubMed1984

Hippocampal mediation of shaking behavior induced by electrical stimulation of the perforant path in the rat.

Perforant path stimulation in awake, unrestrained rats caused frequency-dependent shaking behavior in the absence of detectable epileptiform activity. Granule cell discharge, monitored by evoked field potentials, was necessary for the induction of shaking behavior. Direct stimulation of the granule cell layer also caused shakes. Intracerebroventricular injections of kainic acid destroyed hippocampal CA3 pyramidal cells and blocked the shake response. These results indicate that hippocampal granule cell discharge mediates stimulation-induced shaking behavior, and, that epileptiform activity is not required for the induction of shaking behavior by electrical stimulation.

Animals↗
PubMed1984

A double-blind study of oral acyclovir for suppression of recurrences of genital herpes simplex virus infection.

Patients with frequently recurring genital herpes were enrolled in a double-blind placebo-controlled trial comparing 200-mg acyclovir capsules, given five or two times daily, with placebo. Of 47 placebo recipients, 44 (94 per cent) had recurrences during the 120-day treatment period, compared with 13 (29 per cent) of 45 patients treated with acyclovir five times daily and 18 of 51 (35 per cent) treated with acyclovir twice daily (P less than 0.001 for each regimen compared with placebo). The median time to the first clinical recurrence was 18 days in placebo recipients, compared with over 120 days in both acyclovir-treated groups (P less than 0.001 for both groups compared with placebo). The mean monthly recurrence rate during the medication period was 0.86 in placebo recipients, compared with 0.13 in patients treated with acyclovir five times daily and 0.14 in patients treated with acyclovir twice daily (P less than 0.001 for both groups compared with placebo). While receiving therapy, 86 of 96 acyclovir-treated patients had over a 50 per cent reduction in their pretreatment recurrence rate. Breakthrough recurrences in acyclovir recipients were of shorter duration and associated with a lower frequency of viral shedding than recurrences in placebo recipients. After medication was discontinued, the subsequent recurrence rate returned to pretreatment frequencies. Daily oral acyclovir was well tolerated. We conclude that oral acyclovir given for four months markedly reduces but does not completely prevent recurrences of genital herpes and does not influence the long-term natural history of the disease.

Acyclovir↗
PubMed1984

Treatment of recurrent genital herpes simplex infections with oral acyclovir. A controlled trial.

Two hundred fifty patients were entered into a multicenter trial to evaluate the efficacy and toxicity of orally administered acyclovir for treatment of recurrent genital herpes. The study consisted of part A, in which patients entered the study within 48 hours of the onset of lesions, and part B, in which patients self-initiated therapy as soon as possible after the onset of a recurrent episode. In both parts, patients received either acyclovir (200 mg) or placebo, five times daily for five days. In both parts, the duration of virus shedding and the time to crusting and healing of lesions were shorter among acyclovir recipients than among placebo recipients. In part B, fewer acyclovir recipients formed new lesions during the study medication period than did placebo recipients. When parts A and B were compared directly, the duration of virus shedding and the times required for crusting and healing of lesions were significantly shorter among acyclovir recipients in part B than among acyclovir recipients in part A. No significant differences in the duration of itching and pain or in the times of subsequent recurrence were noted between acyclovir and placebo groups in either part A or part B. No significant toxic or adverse reactions were seen in acyclovir recipients. Oral acyclovir shortens the duration of virus shedding and the duration of lesions in patients with recurrent genital herpes. These effects are more pronounced when therapy is self-initiated by patients early in the course of a recurrent episode.

Acyclovir↗
PubMed1984

Influence of naloxone on the effects of LSD in monkeys.

Three stump-tailed monkeys were trained in an appetitive behavioral task. Administration of 0.1 mg/kg of lysergic acid diethylamide (LSD) moderately disrupted performance acutely, and produced abnormal motor activity. With repeated administration of LSD, motor activity and task responding returned to normal. When 1.0 mg/kg of naloxone was administered prior to administration of LSD in a crossover design, appetitive responding was abolished acutely in all animals and behavior was substantially more disrupted than with LSD alone. Tolerance did not occur with repeated administration of this combination of drugs. Endorphins and/or opiate receptors may act to attenuate the effects of hallucinogenic agents, and may subserve the development of tolerance to these effects.

Animals↗
PubMed1983

Adenovirus type 7b in a children's hospital.

Between August 15 and September 15, 1980, an outbreak of infections due to adenovirus type 7b occurred at Children's Hospital and Health Center, San Diego, California. During that time, four of six patients infected with adenovirus type 7b died. All patients with hospital-acquired disease had underlying respiratory compromise. Cultures, adenoviral serology tests, and histories were obtained from 383 (93%) of the 410 hospital employees. All 11 people from whom adenovirus type 7 was cultured were nurses working in a unit with an infected patient. Seven other employees with negative cultures had a fourfold or greater rise in their adenoviral complement fixation titers. This outbreak demonstrates that adenovirus type 7 infections are capable of causing serious and potentially fatal disease in hospitalized patients and suggests that individuals with underlying respiratory diseases are especially at risk.

Adenoviridae Infections↗
PubMed1983

Sensitive radioimmunoassay for the broad-spectrum antiviral agent ribavirin.

Ribavirin, 1-beta-D-ribofuranosyl-1,2,4-triazole-3-carboxyamide (Virazole; Viratek, Inc., Covina, Calif.), has a broad spectrum of antiviral activity. However, the study of the absorption, metabolism, and excretion of this compound has been limited by the lack of an appropriate assay for ribavirin and its metabolites. Since ribavirin has definite potential for therapeutic use, we developed a radioimmunoassay to measure ribavirin levels in clinical specimens. To prepare an effective immunogen, ribavirin was monosuccinylated and coupled to ovalbumin. The competitive binding radioimmunoassay, in which tritium-labeled ribavirin and rabbit antiribavirin serum were used, was quantitative for ribavirin at concentrations of 1 pmol/100 microliter in urine or plasma samples. The rabbit antibody cross-reacted with the major metabolite of ribavirin, 1,2,4-triazole-3-carboxamide, at a low level (2 to 5%) which did not interfere with ribavirin binding until concentrations of 1,2,4-triazole-3-carboxamide 10- to 100-fold higher than ribavirin were present in mock samples, a condition not present in biological specimens. We used the ribavirin radioimmunoassay to determine the ribavirin concentration in mouse plasma after intraperitoneal administration, in the sera of adults from Sierra Leone after oral or intravenous administration for treatment of suspected Lassa fever, and in the sera of children in the United States after small-particle aerosol administration. Our experience with the radioimmunoassay indicates that it is sensitive, accurate, and reproducible. The assay will permit studies leading to a better understanding of the pharmacology and pharmacokinetics of this potentially useful antiviral drug.

Adult↗
PubMed1983

Intravenous acyclovir for the treatment of primary genital herpes.

Thirty-one patients with first episodes of genital herpes were randomized in a double-blind fashion to intravenous treatment with saline placebo or acyclovir, 5 mg/kg body weight at 8-hour intervals, for 5 days. The median duration of viral shedding from genital lesions after the onset of therapy was significantly shorter for patients given acyclovir (2 days) than for those given placebo (13 days), p less than 0.001. Viral shedding from the pharynx, cervix, urethra, and urine were also shorter in acyclovir-treated patients. (p less than or equal to 0.01 for each comparison). Local and systemic symptoms were shortened by a mean of 5 days and healing of genital lesions by a mean of 12 days in acyclovir-treated patients. (p less than 0.01). Complications during treatment, such as extragenital lesions or urinary retention requiring catheterization, developed in four patients given placebo and in none given acyclovir. (p less than 0.05). Intravenous acyclovir substantially decreases the symptoms, duration of lesions, and complications of primary genital herpes.

Acyclovir↗
PubMed1983

Neonatal herpes simplex virus infection: follow-up evaluation of vidarabine therapy.

An open study of vidarabine (adenine arabinoside) therapy was performed to verify the mortality from neonatal herpes simplex virus infection and to define further long-term morbidity. A total of 39 babies not previously reported were treated with either 15 mg/kg/d (16 newborns) or 30 mg/kg/d (23 newborns) of vidarabine administered intravenously for ten to 14 days. Outcome was compared with that from 56 newborns evaluated in a prior trial. Irrespective of the dose of medication, therapy decreased the mortality in babies with disseminated and CNS disease to 40%. The extent of organ involvement and, in particular, pulmonary herpes simplex infection were predictive of mortality (P = .001, for both). For these babies, 32% achieved normal developmental milestones 2 years after therapy. Disease localized to the skin, eye, and/or mouth was not associated with death. However, neurologic impairment occurred in 12% of this treated group of newborns. These findings underscore the value of vidarabine therapy of neonatal herpes simplex virus infection. However, an increase in dosage did not appear to result in significant improvement in either mortality or morbidity. Further improvement in the mode of therapy and the utilization of more potent antiviral drugs are currently being tested.

Antibodies, Viral↗
PubMed1982

Pharmacokinetics of orally administered acyclovir in patients with herpes progenitalis.

The pharmacokinetics of acyclovir administrated orally in a dose of 200 mg every four hours, five times a day to adults with herpes progenitalis was determined. Peak plasma acyclovir levels are found 1.5 to 1.75 hours after oral administration; peak levels range from 1.4 to 4.0 microM with a mean of 2.5 microM. Acyclovir levels in saliva are well correlated with simultaneous plasma levels, saliva levels being approximately 13 percent of plasma levels. Simultaneous plasma and vaginal secretion acyclovir levels are poorly correlated; peak levels in vaginal secretions range from 0.5 to 3.6 microM.

Acyclovir↗
PubMed1982

Neonatal acyclovir pharmacokinetics in patients with herpes virus infections.

A preliminary analysis is presented of the pharmacokinetics of acyclovir in neonatal patients with herpes simplex virus infections. Mean peak acyclovir levels (microM +/- SD) at 5, 10, and 15 mg/kg per dose were 30.0 +/- 9.9, 61.2 +/- 18.3, and 86.1 +/- 23.5, with corresponding mean trough levels (microM +/- SD) of 5.3 +/- 3.4, 10.1 +/- 8.4, and 13.8 +/- 11.1, respectively. The mean half-life (t 1/2 beta) of acyclovir was 3.78 +/- 1.21 hours. The mean percent urinary recovery of acyclovir (+/- SD) at each dosage level was similar, with an overall mean recovery of 65 percent. The mean acyclovir concentration in urine did not exceed the solubility of acyclovir in bladder urine (1,300 micrograms/ml). Generally, neonatal acyclovir pharmacokinetics was consistent with previous reports from studies of adults.

Acyclovir↗