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Biomedical subjects

B Bean

Publications and source records attributed to B Bean.

At least 19 recordsLinked to original sources
PubMed1992

Antiviral therapy: current concepts and practices.

Drugs capable of inhibiting viruses in vitro were described in the 1950s, but real progress was not made until the 1970s, when agents capable of inhibiting virus-specific enzymes were first identified. The last decade has seen rapid progress in both our understanding of antiviral therapy and the number of antiviral agents on the market. Amantadine and ribavirin are available for treatment of viral respiratory infections. Vidarabine, acyclovir, ganciclovir, and foscarnet are used for systemic treatment of herpesvirus infections, while ophthalmic preparations of idoxuridine, trifluorothymidine, and vidarabine are available for herpes keratitis. For treatment of human immunodeficiency virus infections, zidovudine and didanosine are used. Immunomodulators, such as interferons and colony-stimulating factors, and immunoglobulins are being used increasingly for viral illnesses. While resistance to antiviral drugs has been seen, especially among AIDS patients, it has not become widespread and is being intensely studied. Increasingly, combinations of agents are being used: to achieve synergistic inhibition of viruses, to delay or prevent resistance, and to decrease dosages of toxic drugs. New approaches, such as liposomes carrying antiviral drugs and computer-aided drug design, are exciting and promising prospects for the future.

Adjuvants, Immunologic↗
PubMed1992

Characteristics of somatotropin and prolactin profiles in young dairy sires before and after a 72-hour fast during different seasons.

Serial blood samples were collected from young (mean = 275 d of age) AI sires at 20-min intervals for an 8-h period before and after a 72-h fast. Samples were collected from four different groups of young sires in January (n = 23), April (n = 31), July (n = 27), and October (n = 24). Samples were collected for only 6 h for the July group. Plasma somatotropin (ST) and prolactin (PRL) data were analyzed by PULSAR, a computerized peak detection program. The PULSAR parameters, except for number of peaks detected, were not different (P greater than .05) when calculated using data from the entire 8-h period or just the first 6 h. Because some endocrine characteristics as defined by PULSAR were influenced by season, deviated values were calculated for those characteristics within seasonal groups by subtracting the mean of that group from each individual observation for all PULSAR parameters. Number of ST peaks was correlated (P less than .01, r = .26) with USDA pedigree index (PI) for fat yield (PIF), sire predicted transmitting ability for fat (PTAF; P less than .01, r = .30), Northeast AI Sire Comparison (NEAISC) PIF (P less than .05, r = 24), and sire PTAF (P less than .01, r = .33). No ST pulsatile characteristics after fasting were correlated (P greater than .05) with PI. Prolactin peak length was negatively related to USDA PIF (P less than .05, r = -.23) before fasting and positively correlated (P less than .05, r = .26) after fasting.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1991

Somatotropin and prolactin profile characteristics in proven AI dairy sires.

Blood samples were collected at 20-min intervals for 8 h from 16 Holstein sires, each of which had U.S. Department of Agriculture (USDA) and Northeast AI Sire Comparison (NEAISC) progeny test evaluation data available. Plasma somatotropin (ST) and prolactin (PRL) concentrations were measured, and resulting endocrine profiles were analyzed by PULSAR, a microcomputer-based hormone peak-detection program. The number of ST peaks during the sampling period was negatively related to USDA Predicted Transmitting Ability (PTA) for fat yield, milk, and fat product value (PTA+), and for milk, fat, and protein product value (PRO+), and ST peak length was negatively related to PTA for protein percentage (PTA %P). Interpeak interval for ST was positively related to NEAISC percentage of Protein Deviation (%P). Prolactin peak length was correlated positively with both USDA PTA %P and NEAISC %P, and peak frequency was correlated positively with NEAISC %P. Interpeak interval for PRL was related positively to NEAISC Milk and Fat Deviations. Area under PRL profile was negatively related (P less than .05) to USDA PTA+ and PRO+, and NEAISC Fat Deviation and Dollars. The results indicated that endocrine traits in mature dairy sires are correlated with genetic merit for economically important production traits and suggested that such profile characteristics may be useful in selecting young sires for progeny testing programs.

Animals↗
PubMed1991

Rapid staining for the sperm penetration assay using a bisbenzimide dye.

Our rapid staining method, accomplished by adding the vital fluorochrome bisbenzimide (Hoechst 33342) directly into the sperm droplet before fertilization, eases visual interpretation of sperm penetration and decondensation. For both within- and between-experiment comparisons, inclusion of bisbenzimide did not influence the overall SPA score or the progress of sperm-egg interaction. These results suggest that bisbenzimide can be used routinely to facilitate scoring of the SPA.

Animals↗
PubMed1990

Cytomegalovirus. An update for primary care physicians.

Cytomegalovirus infection is spread in various ways--from mother to fetus or baby, from small children in day-care centers to caregivers and parents, by blood transfusions, by sexual contact. Although the illness is usually inconsequential, congenital infection can have severe consequences, including mental retardation and hearing loss. Dr Bean describes the different aspects of this virus and discusses a promising vaccine that may prevent congenital disease.

Acquired Immunodeficiency Syndrome↗
PubMed1990

Surveillance for persistent bovine viral diarrhea virus infection in four artificial insemination centers.

Four large bovine artificial insemination centers implemented a program of surveillance of resident and newly acquired bulls for persistent bovine viral diarrhea virus infection. Infection was identified in 12 of 1,538 bulls. Several clinical abnormalities, including acute and chronic mucosal disease, were evident among the persistently infected bulls. Semen produced by such bulls consistently contained bovine viral diarrhea virus, and such contamination was not always accompanied by diminished seminal quality. Infected bulls were detected by means of virus isolation tests performed on blood specimens, but not by use of serologic testing. Ten of the 12 persistently infected bulls were results of embryo transfer. Virologic surveillance of breeding herds, artificial insemination and embryo transfer centers, and the cattle trade is necessary to prevent spread of this virus by modern cattle breeding practices. Attention is also necessary to prevent contamination by this virus of the fluids used for recovery, in vitro manipulation, and transfer of bovine embryos.

Animals↗
PubMed1990

Plasma somatotropin and prolactin concentrations in young dairy sires before and after a 24-hour fast.

To examine the efficacy of plasma concentrations of bST or prolactin as predictors of expected daughter performance, blood samples were collected from young Holstein sires. Blood samples were collected at 15-min intervals via jugular cannulas from 1000 until 1600 h (d 1), beginning 4 h after morning hay feeding. Bulls were not fed again until after collection of blood samples on d 2. Samples were collected at 15-min intervals from 1000 until 1300 h on d 2. Peak values and frequency of hormonal secretory patterns of each bull were characterized by an iterative process in which values greater than 2 SD from the mean were flagged as peaks and excluded from the subsequent calculation of SD and mean. The process continued until an iteration in which no new peaks were flagged. Imposition of a 24-h fast did not alter mean basal bST or prolactin concentrations, but reduced mean peak and overall concentrations of both hormones. The number of bST peaks on d 1 was inversely related to both USDA and Northeast Artificial Insemination Sire Comparison Pedigree Index for milk yield and both USDA and Northeast Artificial Insemination Sire Comparison sire PD for milk yield, but was positively correlated on d 2 with USDA Pedigree Index for milk yield. Mean peak bST on d 2 was correlated with Northeast Artificial Insemination Sire Comparison Estimated Breeding Value for fat yield and sire USDA PD for fat yield. Prolactin peak frequency on d 1 was negatively related to Northeast Artificial Insemination Sire Comparison Pedigree Index for milk yield and sire PD for fat yield. Difference between mean prolactin on d 1 and 2 was negatively related to Northeast Artificial Insemination Sire Comparison Pedigree Index for milk yield and Estimated Breeding Value for fat yield. Endocrine parameters in young sires may be related to genetic merit for production parameters.

Animals↗
PubMed1989

Continuous infusion of high-dose acyclovir for serious herpesvirus infections.

Thirteen patients with herpesvirus infections who were unresponsive to at least 72 h of intermittent acyclovir administration received high-dose continuous infusion. Steady-state concentrations were maintained at between 20 and 98 mumol/liter. Of 12 patients who had continuous infusion for greater than 5 days, 7 (58%) resolved their infections, as determined by clinical and virologic parameters, suggesting that continuous infusion may succeed in some patients who do not respond to conventional therapy.

Acyclovir↗
PubMed1988

Therapy of herpes zoster with oral acyclovir.

Oral acyclovir therapy for herpes zoster has been studied in double-blind, placebo-controlled trials of two dosages, 400 mg and 800 mg five times per day for 10 days. Compared with placebo recipients, recipients of the high-dosage acyclovir experienced a significantly shortened period of viral shedding, significantly accelerated time to 50 percent scabbing, significantly accelerated time to 50 percent healing, and after two days of therapy, significantly less frequent formation of new lesions. The duration and severity of acute pain were less in acyclovir recipients, with differences in pain severity achieving statistical significance (p = 0.03) between Days 3 and 10 and correlating with the treatment differences in new lesion formation. In studies of the 400 mg five times per day dose schedule, differences between acyclovir and placebo recipients were not significant. In a six-month follow-up of recipients in the higher dosage study, the acyclovir recipients experienced less post-zoster pain than placebo recipients; differences in the prevalence of pain were most significant for the presence of a persistent pain in the first three months of follow-up. Oral acyclovir at these dosages appears to be free of adverse reactions. In summary, oral acyclovir at a dosage of 800 mg five times per day for 10 days for treatment of acute herpes zoster is superior to 400 mg five times per day and favorably alters the course of the disease.

Acyclovir↗
PubMed1987

Progressive mucocutaneous herpes simplex infection due to acyclovir-resistant virus in an immunocompromised patient: correlation of viral susceptibilities and plasma levels with response to therapy.

Rapidly progressive disease due to acyclovir-resistant herpes simplex has not been described. We report such a case and detail successful patient management using viral sensitivities and plasma acyclovir levels to guide therapy. Response was correlated with plasma levels above those inhibiting viral growth by 50% (ID50) in vitro.

Acyclovir↗
PubMed1987

Cephalothin clearance of Staphylococcus aureus from two experimental infection sites in the presence and absence of local phagocytic cells.

The clearance of Staphylococcus aureus from perforated peritoneal capsules which are accessible to phagocytic cells, and subcutaneous Visking chambers which exclude phagocytes, was studied simultaneously in eight rabbits implanted with both devices. Animals were treated with cephalothin, 100 mg/kg im every 8 h for sixteen doses, beginning 24 h after inoculation of the infection sites with S. aureus (cephalothin MIC 0.125 mg/l, MBC 0.5 mg/l). At the start of cephalothin, subcutaneous chambers contained a higher concentration of S. aureus (8.4 log10 cfu/ml) than peritoneal capsules (6.8 log10 cfu/ml, P less than 0.001). There was a significant bactericidal effect in subcutaneous chambers on both the third and sixth day of treatment (P less than 0.002), whereas in peritoneal capsules this did not occur until day six. The total reduction in bacterial count in subcutaneous chambers (7.0 log10 cfu/ml) was significantly greater than in capsules (4.4 log10 cfu/ml, P less than 0.002). The mean concentration of cephalothin in subcutaneous chambers (10.7 mg/l) was significantly higher than in peritoneal capsules (6.1 mg/l, P less than 0.02), but no difference in in-vitro killing of S. aureus was detected at these concentrations. We conclude that cephalothin clearance of S. aureus from a site accessible to phagocytes was delayed when compared to a phagocyte-inaccessible site.

Animals↗
PubMed1987

Treatment of varicella-zoster virus infections.

Effective antiviral therapy is now available for many forms of infection due to varicella-zoster virus. Acyclovir is the most widely prescribed treatment, but the virus is not exquisitely sensitive to this drug, and others are under study. The goals of therapy differ among different kinds of patients and must be considered when designing a treatment program.

Acyclovir↗