PubMed Health⌕ Search

Biomedical subjects

R B Pollard

Publications and source records attributed to R B Pollard.

At least 145 records · Page 8Linked to original sources
PubMed1976

Early bilateral eighth nerve involvement in meningococcal meningitis.

A male Navy recruit had hearing loss and bilateral otitis media. Meningeal signs, not initially present, developed approximately 48 hours after admission to the hospital. Type Y meningococcus was isolated from blood cultures drawn after two days of ampicillin administered orally. Permanent, bilateral, vestibular and auditory loss resulted, in spite of adequate doses of penicillin. This unusual presentation of bilateral eighth nerve involvement was thought to be due to a localized, bilateral meningococcal labyrinthitis.

Adult↗
PubMed1975

Smoking and respiratory illness in military recruits.

The effect of smoking on respiratory illness was investigated at a naval recruit camp. All recruits entering training during an 11-month period, beginning in February 1971, were included in the study. Questionnaires in regard to smoking habits were administered on arrival and during the last week of training. Facts of illness were obtained from each recruit's health record during the last week of training and abstracted onto electronic accounting machine (EAM) cards. Data on a sample of 1,100 men, who had complete records, were analyzed. Two thirds of the men were smokers on arrival. Heavy smokers had a longer history of smoking. The majority of recruits decreased smoking during training. Significantly more heavy smokers than light smokers or nonsmokers had symptoms of chronic respiratory involvement. No statistically significant increases in respiratory illness were observed in smokers.

Adolescent↗
PubMed1975

Epidemiologic survey of rubella in a military recruit population.

A seroepidemiologic surveillance of rubella infections in arriving male and female Navy recruits indicated that from 82-90% of young adults have hemagglutination (HA) titers of 1:10 or greater. Subsequent to the establishment of a new male recruit camp, there was a 10- to 11-month hiatus of low level rubella infection in the population. Once endemic rubella was established, more than 73.3 per cent of those with no detectable initial titer seroconverted. There was no reported rubella infection at an isolated female recruit camp of about 500 women even though the proportion of susceptibles was similar. However, once the female recruit camp was relocated within the male camp, their experience with rubella became comparable. A small (6.8% men, 5.6% women) number of recruits with pre-existing HA antibody titers had a four-fold or greater rise in titer during training. The great transmissibility of rubella virus in a closed population was illustrated and the ineffectiveness of herd immunity in this setting was evident.

Female↗
PubMed1975

Inappropriate secretion of antidiuretic hormone associated with adenovirus pneumonia.

Metabolic abnormalities compatible with inappropriate secretion of ADH developed during the course of severe viral pneumonia in a 17-year-old Navy recruit. With a regimen of strict fluid restriction, normalization of these abnormalities occurred. Marked leukopenia and hypoxia were also present, but gradually improved with resolution of the pneumonia. Inappropriate ADH secretion has been associated most often with bacterial pneumonia and this patient represents one of the few with viral pneumonia complicated by this syndrome. While the previous cases were assoicated with influenza virus, this patient was infected with adenovirus-7 which is endemic in the military recruit population.

Adenoviridae↗
PubMedDate not supplied

CD8+ type-2 T cells enhance the severity of acute herpes virus infection in mice.

The role of CD8+ suppressor T cells in acute herpes simplex virus type 1 (HSV) infection was investigated in mice. CD8+ CD11b+ TCR-gamma/delta + suppressor T cells (HSV-STC) were demonstrated in spleens of mice infected intraperitoneally (i.p.) with HSV. When HSV-STC from mice infected with a 10 LD50 of HSV (donors) were adoptively transferred to mice 3 days after being infected with a 1 LD50 dose of HSV (recipients), the morbidity and mortality of recipients were greatly increased (mean survival time in days (MSD): 9.4 days; mortality, 100%) as compared with controls that received CD4+ T cells or a whole T-cell lysate from donors (MSD, > 19.6 days or > 19.1 days; mortality, 38% or 50%). The morbidity and mortality of mice exposed to a 1 LD50 of HSV were also increased when they were continuously treated with recombinant murine IL-4. However, the survival rate of mice exposed to a 10 LD50 of HSV increased after multiple treatments of these mice with anti-IL-4 monoclonal antibody. IL-4-producing cells were detected in a population of HSV-STC, and IL-4 was produced when these cells were cultured in the presence of UV-inactivated HSV in vitro. These results indicate that IL-4 plays an important role in the progression of acute HSV infection and, through the production of IL-4, HSV-STC may increase the severity of the acute-phase infection of HSV in mice.

Acute Disease↗
PubMedDate not supplied

Differential reconstitution of zidovudine-induced inhibition of mitogenic responses by interleukin-2 in peripheral blood mononuclear cells from patients with human immunodeficiency virus infection.

Zidovudine (ZDV), an anti-human immunodeficiency virus (HIV) therapy, has been associated with reduction in mortality and improvement of patients with acquired immunodeficiency syndrome (AIDS). The ZDV recipients, however, experience a multitude of side effects of which bone marrow suppression is the most noteworthy, especially among patients with low CD4 cell counts. The effect of ZDV and interleukin-2 (IL-2) on phytohemagglutinin (PHA)-induced proliferative response of peripheral blood mononuclear cells (PBMs) from patients with HIV infection was investigated. ZDV 0.5 micrograms inhibited 40% of PHA-induced thymidine uptake in PBMs from healthy donors or patients with HIV, irrespective of their CD4 cell counts. However, IL-2 (10 U/ml) had differential effect on PHA-induced thymidine uptake that appeared to be dependent on absolute CD4 cell counts. While PBMs from patients with CD4 cell counts of 400/mm3 or more did not respond to IL-2 (low responders), IL-2 enhanced the PHA-induced thymidine uptake in PBMs from patients with CD4 cell counts less than 400/mm3 at an average of 60% (high responders). Moreover, IL-2 restored the ZDV-induced inhibition by almost 100% in the high responder group while it did not affect counts in the low responder group. The production of IL-2 in vitro, in response to PHA or recall antigens, was equivalently inhibited in both groups. These data suggest that ZDV and IL-2 could have an additive effect on immune parameters in certain groups of patients infected with HIV. The differential effect of IL-2 was independent of IL-2 receptor expression.

Acquired Immunodeficiency Syndrome↗
PubMedDate not supplied

Safety profile of nevirapine, a nonnucleoside reverse transcriptase inhibitor for the treatment of human immunodeficiency virus infection.

Nevirapine (NVP) is a nonnucleoside reverse transcriptase inhibitor widely used in combination with other antiretroviral agents for the treatment of human immunodeficiency virus disease. To establish its safety profile, we conducted a review of data from prospective US and international clinical trials involving a total of 906 adult patients and 468 pediatric patients treated with NVP. Drug-related adverse events were similar in adults and children, with rash and nausea most frequently reported in adults and rash and granulocytopenia most frequently reported in children. A separate analysis of rash based on data from adult patients in controlled trials demonstrated a 16% rate of NVP-attributable rash in these patients. Of patients with NVP-associated rash, 65% developed rash within the first 6 weeks of therapy, and it has been shown that a lower lead-in dose (200 mg/d vs the standard 400 mg/d) for the first 2 weeks of NVP treatment reduces the frequency of drug-associated rash. Serious rash (Stevens-Johnson syndrome [SJS] or SJS/toxic epidermal necrolysis transition syndrome) occurred with an incidence of 0.3% and clinical hepatitis with an incidence of 1.0% among NVP-treated patients in clinical trials. Adverse event data from long-term clinical trials demonstrated a lower incidence of NVP-related adverse events than in short-term trials of NVP therapy. An analysis of abnormal laboratory findings using thresholds similar to those found in the prescribing information for other commonly used antiretroviral agents and data from controlled trials in adults showed that the most frequently observed laboratory abnormalities were elevations in liver function test results. Approximately 50,000 patients in the United States had been treated with marketed NVP at the time of writing, and postmarketing surveillance has supported the overall safety profile observed in clinical trials. NVP has been shown to be well tolerated in both adult and pediatric patients.

Adolescent↗
PubMedDate not supplied

Assessment of the presence of cytomegalovirus-neutralizing antibody by a plaque-reduction assay.

Evaluation of the in vitro neutralizing activity of 30 immunoglobulin G (IgG) preparations and seven batches of pooled plasma against human cytomegalovirus (CMV) was performed by plaque-reduction assays. There were definite differences detected by these methods that could permit the selection of preparations with highest titers for clinical trials. The addition of guinea pig complement to the plaque-reduction assay enhanced inhibition of CMV; thus, guinea pig complement should be used in assays of IgG preparations. There was no relationship between the ELISA-derived optical density values of the IgG samples and the titers determined by plaque neutralization. These data suggest that the results of plaque-reduction neutralization assays provide important information about preparations of antibody that may be selected for patient administration. The preparations selected for their high titers by neutralization assays differ significantly from those identified by another method.

Animals↗
PubMedDate not supplied

Efficacy of nevirapine-based HAART in HIV-1-infected, treatment-naive persons with high and low baseline viral loads.

PURPOSE: The objective of this analysis was to assess the efficacy of nonnucleoside reverse transcriptase inhibitor (NNRTI)-containing, protease inhibitor (PI)-sparing, three-drug highly active antiretroviral therapy (HAART) in HIV- 1-infected, treatment-naive patients with high and low baseline viral loads. METHOD: A composite analysis was performed of clinical studies including the NNRTI nevirapine that were presented at international conferences between 1998 and October 2000. In all of the studies, nevirapine was administered in combination with two nucleoside reverse transcriptase inhibitors (NRTIs). For a study to be included in the analysis, more than 25% of participants must have had baseline viral loads >100,000 copies/mL, and more than 25% of participants must have had viral loads <100,000 copies/mL. RESULTS: After 6 months, 139 of 156 (89%) and 82 of 99 (83% ) patients in the low and high baseline viral load groups, respectively, had on-treatment viral loads <200 to 500 copies/mL (depending on assay used). After 12 months, 95 of 124 patients (77%) with lower baseline viral loads and 63 of 76 patients (83%) with high baseline viral loads had on-treatment viral loads below the limit of quantification. CONCLUSION: Baseline viral load does not affect virologic outcome in HIV-1-infected, antiretroviral-naive participants treated with nevirapine-containing, PI-sparing HAART.

Anti-HIV Agents↗
PubMedDate not supplied

Antitumor activity of orally administered SMANCS, a polymer-conjugated protein drug, in mice bearing various murine tumors.

The antitumor activity of an oily formulation of SMANCS (oily SMANCS), which is a product of conjugation between a proteinaceous antitumor antibiotic neocarzinostatin and poly (styrene-co-maleic acid), after oral administration to mice inoculated with various murine tumors was investigated. BALB/c mice, inoculated either s.c. or i.p. with allogeneic (sarcoma-180) or syngeneic (RL male 1 leukemia and Meth A fibrosarcoma) tumors, were treated with oily SMANCS orally or with an aqueous formulation of SMANCS (aqueous SMANCS) i.v. or i.p. Oral administrations of oily SMANCS or i.v. administrations of aqueous SMANCS to mice bearing three types of tumors in the ascites form resulted in a weak inhibition of tumor growth as compared to the complete inhibition of these tumors by aqueous SMANCS administered i.p. In mice bearing solid tumors, tumor growth was inhibited by 63-82% when a 10 mg/kg dose of oily SMANCS was administered orally to these mice. The antitumor potential of oily SMANCS administered orally was comparable to that obtained from solid tumor-bearing mice receiving i.v. doses of aqueous SMANCS. These results suggest that the oral administration of oily SMANCS to mice bearing various solid tumors inhibits the tumor growth as effectively as aqueous SMANCS administered i.v.

Administration, Oral↗
PubMedDate not supplied

Stimulation of host resistance against tumors by glycyrrhizin, an active component of licorice roots.

The effect of glycyrrhizin (GR), a Chinese herbal drug extracted from licorice roots, on the host resistance to tumors was investigated in a murine system. Administration of GR to BALB/c mice, which were inoculated s.c. with 1 x 10(6) cells/mouse of Meth A tumors, resulted in either no antitumor effect (8/20, 40%), a delay in tumor growth (9/20, 45%), or elimination of tumor growth (3/20, 15%) in these mice. In addition, the incidence of Meth A solid tumors was inhibited by GR when mice were inoculated with 1.5 x 10(4) cells/mouse or less of Meth A tumor cells, but not 7.5 x 10(4) cells/mouse or more. These results indicate that in this murine tumor system GR has a very weak antitumor effect. When GR at a dose of 20 mg/kg was administered to mice immunized with allogeneic lymphocytes 1 to 9 days after the immunization, the generation of suppressor macrophages (S-M phi) was clearly reduced as compared with that of S-M phi generated in immunized controls. In addition, when allospecific CTL (allo-CTL), which were generated in alloimmunized mice treated with GR followed by in vitro stimulation with allogeneic lymphocytes in a mixed lymphocyte reaction, were adoptively transferred to tumor-bearing mice treated with GR, the antitumor activity of allo-CTL derived from immunized mice treated with GR was markedly enhanced as compared with that of allo-CTL from immunized mice. Furthermore, established solid tumors were completely eliminated when interleukin-2 immunotherapy was performed in these mice in combination with GR treatments, but not interleukin-2 or GR alone.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMedDate not supplied

Inhibition of tumor growth by the intralesional administration of interleukin-3 into mice implanted with solid tumors.

The antitumor activity of three interleukin-3 (IL-3) preparations administered intralesionally into mice bearing syngeneic solid tumors was investigated. IL-3 preparations used in this study included S-IL-3, which was isolated from the culture fluid of murine inguinal lymph node cells stimulated with an arabinomannan extracted from Mycobacterium tuberculosis (SSM), the culture fluid of WEHI-3 cells (W-IL-3) and recombinant IL-3 (rIL-3). When a 1,500 U/kg dose of S-IL-3 or W-IL-3 was injected intralesionally into BALB/c mice bearing Meth-A solid tumors three time per week beginning 3 days after tumor inoculation, tumor growth was inhibited by 60% or 74% at 24 days after tumor inoculation, respectively. In these experiments, 1 unit of IL-3 activity was determined to be the concentration that induced 50% of maximal proliferation of an IL-3 dependent cell line (FCD-P2 cells). The administration of this dose of rIL-3 inhibited tumor growth by 34%. When these three preparations of IL-3 were pretreated with anti-IL-3 monoclonal antibody in vitro, the antitumor activity, as well as their growth promoting activity on FDC-P2 cells, was eliminated. Since direct cytotoxic activities of these IL-3 preparations against cultured Meth-A tumor cells in vitro have not been demonstrated, these results suggest that their antitumor activities might be expressed through interactions between tumor cells and antitumor effector cells which were stimulated by the intralesional administration of the IL-3 preparations.

Animals↗
PubMedDate not supplied

Release of a mitogenic factor by splenic Lyt 1+ T-cells from mice treated with SSM, an immunomodulator extracted from human type tubercle bacilli.

A production of the soluble factor activity in culture fluids of murine splenic mononuclear cells (SMNC) treated with SSM, an immunopotentiator extracted from Mycobacterium tuberculosis strain Aoyama B, was investigated. The soluble factor activity was determined as a mitogenic activity released from SMNC of mice previously treated with a 500 micrograms/kg dose of SSM (primed SMNC). The mitogenic activity was produced when primed SMNC were challenged in vitro with SSM at a concentration of 5 micrograms/ml. The activity was not produced in culture fluids of primed SMNC treated with anti-Thy 1.2 or anti-Lyt 1.2 monoclonal antibody plus complement followed by a challenge with SSM. However, the production of the activity was not affected by pretreatment of primed SMNC with anti-Lyt 2.2 monoclonal antibody plus complement. Since the non-specific resistance to tumors of mice stimulated with SSM was not demonstrated in mice depleted of Thy 1+ and Lyt 1+ T-cells, and Lyt 1+ T-cells from SSM-treated mice did not show any direct cytotoxic activities against tumor cells in vitro, the soluble factor released from Lyt 1+ T-cells by SSM stimulation may play an important role in developing the non-specific resistance of mice treated with SSM.

Adjuvants, Immunologic↗
PubMedDate not supplied

Cooperation of lymphokine(s) and macrophages in expression of antitumor activity of carboxyethylgermanium sesquioxide (Ge-132).

The administration of IFN containing sera (Ge-sera) obtained from Ge-132-treated mice (Ge-mice) or the passive transfer of macrophages (M phi) to mice bearing ascites tumors resulted in the inhibition of tumor growth. The cooperative role of Ge-sera and Ge-M phi in the display of Ge-132-antitumor activity was studied. When mice were pretreated with antimouse IFN gamma antiserum, no IFN-inducing and antitumor activities of the compound were detected. Cytotoxic activities were detected on peritoneal M phi of mice treated with Ge-sera, and passive transfer of these M phi to tumor-bearing mice resulted in the inhibition of tumor growth. When tumor-bearing mice were pretreated with substances toxic to M phi, there was no antitumor activity of Ge-sera observed. However, there was antitumor activity of Ge-sera in mice depleted of T-cells, even though the antitumor effects of the compound itself were not demonstrable in T-cell depleted mice. Therefore, a part of the antitumor activity of Ge-132 may appear to be expressed as follows: (1) Ge-132 stimulated T-cells to produce circulating lymphokine(s) which were inactivated by anti-IFN gamma treatment; (2) activated M phi were generated from resting M phi by such lymphokine(s); (3) the transplanted tumors were inhibited by these M phi.

Animals↗
PubMedDate not supplied

Importance of T-cells and macrophages in the antitumor activity of carboxyethylgermanium sesquioxide (Ge-132).

The purpose of this study was to investigate the effective mechanisms of Ge-132, an organogermanium compound with immunomodulatory activity, on experimental murine ascites tumors. The antitumor effects of Ge-132 were observed when mice inoculated with Ehrlich carcinoma (allogeneic) or RL male 1 leukemia (syngeneic) cells were treated orally. However, Ge-132 had no activity on EL-4 lymphoma (syngeneic) or Meth A fibrosarcoma (syngeneic). The antitumor activity of Ge-132 was not observed when tumor-bearing mice were treated with trypan blue, carrageenan, or monoclonal anti-Thy 1.2 antibody. However, when natural killer (NK) cells were eliminated from mice bearing RL male 1 or Ehrlich ascites tumors by treatment with anti-asialo GM1 antiserum, the antitumor activity of the compound was unchanged. This suggests that Ge-132 was effective against certain ascites tumors regardless of whether the tumor was syngeneic or allogeneic. Furthermore, its effect might be expressed through host defense mechanisms, including macrophages and/or T-cells.

Animals↗
PubMedDate not supplied

Use of proteinase inhibitors in clinical practice.

Drugs that are currently available for the treatment of human immunodeficiency virus (HIV) infection, the nucleoside analogs, are limited in their usefulness both by the fact that they all act at the same site of virus replication and because of the development of drug resistance. One of the major areas of HIV research therefore has been the development of new drugs, with the proteinase inhibitors showing promise in clinical trials. Proteinase inhibitors act at a different stage in the virus life cycle and are relatively nontoxic. Saquinavir mesylate (Hoffmann-La Roche, Nutley, NJ) is the most extensively tested and appears to have activity, as assessed by immunologic and virologic methods in small trials and in one AIDS Clinical Trials Group study. Continuing research in phase 3 studies will help to clarify the most appropriate use for this drug.

Amino Acid Sequence↗