PubMed Health⌕ Search

Biomedical subjects

R Pollard

Publications and source records attributed to R Pollard.

At least 19 recordsLinked to original sources
PubMed2000

A lower incidence of left-handed writing among young adults in Bulgaria than in the USA.

The incidence of left-handed writing among 590 young Bulgarian adults was 6.4%, significantly lower than that reported in two studies of students in the United States. Of those writing with the right hand, 10.8% stated that they had been forced to change their preferred hand for writing. The parents of the Bulgarian sample had a similar low incidence of left-handed writing (5.9%). Left-handed writing was almost three times more likely if one or both of the parents wrote with the left hand.

Adolescent↗
PubMed1999

Efficacy and safety of delavirdine mesylate with zidovudine and didanosine compared with two-drug combinations of these agents in persons with HIV disease with CD4 counts of 100 to 500 cells/mm3 (ACTG 261). ACTG 261 Team.

To evaluate the antiretroviral activity of delavirdine mesylate, a non-nucleoside reverse transcriptase inhibitor of HIV-1, we performed a phase II, randomized, double-blind, multicenter trial comparing the three-drug combination of delavirdine with zidovudine and didanosine to two-drug combinations of these drugs. Patients with CD4 cell counts between 100 and 500 cells/mm3 without prior or <6 months of monotherapy with zidovudine or didanosine were randomized to one of four arms and observed on a follow-up basis for 48 weeks. In total, 544 patients were evaluated. In those assigned to the three-drug regimen, mean short-term (weeks 4-12) and long-term (weeks 40-48) change in CD4 cells from baseline were 49.3+/-8.1 and 65.4+/-13.4 cells/mm3, respectively; mean short-term and long-term HIV-1 RNA changes from baseline were -1.13 log10+/-0.12 and -0.73+/-0.12 copies/ml, respectively. These responses in CD4 cell counts and HIV-1 RNA levels were better in comparisons with each of the two-drug arms at all study points; however, differences were not consistently significant. Gastrointestinal side effects were experienced by 33% of patients (178 of 544), and 30% (121 of 407) receiving delavirdine experienced rash, only one case of which was severe. In this study, therapy with delavirdine + zidovudine + didanosine was safe and showed modest, but not always significant, antiviral activity and CD4 cell count benefit compared with two-drug regimens with these agents. Key

Adult↗
PubMed1999

Topiramate and metabolic acidosis.

Topiramate (TPM) is a novel antiepileptic medication (AED) with at least three mechanisms of action. A possible fourth mechanism, that of a carbonic anhydrase inhibitor, also may contribute to its antiepileptic properties. We report a patient with intractable epilepsy and normal renal function who developed a normal anion gap metabolic acidosis, which worsened during elective surgery for temporal lobectomy. We believe this side effect of TPM can become clinically significant during surgery, concomitant use of another carbonic anhydrase inhibitor, and potentially with the ketogenic diet.

Acidosis↗
PubMed1999

Massive intraperitoneal hemorrhage from a pancreatic pseudocyst.

Massive bleeding from a pancreatic pseudocyst is a rare condition that poses a diagnostic and therapeutic challenge. A 36-yr-old woman presented with acute pancreatitis due to gallstones. Twenty-two days later, she developed severe abdominal pain and hypotension. CT scan revealed hemorrhage into a pancreatic pseudocyst and a large amount of free blood in the peritoneal cavity. At laparotomy, 8 L of blood was evacuated from the peritoneal cavity and 14 units of blood were transfused. The gastroduodenal artery was found to be the cause of the bleeding and was undersewn. A pancreatic necrosectomy was performed and the cavity was packed. The packs were removed the following day. Postoperatively, pancreatic collections were aspirated under ultrasound guidance on three occasions. She was discharged 50 days after admission and had an open cholecystectomy 1 month later. She remains well 1 yr after surgery.

Acute Disease↗
PubMed1998

Pharmacokinetics of oral ganciclovir alone and in combination with zidovudine, didanosine, and probenecid in HIV-infected subjects.

The aim of this study was to determine whether oral ganciclovir interacted pharmacokinetically with zidovudine (AZT), didanosine (ddI), or probenecid. A multicenter, open-label, randomized, crossover pharmacokinetic study with four phases was undertaken at an outpatient private research center and at university research clinics. Twenty-six HIV-infected adults (23 men, 3 women) with cytomegalovirus (CMV) seropositivity and CD4+ T-lymphocyte count > or =100 cells/microl were studied. Patients had to be stable on antiretroviral therapy for at least 4 weeks. Patients with a history of opportunistic infection or gastrointestinal symptoms were excluded. Measurements included serial blood and urine samples during the dosing intervals at steady state. The steady-state pharmacokinetics of ganciclovir were determined after the participants had stabilized and were tolerating AZT or ddI therapy. When a 1000-mg dose of oral ganciclovir was taken every 8 hours, there was a significant mean increase in Cmax and dosing interval area under the serum concentration time curve over a dosing interval (AUC) for the two antiretroviral drugs: for AZT, 61.6% and 19.5%, respectively; for ddI when administered sequentially (2 hours before ganciclovir), 116.0% and 114.6%; and for ddI administered simultaneously with ganciclovir, 107.9% and 107.1%, respectively. There was no significant change in renal clearance for either antiretroviral drug, suggesting that the interaction did not occur through a renal mechanism. There was no significant change in mean ganciclovir Cmax and AUC(0-8) when coadministered with AZT. Mean increases in Cmax and AUC(0-8) of oral ganciclovir averaged 40.1% and 52.5%, respectively, when coadministered with probenecid, but decreased by 22.1% and 22.7%, respectively, when oral ganciclovir was administered 2 hours after ddI. There was no change in the mean ganciclovir Cmax or AUC(0-8) when administered simultaneously with ddI. The mean renal clearance of oral ganciclovir was not affected by AZT or ddI coadministration intake, but there was a mean decrease of 19% when coadministered with probenecid. We conclude the increased serum concentration and reduced renal clearance of ganciclovir suggests competition with probenecid for secretion at the renal tubule. The mechanism of the interaction of oral ganciclovir with either AZT or ddI remains to be determined. The magnitude of the effect of oral ganciclovir on ddI pharmacokinetics may result in an increase in ddI concentration-related toxicities. Similarly, the small but significant decrease in ganciclovir concentration with sequential combination ddl therapy may impair the efficacy of oral ganciclovir. For HIV-infected patients receiving ganciclovir and ddI, clinicians should recommend administering the two drugs simultaneously, and patients should be monitored closely for ddI-associated toxicities.

Administration, Oral↗
PubMed1998

The regulation of burn-associated infections with herpes simplex virus type 1 or Candida albicans by a non-toxic aconitine-hydrolysate, benzoylmesaconine. Part 2: Mechanism of the antiviral action.

In the accompanying paper, the resistance to infections with HSV type 1 (HSV-1) and Candida albicans was improved in thermally injured mice treated with benzoylmesaconine (BEN), an aconitine-hydrolysate isolated from heated Aconiti tuber, or inoculated with splenic CD4+ T cells from BEN-treated mice (BEN T cells). In this paper, therefore, the antiviral mechanism of BEN T cells (or BEN) on the improved resistance of burned mice to the HSV-1 infection was studied. Burn-associated CD + CD11b+ TCRgamma/delta+ type-2 T cells have been shown to be a key on the increased susceptibility of thermally injured mice to infection with HSV-1 or C. albicans. The susceptibility of T6S-mice, mice inoculated with 1 x 10(6) cells/mouse of T6S cells (a clone of burn-associated type-2 T cells), to HSV-1 infection was similar to that of thermally injured mice. The adoptive transfer of BEN T cells to T6S-mice restores their impaired resistance to HSV-1 infection. The type-2 cytokine levels in sera of T6S-mice were decreased after inoculation of BEN T cells. BEN T cells inhibited the type-2 cytokine production by T6S cells when they were cocultured in vitro. BEN T cells, characterized as CD4+ CD28+ TCRalpha/beta+ Vicia villosa (VV) lectin-adherent T cells, showed non-specific ability to inhibit the cytokine production by various type-2 T cells. From the results of the cytokine-producing profile, BEN T cells were shown to be a different subset of CD4+ T cells from Th1 and Th2 cells, although these three CD4+ T cells had similar properties phenotypically. BEN T cells were induced in normal mice 1-4 days after the oral treatment of BEN (1 microg/kg or more). These results suggest that, through the induction of antagonistic CD4+ T cells against burn-associated type-2 T cells, BEN may improve the resistance of T6S-mice (or thermally injured mice) to the infection of HSV-1.

Aconitine↗
PubMed1998

Clinical assessment of the single use laryngeal mask airway--the LMA-unique.

We conducted a clinical comparison of the laryngeal mask airway (LMA) and the new single use PVC LMA (LMA-Unique) in 100 fasted adult patients undergoing elective surgery. Patients were allocated to one of two groups: group 1 (n = 50) was managed by two consultants and group 2 by two trainee anaesthetists. Airway management was randomized prospectively within each group, and cuff pressure in both devices was maintained at a maximum of 50 mm Hg with upward size substitution if leaks persisted during intermittent positive pressure ventilation (IPPV). Insertion with the recommended technique was successful in all patients (85 first attempt). One patient (group 1) required four attempts for insertion of the LMA-Unique and in one patient (group 2) the LMA-Unique was replaced by a tracheal tube because of persistent leaks during IPPV. In 99 patients IPPV was uneventful. The adjusted mean volume of air for cuff inflation in the LMA-Unique was significantly less in group 1 (P = 0.0013). At fibreoptic laryngoscopic examination, the vocal cords or arytenoids, or both, could be seen in 92% of patients in group 1 and in 90% of patients in group 2. Immediate throat soreness was reported in four patients in group 1 and in seven in group 2. The results suggest that the LMA-Unique was similar in clinical performance to the LMA.

Adult↗
PubMed1998

Paediatrics and medication administration. Some practical issues.

Promotion of safe administration of medication to children can be enhanced by expanding pharmacokinetics in paediatric practice. The absorption, distraction metabolism and excretion of medications vary with the developmental changes that accompany a child's growth. Application of paediatric pharmacokinetics to nursing practice when administering medications to children promotes safety in practice.

Child↗
PubMed1998

Homeostasis, stress, trauma, and adaptation. A neurodevelopmental view of childhood trauma.

All experiences change the brain, but not all experiences affect the brain equally. Because the brain is developing and organizing at such an explosive rate in the first years of life, experiences during this period have more potential to influence the brain in positive and negative ways. Traumatic events disrupt homeostasis in multiple areas of the brain that are recruited to respond to the threat. Use-dependent internalization of elements of the traumatic experience can result in the persistence of fear-related neurophysiologic patterns affecting emotional, behavioral, cognitive, and social functioning. A neurodevelopmental view of childhood trauma can help future clinical and research efforts to define and use child-specific and developmentally informed models to guide assessment, intervention, education, therapeutics, and policy.

Adaptation, Psychological↗
PubMed1997

Cytomegalovirus retinitis after initiation of highly active antiretroviral therapy.

BACKGROUND: In previous natural history studies and clinical trials, AIDS-related cytomegalovirus (CMV) retinitis has occurred primarily in patients with absolute CD4 counts of 50 cells/microL or less (0.05 x 10(9)/L) at the time of diagnosis. METHODS: We report five patients identified from our clinical practices who were diagnosed with CMV retinitis while their CD4 counts were above 195 cells/microL. We also analysed, based on CD4 counts, 76 AIDS patients with newly diagnosed CMV retinitis whose CD4 lymphocyte enumerations were done in laboratories that maintained certification in a common external quality control programme. FINDINGS: 5-24 weeks before retinitis was diagnosed, all five patients had had absolute CD4 lymphocyte counts of less than 85 cells/microL, and 4-7 weeks before diagnosis, all five patients had started taking highly active antiretroviral treatment (HAART) regimens. Only one (4%) of 27 patients enrolled in the trial between July, 1995, and February, 1996, had an absolute CD4 count of more than 50 cells/microL, and none of 27 had an absolute CD4 count of more than 100/microL on entry to the trial. However, from March, 1996 (when indinavir and ritonavir were approved by the FDA for marketing in the USA), to August, 1996, 14 (29%) of 49 patients had CD4 counts of more than 50/microL and seven (14%) of 49 had a CD4 count of more than 100 cells/microL on entry. INTERPRETATION: These findings suggest that the early immunological effects of HAART may not provide sufficient protection to prevent CMV retinitis in patients who have very low CD4 counts when therapy is started. Clinicians should note that CMV retinitis may now occur in patients who have CD4 counts of more than 100 cells/microL.

AIDS-Related Opportunistic Infections↗
PubMed1996

A phase-I study of the safety, pharmacokinetics, and antiviral activity of combination didanosine and ribavirin in patients with HIV-1 disease. AIDS Clinical Trials Group 231 Protocol Team.

A phase-I study was conducted to examine the safety, pharmacokinetics, and activity of combination 2',3'-dideoxyinosine (ddI) and ribavirin against human immunodeficiency virus type 1 (HIV-1)-positive individuals with CD4+ cell counts of < or = 500/microliter. Nineteen patients were enrolled into the study in which ddI monotherapy (200 mg p.o.b.i.d.) was administered for the first 4 weeks, followed by the coadministration of ribavirin (600 mg p.o.q.d.) and ddI (200 mg p.o.b.i.d.) for 8 or 20 additional weeks. The combination regimen was safe and well tolerated. Three patients did not complete 12 weeks of the study because of adverse events or voluntary withdrawal. The pharmacokinetic studies performed at weeks 4, 6, and 12 on specimens collected from the 15 individuals who completed 12 weeks of therapy revealed no pharmacokinetic interaction between ddI and ribavirin. A significant decline from baseline in HIV-1 titer as measured by quantitative HIV-1 culture was detected both during the ddI-monotherapy phase (week 4, p < 0.001) and during the combination-therapy ddI + ribavirin phase (week 12, p < 0.001); the median drop observed was 0.90 log10 at week 4 and 0.92 log10 at week 12. While the addition of ribavirin did not result in further reductions in viremia in the following weeks on study treatment, 13 (81%) of the 16 patients had at least a -0.5 log10 change in viral titer at week 12. The median decline in plasma viral RNA was 0.68 log10 at week 4(p < 0.001) and 0.67 log10 at week 12 (p = 0.005). CD4+ cell counts increased above baseline significantly during the ddI-monotherapy phase of the study (p = 0.0038). The median increase was +26 cells/mm3 at week 4 and +11 cells/mm3 at week 12; for patients who remained on treatment through 24 weeks, the median CD4+ cell count increase was +10 cells/mm3. The L74V ddI resistance-conferring HIV-I reverse-transcriptase mutation emerged in 53% of the patients. Patients with non-syncytium-inducing HIV variants demonstrated greater responses to treatment with larger decreases in virus load and greater increases in CD4+ cell count. Our results reveal that the combination of ddI and ribavirin in HIV-positive patients is safe, well tolerated, without adverse pharmacologic interaction, and associated with significant and sustained declines in virus load over 12 weeks of therapy.

Adult↗
PubMed1996

Ethnic variation of twinning rates in Malawi.

Malawi is a country in South-East Africa with a population of approximately 10 million, over 95% of whom are negro of Bantu origin. The country is divided into 24 administrative districts, each of which provides details of births which are compiled centrally at the Ministry of Health. Using data reported annually by health facilities from 1987-1990, most districts had twinning rates in the range 16 to 24 per 1000 maternities, figures consistent with those of other negro populations in Africa. Two adjoining districts (Rumphi and Mzimba) had rates which were considerably higher, almost 30 per 1000. Although ethnic origin is not recorded in the latest Malawi census, language spoken in the home, which was last recorded in 1966, can be used as a proxy. Rumphi and Mzimba are the only districts with an overwhelming majority of Tumbuka speaking population. These people, who are of both Tumbuka and Ngoni ethnic origin, therefore have an unusually high twinning rate (29.57 per 1000 maternities). The rate for the main ethnic group in Malawi, the Chewa people, was 21.21 per 1000. The district of Thyolo, with a mixed ethnic population, had by far the lowest rate (13.75 per 1000).

Ethnicity↗
PubMed1995

A difference in heights and weights between right-handed and left-handed bowlers at cricket.

Right-handed pitchers have been shown to be significantly taller and heavier than left-handed pitchers. An analysis of 113 professional cricketers in England showed a similar difference between right-handed and left-handed bowlers. On average the right-handers were 1.05 in. taller and 8.30 lb. heavier than the left-handers, differences which were close to significance at the 5% level with this small n.

Animals↗
PubMed1995

Neonatal haematology in Zimbabwe. II: The red cell and white cell parameters.

Red cell and white cell parameters were determined in 600 (310 male and 290 female) normal Black Zimbabwean neonates with a mean +/- sd birth weight of 3.0 +/- 0.4 (range 2.04 to 4.50, median 3.0) kg using a Coulter Counter Model S Plus. Cord anaemia (cord Hb < 13.5 gdl-1) was detected in 60 (10 pc) of the neonates. Although the male babies were significantly heavier than the females (p = 0.004), there were no significant differences (p > 0.05) in the red cell and white cell indices between the two sexes. When the haematological parameters of the 540 (90 pc) non-anaemic (cord Hb > or = 13.5 gdl-1) neonates were analysed, the mean +/- sd values which may serve as local reference standards were: Hb 15.2 +/- 1.8 (range 13.5 to 19.4) gdl-1, Hct 47.3 4.9 (range 38.6 to 60.3) pc, MCV 107.8 +/- 9.4 (range 88.8 to 134.3) fl, MCH 31.9 +/- 3.4 (range 25.2 to 45.2) pg, MCHC 32.9 +/- 1.3 (range 30.0 to 38.3) gdl-1, nucleated red blood cells 6.1 +/- 5.9 (range 0 to 55) per 100 white blood cells, reticulocyte count 5.0 +/- 1.9 (range 0 to 24.0) pc, total leucocyte count 13.8 +/- 4.4 (range 4.6 to 132.8) x 10(9)l-1; differential count: neutrophils 7.30 +/- 2.90 (range 1.72 to 18.02) x 10(9) l-1, lymphocytes 5.67 +/- 2.47 (range 0.98 to 16.14) x 10(9) l-1, monocytes 0.81 +/- 0.83 (range 0 to 5.58) x 10(9) l-1, 1 and eosinophils 0.08 +/- 0.13 (range 0 to 0.72) x 10(9)l-1.(ABSTRACT TRUNCATED AT 250 WORDS)

Africa↗
PubMed1995

Ethnic comparison of twinning rates in California.

A meaningful comparison of the twinning rates of different populations can be hindered by several factors that may influence the rates. Chief among these factors are the sources of data from which the rates are derived and the maternal age structure of the populations. The effects of such factors were minimal when the twinning rates of 14 ethnic groups in California were compared. After standardization for maternal age, twinning rates per 1000 maternities for the main ethnic groups were 13.20 for blacks, 10.05 for whites, and 7.18 for Asians. There were significant differences within the Asian group. The highest rate was for Cambodians (8.57). This rate compares with rates of approximately 6 for Koreans, Thai, and Vietnamese. These rates are similar to those found in Asia but lower than those for Californian Chinese, Japanese, and Filipinos, who have been established in the state for longer. In general, the results provide support for previous reports that twinning rates are modified by both migration and interethnic mixing. Rates for Indians from India were lower than those reported from the Indian subcontinent, whereas the twinning rates for Native Americans (10.15) and Pacific Islanders (10.60) were similar to the rate for US whites.

Birth Rate↗
PubMed1994

Didanosine compared with continuation of zidovudine in HIV-infected patients with signs of clinical deterioration while receiving zidovudine. A randomized, double-blind clinical trial. The Bristol-Myers Squibb AI454-010 Study Group.

OBJECTIVE: To determine the benefits of switching to didanosine compared with continuing zidovudine among patients infected with human immunodeficiency virus (HIV) who have previously used zidovudine and have signs of clinical deterioration. DESIGN: Randomized, double-blind, two-armed, parallel, comparative clinical trial with a blinded, compassionate crossover provision at 12 weeks. SETTING: Outpatient clinics at 19 tertiary care medical centers. PATIENTS: 312 patients infected with HIV who had received zidovudine for 6 months or more, had CD4 cell counts of 300/mm3 or less, and had signs of clinical deterioration within 12 weeks before study entry. INTERVENTION: Peroral didanosine tablets (600 mg/d adjusted for weight, "high dose") or zidovudine capsules (600 mg/d). MEASUREMENTS: Primary study end points were death, a new acquired immunodeficiency syndrome (AIDS)--defining event, or the combination of two new or recurrent HIV-related diagnoses with a 50% decrease in CD4 cells. RESULTS: Switching to didanosine was associated with fewer end points than continuing zidovudine (relative risk [RR] for zidovudine:didanosine = 1.5; 95% Cl, 1.1 to 2.0). This benefit was consistent across subgroups of patients with either AIDS-related complex or AIDS and was most apparent among those with a CD4 count at entry of 100/mm3 or more (RR = 2.2; Cl, 1.1 to 4.4). CONCLUSIONS: This study shows a positive treatment effect for switching from zidovudine to didanosine among patients with either AIDS-related complex or AIDS and validates the common practice of using clinical signs or a decrease in the CD4 count as an indication for changing therapy.

AIDS-Related Complex↗
PubMed1994

Medical liability claims and lawsuits filed against the University of Texas System involving adult psychiatric patients.

A survey was conducted to investigate medical liability claims filed against the University of Texas System (the U.T. System), physicians, and/or institutions concerning care of adult psychiatric patients. There were 34 such claims filed between 1978 and 1991 that had closed by December 1991. In many of these cases, medical record documentation was determined to be inadequate. Of the 34 claims filed, only seven were settled on behalf of U.T. personnel or U.T. institutions. Of these seven settlements, the mean monetary amount paid per case on behalf of U.T. System and non-U.T. System parties was $98,678.57. The two categories with the largest number of claims were 1) cases involving suicides, and 2) cases involving adverse reactions to medication. The largest award was $350,000, paid on behalf of U.T. physicians, a private physician, and non-U.T. institutions for alleged negligent failure to diagnose Cushing's disease. Of this amount, only $150,000 was paid on behalf of U.T. physicians. Risk management strategies should be implemented to address areas of liability in psychiatry residency programs.

Adult↗