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Biomedical subjects

L Bullock

Publications and source records attributed to L Bullock.

At least 19 recordsLinked to original sources
PubMed2006

Pb2+ reduces PKCs and NF-kappaB in vitro.

The mechanism of lead (Pb(2+))-induced neurotoxicity has not yet been fully elucidated. The purpose of this study was to examine the effects of Pb(2+) on several protein kinase C (PKC) isoforms and the nuclear factor-kappaB (NF-kappaB)-I-kappaB kinase-alpha (IKK-alpha) axis in cultured neuronal cells. Neurons were isolated from rat fetal brain at the 18th day of gestation of pregnant Sprague Dawley rats and cultured for 10 days before use. Neurons were exposed to Pb(2+) at concentrations of 10(-10), 10(-9), 10(-8), and 10(-7) mol/L for 14 h and antigens of typical PKC-alpha,beta,gamma; novel PKC (epsilon, delta), atypical PKC (lambda), NF-kappaB (p50), and IKK-alpha were enriched by immunoprecipitation and determined by western blotting. Total, calcium-dependent and independent PKC activities were also determined by counting the transferred gamma-(32) P in the substrate-histone. The results indicated that inorganic Pb(2+) significantly reduced all PKC isoforms (alpha,beta,gamma, epsilon, lambda) except delta, inhibiting the total, calcium-dependent and calcium-independent PKC activities in a dose-dependent manner. Additionally, Pb(2+) gradually reduced NF-kappaB (p50) and IKK-alpha protein levels. This suggests that Pb(2+) exhibits varying preference for individual PKC isoforms but reduces the NF-kappaB-IKK-alpha axis to a similar extent.

Animals↗
PubMed2000

Microclimate monitoring of indoor environments using piezoelectric quartz crystal humidity sensors.

The aim of this paper is to describe indoor microclimate monitoring at two different locations, Sandham Memorial Chapel, in Hampshire, England, and the castle El Alcázar, in Segovia, Spain. Piezoelectric quartz crystal sensors with novel humidity sensitive poly(ethyleneimine) coatings and Pt resistance thermometers were used to measure the relative humidity (RH) and temperature gradients across one of the paintings of the British artist, Stanley Spencer, housed in Sandham Memorial Chapel. The measurement period extended from December 1997 to September 1998. Each coated crystal was set in its own housing from which temperature and RH measuring circuits were connected via a cable to the computer. The 9 month monitoring period incorporated the range in seasons from winter through to autumn. Between December and February the RH at the back of the painting was found to be lower than that at the front. In March and April the reverse was true. Additionally, there were large spikes in the data in some of the months for both RH and temperature, probably caused by direct sunlight falling on the sensors. At the second site monitoring was performed for a shorter period, from December 1997 to early January 1998. It served, however, to show that abrupt changes can occur in the microclimate surrounding the painting. These fluctuations can with time lead to alterations to the paint surface and result eventually in cracking and damage to the art work.

Air Pollution, Indoor↗
PubMed1999

Violence in the emergency department: a survey of health care workers.

BACKGROUND: Violence in the workplace is an ill-defined and underreported concern for health care workers. The objectives of this study were to examine perceived levels of violence in the emergency department, to obtain health care workers' definitions of violence, to determine the effect of violence on health care workers and to determine coping mechanisms and potential preventive strategies. METHODS: A retrospective written survey of all 163 emergency department employees working in 1996 at an urban inner-city tertiary care centre in Vancouver. The survey elicited demographic information, personal definition of violence, severity of violence, degree of stress as a result of violence and estimate of the number of encounters with violence in the workplace in 1996. The authors examined the effects of violence on job performance and job satisfaction, and reviewed coping and potential preventive strategies. RESULTS: Of the 163 staff, 106 (65%) completed the survey. A total of 68% (70/103) reported an increased frequency of violence over time, and 60% (64/106) reported an increased severity. Most of the respondents felt that violence included witnessing verbal abuse (76%) and witnessing physical threats or assaults (86%). Sixty respondents (57%) were physically assaulted in 1996. Overall, 51 respondents (48%) reported impaired job performance for the rest of the shift or the rest of the week after an incident of violence. Seventy-seven respondents (73%) were afraid of patients as a result of violence, almost half (49%) hid their identities from patients, and 78 (74%) had reduced job satisfaction. Over one-fourth of the respondents (27/101) took days off because of violence. Of the 18 respondents no longer working in the emergency department, 12 (67%) reported that they had left the job at least partly owing to violence. Twenty-four-hour security and a workshop on violence prevention strategies were felt to be the most useful potential interventions. Physical exercise, sleep and the company of family and friends were the most frequent coping strategies. INTERPRETATION: Violence in the emergency department is frequent and has a substantial effect on staff well-being and job satisfaction.

Adaptation, Psychological↗
PubMed1996

Nursing education and research in New Zealand.

Changes in nursing education and health care reform in New Zealand have significantly affected nurses engaged in research. Movement in both undergraduate and graduate educational qualifications has stimulated interest in research about health-care problems including cardiovascular disease, cancer, and substance abuse. Our small descriptive survey indicated that most research is qualitative and focuses on clinical care. Lack of funding, isolation from educational settings, and nurses' lack of confidence in their research abilities are major hindrances to the development of nursing knowledge. Limited publication opportunities further complicate dissemination of research.

Education, Nursing, Baccalaureate↗
PubMed1993

Why battering during pregnancy?

This exploratory study was designed to determine the reasons men might beat their female partners during pregnancy from the perspectives of women who had experienced this form of violence. Seventy-nine battered women were recruited by newspaper advertisement and bulletin board postings to take part in a larger study of women's responses to relationship problems. Women battered in their relationships were asked if they had ever been beaten during pregnancy. The 27 (34%) women who had a pregnancy with the abusive partner as the father and had experienced physical abuse during the pregnancy were compared with 24 (30%) women who also had been pregnant by the abuser but had not been abused during pregnancy. The only significant difference between the two groups was that the women battered during pregnancy were more frequently and severely beaten throughout the course of the relationship. Those abused during pregnancy were asked why they thought that had happened. Their answers were thematically analyzed into the categories: (1) jealousy of the unborn child; (2) anger toward the unborn child; (3) pregnancy-specific violence not directed toward the unborn child; and (d) "business as usual." Implications for nursing assessment and interventions for abuse during pregnancy are derived from this analysis.

Adult↗
PubMed1992

Assessing for abuse during pregnancy. Severity and frequency of injuries and associated entry into prenatal care.

OBJECTIVE: To assess the occurrence, frequency, and severity of physical abuse during pregnancy and associated initiation of prenatal care. DESIGN: Stratified, prospective cohort analysis. SETTING: Public prenatal clinics in Houston, Tex, and Baltimore, Md. PARTICIPANTS: Total population-based sample of 691 black, Hispanic, and white pregnant women. All of the women were urban residents and most of the Hispanic women were Mexican American. All participants were invited into the study at the first prenatal visit and were followed up until delivery. MAIN OUTCOME MEASURE: Identification of abuse status. RESULTS: A three-question Abuse Assessment Screen detected a 17% (1/6) prevalence of physical or sexual abuse during pregnancy, which is more than double all previous published reports. When evaluated against nationally tested research instruments, the three-question screen that was asked at the first prenatal visit was sensitive and specific to abuse status. Abuse was recurrent, with 60% of abused women reporting two or more episodes of assault. Location of abuse focused on the head. Frequency and severity of abuse and potential danger of homicide was appreciably worse for white women. Abused women were twice as likely as nonabused women to begin prenatal care during the third trimester. CONCLUSIONS: A simple clinical assessment screen completed by the health care provider in a private setting and with the male partner absent is as effective as research instruments in identifying abused women. Straightforward, routine clinical assessment is recommended as essential in preventing potential trauma, interrupting existing abuse, and protecting health.

Adolescent↗
PubMed1992

Thyroid growth immunoglobulins in feline hyperthyroidism.

Feline hyperthyroidism bears a strong clinical and pathologic resemblance to toxic nodular goiter in humans. To evaluate whether the observed thyroid growth might be due to circulating thyroid antibodies, as has been postulated in humans, we studied the effect of purified immunoglobulin (Ig) G preparations on a rat thyroid follicular (FRTL-5) cell line. When compared with control, hyperthyroid cat IgG caused significantly increased [3H]-thymidine (Tdr) incorporation into DNA (p less than 0.02) and stimulated cellular proliferation 15-fold. Stimulation of 3H-Tdr incorporation tended to be biphasic and could be inhibited completely by a potent, specific TSH receptor blocking antibody. Hyperthyroid cat IgG also significantly inhibited 125I-bTSH binding to porcine thyroid membranes, an effect that could be reproduced using electrophoretically pure IgG and normal cat thyroid membranes. Unlike its effect on growth, hyperthyroid cat IgG did not stimulate intracellular cAMP, and there was no correlation between thyroid function in vivo and IgG growth-promoting activity in vitro. These data suggest that elevated titers of thyroid growth IgGs, probably acting through the TSH receptor, are present in feline hyperthyroidism and may play a role in goiter formation. Unlike growth, the thyroid hyperfunction observed is not IgG dependent. Further study of feline hyperthyroidism may contribute important insights into human nodular goiter and into the mediation of thyroid growth in general.

Adenylyl Cyclases↗
PubMed1991

Assessing for abuse: self-report versus nurse interview.

Estimates are that 1.8 million women are physically abused each year by their husbands. To prevent abuse and promote physical safety, routine assessment is essential. Planned Parenthood of Houston and Southeast Texas added four self-reported abuse assessment questions to their standard intake form completed by all initial and annual-visit clients. After one month of self-report by 477 women, the prevalence of physical abuse was 7.3%. To compare self-report to nurse interview assessment, the same four questions were asked of 300 women coming to the same clinic for initial or annual visits. The reported prevalence of abuse after a nurse interview was 29.3%.

Adolescent↗
PubMed1989

Stability of famotidine 20 and 40 mg/L and amino acids in total parenteral nutrient solutions.

The stability of famotidine in total parenteral nutrient (TPN) solutions and the concentrations of amino acids in the presence of famotidine were determined. Two famotidine concentrations (20 mg/L and 40 mg/L) and two amino acid concentrations (20 g/L and 42.5 g/L) were studied under the following storage conditions: refrigerated for 24 hours and then kept at room temperature (20-22 degrees C) for 24 hours, at room temperature for 48 hours, or refrigerated for seven days. Control TPN solutions were studied under the same storage conditions. TPN solutions also contained dextrose 25%, electrolytes, trace elements, and vitamins. Famotidine concentration was determined at 0, 24, and 48 hours and at seven days by high-performance liquid chromatography. Amino acid concentration was determined in the TPN solutions containing 42.5 g/L of amino acids without famotidine and with famotidine 40 mg/L under both 48-hour storage conditions. At 24 hours, all solutions retained at least 95% of the initial famotidine concentration. Seven of the eight famotidine solutions retained more than 95% of the initial famotidine concentration at 48 hours. All samples refrigerated for seven days retained more than 95% of the initial famotidine concentration. The concentration of amino acids in TPN solutions containing 42.5 g/L of amino acids was not affected by the addition of famotidine 40 mg/L under either 48-hour storage condition. Famotidine in concentrations of 20 mg/L and 40 mg/L is stable under the studied 48-hour storage conditions in TPN solutions containing amino acid concentrations of either 20 g/L or 42.5 g/L.(ABSTRACT TRUNCATED AT 250 WORDS)

Amino Acids↗
PubMed1989

Stability of famotidine 20 and 50 mg/L in total nutrient admixtures.

The stability of famotidine in total nutrient admixtures (TNAs) containing dextrose, an intravenous fat emulsion (IVF), and high or low concentrations of amino acids was studied. Famotidine was added to TNA solutions to final concentrations of 20 and 50 mg/L. TNA 1 contained 20% dextrose, IVF 40 g/L, and amino acids 42.5 g/L, and TNA 2 contained 25% dextrose, IVF 25 g/L, and amino acids 21.25 g/L. Control solutions of TNAs 1 and 2 without famotidine were also studied. All solutions were stored at 4 degrees C for 24 hours and then at 20-22 degrees C for 24 hours. The solutions were observed for signs of creaming or coalescence and measured for pH, famotidine concentration, and particle size at 0, 24, and 48 hours. No signs of creaming or coalescence were observed in control or test solutions throughout the study period. Famotidine in TNAs 1 and 2 showed a less than 5% change in concentration over the 48-hour period. Neither time nor amino acid concentration had any significant effect on famotidine concentration. Similarly, there were no significant differences in emulsion particle size between control solutions and TNAs containing famotidine and no significant changes in particle size over time. Famotidine 20 and 50 mg/L is stable in the TNAs tested when stored at 4 degrees C for 24 hours and then at 20-22 degrees C for 24 hours. Famotidine did not appear to disrupt the integrity of the emulsion system.

Chromatography, High Pressure Liquid↗
PubMed1989

The prevalence and characteristics of battered women in a primary care setting.

Estimates are that 2 million women are battered each year by their male partner. To prevent battering and promote physical safety, Planned Parenthood of Houston and Southeast Texas added four abuse-assessment questions to the standard intake form for all initial and annual-visit clients. To establish the prevalence of battering, all intake forms completed at four clinics during a one-month period were analyzed. A total of 793 forms were reviewed. The prevalence of physical battering was 8.2 percent. When the characteristics of the battered women were compared with the non-battered, statistically significant differences existed. Information on the health consequences of battering are presented along with suggested assessment questions.

Adolescent↗
PubMed1988

TfmLac: a second isolation of testicular feminization in mice.

TfmLac, a new occurrence of the X-linked mutation testicular feminization, has been isolated in a stock of mice and mapped to the same region as the original TfmH mutation. We compared these two mutants to determine if there are differences in their putative residual androgen receptors or androgen responsiveness. Such differences have been reported for Tfm mutations in humans. We found no evidence for induction of ornithine decarboxylase (ODC) activity in TfmLac despite androgen treatment for up to 3 weeks. This is in agreement with findings for TfmH. Both of these mutants expressed small amounts of androgen binding activity which shared some properties with the normal androgen receptors in mouse kidney. The binding was distinguishable between the two mutants, however, as determined by hormone saturation experiments utilizing DNA-cellulose chromatography. These findings confirm the independence of the two mutations and are consistent with their being allelic: both result in severe deficits of androgen binding and response.

Androgen-Insensitivity Syndrome↗
PubMed1986

Dietary fructose in the management of intractable diarrhea of infancy.

Carbohydrate digestion/absorption was evaluated in 11 infants with intractable diarrhea while they were receiving a carbohydrate-free soy-isolate formula. Seven patients were fed within 48 h of admission. Enteral feedings were initiated in the remainder after they had gained 1 kg while receiving parenteral nutrition. All feedings were initially administered by continuous nasogastric infusion. Nine patients were initially fed formula with polymeric glucose; two received fructose as the carbohydrate source, based on a documented history of polymeric glucose intolerance. Five of the nine developed watery, acidic stools while receiving polymeric glucose. All were switched to fructose, which resulted in improvement in stool pH and consistency. Glucose tolerance was normal 1 month after discharge in all seven fructose-requiring infants. Three of six infants have shown a persistent inability to hydrolyze sucrose. Several putative mechanisms of polymeric glucose intolerance are discussed, as well as the apparent association with primary sucrase-isomaltase deficiency in three of the patients. Fructose is an effective alternative carbohydrate source in infants unable to tolerate polymeric glucose, and early initiation of fructose may obviate the need for total parenteral nutrition and prolonged bowel rest.

Diarrhea, Infantile↗
PubMed1985

Stability of ranitidine hydrochloride and amino acids in parenteral nutrient solutions.

The stability of ranitidine hydrochloride in parenteral nutrient (PN) solutions and the effect of ranitidine hydrochloride on the amino acids in the PN solutions were studied. Six PN solutions (three each with amino acid contents of 2.125 and 4.25%) were prepared. Each PN solution also contained dextrose 25%, electrolytes, trace elements, vitamins, and heparin sodium. Ranitidine hydrochloride injection was added to four of the PN samples. Of the final samples, two contained no ranitidine, two contained ranitidine hydrochloride 50 micrograms/mL, and two contained ranitidine hydrochloride 100 micrograms/mL. Admixtures of ranitidine hydrochloride at the two concentrations in 0.9% sodium chloride injection were also prepared. Samples were observed for color change and tested for pH during storage at room temperature. Concentrations of amino acids were measured after 24 hours in samples without ranitidine and in samples containing ranitidine hydrochloride 100 micrograms/mL. Ranitidine hydrochloride content was determined by high-performance liquid chromatography at 12, 24, and 48 hours. No visual changes or pH changes occurred by 24 hours. All PN solutions became darker by 48 hours. The presence of ranitidine hydrochloride did not substantially affect amino acid concentrations. At 24 hours, at least 90% of the initial ranitidine concentrations remained in all samples. In three of the four PN samples at 48 hours, less than 90% of initial ranitidine concentrations remained. Ranitidine hydrochloride in concentrations of 50 and 100 micrograms/mL in parenteral nutrient solutions containing 4.25 and 2.125% crystalline amino acids is stable for 24 hours at room temperature. Under these conditions, concentrations of the amino acids contained in the PN solutions were not affected by the addition of ranitidine hydrochloride.

Amino Acids↗