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K Armstrong

Publications and source records attributed to K Armstrong.

At least 37 records · Page 2Linked to original sources
PubMed2000

Birth weight and altitude: a study in Peruvian communities.

We tested the hypothesis that at high altitude birth weight decreases once a critical barometric pressure (Pb) is reached. Birth weight data covering the 1-year period from November 1997 to October 1998 were collected in Peru from the data files of 15 community and mining centers between sea level and 4575 m altitude. These centers are scattered along the main road that joins Lima (on the Pacific shore) to Cerro de Pasco (4330 m) and surroundings. Above approximately 2000 m (ie, at Pb below approximately 590 mm Hg, inspired O(2) partial pressure of approximately 114 mm Hg) and up to approximately 4500 m altitude birth weight declined at an average of 65 g for every additional 500 m altitude (or 105 g for every additional 50 mm Hg drop in Pb). This pattern did not differ between sexes. Averages and modal distributions of the birth weight from 2 hospitals in Cerro de Pasco (4330 m) serving different social groups were similar. Body length at birth was similar at various altitudes, with the exception of the 2 highest locations above 4500 m, where it was slightly reduced. From these data, together with additional data collected in the North of Peru (Chacas, 3360 m) and with results from other ethnic groups previously published, we conclude that the drop in birth weight at altitude is (1) apparent once the critical Pb of approximately 590 mm Hg is reached, corresponding to an altitude of approximately 2000 m, (2) proportional to the increase in altitude between approximately 2000 m and 4500 m, and (3) independent from socioeconomic factors.

Altitude↗
PubMed2000

Factors associated with decisions about clinical BRCA1/2 testing.

Testing for mutations in BRCA1 and BRCA2 can provide important information about breast and ovarian cancer risk to a small but identifiable subgroup of women. Women who test positive for a BRCA1/2 mutation can pursue more aggressive cancer surveillance and prevention regimens. Among families with known mutations, women who test negative may avoid unnecessary interventions. Currently, little is known about the factors associated with the use of clinical BRCA1/2 testing. The objective of this study was to determine the factors associated with decisions about clinical BRCA1/2 testing among women undergoing clinical BRCA1/2 counseling through a retrospective cohort study of women who participated in a university-based clinic offering breast cancer risk assessment, genetic counseling, and BRCA1/2 testing between January 1996 and April 1998. From the 251 eligible women who responded to a follow-up survey, 125 (50%) had undergone or were undergoing BRCA1/2 testing, 86 (34%) had decided not to undergo testing, and 40 (16%) were undecided about testing. After multivariate adjustment, we found that women who chose to undergo BRCA1/2 testing were more likely to have a known familial mutation [odds ratio (OR), 7.46; 95% confidence interval (CI), 0.97-62.16], more likely to be Ashkenazi Jewish (OR, 6.37; 95% CI, 2.68-15.12), more likely to want cancer risk information for family members (OR, 1.93; 95% CI, 0.99-4.14), more likely to want information about ovarian cancer risk (OR, 1.69; 95% CI, 1.18-3.69), and less likely to be concerned about insurance or job discrimination (OR, 0.45; 95% CI, 0.21-0.94). These associations were also found in the subgroup of women with a predicted probability of a BRCA1 mutation of 25%. Our study suggests that approximately half of eligible women choose to undergo clinical BRCA1/2 testing after participating in counseling. Women who have the highest risk of carrying a mutation, and thus the greatest probability of gaining some useful information from the test results, are most likely to undergo testing. Women who undergo testing are also more interested in ovarian cancer risk information and less concerned about job and insurance discrimination.

Adult↗
PubMed1999

Distribution along a stages-of-behavioral-change continuum for condom and contraceptive use among women accessed in different settings. Prevention of HIV in Women and Infants Demonstration Projects.

The numbers of women of childbearing age in the US with HIV and AIDS from heterosexual transmission continues to rise. Behavioral interventions remain the best means of preventing transmission of HIV. Program planners often implement interventions to promote behavioral change in a wide range of settings such as family planning or sexually transmitted disease clinics, drug treatment facilities, or medical facilities that serve high risk and HIV positive women. Women recruited in different types of settings, however, may differ with respect to their experience with, attitudes toward, and willingness to use condoms and contraception. Such differences should be considered when tailoring interventions to the populations being served. We examined the readiness to use condoms and contraception among 3784 women in four cities recruited in three different types of settings: community, facilities not targeted to HIV positive women and medical facilities for HIV positive populations. Readiness to use condoms or contraception was measured using The Transtheoretical Model of Change. Women reported being in different stages along the continuum of condom and contraceptive use in the three settings. A greater proportion of women in the HIV-facility, 45%, had used condoms consistently for the previous 6 months compared to women in the other two settings (12% and 11%). Similarly, variation across settings was seen for contemplation of consistent contraceptive use to prevent unintended pregnancies. The variability in the distribution of condom and contraceptive use across settings underscores the importance of assessing the readiness for the behavior change and designing interventions that meet the specific needs of the populations being served.

Adolescent↗
PubMed1999

Educational content and the effectiveness of influenza vaccination reminders.

OBJECTIVE: To determine if a mailed patient education brochure (addressing demonstrated reasons for vaccination refusal) would result in a higher rate of influenza vaccination than a mailed postcard reminder without educational content. DESIGN: Randomized, controlled trial. SETTING: Urban, predominantly African-American, low-income community. PARTICIPANTS: There were 740 community-dwelling individuals aged 65 years and older in the study. MEASUREMENTS: Receipt of influenza vaccination and beliefs about influenza and influenza vaccination were measured by telephone survey self-report. MAIN RESULTS: We successfully contacted 202 individuals (69.9%) who received the postcard reminder and 229 individuals (71.1%) who received the educational brochure. People receiving the educational brochure were more likely to report influenza vaccination during the previous vaccination season than those who received the postcard reminder (66.4% vs 56.9%, p =.04). They also reported more interest in influenza vaccination in the coming year. (66.5% vs 57.1%, p =.05). CONCLUSIONS: A mailed educational brochure is more effective than a simple reminder in increasing influenza vaccination rates among inner-city, elderly patients.

Aged↗
PubMed1998

The Escherichia coli mrsC gene is required for cell growth and mRNA decay.

We have identified a gene in Escherichia coli that is required for both the normal decay of mRNA and RNA synthesis. Originally designated mrsC (mRNA stability), the mrsC505 mutation described here is, in fact, an allele of the hflB/ftsH locus (R.-F. Wang et al., J. Bacteriol. 180:1929-1938, 1998). Strains carrying the thermosensitive mrsC505 allele stopped growing soon after the temperature was shifted to 44 degrees C but remained viable for several hours. Net RNA synthesis stopped within 20 min after the shift, while DNA and protein synthesis continued for over 60 min. At 44 degrees C, the half-life of total pulse-labeled RNA rose from 2.9 min in a wild-type strain to 5.9 min in the mrsC505 single mutant. In an rne-1 mrsC505 double mutant, the average half-life was 19.8 min. Inactivating mrsC significantly increased the half-lives of the trxA, cat, secG, and kan mRNAs, particularly in an mrsC505 pnp-7 rnb-500 rne-1 multiple mutant. In addition, Northern analysis showed dramatic stabilizations of full-length mRNAs in a variety of mrsC505 multiple mutants at 44 degrees C. These results suggest that MrsC, directly or indirectly, controls endonucleolytic processing of mRNAs that may be independent of the RNase E-PNPase-RhlB multiprotein complex.

Blotting, Northern↗
PubMed1998

Debriefing of American Red Cross personnel: pilot study on participants' evaluations and case examples from the 1994 Los Angeles earthquake relief operation.

The Multiple Stressor Debriefing (MSD) model was used to debrief 112 American Red Cross workers individually or in groups after their participation in the 1994 Los Angeles earthquake relief effort. Two composite case examples are presented that illustrate individual and group debriefings using the MSD model. A questionnaire which evaluated workers' experience of debriefing, was completed by 95 workers. Results indicated that workers evaluated the debriefings in which they participated positively. In addition, as participant to facilitator ratio increased, workers shared less of their feelings and reactions about the disaster relief operation. These findings, as well as more specific issues about debriefing, are discussed.

Adult↗
PubMed1997

Comparison of five tests for the detection of antibodies against chlamydial (enzootic) abortion of ewes.

Five tests for antibodies against chlamydial (enzootic) abortion of ewes were compared using 255 sera from experimentally (group 1) or naturally (group 2) infected animals, flocks free of the disease (group 3) and individual animals testing positively by the complement fixation test but from flocks with no evidence of chlamydial abortion (group 4). Sera from five specific pathogen-free lambs vaccinated with two different subtypes of Chlamydia pecorum were also included (group 5). All tests used some form of processed culture of C psitiaci as antigen. Specificities, established with group 3 and 4 sera, ranged between 96 per cent (ELISA using lipopolysaccharide antigen) and 59 per cent (Immunocomb). Reactions with group 5 sera suggested that the cause of false positive results in the field might be cross-reactive antibodies against the arthritogenic subtype of C pecorum. Sensitivities, established with groups 1 and 2 sera, ranged between 81 per cent (Immunocomb) and 51 per cent (ELISA using solubilised protein antigen). The minimum sample sizes required to be 95 per cent certain of detecting at least five seropositives in two infected flocks (combined data) were 15 to 48, dependent on the test applied. The Western blot test, applied to a proportion of samples, yielded no false positives with group 3 sera but 31.7 per cent with group 4 sera. Thus, none of the tests in this comparison emerged as sufficiently satisfactory in all respects, suggesting that further improvements in chlamydial serology must come through the use of non-native antigens or in the form of a competitive ELISA.

Abortion, Septic↗
PubMed1996

Paraprofessional delivery of a theory based HIV prevention counseling intervention for women.

This report describes a mid-course process evaluation of an HIV risk-reduction counseling intervention delivered by specially trained peer paraprofessionals. One of the key questions addressed is whether paraprofessionals can successfully implement a theory-based counseling intervention. The project, known as Project CARES, is a 5-year demonstration research project to prevent HIV infection and unplanned pregnancies in women at risk for HIV infection and transmission who were recruited from homeless shelters, drug treatment facilities, and hospital-based service settings for HIV-infected women. Project CARES uses an enhanced counseling intervention based on the Transtheoretical Model, also known as the Stages of Change model, to promote condom and other contraceptive use for women who wish to avoid pregnancy, condom use for disease prevention, and reproductive health service use. Peer paraprofessionals, called advocates, provide stage-tailored counseling using a structured manual which guides them in the selection of specific counseling activities appropriate to a woman's level of readiness to change her behavior. Data from process evaluation forms completed by advocates in Philadelphia and Baltimore document that the delivery of the intervention is consistent with the theoretical model upon which it was based. Paraprofessionals can become skilled in the delivery of a stage-based counseling intervention in health and social service settings. The use of paraprofessionals in HIV prevention service delivery may be a cost-effective way to enhance and extend services for women.

Acquired Immunodeficiency Syndrome↗
PubMed1995

HIV risk status and preventive behaviors among 17,619 women.

OBJECTIVES: To document the percentage of women at high risk for human immunodeficiency virus (HIV) infection among primary care clients, identify their most prevalent risk factors for HIV infection, and examine the relationships between risk status and preventive behaviors for HIV infection. DESIGN: Cross-sectional. SETTING: Urban and nonurban primary care clinics. PARTICIPANTS: Female clients (N = 17,619) who voluntarily completed an HIV risk-assessment form. MAIN OUTCOME MEASURES: HIV risk status, condom use, and previous HIV testing. RESULTS: Using criteria from the Centers for Disease Control, the study found 14% of the sample to be at high risk for HIV infection. Prevalent risk factors were having sex with persons at high risk for AIDS, having sex with more than six persons in a year, and having more than two sexually transmitted diseases. Women at high risk were more likely to be older, urban, and black. Overall, rates of consistent condom use and HIV testing were low, 12% and 7%, respectively. Older women, coupled women, and women of color were least likely to use condoms consistently. Women at low risk were less likely to have had HIV tests. CONCLUSIONS: To prevent HIV infection, nursing interventions can target women of all ages, especially urban and black women. Nurses should use strategies and skills to promote condom use that are different from those they use to encourage HIV testing.

AIDS Serodiagnosis↗
PubMed1995

Adenoviral-mediated gene transfer to fetal pulmonary epithelia in vitro and in vivo.

Vector-mediated gene transfer offers a direct method of correcting genetic pulmonary diseases and might also be used to correct temporary abnormalities associated with acquired, nongenetic disorders. Because the fetus or newborn may be a more immune tolerant host for gene transfer using viral vectors, we used replication defective recombinant adenoviral vectors to test the feasibility of gene transfer to the fetal pulmonary epithelium in vitro and in vivo. Both proximal and distal epithelial cells in cultured fetal lung tissues from rodents and humans diffusely expressed the lacZ transgene 3 d after viral infection. In vivo gene delivery experiments were performed in fetal mice and lambs. Delivery of Ad2/CMV-beta Gal to the amniotic fluid in mice produced intense transgene expression in the fetal epidermis and amniotic membranes, some gastrointestinal expression, but no significant airway epithelial expression. When we introduced the adenoviral vector directly into the trachea of fetal lambs, the lacZ gene was expressed in the tracheal, bronchial, and distal pulmonary epithelial cells 3 d after viral infection. Unexpectedly, reactive hyperplasia and squamous metaplasia were noted in epithelia expressing lacZ in the trachea, but not in the distal lung of fetal lambs. 1 wk after infection, adenovirus-treated fetuses developed inflammatory cell infiltrates in the lung tissue with CD4, CD8, IgM, and granulocyte/macrophage positive immune effector cells. Transgene expression faded coincident with inflammation and serologic evidence of antiadenoviral antibody production. While these studies document the feasibility of viral-mediated gene transfer in the prenatal lung, they indicate that immunologic responses to E1-deleted recombinant adenoviruses limit the duration of transgene expression.

Adenoviruses, Human↗
PubMed1995

Occupational exposure of health care workers (HCWs) to human immunodeficiency virus (HIV): stress reactions and counseling interventions.

As more people become infected with HIV, Health Care Workers (HCWs) have a greater likelihood of being exposed at work. HIV exposure threatens the life of the HCW and can elicit a stress reaction. Although HCWs have reactions similar to those of people who have been exposed to other traumatic events, the nature of this stressor and the length of time it lasts is unique. This article presents counseling interventions that address the needs of the individual HCW during this event. These counseling guidelines promote the HCW's discussion of the event and any relevant past unresolved traumatic experiences; evaluate and aid the worker and his or her support system; provide information on stress reactions and HIV; examine the HCW's practice methods; and helps to reintegrate the HCW back into the work environment.

Adaptation, Psychological↗
PubMed1995

Assessing the safety of pediatric laparoscopic surgery.

We studied deviations from normal physiology in piglets (n = 10; average weight 5.75 kg) during carbon dioxide (CO2) pneumoperitoneum. Cardiopulmonary data were gathered during varying intraabdominal pressures (IAP = 8, 12, 15, 20 mm Hg), each sustained for 10 mins. Each animal was its own preinsufflation and exsufflation control. A rapid, significant rise in arterial CO2 pressure from preinsufflation (46.5 +/- 6.7 mm Hg) to insufflation at 20 mm Hg (72.9 +/- 15 mm Hg; p < 0.05) initiated further cardiac adjustments. Responses included a sustained increase in cardiac index (presufflation = 3.1 +/- 1.4; 20 mm Hg IAP = 3.6 +/- 1.2), increased heart rate (preinsufflation = 121 +/- 21; 20 mm Hg IAP = 150 +/- 28; p < 0.05), and left ventricular stroke work (20 mm IAP = 22.7 +/- 8.9; exsufflation 20 min = 15.3 +/- 9.4 g.m/m2; p < 0.05). There was a significant arterial-end CO2 tidal difference throughout insufflation, as great as 15 mm Hg (p < 0.05), suggesting increasing ventilation dead space. Core temperature decreased significantly from preinsufflation (35.3 +/- 1.3 degrees C) to 20 mm Hg IAP (33.6 +/- 1.5 degrees C, p < 0.05). We suggest the following guidelines based on the above data: (a) preoperative examination screening for cardiopulmonary abnormalities; (b) fluid replacement to normal hydration only; (c) cuffed endotracheal tubes for effective ventilation; (d) careful adjustment of minute ventilation to achieve normocapnia; (e) CO2 warming; (f) maximal insufflation pressure of 12 mm Hg; (g) postoperative care emphasizing respiratory and thermoregulation status.

Abdomen↗
PubMed1994

Neurasthenic fatigue, chemical sensitivity and GABAa receptor toxins.

Following observation of fatigue syndromes in people who have been occupationally exposed to pesticides and insecticides which exert their toxicity through the GABAa receptor, we have formulated the hypothesis that fatigue syndromes in general may be secondary to altered sensitivity of the GABAa receptor. We discuss the possible involvement of organochlorine compounds which are widespread in the environment. Organophosphate compounds may have similar toxic effects through damaged cholinergic input to the dentate gyrus of the hippocampus where cholinergic and GABAergic transmission are closely linked.

Adult↗
PubMed1994

Blood lipid concentrations and other cardiovascular risk factors among Saudis.

A study of 1005 family practice attenders at King Fahad National Guard Hospital was conducted during February 1993 to determine the prevalence of hyperlipidaemia and its association with participants' sociodemographic characteristics and clinical problems. The percentage of patients with total serum cholesterol concentration (TSCC) of 5.2-6.8 mmol/l was 39.3%, while those with TSCC exceeding 6.8 mmol/l was 9.5%. Hypertriglyceridaemia (TG > 2.5 mmol/l) was found in 5%. TSCC increased progressively with age up to the seventh decade. TSCC was higher among obese and diabetic patients than others. Obesity body mass index (BMI) > 29.9 kg/m2 was found in 32.8%, diabetes mellitus in 24.2%, hypertension in 11.1% and both diabetes and hypertension in 6.4%. There is an urgent need to equip primary health care teams with training and resources to help them give proper dietary advice, modify the local lifestyle and screen at least high-risk groups for hyperlipidaemia and other coronary risk factors.

Adult↗