Biomedical subjects

K Ford

Publications and source records attributed to K Ford.

At least 55 records · Page 3Linked to original sources

PubMed2000

A lack of tolerance to the anxiolytic effects of diazepam on the plus-maze: comparison of male and female rats.

RATIONALE: The demonstration of tolerance to the anxiolytic effects of benzodiazepines remains inconsistent. OBJECTIVES: The present study tested the hypothesis that intact and gonadectomized male and female rats might exhibit differential tolerance to the anxiolytic effects of diazepam (DZ). METHODS: Following acute (3 days) or chronic (3 weeks) DZ exposure, all animals were tested on the elevated plus-maze and immediately sacrificed for analysis of corticosterone, adrenocorticotropin hormone, estrogen and progesterone levels in serum. In experiment 2, following acute or chronic DZ exposure, animals were treated with a DZ challenge dose on the test day. RESULTS: In experiment 1, both acute and chronic DZ treatment similarly enhanced percentage open arm time and entries, regardless of the hormonal status of the animal. The results of experiment 2 showed that both acute and chronic DZ-treated animals exhibited a significantly higher percentage open arm time than control animals after the DZ challenge dose, and males and females did not differ in their responses to DZ exposure. CONCLUSIONS: The findings from these experiments suggest that tolerance to the anxiolytic effects of DZ did not develop in males or females, and that the hormonal status of the animal does not significantly alter the anxiolytic effects of DZ following either acute or chronic exposure. Following plus-maze exposure, females had significantly higher corticosterone levels than males and acute DZ treatment diminished this stress response.

Adrenocorticotropic Hormone↗

PubMed2000

Gender and gonadal hormone effects in the olfactory bulbectomy animal model of depression.

Major depressive disorder (MDD) affects women to a greater extent then men; however, the few studies that have examined the role of gender in an animal model of depression have shown inconsistent results. The purpose of the present study was to determine if the gonadal hormone milieu of the animal modulated behavioral changes following olfactory bulbectomy (OBX), a well-documented animal model of depression. Body weight, sucrose preference levels and open-field activity levels were measured once a week for a period of 2 weeks in gonadally intact and gonadectomized male and female rats. Following these baseline measurements, animals underwent either OBX or sham surgery. Body weight, sucrose preference and activity levels were assessed for 4 weeks post-OBX surgery. OBX-gonadectomized animals exhibited higher activity levels than OBX gonadally intact and control animals. This effect of gonadectomy was more robust in males. OBX-females (both intact and gonadectomized) exhibited significantly lower sucrose preference levels than OBX-males (both intact and gonadectomized) and control animals. These results suggest that the gonadal hormone milieu of the animal plays a role in modulating sucrose preference and activity levels following OBX.

Animals↗

PubMed2000

Patterns of union formation among urban minority youth in the United States.

Since 1990, several large surveys of sexual behavior have been conducted. In addition to collecting general information on sexual histories, such as number of partners in the previous year and whether subjects ever used condoms, these studies collected information on sexual behavior with specific partners, or "partnerships." The data are useful both for testing of substantive hypotheses about the determinants of behavior as well as for disease transition modeling. The objective of this paper is to use partnership histories to describe the union formation patterns of low-income youth living in Detroit. Data from the partnership histories will be used to illustrate the types of statistics that can be generated from these histories. Data will be presented on the number and types of unions (married/cohabiting, "knew well," "casual"), the frequency and duration of these unions, the types of intercourse reported in each type of union, the patterns of mixing by age and ethnic group in each type of union, concurrency in unions, and condom use in unions.

Adolescent↗

PubMed2000

Overexpression of DeltaFosB transcription factor(s) increases bone formation and inhibits adipogenesis.

Members of the AP-1 family of transcription factors participate in the regulation of bone cell proliferation and differentiation. We report here a potent AP-1-related regulator of osteoblast function: DeltaFosB, a naturally occurring truncated form of FosB that arises from alternative splicing of the fosB transcript and is expressed in osteoblasts. Overexpression of DeltaFosB in transgenic mice leads to increased bone formation throughout the skeleton and a continuous post-developmental increase in bone mass, leading to osteosclerosis. In contrast, DeltaFosB inhibits adipogenesis both in vivo and in vitro, and downregulates the expression of early markers of adipocyte differentiation. Because osteoblasts and adipocytes are thought to share a common precursor, it is concluded that DeltaFosB transcriptionally regulates osteoblastogenesis, possibly at the expense of adipogenesis.

Adipocytes↗

PubMed2000

Fusagene vectors: a novel strategy for the expression of multiple genes from a single cistron.

Transduction of cells with multiple genes, allowing their stable and co-ordinated expression, is difficult with the available methodologies. A method has been developed for expression of multiple gene products, as fusion proteins, from a single cistron. The encoded proteins are post-synthetically cleaved and processed into each of their constituent proteins as individual, biologically active factors. Specifically, linkers encoding cleavage sites for the Golgi expressed endoprotease, furin, have been incorporated between in-frame cDNA sequences encoding different secreted or membrane bound proteins. With this strategy we have developed expression vectors encoding multiple proteins (IL-2 and B7.1, IL-4 and B7.1, IL-4 and IL-2, IL-12 p40 and p35, and IL-12 p40, p35 and IL-2 ). Transduction and analysis of over 100 individual clones, derived from murine and human tumour cell lines, demonstrate the efficient expression and biological activity of each of the encoded proteins. Fusagene vectors enable the co-ordinated expression of multiple gene products from a single, monocistronic, expression cassette.

Animals↗

PubMed2000

Normal circulating adult human red blood cells contain inactive NOS proteins.

Human red blood cells (RBCs) are considered to play a significant role in both blood pressure (BP) regulation and tissue oxygenation, because they can bind as well as release previously bound nitric oxide (NO) from hemoglobin (Hb) and other intracellular components. Two reports indicate that the human RBC possesses nitric oxide synthase (NOS) activity-by the accumulation of nitrite across a membraned chamber in one and by the hydrolysis of labeled L-arginine, presumably to labeled L-citrulline, in the other. Furthermore, NOS proteins have been identified by immunoblot in RBCs. If true, the presence of NOS activity would convert the human RBC to a donor with limited ability to bind exogenously generated NO. In considering the importance of the question of the presence or not of NO synthetic capacity of this cell in BP regulation and tissue perfusion, whether human RBCs are, indeed, able to hydrolyze L-arginine to L-citrulline, the coproduct of NO was explored. RBC samples collected from control subjects were assayed for NOS activity by incubation of homogenized cellular fractions with labeled tritiated L-arginine in the presence of 0.5 mmol/L NADPH. By this method, the amino acid coproduct of NO, tritiated L-citrulline, would be recovered in the supernatant after removal of unused substrate by cationic resin treatment. At first, activity appeared to be present in the RBC supernatant but not in the pellet. However, activity was not suppressed by known inhibitors of NOS, whereas activity was suppressed by norvaline, an inhibitor of arginase activity with no known effect on NOS. By contrast, RBC arginase activity was not inhibited by N(omega)-nitro-L-arginine, NG-methyl-L-arginine, or aminoguanidine, known inhibitors of NOS, but was inhibited by norvaline. The label recovered by thin-layer chromatography was determined not to be tritiated L-citrulline but was instead tritiated L-ornithine, the product of arginase activity. Thus the enzymatic hydrolysis of L-arginine was not caused by NOS but was a result of the action of the enzyme arginase, which abounds in this cell. However, proteins interacting with antibodies to the endothelial and inducible isoforms of NOS were detected in human RBCs by immunoblot. Together, these findings indicate that human RBCs collected from normal adult individuals possess proteins that react with monoclonal antibodies to the Inducible and endothelial isoforms of NOS, but the proteins are without catalytic activity.

Arginase↗

PubMed2000

AIDS and STD knowledge, condom use and HIV/STD infection among female sex workers in Bali, Indonesia.

The objectives of this paper were to examine changes in AIDS/STD knowledge and behaviour from 1992-1998, current levels of STD infection and psychosocial and demographic determinants of condom use and STD infection among female sex workers. Data for the study were drawn from cross-sectional surveys of female sex workers conducted in 1992, 1994 and 1997-8. For each survey, women participated in a face-to-face interview in the brothel complexes. Survey questions included information on AIDS/STD knowledge, demographics, sexual history and psychosocial factors related to condom use. After the last survey, women were offered a vaginal exam for STD diagnosis and treatment. Sera were tested for HIV infection (anonymous, Elisa/Western blot) and syphilis (TYPHA, RPR). Cervical mucous was tested for chlamydia (LcX), gonorrhea (LCx), herpes (pcr) and HPV (pcr). Knowledge of AIDS and awareness of STDs has increased tremendously in this population since 1992. Reported condom use has also increased substantially (69.9%). Perceived susceptibility toward HIV infection remains low. Ineffective preventive strategies such as medication use continue to be common. HIV infection remains very low in this population (0.2%), although the prevalence of other STDs such as gonorrhea (60.5%), chlamydia (41.3%) and HPV (37.7%) were very high. STD knowledge and self-efficacy were significantly related to condom use as were the sex workers' perceived susceptibility to STD and HIV infection. Women with a larger number of partners were more likely to be infected with gonorrhea, chlamydia and HIV. Women who had come to Bali recently were more likely to be infected with HIV and gonorrhea.

Adult↗

PubMed2000

Evaluation of a peer education programme for female sex workers in Bali, Indonesia.

The objective of this paper is to evaluate a peer education programme for female sex workers in Bali, Indonesia. Sex workers participated in face-to-face interviews and STD exams in August-September 1998. In October 1998 one woman from each of 30 clusters was selected to be a peer educator and received a 2-day training on AIDS, STDs, condom use, and condom negotiation. After training, the peer educators were visited twice a week by field workers to answer questions and offer support. All sex workers received group education every 2 months. In January-February 1999, the sex workers again participated in face-to-face interviews and examinations. One month after peer education training, only 50% of the peer educators were still working in the clusters where they were trained. To evaluate the impact of the peer educators, sex workers in clusters where a peer educator continued to work were compared with sex workers in clusters where women did not continue to work (n=189). In clusters where women continued to work, there were higher levels of AIDS knowledge (P < 0.05), STD knowledge (P < 0.05) and condom use (82 vs 73%, P=0.15). The prevalence of Neisseria gonorrhoeae infection was also lower in clusters with a peer educator (39% vs 55%, P=0.05) than in clusters without a peer educator.

Female↗

PubMed1999

Breast cancer screening, diagnosis, and treatment.

The incidence of breast cancer in US women remains disturbingly high, and unfortunately primary care physicians still frequently encounter patients in whom the disease is suspected or, even worse, confirmed. Fortunately, however, the body of knowledge surrounding the disease has grown dramatically during the past decade, and major advances have been made in the understanding of breast cancer risk, prevention, diagnosis, and treatment. Controversies persist, particularly those concerning the screening of younger women, but consensus now exists regarding many clinical issues relevant to primary care practice. Although multidisciplinary subspecialty expertise must be made available to all women with known or suspected breast cancer, the primary care physician has an important role to play when dealing with patients with this condition. The following article focuses on what primary care practitioners need to know to expertly contribute to the diagnosis, counseling, and initial treatment of women with this disease.

Adult↗

PubMed1999

Lack of sex differences in anxiety behaviors during precipitated benzodiazepine withdrawal in rats.

Nonprecipitated benzodiazepine (BZ) withdrawal has been reported to increase anxiety levels in rats. The present experiment determined if gender or hormonal status would modulate putative changes in anxiety-related behaviors during precipitated BZ withdrawal in rats. Intact and gonadectomized male and female rats were treated for 4 weeks with empty or diazepam (DZ)-filled silastic capsules. Animals were injected with the BZ antagonist flumazenil (RO15-1788; 5 mg/kg, i.p.) or vehicle, and immediately placed on the elevated plus-maze. Following the 10-min behavioral test, rats were decapitated and trunk blood was collected to measure corticosterone and gonadal hormone levels. During precipitated BZ withdrawal rats showed significantly decreased percent open-arm time; however, this finding was confounded by a significant decrease in activity levels (e.g., closed-arm entries and total-arm entries). Precipitated BZ withdrawal did not significantly attenuate percent open-arm entries, which factors out drug-induced changes in activity levels, compared to vehicle control animals. Overall, the results of this experiment suggest that precipitated BZ withdrawal does not significantly increase anxiety levels when compared to control animals.

Animals↗

PubMed1999

Sexual experiences and condom use of heterosexual, low-income African American and Hispanic youth practicing relative monogamy, serial monogamy, and nonmonogamy.

BACKGROUND AND OBJECTIVES: To describe (a) demographic characteristics, (b) sexual history, (c) perceived HIV susceptibility, and (d) current sexual behavior, condom use, and alcohol and marijuana use of heterosexual, low-income African American and Hispanic youth categorized as relatively monogamous (n = 577), serial monogamous (n = 171), or nonmonogamous (n = 278). STUDY DESIGN: Data were drawn from personal interviews with a probability sample of low-income youth, age 15 to 24 years, conducted in Detroit in 1991. RESULTS: Many group differences were found. For example, relatively monogamous youth were most likely to be female and Hispanic and to have engaged in unprotected intercourse. Serial monogamous youth were younger and most likely to have used condoms at last intercourse. Nonmonogamous youth initiated intercourse earlier and were most likely to have experienced oral and anal intercourse and to have used alcohol and marijuana. CONCLUSION: Risk reduction programs may need to be tailored differently to accommodate the needs of these three distinct subgroups of youth.

Adolescent↗

PubMed1999

User views of a regional secure unit--findings from a patient satisfaction survey.

This paper includes key findings of a patient satisfaction survey, conducted within an English Medium Secure Unit, offering care and treatment for 45 male and female mentally disordered offenders. It aims to identify patients' perceptions of the quality of their care and other aspects of their lives within the secure unit. Following permission from the local Ethics Committee, two interviewers collected data within a two week period, using a semi-structured interview schedule. All but three of the respondents agreed to be interviewed. Talking to nurses was perceived as highly satisfying. However, provision for specific cultural and women's needs, facilities for visitors, opportunities to practise religious beliefs and access to care plans were highlighted as unsatisfactory. The study concludes with recommendations for improvement, some of which have already been considered and implemented.

Commitment of Persons with Psychiatric Disorders↗

PubMed1998

Alcohol use, perceptions of the effects of alcohol use, and condom use in urban minority youth.

This study examined the relations between alcohol use, perceived effects of alcohol use, and condom use in three different types of sexual partners in African American and Hispanic youth. Data were drawn from a household probability sample of minority youth (N = 1435) living in Detroit. Relationships were examined among three types of sexual partners: "married/lived with" partners, "knew well" partners, and "casual" partners. The effects of alcohol on condom use and perceived effects of alcohol on condom use were investigated using multiple regression with controls for demographic variables and sexual history. The quantity of alcohol consumed with partners was negatively related to condom use in all types of partners. The quantity of alcohol use was also negatively related to the perceived effect of alcohol use on condom use only with "knew well" partners.

Adolescent↗

PubMed1998

Factors related to condom use among four groups of female sex workers in Bali, Indonesia.

This article tests a behavioral model of condom use for four groups of female commercial sex workers. Data were drawn from a study of 614 female sex workers conducted in Bali, Indonesia. AIDS knowledge, risk behaviors, and factors related to condom use varied substantially among the four groups of women and reflect the social context of their work. Interventions for each group need to reflect these differences. Important factors to consider include the level of AIDS and STD knowledge in their environment, the characteristics of the clients served, and the degree of supervision that they receive.

Acquired Immunodeficiency Syndrome↗

PubMed1997

Correlates of condom use among female prostitutes and tourist clients in Bali, Indonesia.

This study examines the commercial sex activity of both tourist client and local prostitute groups in the host country of Indonesia. The study provides a profile of social and behavioural characteristics of foreign tourist men and Indonesian women engaging in commercial sex, using cross-sectional data gathered in the tourist resort town of Kuta, Bali. Univariate statistical analysis and multiple logistic regression are used to assess psychosocial and other factors associated with consistent condom use in commercial sex encounters, drawing from the Health Belief model and social cognitive theory. Results from both respondent groups indicate that condom use is high between tourist clients and female Indonesian sex workers, although not 100% consistent. Beliefs about condom efficacy and effects on pleasure, as well as susceptibility to STD infection were related to condom use for female sex workers. Beliefs about condoms being too much trouble, and self-efficacy were related to condom use for tourist clients.

Adolescent↗

PubMed1997

Sexual networks of African-American and Hispanic youth.

BACKGROUND AND OBJECTIVES: To describe the characteristics of several types of sexual partners of African-American and Hispanic urban youth and to determine the association of these characteristics with condom use, contraceptive use, experience with sexually transmitted diseases, and sexual practices. STUDY DESIGN: Data were drawn from personal interviews with a probability sample of low-income urban youth, age 15 to 24 years, conducted in Detroit in 1991 (N = 1,435). RESULTS: Although both ethnic groups tended to form partnerships most often within their own group. Hispanics had sexual partners who varied by ethnicity much more than did African Americans. Furthermore, the longer-term relationships, those that resulted in marriage or cohabitation, were more likely to be with Hispanic partners than were other relationships. Hispanic men were also more likely to report white partners than were Hispanic women. In contrast, for African-American men and women, most reported relationships were with other African Americans. Regardless of ethnicity or relationship type, women had older partners than did men. Partner differences in age or ethnicity showed few or no differences in condom use, reports of sexually transmitted disease, oral intercourse, or use of contraceptive methods. CONCLUSIONS: Although relationships with people of similar age and ethnicity are common, bridges exist for transmission of sexually transmitted infection between different age and ethnic groups.

Adolescent↗

PubMed1996

Heterosexual experiences and partnerships of urban, low-income African-American and Hispanic youth.

We have used data from a probability sample of African-American and Hispanic youth living in low-income urban household to describe their heterosexual experiences and the influence of relationships with different kinds of sexual partners (married/lived with, well known, casual) on types of intercourse (oral, anal, vaginal), condom use, and use of other birth control methods. The Generalized Estimating Equation method for data sets with multiple observations on the same subject was used to examine whether an individual's behavior differs with different kinds of partners and how behavior with a given partner is affected by experience with other relationships. Results indicate that (a) with the exception of African-American men, sexual and contraceptive behavior varied considerably with different kinds of partners; (b) heterosexual oral and anal intercourse is more common among Hispanic than African- American youth; and (c) regardless of experience with other relationships, consistent condom use as well as use of any type of contraceptive method tend to be less likely with a casual sex partner. Data regarding percentages of consistent condom use (20%-45%) and increased involvement in risky behavior associated with multiple partners further emphasize the need for interventions that enhance condom use and discourage involvement with multiple partners.

Adolescent↗

PubMed1996

Sexually transmitted diseases: experience and risk factors among urban, low income, African American and Hispanic youth.

OBJECTIVES: The objectives of this study were to assess: (1) ethnic and gender differences in reporting of diagnoses of sexually transmitted diseases (STDs), symptoms related to STDs and sexual behavior and (2) behavioral risk factors for STDs in a probability sample of low income African American and Hispanic youth. METHODS: Data were analyzed from a household probability sample of youth. The study collected data on self reported STDs, symptoms of STDs and sexual behavior. The sample was drawn from households in low income areas of urban Detroit: 1435 African American and Hispanic low income youth age 15-24 living in Detroit were interviewed face to face in 1991. RESULTS: Patterns of sexual activity as well as experience with STDs differ by ethnicity and gender. Within ethnic groups, women report more symptoms of STDs. Risk factors for diagnosed STDs included age, a young age at first intercourse, numbers of sexual partners, oral intercourse and anal intercourse. CONCLUSIONS: The data underscore the importance of development of effective safer sex intervention programs for these youth as well as careful assessment of STD risks in medical clinics serving these youth.

Adolescent↗