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C Valentine

Publications and source records attributed to C Valentine.

16 recordsLinked to original sources
PubMed1998

FGF signaling activates STAT1 and p21 and inhibits the estrogen response and proliferation of MCF-7 cells.

Normal breast tissue as well as most breast tumors are dependent on estrogen for growth. Breast tumors often progress to a hormone-independent state which is associated with poor prognosis. It has been proposed that activation of growth factor signaling pathways in the tumor cells may free them from hormonal control. Certain growth factors can mimic estrogen responses by activating the estrogen receptor via its phosphorylation by mitogen-activated protein (MAP) kinase. In this report, however, we show that fibroblast growth factor (FGF), despite activating MAP kinase, is growth-inhibitory for estrogen-dependent MCF-7 breast cancer cells. MCF-7 cells treated with FGFs exhibit slower growth than controls in both the presence and absence of estrogen, with a concomitant increase in the number of cells in G0/G1. Expression of a constitutively activated FGF receptor in these cells further decreases their growth rate, which is no longer influenced by FGF treatment. Activation of the FGF signaling pathway also reduces the induction of an estrogen-responsive CAT reporter plasmid by estrogen, an effect which appears to be independent of serine 118 in the estrogen receptor, a MAP kinase target site. The inhibitory effects of FGF are probably mediated through the sustained induction of the cyclin kinase inhibitor p21/WAF1/CIP1, which is upregulated at the mRNA and protein level by FGF. FGF treatment also results in the phosphorylation of STAT1. This upregulation of p21 and phosphorylation of STAT1 is not detectable in T47D breast cancer cells upon which FGF has no inhibitory effect.

Breast Neoplasms↗
PubMed1996

Comparison of an automated enzyme immunoassay with a direct fluorescent antibody test and polymerase chain reaction for the detection of Chlamydia trachomatis in diagnostic specimens from male patients.

Endourethral swabs and first-pass urine (FPU) samples from 148 male patients were tested for Chlamydia trachomatis by an automated enzyme immunoassay (EIA) (Vidas; bioMérieux, France), a direct fluorescent antibody (DFA) test (MicroTrak; Syva, USA) and two polymerase chain reaction (PCR) methods. Chlamydia trachomatis was considered present if a specimen was positive by at least two methods. This expanded criterion identified 27 patients (18%) as truly infected. One of the PCR methods was most sensitive for both types of specimen. When the recommended cut-off value of Vidas was reduced by 50%, its sensitivity on endourethral swabs was comparable to that of the DFA test, but the DFA test performed better with FPU. In general, FPU was suitable only for PCR.

Chlamydia Infections↗
PubMed1996

Venus and Freud: an educational opportunity?

OBJECTIVE: To discuss the importance of genitourinary medicine as a core component for a new problem based medical undergraduate curriculum and to describe the advantages of consensus group method as a means of identifying learning objectives for an integrated course. METHODS: A group of experts in the field of sexual health was convened around the module on sexual health. It was led by a genitourinary specialist and aided by a curriculum facilitator. Group contributors represented a wide variety of disciplines and included a medical student. The group met on three occasions for 1.5 hours. RESULTS: The identified learning objectives are presented under the course themes. The values and relevance of the individual objectives are discussed with particular reference to an integrated curriculum which combines clinical and basic science in a problem based learning (PBL) format. The communication skills and attitudes necessary to take a competent sexual history are stressed. Links with other relevant modules in the PBL curriculum are described to show how the topic of sexual health develops throughout the course. Learning methods, resources and assessment procedures are also outlined. CONCLUSION: The educational potential of sexual health and behaviour as a core topic for a novel integrated course is considerable and merits a greater importance than it appears to receive in current undergraduate courses.

Education, Medical, Undergraduate↗
PubMed1995

A family planning intervention to reduce vertical transmission of HIV in Rwanda.

OBJECTIVES: Since contraception is an effective way of preventing the vertical transmission of HIV, we evaluated the impact of a family planning intervention on hormonal contraceptive use and incident pregnancy in a group of HIV-positive and HIV-negative urban Rwandan women. SUBJECTS AND METHODS: In a longitudinal cohort study, 502 women who were not pregnant or infertile and who had been previously HIV tested and counseled viewed an informational video about hormonal contraception followed by a facilitated discussion. They were given access to oral or injectable hormonal contraception and Norplant at the research clinic; those who used these methods were seen every 3 months. RESULTS: Of the 330 HIV-positive and 172 HIV-negative women who underwent the intervention, 120 either became new hormonal method users (n = 40), continued their previous use of a hormonal method (n = 64), or switched to another hormonal method (n = 16) following the intervention. There was a shift to use of longer lasting hormonal methods, and the annualized attrition rate was < 15%, compared to > 50% prior to the intervention. Rates of oral and injectable contraceptive use were similar among HIV-positive and HIV-negative women. Nine per cent of HIV-positive women became pregnant in the year after the intervention compared to 22% in a prior 12 month period when contraceptives were not provided at the study site. The corresponding proportions for HIV-negative women were 20% after the intervention versus 30% before the intervention. CONCLUSIONS: Access to and information about hormonal contraceptives resulted in increased use and reduced attrition among both HIV-positive and HIV-negative women in this study. The reduction in incident pregnancy was greatest among HIV-positive women, suggesting that factors other than access to hormonal contraceptives may have influenced fertility outcomes. Knowledge of HIV serostatus may have an important influence on family planning decisions.

Adolescent↗
PubMed1992

Gastrointestinal priming prior to full enteral nutrition in very low birth weight infants.

Priming of the gastrointestinal (GI) tract with low-volume feedings before giving full enteral feedings to very premature, high-risk infants is a controversial practice. We designed a study of infants weighing less than 1,250 g and receiving total parenteral nutrition to determine whether GI priming would hasten weight gain, improve tolerance of subsequent feedings, enhance nutritional status, and increase serum concentration of gastrin, a hormone trophic for intestinal growth. Infants were randomly assigned to receive total parenteral nutrition (TPN) alone (N = 21) or GI priming plus TPN (N = 19) for 12 days beginning on day 3 of life. Full-strength premature infant formula was used for priming. Both groups received the same total nutrition. Beginning on day 15, feedings in both groups were increased daily to a maximum of 120 kcal/kg/day on day 20, where they were maintained until day 30. After day 30, the feedings were modified according to the infants' condition. The groups did not differ in birth weight, gestational age, or 5-min Apgar scores. GI-primed infants had improved feeding tolerance after day 20 and a faster rise in serum gastrin during the initial phase of the study. There was no significant difference in weight gain. GI priming improves tolerance of feedings, accelerates rate of rise of serum gastrin during the first weeks of life, and does not increase the risk of feeding complications when compared to TPN alone. This may lead to more rapid maturation of the GI tract in primed infants.

Eating↗
PubMed1990

Scientifically-based strategies for nutrition of the high-risk low birth weight infant.

Technological advances in the intensive care of low birth weight (LBW) infants have resulted in major increases in their survival. New challenges in meeting their nutritional needs have emerged. Very low birth (VLBW) weight infants have very little body fat or glycogen reserves at birth, making them susceptible to starvation. If fed enterally, they require at least 120 calories/kg per day for growth. Numerous immaturities in the gastrointestinal tract and liver limit protein digestion, absorption, and metabolism. Several amino acids not considered essential to the older child or adult are essential to the VLBW infant. Supplying a high protein load with an inappropriate amino acid composition may lead to metabolic imbalances. The digestion and absorption of fats differs from the older child or adult. Lingual and gastric lipases are important, and the lack of bile acids limits fat absorption. Lipoprotein lipase deficiency causes problems when too much fat or fat of incorrect composition is provided. There are controversies regarding the most appropriate carbohydrate source, but research shows that lactose remains an important carbohydrate source for most of these infants. Calcium, magnesium, and phosphorus requirements pose questions in both enterally and parenterally nourished infants. Studies of iron usage suggest that VLBW infants fed either human milk or formula should receive iron supplements. Vitamin E may be helpful in preventing oxygen toxicity. Vitamin D deficiency contributes to bone demineralization and rickets. Controversy exists regarding the correlation between vitamin A nutrition and development of chronic lung disease. Guidelines have been developed for recommended intakes, but much needs to be learned to provide a sound scientific basis upon which to provide optimal nourishment for the high risk, LBW infant.

Enteral Nutrition↗
PubMedDate not supplied

Defining aggression.

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Aggression↗