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Biomedical subjects

T M Price

Publications and source records attributed to T M Price.

At least 19 recordsLinked to original sources

Fulminant hepatic failure due to herpes simplex after hysteroscopy.

BACKGROUND: Fulminant hepatic failure due to herpes simplex in healthy adults is a rare condition with a high mortality rate. The lack of specific symptoms and the absence of typical herpetic lesions in a majority of cases contribute to delayed diagnosis. CASE: We describe a fatal case of fulminant hepatic failure due to herpes simplex in a healthy woman presenting after laparoscopy and hysteroscopy for tubal infertility. The patient lacked evidence of mucocutaneous lesions or jaundice. The surgery likely contributed to viral dissemination. CONCLUSION: Although rare, disseminated herpes should be considered a possible cause of postsurgical pelvic infections, even in the absence of ulcerative lesions. Until a definitive diagnosis is made, antiviral therapy should be considered in patients with high fever, leukopenia, and abnormal liver function.

Adult↗

Differential transcriptional activation of peroxisome proliferator-activated receptor gamma by omega-3 and omega-6 fatty acids in MCF-7 cells.

While the role of dietary fats in breast cancer remains controversial, the recent cloning of peroxisome proliferator-activated receptor gamma (PPARgamma), a nuclear hormone receptor, from human breast cancer cells lines provides a potential molecular link. Several fatty acids from four classes of dietary fats were tested for their ability to mediate the transcriptional activity of PPARgamma in MCF-7 and MDA-MB-231 cells using growth media with minimal serum. Whereas omega-3 fatty acids inhibit transactivation of PPARgamma to levels below control, omega-6, monounsaturated and saturated fatty acids stimulate the activity of the transcriptional reporter. These studies indicate that individual fatty acids differentially regulate the transcriptional activity of PPARgamma by selectively acting as agonists or antagonists. Furthermore, the transcriptional activation of PPARgamma correlates with cell proliferation in MCF-7 cells. Understanding the effects of individual fats on breast cancer cells and PPARgamma transactivation could provide important new insights into the epidemiology of breast cancer and the role of dietary fat.

Base Sequence↗

Presence of leptin in breast cell lines and breast tumors.

Leptin is the product of the ob gene, reported to be secreted exclusively from adipocytes and thought to control satiety by providing information to the central nervous system. However, the function of leptin appears to be more complex because multiple studies demonstrate its role in hematopoiesis, reproduction, and immunity. In addition, several nonadipose sources of leptin have been reported. The purpose of this study was to examine several breast cancer cell lines and ductal carcinomas of the breast for expression of leptin messenger RNA (mRNA) and protein. For tumor studies, specimens were preassayed for contaminating adipose tissue. Northern blot analyses demonstrated leptin mRNA in several breast cancer cell lines (MCF-7, T47D, and MDA-MB-231), a normal breast epithelial cell line (MCF10A), and four breast tumors. Leptin protein was identified in T47D breast cancer cells by indirect immunofluorescent staining and in samples of the same breast tumors used for Northern studies by enzyme-linked immunosorbent assays (ELISA). This preliminary study suggests that leptin is expressed in malignant epithelial cells of the breast. Further investigation is needed to determine whether this protein plays a role in breast carcinogenesis.

Adipose Tissue↗

Control of air quality in an assisted reproductive technology laboratory.

OBJECTIVE: To investigate the effect of improved air quality on IVF and subsequent embryo development. DESIGN: Retrospective cohort study. SETTING: Hospital-based IVF facility composed of an anteroom, a cleanroom, and an adjacent operating room. PATIENT(S): Two-hundred seventy-five couples requesting IVF between 1993 and 1997. INTERVENTION(S): None. MAIN OUTCOME MEASURE(S): Particle counts (sizes 0.3, 0.5, 1.0, and 5.0 microm); IVF rates; and embryo quality (stage and grade). RESULT(S): Clinical pregnancy rates decreased from 35% in 1993 to 16% in 1994 (numerous construction odors were detected during 1994) and increased steadily after the cleanroom was built (rates for 1995-1997 were 20%, 32%, and 59%, respectively). Fertilization rates decreased between 1993 (74%) and 1994 (60%) and then steadily increased after cleanroom installation (62% in 1995, 71% in 1996, and 69% in 1997). The proportion of embryos past the four-cell stage decreased from 66% in 1993 to 61% in 1994 but then increased steadily in the years after the cleanroom was built (78%, 77%, and 83% in 1995, 1996, and 1997, respectively). During the same 5-year period, there were no differences in embryo quality or number of embryos transferred. CONCLUSION(S): Construction of a Class 100 cleanroom improved air quality and IVF rate and increased the number of embryos past the four-cell stage available for transfer.

Adult↗

Estrogen regulation of adipose tissue lipoprotein lipase--possible mechanism of body fat distribution.

OBJECTIVE: The purpose of this study was to evaluate the regulation of lipoprotein lipase activity, protein mass, and messenger ribonucleic acid by estradiol. STUDY DESIGN: Premenopausal women not taking exogenous sex steroids had transdermal 17 beta-estradiol and placebo patches placed in the gluteal region during the early follicular phase of the menstrual cycle. Adipose biopsies were performed from beneath the patches. Adipose tissue lipoprotein lipase activity was determined by a radiometric assay, protein mass was determined by enzyme-linked immunosorbent assay, and messenger ribonucleic acid level was determined by Northern analysis. Comparisons between the treated and placebo sides were analyzed by nonparametric statistics. RESULTS: Adipose tissue from beneath the 17 beta-estradiol patch had significantly decreased lipoprotein lipase activity and extracellular protein mass than did adipose tissue from beneath the placebo patch. There was no difference in lipoprotein lipase messenger ribonucleic acid levels. CONCLUSION: Estrogen decreases lipoprotein lipase activity by a posttranscriptional modification of protein levels. A hypothesis of sex steroid regulation of body fat distribution is proposed.

Adipose Tissue↗

Validity and cost-effectiveness of antisperm antibody testing before in vitro fertilization.

OBJECTIVE: To determine the usefulness of and cost-effectiveness of antisperm antibody testing in the prediction of poor fertilization rates in couples undergoing IVF. DESIGN: Retrospective cohort study. SETTING: A hospital-based reproductive endocrinology and infertility practice. PATIENT(S): Male partners of 251 couples undergoing IVF between 1992 and 1997. MAIN OUTCOME MEASURE(S): Fertilization rates in couples undergoing conventional IVF. RESULT(S): One hundred nineteen couples were evaluated for antisperm antibodies; fertilization rates were similar in those couples whose husbands were and were not tested (64% versus 68%). Antisperm antibodies were detected in 16 men. Four (25%) of the 16 couples whose husbands had antisperm antibodies fertilized < or = 50% of oocytes, compared with 31 (30%) of the 103 couples whose husbands did not have these antibodies. Overall, 21 couples (8.4%) experienced complete fertilization failure. In a program that included antisperm antibody testing for selected couples and intracytoplasmic sperm injection (ICSI) for those who tested positive, it would cost $11,735 to prevent a fertilization failure (assuming ICSI were 100% effective), whereas it would cost $9,250 to perform ICSI in a second IVF cycle for those who initially failed. CONCLUSION(S): In this practice setting, antisperm antibody testing has low sensitivity in predicting low or no fertilization and does not appear to be cost-effective when selectively ordered as part of an IVF workup.

Adult↗

Identification of progesterone receptor in human subcutaneous adipose tissue.

Sex steroids are postulated to play a role in adipose tissue regulation and distribution, because the amount and location of adipose tissue changes during puberty and menopause. Because of the nature of adipose tissue, receptors for the female sex steroids have been difficult to demonstrate. To date, estrogen receptor messenger RNA and protein have been identified in human subcutaneous adipose tissue, but the presence of progesterone receptor (PR) has not been reported. In this study, we demonstrate PR message by Northern blot analysis in RNA isolated from the abdominal subcutaneous adipose tissue of premenopausal women. These preliminary studies revealed that PR messenger RNA levels are higher in the stromal-vascular fraction as opposed to the adipocyte fraction. Western blot analysis demonstrates both PR protein isoforms (human PR-A and human PR-B) in human subcutaneous adipose tissue. Using an enzyme-linked immunosorbent assay, total PR could be quantitated. These studies substantiate that sex steroid receptors are present in human adipose tissue, thereby providing a direct route for regulation of adipose tissue by female sex steroids.

Abdomen↗

MCF-7 and T47D human breast cancer cells contain a functional peroxisomal response.

Peroxisome proliferator-activated receptors (PPARs) are ligand-activated nuclear receptors that regulate transcription of target genes. Since attempts have been made to correlate the ingestion of high-fat diets, itself a peroxisome proliferator, with the occurrence of breast cancer, we set about to determine if human breast cancer cells contained a functional PPAR. In this report we demonstrate the presence of an mRNA in two breast cancer cell lines (MCF-7 and T47D) which is specifically recognized by a mouse PPARgamma2 probe. Furthermore, in gel shift assays a consensus PPAR response element (PPRE) was specifically bound by nuclear extracts from MCF-7 cells and was further retarded by antibodies raised to mouse PPARgamma. Finally, when transfected with a PPRE-luciferase transcriptional reporter construct, transcription was increased in response to activators of PPAR and its dimmeric partner the retinoic acid X receptor (RXR). These data indicate that peroxisomal proliferators are capable of mediating transcription in human breast cells and suggest the possibility of a physiological role in the breast.

Blotting, Northern↗

Single-dose pharmacokinetics of sublingual versus oral administration of micronized 17 beta-estradiol.

OBJECTIVE: To investigate the pharmacokinetic profiles of different doses of micronized 17 beta-estradiol administered by oral or sublingual routes. METHODS: Single doses of micronized 17 beta-estradiol were administered orally (1 mg, 0.5 mg) or sublingually (1 mg, 0.5 mg, 0.25 mg) to six postmenopausal women in a randomized clinical trial. We calculated pharmacokinetic parameters for estradiol (E2) and estrone (E1) of maximum serum concentration, time to maximum serum concentration, terminal half-life, area under the concentration curve, and oral clearance. Serum levels of E1 sulfate also were compared at 4, 12, and 24 hours after dosing. RESULTS: Sublingual administration resulted in rapid absorption with significantly higher E2 levels than did comparable oral dosing. Estrone levels did not vary with route of administration but correlated with the dosage administered. Estrone sulfate levels correlated with the dosage administered and also tended to be higher with sublingual administration. Sublingual administration resulted in a significantly lower E1 to E2 ratio during the 24 hours than did oral administration. CONCLUSION: Sublingual administration of micronized 17 beta-estradiol results in a rapid, burst-like absorption into the systemic circulation, yielding high E2 levels that fall rapidly over the first 6 hours.

Administration, Oral↗

Differences in the estrogen content of breast adipose tissue in women by menopausal status and hormone use.

OBJECTIVE: To determine the levels of free estrone (E1) and estradiol (E2) in breast adipocytes of premenopausal women, premenopausal women using oral contraceptives (OCs), postmenopausal women, and postmenopausal women using estrogen replacement therapy (ERT). METHODS: Breast adipose tissue was obtained from 36 premenopausal and 29 postmenopausal women, and adipocytes were separated from stromal and epithelial cells through collagenase digestion and centrifugation. Oil was rendered from adipocytes, and E1 and E2 levels were measured by specific radioimmunoassays after extraction with methanol-water. RESULTS: Estrone and E2 levels were approximately 2.4- and 7.8-fold higher, respectively, in premenopausal women than in postmenopausal women. In premenopausal women, E1 and E2 correlated with the time since last menses (R2 = .55 and .62, respectively), whereas in postmenopausal women, E1 and E2 correlated with body mass index (BMI) (r = .48 and .52, respectively). Estrone levels were always greater than E2 levels in adipocytes, with the E1/E2 ratio being 2.7-fold higher in postmenopausal women than in premenopausal women. The use of OCs decreased E1 and E2 levels in premenopausal women, and ERT increased levels in postmenopausal women. CONCLUSION: Free estrogen in breast adipocytes is characterized by E1 dominance, with levels in premenopausal women correlating with the menstrual cycle and levels in postmenopausal women correlating with BMI.

Adipocytes↗

Relationship between adipose stromal-vascular cells and adipocytes in human adipose tissue.

OBJECTIVE: To determine the relative amounts of RNA and DNA from adipocytes and adipose stromal-vascular cells to better assess differential gene expression for estrogen receptor and cytochrome P450 aromatase in the two cell fractions of adipose tissue. STUDY DESIGN: Colorimetric and fluorometric assays were used to measure total RNA and DNA, and the relative cell numbers as well as the relative contribution of RNA from adipocytes and stromal-vascular cells were assessed. RESULTS: Adipocytes and stromal-vascular cells exist in a ratio of 2/1. RNA/DNA ratios are the same in the two cell fractions. CONCLUSION: In human subcutaneous adipose tissue, adipocytes are twice as numerous as stromal-vascular cells. The overall transcriptional activity of the cell types appears similar.

Adipocytes↗

Ablation of luteal phase symptoms of Menière's disease with leuprolide.

Symptoms of Menière's disease in women may be exacerbated during the luteal phase of the menstrual cycle. This suggests a role for progesterone production and subsequent fluid redistribution as a predisposing factor for Menière's symptoms. We report the use of leuprolide acetate, a gonadotropin-releasing hormone agonist, in a woman with cyclic Menière's symptoms. This drug, which abolishes gonadotropin-dependent ovarian sex steroid production, alleviated the patient's symptoms during therapy. This observation offers further support to the hypothesis of sex hormone-related exacerbations of Menière's symptoms and provides a possible future treatment option for this debilitating disease.

Adult↗

Single- and multiple-dose pharmacokinetics of a low-dose oral contraceptive in women with chronic renal failure undergoing peritoneal dialysis.

OBJECTIVE: Our purpose was to compare the pharmacokinetic parameters of oral administration of a 35 micrograms ethinyl estradiol, 1 mg norethindrone pill in peritoneal dialysis patients and normal women. STUDY DESIGN: A single-dose study was performed with five patients and four controls, followed by a multiple-dose study with five subjects in each group. Pharmacokinetic parameters were calculated by noncompartmental analysis and statistical analysis performed with Mann-Whitney U testing. RESULTS: There is no difference in the pharmacokinetic parameters for norethindrone in peritoneal dialysis patients compared with normal women. During multiple dosing an increased area under the concentration curve and decreased apparent oral clearance was observed for ethinyl estradiol in peritoneal dialysis patients compared with normal women. CONCLUSION: Peritoneal dialysis patients have decreased apparent oral clearance of ethinyl estradiol, leading to slightly higher serum concentrations compared with women with normal renal function. The clearance of norethindrone is the same in peritoneal dialysis patients and normal women.

Adult↗

Determination of estrogen receptor messenger ribonucleic acid (mRNA) and cytochrome P450 aromatase mRNA levels in adipocytes and adipose stromal cells by competitive polymerase chain reaction amplification.

Clinical evidence suggests that sex hormones affect adipose tissue metabolism and deposition. To investigate the biosynthesis and possible action of estrogen in adipose tissue, we report the use of competitive, specific polymerase chain reaction amplifications to determine levels of estrogen receptor (ER) messenger RNA (mRNA) and cytochrome P450 aromatase mRNA in adipocytes and adipose stromal cells. This extremely sensitive technique uses coamplification of a homologous animal species complementary RNA to control for differences in amplification efficiencies. The DNA amplification products are identified by Southern hybridization with species-specific radiolabeled oligonucleotide probes. Abdominal adipose tissue obtained from female patients during elective abdominoplasty was separated by collagenase digestion and centrifugation into floating adipocytes and pelleted adipose stromal cells. Our results demonstrate higher ER mRNA levels in adipocytes compared to adipose stromal cells, whereas cytochrome P450 aromatase mRNA levels are higher in adipose stromal cells compared to adipocytes. The finding of ER mRNA in adipose tissue suggests the presence of the ER in adipose tissue. In addition the inverse correlation of ER mRNA and cytochrome P450 aromatase mRNA levels in adipocytes and adipose stromal cells suggests a paracrine relationship whereby estrogen produced by adipose stromal cells affects adjacent adipocytes.

Adipocytes↗

A link between breast cancer and local estrogen biosynthesis suggested by quantification of breast adipose tissue aromatase cytochrome P450 transcripts using competitive polymerase chain reaction after reverse transcription.

C19 steroids are converted to estrogens in a number of tissues by a specific form of cytochrome P450, namely aromatase cytochrome P450 (P450arom). Adipose tissue is the principal site of estrogen formation in postmenopausal women. Aromatase activity as well as P450arom transcripts primarily reside in the stromal cell component of the adipose tissue. Studies designed to investigate whether increased local aromatase activity in breast adipose tissue influences the growth of breast cancers have yielded discrepant results. In an attempt to clarify this controversy, adipose tissue was obtained from the four breast quadrants at the time of mastectomy (n = 13) performed for removal of a tumor. Breast fat P450arom messenger RNA levels were quantified and compared between the four quadrants within each specimen using competitive polymerase chain reaction after reverse transcription in which 10 micrograms human adipose total RNA together with 1 pg rat complementary RNA (internal standard) were reverse transcribed and coamplified. In 9 out of 13 patients (69%), highest P450arom transcript levels colocalized to the quadrants bearing tumors. This correlation was statistically significant (P < 0.001). The regional distribution of P450arom transcripts in breast adipose tissue of disease-free individuals, obtained during reduction mammoplasty (control group, n = 9), did not favor any particular region of the breast. We also quantified by morphometry the histological components of the adipose tissue samples from each quadrant in mastectomy specimens. The distribution of stromal cells significantly correlated with the distribution of P450arom transcript levels, in that quadrants containing highest proportions of stromal cells matched to highest transcript levels (P < 0.01). Although the quadrants bearing tumors contained the highest percentage of stromal cells, this correlation was not statistically significant. The adipose tissue surrounding a breast tumor displays increased estrogen biosynthesis, which may promote tumor growth. It is further suggested that the distribution of stromal cell components in breast adipose tissue gives rise to locally elevated P450arom expression, which in turn may favor neoplastic development and growth in these predisposed areas of the breast. The correlation between the presence of a tumor and elevated P450arom levels in the proximal adipose tissue is independent of tumor size, node involvement, histological type or grade, estrogen/progesterone receptor status, DNA index, or S-phase fraction.

Adipose Tissue↗