Search PubMed⌕ Search

Biomedical subjects

D Foreman

Publications and source records attributed to D Foreman.

At least 37 records · Page 2Linked to original sources
PubMed1997

Cell attachment to, and contraction of, the retina in vitro.

PURPOSE: To examine the behavior of fibroblasts and retinal pigment epithelial cells after attachment to the retinal surface in vitro to elucidate the pathobiology of the early stages of epiretinal membrane formation. METHODS: Human retinal pigment epithelial (HRPE) cells and bovine Tenon's capsule fibroblasts (BTFs) were seeded onto the surface of bovine retinal explants maintained in organ culture. The changes induced in the underlying retina, including contraction, were assessed during a period of up to 10 days. Immunohistochemistry was used to assess proliferation of the seeded cells and to determine deposition of extracellular matrix. RESULTS: Explants of bovine neuroretina were maintained in organ culture, with good morphologic preservation of the inner limiting lamina and inner retinal layers, for 7 to 10 days. The HRPE cells and the BTFs attached to the retinal surface and exerted tractional forces, producing partial- and full-thickness retinal folding. Contraction commenced within 24 hours of attachment of the cells and continued for several days, with most of the contraction occurring within the next 48 to 72 hours. The HRPE cells and BTFs were found to be equally contractile. Deposition of cellular fibronectin (but not collagen type I) was demonstrated. CONCLUSIONS: The contractile cellular membranes generated in this organ culture system exhibit many of the morphologic and functional features of epiretinal membranes found in the early stages of proliferative vitreoretinopathy.

Adult↗
PubMed1996

The descriptive assessment for psychiatric art. A new way of quantifying paintings by psychiatric patients.

This pilot study reports the development of a coding system for quantitative analysis of paintings produced by psychiatric patients. Color, color intensity, quality of line, space covered, and subjectively judged emotional tone as characteristics of paintings were recorded in each section of a grid superimposed over the picture. A sample of 39 psychiatric patients were classified into 4 groups using ICD-10 criteria: depression, psychosis, brain injury, and drug abuse. Six independent raters achieved excellent reliability across all scales on each of eight pictures. Analysis of variance results show that each diagnostic group differed on 4 of 13 variables: yellow, orange, color intensity, and line (p < .02). The prospects for further research are discussed.

Adult↗
PubMed1996

Can one induce premenstrual symptomatology in women with prior hysterectomy and bilateral oophorectomy?

Nine women who had undergone hysterectomy and oophorectomy and who previously suffered from severe premenstrual syndrome (PMS) were given estrogen and progesterone in a naturalistic single-blind paradigm. The 13-item Beck Depression Inventory, Spielberger State Anxiety Inventory, Menstrual Distress Questionnaire and the Daily Ratings Form of the Premenstrual Assessment Form were all given daily. Estradiol and progesterone concentrations were estimated. When results from all subjects were considered together, these measures were not correlated with hormonal status. However, individual subjects showed correlations between some symptom scores and serum progesterone concentrations. We conclude that women diagnosed as having PMS do not respond in a uniform fashion to ovarian hormones. Further quantitative studies are needed to relate these individual differences to the syndrome of PMS.

Drug Therapy, Combination↗
PubMed1995

Inhibin is present in the corpus luteum of pseudopregnant rats and can interact with progesterone to inhibit resumption of estrous cycles.

The corpora lutea (CL) of ovaries of adult pseudopregnant (PSP) rats were stained by immunohistochemistry for inhibin alpha subunit using sheep alpha-chain1-27 antibody as a measure of inhibin content. Staining was light in estrous cycle CL (stage III), increased in Day 2 and Day 4 PSP CL and reached maximal density on day 6 PSP when both large cells and many small cells stained. Staining was decreased in CL from 8 and 10 day PSP. Granulosa cells of growing follicles showed light stain on days 8 and 10 of PSP. Adult female rats were treated for 5 days beginning at estrous cycle Stage III (cornified masses). In Experiment 1, three groups of rats were used: 1. implanted with 30mm progesterone capsules and injected with saline, 2. implanted with 30mm progesterone capsules and injected with 10 ng rh inhibin A daily, 3. implanted with empty capsules and injected with 10 ng rh inhibin A daily. Both groups of rats with progesterone implants had significantly slower return of cycling after removal of the capsules than did the rats injected with 10ng rh inhibin A alone. In Experiment 2, the same treatments were given except that 20ng of rh inhibin A (10ng 2x/day) was given to both inhibin treatment groups. Rats treated with progesterone and 20ng inhibin had a significantly slower return of cyclic activity (4.4 days) over that found in the other two treatment groups. We conclude that the absence of cyclic activity in PSP rats is possibly due to the secretion of both inhibin and progesterone by the CL.

Animals↗
PubMed1994

Cytochrome P-450 levels of immature rat ovaries during early follicular development: quantification, cellular and subcellular distribution, enzymatic activity and response to FSH in vivo and in vitro.

Absolute values of cytochrome P-450 (cyt. P-450) content were determined by dual beam spectrophotometry in mitochondrial and microsomal fractions of granulosa cells and stroma (theca and interstitial cells) obtained from ovaries of immature rats treated with diethylstilbestrol (DES) or with DES and FSH. Cholesterol side-chain cleavage activity and aromatase activity were also measured in relevant cell fractions. The cyt. P-450 content in the granulosa cell mitochondria was significantly increased in FSH-treated animals (cyt.P-450 in nmols/mg protein, mean +/- SE: DES-treated 0.027 +/- 0.00213, N = 9; DES/FSH-treated 0.0668 +/- 0.0120, N = 13, P = 0.014). The increased cyt. P-450 content was associated with an increase in cholesterol side-chain cleavage activity confirming the functional relevance of the spectrophotometric measurements. The increase in cyt. P-450 content in stroma after FSH treatment was not statistically significant but there was a significant increase in cholesterol side-chain cleavage activity. The cholesterol side-chain cleavage activity of intact granulosa cells from secondary follicles of DES-treated rats was significantly stimulated by in vitro exposure to FSH during 2 hr assay incubations. A significant cyt. P-450 content was detected in the microsomal fraction of granulosa cells from DES-treated rats which was not associated with aromatase activity. Granulosa cell microsomal cyt. P-450 content was not significantly altered by in vivo FSH treatment despite a dramatic increase in aromatase activity of such microsomal preparations.

Animals↗
PubMed1993

Diabetes prevents the normal responses of the ovary to FSH.

FSH in vitro stimulates increased oxygen uptake by isolated follicular granulosa cells from immature rats treated with diethylstilbestrol (DES) when substrates are present (glucose, glutamate, pyruvate or fumerate) or are completely absent. However, when glucose is the only substrate or when any single substrate is omitted from the buffer, FSH has no effect. FSH in vitro also increases the uptake of glucose and the formation of 14CO2 from [1-6 14C]-glucose. Granulosa cells from diabetic immature rats treated with DES did not show increased oxygen uptake with in vitro FSH. Diabetic cells had similar receptor binding of FSH to that of control non-diabetic cells. The addition of both insulin and FSH in vitro to buffer with diabetic granulosa cells gave increased oxygen uptake over that of control cells from diabetic rats. The insulin stimulation of oxygen uptake by FSH in cells from diabetic rats was not duplicated by either epidermal growth factor (EGF) or insulin-like growth factor I (IGF-1). Follicle counts of ovaries from diabetic and control immature rats treated with DES showed increased atresia in the diabetic ovaries after only 44 hr. of diabetes. Follicle counts of ovaries from adult diabetic rats showed increased atresia in 24 hours after induction of diabetes at proestrus. Follicle counts of pseudopregnant rats showed increased atresia by 3 days after diabetes was induced. We conclude that diabetes prevents normal follicle growth stimulated either by exogenous DES or by endogenous hormones secreted during proestrus.

Animals↗
PubMed1992

Evidence that the prostaglandin E2 receptor and the anhydrolevuglandin E2 receptor in the rat uterus are the same receptor.

Anhydrolevuglandin E2 (AnLGE2) is closely related to prostaglandin E2 (PGE2) and has been found to inhibit the uterotonic activity of PGE2. The binding of PGE2 and its inhibition by AnLGE2 has been determined in rat uterine membrane fractions. AnLGE2 inhibited the binding of 3HPGE2 in a dose related fashion. 3HAnLGE2 also binds to rat uterine membrane fractions and its binding is inhibited by PGE2 in a dose related fashion. These data support previous physiological observations that AnLGE2 inhibits the actions of PGE2 by acting at the PGE2 receptor. Thus, AnLGE2 appears to be a specific inhibitor of PGE2 actions at its uterine receptors.

Animals↗
PubMed1992

Physiological evidence for the possible existence of anhydrolevuglandin E2-like activity in extracts and media from uteri of rats.

Physiological evidence is presented for the possible existence of anhydrolevuglandin E2-like activity in extracts of uteri from diestrous rats and after treatment of adult rats with estradiol and progesterone. The extracts were able to inhibit contractions in rat uterine preparations stimulated by PGE2. Uteri of vaginal Stage 3 (metestrus) were quiescent and showed decreased responsiveness to PGE2 and PGF2 alpha. These uteri showed some contractility when incubation medium from diestrous uteri (Stage 5) were transferred to them and incubation medium from them inhibited the contractility of Stage 5 uteri. When incubation media were exchanged between contractile uteri from of stages other than Stage 3, there was no change in the contraction patterns. Taken together, we believe these data indicate that AnLGE2 may be a normal constituent of the rat uterus and is physiologically increased during Stage 3 (metestrus) of the estrous cycle.

Animals↗
PubMed1990

31P nuclear magnetic resonance (NMR) identification of sugar phosphates in isolated rat ovarian follicular granulosa cells and the effects of follicle-stimulating hormone.

Immature female rats (23-30 days old) were implanted subcutaneously with diethylstilbestrol (DES) in silastic capsules. After 48 h their ovaries were removed and the granulosa cells isolated (Foreman et al. (1984) Life Sci. 35, 1273-1279). The cells were incubated in Hepes balanced saline buffer with substrates with or without follicle-stimulating hormone (FSH). At the end of incubation perchloric acid extracts were made for 31P NMR spectroscopy. The resonances of fructose 1-phosphate, fructose 6-phosphate, glucose 1-phosphate, and ribose 5-phosphate were identified in the granulosa cell extracts. The relative intensities of fructose 6-phosphate to ribose 5-phosphate decreased after incubation with FSH in vitro. This suggests that FSH increases the activity of the pentose pathway within 1 h. Thus, FSH can acutely activate those metabolic pathways which provide nicotinamide-adenine dinucleotide phosphate (NADPH) to be used in steroid synthesis and cholesterol mobilization.

Animals↗
PubMed1990

Locomotion, active choice, and spatial memory in children.

In two studies, children between 4 and 6 years old were tested on a radial search task requiring nonredundant sampling of eight identically labeled positions in a room. In the training phase (5 days), children made free choices by walking between positions, were passively transported in a pushchair, actively directed their own route from a pushchair, or were led on foot to positions selected by the experimenter. When tested (whether walking or directing while seated in a pushchair), children who had either walked independently or directed the experimenter while being pushed performed competently; those led on foot without spatial choice performed almost as well. Only the children who had neither independent locomotor experience nor autonomous choice performed very poorly. The results are related to neurobiological models of spatial cognition and may have implications for the transportation of children with mobility problems.

Child, Preschool↗
PubMed1988

Anhydrolevuglandin D2 inhibits the uterotonic activity of prostaglandins F2 alpha and D2.

Anhydrolevuglandin D2 (AnLGD2), which is produced from PGH2 by a water-induced rearrangement and subsequent dehydration, is uterotonic. However, increasing concentrations caused decreased responses of the uterine horns. AnLGD2 inhibited responses of uteri to stimulation by specific prostaglandins. PGF2 alpha was inhibited at an AnLGD2:PGF2 alpha ratio of 0.05:1 with 5 to 25 pg/ml concentrations of PGF2 alpha. The response to PGD2 was inhibited at an AnLGD2:PGD2 ratio of 0.05:1 with PGD2 concentrations of 5 to 75 pg/ml. In contrast, the uterotonic effects of PGE2 were not inhibited by AnLGD2. When AnLGD2 was added to baths with contracting uteri it inhibited contractions less if the exposure period was 5 min than if it was 10 min. The longer exposure times produced prolonged inhibition of contractile activity with bath concentrations of AnLGD2 as little as 2.5 pg/ml.

Animals↗
PubMed1987

Effects of E2 levuglandins on the contractile activity of the rat uterus.

The effects of E2 levuglandins on the contractile activity of rat uterine horns were studied. LGE2, AnLGE2, delta 9-LGE2 and the synthetic epimer, 8-epi-delta 9-LGE2 all induced contractions in a dose-response fashion. AnLGE2 gave decreased responses with increased bath concentrations. Paired comparisons showed potent and selective inhibitory effects of AnLGE2 on the uterotonic activity of prostaglandins. AnLGE2 inhibited the uterotonic activity of PGE2 at a 0.1:1 ratio, of PGD2 at a 1:1 ratio, but did not inhibit the activity of PGF2 alpha. Exposure of spontaneously contracting uteri to high concentrations of AnLGE2, or prolonged exposure to lower concentrations, suppressed contractions.

Animals↗
PubMed1987

Management of neurosurgical problems in pregnancy.

The effects of pregnancy on neurosurgical disease are complex and require a detailed knowledge of physiology, anatomy, and pharmacology. The following article details the pathophysiology and treatment of the more common disorders of the nervous system seen during pregnancy.

Adult↗
PubMed1984

The effects of gonadotropins on metabolism of isolated rat granulosa cells.

FSH in vitro, but not LH, increased the O2 uptake of isolated granulosa cells from 23 day old rats previously treated with DES or with DES and FSH. Dose response studies showed that the cells were most sensitive to FSH when the cellular binding of FSH was highest. LH increased the O2 uptake of granulosa cells of untreated 30 day old rats. DES treatment inhibited the LH induced rise in O2 uptake when the rats were implanted with DES capsules unless FSH was injected to induce LH receptors. Addition of dbcAMP in vitro increased O2 uptake of granulosa cells from 30 day old rats at concentrations 10X lower than those required to stimulate O2 uptake in cells from 23 day old rats treated with DES alone.

Animals↗
PubMed1984

Plasma progesterone levels and corpus luteum morphology in the female prairie dog (Cynomys ludovicianus).

Plasma progesterone levels in female prairie dogs were determined by a radioimmunoassay specific for progesterone. Plasma progesterone levels were determined in samples taken before estrus, at estrus, during the luteal phase, and during anestrus from females maintained all year in the laboratory. Progesterone levels were also determined in plasma samples taken in the laboratory from two pregnant and three postparturient females captured in the field. Progesterone levels were low before estrus and continued low during estrus. They rose on the first week after estrus to 0.8 ng/ml or above and continued at or above this level for 9-14 weeks following estrus. Gestation in prairie dogs is 35 days in this species. Progesterone levels of three postparturient females were above 1.0 ng/ml for 7 weeks after their arrival in the laboratory. These females all had uterine scars showing that they had delivered their litters before they were captured. Two females were determined to be pregnant at the time of their capture. These females later reabsorbed their fetuses (determined by laparotomy). Progesterone values of samples from these females were all above 1.0 ng/ml except for one low value in one female which occurred 3 weeks after her capture and after reabsorption of her fetuses was in progress. The cells of the corpus lutea (CL) of nonpregnant, pregnant, and postparturient females had well-developed rings of cytoplasmic basophilia but as the CL regressed this pattern became disorganized and disappeared. The function of this basophilia is not known. The long luteal phase found in female prairie dogs is compared to those found in other species of mammals. This is the first annually breeding rodent reported to have a longer luteal phase that the period of gestation.

Animals↗
PubMed1984

Follicular growth and atresia during the last half of the luteal phase of the guinea pig estrous cycle: relation to serum progesterone and estradiol levels and utero-ovarian blood flow.

The relationships among follicular growth, changes in serum progesterone (P) and estradiol (E) levels, and utero-ovarian blood flow (OBF) through the guinea pig ovary were examined during days 7-16 of the luteal phase (day 0 = estrus) of the estrous cycle and during the subsequent ovulatory (proestrous-estrous) period. Follicles were classified as either viable or atretic based on strict criteria and grouped according to diameter. No changes in follicular growth were observed between days 7-9 of the cycle when serum P levels were elevated and OBF was at low rates. Between days 13-15 when serum P levels were low and both OBF and serum E levels were rising, there was a dramatic increase in the number of viable follicles present in all follicle classes. As the percentage of viable follicles increased, the number of atretic follicles in each size population decreased. Peaks in the number of large follicles (300-450 microns), OBF, and serum E levels were observed during the subsequent ovulatory period. These data suggest that as luteal activity declines during the last half of the estrous cycle, follicular recruitment and growth are stimulated. The concomitant elevations in OBF suggest a supportive role for this parameter in follicular development. In turn, the subsequent elevation in serum E levels serves as an index of follicular maturation. These data suggest that the elevated P levels during the luteal phase of the estrous cycle may either directly or indirectly, through the regulation of gonadotropin secretion, regulate follicular growth in the guinea pig.

Animals↗