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Biomedical subjects

C Bergh

Publications and source records attributed to C Bergh.

At least 73 records · Page 4Linked to original sources
PubMed1995

Effect of recombinant human gonadotrophins on oocyte meiosis and steroidogenesis in isolated pre-ovulatory rat follicles.

In order to study the effects of recombinant human luteinizing hormone (LH) and recombinant follicle stimulating hormone (FSH) on the pre-ovulatory follicle, immature pregnant mare's serum gonadotrophin-treated rats were used. Follicles were isolated by dissection and incubated for 4 h in medium 199 containing different concentrations of the gonadotrophins. In control medium the follicle-enclosed oocytes remained arrested in prophase I, but in the presence of recombinant human LH or recombinant human FSH, a concentration-dependent increase in the proportion of oocytes which underwent germinal vesicle breakdown (GVB) was seen. The lowest effective concentration of recombinant human LH was 10-50 ng/ml, and at 1000 ng/ml 97% of the oocytes underwent GVB. Recombinant human FSH was also effective, albeit slightly less so than recombinant human LH. Follicular oestradiol accumulation was stimulated up to 5-fold, both gonadotrophins showing similar effectiveness. Follicular progesterone and testosterone accumulation was markedly stimulated by recombinant human LH, giving a maximal 20-fold and 15-fold increase respectively. A 5-fold stimulation of progesterone production was found with recombinant human FSH. When submaximal concentrations of recombinant human LH and recombinant human FSH were combined, an additive effect was found on oocyte meiosis and on oestradiol and progesterone accumulation. The results are in agreement with previous studies using pituitary gonadotrophin and show that both recombinant human LH and recombinant human FSH have intrinsic effects on oocyte meiosis and steroidogenesis. It is likely that in the physiological situation in vivo, both gonadotrophins contribute to regulate these events in the peri-ovulatory period.

Animals↗
PubMed1994

Adjuvant growth hormone treatment during in vitro fertilization: a randomized, placebo-controlled study.

OBJECTIVES: To explore the effect of recombinant, human GH on follicular development and oocyte retrieval after gonadotropin stimulation with the addition of GH or placebo to a standard IVF treatment regimen. Further, to investigate whether GH is a more effective adjuvant if the standard treatment regimen is preceded by GH injections. DESIGN: A randomized, double-blind, parallel, placebo-controlled study. SETTING: The IVF unit at university hospital. PATIENTS: Forty normally ovulating women, age 25 to 38 years, with infertility because of tubal factors and being classified as "poor responders" with at least two previously performed and failed IVF attempts. INTERVENTIONS: Human, recombinant GH (Genotropin, Kabi Pharmacia, Uppsala, Sweden) or placebo (0.1 IU/kg body weight per day) was given SC as pretreatment during down regulation with GnRH and during stimulation with hMG according to the randomized protocol. MAIN OUTCOME MEASURES: Number of oocytes retrieved after stimulation, total amount of gonadotropin used, time required for stimulation, number of follicles developing, rate of fertilization, and cleavage in vitro. Further, the quality of embryos, development of the endometrium, rate of clinical pregnancy, and serum and follicular fluid (FF) concentrations of insulin-like growth factor I (IGF-I), insulin-like growth factor binding protein-1 (IGFBP-1), and IGFBP-3 were estimated. RESULTS: The number of oocytes retrieved did not differ significantly between the groups, nor did the amount of hMG required for stimulation. The fertilization rate increased in patients who had received GH. Growth hormone caused a significant increase in serum and FF levels of IGF-I. An increase in serum IGFBP-3 could also be recorded in patients who had received GH. CONCLUSION: Although certain beneficial effects were noted in GH-treated patients, the overall results did not support GH as a clinically useful adjuvant treatment.

Adjuvants, Pharmaceutic↗
PubMed1993

Regulation of androgen production in cultured human thecal cells by insulin-like growth factor I and insulin.

OBJECTIVES: To investigate if human thecal cells contain messenger ribonucleic acid (RNA) encoding insulin-like growth factor I (IGF-I) and insulin receptors and if IGF-I and insulin could stimulate androgen production in thecal cells. DESIGN: Poly-adenine+ RNA was extracted from fresh thecal tissue, and the expression of the genes encoding insulin and IGF-I receptors were analyzed. Isolated thecal cells were cultured 4 to 6 days with and without hormones. SETTING: Procedures were performed in a university laboratory. PATIENTS: Eight women in the follicular phase of natural cycles were undergoing gynecological laparotomy for reasons unrelated to ovarian pathology. The leading follicle(s) was excised, and dispersed cells of the theca interna layer were isolated through combined mechanical and enzymatic techniques. INTERVENTIONS: Luteinizing hormone (LH), IGF-I, and insulin were added to the cell cultures. MAIN OUTCOME MEASURE: The expression of IGF-I receptor and insulin receptor transcripts were analyzed by Northern blot. Medium levels of androstenedione and testosterone were measured by radioimmunoassay. RESULTS: In the separated thecal tissue both IGF-I receptor and insulin-receptor transcripts were detected. Insulin-like growth factor I and insulin potentiated LH-induced androgen secretion while having less pronounced effects on basal androgen production. CONCLUSION: The present study demonstrates that both insulin and IGF-I receptor genes are expressed and that insulin and IGF-I can stimulate steroid production in human thecal cells. The study provides further support for the hypothesis that IGF-I and insulin may be involved both in physiological regulation of ovarian function as well as in its pathophysiology.

Androgens↗
PubMed1993

Steroid production in cultured thecal cells obtained from human ovarian follicles.

During follicular maturation there is a co-ordinated hormonal regulation of the theca and granulosa cells. It is generally believed that granulosa cell proliferation and differentiation are promoted mainly by follicle stimulating hormone (FSH) and that luteinizing hormone (LH) regulates the function of the theca cells. The aim of the present study was to examine the effect of LH/human chorionic gonadotrophin (HCG) on steroid production in human thecal cells. Isolated follicles (5-20 mm) were obtained during the follicular phase of the menstrual cycle in 10 women undergoing gynaecological laparotomy for reasons unrelated to ovarian pathology. The leading follicle(s) was excised and dispersed cells of the theca interna layer were isolated through combined mechanical and enzymatic techniques. The thecal cells were cultured 4-6 days with and without LH/HCG. Medium levels of androstenedione, testosterone and progesterone were measured by radioimmunoassay. Isolated thecal cells, cultured for 6 days, showed a high sensitivity to stimulation by LH/HCG. Steroid secretion was highest during days 0-2 and then declined gradually. LH/HCG stimulated steroid production in a dose-dependent way with the maximal stimulatory effect of LH at a concentration of 1-10 ng/ml, and of HCG at 0.01-0.1 IU/ml. The important question, especially in clinical situations, of the optimal level of LH for normal follicular maturation, remains to be answered. The present study is compatible with the view that thecal cell steroidogenesis in vivo is close to maximally stimulated by normal basal LH levels.

Cells, Cultured↗
PubMed1992

Height, body mass index and mortality: do social factors explain the association?

The aim of the study was to analyse the effects on mortality of body height and body mass index (BMI) in young men, taking into account social and behavioural characteristics in early youth. The study is a 20-year follow-up of all Swedish men (n = 50,465) conscripted for military service in 1969-70. Baseline data on body height and weight as well as interview and questionnaire data on social and behavioural characteristics were linked to mortality data up to the end of 1988. Nine hundred and forty-six men died during the follow-up. We found a significant increase in mortality by decreasing body height; persons below 165 cm had an almost twofold increased mortality compared with those of average height. This association was reduced to the limit of statistical significance when we controlled for social and behavioural characteristics in a multivariate model. Persons with a BMI above 30 had a more than twofold increased mortality compared with those of average BMI. This association remained highly significant in a multivariate model. We thus confirmed previous findings of an inverse association between body height and mortality, but found that this association was almost entirely due to social background factors. The independent association between BMI and mortality may indicate a stronger genetic influence on BMI than on body height.

Adult↗
PubMed1992

Insulin-like growth factor-I stimulates amino acid accumulation in cultured human granulosa cells.

In order to study the effect of insulin-like growth factor (IGF)-I on amino acid transport, granulosa-luteal cells were obtained from stimulated cycles in women undergoing in-vitro fertilization. The cells were precultured for 1-3 days in serum-containing medium. The medium was then changed to serum-free with added IGF-I and/or human chorionic gonadotrophin (HCG). Following 24 h culture, the cellular uptake of [14C]alpha-aminoisobutyric acid AIB (0.1 mM, 0.6 mCi/ml) was studied during a 2-6 h incubation. The results showed that IGF-I (10-100 ng/ml) consistently stimulated AIB uptake to levels which were 44 +/- 7% above the control (n = 11 experiments). The stimulatory effect of IGF-I was abolished by HCG and was reduced by IGF-binding protein. In conjunction with previous findings that IGF-I stimulates the uptake and incorporation of thymidine into DNA, these results suggest that IGF-I is involved in growth of human granulosa-luteal cells.

Amino Acids↗
PubMed1992

Expression of functional growth hormone receptors in human granulosa cells.

Both clinical and experimental evidence suggest that growth hormone may be of importance for ovarian function. The present study investigated whether growth hormone receptors are expressed in human granulosa cells. Granulosa cells were isolated either from natural cycles or from stimulated cycles in the course of in-vitro fertilization. Total RNA hybridized with a 32P-labelled rat growth hormone receptor cRNA probe revealed one major transcript with an estimated size of 4.5 kb and one minor transcript with an estimated size of 1.3 kb. Biotinylated growth hormone was used to analyse growth hormone binding. Competitive growth hormone binding was detected in freshly isolated granulosa cells, as well as in cultured cells. Growth hormone augmented basal and/or follicle stimulating hormone-stimulated steroidogenesis in granulosa cells obtained from patients with natural cycles, but the response to growth hormone stimulation showed considerable variation. We conclude that functional growth hormone receptors are present in human granulosa cells and that growth hormone, therefore, may have an important role in ovarian function.

Analysis of Variance↗
PubMed1992

Sonographic evaluation of the endometrium in in vitro fertilization IVF cycles. A way to predict pregnancy?

The endometrial thickness and echogenic pattern were prospectively evaluated in 100 patients undergoing IVF-treatment. On the day before oocyte aspiration (day-1) the endometrium was significantly thicker in the group of patients achieving an ongoing pregnancy than in the group that failed to conceive. The minimal endometrial thickness on day-1 compatible with an ongoing pregnancy was 9 mm. Before oocyte aspiration two different endometrial patterns could be distinguished, a multilayered, 'triple line', hypoechogenic endometrium (A) and an isoechogenic pattern (B). Other studies have, in addition, described a hyperechogenic endometrium with a poor pregnancy rate but that pattern could in the present study only be demonstrated after follicle aspiration, 32 clinical pregnancies occurred. Among patients with endometrial pattern A, 36% conceived and among patients with pattern B 23% conceived which was not significantly different. It is concluded that the day before aspiration an endometrial thickness of at least 9 mm appears to be required for an ongoing pregnancy. In all cases a triple line (hypo-or isoechogenic) pattern was evident before aspiration.

Adult↗
PubMed1991

Effects of insulin-like growth factor I and growth hormone in cultured human granulosa cells.

Human granulosa cells, obtained either from natural or stimulated cycles, were cultured, and the response to IGF-I and GH was analyzed. It was found that IGF-I alone stimulated thymidine incorporation in both types of granulosa cells. Furthermore, IGF-I alone and in combination with FSH or LH enhanced estradiol and progesterone production. In a limited series of experiments, GH in combination with FSH was found to stimulate steroidogenesis in granulosa cells obtained from natural, but not from stimulated, cycles.

Adult↗
PubMed1991

Effect of insulin-like growth factor I on steroidogenesis in cultured human granulosa cells.

The effect of IGF-I on steroidogenesis in human granulosa cells was studied. Granulosa cells were obtained from follicles of both natural and stimulated cycles. The cells were cultured 4 to 6 days and the effect of IGF-I (1 to 100 micrograms/l) on basal, LH- and FSH-stimulated steroidogenesis was studied. It was found that in granulosa cells from follicles of natural cycles, FSH as well as IGF-I significantly stimulated progesterone and estradiol production in a majority of the experiments. A synergistic effect of FSH and IGF-I could be seen when low (1 and 10 micrograms/l) concentrations of the two hormones were used. Also in granulosa luteal cells from stimulated cycles a stimulatory effect of IGF-I on estradiol as well as progesterone production was observed. The present results suggest that IGF-I in combination with gonadotropins has a physiological role in the human follicle in controlling differentiation of the granulosa cells.

Adult↗
PubMed1990

K-Cl cotransport in LK sheep erythrocytes: kinetics of stimulation by cell swelling.

The effects of osmotic cell swelling were studied on the kinetics of Cl-dependent K+ influx, K-Cl cotransport, in erythrocytes from sheep of the low K+ (LK) phenotype. Swelling approximately 25% stimulated transport by increasing maximum velocity (Jmax) approximately 1.5-fold and by increasing apparent affinity for external K (Ko) nearly twofold. Dithiothreitol (DTT) was shown to be a partial, reversible inhibitor of K-Cl cotransport. It inhibited in cells of normal volume by reducing Jmax more than twofold; apparent affinity for Ko was increased by DTT, suggesting that DTT stabilizes the transporter-Ko complex. Cell swelling reduced the extent of inhibition by DTT: Jmax was inhibited by only about one-third in swollen cells, and apparent affinity was only slightly affected. This result suggested that DTT does not act directly on the transporter, but on a hypothetical regulator, an endogenous inhibitor. Swelling relieves inhibition by the regulator, and reduces the effect of DTT. Reducing intracellular Mg2+, Mgc, stimulated cotransport. Swelling of low-Mg2+ cells stimulated transport further, but only by raising apparent affinity for Ko nearly threefold: Jmax was unaffected. Thus effects of swelling on Jmax and apparent affinity are separable processes. The inhibitory effects of Mgc and DTT were shown to be additive, indicating separate modes of action. There appear to be two endogenous inhibitors: the hypothetical regulator, which holds affinity for Ko, low; and Mgc, which affects Jmax, perhaps by holding some transporters in an inactive form. Swelling stimulates transport by relieving both types of inhibition.

Animals↗
PubMed1989

[Short-term survival in severe acute pancreatitis. Role of peritoneal lavage and conservative surgery].

We evaluated the results of peritoneal lavage and conservative surgery in 64 consecutive patients with severe acute pancreatitis, 73.4% of patients had associated cholelithiasis. Early resective surgery, specially in patients with necro-hemorrhagic pancreatitis and respiratory failure, was associated to a high mortality. Peritoneal lavage was started earlier in survivors and was effective in decreasing pain and amylase levels, but not in correcting hypoxemia. 29% of patients died in shock, which developed early and was mostly toxic in patients older than 50 as opposed to septic in younger patients. Actuarial survival rate was 50% at 1 month. Poor risk factors included admission after 48 hr, resective surgery, age greater than 50 years and failure to use peritoneal lavage.

Actuarial Analysis↗
PubMed1985

Effect of nicotine on passive avoidance behaviour and motoric activity in mice.

In this study the effect of different doses of nicotine (0.125; 0.250; 0.500 mg/kg) on motoric activity in mice was tested by a T-maze model both during dark and light phase of the diurnal cycle. Low doses of nicotine (0.125 mg/kg; 0.250 mg/kg) increased motoric activity during the day. During the dark phase no stimulation was seen. A higher dose of nicotine (0.500 mg/kg) decreased motoric activity both during dark and light phase of the diurnal cycle. A positive effect on retention time in a passive avoidance model was observed when mice were pretreated with 0.125 mg/kg nicotine. No significant effect was observed with 0.500 mg/kg nicotine. Thus, a low dose of nicotine which increases motoric activity also seem to have a positive effect on learning/memory mechanisms studied by a passive avoidance behaviour model.

Animals↗