The effect of epidermal growth factor in human granulosa cells varies with follicle size

The distribution of the zot gene that encodes the zonula occludens toxin, a newly described toxin of Vibrio cholerae, among clinical, environmental and food isolates of V. cholerae 01 and non-01 was investigated. Both the zot gene and the ctx gene that encode cholera toxin were found in 247 of 257 clinical strains and 62 of 415 environmental or food isolates of V. cholerae 01. The zot gene, but not the ctx gene was found in 37 strains (one clinical strain and 36 environmental or food isolates). In addition, two of 31 clinical strains and six of 98 environmental or food isolates of V. cholerae' non-01 possessed both the zot gene and the ctx gene. These results demonstrated the predominantly concurrent occurrence of the zot gene and ctx genes among strains of V. cholerae 01 which suggests a possible synergistic role of ZOT in the causation of acute dehydrating diarrhea produced by V. cholerae 01.     

The effect of recombinant follicle stimulating hormone (Gonal-F) on endogenous luteinizing hormone secretion in women

Parenteral administration of follicle stimulating hormone (FSH) has been shown to lower luteinizing hormone (LH) concentrations in women undergoing ovulation induction. This study was designed to explore the physiological mechanism of this effect. Seven healthy women were recruited into a double-blind placebo-controlled study. LH secretion, after the administration of variable i.v. boluses (37.5, 75 and 150 IU) of recombinant FSH (Gonal-F), was evaluated. LH was measured at 10 min intervals for 2 h before and 4 h after the FSH/placebo infusion. LH pulse frequency and amplitude were evaluated and there was no significant difference between control and trial cycles for each subject. A linear regression analysis revealed that in the group receiving 150 IU FSH, the mean plasma LH concentration decreased significantly due to a reduction tonic LH secretion. This could be a result of the suppression of secretion or an alteration of clearance. This decrease was not seen in the other dosage groups, revealing that above a dosage threshold, FSH reduced non-pulsatile LH secretion. Therefore the effect of FSH in this study exposed the likely presence of two components of LH concentration: an FSH-sensitive, non-pulsatile tonic secretion and a gonadotrophin-releasing hormone-stimulated, pulsatile release that is unaffected by FSH. Although an indirect effect involving ovarian regulation is not excluded, the rapidity of the effect suggests that FSH acts directly on the pituitary gland.     

Follicle stimulating hormone alone supports follicle growth and oocyte development in gonadotrophin-releasing hormone antagonist-treated monkeys

Both follicle stimulating hormone (FSH) and luteinizing hormone (LH) are proposed requirements for follicular growth and steroidogenesis; however, the role of LH in primate folliculogenesis is unclear. Follicular stimulation by recombinant human FSH (n = 5) with and without recombinant LH (1:1; n = 6) following 90 days of gonadotrophin-releasing hormone (GnRH) antagonist (Antide) treatment in macaques was evaluated. Human chorionic gonadotrophin (HCG) was administered when six follicles > or = 4 mm were observed. Oocytes were aspirated 27 h later and inseminated in vitro. Chronic Antide reduced serum oestradiol and bioactive LH to concentrations observed in hypophysectomized rhesus monkeys. Multiple follicular growth required a longer interval following recombinant FSH (12 +/- 1 days) than recombinant FSH+recombinant LH (9 +/- 0.2 days), but the total number of follicles/animal did not differ between groups. The day prior to HCG, oestradiol concentrations were 4-fold less following recombinant FSH compared to recombinant FSH+recombinant LH. With recombinant FSH, more oocytes completed meiosis to metaphase II (51%) and fertilized (89 +/- 5%) relative to recombinant FSH+recombinant LH (12 and 52 +/- 11% respectively). Follicular growth and maturation in LH-deficient macaques occurred with FSH alone. Thus, LH is not required for folliculogenesis in primates. Higher fertilization rates following follicular stimulation with FSH alone suggest that the presence of LH with FSH (1:1) during the pre-ovulatory interval impairs gametogenic events in the periovulatory period.     

Effect of growth hormone administration on circulating levels of luteinizing hormone, follicle stimulating hormone and testosterone in normal healthy men

A new area of growth hormone (GH) therapy in adults is the treatment of infertility. The aim of this study was to evaluate the effects of pharmacological GH administration on the secretion of pituitary and gonadal hormones in normal men. Eight healthy men, 23-32 years of age (mean 28.1 years), with a normal body mass index were studied in a double-blind, placebo-controlled crossover design. All participants had a normal semen analysis before entering the study. Each participant was treated with placebo and GH (12/IU/day, Norditropin; Novo Nordisk, Denmark) during two different 14-day periods, separated by a 6 week washout period. Administration of GH for 14 days resulted in a significant increase in serum insulin-like growth factor I (IGF-I; P < 0.01) but no changes occurred in IGF-I values during placebo treatment. The concentrations of follicle stimulating hormone and luteinizing hormone displayed no change during the two periods and did not differ between the GH treatment period and the placebo period. The concentration of testosterone was unchanged during the placebo/GH periods and there was no difference between the GH treatment period and the placebo period. We conclude that GH treatment for 14 days in normal healthy men does not affect gonadotrophin or testosterone patterns.     

The effect of indomethacin on the secretion of human salivary epidermal growth factor

The first case of cutaneous lymphatic sporotrichosis from Nagaland and a case of cutaneous sporotrichosis from Kerala who had acquired infection from Assam are reported. The diagnosis in both cases were established by isolating Sporothrix schenckii from multiple cutaneous lesions. The dimorphic nature of fungus was established in vitro by demonstrating the mycelial phase at 25-30 degrees C and yeast phase at 37 degrees C and pathogenicity to white mice. Both the patients were successfully treated with oral administration of potassium iodide for 3 months.     

The effect of epidermal growth factor on the growth potential of epithelial cells from human lens

The growth promoting effect of epidermal growth factor (EGF) was studied in cultures of epithelial cells from human normal and cataractous lenses. The growth potential of lens epithelial cells was measured by MTT assay. The concentration of EGF in culture medium were classified into 7 groups (0 ng/ml-10(3) ng/ml). When the concentration of EGF was 1 ng/ml, EGF induced the highest increase of growth potential epithelial cells compared with an EGF-free group.     

Meiotic and developmental competence of mouse antral oocytes

Mouse antral oocytes show two different patterns of chromatin organization, defining oocytes with or without chromatin surrounding the nucleolus (SN: surrounded nucleus; NSN: not surrounded nucleus). We have previously shown that upon injection of eCG, NSN antral oocytes shift towards the SN kind of chromatin organization. We hypothesized that these newly formed SN oocytes were those that would have been ovulated after an ovulatory stimulus. The main objective of this study was to investigate the meiotic and developmental competence of these two types of oocytes. SN and NSN antral oocytes were isolated after i.p. administration of eCG + hCG or eCG-only, in vitro-cultured until completion of metaphase II, and inseminated with capacitated spermatozoa; and their development to the 4-cell stage was examined. This study demonstrates 1) that SN and NSN oocytes isolated after injection of eCG + hCG are capable of embryonic development, but not beyond the 2-cell stage; and 2) that SN and NSN oocytes isolated after injection of eCG-only are capable of developing to the 2-cell stage, but a significantly higher number (11.9%) of SN oocytes than NSN oocytes (1.5%) reach the 4-cell stage. SN- and NSN-like oocytes have also been described in the antral compartment of human, rat, monkey, pig, and bovine ovaries. The findings reported in this paper may contribute to improved procedures for in vitro fertilization of humans and farm animals.     

The effect of gonadotrophin releasing hormone and follicle stimulating hormone in conjunction with pregnant mare serum gonadotrophin on the superovulatory response in crossbred sheep in India

The effectiveness of triple-marker testing as screening for Down syndrome needs to be evaluated by means of formal meta-analytic techniques. We did a MEDLINE search to identify studies evaluating the detection of Down syndrome by use of the triple-marker test. Reference lists of articles were also checked. Papers published in either English, French, or German from 1966 to November 1996 were eligible for this review. Twenty cohort studies were identified. Results of sensitivities and false-positive rates from different subgroups of the study sample were compared by using summary receiver-operating characteristic curve analysis. Medians of sensitivities and false-positive rates were also estimated. A total of 194,326 patients were included. In women of all ages, the medians for sensitivities were 67, 71, and 73 percent when the cutoffs used were 1:190-200, 1:250-295, and 1:350-380, respectively. The median false-positive rates fluctuated between 4 and 8 percent. For women at or above 35 years old, the medians of sensitivity and false-positive rate were 89 and 25 percent, respectively, when the chosen cutoff was 1:190-200. In patients below 35 years old, the median sensitivity was 57 percent if the cutoff used was 1:250-295. Summary receiver-operating characteristic curves showed that 1:190 was the best cutoff for predicting Down syndrome. The triple-marker testing is an effective screening method of detecting Down syndrome pregnancies. It is less effective in younger than in older age groups and may be offered as an alternative to amniocentesis to pregnant women over 35.     

Developmental potential of embryos produced by in-vitro fertilization from gonadotrophin-releasing hormone antagonist-treated macaques stimulated with recombinant human follicle stimulating hormone alone or in combination with luteinizing hormone

We previously demonstrated, in luteinizing hormone (LH)-deficient macaques, that follicular growth and maturation occurred with administration of exogenous (recombinant human) follicle stimulating hormone (r-hFSH) alone, and that the oocytes recovered fertilized at a notably higher rate than their counterparts from animals receiving both r-hFSH and r-hLH (Zelinski-Wooten et al., 1995). Here, the developmental potential of embryos produced from animals treated with r-hFSH alone or in combination with r-hLH was evaluated. Embryos (n = 127) were cryopreserved, thawed and either co-cultured on buffalo rat liver cells until the hatched blastocyst stage or transferred to synchronized recipients. Although embryos from each treatment group demonstrated a similar ability to develop to hatched blastocysts with a definitive inner cell mass, a significant difference was seen in cryosurvival (56 versus 78%) and in developmental rate to the hatched blastocyst (12 versus 10 days) between embryos from the r-hFSH alone and the combination group respectively. Pregnancies resulted following oviductal embryo transfers in both groups, with corpus luteum rescue occurring on days 12-16 of the luteal phase. In summary, r-hFSH alone during the pre-ovulatory interval is adequate for the gametogenic events required to produce embryos that develop either in vitro or in vivo; however, exposure to r-hLH may improve embryo viability and the rate of development.     

The 24-hour rhythms in plasma growth hormone, prolactin and thyroid stimulating hormone: effect of sleep deprivation

Twenty-four hour secretory rhythms of growth hormone (GH), prolactin (PRL) and thyroid stimulating hormone (TSH) were investigated in 9 normal adult men by means of serial blood sampling at 30 min intervals. The profiles of pituitary hormones were compared in 6 subjects between in normal nocturnal sleep condition and in delayed sleep condition. Plasma GH was measured with use of highly sensitive enzyme immunoassay (EIA) recently developed. Plasma TSH was also evaluated by highly sensitive time-resolved fluorometric immunoassay (TR-FIA). Time series analysis of plasma GH and PRL was performed by auto- and cross- correlation and spectral analysis. The detection limit of EIA for GH was 0.3 pg/ml and all plasma GH levels were within the detectable range of this EIA. Cross-correlation and spectral analysis suggested the presence of approximately 2-3 h rhythmicity of plasma GH. Plasma PRL appeared to have some 24-hour rhythmicity besides its sleep-dependent component. Sleep deprivation caused marked elevation of plasma TSH during night time. It is suggested that there appears two mechanisms regulating GH secretion: one has a sleep-independent and ultradian rhythm and another has a sleep-dependent rhythm.     

The effect of portal hypertension on transforming growth factor-alpha and epidermal growth factor receptor in the gastric mucosa of rats

BACKGROUND: The physical activity levels of US children are declining. Opportunities for physical activity within city schools are constrained by time and space limits. This study determined whether a supplemental program of physical activity would significantly alter the fitness levels of low-income, minority, urban elementary schoolchildren. METHODS: Ninety-nine students from two Cleveland Public Schools served as subjects. One school received a 15-week intervention program where teams of two medical students met with urban elementary schoolchildren three times a week for physical activity sessions. The other school served as a control and received no supplemental activity other than a regularly scheduled physical education class held once a week. We obtained field measurements of skinfold thickness, heart rate response to submaximal exercise, and sit and reach flexibility. RESULTS: The supplemental activity group showed significant improvements in flexibility, body composition, and heart rate response to submaximal exercise. CONCLUSIONS: This investigation indicates that a program of fitness activities conducted within the classroom can significantly improve levels of fitness in urban elementary schoolchildren.     

Immunocytochemical localization of transforming growth factor alpha, epidermal growth factor and epidermal growth factor receptor in the cat endometrium and placenta

Hoxb-5 is one of the few homeobox genes strongly expressed in the developing mouse lung. To explore the hypothesis that Hoxb-5 acts to regulate epithelial cell fate and branching morphogenesis in the developing lung, we studied the temporal, spatial, and cell-specific expression of Hoxb-5 from gestational day (d) 13.5 to postnatal day (P) 2. Immunocytochemistry demonstrated regional localization of Hoxb-5 protein to developing conducting airways and surrounding mesenchyme. The cellular expression pattern changed from diffusely positive nuclei of mesenchymal cells on d13.5 to become more localized to nuclei of subepithelial fibroblasts and some adjacent columnar and cuboidal epithelial cells on d14.5. After d14.5, Hoxb-5 protein expression continued to decrease in mesenchymal cells distal from developing airways, but persisted in fibroblasts underlying conducting airways. Hoxb-5 protein expression persisted in nuclei of columnar and cuboidal epithelial cells on d16.5 and d17.5, with expression in low cuboidal epithelial cells as well from d17.5 to P2. Western blot analysis showed temporal and quantitative changes in Hoxb-5 protein expression with peak expression on d14.5-15.5. We conclude that Hoxb-5 protein is developmentally regulated in a temporal, spatial, and cell-specific manner throughout the pseudoglandular, canalicular, and terminal saccular periods of lung development in the mouse. This localization and expression pattern suggests that Hoxb-5 may influence branching morphogenesis, cell-cell communication, cell fate, and differentiation of conducting airway epithelia.     

Plasma levels of estrogen, luteinizing hormone, and follicle stimulating hormone following castration and estradiol implant

Plasma levels of luteinizing hormone, follicle stimulating hormone, and estrogen were studied serially in 20 patients before and after hysterectomy and bilateral salpingo-oophorectomy. Ten patients received an implant of estradiol-17 beta (100 mg) at the time of operation. Ten patients who did not receive an implant acted as controls. Patients recorded the severity of vasomotor symptoms before and after hysterectomy. In those patients who did not receive an implant, plasma estrogen levels fell from a mean preoperative level of 18.1 +/- 10.4 ng/100 ml to 8.7 +/- 1.4 ng/100 ml by 24 hours after oophorectomy and they remained in this range for the 6 months of the study. No significant change in the plasma estrogen level was noted after oophorectomy in those patients who received an implant. The implant prevented the rise in gonadotropin levels and the appearance of vasomotor symptoms seen in those patients who underwent oophorectomy without an implant. Insertion of an implant into oophorectomized patients caused the plasma estrogen level to return to premenopausal levels within 2 weeks and the gonadotropin levels to premenopausal values within 6 weeks. Hot flashes were alleviated within 2 to 6 days. The usefulness of this type of therapy in preventing the appearance of vasomotor symptoms at the time of oophorectomy in premenopausal patients is confirmed.     

The neurotrophic action and signalling of epidermal growth factor

Epidermal growth factor (EGF) is a conventional mitogenic factor that stimulates the proliferation of various types of cells including epithelial cells and fibroblasts. EGF binds to and activates the EGF receptor (EGFR), which initiates intracellular signalling and subsequent effects. The EGFR is expressed in neurons of the cerebral cortex, cerebellum, and hippocampus in addition to other regions of the central nervous system (CNS). In addition, EGF is also expressed in various regions of the CNS. Therefore, EGF acts not only on mitotic cells, but also on postmitotic neurons. In fact, many studies have indicated that EGF has neurotrophic or neuromodulatory effects on various types of neurons in the CNS. For example, EGF acts directly on cultured cerebral cortical and cerebellar neurons, enhancing neurite outgrowth and survival. On the other hand, EGF also acts on other cell types, including septal cholinergic and mesencephalic dopaminergic neurons, indirectly through glial cells. Evidence of the effects of EGF on neurons in the CNS is accumulating, but the mechanisms of action remain essentially unknown. EGF-induced signalling in mitotic cells is better understood than that in postmitotic neurons. Studies of cloned pheochromocytoma PC12 cells and cultured cerebral cortical neurons have suggested that the EGF-induced neurotrophic actions are mediated by sustained activation of the EGFR and mitogen-activated protein kinase (MAPK) in response to EGF. The sustained intracellular signalling correlates with the decreased rate of EGFR down-regulation, which might determine the response of neuronal cells to EGF. It is likely that EGF is a multi-potent growth factor that acts upon various types of cells including mitotic cells and postmitotic neurons.     

Interaction between adrenaline and epidermal growth factor in the control of liver glycogenolysis in mouse

Epidermal growth factor (EGF) stimulates glycogenolysis in mouse liver, but the effect requires concentrations that are only achieved in plasma upon adrenergic stimulation of EGF release from submandibular salivary glands. Thus, we studied the interaction between adrenaline and EGF in liver glycogen metabolism, both in whole animals and in isolated hepatocytes. Adrenaline administered to anesthetized mice stimulated both the endocrine secretion of EGF from submandibular salivary glands and the degradation of glycogen in the liver. In sialoadenalectomized mice, adrenaline administration did not increase plasma EGF concentration. In these animals, the glycogenolytic response to adrenaline was enhanced. The sensitivity of hepatocytes to adrenaline was similar in cells from sialoadenalectomized and sham-operated mice. EGF, added to isolated hepatocytes, reduced the glycogenolytic effect of adrenaline (the maximal effect but not the ED50). Adrenaline stimulated glycogen degradation through both an alpha1-adrenergic mediated Ca2+ increase and a beta-adrenergic-mediated cAMP increase. EGF did not interfere with the rise of cytosolic Ca2+ but decreased the cAMP signal. EGF did not decrease the glycogenolytic effect of phenylephrine or VP (which increased cytosolic Ca2+ but not cAMP), but EGF decreased both the glycogenolytic effect and the cAMP signal generated by glucagon or forskolin. EGF did not interfere with the glycogenolytic effect of CPT-cAMP or bt2-cAMP. The effect of EGF on cAMP was blocked by 3-isobutyl-1-methylxanthine. These results demonstrate that the effect of EGF on the glycogenolytic action of adrenaline involves interference with the generation of the cAMP signal. We suggest that EGF induces such an effect through the activation of a phosphodiesterase.     

The effect of epidermal growth factor and transforming growth factor beta 1 on proliferation and differentiation of urothelial cells in urinary bladder explant culture

The presence of the virulence markers K1 capsule, serum resistance, aerobactin, S and P/PR fimbriae were examined in a total of 395 E. coli strains from different extraintestinal infections and in 81 faecal isolates of healthy volunteers using specific DNA probes and classical phenotypic methods. All markers were more frequently detected when genotypic assays were applied. The simultaneous occurrence of 3-4 virulence determinants was typical for isolates derived from patients with septicaemia or meningitis. Isolates from blood cultures and cerebrospinal fluid were expressing the virulence phenotypes to a greater extent than isolates from urine or faeces. The use of colony hybridization with specific oligonucleotide and polynucleotide probes for the detection of virulence determinants has been proven to be more specific and reliable than phenotypic approaches.     

Histological evaluation of endometrium on the day of oocyte retrieval after gonadotrophin-releasing hormone agonist-follicle stimulating hormone ovulation induction for in-vitro fertilization

The objective of this study was to evaluate the histopathological characteristics of endometrial biopsies taken on the day of oocyte recovery in in-vitro fertilization (IVF) cycles with a satisfactory response to ovulation induction. A group of 33 patients who went through ovulation induction for IVF, and in whom an endometrial polyp was suspected on transvaginal ultrasonography during the monitoring phase, were studied. Following oocyte recovery, hysteroscopy, polypectomy and endometrial curettage were performed. Dating of endometrial glands and stroma was carried out in the tissue not containing the polyps. The total dose of follicle stimulating hormone (FSH), duration of ovulation induction, peak oestradiol and luteinizing hormone (LH) concentrations, thickness of endometrium and number of oocytes were recorded and compared to the endometrial dating of the specimens. In 15 cycles (45.5%), the endometrium was classified as 'in phase' (group I), 'advanced' by 2-4 days in a further 15 (45.5%, group II), and in the remaining three cycles (9%) it was delayed in maturation (group III). Younger age was correlated with advanced staging of the endometrium (r = -0.42; P = 0.015). Women with 'in phase' and 'advanced' maturation were similar in their response to ovulation induction; however, there was a strong correlation between advanced dating of endometrium and number of oocytes retrieved (r = 0.49; P = 0.04). Endometrial staging on the day of oocyte retrieval varied widely in patients treated by the same gonadotrophin-releasing hormone agonist (GnRHa)/FSH protocol for ovulation induction. This difference was not predictable by parameters monitored through the cycles.