Peptide-induced T cell receptor down-regulation on naive T cells predicts agonist/partial agonist properties and strictly correlates with T cell activation

Recent experiments defining T cell agonists, partial agonists and antagonists have suggested that the T cell can discriminate between subtle differences in interactions leading to T cell activation. To further understand the complexities of T cell activation, we have analyzed the requirements for the induction of a variety of effector functions using naive T cells and a variety of altered peptide ligands. Using a strong agonist peptide, massive T cell receptor (TCR) down-regulation correlated with a wide range of effector functions that were all induced above the same threshold peptide concentration. Interestingly, the kinetics of TCR down-regulation correlated with the concentration of the peptide, whereas the maximal degree of TCR down-regulation correlated with the induction of all monitored effector functions. A selected group of altered peptide ligands was also examined that were able to render target cells susceptible for lysis by effector cytotoxic T lymphocytes. The extent of TCR down-regulation induced by these peptides corresponded to the induction of a subset of effector functions. These studies have shown that the extent of TCR down-regulation defines the strength of TCR-mediated "signal 1" which correlates with the spectrum of effector functions activated within the T cell. Thus, activation of different T cell functions requires the triggering of distinct numbers of TCR. The different parameters that influence TCR down-regulation define important distinctions between our results and previously reported findings with T cell clones and may outline decisive parameters for the consequences of T cell activation in vivo.     

Comparative neuroprotective properties of the benzodiazepine receptor full agonist diazepam and the partial agonist PNU-101017 in the gerbil forebrain ischemia model

A high-performance liquid chromatographic method has been developed for the determination of propiverine hydrochloride (P4) and its main metabolite, propiverine N-oxide (P4NO) in human serum. P4 has been shown to be efficacious in those patients who have either idiopathic bladder instability, or neurogenic bladder (detrusor hyperflexia) resulting from spinal cord injuries. In the present method, the analytes were extracted from serum (1 ml, pH 8) into methyl tert.-butyl ether. The separation was performed on a reversed-phase C8 (RP-select B) column using phosphate buffer-acetonitrile (30:70, v/v). UV absorption was used for measuring the analytes, with a limit of quantitation of about 10 ng/ml, which is appropriate for pharmacokinetic studies.     

Comparative effects of the selective estrogen receptor modulators (-)-, (+)- and (+/-)-Z bisdehydrodoisynolic acids on metabolic and reproductive parameters in male and female rats

Doisynolic acids are non-steroidal estrogenic compounds originally obtained from alkali fusion of estrone and equilenin. Z-bisdehydrodoisynolic acids (Z-BDDA) exhibit a low binding affinity accompanied by a disproportionately high biologic activity. Two experiments were designed to investigate the chronic effects of (+)-, (-)- and (+/-)-Z-BDDA and (+)-17beta-estradiol (E2) in male and female rats. The (+)-, (-)- and (+/-)-forms Z-BDDA were prepared and injected, daily for four to six weeks into male and female rats and changes in body weight, food intake, metabolic parameters, and reproductive parameters were investigated. Results from both experiments demonstrate that in male and female rats, (+)- and (+/-)-Z-BDDA had similar estrogenic effects on reproductive organ weight. Surprisingly, (-)-Z-BDDA did not induce the increase in uterine weight observed with (+)- and (+/-)-Z-BDDA and E2, demonstrating selective estrogen receptor modulation (SERM). Beneficial metabolic effects, although compound- and gender-specific, included a significant weight repression, reduction in cholesterol, reduction in blood glucose, and positive alterations in body fat distribution. Future research defining the optimal dosages of (-)-Z-BDDA that will maximize beneficial effects and minimize undesirable effects on reproductive tissues will lead to more efficacious treatment options for endocrine-responsive conditions in males and females.     

Steady-state methadone effect on generalized arousal in male and female mice.

Methadone is widely used in treatment of short-acting opiate addiction. The on-off effects of opioids have been documented to have profound differences from steady-state opioids. The authors hypothesize that opioids play important roles in either generalized arousal (GA) or aversive state of arousal during opioid withdrawal. Both male and female C57BL6 mice received steady-state methadone (SSM) through osmotic pumps at 10 or 20 mg/kg/day, and GA was measured in voluntary motor activity, sensory responsivity, and contextual fear conditioning. SSM did not have any effect on those GA behaviors in either sex. Females had higher activity and less fear conditioning than males. The effects of SSM on stress-responsive orexin gene expression in the lateral hypothalamus (LH) and medial hypothalamus (MH, including perifornical and dorsomedial areas) were measured after the behavioral tests. Females showed significantly lower basal LH (but not MH) orexin mRNA levels than males. A panel of GA stressors increased LH orexin mRNA levels in females only; these increases were blunted by SSM at 20 mg/kg. In summary, SSM had no effect on GA behaviors. In females, SSM blunted the GA stress-induced LH orexin gene expression. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The effect of diabetes on sexual behavior and reproductive tract function in male rats

As part of a study of the diversity of myosins, we have cloned a cDNA encoding a myosin-like protein from Arabidopsis thaliana. This is the first molecular motor of any kind to be cloned from a higher plant. The predicted polypeptide (molecular weight 131 kDa) has a motor domain (head) very similar to those of other myosins, but the remainder of the sequence is unusual. The tail contains four potential calmodulin binding sites ("IQ-motifs"), but no sequence motifs suggestive of actin or phospholipid binding, like those found in other myosins. There is also a small region of probable alpha-helical coiled-coil, which suggests that the molecule could be dimeric, though unlikely to form filaments. The N-terminal and C-terminal regions of the molecule are unique. We present a phylogenetic analysis of myosin head sequences, which suggests that this is a new type of myosin.     

Effect of fasting and immobilization stress on estrogen receptor immunoreactivity in the brain in ovariectomized female rats

The present study examined the effect of 48-h fasting and 1-h immobilization on estrogen receptor immunoreactivity in selected hypothalamic areas and the nucleus of the solitary tract (NTS) in ovariectomized rats. Fasting induced an increase in ER-immunoreactive cells in the paraventricular nucleus (PVN), periventricular nucleus (PeVN) and NTS compared with the unfasted control group. Similarly, immobilization caused an increase in ER-positive cells in the same areas, PVN, PeVN and NTS, versus the non-immobilized group. There was no significant increase in the number of ER-immunoreactive cells in the preoptic area (POA), arcuate nucleus (ARC) or ventromedial hypothalamic nucleus (VMH) following fasting and immobilization. Our previous work in ovariectomized rats with estrogen microimplants in the brain revealed that the PVN and A2 region of the NTS are the feedback sites of estrogen in activating the neural pathway to suppress pulsatile LH secretion during 48-h fasting. The result in the food-deprived rats suggests that estrogen modulation of the suppression of LH secretion during fasting is partly due to the increase in estrogen receptors in the PVN and A2 region. The physiological significance of the increase in neural ER following immobilization remains to be elucidated.     

Effects of humidity on reproductive behavior in male and female zebra finches (Taeniopygia guttata).

Zebra finches (Taeniopygia guttata) are regarded as opportunistic breeders with reproductive behaviors mediated by short-term proximal environmental conditions. This article provides experimental evidence for the role of humidity in reproductive behaviors. Zebra finches were subjected to experimentally manipulated high levels of relative humidity. Males gathered more nest material and sang more. Females showed no relationship between humidity and gathering nest materials, egg laying, or changes in rates of vocalization. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

A further contribution to the question of trophic and hormonal influences on the noradrenaline content of the male reproductive tract: effect of combined androgen and estrogen treatment of prepuberally castrated rats

The pressor response to the intracisternal (i.c.) injection of carbachol (1 mug) in anesthetized rats was analyzed. This response was significantly reduced by the intravenous (i.v.) injection of guanethidine (5 mg), hexamethonium (10 mg) or phentolamine (5 mg), and conversely, potentiated by i.v. desmethylimipramine (0.3 mg), while propranolol (0.5 mg) i.v. selectively inhibited the enlargement of pulse pressure and the tachycardia following i.c. carbachol (1 mug). On the other hand, the pressor response to i.c. carbachol (1 mug) was almost completely blocked by i.c. atropine (3 mug) or hexamethonium (500 mug), and significantly reduced by i.c. chlorpromazine (50 mug) but significantly potentiated by i.c. desmethylimipramine (30 mug). The pressor response to i.c. carbachol (1 mug) remained unchanged after sectioning of the bilateral cervical vagal nerves but disappeared after sectioning of the spinal cord (C7-C8). From the above result it is suggested that the pressor response to i.c. carbachol ortral and peripheral adrenergic mechanisms, and that the sympathetic trunk is the main pathway.     

Effects of 5-HT1A receptor antagonists on hippocampal 5-hydroxytryptamine levels: (S)-WAY100135, but not WAY100635, has partial agonist properties

The role of carcinogenic PAH in soot- and carbon black-related lung tumour induction in rats was investigated after intratracheal administration of carbon blacks (CB) and two types of diesel soot (DS), either as original or as toluene extracted particles. The total particle dose per animal was 15 mg subdivided into 16-17 weekly applications. There was one vehicle control and two groups were treated with a total dose of either 30 or 15 mg pure BaP as positive control. The main tumour results were: (a) original DS induced a higher tumour rate than extracted DS; (b) the carcinogenic potency of extracted CB probably depends on the size of the primary carbon particles and on the specific surface area of the particles; (c) extracted DS covered with 11 micrograms BaP per mg carbon particles caused a lower lung tumour rate than original DS containing only 0.9 ng BaP per mg, but a variety of other PAH and NO2-PAH; (d) a total dose of 15 mg pure BaP caused a lung tumour rate very similar to that of 30 mg extracted DS, 15 mg original DS or 15 mg Printex 90T CB extracted or covered with approximately 29.5 micrograms BaP per mg CB.     

Actions of testosterone in prepubertal and postpubertal male hamsters: dissociation of effects on reproductive behavior and brain androgen receptor immunoreactivity

This study examines differences by age cohort in (a) the frequency of prayer, (b) racial and gender variation in prayer, and (c) religious and sociodemographic correlates of prayer. Analyses are conducted across four age cohorts (18-30, 31-40, 41-60, > or = 61) using data from the 1988 National Opinion Research Center (NORC) General Social Survey (N = 1,481). Findings reveal that prayer is frequently practiced at all ages, but more frequently in successively older cohorts. In addition, females and, to a lesser extent, African Americans pray more frequently than males and Whites, respectively. Further, hierarchical multiple regression analyses reveal statistically significant associations across age cohorts between prayer and key measures of religious behavior, feeling, belief, and experience.     

Cerebral ischemia in gerbils: effects of acute and chronic treatment with adenosine A2A receptor agonist and antagonist

Despite significant progress in understanding of the potential of adenosine A1 receptor-based therapies in treatment of cerebral ischemia and stroke, very little is known about the effect of selective stimulation of adenosine A2A receptors on the outcome of a cerebrovascular arrest. In view of a major role played by adenosine A2 receptors in the regulation of cerebral blood flow, we have investigated the effect of both acute and chronic administration of the selective adenosine receptor agonist 2-[(2-aminoethylamino)-carbonylethylphenylethylamino]-5'-N- ethylcarboxoamidoadenosine (APEC) and antagonist 8-(3-chlorostyryl)caffeine (CSC) on the outcome of 10 min ischemia in gerbils. Acute treatment with APEC improved recovery of postischemic blood flow and survival without affecting neuronal preservation in the hippocampus. Acute treatment with CSC had no effect on the cerebral blood flow but resulted in a very significant protection of hippocampal neurons. Significant improvement of survival was present during the initial 10 days postischemia. Due to subsequent deaths of animals treated acutely with CSC, the end-point mortality (14 days postischemia) in this group did not differ statistically from that seen in the controls. It is, however, possible that the late mortality in the acute CSC group was caused by the systemic effects of brain ischemia that are not subject to the treatment with this drug. Chronic treatment with APEC resulted in a statistically significant improvement in all studied measures. Although chronic treatment with CSC improved postischemic blood flow, its effect on neuronal preservation was minimal and statistically insignificant. Mortality remained unaffected. The results indicate that the acute treatment with adenosine A2A receptor antagonists may have a limited value in treatment of global ischemia. However, since administered CSC has no effect on the reestablishment of postischemic blood flow, treatment of stroke with adenosine A2A receptor antagonists may not be advisable. Additional studies are necessary to elucidate whether chronically administered drugs acting at adenosine A2 receptors may be useful in treatment of stroke and other neurodegenerative disorders.     

病例对照Meta分析显示男性乳腺癌与女性乳腺癌预后相同

Objective: Male breast cancer (MBC) is a rare disease, and studies to compare the prognosis between the MBC and female breast cancer (FBC) available now were case-control studies and population-based studies, however, with controversial outcomes. To further investigate whether sex affects the prognosis of breast cancer, we performed a meta-analysis based on all the peered papers. Methods: The PubMed database was screened. Subsequently, the hazard ratios (HRs) for overall survival (OS) and disease special survival (DSS), were pooled using the Review Manager 5.0 package. Results: This study comprised of 254 MBC and 733 FBC patients enrolled in six case-control studies. There was no statistically significant heterogeneity among the trials for either outcome variable. The pooled HR showed that there was no significant difference in 5-year or 10-year DSS (HR: 1.25, 95% CI: 0.76-2.08; HR: 1.04, 95% CI: 0.66-1.59) and 5-year or 10-year OS (HR: 0.76, 95%CI: 0.51-1.14; HR: 0.74, 95% CI: 0.54-1.02) between MBCs and FBCs. Conclusion: MBC and FBC with similar prognosis are found in this meta-analysis based on only case-control studies which matched main potential prognostic factors such as age, clinical stage, and time at diagnosis.     

Differences in partial agonist action at cholecystokinin receptors of mouse and rat are dependent on parameters extrinsic to receptor structure: molecular cloning, expression and functional characterization of the mouse type A cholecystokinin receptor

The mouse cholecystokinin (CCK) receptor is functionally distinct from the extensively studied rat receptor on the basis of differences in binding and biological activity of phenethyl ester analogs of CCK. These are partial agonists at the rat receptor and full agonists at the mouse pancreatic receptor. To explore this, we cloned the cDNA for the mouse type A CCK receptor, established a receptor-bearing Chinese hamster ovary (CHO) cell line and characterized its binding and biological characteristics. Despite 25 differences in amino acid sequence from the rat receptor, including a seven-amino acid insertion in the third intracellular loop, mouse and rat receptors were functionally indistinguishable when expressed in CHO cells. Of note, in the mouse pancreatic cell environment, a stable analog of guanosine triphosphate significantly inhibited binding of CCK-OPE, whereas it had no effect on binding to the same receptor on the CHO-CCKM cell line or to the rat receptor in either environment of the acinar cell. This likely reflects a difference in coupling of the mouse receptor to its G protein in the natural environment of the acinar cell. This may relate to differences extrinsic to the receptor, in the stoichiometry or character of G proteins or in the composition or organization of the lipid environment of the mouse acinar cell membrane. Although this may require complementation of the unique sequence of the mouse receptor, that structure alone is insufficient to explain this phenomenon. Receptor microenvironment makes an important, yet often ignored, contribution to receptor function.     

The effect of female age and ovarian reserve on pregnancy rate in male infertility: treatment of azoospermia with sperm retrieval and intracytoplasmic sperm injection

Factors other than spermatozoa could be the major determinant of the success of assisted reproduction treatment in cases of male infertility. Our aim was to evaluate the effect of the wife's age and ovarian reserve on assisted reproduction success rates in the most severe type of male infertility, i.e. azoospermia. A total of 249 consecutive couples suffering from male infertility caused by azoospermia underwent microsurgical epididymal sperm aspiration (MESA) or testicular sperm extraction (TESE) with intracytoplasmic sperm injection (ICSI). Of these men, 186 had irreparable obstructive azoospermia, and 63 had non-obstructive azoospermia due to testicular failure. Neither the pathology, the source, the quantity, nor the quality of spermatozoa had any effect on fertilization or pregnancy rates. Maternal age and ovarian reserve (number of eggs) had no effect on fertilization or embryo cleavage, but did dramatically affect the embryo implantation, pregnancy and delivery rates. Wives of azoospermic men who were in their 20s had a 46% live delivery rate per cycle, wives aged 30-36 years had a 34% live delivery rate per cycle, wives aged 37-39 years had a 13% live delivery rate per cycle, and wives > or = 40 years had only a 4% live delivery rate per cycle. The number of eggs retrieved also affected pregnancy and delivery rate, but to a lesser extent than age. In virtually all cases of obstructive azoospermia, and in 62% of cases with non-obstructive azoospermia caused by germinal failure, sufficient spermatozoa could be retrieved to perform ICSI, with normal fertilization and embryo cleavage. However, the pregnancy rate and the live delivery rate were dependent strictly on the age of the wife, and on her ovarian reserve. Unfortunately, exaggerated claims of high pregnancy rates can thus easily be made by manipulating, in a very simple way, selection for female factors.     

Differential colocalization of estrogen receptor beta (ERbeta) with oxytocin and vasopressin in the paraventricular and supraoptic nuclei of the female rat brain: an immunocytochemical study

Evidence exists for the localization of the newly identified estrogen receptor beta (ERbeta) within the rat paraventricular nucleus (PVN) and supraoptic nucleus (SON), regions which lack ERalpha. Presently, we investigate whether ERbeta-like-immunoreactivity (-ir) is found within cells of several major neuropeptide systems of these regions. Young adult Sprague-Dawley rats were ovariectomized (OVX), and 1 week later half of the animals received estradiol-17beta (E). Dual-label immunocytochemistry was performed on adjacent sections by using an ERbeta antibody, followed by an antibody to either oxytocin (OT), arginine-vasopressin (AVP), or corticotropin releasing hormone. Nuclear ERbeta-ir was identified within SON and retrochiasmatic SON, and in specific PVN subnuclei: medial parvicellular part, ventral and dorsal zones, dorsal and lateral parvicellular parts, and in the posterior magnocellular part, medial and lateral zones. However, the ERbeta-ir within magnocellular areas was noticeably less intense. OT-/ERbeta-ir colocalization was confirmed in neurons of the parvicellular subnuclei, in both OVX and OVX+E brains ( approximately 50% of OT and 25% of ERbeta-labeled cells between bregma -1.78 and -2.00). In contrast, few PVN parvicellular neurons contained both AVP- and ERbeta-ir. As well, very little overlap was observed in the distribution of cells containing corticotropin releasing hormone- or ERbeta-ir. In the SON, most nuclear ERbeta-ir colocalized with AVP-ir, whereas few OT-/ERbeta-ir dual-labeled cells were observed. These findings suggest that estrogen can directly modulate specific OT and AVP systems through an ERbeta-mediated mechanism, in a tissue-specific manner.     

Comparative study of the effect of glucocorticoids on nitrogen metabolism in adult male and non-laying female quail (Coturnix coturnix japonica)

The effects of glucocorticoids on nitrogen metabolism have been studied in three different groups of quail: a) control animals; b) quail treated with cortisol; c) quail treated with corticosterone. All the experiments were carried out in adult male and non-laying female animals. During the 7 day period that the experiments lasted, hormones were administered daily by via oral at 4 mg/100 g body weight/7 day doses. While body weight, food intake, nitrogen balance and liver weight, in the treated animals stayed under the values of the control group, in both males and females, their uric acid excretion and hepatic glycogen were always higher. Values, in general, were similar for both males and females.     

A transient effect of estrogen on calcium currents and electrophysiological responses to gonadotropin-releasing hormone in ovine gonadotropes

Episodic release of luteinizing hormone (LH) by the pituitary gland is controlled by hypothalamic gonadotropin-releasing hormone (GnRH). In the period leading up to the preovulatory surge of LH, estrogen increases the number of pituitary receptors for GnRH and sensitises the gonadotropes to GnRH. The postreceptor events that are responsible for the increase in responsiveness to GnRH are not clearly delineated, but LH release is known to be Ca2+ dependent. The present study addressed the question as to whether or not estrogen may act to modify voltage-dependent Ca2+ entry in normal gonadotropes. Primary cultures enriched in gonadotropes or somatotropes were produced from anestrous female sheep. Conventional whole-cell patch-clamp recording was used to measure inward membrane current in the absence of GnRH treatment, with and without 10 nM estradiol-17beta (E2) treatment for 0 to 36 h. Nystatin-perforated whole-cell patch-clamp recording was used to record membrane voltage responses to GnRH. Ca2+ current density (ICa, pA/pF) began to increase after 2 h exposure to E2, and reached peak values of about 200% of control by 16-20 h (p < 0.005), then declined. If E2 was withdrawn at 24 h, ICa returned towards control values by 36 h. If E2 treatment was continued beyond 24 h, however, ICa fell to about 75% of control by 36 h (p < 0.005). Actinomycin D prevented the enhancement of ICa. E2 was without effect on Na+ current density in gonadotropes, or on ICa in somatotropes. The proportion of ICa carried by L-type and N-type channels in gondadotropes was not changed by E2. Ovine gonadotropes respond to GnRH with membrane potential fluctuations driven by periodic activation of Ca2+-dependent K+ channels, and synchronised action potential generation. This response was found to be sensitive to E2. Responses were categorised according to the pattern of activity evoked by 10 nM GnRH. Without E2 treatment, 11/14 cells responded with oscillations and 3/14 cells responded with spiking (hyperpolarizations following single action potentials). After 20 h 10 nM E2, just 1/14 cells responded with hyperpolarizing oscillations while 13/14 cells showed spiking activity. The predominance of the spiking pattern in E2-treated cells is consistent with the increased Ca2+ flux, and with enhanced LH release. We conclude that E2 has a transient effect on gonadotropes to enhance voltage-gated Ca2+ channel function. The time-course and biphasic nature of the influence of E2 on ICa may be physiologically appropriate to the preovulatory LH surge. Enhanced Ca2+ influx may participate in increased Ca2+-dependent hormone release, while the delayed inhibitory action of E2 on ICa may serve to limit the duration of the surge.     

Effect of long-term treatment with synthetic oestrogens on plasma lipids and arterial vessels in male rabbits (author's transl)

The effects of long-term treatment with synthetic oestrogens (Retalon retard, Sanabo Ltd., Wien, 5 mg/kg i.m. at weekly intervals) were investigated in 12 male rabbits and compared with the data obtained in 9 saline-treated control animals. After 6 months of treatment the oestrogen group showed significantly higher plasma phospholipid (p less than 0.005) and cholesterol (p less than 0.01) concentrations than the control group. However, histological examination of various important arterial vessels (the aorta and the coronary, cerebral, limb and renal arteries) revealed no pathological changes indicative of premature atherosclerosis in either the oestrogen group or in the control group. It is concluded that long-term treatment with synthetic oestrogens does not result in a higher incidence of atherosclerosis in rabbits.