Mutational analysis of EGFR signaling pathway genes in lung adenocarcinomas

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Background: About fifty percent of lung adenocarcinomas harbor somatic mutations in six genes that encode signaling proteins in the EGFR signaling pathway, i.e. EGFR, HER2/ERBB2, HER4/ERBB4, PIK3CA, BRAF, and KRAS. We performed mutational profiling of a large cohort of lung adenocarcinomas to uncover other somatic mutations that could contribute to lung tumorigenesis. Methods: We analyzed genomic DNA from 261 resected, clinically well-annotated non-small cell lung cancer (NSCLC) specimens. 90% of tumors were adenocarcinomas, and 10% were squamous cell carcinomas. The coding sequences of 39 genes, encoding proteins mostly in the EGFR signaling cascade and FGFR1–4, were screened for somatic mutations via high-throughput dideoxynucleotide sequencing of PCR-amplified gene products. Mutations were considered to be somatic only if they were found in an independent tumor-derived PCR product but not in matched normal tissue. Results: First-pass analysis of 9 MB of tumor sequence identified 199 distinct types of genetic variants that differed from published reference sequences. At least one variant was found in each gene analyzed. In addition to 6 variants found in RAS genes, we further examined the 94 variants localized to exons encoding the kinase domain of respective proteins. We have thus far identified known somatic mutations in EGFR, KRAS, BRAF, and PIK3CA, in addition to a number of previously unreported single nucleotide polymorphisms (SNPs). Conclusions: Mutational profiling of genes that encode for components of the EGFR signaling pathway has revealed multiple putative genetic variants in lung adenocarcinomas. Further analysis of potential somatic mutations is in progress.

No significant financial relationships to disclose.

Who gets what symptom? Effects of psychiatric cofactors and nicotine dependence on patterns of smoking withdrawal symptomatology

The present study used logistic regression techniques to examine the extent to which depression, anxiety, disordered eating, and nicotine dependence increased risk of experiencing craving and the eight DSM-IV withdrawal symptoms (depressed mood, insomnia, irritability, anxiety, difficulty concentrating, restlessness, decreased heart rate, increased appetite) during smoking abstinence, assessed retrospectively. Data were provided by a racially diverse sample of 365 male and female smokers recruited to participate in laboratory studies. Results indicate that variables known to be associated with smoking are risk factors for distinct and only somewhat overlapping patterns of symptomatology. Smokers scoring high on measures of anxiety, depression, or disordered eating were at increased risk primarily of experiencing withdrawal symptomatology pathognomonic to their particular disorder, whereas smokers scoring high on nicotine dependence appeared to be at increased risk of experiencing a syndromal pattern of withdrawal, encompassing craving and insomnia as well as cognitive/affective symptoms. Our results support the possibility that some individuals use smoking as a form of self-medication and suggest that elucidation of patterns of withdrawal symptomatology may contribute to improved specification of smoking phenotypes as well as facilitate treatment-matching.

Effects of menstrual phase and smoking abstinence in smokers with and without a history of major depressive disorder

Although considerable progress has been made towards understanding the role of menstrual cycle phase in smoking, little is known about the possible effects of menstrual phase upon nicotine intake, withdrawal symptomatology, and craving in women with psychiatric cofactors. Fourteen women with and without a history of Major Depressive Disorder (MDD) were studied during five biologically-confirmed phases over the course of one menstrual cycle: smoking logs, salivary cotinine, and ratings of craving and withdrawal were collected daily. During a second cycle, subjects remained abstinent for 3 consecutive days during the postmenses and premenstrual phases. Although a significant omnibus F-test emerged for cigarettes per day across phases during ad libitum smoking, only trends were observed post hoc and supported midcycle rather than premenstrual elevations. There were no significant phase differences for cotinine. Withdrawal symptomatology was markedly elevated during smoking abstinence and in women with a history of depression. but showed no evidence of phase effects. Thus, the hypothesis that depressed individuals would be differentially affected by phase and abstinence was not strongly supported by our results, though overall elevations emphasize the need for special attention to withdrawal severity in this population. Craving was significantly elevated during smoking abstinence and was significantly higher during postmenses, consistent with the midcycle elevation in smoking rate, but showed no group differences. Our findings overall lend little support for the need to control for menstrual phase under conditions of ad libitum smoking. The strong association of self-reported menstrually related dysphoria during abstinence with both craving and withdrawal symptoms, however, is consistent with an exacerbation of smoking abstinence effects in women with severe menstrual symptomatology.

Abstinence effects and reactivity to nicotine during 11 days of smoking deprivation

The purpose of the present study was to investigate smoking abstinence effects and the dissipation of tolerance (reactivity to nicotine) under controlled laboratory conditions. Seventeen male and female regular smokers were tested first in a session following ad libitum smoking and then in an additional five sessions over the course of 11 days during which they abstained from smoking. A metered dose of nicotine was administered via intranasal spray to ensure standard exposure, and pre- and post-dosing measures of heart rate, blood pressure, cortisol, galvanic skin response (GSR), craving, and several DSM-IV withdrawal symptoms (anxiety, irritability, restlessness, difficulty concentrating, and appetite) were collected. Prior to the nicotine test dose during deprivation sessions, heart rate and systolic blood pressure evinced elements of both an 'offset abstinence pattern' (deflection in a direction opposite to that produced by smoking) and a 'transient abstinence pattern' (deflection followed by a subsequent return); for cortisol, an offset pattern was observed, whereas for GSR and craving, a transient pattern was found. With respect to loss of tolerance, heart rate reactivity was found to increase significantly after 2 days' abstinence from nicotine, and the increase was sustained in subsequent sessions. Cortisol reactivity revealed more gradual dissipation, with significant differences evident only after 9 days of abstinence. These findings extend research on nicotine abstinence effects and on the dissipation of tolerance to nicotine deprivation intervals of nearly 2 weeks and confirm prior observations of variability across different response systems.

Initial exposure to nicotine in college-age women smokers and never-smokers: a replication and extension

Recent research suggests that people who become smokers may be more sensitive to the positive effects of nicotine upon initial exposure than those who do not take up smoking. The present study was designed to extend these findings to a sample of college-age women never-smokers and light smokers. Subjects were asked to rate pleasurable and displeasurable sensations upon first smoking and to indicate the presence or absence of pleasurable rush or buzz, relaxation, dizziness, nausea, and cough. Pleasurable sensations were marginally greater in smokers; pleasurable rush or buzz and dizziness were significantly more likely to be reported by smokers. Relaxation, displeasurable sensations, nausea, and cough did not differ significantly between groups. Fagerstrom Test for Nicotine Dependence scores significantly predicted pleasurable but not displeasurable sensations; Center for Epidemiological Studies-Depression scores predicted neither. These findings lend further support to the following conclusions: (1) people who become cigarette smokers experience more pleasurable sensations upon initial exposure to tobacco than their never-smoking counterparts; and (2) unpleasant reactions to the first cigarette do not protect against subsequent smoking.

Effects of menstrual phase on reactivity to nicotine

The possible impact of menstrual phase upon reactivity to nicotine was investigated in 12 healthy women smokers. Controlled doses of nicotine were administered via an intranasal aerosol delivery device to overnight-deprived women smokers in four hormonally verified menstrual phases. Physiological, biochemical, and subjective measures were collected. Cycle-related symptomatology differed significantly across phase, with lowest values during the mid-follicular phase. No significant differences were found for baseline variables, including withdrawal measures. Nicotine increment was stable across phase, confirming reliability of the dosing method. No significant menstrual phase differences were found for physiological, subjective, or biochemical responses to nicotine. Pending investigations conducted over longer intervals, in a wider variety of subjects; findings suggest that for this type of study, complex strategies to control for menstrual-cycle phase effects may be unnecessary.

Pharmaceutical industry screening for new antiepileptic drugs

It is clear that in coming years, many interesting new compounds will emerge from these and other strategies for drug discovery. In previous strategies of anticonvulsant discovery, whole-animal models of seizures were utilized from the initial stages; however, with the newer strategies, it will become necessary to select promising drug targets for clinical trials in epilepsy that have well-defined molecular targets of action but poorly defined actions in various animal seizure models. The new pharmaceutical discovery technologies of mass screening, cloned drug targets, and combinatorial chemistry will assist in the efficient discovery of novel drug candidates. Incidentally, these techniques also will minimize the use of large numbers of living laboratory animals for anticonvulsant drug screening.

Nicotine dependence and withdrawal in alcoholic and nonalcoholic ever-smokers

We compared nicotine dependence and withdrawal in male alcoholic and control ever-smokers, controlling for relevant demographic and clinical variables. Alcoholics were more likely to meet criteria for moderate or severe nicotine dependence and endorse more nicotine dependence symptoms. Symptoms reported more frequently by alcoholics included: (a) using nicotine in larger amounts or over a longer time than intended; (b) continued use despite problems caused or exacerbated by nicotine; (c) marked tolerance; and (d) experiencing characteristic nicotine withdrawal symptoms. Alcoholics also smoked more heavily. Other than "headaches," and "decreased heart rate," alcoholics consistently endorsed nicotine withdrawal symptoms at a higher rate. After controlling for demographic and clinical variables and level of nicotine dependence, only "feel depressed" differed significantly between groups. Our research supports previous findings suggesting that nicotine dependence is more severe in those with a history of alcohol dependence. As a result, alcoholics may experience greater discomfort from nicotine withdrawal upon smoking cessation.

Metabolic and orexigenic effects of intracerebroventricular neuropeptide Y are attenuated by food deprivation

Administration of neuropeptide Y (NPY) into the hypothalamus or cerebral ventricles has been shown to increase food intake, the secretion of hormones such as insulin, glucagon and corticosterone and to alter the metabolism of carbohydrate and lipids. It has been suggested that metabolic effects of hypothalamic NPY may contribute to fat accretion in some types of obesity and to the metabolic and behavioural adaptation to food deprivation. However, it is currently unknown if different nutritional states alter the responses to hypothalamic NPY. Consequently, we have compared the effects of NPY injected into the third ventricle (ICV) in the fed and overnight-fasted state on ingestive behaviour, on insulin, glucagon and corticosterone secretion before, and following, an IV glucose bolus (IVGTT) and on blood glucose following an intra-arterial insulin bolus (ITT). Studies were performed on conscious, unrestrained adult female rats. In the fed state, 2 and 6 micrograms ICV NPY produced a potent orexigenic and dypsogenic effect. In the fasted state, the 2 micrograms dose had a dypsogenic effect, while only the 6 micrograms dose had a significant orexigenic effect. In the fed but not fasted state, 3 micrograms ICV NPY increased plasma glucagon and corticosterone levels and attenuated the decline in blood glucose during the ITT. By contrast, in both fed and fasted groups, 3 micrograms ICV NPY potentiated the insulin secretory responses during the IVGTT. We conclude that, apart from stimulating insulin secretion, the acute metabolic and orexigenic responses to ICV NPY in this study were substantially reduced or abolished by overnight fasting. Therefore, behavioural and metabolic responses to endogenous hypothalamic NPY may also be more significant in the fed than the fasted state.

Intracerebroventricular neuropeptide Y acutely influences glucose metabolism and insulin sensitivity in the rat

Acute administration of neuropeptide Y(NPY) into the hypothalamus and third cerebral ventricle (ICV) increases respiratory quotient, reduces energy expenditure and increases circulating, insulin, glucagon and corticosterone. Therefore, it is likely that hypothalamic NPY has acute effects on the metabolism of fuels, such as glucose. To test this hypothesis, we determined if ICV infusion of NPY influences glucose metabolism and its sensitivity to insulin in conscious, unrestrained rats, not given access to food. Glucose turnover was 4.7+/-0.3 mg/min, 45-55 min after ICV NPY was administered at 3 microg/h vs 3.7+/-0.2 (P<0.05) for ICV saline. In a time course study, glucose turnover was significantly increased 30 min, and remained elevated at 50 min after starting a similar ICV NPY infusion. In neither study was plasma glucose, insulin, glucagon or corticosterone significantly affected by ICV NPY. During an hyperinsulinaemic euglycaemic clamp, the glucose infusion rate corrected for body weight and insulin concentration, M/I was 0.22+/-0.03 for NPY vs 0.36+/-0.05 mg min(-1) kg(-1) microU(-1) ml (P<0.05) for saline. NPY treatment prevented the decline in glucose production rate but did not influence the rise in glucose disposal rate resulting from hyperinsulinaemia. It was concluded that ICV NPY rapidly stimulates glucose turnover by a mechanism that does not depend on changes in insulin, glucagon or corticosterone secretion. Furthermore, ICV NPY decreased insulin sensitivity by reducing the effect of insulin on glucose production but not on whole body glucose disposal.

Intracerebroventricular neuropeptide Y produces hyperinsulinemia in the presence and absence of food

Acute administration of neuropeptide Y into the hypothalamus or cerebral ventricles produces hyperphagia and hyperinsulinemia. However, it is not known to what extent the hyperinsulinemia depends on the food intake. Consequently, serum insulin and glucose, as well as food and water consumption, were measured over 3 h, following injection of 1-20 micrograms neuropeptide Y into the third ventricle of adult female rats. In the presence of food, 1-10 micrograms neuropeptide Y produced a dose-dependent increase in food and water intake and serum insulin. Insulin levels were closely correlated with the quantity of food ingested. In the absence of food, 1-20 micrograms neuropeptide Y produced a dose-dependent increase in water intake, whereas 1-5 micrograms produced a does-dependent increase in serum insulin. We concluded that ICV neuropeptide Y can stimulate insulin secretion even at low doses and this response does not completely depend on food intake.

Some acute effects of intracerebroventricular neuropeptide Y on insulin secretion and glucose metabolism in the rat

Acute administration of neuropeptide Y(NPY) into the hypothalamus and cerebral ventricles can stimulate insulin secretion in the absence of available food. However, the relationship of this effect to blood glucose and other hormones which regulate glucose metabolism remains unclear. The purpose of this study was to compare the effects of NPY injected into the third ventricle (ICV) on serum insulin, glucose, glucagon, corticosterone and non-esterified fatty acids. Studies were performed on conscious, unrestrained female rats, not given access to food. ICV NPY, 2 and 5 micrograms produced an increase in serum insulin and glucagon, while the 5 micrograms dose only increased plasma glucose transiently and increased non-esterified fatty acids for a longer period. Corticosterone was not affected by ICV NPY. The insulinaemic response to i.v. glucose, 0.5 g/kg was doubled by ICV NPY, 4 micrograms. The maximal insulin levels were 113 +/- 18 for ICV NPY versus 67 +/- 8 microU/ml for ICV saline-treated animals. The glycaemic response was not altered. The hypoglycaemic response to i.v. insulin, 0.15 U/kg was significantly attenuated by ICV NPY, 5 micrograms. We concluded that ICV NPY promotes insulin secretion in the absence of available food and may potentiate the insulinaemic response to hyperglycaemia. Furthermore, possibly through its effects on glucagon and non-esterified fatty acids, ICV NPY may decrease the ability of insulin to control glucose metabolism.

Effects of gold thioglucose on neuropeptide Y messenger RNA levels in the mouse hypothalamus

Elevated hypothalamic neuropeptide Y (NPY) expression is found in several rodent genetic models of obesity, but any association in nongenetic models of obesity is unclear. Consequently, we have measured NPY mRNA levels in the ventromedial hypothalamus of a well-characterized model of obesity, the gold thioglucose (GTG)-injected mouse. Fourteen days after injection (early stage), animals were hyperphagic but not obese, hyperglycemic, or overtly hyperinsulinemic. Ten weeks after treatment (late stage), animals were obese, markedly hyperinsulinemic, and hyperglycemic. In both the early and late stages, NPY mRNA levels were reduced in the arcuate nucleus of GTG-injected animals. Although overnight fasting doubled NPY mRNA levels in control animals, there was no change at either stage in GTG-injected animals. NPY mRNA levels in the deep layers of the cerebral cortex and in the dentate gyrus were not affected by GTG treatment or overnight fasting. We conclude that GTG treatment reduces the expression of NPY mRNA in the arcuate nucleus and that, therefore, increased hypothalamic NPY expression is unlikely to be an important factor causing the obesity and other metabolic changes found in this model.

Role of hypothalamic neuropeptide Y gene expression in body weight regulation

Hypothalamic neuropeptide Y (NPY) may be involved in the hyperphagia that follows food deprivation associated with significant weight loss. However, it is unclear whether NPY is involved in body weight regulation under more physiological circumstances. Consequently, we measured body weight, food intake, arcuate nucleus (ARC) NPY mRNA, serum glucose, and insulin in male Wistar rats after 48 h of food deprivation and various refeeding protocols. Food deprivation produced a twofold increase in NPY mRNA, whereas 3 days of ad libitum refeeding returned body weight and NPY mRNA to control. If hyperphagia was prevented for 5 days during refeeding, then neither body weight nor NPY mRNA normalized. There were strong negative correlations between ARC NPY mRNA and both loss of body weight and serum insulin levels. These data suggest that hypothalamic NPY gene expression plays a role in control of body weight under physiological conditions. The data further suggest that NPY mRNA may be decreased by peripheral insulin levels.

Effects of menstrual phase on nicotine, alcohol, and caffeine intake in smokers

To determine whether cigarette smoking and other drug use are affected by menstrual phase, daily diaries rating menstrual symptomatology, smoking, and alcohol and caffeine intake in female smokers were examined. Women with premenstrual symptomatology were excluded. Menstrual symptomatology peaked during menses and was accounted for primarily by symptoms indicative of physical discomfort. Smoking did not differ as a function of menstrual phase, nor did there emerge any systematic intrasubject correlation between symptomatology and smoking. Alcohol and caffeine intake also failed to show phase-related differences. It was concluded that substance intake is highly stable across the menstrual cycle in female smokers.

Effects of menstrual phase on intake of nicotine, caffeine, and alcohol and nonprescribed drugs in women with late luteal phase dysphoric disorder

To investigate the possibility that cigarette smoking and other drug use are affected by menstrual phase in smokers with Late Luteal Phase Dysphoric Disorder (LLPDD), we examined daily diaries rating menstrual symptomatology, smoking, alcohol and nonprescription drug use, and caffeine intake in nine female smokers meeting criteria for LLPDD. Menstrual symptomatology peaked during the premenstrual phase. Smoking, alcohol, and nonprescription drug intake were increased during menses; caffeine intake was unaffected by phase. No systematic intrasubject correlation between symptomatology and smoking was detected. It was concluded that in women with LLPDD, smoking and alcohol and nonprescription drug intake appear to vary as a function of menstrual phase. The lack of intrasubject correlations between symptomatology and intake, and the failure of peak intake to coincide with peak symptomatology, however, indicate that these effects cannot be explained simply as "self-medication" of acute episodes of dysphoric mood.

Effects of streptozotocin-induced diabetes mellitus and insulin treatment on neuropeptide Y mRNA in the rat hypothalamus

Levels of neuropeptide Y and neuropeptide Y mRNA are increased in the arcuate nucleus of severely diabetic rats which may be the result of the associated marked hypoinsulinaemia. We hypothesised that if neuropeptide Y mRNA is regulated by physiological changes in circulating insulin, then the relatively minor changes in circulating insulin found in mild diabetes would also affect neuropeptide Y expression and its response to changing insulin levels should be rapid. Neuropeptide Y mRNA was quantified by in situ hybridisation through the rostral, mid and caudal levels of the arcuate nucleus of adult female rats. Neuropeptide Y mRNA was significantly increased at all three levels of the arcuate nucleus, 7 days after i.v. administration of 40 mg/kg streptozotocin. Neuropeptide Y mRNA was not further increased in the arcuate nucleus of animals given 50 mg/kg streptozotocin. In the former group, serum glucose was increased but insulin levels and body weights were the same as in control rats. In the 50 mg/kg streptozotocin group, serum glucose was further increased while serum insulin and body weight were reduced. In addition, neuropeptide Y mRNA was not altered in the hypothalamic dorsomedial nucleus or the thalamic reticular nucleus. When diabetic rats were treated for 20 h with s.c. insulin, there was decreased neuropeptide Y mRNA in the arcuate nucleus. We conclude that neuropeptide Y mRNA in the arcuate nucleus is responsive to small changes in circulating insulin levels and the response occurs within 20 h. These data support that circulating insulin may contribute to control of neuropeptide Y expression under physiological conditions.

The female weight-control smoker: a profile

Hypothesizing the existence of a subgroup of female smokers for whom nicotine masks, and abstinence unmasks, a tendency toward hyperphagia and perhaps even subthreshold disordered eating, we compared female "weight-control smokers" (WC; n = 46) and "non-weight-control smokers" (NWC; n = 52) on smoking- and eating-related variables. We also examined the relationship between weight-control smoking and withdrawal symptomatology during 48-hours of nicotine abstinence (n = 23). Although WC were not more depressed, anxious, or nicotine-dependent than NWC, they were significantly more likely to report weight gain and increased hunger during abstinence; they also scored higher on Cognitive Restraint and Disinhibition (Three-Factor Eating Questionnaire). The expected correlation of cotinine with weight emerged for NWC but not for WC. Weight-control smoking correlated with increased eating during abstinence. Our findings suggest that WC use dietary restraint as well as smoking to manage weight, and that abstinence may precipitate episodes of disinhibited or binge eating. If WC overinclude women vulnerable to excess or unpredictable eating and consequently to substantial weight gain that can be managed by nicotine, highly focused treatment strategies may be helpful.

Cytogenetic studies of an adrenal cortical carcinoma

Cytogenetic findings in the third reported case of adrenal cortical carcinoma are described. In contrast to the two previous cases, hypodiploidy characterized almost all cells, which had as many as eight abnormal chromosomes in each cell analyzed.

Inhibition of hypothalamic neuropeptide Y gene expression by insulin

Insulin acts in the brain to suppress feeding, whereas neuropeptide Y (NPY) has the opposite effect. Since fasting lowers plasma insulin levels and increases hypothalamic synthesis of NPY, we proposed that insulin may inhibit hypothalamic NPY gene expression. To test this hypothesis, we used RIA and in situ hybridization histochemistry to determine if centrally administered insulin could reduce levels of both NPY and its messenger RNA (mRNA) in discreet hypothalamic regions during fasting. Three groups of Long-Evans rats were entered into a 72-h study protocol. One group was fed ad libitum during this period, while the others were fasted. Fed rats received intracerebroventricular (icv) injections of saline vehicle at 12-h intervals, whereas fasted groups received icv vehicle alone or with insulin (4 mU/12 h). In vehicle-only treated rats, fasting significantly increased expression of preproNPY mRNA in the arcuate nucleus to 179 +/- 20% of fed controls. Administration of icv insulin during fasting abolished this increase (99 +/- 14% of fed controls; P less than 0.05 vs. fasted, vehicle-treated rats). Central insulin administration during fasting also reduced immunoreactive NPY concentrations in samples punched from the paraventricular nucleus (PVN) (875 +/- 122 pg/punch) to levels below vehicle-only treated rats (1396 +/- 435 pg/punch; P less than 0.05), similar to free-feeding control values (814 +/- 170 pg/punch). By comparison, neither fasting nor central insulin administration altered NPY levels in four other hypothalamic regions (supraoptic, ventromedial, dorsomedial, and arcuate nuclei). Continuous icv insulin infusion at a lower dose (2 mU/day) produced a similar result during a shorter period (48 h) of food deprivation in Wistar rats. In this study, central insulin infusion also inhibited the fasting-related increase in arcuate preproNPY mRNA levels and did not affect plasma glucose or insulin levels. This suggests that insulin acts locally to inhibit hypothalamic NPY mRNA expression. We conclude that the increase of levels of NPY in the PVN and preproNPY mRNA in the arcuate nucleus during fasting are inhibited by icv insulin. Fasting, therefore, increases NPY biosynthesis along an arcuate nucleus-PVN pathway in the hypothalamus via a mechanism dependent on low insulin levels.

Localization of type I insulin-like growth factor receptor messenger RNA in the adult rat brain by in situ hybridization

Using multiple 35S-labeled oligonucleotide probes concurrently, the type I insulin-like growth factor receptor (IGF-I-R) mRNA was demonstrated by Northern blot hybridization in newborn and adult rat brain as a single species of approximately 11 kilobases. The probes were used to localize IGF-I-R mRNA by in situ hybridization in slices of adult rat brain. The highest levels of IGF-I-R mRNA expression were found in the glomerular and mitral cell body layers of the olfactory bulb, the granule cell body layers of the dentate gyrus and cerebellum, the pyramidal cell body layers of the piriform cortex and Ammon's horn, and the choroid plexus. The lowest levels of IGF-I-R mRNA expression were found in white matter. At the cellular level, IGF-I-R mRNA was expressed by a variety of neurons, by epithelial cells of the choroid plexus, and by ependymal cells of the third ventricle. Of the neuron types studied, the highest levels of IGF-I-R mRNA were consistently found in perikarya of mitral and tufted cells in the olfactory bulb, in pyramidal cells of the piriform cortex and Ammon's horn, and in granule cells of the dentate gyrus. There was a close congruency between the distribution of IGF-I binding and IGF-I-R mRNA at the regional level. Neuropil layers in the cerebral cortex, olfactory bulb, hippocampus, and cerebellum contained a high level of IGF-I binding, whereas the adjacent cell body layers contained a high level of the IGF-I-R mRNA. We conclude that in these regions, IGF-I-R mRNA is synthesized in neuronal cell bodies, and the receptors are transported to axons and dendrites in adjacent synapse-rich layers, where appropriate IGF effects are achieved.

Central insulin administration reduces neuropeptide Y mRNA expression in the arcuate nucleus of food-deprived lean (Fa/Fa) but not obese (fa/fa) Zucker rats

By acting in the brain, insulin suppresses food intake, whereas neuropeptide Y (NPY) has the opposite effect. Since fasting increases NPY gene expression in the hypothalamic arcuate nucleus (ARC) and also lowers circulating insulin levels, we hypothesized that the anorexiant effect of insulin could result from insulin inhibition of NPY gene transcription in the ARC. Therefore, we determined whether the administration of insulin (200 mU per 12 hrs) into the 3rd cerebral ventricle of lean (Fa/Fa) female Zucker rats (n = 5) during 48 hrs of food deprivation reduces the expression of preproNPY mRNA in the ARC compared to vehicle-treated controls (n = 5). Coronal sections of rat brain were hybridized with an oligonucleotide probe complementary to preproNPY mRNA and apposed to x-ray film. Hybridization was quantified in both the ARC and the hippocampal dentate gyrus by computerized image analysis of the resulting autoradiographs. Central insulin significantly reduced the area of hybridization in the ARC (0.235 +/- 0.017 mm2; mean +/- SE) compared to vehicle-treated controls (0.331 +/- 0.037 mm2; p less than 0.05), but was without effect in the hippocampus. Thus, insulin reduced the expression of mRNA for NPY specifically in the ARC. Since the genetically obese (fa/fa) Zucker rat is insensitive to the anorexiant effect of insulin and over-expresses NPY in the ARC, we next tested the hypothesis that insulin does not suppress NPY mRNA expression in the ARC of these rats. Consistent with this hypothesis, central insulin administration to obese Zucker rats during 48 hrs of food deprivation (n = 6) did not lower hybridization area in the ARC compared to vehicle alone (n = 4) (0.286 +/- 0.036 vs. 0.248 +/- 0.019 mm2; p greater than 0.05). We conclude that insulin suppresses the expression of mRNA for NPY in the ARC of fasted lean but not obese Zucker rats. Regulation of hypothalamic NPY gene expression by insulin may account for its anorexiant effect, and a defect in this action may contribute to certain forms of obesity.

Localization of insulin receptor mRNA in rat brain by in situ hybridization

Insulin receptor mRNA was demonstrated in rat brain slices by in situ hybridization with three 35S-oligonucleotide probes and contact film autoradiography. Specificity was confirmed by showing that (a) excess unlabeled probe abolished the signal, (b) an oligonucleotide probe for rat neuropeptide Y mRNA showed a different distribution of hybridization signal, and (c) the distribution of insulin receptor binding was consistent with the distribution of insulin receptor mRNA. Insulin receptor mRNA was most abundant in the granule cell layers of the olfactory bulb, cerebellum and dentate gyrus, in the pyramidal cell body layers of the pyriform cortex and hippocampus, in the choroid plexus and in the arcuate nucleus of the hypothalamus.

Total bladder replacement in the male and female using the ileocolonic segment (LeBag)

A group of 11 patients, 2 female and 9 male, underwent total bladder replacement using the ileocolonic segment (LeBag technique) with anastomosis of the bowel to the urethra. The diagnosis was invasive bladder cancer in 10 patients and severe intractable interstitial cystitis in 1. The surgical technique in the male patients was modified to simplify the procedure. The 2 female patients underwent insertion of an artificial sphincter around the bowel segment for a continence mechanism. One patient died 6 weeks post-operatively from a severe coagulopathy. Five of the 9 male patients are continent day and night, relying on their own residual sphincter mechanism, but the remaining 4 required insertion of the artificial urinary sphincter to achieve social continence. The surviving female patient is totally continent. All patients have voiding intervals of 4 to 6 h during the day and are thus continent both day and night, but in some cases the artificial sphincter was necessary to achieve this. Loss of the normal bladder-sphincter reflexes following cystectomy may account for the high incidence of nocturnal incontinence observed in most series. Total bladder replacement is now possible in both male and female patients, thus avoiding an abdominal stoma.

Artificial insemination with donor semen: the necessity of frequent donor screening

Artificial insemination with donor semen has become a well established alternative for couples with untreatable male factor infertility. Because of the widespread use of donor insemination, and the increasing awareness and prevalence of sexually transmitted diseases, the American Fertility Society recently redrafted procedural guidelines for the use of donor screening for insemination. Our series of donor screenings is reported to emphasize the necessity of donor evaluations at frequent intervals. From June 1986 through August 1987, 48 healthy male volunteers presented as potential semen donors for our donor program. Each was evaluated with a careful medical history, physical examination and 2 semen analyses for evidence of sexually transmitted disease. On initial evaluation, no donor presented with a positive human immunodeficiency virus antibody, abnormal karyotype, elevated serum glutamic oxaloacetic transaminase, rapid plasma reagent, or positive cultures for Chlamydia or Mycoplasma. One potential donor was excluded because of a positive hepatitis B-core antibody and 1 because of a positive IgM test for cytomegalovirus. At initial examination 3 potential donors had a positive culture for Ureaplasma; all 3 were treated with 3 weeks of tetracycline, and repeat cultures were all negative. Routine followup screening was performed on all donors at 3-month intervals for all sexually transmitted diseases. During this 14-month period cultures converted to positive for Ureaplasma in 4 donors. Furthermore, 1 donor at 6 months contracted gonorrhea. He was treated but no longer used as a donor. Since initiation of the outlined protocol more than 800 inseminations have been performed using fresh semen with no case of sexually transmitted diseases reported from our recipients. We conclude that careful sexual history, and frequent donor and semen evaluation are necessary for prevention of diseases that might be transmitted sexually. If these precautions are strictly observed use of donor semen is safe and effective.

Ontogeny of insulin binding in different regions of the rat brain

Insulin binding was measured on crude mitochondrial or plasma membranes prepared from different rat brain regions during postnatal development. In the cerebral cortex and brainstem, insulin binding decreased 60-70% between birth and the adult period. In the cerebellum, insulin binding doubled in the first 10 postnatal days and then decreased 40% in the adult, while in the olfactory bulb, insulin binding changed little during postnatal development. Postnatal reductions of insulin binding in cerebral cortex and brainstem were from a loss of binding sites and not from a change in binding affinity. Of the major postnatal developmental processes, maximal insulin binding was most closely associated with neuronogenesis, less closely with gliogenesis and not with synaptogenesis, neural process formation or myelination.

Management of urinary incontinence after prostatectomy with the artificial urinary sphincter

A total of 37 patients underwent implantation of the artificial urinary sphincter for urinary incontinence after prostatectomy. Followup was 4 to 96 months, with a mean of 37 months. Social continence was achieved in 94.5 per cent of the patients. No abnormality of detrusor function was found in any patient. Prior pelvic irradiation appears to increase the risk of cuff erosion. Routine nocturnal deactivation of the device together with primary deactivation is recommended to decrease the incidence of cuff erosion in this patient group.

Effect of starvation on insulin receptors in rat brain

To determine the effect of starvation on brain insulin receptors, rats were fed 4 g of chow/day for 14 days and then P2 fraction membranes were prepared from different brain regions. Compared to the fed state, there was an 18% reduction of insulin binding in olfactory bulbs from starved animals, but no change in the cerebellum, frontal cortex, amygdala, medial hypothalamus or lateral hypothalamus. A 15% reduction of olfactory bulb insulin binding was obtained by totally starving animals for four days. When membrane content was measured using the plasma membrane marker Na/K ATPase, insulin binding decreased by 26% and 14% in olfactory bulb membranes from starved and totally starved animals, respectively. The starvation-induced change in olfactory bulb binding was due to a loss of binding sites and not a decrease in binding affinity. Non-specific catabolism of protein and a change in the composition of membranes following starvation were excluded as causes for this effect. As streptozotocin induced diabetes had no effect on brain insulin binding, it was concluded that hypoinsulinaemia associated with starvation had not caused the reduction in olfactory bulb binding. Under similar conditions of starvation and diabetes, insulin binding in liver plasma membranes increased 26% and 38%, respectively. At 8 and 14 days of starvation, the reductions in olfactory bulb insulin binding and body weight were similar. On refeeding for three days, there was no increase in insulin binding, although body weight increased 7%. On refeeding for eight days, olfactory bulb insulin and body weight had returned to near normal.(ABSTRACT TRUNCATED AT 250 WORDS)

Male urinary incontinence. What do you do?

Urinary incontinence is a common ailment in men. Treatment, although readily available, is often overlooked. An understanding of the anatomy and physiology of the continence mechanism aids in proper diagnostic evaluation. Determination of the cause involves a complete history and physical examination, urodynamic studies, and radiologic tests. Treatment of incontinence is based on the specific cause. In general, conservative management with pharmacologic manipulation is the primary form of treatment. Surgical intervention, when indicated, offers a high success rate, particularly since the advent of the artificial urinary sphincter.

Subcellular localization of rat brain insulin binding sites

Fractions and subcellular structures were prepared from rat brain homogenate and their purity was assessed using enzyme markers, gamma-aminobutyric acid binding, DNA content, and electron microscopy. Insulin binding was highest on the plasma membrane preparations and approximately 50% less so on brain homogenate crude mitochondrial (P2), myelinated axon, and synaptosome preparations. Very low levels of binding were found on mitochondria and nuclei. Differences in binding between fractions were due to numbers of binding sites, and not variable binding affinity. There was a close relationship between insulin binding and the activity of Na/K ATPase (E.C. 3.6.1.4) in all fractions (r = 0.98). Insulin binding to the P2 was compared with plasma membrane fractions in seven brain regions, and the results demonstrated the same close relationship between insulin binding and plasma membrane content in all regions except hypothalamus. Plasma membrane insulin binding was well represented by the binding on P2 membranes in all regions except hypothalamus and brainstem. It was concluded that insulin binding is distributed evenly over the surface of brain cells and is not increased on nerve endings.

Predictive parameters of successful varicocele repair

A total of 130 men presenting with oligospermia and clinically identifiable scrotal varicoceles was evaluated, treated surgically and followed for 1 year for pregnancy rate. The treatment outcome was compared to an age-matched cohort of 83 oligospermic men who had received empirical medical therapy with clomiphene citrate (25 mg. per day) for the same 1-year interval. This study was done to contrast treatment modalities in infertility and not as a strict control. Only eugonadotropic patients in both groups were used for comparison. In the varicocele group the over-all pregnancy rate was 38.5 per cent. Four variables (a lack of testicular atrophy, sperm density greater than 50 million per ejaculate, sperm motility 60 per cent or more and serum follicle-stimulating hormone values less than 300 ng. per ml.) proved to be accurate preoperative predictors of postoperative pregnancy success. Four other variables (varicocele size and laterality, sperm forward progression greater than 2 and normal sperm morphology 60 per cent or more) did not yield statistically significant rates of improvement in pregnancy postoperatively. The pregnancy rate of the eugonadotropic patients undergoing varicocele repair was 45.8 per cent. Despite statistical similarity in patient age, sperm density and mean gonadotropin levels the medically treated patients had a pregnancy rate of only 25.5 per cent, significantly lower than the surgically treated patients. In summary, patients with an identifiable varicocele had a greater chance of achieving a pregnancy following surgical correction than did those treated with empirical drug therapy. In addition, certain preoperative variables in the physical and laboratory analyses appeared to portend a greater surgical response.

Relationship of nonreturn rates of dairy bulls to binding affinity of heparin to sperm

The binding of the glycosaminoglycan [3H] heparin to bull spermatozoa was compared with nonreturn rates of dairy bulls. Semen samples from five bulls above and five below an average 71% nonreturn rate were used. Samples consisted of first and second ejaculates on a single day collected 1 d/wk for up to 5 consecutive wk. Saturation binding assays using [3H] heparin were performed to quantitate the binding characteristics of each sample. Scatchard plot analyses indicated a significant difference in the binding affinity for [3H] heparin between bulls of high and low fertility. Dissociation constants were 69.0 and 119.3 pmol for bulls of high and low fertility, respectively. In contrast, the number of binding sites for [3H] heparin did not differ significantly among bulls. Differences in binding affinity of [3H] heparin to bull sperm might be used to predict relative fertility of dairy bulls.

Genetic nature of regression of Rous sarcoma virus-induced tumors in crosses of Regional Poultry Research Laboratory lines 6 and 7(2)

Regional Poultry Research Laboratory (RPRL) inbred lines 6(1), 6(3), and 7(2) and F1, F2, and reciprocal backcross progenies of these lines were used to investigate host-gene effects upon the regression of Rous sarcoma virus (RSV)-induced tumors. Lines 6(1) and 6(3) were susceptible to subgroup A and C lymphoid leukosis (LL) viruses and line 7(2) was resistant to subgroup A but was segregating for susceptibility to subgroup C LL virus. Viruses of RSV subgroups A and C were used. Lines 6(1), 6(3), and 7(2) were homozygous for shared blood group alleles B2, C5, L1 and r. The incidence of tumor regression was higher in line 6(3) than in 7(2), and in reciprocal F1 crosses of these lines was of the same order of magnitude as in line 6(3). Progeny from F1 generation parents mated to line 6(3) had a higher frequency of regression than offspring from F1 generation parents mated to line 7(2). The frequency of regression in F2 generation offspring was intermediate between the two backcrosses. The data suggest that either a locus (or loci) other than L and B has a role in Rous tumor regression in this species or the immune response region of the B blood group-major histocompatibility complex differs in the two lines even though the serological and/or graft vs. host regions have not been shown to differ.