The association between early menopause and risk of ischaemic heart disease: Influence of Hormone Therapy

Randomised clinical trials find no protection against development of ischaemic heart disease by use of Hormone Therapy (HT) after the age of 50 years. Observational studies suggest that early menopause is a risk factor for ischaemic heart disease. Yet, a clinical very relevant question is whether HT reduces this risk associated with early menopause.

OBJECTIVE

To analyse whether early menopause based on various causes are independent risk factors for ischaemic heart disease, and to investigate whether the risks are modified by use of HT.

METHODS

In a prospective cohort study questionnaires were mailed to Danish female nurses above 44 years of age in 1993. Information on menopause, use of HT and lifestyle was obtained. In total 19,898 (86%) nurses fulfilled the questionnaire, among them 10.533 were postmenopausal with definable menopausal age, free of previous ischaemic heart disease, stroke or cancer. Through individual linkage to national register incident cases of ischaemic heart disease were identified until end of 1998.

RESULTS

Menopause below both age 40 and 45 was associated with an increased risk of ischaemic heart disease, seeming most pronounced for women who had an early ovariectomy but also among spontaneous menopausal women. Generally HT did not reduce the risk except for the early-ovariectomised women, where no increased risk of ischaemic heart disease for HT users was found.

CONCLUSION

We found an increased risk of ischaemic heart disease associated with early removal of the ovaries that might be reduced with HT. The present study need confirmation from other studies but suggests that early ovariectomised women could benefit from HT.

Obesity and sarcopenia after menopause are reversed by sex hormone replacement therapy

OBJECTIVE

Menopause is linked to an increase in fat mass and a decrease in lean mass exceeding age-related changes, possibly related to reduced output of ovarian steroids. In this study we examined the effect of combined postmenopausal hormone replacement therapy (HRT) on the total and regional distribution of fat and lean body mass.

RESEARCH METHODS AND PROCEDURES

Sixteen healthy postmenopausal women (age: 55 +/- 3 years) were studied in a placebo-controlled, crossover study and were randomized to 17beta estradiol plus cyclic norethisterone acetate (HRT) or placebo in two 12-week periods separated by a 3-month washout. Total and regional body composition was measured by DXA at baseline and in the 10th treatment week in both periods. Changes were compared by a paired Student's t test.

RESULTS

The change in body weight during HRT was equal to the change during placebo (-24.6 g vs. -164 g, p = 0.42), but relative fat mass was significantly reduced (-0.5% vs. +1.24%, p < 0.01). During HRT, compared with during placebo, lean body mass increased (+347 g vs. -996 g, p < 0.01) and total fat mass decreased (-400 g vs. +836 g, p = 0.06). Total bone mineral content increased (+28.9 g vs. -4.4 g, p = 0.04) and abdominal fat decreased (-185 g vs. +253 g, p = 0.04) during HRT compared with placebo.

DISCUSSION

HRT is linked to the reversal of both menopause-related obesity and loss of lean mass, without overall change in body weight. The increase in lean body mass during HRT is likely explained by muscle anabolism, which in turn, prevents disease in the elderly.

Penile erection: possible role for vasoactive intestinal polypeptide as a neurotransmitter

Concentrations of vasoactive intestinal polypeptide were measured in blood drawn from the cavernous spaces of corpus cavernosum of the human penis during tumescence and erection, and the effect of injecting the polypeptide into the cavernous spaces was studied. A significant release of the polypeptide was shown during tumescence and erection. Injection of exogenous vasoactive intestinal polypeptide induced erection. These findings support the concept of vasoactive intestinal polypeptide as a neurotransmitter in penile erection and suggest that it might have a clinical use in patients suffering from erectile dysfunction.

Hormone replacement therapy and risk of non-fatal stroke

BACKGROUND

The effect of postmenopausal hormone replacement therapy (HRT) on the risk of subtypes of stroke is as yet unclear. To investigate the effect of oestrogen and combined oestrogen-progestagen therapy on the risk of non-fatal haemorrhagic and thromboembolic stroke, we carried out a case-control study.

METHODS

From the Danish National Patient Register we identified all Danish women aged 45-64 years who had a non-fatal, first-ever cerebrovascular attack during 1990-92. Two age-matched controls were randomly selected for each case from the Danish National Person Register. Important correlates of hormone use and stroke, on which information was obtained from postal questionnaires, were controlled for by multivariate analyses based on log-linear graphical models. The analyses included data on 1422 cases classified in four subtypes of stroke (160 subarachnoid haemorrhage, 95 intracerebral haemorrhage, 846 thromboembolic infarction, 321 transient ischaemic attack) and 3171 controls.

FINDINGS

After adjustment for confounding variables and correction for the trend in sales of HRT preparations, no significant associations were detected between current use of unopposed oestrogen replacement therapy and non-fatal subarachnoid haemorrhage (odds ratio 0.52 [95% CI 0.23-1.22]), intracerebral haemorrhage (0.15 [0.02-1.09]), or thromboembolic infarction (1.16 [0.86-1.58]), respectively, compared with never use. Current use of combined oestrogen-progestagen replacement therapy had no significant influence on the risk of subarachnoid haemorrhage (1.22 [0.79-1.89]), intracerebral haemorrhage (1.17 [0.64-2.13]), or thromboembolic infarction (1.17 [0.92-1.47]). A significantly increased incidence of transient ischaemic attacks among former users of HRT and among current users of unopposed oestrogen may to some extent be explained by selection--HRT users being more aware of symptoms than non-users.

INTERPRETATION

Unopposed oestrogen and combined oestrogen-progestagen replacement therapy have no influence on the risk of non-fatal thromboembolic or haemorrhagic stroke in women aged 45-64 years.

Risk factors among young women with endometrial cancer: a Danish case-control study

OBJECTIVE

This study was undertaken to identify and quantify risk factors for endometrial cancer among young women.

STUDY DESIGN

This case-control study included all Danish women <50 years old who had endometrial cancer diagnosed during the period 1987 to 1994. A total of 237 case patients and 538 population control subjects matched with the case patients for age and residence were included in the analysis.

RESULTS

Women with a family history of endometrial cancer had an odds ratio for endometrial cancer of 2.1 (95% confidence interval, 1.1-3.8)). Completion of 1 term pregnancy implied an odds ratio of 0.6 (95% confidence interval, 0.3-1.1). The risk of endometrial cancer decreased significantly with increasing age at first birth and with the number of induced abortions. Use of oral contraceptives for 1 to 5 years decreased the risk of endometrial cancer (odds ratio, 0.2; 95% confidence interval, 0.1-0.3). The odds ratio for endometrial cancer among women who received hormone replacement therapy for 1 to 5 years was 3.1 (95% confidence interval, 1.4-7.0). Body mass index was not demonstrated to be an independent risk factor in this study. The protective impacts of the different exposures (risk factors) can be expressed as etiologic fractions, which indicate how much each exposure reduces the occurrence of endometrial cancer compared with a situation without the existence of that particular exposure. These fractions were as follows: oral contraceptive use for > or =1 year, -45%; 2 term pregnancies, -88%; age > or =30 y when giving birth for the first time, -38%; and a history of incomplete pregnancy, -16%.

CONCLUSION

A number of risk factors for endometrial cancer are common to premenopausal and postmenopausal women: family history, reproductive history, hormone replacement therapy, and the use of oral contraceptives. Among young women reproductive variables imply the greatest prophylactic potential.

Assessment of performance measures and learning curves for use of a virtual-reality ultrasound simulator in transvaginal ultrasound examination

OBJECTIVE

To assess the validity and reliability of performance measures, develop credible performance standards and explore learning curves for a virtual-reality simulator designed for transvaginal gynecological ultrasound examination.

METHODS

A group of 16 ultrasound novices, along with a group of 12 obstetrics/gynecology (Ob/Gyn) consultants, were included in this experimental study. The first two performances of the two groups on seven selected modules on a high-fidelity ultrasound simulator were used to identify valid and reliable metrics. Performance standards were determined and novices were instructed to continue practicing until they attained the performance level of an expert subgroup (n = 4).

RESULTS

All 28 participants completed the selected modules twice and all novices reached the expert performance level. Of 153 metrics, 48 were able to be used to discriminate between the two groups' performance. The ultrasound novices scored a median of 43.8% (range, 17.9-68.9%) and the Ob/Gyn consultants scored a median of 82.8% (range, 60.4-91.7%) of the maximum sum score (P < 0.001). The ultrasound novices reached the expert level (88.4%) within a median of five iterations (range, 5-6), corresponding to an average of 219 min (range, 150-251 min) of training. The test/retest reliability was high, with an intraclass correlation coefficient of 0.93.

CONCLUSIONS

Competence in the performance of gynecological ultrasound examination can be assessed in a valid and reliable way using virtual-reality simulation. The novices' performance improved with practice and their learning curves plateaued at the level of expert performance, following between 3 and 4 h of simulator training.

Objective assessment of gynecologic laparoscopic skills using the LapSimGyn virtual reality simulator

BACKGROUND

Safe realistic training and unbiased quantitative assessment of technical skills are required for laparoscopy. Virtual reality (VR) simulators may be useful tools for training and assessing basic and advanced surgical skills and procedures. This study aimed to investigate the construct validity of the LapSimGyn VR simulator, and to determine the learning curves of gynecologists with different levels of experience.

METHODS

For this study, 32 gynecologic trainees and consultants (juniors or seniors) were allocated into three groups: novices (0 advanced laparoscopic procedures), intermediate level (>20 and <60 procedures), and experts (>100 procedures). All performed 10 sets of simulations consisting of three basic skill tasks and an ectopic pregnancy program. The simulations were carried out on 3 days within a maximum period of 2 weeks. Assessment of skills was based on time, economy of movement, and error parameters measured by the simulator.

RESULTS

The data showed that expert gynecologists performed significantly and consistently better than intermediate and novice gynecologists. The learning curves differed significantly between the groups, showing that experts start at a higher level and more rapidly reach the plateau of their learning curve than do intermediate and novice groups of surgeons.

CONCLUSION

The LapSimGyn VR simulator package demonstrates construct validity on both the basic skills module and the procedural gynecologic module for ectopic pregnancy. Learning curves can be obtained, but to reach the maximum performance for the more complex tasks, 10 repetitions do not seem sufficient at the given task level and settings. LapSimGyn also seems to be flexible and widely accepted by the users.

Spontaneous abortion: a prospective cohort study of younger women from the general population in Denmark. Validation, occurrence and risk determinants

OBJECTIVE

To assess the occurrence of spontaneous abortion, comparing two different data sources. To estimate the rate of spontaneous abortion over a 2-year period, and examine potential predictors of the risk for incident spontaneous abortion.

METHODS

We used interview data from a population-based prospective cohort study comprising 11,088 women and data from a linkage of the cohort with the Hospital Discharge Register to compare spontaneous abortions as reported in the interview with those identified in the register. Based on interview data, we estimated the rate of spontaneous abortion during the two-year follow-up. Finally, risk determinants for incident spontaneous abortion were analyzed by means of logistic regression.

RESULTS

A total of 654 spontaneous abortions before enrolment in the study were reported by the women compared to 531 abortions found in the register. More than 80% of the spontaneous abortions identified from both sources were recorded in the same year. During follow-up a total of 20.9% of pregnancies intended to be carried to term ended as a spontaneous abortion. In the risk factor analysis, we found that previous spontaneous abortion, being single, never having used oral contraceptives, and use of intrauterine device were associated with increased risk of subsequent spontaneous abortion. In addition, it was indicated that a short interpregnancy interval following a spontaneous abortion may confer an increased risk of abortion in the subsequent pregnancy.

CONCLUSION

We found a high rate of spontaneous abortion in the present study and an acceptable agreement between information obtained by interview and register information. More than 25% of the spontaneous abortions were only reported by the women, and this could not be explained by erroneously reported induced abortions, and may be early, nonhospitalized abortions. We confirm that number of previous spontaneous abortions is a strong determinant, and our data may also indicate a role of previous contraceptive habits. A role of the length of interpregnancy interval in the risk of spontaneous abortion cannot be ruled out.

Reliable and valid assessment of ultrasound operator competence in obstetrics and gynecology

OBJECTIVES

To explore the reliability and validity of a recently developed instrument for assessment of ultrasound operator competence, the Objective Structured Assessment of Ultrasound Skills (OSAUS).

METHODS

Three groups of 10 doctors with different levels of ultrasound experience in obstetrics and gynecology were included. The novices had less than 1 month of experience, the intermediate group had 12-60 months of experience and the senior participants were all consultants. Fifteen participants performed transabdominal fetal biometry and the other 15 participants performed systematic transvaginal gynecological ultrasound scans. All scans were video-recorded and assessed by two blinded consultants using the OSAUS scale. The OSAUS scores were compared between the groups using the Kruskal-Wallis test, and pass/fail scores were determined using the contrasting-groups method of standard setting.

RESULTS

For the transabdominal fetal biometry examinations, the mean ± SD OSAUS scores of the novices, intermediates and senior participants were 1.5 ± 0.4, 3.3 ± 0.6 and 4.4 ± 0.4, respectively (P = 0.003). For the systematic transvaginal scans, the mean ± SD OSAUS scores of the novices, intermediates and senior participants were 1.8 ± 0.2, 3.1 ± 0.1 and 3.9 ± 0.5, respectively (P = 0.003). Post-hoc comparisons showed significant differences between each of the groups for both types of scans. The pass/fail score was 2.5 for the transvaginal scan and 3.0 for the transabdominal biometry examinations. The inter-rater reliability was 0.89.

CONCLUSIONS

Ultrasound competence can be assessed in a reliable and valid way using the OSAUS scale. The pass/fail scores may be used to help determine when trainees are qualified for independent practice.

Vasoactive intestinal polypeptide (VIP) as a putative neurotransmitter in penile erection

The localization of vasoactive intestinal polypeptide (VIP) in the male genitourinary tract was investigated in the rabbit and man by means of radioimmunoassay and immunohistochemistry. In addition, the in vitro effect of VIP upon penile smooth muscle from man, the Vervet monkey, and the rabbit was investigated. Significant concentrations of VIP immunoreactivity were found in the human penis and all the organs of the rabbit genital tract apart from the testis. VIP immunoreactive nerve fibres were observed in the erectile tissue of the human and rabbit penis and in the other organs of the rabbit genital tract apart from the testis. Fibres were most abundant in association with blood vessels, in smooth muscle tissue, and subepithelially in glandular tissue. Strips of smooth muscle taken from the corpus cavernosum of Vervet monkey and man showed a dose-dependent relaxation in response to VIP at concentrations of 6 X 10(-8) mol X L-1 and 6 X 10(-7) mol X L-1. The data indicate that VIP may be an inhibitory neurotransmitter involved in the nervous control of penile erection.

Fast track hysterectomy

OBJECTIVE

To identify factors limiting early discharge after laparoscopically assisted vaginal hysterectomy (LAVH) and abdominal hysterectomy, in a fast track setting with emphasis on information, treatment of pain, early mobilization, and early food intake.

STUDY DESIGN

A prospective, descriptive study of 32 unselected women allocated to either abdominal hysterectomy (n=16) or LAVH (n=16). The patients received the same information, care, and advice for the perioperative period except for an assumed 1-day hospital stay in the LAVH-group and 2 days in the abdominal group.

RESULTS

Patients were discharged median 1 day (1-3) after LAVH and 2 days (2-4) after abdominal hysterectomy. Work was resumed median 23 days after abdominal hysterectomy and 28 days after LAVH (P > 0.05).

CONCLUSIONS

The study questions the previously proposed advantages of shortened hospitalization and convalescence after LAVH compared with abdominal hysterectomy. Further studies with active rehabilitation are needed to demonstrate real differences between laparoscopic and open hysterectomy.

Vasoactive intestinal polypeptide (VIP) provokes vaginal lubrication in normal women

The human vagina is known to be heavily innervated by vasoactive intestinal polypeptide (VIP) immunoreactive nerve fibres. In the present study we have examined the effect of VIP (900 pmol x kg-1 x h-1, IV during 30 min) on vaginal lubrication and blood flow in fourteen normal non-pregnant women. Vaginal blood flow was measured by the heat clearance technique and the vaginal lubrication quantified by the weight gain of preweighed filter papers placed on the surface of the vaginal wall for 30 min. Arterial blood pressure, pulse frequency and the concentration of VIP in peripheral blood were monitored. VIP (median concentrations of 200-300 pmol x l-1) induced a significant increase in vaginal blood flow accompanied by a 100% increase in vaginal lubrication (from 27 mg/cm2 to 53 mg/cm2). The VIP infusion lead to a significant increase in pulse frequency and a significant fall in diastolic arterial blood pressure. The findings suggest that VIP may participate in the control of the local physiological changes observed during sexual arousal: genital vasodilation and increase in vaginal lubrication.

Vasoactive intestinal polypeptide and the female genital tract: relationship to reproductive phase and delivery

Recently, vasoactive intestinal polypeptide (VIP) has been localized in nerve fibers in the human female genital tract. In the present investigation, the effect and concentration of VIP was studied in uterine tissue from pregnant and nonpregnant women, and the plasma concentration of VIP was measured in relationship to diurnal rhythm, intake of food, menstrual cycle, pregnancy, labor, age, and sexual arousal. In vitro VIP inhibited the contractions of the nonpregnant but not of the pregnant uterus. The median concentration of VIP in myometrium from pregnant women (less than 0.1 pmole/gm) was significantly lower than that in myometrium from nonpregnant women (1.6 pmoles/gm). The venous plasma concentrations of VIP during labor (10.5 to 13.0 pmoles/L) were significantly higher than those during pregnancy (2.0 to 5.0 pmoles/L) and the menstrual cycle of VIP increased significantly during sexual arousal, from 4.0 to 8.5 pmoles/L. The median arterial and venous concentrations in the umbilical cord (12.5 and 14.5 pmoles/L, respectively) were significantly higher than the concentration in maternal peripheral venous blood (5.2 pmoles/L). The plasma concentrations of VIP were not related to intake of food, diurnal rhythm, menstrual cycle, or age. The conclusion is that the function of VIP may be related to pregnancy, delivery, and sexual stimulation.

Does caffeine and alcohol intake before pregnancy predict the occurrence of spontaneous abortion?

BACKGROUND

Consumption of caffeine and alcohol is suspected to affect pregnancy outcome. Use of both stimulants is widespread and even minor effects on fetal viability are of public health interest.

METHODS

We performed a nested case-control study using prospective data from a population-based cohort comprising 11088 women aged 20-29 years. From this cohort, women who experienced either a spontaneous abortion (n = 303) or who gave birth (n = 1381) during follow-up [mean time: 2.1 years (range: 1.6-3.4)] were selected. Associations between self-reported exposures to caffeine and/or alcohol at enrolment and spontaneous abortion were analysed by means of logistic regression.

RESULTS

Compared with women with a pre-pregnancy intake of <75 mg caffeine per day, the adjusted odds ratio (95% confidence interval) for spontaneous abortion was 1.26 (0.77-2.06), 1.45 (0.87-2.41), 1.44 (0.87-2.37) and 1.72 (1.00-2.96) for a pre-pregnancy intake on 75-300, 301-500, 501-900 and >900 mg caffeine per day respectively (P = 0.05 for trend). A pre-pregnancy intake of alcohol was not a predictor for spontaneous abortion.

CONCLUSIONS

A high intake of caffeine prior to pregnancy seems to be associated with an increased risk of spontaneous abortion, whereas a low-to-moderate alcohol intake does not influence the risk.

Vasoactive intestinal polypeptide as a neurotransmitter in the female genital tract

Vasoactive intestinal polypeptide (VIP) has been demonstrated in nerve fibers of the female genital tract localized in synaptic vesicles. The VIP-containing nerve fibers seem to innervate nonvascular smooth muscle, blood vessels, and epithelial cells. Evidence is accumulating that VIP fulfills a number of the classical criteria to be a neurotransmitter in the female genital tract. It is likely that VIP is the mediator of genital functions, which are controlled by noncholinergic, nonadrenergic nerve fibers. VIP seems to play a role in the local nervous control of uterine smooth muscle, e.g., opening of the uterotubal junctions, and to be involved in vasodilatation in the uterus as wells as the vagina. In conclusion, a third or peptidergic division of the autonomic nervous system seems to participate in the nervous control of reproduction.

Which factors are associated with trainees' confidence in performing obstetric and gynecological ultrasound examinations?

OBJECTIVE

To explore the association between clinical training characteristics and trainees' level of confidence in performing ultrasound scans independently.

METHODS

A cross-sectional e-survey was distributed to members of the national societies of junior obstetricians/gynecologists in Denmark, Sweden and Norway (n = 973). Multiple linear regression models were used to explore the effect that amount of time spent in specialized ultrasound units and clinical experience had on trainees' confidence in performing ultrasonography independently. Exploratory factor analysis was used to identify factors that contributed to trainees' confidence in performing ultrasonography. Trainees' ultrasound confidence was finally compared with their expected levels of performance.

RESULTS

Of the 682 respondents (response rate 70.1%), 621 met the inclusion criteria. Clinical experience and time spent in specialized ultrasound units were predictors of trainees' confidence in performing ultrasonography independently (P < 0.001). Trainees required more than 24 months of clinical experience and 12-24 days of training in specialized ultrasound units in order to feel confident about performing transvaginal and transabdominal ultrasound scans independently. Three factors were related to ultrasound confidence: technical aspects, image perception and integration of scan into patient care. There were significant differences between trainees' level of confidence and their expected levels of performance (P < 0.001).

CONCLUSIONS

Clinical experience and time spent in specialized ultrasound units were predictors of trainees' confidence in performing ultrasonography independently. Discrepancies between trainees' confidence and their expected levels of performance raised concerns about the adequacy of current ultrasound training programs.

The regional distribution of receptors for vasoactive intestinal polypeptide (VIP) in the rat central nervous system

The regional distribution of receptors for vasoactive intestinal polypeptide (VIP) was studied in the rat central nervous system (CNS). The specific binding was highest in cerebral cortex, limbic forebrain and cerebellum, whereas moderate to low binding was found in hypothalamus, thalamus, brainstem and pituitary. The lowest binding was observed in pons and spinal cord. Scatchard analysis showed curvilinear plots with upward concavity, which was interpreted as two classes of binding sites. The Kd values were similar in all regions and calculated as 2.4 and 62 nmol/liter, respectively. The variations of specific [125I]VIP binding were due to differences in the total amount of receptors and were in the range of 1.7-8.6 pmol per mg protein. The regional distribution of VIP receptors was parallel with the occurrence of VIP-containing nerve terminals with exceptions of cerebellum, olfactory areas and nucleus caudatus, where a greater number of receptors than expected from the VIP content was found. In these regions, VIP may interact with receptors for a different, but homologous neuropeptide. In conclusion, the regional distribution of VIP receptors in CNS gives further evidence for the role of VIP as a central neurotransmitter.

Vaginal physiology during menstruation

We studied 18 young healthy women on the second, fourth, and 14th day of their menstrual cycle. Vaginal fluid was collected for measurement of oxygen and carbon dioxide tension (PO2 and PCO2) and specimens were collected for bacteriologic examination. The vaginal pH was measured at four different sites and the redox potential was measured in the top of the vagina. Staphylococcus aureus was found in three women. The PO2 ranged from 0 to 77 mm Hg on day 2; 0 to 76 mm Hg on day 4; and 0 to 53 mm Hg on day 14. The mean PCO2 (+/- SE) was 46 +/- 2 mm Hg on day 2; 62 +/- 4.5 mm Hg on day 4; and 50.6 +/- 8.5 mm Hg on day 14. The mean vaginal pH (+/- SE) was significantly higher on day 2 (6.6 +/- 0.3) compared with day 4 (5.3 +/- 0.3) and day 14 (4.2 +/- 0.2). The redox potential was significantly higher on day 14 compared with day 2 and day 4. No differences were found in values of women who took birth control pills and those of the women who did not.

Insulin receptors in rat brain cortex. Kinetic evidence for a receptor subtype in the central nervous system

Binding kinetics of porcine 125I-insulin were studied in synaptosomal and microsomal fractions of rat brain cortex. Receptor binding was temperature- and pH-dependent with optimum at 4 degrees C and pH 8.0-8.3. At 15 degrees C, steady state binding was heterogenous, and Scatchard analysis revealed two classes of receptors with Kd of 2 nmol/l and 40 nmol/l in amounts of 50 pmol/g and 200 pmol/g of membrane protein. Dissociation kinetics were biexponential with T1/2 of about 5 min and 180 min, and in contrast to other cell-types, not influenced by negative cooperativity. No receptor-mediated insulin degradation was detectable at 37 degrees C in the presence of bacitracin. Insulin analogues inhibited 125I-insulin binding with potencies relative to porcine insulin (%): human insulin 100, rat insulin (I + II) 71, coypu insulin 47, rat multiplication stimulating activity 8, porcine proinsulin 5, among which the three last values were significantly higher than in rat liver and fat cells. No competition was observed with porcine relaxin and mouse nerve growth factor up to about 1 mumol/l. Receptors were present in all regions of central nervous system with highest concentrations in the cerebral cortex, cerebellum and olfactory bulb, and lowest in the pons, medulla oblongata and spinal cord. In conclusion, insulin receptors in rat brain cortex are functionally different from other tissues regarding the insulin specificity and the absence of negative cooperativity. It is suggested that an insulin receptor subtype in rat brain mediates the growth activity of insulin on nerve cells.

Intracavernous self-injection with vasoactive intestinal polypeptide and phentolamine in the management of erectile failure

A total of 52 men, median age 55 years (range 28 to 74 years), with erectile failure was treated with vasoactive intestinal polypeptide and phentolamine. Impotence was classified as psychogenic in 3 patients, psychogenic/arteriogenic in 3, arteriogenic in 25, arteriogenic/neurogenic in 4, neurogenic in 5, venous leakage/psychogenic in 2, venous leakage/neurogenic in 1 and following venous leak surgery in 9. The patients were treated with 30 micrograms vasoactive intestinal polypeptide and 0.5 to 2.0 mg. phentolamine. A total of 1,380 self-injections was given and the number of injections per patient varied from 5 to 245. No patient had priapism, corporeal fibrosis or other serious complications. After sexual stimulation all patients obtained erection sufficient for penetration. Following ejaculation rigidity decreased normally. The median duration of treatment was 6 months (range 1 to 22). Nine patients discontinued treatment. One patient with severe arteriosclerosis experienced decreased effectiveness of the drug and received a penile prosthesis. Five patients elected not to perform self-injection any longer, 1 psychogenic impotent patient was cured, and 1 patient discontinued therapy due to palpitation and sweating. One patient died of a myocardial infarction not associated with this therapy.