Activation of central melanocortin receptors by MT-II increases cavernosal pressure in rabbits by the neuronal release of NO

1. Melanotan-II had been reported to cause penile erections in men with erectile dysfunction. In the present study, we investigated the mechanisms by which systemic administration of MT-II increases intracavernosal pressure in anaesthetized rabbits. 2. MT-II (10 microM) had no effect on electrical field stimulation-evoked relaxations of rabbit corpus cavernosal strips in vitro. 3. Intravenous injection of MT-II (66 and 133 microg kg(-1) elicited dose-related increases in cavernosal pressure. SHU 9119 (3 microg kg(-1), i.v.), a non-selective antagonist of MC(3) and MC(4) receptors did not significantly affect either cavernosal pressure or systemic blood pressure but abolished the MT-II-induced increases in cavernosal pressure. SHU 9119 also inhibited the depressor response produced by MT-II. 4. Intracavernosal injection 100 microl of the cocktail containing phentolamine mesylate (1 mg ml(-1)), papaverine (20 mg ml(-1)) and PGE1 (20 microg ml(-1)) increased the cavernosal pressure by about 4 fold. 5. The role of NO-cyclic GMP dependent pathway to MT-II-induced increases in cavernosal pressure was investigated by bilateral transection of the pudendal nerves and by inhibition of NO synthase with L-NAME (20 mg kg(-1), i.v. over 30 min). Ablation of the pudendal nerves or pretreatment with L-NAME abolished the MT-II-induced increases in intracavernosal pressure in anaesthetized rabbits. 6. The data suggest that activation of central melanocortin receptors by MT-II increases cavernosal pressure by the neuronal release of NO.

Impact of Transcendental Meditation on cardiovascular function at rest and during acute stress in adolescents with high normal blood pressure

OBJECTIVE

This study examined the impact of the Transcendental Meditation (TM) program on cardiovascular (CV) reactivity in adolescents with high normal BP.

METHOD

Thirty-five adolescents [34 African Americans (AAs), 1 Caucasian American (CA); ages 15-18 years] with resting systolic blood pressure (SBP) between the 85th and 95th percentile for their age and gender on three consecutive occasions, were randomly assigned to either TM (n=17) or health education control (CTL, n=18) groups. The TM group engaged in 15-min meditation twice each day for 2 months including sessions during school lunch break. Primary CV outcome measures were changes in blood pressure (BP), heart rate (HR), and cardiac output (CO) at rest and in response to two laboratory stressors, a simulated car driving stressor and an interpersonal social stressor interview.

RESULTS

The TM group exhibited greater decreases in resting SBP (P<.03) from pre- to postintervention, compared to the CTL group. The TM group exhibited greater decreases from pre- to postintervention in SBP, HR, and CO reactivity (P's<.03) to the simulated car driving stressor, and in SBP reactivity (P<.03) to the social stressor interview.

CONCLUSION

The TM program appears to have a beneficial impact upon CV functioning at rest and during acute laboratory stress in adolescents at-risk for hypertension.

Randomised controlled trial of an interactive multimedia decision aid on benign prostatic hypertrophy in primary care

OBJECTIVE

To determine whether a decision aid on benign prostatic hypertrophy influences decision making, health outcomes, and resource use.

DESIGN

Randomised controlled trial.

SETTING

33 general practices in the United Kingdom.

PARTICIPANTS

112 men with benign prostatic hypertrophy.

INTERVENTION

Patients' decision aid consisting of an interactive multimedia programme with booklet and printed summary.

OUTCOME MEASURES

Patients' and general practitioners' perceptions of who made the decision, decisional conflict scores, treatment choice and prostatectomy rate, American Urological Association symptom scale, costs, anxiety, utility, and general health status.

RESULTS

Both patients and general practitioners found the decision aid acceptable. A higher proportion of patients (32% v 4%; mean difference 28%, 95% confidence interval 14% to 41%) and their general practitioners (46% v 25%; 21%, 3% to 40%) perceived that treatment decisions had been made mainly or only by patients in the intervention group compared with the control group. Patients in the intervention group had significantly lower decisional conflict scores than those in the control group at three months (2.3 v 2.6; -0.3, -0.5 to -0.1, P<0.01) and this was maintained at nine months. No differences were found between the groups for anxiety, general health status, prostatic symptoms, utility, or costs (excluding costs associated with the video disc equipment).

CONCLUSIONS

The decision aid reduced decisional conflict in men with benign prostatic hypertrophy, and the patients played a more active part in decision making. Such programmes could be delivered cheaply by the internet, and there are good arguments for coordinated investment in them, particularly for conditions in which patient utilities are important.

Randomised controlled trial of an interactive multimedia decision aid on hormone replacement therapy in primary care

OBJECTIVE

To determine whether a decision aid on hormone replacement therapy influences decision making and health outcomes.

DESIGN

Randomised controlled trial.

SETTING

26 general practices in the United Kingdom.

PARTICIPANTS

205 women considering hormone replacement therapy.

INTERVENTION

Patients' decision aid consisting of an interactive multimedia programme with booklet and printed summary.

OUTCOME MEASURES

Patients' and general practitioners' perceptions of who made the decision, decisional conflict, treatment choice, menopausal symptoms, costs, anxiety, and general health status.

RESULTS

Both patients and general practitioners found the decision aid acceptable. At three months, mean scores for decisional conflict were significantly lower in the intervention group than in the control group (2.5 v 2.8; mean difference -0.3, 95% confidence interval -0.5 to -0.2); this difference was maintained during follow up. A higher proportion of general practitioners perceived that treatment decisions had been made "mainly or only" by the patient in the intervention group than in the control group (55% v 31%; 24%, 8% to 40%). At three months a lower proportion of women in the intervention group than in the control group were undecided about treatment (14% v 26%; -12%, -23% to -0.4%), and a higher proportion had decided against hormone replacement therapy (46% v 32%; 14%, 1% to 28%); these differences were no longer apparent by nine months. No differences were found between the groups for anxiety, use of health service resources, general health status, or utility. The higher costs of the intervention were largely due to the video disc technology used.

CONCLUSIONS

An interactive multimedia decision aid in the NHS would be popular with patients, reduce decisional conflict, and let patients play a more active part in decision making without increasing anxiety. The use of web based technology would reduce the cost of the intervention.

[Vaginismus--a psychiatric perspective, "secrets" and other psychodynamic causes]

Vaginismus is a disorder involving both psychiatry and gynecology. Psychiatric help is sought in only a small proportion of cases, although it is probable that the psychological etiology of the disorder is more frequent than generally recognized. This article deals with the causes and psychological circumstances of the disorder. Five cases are presented. In the first three cases, primary vaginismus caused unconsummated marriage in young women of religious or traditional background. In these cases a "secret" was revealed relating to a previous sexually related experience. This provides the basis for therapy. The other cases describe secondary vaginismus which appeared in older women who developed the symptom after a number of years of marriage. This article discusses the different psychotherapeutic approaches for the two types of cases. In the former cases, therapy may be brief and the prognosis is favorable. In the second case type, there is often more significant personality or marital pathology requiring prolonged and extensive psychotherapy. The authors stress the need for physicians to be mindful of cases of vaginismus requiring psychiatric intervention rather than gynecological treatment.

An HIV-1 transgenic rat that develops HIV-related pathology and immunologic dysfunction

We report, to our knowledge, the first HIV type 1 (HIV-1) transgenic (Tg) rat. Expression of the transgene, consisting of an HIV-1 provirus with a functional deletion of gag and pol, is regulated by the viral long terminal repeat. Spliced and unspliced viral transcripts were expressed in lymph nodes, thymus, liver, kidney, and spleen, suggesting that Tat and Rev are functional. Viral proteins were identified in spleen tissue sections by immunohistochemistry and gp120 was present in splenic macrophages, T and B cells, and in serum. Clinical signs included wasting, mild to severe skin lesions, opaque cataracts, neurological signs, and respiratory difficulty. Histopathology included a selective loss of splenocytes within the periarterial lymphoid sheath, increased apoptosis of endothelial cells and splenocytes, follicular hyperplasia of the spleen, lymphocyte depletion of mesenteric lymph nodes, interstitial pneumonia, psoriatic skin lesions, and neurological, cardiac, and renal pathologies. Immunologically, delayed-type hypersensitivity response to keyhole limpet hemocyanin was diminished. By contrast, Ab titers and proliferative response to recall antigen (keyhole limpet hemocyanin) were normal. The HIV-1 Tg rat thus has many similarities to humans infected with HIV-1 in expression of viral genes, immune-response alterations, and pathologies resulting from infection. The HIV-1 Tg rat may provide a valuable model for some of the pathogenic manifestations of chronic HIV-1 diseases and could be useful in testing therapeutic regimens targeted to stages of viral replication subsequent to proviral integration.

Effects of position and speed on joint torques and knee shear after ACL injury

PURPOSE

The purpose of this study was to assess the effect of joint position and movement speed on hip (HT) and knee (KT) extensor torque, HT/KT ratio (HKR), and anterior tibial shear (S) in presurgical-ACL deficient (PRE; N = 15), post-ACL reconstructed (POST; N = 15), and uninjured controls (CON; N = 15).

METHODS

Measurements were recorded on a semirecumbent variable resistance, closed-chain dynamometer. Tests were conducted at 1 and 1.5 Hz and maximum speed at 33% and 50% 1RM. HT, KT, and S were recorded during the extension phase of the cycle (85 degrees -25 degrees of knee flexion).

RESULTS

KT was greatest when the knee was more flexed, whereas HT dominated when it was more extended. This suggests that the hamstrings, as a component of the hip extensors, may generate considerable propulsive force during knee extension, which may help counter anterior tibial shear. S increased whereas KT decreased, suggesting that the quadriceps continue to generate shear force despite the decreasing mechanical advantage producing KT. Increasing knee extension speed significantly decreased S in the POST and CON groups. The correlations between KT and S changed from significantly negative to significantly positive as the knee extended from 85 degrees to 25 degrees in the POST and CON groups. This may be related to the orientation of the patellar tendon, relative to the tibial longitudinal axis that shifts from a posterior to anterior direction, as the knee extends.

CONCLUSIONS

Joint position and movement speeds affect the magnitude of hip and knee torques and anterior tibial shear. Reducing the magnitude of S during heavy loads may be a normal phenomenon, and POST surgical subjects may retain or regain this function by 1 yr after surgery.

Discrimination between individual humans by domestic fowl (Gallus gallus domesticus)

1. We demonstrate that Barred-Rock and Isa-Brown hens can discriminate between the presence of 2 different humans and use this information as a cue for whether or not to make an operant response. 2. This demonstration in domestic fowl, the first of its kind in any avian subject, is consistent with a growing body of evidence that many species, including agricultural animals, are surprisingly adept at differentiating between humans. 3. Such a discriminative ability carries considerable implications for issues related to husbandry, production and welfare.

Cardiovascular (CV) responsivity and recovery to acute stress and future CV functioning in youth with family histories of CV disease: a 4-year longitudinal study

Blood pressure (BP) and heart rate (HR) data obtained during supine rest, in response to and recovery from four laboratory stressors in a baseline year were used to predict supine resting BP and HR values obtained during each of four consecutive annual follow-up evaluations. Subjects were 385 normotensive youth [95 African American (AA) males, 106 AA females, 92 European American (EA) males, 92 EA females] (mean age 12.7+/-2.6 at baseline year) with a positive family history of cardiovascular disease (CVD). During the baseline evaluation subjects were presented with four laboratory stressors (namely, postural change, video game challenge, social competence interview, and parent--child conflict discussion). The BP and HR values taken during each of the laboratory stressors and during the post stressor recovery periods were converted to z-scores which were averaged to yield aggregate measures for systolic and diastolic BP and HR responsivity and recovery. The data obtained during the baseline evaluation were subsequently used to predict the follow-up values of supine resting BP and HR. The prediction models were fairly consistent across each of the 4 follow-up years. Responsivity or recovery accounted for up to 6% of the total variance after accounting for baseline values. Within the prediction models responsivity or recovery accounted for 4--56% of the variance. The predictive value of the derived models did not decline from one annual evaluation to the next over the length of the study. CV recovery may supplement resting and responsivity in the prediction of future development of CVD

The wandering psychiatric emergency room--design, location and transformations

We describe the changes in location and philosophy of a psychiatric emergency room over a period of 20 years. Four phases are described in which location, size, modes of access as well as internal and external boundaries reflect philosophies of treatment and the evolving identity of a psychiatric emergency room. The four phases include an early embryonic stage, a second stage involving rapid development of services, a third stage involving regression and consolidation and a fourth stage representing a fully developed independent service. The authors stress both external and rational considerations, such as mental health policies and budget, as well as unconscious irrational processes, which reflect the dynamic forces within the organization.

Determination of twin zygosity: a comparison of DNA with various questionnaire indices

This study examined cross-validation and test-retest reliability of questions and questionnaire indices commonly used for twin zygosity classification. Mothers of 58 monozygotic (MZ) and 52 dizygotic (DZ) same sex twin pairs were interviewed by telephone to answer questions regarding the similarity of their twins (mean age = 14.6 +/- 2.8 years). A logistic regression equation correctly classified 91% of both MZ and DZ twin pairs in our sample using 7 of the 12 zygosity questions. The internal consistency for the total questionnaire (Cronbach's alpha) was 0.88. The median two month temporal stability estimate for the individual questions was r = .56 and r = .79 for the test total. For the cross-validation, zygosity classification indices taken from 9 previous studies were applied to our sample and compared to classification according to DNA microsatellite analyses (agreement range = 44 to 100%). The accuracy of the classification indices was significantly lower than the original studies for 62% of the comparisons. If zygosity determination with DNA markers or blood group typing for all subjects is not feasible, rather than using classification indices based on other studies, an optimal classification scheme can be achieved by using a zygosity questionnaire of which the reliability and validity of the questions is established in a random subsample of the same twin cohort.

Schizophrenia patients demonstrate a dissociation on declarative and non-declarative memory tests

Declarative memory refers to the recall and recognition of factual information. In contrast, non-declarative memory entails a facilitation of memory based on prior exposure and is typically assessed with priming and perceptual-motor sequencing tasks. In this study, schizophrenia patients were compared to normal comparison subjects on two computerized memory tasks: the Word-stem Priming Test (n=30) and the Pattern Sequence Learning Test (n=20). Word-stem Priming includes recall, recognition (declarative) and priming (non-declarative) components of memory. The schizophrenia patients demonstrated an impaired performance on recall of words with relative improvement during the recognition portion of the test. Furthermore, they performed normally on the priming portion of the test. Thus, on tests of declarative memory, the patients had retrieval deficits with intact performance on the non-declarative memory component. The Pattern Sequence Learning Test utilizes a serial reaction time paradigm to assess non-declarative memory. The schizophrenia patients' serial reaction time was significantly slower than that of comparison subjects. However, the patients' rate of acquisition was not different from the normal comparison group. The data suggest that patients with schizophrenia process more slowly than normal, but have an intact non-declarative memory. The schizophrenia patients' dissociation on declarative vs. non-declarative memory tests is discussed in terms of possible underlying structural impairment.

The effects of life events on cardiovascular reactivity to behavioral stressors as a function of socioeconomic status, ethnicity, and sex

OBJECTIVE

The purposes of this study were 1) to examine the effects of stressful life events on cardiovascular reactivity to acute laboratory stressors in youth and 2) to determine whether these effects varied as a function of socioeconomic status, ethnicity, and/or sex.

METHODS

Four hundred eighty-three youths (mean age = 16.7 years; 249 Caucasian Americans [126 males, 123 females] and 234 African Americans [109 males, 125 females]) completed the Adolescent Resources Challenge Scale (ARCS), a measure of stressful life events, and underwent two laboratory stressors (a car-driving simulation and the Social Competence Interview) during which blood pressure, heart rate, cardiac output, and total peripheral resistance were assessed.

RESULTS

Youths who reported high levels of stressful life events showed smaller increases in blood pressure (both systolic and diastolic) and heart rate to the car-driving simulation but larger increases in cardiac output in response to the Social Competence Interview than did youths who reported low levels of stressful life events. The effect of stressful life events on cardiovascular reactivity was not moderated by sex, ethnicity, or socioeconomic status. Higher family socioeconomic status was associated with greater blood pressure, heart rate, and cardiac output increases in response to the Social Competence Interview.

CONCLUSIONS

The attenuating effects of stressful life events on cardiovascular reactivity in response to car-driving simulation in youths are consistent with an inoculation effect, whereas the potentiating impact of stressful life events on reactivity observed during the social stressor interview is compatible with a possible cost of coping effect.

Can rabbits tell humans apart?: Discrimination of individual humans and its implications for animal research

To predict when food reward was available, 12 New Zealand White rabbits were trained to discriminate between two humans. All subjects had significantly higher response rates and greater behavioral arousal in the presence of the positive stimulus person. The ability to discriminate between individual humans sets the stage for unanticipated Pavlovian conditioning, which may have considerable implications for animal research in behavioral and biomedical settings.

Human hip and knee torque accommodations to anterior cruciate ligament dysfunction

It has been postulated that the adaptations of lower extremity function exhibited by anterior cruciate ligament (ACL) deficient and post-ACL surgical patients represent early accommodations to the loss of ACL function after injury so that excessive anterior displacement of the tibia is prevented. Prior studies have suggested that compensation patterns in ACL deficient and post-ACL surgical subjects may affect joint moments of the knee as well as the hip. However, the variance in knee and hip forces between ACL deficient, post-surgical ACL and uninjured groups has not been clearly elucidated. The purpose of this study was to assess hip:knee extensor torque ratios relative to anterior tibia shear in pre-surgical-ACL deficient, post-surgical and uninjured subjects. Measurements of hip and knee joint moments and anterior tibia shear were recorded from 45 injured and uninjured subjects (21 men, 24 women) during lower extremity, variable resistance exercise. Anterior tibia shear was computed by decomposing joint moments and reaction forces according to a model derived from cadaver knee dissections and radiography, in combination, to estimate the tibio-femoral compressive and shear forces generated by the patellar tendon at various angles throughout the knee joint range. Three groups of subjects were studied: recently injured ACL deficient pre-surgical subjects who were scheduled for immediate surgery (PRE; n = 15); postsurgical subjects who had undergone ACL reconstructive surgery at least 1 year prior to testing (POST; n = 15); and uninjured controls (CON; n = 15). All PRE and POST subjects had a normal contralateral limb. Tests were conducted under six conditions: 1 and 1.5 Hz cadence and maximal speed at 33% and 50% one repetition maximum resistance. The results revealed that the hip:knee ratios were significantly greater for the post-ACL surgical group than the PRE and CON groups (P<0.01; P<0.03). There were significant negative correlations between the hip extensor:knee extensor torque ratios and maximal anterior tibia shear across all groups. The hip:knee extensor torque ratio increased with decreased anterior tibia shear in all groups with significant correlations ranging from -0.55 to -0.88 (P<0.01) for the injured limbs of PRE and POST groups, and -0.64 to -0.78; (P<0.01) for the CON group. The highest overall correlations were found for the post-surgical subjects. The results revealed that anterior tibia shear declined significantly with speed (P<0.01) in all groups. However, the converse was true for the hip:knee extensor torque ratio across speeds. The ratio increased significantly with speed (P<0.001) for all groups at the 33% and 50% resistances. The results suggest (1) that post-ACL surgical subjects appear to accommodate to ACL substitution by using hip extensors to a significantly greater extent than the uninjured controls in closed-chain lower extremity exercise; (2) that the hip:knee extensor torque ratio is significantly related to the magnitude of anterior tibia shear; and (3) that the anterior tibia shear is significantly reduced as speed increases in closed-chain lower extremity exercise.