Familiarity with conspecific odor and isolation-induced aggressive behavior in male mice (Mus domesticus)

Male Swiss CD-1 mice (Mus domesticus, n = 60) were isolated for 24 days. In the isolation group mice were exposed to their own odor; in the familiarity group mice were familiarized with pairmates' odor by daily exchange of bedding; and in the unfamiliarity group subjects (exposed) were familiarized with pairmates' odor, whereas the pairmates (nonexposed) were familiarized with odors of other isolated mice. Aggressive behavior was scored during 20-min sessions. Familiarity with the pairmate's odor (familiarity and exposed subgroups) caused an enhancement of aggressive behavior, shown by the highest frequency of tail rattling and offensive upright posture and by a decrease in latency to the 1st attack. Nonexposed subjects showed high values of submissive upright posture, screaming, fleeing, and freezing. The results suggest that dominantlike behavior, acquired in social isolation, may be directed toward a conspecific whose odor is familiar.

[Anterograde and retrograde cardioplegia in myocardial revascularization. An intraoperative contrast echographic study]

The aim of this study was to assess the distribution of antegrade and retrograde cardioplegia with intraoperative contrast echocardiography in patients undergoing coronary artery bypass grafting. Fifteen patients with chronic stable angina pectoris and severe coronary artery disease were studied. The severity of coronary artery disease was assessed at coronary angiography, using the Jeopardy Score System. The presence and the extent of collateral circulation was evaluated on the basis of preoperative coronary angiography and graded as: absent or poor; good or excellent. Coronary revascularization was carried out during extracorporeal circulation and myocardial protection was performed with antegrade (aortic root) and retrograde (right atrial) cardioplegia. The echo contrast agent was sterilely prepared 1 hour prior to surgery and consisted of a solution of sonicated 5% human albumin microbubbles. Two ml of sonicated albumin were injected along with antegrade cardioplegia and 4 ml with retrograde cardioplegia. The echocardiographic images were obtained with transesophageal echocardiography in the transgastric left ventricular short-axis view. Images were recorded on videotape for off-line planimetric measurement of percent myocardial opacification. Data were analyzed with the analysis of variance. Multiple comparisons were made with Student's paired t test and using Bonferroni's correction. Myocardial opacification was 58.9 +/- 12.9% during antegrade cardioplegia and 77.5 +/- 16.4% during retrograde cardioplegia (p = 0.003). This overall difference was mainly due to the impact of collateral circulation in the distribution of antegrade cardioplegia. Patients with absent or poor collateral circulation showed a lower degree of myocardial opacification than patients with good or excellent myocardial opacification (44.3 +/- 12.0% versus 64.2 +/- 8.6%; p < 0.02).(ABSTRACT TRUNCATED AT 250 WORDS)

Prenatal oxazepam effects on cocaine conditioned place preference in developing mice

The positively reinforcing and activity enhancing effects of IP cocaine (0, 5, or 25 mg/kg) were assessed at three ages (14-17, 21-24, and 28-31 days) in outbred CD-1 mouse pups treated prenatally by either oxazepam (OX, 15 mg/kg PO twice/day on days 12-16 of pregnancy) or vehicle (VEH). A 4-day unbiased conditioned place preference (CPP) procedure was used with combined visual and tactile cues (white walls and wide-mesh metal floor versus black walls and narrow-mesh floor). A single 25 mg/kg cocaine dose produced CPP in both prenatal groups of 28-31 day-old mice. At the two younger ages, a significant cocaine CPP was found in prenatal OX mice but not in vehicle animals; the latter apparently developed CPP less readily than the offspring of indisturbed dams in a previous experiment. On the other hand, prenatal OX did not produce substantial changes in the developmental profile of cocaine effects on locomotor activity, consisting of a dose-related response enhancement which is much more marked at 22 and 29 days than before weaning.

Testing practices and spread of HIV among sexual partners of HIV-positive haemophiliacs in Italy. Gruppo Italiano Coagulopatie Congenite

OBJECTIVES

To evaluate rates and predictors of testing and HIV positivity among the sexual partners of Italian HIV-positive haemophiliacs.

METHODS

Our index cases were 602 sexually active HIV-positive haemophiliacs (aged 18 years or more) enrolled in the Italian Registry of Haemophilia. Data on the demographic and clinical status of the haemophiliacs, whether their partners had undergone HIV testing, and the results of these tests were collected.

RESULTS

To date, 205 (34.1%) partners of HIV-positive haemophiliacs have been tested for HIV, of whom 27 (13.2%) were seropositive. On univariate analysis, haemophiliacs who were unmarried, younger, and asymptomatic were less likely to have partners who had been tested for HIV (P << 0.001). On multivariate analysis, unmarried status [odds ratio (OR), 8.4; 95% confidence interval (CI), 5.4-13.1; P << 0.001] and younger age (OR, 1.9; 95% CI, 1.1-3.2) again predicted a higher rate of non-tested partners. There was no association between the demographic and medical characteristics of HIV-seropositive haemophiliacs and the risk of HIV positivity among their sexual partners.

CONCLUSION

This study demonstrates that a high proportion of sexual partners of HIV-positive haemophiliacs have not yet been tested for HIV. The single most important predictor of not being tested was the marital status of the index case. These results emphasize the need to strengthen prevention programmes aimed at minimizing the risk of heterosexual HIV transmission, particularly among younger unmarried haemophiliacs.

Selective changes in mouse behavioral development after prenatal benzodiazepine exposure: a progress report

1. Animal studies of the effects of early exposure to CNS agents devoid of a major teratogenic potential must assess possible deviations from normal behavioral development in both a stage-specific and a behavior-specific fashion; several experiments on prenatal benzodiazepine (BDZ) exposure are reviewed, illustrating such an assessment strategy and discussing caveats on experimental designs and statistical analysis. 2. The offspring of mouse dams treated in late pregnancy with oxazepam (15 mg/kg p.o. twice daily on days 12-16) show a mild and reversible impairment in somatic and neurobehavioral development which is unlikely to be responsible for a series of other more specific changes. 3. The treatment produces a selective reduction of locomotor activity and amphetamine hyperactivity at the end of the second postnatal week, as well as a selective impairment of active avoidance at the young adult stage, in the absence of similar changes in scopolamine hyperactivity and passive avoidance. 4. The treatment also prevents the appearance at 28 days of morphine hyperactivity and of rebound hyperactivity after muscimol depression, without modifying the developmental profile of pain reactivity and of morphine and muscimol analgesia. 5. Young adult females previously exposed to oxazepam in utero show a marked enhancement of maternal aggression towards male intruders; mother-pup interactions are also modified, leading either to reduced or to exaggerated maternal care as a function of fostering procedures. 6. Overall, several effects of prenatal BDZ exposure appear to be amenable to modifications in monoaminergic system functions and/or to an accelerated development of GABAergic mechanisms; some of the changes in social and parental interactions, however, point to subtle modifications in the balance between different components of the fear-defensive repertoire, possibly due to an altered stimulus reactivity by mechanisms which are still poorly understood.

High-intensity nociceptive stimuli minimize behavioral effects induced by restraining stress during the tail-flick test

Analgesia following exposure to various stressors is a well-documented phenomenon. Restraint of an animal during the tail-flick test (TFT) represents a potent stressor that can induce both altered baseline latencies and enhanced response to opioids. The present study shows that the use of higher stimulus intensities during TFT minimizes the stress influences produced by restraint on the animal's response rendering the test more sensitive to the pharmacological action of analgesic drugs.

Transcranial Doppler in spontaneous attacks of migraine

BACKGROUND AND PURPOSE

Our aim in this study was to compare headache-free and spontaneous migraine measurements of blood flow velocity and the pulsatility index in the anterior cerebral artery, middle cerebral artery, and posterior cerebral artery.

METHODS

Thirty-one patients (nine having experienced migraine with aura and 22 migraine without aura) were studied in headache-free periods and during spontaneous migraine attacks with transcranial Doppler ultrasonography.

RESULTS

During attacks of migraine with aura, blood flow velocities (particularly the diastolic velocity [p = 0.05]) were reduced while the pulsatility index increased (p = 0.05), whereas a generalized increase in diastolic velocity (p less than 0.02) and a decrease in the pulsatility index (p = 0.05) were observed during attacks of migraine without aura. Significant variations of blood pressure and heart rate were never found.

CONCLUSIONS

These findings are consistent with constriction of resistance vessels in migraine with aura and dilatation of the vessels in migraine without aura. This disparity could be due to a difference between the two migraine types or could be related to the fact that in this study the time interval between headache onset and transcranial Doppler was shorter in the migraine-with-aura group. The latter explanation would apply if, in fact, both types of migraine evolve from hypoperfusion to hyperperfusion during their time course, although perhaps with a difference in intensity.

Effects of different parametric estimates of seroconversion time on analysis of progression to AIDS among Italian HIV-positive haemophiliacs

The purpose of this study was to estimate seroconversion time using different parametric methods and to assess their influence on the estimation of the incubation time between HIV infection and onset of AIDS. Study subjects were 712 HIV-positive haemophiliacs enrolled in the Italian National Registry of patients with congenital coagulation disorders. Seroconversion time was estimated using the mid-point of each seroconversion interval (MID), the median of each interval under an estimated uniform distribution with cutpoints at December 1981 and December 1985 (MUU), the median of each interval under an estimated Weibull distribution (MUW), and the median of three random values drawn from each interval under the Weibull distribution (RUW). Kaplan-Meier survival analysis showed that the cumulative incidence of AIDS over a 7-year period was 11.6 per cent (SE 1.3 per cent) when using the MID estimate of seroconversion time, 10.8 per cent (1.2 per cent) with the MUU estimate, and 13.4 per cent (1.3 per cent) and 12.3 per cent (1.3 per cent) when using MUW and RUW estimates, respectively. This study demonstrates that the estimate of seroconversion time does not seem to be a major factor affecting estimates of AIDS incidence since the different techniques for estimating HIV seroconversion time yielded very similar results.

Development of GABAergic modulation of mouse locomotor activity and pain sensitivity after prenatal benzodiazepine exposure

Outbred CD-1 mice were exposed to oxazepam (15 mg/kg PO twice/day) on days 12-16 of fetal life, i.e., at a critical ontogenetic stage of Type II benzodiazepine (BDZ) receptor increase, and fostered at birth to untreated dams. Locomotor activity (single 30-min session in a Varimex apparatus), hot-plate responding, and muscimol (GABAa agonist) effects thereon [see normative data in (16)] were assessed on postnatal day 14, 21, or 28. Prenatal oxazepam did not affect the development of hot-plate responding and muscimol analgesia; however, it reduced activity on day 14 (as in previous studies) and modified the profile of muscimol effects at 21 days (time of first appearance of an adult-like pattern of activity) and at 28 days. Specifically, oxazepam mice showed a faster recovery from the initial depression after 1 mg/kg of muscimol at the former age and a lack of rebound hyperactivity at the latter age. These effects might be explained either 1) by an accelerated development of GABAergic regulatory mechanisms, or 2) by the same monoaminergic system changes which can account for other effects of prenatal BDZ exposure (1,3). In any event, the dissociation phenomena found in the present study strengthen the notion that GABAergic influences contribute to the modulation of locomotor activity and of pain reactivity by mechanisms which are at least in part separate from each other (16).

Chronic treatment with MIF-1 prevents the painful stimuli threshold elevation induced by neonatal handling in mice

Chronic postnatal stressful handling results in a hyposensitivity to thermal nociceptive stimuli. This phenomenon is strongly affected by manipulations of the opioid system. In the present experiment, we report that chronic treatment with MIF-1 during the neonatal period prevents the behavioral alterations induced by handling while it is completely ineffective if injected acutely before antinociceptive testing by the tail flick test at 45 days of life.

Transcranial Doppler (TCD) after nitroglycerin in migraine without aura

Nitroglycerin, a vasodilating agent, was administered sublingually in migraine without aura patients and in healthy volunteers. Systolic, diastolic and time-mean flow velocity and pulsatility index, were measured by transcranial Doppler sonography in the major intracranial arteries before and after nitroglycerin administration. Following nitroglycerin administration, a significant decrease in systolic and time-mean velocity and pulsatility index was observed in migraine patients, whereas in control subjects only time-mean velocity decreased significantly. Based on those findings we hypothesize a more marked responsiveness to nitroglycerin in migraine patients as compared to healthy subjects.

Ventricular conduction defects and atrial fibrillation after coronary artery bypass grafting. Multivariate analysis of preoperative, intraoperative and postoperative variables

Preoperative, intraoperative and postoperative variables, which might play a role in the development of ventricular conduction defects (VCD) and atrial fibrillation (AF) following coronary artery bypass grafting (CABG), were evaluated in 236 consecutive patients. VCD and AF developed postoperatively in 15.5% of patients: 4.5% had VCD (subgroup A), 11.0% had AF (subgroup B). In 84.5% of patients VCD and AF did not occur (subgroup C). Univariate analysis showed statistically significant differences between subgroups A and C with respect to: left main significant stenoses and number of diseased vessels. Bypass pump time and aortic cross-clamp time were significantly longer in subgroup B. Multivariate analysis showed a significantly greater incidence of left main disease and of right coronary artery occlusion associated with significant stenosis of the proximal left anterior descending artery in subgroup A. In subgroup B, the duration of aortic cross-clamp time was significantly higher. Ischaemic injury, with increasing duration of cardioplegic arrest, seems to play a key role in the development of AF. Nonhomogeneous cardioplegic delivery to critical areas of myocardium, and particularly to the specialized conducting system, may cause VCD after CABG.

Nimodipine in migraine: clinical efficacy and endocrinological effects

Serum prolactin is increased during chronic flunarizine treatment of patients suffering from migraine. In order to clarify the role of calcium in control of the secretion of anterior pituitary hormones, a study has now been made of the effects of chronic nimodipine and propranolol treatment of migraine patients on prolactin (PRL), luteinizing hormone (LH) and growth hormone (GH) levels. 11 patients were treated with nimodipine and 8 with propranolol for four months. A statistically significant reduction in the frequency of the attacks was demonstrated in both groups. No significant change was found in the hormones levels during nimodipine treatment.

Progression to AIDS among Italian HIV-seropositive haemophiliacs. Italian Group

To investigate the interval between HIV-1 infection and the development of clinical AIDS among Italian patients with congenital coagulation disorders, a national cohort study was undertaken in 1988. Information was collected both retrospectively and prospectively on 499 HIV-1-positive patients enrolled in an ongoing national registry of patients with congenital coagulation disorders. Two methods were used to estimate each patient's seroconversion date: the mid-point between the last negative (either known or estimated) and the first positive test, and the median under a Weibull distribution, which was assumed to fit seroconversion data. The two methods of estimating the seroconversion time yielded similar results. The actuarial incidence of AIDS was estimated using the Kaplan-Meier survival analysis at 12.8% (95% confidence interval = 9.7-15.9) over 7 years for Italian haemophiliacs. Progression appears to be slow in the first 5 years after the infection, and to rise steadily thereafter. A strong association between faster progression and older age at seroconversion was found. Zidovudine-treated individuals seem to have a slower progression than untreated individuals, after controlling for CD4, but there was no association between progression and type and severity of the congenital disorder.

Morphine effects on mouse locomotor/exploratory activity: test dependency, test reliability, uni- and multi-variate analyses

Drug and toxicant effects on locomotor/exploratory activity can be quite variable depending on the test and the schedule of exposure. In neurobehavioral toxicology and teratology, these interactions can affect the inferences based on the use of selected drugs as probes to assess which regulatory mechanisms are affected by one or the other treatment. The present experiments were aimed at comparing morphine effects in CD-1 mice under three conditions, namely, Varimex apparatus (VAR), toggle floor box (TOGGLE), videotape recording (VIDEO) in a home cage environment. Morphine HCI (0, 10, 33, or 100 mg/kg) was given IP 20 min before the start of a 30-min test session. The same procedure was repeated 24 h later. Results of VAR and TOGGLE tests were: dose 10 was largely ineffective; dose 33 induced depression in VAR and hyperactivity in TOGGLE; dose 100 enhanced activity in TOGGLE. There were no differences between session 1 and 2. VIDEO: Univariate analysis results showed that morphine produced a dose-dependent depression of Rearing and Grooming, and an enhancement of Crossing, again without changes due to repeated exposure. Results of Principal Component Analysis supported a response competition model of the changes observed in the mouse behavioral profile. The videorecording (VIDEO) procedure is the one providing the most accurate picture of changes in locomotor/exploratory activity and drug effects thereon, also allowing a more comprehensive statistical analysis of the relationships between various types of response changes.

MIF-1 can accelerate neuromotor, EEG and behavioral development in mice

Newborn mice were injected SC daily with 1 mg/kg of MIF-1 or saline during the first 19 days of life. The progress of each pup was monitored for physical (body weight, eye and ear opening), neurobehavioral (reflexes) and neurophysiological (EEG) development until the weaning stage. In early adulthood (40 days of age) mice were tested on a maze learning task. Results indicate that MIF-1 can accelerate neurologic (days 3-9), somatic (days 10-14) and electroencephalographic (days 16-19) parameters, and that the effects of treatment last into the early adult stage with increased learning abilities in an appetitive task.

Problems of test choice and data analysis in behavioral teratology: the case of prenatal benzodiazepines

Higher-tier tests for the assessment of early treatment effects should be aimed at providing specific information on the behavior processes affected, rather than simply at extending the descriptive data base. The contrast between positive and negative results can be useful to point out possible mechanisms of action. For example, late prenatal oxazepam exposure of mice produced a reduction of the amphetamine hyperactivity at the end of the second postnatal week, but did not significantly affect the response to scopolamine at the end of the third week. An impairment of active locomotor avoidance was observed at the young adult stage, which contrasted with the absence or scarcity of changes in passive avoidance and extinction responding in the same go-no go tests. These changes in response-activating mechanisms appear to be in agreement with the medium- and long-term effects on CNS monoamine metabolism described in the literature. As concerns statistical analysis, dichotomous or polytomous data obtained, e.g., by the Fox battery are not yet amenable to an adequate processing, due to the shortcomings of the available nonparametric tests. By contrast, mixed-model ANOVAs can cope with complex data obtained, e.g., in activity and learning tests. However, the available checks on various assumptions (normality, homogeneity of variance, sphericity) are not valid when nested factors, block factors and repeated measures coexist. Finally, the more usual cross-fostering procedures provide adequate information on some aspects (e.g., separation of main effects of prenatal treatments from postnatal maternal effects) but not on others.(ABSTRACT TRUNCATED AT 250 WORDS)

Discriminant analysis of Hodgkin's disease and non-Hodgkin's lymphomas by age and serum proteins

Immunonephelometric evaluations of 13 serum proteins were made in 71 patients with two types of lymphoproliferative diseases: Hodgkin's disease (32 patients) and non-Hodgkin's lymphomas (39 patients). The subjects were differentiated by discriminant analysis by means of age and three selected proteins: properdin factor B, IgM and ceruloplasmin. The results obtained permitted classification of 90% of the cases reported.