Event-Related Brain Potentials in Elderly Dippers and Nondippers with Recently Diagnosed Hypertension

Several studies have shown a relationship between blood pressure (BP) and cognitive function. Yet very few studies have addressed circadian BP patterns in this context, perhaps due to poor availability of suitable methods to detect slight changes in the cognitive state. Today, brain event-related potentials (ERPs) allow us to detect subclinical changes in cognitive function. We enrolled 30 elderly patients with recently diagnosed hypertension (<2 years) that had never been treated: 18 dippers and 12 nondippers. Patients underwent 24-h ambulatory blood pressure monitoring (ABPM). Careful assessment of their cognitive state was carried out using the mini mental state examination (MMSE), and the recording of P300 and N2 ERPs. No significant differences between the two groups were found. MMSE scores in dippers and nondippers were similar (29.5+/-0.71 vs. 29.3+/-1.07, respectively; p =0.611), as were P300 latency values (377.78+/-33.28 vs. 364.67+/-35.12 in the central (Cz) position, p =0.310; 379.22+/-32.94 vs. 365.25+/-35.07 in the occipital (Pz) position, p =0.277) and N2 wave latency values (253.83+/-24.9 vs. 249.17+/-24.47 in the Cz position, p =0.617; 251.56+/-25.86 vs. 246.58+/-25.46 in the Pz position, p =0.608). These data show no association between the nondipping pattern and lower cognitive function in elderly subjects with recent hypertension.

Detecting assumption violations in mixed-model analysis of variance

Parametric analysis of variance (ANOVA) is frequently used to analyse experimental data, yet for the results to be considered as accurate, certain assumptions must be respected: the normality of the distribution of the sampled data, the homogeneity of variance among the groups being compared (i.e., homoscedasticity), and, in certain cases, sphericity. The present work focuses on the methods for detecting violations of these assumptions and provides an example of the application of these methods.

Comparative analysis of clinical features and prognostic factors in resected bronchioloalveolar carcinoma and adenocarcinoma of the lung

BACKGROUND

Over the past few years, clinical, radiological and pathological classification of lung adenocarcinoma and its subtypes, particularly bronchioloalveolar carcinoma (BAC), has radically changed.

PATIENTS AND METHODS

Out of a series of 384 non-small cell lung cancer (NSCLC) patients, submitted to surgical resection and followed-up in our Department from 1981 to 1999, the data of 151 adenocarcinomas (35 BAC and 116 non-BAC) were reviewed and analyzed for prognosis.

RESULTS

BAC and non-BAC series were similar in clinical and radiographic findings, type of resection and stage. Stage I was a dominant favorable prognostic factor (10-year survival: 58% of BAC, 41.2% of non-BAC), albeit associated with a significant risk of second primary metachronous lung tumor (10-year risk: 25% of BAC, 32% of non-BAC). Other independent prognostic factors were: absence of lymph node involvement for BAC and stage III-IV for non-BAC. In term of prognosis, advantages of BAC over non-BAC were fewer cases with lymph node involvement, increased presence of "well-differentiated" cells (p = 0.016) and lower incidence of a second primary metachronous tumor. Moreover BAC patients with a single nodule or mass also had a higher survival expectancy (mean survival: 77 months versus 56 for non-BAC). An unfavorable feature was the higher incidence of diffuse or multicentric radiological forms (p = 0.012). For both groups the presence of multiple or satellite nodules remain a diagnostic and surgical challenge: in BAC cases the evaluation of clonality is recommended.

Long-term effects of acute perinatal asphyxia on rat maternal behavior

In this study we used a rat model of graded perinatal asphyxia to study the long-term consequences of this manipulation on rat maternal behavior at adulthood. Rats were delivered by cesarean (C) section and the pups, still in the uterus horns, were placed into a water bath at 37 degrees C for periods of 0 (controls) or 20 min (asphyxia). Subsequently, female pups were given to surrogate mothers, weaned at 21 days postnatally and then left undisturbed until adulthood, when they were mated. Once they gave birth, on postnatal days (Pnds) 1, 3, 5, 7, 9, 11 and 13 they were observed in the home cage five times per day to assess their maternal behavior in an undisturbed condition. In addition, maternal behavior was observed for 30 min in a novel cage on Pnds 4 and 8. Perinatal asphyxia affected maternal behavior in the home cage, hypoxic females being more often found outside the nest area and performing more often behaviors such as self-grooming. Principal component analysis confirmed a more 'active' behavioral profile for hypoxic females. Hypoxic mothers were characterized by a longer latency to perform on-nest behavior and by a reduced frequency of pup retrieval and licking in the novel cage. No significant differences in corticosterone secretion in response to an acute stressor were found in dams belonging to the different treatments or in the body weights of the offspring. These results are suggestive of an arousal deficit due to perinatal hypoxia and point to the dopaminergic system as a potential neurochemical target for an early hypoxic insult.

Study of the effects of electroacupuncture in a rodent model of cerebral ischaemia

The effects of electroacupuncture (EA) has been studied in a model of global cerebral ischaemia performed in gerbils through the bilateral carotid artery occlusion (BCAO). Animals, under isofluorane anaesthesia, underwent 5 min of BCAO and were killed after 7 days. The effects of EA were evaluated both on functional (with electrophysiological recordings of synaptic potentials in hippocampal slices) and morphological parameters (by counting the number of survived neurons in CA1 area of the hippocampus). The results demonstrated that the treatment of animals with EA (5 min before, during and 20 min after BCAO and 30 min per day in the following 5 days) did not modify either the ischaemia-induced reduction of synaptic potentials amplitude, either ischaemia-induced neuronal loss in the hippocampus. We conclude that, at least in this animal model of cerebral ischaemia, EA does not exert a neuroprotective effect.

Folate status and homocysteine level in Italian patients aged under 60 on oral anticoagulant therapy

BACKGROUND

Folate deficiency occurs frequently and the related hyper-homocysteinaemia is considered a risk factor for thrombosis. We investigated folate status and homocysteine (Hcy) concentration in patients under 60 years on oral anticoagulant therapy (OAT) for previous venous or arterial thrombosis and in healthy blood donors.

PATIENTS AND METHOD

Thirty-nine patients (mean age 35.2 years) on OAT for longer than 6 months and forty 44 healthy blood donors (mean age 36.0 years) were evaluated. Diet, serum folate (SF), red blood cell folate (RCF), homocysteinaemia, vitamin B12 levels and the mutation C677T of methylenetetrahydrofolate-reductase (MTHFR) gene were determined.

RESULTS

The mean SF and Hcy concentrations were significantly higher in patients compared with blood donors (SF = 17.7 versus 10.5 nmol/L, P < 0.0001; Hcy = 11.7 versus 8.9 micromol/L, P = 0.009). Twelve out of 39 patients and 7 out of 44 blood donors were homozygous for the mutation C677T of MTHFR gene. Among the remaining subjects, non-homozygous for the mutation, the patients (27) had mean SF and Hcy levels significantly higher than the (37) blood donors (SF = 18.1 versus 10.8 nmol/L, P < 0.0001; Hcy = 10.3 versus 7.9 micromol/L P < 0.0006).

CONCLUSION

Italian patients aged under 60 years on OAT and non-homozygous for the mutation C677T of MTHFR gene, had SF and Hcy concentrations significantly higher than the control group.

Degree of social contact affects the emission of food calls in the common marmoset (Callithrix jacchus)

The aim of this study was to investigate whether the emission of food calls in common marmosets (Callithrix jacchus) is influenced by different social contexts. Food calls are emitted by this species only in the presence of preferred food. If these calls have any communicative function, it may be that individuals produce food calls in order to call family mates toward the food source. If this is the case, the number of calls produced should vary in accordance with the number of family mates present at the moment of the discovery of the food, i.e., the fewer family mates nearby, the more food calls are emitted. This hypothesis was tested with five pairs of common marmosets, by recording the number of food calls emitted in four experimental conditions: 1). isolation: completely isolated from the family mates; 2). visual isolation: separated by a wooden panel from the family mates; 3). visual contact: separated by a wire-mesh from the family mates; and 4). physical interaction: together with the family mates. The results show that the proportion of intervals during which food calls were produced by the pairs was significantly different in the four experimental conditions. It decreased from the isolation and visual isolation condition, through the visual contact condition, reaching the lowest value in the physical interaction condition. The variation observed in the proportion of intervals during which food calls were emitted, in relation to different social contexts, is an indication in favor of the communicative function of this vocalization.

[Effects of socio-environmental factors on neurocognitive performance in premature or low-birth weight preschoolers]

Severely preterm neonates (gestational age < or = 32 weeks) and/or very low birth weight (VLBW, with weight at birth < or = 1500 g) are 2% of all newborns, with a rising incidence due to the increase of multiple gestations and of pregnancies at advanced age. These neonates may be affected by severe neurological pathologies (6-10% of cases), but they often have minor disabilities (such as distractibility, hyperactivity, learning and social competence disabilities, deficit of motor development) difficult to be early diagnosed, and frequently recognized only at pre-school or school age. A review of the current knowledge about the effects of potential risk factors responsible for deficits of neurocognitive development in pre-school age and for postnatal distress of mothers, and their inter-correlations, is reported.

Nutrient intake of Italian women during lactation

OBJECTIVES

Very few data have been published concerning the actual energy and nutrient intakes of lactating women; in particular there have been no reports concerning Italian women. We report our findings on the energy and macronutrient intakes of a group of exclusively breast-feeding Italian women. Differences between the actual intakes and Italian Recommended Dietary Allowances are also discussed.

SUBJECTS

Healthy lactating women aged 27-36 years were recruited in the three major geographical areas of Italy (North, Central, and South)

METHODS

Dietary evaluation was based on two consecutive 24-hour recalls from each mother (dietary data, n = 125). Energy and nutrient intakes were estimated using a nutritional database. Statistical analysis was performed using parametric and non-parametric tests.

RESULTS

Mean energy intakes for the whole country are below recommended values, while the protein intake, and the percentages of energy from fat and saturated fatty acids are higher than the recommended values. The amount of polyunsaturated fats is within the recommended intake. The percentage of energy from carbohydrates and the amount of fiber are lower than the recommended Italian levels.

CONCLUSION

The results obtained in this sample of lactating women seem to point to a low energy intake associated with a moderate imbalance in the distribution of energy percentages from macronutrients.

Hypertonic saline solution: a safe alternative to mannitol 18% in neurosurgery

BACKGROUND

To evaluate the usefulness of hypertonic saline solutions (HTS) as an alternative to mannitol in neurosurgery.

METHODS

Thirty patients subjected to craniotomy for supratentorial cerebral tumors were randomly divided in to three Groups: M: had mannitol 0.5 g.kg-1 as bolus at the start of skin incision, and postoperatively 0.5 g.kg-1 daily three times a day for 3 days (72 hrs); HM: had mannitol 0.25 g.kg-1 as bolus at the start of skin incision plus 3% HTS, 20 ml.h-1 intraoperatively and mannitol 0.25 g.kg-1 daily three times a day for 3 days plus HTS in the concentration of 3% in the first day and 2% and 1% the second and the third day after surgery; H: had 3% HTS 3.5 ml kg-1 as bolus at the start of skin incision plus 3% HTS, 20 ml hr-1 intraoperatively and 3% HTS, 20 ml h-1 on the first day and 2% and 1% the second and the third day after surgery. FR, MAP, ICP, CVP and diuresis were continuously monitored intraoperatively and postoperatively for 72 hrs. ICP was monitored intraoperatively until dural opening and in the postoperative period for 72 hrs at least.

RESULTS

Diuresis was increased in the first and second Group (M and HM) more than in the H Group especially in the postoperative period, but this change was not a significative one (35.31 ml.kg-1.h-1+/-4.57 and 36.56+/-3.92 vs 3.23 ml.kg-1.h-1). Mean serum Na+ values declined in the postoperative period, in Groups M and MH and remained stable in the postoperative period in the Group H (137.6+/-7 mEq.l-1 and 136.5+/-6.5 mEq.l-1 vs 139.2+/-5 mEq.l-1). Serum osmolality increased significantly in the postoperative period in group H and remained unchanged in the same period in Group M and MH. Potassium values declined significantly during the whole period in all groups but remained in a normal clinical range. CVP values decreased in Groups M and MH in the postoperative period, and increased although not significantly in the postoperative period in the Group H patients. Ht values declined significantly in all groups without differences among the groups although the reduction was greater in group H.

CONCLUSIONS

HTS can safely be used in humans they obtain a reduction of ICP without reducing CVP, serum osmolality and Na+ serum values. Our data underline the possibility of their use as an alternative to mannitol in the treatment of patients scheduled for intracranial surgery, especially when multiple doses are needed.

Calf and shin muscle oxygenation patterns and femoral artery blood flow during dynamic plantar flexion exercise in humans

The effects of dynamic plantar flexion exercise [40, 60, and 80 contractions.min-1 (cpm)] on calf and shin muscle oxygenation patterns and common femoral artery blood flow (Qfa) were examined in six female subjects [mean age 21 (SD 1) years] who exercised for 1 min at 33% of their maximal voluntary contraction at ankle angles between 90 degrees and 100 degrees. Spatially resolved near-infrared spectroscopy was used to measure medial gastrocnemius, lateral soleus (synergist) and anterior tibialis (antagonist) muscle oxygen saturation (SO2, %). Qfa was measured by ultrasound Doppler. The SO2 changed significantly only in the medial gastrocnemius and its decrease (up to about 30%) was independent of the contraction frequencies examined. The increase in Qfa, at the end of exercise, was highest at 80 cpm. When the exercise at 60 cpm was prolonged until exhaustion [mean 2.7 (SD 1.1) min], medial gastrocnemius SO2 decreased, reaching its minimal value [mean 30 (SD 10)%] within the 1st min, and had partially recovered before the end of the exercise with concomitant increases in total haemoglobin content and Qfa. These results suggest that the medial gastrocnemius is the muscle mostly involved in dynamic plantar flexion exercise and its oxygen demand with increases in contraction frequency and duration is associated with an up-stream increase in Qfa.

Multidimensional aspects of pain in HIV-infected individuals

To study the prevalence, intensity, and quality of pain in patients with human immunodeficiency virus (HIV) infection and to evaluate factors influencing the different components of pain, a self-administered multidimensional pain questionnaire (Italian Pain Questionnaire [IPQ]) was administered to 153 HIV patients admitted to the Department of Infectious Diseases of a teaching hospital over a 7-month period. Ninety-three (60.8%) patients experienced pain for a total of 131 pain sites. The intensity and the nonsensorial components of pain were greater in ward patients compared to outpatients. In 70% of pain syndromes it was not possible to define the etiology at the time of the visit. Pain was observed more frequently in intravenous drug users (IDUs) (72.9%) compared to patients with other HIV modalities of transmission (50.6%) (p = 0.008). The mean value of sensory class was greater in patients who were not IDUs. Within IDUs group there was a predominance of descriptors of the affective class over the sensory class. The prevalence of pain is high in HIV-infected individuals. The different components of pain are influenced by the modality of transmission and the setting of care. The assessment of scores of different components of pain could help to select and monitor appropriate interventions in pain control.

Attractivity and social preferences in mice (Mus musculus domesticus): the role of prepubertal sexual segregation and of precocious weaning

Mice (Mus musculus domesticus) were raised (Postnatal Day 15 to 25) in single- or mixed-sex litters and precociously (Day 15) or regularly (Day 25) weaned. When they were faced as adults with a basic social choice--between two stimulus mice raised in litters of different sex composition but both of the same sex as the chooser--mice raised in mixed-sex litters were preferred. In the sociosexual choice-between a male and a female, both from the single- or the mixed-sex group--the opposite-sex preference was expressed. Both these preferences were abolished by the sexual segregation of the choosers. This variable hardly affected potential mate choice--between two stimulus mice both of the opposite sex of the chooser but raised in litters of different sex composition. Data indicate that socially mediated behavioral plasticity has a major role in the early shaping of adult individual differences both in attractive stimulus properties and in sociosexual preferences.

Event-related potentials in the elderly with new mild hypertension

Hypertension is a risk factor for cerebrovascular diseases (CVD) and cognitive impairment and the relative risk of CVD at every level of blood pressure (BP) is greater among the elderly. We submitted 20 elderly affected by new mild hypertension and 10 elderly normotensives to 24-hour ambulatory BP monitoring (ABPM), to evaluate their cognitive state using the Mini-Mental-State-Examination and to the recording of related acoustic evoked potentials (P300 and N2). We did not find significant differences for P300 latency between hypertensives and normotensives, while N2 latency recording showed a statistically significant protracted value in elderly hypertensives. In these patients we found a significant correlation between the N2 latency and systolic blood pressure values recorded by ABPM. These results demonstrated early functional alterations of cognitive state in elderly hypertensives, that are related to systolic blood pressure and future data might point to an earlier use of therapy.

Study of immunological and virological parameters during thalidomide treatment of SIV-infected cynomolgus monkeys

The potential therapeutic utility of thalidomide (Thd), an effective inhibitor of tumor necrosis factor (TNF)-alpha in vitro, was investigated in cynomolgus monkeys (Macaca fascicularis) at 10 months after infection with simian immunodeficiency virus (SIV). Thd-treated macaques (n = 8) received an oral dose (10 mg) daily for 7 days, followed by a wash-out period of 5 weeks. A 2nd cycle of treatment was performed on the same animals at higher doses (20 mg Thd/day) for 14 days. The control monkeys (n = 7) received a placebo for the same period of time. In the present study, we show that Thd, in addition to inhibiting TNF-alpha production after in vitro mitogen stimulation of peripheral blood mononuclear cells (PBMCs), was able to restore the proliferative responses to SIV peptides in monkeys that were infected with SIV. Interestingly, we found that such effects are associated with an increased expression of CD28 cell surface receptors on CD4+ T-cells paralleled by a decrease on CD8+ T-cells. At the same time, significant reduction in either cell-associated viral load or plasma viral RNA was not observed among the SIV-infected monkeys during the two treatment cycles, when compared with the placebo group.

Fluctuating asymmetry, size and mating success in males of Ischnura elegans (Vander Linden) (Odonata: Coenagrionidae)

Fluctuating asymmetry (FA) is thought to be an indicator of developmental stability and negatively related to male mating success in many animal taxa. We investigated the relationships between mating success of males, body size and FA for both wing length and number of setae on the legs in the damselfly Ischnura elegans. Males were classified as mated or unmated at the time of sampling. Fluctuating asymmetry, expressed as right-left differences, showed normal distributions without evidence of directional asymmetry or antisymmetry. Univariate analyses showed a significant negative correlation between size and mating success, and significant negative correlations between FA and mating success for both characters. On the other hand, with a multivariate analysis, new to studies on FA, the effect of body size was still significant but FA did not reach significance for either character. We conclude that the multivariate analysis should be used to assess the role of the different factors affecting mating success. Copyright 2000 The Association for the Study of Animal Behaviour.

Clinical and immunologic response without decrease in virus load in patients with AIDS after 24 months of highly active antiretroviral therapy

This study reports an analysis of clinical, virological, and immunologic outcomes in a cohort of 77 multidrug-experienced AIDS patients during 24 months of highly active antiretroviral therapy (HAART). Our results have shown a reduced risk of AIDS complications, prolonged survival, and immunologic benefit even in the absence of sustained virus suppression. The degree of immunodepression, the risk factors for HIV-1 infection, the use of 2 drugs instead of 3, and a change in protease inhibitor were independently correlated with virological failure. In the majority of studied patients, an increase in CD4+ T cells was observed after HAART. However, the increase was more pronounced in patients who showed a decrease in virus load than in those who did not. Moreover, we observed an absence of relapses among patients who permanently discontinued prophylaxis for Cytomegalovirus retinitis and atypical mycobacterial infections. Peripheral lipodystrophy developed in the majority of patients, regardless of treatment used and virological outcome.

Behavioural effects of endocrine disrupting chemicals on laboratory rodents: statistical methodologies and an application concerning developmental PCB exposure

Appropriate behavioural tests and adequate statistical tools may help to establish the ED properties of a given compound by pointing out the alterations of selected behavioural endpoints. Frequently, laboratory collected data consist of frequencies and/or durations of specific items, and the analysis of variance (ANOVA) technique is performed to assess whether the investigated factors affect these behavioural endpoints. Moreover, when numerous aspects of behaviour are investigated simultaneously, Principal Component Analysis (PCA), a multivariate technique, may be very useful to reduce the overwhelming number of correlated original variables to a few orthogonal artificial variables (factors). Continuous Time Markov Chain (CTMC) models may be applied to analyse the time structure of a behavioural pattern when data consist of sequences of events and the time points at which they occur. Moreover, the Cox Proportional Hazard Model, a methodology originally developed for the analysis of failure time data, may help to evidence the effects of a given treatment on behavioural sequences when the assumptions of CTMC models are not fully satisfied. Analyses on data from mice of the outbred CD-1 strain (controls in a study of toxicity and exposed to PCB during development) are presented as examples to show how adequate statistical analyses and appropriate behavioural tests may reveal relevant effect of treatments otherwise not easily detected.

Serum phospholipids are the main environmental determinants of activated factor VII in the most common FVII genotype. European Union Concerted Action "Clotart"

BACKGROUND AND OBJECTIVE

Numerous studies have emphasized the role of triglyceride-rich lipoproteins and of Factor VII (FVII) polymorphisms in determining levels of FVII activity.

DESIGN AND METHODS

This study was undertaken to evaluate the role of other lipid fractions and the interaction between lipids and FVII in subjects with recognised genotypes. Volunteer subjects (n=459) from 5 European countries were studied. Blood samples were drawn irrespective of the time of day or fasting status. Levels of FVII activity (FVIIc), activated FVII (FVIIa) and FVII antigen (FVIIAg) were evaluated with reference to a number of lipid parameters (HDL-, LDL- and total cholesterol, triglycerides, phospholipids, lipoprotein(a), and apoliproptein A1). The two most common FVII polymorphisms were analyzed in combination (353R/Q and 5'F7; alleles M1/M2 and A1/A2, respectively).

RESULTS

Homozygotes for the A1 and M1 alleles (M11/A11) had significantly higher FVII levels. At multiple regression analysis the strongest predictor of FVIIa and FVIIc was the concentration of phospholipids. This interaction was confined to the A11M11 genotype subjects.

INTERPRETATION AND CONCLUSIONS

These data indicate that lipids contribute mainly to FVIIa levels through their phospholipid content, and that the degree of this contribution is strictly dependent on FVII genotypes.

The role of high resolution pulsed and color Doppler ultrasound in the differential diagnosis of benign and malignant lymphadenopathy: results of multivariate analysis

BACKGROUND

The role of high resolution pulsed and color Doppler ultrasound in the differential diagnosis of benign and malignant lymphadenopathy is still unclear.

METHODS

High resolution pulsed and color Doppler ultrasound was used prospectively to investigate superficial lymph node enlargement in 71 patients undergoing surgical biopsy at the onset of lymphadenopathy. The aim of this study was to define, in multivariate analysis, the ultrasonographic parameters useful in the differential diagnosis of benign and malignant lymphadenopathy.

RESULTS

Volume, vascularization score, pulsatility index, and resistive index were significantly higher in the 53 malignant lymph nodes studied than in the 18 benign lymph nodes studied. The long-to-short axis ratio was significantly lower in neoplastic lymph nodes than in reactive lymph nodes. Stepwise logistic regression selected only the long-to-short axis ratio and the vascularization score as parameters that independently and significantly contributed to the differentiation of neoplastic from reactive lymph nodes. The diagnostic efficiency of the combined criteria evaluated by the area under the receiver operating characteristic curve was 0.8339.

CONCLUSIONS

High resolution pulsed and color Doppler ultrasound may provide information that is useful in making correct differential diagnoses of malignant or benign lymphadenopathy.

Elevated novelty seeking and peculiar d-amphetamine sensitization in periadolescent mice compared with adult mice

Novelty seeking as well as amphetamine sensitization were studied in adult (postnatal day "PND" > 60) and periadolescent (PND 3343) mice treated with saline or amphetamine (2 or 10 mg/kg once per day) for 3 days in a familiar environment. After a 48-hr wash-out period, mice were challenged with either saline or amphetamine (2 mg/kg) in the same environment. When given a choice, animals showed a preference for a novel environment, an effect more marked in periadolescents. Acute amphetamine strongly increased novelty seeking in adults, whereas it had an opposite effect in periadolescents. Adult mice in the chronic amphetamine 2 group showed a conditioned preference for the drug-paired compartment, whereas an aversion characterized adult mice in the amphetamine 10 group. Periadolescents in the latter group exhibited a greater sensitization of the locomotor response, but did not show the compulsive licking typical of adults. This appears to be a useful model to study psychobiological risk factors involved in vulnerability to addiction during human adolescence.

Effects of prenatal AZT on mouse neurobehavioral development and passive avoidance learning

Recent evidence has shown that perinatal administration of zidovudine (AZT) to HIV-infected mothers reduces the risk of maternal-infant transmission of the virus. Treatment of pregnant seropositive women with AZT is becoming a common medical practice, despite the paucity of information about the potential neurotoxic/behavioral-teratogenic effects of AZT on the developing organism. The aim of the present study is to evaluate in mice the short-, medium-, and long-term effects of prenatal exposure to AZT on neurobehavioral development. Pregnant mice were given 0.2, 0.4, and 2.0 mg/ml AZT in drinking water from day 10 of gestation to delivery. Offspring's viability was severely affected in the 2.0 mg/ml AZT group. Thus, behavioral analysis was carried out in offspring of 0.2 and 0.4 mg/ml AZT-treated females only. Some limited but significant alterations were found, such as stunted body weight, delayed appearance of the pole-grasping reflex, and a slight impairment in the acquisition phase of a passive avoidance response. Moreover, sexual differences in some items of the social behavior repertoire appeared to be affected by AZT treatment.

Limited changes in handedness and morphine reactivity in CD-1 mice after pre- and postnatal ozone exposure

Outbred CD 1 mice were either not exposed (control group) or exposed to ozone (O3) (0.3, 0.6, or 0.9 ppm), during foetal and neonatal life until the time of weaning (postnatal day (PND) 26). On PND 70 the subjects were tested for handedness using a paw preference task assessing both the animals' capability to reach a food pellet in a feeding tube and the individual preference for the use of one of the other forepaw. O3 exposure did not affect the animals' capability to learn the task but caused changes in handedness. Specifically, females exposed to the intermediate O3 concentration showed a reduced preference for the right paw than both their same-sex controls and 0.6 ppm males. On PND 100, mice underwent a hot plate test after IP treatment by either saline or morphine HCl (10 mg/kg). The results were generally in the direction of reduced drug sensitivity after exposure to the highest concentration. The evidence for this effect was more robust in the case of an organised avoidance response (wall-rearing) than in the case of a reflexive response (limb withdrawal); in the case of the former, latency data showed an effect on both males and females while frequency data showed an effect only in females. Overall, the O3 effects are suggestive of subtle CNS changes affecting mouse behavioural responses.

Behavioural characterization of interleukin-6 overexpressing or deficient mice during agonistic encounters

Interleukin-6 (IL-6) is a cytokine released by activated immune cells which has been shown to affect brain function. In this experiment aggressive and affiliative behaviour exhibited during agonistic encounters by transgenic male mice either not expressing (IL-6 -/-) or overexpressing (NSE-hIL-6) IL-6 in the central nervous system was investigated. All subjects were isolated for 24 days before the aggressive encounter and were 52 days old at the time of testing. Subjects were placed for 5 consecutive days in a neutral cage for 15 min with an opponent of the Balb/c strain that had been previously isolated for the same amount of time. The first and the last test sessions were videotaped to evaluate the first approach and the establishment of the social role, respectively. A number of behavioural categories were later scored. When compared with wild-type controls, IL-6 -/- mice showed a higher degree of aggressive behaviour as indicated by a higher frequency of Offensive Upright Posture, an effect more pronounced on the fifth encounter. On the contrary, NSE-hIL-6 subjects showed a tendency to be more involved in affiliative-type social interactions, displaying a higher frequency and duration of behaviours such as Anogenital, Nose or Body Sniff. IL-6 -/- mice showed a clear tendency to exhibit less affiliative interactions compared with their controls while dopamine levels were found to be modified in a number of brain regions in these mice. Overall, these data suggest that IL-6 affects both aggressive and affiliative-type interactions, although the behaviour of the NSE-hIL-6 subjects was less affected than that of the IL-6 -/- group. The effects of the genetic background of the animal in screening the outcome of gene manipulations on behaviour are also discussed.