Behavioural and neurochemical effects induced by chronic mild stress applied to two different rat strains

Chronic mild stress (CMS) has been reported to induce an anhedonic-like state in rats that resembles some of the symptoms of endogenous depression in humans. In the present study, CMS-induced behavioural responses along with neurochemical alterations in dopaminergic and serotonergic function in prefrontal cortex, striatum, hypothalamus and hippocampus were examined following treatment with imipramine in Wistar and Sprague-Dawley rats. The CMS procedure lasted 7 weeks in total. Once per week, a 1-h preference test for 1% sucrose solution was conducted. Treatment with imipramine (10mg/kg i.p., once daily) commenced after experimental week 3. CMS induced significant reductions in absolute and relative sucrose intake and sucrose preference in both rat strains but their temporal pattern was different especially during the weeks 0-3. These effects were reversed by IMI. An increase in the dopaminergic and a decrease in the serotonergic activity were observed in the prefrontal cortex in both rat strains following CMS. A decrease in the striatal dopaminergic activity and an increased hippocampal serotonergic activity were also seen in both rat strains following CMS. In Wistar rats, dopaminergic and serotonergic activities were enhanced in the hypothalamus whereas in Sprague-Dawley rats no such stress-induced changes were observed. Notably, the clear decrease in sucrose consumption observed in stressed Wistar rats could be directly associated with a respective increase in the dopaminergic hypothalamic activity. Chronic treatment with imipramine normalized all neurochemical alterations induced by CMS. Our results suggest that a specific and regionally differentiated serotonin-dopamine interaction is directly related to the observed stress-induced anhedonia.     

X chromosome inactivation patterns in brain in Rett syndrome: implications for the disease phenotype

Skewed X chromosome inactivation (XCI) has been implicated in modulating the severity of Rett syndrome (RTT), although studies by different groups have yielded conflicting results. In this study we have characterised the XCI pattern in various neuroanatomical regions of nine RTT brains and non-neural tissue in two of these patients to determine whether or not variable XCI patterns occur in different brain regions or somatic tissues of the same patient. The mean XCI patterns for frontal and occipital cortex were compared between RTT and control subjects, and showed no significant differences when comparing RTT frontal to control frontal cortex or RTT occipital to control occipital cortex. However, one RTT subject displayed variability across the different neuroanatomical regions of the brain and skewing in some non-neural tissues. This observation adds another dimension to the epigenetic factors that may contribute to the phenotype in RTT. It also mandates that caution should be exercised in factoring XCI, including assumptions based on the blood XCI pattern, into the development of phenotype-genotype correlations.     

Health service use in Rett syndrome

Rett syndrome is a severe neurodevelopmental disorder affecting girls, caused by mutations in the MECP2 gene. There are no population-based data on the extent and determinants of health service use in this disorder. The population-based registry, the Australian Rett Syndrome database, was the source of phenotype data. This also contains data from mutation screening and X-inactivation studies. Data on retrospective (n = 152) and prospective (n = 162) health service use were collected in 2000 from a questionnaire and a calendar study, respectively. Health service use was highest in younger cases (P = .001) and lowest in cases with milder phenotypes (P < .001). Random X-inactivation was associated with service use (P = .02). Maternal education, phenotype, and individual mutations were determinants of health service use. The use of a retrospective and prospective data set enabled accurate assessment of service use in Rett syndrome. Both genetic and sociodemographic determinants of health service use were identified, with important implications for the optimal and equitable management of children with Rett syndrome.     

Management of ovarian cysts with aspiration and methotrexate injection

PURPOSE: To evaluate prospectively ultrasonography (US)-guided cyst aspiration and methotrexate injection in the management of simple and endometriotic ovarian cysts in selected patients. MATERIALS AND METHODS: Authors obtained informed patient consent and approval from hospital ethics committee. Study included 162 female patients (aged 15-77 years) with simple or endometriotic ovarian cysts (3.0-10.6 cm) at a tertiary hospital. Criteria for inclusion in the study were (a) persistence of the cyst for at least 6 months, (b) benign appearance of the cyst at US, and (c) normal serum CA-125 level measurement before the procedure. Authors performed transabdominal aspiration of the cysts with direct US guidance and injection of methotrexate (30 mg). Cytologic examination was performed in all cases. Follow-up US was performed at 1, 3, and 6 months. If the cyst persisted, the procedure could be repeated. Main outcome measure was resolution or persistence of cysts. chi(2) Test or Mantel-Haentszel chi(2) tests for univariate analysis and multiple logistic regression were used for multivariate statistical analysis. RESULTS: Of 162 patients, 148 were available for follow-up. Malignant cells were not found in any of the cases at cytologic examination. At follow-up US, cysts had disappeared in 124 patients (83.8%) and persisted in 24 (16.2%). Cyst diameter proved to be a significant prognostic factor for cyst resolution (P = .01). No major complications were observed. Patients received neither analgesia nor antibiotics. CONCLUSION: US-guided transabdominal aspiration of cyst fluid and subsequent methotrexate injection appears to be an alternative treatment for both simple and endometriotic ovarian cysts in selected cases.     

Recovery during high-intensity intermittent anaerobic exercise in boys, teens, and men

PURPOSE: This study examined the effects of age on recovery of peak torque of knee extensors (PTEX) and flexors (PTFL), and total work (TW) during high-intensity intermittent 30-s (HI30) and 60-s (HI60) exercise in boys (N=19; age, 11.4+/-0.5 yr), teens (N=17; age, 14.7+/-0.4 yr), and men (N=18; age, 24.1+/-2.0 yr). METHODS: Each age group's subjects were subdivided to participate in an HI30 or an HI60 protocol. The HI30 involved 4x18 maximal knee extensions and flexions (1-min rest between sets), and the HI60 comprised of 2x34 reps (2-min rest). PTEX (N.m.kg), PTFL (N.m.kg), and TW (J.kg) were recorded at each set. The percent recovery of PTEX, PTFL, and TW was calculated as percent of the value achieved in the first set. RESULTS: In HI60, the percent recovery for PTEX, PTFL, and TW after the first set was higher in boys compared with teens and men (P<0.01). In HI30, the percent recovery for PTEX, PTFL, and TW was higher in boys compared with men in all sets (P<0.01), and in teens compared with men in the last two sets (P<0.05). The percent recovery of PTFL and TW was higher in boys compared with teens in the last two sets (P<0.05). Lactate increase was most pronounced in men, less pronounced in teens, and least pronounced in boys (P<0.01). Heart rate recovered faster in boys compared with teens and men in both protocols (P<0.05). CONCLUSIONS: The recovery was faster in boys than in teens and men during HI30 and HI60, as evident by the greater percent recovery in boys for a given time. Furthermore, it appears that the rate of recovery during HI30 and HI60 anaerobic exercise is maturity dependent.     

Actinomycotic liver abscess. Case report and review of the literature

Actinomycosis is a chronic suppurative, granulomatous disease, which is characterized clinically by extensive necrosis and abscess formation, and histologically by the presence of the so-called "sulphur granules". Actinomycosis is generally classified as being of cervicofacial, thoracic or abdominal type. The objective of this study is the presentation of a case of actinomycotic liver abscess that we encountered in our department 5 years ago, along with a brief review of this rare disease. A 39-year-old male non-Greek Caucasian patient presented with high fever, malaise, anorexia, vomiting after food ingestion and right upper quadrant pain. Leucocytosis with a left shift was present, and ultrasonography demonstrated a mass of mixed composition in the anterior part of the right hepatic lobe, measuring 6.8 x 4.6 cm, suggestive of an abscess or haemangioma. MRI scan confirmed the presence of a space-occupying lesion, suggestive of an abscess. The patient was submitted to surgical drainage of the hepatic abscess. The culture of the purulent material was found to be sterile, while the histochemical examination of the specimen demonstrated the presence of actinomycosis. The patient had an uneventful postoperative course and after discharge received prolonged chemoprophylaxis. Actinomycotic liver abscess is a very rare clinical entity, and only 57 cases have been reported in the English literature. Due to the rarity of the disease and the limited number of reported cases, we considered it useful to report this case.