Facilitation by 8-OH-DPAT of passive avoidance performance in rats after inactivation of 5-HT(1A) receptors.

1. Pretraining administration of 8-hydroxy-2-di-n-propylamino-tetralin (8-OH-DPAT 0.1 mg kg(-1)), a 5-HT(1A) receptor agonist, or buspirone (1 mg kg(-1)), a 5-HT(1A) receptor partial agonist, markedly impaired passive avoidance retention in rats 24 h later. The effect of 8-OH-DPAT was prevented by the 5-HT(1A) receptor antagonists, NAN-190 and WAY-100635, at doses without any intrinsic effect. 2. N-ethoxycarbonyl-2-ethoxy-1,2-dihydroquinoline (EEDQ 10 mg kg(-1)), an alkylating agent that inactivates different G-protein coupled receptors, impaired retention performance when given 48 h pretraining. The disruptive effect of EEDQ was reversed by 8-OH-DPAT or buspirone, given 30 min before training. 3. Non-specific actions did not account for 8-OH-DPAT-induced reversal of the EEDQ effect since no significant difference in locomotor activity or in pain threshold was found between rats receiving EEDQ or EEDQ+8-OH-DPAT. 4. When NAN-190 (1 mg kg(-1)) or WAY-100635 (0.5 mg kg(-1)) were given before 8-OH-DPAT to EEDQ-pretreated animals, the reversal by 8-OH-DPAT of EEDQ-induced retention impairment was still more pronounced. However, no EEDQ reversal by 8-OH-DPAT was found when 5-HT(1A) receptors were protected by WAY-100635 (10 mg kg(-1)) 30 min before EEDQ. 5. In the hippocampus of EEDQ-treated rats, 5-HT(7) receptors were less inactivated than 5-HT(1A) receptors and significant increases were found in 5-HT(1A) but not in 5-HT(7) receptor mRNA levels. Ritanserin and methiothepin (10 mg kg(-1) each), antagonists with higher affinity at 5-HT(7) than at 5-HT(1A) receptors, prevented the retention impairment induced by EEDQ but did not significantly protect against 5-HT(7) receptor inactivation. 6. The results indicate that the facilitatory effect of 8-OH-DPAT is not mediated through 5-HT(1A) receptors and suggest that other 8-OH-DPAT-sensitive receptors could be involved in the dual effect of 8-OH-DPAT on passive avoidance performance in rats.

Anxiogenic-like effects and reduced stereological counting of immunolabelled 5-hydroxytryptamine6 receptors in rat nucleus accumbens by antisense oligonucleotides.

The physiological role of 5-hydroxytryptamine6 receptors in the central nervous system has not yet been elucidated. The high affinity of various psychotropic drugs for 5-hydroxytryptamine6 receptors has led to the suggestion that this receptor type may be a novel target in neuropsychiatry. We have found that continuous intracerebroventricular administration of a 5-hydroxytryptamine6 receptor antisense oligonucleotide, but not of a missense oligonucleotide, produced an anxiogenic-like response in rats using two different models of anxiety, the social interaction test and the elevated plus-maze. Neither oligonucleotide treatment modified locomotor activity, rectal temperature or food intake, suggesting a low or null neurotoxicity. The effectiveness of the treatment with the designed antisense oligonucleotide to block the synthesis of the protein encoded by the target mRNA was assessed by immunolabelling 5-hydroxytryptamine6 receptors in the nucleus accumbens, where this receptor is highly expressed, using previously characterized specific antibodies. The density of the immunostaining was quantified by means of an unbiased three-dimensional stereologic procedure, which revealed a significant reduction (-25%) in the number of immunolabelled neuronal elements. These results suggest that, in addition to other 5-hydroxytryptamine receptor subtypes, 5-hydroxytryptamine6 receptors in the nucleus accumbens may participate in anxiety-related neurobiological mechanisms.

Effect of chronic antidepressant treatment on transcription factor binding activity in rat hippocampus and frontal cortex.

1. The effect of chronic antidepressant administration on CRE-, SP1- and GRE-binding activity was studied in rat hippocampus and frontal cortex. 2. Fluoxetine and desipramine (3 and 10 mg/kg/day respectively) were given to rats for 21 consecutive days. The animals were killed 3 hr after the last injection and nuclear extracts were prepared to perform the DNA-protein reaction with consensus CRE, SP1 and GRE oligonucleotides. 3. Gel-shift assays showed that CRE-binding activity was increased in both frontal cortex and hippocampus by chronic fluoxetine treatment. Desipramine, however, only enhanced this activity in the frontal cortex. 4. Chronic fluoxetine decreased SP1-binding activity in the two selected brain regions. Again, desipramine only produced a significant reduction in the frontal cortex. 5. GRE-binding in the hippocampus was only enhanced by desipramine. Since chronic desipramine, and not fluoxetine, is able to increase hippocampal glucocorticoid receptor (GR) expression, interactions of GR with CREB and SP1 may determine the lack of effect of desipramine on binding activity of the two latter transcription factors in this brain region. 6. Overall, the results show a differential and region-specific effect of chronic, and not acute, antidepressant treatment on the DNA-binding activities studied and are consonant with the possible role of changes in gene expression in the mechanism of antidepressant action.

Risk factors associated with taeniasis-cysticercosis in Lagamar, Minas Gerais State, Brazil.

An epidemiological survey was carried out in 3,344 people of an urban town in Lagamar, Minas Gerais, Brazil--during 1992-1993, to evaluate the main risk factors related to taeniasis and cysticercosis. A total number of 875 (78.9%) houses were visited and 1080 (32.3%) subjects were clinically examined. Poor sanitary conditions were positively associated with former history of taeniasis or seizures in households (p < 0.05). It was remarkable the positive relationship between taeniasis and seizures when households were questioned and subjects were clinically evaluated (p < 0.05). The relative risk of seizures was 2.3 between households and 1.7 for individuals clinically examined respectively. The breeding of swine nearby and the chronic carriers of taeniasis are determinant factors in the maintenance of the epidemiological link between taeniasis and cysticercosis in endemic areas.

Risk factors associated with taeniasis-cysticercosis in Lagamar, Minas Gerais State, Brazil

An epidemiological survey was carried out in 3,344 people of an urban town in Lagamar, Minas Gerais, Brazil--during 1992-1993, to evaluate the main risk factors related to taeniasis and cysticercosis. A total number of 875 (78.9%) houses were visited and 1080 (32.3%) subjects were clinically examined. Poor sanitary conditions were positively associated with former history of taeniasis or seizures in households (p < 0.05). It was remarkable the positive relationship between taeniasis and seizures when households were questioned and subjects were clinically evaluated (p < 0.05). The relative risk of seizures was 2.3 between households and 1.7 for individuals clinically examined respectively. The breeding of swine nearby and the chronic carriers of taeniasis are determinant factors in the maintenance of the epidemiological link between taeniasis and cysticercosis in endemic areas.

Foi realizado inquérito epidemiológico em 3344 indivíduos da área urbana de Lagamar, Minas Gerais, Brasil, durante 1992-1993 para avaliar os principais fatores de risco relacionados com teníase e cisticercose. Foram visitadas 875 (78,9%) casas e examinados clinicamente 1080 (32,3%) indivíduos. As condições sanitárias deficientes estiveram associadas estatisticamente com história anterior ou atual de teníase ou de convulsões entre os membros de cada família (p < 0,05). A correlação entre teniase e convulsões foi evidenciada tanto no inquérito domiciliar como durante a avaliação clínica dos indivíduos (p < 0,0001). O risco relativo de convulsões foi de 2,3 entre os moradores entrevistados no domicílio e 1,7 entre os indivíduos que compareceram para exame clínico, respectivamente. A criação de suínos no peridomicílio e os portadores crônicos de teníase são fatores determinantes na perpetuação do elo epidemiológico teníase-cisticercose nas áreas endêmicas.

[The epidemiological aspects of taeniasis-cysticercosis in an endemic area of Lagamar, Minas Gerais]. / Aspectos epidemiológicos da teníase-cisticercose na área endêmica de Lagamar, MG.

An epidemiological inquiry of humancysticercosis due to Taenia solium was carried out in Lagamar, Minas Gerais State, Brazil, in 1992. A survey of 1109 houses with 3344 inhabitants was made. The inquiry included 875 (86%) families and the questionnaire was answered by an informer, who was the father in 80% of the cases. One hundred pigsties, sheltering 406 swines in extremely precarious conditions, were found in 100 (11.4%) houses. A history on taeniasis in some member of the family was verified in 300 (34.2%) houses. A history of seizures was referred to by 125 (14.2%) of families. The outset of convulsion in adult age was characterized in 39 (37.8%) families. A history of mental disorder was reported in 53 (6.0%) of houses. Stool examinations were positive for Taenia spp in 24 (1.3%) of samples examined.

Ultrasound and dual X-ray absorptiometry densitometry in women with hip fracture.

To assess the usefulness of the measurement of the os calcis by ultrasound, a method that probably reflects bone quality as well as density, we have studied 54 women with hip fracture of the proximal femur and a control group. Ultrasound evaluation of the os calcis [broadband ultrasound attenuation (BUA), speed of the sound (SOS), and a combined index ("stiffness")], and bone mineral density (BMD) determination over the proximal femur by dual X-ray absorptiometry (DXA) were performed. Weight, BMD, and ultrasound values in the hip fracture patients were significantly lower than controls (P < 0.001). The Z-scores for BUA and stiffness were not different than that for femoral neck, Ward's triangle or trochanteric BMD (between -1.7 and -1.5). The odds ratios determined by receiver-operating characteristics (ROC) analysis were greater at the femoral neck (25.1) and BUA (24.4). Intermediate values were found at stiffness (16.9), Ward's triangle (12.8), and trochanter (11.1), and lower values were obtained at SOS (4.2). In turn, patients with trochanteric hip fractures had a significantly lower femoral neck and Ward's triangle BMD, stiffness, and BUA than patients with cervical hip fractures. Comparing a subgroup of 30 women with hip fractures without vertebral fractures with an age-matched group of 87 women with osteoporotic vertebral fractures, both groups were of similar weight and BMD but all ultrasound values were significantly lower in the hip fractures compared with vertebral fracture patients (P < 0.05 - P < 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

[Neurologic and laboratory findings in a population of an endemic area for taeniasis-cysticercosis, Lagamar, MG, Brazil (1992-1993)]. / Achados neurológicos e laboratoriais em população de área endêmica para teníase-cisticercose, Lagamar, MG, Brasil (1992-1993).

A clinic-epidemiological enquiry was conducted on in an endemic area for teniasis-cysticercosis. From the whole population 1080 (32.2%) individuals were examined. We found 198 (18.3%) individuals referring teniasis-bearing in the past, and 103 (9.5%) affirming to have had convulsions, either in the past or present. From the last group, 39 (37.8%) indicated that the crisis had begun in adulthood. From the group of patients presenting convulsions, 62 (62%) had laboratory tests performed. Computed tomography showed intracranial calcifications in 21 (33.8%) patients, variable in number and location, suggesting neurocysticercosis and no evidence of disease activity. Electroencephalograms showed abnormal waves in 21 (33.8%) patients and cerebrospinal fluid analyses were altered in 27 (43.5%) cases, having detected eosinophils only in 3 (4.8%) patients. Spinal fluid tests for cysticercosis through enzyme linked immunosorbent assay (ELISA) or indirect immunofluorescence were taken in only 26 (41.9%) patients, obtaining positive results in 6 (23%) samples. Varying upward shifts of protein levels were found in spinal fluid analysis. Assuming that all epidemiologic risk factors for teniasis-cysticercosis in the studied region and its correlation with the laboratory alterations described in convulsing crisis, a prevalence of 1.9% for neurocysticercosis was found.