[Prospective study of rotavirus infections in Belém, Pará, Brazil: clinical and epidemiological features].

A prospective study of acute diarrhoeal diseases was carried out from April 1990 to September 1992 with the purpose of assessing the immunogenicity, safety and efficacy of a Rhesus-human reassortant rotavirus ("RRV-TV") vaccine, involving 540 children living in Belém, Pará, Brazil. As half of the children received placebo, this trial provided the opportunity of broadening the knowledge on both clinical and epidemiological aspects of rotavirus infection in the Amazon region. There were 2,789 diarrhoeal episodes during the above mentioned period, of which 86 (3.

Nosocomial transmission of an avian-like rotavirus strain among children in Belém, Brazil.

An atypical group-A rotavirus strain, with an electrophoretype displaying 5 segments in the first dsRNA size class, was detected among 3 hospitalized children less than 2 years old. Detection occurred initially 24 h after admission in a non-diarrhoeic child hospitalized because of acute respiratory infection. The second detection involved a child who occupied a different room within the same ward and who developed nosocomial diarrhoea 48 h later.

Prevalence of antibodies to Norwalk virus among Amerindians in isolated Amazonian communities.

The seroepidemiology of Norwalk virus infections was examined among Amerindians belonging to eight relatively isolated communities in the Amazon region by means of a new enzyme immunoassay using recombinant Norwalk virus antigen. The seroprevalence of antibodies to Norwalk virus ranged from 39% in the Maiogong to 100% in the Kubenkrankrein. The distribution of antibody levels varied greatly among groups; five of the eight communities had an antibody prevalence greater than 90% with many high values (> 100 units), while three had both a low seroprevalence and a preponderance of low values (< 100 units).

Neutralizing antibody immune response in children with primary and secondary rotavirus infections.

We have characterized the neutralizing antibody immune response to six human rotavirus serotypes (G1 to G4, G8, and G9) in Brazilian children with primary and secondary rotavirus infections and correlated the response with the G serotype of the infecting rotavirus strain. Twenty-five children were studied: 17 had a single rotavirus infection, 4 were reinfected once, and 4 experienced three infections. Two of the reinfections were by non-group A rotaviruses.

Isolation and characterization of pollen-specific maize genes with sequence homology to ragweed allergens and pectate lyases.

A cDNA clone (Zm58.1) was isolated by differential screening from a cDNA library made to mature Zea mays pollen, and shown to be pollen-specific by RNA blot analysis. When this partial-length clone was used to probe a genomic library, a similar but distinct pollen-specific genomic clone (68% sequence identity) was isolated (Zm58.

Role of striatal dopamine in the lordosis behaviour.

Effects of intrastriatal injections of haloperidol (Dopamine antagonist) and D-amphetamine (Dopamine agonist) on lordosis behaviour were studied in ovariectomized female albino rats, after priming with subcutaneous injections of estrogen and progesterone. The lordosis quotient (LQ) significantly increased after haloperidol, and decreased following D-amphetamine treatment. However, the inhibitory effect of D-amphetamine was transient and could be reversed by haloperidol in the same animal when given one hour after the D-amphetamine injection.

Effect of intensity and duration of stress on male sexual behaviour.

Male rats were exposed to four different stress conditions, varying in duration and intensity, during separate periods and their copulatory behaviour was studied. The number of mounts and time spent in other sexual behaviours were reduced with intensity of stressor being primarily responsible rather than prolongation of duration of a less severe stress condition.

Rotavirus serotypes and electrophoretypes among children attending three paediatric hospitals in Belem, Brazil.

From March to September 1988 stool specimens of 101 hospitalized diarrhoeic infants and children, aged 1-24 months were examined by enzyme-linked immunosorbent assay (ELISA) for the presence of rotavirus antigen. This agent was found in 40 (40 per cent) of the 101 episodes of acute diarrhoea, and strains were both characterized by analysis of RNA in polyacrilamide gel and serotyped by ELISA using serotype-specific monoclonal antibodies. The highest frequency of rotavirus positivity was 80 per cent in the 16-18 month age group.

Effect of stress on organ weight in rats.

The effect of 90 minute supine restraint or forced swim stress, on weights of various organs in sixty adult male albino rats was studied. One group of twenty rats served as control; second group of twenty was immobilized and third group of twenty was forced to swim in water at room temperature. The animals were studied for a period of 15 days.

Effect of interaction between glucose or sodium chloride ingestion and ovarian hormones on some endocrine organs in rats.

Adult female rats with normal oestrus cycles (control), ovariectomized (OVX), ovariectomized with estradiol treatment (OVX-EB) and ovariectomized with progesterone treatment (OVX-P), were provided with Glucose (G/W) or Saline (S/W) through a two bottle preference. They were given food pellets ad libitum. At the end of 3 weeks' period the animals were sacrificed and pituitary, thyroid, adrenal and pancreas were removed and weighed.

Role of caudate nucleus on modulation of blood pressure responses in cat.

Changes in blood pressure, heart rate and respiration were studied in 15 cats on bilateral stimulation of rostral, middle and caudal regions of caudate nucleus. Hypotensive response was obtained on stimulation of anterior caudate nucleus, which changed to pressor response when posterior caudate nucleus was stimulated. Biphasic blood pressure responses were recorded on stimulation of middle caudatal area.

Differential role of ovarian hormones for taste preferences in rats.

The effects of estrogen (OVX-EB) and progesterone (OVX-P) administration to ovariectomized (OVX) rats on food and fluid intakes were studied in fifty five animals grouped into three series. Animals in each series were given a choice of two fluids viz. tap water and either 5% glucose (5 G/W) or 12% glucose (12 G/W) or 1.

Dissection of a pollen-specific promoter from maize by transient transformation assays.

We have previously reported the isolation and characterization of a gene (Zm13) from Zea mays which shows a pollen-specific pattern of expression. Stably transformed tobacco plants containing a reporter gene linked to portions of the Zm13 5' flanking region show correct temporal and spatial expression of the gene. Here we present a more detailed analysis of the 5' regions responsible for expression in pollen by utilizing a transient expression system.

Effects of adrenalectomy on brain weight, body weight and weight of certain endocrine organs in rats.

Albino rats, both males and females were adrenalectomized (Adx.), either on the eleventh or the twenty fifth day after birth and the body weights recorded daily until the sixtieth day when all the animals were sacrificed. Brain (cerebrum and cerebellum), pituitary, thyroid and gonads were weighed post mortem.

Role of acetylcholine and dopamine in dorsal hippocampus on hoarding behavior in rats.

The probable roles of Acetylcholine (Ach) and Dopamine (DA) in the modulation of instinctual behaviors of feeding and hoarding (HS), as also the body weight and vaginal cyclicity (EI), were studied by instillation of Atropine (Ach antagonist), Haloperidol (DA antagonist) and Apomorphine (DA agonist) in the dorsal hippocampus of nonpregnant female rats. It was observed that the HS was significantly decreased with both Atropine and haloperidol and increased with Apomorphine, although the food intake was decreased with the three chemicals. It appears that action of both Ach and DA on the dorsal hippocampus has a positive influence on hoarding behavior.

Effect of mid-dorsal caudate nucleus on conditioning for pain stimulus in rats.

Male rats were subjected to conditioning, with light source as conditioned stimulus, followed by a noxious stimulus applied to the tail as unconditioned stimulus. There was development of conditioned response after a few days, which was inhibited later on.

Promoter sequences from a maize pollen-specific gene direct tissue-specific transcription in tobacco.

A set of 5' promoter deletions from Zmg13, a genomic clone of a pollen-specific gene of maize, has been transcriptionally fused to a beta-glucuronidase (GUS) reporter gene in the binary vector pBI101. Tobacco leaf disks were transformed and mature plants analyzed for GUS activity directed by the Zmg13 promoter constructs. Transgenic plants containing the 375 bp Zmg13 sequence from -314 to +61 relative to the transcription start site transcribed GUS RNA and expressed active GUS enzyme in mature pollen but not in leaves.

Variations in hoarding behavior following regional hippocampal lesions in rats.

Instinctual behaviors of feeding (food intake) and hoarding (HS) so also the body weight and estrus cycles (EI) were studied before and after discrete bilateral electrolytic lesions of dorsal hippocampus in female rats. Following the lesions, there was significant increase in food intake, body weight, hoarding score and disruption of 4-5 days estrus cycles with EI of more than one, as compared to the control (prelesioned) period and the sham operated rats. Lesions of ventral hippocampus in the earlier study (Indian J exp Biol, 26 (1988) 53) had shown a significant decrease in hoarding thus suggesting a differential role of the hippocampus probably mediated through the amygdala and/or hypothalamus both of which either alone or together exert a more direct and pivotal control in the feeding and hoarding behaviour.

Atypical rotavirus among diarrhoeic children living in Belém, Brazil.

Atypical rotaviruses were detected in faeces from two diarrhoeic children living in Belém, Pará, Brazil. Rotavirus particles were detected by electron microscopy and the RNA electrophoresis showed patterns which were compatible with group C rotaviruses. Tests for the presence of group A antigen by enzyme-linked-immunosorbent assay (ELISA) were negative.

Naturally occurring serotype 2/subgroup II rotavirus reassortants in northern Brazil.

Nine serotype 2 human rotavirus strains were isolated in a community-based longitudinal study in Northern Brazil. Five of these strains had a 'long' RNA electrophoretic pattern and all five strains were determined to belong to subgroup II by ELISA assay, in contrast to properties common to serotype 2 human rotaviruses previously characterized. Hybridization studies of one of these unusual strains with 32P-labelled mRNAs derived from the prototype human strains Wa (serotype 1, subgroup II) and S2 (serotype 2, subgroup I) suggested that it was generated by a reassortment event in nature, in which a subgroup II, 'long' electropherotype rotavirus exchanged its serotype-specific gene and gene number 10 for the equivalent genes from a serotype 2, 'short' electropherotype virus.

Effect of dorsal hippocampal lesion compared to dorsal hippocampal blockade by atropine on reference memory in vision deprived rats.

In order to study the primacy of the hippocampus in place learning function 24 male adult albino rats were hippocampally-lesioned in dorsal hippocampus involving fornical damage (group I); sham operated for comparison with group I (group II); cannulated for instillation of atropine sulphate in the same loci as group I (group III); and cannulated for instillation of saline which served as control for group III (group IV). All the animals were enucleated and their reference memory (long-term memory) was tested, using open 4-arm radial maze. There was loss of reference memory in groups I and III.

Ingestive behaviour of starved rats after single intraperitoneal injection of fresh plasma from well-fed rats.

Ingestive behaviour of control and experimental rats following 96 hours of starvation was studied. The control animals were injected normal saline intraperitoneally (I.P.