AVALIACAO DO EFEITO DO VENENO DE APIS MELLIFERA EM CULTURAS DE E. COLI, S. TYPHIMURIUM E Y. ENTEROCOLITICA TRATADAS COM BLEOMICINA

Apis mellifera bee venom (Africanized honey bee) was tested for the ability to protect against the lethal effect of bleomycin, an antibiotic and antineoplastic agent. Since the radioprotective effect of the venom has been observed on the other biological systems, in the present study the venom was applied to cultures of enterobacteria treated with bleomycin, a radiomimetic agent. The venom did not act as a protective agent against bleomycin in E. coli, S. typhimurium or Y. enterocolitica.

GLICOALCALOIDES DOS FRUTOS DO SOLANUM FLACCIDUM VELL

From the fruits of Solanum flaccidum Vell, two glycoalkaloids (solamargine and solasonine) and one aglycone (solasodine) were isolated and identified.

O RATO COMO MODELO EXPERIMENTAL DO DIABETES - ESTUDO CLINICO-LABORATORIAL

In this study, 90 Wistar rats were used. They were equally divided into three experimental groups - control group (CG), diabetic group (DG) and treated diabetic group (TG). The analyzed parameters were clinical (behavior, activity, general aspect, weight, water ingestion and diuresis) and biochemical (fasting glycemia and urinary glycosis). The diabetes was induced by alloxan and, then, treated with insulin associated to oral hypoglycemic (acarbosis). Observations were made at 5 experimental moments, as it follows: 1, 3, 6, 9, and 12 months after the diabetes induction. The results were submitted to variance analysis, with 5% of significance level. The DG presented lower weight and higher diuresis level than the CG and TG. The water ingestion of the CG was similar to TG. The glycemia levels were higher in DG than in CG, at every experimental moment. The TG, however, presented glycemia similar to the CG, except for the dosages at 3, and 9 months. They urinary glycosis of the DG and TG were similar between themselves, but higher than the one of the CG.

CAPACIDADE DE ABSORCAO DE AGUA, OLEO E FORMACAO DE ESPUMA DA FARINHA E CONCENTRADO PROTEICO DE FEIJAO-GUANDU (CAJANUS FLAVUS DC.)

Pigeonpea protein concentrate was prepared from full-fat decorticated raw flour. The water holding capacity of pigeonpea flour of decorticated seeds is 75% and its oil absorption capacity a 30%. The water holding capacity of the protein concentrate is three times the dry weight. The oil absorption capacity of the concentrate was 1,29 mL oil/g protein. The whipping capacity of the pigeonpea flour and its protein concentrate were evaluated.

Effects of protein malnutrition on glucose tolerance in rats with alloxan-induced diabetes

Protein-calorie malnutrition produces glucose intolerance and reduced insulin release in response to glucose. Rats adapted to low- or high-protein diets show an increased resistance to the diabetogenic action of a single dose of streptozotocin or alloxan. To determine the effects of dietary protein level on pancreatic function, we measured serum glucose levels under basal conditions and during the oral glucose tolerance test (GTT) performed before and after a single dose of alloxan administered to rats fed a 25% or a 6% protein diet for a period of 8 weeks. The incidence of mild hyperglycemia (serum glucose > 250 mg/dl) was greater among the rats fed the 25% protein diet (81%) than among those fed the 6% protein diet (42%). During the GTT performed before alloxan administration the serum glucose levels of the rats fed the 6% protein diet were not found to be significantly different from those of rats fed the 25% protein diet. During the GTT performed after alloxan injection all rats showed intolerance to the substrate (serum glucose > 160 mg/dl 120 min after glucose administration) regardless of whether basal serum glucose was normal or high. In summary, alloxan was less effective in producing basal hyperglycemia in the rats fed the 6% protein diet than in those fed the 25% protein diet but caused glucose intolerance during the oral GTT in both groups. Thus, it seems that feeding a 6% protein diet to rats offers only partial protection against the toxic effects of alloxan.

Experimental surgery of the facial nerve. Assessment of the intraperitoneal use of exogenous gangliosides

Compression and section of the facial nerve were performed in 48 rats in order to study the anatomopathological alterations occurring after daily intraperitoneal injections of 100 mg of exogenous gangliosides (Sinaxial®) for 45, 90, 180 days. In groups submitted to nerve compression, the histopathological changes were discrete and in the 180-day subgroups the nerve was practically normal. In animals submitted to section and neurorrhaphy there was formation of an amputation neuroma, a granuloma around the suture, axonal unstructuration and inter and perineural fibrosis. No significant differences were observed between the groups submitted or not to injection of exogenous gangliosides, indicating that the major factors involved in the quality of nerve regeneration were the technique and the formation of fibrosis and of an amputation neuroma.

Role of androgenic deprivation on the contractile response to norepinephrine in vas deferens isolated from rats submitted to swimming-stress

The effects of androgenic deprivation induced by castration on the norepinephrine contractile response of vas deferens from rats, which have been submitted to acute swimming-stress were determined. Acute swimming-stress led to subsensitivity to norepinephrine in vas deferens excised from intact rats. Similarly, castration also induced subsensitivity to norepinephrine, but no further subsensitivity occurred in organs from castrated rats submitted to acute stress. The results indicate a different response to norepinephrine in terms of relative responsiveness ratio, when vas deferens was excised from castrated rats or castrated rats submitted to acute stress. It is suggested that androgenic steroids modulate the recovery of homeostasis in rat vas deferens during acute stress, and that this effect may involve mechanisms that affect both the sensitivity of adrenergic receptors and the system of neuronal uptake of catecholamines.

Reinforcing properties of fencamfamine: Involvement of dopamine and opioid receptors

Fencamfamine (FCF) is a psychostimulant classified as an indirect dopamine agonist. The conditioning place preference (CPP) paradigm was used to investigate the reinforcing properties of FCF. After initial preferences had been determined, animals were conditioned with FCF (1.75, 3.5, or 7.0 mg/kg; IP). Only at the dose of 3.5 mg/kg FCF produced a significant place preference. Pretreatment with SCH23390 (0.05 mg/kg, SC) or naloxone (1.0 mg/kg SC) 10 min before FCF (3.5 mg/kg; IP) blocked both FCF-induced hyperactivity and CPP. Pretreatment with metoclopramide (10.0 mg/kg; IP) or pimozide (1.0 mg/kg, IP), respectively, 30 min or 4 h before FCF (3.5 mg/kg; IP), which blocked the FCF-induced locomotor activity, failed to influence place conditioning produced by FCF. In conclusion, the present study suggests that dopamine D 1 and opioid receptors are related to FCF reinforcing effect, while dopamine D 2 subtype receptor was ineffective in modifying FCF-induced CPP.

Pituitary-adrenal activity and opioid release in ponies during thiopentone/halothane anaesthesia

The effect of thiopentone/halothane anaesthesia on the release of endogenous opioid, adrenocorticotrophin, arginine vasopressin, cortisol and catecholamine was investigated in ponies. The contribution made by halothane itself was studied by maintaining six ponies with a constant 12 per cent end tidal halothane concentration and five with a concentration ranging between 0.8 and 12 per cent. Cardiorespiratory depression was more prolonged in the ponies receiving a constant 1-2 per cent end tidal halothane concentration than in those which received less halothane. Plasma lactate concentration increased and haematocrit decreased during halothane anaesthesia. The concentrations of met-enkephalin, dynorphin and catecholamines did not change and those of β-endorphin, adrenocorticotrophin, arginine vasopressin and cortisol increased during halothane anaesthesia. Halothane appeared to be a major stimulus to pituitary adrenocortical activation because the adrenocortical secretion was proportional to the amount of halothane inhaled. β-endorphin increased proportionally more than adrenocorticotrophin and their plasma concentrations were not correlated, suggesting that they have independent secretion mechanisms.

Metabolic adaptations induced by long-term fasting in quails

After up to 21 days without food, adult male quails (Coturnix coturnix japonica) lost about 45% of the initial body weight (100-150 g). As in naturally fast-adapted and larger birds, three phases were identified during prolonged fasting in quails. Phase I lasted 2-3 days and was characterized by a rapid decrease in the rate of body weight loss and high fat mobilization. Phase II was longer and characterized by a slow and steady decline in the rates of body weight loss and of nitrogen excretion. The third (critical) period was marked by an abrupt increase in the rates of body weight loss and of nitrogen excretion. Despite their small size, the duration of phase II in quails was relatively long, a clear advantage for the study of the relationships between the several metabolic events that occur during this crucial adaptative period. Also, the beginning of phase III could be precisely determined. Changes in blood glucose, plasma FFA and triacylglycerols levels, as well as in liver and carcass lipid content were similar to those found in other species of birds. Therefore, quails seem to be a suitable model to investigate the biochemical mechanisms involved in the metabolic adjustments to prolonged food deprivation in non fasting-adapted birds. © 1995.

Cellulose degradation by Leucocoprinus gongylophorus, the fungus cultured by the leaf-cutting ant Atta sexdens rubropilosa

Leucocoprinus gongylophorus, the fungus cultured by the leaf-cutting ant Atta sexdens rubropilosa, is able to degrade efficiently cellulose, microcrystaline cellulose, carboximethylcellulose, and cellobiose. Analysis of the degradation products indicate that the fungus produce extracellular β-glucosidase, exo- and endo-glucanase. The importance of cellulose degradation to the association of fungus and ant is discussed.

Total intravenous anaesthesia in ponies using detomidine, ketamine and guaiphenesin: Pharmacokinetics, cardiopulmonary and endocrine effects

Pharmacokinetics and some pharmacological effects of anaesthesia induced by a combination of detomidine, ketamine and guaiphenesin were investigated in eight ponies. Cardiopulmonary function was studied and plasma met-enkephalin, dynorphin, β-endorphin; arginine vasopressin, adrenocorticotrophin, cortisol, 11-deoxycortisol and catecholamine concentrations were measured. The combination produced slight cardiorespiratory depression, hyperglycaemia and a reduction in haematocrit. There were no changes in plasma opioids, pituitary peptides or catecholamines. Plasma cortisol concentration decreased and plasma 11-deoxycortisol increased indicating a suppression of steroidogenesis. Steady state ketamine and guaiphenesin concentrations were attained during the infusion period, and ketamine concentrations likely to provide adequate analgesia for surgical operations were achieved (more than 2.2 μg ml-1). Steady state detomidine concentration was not attained. The ponies took on average 68 minutes to recover to standing and the recovery was uneventful.

CONDICOES BACTERIOLOGICAS DE LEITE CRU E DE LEITE PASTEURIZADO NA REGIAO DE ARARAQUARA, SP, BRASIL

Milk can be an important spreading vehicle of pathogenic agents mainly for young children who are an important group of milk consumers. 135 milk samples (77 of raw milk and 58 of pasteurized milk) were analysed in order to verify the number of heterotrophic bacteria, of Staphylococcus aureus and of total coliforms, as well as to determine presence of Salmonella, Shigella, enteropathogenic Escherichia coli (EPEC) and enteroinvasive Escherichia coli (EIEC). The results were negative for Salmonella, Shigella and EIEC. EPEC serotypes 0:28, 0:111 and 0:55 were isolated in 4 of raw milk samples. The heterotrophic bacteria was found in counts over 30.000 UFC/mL in 91%, 25% and 68,75% respectively of raw milk, milk grade B and grade C. Counts over 30.000 coliforms/mL were found in 70,13%, 6,25% and 6,24% of the raw milk, B and C, respectively. 32,40% of the raw milk had counts of S. aureus over 3.000 UFC/mL.

Immunochemical study of a Paracoccidioides brasiliensis polysaccharide-like antigen

The polysaccharide antigen from P. brasiliensis has been largely employed in serologic tests, as well as in skin tests, to evaluate cellular immunity. SDS-PAGE analysis of this antigen has revealed a variability in the number of bands exhibited by isolates SN, 265, 339, 113 and 18 (7 to 16 bands). The antigens obtained from isolates 2, PTL, 192 and Adel showed two or three bands. Glycoprotein analysis demonstrated a broad region between 50 and 90 kDa. Major bands of 48 and 30 kDa were present in almost all antigens. Optimal complement fixing dilution appears to be unaffected by the number of bands presented by different antigens. The immunoblot analysis revealed that the 90 and 30 kDa bands were mainly recognized by sera from paracoccidioidomycosis patients. Bands of high molecular weight were also recognized by most of the sera studied. Sera from histoplasmosis recognized the 94 kDa band. In conclusion, although the isolates exhibit quantitative variability in the number of fractions, it is possible to use only one or two samples given the greatest frequency of reactivity is seen in the 30 and 90 kDa fractions.

Synaptonemal complex formation in spermatocytes of the autotriploid rainbow trout, Oncorhynchus mykiss (Pisces, Salmonidae)

Meiotic cells of triploid male rainbow trouts were analyzed by a surface-spreading SC technique in order to show the process of chromosome synapsis. At zygotene the formation of SCs involved, almost exclusively, two sets of lateral elements (LEs), and the remaining set of LEs presented different synaptic configurations involving one, two, three, or four LEs. The absence of SCs involving more than two LEs from mid- to late pachytene indicates that the multivalents produced by synapsis involving more than two LEs, are eliminated before the end of pachytene; thus, the mechanism of chromosome pairing in triploid male rainbow trouts produces, almost exclusively, bivalents with a probable extensive nonhomologous synapsis involving the extra set of chromosomes.