Effects of anti-inflammatory drugs on fever and neutrophilia induced by Clostridium difficile toxin B

This study investigated the ability of Clostridium difficile toxin B, isolated from the VPI 10463 strain, to induce fever and neutrophilia in rats. Intravenous injection of toxin B (0.005-0.5 mug/kg) evoked a dose-dependent increase in body temperature. The febrile response to 0.5 mug/kg of the toxin started in 2.5 h, peaked at 5 h, and subsided fully within 24 h. Toxin B also induced a dosedependent neutrophilia. Pretreatment with indomethacin (2 mg/kg, i.p.) did not affect the neutrophilia induced by toxin B, but significantly reduced the febrile response measured 4 to 8 h after toxin B injection. Dexamethasone (0.5 mg/ kg) also markedly diminished the febrile response induced by toxin B. These results show that Clostridium difficile toxin B induced a febrile response susceptible to inhibition by dexamethasone and indomethacin. Furthermore, they suggest that prostaglandins are not involved in the neutrophilia caused by this toxin.     

Neurochemical effects ofl-pyroglutamic acid

The effect ofl-pyroglutamic acid, a metabolite that accumulates in pyroglutamic aciduria, on different neurochemical parameters was investigated in adult male Wistar rats. Glutamate binding, adenylate cyclase activity and G protein coupling to adenylate cyclase were assayed in the presence of the acid.l-pyroglutamic acid decreased Na⁺-dependent and Na⁺-independent glutamate binding Basal and GMP-PNP stimulated adenylate cyclase activity were not affected by the acid. Furthermore, rats received unilateral intrastriatal injections of 10–300 nmol of bufferedl-pyroglutamic acid. Vehicle (0.25 M Tris-Cl, pH 7.35–7.4) was injected into the contralateral striatum. Neurotoxic damage was assessed seven days after the injection by histological examination and by weighing both cerebral hemispheres. No difference in histology or weight could be identified between hemispheres. These results suggest that, although capable of interfering with glutamate binding, pyroglutamate did not cause a major lesion in the present model of neurotoxicity.     

Distribution of the genus Ancylostoma (Dubini, 1843) along the digestive tube of the dog (author's transl)

The A. A. studied the distribution of nematodes of the genus Ancylostoma (Dubini, 1843) along the digestive tube of 45 dogs. For the collection of the worms they used the method developed by Mello and Campos. The distribution found was: 97,5% in the jejunum, 1,2% in the ileon, 0,7% in the duodenum, 0,3% in the colon, 0,2% in the cecum and 0,1% in the stomach.     

Tissue tropism of different Trypanosoma cruzi strains.

A systematic study of the distribution of intracellular parasites in the organs and tissues was performed in groups of mice inoculated with 4 different Trypanosoma cruzi strains. An extremely high parasitism of spleen, liver, and bone marrow was observed in mice inoculated with Y and Berenice strains; with CL strain, however, parasites were almost absent in those organs. Bloodstream forms apparently present differences which facilitate or prevent their uptake by macrophages from the mononuclear phagocytic system. Parasitism of the smooth muscle from hollow organs was significantly higher with ABC and Berenice strains than with Y and CL. The importance of the distribution of intracellular stages in the pathogenesis of the disease is discussed.     

Pulmonary Embolectomy

Embolectomy was carried out in eight patients with pulmonary emboli. Angiographic diagnosis was obtained in six, and in two cases pulmonary angiography could not be done because of the very critical condition of the patients. In the latter two, diagnosis was made based only on clinical findings. Two patients died in the operating room (25 percent). Six patients were discharged in good condition.It is emphasized that pulmonary embolectomy should be done in cases of pulmonary emboli when a clinical status of shock is present (systolic blood pressure less than 80 mm of mercury and the patient in low cardiac output syndrome) and when there is no response to medical treatment regardless of the degree of obstruction in the pulmonary arterial tree.     

High cell density reactor for the production ofLactobacillus plantarum

Summary The production of a flocculent strain ofLactobacillus plantarum was performed in a high cell density reactor: a fluidized bed reactor (FBR) with a settler and an external cell recirculation. Two variables were assessed, the recirculation rate (R) and the dilution rate (D). The effect of the latter is much more important than the effect of the former in ensuring a quick start up in the flocculation process. The cell volumetric productivities obtained with this system increase directly with dilution rate and recirculation rate. The values of cell volumetric productivities obtained are considerably higher than those obtained in continuous stirred tank reactors (CSTR) and much higher than in batch reactors.     

Transcription efficiency of human apolipoprotein A-I promoter varies with naturally occurring A to G transition.

In human, the gene coding for apolipoprotein A-I (apo A-I), a protein of the plasma lipid transport system, is expressed only in the liver and the intestine. A naturally occurring A to G substitution in the promoter at position -78 was shown to be associated with high density lipoproteins (HDL) in females. We have studied the effect of this mutation on promoter activity using various lengths of promoter sequences and the CAT reporter gene system. Transient expression studies after introduction of these constructs into Hep 3B cells revealed that in the region spanning -330 to +1 of the promoter an A to G substitution increases the activity approximately twofold. On the other hand, when further upstream region (-1469 to +397) is also included, the promoter activity seems comparable in both alleles. Our results show how minimal sequence variations can affect the in vitro analysis of promoter activity.     

Effects of domain connection and disconnection on the yields of in-plane bimolecular reactions in membranes.

It has recently been shown (Vaz, W.L.C., E.C.C. Melo, and T.E. Thompson. 1989. Biophys. J. 56:869-875; 1990. Biophys. J. 58:273-275) that in lipid bilayer membranes in which ordered and disordered phases coexist, the ordered phase can form a two-dimensional reticular structure that subdivides the coexisting disordered phase into a disconnected domain structure. Here we consider theoretically the yields of bimolecular reactions between membrane-localized reactants, when both the reactants and products are confined to the disordered phase. It is shown that compartmentalization of reactants in disconnected domains can lead to significant reductions in reaction yields. The reduction in yield was calculated for classical bimolecular processes and for enzyme-catalyzed reactions. These ideas can be used to explain certain experimental observations.     

Biochemical diversity and genetic distance in two species of the genusSaguinus

A comparative study of 20 blood genetic systems was performed on three populations of genusSaguinus: S. fuscicollis weddelli, S. midas niger, andS. midas midas. Some markers are useful for the characterization of the two species.ADA ⁵, ADA⁶, CA2³, CA2⁴, andES2 ² occur only inS. fuscicollis whileADA ⁴is fixed inS. midas. S. midas midas showed heterozygosity value comparable to those previously obtained for the genusAlouatta. Estimates of genetic distance betweenS. fuscicollis andS. midas species of about 14% are in accordance with those referred to in the literature for interspecific differences. Genetic distances between subspecies ofSaguinus midas were nearly 3%, which is within the range for subspecies.