Cytotoxicity of a low molecular weight fraction from Aloe vera (Aloe barbadensis Miller) gel.

The cytotoxicity of a low mol. wt fraction (LMWF) obtained from Aloe vera gel was determined by two different assays. Firstly, exposure of monolayers of chicken fibroblasts to LMWF induced disruption of intercellular junctions and detachment of individual cells from the bottom of the flask, with formation of cell-free gaps in the monolayer.

Involvement of a 50-kDa mRNP protein from Saccharomyces cerevisiae in mRNA binding to ribosomes.

A yeast 50-kDa mRNA-binding protein (50mRNP) is found selectively associated with the 48S and 80S initiation complexes. This protein is structurally related to the translational elongation factor EF-1alpha. The protein reacts with antibodies directed against EF-1alpha and, similarly, EF-1alpha recognizes antibodies against the 50mRNP protein.

The novel HLA-DRB1*0807 allele is present in a Carib Amerindian population: the Yucpa.

Nucleotide sequences of five novel HLA-DRB1*08 alleles have been recently reported but their frequency in different populations is still unknown. The presence of DRB1*08 variants among Carib-speaking Yucpa Amerindians of the Perijá Range in the border between Colombia and Venezuela was tested by PCR-DNA typing. DRB1*0807 was the only DRB1*08 variant found in this population with a frequency of 0.

[High- and low-risk molecular sequences in autoimmune diseases. An analysis of type I diabetes in Latin America].

Type I diabetes is an autoimmune and a polygenic disease, in which MHC-class II genes contribute to 48% of the disease. The aim of the present study, is to provide a guideline to understanding the molecular association of these genes, through the immunogenetic analysis of 3 Latin american mestizo populations. We included 606 individuals, 349 patients with DMDI and 257 healthy controls coming from 3 geographical areas: Mexico City, Mexico; Caracas, Venezuela and Medellin, Colombia.

The toad skin NaCl check-valve.

Short-circuited toad skins exposed to chloride-containing Ringer's on the outer side exhibit a large inward chloride flux. Conversely, toad skins exposed to nominally chloride-free Ringer's externally and chloride Ringer's internally manifest a very low chloride outflux. This chloride-dependent rectification of chloride flux serves to conserve NaCl transported from low NaCl concentration outer solutions to which amphibians are normally exposed.

Growth enhancement in transgenic tilapia by ectopic expression of tilapia growth hormone.

The generation of transgenic fish with the transfer of growth hormone (GH) genes has opened new possibilities for the manipulation of growth in economically important fish species. The tilapia growth hormone (tiGH) cDNA was linked to the human cytomegalovirus (CMV) enhancer-promoter and used to generate transgenic tilapia by microinjection into one-cell embryos. Five transgenic tilapia were obtained from 40 injected embryos.

An endo-beta-1,4-glucanase gene (celA) from the rumen anaerobe Ruminococcus albus 8: cloning, sequencing, and transcriptional analysis.

A genomic library of Ruminococcus albus 8 DNA was constructed in Escherichia coli using bacteriophage lambda ZapII. This library was screened for cellulase components and several Ostazin brilliant red/carboxymethyl cellulose positive clones were isolated. All of these clones contained a common 3.

Extended HLA haplotypes among the Bari Amerindians of the Perija Range. Relationship to other tribes based on four-loci haplotype frequencies.

Extended HLA haplotypes among Bari Amerindians living at the Perija Range on the limits between Colombia and Venezuela have been defined using serology for class I, electrophoresis and immuno-fixation for Bf and C4, and PCR-SSO for class II loci typing. Haplotypes were assigned based on family studies and gene frequencies were calculated using a subset of less related subjects selected from the genealogy. No rare class III variants were observed, but the characteristic low HLA diversity of isolated Amerindians populations present also in the Bari extends to Bf and C4.

[Diarrhea due to microsporidia in a patient with AIDS].

A 26-year-old male AIDS patient with diarrhea of two-months evolution is reported here. The most relevant intestinal pathogens, including Cryptosporidium parvum, were ruled out by routine microbiological tests. Stool samples stained with an "oblong" Ziehl-Neelsen method (fucsin, 7 min instead of 3 min) allowed visualization of organisms resembling microsporidia.

Cell loss and tumor growth revisited.

Cell loss is a biological phenomenon that occurs in normal and neoplastic tissue and is an important kinetic factor which contributes to the dynamic state of tumor growth. This relevant phenomenon which was introduced by tumor biologists in the early 1970s while studying tumor growth kinetics has been largely neglected in cancer therapy, although with adequate research it may hold potential for future strategies in cancer treatment. Cell loss occurs through various mechanisms which include exfoliation, metastasis, differentiation and cell death.

Clinical usefulness of mean corpuscular volume and red cell distribution width in iron deficient blood donors.

The clinical efficacy of the red cell distribution width (RDW > 14.2%) and the mean corpuscular volume (MCV < 83.5 fL) in detecting iron deficiency was evaluated in female blood donors.

Effect of plasma freezing temperature, anticoagulant and time of storage on factor VIII:C activity in cryoprecipitate.

The influence of ACD and CPDA-1 anticoagulants, and storage time for 3 and 6 months on F VIII:C activity were compared in cryoprecipitate obtained at -70 degrees C, and -30 degrees C plasma freezing temperature. To eliminate variations in F VIII:C activity between donor plasma, the cryoprecipitation at -70 degrees C and -30 degrees C was made in paired plasma volumes (approximately 100 ml) from each blood unit. Employing ACD plasmas (n = 50), there was no significant difference in F VIII:C activity between cryoprecipitate prepared at -70 degrees C (mean = 31.

Association of ribosomal subunits. A new functional role for yeast EF-1 alpha in protein biosynthesis.

A yeast ribosomal subunit association factor (AF) has been purified from a high-salt ribosomal wash. The purified enzyme is a thermostable protein that associates ribosomal subunits at low Mg2+ concentration without requiring energy. It appears to be an aggregate of trimers or dimers (molecular mass 125 or 79 kDa) which on sodium dodecyl sulfate gels shows the presence of a major protein band whose estimated molecular mass is 43 kDa.

[Chylous ascites secondary to a carcinoid tumor].

A 68-year-old male with abdominal swelling and wasting of one month's evolution had chylous ascites. The clinical study of the patient showed a retroperitoneal tumor and a distal jejunum and mesenterium affliction. There were metastatic nodules in peritoneum, epiploic appendix and malignant pleural effusion.

Bile acid profile as early indicator of allograft function during orthotopic liver transplantation.

Orthotopic liver transplantation was performed in 20 pigs. Serum total bile acids (STBA) were determined and their profile compared with standard early function parameters: total bilirubin, aspartate aminotransferase (AST), alanine aminotransferase (ALT) and lactic acid. In phase I, the STBA level was 32.

Importance of polysomal mRNA-associated polypeptides for protein synthesis initiation in yeast.

The polysomal mRNA from the cell-free system of the yeast Saccharomyces cerevisiae, in the absence of exogenous energy, binds to the 40S ribosomal subunit thus forming a 48S preinitiation complex which, with energy added, is converted into 80S initiation complex. By using ribosomes with a high affinity to polysomal mRNA (pmRNA) from an edeine-resistant mutant of S. cerevisiae in place of wild-type ribosomes, increased quantities of the 48S preinitiation complex are obtained.

An altered ribosomal protein in an edeine-resistant mutant of Saccharomyces cerevisiae.

The r-proteins of an edeine-resistant mutant of Saccharomyces cerevisiae were compared to those of the wild-type strain by using two different two-dimensional electrophoretic techniques: (1) the Kaltschmidt-Wittmann method and, (2) the Kaltschmidt-Wittmann system, in the first dimension and the Na Dodecyl-SO4 system in the second. With the first technique, the results indicate that the patterns of basic ribosomal proteins are similar in the two strains. However, the pattern of acidic ribosomal proteins of the mutant revealed an additional protein band with respect to the normal one.

Definition of DW8.2 by primary and secondary mixed lymphocyte cultures.

Using HLA-DW8 homozygous typing cells (HTC) of different ethnic origin it is possible to identify three subgroups of the DW8/DRW8 product (Mickelson et al., 1983). To further characterize the DW8.

Mechanism of inhibition by lithium of sodium transport in the toad bladder.

Lithium transport across the urinary bladder of Bufo marinus has been studied by means of the short-circuit current technique, as well as unidirectional ion flux measurements. Exposure to lithium of the epithelial (mucosal) surface of this preparation led to a slow, progressive decrease of ion transport, with increasing discrepancy between short-circuit current and lithium influx; in fact there was still an appreciable lithium influx across bladder exposed to amiloride even though short-circuit current was suppressed. Ohmic conductance and sodium efflux barely increased under these circumstances.