Search PubMed⌕ Search

Biomedical subjects

A Alonso

Publications and source records attributed to A Alonso.

At least 433 records · Page 24Linked to original sources
PubMed1985

A new HLA Bw16 subtype defined in both Negroid and Saudi Arabian populations.

Serological identification of a new HLA-Bw16 subtype, B39B, was made by the analysis of reaction patterns of many alloantisera and one monoclonal antibody. The B39B pattern of reactivity was shown to be distinct from HLA-Bw38, Bw39, and 8w57. Cytotoxicity testing before and after absorption suggests that the B39B specificity belongs to the HLA-B7 cross-reactive group. The B39B was clearly demonstrated in two families. This antigen was detected in Negroids and Saudi Arabian Caucasoids but not in a large panel of British Caucasoids.

Black People↗
PubMed1985

HLA polymorphisms in Saudi Arabs.

The HLA-A, -B, -C, -DR, Bf and GLO phenotypes of 109 unrelated Saudi Arab males have been determined. HLA-A and -B antigen frequencies were compared with data reported for European Caucasoids and various Arab populations. Most similarities in antigen frequencies were seen between Saudi Arab and Iraqi populations. A high frequency of Bw50 was observed in Saudi Arabs. The frequencies of HLA-DR antigens in Saudi Arabs were compared to European Caucasoids. HLA-DR7 was at high frequency in Saudi Arabs. Linkage disequilibria between alleles of HLA loci was examined. Many instances of previously reported antigen associations were seen in Saudi Arabs, together with a number of associations which have not been described elsewhere. HLA-Cw6-Bw50-DR7-BfS0.7 is suggested as being a common haplotype in Saudi Arabs.

Complement Factor B↗
PubMed1985

HLA polymorphisms in Nigerians.

The HLA class I and class II phenotypes of a panel of 114 unrelated Nigerians have been determined. The panel was tested for all the known class I antigens and comparisons of the HLA-A and -B frequencies with those of other African Negroid populations revealed some differences. Only limited comparisons could be made for the HLA-DR and -D frequencies as these are not available for any well-defined African Negroid population. The data concerning the class II antigens of this panel are the most interesting. Half of the DRw11-positive panel members are DQw3 negative and DQw1 positive. In addition, there is dissociation of some HLA-D and -DR specificities, a number of panel members are positive for an HLA-D specificity and are negative for the corresponding HLA-DR specificity. Our results show the value of population studies in the investigation of the relationship between the different HLA class II antigens.

Black People↗
PubMed1985

Mouse immunoglobulin gene rearrangements. The sequence of a nonexpressed lambda 3-chain gene.

A functionally defective lambda 3-immunoglobulin chain gene has been cloned from plasmacytoma HOPC-1 (gamma 2b, lambda 1). The lambda 3 gene resulted from the juxtaposition of the germline V lambda 1 sequence with a J lambda 3 C lambda 3 gene segment. DNA sequencing of the rearranged V lambda 1 J lambda 3 exon showed the presence of a single base pair deletion at the site of V-J joining. The alteration in the reading frame caused by this deletion generated a stop codon at the 3' end of J lambda 3, thus rendering this gene nonfunctional for light chain production. In addition, a one-point mutation in the J lambda 3-C lambda 3 intron distinguishes the rearranged gene from the unrearranged counterpart. The implications that this rearrangement has in terms of the mechanism of somatic mutations and of selective proliferation of B cells mediated by antigen stimulation are discussed.

Animals↗
PubMed1984

Drosophila melanogaster U1 snRNA genes.

We have isolated and characterized a recombinant which contains a Drosophila melanogaster U1 small nuclear RNA (snRNA) gene colinear with the published snRNA sequence. Southern hybridizations of the fly genomic DNA, using as probe a plasmid containing only the coding region of the gene, shows that the fly contains at most three or four genes and very few related sequences for the small nuclear U1 RNA. These genes were localized by in situ hybridization at different chromosomal loci and show no spatial relationship to the U2 snRNA genes.

Animals↗
PubMed1984

Divergence of U2 snRNA sequences in the genome of D. melanogaster.

Four different U2-snRNA genes/related sequences of D. melanogaster were cloned and characterized. The sequences of all four genes suggest that they were generated by a DNA-mediated mechanism. These genes/related sequences were found to be located in two loci, each locus containing two U2 snRNA sequences. Using coding sequences as well as flanking sequences as hybridization probes against polytene chromosomes of D. melanogaster Oregon R we were able to map these loci separately at positions 34BC and 84C. By Northern analysis we observed that the quantities of U2- and U1-snRNA are coordinated and change during the embryonic development of the fly.

Animals↗
PubMed1984

A study of the reciprocal connections between the septum and the entorhinal area using anterograde and retrograde axonal transport methods in the rat brain.

The reciprocal connections between the septum and the entorhinal area (EA) was studied in the rat brain using antero- and retrograde axonal transport methods. After injections of large volumes (2 X 100 nl) of horseradish peroxidase (HRP) conjugated to wheat-germ agglutinin (WGA) into the medial septum (MS) and the diagonal band of Broca (dbB), anterogradely transported HRP-WGA was found primarily in layers II and IV of the medial and lateral EA. Injections of HRP-WGA (50-100 nl) or fluorescent dyes (50-100 nl) into different parts of the retrohippocampal region resulted in labeling, by retrograde axonal transport, of cells in the MS and dbB, both ipsi- and contralateral to the injected hemisphere. The labeled cells were either small (long axis of soma: 10-15 micron), round, and oval, or medium (15-25 micron) to large (25-35 micron) of fusiform or multipolar shape. By using the method of retrograde fluorescent double labeling, the septal afferents to the EA were found to give off collaterals to other parts of the hippocampal region. A much smaller number of septal cells appeared to send bilateral projections to the EA of both hemispheres. Studies employing retrograde transport of HRP in combination with acetylcholinesterase (AChE) histochemistry on the same tissue section showed that, while a large number of cells projecting to the EA contain AChE, many projecting cells are devoid of AChE reaction products. These findings suggest that the septo-entorhinal projection consists of a cholinergic as well as a noncholinergic component. The entorhinal efferents to the septum were studied after injections of HRP-WGA into different parts of the retrohippocampal region. Labeled fibers could be traced through the fimbria to their terminal fields in the intermediate parts of the lateral septal nucleus and to the most lateral aspect of the vertical limb of the dbB. The cells giving rise to this projection were situated in layer IV of the medial and layers II through V of the lateral EA. Taken together, the present findings demonstrate a close anatomical relationship between the septum and the entorhinal area, in addition to the better known connections between the septum and the Ammon's horn.

Acetylcholinesterase↗
PubMed1984

Drosophila melanogaster U1 and U2 small nuclear RNA genes contain common flanking sequences.

The flanking sequences of three U2 genes (or pseudogenes) and one U1 gene of Drosophila melanogaster have been determined. Comparison of the sequences reveals a remarkable homology between position -30 and -65 upstream from the structural genes, starting with a TATA box-like sequence. The 3' flanking regions are also conserved in all genes and contain a canonical A-A-T-A-A-A polyadenylation signal.

Animals↗
PubMed1984

Metabolic imbalance in a Saccharomyces cerevisiae mutant unable to grow on fermentable hexoses.

A mutant of Saccharomyces cerevisiae unable to grow on fermentable hexoses has been studied. The mutant grew normally on galactose or maltose. It was also able to grow on a medium containing glucose or fructose with a 25-fold excess of D-xylose. Assay of the glycolytic enzymes in vitro did not show differences between the parental and the mutant strains. Upon addition of fructose, metabolites up to triose phosphates accumulated and the ATP dropped to low levels. It is proposed that an imbalance between the initial and final segments of glycolysis that depletes the cell of ATP produces the observed phenotype.

Adenosine Triphosphate↗
PubMed1984

DR, C4, and Bf allotypes in juvenile rheumatoid arthritis.

HLA-DR, C4, and Bf typing was performed in 99 patients with juvenile rheumatoid arthritis (JRA). DR1 was found with higher frequency in patients with polyarticular JRA than in controls (P less than 0.05). DR3 was more common in patients with fever and/or rash than in those without these manifestations (P less than 0.05). A significant negative association between JRA and C4A6 (P less than 0.05), C4BQ0 (P less than 0.0005), and BfF1 (P less than 0.05) was found. It is possible that a disequilibrium between DR and C4/Bf genes plays a role in the pathogenesis of JRA.

Arthritis, Juvenile↗
PubMed1984

A sulfate, sulfite and thiosulfate incorporating system in Candida utilis.

Sulfate, sulfite and thiosulfate incorporation in the yeast Candida utilis is inhibited by extracellular sulfate, sulfite and thiosulfate and by sulfate analogues selenate, chromate and molybdate. The three processes are blocked if sulfate, sulfite, thiosulfate, cysteine and homocysteine are allowed to accumulate endogenously. Incorporation of the three inorganic sulfur oxy anions is inactivated by heat at the same rate. Mutants previously shown to be defective in sulfate incorporation are also affected in sulfite and thiosulfate uptake. Revertants of these mutants selected by plating in ethionine-supplemented minimal medium recovered the capacity to incorporate sulfate, sulfite and thiosulfate. These results taken together with previous evidence demonstrate the existence of a common sulfate, sulfite and thiosulfate incorporating system in this yeast.

Biological Transport, Active↗
PubMed1984

Sarcomatoid carcinoma (so-called pseudosarcoma) of the larynx simulating malignant giant cell tumor of soft parts. A case report.

A tumor of the larynx composed of a small infiltrating and well-differentiated squamous cell carcinoma and a large polypoid sarcomatous mass showing the histologic features of the malignant giant cell tumor of soft parts (MGCT) is reported. Other types of sarcomatous components have been described with squamous cell carcinoma (SCC) of the larynx and names such as pseudosarcoma, carcinosarcoma, and spindle cell carcinoma have been used for these peculiar tumors. Because most data support that the sarcomatous component is an unusual carcinoma transformation due to unknown factors the authors prefer the term sarcomatoid carcinoma. Sarcomatoid carcinomas having the features of MGCT have been described in multiple epithelial organs. Therefore, an extensive search for a carcinoma component always should be carried out in tumors arising in any organ, including the larynx, and showing the typical histologic features of MGCT.

Carcinoma, Squamous Cell↗
PubMed1984

HLA polymorphisms in a Shanghai Chinese population.

The frequencies of the HLA-A, B, C, D, DR and MB antigens have been determined in a homogeneous Shanghai Chinese population. Comparisons with the HLA-A and -B frequencies in other subsets of the Chinese population revealed some marked differences. No comparisons were possible for the D, DR and MB antigens since there were no previous studies of the antigens in those loci. We suggest that studies of the Chinese population should be confined to clearly defined homogeneous subsets. In this manner, the confounding effect of population heterogeneity may be avoided, and it is this heterogeneity which calls for extensive surveys of the huge Chinese population.

Asian People↗
PubMed1984

Spontaneous hematomas caused by microangiomatosis of the basal ganglia. Presentation of two cases in the newborn period.

We present 2 cases of tumors of the gray basal nuclei with intraventricular hemorrhage and secondary hydrocephalus. Because of the patients' ages, the absence of traumatic antecedents and the angiographic characteristics, the findings were diagnosed as gliomas. In both cases, the existence of hematomas provoked by microangiomatosis was proved after the operation. The differential diagnostic between these two entities is discussed.

Angiomatosis↗