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Biomedical subjects

M Mata

Publications and source records attributed to M Mata.

At least 73 records · Page 4Linked to original sources
PubMed1991

Differential distribution of (Na,K)-ATPase alpha isoform mRNAs in the peripheral nervous system.

mRNA transcripts for 3 isoforms of the alpha subunit of (Na,K)-ATPase have been previously identified in the nervous system (designated alpha 1, alpha 2, and alpha 3). In order to study the localization and expression of the different alpha isoforms in the peripheral nervous system, we prepared probes from the unique 3' untranslated region of alpha 1 cDNA, and from the translated region of alpha 3 cDNA. These probes were used in dot blot and in situ hybridization assays of rat spinal cord, dorsal root ganglia (DRG), and sciatic nerve. Within the ventral horn of lumbar spinal cord, alpha 1 mRNA was found in a discrete set of laterally placed motor neurons, while alpha 3 was found in all the identified neurons of the spinal cord, including those motor neurons containing alpha 1. In the lumbar DRG, alpha 3 was uniformly distributed in DRG neurons, while alpha 1 was abundant in some neurons but little or none was found in other neurons. Satellite cells contained neither isoform. Schwann cells in sciatic nerve were labeled with the alpha 1 probe in a perinuclear distribution, but contained no detectable alpha 3. Dot blot analysis showed alpha 1 and alpha 3 in spinal cord and DRG, but only alpha 1 in peripheral nerve.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1991

Differential distribution of (Na, K)-ATPase alpha isoforms in the central nervous system.

1. mRNA transcripts for three isoforms of the alpha subunit of (Na,K)-ATPase have been previously identified in the rat nervous system and designated alpha 1, alpha 2 and alpha 3. 2. In order to study the localization and expression of the different alpha isoform mRNAs on a regional and cellular level in the brain, we prepared probes from the unique 3' untranslated region of rat alpha 1 cDNA and from a segment containing a portion of the translated region of rat alpha 3 cDNA. These probes were used in dot blot and in situ hybridization assays of rat brain. 3. alpha 1 mRNA was found predominantly in cerebral cortex, dentate gyrus of hippocampus, and specific isolated brain-stem nuclei such as locus ceruleus and motor nuclei V and VII. In contrast alpha 3 mRNA was found predominantly in pyramidal neurons in the deep layers of cerebral cortex, in both pyramidal and dentate gyrus neurons of the hippocampus, and in neurons of most subcortical structures of the thalamus, basal ganglia, and brain-stem nuclei. 4. In the cerebellum, Purkinje cells showed predominantly alpha 3, as did stellate and basket cells. The granule cells contained predominantly alpha 1. 5. These experiments show that mRNAs for both alpha 1 and alpha 3 isoforms of (Na,K)-ATPase are found in neurons of the CNS. The isoforms have unique cellular and regional distributions, which in some cases overlap.

Animals↗
PubMed1991

Immunocytochemical demonstration of Na+,K(+)-ATPase in internodal axolemma of myelinated fibers of rat sciatic and optic nerves.

We used postembedding electron microscopic immunocytochemistry with colloidal gold to determine the ultrastructural distribution of Na+,K(+)-ATPase in the sciatic and optic nerves of the rat. Using a polyclonal antiserum raised against the denatured catalytic subunit of brain Na+,K(+)-ATPase, we found immunoreactivity along the internodal axolemma of myelinated fibers in both nerves. This antiserum did not produce labeling of nodal axolemma. These results suggest that an important site of energy-dependent sodium-potassium exchange is along the internodal axolemma of myelinated fibers in the mammalian CNS and PNS and that there may be differences between the internodal and nodal forms of the enzyme.

Animals↗
PubMed1991

Species and type phages of lactococcal bacteriophages.

Lactococcal phages are classified according to morphology and DNA homology. Phages are differentiated into 12 phage species, and type phages of each species are proposed. Members and possible members of each species are named. Available data on type phages are tabulated including morphology, DNA characteristics and phage protein bands.

Bacteriophages↗
PubMed1990

Cloning, expression and sequence analysis of an endolysin-encoding gene of Lactobacillus bulgaricus bacteriophage mv1.

The lysA gene specifying an endolysin of Lactobacillus delbrueckii subsp. bulgaricus bacteriophage mv1, was cloned and expressed in Escherichia coli. The 4.05-kb restriction fragment containing this gene was analysed by restriction and deletion mapping, and by subcloning. The nucleotide sequence of a 1150-bp fragment coding for an active lysin was determined. The lysA gene consists of 585 bp and codes for a protein of a deduced Mr of 21,120, which agrees with the size based on in vivo transcription/translation studies. The deduced amino acid sequence of the mv1 lysin (LysA) was compared to that of other known lytic enzymes. Significant homology was observed with the N-terminal portion of the muramidase of the fungus Chalaropsis and that of the muramidase of the Streptococcus pneumoniae phage Cp-1, suggesting that LysA might be a muramidase. In E. coli, the cloned lysA gene was able to complement the muramidase-defective bacteriophage lambda Ram5, proving that the products of these two genes are interchangeable. The lysA gene is preceded by an open reading frame with unknown function and no characteristic prokaryotic promoter sequences could be detected upstream from lysA, suggesting that this gene is part of an operon.

Amino Acid Sequence↗
PubMed1990

S100 is preferentially distributed in myelin-forming Schwann cells.

In order to elucidate the role of S100 protein in vivo we used postembedding electron microscopical immunocytochemistry with commercially available antibodies to S100, and secondary antibodies conjugated to colloidal gold to determine the distribution of S100 protein in the sciatic nerve and the cervical sympathetic trunk of the rat. We found that S100 immunoreactivity in Schwann cells was differentially distributed. The amount of S100 immunoreactivity in myelinated fibres appeared to correlate directly with the thickness of the myelin sheath formed by the Schwann cell. Unmyelinated fibres were identical to the small myelinated fibres in S100 immunoreactivity. Within the Schwann cells, the immunoreactivity was seen in the nucleus and in the perikaryal cytoplasm, as well as in the Schmidt-Lanterman clefts and in the paranodal loops at the node of Ranvier, but not in the myelin itself. Using these antibodies we did not see reproducible or convincing intra-axonal immunoreactivity in normal nerve. These results suggest that in Schwann cells S100 expression may be related to axon diameter and degree of myelination. Future studies of S100 expression in development or in response to injury may clarify the role of S100 in Schwann cell biology.

Animals↗
PubMed1990

Taxonomic differentiation of 101 lactococcal bacteriophages and characterization of bacteriophages with unusually large genomes.

Sixty-three virulent bacteriophages of Lactococcus lactis were differentiated by DNA-DNA hybridization. The results, including those of a previous classification of 38 phages of the same bacterial species (P. Relano, M. Mata, M. Bonneau, and P. Ritzenthaler, J. Gen. Microbiol. 133:3053-3063, 1987) show that 48% of the phages analyzed belong to a unique DNA homology group (group III). Phages of this most abundant group had small isometric heads. Group I comprised 29% of the phages analyzed and was characterized by a small phage genome (19 to 22 kilobases) and a particular morphology with a prolate head. Like group III, this group contained representative phages of other classifications. Group II (21%) included virulent and temperate phages with small isometric heads. Two large isometric-headed phages, phi 109 and phi 111, were not related to the three DNA homology groups I, II, and III. The genome of phi 111 was unusually large (134 kilobases) and revealed partial DNA homology with another large isometric phage, 1289, described by Jarvis (type e) (A. W. Jarvis, Appl. Environ. Microbiol. 47:343-349, 1984). The protein compositions of phi 111 and 1289 were similar (three common major proteins of 21, 28, and 32 kilodaltons).

Bacteriophages↗
PubMed1990

[A drug prescription study in chronic pathology at a primary care center].

To evaluate the characteristics of the drug used for the therapy of chronic diseases, 1588 prescriptions from a sample of 549 continued drug prescription forms were evaluated. Every patient had a mean number of 2.9 drugs, 2.14 diagnoses and 1.41 drugs per diagnosis. The patients over 65 years had a higher number of drugs and diagnoses. A smaller number of diagnoses but a higher number of drugs per diagnoses was found for males. The drug subgroups with higher prescription rates were cardiac drugs (12.3%), diuretics (11.2%) and analgesics (9.9%). The most common diagnoses were hypertension and osteoarthritis, with 17.6% and 13.6% of prescriptions, respectively. A high rate of patients receiving vasodilators (12%) and benzodiazepines (14.7%) was found. The usefulness of the continued prescription forms for the control of chronic treatments is emphasized.

Age Factors↗
PubMed1990

[Ischemic cardiopathy in primary care. A descriptive study].

A descriptive study of ischemic heart disease in a primary care center is reported. From the recording systems 112 patients with IHD (9 of them dead) were identified. The calculated incidence and prevalence rates were 1.9/1000 and 10.9/1000, respectively. There were remarkably high rates of cardiovascular risk factors. The most common forms of presentation were myocardial infarction in males and angina in females. The physicians of the primary care center played a role in the diagnosis in 17% of patients. In addition, the disease was exclusively managed in the primary care center in 29% of patients, most of them over 65 years of age. The role of the primary care physician in the diagnosis and control of this condition is emphasized.

Age Factors↗
PubMed1989

Genome comparison of Lactococcus strains by pulsed-field gel electrophoresis.

The two restriction enzymes SmaI and ApaI were found to produce distributions of DNA fragments useful for genome analysis of some lactic acid bacteria (Lactococcus lactis and Streptococcus salivarius subsp. thermophilus) by pulsed-field gel electrophoresis. The genome size was estimated to be 1750 to 2500 kb depending on the species. Each strain displayed unique restriction patterns; nevertheless, the percentage of the comigrating fragments of two isogenic or closely related strains was about 80% and fell to 20-40% when the patterns of two non-related strains of the same species or two strains belonging to different species were compared.

DNA, Bacterial↗
PubMed1989

Ca++-ATPase in the central nervous system: an EM cytochemical study.

Ca++-ATPase plays an important role in regulation of the intracellular Ca++ concentration. Biochemical studies of brain have demonstrated that Ca++-ATPase co-purifies with synaptosomes, with synaptic plasma membrane and synaptic vesicle fractions. To better understand the role of this enzyme in normal brain function, we used an electron microscopic (EM) cytochemical method to determine the localization of Ca++-ATPase in rat brain. Reaction product occurred along cytoplasmic membranes. Specific areas of increased reaction product were seen at many but not all post-synaptic densities. Intracellular Ca++-ATPase reaction product was associated with all synaptic vesicles examined and with the Golgi and smooth endoplasmic reticulum (SER). Unlike the situation in peripheral nerve, Ca++-ATPase at the node of Ranvier in the CNS localized preferentially to the nodal axolemma. The localization of Ca++-ATPase at synaptic vesicles agrees with the biochemical evidence for its localization and with the cytochemical evidence for Ca++-ATPase sequestration in those vesicles. The restricted localization at postsynaptic densities suggests that it may be involved in extrusion of Ca++ at synapses where neurotransmitter release causes Ca++ influx.

Animals↗
PubMed1988

Calmodulin distribution in peripheral nerve: an EM immunocytochemical study.

We used electron microscopic immunocytochemistry to study the distribution of calmodulin in rat sciatic nerve. Calmodulin immunoreactivity was found throughout the axoplasmic matrix, but particularly along microtubules. Schwann cell cytoplasm and nuclei demonstrated immunoreactivity, while compact myelin did not. There was particularly intense immuno-gold deposition within Schmidt Lanterman clefts. At the nodes of Ranvier, calmodulin appeared preferentially in the paranodal region, along the apposition of the axolemma to the paranodal loops of myelin and extending into the paranodal loops. The presence of calmodulin immunoreactivity along microtubules supports biochemical and pharmacological evidence of calmodulin involvement in regulating the assembly and phosphorylation of microtubules, and in fast axonal transport along microtubules. The co-localization of paranodal calmodulin immunoreactivity with Ca-ATPase activity demonstrated cytochemically (Mata et al., Brain Research, in press) supports the notion that the paranodal Ca-ATPase activity may be regulated by calmodulin, and agrees with the in vitro biochemical evidence for Ca-ATPase of other cells.

Animals↗
PubMed1988

Cytochemical localization of Ca2+-ATPase activity in peripheral nerve.

We used an electron microscopic cytochemical method to determine the localization of Ca2+-ATPase in rat peripheral nerve. We found that reaction product occurred along most cytoplasmic membranes in the dorsal root ganglia (DRG). Unmyelinated axons demonstrated reaction product on the axolemma diffusely along their length. Myelinated fibers, in contrast, had reaction product limited to the axolemma in the paranodal region. Internodal axolemma never showed reaction product and nodal axolemma was only occasionally stained, usually in sections reacted for the maximum times. Schwann cell plasma membranes uniformly showed reaction product. The restricted localization of Ca2+-ATPase to the paranodal region of myelinated fibers suggests that calcium efflux may occur principally at those sites.

Animals↗
PubMed1988

Present state of lactic acid bacteria phage taxonomy.

Recent developments in molecular taxonomy of bacteriophages of lactobacilli and lactic streptococci are presented. DNA homology appears to be the most valid criterion in studying phage taxonomy. For each bacterial species, phages can be classified in a few families according to this criterion. A fair correspondence is observed between the groups differentiated by DNA-DNA hybridization and those differenciated by protein composition. In 2 bacterial species, a close relatedness between some virulent and temperate phages has been demonstrated. The presence of homologous sequences in the genome of various phages may play an important role in their evolution. For future taxonomic studies, some phages representative of DNA homology groups are proposed as reference phages.

Bacteriophages↗
PubMed1988

Molecular taxonomy of Lactobacillus phages.

Forty-eight strains of lactobacilli used as starter strains in the dairy industry were examined for lysogeny after treatment with mitomycin C. Two strains of L. delbrueckii subsp. bulgaricus were able to produce active phages. These temperate phages as well as 4 virulent phages isolated during abnormal fermentations were compared to a previously characterized phage mv4 which is temperate. All these phages were shown to be partially homologous by DNA-DNA hybridization. Genes that code for viral proteins seem to be well conserved since 2 major virion polypeptides of 18 (or 19) kD and 34 kD could be detected in the protein composition of each phage. Immunoblotting studies of the 7 phages using serum raised against phage mv4 confirmed that the proteins of the different phages were related. All these phages can be classified in the previously constituted group a, which now comprises 4 temperate and 15 virulent phages. These results show that some virulent phages appearing during abnormal fermentations and some temperate phages isolated by appearing during abnormal fermentations and some temperate phages isolated by induction of starter strains can be closely related genetically. Five virulent phages of L. helveticus were also compared according to their restriction pattern and their DNA homology. They were shown to be related to one another, but unrelated to phages of other lactic acid bacteria species.

Bacteriophages↗
PubMed1988

Distribution of albumin-like immunoreactivity in rat sciatic nerve after nerve crush injury.

To understand better the role of local factors in the response of peripheral nerve to crush injury, we studied the distribution of albumin-like immunoreactivity (A-LI) in the rat sciatic nerve from one day to eight weeks (wk) after a crushing injury; we used electron microscopic immunocytochemistry. In the nerve distal to the crush degenerating axons demonstrated intra-axonal A-LI, and by one wk most of the Schwann cells also showed A-LI. As regenerating sprouts entered the distal nerve, those Schwann cells in contact with sprouts lost their A-LI, while those cells not in contact with axons retained immunoreactivity up to eight wk after injury. Proximal to the nerve crush many axons showed intra-axonal A-LI from one to two wk after injury, despite appearing normal ultrastructurally. This immunoreactivity diminished as the distance from the crush site increased. Many Schwann cells proximal to the crush also showed A-LI from one to four wk after injury. These findings suggest that an albumin-like protein may play a role in the response of Schwann cells and axons to injury.

Animals↗