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Biomedical subjects

J Gutierrez

Publications and source records attributed to J Gutierrez.

At least 19 recordsLinked to original sources
PubMed1995

Purification, characterization, and partial amino acid sequence of a G protein-activated phospholipase C from squid photoreceptors.

Invertebrate visual transduction is thought to be initiated by photoactivation of rhodopsin and its subsequent interaction with a guanyl nucleotide-binding protein (G protein). The identities of the G protein and its target effector have remained elusive, although evidence suggests the involvement of a phospholipase C (PLC). We have identified a phosphatidylinositol-specific PLC from the cytosol of squid retina. The enzyme was purified to near-homogeneity by a combination of carboxymethyl-Sepharose and heparin-Sepharose chromatography. The purified PLC, identified as an approximately 140-kDa protein by sodium dodecyl sulfate-polyacrylamide gels, hydrolyzed phosphatidylinositol 4,5-bisphosphate (PIP2) at a rate of 10-15 mumol/min/mg of protein with 1 microM Ca2+. The partial amino acid sequence of the protein showed homology with a PLC cloned from a Drosophila head library (PLC21) and lesser homology with Drosophila norpA protein and mammalian PLC beta isozymes. Reconstitution of purified squid PLC with an AlF(-)-activated 44-kDa G protein alpha subunit extracted from squid photoreceptor membranes resulted in a significant increase in PIP2 hydrolysis over a range of Ca2+ concentrations while reconstitution with mammalian Gt alpha or Gi 1 alpha was without effect. These results suggest that cephalopod phototransduction is mediated by G alpha-44 activation of a 140-kDa cytosolic PLC.

Amino Acid Sequence↗
PubMed1995

Acute acalculous cholecystitis due to Vibrio cholerae.

The case of a 57-year-old woman admitted with symptoms and signs suggesting an intestinal infection caused by Vibrio cholerae, and who also developed a clinical picture compatible with acute cholecystitis, is presented. Cholera was diagnosed by examining a fresh sample of stools and cultures. An abdominal sonogram disclosed signs of acute acalculous cholecystitis. She underwent cholecystectomy, and cultures of a clear fluid and a "milky" sediment found within the gallbladder were also positive for V. cholerae. This microorganism was seen at the gallbladder mucosa microscopically. The strain was serotyped V. cholerae 01 (El Tor) Ogawa and was the etiology of the acute acalculous cholecystitis in this patient.

Acute Disease↗
PubMed1995

Three-year study of antibody to Borrelia burgdorferi in southern Spain.

The prevalence of anti-Borrelia burgdorferi antibodies was studied in Granada, Spain, between January 1991 and November 1993 in 354 patients with suspected Lyme disease (group 1); in 50 patients either with syphilis (n = 32) or without syphilis but with a positive Rapid Plasma Reagin test (n = 18) (group 2); and in 150 healthy subjects (group 3). In addition, intrathecal antibody production was evaluated by EIA in CSF samples obtained from 117 patients in group 1. Anti-Borrelia burgdorferi antibodies were detected by EIA in 58 patients (16.4%) in group 1, 29 (8.2%) of whom were positive by Western blot. Intrathecal antibody production was detected in one patient. In group 2, 8 (16%) patients had a positive EIA result, but none of these was confirmed by Western blot. western blot was negative for all subjects in group 3. The results of this study indicate that anti-Borrelia burgdorferi antibodies are not uncommon in our area, although Lyme disease is rare.

Antibodies, Bacterial↗
PubMed1995

Antibodies to human immunodeficiency virus (HIV-1) in autoimmune diseases: primary Sjögren's syndrome, systemic lupus erythematosus, rheumatoid arthritis and autoimmune thyroid diseases.

The aetiology of autoimmune diseases remains unknown. The relationship between virus, and more recently retrovirus, has been suggested with this group of diseases. Immunoblotting is a useful method for determining the presence of proteins coded by different retrovirus genes. Since the prevalence of these types of proteins in patients with primary Sjögren's syndrome (SS), systemic lupus erythematosus (SLE), rheumatoid arthritis (RA) and autoimmune thyroid diseases has not been fully established, the aim of this work was to determine the prevalence of antibodies to immunodeficiency human virus type 1 (HIV-1) proteins in these diseases and their possible relationship with the presence of anti-nuclear, anti-DNA, anti-SSA (Ro) and anti-SSB (La) autoantibodies. Antibodies to human immunodeficiency virus (HIV-1) were studied in a group of 341 patients with autoimmune diseases (77 SS, 98 SLE, 75 RA, 91 autoimmune thyroid diseases) and 126 blood donors as a control group. A Western blot was used to detect antibodies to HIV-1, and a double polymerase chain reaction (PCR) using nested primers in the gag and pol gene of HIV-1. Antinuclear antibodies, anti-DNA, anti-SSA (Ro) and anti-SSB (La) were determined by enzyme-linked immunosorbent assays. At least one band was shown on immunoblotting in 26% of patients with autoimmune diseases and 35% of controls. The presence of antibodies to p55 or p68 proteins in patients with SS or SLE proved to be the only statistically significant difference between the other autoimmune diseases studied and the control group. These antibodies were not associated with autoantibodies ANA, DNA, SSA (Ro) or SSB (La).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1995

Sonography of pancreatic disease in infants and children.

The usefulness of sonography in evaluating the pancreas in infants and children is well known. Its usefulness is due to the optimal sonic window provided by the relative lack of fat tissue and the large left hepatic lobe in children. A wide spectrum of pancreatic pathologic conditions can be identified sonographically in children, including congenital abnormalities; inflammatory, cystic, pseudocystic, and neoplastic lesions in usual and unusual manifestations; rare processes such as nesidioblastosis and Schwachman-Diamond syndrome; and pancreatic involvement in systemic disease. Multiple pathologic processes can affect the pancreas focally or diffusely, making diagnosis difficult in some instances, since the pancreatic response is limited to changes in echogenicity and size independent of the cause. Sonography is rapid, accurate, and noninvasive and does not require patient sedation. It is the modality of choice for evaluating suspected pancreatic disease, since it allows not only direct visualization of the pancreas but also evaluation of adjacent organs.

Adolescent↗
PubMed1995

Polyneuropathy in juvenile dermatomyositis.

We describe 2 patients in whom juvenile dermatomyositis (DM) was associated with well defined clinical polyneuropathies, and review the clinical and serological data. Light and electron microscopy were used to study muscle and nerve tissues from one patient. Neuropathy in our patients was associated with ulcerative skin lesions and elevated serum levels of factor VIII related antigen. Light microscopic studies of muscle revealed perifascicular atrophy and microinfarcts consistent with juvenile DM. Light microscopy of the affected sural nerve showed axonal degeneration. Electron microscopy of the same nerve demonstrated capillary endothelial inclusions characteristic of those observed as manifestations of early endothelial injury in juvenile DM muscle tissue. Polyneuropathy in patients with juvenile DM is a rare complication and is likely due to ischemia secondary to endothelial damage.

Biopsy↗
PubMed1994

Brain potentials and the availability of semantic and phonological codes over time.

ERPs were recorded from subjects performing semantic and rhyme matching tasks using either spoken words, printed words or pictures as stimuli. Mismatches enhanced N400 (in the semantic task) and N450 (in the rhyme task). Onset and peak latencies were shorter for N450 than for N400 with spoken words; this relationship was inverted for pictures. Thus these latencies could index availability of semantic and phonological codes. For printed words, the latencies were shorter for N400 than N450, a result that supports direct-access modes of reading with late phonological code activation. The longer latencies found for N400 and N450 to pictures could suggest longer initial decoding for pictures with respect to words.

Adolescent↗
PubMed1994

Intraspecific diversity of the Cassava green mite Mononychellus progresivus (Acari: Tetranychidae) using comparisons of mitochondrial and nuclear ribosomal DNA sequences and cross-breeding.

Intraspecific diversity in Cassava Green Mite Mononychellus progresivus Doreste was examined using individuals collected in Benin and the Congo and in Columbia and Brazil. Comparisons were based on mitochondrial and ribosomal DNA sequences and the results of several cross-breeding experiments. Sequence variation was examined in a total of 1139 base pairs (bp) constituting the ITS2 ribosomal DNA (805 bp) and a fragment of the Cytochrome Oxidase I (COI) gene (334 bp). Sequence divergence is low, ranging from 0% to 2.1% for COI and from 0% to 0.4% for ITS2. Inter-strain comparisons have shown that the two African populations appear to be identical. They were similar to the Colombian population while the Brazilian population was clearly different. The data support the hypothesis of a single introduction of the species in the two African populations. Crossing experiments have shown partial hybrid sterility, suggesting a genetic incompatibility consistent with differences detected by sequence data. The results show the usefulness of molecular markers as a tool for determining taxonomic status and dispersion paths in spider mites.

Animals↗
PubMed1994

Evaluation of a new reagent for anti-cytomegalovirus and anti-Epstein-Barr virus immunoglobulin G.

The Enzygnost alpha method was tested against the complement fixation test and anti-VCA immunofluorescence to determine the respective titers of anti-cytomegalovirus and anti-Epstein-Barr virus immunoglobulin G antibodies. For cytomegalovirus, the Enzygnost results showed 97.99% agreement with the readings obtained by the alternative method, with 100% sensitivity and 93.7% specificity. For Epstein-Barr virus, Enzygnost showed 97.71% agreement, 100% sensitivity, and 91.11% specificity.

Adult↗
PubMed1994

Caustic sclerosing cholangitis. Report of four cases and a cumulative review of the literature.

We report on four patients of our own and another thirty-six from the literature, who developed almost identical and unusual clinical syndromes after surgical treatment of hydatid disease of the liver, with the aim of showing the extremely serious nature of the problem that can ensue. An association of four factors seems to be necessary to promote caustic sclerosing cholangitis: a) injection of a scolicidal agent (formalin, hypertonic saline, ethanol, silver nitrate or iodine solution) into the cyst cavity; b) a communication between the cyst and the biliary tree; c) a condition that prolongs the exposure of the biliary tree to the scolicidal; and d) a particular sensitivity to the scolicidal agent. While this last condition cannot be anticipated, we may justifiably conclude that surgeons should not inject a scolicidal solution into the hydatid cyst, but prevent intra-abdominal diffusion of the parasite by using hydrogen peroxide, gauze pads moistened by a scolicidal solution or by preoperative chemotherapy with albendazole. Caustic sclerosing cholangitis has an earlier onset of symptoms and a more rapidly progressive nature than primary sclerosing cholangitis. In foresight, serum alkaline phosphatase should be monitored and, when raised, a retrograde endoscopic cholangiogram and/or a liver biopsy should be performed. Digestive shunt surgery should be avoided and the possibility of liver transplantation has to be periodically evaluated.

Adolescent↗
PubMed1994

Evaluation of the ATB 32C, automicrobic system and API 20C using clinical yeast isolates.

The ATB 32C (bioMerieux, Spain), AMS-YBC (Vitek System, bioMerieux, Spain) and API 20C (bioMerieux, Spain) systems were evaluated for their reliability in identifying 100 clinical yeast isolates. The ATB 32C, AMS-YBC and API 20C systems correctly identified 97%, 98% and 100% of the isolates respectively. There were no significant differences in incubation periods between ATB 32C and AMS-YBC systems. One isolate of Candida tropicalis was wrongly identified by the ATB 32C and the AMS-YBC systems. The Saccharomyces cerevisiae isolate was wrongly identified by the ATB 32C system while the AMS-YBC failed to identify it and a third isolate of Candida krusei was wrongly identified by the ATB 32C system. The overall accuracy and rapidity of the ATB 32C and AMS-YBC systems were sufficient to permit recommendation of either of these systems for routine use in the clinical microbiology laboratory, although the first system enjoys the advantages of having a wider data-base and the possibility of manual reading.

Automation↗
PubMed1992

Identity of 4a-carbinolamine dehydratase, a component of the phenylalanine hydroxylation system, and DCoH, a transregulator of homeodomain proteins.

The principal pathway for the metabolism of phenylalanine in mammals is via conversion to tyrosine in a tetrahydrobiopterin-dependent hydroxylation reaction occurring predominantly in the liver. Recently, the proposal that certain hyperphenylalaninemic children may have a deficiency of carbinolamine dehydratase, a component of the phenylalanine hydroxylation system, has widened the interest in this area of metabolism. Upon cloning and sequencing the dehydratase, we discovered that this protein is identical to DCoH, the cofactor which regulates the dimerization of hepatic nuclear factor 1 alpha, a homeodomain transcription factor. The identity of the nuclear and cytoplasmic proteins is demonstrated by size, immunoblotting, stimulation of phenylalanine hydroxylase, and dehydratase activity. The evolution of the dual functions of regulation of phenylalanine hydroxylation activity and transcription activation in a single polypeptide is unprecedented.

Amino Acid Sequence↗
PubMed1992

Molecular approach in spider mites (Acari: Tetranychidae): preliminary data on ribosomal DNA sequences.

DNA sequence data were used to examine phylogenetic relationships between six species of economically important Tetranychidae mites: Eotetranychus carpini (Oudemans), E. pruni (Reck), Tetranychus pacificus McGregor, T. mcdanieli McGregor, T. turkestani Ugarov & Nikolski and T. urticae Koch. With primers directed toward conserved elements flanking the target region, the Polymerase Chain Reaction was used to amplify the ITS2 spacer of the ribosomal DNA molecule. The nucleotide sequence of a 300-bp fragment of the ITS2 was determined by direct sequencing and nucleotide divergence used for intra-generic comparison in mites. The resulting phylogenetic tree expressing interspecific relationships in genus Tetranychus agrees with morphological data. The study demonstrates the usefulness of the approach in the assessment of the systematics and evolution of the group.

Acari↗
PubMed1991

Effect of intrathoracic pressure on plasma arginine vasopressin levels.

Abdominal distention during pneumoperitoneum results in a marked increase in plasma arginine vasopressin levels, which has been ascribed to an increase in intrathoracic pressure. Because of this relationship, tense ascites could contribute to nonosmotic release of antidiuretic hormone, to the development of hyponatremia, and eventually to further ascites formation. The effect of pneumoperitoneum, thoracocentesis, and paracentesis on plasma arginine vasopressin levels was studied in three groups of patients, and the mechanism by which these maneuvers may induce these changes was investigated. Patients with pleural effusion, pneumothorax, or ascites showed a significant increase in plasma arginine vasopressin levels, and thoracocentesis or paracentesis resulted in a decrease in these levels. Plasma vasopressin levels increased significantly during pneumoperitoneum, as did intrathoracic and atrial pressures; the atrial transmural pressure gradient declined. However, no changes in plasma levels of norepinephrine, aldosterone, and renin activity were observed during pneumoperitoneum. Changes in plasma arginine vasopressin levels correlated with the changes in intrathoracic and atrial pressures and transmural pressure gradient. The authors conclude that increased intrathoracic pressure is associated with an increase in plasma arginine vasopressin levels and propose that ascites could be a factor promoting vasopressin release by acting on intrathoracic volume receptors in decompensated cirrhotics.

Adult↗
PubMed1991

Some plasma hormones and metabolites in the Pyrenean brown trout (Salmo trutta fario).

1. Pyrenean brown trout (Salmo trutta fario) from 200 to 1700 g were analysed in lots of 12 specimens in March, April, July and October 1988, and in January 1989. 2. Hormones (insulin, glucagon, cortisol) and metabolites (glucose, lactate, proteins, triglycerides) were determined in plasma. 3. Body parameters (length and weight) increased progressively, while plasma metabolites and hormones were more dependent on seasonal and sexual conditions. 4. Plasma insulin presented a maximum in spring (11 ng/ml) and a minimum in January (5 ng/ml). A clear relationship between insulin and annual growth rates was established. Plasma glucagon showed annual values between 700 and 1500 pg/ml, with significant seasonal variations. The molar ratio glucagon/insulin oscillated from 0.21 in January to 0.38 in July. 5. Plasma glucose variations agreed with those of pancreatic hormones, especially evident with glucagon levels. Proteins were more uniform throughout year, and plasma lipids were especially associated to the reproductive state in females.

Animals↗
PubMed1991

A comparative study of the activity of first and second generation cephalosporins and their combinations with beta-lactamase inhibitors against Bacteroides fragilis.

The sensitivity of 160 strains of Bacteroides fragilis, 74 beta-lactamase-positive and 86 negative, to two first generation and four second generation cephalosporins, alone and in combination with clavulanic acid and sulbactam, was investigated. For the susceptibility test the dilution method in agar was used. The detection of beta-lactamase production by this micro-organism was performed by means of the method using chromogenic cephalosporin of Nitrocefin. In both strains an important improvement in the activity of cephalothin, cephazolin, cefonicid and cefamandole was noted when they were combined with the two inhibitors. In combinations of cefoxitin and cefmetazole, no significant improvement was evident in the values of the parameters studied in the beta-lactamase-producing strains; and even in beta-lactamase-negative strains these values showed only a slight increase.

Bacteroides fragilis↗