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Biomedical subjects

J Gutierrez

Publications and source records attributed to J Gutierrez.

At least 55 records · Page 3Linked to original sources
PubMed1997

Comparative evaluation of the mycobacteria growth indicator tube with the BACTEC 460 TB system and Löwenstein-Jensen medium for isolation of mycobacteria from clinical specimens.

SETTING: The utilization of new simples and rapid methods of diagnosis is currently of great interest for tuberculosis control. OBJECTIVE: The Mycobacteria Growth Indicator Tube (MGIT) was evaluated and compared with the BACTEC 460 TB system and Löwenstein-Jensen (LJ) medium for isolation capacity and detection time of mycobacteria. DESIGN: In total 337 specimens from various body sites of 276 patients were tested for the presence of mycobacteria. Specimens were decontaminated using the standard Na OH-NALC method, then processed in MGIT broth, in BACTEC vial, and on LJ medium for comparative study. Ziehl Neelsen staining was used as a reference. RESULTS: MGIT had 95.4% sensitivity, 100% specificity, 100% positive predictive value, and 89.3% negative predictive value. The clinical concordance between MGIT and LJ medium was 0.87 and between MGIT and BACTEC, 0.96. The mean time to detection for Mycobacterium tuberculosis was 11 days (range 7-31 days) with MGIT. For M. avium and other atypical mycobacteria, the mean time to detection were 3 and 8 days, respectively. CONCLUSION: The Mycobacteria Growth Indicator Tube appears to be a rapid, easy-to-use system with a high accuracy for detecting mycobacteria directly from clinical specimens.

Bacteriological Techniques↗
PubMed1996

Biologic activities of iodinated analogues of Tyr0-bradykinin and bradykinin-Ile10-Tyr11 assessed in the rat uterus and the guinea pig ileum.

1. The biological activity of bradykinin (BK) and analogues containing ofr in extended N- or C-terminal portions of the molecule, as well as that of their iodinated products, was compared in isolated rat uterus and guinea pig ileum preparations. 2. BK-Tyr10 and BK-Ile10-Tyr11 were obtained by solid phase synthesis employing fmoc chemistry. 3. Iodination of BK-Ile10-Tyr11 and Tyr0-BK was performed using iodobeads, and the products were purified by reverse-phase HPLC. 4. The relative potency (RP) of noniodinated analogues in the uterus was: Tyr0-BK (1.3) = BK (1.0) > BK-Ile10-Tyr11 (0.45) > > BK-Tyr10 (0.02) and BK (1.0) > BK-Ile10-Tyr11 (0.25) = Tyr0-BK (0.22) > > > BK-Tyr10 (0.002). The RP of mono-iodo (MI) and di-iodo (DI) products was: BK (1.0) > DI-BK-Ile10-Tyr11 (0.63) = DI-Tyr0-BK (0.63) > MI-Tyr0-BK (0.46) = MI-BK-Ile10-Tyr11 (0.40). 5. The RP of noniodinated analogues in the guinea pig ileum was: BK (1.0) > MI-Tyr0-BK (0.39) > MI-BK-Ile10-Tyr11 (0.17) = DI-Tyr0-BK (0.16) = DI-BK-Ile10-Tyr11 (0.13). 6. Differences in RP of 8-10 fold for Tyr0-BK or BK-Tyr10 and 2-fold for BK-Ile10-Tyr11 were observed between the two preparations used, indicating possible receptor differences. 7. Iodination caused a reduction in the RP of the analogues in both preparations. 8. In the rat uterus, the changes in the RP of the Tyr0-BK analogues were more evident than those observed with the iodinated analogues of BK-Ile10-Tyr11, indicating that iodination causes different changes in RP, according to the localization of the Tyr in the molecule. 9. The data support the idea that iodinated analogues of BK-Ile10-Tyr11, with intact N-terminal portion, may be as useful as iodinated analogues of Tyr0-BK for the study of BK receptors.

Amino Acids↗
PubMed1996

Mitochondrial COI sequences in mites: evidence for variations in base composition.

Studies of mitochondrial DNA sequences in a variety of animals have shown important differences between phyla, including differences in the genetic codes used, and varying constraints on base composition. In that respect, little is known of mites, an important and diversified group. We sequenced a portion (340 nt) of the cytochrome oxidase subunit I (COI) encoding gene in twenty species of phytophagous mites belonging to nine genera of the two families Tetranychidae and Tenuipalpidae. The mitochondrial genetic code used in mites appeared to be the same as in insects. As is generally also the case in insects, the mite sequences were very rich in A + T (75% on average), especially at the third codon position (94%). However, important variations of base composition were observed among mite species, one of them showing as little as 69% A + T. Variations of base composition occur mostly through synonymous transitions, and do not have detectable effects on polypeptide evolution in this group.

Animals↗
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↗
PubMed1993

Acute meningoencephalitis as the sole manifestation of Q fever.

The case of a 25-year old man who presented with meningoencephalitis as the sole clinical manifestation of Q fever is described. Serological studies revealed the presence of IgM and IgG antibodies to Coxiella burnetii. The patient responded favourably to a ten-day course of i.v. ceftriaxone and was discharged without any neurological sequelae.

Acute Disease↗
PubMed1993

Secretoneurin--a neuropeptide generated in brain, adrenal medulla and other endocrine tissues by proteolytic processing of secretogranin II (chromogranin C).

Secretogranin II (chromogranin C), originally described as tyrosine sulfated protein of the anterior pituitary, is present in large dense core vesicles of several endocrine cells and neurons. We raised antisera in rabbits to conjugates of two synthetic peptides (bovine secretogranin 133-151 and rat secretogranin 154-186) flanked in the primary structure of secretogranin II by pairs of basic residues and used them to investigate the proteolytic processing of this protein by immunoblotting and a newly developed radioimmunoassay. The sensitivity of this assay was 30 fmol for secretogranin 154-186 and 60 fmol for secretogranin 133-151. The highest degree of processing of secretogranin II (> 90%) occurs in brain. One of the peptides (secretogranin 133-151) is not generated to any significant extent. The other peptide, secretogranin 154-186, however, is formed in vivo, and in brain the free peptide apparently represents the predominant form. The highest concentrations of secretogranin 154-186 are found in the hypothalamus, two- to six-fold lower levels are present in the hippocampus, caudate nucleus, thalamus and brainstem. These concentrations are comparable to those of established neuropeptides. In order to indicate the special relevance of secretogranin II and of this peptide for brain we have named this peptide secretoneurin. The newly developed radioimmunoassay for this peptide will be a useful tool to establish its physiologic role in brain.

Adrenal Medulla↗