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I Gonzalez

Publications and source records attributed to I Gonzalez.

At least 37 records · Page 2Linked to original sources
PubMed1998

Identification of a gene encoding a methyl-accepting chemotaxis-like protein form Campylobacter coli and its use in a molecular typing scheme for campylobacters.

Using PCR amplification with degenerate primers, a gene (tlpA) form Campylobacter coli encoding a putative 63x0 kDa polypeptide which exhibited significant identity with bacterial methyl-accepting chemotaxis proteins (MCPs) was identified. A mutant containing an inactivated copy of the tlpA A gene showed a wild-type chemotactic response to all of the chemo-attractants tested. A DNA probe based on the Highly Conserved Domain (HCD) of TlpA revealed the presence of multiple copies of genes encoding MCP-like proteins in both Camp. coli and Camp. jejuni. The arrangement of restriction sites within, and proximal to, genes with homology to the HCD probe varied among strains, resulting in a high degree of polymorphism. It is demonstrated here that a DNA probe compromising the HCD region of MCP-like proteins can be used, in Southern hybridization-based assays, to provide novel information which allows the discrimination of individual strains of Camp. coli and Camp. jejuni.

Amino Acid Sequence↗
PubMed1998

Corynebacterium camporealensis sp. nov., associated with subclinical mastitis in sheep.

Four strains of a hitherto-unknown catalase-positive, facultatively anaerobic Corynebacterium species were isolated from the milk of sheep affected by subclinical mastitis. The most characteristic phenotypic reactions of the four strains were their weak fermentative acid production from glucose, their failure to produce acid from mannitol, xylose, sucrose and maltose, and a strong CAMP reaction with Staphylococcus aureus. Chemotaxonomic investigations revealed the presence of a cell wall based on meso-diaminopimelic acid and short-chain mycolic acids, which is consistent with the genus Corynebacterium. A comparative 16S rRNA gene sequence analysis confirmed that the organisms from sheep were members of the genus Corynebacterium, where they formed a distinct subline, exhibiting > 4% sequence divergence with other known Corynebacterium species. Based on both phenotypic and phylogenetic findings, a new species, Corynebacterium camporealensis, is proposed. The type strain of Corynebacterium camporealensis is CECT 4897 (= CRS-51T).

Animals↗
PubMed1997

Mating type switching in yeast controlled by asymmetric localization of ASH1 mRNA.

Cell divisions that produce progeny differing in their patterns of gene expression are key to the development of multicellular organisms. In the budding yeast Saccharomyces cerevisiae, mother cells but not daughter cells can switch mating type because they selectively express the HO endonuclease gene. This asymmetry is due to the preferential accumulation of an unstable transcriptional repressor protein, Ash1p, in daughter cell nuclei. Here it is shown that ASH1 messenger RNA (mRNA) preferentially accumulates in daughter cells by a process that is dependent on actin and myosin. A cis-acting element in the 3'-untranslated region of ASH1 mRNA is sufficient to localize a chimeric RNA to daughter cells. These results suggest that localization of mRNA may have been an early property of the eukaryotic lineage.

Actins↗
PubMed1997

Maternal exposure to delta 9-tetrahydrocannabinol (delta 9-THC) alters indolamine levels and turnover in adult male and female rat brain regions.

Perinatal exposure to delta 9-THC has been shown to produce effects on brain development. In this study we evaluated the changes induced by maternal exposure to delta 9-THC (5 mg/kg per day) from gestational day 5 to postnatal day 24 in eight discrete brain areas on the central serotoninergic system in both adult male and female rats. These result show that maternal exposure to delta 9-THC from gestational day 5 to postnatal day 24 affects development of the various central indoleaminergic system of the offsprings brain. Perinatal exposure to delta 9-THC decreased the levels of 5-HT in hypothalamus and rostral neostriatum in exposed males, and also decreased the levels of 5-HT in ventral hippocampus, septum, and midbrain raphe nuclei in both exposed males and females. Perinatal exposure to delta 9-THC increased the levels of 5-HIAA in dorsal hippocampus, hypothalamus, septum, midbrain raphe nuclei, and rostral neostriatum in exposed males and females. We have also found differences between nonexposed males and females in several brain regions. Our results confirm a regional and sexual specificity in endogenous levels of indoleamine after perinatal delta 9-THC treatment, being the midbrain raphe nuclei the most affected area.

Animals↗
PubMed1997

Disruption of the clathrin heavy chain-like gene (CLTCL) associated with features of DGS/VCFS: a balanced (21;22)(p12;q11) translocation.

The smallest region of deletion overlap in the patients we have studied defines a DIGeorge syndrome/velocardiofacial syndrome (DGS/VCFS) minimal critical region (MDGCR) of approximately 250 kb within 22q11. A de novo constitutional balanced translocation has been identified within the MDGCR. The patient has some features which have been reported in individuals with DGS/VCFS, including: facial dysmorphia, mental retardation, long slender digits and genital anomalies. We have cloned the breakpoint of his translocation and shown that it interrupts the clathrin heavy chain-like gene (CLTCL) within the MDGCR. The breakpoint of the translocation partner is in a repeated region telomeric to the rDNA cluster on chromosome 21p. Therefore, it is unlikely that the patient's findings are caused by interruption of sequences on 21p. The chromosome 22 breakpoint disrupts the 3' coding region of the CLTCL gene and leads to a truncated transcript, strongly suggesting a role for this gene in the features found in this patient. Further, the patient's partial DGS/VCFS phenotype suggests that additional features of DGS/VCFS may be attributed to other genes in the MDGCR. Thus, haploinsufficiency for more than one gene in the MDGCR may be etiologic for DGS/VCFS.

Abnormalities, Multiple↗
PubMed1997

Specific identification of the enteropathogens Campylobacter jejuni and Campylobacter coli by using a PCR test based on the ceuE gene encoding a putative virulence determinant.

A PCR method for the rapid identification and discrimination of thermophilic Campylobacter jejuni and Campylobacter coli was developed by using a gene encoding a protein involved in siderophore transport (ceuE). A nucleotide sequence divergence of approximately 13% in the ceuE genes of C. jejuni and C. coli facilitated the design of two species-specific PCR primer sets. The specificity of the PCR amplification reactions was confirmed by using two nonradioactively labelled species-specific internal oligonucleotide hybridization probes for each of these species.

Base Sequence↗
PubMed1997

Cla4p, a Saccharomyces cerevisiae Cdc42p-activated kinase involved in cytokinesis, is activated at mitosis.

Yeasts have three functionally redundant G1 cyclins required for cell cycle progression through G1. Mutations in GIN4 and CLA4 were isolated in a screen for mutants that are inviable with deletions in the G1 cyclins CLN1 and CLN2. cln1 cln2 cla4 and cln1 cln2 gin4 cells arrest with a cytokinesis defect; this defect was efficiently rescued by CLN1 or CLN2 expression. GIN4 encodes a protein with strong homology to the Snflp serine/threonine kinase. Cla4p is homologous to mammalian p21-activated kinases (PAKs) (kinases activated by the rho-class GTPase Rac or Cdc42). We developed a kinase assay for Cla4p. Cla4p kinase was activated in vivo by the GTP-bound form of Cdc42p. The specific activity of Cla4p was cell cycle regulated, peaking near mitosis. Deletion of the Cla4p pleckstrin domain diminished kinase activity nearly threefold and eliminated in vivo activity. Deletion of the Cla4p Cdc42-binding domain increased kinase activity nearly threefold, but the mutant only weakly rescued cla4 function in vivo. This suggests that kinase activity alone is not sufficient for full function in vivo. Deletion of the Cdc42-binding domain also altered the cell cycle regulation of kinase activity. Instead of peaking at mitosis, the mutant kinase activity exhibited reduced cell cycle regulation and peaked at the G1/S border. Cla4p kinase activity was not reduced by mutational inactivation of gin4, suggesting that Gin4p may be downstream or parallel to Cla4p in the regulation of cytokinesis.

Cell Cycle↗
PubMed1997

A follow-up study of multibacillary Hansen's disease patients treated with multidrug therapy (MDT) or MDT + immunotherapy (IMT).

Multibacillary (MB) leprosy patients treated with multidrug therapy (MDT) or MDT + immunotherapy (IMT) with BCG + heat-killed Mycobacterium leprae were tested annually for their ability to proliferate in vitro to the mycobacterial antigens BCG, M. leprae soluble extract, and intact M. leprae. IgM antibody responses to phenolic glycolipid I (PGL-I) were measured, as well as serum nitrite levels in patients' sera, before, during and after treatment. Patients who received only MDT did not present cellular reactivity to intact M. leprae antigens, in contrast to the results obtained with BCG, which elicited reactivity at time zero, that increased after treatment. Regarding PGL-I antibody variations in relation to the initial value, we observed a statistically significant marked decrease at the end of 2 years which continued to fall in successive evaluations. MB patients showed high initial serum nitrite concentrations which dropped drastically with treatment. This decay was apparently associated with the bacillary load present in these patients. The group submitted to IMT + MDT showed high and long-lasting T-cell responses to mycobacterial antigens in a significant number of initially unresponsive MB patients. There was a marked increase to M. leprae soluble extract and BCG, as well as a more variable response to whole bacilli. The antibody levels in this group of patients are sustained for a somewhat longer period and decreased more slowly during the 5-year follow up.

Antibodies, Bacterial↗
PubMed1995

Liver transplantation in patients with Budd-Chiari syndrome.

Patients with Budd-Chiari syndrome (obstruction of the hepatic veins) and associated hepatic insufficiency may be candidates for orthotopic liver transplantation (OLT). In our series of 405 OLT patients, 3 were transplanted due to Budd-Chiari syndrome (0.7%). The indication for liver transplantation in these patients was severe hepatic insufficiency (chronic in two and acute in the third one). Morphologic study of the obstructions revealed apparently different causes, including thrombi, membranous webs in hepatic veins, and hydatid cyst compression. The surgical technique employed in these transplantations was similar to that for other etiologies. Due to its implications for the future course of OLT, it is important to determine the exact etiology of Budd-Chiari syndrome in the pretransplant period and to treat the patients with early and long-term anticoagulant therapy to avoid syndrome recurrence.

Adolescent↗
PubMed1995

Hereditary xerocytosis: a report of six unrelated Spanish families with leaky red cell syndrome and increased heat stability of the erythrocyte membrane.

Hereditary xerocytosis (HX) is a rare haemolytic disease due to dehydrated red blood cells (RBCs). A unique feature of this syndrome is that affected members often show normal or near normal haemoglobin levels despite clinical and laboratory evidence of mild to moderate haemolysis. The diagnostic clue is the association of markedly increased RBC Na+ + K+ fluxes with low total cation (Na+ + K+) content. 11 patients of six unrelated families of Spanish origin with HX have been studied from clinical, genetical and biological points of view. In addition, we have investigated the sensitivity of RBC membrane to heat at three different incubation times (15, 30 and 60 min) and two different temperature values (46 degrees C and 49 degrees C). Under these conditions control RBCs (50 normal subjects) exhibited at 49 degrees C and 30 min a maximum of 30% fragmented RBCs. This value increased to 80% after 60 min of incubation. In contrast, patients with HX showed significantly lower percentages of fragmented RBCs at both 30 and 60 min of incubation (maximum 10% and 30%, respectively). In an attempt to determine if increased heat stability was unique to HX RBCs, several other congenital membranopathies with haemolytic anaemia were also studied. The degree of fragmentation, except in one case of HPP (which was strongly increased), did not differ from the control group. Electrophoretic studies of membrane proteins performed in RBCs of all the patients with HX did not explain any qualitative nor quantitative abnormality. In addition to its physiopathological interest, study of RBC heat stability, together with other haematological parameters (increased MCHC and decreased RBC osmotic fragility), may be useful for HX diagnosis, especially in laboratories which are not equipped to evaluate RBC membrane permeability.

Anemia, Hemolytic↗
PubMed1995

The effect of recovery conditions on the apparent heat resistance of Bacillus cereus spores.

The effect of recovery media and incubation temperature on the apparent heat resistance of three ATCC strains (4342, 7004 and 9818) of Bacillus cereus spores were studied. Nutrient Agar (NA), Tryptic Soy Agar (TSA), Plate Count Agar (PCA) and Milk Agar (MA) as the media and temperatures in the range of 15-40 degrees C were used to recover heated spores. Higher counts of heat injured spores were obtained on PCA and NA. The optimum subculture temperature was about 5 degrees C below the optimum temperature for unheated spores. No significant differences in heat resistance were observed with the different recovery conditions except for strains 4342 and 9818 when MA was used as plating medium. Large differences in D-values were found among the strains (D100 = 0.28 min for 7004; D100 = 0.99 min for 4342; D100 = 4.57 min for 9818). The 7004 strain showed a sub-population with a greater heat resistance. The z values obtained for the three strains studied under the different recovery conditions were similar (7.64 degrees C +/- 0.25).

Bacillus cereus↗
PubMed1994

The relationship between pes cavus and idiopathic scoliosis.

STUDY DESIGN: The incidence of pes cavus and scoliosis was studied in three groups of patients. Group A contained 130 patients with idiopathic scoliosis, Group C contained 210 patients with idiopathic pes cavus, and Group B (control) contained 200 patients of similar age. OBJECTIVES: To investigate the joint presentation of pes cavus and idiopathic scoliosis, because both deformities may share a common etiology linked to muscle imbalance. SUMMARY OF BACKGROUND DATA: Sixty five percent of Group A patients (85 of 130) had an abnormally high plantar arch, compared to only 9.5% (19 of 200) of Group B control subjects. Nine percent (20 of 210) of the patients in Group C had scoliosis curves, compared to only four patients in Group B. METHODS: Radiographs were taken to determine the type of scoliosis curve, its location, and its magnitude, and to identify the incidence of spina bifida occulta in the three groups. The incidence and degree of pes cavus were established by means of foot prints. Statistical analyses were performed on all results. RESULTS: A statistically significant relationship (P < 0.01) was found for the incidence of pes cavus between Group A (scoliosis) and Group B (control), and for the incidence of scoliosis between Group C (pes cavus) and Group B (control). No statistical significance was observed for the other relationships investigated (sex, curve location, magnitude, spina bifida). CONCLUSIONS: There was a significant correlation between scoliosis and pes cavus--spina bifida was not an etiologic factor. Therefore, in certain patients where scoliosis and pes cavus present jointly, deformity may be secondary to altered balance or to disorders of the central nervous system.

Adolescent↗
PubMed1994

Study of the retinal fiber layer in patients with acquired immunodeficiency syndrome.

A study using the monochromatic photography technique to examine the retina of a group of patients with human immunodeficiency virus (HIV) infections in different degrees of evolution and with no history of opportunistic retinal infection revealed the existence of lesions on the level of the retinal nerve fiber layer. The lesions detected included wide, slit-like defects; sector defects; and generalized diffuse atrophies. Both the sector defects and the diffuse atrophies appeared at times to be related to retinal cotton-wool exudates, but at other times they occurred in eyes with no observable retinal pathology. The results of this study can be interpreted as "in vivo" confirmations of the findings obtained by other authors in the postmortem study of optic nerves of patients with acquired immunodeficiency syndrome (AIDS), presenting a generalized degenerative process of the optic nerve with a loss of up to 40% of the axons of the retinal ganglion cells. In some cases, the results obtained in our study directly related the presence of cotton-wool exudates to the production of lesions in the retinal nerve fiber layer, whereas in other cases, the fiber lesions did not appear to be secondary to the cotton-wool exudates. Therefore, a primary lesion of the retinal ganglion cells or of the optic nerve fibers could be considered, as studies by other authors have suggested.

Acquired Immunodeficiency Syndrome↗
PubMed1993

In vitro replication of plasmids containing human ribosomal gene sequences: origin localization and dependence on an aprotinin-binding cytosolic protein.

We previously investigated the role of an aprotinin-binding protein (ADR) in the initiation of DNA replication in isolated quiescent nuclei. In the present study, we have used a cell-free DNA replication system to test the ability of plasmid vectors which contain sequences from the human ribosomal RNA gene to serve as replicative templates in vitro when exposed to ADR-containing preparations. Significant dTTP incorporation was seen using DNA from either a 7-kb sequence in the 5' spacer region (CHE) or a 7-kb sequence which begins near the end of the 28S coding region and extends into the 3' spacer region (ADBB), while sequences from other regions of the rRNA gene mediated little or no dTTP incorporation. The characteristics of plasmid-directed dTTP incorporation indicate that most incorporation is due to DNA replication and not repair or damage-initiated processes. To conclusively demonstrate origin-dependent replication in the plasmid system and to further map replication origins, an approach was developed using ddGTP to restrict the length of daughter strands followed by hybridization of these replication products to restriction fragments spanning the putative origin region. This approach allowed us to identify replication origin activity apart from parent strand repair or synthesis initiated at random damaged sites. One of the origins was localized to a 1375-bp fragment within the 5' spacer region, and this fragment contains sequences homologous to those found in other replication origins.

Aprotinin↗
PubMed1993

Neurologic complications in liver transplantation.

A retrospective review is presented of neurologic complications in our first 143 consecutive adult patients (208 liver transplants in 143 adults and 18 children) undergoing liver transplantation. Nineteen (13.2%) of the 143 patients developed neurologic complications in the postoperative period. Immunosuppression was initiated intraoperatively with steroids with the addition of azathioprine on Day 1 and cyclosporine, adjusted by RIA to a level of 400-600 ng/ml, on Day 2 post-transplantation. Azathioprine is discontinued in the third month. Fourteen of the 19 patients (73.6%) presented with CNS complications characterized by: diffuse multifactorial encephalopathy (5 patients); leukoencephalopathy (2 patients) which required temporary (1 case) or permanent (1 case) discontinuation of cyclosporine A; hemorrhage (in 2 cases due to arterial hypertension and coagulopathy and another due to unknown causes); ischemic/anoxic injury secondary to cardiorespiratory arrest (2 patients) or arteriothrombosis (1 patient); and myelopathy (1 patient) due to vertebral compression (T10-T11) secondary to osteoporosis. The diagnostic studies most often employed were computed tomographic (CT) (85.7%) and electroencephalography (EEG) (42.8%). Five of 19 patients (26.3%) suffered peripheral nervous system (PNS) complications: 1 patient with reversible Claude-Bernard-Horner Syndrome caused by central venous catheterization during anesthesia; 2 patients with peroneal nerve palsy due to compression below the knees by operating room table supports; 1 patient with an irreversible lesion of the right recurrent laryngeal nerve secondary to prolonged intubation and central venous catheterization; and 1 patient with a reversible lesion of the left brachial plexus secondary to inadvertant hyperextension of the upper extremity on the O.R. table due to the need for dialysis and catheterization of the axillary vein for veno-venous bypass.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1992

Human ribosomal RNA gene repeats are localized in the dense fibrillar component of nucleoli: light and electron microscopic in situ hybridization in human Sertoli cells.

The distribution of the human ribosomal gene repeat within human Sertoli cell nucleoli was investigated with the help of DNA-DNA in situ hybridization at the light and electron microscopic level. Probes from both the transcribed part of the gene repeat and the "non-transcribed" spacer were found to hybridize predominantly to the dense fibrillar component of nucleoli. It therefore can be concluded that the dense fibrillar component of nucleoli is the major site of the intranucleolar location of the ribosomal DNA. This holds true not only for the dense fibrillar component adjacent to fibrillar centers, but also for the dense fibrillar component remote from the fibrillar centers.

Cell Nucleolus↗