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C Vargas

Publications and source records attributed to C Vargas.

At least 19 recordsLinked to original sources
PubMed1995

Isolation of cryptic plasmids from moderately halophilic eubacteria of the genus Halomonas. Characterization of a small plasmid from H. elongata and its use for shuttle vector construction.

Three cryptic plasmids have been isolated from moderately halophilic eubacteria belonging to three species of the genus Halomonas. These three plasmids were designated pHE1 (4.2 kb, isolated from H. elongata ATCC 33174), pHI1 (48 kb, isolated from "H. israelensis" ATCC 43985), and pHS1 (ca. 70 kb, isolated from H. subglaciescola UQM 2927). Because of its small size, the plasmid pHE1 was selected for further characterization and construction of a shuttle vector for Halomonas strains. pHE1 was cloned into pBluescript KS and a detailed restriction map was constructed. Hybridization experiments excluded the existence of sequences homologous to pHE1 in total DNA from other strains of the genus Halomonas. Moreover, no DNA homology with pMH1, the only plasmid described so far from moderate halophiles, was found. Since pHE1 appeared to be unable to replicate in Escherichia coli cells, a number of mobilizable pHE1-derived hybrid plasmids were constructed that could be selected and maintained both in E. coli and in H. elongata. Finally, an improved shuttle vector, pHS15, was generated. The vector pHS15 contains an origin of replication from E. coli as well as one from H. elongata, a streptomycin resistance gene for positive selection in moderate halophiles, a number of unique restriction sites commonly used for cloning, and the mobilization functions of the broad host range IncP plasmid RK2. The vector pHS15 was readily mobilized by the RK2 derivative pRK2013 to all Halomonas strains tested so far. This is the first report on the development of a cloning vector useful for moderately halophilic eubacteria.

Genetic Vectors↗
PubMed1995

Characterization of the cycHJKL genes involved in cytochrome c biogenesis and symbiotic nitrogen fixation in Rhizobium leguminosarum.

Mutants of Rhizobium leguminosarum bv. viciae unable to respire via the cytochrome aa3 pathway were identified by the inability to oxidize N,N'-dimethyl-p-phenylenediamine. Two mutants which were complemented by cosmid pIJ1942 from an R. leguminosarum clone bank were identified. Although pea nodules induced by these mutants contained many bacteroids, no symbiotic nitrogen fixation was detected. Heme staining of cellular proteins revealed that all cytochrome c-type heme proteins were absent. These mutants lacked spectroscopically detectable cytochrome c, but cytochromes aa3 and d were present, the latter at a higher-than-normal level. DNA sequence analysis of complementing plasmids revealed four apparently cotranscribed open reading frames (cycH, cycJ, cycK, and cycL). CycH, CycJ, CycK, and CycL are homologous to Bradyrhizobium japonicum and Rhizobium meliloti proteins thought to be involved in the attachment of heme to cytochrome c apoproteins; CycK and CycL are also homologous to the Rhodobacter capsulatus ccl1 and ccl2 gene products and the Escherichia coli nrfE and nrfF gene products involved in the assembly of c-type cytochromes. The absence of cytochrome c heme proteins in these R. leguminosarum mutants is consistent with the view that the cycHJKL operon could be involved in the attachment of heme to apocytochrome c.

Amino Acid Sequence↗
PubMed1995

Diagnostic laparoscopy: a 5-year experience in a hepatology training program.

Diagnostic laparoscopy continues to have a role in the evaluation and diagnosis of acute and chronic liver diseases, primary and metastatic liver tumors, and peritoneal diseases. We retrospectively reviewed the records of 1794 diagnostic laparoscopies performed at our institution from 1987 to 1992 to identify the indications, results, and safety of this procedure in our training program. A definitive diagnosis was made in 91% of cases with biopsy performed in 93%. Chronic liver disease was evaluated in 890 patients, and a diagnosis was made in 98%. Four hundred thirty-seven patients were evaluated for suspected primary or metastatic carcinoma, and a diagnosis was made in 85%. Ascites was evaluated in 73 patients, and a diagnosis was made in 82%. One-hundred sixty-four patients were evaluated for abnormal liver function tests, and a diagnosis was made in 91%. HIV-related liver function test abnormalities were evaluated in 67 patients, and a diagnosis was made in 81%. One hundred sixty-three patients underwent diagnostic laparoscopy for the evaluation of hepatomegaly, splenomegaly, unexplained portal hypertension, fever of unknown origin, and cholestasis, and a diagnosis was made in 74% of cases. Eight major complications (including abdominal viscus perforation, hemobilia, splenic laceration, bleeding) and thirty-one minor complications were seen. Our findings confirm that diagnostic laparoscopy is a safe and valuable procedure in the evaluation of chronic liver disease.

Chronic Disease↗
PubMed1995

Procollagen-III peptide and chronic viral C hepatitis.

UNLABELLED: Chronic hepatitis develops in at least half of persons acutely infected with hepatitis C virus (HCV). Ten to 25% of these patients will develop cirrhosis. Serum procollagen-III peptide (PIIIP) may be of value in predicting the development of chronic active fibrogenic liver disease. It has been reported that in chronic viral C hepatitis, the levels of hepatitis C virus-RNA (HCV-RNA) correlate directly with the severity of hepatic histology and inversely with response to interferon therapy. OBJECTIVES: The aims of this study were to correlate the level of PIIIP with HCV-RNA concentrations, ALT values, and histological severity in patients with chronic viral C hepatitis. METHODS: Eighty-six patients with chronic C hepatitis were divided into three groups: group I (n = 34), mild chronic active hepatitis, group II (n = 25), moderate to severe chronic active hepatitis, and group III (n = 27), cirrhosis. HCV-RNA was measured by Quantiplex, and PIIIP was measured by radioimmunoassay-gnostic assay. RESULTS: Mean +/- SD level of ALT in group I was 114 +/- 48 U/L, group II was 169 +/- 115 U/L, and group III was 160 +/- 94 U/L. The mean +/- SD level of HCV-RNA in group I was 110 +/- 130 x 10(5) Eq/ml, in group II was 140 +/- 140 x 10(5) Eq/ml, and in group III was 70 +/- 80 x 105 Eq/ml. The mean +/- SD level of PIIIP in group I was 0.6 +/- 0.2 U/ml, in group II was 0.9 +/- 0.4 U/ml, and in group III was 1.2 +/- 0.6. There was a significant difference in the levels of PIIIP among the three groups (p = 0.0001). There was no correlation among ALT, HCV-RNA, and PIIIP in any of the three groups. CONCLUSIONS: PIIIP peptide determinations in patients with chronic viral C hepatitis are reflective of histological severity and may provide relatively noninvasive means of following disease progression.

Alanine Transaminase↗
PubMed1994

Identification of a gene encoding a thioredoxin-like product necessary for cytochrome c biosynthesis and symbiotic nitrogen fixation in Rhizobium leguminosarum.

A Tn5-induced mutant of Rhizobium leguminosarum bv. viciae could not form nitrogen-fixing nodules on pea or vetch because of a lesion in electron transport to oxygen. The mutant lacked spectroscopically detectable cytochromes c and aa3. No proteins containing c-type cytochrome could be identified in the mutant by heme staining of proteins fractionated on polyacrylamide gels, indicating that the mutant was defective in maturation of all c-type cytochromes. The Tn5 mutation was determined to be located in a gene that was called cycY. The cycY gene product is homologous to the thioredoxin-like protein HelX involved in the assembly of c-type cytochromes in Rhodobacter capsulatus and to an open reading frame from a Bradyrhizobium japonicum gene cluster containing other genes involved in cytochrome c biogenesis. Our observations are consistent with CycY functioning as a thioredoxin that reduces cysteine residues in apocytochromes c before heme attachment.

Amino Acid Sequence↗
PubMed1994

Extinction of Vibrio cholerae in acidic substrata: contaminated cabbage and lettuce treated with lime juice.

Lime juice killed millions of Vibrio cholerae O1, El Tor, Inaba, present on cabbage and lettuce contaminated in the laboratory. The lethal effect was evident within 5 min of exposure to lime juice. No vibrios could be recovered at dilution 1:10 using alkaline peptone water (APW) and thiosulfate-citrate-bile salts-saccharose agar (TCBS). More than 99.9% of the initial inoculum was effectively destroyed. The number of vibrios killed by lime juice was 2 to 6 logarithms greater than the maximum infecting dose, and 4 to 8 logs greater than the minimum infecting dose for cholera El Tor. The time interval needed for killing was smaller than the usual waiting time for serving food in homes and restaurants. The addition of lime juice to non-acidic foods, beverages and water, is strongly recommended to prevent infection with cholera vibrios and other acid-sensitive microorganisms. This measure is particularly important for rural and slum populations in the tropics and subtropics.

Cholera↗
PubMed1994

[The pectoral implant of an automatic defibrillator by cardiologists in an electrophysiology laboratory].

We have performed 2 implantations of transvenous automatic cardioverter defibrillator in a cardiac laboratory devoted to electrophysiology and pacemaker implantation. This is a preliminary experience with a novel implant strategy. Cardiologists were the primary operators. The automatic cardioverter defibrillator were placed in a subcutaneous pectoral region, with a non-thoracotomy lead system. The automatic cardioverter defibrillator were two Medtronic 7219D PCD Jewel, with a Transvene system. There were no perioperative complications. Acceptable defibrillation threshold were obtained in both patients, 12 and 20 J, respectively. Leads were inserted percutaneously through the left subclavian vein. After 8 months of follow-up the patients continue to tolerate the device satisfactorily. Implantation of automatic cardioverter defibrillator systems by trained cardiologists in an electrophysiology laboratory is safe and feasible. Moreover, its cost-effectiveness is superior, the saving includes the surgeons, and the reduction of stay in unit of intensive care and hospitalization.

Defibrillators, Implantable↗
PubMed1993

[Hepatitis C virus antibodies in chronic non-alcoholic liver disease].

The presence of hepatitis C virus antibodies was studied in 64 patients with non alcoholic liver disease and found in 11 (17%). The greater frequency of positive antibodies was found among patients with cryptogenetic liver disease, specially those without serum auto-antibodies (32%). The antibody was unusually found (0 to 11%) in non alcoholic liver diseases of other etiologies. It is concluded that hepatitis C virus chronic infections may be the etiology of an important number of non alcoholic chronic liver diseases.

Adult↗
PubMed1992

Characterization of a plasmid from moderately halophilic eubacteria.

A plasmid has been isolated for the first time from moderately halophilic eubacteria. Halomonas elongata, Halomonas halmophila, Deleya halophila and Vibrio costicola were found to harbour an 11.5 kbp plasmid (pMH1). The plasmid was isolated and characterized after transformation into Escherichia coli JM101 cells. A restriction map was constructed, and unique restriction sites for EcoRI, EcoRV and ClaI were detected. The occurrence of such a plasmid in the original halophilic strains was confirmed by Southern hybridization. The plasmid carries genetic determinants that mediate resistance to kanamycin, tetracycline, and neomycin. This property, together with its relatively small size, its stability in E. coli cells, and the presence of unique restriction sites, makes pMH1 a good candidate for the development of a cloning vector for moderate halophiles.

Drug Resistance, Microbial↗
PubMed1992

[Prevalence of chronic diseases in young postpartum women].

Five hundred women 20 to 29 years of age were evaluated 48 hr after delivery to detect the presence of chronic diseases. An overall prevalence of 14.4% was found. Circulatory, osteo muscular, connective tissue and endocrine, metabolic and immune related disorders constituted the main groups of diseases detected. Leading diagnosis were hypertension, scoliosis, gallstones and goiter. No differences were found in type of delivery when comparing healthy and chronic disease affected women. Chronic disease in younger females should be further studied in order to avoid complications, sequelae and to improve reproductive conditions in this population.

Adult↗
PubMed1992

Hepatic actinomycosis presenting as liver mass: case report and review of the literature.

Primary hepatic actinomycosis is an uncommon entity. We report the case of a young man with past history of an appendectomy who presented with fever, weight loss and a liver mass that was initially suspected to be neoplastic. Percutaneous liver biopsy revealed actinomyces-like organisms. The patient was treated with intravenous and oral penicillin with good therapeutic response. Review of the literature and correlation between hepatic actinomycosis and previous appendectomy are considered.

Actinomyces↗
PubMed1991

Immediate post-exposure effects of high-peak-power microwave pulses on operant behavior of Wistar rats.

Behavioral effects of high-peak-power microwave pulses on Wistar rats were studied by operant schedules. Each of twelve rats that had been trained to press a lever to receive food pellets was assigned randomly in groups of four to three different schedules of reinforcement: fixed-ratio (FR), variable-interval (VI), and differential-reinforcement-of-low-rates (DRL). After achieving a steady baseline performance, each animal was exposed for 10 min to 1.25-GHz microwave radiation at 1-MW peak-power (10-microseconds pulse width). Each pulse produced a peak whole-body SA and SAR of 2.1 J/kg and 0.21 MW/kg. Total doses (SAs) were set to 0.50, 1.5, 4.5, and 14 kJ/kg by adjusting the pulse-repetition rate. The corresponding time-averaged whole-body SARs were 0.84, 2.5, 7.6, and 23 W/kg. A microwave-transparent animal holder was used to keep the animal's body axis parallel to the E-field. Exposures at the highest dose caused an average colonic temperature rise of 2.5 degrees C and these animals failed to respond at all for about 13 minutes after the exposure. Their colonic temperatures had decreased to 1.1 degrees C, or less, above their pre-exposure (normal) temperature level when they began to respond. The FR and VI animals failed to reach their baseline levels of performance thereafter, while those on the DRL schedule displayed variable effects. No behavioral effects were found at the lower dose levels. It is concluded that the behavioral perturbations produced by pulsed microwave irradiation were thermal in nature.

Animals↗
PubMed1991

Circadian variations in the superoxide production, enzyme release and neutrophil aggregation in patients with rheumatoid arthritis and controls.

Patients with rheumatoid arthritis (RA) experience fluctuations of symptoms throughout the day. These could be due to mechanical changes or modification of the inflammatory mechanisms. In the present paper we studied fluctuations of superoxide production (O2), enzyme release (beta-glucuronidase and lysozyme) and neutrophil aggregation in the peripheral blood of eight healthy volunteers and eight patients with RA. Although enzyme release was greater in patients with RA, no significant difference was found throughout the day, neither in control nor in patients. Similar results were obtained when studying neutrophil aggregation. On the contrary, the superoxide production, determined at 8:00, 14:00, and 20:00 h, was 6.3 +/- 0.5, 4.40 +/- 0.4 and 6.26 +/- 0.3, respectively, in patients with RA and 6.65 +/- 0.7, 4.7 +/- 0.7 and 7.27 +/- 0.4 in the controls. The values obtained at 14:00 h were significantly lower (alpha = 0.01). There were no differences in the curve form between patients and controls.

Arthritis, Rheumatoid↗
PubMed1990

Identification and cloning of nodulation genes and host specificity determinants of the broad host-range Rhizobium leguminosarum biovar phaseoli strain CIAT899.

Rhizobium leguminosarum biovar phaseoli type II strain CIAT899 nodulates a wide range of hosts: Phaseolus vulgaris (beans), Leucaena esculenta (leucaena) and Macroptilium atropurpureum (siratro). A nodulation region from the symbiotic plasmid has been isolated and characterized. This region, which is contained in the overlapping cosmid clones pCV38 and pCV117, is able to induce nodules in beans, leucaena and siratro roots when introduced in strains cured for the symbiotic plasmid, pSym. In addition, this cloned region extends the host range of Rhizobium meliloti and R. leguminosarum biovar (bv.) trifolii wild-type strains to nodulate beans. Analysis of constructed subclones indicates that a 6.4kb HindIII fragment contains the essential genes required for nodule induction on all three hosts. Rhizobium leguminosarum bv. phaseoli type I strain CE3 nodulates only beans. However, CE3 transconjugants harbouring plasmid pCV3802 (which hybridized to a nodD heterologous probe), were capable of eliciting nodules on leucaena and siratro roots. Our results suggest that the CIAT899 DNA region hybridizing with the R. meliloti nodD detector is involved in the extension of host specificity to promote nodule formation in P. vulgaris, L. esculenta and M. atropurpureum.

Cloning, Molecular↗
PubMed1990

Drownings in Minnesota, 1980-85: a population-based study.

We conducted a population-based study of drownings in Minnesota from 1980 through 1985. Five hundred and forty-one drownings (2.1 per 100,000 person-years) were identified from death certificates and from incident reports filed with the Minnesota Department of Natural Resources. Most drownings (334, 62 percent) occurred during summer months (May-August) and involved boating (42 percent) and swimming (35 percent) events. However, 62 drownings (11 percent) occurred during winter months (December-February) and primarily involved snowmobiles and motor vehicles (71 percent) breaking through ice on lakes and waterways. The risk of drowning, estimated by the ratio of drownings to number of water-related activities, was highest during March and April, when the ice on lakes and waterway surfaces is melting, and during October and November, when lake and waterway surfaces are starting to freeze. Drowning rates were highest for males (3.7 per 100,000 person-years), persons 15 to 25 years of age (3.3 per 100,000 person-years), and children less than 5 years of age (2.5 per 100,000 person-years). These data can be used to target prevention strategies, particularly in northern climates.

Adolescent↗
PubMed1990

[Entero-urinary fistula. A study of 22 cases].

We performed a retrospective study on 22 patients with entero-urinary fistulas that had been diagnosed and treated at the Hospital Clinico i Provincial in Barcelona during the period spanning 1981-1988. Fistulas were classified according to the organs or parts with which they communicated. Among the important etiogenic conditions were diverticular disease of colon. Crohn's disease, actinic lesions, trauma and xanthogranulomatous pyelonephritis. The clinical manifestations were principally urological in the form of recurrent urinary infection and terminal pneumaturia. The most useful diagnostic techniques were cystoscopy; serial voiding cystourethrography (SVCU), retrograde urethrography and pyelography. Treatment was by surgery in all cases. Diversion procedures or surgical excision of the fistulous tract were performed as warranted by each case. The etiopathogenic, morphological and therapeutical aspects of vesico-enteric fistulas are discussed.

Adolescent↗