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Biomedical subjects

J C Rodríguez

Publications and source records attributed to J C Rodríguez.

At least 19 recordsLinked to original sources
PubMed2000

Detection of Oestrus ovis and associated risk factors in sheep from the central region of Yucatan, Mexico.

A cross-sectional epidemiologic study was conducted in order to detect the presence of and to estimate the seroprevalence of Oestrus ovis L. infection in flocks of sheep from the central region of the state of Yucatan, Mexico. The risk factors associated with disease were also identified. A sample size of 10 animals per farm was used to detect seropositive animals, considering a 30% prevalence and 95% confidence level. Blood samples of 689 sheep from 88 flocks were collected and a questionnaire with questions about the flock and the host was applied. The thin layer immune assay test was used. The risk factors were screened using logistic regression procedures. 77% of the flocks had at least one-positive animal with antibodies against O. ovis. The overall seroprevalence and standard error was 30.6 +/- 3.5%. Only flock size and sheep nose color showed association (P < 0.05) with the disease. The odds ratios for flocks with less than 11 and with 11 to 25 sheep, as related to herds with 25 or more sheep, were 0.74 and 1.73, respectively. Sheep with dark noses had a higher risk (OR = 1.46) compared with sheep having light noses (P < 0.05).

Age Factors↗
PubMed2000

Expression and prognostic significance of pepsinogen C in gastric carcinoma.

BACKGROUND: In this study we evaluated the expression and clinical significance of pepsinogen C, an aspartic proteinase involved in the digestion of proteins in the stomach, in patients with gastric cancer. METHODS: Pepsinogen C expression was examined by immunohistochemical methods in a series of 95 gastric carcinomas. The prognostic value of pepsinogen C was retrospectively evaluated by multivariate analysis taking into account conventional prognostic parameters. Follow-up period of patients was 21.4 months. RESULTS: A total of 25 (26.3%) gastric carcinomas stained positively for pepsinogen C. The percentage of pepsinogen C-positive tumors was higher in well-differentiated (50%) than in moderately differentiated (19.5%) and poorly differentiated (21.9%) tumors (P < .05). Similarly, significant differences in pepsinogen C immunostaining were found between node-negative and node-positive tumors (47.1% vs. 14.7%; P < .001). In addition, statistical analysis revealed that pepsinogen C expression was associated with clinical outcome in gastric cancer patients. Low pepsinogen C levels predicted short overall survival periods in the overall group of patients with gastric cancer (P < .001), and in 71 patients with resectable carcinomas (P < .005). Multivariate analysis according to Cox's model indicated that pepsinogen C immunostaining was an independent predictor of outcome for both overall and resectable gastric cancer patients (P < .05, for both). CONCLUSIONS: The expression of pepsinogen C in gastric cancer may represent a useful biological marker able to identify subgroups of patients with different clinical outcomes.

Adult↗
PubMed2000

A rapid procedure to prepare cefotaxime.

A rapid procedure is reported for the synthesis of cefotaxime, by acylation of the 7-amino cephalosporanic acid with the 2-mercaptobenzothiazolyl thioester of (Z)-2-[2-aminothiazol-4-yl]-2-methoxyimino acetic acid (MAEM) that is a commercial reagent. The reaction was carried out at room temperature for 1 h, obtaining 95% yield. 2-Mercaptobenzothiazole was recovered as a side-product with a high purity and yield. The proposed method differentiates from those reported previously for a shorter time and very mild reaction condition, as well as for a ready for use reagent.

Cefotaxime↗
PubMed2000

Application of four molecular techniques for typing outbreak-associated Mycobacterium tuberculosis strains.

We applied four molecular techniques for the typing of strains of Mycobacterium tuberculosis associated with outbreaks: RFLP of the IS6110 insertion sequence, spoligotyping, RAPD, and PCR-IS6110. All 4 techniques were applied to 18 strains which were shown by epidemiological data to be involved in 6 outbreaks. All the methods classified the strains into the same groups as the classical epidemiological data did, but RFLP of the IS6110 insertion sequence and spoligotyping are laborious techniques requiring more than a full day's work, whilst RAPD and PCR IS6110 are simple methods easily incorporated into the daily routine. Nevertheless, a large-scale process of standardization and evaluation is necessary in order to be able to establish the true value of the latter two methods as intraspecific characterization markers for M. tuberculosis isolates.

Bacterial Typing Techniques↗
PubMed2000

Hyaluronic acid as prognostic marker in resectable colorectal cancer.

BACKGROUND: Hyaluronic acid (HA), an extracellular high molecular mass polysaccharide, is thought to be involved in the growth and progression of malignant tumours. The objective of this work was to evaluate the cytosolic HA content in resectable colorectal cancer, its possible relationship with clinicopathological parameters of tumours and its prognostic significance. METHODS: Cytosolic HA levels were examined by radiometric assay in 120 patients with resectable colorectal cancer. The mean follow-up period was 33.4 months. RESULTS: Cytosolic HA levels of tumours ranged widely, from 30 to 29 412 ng per mg protein. Intratumour HA levels were significantly correlated with Dukes stage (P < 0.005), and were higher in patients with advanced tumours (mean(s.e.m.) 2695(446), 2858(293) and 5274(967) ng per mg protein for stages A, B and C respectively). In addition, Cox multivariate analysis demonstrated that tumour HA levels higher than 2000 ng per mg protein predicted shorter relapse-free survival and overall survival periods (both P < 0.05). CONCLUSION: There is a wide variability in cytosolic HA levels in colorectal carcinomas, which seems to be related to the biological heterogeneity of these tumours. In addition, high tumour cytosolic HA levels were associated with an unfavourable outcome in patients with resectable colorectal cancer. HA may provide additional information to that given by other biochemical markers currently used in colorectal cancer.

Adult↗
PubMed2000

Susceptibility of Plutella xylostella (L.) (Lepidoptera: Plutellidae) populations in Mexico to commercial formulations of Bacillus thuringiensis.

Populations of diamondback moth, Plutella xylostella (L.), sampled from commercial fields of crucifers in three states of Mexico, were tested for susceptibility to commercial formulations of Bacillus thuringiensis subsp. kurstaki (Berliner) (Dipel 2X), B. thuringiensis subsp. aizawai (XenTari), delta endotoxin Cry 1C (MC), and CryIA(c) (MVP), and a mixture of B. thuringiensis subsp. kurstaki and subsp. aizawai (Agree). Leaf-dip bioassays confirmed variation in susceptibility of up to 13-fold for MVP, 12-fold for Dipel 2X, sevenfold for XenTari, fivefold for Agree, and less than fivefold for MC. Comparisons with previously published data indicate that at least the 12-fold variation in Dipel 2X would result in significant differences in control in the field. Based on the LC99 values observed for the products, we propose discriminating concentrations for each product. To ensure continued performance in the field we suggest that a resistance monitoring program be implemented to detect any changes in susceptibility to B. thuringiensis products and specific toxins and that their use be restricted to one generation per crop and that they be rotated with other groups of insecticides. Furthermore, we suggest enforcement of a crucifer host-free period and the development and implementation of cultural and biological control strategies to reduce overall population pressure so that fewer insecticidal treatments will be needed.

Animals↗
PubMed2000

[Extra-intestinal infections caused by non-typhi Salmonella serotypes. 9 yrs' experience].

BACKGROUND: The most characteristic finding in non typhoid Salmonella serotype infection is acute gastroenteritis which is usually benign and self-limiting. However, more serious extraintestinal findings, such as bacteraemia and focal infections localized to any organ may appear. PATIENTS AND METHODS: The objective of this article is to describe the most important characteristics of the extraintestinal infections due to non typhoid Salmonella serotypes observed in our hospital between December 1991 and August 1999. To do so, we reviewed the clinical histories of patients in which extraintestinal non typhoid Salmonella serotypes was isolated, applying a clinicomicrobiological protocol. RESULTS: Salmonella enterica was isolated on 1,543 occasions, of which 25 (1.6%) were Salmonella serotype Typhi and 1,518 (98.3%) non typhoid serotypes. Of the patients with non typhoid serotypes infections, 27 had extraintestinal infection (1.8%). The most frequently isolated was the serotype typhimurium (50% of cases) followed by enteritidis (26% of cases) and hadar (7.1% of cases). Regarding the clinical picture, bacteraemias secondary to gastroenteritis and focal infections occurred with the same frequency (35.7%); the remaining were primary bacteraemias. Eight patients were under 10 years of age and 15 patients were over 60. In 57.1% of the patients there was underlying disease. CONCLUSIONS: Extraintestinal non typhoid Salmonella serotypes infections make up 1.8% of all salmonellosis and most of them occur in childhood or in the elderly. Transitory bacteraemias in the context of acute gastroenteritis occur mainly in children. The greatest risk of acquiring focal infections is associated with the existence of underlying illness or immunodepression.

Adolescent↗
PubMed2000

[Mycobacterium chelonae and solitary rectal ulcer].

Solitary rectal ulcer is of varied etiology and the appearance of this syndrome due to Mycobacterium chelonae is exceptional. We present a case of a solitary rectal ulcer associated with Mycobacterium chelonae subspecies chelonae in an immunocompetent individual. This microorganism is involved in cutaneous, ocular, pulmonary and soft tissue infections. Treatment of infections has traditionally been surgical, although various antibiotic treatments have been used depending on the sensitivity of the microorganism, the severity of the infection and the surgical possibilities.

Adolescent↗
PubMed1999

Isolation of pig mitochondrial 3-hydroxy-3-methylglutaryl-CoA synthase gene promoter: characterization of a peroxisome proliferator-responsive element.

Low expression of the mitochondrial 3-hydroxy-3-methylglutaryl-CoA (HMG-CoA) synthase gene during development correlates with an unusually low hepatic ketogenic capacity and lack of hyperketonaemia in piglets. Here we report the isolation and characterization of the 5' end of the pig mitochondrial HMG-CoA synthase gene. The 581 bp region proximal to the transcription start site permits transcription of a reporter gene, confirming the function of the promoter. The pig mitochondrial HMG-CoA synthase promoter is trans-activated by the peroxisomal proliferator-activated receptor (PPAR), and a functional response element for PPAR (PPRE) has been localized in the promoter region. Pig PPRE is constituted by an imperfect direct repeat (DR-1) and a downstream sequence, both of which are needed to confer PPAR-sensitivity to a thymidine kinase promoter and to form complexes with PPAR.retinoid X receptor heterodimers. A role of PPAR trans-activation in starvation-associated induction of gene expression is suggested.

Amino Acid Sequence↗
PubMed1999

Expression of pepsinogen C in gynecomastias and male breast carcinomas.

Pepsinogen C is a proteolytic enzyme involved in the digestion of proteins in the stomach; it is also synthesized by a significant percentage of female breast carcinomas. In addition, it has been demonstrated that pepsinogen C is one of the few proteins induced by androgens in breast carcinoma cells. Here we evaluate the expression of pepsinogen C by immunoperoxidase staining in normal breast tissue from 3 male patients, 15 gynecomastia tissues, 2 male in situ breast carcinomas, and 68 male invasive breast carcinomas. Pepsinogen C immunostaining values were quantified in male breast tumors using the HSCORE system, which considers both the intensity and the percentage of cells staining at each intensity. The results indicated positive immunohistochemical staining for pepsinogen C in all gynecomastia tissues, the two in situ ductal carcinomas, and 52 of 68 invasive breast carcinomas (76.4%). The three normal breast tissues analyzed showed negative staining for pepsinogen C, whereas invasive tumors showed clear differences among them with regard to the intensity and percentage of staining cells. In addition, pepsinogen C scores were significantly higher in well-differentiated (grade I, 188.7) and moderately differentiated (grade II, 145.8) tumors than in poorly differentiated (grade III, 98.5) tumors (p = 0. 032). Similarly, significant differences in pepsinogen C content were found between estrogen receptor (ER)-positive tumors and ER-negative tumors (158.5 vs. 44.3, respectively; p = 0.009). Patients with pepsinogen C-positive tumors reached longer relapse-free and overall survival periods than did those with tumors with negative staining, but no statistical differences were observed between survival curves calculated for these two groups of patients. This results demonstrate expression of pepsinogen C by gynecomastias and by a high percentage of male breast carcinomas and may indicate an important role of pepsinogen C in the pathophysiology of male breast diseases.

Adolescent↗
PubMed1999

Expression and clinical significance of apolipoprotein D in male breast cancer and gynaecomastia.

BACKGROUND: Apolipoprotein D (Apo D) is a protein component of the human plasma lipid transport system which is present in benign and malignant human breast tissues. This study analysed the expression of Apo D in men with gynaecomastia or breast cancer, and evaluated its use as a prognostic marker in breast cancer. METHODS: Immunohistochemical expression of Apo D was examined in specimens from 15 men with gynaecomastia, two with in situ breast carcinoma and 68 with invasive male breast cancer. Median follow-up in patients with breast cancer was 44 months. RESULTS: All gynaecomastia specimens, both in situ carcinomas and 57 invasive carcinomas (84 per cent) stained positively for Apo D. Apo D values were significantly correlated with axillary node involvement and histological grade of the tumours. In men with breast cancer univariate analysis showed a statistical association between node status and Apo D content with relapse-free survival (P < 0.001) and overall survival (P < 0.05). Cox multivariate analysis showed that Apo D was a significant indicator of relapse-free survival (P = 0. 0089), but node status was the strongest factor able to predict both relapse-free (P = 0.0336) and overall (P = 0.0346) survival. CONCLUSION: Apo D was expressed in gynaecomastia and a high percentage of male breast carcinomas. There was a positive association of Apo D content in male breast tumours with favourable outcome. Apo D expression was a significant independent indicator of relapse-free survival in male breast cancer.

Adolescent↗
PubMed1999

[Biodistribution of 99mTC-HMPAO in healthy rats and B16 melanoma carriers].

Scintigraphic studies carried out in melanoma patients have demonstrated that the 99mTc-HMPAO complex makes it possible to locate the lesion. A biodistribution and pharmacokinetic study of the 99mTc-HMPAO complex was carried out in B16-melanoma tumor healthy and carrier mice after an intravenous injection. Radioactivity was measured in the liver, kidneys, spleen, stomach, brain, blood and tumor. It was seen that at 15 minutes of the injections, 40% of the total activity distributed in the animal body was recorded in the tumor. An interesting effect observed is an increase in the tissue distribution curves in both experimental groups at 1-2 hours post-injection. According to the seriated imaging study results with 99mTc-HMPAO in B16 melanoma bearing mice, the best image is obtained 10-30 minutes after the injection.

Animals↗
PubMed1999

[Evolution of resistance to quinolones in Salmonella enterica in our setting].

Salmonella enterica is mainly associated with acute gastroenteritis; however, it is also associated with other more severe disease processes, for which quinolones are the treatment of choice. We retrospectively studied the evolution of resistance to nalidixic acid and ciprofloxacin of all the clinical isolates of S. enterica from 1992 to 1998 in our hospital environment. A total of 848 strains from feces, blood and other locations were studied. We detected an increase in the resistance to nalidixic acid from 12% in 1992 to 21.3% in 1998, especially in the Enteritidis and Hadar serotypes. We did not detect resistance to ciprofloxacin, but there was in increase in the MIC in the nalidixic acid-resistant strains. Although this is interpreted as sensitive according the the NCCLS criteria, if we apply the cutoff points established by MENSURA, 89.46% of the strains do not fit into this category (S <0.12 mg/l). This puts into question the utility of quinolones in the long-term treatment of severe disease processes produced by this type of strain.

Anti-Infective Agents↗