PubMed Health⌕ Search

Biomedical subjects

J M Rodríguez

Publications and source records attributed to J M Rodríguez.

At least 37 records · Page 2Linked to original sources
PubMed2003

Differentiation of Enterococcus faecium from Lactobacillus delbrueckii subsp. bulgaricus and Streptococcus thermophilus strains by PCR and dot-blot hybridisation.

Variations in length and sequence of the 16S/23S spacer region of Enterococcus faecium provided the basis for development of simple PCR and dot-blot hybridisation assays that enabled the differentiation of potentially probiotic Enterococcus faecium strains from Lactobacillus delbrueckii subsp. bulgaricus and Streptococcus thermophilus. Such assays may be useful for differentiation of yoghurt starter cultures and enterococcal strains when they are simultaneously present in probiotic food products.

Adult↗
PubMed2003

Heterologous production of bacteriocins by lactic acid bacteria.

Over the last two decades, bacteriocins produced by lactic acid bacteria (LAB) have been the subject of considerable research and industrial interest due to their potential as food biopreservatives. The development of heterologous expression systems for such antimicrobial compounds may offer a number of advantages over native systems, such as facilitating the control of bacteriocin gene expression or achieving higher production levels. In addition, the heterologous production by food-grade LAB offers an attractive method for overcoming some of the adverse situations that may affect the effectiveness of some bacteriocins in food systems. Construction of multibacteriocinogenic strains or acquisition of antimicrobial properties by industrial strains are further objectives that can be achieved through the use of heterologous gene expression systems. The development of new biotechnological tools and recent advances in LAB genetics account for the escalating number of studies dealing with heterologous production of bacteriocins by such hosts. This paper reviews the literature published on the subject and compares the different experimental strategies that have been used up to the present for this purpose.

Bacteriocins↗
PubMed2003

Role of liver transplantation in the management of metastatic neuroendocrine tumors.

INTRODUCTION: In the majority of patients transplanted for unresectable liver metastases, long-term results are disappointing because of early tumor recurrence. Due to its biologically less aggressive nature, neuroendocrine metastases (NM) may represent a good indication for liver transplantation (LT). PATIENTS AND METHODS: Between January 1996 and May 2000, five patients with NM were transplanted. The primary tumors were located in the pancreas (n=4) and the small bowel (n=1). In three cases there were symptoms related to hormone production: two carcinoids, and one gastrinoma. The management of primary tumors was sequential in three patients with the tumor being resected before LT (one Whipple procedure and two left pancreatectomies). In two patients the resections of the primary tumors and the LT were simultaneous namely one bowel resection and one left pancreatectomy. All patients were treated with chemotherapy. RESULTS: Two patients developed recurrent disease succumbing at 15 months (nonfunctioning NE pancreatic head tumor) and 17 months (carcinoid of the pancreatic tail) post-LT. Another patient died at 3 months post-LT due to technical complications. The other two patients are alive and free of recurrence. CONCLUSION: Despite the promising results obtained with LT for NM, our experience indicates that patients must be carefully selected. Perhaps the use of more aggressive chemotherapeutic protocols combined with an individualized approach will improve the results.

Adult↗
PubMed2003

Fulminant hepatic failure and liver transplantation: experience of Virgen de la Arrixaca Hospital.

INTRODUCTION: For patients with fulminant hepatic failure who show a poor evolution despite medical treatment, liver transplantation is an option, with survival rates of greater than 50%. The ideal time to perform the transplant is controversial, as it must not be done too soon (when the liver disease is still reversible) or too late (when the patient is in an irreversible clinical situation). PATIENTS AND METHODS: Retrospective review of the clinical histories of 34 patients admitted to our hospital with a diagnosis of fulminant hepatic failure included 26 who underwent transplantation. The most frequent cause was viral (n=10, 38%); with no etiology established in 11 cases (42%). Thirteen patients had preoperative complications, the most frequent being renal insufficiency. As for degree of AB0/DR compatibility, 13 cases were identical (40%), 17 compatible (51%), and the other three incompatible (9%). RESULTS: Thirty-three transplants were performed in 26 patients: four were retransplants due to chronic rejection, two for primary graft failure, and one for hyperacute rejection. The overall mortality rate was 46% (12 patients). The most frequent cause of death was infection (50%). The overall actuarial survival rate was 68% at 1 year, 63% at 3 years, and 59% at 5 years. The factors associated with a poor prognosis were renal and respiratory insufficiency, a grade D electroencephalogram, and encephalopathy grades III and IV, the last being the only prognostic factor identified in the multivariate analysis. The prognostic factors for mortality were a grade D electroencephalogram, encephalopathy grades III and IV and respiratory insufficiency, the last being the only prognostic factor identified in the multivariate analysis. CONCLUSION: Good results of transplantation for the management of fulminant hepatic failure depends on optimal selection of transplant candidates, which means identifying them early, reducing the waiting time, and excluding factors associated with a poor prognosis.

Analysis of Variance↗
PubMed2002

Prognostic factors in thymic epithelial neoplasms.

OBJECTIVES: The primary thymic epithelial neoplasms (PTENs) are uncommon tumours with a broad spectrum of both biological and morphological features. The aim of this study is to analyse the prognostic factors that influence survival. METHODS: Forty-four patients with a complete follow-up were analysed. Nine patients (20.5%) were asymptomatic, the most common symptoms in the rest being myasthenia gravis and dyspnoea. All the patients underwent surgery, 30 cases (68.2%) receiving total thymectomy and the rest a partial resection or biopsy. Marino-Müller's histological classification showed the mixed type to be the most common (52.3%). Clinical staging was done according to the Masaoka classification, which gave the most common stage as stage III (34.1%). RESULTS: Twelve patients died during a mean follow-up of 8.2 +/- 3.5 years. The accumulated survival rate was 77% at 5 years and 60% at 10 years. Analysis of the survival curves shows significant differences (P<0.05) when considering surgical technique, clinical staging and histological subtype. The multivariate analysis shows the only parameters with prognostic significance in PTENs to be clinical staging and histological type (P<0.001). CONCLUSIONS: The most important prognostic factors in PTENs are Masaoka's clinical staging and Marino-Müller's histological subtype.

Adolescent↗
PubMed2001

The molecular basis of 3-methylcrotonylglycinuria, a disorder of leucine catabolism.

3-Methylcrotonylglycinuria is an inborn error of leucine catabolism and has a recessive pattern of inheritance that results from the deficiency of 3-methylcrotonyl-CoA carboxylase (MCC). The introduction of tandem mass spectrometry in newborn screening has revealed an unexpectedly high incidence of this disorder, which, in certain areas, appears to be the most frequent organic aciduria. MCC, an heteromeric enzyme consisting of alpha (biotin-containing) and beta subunits, is the only one of the four biotin-dependent carboxylases known in humans that has genes that have not yet been characterized, precluding molecular studies of this disease. Here we report the characterization, at the genomic level and at the cDNA level, of both the MCCA gene and the MCCB gene, encoding the MCC alpha and MCC beta subunits, respectively. The 19-exon MCCA gene maps to 3q25-27 and encodes a 725-residue protein with a biotin attachment site; the 17-exon MCCB gene maps to 5q12-q13 and encodes a 563-residue polypeptide. We show that disease-causing mutations can be classified into two complementation groups, denoted "CGA" and "CGB." We detected two MCCA missense mutations in CGA patients, one of which leads to absence of biotinylated MCC alpha. Two MCCB missense mutations and one splicing defect mutation leading to early MCC beta truncation were found in CGB patients. A fourth MCCB mutation also leading to early MCC beta truncation was found in two nonclassified patients. A fungal model carrying an mccA null allele has been constructed and was used to demonstrate, in vivo, the involvement of MCC in leucine catabolism. These results establish that 3-methylcrotonylglycinuria results from loss-of-function mutations in the genes encoding the alpha and beta subunits of MCC and complete the genetic characterization of the four human biotin-dependent carboxylases.

Adult↗
PubMed2001

Optimization of enterocin P production by batch fermentation of Enterococcus faecium P13 at constant pH.

The influence of pH on growth, enterocin P production and glucose consumption by Enterococcus faecium P13 was studied during anaerobic batch fermentation in MRS broth at 32 degrees C in a fermentor. Growth and glucose consumption were maximal at pH 7.0. Enterocin P production displayed primary metabolite kinetics and was strongly dependent on pH. A maximum antimicrobial activity of 1,949 bacteriocin units (BU) ml(-1) was obtained at pH 6.0, which represented a four-fold increase compared with the antimicrobial activity obtained without pH regulation. The pH exerted a marked effect on the decrease in bacteriocin activity, with the decrease being maximal at pH 7.0. In this report, we propose models for the growth of E. faecium P13 as well as enterocin P production and inactivation. Enterocin P production decreased when potentially stress-inducing compounds (NaCl or ethanol) were included in the growth medium.

Adsorption↗
PubMed2001

Antibiotic prophylaxis in incisional hernia repair using a prosthesis.

Antibiotic prophylaxis in clean surgery with implantation of prosthetic material is widely accepted, although there are no studies on its use in abdominal incisional hernia repair. The objective was to evaluate antibiotic chemoprophylaxis in incisional herniorrhaphy with the implantation of prosthetic material. A prospective non-randomized study (1990-1998) was conducted to analyse 216 patients undergoing surgery for abdominal incisional hernia who required a prosthesis (polypropylene) in the reconstruction and who met the criteria for clean surgery. Risk factors were observed in 31.5%, the most frequent being diabetes and obesity. The incisional hernia was located mostly in the abdominal midline and in 64.4% measured over 10 cm. Antibiotic prophylaxis was administered in 140 patients (64.8%) via the systemic route, the antibiotics being first- or second-generation cephalosporins or amoxicillin-clavulanic acid. Surgical wound infection occurred in 39 patients (18.1%), 19 who had received antibiotic prophylaxis (13.6%) and 20 who had not (26.3%). In multivariate analysis using logistic regression, the variables with statistical significance for local septic infection were antibiotic prophylaxis and number of risk factors. We can conclude therefore that antibiotic chemoprophylaxis is useful in abdominal incisional herniorrhaphy surgery with implantation of prosthetic material for reducing local septic complications.

Aged↗
PubMed2001

Anti-proliferative effect of two lactic acid bacteria strains of human origin on the growth of a myeloma cell line.

AIMS: Twenty lactic acid bacteria strains were isolated from human faeces and tested by MTT assay for stimulation or inhibition of the proliferation of Vero and myeloma cells. METHODS AND RESULTS: None of the strains significantly affected the proliferation of Vero cells. However, two isolates (HN1 and HA8) showed a strong inhibition of myeloma cell proliferation (16.7 and 5.0%, respectively) by MTT assay. CONCLUSION: Both strains have an anti-proliferative effect on a tumoral cell line. SIGNIFICANCE AND IMPACT OF THE STUDY: The beneficial effect of LAB cancer therapy has been linked to their ability for immunomodulation.

Adjuvants, Immunologic↗
PubMed2001

Extrathyroid spread in papillary carcinoma of the thyroid: clinicopathological and prognostic study.

INTRODUCTION: The extrathyroid spread (ETS) is one of the risk factors that influence mortality and recurrence in patients with papillary carcinoma of the thyroid (PCT). The aim of this study is to analyze the clinical and histologic features and follow-up of a series of patients with ETS undergoing surgery for PCT and to identify patients with a greater risk of presenting with ETS. MATERIAL AND METHODS: Retrospective study of a series of 200 patients undergoing surgery for PCT, of whom 47 (23.5%) presented with ETS. The clinical and histologic features and follow-up of the patients with ETS were compared with those without ETS using the Pearson chi(2) test. We used a logistics regression model to perform a multivariant analysis for ETS. The survival and disease-free interval rates were calculated using the Kaplan-Meier method. RESULTS: ETS is most associated with patients over 50 years of age, with tumors over 4 cm that are not encapsulated, with lymph node metastasis, and with certain PCT histologic subtypes after the multivariant analysis. The overall rate of recurrence and mortality in patients with ETS was much higher than in patients without ETS. CONCLUSIONS: PCT patients with ETS have a greater risk of tumor-related recurrence and mortality than patients without ETS. There are patients with certain clinical and histologic features who have a greater risk of presenting with ETS.

Adolescent↗