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Biomedical subjects

F Rodriguez

Publications and source records attributed to F Rodriguez.

At least 37 records · Page 2Linked to original sources
PubMed1997

Comparative trial of 3 days of azithromycin versus 10 days of clarithromycin in the treatment of children with acute otitis media with effusion.

The authors compared the efficacy, safety and tolerance of azithromycin and clarithromycin in pediatric patients with acute otitis media. A randomized, open clinical trial was performed comparing azithromycin and clarithromycin in children aged 6 months to 12 years of age with acute otitis media with effusion. Patients were allocated to azithromycin at 10 mg/kg once daily for 3 days or to clarithromycin at 15 mg/kg day divided into two equal doses for 10 days. Clinical examinations and tympanometric evaluations were performed at baseline, day 3-5, day 10-14, day 28-30 and day 50-60. Tympanocentesis fluid cultures were collected at enrollment and urine and blood samples were obtained at baseline and day 10-14. Of 100 patients enrolled, 97 were considered evaluable. The most common middle ear pathogens were Streptococcus pneumoniae (60%), Haemophilus influenzae (15%) and Staphylococcus aureus (13%). Fifty patients (100%) treated with azithromycin and 45 (95.7%) patients treated with clarithromycin had a satisfactory clinical response. Rates of persistence of middle ear effusion and possible drug related side effects were comparable. Based on the efficacy and safety results, azithromycin for 3 days and clarithromycin for 10 days are considered to represent an attractive alternative for the treatment of children with acute otitis media.

Anti-Bacterial Agents↗
PubMed1997

Lack of correlation between codon 12 K-ras mutations and major histocompatibility complex antigens in bronchogenic carcinomas.

In experimental systems, an association between K-ras activity and expression of major histocompatibility complex (MHC) molecules has been reported. In this study, 52 surgically resected bronchogenic carcinomas were studied for human leukocyte antigen (HLA) class I and II expression, and for the presence of point mutations in codon 12 of the K-ras gene. HLA class I loss was detected in 18 carcinomas, and most of the tumors (43 cases) were found negative for HLA class II antigen expression by the APAAP technique with specific monoclonal antibodies. Analysis using the polymerase chain reaction (PCR), together with selective hybridization using mutation-specific synthetic oligonucleotides, demonstrated K-ras mutations in five cases, all of them corresponding to the adenocarcinoma subtype (31.2% of the adenocarcinomas included in our study) with a poor degree of differentiation. We did not find any correlation between K-ras mutations and HLA class I and II expression in bronchogenic carcinomas. Therefore, it would appear that downregulation of MHC antigens by point mutations of K-ras does not take place in vivo.

Carcinoma, Bronchogenic↗
PubMed1997

"H" reflex as a measure of subclinical uremic polyneuropathy in children with chronic renal failure.

Uremic polyneuropathy (UPNP) is a serious complication of chronic renal failure (CRF) in adults; however, its prevalence is unknown in the pediatric population. An easy-to-perform maneuver for its detection in children is the evaluation of "H" reflex. The objective of this study was to validate the usefulness of the "H" reflex maneuver for the diagnosis of UPNP in pediatric dialysis patients for CRF. Thirty-seven CRF patients were paired with healthy controls by age and sex. The patients were being treated with dialysis or one of its variants. Information was obtained regarding diagnosis, duration, and control of dialysis. Neurological examination was performed, conduction velocities in sensory and motor nerves were measured, and "H" reflex elicited bilaterally. Peripheral polyneuropathy was determined by the presence of at least two nerves with alterations in latency and/or conduction velocities. It was found that 59.4% (22/37) of the children with CRF treated with dialysis developed UPNP, 17 with ambulatory peritoneal dialysis, and 5 with hemodialysis. There was no difference in diagnosis, duration of dialysis, or control of the same in these patients from other CRF patients who did not have UPNP. All patients were clinically asymptomatic. "H" reflex showed a sensibility of 44%, a specificity of 87%, a predictive value positive of 66%, and a predictive value negative of 76%, when measured to 28 msec. With a 30 msec duration specificity rises to 95%. UPNP presents asymptomatically in pediatric patients. "H" reflex is an adequate screening test for the selection of pediatric patients to be tested further.

Adolescent↗
PubMed1997

Comparison of the response to the recombinant vaccine against hepatitis B virus in dialyzed and nondialyzed children with CRF using different doses and routes of administration.

In patients with chronic renal failure (CRF), parenteral transmission of the hepatitis B virus (HBV) is common. The response to the recombinant vaccine is 50%-80% of seroprotection. Therefore, to improve seroprotection, different strategies such as dose augmentation, vaccination at the predialysis stage, subcutaneous application, and using interleukin were tried, with unsatisfactory results. In children, there are no studies demonstrating the efficacy of the vaccine. The aim of this study was to evaluate the efficacy of the recombinant vaccine in children with CRF, in late as well as early phases, through the quantification of antibodies against the surface antigen in response to different doses of the vaccine against HBV. There were 103 patients who were assigned to three groups: (1) 25 patients with CRF in the early phase (undergoing pharmacological treatment only); (2) 67 patients with CRF in the late phase (treatment with peritoneal dialysis or hemodialysis); (3) 11 patients with CRF in the early phase (undergoing low-dose pharmacological treatment only). The antibodies against the serum antigen (HBsAg) were measured by the aEIA method. Urea, creatinine, and creatinine clearance were measured at 0, 2, and 12 months. In our seroprotection results we observed that group 1 and 3 developed earlier seroconversion (50% first month). In patients undergoing dialysis the seroconversion happened in 91% at month 13, but with lower concentration than group 1 and/or group 3 (p < 0.05). In conclusion, there is a better response in predialysis patients. The levels of antibodies are similar in groups 1 and 3 (with small doses), which are similar to the complete doses for an efficient immunity in children with chronic renal failure.

Adolescent↗
PubMed1996

Chronic delta hepatitis: is the prognosis worse when associated with hepatitis C virus and human immunodeficiency virus infections?

Eighty-six patients were followed for 6.5 years to study the epidemiological, virological, and histological course of chronic delta hepatitis and the relationship of this disease with HIV and HCV infection. Patients were classified into four groups according to simultaneous HCV and/or HIV infection: group 1, HDV infection (20 cases); group 2, HDV and HCV infection (11 cases); group 3, HDV and HIV infection (12 cases), and group 4, HDV, HCV, and HIV infection (43 cases). All but 14 patients were asymptomatic at presentation. Liver histology showed chronic active hepatitis in 53 cases and cirrhosis in 19 cases. During followup, 52 patients remained asymptomatic, 34 developed hepatic dysfunction, 28 died, and 1 received a liver transplant. Among the 28 patients who died, 4 had HDV infection; 3 HDV and HCV infection; 3 HDV and HIV infection; and 18 HDV, HCV, and HIV infection. Death was due to liver failure in 16 (57%), AIDS in 10 (36%), and was unrelated to liver disease in 2 (8%) cases. There results demonstrate that chronic delta hepatitis is a severe disease, especially among drug users with HIV and HCV infection. The high morbidity and mortality of chronic delta hepatitis justifies the use of antiviral therapy to modify the natural course of the disease.

Adolescent↗
PubMed1996

PAH content and mutagenicity of marine sediments from the Venice lagoon.

Sediments from the Venice lagoon, a polluted coastal environment in northeastern Italy, were assayed for mutagenicity and content of several toxic microcontaminants, which included selected polycyclic aromatic hydrocarbons (PAHs); the latter are specifically dealt with in this paper. Samples were collected at three lagoon sites with reasonably distinct environmental features--urban, industrial, or agricultural--and at two others considered to be under mixed pollution influences; a sixth sample was obtained from an open sea area to act as background control. The organic matter (EOM) associated with the mineral substrata was extracted; after cleanup, analyte determination was carried out by HRGC-LRMS(SIM) using isotopically labeled compounds as internal standards. Cumulative levels of the selected PAHs were found to be in the range of 0.065 to 0.46 micrograms/g of dry matrix at five sites; a much higher concentration (48 micrograms/g) was detected in the sample from the urban environment. The remarkable PAH level increase at this site was mostly accounted for by the concurrent, apparent increase of EOM contamination as PAH concentration was seen to reach 32 micrograms/mg of EOM from < 1 microgram/mg at the five remaining sites. Mutagenicity assays with Salmonella typhimurium strains TA98 and TA100 of marine sediment organic extracts also highlighted a distinct activity in the sample from the urban site. Further fractionation and analysis of this extract pointed to PAHs as the main mutagenic component present in the sediment matrix, possibly accounting for up to approximately 70-80% of the entire mutagenic potential detected.

Environmental Exposure↗
PubMed1996

The structural protein p54 is essential for African swine fever virus viability.

Protein p54, one of the most antigenic structural African swine fever virus (ASFV) proteins, has been localized by immuno-electron microscopy in the replication factories of infected cells, mainly associated with membranes and immature virus particles. Attempts to inactivate the p54 gene from ASFV by targeted insertion of beta-galactosidase selection marker was uniformly unsuccessful, suggesting that this gene is essential for virus viability. To demonstrate that, we inserted in the TK (thymidine kinase) locus of the virus a construction containing a second copy of the p54 gene and beta-glucuronidase selection marker under the control of p54 and p73 promoters, respectively. Virus mutant clones expressing a second copy of p54 and beta-glucuronidase were used to achieve deletion mutants of the original copy of the gene. Virus mutants expressing only the second inserted copy of p54 and the two selection markers mentioned above were successfully obtained. Therefore, we have demonstrated that the p54 gene product plays an essential role in virus growth, characterizing for the first time in ASFV an essential virus gene.

African Swine Fever Virus↗
PubMed1996

Detection of Mycoplasma mycoides subspecies mycoides by monoclonal antibody-based sandwich ELISA.

Monoclonal antibodies (MAbs) were produced from a mouse immunised with Mycoplasma mycoides subsp. mycoides small colony (MmmSC) antigen and their use to detect and differentiate strains within the Mycoplasma mycoides cluster investigated in an antigen capture ELISA format. The MAbs produced could not distinguish between MmmSC and M. mycoides subsp. mycoides large colony (MmmLC) strains. However, the sandwich ELISAs developed were able to specifically distinguish these two biotypes from the other four members of the M. mycoides cluster, and from all other mycoplasma or bacteria species examined. The most sensitive application of the test was a combination of enrichment and capture by overnight or 48-h incubations of samples inoculated into mycoplasma broth in antibody-coated microtiter wells.

Animals↗
PubMed1996

Radiofrequency as a lesioning model in experimental spinal cord injury.

Many models have been developed to study spinal cord injury (SCI), such as cryogenic lesioning, hot water injury, scalpel lesioning, compressive trauma using clips, electromechanical devices, extradural cuffs, and weight-drop techniques. In this study, the radiofrequency (RF) lesion was used for inducing an experimental SCI in cats. The neuropathology was correlated with the MRI. In this model, 4 cats were injured at the thoracic spinal cord (T11-T12) with a lesion of 65 degrees C for 1 min using a micromanipulated penetrating RF electrode. The MRI of the lesions after 2, 3, 5, and 6 weeks post-injury as well as the correlative histological changes were obtained. The RF-induced lesion was discrete with little spreading across the spinal cord. There was a good correlation between the histopathology findings and the MRI. We conclude that experimental RF lesioning of the spinal cord can produce a consistent lesion with predictable histopathological changes in experimental animals. A 65 degree C injury for 1 min induced a clinical picture of an incomplete SCI. The RF lesioning should be considered as a new model to study SCI, particularly those with a penetrating component.

Animals↗
PubMed1996

Collagen dysplasia in a litter of Garafiano shepherd dogs.

A connective tissue disease resembling the human Ehlers-Danlos syndrome is reported in three Garafiano shepherd dogs from the same litter. The clinical signs included skin hyperextensibility and fragility, joint laxity, and ocular lesions. Microscopical studies showed abnormalities in the packing of collagen in fibrils and fibres in the skin. Systemic connective tissue defects were demonstrated in one necropsied puppy.

Animals↗
PubMed1996

An immunohistochemical method of detecting Mycoplasma species antigens by use of monoclonal antibodies on paraffin sections of pneumonic bovine and caprine lungs.

Lung samples from pneumonic lesions in cattle and goats, naturally or experimentally infected with strains of the Mycoplasma mycoides cluster, were fixed in formalin and embedded in paraffin. An immunohistochemical technique using monoclonal or polyclonal antibodies was performed on tissue sections in order to detect Mycoplasma antigens. Four monoclonal antibodies (MAbs), one (2A3) raised against M. mycoides ssp. mycoides small colony (SC) and large colony (LC), two (1D3 and 5E5) against M. mycoides ssp. capri, and one (5A10) against M. bovis, were used. A range of polyclonal antibodies, raised to the individual subspecies of the M. mycoides cluster, and one to Pasteurella haemolytica, was also used. The MAb 2A3 showed positive immunostaining in lung sections from cattle and goats naturally and experimentally infected with M. mycoides ssp. mycoides SC and LC, but not with pneumonic lesions of cattle and goats due to other members of the M. mycoides cluster, M. bovis or Pasteurella spp. The MAb 1D3 showed immunostaining in lung sections from goats naturally and experimentally infected with M. mycoides ssp. capri, but again not with pneumonic lesions caused by other members of the M. mycoides cluster, M. bovis or Pasteurella spp. The MAb 5E5 immunoreacted in sections from pneumonic lesions from all animals infected with one of the three M. mycoides cluster subspecies used in the study, but not with M. bovis or Pasteurella infected tissue. Immunoreaction was mainly found in the cell debris around necrotic areas, as well as in macrophages, neutrophils and epithelial cells. The localization of antigens of the M. mycoides cluster using polyclonal antisera followed basically the same pattern as that obtained with the monoclonals. However, a wide cross reactivity was found between different antisera and relatively high background immunostaining was also seen, especially in necrotic areas. The results suggest that immunohistochemical methods using monoclonal antibodies are useful tools for the diagnosis and study of the pathogenesis of pneumonia caused by the Mycoplasmas of the M. mycoides cluster.

Animals↗
PubMed1996

Nephroprotective effect of cilastatin in allogeneic bone marrow transplantation. Results from a retrospective analysis.

Cilastatin, an inhibitor of the tubular brush border enzyme dehydropeptidase-I, is added in a fixed combination to imipenem. Cilastatin has been demonstrated in different animal models and in one clinical trial, to reduce the nephrotoxicity associated with cyclosporin A. To evaluate a possible nephroprotective effect of cilastatin following allogeneic BMT we conducted a retrospective analysis of 104 patients transplanted in our BMT Unit from January 1991 to January 1995. Imipenem/cilastatin (I/C) was used in a non-randomized manner in 64 patients during this period. Acute renal failure (ARF) was diagnosed in 32 patients (30%). ARF was not associated with gender, sepsis, conditioning regimen, underlying disease, bilirubin, or age. VOD occurred in 12/32 (37.5%) of patients with ARF whereas it occurred in only 7/72 (9.7%) of patients without ARF (P < 0.0007). ARF was not correlated with use of aminoglycosides, vancomycin, ciprofloxacine, ceftazidime or amphotericin-B. However, 13 patients of 64 exposed to I/C (20.3%) developed ARF vs 19 of 40 patients (47.5%) who were not exposed to I/C (P < 0.003; OR 0.28). Stratified analysis and multiple logistic regression confirmed the I/C nephroprotective action. The mean cyclosporin A levels in the I/C group were significantly decreased (208.6 +/- 64.9) vs the non-I/C group (265 +/- 118). We conclude that these results suggest I/C may counteract acute cyclosporin A nephrotoxicity following BMT and further prospective clinical trials are needed to confirm if routine administration of cilastatine confers benefit in the BMT setting.

Acute Kidney Injury↗
PubMed1995

Highly specific confirmatory western blot test for African swine fever virus antibody detection using the recombinant virus protein p54.

A Western blot technique using a recombinant protein has been developed to confirm positive results obtained in African swine fever (ASF)-specific antibody detection by ELISA. The new confirmatory Western blot is based on the use of protein p54, one of the most antigenic ASF virus structural proteins, expressed in Escherichia coli fused to the N-terminus of MS2 polymerase. The recombinant Western blot assay was highly specific and equally sensitive for ASF virus-infected pigs detection as the conventional Western blot, which uses virus-induced proteins ranging in molecular weight between 23 and 35 kDa. The novel Western blot assay provides a simpler interpretation of the test, eliminates the possibility of false-positive reactions produced by cellular compounds that contaminate the antigen employed in the conventional technique, and avoids the use of live virus in antigen production.

African Swine Fever↗
PubMed1995

Undetectable expression of genomic progesterone receptor in human spermatozoa.

The expression of genomic progesterone receptor in human ejaculated spermatozoa was investigated. Spermatozoa from 10 fertile donors who exhibited normal semen parameters were analysed. Indirect immunofluorescence and an enzyme immunoassay using monoclonal antibodies against genomic progesterone receptor were used. Different types of spermatozoa were studied: fresh, post-swim-up (migrated), capacitated and post-artificial induction of the acrosome reaction by calcium ionophore A23187. Progestin receptor-rich T47D human breast cancer cells were used as a positive control, and progestin receptor-poor MDA-MB-231 human breast carcinoma cells were used as a negative control. Genomic progesterone receptor was not detected in fresh, migrated, capacitated and post-acrosome reaction induction human spermatozoa and MDA-MB-231 cells by either indirect immunofluorescence or enzyme immunoassay. However, in T47D cells a mean concentration of 1043.2 +/- 125.2 fmol genomic progesterone receptor/mg protein was observed by enzyme immunoassay, and indirect immunofluorescence results were positive using both flow cytometry and fluorescence microscopy. These findings suggest that the effect of progesterone on human spermatozoa is not mediated by genomic progesterone receptor.

Antibodies, Monoclonal↗
PubMed1995

An operon encoding a novel ABC-type transport system in Bacillus subtilis.

Downstream from the surfactin synthetase operon in Bacillus subtilis a new operon-type structure has been localized which, on the basis of sequence determination, potentially encodes an ABC-type transport system. The 268 amino acid protein, the product of orf1, represents the solute-binding component of the system whereas the orf2 product, a 234 amino acid protein, is the transmembrane component. Finally orf3 potentially encodes a typical 241 amino acid ATP-binding protein involved in energy supply. Comparison of the three proteins with the subunits of other ABC-type systems suggests that this new system is involved in amino acid transport.

ATP-Binding Cassette Transporters↗