Biomedical subjects

J Molina

Publications and source records attributed to J Molina.

At least 55 records · Page 3Linked to original sources

PubMed1999

Comparative analysis of quantification of viral load in patients infected with hepatitis C virus: quantiplex HCV RNA assay and amplicor monitor assay.

OBJECTIVE: two standardized techniques, Quantiplex HCV RNA 2.0 (bDNA) and Amplicor Monitor, were evaluated for the quantification of hepatitis C virus (HCV) load. Our objectives were: 1) to determine the relationship between viral load and genotype, and 2) to evaluate viral load in serial serum samples and in patients with normal or slightly elevated liver enzyme values in an area with a high prevalence of genotype 1. RESULTS: the viral loads detected with the two methods correlated significantly (r = 0.7, p < 0.0001), but viral load was smaller with the Monitor than with the Quantiplex assay, and was independent of genotype. The Monitor/Quantiplex ratio was lower in patients with a non-1 genotype than in patients with genotype 1b. Virological characteristics were similar in patients with normal or slightly elevated enzyme levels and in patients with elevated enzyme values. Neither method showed a relationship between viral load and age, sex, duration of the infection, mode of transmission, or histological activity index. CONCLUSION: viral load was not dependent on genotype. Measurement of viral load in a single serum sample adequately reflected the viral load measured in several serum samples from patients with chronic HCV infection. Patients with normal liver enzyme levels are not good candidates, in virological terms, for treatment with interferon.

Adolescent↗

PubMed1999

Childhood-onset systemic lupus erythematosus: a comparative study of African Americans and Latin Americans.

This study compared the clinical and serologic features in two different ethnic groups of patients with childhood-onset systemic lupus erythematosus (SLE). One hundred seventy-one SLE patients comprised the study population; 61 (55 girls and 6 boys) were African American with age at onset of 13 +/- 2.9 years, and 110 (97 girls and 13 boys) were Latin American (Colombian) with age at onset of 13 +/- 3.2 years. Clinical, demographic, and laboratory data were obtained by chart review using a standard data collection form. African-American patients more commonly manifested discoid skin lesions, malar rash, pulmonary fibrosis, and pleuritis, and less commonly manifested photosensitivity, livedo reticularis, and vascular thrombosis than did Latin Americans. In addition, there was a higher frequency of anti-dsDNA, anti-Sm, anti-RNP, and anti-Ro positivity among African-Americans compared with Latin-American patients. These results suggest the presence of ethnic differences in the clinical expression of SLE.

Adenosine Triphosphatases↗

PubMed1998

Flow cytometric DNA analysis and p53 protein expression show a good correlation with histologic findings in patients with Barrett's esophagus.

BACKGROUND: There is a considerable degree of subjectivity and, therefore, substantial interobserver and intraobserver disagreement in the diagnosis and grading of dysplastic lesions in Barrett's esophagus (BE). The aim of this study was to evaluate the usefulness of DNA flow cytometry and immunohistochemical staining for p53 protein as objective methods to complement the conventional histologic diagnosis of dysplasia in patients with this disease. The most common problems and the possible advantages of using these procedures are analyzed briefly in this article. METHODS: Formalin fixed, paraffin embedded tissue from 55 patients diagnosed with BE were processed for flow cytometric measurements (ploidy and proliferation index) and p53 immunostaining. RESULTS: Both the cytometric data and the positivity of staining for p53 revealed a statistically significant increase throughout the following sequence: no dysplasia --> indefinite for dysplasia --> low grade dysplasia --> high grade dysplasia --> adenocarcinoma. There was also a highly significant correlation between the results of the cytometric study and the positivity of staining for p53. CONCLUSIONS: In the future, the use of this procedure could play an important role in the evaluation of patients with BE. Considering that staining for p53 is technically simple, economical, and quick, and the materials required are available to most pathology laboratories, this method appears to be a firm candidate for application as a biomarker in BE. The authors have shown that it is possible to obtain adequate results for cytometric analysis with small formalin fixed, paraffin embedded biopsies if a strict protocol for the acceptance of tissue samples and/or histograms is observed.

Adenocarcinoma↗

PubMed1998

Flow-injection spectrophotometric determination of diclofenac sodium in pharmaceuticals and urine samples.

A sensitive and fast flow-injection spectrophotometric method for the determination of diclofenac sodium based on the formation of coloured compound with Ce(IV)-3-methyl-2-benzothiazolinone hydrazone hydrochloride (MBTH) in H2SO4 3 x 10(-2) M medium is proposed. Using the peak height as a quantitative parameter diclofenac was determined at 580 nm over the range 0.20-8.0 micrograms ml-1. The proposed method was successfully applied to the determination of diclofenac in pharmaceuticals and urine samples.

Anti-Inflammatory Agents, Non-Steroidal↗

PubMed1998

Inhibition of phagocytic activity by the N-acetyl-D-galactosamine-specific lectin from Amaranthus leucocarpus.

Amaranthus leucocarpus lectin (ALL), specific for N-acetyl-D-galactosamine, induces inhibition of the erythrophagocytic activity of resident murine peritoneal macrophages and of the macrophage-like cell line J-774. This effect was observed only in macrophages that were Mac-2 (CD11c/CD18 or CR4) negative, indicating that macrophage activation induces important modification to the glycosylation (mainly O-glycosylation) of the membrane. Receptors for IgM and C3b remain unaltered after lectin treatment. Ultrastructural analysis revealed (a) that ALL induced the formation of pinocytic vacuoles, and (b) a regular distribution over the macrophage membrane as well as endosomal vesicles of the gold labeled ALL. Our results suggest that macrophage membrane glycoproteins with constitutive N-acetyl-D-galactosamine residues participate in the regulation of pinocytic-phagocytic vacuole formation.

Acetylgalactosamine↗

PubMed1998

Clinical features and investigations in patients with columnar-lined oesophagus.

BACKGROUND: It is unclear why some patients with a columnar-lined oesophagus present with intestinal metaplasia and others do not. The physiopathological and clinical implications of the length of the metaplastic segment are also controversial. The aim of the study was to determine whether the length of the metaplasia and the presence of intestinal epithelium are related to the clinical, manometric and pHmetric data in patients with columnar-lined oesophagus. METHODS: A comparison of clinical, endoscopic, pathological, manometric and pHmetric data was made between patients with columnar-lined oesophagus of 3-5 cm (n=31) and those with a metaplastic segment of 5 cm or more (n=28); the same comparison was made between patients who had specialized intestinal metaplasia (n=37) and those who did not (n=22). RESULTS: No significant difference was found in any of the variables studied except for associated inflammatory lesions above the columnar epithelium which were more frequent in patients with a shorter metaplastic segment (P < 0.05). CONCLUSION: Neither the length of the metaplastic segment nor the presence of intestinal metaplasia was related to a more evolved gastro-oesophageal reflux disease, a poorer oesophageal clearing function or higher acid reflux rates.

Adult↗

PubMed1998

Antiproliferative effects and mechanism of action of SCH 56592 against Trypanosoma (Schizotrypanum) cruzi: in vitro and in vivo studies.

We have investigated the antiproliferative effects of SCH 56592, a new experimental triazole, against Trypanosoma (Schizotrypanum) cruzi, the etiological agent of Chagas' disease in Latin America. SCH 56592 blocked the proliferation of the epimastigote form of the parasite in vitro at 30 nM, a concentration 30- to 100-fold lower than that required with the reference compounds ketoconazole and itraconazole. At that concentration all the parasite's endogenous sterols (ergosterol, 24-ethyl-cholesta-5,7,22-trien-3 beta-ol, and its 22-dihydro analogs), were replaced by methylated sterols (lanosterol and 24-methylene-dihydrolanosterol), as revealed by high-resolution gas chromatography coupled with mass spectrometry. This indicated that the primary mechanism of action of the drug was inhibition of the parasite's sterol C-14 alpha demethylase. Against the clinically relevant intracellular amastigote form, grown in cultured Vero cells at 37 degrees C, the MIC of SCH 56592 was 0.3 nM, again 33- to 100-fold lower than that of ketoconazole or itraconazole. In a murine model of acute Chagas' disease, SCH 56592 given at > or = 10 mg/kg of body weight/day for a total of 43 doses allowed 85 to 100% survival and 90 to 100% cure of the surviving animals, as verified by parasitological, serological, and PCR-based tests, while ketoconazole given at 30 mg/kg day allowed 60% survival but only 20% cure. In a murine model of chronic Chagas' disease, SCH 56592 was again more effective than ketoconazole, providing 75 to 85% protection from death, with 60 to 75% parasitological cures of the surviving animals, while no parasitological cures were observed with ketoconazole. The results indicate that SCH 56592 is the most powerful sterol biosynthesis inhibitor ever tested against T. cruzi and may be useful in the treatment of human Chagas' disease.

Animals↗

PubMed1998

The synaptic process in Locusta migratoria spermatocytes by synaptonemal complex analysis.

We describe the synaptic process during meiotic prophase in spermatocytes from Locusta migratoria, using synaptonemal complex (SC) spreads analyzed by light (LM) and electron (EM) microscopy. At leptotene, a stage of short duration, unpaired axial elements begin to be assembled. Synapsis starts at zygotene, beginning usually at the terminal regions of the bivalents, either at the proximal, centromeric end or at the distal, non-centromeric end; interstitial initiation of synapsis was only occasionally observed in the longer chromosomes. Pairing is asynchronous, and shorter chromosomes are the first to complete synapsis. At pachytene all bivalents are fully synapsed. Diplotene is characterized by the progressive fragmentation of SCs; fragmentation is asynchronous, and affects mainly the longer chromosomes, while the shorter ones maintain their morphology up to late diplotene.

Animals↗

PubMed1998

Pancreaticoduodenectomy due to cancer in the elderly.

The elderly have traditionally been excluded from pancreaticoduodenectomy due to the high morbimortality of this procedure. Six cases of pancreaticoduodenectomy) 5 cephalic and 1 total) for periampullary tumors in patients over 70 are reported. There was no mortality. We conclude that, in selected cases, pancreaticoduodenectomy can be performed safely in the elderly.

Age Factors↗

PubMed1998

Acute ulnar collateral ligament injuries of the thumb metacarpophalangeal joint: an anatomical and clinical study.

Treatment of acute injuries of the ulnar collateral ligament of the metacarpophalangeal joint of the thumb remains controversial owing to the difficulty involved in establishing an accurate diagnosis. Conservative treatment may be successful in sprains, but surgical repair has been advocated when the ligament is completely torn. The authors performed a comparative study of the anatomical lesions of the metacarpophalangeal joint of the thumb with respect to degrees of instability. The study was conducted on fresh specimens and retrospectively in surgically treated patients. Instabilities greater than 30 degrees were found to correspond to complete rupture of the ulnar collateral ligament of the metacarpophalangeal joint of the thumb, and the stump of the ligament was found on the adductor aponeurosis in 5 out of 20 cases. In 2 out of 9 cases of avulsion-fractures, the fragments were rotated 90 degrees although on x-rays they appeared slightly displaced. It is concluded that surgical repair is the treatment of choice for instabilities greater than 30 degrees and for avulsion-fractures.

Acute Disease↗

PubMed1997

Urinary albumin excretion rate and cardiovascular disease in Spaniard type 2 diabetic patients.

To assess the prevalence of urinary albumin excretion abnormalities and their associations with cardiovascular disease or its classical risk factors in type 2 diabetes mellitus, 1348 clinic-proceeding patients have been studied retrospectively. The overnight urinary albumin excretion rate, blood pressure, smoking, ophthalmic and cardiovascular status, current therapies, estimates of glycemic control, plasma lipids, serum creatinine and uric acid have been ascertained. 767 (56.8%) patients were found normoalbuminuric, 461 (34.1%) microalbuminuric and 120 (8.9%) macroalbuminuric. In bivariate analyses, the urinary albumin excretion rate had statistically significant (P < 0.05) relationships with age, duration of diabetes, male sex, waist-to-hip ratio, systolic and diastolic pressure, coronary heart disease, cerebrovascular disease, peripheral vascular disease, hypertension, antihypertensive therapy, laser-treated retinopathy, kind of treatment, smoking habit, fasting glycaemia, HbA1c, creatinine, uric acid, triglycerides, high density lipoprotein (HDL)-cholesterol and apolipoprotein B. Borderline statistically significant (P < 0.1) relationships were found with hypolipidaemic therapy, insulin dose, non-HDL-cholesterol, apolipoprotein A1 and lipoprotein (a). In a multivariate stepwise logistic regression model, HbA1c, hypertension, male sex, age, diastolic blood pressure, coronary heart disease and body-mass index were sequentially selected as variables independently associated with microalbuminuria. Serum creatinine, HbA1c, male sex and hypertension were sequentially selected as independently associated with macroalbuminuria. Micro and macroalbuminuria are frequent abnormalities associated with poorly controlled and complicated disease, with overt cardiovascular disease and its classical risk factors as well as with the male sex.

Aged↗

PubMed1997

Plasmid Transfer between Spatially Separated Donor and Recipient Bacteria in Earthworm-Containing Soil Microcosms.

Most gene transfer studies have been performed with relatively homogeneous soil systems in the absence of soil macrobiota, including invertebrates. In this study we examined the influence of earthworm activity (burrowing, casting, and feeding) on transfer of plasmid pJP4 between spatially separated donor (Alcaligenes eutrophus) and recipient (Pseudomonas fluorescens) bacteria in nonsterile soil columns. A model system was designed such that the activity of earthworms would act to mediate cell contact and gene transfer. Three different earthworm species (Aporrectodea trapezoides, Lumbricus rubellus, and Lumbricus terrestris), representing each of the major ecological categories (endogeic, epigeic, and anecic), were evaluated. Inoculated soil microcosms, with and without added earthworms, were analyzed for donor, recipient, and transconjugant bacteria at 5-cm-depth intervals by using selective plating techniques. Transconjugants were confirmed by colony hybridization with a mer gene probe. The presence of earthworms significantly increased dispersal of the donor and recipient strains. In situ gene transfer of plasmid pJP4 from A. eutrophus to P. fluorescens was detected only in earthworm-containing microcosms, at a frequency of (symbl)10(sup2) transconjugants per g of soil. The depth of recovery was dependent on the burrowing behavior of each earthworm species; however, there was no significant difference in the total number of transconjugants among the earthworm species. Donor and recipient bacteria were recovered from earthworm feces (casts) of all three earthworm species, with numbers up to 10(sup6) and 10(sup4) bacteria per g of cast, respectively. A. trapezoides egg capsules (cocoons) formed in the inoculated soil microcosms contained up to 10(sup7) donor and 10(sup6) recipient bacteria per g of cocoon. No transconjugant bacteria, however, were recovered from these microhabitats. To our knowledge, this is the first report of gene transfer between physically isolated bacteria in nonsterile soil, using burrowing earthworms as a biological factor to facilitate cell-to-cell contact.

Journal Article↗

PubMed1997

Ethnic differences in the clinical expression of systemic lupus erythematosus: a comparative study between African-Americans and Latin Americans.

Since ethnic differences in the disease expression of systemic lupus erythematosus (SLE) have been recognized, we compared the clinical and serological features in two different ethnic groups of patients with SLE. The study population consisted of 222 African-American and 300 Latin American (Colombian) SLE patients. Clinical, demographic, and laboratory data were obtained by chart review using a standard data collection form. African-American patients more commonly manifested discoid skin lesions, pulmonary fibrosis, and pleuritis, and less commonly manifested photosensitivity, livedo reticularis, and vascular thrombosis than did Latin Americans. In addition, there was a higher frequency of anti-Sm, anti-RNP, and anti-Ro positivity among African-American patients compared with Latin Americans. These results are additional evidence for the presence of ethnic differences in the clinical expression of SLE.

Adolescent↗

PubMed1997

Variability of anticardiolipin antibody isotype distribution in 3 geographic populations of patients with systemic lupus erythematosus.

OBJECTIVE: To investigate the prevalence of anticardiolipin antibodies (aCL) and isotype distribution and their clinical associations with the features of the antiphospholipid syndrome (APS) in 3 different ethnic groups of patients with systemic lupus erythematosus (SLE). METHODS: The study population consisted of 152 African-American, 136 Afro-Caribbean (Jamaican), and 163 Hispanic (Colombian) unselected patients with SLE. Serum samples were studied for the prevalence of aCL and isotype distribution. All aCL measurements were performed in the same laboratory by ELISA. RESULTS: Positive results for 1 of the 3 aCL isotypes were found in 42 African-Americans (28%), 28 Afro-Caribbeans (21%), and 43 Hispanics (26%). IgG aCL was the dominant isotype in Hispanic and African-American patients, while IgA was the dominant isotype in Afro-Caribbeans. Of note, IgA aCL was found in all Afro-Caribbean patients who were aCL positive, while only 3 patients in this group had IgG aCL and 2 had IgM aCL. Clinical features of the APS were found to correlate better in Hispanics than in African-Americans and Afro-Caribbean patients with aCL isotypes. CONCLUSION: Our data suggest the existence of ethnic differences in the prevalence and isotype distribution of aCL as well as in their clinical relevance in patients with SLE. Further studies of the role of genetic and/or environmental factors in the observed differences are required.

Adolescent↗

PubMed1997

Gastric surgery does not increase the risk of developing Barrett's esophagus.

OBJECTIVE: Barrett's esophagus is currently believed to be related to severe and prolonged pathological acid gastroesophageal reflux. However, other factors have been discussed, especially pancreatic biliary reflux. To determine the importance of pancreatic-biliary reflux in the genesis of Barrett's esophagus, we assessed the prevalence of Barrett's esophagus in patients with an intact stomach and in those with previous gastric surgery. METHODS: This is a retrospective study in which 22,236 upper digestive endoscopy reports were reviewed and classified into two groups: intact stomach (n = 21,023) and operated stomach (n = 1,213). In turn, these two groups were divided into five subgroups according to surgical techniques. In each of the groups and subgroups, we calculated the percentage of patients with esophagitis, the percentage of esophagitis patients with Barrett's esophagus, and the percentage of Barrett's esophagus patients with complications. Results were compared by chi2 test. RESULTS: With regard to the prevalence of Barrett's esophagus, we found no significant differences between the study groups. CONCLUSIONS: We conclude that previous gastric surgery does not increase the risk that esophagitis patients will develop Barrett's esophagus.

Adolescent↗

PubMed1996

Cure of short- and long-term experimental Chagas' disease using D0870.

Chagas' disease, a protozoan infection by the kinetoplastid Trypanosoma cruzi, constitutes a major public health problem in Latin America. With the use of mouse models of both short- and long-term forms of the disease, the efficacy of D0870, a bis-triazole derivative, was tested. D0870 was able to prevent death and induced parasitological cure in 70 to 90 percent of animals, in both the short- and long-term disease. In contrast, currently used drugs such as nifurtimox or ketoconazole prolonged survival but did not induce significant curing effects. D0870 may be useful in the treatment of human long-term Chagas' disease, a condition that is currently incurable.

Animals↗

PubMed1996

Use of linkage disequilibrium approaches to map genes for bipolar disorder in the Costa Rican population.

Linkage disequilibrium (LD) analysis provides a powerful means for screening the genome to map the location of disease genes, such as those for bipolar disorder (BP). As described in this paper, the population of the Central Valley of Costa Rica, which is descended from a small number of founders, should be suitable for LD mapping; this assertion is supported by reconstruction of extended haplotypes shared by distantly related individuals in this population suffering low-frequency hearing loss (LFHL1), which has previously been mapped by linkage analysis. A sampling strategy is described for applying LD methods to map genes for BP, and clinical and demographic characteristics of an initially collected sample are discussed. This sample will provide a complement to a previously collected set of Costa Rican BP families which is under investigation using standard linkage analysis.

Adult↗

PubMed1996

Enteroaggregative Escherichia coli heat-stable enterotoxin is not restricted to enteroaggregative E. coli.

Enteroaggregative Escherichia coli (EAggEC) have been implicated as diarrheal pathogens in several settings. Some EAggEC produce a distinct heat-stable enterotoxin named EAST1. The distribution and prevalence of the EAST1 gene in selected groups of bacterial enteropathogens were determined by colony hybridization. One hundred percent of 75 O157:H7 enterohemorrhagic E. coli (EHEC), 41% of 227 EAggEC, 41% of 149 enterotoxigenic E. coli, 22% of 65 enteropathogenic E. coli (EPEC), and 38% of 47 E. coli stool isolates from asymptomatic children hybridized with an EAST1 DNA probe. None of 55 enteroinvasive E. coli, 12 Yersinia enterocolitica, or 20 Vibrio cholerae non-O1 strains were EAST1 probe-positive. Concordance between EAST1 genotype and enterotoxicity was shown in examined strains of EAggEC, EHEC, and EPEC. The gene encoding EAST1 is more broadly distributed among diarrheogenic E. coli than previously known and may represent an additional determinant in the pathogenesis of E. coli diarrhea.

Bacterial Adhesion↗