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Biomedical subjects

J Miranda

Publications and source records attributed to J Miranda.

At least 19 recordsLinked to original sources
PubMed2000

Expression pattern of Rhizobium etli ccmIEFH genes involved in c-type cytochrome maturation.

In different bacterial species, ccmIEFH genes have been suggested to code for subunits of a bacterial haem-lyase catalyzing the covalent attachment of haem to c-type apoproteins. In Rhizobium etli CE3 there are two copies of ccmIEFH: one in the chromosome and the other located in plasmid pf. However, the null phenotype of chromosomal ccmF mutant indicates that the gene locus of plasmid pf is not functional. Two ccmI chromosomal mutants, previously isolated, produced detectable levels of c-type cytochromes under certain culture conditions in contrast with the ccmF mutant, suggesting that ccmF could be transcribed independently. The transcriptional organization of ccmIEFH operon was established. Two promoters from the chromosomal locus were mapped by primer extension, one located upstream of ccmI and the second located upstream of ccmF. The regulation of the expression of both promoters was studied using appropriate lacZ gene fusions (ccmI-lacZ and ccmEF-lacZ). The ccmI-lacZ gene fusion was expressed in complex medium, during exponential growth, under microaerobic conditions and in a R. etli mutant that accumulates reducing power, conditions where a higher respiration rate could be limited by c-type cytochrome content. The ccmEF-lacZ fusion was also primarily expressed in complex medium and under microaerophilic conditions. The finding of two independent promoters in this gene locus could suggest that the step catalyzed by CcmFH could be a rate-limiting step for c-type cytochrome assembly under certain culture conditions.

Amino Acid Sequence↗
PubMed2000

Impact of disseminating quality improvement programs for depression in managed primary care: a randomized controlled trial.

CONTEXT: Care of patients with depression in managed primary care settings often fails to meet guideline standards, but the long-term impact of quality improvement (QI) programs for depression care in such settings is unknown. OBJECTIVE: To determine if QI programs in managed care practices for depressed primary care patients improve quality of care, health outcomes, and employment. DESIGN: Randomized controlled trial initiated from June 1996 to March 1997. SETTING: Forty-six primary care clinics in 6 US managed care organizations. PARTICIPANTS: Of 27332 consecutively screened patients, 1356 with current depressive symptoms and either 12-month, lifetime, or no depressive disorder were enrolled. INTERVENTIONS: Matched clinics were randomized to usual care (mailing of practice guidelines) or to 1 of 2 QI programs that involved institutional commitment to QI, training local experts and nurse specialists to provide clinician and patient education, identification of a pool of potentially depressed patients, and either nurses for medication follow-up or access to trained psychotherapists. MAIN OUTCOME MEASURES: Process of care (use of antidepressant medication, mental health specialty counseling visits, medical visits for mental health problems, any medical visits), health outcomes (probable depression and health-related quality of life [HRQOL]), and employment at baseline and at 6- and 12-month follow-up. RESULTS: Patients in QI (n = 913) and control (n = 443) clinics did not differ significantly at baseline in service use, HRQOL, or employment after nonresponse weighting. At 6 months, 50.9% of QI patients and 39.7% of controls had counseling or used antidepressant medication at an appropriate dosage (P<.001), with a similar pattern at 12 months (59.2% vs 50.1%; P = .006). There were no differences in probability of having any medical visit at any point (each P > or = .21). At 6 months, 47.5% of QI patients and 36.6% of controls had a medical visit for mental health problems (P = .001), and QI patients were more likely to see a mental health specialist at 6 months (39.8% vs 27.2%; P<.001) and at 12 months (29.1% vs 22.7%; P = .03). At 6 months, 39.9% of QI patients and 49.9% of controls still met criteria for probable depressive disorder (P = .001), with a similar pattern at 12 months (41.6% vs 51.2%; P = .005). Initially employed QI patients were more likely to be working at 12 months relative to controls (P = .05). CONCLUSIONS: When these managed primary care practices implemented QI programs that improve opportunities for depression treatment without mandating it, quality of care, mental health outcomes, and retention of employment of depressed patients improved over a year, while medical visits did not increase overall.

Adult↗
PubMed1999

Biased TCR repertoire in infiltrating lesional T cells in human Bancroftian filariasis.

To investigate the hypothesis that T cells recognizing specific Ags localize to the site of disease activity in human bancroftian filariasis, we have compared the repertoire of TCR Vbeta gene segments in lesions vs blood in individual patients by RT-PCR ELISA. Vbeta14 and Vbeta24 were overrepresented (5% greater in tissue compared with PBMCs and/or tissue/PBMC ratios in the highest 5% of all tissue/PBMC ratios for all Vbetas for all subjects) in 50% and 40% of study subjects, respectively. Overrepresentation of these two Vbetas did not occur in any control subject. In comparing three patient groups, the proportion of individuals meeting at least one criterion for Vbeta14 overrepresentation was shown to increase in tandem with our current concepts of disease progression (asymptomatic filariasis = 25%; clinical filariasis with active infection = 60%; clinical filariasis without active infection = 71%). In 6 of the 10 individuals with Vbeta14 overrepresentation, Vbeta14 represented >20% of the entire lesional Vbeta repertoire. All but one of the 20 study subjects had at least one Vbeta gene segment that was overrepresented in tissue compared with PBMCs. Only a small number of Vbetas, usually three or less, were overrepresented in any single filariasis patient. However, in the same tissue, no differences between patient groups were found when IFN-gamma, TNF-alpha, IL-4, IL-5, and IL-12 mRNA expression were examined. Taken together, these findings suggest that, in principle, in essentially all patients, whether with subclinical or with clinical filariasis, distinct and limited T cell populations are concentrated in affected tissue.

Animals↗
PubMed1999

Organophosphate neuropathy due to methamidophos: biochemical and neurophysiological markers.

Neuropathy target esterase (NTE), the putative target enzyme for organophosphate induced delayed polyneuropathy (OPIDP), can be measured in lymphocytes but has rarely been assessed in acute human poisoning. Serum autoantibodies to nervous system proteins develop in hens poisoned with neuropathic insecticides and also have not been studied after human poisoning. Serial lymphocyte NTE (LNTE) was measured in a 16-year-old boy after acute poisoning with methamidophos for evaluation as a predictor of subsequent neuropathy. The profiles of serum autoantibodies to neurofilament triplet proteins, myelin basic protein, and glial fibrillary acidic protein were measured in order to characterize changes occurring as a result of OPIDP. Clinical neuropathy characterized by steppage gate and profound lower extremity weakness, decreased grip and pinch strength, and decreased ulnar and absent tibial compound muscle action potentials developed 2 weeks following poisoning. Sensory examination and nerve conduction studies were normal. On day 3 following poisoning LNTE was depressed (77% compared with subsequent baseline enzyme activity). Marked increases in serum immunoglobulin G (IgG) autoantibodies to glial fibrillary acidic protein and to neurofilament 200 were observed after the development of OPIDP. We conclude that inhibition of lymphocyte NTE is predictive of subsequent OPIDP. Serum autoantibody titers to nervous system proteins may be useful markers of neuropathy.

Adolescent↗
PubMed1999

Treating depressed older adults in primary care: narrowing the gap between efficacy and effectiveness.

There is a gap between the efficacy of treatments for late-life depression under research conditions and the effectiveness of treatments as they occur in the "real world" of primary care. Considerable evidence supports the efficacy of treatments for late-life depression, but many depressed older adults either are not recognized or do not receive effective treatment for depression in primary care. Older adults face a range of special treatment barriers: knowledge deficits; losses and social isolation; multiple medical problems; and lack of financial resources. More research is needed to understand these barriers and to study the effectiveness of multifaceted, population-based disease management interventions for late-life depression in primary care.

Aged↗
PubMed1999

Enhanced nitrogen fixation in a rhizobium etli ntrC mutant that overproduces the bradyrhizobium japonicum symbiotic terminal oxidase cbb3

The ntrC gene codes for a transcriptional activator protein that modulates gene expression in response to nitrogen. The cytochrome production pattern of a Rhizobium etli ntrC mutant (CFN2012) was studied. CO difference spectral analysis of membranes showed that CFN2012 produced a terminal oxidase similar to the symbiotic terminal oxidase of bacteroids in free-living cells under aerobic conditions, with a characteristic trough at 553 nm. CFN2012 produced two c-type cytochromes with molecular masses of 27 and 32 kDa, in contrast with the wild-type strain, which produced only a 32-kDa c-type cytochrome. The expression levels of the R. etli fixNOQP operon, which codes for terminal oxidase cbb3, were not affected by the ntrC mutation. However, the production levels of the two c-type cytochromes (27 and 32 kDa) were enhanced at least eightfold when the Bradyrhizobium japonicum fixNOQP operon was expressed in CFN2012 from the nptII promoter (pMSfixc), suggesting that these proteins are subunits FixO (27 kDa) and FixP (32 kDa) of cbb3 and that CFN2012/pMSfixc overproduced this terminal oxidase. CFN2012/pMSfixc showed a significant increase in its symbiotic performance as judged by the determination of nitrogenase activities of plants inoculated with this strain, suggesting that the overproduction of cbb3 terminal oxidase correlates with an enhancement in symbiotic nitrogen fixation.

Journal Article↗
PubMed1998

Isolation of Sinorhizobium meliloti Tn5 mutants with altered cytochrome terminal oxidase expression and improved symbiotic performance.

The relationship between whole-cell redox potential, cytochrome composition in free-living culture and symbiotic activity of Sinorhizobium meliloti was studied. Three Tn5-induced mutants with increased cellular redox potential were generated. Stationary cultures of mutants Tb9 and Tb16 in contrast to the parental strain produced the b-type terminal oxidase that may be similar to the symbiotically essential cytochrome oxidase cbb3 of Bradyrhizobium japonicum. Increase in the symbiotic effectiveness of all three mutants and in O2 consumption rate in free-living cultures was observed. Mutants Tb1 and TB16 were also characterized by an increase in fixNOQP gene expression. Consequently, the mutations probably affect at least two different steps of rhizobial respiratory metabolism operating both in free-living cells and endosymbiotic forms.

Bacterial Proteins↗
PubMed1998

Rhizobium etli cycHJKL gene locus involved in c-type cytochrome biogenesis: sequence analysis and characterization of two cycH mutants.

The cycHJKL gene locus was cloned from Rhizobium etli by the rescue of a Tn5mob insertion of a mutant (IFC01) which was affected in the production of c-type cytochromes. The cycH, cycJ, cycK and cycL genes are proposed to code for different subunits of a haem lyase complex involved in the attachment of haem to cytochrome c apoproteins. CycH of 365 aa shared 27, 36, 47 and 63% identity with CycH from Paracoccus denitrificans, Bradyrhizobium japonicum, R. meliloti, and R. leguminosarum, respectively. CycJ of 153 aa shared 52, 71, and 85% identity to the cycJ gene product of B. japonicum, R. meliloti, R. leguminosarum, respectively. CycK of 666 aa shared 62, 73, and 90% homology with CycK from B. japonicum, R. meliloti, and R. leguminosarum, respectively, while CycL of 151 aa shared 57, 67 and 86% hómology with CycL from the abovementioned species. The Tn5mob insertion present in the IFC01 strain was located in the cycH gene. This strain was able to infect bean plants, but unable to fix nitrogen during symbiosis. A previously described R. etli cytochrome c-deficient MuD1lac-induced mutant (CFN4202) that induced empty nodules on Phaseolus vulgaris, also have lesions in cycH. Complementation analysis suggested that the MuD1lac insertion of the CFN4202 strain was polar on expression of genes downstream of cycH in contrast with the Tn5mob insertion present in IFC01, which showed no polarity on cycJKL. Our data suggest that CycH may not be essential for the infection process, but is necessary for nitrogen fixation.

Bacterial Proteins↗
PubMed1998

Depression by miconazole of heat-induced respiratory-deficiency in Saccharomyces cerevisiae.

Miconazole, at 0.2 microM, decreased, by two orders of magnitude, the specific mutation rate of Saccharomyces cerevisiae to respiratory-deficient mutants (petites), which had been induced at either 37 degrees C or 39 degrees C. Identical concentrations of ketoconazole did not change the mutation rate. The results fit in the mechanisms of action which have been proposed for imidazole antimycotics, and constitute further support for the hypothesis that the targets of thermal death, in petite-positive associately-profiled yeasts, lie in the mitochondria.

Antifungal Agents↗
PubMed1998

Allele frequency distributions of the polymorphic STR loci HUMVWA, HUMFES, HUMF13A01 and the VNTR D1S80 in a Filipino population from Metro Manila.

Allele frequency distributions at the short tandem repeat (STR) loci HUMVWA, HUMFES, HUMF13A01 and of the variable number of tandem repeat (VNTR) locus D1S80 were determined in a Filipino population from Metro Manila (103 individuals) by use of the polymerase chain reaction (PCR) followed by polyacrylamide gel electrophoresis (PAGE). The exact test demonstrated that all four loci had no deviations from Hardy-Weinberg equilibrium (HWE) with the only reservation that the exact test p-value for F13A01 is weak. The discriminating power is 0.82 for D1S80, and the expected exclusion chance is 0.85 for F13A01, 0.83 for FES, and 0.93 for VWA. The observed heterozygosity rates are 0.63 for D1S80, 0.66 for F13A01, 0.67 for FES, and 0.80 for VWA. The exact test for independance between all loci gave a p-value of 0.0195. This is the first time that Filipino population data of DNA loci of forensic importance are reported.

Alleles↗
PubMed1998

Unmet mental health needs of women in public-sector gynecologic clinics.

OBJECTIVE: We examined the mental health needs of poor young women seen in public-sector gynecologic settings. STUDY DESIGN: Participants were 205 ethnically diverse women, mean age 29 years, seen by gynecologists at San Francisco General Hospital, all either uninsured or receiving public medical assistance. An interview with an instrument designed to diagnose mood, anxiety, alcohol, and eating disorders in medical patients, the Prime-MD, was used to assess current mental disorders. Any history of sexual or other physical assault was recorded. Receipt of primary care was scored for comprehensiveness. RESULTS: The rates of current psychiatric disorders were extremely high; 21.5% had current major depression. The prevalence of anxiety disorders was also elevated among these women. Many had a history of sexual trauma, and 28% had been the victims of unwanted intercourse. Finally, many reported behaviors that pose serious health risks. For example, 32% smoked and 2% used illicit drugs. Fewer than half had access to comprehensive primary medical care. CONCLUSIONS: Young, poor women who seek care in public-sector gynecologic clinics would benefit from comprehensive medical care addressing their psychosocial needs.

Adult↗
PubMed1998

[Acute abdomen: other initial symptom of abdominal lymphangioma].

Lymphangiomas are benign tumors, their growth are slow, customarily without symptoms, their location more frequent are in head or neck and they're diagnosed before the two first life years frequently. Their etiology continues uncertain, being accepted the congenital origin. We report on three cases of abdominal lymphangioma beginning as an acute abdomen. The importance of these cases is based mainly in the low frequency of presentation of these tumors in this location (2-5% of the lymphangiomas) and in their initial symptomatology.

Abdomen, Acute↗
PubMed1997

Cantrell's pentalogy. Report of four cases and their management.

Four neonates with the uncommon Cantrell's pentalogy seen in our hospital within a 6-month period without any apparent factor in common are described, with a review of the world literature. The first case was diagnosed prenatally at 15 weeks' gestation, the earliest intrauterine finding in the literature. The occurrence of imperforate anus with the syndrome, observed in one of the cases, has not been previously reported. Two were operated upon and only one of the four survived. This high mortality was confirmed by similar cases reported by other authors.

Abdominal Muscles↗
PubMed1997

Genetic evidence for 5-aminoimidazole-4-carboxamide ribonucleotide (AICAR) as a negative effector of cytochrome terminal oxidase cbb3 production in Rhizobium etli.

A Rhizobium etli Tn5mob-induced mutant (CFN035) exhibits an enhanced capacity to oxidize N,N,N',N', tetramethyl-p -phenylenediamine (TMPD), a presumptive indicator of elevated cytochrome c terminal oxidase activity. Sequencing of the mutated gene in CFN035 revealed that it codes for the amidophosphoribosyl transferase enzyme (PurF) that catalyzes the first step in the purine biosynthetic pathway. Two c-type cytochromes with molecular weights of 32 and 27 kDa were produced in strain CFN035, which also produced a novel CO-reactive cytochrome (absorbance trough at 553 nm), in contrast to strain CE3 which produced a single 32 kDa c-type protein and did not produce the 553 nm CO-reactive cytochrome. A wild-type R. etli strain that expresses the Bradyrhizobium japonicum fixNOQP genes, which code for the symbiotic cytochrome terminal oxidase cbb3, produced similar absorbance spectra (a trough at 553 nm in CO-difference spectra) and two c-type proteins similar in size to those of strain CFN035, suggesting that CFN035 also produces the cbb3 terminal oxidase. The expression of a R. etli fixN-lacZ gene fusion was measured in several R. etli mutants affected in different steps of the purine biosynthetic pathway. Our analysis showed that purF, purD, purQ, purL, purY, purK and purE mutants expressed three-fold higher levels of the fixNOQP operon than the wild-type strain. The derepressed expression of fixN was not observed in a purH mutant. The purH gene product catalyzes the conversion of 5-aminoimidazole-4-carboxamide ribonucleotide (AICAR) to 5-form-aminoimidazole-4-carboxamide ribonucleotide (FAICAR) and inosine. Supplementation with AICA riboside lowered the levels of fixN expression in the purF mutants. These data are consistent with the possibility that AICAR, or a closely related metabolite, is a negative effector of the production of the symbiotic terminal oxidase cbb3 in R. etli.

Amidophosphoribosyltransferase↗
PubMed1997

Oral Cancer Case Finding Program (OCCFP).

The aim of the Oral Cancer Case Finding Program (OCCFP) is to reduce the morbidity and mortality rates of oral cancer in Cuba. This program is based on health education of the whole population and a thorough examination of the oral complex, by specially trained stomatologists, of patients attending every stomatological care centre. Between 1983 and 1990, 10,167,999 such patients were examined country-wide and a total of 30,478 were referred as presenting some sort of alteration; 8259 complied with their referral. In this group, 2367 leucoplakias and 853 other precancerous lesions were diagnosed and treated. These 3220 premalignancies should have some influence on the cancer morbidity rates. Five hundred and eighty-one epidermoid carcinomas and 127 other malignant neoplasms were also detected for a total of 708 malignancies. The effectiveness of this program can be evaluated by the increments in diagnoses of Stage I oral cancer from 22.8% to 48.2% on account of the most advanced stages (II, III and IV) which decreased from 77.2% to 51.8%. The object of this paper is to present the results of OCCFP up to 1990.

Cuba↗
PubMed1997

Case-finding instruments for depression. Two questions are as good as many.

OBJECTIVE: To determine the validity of a two-question case-finding instrument for depression as compared with six previously validated instruments. DESIGN: The test characteristics of a two-question case-finding instrument that asks about depressed mood and anhedonia were compared with six common case-finding instruments, using the Quick Diagnostic Interview Schedule as a criterion standard for the diagnosis of major depression. SETTING: Urgent care clinic at the San Francisco Department of Veterans Affairs Medical Center. PARTICIPANTS: Five hundred thirty-six consecutive adult patients without mania or schizophrenia. MEASUREMENTS AND MAIN RESULTS: Measurements were two questions from the Primary Care Evaluation of Mental Disorders patient questionnaire, both the long and short forms of the Center for Epidemiologic Studies Depression Scale, both the long and short forms of the Book Depression Inventory, the Symptom-Driven Diagnostic System for Primary Care, the Medical Outcomes Study depression measure, and the Quick Diagnostic Interview Schedule. The prevalence of depression, as determined by the standardized interview, was 18% (97 of 536). Overall, the case-finding instruments had sensitivities of 89% to 96% and specificities of 51% to 72% for diagnosing major depression. A positive response to the two-item instrument had a sensitivity of 96% (95% confidence interval [CI], 90-99%) and a specificity of 57% (95% CI 53-62%). Areas under the receiver operating characteristic curves were similar for all of the instruments, with a range of 0.82 to 0.89. CONCLUSIONS: The two-question case-finding instrument is a useful measure for detecting depression in primary care. It has similar test characteristics to other case-finding instruments and is less time-consuming.

Adult↗