PubMed Health⌕ Search

Biomedical subjects

O Gomez

Publications and source records attributed to O Gomez.

15 recordsLinked to original sources
PubMed2006

Middle cerebral artery pulsatility index: reliability at different sampling sites.

OBJECTIVES: To analyze the interobserver reliability of measurement of the middle cerebral artery (MCA) pulsatility index (PI) at two different sampling sites. METHODS: This study included 100 consecutive singleton pregnancies between 24 and 40 weeks with normal fetal growth. The PI was calculated by two independent operators at proximal and distal sampling sites of the near-field MCA. Reliability analyses were performed between observers at each sampling site by means of the intraclass correlation coefficient (ICC) for agreement. Differences between observers were explored and agreement limits calculated by means of the Bland-Altman test. RESULTS: Satisfactory flow velocity waveforms were obtained successfully in each fetus at both sampling sites. Peak systolic, end-diastolic and time-averaged maximum velocities were significantly higher at the proximal compared with the distal sampling site. Conversely, PI was significantly higher at the distal compared with the proximal site. ICCs for PI were 0.3 and 0.33 at the proximal and the distal sampling sites, respectively. The 95% interval of the PI differences between observers were +0.91 and -1.14 at the proximal and +1.03 and -1.08 at the distal sampling sites. In about 30% of the cases the PI difference between observers was greater than 0.5 at both sampling sites. CONCLUSIONS: Moderate interobserver reliability in the measurement of end-diastolic and time-averaged maximum MCA flow velocities results in limited agreement of the PI calculation at both proximal and distal sampling sites. These results may preclude its clinical applicability.

Adolescent↗
PubMed1999

Using the CLARION cochlear implant in cochlear ossification.

This paper is a retrospective review of 5 patients with various degrees of cochlear ossification who were implanted with the CLARION Multi-Strategy Cochlear Implant. Preoperative computed tomography scans, intraoperative findings, surgical technique, and hearing outcomes are discussed in a case report format. Full implantation was achieved in all cases by a systematic approach that included drill-through of proximal obstruction (2 cases), scala vestibuli insertion (2 cases), and complete drill-out (1 case). The only complication was delayed wound healing in a patient with sickle cell disease, chronic active hepatitis, and steroid dependency on antimetabolite therapy. Early results show that the 4 patients with at least 3 months of experience have a mean open-set sentence recognition score of 55% and a mean open-set word recognition score of 24%. The conclusion is that implantation of the Clarion device in ossified cochleas can be successful in all degrees of ossification and can provide significant hearing benefit.

Adolescent↗
PubMed1999

Hearing results with deep insertion of cochlear implant electrodes.

OBJECTIVE: This study aimed to investigate the relationship of electrode insertion length and speech recognition in patients using Nucleus-22 cochlear implants. STUDY DESIGN: The study design was a retrospective review of a consecutive clinical series. SETTING: The study was conducted at an academic medical center. PATIENTS: Thirty-one postlingually deafened adults with at least 6 months' experience with a Nucleus-22 cochlear implant using Spectra-22 processor and SPEAK strategy participated. MAIN OUTCOME MEASURES: Open-set speech recognition scores for words and sentences were measured. RESULTS: Insertion length ranged from 22 rings (estimated 17 mm) to 32 rings (estimated 25 mm). Mean word recognition score was 35%. Mean sentence score was 69.6%. Statistical analysis showed no correlation between insertion depth and word or sentence scores. CONCLUSION: Insertion of the Nucleus-22 array beyond 22 rings does not improve performance in speech recognition. This finding cannot be generalized to other electrodes or processing strategies.

Adult↗
PubMed1997

Epidemiological study of Taenia solium infections in a rural village in Honduras.

An epidemiological study was conducted in a Honduran rural community in 1991, to determine the local prevalence and associated risk factors of Taenia infection. The seroprevalence of anti-cysticercus antibodies, investigated by ELISA (N = 526), was found to be 30%. The prevalence of intestinal infections with Taenia and other parasites was investigated, by formol-ether concentration of three stool samples from each subject (N = 536). Almost all (96%) of the subjects carried at least one of the 17 species of intestinal parasite identified, 11 (2%) of them (nine of them female) being found to be infected with Taenia spp. When nine of these 11 were given niclosamide, four expelled Taenia segments, all of which were identified as T. solium after carmine staining. Risk factors associated with seropositivity were earthen floor, overcrowding, previous taeniasis and living in the same household as a person reporting previous taeniasis. Four years later (1995), a follow-up study in a sub-sample of the previously studied population revealed that 34% of the subjects were seropositive for anti-Taenia solium antibodies (as determined by a cysticercosis-specific, enzyme-linked, immunoelectrotransfer, blot assay) and that 1.5% had taeniasis. Taeniasis and cysticercosis therefore appear to be important public-health problems in rural areas of Honduras, as they are in other countries of Latin America. Large-scale studies need to be conducted to facilitate the design of programmes to control these diseases.

Adolescent↗
PubMed1994

Tracking of elevated systolic blood pressure among lean and overweight adolescents: the Minneapolis Children's Blood Pressure Study.

OBJECTIVE: To determine whether elevated blood pressure tracks to a greater degree in overweight than in lean children. DESIGN: Prospective cohort study. METHODS: We examined 758 adolescents (mean age 13.4 years) who participated in a longitudinal study of blood pressure. The degree of tracking was examined by cross-classification of sex-specific tertiles of systolic blood pressure (SBP) and body mass index determined at baseline and 5 years later. Those children that were in the highest tertile of SBP and body mass index were considered to be 'overweight with elevated blood pressure'. Those that were in the highest tertile of SBP but lowest tertile of body mean index were considered to be 'lean with elevated blood pressure'. RESULTS: Of those boys that were initially classified as lean with elevated blood pressure, 38% remained so classified compared with 54.6% of those that were initially classified as overweight with elevated blood pressure. Among the girls the respective proportions were 48 and 44.2%. The subjects of each sex who were lean with elevated blood pressure were significantly shorter at baseline than their overweight counterparts, and over the follow-up period experienced a greater mean increase in SBP than their overweight peers. This difference was almost totally explained for the boys once the difference in height change was taken into account. For the girls a difference of 5.9 mmHg remained after covariate adjustment for the change in height. CONCLUSION: These results fail to support the hypothesis that blood pressure tracks differently in obese and in lean adolescents, particularly once differences in sexual maturation are considered.

Adolescent↗
PubMed1992

Familial resemblance of body fat distribution: the Minneapolis Children's Blood Pressure Study.

Although many reports have shown that obesity (as defined by weight for height indices) tends to run in families, considerably fewer data are available concerning the familial resemblance of body fat distribution as defined by the waist to hip ratio (WHR), which is a risk factor for coronary heart disease. This question was examined among 712 participants of the Minneapolis Children's Blood Pressure Study. For each family member separately (son, daughter, father and mother) the distribution of the WHR was divided into quintiles. Quintiles of WHR were cross-classified between child and parent to examine the proportion of subjects clustering in each quintile. A significantly higher than expected proportion of parent-child WHRs clustered in the top quintile. For example, 42.5% of sones were placed in the top quintile of their father's WHR (P less than 0.001) and 36.7% of daughters were placed in the top quintile of their mother's WHR (P less than 0.001). Multiple linear regression analyses revealed that these findings were independent of parent and child body mass indices and other covariates. These results indicate significant familial aggregation of body fat distribution and may aid in suggesting specific primary preventive strategies targetted at appropriate families to reduce the risk of cardiovascular disease.

Adipose Tissue↗
PubMed1991

Molecular analysis of MHC-class-I alterations in human tumor cell lines.

Molecular characterization of HLA-class-I expression was investigated in human tumor cell lines at the protein and mRNA levels using locus-specific monoclonal antibodies (MAbs) and probes. Some cell lines exhibited a differential expression of HLA-A and HLA-B products and also showed differences in the inducibility of HLA-class-I genes by gamma-IFN. Thus, gamma-IFN stimulation induced predominantly HLA-B mRNA in the HeP-2 cell line, which showed imbalances in basal levels of HLA-A and HLA-B expression. This unequal inducibility of HLA genes may imply that locus-specific regulatory mechanisms are involved in the expression of individual HLA products. The specific mechanism controlling the differential expression of HLA subsets appears to be independent of c-myc activity. Northern blot analysis found no relationship between c-myc mRNA levels and specific mRNA for HLA-A and HLA-B antigens.

Antibodies, Monoclonal↗
PubMed1991

Characterization of CD44 antigen during lymphoid ontogeny.

We studied immunohistological and biochemical aspects of the CD44 molecule with a mAb produced in our lab: GRHL-1. The characteristic expression of this antigen in cells of B lineage was analyzed. This mAb showed identical immunohistological patterns of reactivity to other mAbs included in CD44 cluster, on a variety lymphoid and nonlymphoid human tissues, and demonstrated similar bands on SDS-PAGE of 125I labeled lymphocyte lysates. This antigen is limited to cells of mature phenotype, and disappears in proliferating B cells in the germinal centers of the lymphoid follicles. CD44 is absent in pre-B and Burkitt cell lines. PKC activation mediate in vitro differentiation of pre-B cell lines. However, it is not involved in up-regulation of CD44 antigen expression.

Antibodies, Monoclonal↗
PubMed1990

Protein kinase C-mediated regulation of the expression of CD14 and CD11/CD18 in U937 cells.

We used the U937 cell line to analyze CD14, CD11/CD18, HLA class-I and DR antigen expression during PMA-induced differentiation. Treatment of U937 cells with PMA markedly increased CD14, CD11a, CD11b and CD18 antigen expression, and slightly increased CD11c expression. Protein kinase C may play a major role in regulating the expression of these antigens. The protein kinase inhibitor H7 abrogated the inductive effect of PMA. Calcium ionophore, when added alone or in the presence of PMA, had no effect. The inhibitory effect of the calcium antagonist verapamil, EGTA, and of chlorpromazine, an antagonist of calcium-binding proteins, supports a role for calcium-dependent protein kinase C in the up-regulation of CD14 and CD11/CD18 surface expression. The specific calmodulin inhibitors R24571 and W7 had no effect on antigen expression. Our findings suggest that protein kinase C activation is an important step in the PMA-induced differentiation of U937 cells.

Antigens, CD↗
PubMed1988

Cardiovascular risk factor change--1973-74 to 1980-82: the Minnesota Heart Survey.

Reductions in population risk factor levels, including blood pressure, blood cholesterol, and cigarette smoking may be associated with the observed decline in cardiovascular disease (CVD) mortality rates. However, few recent population-based comparisons of risk trends are available. To evaluate changes in these risk characteristics in the recent period, data were compared from two surveys performed in the same metropolitan area using similar methods. The Lipid Research Clinic (LRC) Prevalence Study surveyed a population sample of 4185 adults aged 25-59 in 1973-74. The Minnesota Heart Survey (MHS) surveyed a population sample of 2914 adults of the same age in the same metropolitan area in 1980-82. The average systolic and diastolic blood pressures were significantly lower in the 1980-82 survey averaging 1.5/3.8 mmHg for men and 1.6/2.8 mmHg for women. The use of anti-hypertensive medications increased significantly over the period while the prevalence of hypertension was similar. Significant declines in mean serum cholesterol were also observed in 1980-82, averaging 3.3 mg/dl for men and 5.5 mg/dl women. The prevalence of regular cigarette smoking in men was also lower in 1980-82, 36.3 vs 42.1% in 1973-74. Women had a lower prevalence of smoking (38.8-35.6%) but the average woman smoker increased consumption of cigarettes while the average man did not. These observations suggest that population risk defined by these characteristics is declining which may explain part of recent Minnesota trends in CVD mortality and could have a favorable effect on future disease patterns.

Adult↗
PubMed1977

Depressive subtypes, blood pressure changes and response to treatment.

Blood pressure changes during treatment with an intravenous tricyclic (chlorimipramine) were systematically assessed on twenty depressed patients diagnosed as primary or secondary affective disorders according to research diagnostic criteria. Patients with primary affective disorder showed a significantly greater decline in systolic blood pressure during this treatment than patients with secondary affective disorder. The decline in the blood pressure paralleled clinical improvement. Differential changes in blood pressure appear to be one more instance of constitutional differences for depressive subtypes, and may prove to be practical and reliable predictors of treatment response to tricyclic antidepressants.

Adult↗