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Biomedical subjects

A Moore

Publications and source records attributed to A Moore.

At least 181 records · Page 10Linked to original sources
PubMed1998

The epidemiology of Haemophilus influenzae type b carriage among infants and young children in Santo Domingo, Dominican Republic.

BACKGROUND: Whether herd immunity will occur with widespread Haemophilus influenzae type b (Hib) vaccination in developing countries is dependent on whether the vaccines are capable of reducing carriage in these settings. However, few population-based studies of Hib carriage in developing countries exist. METHODS: To study Hib carriage in the Dominican Republic, we collected nasopharyngeal swab specimens from a population-based sample of 983 children 0 to 47 months old in a periurban area of Santo Domingo. RESULTS: Nasopharyngeal swabs of 76 (7.7%) children were positive for Hib. Hib carriage varied by age group with a low of 1.5% among 0 to 5 month olds, a peak of 12.5% in 6 to 11 month olds and prevalence rates of 6.0, 7.9 and 9.8% among 1-, 2- and 3-year-olds, respectively. Hib carriage was 51% lower among currently breast-fed 6 to 11 month olds than among those not currently breast-fed (18.2% vs. 9.0%; P=0.08). CONCLUSIONS: Infants and young children in Santo Domingo have high rates of Hib carriage, characterized by an early peak in carriage that corresponds with the peak of risk for Hib meningitis. The ability of Hib vaccines to diminish carriage to levels that will effectively reduce transmission and lead to herd immunity in this setting needs to be determined.

Carrier State↗
PubMed1998

Prognosis of congenital diaphragmatic hernia.

Congenital diaphragmatic hernia (CDH) contributes significantly to perinatal morbidity and mortality. This retrospective study examines the experience of a major teaching hospital to establish survival rates and factors influencing outcome. Survival rates were found to relate closely to the stage at which the diagnosis was made and the presence of associated anomalies. Ultrasound diagnosis early in pregnancy is associated with a higher mortality rate than diagnosis made late in pregnancy or after delivery. Logistic regression analysis and chi-squared analysis did not establish to a significant degree that any factor, alone or in combination, was a reliable prognostic indicator. It is acknowledged, however, that figures in this series are small. Survival figures are presented to facilitate reliable parental counselling. In particular, the presence of associated major anomalies and the gestational age at which diagnosis is made are of critical importance in accurately counselling parents regarding the prognosis for survival. In this study, excluding terminations, the mortality rate for isolated CDH diagnosis before the 21st week was 45.5%, with a corresponding survival rate of 54.5%. Once the infant was liveborn, however, the survival rate rose to 68.0%, and if the infant survived transfer to a paediatric surgical unit, the survival rate in this study was 73.9 %.

Abnormalities, Multiple↗
PubMed1998

Two-year experience with rate-modulated pacing controlled by mixed venous oxygen saturation.

Mixed venous oxy-hemoglobin saturation (MVO2) is a physiological variable with several features that might be desirable as a control parameter for rate adaptive pacing. Despite these desirable characteristics, the long-term reliability of the MVO2 sensor in vivo is uncertain. We, therefore, designed a study to prospectively evaluate the long-term performance of a permanently implanted MVO2 saturation sensor in patients requiring VVIR pacing. Under an FDA approved feasibility study, eight patients were implanted with a VVIR pulse generator and a right ventricular pacing lead incorporating an MVO2 sensor. In order to accurately assess long-term stability of the sensor, patients underwent submaximal treadmill exercise using the Chronotropic Assessment Exercise Protocol (CAEP) at 2 weeks, 6 weeks, and 3, 6, 9, 12, 18, and 24 months following pacemaker implantation. Paired maximal exercise testing using the CAEP was also performed with the pacing system programmed to the VVI and VVIR modes in randomized sequence with measurement of expired gas exchange after 6 weeks and 12 months of follow-up. During maximal treadmill exercise the peak exercise heart rate (132 +/- 9 vs 71.5 +/- 5 beats/min, P < 0.00001) and maximal rate of oxygen consumption (1,704 +/- 633 vs 1382 +/- 407 mL/min, P = 0.01) were significantly greater in the VVIR than in the VVI pacing mode. Similarly, the duration of exercise was greater in the VVIR than the VVI pacing mode (8.9 +/- 3.6 min vs 7.6 +/- 3.7 min, P = 0.04). The resting MVO2 and the MVO2 at peak exercise were similar in the VVI and VVIR pacing modes (P = NS). However, the MVO2 at each comparable treadmill exercise stage was significantly higher in the VVIR mode than in the VVI mode (CAEP stage 1 (P = 0.005), stage 2 (P = 0.04), stage 3 (P = 0.008), and stage 4 (P = 0.04). The correlation between MVO2 and oxygen consumption (VO2) was excellent (r = -0.93). Telemetry of the reflectance of red and infrared light and MVO2 in the right ventricle during identical exercise workloads revealed no significant change over the first 12 months of follow-up (ANOVA, P = NS). The chronotropic response to exercise remained proportional to VO2 in all patients over the first 12 months of follow-up. The time course of change in MVO2 during maximal exercise was significantly faster than for VO2. At the 18- and 24-month follow-up exercise tests, a significant deterioration of the sensor signal with attenuation of chronotropic response was noted for 4 of the 8 subjects with replacement of the pacing system required in one patient because of lack of appropriate rate modulation. Rate modulated VVIR pacing controlled by right ventricular MVO2 provides a chronotropic response that is highly correlated with VO2. This parameter responds rapidly to changes in workload with kinetics that are more rapid than those of VO2. Appropriate rate modulation provides a higher MVO2 at identical workloads than does VVI pacing. Although the MVO2 sensor remains stable and accurate over the first year following implantation, significant deterioration of the signal occurs by 18-24 months in many patients.

Adult↗
PubMed1998

MR imaging of gene delivery to the central nervous system with an artificial vector.

PURPOSE: To determine whether gene delivery by means of a synthetic no viral DNA delivery system that is capable of gene transfer can be mapped with magnetic resonance (MR) imaging. MATERIALS AND METHODS: The DNA delivery system consisted of aminated (poly-L-lysine-conjugated) dextran chains anchored together with a central superparamagnetic core. Three different types of constructs were synthesized that differed in their amino content and, thus, DNA-loading capacity. The model plasmid consisted of complementary DNA encoding for humanized green fluorescent protein. Constructs were tested in cell culture and in vivo in a rat model. RESULTS: All three constructs were capable of transfecting human cells in culture with transfection efficiencies ranging from 0.3% to 4.1%, which is similar to that of diethylaminoethyl-dextran. MR imaging experiments showed that DNA constructs induced signal intensity changes that co-localized with phosphorus-33-labeled plasmid distribution at autoradiography. After injection of the constructs into the corpus callosum of rats, weak green fluorescent protein expression of neuronal and glial cells could be detected at immunohistologic examination. CONCLUSION: Dextran-based nonviral DNA delivery systems are capable of transfecting cells and can be visualized with MR imaging.

Amino Acids↗
PubMed1998

Stage- and subcellular-specific expression of Id proteins in male germ and Sertoli cells implicates distinctive regulatory roles for Id proteins during meiosis, spermatogenesis, and Sertoli cell function.

Immunohistological detection of each of the four Id proteins (Id1-Id4) in sections of mouse testis revealed a unique temporal and spatial expression pattern for each Id protein during spermatogenesis. Furthermore, each Id protein displayed a distinctive, dynamic pattern of subcellular distribution. Id1 was uniquely expressed in MI/MII spermatocytes undergoing meiotic division. Id4 protein was detectable in the cytoplasm of type A1 spermatogonia, as well as in late pachytene and in diplotene spermatocytes. Id2 protein, which was most abundant in Sertoli cell nuclei, was also detectable in pachytene and diplotene spermatocytes, but as with Id4, it was absent from MI/MII cells. In postmeiotic spermatids, Id1, Id2, and Id4 proteins were expressed in a stage- and subcellular-specific manner. Expression of Id3 was restricted to Sertoli cell cytoplasm. In malignant seminoma cells, all four Id proteins were abundantly expressed with accompanying changes in their subcellular distribution. The observed expression of Id proteins in postproliferative Sertoli cells and spermatids and during specific stages of meiosis implies novel functional roles for this class of transcriptional regulator during spermatogenesis.

Animals↗
PubMed1997

Hospitals' bugbear.

Explore the source record for details and available documents.

Anti-Bacterial Agents↗
PubMed1997

Suspected ehrlichial infection in five cats from a household.

Ehrlichiosis is a poorly recognized condition of cats that may be associated with anemia, leukopenia, thrombocytopenia, or dysproteinemia. Affected cats may have indirect fluorescent antibody titers to Ehrlichia canis and E risticii. We reviewed the clinical evaluation and response to treatment of 5 cats in a household where ehrlichial disease was suspected as the cause of recurrent leukopenias and thrombocytopenias. All of the cats had E risticii indirect fluorescent antibody titers and western blot confirmation of antibodies to 4 of the 9 major antigens of E risticii. Response to doxycycline was monitored serologically and hematologically in each cat, and indicated that administration of doxycycline at a dosage of 10 mg/kg of body weight, PO, every 12 hours, for a minimum of 21 days is necessary for treatment of this condition.

Animals↗
PubMed1997

Better maternal outcomes are achieved with dexamethasone therapy for postpartum HELLP (hemolysis, elevated liver enzymes, and thrombocytopenia) syndrome.

OBJECTIVE: Our purpose was to determine whether the routine initiation of dexamethasone therapy in patients with postpartum HELLP (hemolysis, elevated liver enzymes, and thrombocytopenia) syndrome produces specific and general therapeutic benefits. STUDY DESIGN: In this retrospective, analytic study the puerperal courses of 43 women with postpartum HELLP syndrome who were treated with dexamethasone were compared with those of 237 similar patients who did not receive corticosteroids. Dexamethasone 10 mg intravenously at 12-hour intervals was given until disease remission was noted in treated patients, at which time up to two additional 5 mg intravenous doses were given at 12-hour intervals. RESULTS: The two patient groups were similar in regard to mode of delivery, gestational age, parity, and frequency of eclampsia. Compared with control subjects, dexamethasone-treated postpartum patients were more ill with significantly higher (p < 0.05) admission mean arterial blood pressure, higher serum uric acid level, and severe proteinuria. Dexamethasone administration was associated with a more rapid normalization of platelet counts and lactic dehydrogenase values. Most impressive was a clinically significant reduction of indicated transfusion and respiratory therapy, invasive hemodynamic monitoring, infectious or bleeding-related morbidity, and length of postpartum hospital course. CONCLUSIONS: Patients who received dexamethasone for postpartum-onset HELLP syndrome experienced a shorter disease course, faster recovery, less morbidity, and less need for other interventionist therapy compared with patients with HELLP syndrome who did not receive dexamethasone.

Adult↗