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Biomedical subjects

C Chase

Publications and source records attributed to C Chase.

At least 19 recordsLinked to original sources
PubMed2002

A clinical prediction rule to identify premenopausal women with low bone mass.

Identifying premenopausal women at risk for osteoporosis and related fractures is a potentially important way to reduce the burden of illness from this disease as low peak bone mass is a risk factor for postmenopausal osteoporosis. We examined predictors of 'low' peak bone mass in 668 healthy, pre-menopausal, Caucasian women ages 18-35 years. Predictors of bone mass were assessed using a detailed, standardized interview. Bone mass was assessed using two measures: dual-energy X-ray absorptiometry (DXA) at the femoral neck and lumbar spine, and quantitative ultrasound (QUS) of the heel, which evaluates stiffness, speed of sound (SOS) and broadband ultrasound attenuation (BUA). Bone mass was considered 'low' if the corresponding Z-score was <-1.00 (DXA values, stiffness) or if values were in the lowest quintile (BUA, SOS). Using multivariate logistic regression modeling, predictors of low bone mass based on QUS, DXA or both were determined. The mean age of the cohort was 27.3 years. Independent predictors of low bone mass by both DXA and QUS were: low body weight, menarche at age 15 years or later and physical inactivity as an adolescent. Individuals with all three risk factors had a 92% chance of having low bone mass using both techniques. This suggests that a simple risk factor assessment can identify most young women with low peak bone mass. Early intervention in this group of women may reduce the risk for osteoporosis in later life.

Absorptiometry, Photon↗
PubMed2001

Head growth and neurodevelopment of infants born to HIV-1-infected drug-using women.

OBJECTIVE: To describe neurodevelopment and head growth in HIV-1-infected and exposed uninfected infants with and without in utero exposure to opiates and cocaine. METHODS: Using data from a multicenter cohort study of HIV-1-infected women and their children, the authors fit repeated measures regression models to estimate the effects of HIV-1 infection and in utero hard drug exposure on head circumference and Bayley Scales of Infant Development standard scores during the first 30 months. RESULTS: Of the 1,094 infants included in the analysis, 147 (13%) were HIV-1-positive and 383 (35%) were exposed in utero to opiates or cocaine (drug-positive). Mean 4- month Bayley mental scores were lower in infants with only HIV-1 positivity (HIV-positive and drug-negative) (-8.2 points, p < 0.0001) or only drug exposure (HIV-negative and drug-positive) (-4.4 points, p = 0.0001) and tended to be lower in infants with both factors (HIV-positive and drug-positive) (-3.7 points, p = 0.0596), compared with those who were HIV-1-negative and not drug exposed (HIV-negative and drug-negative). However, by 24 months of age, there was no longer a decrement among HIV-negative and drug-positive infants, whereas HIV-1 infection was still associated with a decrement relative to uninfected infants. Similar results were seen for Bayley motor scores and for head circumference Z scores. CONCLUSIONS: HIV-1 infection and in utero opiate and cocaine exposure decrease birth head circumference and slow neurodevelopment at 4 months. At 24 months of age, however, only HIV-1 infection is associated with decreased neurodevelopment and head circumference. There may be some postnatal recovery from the effects of in utero hard drug exposure. Importantly, the detrimental effects of HIV-1 positivity and maternal hard drug use on neurodevelopment at 4 months are not additive, although they are additive for birth head circumference.

Adolescent↗
PubMed2000

Gonadotropin-releasing hormones in the brain and pituitary of the teleost, the white sucker.

The present study investigated GnRH forms within the brain of a representative of the order Cypriniformes, the white sucker, Catostomus commersoni, using HPLC, RIA, and immunocytochemistry. Several immunoreactive (ir) GnRH forms were identified in the brain of the white sucker by chromatography and radioimmunoassay, including ir-salmon GnRH, ir-lamprey GnRH-I and -III, and ir-chicken GnRH-II. Results from immunocytochemical studies were consistent with multiple GnRH forms distributed in different patterns, particularly for fibers. Neuronal perikarya containing ir-salmon GnRH and ir-lamprey-like GnRH were found laterally within the preoptic area and rostral hypothalamus. Cells containing exclusively ir-salmon GnRH appeared slightly more rostrally, but in the same region. Fibers containing ir-salmon GnRH and ir-lamprey-like GnRH were seen throughout the caudal telencephalon and extended into the diencephalon, toward the pituitary. Fibers containing ir-chicken-II-like GnRH were also seen in the caudal telencephalon, but were concentrated more dorsally in the diencephalon. Within the pituitary, fibers containing ir-salmon GnRH and ir-lamprey-like GnRH entered the neurohypophysis, but differed in their destinations. Fibers containing ir-salmon GnRH remained within the neurohypophysis, while fibers containing ir-lamprey-like GnRH targeted adenohypophyseal tissue. These findings are consistent with the hypothesis that multiple GnRH forms with multiple functions exist within the brain and pituitary of teleosts and provide further evidence of a lamprey-like GnRH within an early evolved teleost species.

Amino Acid Sequence↗
PubMed2000

Evidence for lamprey GnRH-I and -III-like molecules in the brains of the southern hemisphere lampreys Geotria australis and Mordacia mordax.

The present study has characterized gonadotropic releasing hormone (GnRH)-like molecules in the brains of representatives of the two southern hemisphere families of lampreys, Geotriidae and Mordaciidae. Chromatographic and immunocytochemical evidence showed that the brains of Geotria australis and Mordacia mordax contain two forms of GnRH-like molecules. These two forms correspond to lamprey GnRH-I and -III, which were first sequenced from the brain of the anadromous sea lamprey Petromyzon marinus, a representative of the family Petromyzontidae that is found only in the northern hemisphere. In chromatographic studies (HPLC) using lamprey GnRH-I and -III antiserum, two early eluting GnRH forms coeluted with synthetic lamprey GnRH-I and -III standards. Our studies thus indicate that, despite their apparently long period of separation, the three families of extant lampreys have each retained both of the lamprey GnRH (-I and -III forms) molecules. Moreover, immunocytochemical localization of lamprey GnRH indicated that the pattern of its distribution in the adult brain of at least one of these southern hemisphere lampreys (G. australis) is similar to that previously described for P. marinus. Distribution of GnRH in the brain of larval G. australis was not as extensive as that in larval P. marinus, which may account for the later gonadal development in the former species. The fact that lamprey GnRH-I and -III are the dominant GnRH forms in all three families of lampreys implies that these neurohormones have an ancient origin.

Animals↗
PubMed2000

Artifactual electrocardiographic change mimicking clinical abnormality on the ECG.

Electrocardiographic artifact is a common finding in patients requiring evaluation and monitoring in the prehospital, emergency department, or intensive care unit settings. Artifact results from both internal (physiological) and external (nonphysiological) sources. In most instances, artifact is recognized as an incorrect electrocardiographic signal--its only impact producing interference in electrocardiogram interpretation; artifact may also produce electrocardiographic signals which mimick disease--these signals the physician must recognize as artifact.

Adult↗
PubMed2000

Early cognitive and motor development among infants born to women infected with human immunodeficiency virus. Women and Infants Transmission Study Group.

OBJECTIVE: To examine the frequency, timing, and factors associated with abnormal cognitive and motor development during the first 30 months of life in infants born to women infected with human immunodeficiency virus type 1 (HIV-1). METHODS: Serial neurodevelopmental assessment was performed with 595 infants born to women infected with HIV-1 in a multicenter, prospective, natural history cohort study. Survival analysis methods were used to evaluate 6 outcome events related to abnormal cognitive and motor growth (time to confirmed drop of 1 SD, time to first score <69, and time to confirmed drop of 2 SD) in Bayley Scales of Infant Development Mental Developmental Index (MDI) and Psychomotor Developmental Index (PDI) scores among infected (n = 114) and uninfected (n = 481) infants. Proportional hazards modeling was used to evaluate the effects of HIV infection status, prematurity, prenatal exposure to illicit drugs, maternal educational attainment, and primary language. RESULTS: HIV-1 infection was significantly associated with increased risk for all outcome events related to abnormal mental and motor growth. Differences between infected and uninfected infants were apparent by 4 months of age. Prematurity was associated with increased risk for MDI <69 and PDI <69. Maternal education of <9 completed years was associated with increased risk for MDI <69. Neither prenatal exposure to illicit drugs nor primary language other than English was associated with abnormal development. CONCLUSION: A significant proportion of infants with HIV-1 infection show early and marked cognitive and motor delays or declines that may be important early indicators of HIV disease progression. These abnormalities are independent of other risk factors for developmental delay.

Adolescent↗
PubMed1999

Bone mineral density testing and osteoporosis education improve lifestyle behaviors in premenopausal women: a prospective study.

One way to decrease the risk of osteoporosis is to maximize peak bone mass. Peak bone mass may be moderately influenced by lifestyle behaviors: increasing calcium and exercise, decreasing alcohol intake and smoking may increase peak bone mass. We examined the effects of osteoporosis education and bone mineral density (BMD) testing on self-reported lifestyle behaviors in 669 premenopausal women enrolled in a prospective study to assess determinants of peak bone mass. Study participants completed a questionnaire that assessed lifestyle behaviors, received pamphlets about osteoporosis, and had BMD testing. One year later, the women completed a similar questionnaire. After education about osteoporosis and BMD testing, women reported that they were less likely to smoke (odds ratio [OR] = 0.55; 95% confidence interval [95% CI]: 0.28-1.0), consume alcohol (OR = 0.13; 95% CI: 0.04-0.34), and caffeinated beverages (OR = 0. 43; 95% CI: 0.27-0.68). Women were more likely to use calcium supplements (OR = 4.3; 95% CI: 3.04-6.2), vitamin D supplements (OR = 12.6; 95% CI: 7.4-22.9), and drink at least one glass of milk a day (OR = 13.3; 95% CI: 7.8-23.9). Further, women with low bone mass were more likely to use calcium supplements (OR = 1.7; 95% CI: 1.2-2.3) and vitamin D supplements (OR = 1.6; 95% CI:1.1-2.2) compared with women who had normal bone mass. Thus, our intervention improved self-reported lifestyle behaviors in premenopausal women. Such behaviors may ultimately increase peak bone mass and decrease the risk of developing osteoporosis.

Adult↗
PubMed1999

A 15-week experimental exposure of pigs to airborne dust with added endotoxin in a continuous flow exposure chamber.

The purpose of this study was to evaluate the effect of longterm exposure to airborne dust and endotoxin on the respiratory system of pigs. A continuous flow exposure chamber was built for the purpose of exposing pigs to selected airborne contaminants. Pigs (n = 6) were exposed to a combination of a very fine corn/soybean meal (40.6 mg/m3) with added lipopolysaccharide (LPS; 12.4 microg/m3) for 8 h/d over 5 d for 15 wk (75 d of exposure). Control pigs (n = 6) were housed in a room with minimal contamination of these airborne contaminants. Surprisingly, dust in the exposure chamber and the control room was highly contaminated with peptidoglycan. Changes in the lung were monitored by collecting bronchoalveolar lavage (BAL) fluid for cytology at 5 different time points throughout the exposure period. Blood samples were collected at the same time for hematology. A non-specific respiratory inflammatory response was found in exposed and control pigs, as suggested by the increased neutrophils in BAL fluid and the small inflammatory areas in the lung tissue. No macroscopic lung lesions were observed in control or exposed pigs. The findings in the control pigs imply that even low dust concentrations and possibly peptidoglycan contamination can induce cellular changes in the BAL fluid and that a true control pig does not exist. In addition, the exposed pigs developed a mild eosinophilia, indicating an allergic response to the airborne contaminants.

Air Pollutants↗
PubMed1998

Manual-based group psychotherapy for bipolar disorder: a feasibility study.

BACKGROUND: The Life Goals Program is a structured, manual-based group psychotherapy program for bipolar disorder that seeks to improve patient participation in medical model treatment (phase 1) and assist patients in meeting functional status goals (phase 2). The goals of this initial study were (a) to determine whether the procedures could be exported from the authors to other therapists and (b) to quantify tolerability and impact of procedures on patients. METHOD: Four therapists across 2 sites and 29 patients from the Veterans Affairs (VA) Medical Center were studied in an open feasibility study. Therapists were trained, and subsequent compliance with manual procedures was quantified. Several process indices measuring tolerability and impact on patients were analyzed. RESULTS: Therapists covered 90% to 96% of phase 1 psychoeducational content, indicating excellent fidelity to manual procedures. Sixty-nine percent of patients completed phase 1, and participation scores were in the good to excellent range for 56%. Completion of phase 1 was associated with significant increase in knowledge about bipolar disorder. Fourteen (70%) of 20 patients enrolled in phase 2 reached their self-identified, behaviorally based goal (48% of the total sample who began phase 1 of the program). Mean +/- SD time to goal completion was 8.7 +/- 5.3 months (median [95% confidence interval] = 7 [5.1-12.3 months]; range, 2-17 months). CONCLUSION: The manual-based intervention can be exported with fidelity to other therapists and sites (for phase 1). Data indicate reasonable tolerability and good achievement of process (for phases 1 and 2) for those who accept this group modality. Comparison with other manual-based psychotherapies indicates remarkable consistency regarding content for psychotherapy for bipolar disorder; major differences among the psychotherapies include mode of delivery and relative emphasis of specific components.

Adult↗
PubMed1996

Disorders of affective and linguistic prosody in children after early unilateral brain damage.

Prosody is that quality of speech that imparts meaning by changes in intonation, pitch, and stress. The right hemisphere (RH) appears to be dominant for affective prosody in adults, while the left hemisphere (LH) mediates the more linguistic aspects of nonverbal communication. Few similar studies have been reported of individuals who suffered early unilateral brain damage, when brain reorganization or plasticity might be expected to play a role in ameliorating the adverse effects of focal brain damage. In this study, comprehension and expression of affective and linguistic prosody were tested in subjects with documented unilateral brain damage of pre- or perinatal onset and in matched controls. Both RH- and LH-lesion groups demonstrated difficulty on tasks involving expression of affective prosody, and on tests of linguistic prosody, compared with controls. Only the RH-lesion group was impaired on an affective comprehension task. The results indicate that even after very early unilateral brain damage, prosodic deficits may be present. However, only for affective comprehension does the side of the lesion appear to determine such deficits. The findings suggest that during brain development there is not clear brain lateralization for prosody and there may be bilateral representation for these skills during early development. There may be limitations to the ability of the developing brain to reorganize after early injury.

Adolescent↗
PubMed1996

Appendicitis complicating pregnancy.

Abdominal pain is a common symptom in pregnancy. Its etiology is diverse and diagnosis often poses a problem. Inflammatory disorders of extra-uterine origin such as appendicitis should always be considered as a possible cause. Three cases of appendicitis complicating pregnancy managed at the Queen Elizabeth Hospital, Barbados during the year 1993 are documented. Two presented in the antenatal period and the third postpartum. The clinical manifestations and the difficulties encountered in diagnosis are emphasised.

Adult↗
PubMed1995

Early neurodevelopmental growth in children with vertically transmitted human immunodeficiency virus infection.

OBJECTIVE: To examine mental and motor development in children with vertically transmitted human immunodeficiency virus (HIV) infection in the first 30 months of life. DESIGN: Prospective longitudinal study comparing two groups: children with HIV infection and HIV-exposed but uninfected children. SETTING: Pediatric Immunodeficiency Clinic at Boston (Mass) City Hospital, Boston University Medical Center. STUDY PARTICIPANTS: Twenty-four children with vertically transmitted HIV infection and 27 children who were born to HIV-infected mothers and became HIV negative served as controls. Socioeconomic status, gestational age, and prenatal drug exposure were comparable in the two groups. MEASUREMENTS/RESULTS: Using the Bayley Scales of Infant Development, all children were assessed at least once between 4 and 16 months and again between 17 and 30 months of age. Individual mean mental and motor scores were calculated for the early and later age span. Motor development in the infected group was delayed in comparison to the seroreverter group in both age spans and remained stable in both groups over time. Mental development was comparable in the two groups at 4 to 17 months, but HIV infection was associated with delay in mental development at 17 to 30 months of age. CONCLUSION: Early and persistent delay in motor development and deceleration in mental development in late infancy distinguishes many children who are HIV infected from exposed but uninfected children, but there is significant variability in early neurodevelopmental outcome among children with HIV infection.

Acquired Immunodeficiency Syndrome↗