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Biomedical subjects

R Howell

Publications and source records attributed to R Howell.

17 recordsLinked to original sources
PubMed1991

Rapid culture confirmation of herpes simplex virus by a monoclonal antibody-based enzyme immunoassay.

Rapid confirmation of herpes simplex virus (HSV) is essential in many clinical settings. Viral isolation in cell culture is the standard method for diagnosing HSV infection, with confirmation by specific immunological staining. The performance of the Rapid Absorbent Matrix Pad (RAMP) HSV culture confirmation test was evaluated with specimens obtained from 71 patients with suspected HSV infection and inoculated into African green monkey kidney cell lines. Forty-one culture-positive specimens were confirmed to be HSV by both the RAMP HSV test and the Bartels HSV immunoperoxidase test. Thirty immunoperoxidase-negative specimens were also negative in the RAMP HSV test. The sensitivity and specificity of the RAMP HSV test were 100%. Twelve specimens positive for cytomegalovirus, adenovirus, or enterovirus tested negative by the RAMP HSV test. Thus, the RAMP HSV test was faster than, easier to perform than, as sensitive as, and as specific as other well-documented confirmation methods.

Antibodies, Monoclonal↗
PubMed1991

The histologic reliability of laser cone biopsy of the cervix.

Laser conization of the cervix has been advocated as the technique of choice for the treatment of cervical intraepithelial neoplasia (CIN) in preference to ablative techniques, because it provides a specimen for histologic diagnosis while retaining the advantages of an outpatient procedure with minimal short- and long-term morbidity. To determine whether specimens so obtained are adequate for reliable histologic diagnosis, we reviewed 77 laser conizations performed for lesions confirmed to contain CIN in a colposcopically directed biopsy and satisfying the criteria for local ablation and scored the cones for the presence of epithelial denudation and laser coagulation artifact that interfered with the diagnosis of CIN or the assessment of the margins of excision. Thirty specimens (39%) were negative for CIN. Twenty-eight (36%) showed extensive epithelial denudation, ten (13%) contained coagulation artifact that made recognition of CIN extremely difficult or impossible, and in 11 (14%), assessment of margins was extremely difficult or impossible because of laser coagulation artifact. We conclude that these difficulties with the histologic interpretation of laser cone specimens make it an unsuitable excisional technique when reliable histologic diagnosis of cervical lesions is required.

Adult↗
PubMed1989

Circulating levels of placental protein 12 in complications of first trimester pregnancy.

Serum placental protein 12 (PP12) levels were determined in 34 women with threatened miscarriage in whom a diagnosis of anembryonic pregnancy (n = 19), missed abortion (n = 4), complete or incomplete abortion (n = 5), hydatidiform mole (n = 1) and subsequent abortion of a live fetus (n = 5), was made ultrasonically and confirmed by histological examination. Twenty-four of the 34 patients had one or more levels between the 10th and 90th centiles of the reference range. In 7 of the 19 patients (37%) with anembryonic pregnancy and in 3 of the 4 patients (75%) with a missed abortion, PP12 levels were markedly elevated. However, in cases where serial measurements were available (n = 6), PP12 levels were seen to fall in all cases. It is concluded that pregnancies that have failed or will subsequently fail in the first or second trimester are not associated with depressed maternal PP12 levels, suggesting that the decidual synthesis of this protein is independent of the presence or viability of the fetus.

Abortion, Spontaneous↗
PubMed1989

Philippino and Vietnamese women--a study of intrapartum differences.

The pregnancies of 140 Philippino women (168 deliveries) and 198 Vietnamese women (250 deliveries) were compared to those of Australian-born women delivered at the Mater Mothers' Hospital, Brisbane over the 5-year period 1980-1984 with the aim of detecting differences in their labour and mode of delivery. The Philippino women were predominantly married to Caucasian men whereas the Vietnamese women were married to Vietnamese men. The study assesses the clinical impression that this difference between the 2 groups affects intrapartum outcome. Birth-weights of the babies of Philippino women followed the same pattern as those of Australian women while Vietnamese women delivered smaller babies. Philippino primiparas had increases in all parameters of labour studied, notably an increased Caesarean section rate, especially those performed in the second stage. Comparable increases were not found in either Philippino multiparas or Vietnamese women. Based on these results 'relative' cephalopelvic disproportion is postulated among the Philippino women.

Adult↗
PubMed1989

Levels of the small insulin-like growth factor-binding protein are strongly related to those of insulin in prepubertal and pubertal children but only weakly so after puberty.

We have looked at the relationship between fasting levels of insulin and a small insulin-like growth factor (IGF)-binding protein (IBP-1) in a cross-sectional study of 116 normal subjects aged 5-48 years. The relationship between IBP-1 and insulin was also examined within individual normal children in overnight profiles of IBP-1 and insulin obtained from two children at each stage of puberty (Tanner stages 1-5). In the cross-sectional study high levels of IBP-1 were found in early childhood and these fell throughout puberty as fasting levels of insulin rose. Multiple regression analysis revealed that both these changes were predominantly due to pubertal development rather than to age. After the age of 16 IBP-1 levels remained low despite fasting insulin levels returning to prepubertal levels. A strong negative correlation was obtained between IBP-1 and insulin in children of 5-16 years (r = -0.63; n = 60; P less than 0.001), no such relationship being found after the age of 16. In the second study, IBP-1 underwent a marked circadian variation in all cases and an inverse correlation with insulin, measured at the same time, was obtained at pubertal stages 1 to 4, but not at stage 5 (pooled data stages 1-4, r = -0.69; n = 53; P less than 0.001). We have demonstrated that a potential inhibitor of IGF-activity is inversely related to insulin throughout the period of active GH-related growth and that this relationship weakens after puberty.

Adolescent↗
PubMed1988

Circadian variation of GH-independent IGF-binding protein in diabetes mellitus and its relationship to insulin. A new role for insulin?

Evidence is accumulating that a non-GH dependent insulin-like growth factor-binding protein (IGF-BP) is not only a carrier protein but also has an active role in the growth process. We have measured levels of this IGF-BP, using a specific RIA, over 12 or 24-h periods in 11 adolescents with diabetes mellitus and five normal adults. In each of the normal the IGF-BP was undetectable for most of the day but with a broad nocturnal peak observed, with levels up to 50 micrograms/l. The levels of IGF-BP were unrelated to the secretory pattern for GH but correlated inversely with the concentration of circulating insulin. In the diabetics a very similar pattern was observed, but with detectable levels throughout the day and much higher peak levels seen at night. Peak levels were up to 120 micrograms/l if a long-acting insulin preparation was administered in the evening but were 400-500 micrograms/l if the long-acting preparation was administered in the morning. The IGF-BP was strongly correlated with plasma glucose in this latter group. In a further group of diabetics overnight profiles were obtained on two separate nights, a normal night and a night with euglycaemia maintained with a glucose clamp technique. Euglycaemia failed to affect peak levels of the binding protein, although the shape of the nocturnal peak was altered consistent with the altered pattern of circulating free insulin. In this group a strong inverse correlation was obtained between the IGF-BP and free insulin levels.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1977

Influence of p-chloroamphetamine on female sexual reflexes and brain monoamine levels.

The effect of p-chloroamphetamine(PCA) on female sexual reflexes was biphasic. Administration of PCA to receptive females initially terminated ongoing sexual behavior and this effect was correlated with the release of monoamines, particularly serotonin (5-HT). Sexual reflexes were abolished within 15 min of PCA injection. Other reflexes, including reciprocal forepaw treading, lateral head weaving, hindlimb abduction and Straub tail, were elicited by PCA. The long term infuence of PCA was the opposite. A facilitation of female sexual behavior occurred accompanied by a relatively specific depletion of 5-HT (10 mg/kg, 66% depletion; 20 mg/kg, 80% depletion) with both dopamine and norepinephrine depleted by less than 15%. This long term facilitation of female sexual reflexes was not blocked by dexamethazone suggesting that PCA was acting directly on the neural substrate for mating and did not produce it facilitation via adrenal progesterone. This biphasic infuence of PCA on mating reflexes, paralleling its effect on monoamine transmission, suggests serotonergic involvement in the integration of mating behavior.

Amphetamines↗
PubMedDate not supplied

Cytomegalovirus infection in children with AIDS.

Data for 38 children perinatally exposed to human immunodeficiency virus (HIV) were evaluated to determine the impact of cytomegalovirus (CMV) infection on the course of perinatally acquired HIV infection. Thirteen children belonged to the P0 (indeterminate) group, one to the P1 (asymptomatic) group, and 24 to the P2 (symptomatic) group, per the classification of the Centers for Disease Control. Of the 24 children in the P2 group, 10 died. The mean follow-up time was 22.8 months for the 10 children who died and 16.3 months for the 13 children in the P0 group. Serial cultures of urine were performed for all 38 patients. CMV was isolated from seven of 10 children who died and from four of 14 children who survived (P less than .05). Only one of the 13 P0 children was culture-positive for CMV, as compared with 11 of 24 P2 children (P less than .05). All CMV-infected children continued to demonstrate CMV viruria in serial cultures. The mean age at the time of the first culture positive for CMV was 13 months. Microcephaly was present in 15 (65%) of 23 P2 children but in none of the P0 and P1 children (P less than .05). Eight of 11 CMV-infected children were microcephalic; seven of 12 children not infected with CMV were microcephalic (P greater than .05). These data suggest that the prevalence of active CMV infection is significantly higher in P2 children than in P0 and P1 children. In addition, there is a significant association between CMV infection and mortality among P2 children.

Acquired Immunodeficiency Syndrome↗
PubMedDate not supplied

Ultrastruct of oral cells with bar-shaped nuclear chromatin.

Scrapings were taken from the frenulum of the lower lip to obtain cells with bar-shaped nuclear chromatin. They were subjected to routine electron microscope processing, sectioning and visualization. Specimens from the lower frenulum of autopsy patients were prepared for light microscope identification of the bar-chromatin cell in tissue. The ultrastructure of the bar-chromatin cell cytoplasm resembled that of normal squamous intermediate cells, but the nuclear chromatin was composed of pleomorphic masses which formed an irregular band on the long axis of the nucleus. In the normal intermediate cell the clumps of chromatin were dispersed randomly. Cells with bar chromatin were found in the stratum spinosum of the oral squamous epithelium.

Cell Membrane↗