Biomedical subjects

P Henderson

Publications and source records attributed to P Henderson.

11 recordsLinked to original sources

PubMed1992

Measurement of markers of activated coagulation in antithrombin III deficient subjects.

Functional antithrombin III levels were measured by factor Xa inhibition in 63 members of a large family with type 2 antithrombin III deficiency and individuals were classified as antithrombin III deficient or non-deficient according to the results. F1 + 2 and TAT complexes were measured using an ELISA and FPA levels were measured by radioimmunoassay. Thirty subjects (48%) were classified as antithrombin III deficient and 33 (52%) as antithrombin III non-deficient. The mean level of F1 + 2 was significantly higher in the deficient adults (0.87 +/- 0.26) compared to both the non-deficient adults (0.70 +/- 0.21) (p = 0.03) and the deficient adults receiving warfarin (0.16 +/- 0.01) (p less than 0.001). The differences in the mean values of TAT complexes and FPA between deficient and non-deficient individuals were not statistically significant. These findings suggest that untreated antithrombin III deficient subjects generate more thrombin than their non-deficient family members and that warfarin inhibits this thrombin formation. In this cross-sectional study, it is not possible to correlate the levels of the surrogate makers with future clinical outcome.

Adolescent↗

PubMed1992

Thrombosis in antithrombin-III-deficient persons. Report of a large kindred and literature review.

PURPOSE: To estimate the prevalence of objectively proven thrombotic complications in antithrombin-III-deficient persons. STUDY DESIGN: Cross-sectional study and a critical review of the literature. DATA SOURCES AND EXTRACTION: The prevalence of thrombosis in antithrombin III-deficient and -nondeficient family members of a large kindred was estimated by history, review of diagnostic tests, and examination for venous reflux by Doppler ultrasonography, as an indicator of previous venous thrombosis. A MEDLINE search and literature review of the published English- and French-language literature from 1966 to 1990 that described antithrombin-III-deficient families was done, and the following information was obtained: the prevalence of thrombosis in deficient and nondeficient family members, the presence or absence of risk factors for thrombosis (surgery, pregnancy, the postpartum state, use of oral contraceptives, immobilization, metastatic cancer, major trauma) at the time of the thrombotic event, and age of onset of the first episode of thrombosis. The validity of the studies was assessed according to predetermined criteria. RESULTS: Sixty-seven research subjects were evaluated. Six of 31 (19.4%) antithrombin-III-deficient subjects compared with none of 36 (0%) nondeficient subjects had had one or more thrombotic events. The initial episode in five of six subjects had occurred in association with risk factors for thrombosis. The literature search indicated that the pooled prevalence of symptomatic venous thrombosis among the deficient subjects was 51%, but objective testing was done in only 17% of these subjects at the time of presentation. CONCLUSION: Based on the data from this antithrombin-III-deficient kindred, lifelong anticoagulant prophylaxis does not appear to be warranted in asymptomatic carriers, and prophylaxis could be limited to periods of high risk for thrombosis.

Adolescent↗

PubMed1992

Pharmacokinetics of lignocaine in children after infiltration for cleft palate surgery.

We have studied the pharmacokinetics of lignocaine in children after local infiltration for cleft palate surgery. After induction of anaesthesia, lignocaine 2.5 mg kg-1 with adrenaline 1:200,000 was injected into the palate. Blood samples were collected before and at 2, 5, 10, 15, 20, 30, 60 and 120 min after infiltration. Plasma concentrations of lignocaine were measured by a gas-liquid chromatographic technique. There were no signs of systemic toxicity on routine monitoring of the patients and the peak plasma concentrations were less than the accepted toxic values. Mean half-life was 72.9 (SEM 9.9) min, similar to that found previously in adults and children. However differences in mean clearance (24.6 (2.04) ml kg-1 min-1) and volume of distribution (0.80 (0.07) litre kg-1) were found between this and previous studies.

Anesthesia, General↗

PubMed1989

Serotonin-immunoreactive neurons in the brain of Manduca sexta during larval development and larval-pupal metamorphosis.

The developing serotonergic system of the tobacco hornworm, Manduca sexta, has been studied immunocytochemically in whole mount preparations of brain-retrocerebral complexes. The distribution of serotonin-immunoreactive cell bodies, fibers and terminal fields has been analysed during larval and larval-pupal development using a specific rabbit antiserum against serotonin-hemocyanin conjugates. The serotonergic system was conserved from the fourth to the fifth larval stadium, with minimal changes occurring until the onset of pupal development. At this time, alterations in the distribution of serotonin-immunoreactive cells and processes were observed, including the apparent disappearance of some cell bodies and terminals. Nevertheless, the overall appearance of this system in the pupal brain was not significantly different from that in the larva. The larval pattern was characterized by eight bilateral groups of cell bodies which sent thick bridges of fibers across the midline, a feature strikingly similar to the serotonergic system in vertebrate embryos. In addition, three bilateral immunoreactive fields of arborization were observed around and ventral to these cell groups, together with regions of serotonin immunoreactivity in the medial and lateral protocerebral lobes. The central body, larval antennal centers, larval accessory lobes, and the tritocerebrum were also immunoreactive. Fibrous networks of serotonergic processes were usually observed around nerves emanating from the brain, including the connectives from the brain to the corpus cardiacum and corpus allatum. Smaller varicosities were observed in the interior of these neurohemal and glandular organs, and a network of 5-HT fibers was occasionally found around the corpus cardiacum and corpus allatum. The possible relationship of serotonin to cerebral neuroendocrine functions during the postembryonic development of M. sexta is discussed.

Animals↗

PubMed1989

Establishing an enteral product formulary.

An ever-increasing number of enteral nutrition products is being marketed to hospitals for use with nutritionally compromised patients. At the Clinical Center, National Institutes of Health, Bethesda, MD, the nutrition department created a formulary management committee, which developed a system that aligned formulary product selection with the enteral needs of the patients, provided an ongoing system of formulary management, and provided extensive education to dietitians on product formulation. The formulary system involved a stepwise process: determination of categories of products to be considered and criteria for product selection, identification of enteral needs of patients at nutritional risk within the institution, review of current literature on formulation of all major enteral products, and taste evaluation of products to be used orally. Composition of the formulary was then determined, and interdepartmental efforts for implementation were coordinated. The overall department impact included a 37% reduction in variety of products stocked, the creation of an annual update system, and extensive dietitian education on product formulation and usage. The direct impact on patient care was the provision of a formulary specifically targeted to meet the enteral needs of those patients at nutritional risk within the institution.

Enteral Nutrition↗

PubMed1989