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Biomedical subjects

L Wilkinson

Publications and source records attributed to L Wilkinson.

At least 55 records · Page 3Linked to original sources
PubMed1986

Chronic corticosterone administration in rats: behavioral and biochemical evidence of increased central dopaminergic activity.

Chronic corticosteroid treatment in humans in frequently complicated by behavioral changes. The present study suggests that chronic steroid administration in rats has distinct neurochemical consequences which are behaviorally relevant. Ten male Sprague-Dawley rats received 7 daily injections of corticosterone, following which they exhibited increased caudate homovanillic acid as well as an attenuated decline in vertical and ambulatory movement (functional measures of dopamine activity) compared to placebo-treated rats. A subgroup of steroid-treated rats which was more behaviorally responsive to corticosterone also showed increased caudate 5-hydroxyindole acetic acid and decreased prefrontal cortex dopamine and serotonin. These results are discussed in relation to the known behavioral side effects of chronic corticosteroid administration in man and the psychiatric manifestations of naturally occurring states of hypercortisolemia.

Animals↗
PubMed1986

Valva ileocaecalis: preservation during ileocolonic surgery employing a rodent experimental model.

Experimental and clinical data suggest that the valva ileocaecalis under neurogenic and hormonal influences, modulates antegrade and retrograde flow of succus entericus. A priori reasoning suggests that this function may influence nutrient absorption by and intraluminal endogenous microbial flora within the ileum. The hypothesis to be tested was, can anatomical and functional integrity of the valva ileocaecalis be preserved during the performance of a right hemicolectomy with reestablishment of intestinal continuity via a cecocolostomy? The methodology involved utilization of Lewis male rats weighing approximately 500 gm. General anesthesia was induced for all procedures. The animals were randomly assigned to three groups (10 animals/group): (A) sham operation; (B) pericecal dissection (preservation of the arteria et vena ileocolica); and (C) periileal dissection (ligation of the aforementioned vessels). Celiotomy was performed employing standard clean techniques, and was accompanied by a right hemicolectomy and an end-to-end or end-to-side cecocolostomy. Function of the heterotopic valva ileocaecalis was assessed 6-12 weeks post-operatively employing radiographic criteria (fluoroscopic analysis after intraluminal instillation of barium sulfate). Light microscopic analysis was performed subsequent to the radiographic studies. Periileal dissection associated with ligation of the arteria et vena ileocolica uniformly resulted in anastomotic disruption. Pericecal dissection associated with preservation of those vessels resulted in uniform anastomotic integrity, although two animals succumbed secondary to pneumonitis within 5 post-operative days. Radiographic analysis of the heterotopic valva ileocaecalis revealed intermittent antegrade and no retrograde flow of contrast material, which suggested functional integrity. Qualitative light microscopic analysis revealed architectural integrity.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1985

Neurological findings in high-risk children: childhood assessment and 5-year followup.

The results of the two neurological examinations of the Israeli children, both original and followup, are presented. The multidimensional scalogram analysis technique was used to identify children with multiple areas of neurological dysfunction. These children consisted almost exclusively of the offspring of schizophrenic patients: 22 of the 50 index cases were in this region of poor functioning during at least one of the testing periods, as compared with only 3 of the 50 control cases. The most common neurological signs were "soft" perceptual-sensory signs, poor motor coordination, poor right-left orientation, poor balance, and motor overflow. No "hard" neurological differences were found between the groups. This is the first major report of long-term stability of neurological soft signs in the offspring of schizophrenic persons.

Adolescent↗
PubMed1984

Increased IgG molecules bound to the surface of red blood cells of patients with sickle cell anemia.

We have used the complement-fixing antibody consumption ( CFAC ) test to detect small concentrations of IgG on red blood cells from patients with hemolytic anemias that are not thought to be caused by an immune mechanism. Although patients with hereditary spherocytosis, pyruvate kinase deficiency, and mechanical hemolytic anemias generally had normal concentrations of IgG bound to their red cells (less than 25 molecules IgG per red cell), we found that 39/62 (63%) patients with sickle cell anemia had elevated values. These 39 patients had a mean of 195 and a maximum of 890 molecules of IgG per red cell. None of the patients had been transfused within the previous 90 days, and some had never been transfused. Direct antiglobulin tests were positive in only two instances and autoantibodies were not found in the serum of any patient. However, eluates from the red cells of 6 of 23 patients demonstrated antibody activity against all of a panel of normal red cells by the indirect antiglobulin test. There was no correlation between the number of IgG molecules on patients' red cells and the severity of their anemia, the incidence of painful sickle cell crises, the reticulocyte count, or with blood transfusion history. We conclude that further study of immunohematologic abnormalities in patients with sickle cell anemia is warranted, especially in view of previous reports in this population of patients with red cell autoantibodies, autoimmune hemolytic anemia, hemolytic transfusion reactions without detectable alloantibodies, and an association of some episodes of pain crises with immunologically mediated red cell destruction.

Adolescent↗
PubMed1983

Diabetes, a hypercoagulable state? Hemostatic variables in newly diagnosed type 2 diabetic patients.

37 type 2 diabetic patients with no clinical evidence of retinopathy or vascular disease were studied at diagnosis and following control of hyperglycaemia for evidence of abnormalities of coagulation, fibrinolysis and platelet behaviour. 38% showed hyperactive platelets, demonstrating either in vitro hyperaggregability, circulating platelet aggregates, or raised plasma beta-thromboglobulin levels. 36% showed abnormally raised factor VIII coagulant activity (FVIIIc) levels, though this was mainly in female patients. The mean level of FVIIIc decreased with treatment. Anti-thrombin III (AT-III) levels were decreased, and 33% of the patients had levels less than 80%. In this group AT-III increased following treatment. No abnormalities of fibrinolysis were demonstrated. These findings support the concept that diabetes can be associated with a hypercoagulable state, which is not necessarily dependent on the presence of overt vascular disease, or correlated with the degree of chronic hyperglycaemia (HbA1c levels).

Adenosine Diphosphate↗
PubMed1982

Platelet activation during exercise-induced myocardial ischaemia.

Twenty-six normal subjects (aged 18-52) and eighteen patients with ischaemic heart disease (aged 36-67) underwent maximal 12 lead ECG treadmill exercise testing. Coronary angiography was performed on sixteen of the patients. In-vivo platelet activation was assessed by measuring plasma levels of the platelet specific protein beta-thromboglobulin (beta-tg). The mean beta-tg levels pre- and post-exercise in the normal subjects were 47 (SD: 42- 26-85) ng/ml and 48 (29-78) ng/ml respectively, and in the patient group 68 (43-107) ng/ml and 70 (45-109) ng/ml. There was a significant difference between the two groups at rest (p less than 0.05), but there was no change in either following exercise. Post exercise beta-tg levels showed no correlation with the degree of induced ischaemia as judged by ST segment depression and the number of leads involved. Resting beta-tg levels, however, were positively correlated with the presence and extent of angiographically demonstrable coronary disease (r = 0.53, p less than 0.05). We conclude that in vivo platelet activation is present at rest in patients with coronary artery disease, and whilst related to the presence and extent of such disease is unrelated to induced ischaemia.

Adolescent↗
PubMed1982

Is arson an aggressive act or a property offence? A controlled study of psychiatric referrals.

Arsonists seen for psychiatric assessment were compared to property offenders and to violent offenders on a number of clinical measures. It was found that arsonists were a mixture of the two groups but the majority aligned with property offenders in personality, diagnosis, criminal and violence history, family background, alcohol and drug use as well as in sexual behaviour. Significantly 18% of arsonists were mentally retarded. The act of arson was examined in detail using reliable ratings. While there was no obvious motive in two-fifths of the cases, revenge with underlying anger was most frequently a recognized motive for arson. The provocateur for the act of arson was not always readily identifiable and in over half the cases more than one person or an institution was the stimulus for the fire. Directions for future study were discussed.

Adult↗
PubMed1981

Infants at risk for schizophrenia. The Jerusalem Infant Development Study.

The development of infants born to parents with serious mental disorders was followed up from birth through the first year of life. An individual-differences approach to statistical analysis. Multidimensional Scalogram Analysis (MSA), was shown to be an effective statistical procedure for examining heterogeneous psychiatric populations. The MSA revealed the existence of a subgroup of infants born to schizophrenics who repeatedly performed poorly in motor and sensorimotor areas of functioning during their first year of life. These infants were especially vulnerable to external insults, and many had low to low-normal birth weights. These findings, taken together with similar findings from other investigations, add support to the hypothesis that these infants may have a genetically determined neurointegrative deficit.

Adult↗
PubMed1981

Thermography in the assessment of peripheral joint inflammation--a re-evaluation.

The reproducibility and sensitivity of quantitative infra-red thermography as a measure of peripheral joint inflammation was reassessed. Experiments were carried out in a temperature-controlled room at 20 degrees C. Initial stabilization experiments showed that in normal, medium sized, joints, there was an initial rapid cooling phase followed by a slower cooling phase which lasted longer than two hours. In the knees the differences between normal and active rheumatoid joints increased the longer patients remained in the room but for practical reasons a 30-minute stabilization period was subsequently chosen. In views of hands and fingers, rebound increases in skin temperature after entering the room, together with lesser differences between inflamed and non-inflamed joints, were found. The results suggested that the thermographic technique examined was adequate for detecting inflammatory changes in knee, ankles and elbows but unsatisfactory for quantification of inflammation in the small joints of the hands.

Adult↗
PubMed1981

Admission decisions and performance during medical school.

This study compared a group of 24 applicants who were interviewed and accepted at the Yale University School of Medicine but went to other medical schools (AYEs) with a group of 27 applicants who attended the same schools but had been rejected at Yale following an interview and committee deliberation (NAYs). Measures of performance during medical school included scores on Parts I and II of the examinations of the National Board of Medical Examiners and evaluations from the dean's office at each student's medical school. No relationship was found between admission decisions and performance during medical school when AYEs and NAYs attending the same medical schools were compared.

Connecticut↗