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Biomedical subjects

J Davis

Publications and source records attributed to J Davis.

At least 361 records · Page 20Linked to original sources
PubMed1988

Pulmonary hypertension and persistent fetal circulation in the newborn.

Despite these infants' very significant medical instabilities, which require vigorous therapeutic intervention, we have seen a population of infants with little in the way of persistent residual problems. Although many of their pulmonary complications persist after hospital discharge, most resolve within the first year of life. In addition, there are few neurodevelopmental disabilities encountered in such a high-risk population of children.

Epoprostenol↗
PubMed1988

Symptoms and time to presentation and treatment in ocular melanoma: the Western Canada Melanoma Study.

Reports on all ocular melanomas newly diagnosed between Apr. 1, 1979, and Mar. 31, 1981, were obtained from the cancer registries of British Columbia, Alberta, Saskatchewan and Manitoba. Of the 90 cases, 87 were in patients aged 20 to 79 years, 64 of whom were interviewed about their initial symptoms. Three symptoms--loss of part of the visual field (in 33% of patients), photopsia (in 20%) and blurred vision (in 20%)--emerged as the main indicators of disease. In 17% of cases the tumour was discovered as an incidental finding on ocular examination. The length of delay before consulting a physician was generally short in symptomatic patients, with 85% reporting that they saw a physician within 3 months of onset of the first symptom. Of the 30 patients who received definitive treatment 4 months or more after initial presentation, 13 were seen by general practitioners who delayed before referring the patient to an ophthalmologist. Continuing medical education is needed to ensure earlier referral to ophthalmologists by general practitioners of patients with ocular melanoma.

Adult↗
PubMed1987

Catecholamine metabolism and disposition in healthy and depressed subjects.

Depressed patients as a group have been found to excrete greater amounts of catecholamines (CAs) and metabolites than healthy control subjects, but these differences were not uniform for all metabolites. Patients may differ from controls in the metabolism and/or disposition of CAs. We analyzed the suggested metabolic-dispositional differences by determining 24-hour urine values for norepinephrine (NE), epinephrine (E), normetanephrine (NM), metanephrine (M), vanillylmandelic acid (VMA), and 3-methoxy-4-hydroxyphenylglycol (MHPG). For each subject, we calculated ratios of CAs or metabolites to an estimate of CA synthesis and determined ratios of CAs and metabolites to each other based on a precursor-product paradigm. The results indicate that as a group, patients have modestly but significantly greater CA synthesis rates than controls; patients excrete disproportionately more NE and E and disproportionately less MHPG relative to estimated CA synthesis, as well as other metabolites, than do controls; in contrast to NE, E, and MHPG, the increased NM, M, and VMA excretion rates by patients are proportional to each other as well as to the increase in CA synthesis; and the differences in NE, E, and metabolite excretion in the patients as a group are due principally to unipolar rather than bipolar depressives. The differences would be expected if patients, relative to controls, released more NE and E into the circulation. These data indicate the need to measure several CAs and metabolites when evaluating differences between groups since the significance of any given metabolite value needs to be examined in the context of total CA and metabolite production and excretion.

Adult↗
PubMed1987

Implementation of a semiclosed large scale counterflow centrifugal elutriation system.

A semiclosed counterflow centrifugal elutriation system that minimizes the risks of contamination and cell loss is presented. A detailed description of the configuration of the system and its sterilization and assembly is provided along with examples of its application to large-scale separation of leukapheresis buffy coat and cadaveric bone marrow. We are currently using this system to deplete lymphocytes from human bone marrow prior to use in allogeneic bone marrow transplantation. The implementation of a semiclosed system increases the safety, ease of operation, and reproducibility of a technique that has the potential for a wide range of clinical applications.

Cell Separation↗
PubMed1987

Lymphatic endothelial cell line (CH3) from a recurrent retroperitoneal lymphangioma.

An endothelial cell line derived from a massive recurrent chyle-containing retroperitoneal lymphangioma was isolated in monolayer culture. Scanning and transmission electron microscopy and immunohistochemistry confirmed a close resemblance to blood vascular endothelium with typical cobblestone morphology, positive immunofluorescence staining for endothelial marker Factor VIII-associated antigen and fibronectin, and prominent Weibel-Palade bodies. The endothelial cells also exhibited other ultrastructural features characteristic of lymphatic endothelium, including sparse microvillous surface projections, overlapping intercellular junctions, and abundant intermediate filaments. This endothelial cell line represents a new source of proliferating lymphatic endothelium for future study, including structural and functional comparison to blood vascular endothelium.

Adult↗
PubMed1987

Augmented preexcitation assessed by scintigraphic phase analysis during atrial pacing.

We sought to characterize the effect of augmented preexcitation on the phase image pattern associated with scintigraphic acquisition during conduction via accessory arteriovenous connections. For this reason we assessed phase image scintigraphy, acquired in sinus rhythm and during rapid atrial pacing in 12 patients with documented right (five patients) or left (seven patients) lateral accessory pathways. Augmented preexcitation during atrial pacing was documented at electrophysiologic study in all patients during atrial pacing at similar rates. Phase analysis was abnormal in only 8 patients during sinus rhythm but in all 12 patients during atrial pacing. Atrial pacing brought a significant delay in both mean left and right ventricular phase angles, LV phi and RV phi, respectively. With atrial pacing, the site of earliest phase angle, interpreted to indicate the site of earliest excitation, shifted to the site of the accessory pathway. There was increased relative "prematurity" of the mean phase angle of the ipsilateral ventricle and an absolute increase in the difference between mean and earliest left and right ventricular phase angles, delta phi (LV-RV) and delta phi 0 (LV-RV), respectively. In patients with right-sided pathways, delta phi (LV-RV) increased from 9.5 +/- 12.6 degrees to 47.9 +/- 22.8 degrees, whereas delta phi 0 (LV-RV) increased from 28.1 +/- 18.0 degrees to 67.6 +/- 25.0 degrees (both p less than 0.05). Patients with left-sided pathways demonstrated similar changes in which delta phi (LV-RV) decreased from 2.9 +/- 10.8 degrees to -26.5 +/- 9.0 degrees and delta phi 0 (LV-RV) decreased from 3.4 +/- 14.2 degrees to -27.4 +/- 17.9 degrees (both p less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1987

Changes in urinary catecholamines and their metabolites in depressed patients treated with amitriptyline or imipramine.

The effects of treatment with amitriptyline (AMI) or imipramine (IMI) on changes in catecholamines and their metabolites in urine were studied in 95 unipolar and bipolar depressed patients. For the entire group, not separated by drug, substantial reduction in concentrations of all metabolites, but not catecholamines, occurred. Although catecholamine and metabolite change was similar for most substances assayed, there were some specific drug and diagnostic group differences. Vanillylmandelic acid (VMA) reduction was limited to bipolar patients; metanephrine (M) reduction to unipolar patients. Greater M and 3-methoxy-4-hydroxyphenylglycol (MHPG) reduction were associated with response in unipolar, but not bipolar patients. In bipolar, but not unipolar patients, norepinephrine (NE) rose in responders in contrast to reductions among nonresponding bipolar patients. The results suggest that effectiveness of blockade of reuptake of norepinephrine may be relatively more important for recovery in bipolar than in unipolar patients. Study of a battery of amine substances may contribute more information to our understanding of antidepressant drug effects on aminergic systems than analyses of MHPG alone.

Adult↗
PubMed1987

Tamoxifen therapy in recurrent epithelial ovarian carcinoma.

Thirty-seven patients with recurrent epithelial ovarian carcinoma were entered into a trial of tamoxifen therapy (10 mg BID) to determine the effect on long-term survival. Thirty-one patients were evaluable with follow-up ranging from 6 to 42 months since initiation of hormonal therapy. All patients were heavily pretreated with multiple chemotherapeutic regimens (median 3). There was 1 complete responder (3.2%), 2/31 (6.4%) had a partial response, 6/31 (19.3%) had stable disease, and 22/31 (71%) had progressive disease. Twenty-four patients are dead (23 from advanced carcinoma, 1 from cardiac causes); 5 patients are alive with disease; 2 patients are lost to follow-up. Median survival of nonresponders was 7 months versus 16 months for responders (CR + PR + stable disease) (P = 0.001 life table analysis). Of the 9 responders, 7 had poorly differentiated tumors (grades 3 or 4), and 2 had moderately differentiated tumors (grade 2). Eleven patients had estrogen and progesterone receptor studies (ER, PR). No correlation between response rate and receptor status was evident. We conclude that although significant disease regression is unlikely to result from tamoxifen therapy, there may be a subset of patients who can benefit from the cytostatic properties of hormonal manipulation.

Carcinoma↗
PubMed1987

Juvenile sex offenders: development and correction.

This paper addresses the developmental nature of sexually abusive behaviors as they apply to juvenile male sexual offenders. Socialization and sexual victimization are discussed. Three case histories elucidate and support the discussion of the development of victim offending. Significant treatment issues of juvenile male sexual offenders center around the sexual assault cycle which provides a framework for sexual offenders to conceptualize and understand the cognitive, behavioral, psychological, and situational factors which have resulted in their offense(s). Although sexual offenders and sexual offenses are each unique, the sexual assault cycle offers a means of addressing essential commonalities in the treatment of juvenile sexual offenders. Sexual offender specific treatment is viewed as essential for decreasing the risk of further sexual offenses, and thus decreasing the incidence of sexual victimization.

Adolescent↗
PubMed1987

Rapid dynamic CT scanning to distinguish schizophrenic from normal subjects.

Rapid dynamic computerized axial tomography (CT) density-time curves were used to detect abnormal brain regions in groups of controls and DSM-III diagnosed schizophrenics. Density-time curves were designated as plateau curves if, following a bolus injection of contrast material, they exhibited a plateau from the peak value rather than a decrease. Five of the 10 schizophrenics versus none of the 11 controls were found to possess two or more plateau curves. The physiological basis for the plateau curves is not known, but an increase in blood-brain-barrier permeability could be involved.

Adult↗
PubMed1987

Antepartum predictors of fetal distress in postterm pregnancy.

The purpose of this study was to determine the efficacy of combining nonstress testing with ultrasound assessment of amniotic fluid volume for the antenatal evaluation of the postterm fetus. Postterm patients (884) were managed with amniotic fluid assessments and nonstress tests (including evaluation for variable and late decelerations) twice a week. There were no perinatal deaths or major neonatal morbidity. However, the antenatal testing sensitivity, specificity, negative, or positive predictive values were not improved by combining the two tests. Individually, amniotic fluid assessment was just as accurate a predictor of fetal well-being and was a significantly more sensitive test than the nonstress test. In addition, antenatal predictors of fetal distress and intrapartum signs of fetal distress were almost exclusively those reflective of umbilical cord compromise. These findings stress the importance of antenatal screening for signs of umbilical cord compromise as an early indication of potential fetal compromise. Although the results also suggest that amniotic fluid assessment is superior to the nonstress test, they do not conclusively support the use of amniotic fluid assessment as the sole parameter for postterm antenatal surveillance.

Amniotic Fluid↗
PubMed1987

The principles and use of the neodymium-YAG laser in gynaecological surgery.

The neodymium-yttrium aluminium garnet (Nd-YAG) laser is one of the most recent surgical instruments to be exploited by gynaecologists. This review discusses the manner in which this laser interacts with tissue compared to other surgical lasers. The safety precautions necessary in using this laser are outlined in view of the potential risk of injury to theatre personnel. This is particularly important with respect to the eye. The most valuable application of the Nd-YAG laser to the gynaecologist is its use in ablating the endometrium in cases of menorrhagia. This technique is successful on account of the coagulating properties of this laser. The endometrium is destroyed to a depth sufficient to ablate the basal layer and bleeding is controlled by the coagulation of vessels. Much of the clinical part of this paper deals with this subject, detailing the choice of patients and the particular risks of the technique and discussing some of the problems. Other uses are outlined. Many of these are equally well treated by other and better-established methods. Undoubtedly the future will see many developments and more applications will become apparent.

Colposcopy↗
PubMed1987

Encephalomyelitis associated with leukemia in a child.

A case of an encephalomyelitis in a child with acute lymphoblastic leukemia is reported. The patient was a 5-year-old boy who developed seizures, progressive confusion, and coma after radiation and intrathecal methotrexate therapy. Computed tomography (CT) of the brain showed bilateral hypodensities in the posterior parietal and temporal regions. At autopsy, perivascular inflammation, microglial nodules without intranuclear viral inclusions, and bilateral necrosis of the temporoparietal and hippocampal regions were seen in the brain and spinal cord. Paraneoplastic encephalomyelitis is generally recognized in adult patients with underlying malignancy but, to our knowledge, has not been reported in children with leukemia. This report should alert the clinicians to an entity that must be included in the differential diagnosis of leukemic children with progressive neurologic disorder.

Brain↗