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Biomedical subjects

L Horton

Publications and source records attributed to L Horton.

31 records · Page 2Linked to original sources
PubMed1989

Serious respiratory consequences of detergent ingestions in children.

After ingesting or inhaling laundry detergent powder, eight children required hospital admission. The predominant symptoms were stridor, drooling, and respiratory distress. All but one patient underwent endoscopy of the airways and the esophagus, five children were admitted to the intensive care unit, and four children required endotracheal intubation. Laundry detergent ingestions are generally considered to have minor consequences, and there exists a paucity of literature on the subject. Evidence of significant morbidity incurred because of ingestion or inhalation of sodium carbonate-containing laundry detergent powder is presented, together with a review of the existing literature.

Burns, Chemical↗
PubMed1987

The quantitative distribution of cytosolic androgen receptors in microdissected areas of the male rat brain: effects of estrogen treatment.

Estrogen and androgen synergize in the regulation of various neuroendocrine functions. To determine a potential cellular basis of this synergism, we measured androgen receptor (AR) in the cytosol of 16 hypothalamic and limbic nuclei and subregions in castrated male rats and castrated rats treated with estradiol. Androgen receptor was measured by a previously validated in vitro binding assay using the synthetic androgen methyltrienolone [( 3H]R1881). Male Sprague-Dawley rats (250-350 g) were castrated 2 weeks before the implantation of a 2.5-cm Silastic capsule filled with crystalline 17 beta-estradiol. Control rats were sham implanted. Estrogen treatment lasted for 1 week, after which time the animals were killed, their brains were frozen and sectioned, and individual nuclei and subregions were removed by a tissue punch technique. Tissue from six rats were combined for each determination. The highest levels of AR were found in the ventromedial nucleus (16.5 +/- 1.4 fmol/mg protein), medial preoptic area (12.1 +/- 1.4 fmol/mg protein), bed nucleus of the stria terminalis (11.6 +/- 1.4 fmol/mg protein), lateral septum (11.4 +/- 1.4 fmol/mg protein), arcuate nucleus-median eminence (10.9 +/- 2.1 fmol/mg protein), and medial amygdala (10.3 +/- 0.9 fmol/mg protein). Estrogen treatment resulted in significant increases in AR in medial preoptic area (14.8 +/- 0.6 fmol/mg protein; P less than 0.05) and medial amygdala (14.6 +/- 1.2 fmol/mg protein; P less than 0.02). Subsequent studies using block-dissected hypothalamus-preoptic area, anterior pituitary, and prostate revealed significant estrogen-mediated elevations in AR in anterior pituitary cytosol [42.2 +/- 3.0 vs. 26.4 +/- 1.6 fmol/mg protein (control); P less than 0.01], but not in hypothalamus-preoptic area or prostate cytosols. Estrogen treatment had no effect on AR affinity. The binding of [3H]R1881 was specific for AR and was not affected by the addition of radioinert progesterone to the incubation tube. Estimates of AR concentration were similar regardless of whether [3H]R1881 or [3H]dihydrotestosterone was used as the ligand. In this study, we describe the distribution of AR throughout the hypothalamus and limbic areas using biochemical techniques. In addition, we have identified some cellular events that may mediate the synergistic actions of estrogen and androgen on the neuroendocrine system.

Animals↗
PubMed1982

Simultaneous contrast imaging of the left ventricle by two-dimensional echocardiography and standard ventriculography.

Simultaneous contrast two-dimensional echocardiograms and contrast ventriculograms were analyzed for 19 cardiac cycles in 6 patients. Ventriculographic volume was underestimated by 10 +/- 4.5% (p less than .001) by the contrast echocardiograms, despite good correlation (r = 0.88). Discrepancies could not be assigned to changes in volume between studies nor to a lack of precise endocardial definition. Simultaneous imaging demonstrated that the ultrasonic transducer was located 33 degrees cephalad to the cardiac apex. Although angiographic volume was severely underestimated, ejection fraction (r = 0.93) and stroke volume (r = 0.90) could be calculated from two-dimensional echocardiograms using regression equations.

Adult↗
PubMed1977

Streptozotocin-induced renal tumours in rats.

Forty-six separate renal tumours developed in 36/80 Wistar male rats given a single i.v. dose of streptozotocin (25 mg/kg body wt) to induce diabetes mellitus. Fourteen of the tumours were epithelial in type, 8 were wholly mesenchymal and 24 were largely mesenchymal but also contained epithelial elements. The purely epithelial tumours correspond to the renal adenomas and adenocarcinomas seen in man. The mesenchymal tumours were composed either of undifferentiated spindle cells or of a mixutre of poorly differentiated mesenchyme and epithelial glands. Microscopically, the mixed tumours resembled the nephroblastomas seen in man; both elements appeared to be malignant, but in the absence of metastases this remains unproven. The management of the diabetic state did not influence the incidence of tumours, but insulin appeared to enhance tumour growth.

Animals↗
PubMed1976

The haematology of hypothyroidism.

In an unselected series of 202 patients with hypothyroidism anaemia was present on diagnosis in 39 of 172 women and 14 of 30 men. Microcytic anaemia was present in only nine patients in the entire series. The average of the mean corpuscular volume (MCV) of all the patients was 90 fl. Fifty-three of 118 patients who were studied in detail had normal serum concentrations of vitamin B12, folic acid and iron. The haemoglobin was low in 13 of these 53 patients and rose on treatment with thyroxine alone. The MCV exceeded 90 fl in 29 of these 53 patients and in three it was greater than 100 fl. The MCV invariably fell on treatment with thyroxine even if the initial value was within the normal range. Nine of this group of 53 patients had both anaemia and an increased MCV--the macrocytic anaemia of hypothyroidism. A minor degree of anisocytosis of the red blood cells, which was reduced by treatment with thyroxine, was also demonstrated. Acanthocytes were present in the blood films of 32 out of 172 patients but in only five did the abnormal cells comprise more than 0-5 per cent of the red cell population. The incidence of new cases of pernicious anaemia diagnosed concurrently with the hypothyroidism in the carefully studied group of 118 patients was 8-5 per cent. The MCV of hypothyroid patients with low levels of vitamin B12 was often no greater than in patients with uncomplicated hypothyroidism. The MCV is not therefore a useful discriminant in the diagnosis of pernicious anaemia in hypothyroidism. The serum iron concentration was less than 12 mumol/1 in 60 out of 118 patients. The total iron binding capacity of the serum was increased in only 21 of these 60 patients. In 42 hypothyroid patients the low serum iron concentration was not associated with low levels of either vitamin B12 or folate and of these patients 22 were anaemic. Despite the very low percentage saturation of the iron binding capacity in all of these patients with a low serum iron, a lack of iron did not seem to be the usual determinant of anaemia when it occurred.

Acanthocytes↗
PubMedDate not supplied

Multidimensional pain assessment in premature neonates: a pilot study.

OBJECTIVE: To describe the physiologic and behavioral responses of premature neonates to a painful stimulus. DESIGN: Descriptive. SETTING: Secondary-level neonatal unit in a large metropolitan university teaching hospital. PARTICIPANTS: Forty neonates between 32 and 34 weeks' postconceptual age and less than 5 days' postnatal age. MAIN OUTCOME MEASURES: Physiologic (heart rate, oxygen saturation, and intracranial pressure) and behavioral (facial expression and cry) outcomes observed during a routine heel stick. RESULTS: Physiologic responses were significant, but were not specific to pain. Behavioral responses were more promising and indicated that premature neonates were capable of responding in a manner similar to full-term neonates. CONCLUSIONS: Premature neonates are capable of expressing their pain in a manner similar to healthy, full-term neonates. Factors that alter this response were not clearly delineated. Further research is needed to determine more precise patterns of response in this age group.

Age Factors↗