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Biomedical subjects

L Harris

Publications and source records attributed to L Harris.

At least 163 records · Page 9Linked to original sources
PubMed1986

Endodermal sinus tumor of the mediastinum. A report of seven cases and review of the literature.

Primary mediastinal endodermal sinus tumor is rare, and to date only 49 cases have been described in the English-language literature. Seven new cases are reported. Light microscopic examination showed characteristic features including papillary, reticular, tubular and solid growth patterns, complete or incomplete Schiller-Duval bodies and intracellular or extracellular periodic acid-Schiff-positive material. Immunohistochemical studies showed alpha-1-antitrypsin in seven, alpha-fetoprotein in seven, keratin in six, and carcinoembryonic antigen in four cases. The beta subunit of human chorionic gonadotropin, albumin, fibronectin, and transferrin were not found in any case. Electron microscopic studies performed in four cases showed intracellular and extracellular basement membrane-like material, multiple large multivesicular bodies, desmosomes and microvilli. Mediastinal endodermal sinus tumor can and must be differentiated from poorly differentiated adenocarcinoma metastatic or extending to the mediastinum because of the distinctly different prognoses and therapies. In spite of modern chemotherapy, the prognosis of mediastinal endodermal sinus tumor remains poor. The single most important prognostic indicator is whether the tumor mass can be completely excised before or after chemotherapy.

Adolescent↗
PubMed1986

Effect of delta 9-tetrahydrocannabinol on herpes simplex virus type 2 vaginal infection in the guinea pig.

The present investigation was undertaken to determine whether delta 9-tetrahydrocannabinol (delta 9-THC) decreases host resistance to herpes simplex virus type 2 vaginal infection in the guinea pig. The guinea pig was selected as the host since it has been shown to express a spectrum of primary herpes genitalis which is similar to that in humans. Animals were administered delta 9-THC or vehicle intraperitoneally on Days 1-4, 8-11, and 15-18. Herpes simplex virus was introduced intravaginally on Day 2. Host resistance to virus infection was assessed by comparing frequency and severity of lesions, virus shedding, and animal mortalities. Virus-infected animals treated with drug at doses of 4 and 10 mg/kg exhibited significantly greater severity of genital disease during the 30-day period of study when compared to virus-inoculated vehicle controls. A direct relationship was noted between dose of delta 9-THC and cumulative mortalities on Day 14 following primary infection. These results indicate that delta 9-THC decreases host resistance to herpes simplex virus type 2 vaginal infection in the guinea pig.

Animals↗
PubMed1984

Amiodarone for long-term management of patients with hypertrophic cardiomyopathy.

Fifty-three patients with hypertrophic cardiomyopathy who had serious arrhythmias (45 patients), refractory chest pain (5 patients) or a high risk of sudden death (3 patients) received amiodarone for 6 to 96 months (median 18) after completion of a loading and an initial maintenance period. The dose of amiodarone was altered by 50 to 200 mg/day at 3- to 6-month intervals, guided by electrocardiographic monitoring, plasma drug level measurements and side-effect questionnaires. Ventricular tachycardia was suppressed in 24 patients (92%) with doses of 100 to 400 mg/day (median 300); none died suddenly during a mean follow-up of 27 months. Although symptomatic episodes of frequent or prolonged supraventricular tachycardia or paroxysmal atrial fibrillation/flutter were abolished in 8 of 9 patients on 100 to 600 mg/day (median 300), in 1 patient incessant atrial flutter developed that was relatively refractory to direct-current cardioversion. In 11 patients with atrial fibrillation, sinus rhythm was restored in 7 (after direct-current cardioversion in 3) with doses of 100 to 600 mg/day (median 300) and has been maintained in 5 with associated improvement in symptoms. Despite discontinuation of beta-blocker therapy, chest pain was unchanged in 17 patients, was impaired in 11 and was worse in only 2. Amiodarone was discontinued in 3 patients; in 1 because of hair loss, in 1 because of neurologic symptoms and in 1 because of facial discoloration; in the latter 2 patients, amiodarone was restarted after 1 and 14 months, and was tolerated and effective at the lower dosage.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1984

Treatment of painful diabetic polyneuropathy with mixed gangliosides.

We studied 18 patients with painful diabetic neuropathy in a double-blind study of 40 mg per day of mixed gangliosides. Diabetes control was maintained throughout by analysis of serum glucose and glycosylated hemoglobin levels. Median motor and sensory, and peroneal motor conductions we evaluated in placebo and treated groups before and after a treatment period of three months. All conductions were performed by one technician on a TECA-4 EMG machine with surface temperature controlled at 37 degrees C. There was a definite improvement in nerve conductions in the treated group, particularly noted in the median sensory conductions. We have demonstrated a difference between right and left-sided conductions in the same patients confirming that this illness, at least from an electrophysiological point of view is asymmetric. Clinical improvement was variable but when present was dramatic. Side effects of this drug were minimal. Half of the patient complained of a transient increase in pain during the first two weeks of treatment. No patient stopped the drug because of this complaint. We conclude that in this three-month study mixed gangliosides caused a significant improvement in some nerve conductions without significant side effects. Further studies seem warranted to determine the nature and extent of this effect.

Adult↗
PubMed1984

Protection against diisopropylfluorophosphate intoxication by pyridostigmine and physostigmine in combination with atropine and mecamylamine.

Atropine (A), mecamylamine (M), pyridostigmine (Py) and physostigmine (Ph) are pretreatment components of Mix I (A = 0.79, M = 0.79, Py = 0.056 mg/kg) and Mix II (A = 0.79, M = 0.79, Ph = 0.026 mg/kg). They have been successfully used in antagonizing Soman intoxication in experimental animals. Rats were pretreated with either Mix I or Mix II and subsequently exposed to diisopropylfluorphosphate (DFP). Pretreatment with Mix I or Mix II (i.m.) 30 min before DFP (i.v.) protected rats from the lethal effects of DFP. The protective ratios were 2.8 (Mix I) and 6.9 (Mix II). Changes in brain levels of acetylcholine (ACh) were measured to help understand the basis for effectiveness of these pretreatments. In the absence of DFP, pretreatments had no significant (P greater than 0.05) effect on bound or free ACh. Pretreatment did not prevent the DFP-induced rise in bound and free ACh nor the agent-induced physical incapacitation at 30 min post exposure. At 2 h after DFP exposure, rats pretreated with Mix II, but not Mix I, showed significant recovery from signs of physical incapacitation. At 30 min after the administration of 3.3 mg/kg of DFP (i.v.), the levels of free and bound ACh in rats given Mix I or Mix II pretreatment increased above control levels by 705% and 116% and 120% and 43%, respectively. By 2 h after DFP, cerebral ACh levels had changed to 437% and 91% with Mix I pretreatment and 26% and 50% with Mix II pretreatment. These data suggest a correlation between DFP-induced increases in the levels of cerebral ACh, possibly free, and physical incapacitation.(ABSTRACT TRUNCATED AT 250 WORDS)

Acetylcholine↗
PubMed1983

Side effects and possible contraindications of amiodarone use.

With the increasing use of amiodarone, several unwanted effects have been recognized. We reviewed 140 patients treated with amiodarone over a 5-year period in an attempt to identify patients at risk, to assess the incidence of these effects and their possible relation to dose, and to determine their outcome. The most common effect was photosensitivity (57% of patients responding to a questionnaire), whereas asymptomatic corneal microdeposits were found in all patients undergoing ophthalmologic examination. In contrast, symptomatic eye changes (colored halos) and slate-gray skin pigmentation were rare. Of the metabolic alterations, the rise in hepatic enzymes correlated with dose and plasma drug and metabolite concentrations (r = 0.59, p less than 0.001; r = 0.62, p less than 0.001, respectively) but was not associated with clinical disease. This relation to dose was not evident in patients developing clinical thyroid abnormalities (two hypothyroidism, two hyperthyroidism), all of whom had normal thyroid function prior to therapy. Four of the five hypothyroid patients were over 70 years of age. No patients developed peripheral neuropathy, but tremor and sleeplessness were common complaints (30% and 28% of patients, respectively) that responded to a decrease in dose. One patient with an abnormal chest x-ray film prior to therapy developed pulmonary fibrosis. We suggest the restricted use of high doses of amiodarone for protracted periods. Patients at particular risk are the older age group (hypothyroidism) and those with abnormal lung function prior to therapy who may be predisposed to pulmonary alveolitis. Most of the observed unwanted effects resolve when amiodarone is decreased in dose or discontinued.

Aged↗
PubMed1983

A Comparison of Pigment-Protein Complexes among Normal, Chlorophyll-Deficient and Senescent Soybean Genotypes.

Pigment-protein complexes were isolated from chloroplasts of normal green and several types of chlorophyll-deficient soybeans. The complexes were separated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and comparisons were made between normal and chlorophyll-deficient genotypes of the relative amounts of chlorophyll associated with Photosystem I (PSI), Photosystem II (PSII), light-harvesting, and free pigment complexes.Chlorophyll-deficient genotypes, compared to normal green genotypes, have fewer light-harvesting complexes and a higher ratio of PSII to PSI complexes. Chlorophyll associated with PSII in yellow genotypes is in relatively higher amounts in spite of the fact that these genotypes have much less grana stacking than normal green genotypes. Although PSII activity has been associated with appressed regions of grana in normal plants, our work shows that the association does not always hold true.

Journal Article↗
PubMed1983

Renal elimination of amiodarone and its desethyl metabolite.

Two patients in chronic renal failure receiving amiodarone for the treatment of refractory arrhythmias were commenced on dialysis, in one case, intermittent peritoneal dialysis, in the other, haemodialysis. Plasma concentrations of amiodarone and its desethyl metabolite were consistent with the dose received, whilst neither compound was recovered in the dialysate. In these patients and in 10 additional patients with normal renal function taking amiodarone, only negligible amounts of either compound were detected in urine. These findings suggest that amiodarone may be a suitable antiarrhythmic agent for use in patients with chronic renal failure.

Amiodarone↗
PubMed1983

Value analysis.

Explore the source record for details and available documents.

Costs and Cost Analysis↗
PubMed1983

Effect of psychosocial stimulation on mental development of severely malnourished children: an interim report.

The effect of adding psychosocial stimulation to the treatment of severely malnourished children was studied. The study period covered children from the time they left the hospital to 24 months later. The children's developmental levels (DQs) were compared with those of two other groups who were in the hospital--an adequately nourished group with diseases other than malnutrition, and a severely malnourished group who received standard hospital care only. The children receiving intervention had structured play sessions in the hospital and were visited weekly for 2 years after returning home. During the visits paraprofessionals showed mothers how to continue structured play with their children. The malnourished children who did not receive intervention showed a marked deficit in developmental level compared with that of control children throughout the study. The control children showed a decline in developmental level with age, which is characteristic of disadvantaged children. The children receiving intervention showed marked improvements and by 24 months were ahead of the children who did not receive intervention in every subscale and were head of the adequately nourished children in two subscales. Both groups of malnourished children remained behind the control children in nutritional status and locomotor development.

Anthropometry↗