Transesophageal echocardiographic diagnosis of multicentric left ventricular myxomas mimicking a left atrial tumor.

We report a case of multicentric left ventricular myxomas with prolapse of one myxoma into the left atrium during ventricular systole that mimicked a left atrial tumor. The transthoracic echocardiogram showed large masses in the region of the mitral valve leaflets consistent with vegetations or tumors. A computed tomographic scan of the chest demonstrated two distinct left atrial masses, one of which appeared to prolapse from the left atrium into the left ventricle.

Psammomatous melanotic schwannoma: an additional component of Carney's complex. Report of a case.

The authors report a case of Carney's complex (the complex of myxomas, spotty pigmentation, and endocrine overactivity) in a 32-year-old white man. Psammomatous melanotic schwannoma has recently been included as a component of this disorder. The complex was recognized after a psammomatous melanotic schwannoma was resected from the sacral canal.

In vitro penetration of pesticides through human newborn foreskin.

The in vitro dermal penetration of 14C-labelled parathion, fenvalerate, carbofuran, and lindane through fresh full-thickness human newborn foreskin was determined at 1, 6, 24, and 48 h. The pesticides were applied to a constant dosing area (0.031 cm2), and a fixed dose (1.

A method for preparing mouse skin for assessing in vitro dermal penetration of xenobiotics.

A method is described for preparing mouse skin for assessment of in vitro penetration of dermally applied compounds. Separation of the epidermis from the dermis was attempted using a dermatome, heat, trypsin and collagenase. When mouse skin was incubated in a collagenase solution and separated using water, the hypodermis and part of the dermis were separated from the epidermis while leaving the hair follicles and hair shafts intact.

Macrophage uptake of a lipoprotein-sequestered toxicant: a potential route of immunotoxicity.

An experimental system was chosen to investigate the bioactivity of a lipoprotein-sequestered toxicant at the cellular level based on recent studies demonstrating receptor-mediated uptake of lipoproteins by macrophages. Rat peritoneal exudate cell suspensions (PEC) were exposed to DDT and lipoprotein-sequestered DDT, followed by measurement of DDT uptake, metabolism, and cellular toxicity. In vitro uptake assays demonstrated that PEC suspensions treated for 10, 20, and 30 min with 2.

Target ricin by coupling to an anti-macrophage monoclonal antibody.

By altering the receptor binding specificity of the highly potent natural toxin ricin, a macrophage specific immunotoxin was developed. Ricin ordinarily does not demonstrate cell type specificity and is capable of binding and entering cells through galactose containing receptors resulting in rapid cell death. A murine anti-rat peritoneal macrophage IgGl monoclonal antibody, B-6, was developed to serve as a target specific carrier for ricin.

Transport of conjugates of toxicants by blood proteins.

Binding of naphthol and its glucoside and glucuronide conjugates by blood proteins was studied in vitro and in vivo. Binding was found to be primarily to the albumin fraction of human blood and the binding constants were moderate to low. Both in vivo (mice) and in vitro (human) experiments suggest that a substantial portion of naphthol and two conjugates are transported in bound form to the site of elimination.

A rapid spectrophotometric method for assessing macrophage phagocytic activity.

The method described provides a rapid and inexpensive in vitro assay of phagocytosis by mononuclear phagocytes. This assay utilizes yeast cells, stained with congo red, as the target particle and quantitation is performed spectrophotometrically. An attractive feature of this assay is that phagocytic activity is assessed using large sample sizes, in this case approximately 1 X 10(6) macrophages per sample, resulting in a more accurate evaluation of phagocytosis than assays dependent on microscopic quantitation.

Percutaneous penetration of three insecticides in rats: a comparison of two methods for in vivo determination.

Percutaneous penetration of three insecticides was studied by two methods. The indirect (excretion analysis) and direct (skin patch removal) methods for determining penetration were compared in rats. Radiolabeled solutions of parathion, carbaryl, and DDT were applied to previously shaved rats at the rate of 4 micrograms/cm2.

Comparative penetration of insecticides in target and non-target species.

Dermal penetration of 14C-labeled carbaryl, parathion, DDT, dieldrin and permethrin was compared in American roaches, tobacco hornworms, Japanese quail, grass frogs and mice. Insecticides were absorbed more quickly in mice (one exception) while entry into insects was generally slow. The half time penetration rates for carbaryl ranged from 6 min for frogs to 4600 min for roaches.

In vitro uptake and transfer of chlorinated hydrocarbons among human lipoproteins.

The uptake, distribution, and exchange of chlorinated hydrocarbon insecticides (dieldrin and chlordecone) and biphenyls (2,4,5-2',4',5'-hexachlorobiphenyl and 3-chlorobiphenyl) among human lipoproteins was examined by fluorescence quenching, gel filtration, and ultrafiltration. The chlorinated hydrocarbons were rapidly taken up from solution or silica particles by lipoproteins. The distribution of chlorinated hydrocarbons among the lipoproteins was independent of the amount taken up by the lipoproteins.

Pituitary Cushing's syndrome and Nelson's syndrome: diagnostic criteria, surgical therapy, and results.

Eight patients with pituitary Cushing's syndrome and 2 with Nelson's syndrome were followed from one to ten years after removal of pituitary adenomas. A detailed assessment of the pituitary-adrenal axis was obtained in all patients when last seen, save the first, who had undergone a complete hypophysectomy ten years previously. Long-term observations have shown sustained endocrine cure in 7 of 8 patients with pituitary Cushing's syndrome.

Interaction of insecticides with human plasma lipoproteins.

The binding of chlorinated hydrocarbon, carbamate and organophosphate insecticides to human low density plasma lipoproteins (LDL) and high density plasma lipoproteins (HDL) was studied at pH 7.0 and 16 degrees C and 26 degrees C by equilibrium dialysis, difference spectra and fluorescence. The results suggest interaction to be a partitioning rather than a stoichiometric binding process.

Stomach absorption of intubated insecticides in fasted mice.

Eight 14C-labeled insecticides representing diverse chemical classes were intubated into fasted mice whose stomachs were ligated at the pylorus. Absorption through the stomach was measured at 3 time intervals over a 60-min period and compared to similar absorption studies in the entire gastrointestinal tract. The percent of stomach absorption (as contrasted to total gastrointestinal absorption) varied from 29% (carbaryl) to 10% (nicotine).

Exposure of field workers to organophosphorus insecticides: sweet corn and peaches.

Plasma and red blood cell cholinesterase levels of professional agricultural workers engaged in packing sweet corn and thinning peaches were monitored. Workers with extensive contact with mechanically harvested sweet corn (the corn had been treated one or two days before harvest with a combination of ethyl and methyl parathion) exhibited significant depression of cholinesterase. Gloves, worn by 40% of the workers, provided some protection from absorption of pesticide residues.

Exposure of field workers to organophosphorus insecticides: cotton.

The red blood cell and plasma cholinesterase (ChE) levels of cotton scouts inspecting foliage for insect infestation and damage were monitored. Group means for ChE activity were significantly depressed at one or more time(s) during four of the eight growing seasons studied. Although no symptoms of organophosphate poisoning were confirmed, several scouts exhibited ChE depressions over 50% of pre-exposure levels.

Relation between smoking and levels of DDT and dieldrin in human fat.

The adipose tissue of humans with known patterns of cigarette smoking was collected during 1973-74 and analyzed for DDT components and dieldrin. Although smokers are exposed to high levels of insecticides from smoke of cigarettes and some of these compounds can be stored in adipose tissue, it could not be demonstrated that a relationship exists between smoking habit and residual levels of DDT found in fat. Smokers seem able, through induction of enzymes by substances in tobacco smoke, to metabolize these insecticides at a rate approximately equal to the rate of their intake in the smoke.