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Biomedical subjects

D L Kaplan

Publications and source records attributed to D L Kaplan.

At least 55 records · Page 3Linked to original sources
PubMed1989

Cutaneous segmental neurofibromatosis.

A recent case of cutaneous segmental neurofibromatosis provided the opportunity to review the literature to better understand this rare disease. This cutaneous form of the disease usually appears only on the skin, without other systemic involvement; it is not inherited. Only 19 additional cases in the English literature could be found, three cases with extracutaneous manifestations; three cases were familial. The prognosis for this form of neurofibromatosis is excellent, but examination for evidence of systemic disease is indicated.

Abdomen↗
PubMed1988

Microprobe analysis of chlorpromazine pigmentation.

We describe the histochemical, ultrastructural, and microanalytical features of a skin biopsy specimen obtained from a patient with chlorpromazine pigmentation. Golden-brown pigment granules were present in the dermis, predominantly in a perivascular arrangement. The granules stained positively with the Fontana-Masson stain for silver-reducing substances and negatively with Perl's stain for iron. Electron microscopy revealed dense inclusion bodies in dermal histiocytes, pericytes, endothelial cells, and Schwann cells, as well as lying free in the extracellular matrix. These "chlorpromazine bodies" were quite dense even in unosmicated, unstained ultrathin sections, indicating that the pigmentation is related, at least in part, to the inclusions. Microprobe analysis of the chlorpromazine bodies revealed a striking peak for sulfur, which strongly suggests the presence of the drug or its metabolite within these inclusions.

Adult↗
PubMed1987

Effects of Freon-113 on the survival of bacteria.

An initial investigation was made of the bactericidal and sporicidal activity of the dry cleaning solvent Freon-113 (1,1,2-trichlorotrifluoroethane) under various conditions. Representative bacterial strains selected for this study were Escherichia coli (ATCC 11229), Staphylococcus aureus (ATCC 6538) and spores of Bacillus globigii (Bacillus subtilis var. niger). Various conditions were studied, including temperature, moisture, detergents and organic load. The results of this study indicate that there is the potential for survival of significant levels of micro-organisms in Freon-113 within the conditions evaluated. However, the bactericidal efficiency of this solvent increases significantly against vegetative forms at elevated temperature and, to a greater extent, upon the addition of detergents. Organic material present in the form of soiled fabric was observed to depress this efficacy whereas bacterial spores were virtually unaffected under all conditions evaluated.

Bacillus subtilis↗
PubMed1986

Transferring a clinic-based health education program for children with asthma to a school setting.

Open Airways is a clinic-based health education program for low income, inner city families of children with asthma. The program was transferred to the public schools to test it in a setting more representative of school-age children with asthma, and to provide health education for families not receiving medical care for asthma. During the transfer, the program changed from placing primary responsibility for management on parents to a child-centered program independent of direct parental involvement. Children's attendance increased greatly and a significant number of families not receiving regular medical care for asthma enrolled. Preliminary analysis showed the child-centered program improved children's school performance and asthma management skills. The findings of this study suggest health education programs designed for medical care settings can be adapted successfully for use in the schools and reach new populations of children with chronic diseases.

Asthma↗
PubMed1985

Biodegradation of N-nitrosodimethylamine in aqueous and soil systems.

N-Nitrosodimethylamine (NDMA) was mineralized by microorganisms in aqueous and soil systems. Initial rates of mineralization (micrograms per milliliter per day) were calculated for a wide range of initial concentrations of NDMA (micrograms per milliliter to picograms per milliliter). Log-log plots of the data were fitted with both linear and nonlinear least-squares analyses; however, linear models provided better fits for the kinetic data in all cases. The slopes of the linear fits were not significantly different than 1.0 (P < 0.05); thus, first-order reaction kinetics were in effect over the range of concentrations tested, and saturation kinetics were not achieved. Rate constants (day) and total percent mineralized increased with decreasing initial concentrations of NDMA. Rates of mineralization were reduced in aqueous systems when supplemental carbon was available, whereas in soils, percentages of organic matter and supplemental carbon had little effect on rates of mineralization. Implications of these results for predictions of rates and threshold limits of mineralization activity in natural systems are discussed. A laboratory scale simulated trickling filter containing an activated charcoal bed provided a suitable environment for mineralization of NDMA at concentrations of 50 and 100 mug/ml on a continuous basis. NDMA was not toxic to natural populations of microorganisms at concentrations up to 10 mg/ml. Using high-pressure liquid chromatography coupled with radioactivity detection, we identified formaldehyde and methylamine as intermediates produced during the biodegradation of NDMA.

Journal Article↗
PubMed1984

The sign of Leser-Trélat associated with primary lymphoma of the brain.

The sign of Leser-Trélat has been defined as the sudden appearance of seborrheic keratoses in number and/or size in association with an underlying malignancy. There have been only thirty-two reported cases of the sign of Leser-Trélat since it was first described in 1984. This is the first known case of primary lymphoma of the brain associated with this sign. Until Dantzig's review of the literature in 1973, the only tumor type associated with this sign had been adenocarcinomas of the gastrointestinal tract and the genitourinary tract. Since that time there have been only nine cases reported that were not adenocarcinomas; of those, only four cases have been lymphoproliferative malignancies. We wish to emphasize the need for further reports of this sign to better characterize it and to make physicians more aware of the association between this dermatologic sign and an internal malignancy.

Aged↗
PubMed1982

Biodegradation of glycidol and glycidyl nitrate.

When calcium hydroxide is used to desensitize glycerol trinitrate (nitroglycerine)-containing waste streams, the epoxides glycidol and glycidyl nitrate are formed. The epoxide rings of both compounds are unstable to heat in aqueous solutions, and they open to form glycerol 1-mononitrate and presumably glycerol. These transformations were accelerated by microbial activity. Glycerol 1-mononitrate was slowly denitrated to form glycerol. Glycidol and glycidyl nitrate caused base-pair substitutions in the Ames test for mutagenicity, whereas glycerol 1-mononitrate tests were negative.

Journal Article↗
PubMed1980

Eating style of obese and nonobese males.

Variables traditionally thought to differentiate an obese eating style were examined in six nonobese and six obese males consuming a sandwich lunch. Determinations of meal size, meal duration, bites, bites per sandwich quarter, and various measures of rate of ingestion revealed no significant differences between groups. A trend suggested that the nonobese consumed a greater proportion of their meal during the first half of the meal as compared to the obese. These observations were confirmed in the second experiment, including significant findings of differential patterning of rate. Thus the cumulative intake curves of the nonobese were negatively accelerated, whereas those of the obese more closely approximated a linear curve. In the second experiment six nonobese and six obese males consumed their lunch at normal, fast, and slow rates. A trend indicated that more food was ingested at the fast rate, regardless of weight class. Sandwiches tasted better at the conclusion of meals consumed at rapid rates. Implications for the physiology of satiety and the diagnosis and treatment of obesity are discussed.

Feeding Behavior↗
PubMed1979

Biodegradation of polystyrene, poly(metnyl methacrylate), and phenol formaldehyde.

The biodegradation of three synthetic 14C-labeled polymers, poly(methyl methacrylate), phenol formaldehyde, and polystyrene, was studied with 17 species of fungi in axenic cultures, five groups of soil invertebrates, and a variety of mixed microbial communities including sludges, soils, manures, garbages, and decaying plastics. Extremely low decomposition rates were found. The addition of cellulose and mineral failed to increase decomposition rates significantly.

Animals↗
PubMedDate not supplied

Orientation of silk III at the air-water interface.

A threefold helical crystal structure of Bombyx mori silk fibroin has been observed in films prepared from aqueous silk fibroin solutions using the Langmuir Blodgett (LB) technique. The films were studied using a combination of transmission electron microscopy and electron diffraction techniques. Films prepared at a surface pressure of 16.7 mN/m have a uniaxially oriented crystalline texture, with the helical axis oriented perpendicular to the plane of the LB film. Films obtained from the air-water interface without compression have a different orientation, with the helical axes lying roughly in the plane of the film. In both cases the d-spacings observed in electron diffraction are the same and match a threefold helical model crystal structure, silk III, described in previous publications. Differences in the relative intensities of the observed reflections in both types of oriented samples, as compared to unoriented samples, allows estimations of orientation distributions and the calculations of orientation parameters. The orientation of the fibroin chain axis in the plane of the interfacial film for uncompressed samples is consistent with the amphiphilic behavior previously postulated to drive the formation of the threefold helical silk III conformation.

Air↗
PubMedDate not supplied

A biotinylated undecylthiophene copolymer bioconjugate for surface immobilization: creating an alkaline phosphatase chemiluminescence-based biosensor.

Methodology is described for the creation of a molecular assembly consisting of the enzyme alkaline phosphatase immobilized onto a glass surface using a biotinylated conjugated copolymer, poly(3-undecylthiophene-co-3-thiophenecarboxaldehyde) 6-biotinamidohexanohydrazone. The biotinylated polymer is attached to the inside walls of a silanized glass capillary via hydrophobic interactions, and a streptavidin-conjugated alkaline phosphatase is interfaced with the polymer through the classical biotin-streptavidin interaction. Utilizing a simple optical setup, we can detect the activity of as little as approximately 0.1 fmol of alkaline phosphatase with this molecular assembly. The assembly is mechanically robust and retains the majority of bound enzyme activity for up to 30 days. We have utilized this molecular assembly for the detection of organophosphorus-based pesticides. Both paraoxon and methyl parathion inhibit the enzyme-mediated generation of chemiluminescence signal. We are able to detect paraoxon and methyl parathion concentrations down to 500-700 ppb.

Alkaline Phosphatase↗