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Biomedical subjects

R Grover

Publications and source records attributed to R Grover.

At least 91 records · Page 5Linked to original sources

Dermal exposure and urinary metabolite excretion in farmers repeatedly exposed to 2,4-D amine.

Following multiple exposures to 2,4-D amine salts under normal field conditions in which ground rigs were used, farmers who sprayed once or twice had an average dermal exposure of 655 micrograms 2,4-D acid equivalents (a.e.)/kg a.e. sprayed and an average cumulative urinary metabolite excretion of 10.9 micrograms 2,4-D a.e./kg a.e. sprayed. One very high outlier value was excluded from these averages (F). Following 4 to 7 exposures, the average cumulative dermal exposure was 1,077 micrograms 2,4-D a.e./kg a.e. sprayed and the average cumulative urinary metabolite excretion was 21.5 micrograms 2,4-D a.e./kg a.e. sprayed. The amount of 2,4-D metabolite in urine was significantly correlated with the amount of herbicide sprayed and the time required for the urinary metabolite excretion to return to background concentration was related to the amount sprayed and the number of exposures.

2,4-Dichlorophenoxyacetic Acid↗

Newborn screening for hemoglobinopathies: the benefit beyond the target.

As a result of New York State's Newborn Screening Program 4,565 neonates with trait hemoglobinopathies were identified and 3,200 families were notified of the results of testing their infants in New York City in 1982. Of the 1,531 families (2,190 parents) tested and counseled, 22 parents were diagnosed with sickle cell disease and 39 couples were found to be at-risk for having a child with sickle cell disease. Amniocentesis was performed in 14 of the 28 at-risk pregnant women and three of the four affected pregnancies were terminated. MCH-331001-01 to 04

Anemia, Sickle Cell↗

Procedure for the determination of 2,4-D and dicamba in inhalation, dermal, hand-wash, and urine samples from spray applicators.

Analytical procedures for the simultaneous determination of residues of 2,4-D and dicamba from polyurethane foam plug air samplers, ethylene glycol impregnated glass-fiber filter paper dermal samplers, 1% sodium bicarbonate hand wash solution, and urine are presented. Residues were derivatized with diazomethane and quantitated using electron capture gas chromatography. Recoveries were greater than 80% at the limit of detection in all substrates. The limits of detection for both herbicides were 0.1 microgram/foam plug and 0.5 micrograms/filter paper, and in the urine, 1.7 micrograms/100 mL and 5.0 micrograms/100 mL for dicamba and 2,4-D, respectively.

2,4-Dichlorophenoxyacetic Acid↗

Combined use of autoradiography and enzyme histochemistry in studies on the mammalian testis.

Combined application of the methods of enzyme histochemistry and of autoradiography in one and the same section of tissue provides a method to achieve further informations on the individual cells. Prespermatogenesis and spermatogenesis in rodents with their well defined steps of development and very specific enzymatic patterns of each of the stages of the cycle of the seminiferous epithelium were used as a model to study the double labelling with the aid of the enzyme reaction and labelling with 3-H-thymidine. The techniques applied in this study are described and discussed in detail. Possibilities to elucidate the regeneration mode of the seminiferous epithelium by means of this method are discussed.

Alkaline Phosphatase↗

Pitfalls in diagnosis of osteomyelitis in children with sickle cell disease.

The cases of three children with unusual features of osteomyelitis and sickle cell disease are presented. Two children had salmonella osteomyelitis, one with a recurrence 1.5 years after adequate intravenous therapy. In the second, the bone scan was negative despite verified disease. The causative organism in the third case was Staphylococcus aureus, and there was extensive bone involvement of the radius without symptoms, but with a positive bone scan. It is recommended that the possibility of osteomyelitis be entertained in a child with sickle cell disease whenever there are symptoms and/or objective findings referrable to bone. Radionuclide scans, when used in timely fashion, can assist in the diagnosis, but confirmation can best be achieved by the recovery of microorganisms through blood culture and/or bone aspirate. The choice, dosage, and duration of antibiotic therapy should be determined by causative organisms and by serologic titers.

Anemia, Sickle Cell↗

Current sickle cell screening program for newborns in New York City, 1979-1980.

The newborn screening program mandated by the New York State Public Health Law requires that every baby born in the state be tested for eight conditions including sickle cell anemia. Although sickle cell screening of newborns has been in operation since 1975, the follow-up program for case retrieval to obtain repeat blood samples for definitive diagnosis and referral of diagnosed patients for ongoing medical care was established only in 1979. Of the 106,565 blood samples tested in New York City Newborn Screening Laboratory, March 1, 1979 to February 29, 1980, 141 infants were identified on repeat blood testing as having various forms of sickle cell disease (SS, SC and S beta-Thalassemia) and were referred for ongoing medical care. Data received on 131 patients from follow-up clinics revealed that the disease diagnosis made by the Newborn Screening Laboratory was confirmed in all patients. There were no deaths reported among the study patients (131 infants) followed for the period of 8-20 months despite the life-threatening complications among eight patients. Binomial distribution of the data on Black infants according to the Hardy-Weinberg equation showed reasonable agreement between the observed and computed incidence of various forms of sickle cell disease.

Anemia, Sickle Cell↗

Precursors of human colon carcinoma: a serial section study of colectomy specimens.

All polyps and strips of colonic mucosa 1 to 15 cm from tumor margins were examined for possible precursors of carcinoma in 24 patients undergoing partial colectomy for primary colorectal adenocarcinoma. Of 114 polyps found, 40.4% were adenomatous, and the remainder were hyperplastic or inflammatory or showed normal mucosa. No primarily dysplastic lesions, which could be interpreted as early de novo carcinomas, were found. Serial sections of mucosal strips revealed minute adenomatous foci in 3 of 24 patients, one of whom also showed several patches of exclusively dysplastic epithelium. This finding suggest that carcinoma may rarely arise de novo, but most carcinomas appear to be accompanied by (? preceded by) adenomatous changes.

Adenocarcinoma↗

Evaluation of polyurethane foam as a trapping medium for herbicide vapor in air monitoring and worker inhalation studies.

Polyurethane foam was an efficient adsorbent for trapping vapors of butyl esters of 2,4-D (2,4-dichlorophenoxyacetic acid) and triallate (S-(2,3,3-trichloroallyl)diisopropylthiocarbamate) in high volume air monitoring studies and of butyl esters of 2,4-D, iso-octyl ester of 2,4-D, n-butyl ester of 2,4,5-T (2,4,5-trichlorophenoxyacetic acid), bromoxynil octanoate (2,5-dibromo-4-hydroxybenzonitrile), triallate, and trifluralin (alpha, alpha, alpha-trifluoro-2,6-dinitro-N-N-dipropyl-p-toluidine) in short-term, low volume, worker inhalation exposure studies. The collected herbicide vapor was readily desorbed under soxhlet extraction with n-hexane and subsequently analyzed with electron-capture GLC. The overall efficiencies, for both trapping and extraction, were over 90%, using a single plug, for all herbicides, except triallate. In the case of triallate, two plugs in series were required for efficient trapping under the high volume air monitoring situation.

2,4-Dichlorophenoxyacetic Acid↗

Isoelectric focusing of cells using zwitterionic buffers.

A simple method of isoelectric focusing of cells is described. The pH gradient, superimposed on a density gradient, is developed by generating opposing concentration gradients of two zwitterionic buffers. The method can be used as a cell separation technique or as a means of characterizing the cell type on the basis of the focusing pH. Focusing is rapid and thus the method is of special advantage in its application to cells.

Ampholyte Mixtures↗

Evaluation of the expanded newborn screening program in New York City.

Since September 1974, New York State public health law has mandated that all newborn infants be tested for phenylketonuria, maple syrup urine disease, homocystinuria, histidinemia, galactosemia, adenosine deaminase deficiency, and sickle cell anemia in accordance with regulations of the state commissioner of health. During the period from May 1, 1975, to April 30, 1976, a total of 110,180 babies born in New York City were tested for these seven conditions. One year's experience with the screening program demonstrated a paucity of technological problems, low observed rate of both false-negatives and -positives, and the expected incidence of the conditions of highest prevalence, incidentally found during screening: i.e., sickle cell traits, AS and AC. What is equally apparent in reviewing this first year's experience is the extent to which the New York State law, its structure, and implementation have fallen short of the ultimate objective. The major reason for this failure is lack of funds and facilities in the areas of education, case retrieval, continuing medical care, and counseling. This report is presented with the hope that it will benefit all involved in genetic screening and especially those concerned with establishing similar programs.

Adenosine Deaminase↗

Transient acantholytic dermatosis: a reevaluation.

Transient acantholytic dermatosis is a self-limited, primary acantholytic disease that occurs predominantly in persons over 50 years old. The primary lesions, discrete papules and papulovesicles, are distributed mainly on the chest, back, and thighs and may be intensely pruritic. The disease lasts less than three months in the majority of patients, but occasionally may go on for two or three years. Four distinct histologic patterns are present in the biopsy specimens, namely, Darier-like in which there is focal acantholysis and dyskeratosis overlying suprabasilar clefts; pemphigus vulgaris-like, in which there are a few acantholytic cells above discrete suprabasal clefts having a mostly intact overlying epidermis; Hailey-Hailey-like, in which there are numerous acantholytic cells overlying suprabasilar clefts; and, finally, spongiotic, in which a few acantholytic cells are present within, or contiguous with, spongiotic foci. Some cases show a predominance of one pattern, but more frequently two or more of these patterns can be found in a single biopsy specimen.

Acantholysis↗

Residues of 2, 4-D in air samples from Saskatchewan: 1966-1975.

Residues of 2,4-D (2,4-dichlorophenoxyacetic acid) in air samples from several sampling sites in central and southern Saskatchewan during the spraying seasons in the 1966-68 and 1970-75 periods were determined by gas-liquid chromatographic techniques. Initially, individual esters of 2,4-D were characterized by retention times and confirmed further by co-injection and dual column procedures. Since 1973, however, only total 2,4-D acid levels in air samples have been determined after esterification to the methyl ester and confirmed by gc/ms techniques whenever possible. Up to 50% of the daily samples collected during the spraying season at any of the locations and during any given year contained 2,4-D, with butyl esters being found most frequently. The daily 24-hr mean atmospheric concentrations of 2,4-D ranged from 0.01 to 1.22 mug/m3, 0.01 to 13.50 mug/m3, and 0.05 to 0.59 mug/m3 for the iso-propyl, mixed butyl and iso-octyl esters, respectively. Even when the samples were analysed for the total 2,4-D content, i.e. from 1973 onwards, the maximum level of the total acid reached only 23.14 mug/m3. In any given year and at any of the sampling sites, about 30% of the samples contained less than 0.01 mug/m3 of 2,4-D. In another 40% of the samples, the levels of 2,4-D ranged from 0.01 to 0.099 mug/m3. Only about 30% of the samples contained 2,4-D concentrations higher than 0.1 mug/m3, with only 10% or less exceeding 1 mug/m3. None of the samples, obtained with the high volume particulate sampler, showed any detectable levels of 2,4-D, indicating little or no transport of 2,4-D adsorbed on dust particles or as crystals of amine salts.

2,4-Dichlorophenoxyacetic Acid↗