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Biomedical subjects

W G Mitchell

Publications and source records attributed to W G Mitchell.

69 records · Page 4Linked to original sources
PubMed1979

Pesticide residue concentrations in soils of five United States cities, 1971--urban soils monitoring program.

Soil samples from five metropolitan areas including Baltimore, Maryland; Gadsden, Alabama; Hartford, Connecticut; Macon, Georgia; and Newport News, Virginia were analyzed for elemental arsenic, organochlorine pesticides, and polychlorinated biphenyls (PCBs). A representative number of samples were analyzed for organophosphorus pesticides, but none was detected. All areas exhibited heavy soil concentrations of organochlorine pesticides including sigma DDT, aldrin, dieldrin, photodieldrin, chlordane, heptachlor, heptachlor epoxide, endrin, endrin ketone, and endosulfan sulfate. PCBs were detected in three of the five metropolitan areas. Within the metropolitan areas, samples from the urban, or core city, locations generally had higher pesticide concentrations than did samples from suburban locations. Finally, pesticide residue concentrations were generally higher in soils of metropolitan areas than in nearby agricultural soils.

Arsenic↗
PubMed1978

Pesticide residue levels in soils and crops, 1971--National Soils Monitoring Program (III).

Data from the 1971 National Soils Monitoring Program are summarized. Composite samples of soil and mature crops were scheduled for collection from 1,533 4-hectare sites in 37 states. Analyses were performed on 1,486 soil samples for organochlorines, organophosphates, PCBs, and elemental arsenic; samples were analyzed for atrazine only when pesticide application data indicated current-year use. Organochlorine pesticides were detected in 45 percent of the soil samples in the following order of frequency: dieldrin, sigmaDDT, aldrin, chlordane, and heptachlor epoxide. Most pesticide levels ranged from 0.01 to 0.25 ppm. Crop samples were collected from 729 sites, and all were analyzed for organochlorines. Crop samples were analyzed for organophosphates and atrazine only when pesticide application data indicated current-year use. Organochlorines were detected in 42 percent of the crop samples analyzed, organophosphates in 13 percent, and atrazine in 1 percent.

Arsenic↗
PubMed1976

The computer as an unbiased medical investigator. Experience on an active surgical service.

An adaptable on-line computer system for entry, retrieval, and analysis of medical discharge summaries has been developed and applied in the Trauma Service of a busy city hospital. Each summary occupied 5 to 10 minutes of the physician's time and compared favorably in cost to the standard dictated summary. While the average dictated summary contained 15 +/- 7 relevant facts, the machine-generated summaries were found to have 53 +/- 20 relevant facts. The summaries are well organized, easily comprehensible, and a duplicate copy can be obtained at any time by using the patient's name or number for identification. To date, 495 discharge summaries have been entered and reside in the memory of the computer. Statistical analysis from the data base is done by the computer, thus eliminating human prejudice. It provides facility for rapid and accurate retrospective studies as well as pattern-of-care and individual case review.

Computers↗
PubMed1976

Recurrence of group B streptococcal infection.

It is clear that the group B streptococcus has become a major pathogen of young infants within the comparatively recent past. Further it is clear that, as with other endemic and epidemic pathogens, increasing clinical and laboratory experience brings to light variations not initially evident. In addition, therapy presumably effective in initial cases may not continue to be so. The following papers by coincidence were received over a relatively brief period of time. Hence, for emphasis of some of the problems related to this organism, they are presented as a group.

Ampicillin↗
PubMed1976

Organochlorine pesticide residues in sugarbeet pulps and molasses from 16 states, 1971.

Sugarbeet pulp and molasses from 57 processing plants in 16 States were sampled for pesticide residues. No molasses samples contained detectable pesticide residues, but about 15 percent of the pulp samples contained low levels of dieldrin, toxaphene, or DDT and its degradation products. Sugarbeet pulp, when used as animal feed, can be a source of pesticidal contamination of human food.

Carbohydrates↗
PubMed1976

Pesticide levels in hay and soils from nine states, 1971.

In 1971 hay and soil samples were collected in 9 States to determine the incidence and levels of pesticide residues in hayfields. Residues were detected in 8 percent of the soil samples and 29 percent of the hay samples. DDT and its metabolites, DDE and TDE, were contained in 2 soil samples and 21 hay samples. Heptachlor epoxide and chlordane were detected in 1 soil sample, dieldrin in 5 soil samples, and diazinon in 4 hay samples.

Hydrocarbons, Chlorinated↗
PubMedDate not supplied

Intraparenchymal cerebral cysticercosis in children: a benign prognosis.

This paper reports 26 consecutive cases of cerebral cysticercosis in children, 21 presenting with intraparenchymal mass lesions, two with encephalitic disease, and three with intraventricular (racemous) cysticercosis. The intraparenchymal and encephalitic forms of the disease were benign. Regression of the lesions occurred within four months of diagnosis in all children treated conservatively with antiepileptic drugs, but no antiparasitic drugs. Major morbidity was limited to those patients who were subjected to operative intervention. Intraventricular disease was most malignant; all three patients manifested acute, severely increased intracranial pressure, all required immediate surgical decompression, and one patient died. The apparent overall benign course of intraparenchymal cerebral cysticercosis in children appears not to warrant antiparasitic drug therapy.

Adolescent↗
PubMedDate not supplied

Prognostic significance of acute epilepsia partialis continua.

We present 3 patients in whom epilepsia partialis continua was the presenting sign of an acute, rapidly evolving and catastrophic neurologic illness. Initial seizures were partial simple (i.e., eye deviation in one, finger twitching in one) which progressed to multifocal partial seizures. The course of the epilepsia partialis continua was 36-41 days. Prognosis was uniformly poor (i.e., death in 2, vegetative state in 1); therefore, epilepsia partialis continua in the context of an acute neurologic illness may herald a grim outcome.

Adult↗
PubMedDate not supplied

Reaction time, attention, and impulsivity in epilepsy.

Reaction time, attention, and impulsivity were studied in 112 children with epilepsy (4.5-13 years) using a computerized test. We measured simple reaction time (response with each hand separately to a single stimulus), forced choice reaction time (two stimuli presented in random order, one designated for each hand), and choice reaction time with distraction (two response stimuli, one for each hand, with two additional distracting stimuli randomly inserted). We also measured variability of speed of response and errors of omission and commission. Controls were unaffected children of similar age, ethnic, and socioeconomic backgrounds. Children with epilepsy were significantly slower, more variable, and made more omission errors than control children, even when analysis was limited to epileptic patients with IQ greater than 90, but they did not make more commission (i.e., impulsive) errors. Reaction times were related to IQ, but in general were not related to seizure severity, duration of seizure disorder, or duration of medication use. Untreated patients (N = 13) did not differ from those with antiepileptic drug levels in the therapeutic range on the day of testing (N = 52), but differed significantly from normal patients. Epileptic patients demonstrated significant slowing of reaction time and inattention, but not significant impulsivity, compared to normal children; however, these deficits do not appear to be related specifically to seizure history or treatment.

Adolescent↗
PubMedDate not supplied

Carbamazepine versus phenobarbital for partial onset seizures in children.

Thirty-nine children were treated with either phenobarbital (PB) or carbamazepine (CBZ) for newly diagnosed partial onset seizures. Drug selection was randomized in 33 subjects. Parents and the psychologist evaluating the child were blind to drug identity. Psychometric and behavioral evaluations were done at intake and at 6- and 12-month follow-ups. There were no significant differences between drugs in effect on behavior or cognitive function. CBZ caused more systemic problems. There was a trend toward better seizure control with CBZ, but this was not statistically significant. Although individual children in each group had changes in behavior or cognitive status, neither group changed significantly, in either acute or chronic follow-up.

Carbamazepine↗