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Biomedical subjects

R D Johnson

Publications and source records attributed to R D Johnson.

At least 181 records · Page 10Linked to original sources
PubMed1982

Electrophysiologic studies of cutaneous nerves of the forelimb of the cat.

The cutaneous innervation of the forelimb was investigated in 20 barbiturate-anesthetized cats by using electrophysiological techniques. The cutaneous area (CA) innervated by each cutaneous nerve was delineated in at least six cats by brushing the hair in the CA with a small watercolor brush while recording from the nerve. Mapping of adjacent CA revealed larger overlap zones (OZ) than were noted in the dog. Remarkable findings were that the brachiocephalic nerve arose from the axillary nerve and the CA comparable to that supplied by the cutaneous branch of the brachiocephalic nerve in the dog was supplied by a cutaneous branch of the suprascapular nerve. The CA supplied by the communicating branch from the musculocutaneous to the median nerve was similar in both species except that the communicating branch arose proximal to any other branches of the musculocutaneous nerve in the cat, whereas it was a terminal branch in the dog. The superficial branch of the radial nerve gave off cutaneous brachial branches in the cat proximal to the lateral cutaneous antebrachial nerve. The CA of the palmar branches of the ulnar nerve did not completely overlap the CA of the palmar branches of the median nerve as occurred in the dog; thus an autonomous zone (AZ) for the CA of the palmar branches of the median nerve is present in the cat, whereas no AZ existed for the CA of this nerve in the dog.

Animals↗
PubMed1982

Spinal nerve root origins of the cutaneous nerves arising from the canine brachial plexus.

The spinal nerve root origins of the cutaneous nerves arising from the brachial plexus were investigated in 10 babiturate-anesthetized dogs by stimulating dorsal roots C5 to T2 and recording from each cutaneous nerve. Upon completion of the experiment, the contributions of the spinal nerve ventral branches to the brachial plexus were verified by anatomic dissection. The brachial plexus was formed by the ventral branches of C6 to T2 in 8 dogs, C6 to T1 in 1 dog, and C5 to T1 in 1 dog. The cutaneous branch of brachiocephalicus nerve was formed primarily by contributions from the C6 dorsal root. The cranial lateral cutaneous brachial nerve, a branch of the axillary nerve, was formed predominantly from C6 to C7. The median nerve received contributions primarily from C7, C8, and T1, and the communicating branch from the musculocutaneous to the median nerve contained fibers primarily from C7 and C8. The medial and lateral branches of the superficial branch of the radial nerve arose from C6, C7, C8, and T1, with the medial branch generally arising 1 segment craniad to the lateral. The palmar and dorsal branches of the ulnar nerve arose predominately from C8 and T1, and the caudal cutaneous antebrachial nerve of the ulnar arose predominately from T1 and T2.

Action Potentials↗
PubMed1981

Seminoma metastatic to ureter.

A case of metastatic seminoma to the ureter is presented. The metastasis formed a polypoid intraluminal mass that led to complete obstruction of the ureter, leading to advanced hydronephrosis of the kidney. This is the second case in the world literature of a primary testicular tumor metastasizing to the ureter.

Adult↗
PubMed1981

Pesticide, heavy metal, and other chemical residues in infant and toddler total diet samples--(II)--August 1975-July 1976.

The Food and Drug Administration, U.S. Department of Health and Human Services, initiated the Total Diet Study in 1964 to monitor residues of pesticides and other chemicals ingested in the average diet of the United States' heartiest eater, the young adult male. In August 1974, one-third of the adult market baskets were replaced with infant and toddler market baskets. Averages and ranges of residues for this second in a series of infant and toddler baskets, for August 1975--July 1976, are reported. Included are results of determinations for zinc, cadmium, lead, selenium, arsenic, and mercury. Results of recovery studies conducted with compounds of each residue type are also presented.

Animals↗
PubMed1981

Adaptation of Prostatic-Group-Label Homogeneous Immunoassay to reagent-strip format.

The Prostatic-Group-Label Immunoassay (PGLIA) technique has been incorporated into a reagent-strip format. We report use of flavin N6-(N'-2,4-dinitrophenyl-6-aminohexyl)adenine dinucleotide (DNP-FAD) as the prosthetic group derivative and 6-N-(2,4-dinitrophenyl)aminohexanoic acid (DNP-caproate) as the competing ligand. DNP-FAD not bound by antibody combines with glucose oxidase apoenzyme, which then reacts with glucose and oxygen, and gives color through a peroxidase-linked system. The rate of color generation is thus a function of the DNP-caproate concentration. PGLIA reagent strips are prepared by sequential impregnations of filter paper with an acetone solution of indicator (3,3',5,5'-tetramethylbenzidine); an aqueous solution containing glucose oxidase apoenzyme, the rest of the color generation system, stabilizers, and antibody to DNP; and a solution of DNP-FAD in n-propanol. This preparation permits effective antibody binding, and prevents premature interaction of immunoassay components. A quantitative color response to concentrations of DNP-caproate in the range of 1 to 8 mumol/L was demonstrated with these reagent strips. Prototype PGLIA reagent strips for theophylline and phenytoin have been successfully developed by substituting the appropriate FAD derivative and antibody for the corresponding reagents in the DNP model system.

Aminocaproates↗
PubMed1981

Pesticide, metal, and other chemical residues in adult total diet samples--(XII)--August 1975-July 1976.

This report is on the twelfth in the series on the presence of pesticide and other chemical residues in the average diet of the United States' heartiest eater, the young adult male. Twenty market baskets were collected in 20 U.S. cities that ranged in population from less than 50,000 to 1 million or more. Composites of 12 food classes were analyzed. Averages and ranges of residues found are reported for August 1975 through July 1976, by food class. In addition to the pesticide and chemical residues, data for lead, cadmium, selenium, mercury, arsenic, and zinc are included. The individual items making up the dairy and meat composites in four market baskets were analyzed separately for pesticide residues, and the results are included. Results of recovery studies of pesticides and chemicals within various food classes are also presented.

Adult↗
PubMed1980

Calcium, phosphorus, iron, iodine, and zinc in the "total diet".

Advances in food technology have changed the nutrient composition of foods, raising questions as to whether mineral intakes in the U.S. are now adequate or excessive. When the FDA assayed "market basket" samples collected at the retail level in twenty urban areas of the U.S. during 1974 and 1975, the following minerals and the daily intake as percentages of the U.S. RDAs were found: (a) For adults (based on a 2,800 kcal intake)--calcium, 114; phosphorus, 171; iron, 98; iodine, 428; and zinc, 89; (b) for six-month-old infants--calcium, 163; phosphorus, 173; iron, 47; iodine, 878; and zinc, 112; and (c) for two-year-olds--calcium, 114; phosphorus, 130; iron, 112; iodine, 526; and zinc, 106.

Adolescent↗
PubMed1979

Pesticides and other chemical residues in infant and toddler total diet samples-(I)-August 1974-July 1975.

Since 1964, the Food and Drug Administration, U.S. Department of Health, Education and Welfare, has reported residues of pesticides and other chemicals present in the average diet of the young adult male. The present report is the first in a series of market baskets whose purpose is to monitor the average diet of infants and toddlers for the same residues. Ten market baskets were collected in 10 cities which ranged in population from less than 50,000 to 1,000,000 or more. Averages and ranges of residues found are reported by food class. Results of recovery studies of known residues and chemicals within various food classes are also presented.

Animals↗
PubMed1978

Some problems of alpha-fetoprotein screening.

In two years of a routine screening programme for the detection of neural-tube defects over 6000 women had serum-alpha-fetoprotein (A.F.P.) measured. As a result, 80 women carrying live singleton fetuses were offered amniocentesis under ultrasound control. All neural-tube defects detected at birth were recorded and necropsies were done routinely on abortuses, thus permitting evaluation of the screening programme in terms of false negatives and false positives. 16 amniotic-fluid A.F.P.s were abnormal, 1 for an unaffected fetus; and 2 others were normal for fetuses which had closed lesions. At the serum-A.F.P. stage, 3 lesions were missed. The detection-rate compares favourably with those of other series. However, in a pilot study, routine ultrasonic assessment of gestation yielded a substantial proportion of cases where a serum-A.F.P. deemed normal or abnormal when gestation was assessed clinically would have been misleading. Loss of normal fetuses subsequent to amniocentesis (5 in this series) also has to be taken into account.

Abortion, Therapeutic↗