Search PubMed⌕ Search

Biomedical subjects

J Rothman

Publications and source records attributed to J Rothman.

33 records · Page 2Linked to original sources

Purification and characterization of myosin from calf brain.

Actomyosin complex was extracted from the brain cortex in a medium consisting of low salt, ATP, and EDTA, in the presence of protease inhibitors, followed by ammonium sulfate fractionation. Myosin was then purified from the actomyosin. Myosin obtained according to the procedure used was significantly contaminated with actin high (greater than 200,000 dalton) and low molecular weight proteins. Therefore, an alternative method based on affinity chromatography (Blue Dextran/Sepharose) and gel filtration (Sepharose 4B) was developed to purify myosin. This procedure yielded myosin that was greater than 95% pure as judged by electron microscopy and sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The subunit composition of purified brain myosin was monitored by sodium dodecyl sulfate-polyacrylamide gel also containing a urea gradient. A closely migrating triplet in the heavy chain and three light chains, LC1, LC2, and LC3, of Mr 21,000, 19,000, and 17,000, respectively, were observed. These findings raise the possibility of the existence of myosin isoenzymes in the brain. Brain myosin formed bipolar thick filaments in 0.075 M KCl and MgCl2. At low ionic strength, the Mg2+-ATPase activity of myosin was stimulated 3- to 3.5-fold in the presence of skeletal muscle f-actin. Brain myosin also hydrolyzed other nucleotides; the rate of hydrolysis was ITP greater than ATP approximately equal to CTP greater than GTP approximately equal to UTP. The substrate (ATP) saturation curve in the presence of 10 mM CaCl2 and 0.6 M KCl was complex and consisted of plateau regions. The Arrhenius plot of the Ca-ATPase data was linear, whereas with ITPase, it was biphasic with a break occurring around 20 degrees C.

Actins↗

Pyogenic liver abscesses: successful non-surgical therapy.

Eleven consecutive patients with pyogenic liver abscesses were seen in a 20-month study period. Ten patients were treated with antibiotics alone. All ten had abscesses demonstrated by hepatic scintigraphy or sonography. In six patients purulent material was obtained by percutaneous aspiration of the liver. Blood-cultures were positive in each of the nine patients in whom they were obtained. Nine of the ten patients treated with antibiotics alone were cured; one died from complications of a liver biopsy. These results indicate that pyogenic liver abscesses can be effectively managed by medical therapy and that surgery is rarely required.

Adult↗

Community mental health centers and family service agencies.

This study presents documentation that compares community mental health centers and family service agencies. Although these are complementary in function, their degree of interaction is less than optimal. This paper compares the characteristics of the two systems, using data regarding staff, finances and expenditures, clients, and programs.

Community Health Services↗

Several goals set.

Explore the source record for details and available documents.

Organization and Administration↗

Nephrosonography in the evaluation of renal failure and masses in infants.

The diagnostic accuracy of nephrosonography is compared with conventional radiologic techniques and surgical findings in 13 infants aged 1 day to 14 months, who were in renal failure or had abdominal masses. Ten of the 13 infants presented with marked renal failure and in half of them neither kidneys nor collecting systems were visualized on the first intravenous pyelogram. Normal renal architecture was demonstrated by nephrosonography in three, hypoplastic kidneys in three, hydronephrosis in three, and a combination of hydronephrosis and contralateral multicystic kidney in one. In the three infants without renal failure, only one kidney was demonstrated by IVP; The cystic contralateral kidney in each of them was demonstrated by nephrosonography. In all cases the diagnosis was confirmed by conventional radiologic techniques when renal function had improved or by surgical exploration. This technique appears to be a useful adjunct to conventional radiography in the differential diagnosis of the infant with abnormalities of the urinary tract. Nephrosonography is of especial value when a kidney is not visualized by IVP, and it may appropriately aid in therapeutic decisions regarding the use of invasive procedures in small critically ill infants.

Diagnosis, Differential↗

Death can be proud.

Explore the source record for details and available documents.

Adult↗

Neuronal conduction studies of the median nerve in non-impaired humans: a comparison of accepted techniques.

BACKGROUND AND PURPOSE: There are two commonly accepted techniques used for distal electro-stimulation placement when performing median motor nerve conduction studies. The purpose of this study was to compare latency using two commonly accepted sites of distal stimulation of the median nerve when performing motor nerve conduction studies on non-impaired adult humans. PARTICIPANTS: The sample consisted of 36 non-impaired participants (15 female, 21 male) aged 20 to 40 years. METHODS: Participants were randomly assigned to two groups and tested bilaterally for the median motor nerve. For distal stimulation of the median motor nerve, in the first group, 8 cm was measured from the center of the muscle diagonally to arrive at a point between the flexor carpi radialis and plamaris longus tendons. In the second group, 3.5 cm was measured from the distal wrist crease proximally along the median nerve for the distal stimulation of the median motor nerve. Distal latency of both techniques was obtained. Surface skin temperature of the palm was recorded throughout the procedures. RESULTS: No significant differences were found between the 8 cm and 3.5 cm techniques at p < or = 0. 05 level. COMMENT: Even though no differences were found between the two techniques, the 3.5-cm technique is recommended because of its consistency as an anatomical landmark reducing the potential for measurement error.

Adult↗