Search PubMed⌕ Search

Biomedical subjects

J Baron

Publications and source records attributed to J Baron.

At least 289 records · Page 16Linked to original sources
PubMed1967

Enhanced protein synthesis in a cell-free system from hypertrophied skeletal muscle.

Hypertrophy of the rat soleus muscle was induced by tenotomy of the synergistic muscles. Four days after the operation, the weight of the muscle had increased by 30 percent. The hypertrophied muscle had an increased concentration of DNA and RNA, when compared to the contralateral control soleus. Although the amount of myofibrillar protein increased during the 4-day period, the concentration of this component decreased. Microsomes prepared from hypertrophied muscle had an increased RNA concentration. The combined microsomes and pH-5 enzyme from hypertrophied muscle supported a faster rate of protein synthesis in vitro than the same system prepared from an equal weight of contralateral muscle which was used as a control.

Animals↗
PubMedDate not supplied

Radioimmunoguided surgery benefits for recurrent colorectal cancer.

BACKGROUND: Despite new adjuvant therapy, 50% of patients with colon cancer will have recurrent disease. This study investigated the use of a radiolabeled monoclonal antibody in locating occult tumor during surgery for recurrent colorectal cancer. METHODS: Twenty-two patients with recurrent colorectal cancer underwent surgery using the radioimmunoguided surgery (RIGS) system. All patients were subjected to abdominal and chest computed tomography (CT). Before surgery, patients were injected with the CC49 monoclonal antibody (MoAb), anti-TAG antibody labeled with 125I. Ten patients with elevated carcinoembryonic antigen (CEA) levels and no CT findings had a scintigraphy scan with an anti-CEA MoAb labeled with 99Tc. Human antimouse antibody levels of these patients were within normal limits. Surgical exploration including liver ultrasound examination was followed by survey with a gamma-detecting probe (GDP). RESULTS: There was MoAb tumor localization in 100% of the patients. CT found nine tumor sites, traditional surgical exploration 30, and the GDP 51, with 44 confirmed by pathology (hematoxylin and eosin). The RIGS system found occult tumor in 10 patients (45.4%) and resulted in major changes in surgical procedure in 11 patients. In the 10 patients who had scintigraphy scans, 10 tumor sites were identified, whereas RIGS found an additional eight sites. CONCLUSION: RIGS technology offers a substantial benefit for patients undergoing surgery for recurrent colorectal cancer and a better chance of finding recurrent tumor intraoperatively in patients who have elevated CEA levels with no other CT findings.

Abdominal Neoplasms↗
PubMedDate not supplied

Evaluation of an attenuation correction method for thallium-201 myocardial perfusion tomographic imaging of patients with low likelihood of coronary artery disease.

BACKGROUND: Image artifacts caused by nonuniform photon attenuation are a source of error in interpretation of images during myocardial perfusion single photon emission computed tomography (SPECT). A newly introduced attenuation correction method was evaluated for improvement in image homogeneity during 201Tl SPECT. The method was assessed with a cardiac phantom and in examinations of 42 patients (29 men) with a low likelihood of coronary disease. METHODS AND RESULTS: Simultaneous transmission-emission SPECT was performed with a moving collimated 153Gd line source synchronized with a moving electronic acquisition window for transmission imaging and a novel variable-width electronic exclusion window for emission imaging designed to avoid transmission-to-emission cross talk. The resulting uncorrected and corrected polar maps were analyzed visually and divided into 31 segments for quantitative analysis. Visual analysis of the color-coded mean polar maps showed clear improvement in homogeneity after correction among the phantom, male patients, female patients, and 42 patients combined at stress and redistribution. The male and female mean polar maps showed very little differences in regional count distribution after correction. Quantitative analysis of the mean polar maps showed the following mean segmental counts (%SD) before and after attenuation correction: phantom 88 (9) to 90 (7.5), P = .00005; men at stress 83 (10) to 88 (6), P = .0007, and at redistribution 84 (8) to 88 (6), P = .01; women at stress 86 (7) to 90 (5), P = .0002, and at redistribution 87 (5) to 88 (7), P = .3; patients combined at stress 84 (8) to 88 (6), P = .0004, and at redistribution 85 (7) to 87 (7), P = .03. Inferior/anterior count ratio for men at stress increased after correction from 0.82 to 0.99 and septal/lateral count ratio from 0.94 to 1.02. Inferior/anterior count ratio for men at redistribution increased from 0.86 to 1.06 and septal/lateral count ratio from 0.97 to 1.04. Inferior/anterior count ratio for women at stress increased from 0.95 to 1.03 and septal/lateral count ratio from 0.93 to 1.00. Inferior/anterior count ratio for women at redistribution increased from 1.04 to 1.10, and septal/lateral count ratio decreased from 1.02 to 1.00. CONCLUSION: Improvement in image homogeneity was demonstrated with this attenuation correction method with a cardiac phantom and for patients with low likelihood of coronary artery disease. The slight relative increase in inferior wall counts at redistribution was most likely caused by scatter from the relatively higher liver activity compared with the situation during stress and emphasizes the need for scatter correction. The close similarity in count distribution for the mean male and female polar maps supports use of a sex-independent normal database for quantitative analysis. The reduced variation in corrected images from patient to patient implies increased accuracy for detection of myocardial defects.

Algorithms↗
PubMedDate not supplied

Inheritance of the henny-feathering trait of the Sebright bantam chicken.

The henny -feathering trait of the Sebright bantam chicken is the result of an enhanced rate of estrogen synthesis (aromatase activity) in skin and other peripheral tissues of this bird. To gain insight into the underlying nature of this mutation, we examined the inheritance of this trait using a sensitive isotopic assay for aromatase activity. All birds of the F1 generation obtained by crossing homozygous henny X non- henny chickens expressed increased aromatase in the skin, and the males exhibited henny -feathering plumage. The average rate of aromatase activity in the skin of F1 chicks was approximately half that of homozygous henny chicks. The distribution of increased aromatase activity in the F2 generation and in the backcrosses of F1 to the two types of parental strains suggest that the enzyme activity in extragonadal tissues is regulated predominantly by one autosomal gene. Attempts to demonstrate linkage to several known loci by backcrossing F1 heterozygotes with parental chickens carrying a variety of genetic markers were unsuccessful. We conclude that the enhanced estrogen synthesis in extragonadal tissues in chickens carrying this gene is inherited as an autosomal codominant but that a half maximal level of the enzyme is sufficient to allow full development of female feathering in affected male birds so that henny -feathering is transmitted as a dominant trait.

Animals↗