EMG activity of medial and lateral hamstrings at three positions of tibial rotation during low-force isometric knee flexion contractions.

The purpose of this investigation was to determine how the position of tibial rotation effects the EMG activity of the medial and lateral hamstrings during low-force isometric knee flexion contractions. Forty-five subjects (ages 18-35) with no history of lower extremity injury or disease volunteered for this study. While lying prone, and with surface EMG electrodes secured to the bellies of their right medial (semitendinous and semimembranosus) and lateral (long head of the biceps femoris) hamstring muscles, each subject held the knee in 45° of flexion for 8 s against 5% of their body weight. This was performed three times in each of the positions of neutral tibial rotation, external tibial rotation, and internal tibial rotation. The root-mean-square (RMS) of the EMG activity from these muscles was determined for each of the contractions. A repeated measures ANOVA was used to compare the RMS values of the two muscle groups in the three positions. The average RMS values (in microvolts [mV]) obtained were (means and standard deviation): medial hamstrings in external rotation: 50.74 ± 23.11; in neutral: 65.57 ± 25.35; in internal rotation: 70.73 ± 31.86; lateral hamstrings in external rotation: 66.08 ± 46.99; in neutral: 46.18 ± 39.34; in internal rotation: 27.68 ± 17.86. A statistically significant interaction was found between tibial rotation and hamstring muscle (p < 0.0001). These results are consistent with the presumed function of these muscles in that EMG activity in the medial hamstrings increased when the tibia was rotated internally, whereas the lateral hamstring EMG activity increased when the tibia was rotated externally.

Enzymic serum cholesterol measurement with a basic autoanalyzer and Du Pont aca method.

I compared enzymic methods for total serum cholesterol as used with discrete (Du Pont aca and reagent packs) and continuous-flow (Boehringer Mannheim reagents and the Technicon AuotAnalyzer I) analysis of normal, icteric, and lipemic sera. The regression equation for 24 clear, non-icteric sera was: y (continuous flow) = 0.944x (aca) + 10.69; r = 0.971, Syx +/- 53.7 mg of cholesterol per liter. The continuous-flow system indicated no significant interference when as much as 350 mg of bilirubin was added per liter. Results with the aca method indicated a decrease in apparent cholesterol of about 5 mg/liter per milligram of added bilirubin. Serial diluting of lipemic sera resulted in falsely higher values with the aca method but no clinically significant effect on results with the AutoAnalyzer procedure. Apparent cholesterol as measured with the aca became proportionately greater than AutoAnalyzer values with increasing serum triglyceride concentration.

Observations on possible autoimmune therapeutic effects in experimentally produced rat bladder tumors.

Autoimmune response to normal and tumor bladder tissues in Fisher/Furth rats were obtained. The reaction consisted mainly of severe pericystitis and hemorrhagic lesions. The cellular infiltrate was predominantly lymphocytic including also plasma cells and histiocytes. Serological tests indicated development of host immunological response. 15 of 33 rat bladder tumors involuted entirely in the course of the autoimmune reaction.

An animal model for the study of prostatic adenocarcinoma.

After the injection of the potent carcinogen 9,10-dimethyl-1,2-benzanthracene (DMBA) male rats (Fisher/Furth), mice (Strong A/J), and Golden hamsters, which had been previously conditioned by castration and in which the prostate had become histologically atrophic, developed tumors consistent with prostatic adenocarcinoma. One month after castration, intravenous injections of DMBA were given in the vena cava or jugular vein once a month for 3 months. Three to four months later, histologic evidence of prostate adenocarcinoma was consistently found in each of the groups of castrated animals (11 rats, 22 mice, and 11 hamsters) which survived the experiment. The glands were enlarged grossly and ureteral obstructions were also noted. Metastasis to the lung also occurred in five mice, three rats, and one hamster.

Automation of the homogeneous substrate-labeled fluorescent immunoassay for theophylline in serum: application to the determination of phenytoin and phenobarbital in serum.

A substrate labeled fluorescent immunoassay procedure for serum theophylline has been automated. The method uses the Ames (SLFIA) substrate-labeled fluorescent immunoassay reagents and Technicon AutoAnalyzer equipment. Forty-seven sera analyzed for theophylline by the automated Ames SLFIA procedure and by the Syva EMIT method yielded the regression equation y (Ames) = 0.92x (Syva) + 0.47, SE, sy.x = 1.67, and correlation coefficient r = 0.934. Recoveries ranged from 94.6 to 100% by the automated SLFIA method. Within-run mean and SD for a sample in and above the therapeutic range was 14.5 +/- 0.37 and 22.7 +/- 1.0 mg/L, respectively. Day-to-day reproducibility was 13.4 +/- 0.92 and 24.7 +/- 1.71 mg/L for a sample in and above the therapeutic range, respectively. The automated SLFIA procedure analyzes serum for theophylline at the rate of 40 per hour and gives results comparable to the Syva EMIT method. The same equipment was also used for the SLFIA determination of phenytoin and phenobarbital and yielded reliable results. The manifold and equipment were the same. The only change was the substitution of the Ames phenytoin and phenobarbital reagents for the theophylline reagent.

Autoradiographic studies of oral lichen planus.

3H cytidine autoradiographic labeling patterns have been categorized into those characteristic for neoplastic, preneoplastic, and normal cell types. Specific differences in the patterns of transcription (RNA synthesis) revealed that the histology of a particular lesion generally correlated with (1) the percentage of cells labeled with the isotope, (2) the number of grains per cell, and (3) their intracellular distribution. When these three criteria of labeling were applied to lesions of the oral mucosa, very interesting data were collected on cases of lichen planus. The benign histologic appearance of the oral lichen planus epithelium exhibited a preneoplastic-appearing autoradiogram, an observation which is of particular interest in view of the fact that a small number of patients with this disease develop intraoral squamous cell carcinoma.