The genotoxic activity of glycerol in an in vitro test battery

Glycerol, a widely distributed constituent of food and an additive used in cigarette manufacture, has been tested for genotoxic potential in a battery of short-term genotoxicity assays. Glycerol was evaluated in the Ames Salmonella typhimurium mutagenesis assay (strains TA98, TA100, TA1535, TA1537 and TA1538), in the rat hepatocyte unscheduled DNA synthesis assay, in the Chinese hamster ovary (CHO) chromosome aberration assay, the CHO sister chromatid exchange assay and the CHO mammalian mutagenesis assay. All assays (except the rat hepatocyte unscheduled DNA synthesis assay) were conducted both with and without the addition of Aroclor-induced rat liver S-9. The results of all tests were negative, showing that neither glycerol nor its metabolites have genotoxic activity in the battery of tests used.

Accelerated degeneration of the segment adjacent to a lumbar fusion

Previously reported biomechanical studies on the effects of various types of spinal fusion procedures upon the adjacent segment indicate a significant degree of increased stress at that segment. This study presents 18 patients in whom new symptoms developed from the segment adjacent to a fusion after an average symptom-free interval of 8.5 years (1-38 years). The most common pathologic condition at the adjacent segment was hypertrophic degenerative arthritis of the facet joints. Spinal stenosis was found there in eight cases; severe disc degeneration in five; degenerative spondylolisthesis in two; and spondylolysis acquisita in one.

Lateral lumbar spinal canal stenosis: classification, pathologic anatomy and surgical decompression

The lateral region of the lumbar spinal canal is subject to pathologic alterations which encroach upon the neural structures located within. In order to further understanding and facilitate communication among specialists in diverse disciplines, a subdivision of the lateral region is proposed to comprise three zones: entrance zone, mid-zone and exit zone. The anatomical boundaries of these zones are defined and the pathologic conditions of each are described, and serve as the basis for techniques of surgical decompression when clinically required.

The lumbar facet syndrome

A clinical study was undertaken to formulate better criteria for accurate diagnosis of the lumbar facet syndrome and for predicting treatment response to facet joint injection. Twenty-two consecutive patients with a clinical diagnosis of lumbar facet syndrome, made by conventional diagnostic criteria, who were then treated with facet joint injection, were reviewed for their treatment responses. New diagnostic criteria were formulated based on a scoring system derived from the values observed in this review study. The scoring system has a total of 100 points, allocated as follows: back pain associated with groin or thigh pain, 30 points; well-localized paraspinal tenderness, 20 points; reproduction of pain with extension-rotation, 30 points; corresponding radiographic changes, 20 points; and pain below the knee, -10 points. A score of 60 points or more indicates a very high probability of satisfactory response to facet joint injection (100% prolonged response in this study). When only the conventional criteria were used, the overall results of prolonged relief of pain after facet joint injection was 50%. A "scorecard" system is proposed that may give a higher degree of diagnostic accuracy and predictability of successful response to facet joint injection.

Polyprotein processing in picornavirus replication

The primary translation product of the picornavirus genome is a single large protein which is processed to the mature viral polypeptides by progressive, co- and post-translational cleavages. Replication of the picornaviruses is thus entirely dependent upon the proteolysis of viral precursor proteins. In poliovirus, two virus-encoded proteinases have been identified that catalyze all but the final cleavage of the viral polyprotein. The final processing event, maturation of the virion polypeptide VPO, appears to occur by an unusual autocatalytic serine proteinase-like mechanism. Proteolytic processing of viral precursor proteins is basically similar in all picornaviruses, but recently it has become clear that there are also important differences between these viruses. Understanding of the processing events in picornavirus replication may ultimately lead to the discovery of specific inhibitors of the viral enzymes that could prove clinically useful as anti-viral agents.

The effect of verapamil on cysteamine-induced duodenal ulcer in the rat

To determine the effect of verapamil on experimental duodenal ulcer, pathologic assessment and secretory study were performed in the rats with ulcerogenic dose of cysteamine. The cysteamine increased gastric acid secretion and produced double duodenal ulcers at the proximal protion of the duodenum. Intramuscular injection of verapamil, 3 hours later, produced a significant decreased in gastric acid secretion which lasted at least 4 hours (cysteamine vs. cysteamine+ verapamil; 63.5 +/- 18.4 muEq vs. 25.5 +/- 9.0 muEq during the 1st hour after verapamil administration, 83.1 +/- 24.2 muEq vs. 27.8 +/- 12.3 muEq during the 2nd hour, 110.9 +/- 14.4 muEq vs. 38.5 +/- 25.9 muEq during the 3rd hour, 116.4 +/- 12.1 muEq vs. 40.7 +/- 29.6 muEq during the 4th hour, p less than 0.001). However, cysteamine-induced duodenal ulcers were not alleviated by two doses of intramuscular verapamil administration (4 mg/kg x 2). It is presumed that suppression of gastric acid secretion may not be sufficient to reduce cysteamine-induced duodenal ulcer formation or that verapamil itself may have aggresive effects against duodenum. To illucidate the exact role of verapamil in cysteamine-induced duodenal ulcer, further studies would be needed.

Hodgkin's disease: a reassessment of prognostic factors following modification of radiotherapy

Between 1970 and 1982, 175 patients with Stage IA, B, IIA, B, or IIIA Hodgkin's disease were treated with curative radiotherapy following surgical staging. The patients treated prior to 1975 received either regular extended or total nodal field treatments (Treatment Group 1, N = 65). Unsatisfactory results from this treatment program led to treatment modification in 1975. The modified protocols consisted of low-dose lung irradiation in patients having large mediastinal masses and/or hilar disease, and low-dose liver irradiation for Stage IIIAS+ patients (Treatment Group 2, N = 110). Recurrence-free survival rates improved significantly for various risk groups. Univariate analysis indicated that age, stage, symptoms, mediastinal mass size, number of sites involved, hilar disease, stage, and symptoms were significant risk factors in Treatment Group 1. In Treatment Group 2, only sex was a statistically significant risk factor. Stepwise Cox regression analysis for risk factors selected mediastinal mass size and stage as the most significant prognostic factors in Treatment Group 1. In Treatment Group 2, number of initial disease sites and sex were the most significant risk factors. The results of the study show significant improvement in recurrence-free survival rates in Treatment Group 2. It is concluded that these improvements are due to the modification in treatment.

Screening for plasmids in the genus Clostridium

A plasmid screening was performed on 150 strains out of 75 clostridial species using a modification of the alkaline-lysis procedure. In 26 strains representing 21 species one or more plasmid bands were detected ranging in size from 3 to more than 100 kilobase pairs. Clostridium aceticum proved to contain a single small plasmid (pCA1) of 5.4 kbp as revealed by restriction analysis and electron microscopy. A physical map of pCA1 has been constructed. Spontaneous mutants of C. aceticum defective in autotrophic growth have been isolated. No direct correlation between plasmid content and autotrophy could be found.

The nationwide epidemiological study of mental disorders in korea

The lifetime prevalences of DSM-III mental disorders using Korean version of DIS-III are presented. They were studied in 5,100 adults (aged 18 to 65) in household selected by two stage cluster sampling. Comparisons were made between regions, sex and age groups. International comparison with Epidemiologic Catchment Area program was also made.

Radical treatment of Hodgkin disease with radiation therapy: results of a 15-year clinical trial. The 1985 Erskine lecture

In 1970, the University of Minnesota Hospitals instituted a policy for treatment of patients with stage I, II, and IIIA Hodgkin disease that required complete staging including laparotomy and extended field or total nodal radiation. Evaluation of the results of this policy in 1974 led to modifications of treatment based on analysis of disease recurrences. Since 1974, patients with large mediastinal masses or hilar disease have been treated with whole-lung or half-lung radiation. In addition, patients with stage IIIA disease with positive spleens were treated with liver irradiation. Sixty-five patients with Hodgkin disease treated with extended or total nodal fields and 126 patients treated with the radical radiation approach are evaluated. The use of this treatment modification has changed the prognostic factors and produced an improvement in recurrence-free survival that is statistically significant. The authors suggest that radical radiation therapy is the treatment of choice in patients with stage IA, IIA, or IIIA Hodgkin disease.

Preserved left ventricular systolic function in clinical congestive heart failure

Although clinical congestive heart failure (CHF) is associated with significant left ventricular (LV) systolic dysfunction, recently it has been recognized that LV diastolic dysfunction also may occur in the absence of abnormal systolic performance. A retrospective study evaluated 23 patients with myocardial infarction and CHF who had undergone multigated blood pool scintigraphy and were found to have normal LV ejection fraction (≥ 50%). Average rapid filling velocity (RFV) and slow filling velocity (SFV) were both significantly reduced in CHF patients (5.1 ± 1.3 unit/s, 2.2 ± 1.4 unit/s respectively) compared with normal control group (3.9 ± 1.2 unit/s, 1.3 ± 0.8 unit/s respectively). Rapid filling time and total diastolic time were also significantly prolonged in CHF patients (p<0.01, p<0.05 respectively). There were no significant changes in heart rate and blood pressure between two groups. Thus, normal systolic LV function is encountered in patients with CHF and it appears to be prudent to evaluate diastolic performance as well for optimal therapeutic strategies for CHF patients.

Brain uptake of ketones in rats with differing susceptibility to dietary obesity

The effect of a low- and high-fat diet on the transport of 3-hydroxybutyrate and glucose across the blood brain barrier has been measured in two strains of animals that have a marked difference in the degree of obesity that develops when they eat a high fat diet. The S 5B/Pl rats are resistant to dietary obesity whereas the Osborne-Mendel rats readily develop obesity when eating a high-fat diet. The transport of 3-hydroxybutyrate and glucose across the blood-brain barrier was measured as the ratio of radioactive compound (3-hydroxybutyrate or glucose) to radioactively labeled water by the technique of Oldendorf. The uptake of 3-hydroxybutyrate was significantly higher in the S 5B/Pl rats than in the Osborne-Mendel rats when they were eating either the low-fat diet or the high-fat diet. In addition, there was a significant increase in the transport of 3-hydroxybutyrate in the animals of both strains when eating the high-fat diet as compared to the low-fat diet. However, there was no difference in the transport of glucose between the two strains of rats whether they ate a low-fat or high-fat diet. These data are consistent with the hypothesis that resistance to dietary obesity is associated with increased transport of 3-hydroxybutyrate across the blood-brain barrier.

Induction of Ia antigens on synovial cells by gamma interferon

Gamma interferon (IFN-γ) is a potent inducer of class II MHC antigens (la) in vitro. Enhanced Ia Expression is a characteristic feature of inflamed rheumatoid synovium. We investigated the potential of Ia induction upon non-inflammatory synovial cells under the influences of gamma interferon, alpha interferon and conditional medium from concanavalin A (Con-A) stimulated peripheral blood lymphocytes cultures (Con-A CM), Ia expression on enzyme dispersed cultured synovial cells decreased with time coincident with the loss of macrophage like cells. Addition of gamma interferon induced Ia molecules upon Ia negative synovial cells in a time and dose dependent manner, whereas alpha interferon treatment failed to induced Ia antigen. Con-A CM exerted the ability to induce Ia upon synovial cells. These findings suggest that: (1) Ia antigen expression by synovial tissue is the result of direct T cell influence: (2) non-inflammatory synovium has a potential to modulate Ia molecules under an altered environment.

Biomechanics of lumbosacral spinal fusion in combined compression-torsion loads

The current study investigates the stabilizing effects of three different types of spinal fusion to the juxta-free motion segments and to the fused segment of the lumbosacral spine under combined compression-torsion loads. Sixteen fresh human cadaver lumbosacral spines were tested under a simulated physiologic loading condition. The relative movements of the motion segments, as well as the angular rotations and the center of rotation were then computed and analyzed. The average torsional stiffness of the unfused three-motion segment was found to be 2.35 nm/degree. After fusion, the torsional stiffness did not increase significantly. Under the compression-torsional load, the anterior and bilateral-lateral fusions provided adequate stabilizing effect on the fused segment. The posterior fusion provided the least amount of stabilizing effect. These findings are similar to the results of the compression-bending experiment. Whereas the compression-bending loads produced significantly increased stress at the juxta-free segments, the compression-torsional loads did not produce any significant amount of increase in torsional stress at the juxta-free segments.