Amino acids excess increase SCEs in human lymphocytes

The effects of 21 amino acids on sister-chromatid exchanges (SCEs) in human lymphocytes were investigated. Addition of each of the 21 amino acids, originally in a composition of the culture medium RPMI 1640, at three different concentrations (10 micrograms/ml, 50 micrograms/ml and 100 micrograms/ml) caused a dose-independent increase in SCE frequency. The results indicated that amino acids, although indispensable for cells in vivo and in vitro, may be SCE-inducing agents.

Effects of dNTPs on the sister-chromatid exchange (SCE) frequency in human lymphocytes

The effects of deoxynucloside triphosphates (dNTPs) on the frequency of sister-chromatid exchange (SCE) was studied in human peripheral lymphocytes. Treatment with each dCTP and dTTP did not change the SCE frequency; however, dGTP caused a significant dose-dependent increase in SCE frequency, whereas dATP caused a significantly decreased in SCE frequency. The SCE-increasing effect of the treatment with dGTP could be totally reversed by treatment with equal concentrations of dATP or dCTP. Treatment with a mixture of four equal concentrations of dATP, dGTP, dCTP, dTTP did not alter the SCE frequency. These results suggest that the dNTP pool imbalance was a SCE-effecting factor in human lymphocytes, and that dGTP may be mainly responsible for this effect.

The correlation between the loss of chromosome 14q with histologic tumor grade, pathologic stage, and outcome of patients with nonpapillary renal cell carcinoma

BACKGROUND

Conventional pathologic classifications of human renal cell carcinoma (RCC) give little insight into oncogenesis and little assistance in predicting the clinical behavior of this disease. Identification of specific genetic alterations involved in the development of RCC using fluorescence in situ hybridization (FISH) however, may help provide foundations for classification, prognosis, and clinical management of the patients.

METHODS

Archival, paraffin embedded tissue sections from 30 human non-papillary RCCs were examined with a dual color FISH technique for loss of chromosomes 3p and 14q. Telomeric DNA probes from 3p or 14q and an internal ploidy control probe, centromeric probe of chromosome 2, were applied directly to the tumor sections. The correlations between loss of 3p or 14q, and tumor ploidy, with tumor grade, pathologic stage, and patient outcome were assessed.

RESULTS

Ninety percent of the patients (27) lost chromosome 3p, and 36.7% of the patients (11) had chromosome 14q deletions. The loss of 3p in the samples tested was unrelated to patient age, gender, outcome, tumor stage, or histologic grade. However, the deletion of 14q was significantly correlated with higher stage (P = 0.01), histologic grade (P = 0.01), and patient outcome (P < 10(-4)).

CONCLUSION

The close correlation of 14q loss with higher stage, higher histologic grade, and poorer outcome for patients with nonpapillary RCC indicates that it may be a promising prognostic marker.

[Use of nutrient density in etiologic studies on stomach cancer]

Role of nutrient density played in the genesis of stomach cancer was analyzed with a pair-matched case-control design to explore further the association between dietary nutrient and incidence of stomach cancer. Investigation of 88 pairs of cases with stomach cancer and controls showed high nutrient density of dietary vitamins C and A could protect from stomach cancer with OR of 0.34 and 0.46, respectively, and high of carbohydrate could increase risk of it with an OR of 2.20. Some problems in the use of nutrient density were discussed in the paper.

Expression of activin and activin receptors in pc3 human prostatic-cancer cells

PC3 human prostatic cancer cells, which are androgen-independent and hormone-nonresponsive, were used to examine the possible presence and expression of activin and its receptors in this cell line because activin is a member of transforming growth factor beta (TGF beta) superfamily which has been found to have growth-inhibitory activity. We have studied whether PC3 cells transcribe mRNAs coding for beta A- and beta B-subunits of activin, and activin receptors I, II, and IIB, and whether PC3 cells produce activin proteins. The expression and localization of the mRNAs were elucidated by the reverse transcription-polymerase chain reaction (RT-PCR) and in situ hybridization techniques. The presence of immunoreactivity for activin was determined by immunocytochemistry. We have observed that messenger RNAs encoding activin beta A-, beta B-subunits, and activin receptors I, II, and IIB, but not that of the alpha-subunit of inhibin, were expressed, and activin proteins, but not inhibin, are present in PC3 cells. Furthermore, the RT-PCR products were confirmed by DNA sequencing. We conclude that activins and their receptors are expressed in PC3 and suggest that activins may have autocrine functions in these cells.

[The application of stool excretion alarm systems in patients with permanent colostomies]

Type D16-2 stool excreation alarm system is applied to patients with colostomies. It helps the patient to control stool excreation. The alarm system consists of a probe and alarming parts. The probe is usually put 20 mm into the stoma. The pressure sensitivity of alarming part carried by waist varies from 0.48 to 1.49N/cm2. As the pressure arrives to a certain degree, it will alarm and patient can go to release the stool. 205 patients under the instruction of the nurse used this system and showed the alarm system was sensitive, easy to use and not interrupt patients' daily activities.

The application of Dick instrumentation in spine surgery

From June, 1989 to March, 1991, 24 cases with various spinal disorders were treated in our department using the Dick technique. The results were as follows: In the fresh fracture group (7 cases), all the spine fractures were reduced anatomically: the 2 cases without neurological defects returned to work 3 months after operation; the 3 cases with incomplete paraplegia had rapid neurological recovery; and the 2 cases with complete paraplegia showed no recovery after operation. In the late fracture group (10 cases), traumatic kyphotic curves were partially reduced and back pain was decreased markedly in all: Muscle power was increased significantly in 3 cases; spasticity was remarkably improved in 2 cases; 3 cases obtained complete cure of incontinence; and 4 cases had no significant improvement. In 3 cases with ankylosing spondylitis, the initial average kyphotic curve was 73.3 degrees, while the postoperative average curve was 28.3 degrees. The result of treatment of spinal stenosis due to degenerative spondylolisthesis (1 case) was good; slipping vertebrae were stabilized and fused with the Dick system after thorough decompression. In 1 tumor and 2 Tb-spine cases, the patients recovered and were ambulatory soon after operation.