Heat-stable antigen may be an early marker of extrathymic murine intestinal intraepithelial lymphocytes

Using a system of bone marrow (BM) hematopoietic repopulation of irradiated euthymic and athymic mice, we have examined the early stages of extrathymic T-cell development within the murine small intestine epithelium. During a period of active extrathymic T-cell development, two distinct populations of intraepithelial lymphocytes (IEL) were present. One consisted of CD3+ lymphocytes with phenotypic properties of mature IEL. The other population consisted of a transient IEL subset that increased in abundance between days 5 and 14 post-BM transfer, and then declined. The majority of transient IEL in both types of mice expressed the heat-stable antigen, of which some cells coexpressed CD3 but were void of other markers common to mature T cells. Studies using freshly extracted IEL from normal nonirradiated mice found that approximately 3% to 5% of the IEL had phenotypic properties similar to the transient IEL observed during repopulation of radiation chimeras, indicating that such IEL are present within the gut epithelium of normal, nonirradiated mice. Identification of this IEL subset should greatly facilitate studies of extrathymic IEL development.     

Functional analysis in Saccharomyces cerevisiae of naturally occurring amino acid substitutions in human dihydrolipoamide dehydrogenase

Dihydrolipoamide dehydrogenase is a common component of mammalian multienzyme complexes that decarboxylate alpha-ketoacids and catabolize glycine. The common function is to reoxidize a reduced lipoate component of each complex, thereby preparing that lipoate for another round of catalysis. Regions within dihydrolipoamide dehydrogenase involved in association with other proteins of the complexes are poorly defined, and despite high amino acid sequence conservation through evolution, it is unknown if dihydrolipoamide dehydrogenases are functionally equivalent across species. To address this issue, we asked whether the human enzyme could restore function to the alpha-ketoacid dehydrogenase complexes in a yeast strain deficient in endogenous dihydrolipoamide dehydrogenase. This dihydrolipoamide dehydrogenase null mutant will not grow on non-fermentable carbon sources. The human enzyme expressed from a CEN plasmid complemented the growth phenotype and restored full activity to the pyruvate and alpha-ketoglutarate dehydrogenase complexes. Human dihydrolipoamide dehydrogenases with selected amino acid substitutions were then tested in the null strain for their ability to restore function. Substitutions tested represented naturally occurring candidate mutations identified in an individual with inactive dihydrolipoamide dehydrogenase. A K37E change had full function while a P453L change resulted in reduced dihydrolipoamide dehydrogenase abundance in the mitochondria and no detectable catalytic activity.      

Vitamin D metabolites and growth hormone therapy in uraemic rats: the short-term effect on growth failure and hyperparathyroidism

Summary: The aim of our study was to evaluate the effect of 1,25 dihydroxyvitamin D3 (D), 22-oxacalcitriol (O) or recombinant human growth hormone (GH) on growth failure and hyperparathyroidism in 5/6 nephrectomized uraemic (Ur) rats. Seven groups of rats were studied: (i) sham controls (SC; n =6); (ii) Ur controls (UrC; n =8); (iii) Ur treated either with D (UrD; n =7); (iv) O (UrO, n =8); (v) GH (UrGH; n =7); (vi) D+GH (UrDGH; n =9); or (vii) O+GH (UrOGH; n =7). For 14 days, D and O were administered intraperitoneally daily at 30 ng/kg per day and GH subcutaneously daily at 1.3 i.u./day. Four weeks after 5/6 nephrectomy, plasma creatinine (Cr), plasma and urine calcium (Ca), plasma phosphate (P), ratio of urine Ca/urine Cr, amino-terminal parathyroid hormone (PTH; pg/mL) and Ca/dry bone weight in the left femur (mg/g) were measured. Uraemic controls, UrD, UrO and UrDGH rats were lower in weight gain than SC rats over the study period, but linear growth was not retarded in any uraemic group. Plasma Cr was greatly increased in any Ur group as compared with SC group. Plasma Ca and P concentrations did not differ among each group. the ratio of urine Ca/urine Cr in UrD and UrDGH groups was higher than SC, UrCand UrGH groups. the use of Dor D+GH suppressed PTH, returning the level in these rats to the normal level of the SC rats, while the PTH concentrations in the UrO and UrOGH rats were less decreased. Bone Ca content was enhanced by D+GH and O+GH administration in comparison with UrC rats, but there was no difference in the bone Ca content between UrD and UrDGH rats, and between UrO and UrOGH rats. In conclusion, growth failure in weight was shown in uraemia, but linear growth was not retarded in any uraemic group. 1.25 dihydroxyvitamin D3 and D plus GH successfully suppressed secondary hyperparathyroidism. Further studies are needed in order to elucidate the interactions on bone between vitamin D rnctabolites and GH.     

退化性脊椎病变前方入路手术适应证探讨

目的：探讨退化性脊椎病变前方入路手术的适应证，方法：回顾性分析142例接受过前方手术的病例，根据不同病情，划分出不同组别，。分别讨论其预后，结果：总体疗效评价优等者占82％，一般者占15％，不好者占3％，结论：总结出4项适应证；（1）椎间盘突出症，尤其是中央型突出者以及椎间盘伴有过渡型腰骶变形者。（2）脊椎骨关节病变为主的病灶。（3）I度脊前倾滑脱症者，或其合并有椎间盘病变者。（4）曾接受椎间盘手术，因残余的软骨压迫导致严重的临床症状者。     

Use of a Sterile, Disposable, Radiation-Absorbing Shield Reduces Occupational Exposure to Scatter Radiation During Pectoral Device Implantation

The aim of this study was to demonstrate the effectiveness of a radiation-absorbing shield in reducing physicians' occupational radiation exposure during pectoral device implantation. A sterile, disposable, lead-free radiation-absorbing surgical drape containing x-ray attenuation material was evaluated. Twenty procedures used the radiation absorbing drape, and 20 were performed without the shielding. Radiation exposure was measured using thermoluminescent dosimetry collar badges. Use of the protective shield was associated with a time adjusted 80% reduction in radiation dose (0.009 mrem/s with shielding vs 0.047 mrem/s without shielding, P < 0.05) to the physician performing the procedures. The radiation-absorbing surgical drape did not interfere with technical performance nor add procedural time, and all procedures were successfully completed. This study demonstrates that a sterile, disposable, radiation-absorbing drape provides a convenient means of augmenting conventional radiation shielding. Use of this protective shielding greatly reduces operators' occupational exposure to scatter radiation during pectoral device implantation without compromising sterility or procedural technique. (PACE 2004; 27[Pt. I]:726–729)