P21过表达和P53蛋白蓄积在判断肺癌恶性度与预后的应用研究

应用Ha-ras P21和P53单克隆抗体,采用S-P免疫组织化学方法对86例原发性肺癌进行了研究,前者总阳性率为79.07%,后者为53.48%.细支气管肺泡癌的P21强阳性(++)率明显高于腺泡状腺癌和大细胞癌(P<0.05),分化程度越高,染色越强.阴性(-)和中等阳性(+)的5年存活率明显高于强阳性(++)者.P53蛋白蓄积与肺癌的分型、分化、TNM分期无关,但P53阳性与阴性患者的术后平均存活月数间有着显著的差异(P<0.05),P53染色越强则术后存活月数越短.提示P53蛋白蓄积是判定肺癌预后的指标之一.     

Selective inhibition of prostaglandin biosynthesis by gold salts and phenylbutazone

Gold salts and phenylbutazone selectively inhibit the synthesis of PGF_2α and PGE₂ respectively. Lowered production of one prostaglandin species is accompanied by an increased production of the other. Selective inhibition by these drugs was observed in the presence of adrenaline, reduced glutathione and copper sulphate under conditions when most anti-inflammatory compounds inhibited PGE₂ and PGF_2α syntheses equally. It is postulated that selective inhibitors may have a different mode of action in vivo and beneficial effects may be related to the endogenous ratio of PGE to PGF required for normal function.     

Sublethal damage during cryopreservation of rainbow trout sperm

Although cellular damage during cryopreservation of freshwater fish spermatozoa has been reported in several studies, there is a lack of correlation between this damage and the fertility rates of eggs using postthawed milt. The apparent lack of such correlation may be due to other undetected sublethal cryodamage, which could affect the cell functionality and viability. This may be extremely important for freshwater fish spermatozoa whose ability to fertilize the egg requires dilution in water or hypoosmotic solutions, an hazardous environment for the cells. This study tested the change in cell permeability during cryopreservation, using Hoechst 33258 to assess cell permeability. The permeability of spermatozoa at different times after dilution in several hypoosmotic media were investigated. In the first trial, fresh semen, sperm diluted in freezing media (CPT), and freeze/thawed semen were studied. Three CPT were tested (Me2SO, DMA, and methanol). In the second trial, the addition of egg yolk as a membrane stabilizer was investigated. Samples were frozen at -20 degreesC/min in a programmable cooler and thawed in a 25 degreesC water bath. Dilution in the CPTs slightly increased the susceptibility of cells to damage but freezing/thawing caused a dramatic increase in the fragility of cells, which were killed in a few seconds after their contact with the hypoosmotic solutions. Egg yolk provided a significant protection to the membrane, allowing the cells a greater and more prolonged survival in the fertilization media. Samples frozen with Me2SO displayed the best results. These results are consistent with the achieved fertility rates that demonstrated sublethal cryodamage in the function of the sperm membrane that was not detected by standard procedures. Copyright 1998 Academic Press.     

Waiting for organ transplantation: results of an analysis by an Institute of Medicine Committee

One of the most visible and contentious issues regarding the fairness of the original system of organ procurement and allocation is the argument that it resulted in great disparities in the total amount of time a patient waited for an organ (i.e. the time from registration at a transplantation center to transplant), depending on where he or she lived. In an attempt to resolve this debate, Congress charged the National Academy of Sciences, Institute of Medicine to perform an independent study of the original system and proposed rule changes. In an analysis of approximately 68,000 transplant waiting list records, the committee developed several conclusions and recommendations largely specific to liver transplantation policies. The purpose of this paper is to describe both the results of the study and the statistical foundations of the mixed-effects multinomial logistic regression model that led to the committee's conclusions.     

The effects of polyamine antimetabolites on polyamine-responsive casein kinase activity

The effects of two inhibitors of ornithine decarboxylase activity, alpha-difluoromethylornithine (DMFO) and (2R,5R) 6-heptyne-2,5 diamine (HDA), and an inhibitor of S-adenosylmethionine decarboxylase, methylglyoxal bis-guanylhydrazone (MGBG), were tested on casein kinase activity and endogenous phosphorylation in the cytosol fractions of mouse thyroid and a rat prostate tumor model, Dunning R 3327 MAT LyLu subline. When tested at 5 mM, spermine, DMFO, HDA, and MGBG stimulated mouse thyroid casein kinase activity by 230%, 14%, 65% and 106%, respectively. Similar responses were observed in prostate tumor cytosol. In mouse thyroid cytosol, spermine stimulates 32P incorporation primarily into 3 proteins (MW: 107, 88, and 56 kDa). At 5 mM, MGBG partially reproduces the effects of spermine; HDA is less effective and DMFO is without effect. Similar effects were observed on 3 proteins in prostate tumor cytosol with molecular weights of 91, 41, and 32 kDa. These data provide additional support for the hypothesis that the observed synergistic inhibitory effect of DMFO and MGBG on cell growth may not be due solely to the inhibition of polyamine biosynthesis. Our findings suggest that MGBG-mediated reduction in the phosphorylation of casein kinase substrate should be considered as one locus of action.     

Biphasic effect of cryosurgery of the prostate on lymphocyte proliferation

In a preliminary study, cryosurgery of the prostate in patients with prostatic cancer has been observed to possess a biphasic effect on the proliferative responsiveness of peripheral blood lymphocytes (PBL) to the plant mitogen, phytohaemagglutinin. Phytohaemagglutinin-stimulated PBL cultured in autologous serum obtained up to 1 week postoperatively showed reduction from their preoperative levels. In contrast, cultures in homologous serum showed increased responsiveness following cryosurgery. Although depression of lymphocyte proliferation in autologous serum was transitory, gradually returning to approximate or exceeding levels of lymphocytic reactivity observed preoperatively, such depression may facilitate reduced host surveillance to potential infectious agents and to metastatic tumour cells, leading to an alteration of tumour-host homeostasis. Further studies will be required to delineate the possible clinical significance of the present observations.