Background. Prolonged dialysis is associated with acquired cystic kidney disease (ACKD) and also higher incidence of renal cell carcinoma. Relationship among dialysis, tubular cell proliferation, ...development of cystic change and neoplastic transformation is not clearly known. Whether dialysis causes additional stress on tubular cells is also conjectural. Study of heat shock protein (HSP) expression which are rapidly synthesized in cells in response to a variety of stresses may be helpful in this regard. Methods. To evaluate dialysis induced early changes in end stage renal disease (ESRD), kidneys from eight adult autopsied patients were examined (group I) who were on weekly maintenance haemodialysis for 3–12 months. The heat shock protein (HSP 72/73) expression of tubular epithelial cells and their proliferating cell nuclear antigen (PCNA) labelling index (LI) were studied by immunohistochemistry using monoclonal antibodies. For comparison similar study was carried out in 10 cases of ESRD (Group II) of similar age and sex distribution who were not dialysed. The atrophic tubules were subtyped morphologically into (1) classic, (2) thyroid, (3) endocrine and (4) super tubules. Results. In the dialysed group (I) the percentage of hyperplastic super tubules (10.6 ± 4.1%) was significantly higher than in the non-dialysed group (II) (5.2 ± 1.3%) with a higher PCNA LI (6.8 ± 2.04%) (group II 4.9 ± 1.9%) (P < 0.01 to < 0.001). Though grossly not detected, but microscopic cysts and microadenoma like areas were seen in all the cases in group I with a mean diameter of 522.66 ± 315.25 µm and 494.85 ± 262.46 µm respectively. They were seen in one case of group II. PCNA LI of the cells in microadenoma (7.2 ± 3.1%) and microcysts (6.6 ± 2.6%) were similar to that of super tubules in group I. Quantitation of HSP expression by image analysis (optical density 2.309 ± 0.155) showed a positive correlation (r = 0.7555) (P < 0.001) with PCNA LI in super tubules indicating a higher induction in the dialysed group. Conclusions. This study suggests that haemodialysis may cause injury to tubular cells and aggravate stress on an already compromised situation of ESRD leading to increased cell proliferation and more hyperplastic supertubule formation which may be the forerunner of cyst formation as well as neoplastic transformation.
In the present work variation of the two main parameters–viscosity and critical cooling rate, required for the recent upcoming optical data storage devices, have been analysed for different ...compositions of Se
80-
x
Sb
x
Te
20
(0≤
x
≤9) system. Temperature dependence of viscosity has been determined using the activation energy for glass transition and for crystallization obtained from heating rate dependence of glass transition temperature and peak crystallization temperature from DSC measurements. Vicsocity has been estimated with the help of Vogel-Tamman-Fulcher equation. It has been found that for samples containing Sb≤4 at.%, the viscosity increases with the increase in Sb content. Further increase in Sb concentration causes a decrease in the viscosity. These results are consistent with the structural changes taking place in the Se–Te system with increase in Sb content. Using these values of viscosity and kinetics of crystal nucleation and growth process, the time-temperature-transformation curves were obtained. The critical cooling rate
R
c
is found to increase for Sb>4 at.%. For good reversible phase change optical recording, the critical cooling rate of the material should be high enough so as to get an erasure time of less than 1 µs. From the analysis of the data the suitability of the SeTeSb system for optical recording has been discussed.
The tumor microblood vessels (MBVs) of 25 cases of gliomas of varying grades were studied and compared with those in peritumoral region using both transmission and scanning electron microscopy (TEM ...and SEM). The TEM study revealed numerous villous projections with pinocytotic vesicles (PCVs) and large vacuoles (LVs) concentrated mainly at the luminal aspect in tumor MBVs which increased with increasing severity of edema. The peritumoral MBVs, in addition to showing some increase in villous projections on the luminal surface, also showed increased number of PCVs and LVs concentrated at the abluminal aspect with some of them even communicating with the extravascular space. The SEM study largely corroborated the TEM findings. The sites of formation of PCVs and LVs appeared as small pits or large craters on the luminal surface of the endothelial cells of tumor MBVs. We feel that the morphological evidence of increased permeability in tumor MBVs represents their role in the development of edema and that the occurrence of reverse pinocytosis in peritumoral MBVs is a distinct possibility which may be associated with resorption of edema fluid.
The labeling index (LI) of 216 cases of human brain tumors was determined by the immunohistochemical technique with monoclonal antibody to bromodeoxyuridine (BrdU). The proliferative potential of 110 ...cases was estimated using the intra-operative intravenous infusion of BrdU at a dose of 200 mg/sq m. In another 106 cases, the in vitro technique of incubating freshly resected tumor tissue fragments with 100 microM bromodeoxyuridine was used. The BrdU LI in these tumors was then correlated with the histological types and the data as determined by both the in vivo and in vitro BrdU incorporation were compared. The results indicate that although in vivo and in vitro techniques could possibly provide equivalent data in some histologic types, a clear statistically valid proof however is not apparent from this study.
