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Notes: Aim: Heat shock protein (HSP) expression has been widely implicated in atherogenesis. Vein graft failure following coronary artery bypass graft surgery (CABG) involves medial thickening and neointima formation, a phenomenon mediated by vascular smooth muscle cell (VSMC) proliferation. Superimposed atherogenesis can then result in vein graft failure in as many as 50% of cases within ten years after surgery. In order to explore the possible role of HSP in mediating vein graft disease, the effect of HSP 65 kDA on the proliferation of VSMCS obtained from human saphenous vein was investigated. The role of calcium was also studied using thapsigargin which blocks the release of calcium from intracellular storage pools. Methods: VSMCs were grown from human saphenous vein using standard culture methods. Cells were grown to confluence using DMEM + 10% Foetal Calf serum (FCS). When confluent, cells were trypsinised and cultured onto 96-well plates and rendered quiescent with 0.4% FCS. HSP 65kDA, over a range of concentrations (with and without 10 nM thapsigargin) was added to the cells and proliferation stimulated with 10% FCS and further incubated for 48 hours. Proliferation was assessed by the uptake of 5-bromo-2′ deoxyurindine (Brdu) using colorimetric ELISA and cell counts from which% changes in proliferation were calculated. Results: HSP elicited a dose-dependent increase in the proliferation of VSMCs (〈link href="#t6"〉table 1) an effect completely inhibited by the presence of 10 nM thapsigargin (〈link href="#t6"〉table 1). This concentration of thapsigargin has previously been shown to inhibit VSMC proliferation through depletion of intracellular calcium pools.〈tabular xml:id="t6"〉1〈title type="main"〉 Effect of HSP 65 kDa on VSMC Proliferation (% Change Relative to Zero) [± SEM; n = 6 ]: A) Without Thapsigargin and B) with Thapsigargin *p 〈 0.05 , Compared to Zero; # p 〈 0.05 , A vs. B 〈table frame="topbot"〉〈tgroup cols="7" align="left"〉〈colspec colnum="1" colname="col1" align="left"/〉〈colspec colnum="2" colname="col2" align="center"/〉〈colspec colnum="3" colname="col3" align="center"/〉〈colspec colnum="4" colname="col4" align="center"/〉〈colspec colnum="5" colname="col5" align="center"/〉〈colspec colnum="6" colname="col6" align="center"/〉〈colspec colnum="7" colname="col7" align="center"/〉〈thead valign="bottom"〉 [HSP].(μg/ml) 0 0.001 0.01 0.1 1 10 〈tbody valign="top"〉A0 +46 ± 10* +61 ± 14* +65 ± 18* +60 ± 12* +55 ± 10* B0 −2 ± 0.2# −4 ± 0.4# −10 ± 4# −18 ± 4# −15 ± 3# Conclusions: Since HSP 65 kDa stimulates the proliferation of VSMCs, they may play a role in graft thickening and neointima formation as well as superimposed atherogenesis. As this may result in late vein graft failure, further investigations into the role of HSP expression in vein graft disease is warranted. The inhibition of this HSP-mediated effect by thapsigargin consolidates the crucial role of calcium in mediating VSMC proliferation and that inhibition of this event represents a potential therapeutic strategy for the prevention of vein graft thickening.

Notes: Aim: The vasculopathic impact of homocysteine (HCy) is mediated through the generation of superoxide, a phenomenon augmented by copper (Cu2+). Cardiopulmonary bypass (CPB) also elicits oxidant stress. Since oxygen free radicals may play a role in both early and late vein graft failure, the blood levels of HCy and Cu2+ and related parameters, before and after surgery, were investigated in patients undergoing coronary artery bypass graft surgery (CABG), both with (on pump) and without CPB (off pump). Methods: Blood samples were taken from 20 consecutive patients (10 on-pump and 10 off-pump) undergoing CABG, one day pre-operatively (D0) and one day (D1) and six days (D6) post-operatively. Plasma HCy, serum Cu2+, caeruloplasmin (CP) and vitamin B12 and red cell folate were then measured. Results: Pre-operative (D0) plasma concentrations of HCy were below the accepted risk factor value of 14 μmol/l. At D1 there was a reduction in all parameters in both groups, which is ascribable to hemodilution. However, in both on pump and off pump groups, HCy, Cu2+ and CP were all significantly increased at D6. Concentrations of red cell folate were not significantly altered and serum vitamin B12 was significantly increased at D6, indicating that the increase in HCy was not due to a reduction in these vitamins. When comparing on-pump to off pump, there were no significant differences between any parameter except for Cu2+ which was significantly greater in the on pump group compared to the off pump group at D6.〈tabular xml:id="t5"〉1〈title type="main"〉 Circulating Parameters Following CABG (Means ± SEM; n = 10 ) *p 〈 0.05 vs Pre-Operative Levels and #p 〈 0.05 on Pump vs Off Pump 〈table frame="topbot"〉〈tgroup cols="6" align="left"〉〈colspec colnum="1" colname="col1" align="left"/〉〈colspec colnum="2" colname="col2" align="left"/〉〈colspec colnum="3" colname="col3" align="left"/〉〈colspec colnum="4" colname="col4" align="left"/〉〈colspec colnum="5" colname="col5" align="left"/〉〈colspec colnum="6" colname="col6" align="left"/〉〈thead valign="bottom"〉〈entry morerows="1" valign="top" align="center"〉 HCy (μmol/l) 〈entry morerows="1" valign="top" align="center"〉 Cu2+ (μmol/l) 〈entry morerows="1" valign="bottom" align="center"〉CP (g/l)〈entry morerows="1" valign="top" align="center"〉 Folate (mg/l) 〈entry morerows="1" valign="top" align="center"〉 VitB12 (ng/l) 〈tbody valign="top"〉On pump: D0 10.5 ± 1.3 13.9 ± 3.2 0.30 ± 0.05 388 ± 182 261 ± 75 Off pump: D0 9.8 ± 1.2 13.6 ± 3.3 0.35 ± 0.12 340 ± 78 240 ± 140 On pump: D1 9.2 ± 1.4 10.5 ± 3.2 0.23 ± 0.10 357 ± 168 170 ± 62 Off pump: D1 8.7 ± 1.3 13.2 ± 2.8 0.32 ± 0.10 351 ± 84 190 ± 89 On pump: D6 12.7 ± 1.2* 21.9 ± 2.5*# 0.40 ± 0.04* 394 ± 150 410 ± 160* Off pump: D6 11.1 ± 1.3* 19.0 ± 2.6* 0.40 ± 0.07* 331 ± 57 385 ± 169* Conclusions: Contrary to other reports, the pre-operative plasma concentrations of HCy in this study suggest that HCy is not a risk factor for coronary artery disease. However, following CABG, the significant increase in HCy and Cu2+ may be of pathological importance since Cu2+ augments the release of superoxide from HCy. The greater increase in serum Cu2+ in the on-pump group indicates that CPB may promote oxidant stress through elevation of this potent transition metal.

Notes: Abstract Urinary bladder hypertrophy and hyperplasia are well recognised in diabetic cystopathy. The urinary bladder is known to synthesise endothelin-1 (ET-1), a potent vasoconstrictor peptide with mitogenic properties. Using diabetic New Zealand White (NZW) rabbits, we investigated the potential role of ET receptor subtypes (ETA and ETB) on the proliferation of bladder smooth muscle cells (SMC). Diabetes mellitus was induced in adult male NZW rabbits. After 6 months, control (n=6) and diabetic (n=6) bladders were removed and SMC from the dome and bladder neck were grown using standard explant methodology. At passage two, the cells were made quiescent and then further incubated in foetal calf serum (FCS), control age-matched rabbit serum (CRS) or diabetic rabbit serum (DRS) in the presence or absence of ETA-antagonist (BQ123) or ETB-antagonist (BQ788). SMC proliferation was then measured with 5-bromo-2′deoxy-uracil 24 h later and by cell counting (using a haemocytometer) at 48 h. Neither BQ123 nor BQ788 influenced detrusor or bladder neck SMC proliferation in FCS or CRS. However, in the presence of DRS, BQ123 and BQ788 significantly inhibited diabetic detrusor and bladder neck SMC proliferation at 30 and 100 nmol/l (P 〈 0.03 and P 〈 0.01, respectively). Cell counts were also significantly reduced from the diabetic detrusor and bladder neck (P 〈 0.01 and P 〈 0.03 with BQ123 and BQ788, respectively). These results suggest that ET may play a pathophysiological role in the bladder SMC hyperplasia associated with diabetes mellitus.

Notes: Abstract A case of extramedullary plasmacytoma in the soft tissues of the posterior chest wall of an 80-year old man is reported herein. Immunofluorescence study showed that the tumor cells produced IgGλ. An M-component was also detected in the patient’s serum by paper electrophoresis. Two months following the open biopsy done to establish diagnosis, the tumor underwent spontaneous regression and the M-component in the serum also disappeared. This is the first case report of spontaneous regression of an extramedullary plasmacytoma and the probable reasons for this spontaneous regression are discussed herein.

Notes: Abstract The sequential procedure developed by Bhargava and Srivastava (1973, J. Roy. Statist. Soc. Ser. B, 35, 147–152) to construct fixed-width confidence intervals for contrasts in the means is further analyzed. Second-order approximations for the first two moments of the stopping time and the coverage probability associated with the sequential procedure, are obtained. A lower bound for the number of “additional” observations after stopping is derived, which ensures the “mxact” probability of coverage. Moreover, two-stage, three-stage and “modified” sequential procedures are proposed for the same estimation problem. Relative advantages and disadvantages of these sampling schemes are discussed and their properties are studied.

Notes: Summary The paper presents a comparative study of product estimators proposed byRobson [1957] andMurthy [1964]. It is seen that the Robson's estimator gives a better performance.

Notes: Summary The estimation of the regression coefficient of a population, defined byE (y)= γ+βx, incorporating two preliminary tests of significance has been discussed. The experimenter has two random samples of different sizes from two such populations, as defined above, with regression coefficientsβ 1 andβ 2 respectively, whereβ 2 may possibly be equal toβ 1. Besides this, it is also conjectured that the common conditional varianceσ 2 of the two populations has a specified valueσ 0 2 . The two preliminary tests are used to resolve these two uncertainties.

Notes: Abstract In sample survey methods the use of product estimators was suggested byMurthy [1964] andSrivastava [1966] and were found to serve good purpose provided the two variables viz. the main variable under study and the auxiliary variable have a very high negative correlation between them. The product estimators suggested by them are biased. In the present paper the author has obtained unbiased product estimators (to the first degree of approximation) with the help of the technique developed byQuenouille [1956] and has established that this new estimator is better than the other product estimator in the mean square error sense.