Diffuse large B-cell lymphomas with germinal center B-cell-like differentiation immunophenotypic profile are associated with high apoptotic index, high expression of the proapoptotic proteins bax, bak and bid and low expression of the antiapoptotic protein bcl-xl.

The aim of this study was to analyze the relations between differentiation immunophenotypes and the status of apoptosis and proliferation in diffuse large B-cell lymphomas. Therefore, the bcl6/CD10/MUM1/CD138 differentiation immunophenotypic profiles were studied in relation to (a) the apoptotic index, (b) the apoptosis-associated bcl2 family proteins bcl2, bcl-xl, bax, bak, bad and bid, (c) the proliferation index (Ki67) and (d) the cell cycle proteins cyclin A, cyclin B1, cyclin D3, cyclin E, p53, Rb, p16 and p27 in 79 cases of diffuse large B-cell lymphomas. Two major differentiation immunophenotypic profiles were distinguished: the germinal center B-cell-like profile; 31 cases (bcl6+/CD10+/-/MUM1-/CD138-: 29 cases and bcl6-/CD10+/MUM1-/CD138-: two cases) and the nongerminal center B-cell-like profile (bcl6+/-/CD10-/MUM1+/CD138-); 48 cases. The expression of bax, bak and bid and the apoptotic index were significantly higher in the germinal center B-cell-like profile than in the nongerminal center B-cell-like profile (P=0.045, 0.018, 0.003 and 0.034, respectively). In contrast, the expression of bcl-xl was significantly lower in the germinal center B-cell-like profile than in the nongerminal center B-cell-like profile (P=0.026). The expression of bcl6 and CD10 showed significant positive correlation with the expression of bax (r=0.659, P<0.001 and r=0.240, P=0.033, respectively), bak (r=0.391, P<0.001 and r=0.233, P=0.039, respectively) and bid (r=0.652, P<0.001 and r=0.238, P=0.035, respectively) and significant negative correlation with the expression of bcl-xl (r=-0.536, P<0.001 and r=-0.250, P=0.029, respectively). The expression of MUM1 showed significant negative correlation with the expression of bax (r=-0.276, P=0.014) and bid (r=-0.266, P=0.018) and significant positive correlation with the expression of bcl-xl (r=0.238, P=0.037). The above findings indicate that diffuse large B-cell lymphomas with germinal center B-cell-like immunophenotypic profile are associated with increased apoptosis status, high expression of the proapoptotic proteins bax, bak and bid and low expression of the antiapoptotic protein bcl-xl.     

URINARY BILE ACID CONJUGATES IN EXTRAHEPATIC BILIARY ATRESIA

The urinary excretion of bile acid conjugates was studied after the administration of 24-¹⁴C-labelled chenodeoxycholic acid and cholic acid and their corresponding glycine conjugates labelled with glycine-l-¹⁴T in 5 infants with extrahepatic biliary atresia. Chenodeoxycholic acid-24-¹⁴C and chenodeoxycholyl[l-¹⁴C]glycine were mainly excreted in the form of labelled metabolites with the TLC behaviour of monosulphates of tauro- and glycochenodeoxycholate and glycochenodeoxycholate, respectively. Most of the cholic acid-24-¹⁴C and the cholyl[l-¹⁴C]glycine were found to be excreted in the form of glycocholate. All labelled bile acids were excreted in conjugated form.     

AIDS-RELATED BEHAVIOUR IN ADOLESCENTS: INTERVENTION PROGRAMME WITH INTERNATIONAL APPLICATION

SUMMARY Adolescents and young adults comprise one of the fastest-growing categories of AIDS cases. The results of an opinion survey taken of 3242 adolescents raise serious doubts about the prevalent view that high-risk behaviour is attributable to insufficient information and education on AIDS: female adolescents are found to be at risk despite having the proper knowledge. Five chief factors affected the knowledge and behaviour of adolescents: age, gender, origin, family profession, and parental education. Each of the subpopulations (females, younger adolescents, children in rural areas) has its own characteristics and needs. We describe a permanent and long-term intervention programme, which might be applied in any country.     

Extracellular matrix components in Kimmelstiel Wilson nodules

Summary: The distribution of collagen types I, III, IV, V, VI, fibronectin laminin, tenascin, heparan sulfate proteoglycan and chondroitin sulphate proteoglycan was examined by light microscopy immunocytochemistry (ICC) in paraffin-embedded renal biopsies with nodular diabetic glomeruloscierosis. Immunoglobulin A, G and M, complement (C3c and C1q), fibrinogen and k and γ light chain deposition was also sought by ICC in the same tissue.
Kimmelstiel Wilson (KW) nodules were graded as either evolving (>3 nuclei present +/ - fibrillary appearance) or as late stage (amorphous and acellular). the extracellular matrix (ECM) components present in the evolving KW nodules were the same as those present in normal mesangial matrix but with an increased density. Late stage nodules displayed negative binding for all antibodies in their core with accentuated expression of the normal mesangial matrix components together with complement and 1gM at their periphery. Occasionally, when ruptures in Bowman's capsule (BC) were detected and adhesions between the capsule and the nodular tuft occurred, the interstitial collagens I and III were detected within laminations of Bowman's capsule, in Bowman's space, at adhesion sites and within some nodules.
The results suggest nodular lesions are initially formed by aggregation and/or increase in the normal components of mesangial matrix. the normal mesangial matrix constituent proteins are subsequently relocated to the periphery by amorphous material in which these ECM components are not detected. When BC is disrupted, interstitial collagens I and III may appear in Bowman's space and within nodules.     

Effect of saturable binding on the pharmacokinetics of drugs: a simulation

The time-courses of both total and unbound drug concentrations with time were simulated under conditions of saturable binding to either plasma proteins or tissues, or both, following a single intravenous dose. The curves were either linear, convex, or concave, depending upon the extent of distribution and the intrinsic ability of an eliminating organ to remove drug from the body. Saturable binding should therefore be considered whenever data showing nonlinear semilogarithmic decline are to be interpreted.     

Whole-body exposure to 2.45 GHz electromagnetic fields does not alter anxiety responses in rats: a plus-maze study including test validation

In a first phase of this investigation, a validation of our elevated plus-maze apparatus was performed in male Sprague-Dawley rats by testing anxiety response at various ambient light intensities (200, 30, 10 and 2.5 lux), as well as the effects of diazepam treatment (0.5 and 1.0 mg/kg, i.p. at 30 lux). Anxiety responses were found to decrease with decreasing light intensity and to be attenuated by diazepam treatment. Subsequently, a separate set of rats was exposed to 2.45 GHz EMFs (2 micros pulse width, 500 pulses per second, whole-body and time averaged of SAR 0.6 W/kg +/-2 dB, brain-averaged SAR of 0.9 W/kg +/-3 dB) for 45 min to assess whether EMF exposure altered anxiety responses in the same apparatus. As we made no a priori hypothesis on whether the effects would be anxiogenic or anxiolytic, part of the rats were tested under an ambient light intensity of 2.5 lux, the other one being tested at 30 lux. The low intensity level set the behavioural baseline for the detection of anxiogenic effects, while the higher one corresponded to the detection of anxiolytic effects. Sham-exposed and naive rats were used as controls. Whatever light intensity was used, EMF exposure failed to induce any significant effect on anxiety responses in the plus maze. The present experiment demonstrates that exposure to EMFs, which was previously found to increase the number of benzodiazepine receptors in the rat cortex [Lai H, Carino MA, Horita A, Guy AW. Single vs. repeated microwave exposure: effects on benzodiazepine receptors in the brain of the rat. Bioelectromagnetics 1992;13(1):57-66], does not alter anxiety responses assessed in the elevated plus maze.