Metabolism and biochemical effects of 3,3',4,4'-tetrachlorobiphenyl in pregnant and fetal rats

The metabolism and distribution of a single oral dose of 25 mumol 14C-labelled 3,3',4,4'-tetrachlorobiphenyl (14C-TCB) were investigated in pregnant female Wistar rats and their fetuses. TCB was administered on day 13 of gestation and the elimination was followed for 7 days. Non-pregnant rats were treated similarly for comparison. Fecal elimination of 14C-TCB derived radioactivity was significantly lower in pregnant rats than in non-pregnant rats. The major metabolite found in adult liver and plasma, placental tissue, whole fetuses and fetal plasma was 3,3',4',5-tetrachloro-4-biphenylol (4-OH-TCB). Tissue levels (liver, abdominal fat, skin, skeletal muscle, kidney and plasma) of 14C-TCB-derived radioactivity declined by 65-85% over a 7-day period following administration in the adult animals. However, 14C-TCB-derived radioactivity accumulated more than 100-fold in the fetuses over the same time period, and GC/MS analysis revealed that the fetal accumulation in radioactivity was due primarily to 4-OH-TCB, and not the parent compound. On day 20 of gestation, concentrations of 4-OH-TCB were 14 times greater in fetal plasma than maternal plasma. Treatment with 14C-TCB significantly reduced plasma thyroxine levels by at least 28% up to 7 days after administration in non-pregnant animals and up to 4 days after administration in pregnant rats (31% decrease). By 7 days after administration plasma thyroxine levels had returned to control levels in the TCB-treated pregnant rats. However, fetal plasma thyroxine levels were significantly decreased by 35% in fetuses from 14C-TCB-treated dams 7 days after TCB administration. Hepatic microsomal ethoxyresorufin-O-deethylase (EROD) activity was significantly induced in TCB-treated dams relative to controls at 4 and 7 days after administration, while no EROD activity was detected in hepatic microsomes from control or TCB treated fetal rats at day 20 of gestation. These data suggest that hydroxylated metabolites of polychlorinated biphenyls may play a role in the development toxicity of these compounds.     

Status of cerebral circulation in patients with hemiplegia of vascular and traumatic origin treated with decimeter therapy and an alternating magnetic field

Results of treating 181 patients for hemiparesis after a cerebral stroke or a craniocerebral injury by local exposure of the pathological focus to decimeter electromagnetic waves (DW) and alternating magnetic field (AMF) are presented. It is shown that these treatment methods improve the cerebral circulation and contribute to earlier restoration of the motor functions, especially, if used in combination with sulfide baths, therapeutic physical exercises and massage. The therapeutic effectiveness of the DW- and AMF-therapy is confirmed objectively by so informative examination methods, as rheoencephalography, ultrasonic dopplerography, and thermography.     

Cross-cultural generalizability of personality dimensions: relating indigenous and imported dimensions in two cultures

The cross-cultural generalizability of personality dimensions was investigated by (a) identifying indigenous Philippine dimensions, (b) testing the cross-cultural replicability of the NEO 5-factor model (P. T. Costa & R.R. McCrae, 1992), and (c) relating Philippine and Western dimensions in Philippine and U.S. samples of college students. Filipino self-ratings (N = 536) on indigenous items were factor analyzed, and 6 Philippine dimensions were obtained. Conclusions about the replicability of the 5-factor model in the Philippines (N = 432) depended on whether exploratory, Procrustes, or confirmatory factor methods were used. In regression and joint factor analyses, moderate to strong associations were found between the Philippine dimensions and (a) dimensions from the 5-factor model in both Philippine (N = 387) and U.S. (N = 610) samples, and (b) the Tellegen model (A. Tellegen, 1985; A. Tellegen & N.G. Waller, in press) in a U.S. sample (N = 603).     

PLA2 promotes fusion between PMN-specific granules and complex liposomes

Neutrophil stimulation results in the activation of a variety of phospholipases, including phospholipase A2 (PLA2), which releases arachidonic acid from the 2 position of membrane phospholipids, leaving a lysophospholipid. Because arachidonic acid is known to be a potent fusogen in vitro, we examined the effect of metabolism by PLA2 on the fusion of complex liposomes (liposomes prepared with a phospholipid composition similar to that found in neutrophil plasma membrane). We observed that PLA2 augmented the fusion of complex liposomes with each other as well as with specific granules isolated from human neutrophils, lowering the Ca2+ requirement for fusion by three orders of magnitude. Furthermore, although lysophospholipids inhibited fusion, the incorporation of arachidonic acid into liposome membranes overcame the inhibitory effects of the lysophospholipids. Thus with PLA2 and annexins we were able to obtain fusion of complex liposomes at concentrations of Ca2+ that are close to physiological. Our data suggest that the activation of PLA2 and the generation of arachidonic acid may be the major fusion-promoting event mediating neutrophil degranulation.