Changes in central dopaminergic systems with the expression of Shh or GDNF in mice perinatally exposed to bisphenol-A.

In the previous study, we reported that exposure to bisphenol-A induced the potentiation of dopamine receptor functions in the mouse limbic area, resulting in supersensitivity to methamphetamine-induced pharmacological actions. The present study was undertaken to investigate whether prenatal exposure to bisphenol-A could produce morphological change in dopaminergic neuron and the pattern of expression of genes regulating the dopaminergic neuron development. Here we found that prenatal and neonatal exposures to bisphenol-A increased the tyrosine hydroxylase- and dopamine transporter-like immunoreactivities in the adult mouse limbic area. The present molecular biological study shows that chronic bisphenol-A treatment produced a significant decrease in the dopaminergic neuron development factors, sonic hedgehog and glial cell line-derived neurotrophic factor, which were also decreased by prenatal exposure to bisphenol-A. These results suggest that chronic exposure to bisphenol-A could disrupt the dopaminergic neurotransmission in the process of dopaminergic neuron development.     

The biphasic response of hepatic arterial blood flow caused by vasoactive substances--an experimental study in dogs]

In ten male mongrel dogs, blood flow was measured in the common hepatic artery (CHA), portal vein (PV) and liver tissue before and after the injection of vasoactive substances: angiotensin II (1.0 micrograms/kg), prostaglandin F2 alpha (1.0 micrograms/kg) and vasopressin (0.1 Unit/kg), under observation of the systemic circulation. Each injection caused a biphasic response in CHA blood flow, an initial decrease followed by a marked increase, while PV blood flow decreased. Liver tissue blood flow was reduced just after injection, but soon returned to a normal level. The duration of action was the shortest with prostaglandin F2 alpha and the longest with vasopressin. In using vasoactive substances in pharmaco-angiography, it is important to consider the biphasic response in CHA blood flow as well as the duration of action of these substances.     

A case of Nasu-Hakola's disease with T2-weighted MRI finding of reduced signal intensity in the thalamus and putamen]

A 30-year-old female received a head injury at the age of 22 years. Subsequently neurological and psychiatric symptoms, such as personality change, urinary incontinence, dementia and gait disturbance developed. On admission, her cognitive function was severely impaired. Brain CT disclosed cerebral atrophy, dilatation of the lateral ventricle and calcification of the basal ganglia. Pathologically membranous structures were recognized in bone marrow. On the basis of these clinical findings, a diagnosis of Nasu-Hakola's disease was made. In this case, a T2-weighted MRI finding of reduced signal intensity in the thalamus and putamen was characteristic. This finding may be related to intracranial calcification.     

Heterotopic ischemic pain attenuates somatosensory evoked potentials induced by electrical tooth stimulation: diffuse noxious inhibitory controls in the trigeminal nerve territory.

The purpose of this study was to determine whether the late component of somatosensory evoked potentials (SEP) induced by electrical tooth stimulation and pain intensity are inhibited by heterotopic ischemic stimulation. The tourniquet pressure with 50 mmHg greater than the individual's systolic pressure was applied to the left upper arm for 10 min as ischemic conditioning stimulation. The late component of SEP and visual analogue scale (VAS) were recorded at 4 times and both were significantly decreased when ischemic conditioning stimulation was applied. The maximum reductions in SEP amplitude and the VAS value were 26.1% and 21.2%, respectively, during ischemic conditioning stimulation. After-effect was observed 5 min after removal of the conditioning stimulation. The present study revealed that heterotopic ischemic stimulation attenuated the late component of SEP induced by electrical tooth stimulation, triggering diffuse noxious inhibitory controls (DNIC) and after-effects in the trigeminal nerve territory. It was also suggested that the DNIC effect differs, depending on the intensity, kind, and quality of the test and conditioning stimuli.     

GABAB receptor transduction mechanisms, and cross-talk between protein kinases A and C, in GABAergic terminals synapsing onto neurons of the rat nucleus basalis of Meynert

The transduction mechanisms underlying presynaptic GABA_B receptor-mediated inhibition of transmitter release have been characterized for a variety of synapses in the central nervous system (CNS). These studies have suggested a range of transduction mechanisms, including a role for second messengers such as protein kinases A (PKA) and C (PKC). In the present study, we have examined the intracellular signalling pathways underlying baclofen-induced inhibition of GABA release from terminals synapsing onto rat basalis of Meynert neurons using patch-clamp recordings. Baclofen, a selective GABA_B receptor agonist, reversibly decreased both evoked and spontaneous, miniature, GABAergic inhibitory postsynaptic currents (eIPSCs and mIPSCs, respectively). Such baclofen actions were completely abolished by CGP55845A, a selective GABA_B receptor antagonist, and by staurosporine, a non-selective PKA and PKC inhibitor. The mIPSC frequency was still decreased by baclofen even in the presence of 4 AP, a K⁺ channel blocker, and Cd²⁺, a voltage-dependent calcium channel blocker. Pharmacological activation or inhibition of PKC activity affected basal GABA release and mildly affected the response to baclofen. Inhibition of the cAMP/PKA cascade also affected basal GABA release and, in a subset of neurons, occluded the effects of baclofen, suggesting that the GABA_B receptor-mediated inhibitory action on GABA release was mediated via decreases in PKA activity. In addition, PKA inhibition occluded the effects of PKC modulation on both basal GABA release and on the response to baclofen. Our results characterize the transduction pathway of baclofen at these nucleus basalis of Maynert (nBM) synapses and show, for the first time, some cross-talk between the cAMP/PKA and PKC pathways in mammalian presynaptic nerve terminals.     

Pentoxifylline and intravenous gamma globulin combination therapy for acute Kawasaki disease

We compared the efficacy of oral administration of pentoxifylline (PTX) and intravenous infusions of gamma globulin (IVGG) combination therapy with that of IVGG in reducing the frequency of coronary-artery lesions (CAL) in children with Kawasaki disease (KD), in a randomized trial. All patients with KD received acetylsalicylic acid (30 mg/kg per day), until the 30th day, after the onset of fever, followed by daily acetylsalicylic acid at a dose of 3-5 mg/kg per day there-after, and intravenous IVGG, 200 mg/kg per day, for 5 consecutive days. In addition, patients randomly assigned to PTX and IVGG combination therapy groups received oral PTX at a dosage of 10 mg/kg per day (low-dose) or 20 mg/kg per day (high-dose), in three divided doses until the 30th day. Patients with KD were all free from CAL prior to treatment. We assessed the presence of CAL by two-dimensional echocardiography which was also done prior to treatment and then twice a week after hospital admission. We detected CAL in 3 of 18 patients (16.7%) in the IVGG therapy group, as compared with 2 of 18 patients (11.1%) in the low-dose PTX and IVGG combination therapy group. There were no significant differences between the two groups. In the next study, we detected CAL in 3 of 21 patients (14.3%) in the IVGG therapy group, as compared with none of 22 patients (0%) in the high-dose PTX and IVGG combination therapy group (² = 6.4, P < 0.02). No adverse side-effects were observed in 79 patients with KD.     

Trichloroethylene. I. Carcinogenicity of trichloroethylene.

Trichloroethylene (TCE) as an industrial pollutant may damage human health and can be considered as carcinogen. TCE has been detected in the environment and in various human organs, e.g., liver, kidney and brain etc. There are histological alterations such as depletion of glycogen and hydropic degeneration in the liver, however, other signs of TCE effects can be found in various organs as well. TCE and its metabolites, e.g., trichlorethanol, trichloro-acetic acid and epoxides were recently identified as strong mutagens in Ames mutagenicity test inducing frameshift and base-substitution mutations. TCE induced predominantly hepatocellular carcinoma after long term administration in mice. In these animals, kidneys and liver were supposed to be primary target organs with low epoxy-hydrolase activity. A high level of mitotic gene conversion (or gene rearrangement) was indicated by the metabolism of TCE after repeated administration. Purified TCE by was a weak mutagen in the presence of S9 microsomal fraction of rats and as a consequence, the carcinogenic activity was low in the kidney of rats. However, a dose related increase of Leydig cell tumors was found in male rats.     

Trichloroethylene. II. Mechanism of carcinogenicity of trichloroethylene.

The cancer inducing effect of trichloroethylene (TCE) was studied by various methods. DNA complexing activity and apoptosis inhibition were found to be the key elements of the carcinogenicity of TCE and its metabolites. The ability of TCE to interact with DNA was low, but its incorporation into the RNA and DNA of the brain, testis, pancreas, kidney, liver, lung and spleen, cannot be excluded. Exposure to TCE and its metabolites provides a selective growth advantage to spontaneously occurring mutations in some K- and H-ras oncogenes (as non specific results of secondary DNA or RNA damage). The amount of DNA-TCE adducts was higher in mouse hepatocytes than in rat hepatocytes. These differences may explain the species difference in carcinogenicity of TCE, which was dose dependent (due to metabolism) in mice but independent in rats. The blood level kinetics of TCE confirmed the faster metabolic rate in mice, including peroxisome proliferation and induction in hepatocytes. Dichloroacetic- and trichloroacetic acid were found to be hepatic carcinogens in mice, and the specificity depends on peroxisome proliferation induction. Possibly, TCE and related compounds down regulated apoptosis in mouse liver, and the reduced ability to remove initiated cells by apoptosis could be responsible for liver cancer induction by TCE.     

Overexpression of collagen XVIII is associated with poor outcome and elevated levels of circulating serum endostatin in non-small cell lung cancer.

PURPOSE: The aim of this study was to determine whether collagen XVIII expression is correlated with circulating serum endostatin and whether this has any prognostic value in patients with non-small cell lung cancer (NSCLC). EXPERIMENTAL DESIGN: Serum endostatin levels were measured quantitatively by a competitive enzyme immunoassay, and collagen XVIII expression in tumor tissue was investigated with an immunohistochemical method in a series of 94 patients who underwent surgery for NSCLC. RESULTS: Sixty cases (63.8%) had positive immunohistochemical staining with anticollagen XVIII polyclonal antibodies, including strongly positive staining in 11 (11.7%) cases. The mean (+/- SD) serum endostatin level was 41.6 +/- 34.4 ng/ml in the patient group and 16.3 +/- 10.3 ng/ml in the control group (P < 0.0001). The 11 cases who were strongly collagen XVIII-positive had significantly higher serum endostatin levels than the cases who were negative or weakly positive (P = 0.0297). The 5-year survival rates of negative, weakly positive, and strongly positive patients were 77.8%, 56.9%, and 43.8%, respectively. The cases with strongly positive collagen XVIII expression had a significantly poorer outcome than cases with negative expression (P = 0.0027). A multivariate analysis with Cox proportional hazards model for disease-specific survival revealed that expression of collagen XVIII (strongly positive versus negative; weakly positive versus negative), tumor classification, and regional lymph node classification were independent prognostic factors. CONCLUSIONS: Our results suggest that expression of collagen XVIII in tumor tissue is strongly associated with a poorer outcome in NSCLC and correlates with elevated levels of circulating serum endostatin.