Mutual metabolic suppression between benzene and toluene in man

Summary The exposure intensity during a shift and the metabolite levels in the shift-end urine were examined in male workers exposed to either benzene (65 subjects; the benzene group), toluene (35 subjects; the toluene group), or a mixture of both (55 subjects; the mixture group). In addition, 35 non-exposed male workers (the control group) were similarly examined for urinary metabolites to define background levels. A linear relationship was established between the intensity of solvent exposure and the corresponding urinary metabolite levels (i.e. phenol, catechol and quinol from benzene, and hippuric acid and o-cresol from toluene) in each case when one of the three exposed groups was combined with the control group for calculation. Comparison of regression lines in combination with regression analysis disclosed that urinary levels of phenol and quinol (but not catechol) were lower in the mixture group than in the benzene group when the intensities of exposure to benzene were comparable, indicating that the biotransformation of benzene to phenolic compounds (excluding catechol) in man is suppressed by co-exposure to toluene. Conversely, metabolism of toluene to hippuric acid was suppressed by benzene co-exposure. Conversion of toluene to o-cresol was also reduced by benzene, but to a lesser extent. The significance of the present findings on the mutual suppression of metabolism between benzene and toluene is discussed in relation to solvent toxicology and biological monitoring of exposure to the solvents.     

Pseudo-aneurysm of aortic arch and rupture into pericardium, a case report of successful surgical management

This is a case report of 50 years old male suffering from pyrexia and epigastralgia 2 weeks prior to admission. On the 15th hospital day, he complained chest pain. Chest roentgenography revealed marked expansion of the mediastinum which was not existed upon admission. CT and MRI of the chest demonstrated a pseudoaneurysm of aortic arch at lesser curvature with extension into the pericardium. Exploration of the pericardium through median sternotomy disclosed fully filling with purulent effusion and blood clots. Following irrigation of the pericardial space and tube drainage, chest was closed. Repair of the aneurysm was postponded. Following continues irrigation of the pericardial space for 19 days, tube graft replacement of the aneurysm was performed under femorofemoral bypass and circuratory arrest through left thoracotomy. The aneurysmal space was filled with the omental pedicle to control infection. However, repeated bacteriological examination of the pericardium and aneurysm revealed no growth. Behçet disease was most suspected in report of the pathology.     

A case of pancreatic ductal adenocarcinoma with rapid progress in a young man]

A 17-year-old man was admitted to hospital because of epigastric pain. Various imaging studies showed a solid tumor (4cm in diameter) in the tail of the pancreas, multiple hypovascular tumors in liver. Serum levels of DUPAN2, SPAN1 and NSE were elevated slightly. Biopsy of hepatic tumor demonstrated that tumor cells had eosinophilic cytoplasm generally and unevenly distributed polymorphic nucleus. These data suggested that this tumor is poorly differentiated pancreatic carcinoma originated from the epithelium. Therefore, we administered 5-fluorouracil and cisplatin, combined with gemcitabine. The clinical status improved temporarily by the treatment, however, worsened rapidly. He died 81days after the treatment. Final diagnosis of autopsy was pancreatic ductal adenocarcinoma. Pancreatic ductal adenocarcinoma in the young patients is rare, and we reported this case in addition to consideration on literature.     

Adduct Formation at C-8 of Guanine on in vitro Reaction f the Ultimate Form of 2-Amino-l-methyl-6-phenylimidazo[4,5-b]pyridine with 2'-Deoxyguanosine and Its Phosphate Esters

We examined the reactivity of the N -hydroxyamino derivative of a carcinogenic heterocyclic amine, 2-amino-1-methyl-6-phenylimidazo[4,5- b ]pyridine (PhIP), after its O -acetylation with four 2'-deoxyribonucleoside 3'-monophosphates. ³²P-Postlabeling analysis demonstrated that the levels of adducts with 2'-deoxyguanosine 3'-moiiophosphate were much higher than those with the other three nucleotides. ¹H-NMR, mass spectral and UV absorption spectral analyses of the major adducts formed by N -acetoxy-PhIP with 2'-deoxyguanosine and with its phosphate esters indicated that PhIP bound at the C-8 position of guanine, as previously demonstrated with other heterocyclic amines.     

MORPHOLOGIC SPECTRUM OF LIVER DISEASES AMONG CHRONIC ALCOHOLICS A Comparison between Tokyo, Japan and Cincinnati, U.S.A.

To deliniate the histopathological features of liver diseases seen in Japanese alcoholics, 130 Japanese alcoholic patients were studied in comparison with 238 American alcoholic patients. In Japan female alcoholic patients were extremely rare. The male to female ratio was 127 to 3 in Japan and 152 to 89 in U.S.A. Although all aspects of alcoholic liver disease did exist in Japan, typical cases of acute alcoholic hepatitis with alcoholic hyalins were remarkably smaller in number (9.2% in Japan versus 39.5% in the U.S.A.). The severity based on histopathological findings was also less in the Japanese cases. In contrast to this, 46 percent of Japanese alcoholic patients had chronic hepatitis, and the incidence of multilobular cirrhosis was much greater in Japan wherewith higher prevalence of viral hepatitides.     

Comparison of mercury contents in maternal blood,umbilical cord blood,and placental tissues

Bulletin of Environmental Contamination and Toxicology -     

Effects of increased cardiac mechanical performances on flow rates of cardiac lymph in dogs

Summary Relationship between flow rates of cardiac lymph (LF), and coronary blood flow (CF), coronary perfusion pressure (PP), left ventricular peak systolic pressure (LVSP) and heart rate (HR) was studied in open-chest dogs. Intra-coronary administration of catecholamines (CA) and electrical stimulation of the cardiac sympathetic nerve (ES) increased LF transiently with a concomitant rise in the cardiac mechanical performance, while dipyridamole induced no change in LF in spite of a marked increase in CF. Isoproterenol at doses of 0.3 and 3×10^–8 g/kg induced an increase in LF to 119±4 and 167±20% (mean ±SE); norepinephrine, 0.3 and 3×10^–7 g/kg, to 118±4 and 141±13%; ES at 5 and 20 Hz, to 135±11 and 167±10%, respectively. Peak responses of LF correlated with changes in LVSP (r=0.59,n=51,P<0.001), CF (r=0.53,n=51,P<0.001), PP(r=0.49,n=51,P<0.001) but not with changes in HR (r=0.27,n=51, 0.05<P<0.10). Cardiac pacing also showed a poor correlation between the changes in LF and HR under the same LVSP within the changes in HR up to 134% of control value (r=–0.12,n=17,P>0.50). It is concluded that LF is independent of changes in HR, and increased LF after CA or ES may be caused mainly by an augmented propulsive force.