Increased cytotoxicity of carbon tetrachloride in a human hepatoma cell line overexpressing cytochrome P450 2E1.

Cytotoxic free radicals generated during the metabolism of carbon tetrachloride by cytochrome P450 2E1 (CYP2E1) are thought to cause hepatotoxicity. Here, the cytotoxic effects of carbon tetrachloride in a liver cell line expressing CYP2E1 (HLE/2E1) are compared with those in the mother cell line (HLE). The effects of carbon tetrachloride on the gene expression of HSP70, a potential marker of oxidative stress, were also examined. The viability of HLE/2E1 cells after exposure to carbon tetrachloride was significantly decreased compared with that of HLE cells. Northern blot analysis revealed that the HSP70 mRNA level was significantly increased after carbon tetrachloride treatment in both cell lines, while the magnitude of its increase was much greater in HLE/2E1 cells than in HLE cells. These results suggest that the oxidative stress induced by CYP2E1 plays an important role in the increase in cytotoxicity of carbon tetrachloride in CYP2E1-overexpressing cells.

The effects of epidural block on the distribution of lymphocyte subsets and natural-killer cell activity in patients with and without pain.

Although epidural anesthesia prevents immune suppression during surgery, no reports have elucidated how epidural block affects immune response in nonsurgical patients. We examined changes in proportion of lymphocyte subsets and in natural-killer (NK) cell activity in patients with and without pain. Fifteen patients with pain (Pain group) and 15 preoperative patients without pain (Preoperative group) received three different treatments in random order: epidural block with 7 mL 1% lidocaine, epidural injection of an identical volume of normal saline, and IV injection of 1 mg/kg lidocaine. Blood samples were drawn before and after 30, 60, and 120 min of treatment. During epidural block at 30 and 60 min, both groups showed significantly decreased epinephrine, norepinephrine, and cortisol levels, and the proportion of NK cells decreased, whereas the CD4+/CD8+ ratio increased significantly. NK cell activity in both groups decreased significantly at 30 and 60 min. At 120 min, the variables had all returned to preblock values. During treatments with saline and IV lidocaine, neither group showed significant changes in any of the above variables. We conclude that epidural block causes a transient and significant alteration of lymphocyte subsets and NK cell activity regardless of pain status.

The effects of epidural insertion site and surgical procedure on plasma lidocaine concentration.

We compared the plasma lidocaine concentrations associated with continuous epidural infusion at different insertion sites in patients during surgery using epidural plus general anesthesia. In Study 1, there were 12 patients in each of four surgical groups in whom blood loss was expected to be <400 mL. The four groups were as follows: the lower extremity, the lower abdomen, the upper abdomen, and the lung. Liver surgery was excluded from Study 1. Study 2 comprised patients undergoing radical hysterectomy or radical prostatectomy (a radical operation group, n = 12) and hepatectomy (a hepatectomy group, n = 12) in whom the expected surgical blood loss was more than 1500 mL. All patients initially received 0.1 mL/kg followed by a continuous infusion of 0.1 mL. kg(-1). h(-1) of 1.5% lidocaine, and plasma concentrations of lidocaine were measured at 15, 30, 60, 90, and 120 min and every 60 min thereafter to 300 min. The plasma lidocaine concentration during surgery did not change regardless of the infusion site or the surgical site, other than the liver. The plasma concentrations of lidocaine in the hepatectomy group increased significantly at 180 min (2.9 +/- 0.6 microg/mL, P < 0.01), 240 min (3.5 +/- 0.7 microg/mL, P < 0.01), and 300 min (3.6 +/- 0.74 microg/mL, P < 0.01) compared with that at 15 min (2.0 +/- 0.3 microg/mL), and these values were significantly larger than those in all other groups.

Association between p53 immunostaining and cigarette smoking in squamous cell carcinoma of the esophagus.

BACKGROUND: It is generally accepted that cigarette smoking is closely associated with esophageal squamous cell carcinoma. This study investigated the molecular targets of cigarette smoke in carcinogenesis of the esophagus. METHODS: Seventy-four patients with esophageal squamous cell carcinoma (SCC) were grouped according to daily cigarette consumption: heavy smoking group (group H) (n = 26), moderate smoking group (group M) (n = 39) and non-smoking group (group N) (n = 9). We compared p53 and retinoblastoma (RB) expression among the three groups by immunohistochemistry. In addition, fresh tumor tissues from 30 smokers with esophageal SCC were tested for p53 mutations in exons 5-8 by direct sequencing. RESULTS: Staining for the p53 product was positive in 65.4% of group H, 38.5% of group M and 44.4% of group N. The frequency of positive staining in the group H was significantly higher than in group M (p = 0.033) and in group M + group N (p = 0.034). The difference with respect to the frequency of overexpression of RB was not significant. The patterns of p53 base-pair mutations in direct sequencing study were of five types, most commonly G:C to T:A transversion (35.3%). CONCLUSIONS: Our study suggests that one of the molecular targets of cigarette smoke is the p53 gene. The pattern of p53 point mutations involved a wide range of base-pair changes.

Gene expression of heme oxygenase-1 during glial activation by lipopolysaccharide.

The effect of bacterial lipopolysaccharide (LPS) on the expression of mRNA encoding heme oxygenase-1 (HO-1), which is the rate limiting enzyme in heme catabolism and is also known as heat shock protein 32 (HSP32), was examined in primarily cultured rat glial cells. Treatment of cells with LPS elicited an increase in HO-1 mRNA, accompanying down regulation of delta-aminolevulinate synthase, in a dose-dependent fashion. HO-1 mRNA increased markedly at 12 h after LPS treatment (10 microg/ml) and reached a maximum at 24 h. In contrast, HSP70, a major heat shock protein, slightly increased only at 6 h after LPS treatment and returned to the control level by 12 h. These results suggest that HSPs are induced under separate regulation during glial activation by LPS through oxidative stress, a part of which is likely mediated by intracellular free heme.

Antioxidant roles of cellular ubiquinone and related redox cycles: potentiated resistance of rat hepatocytes having stimulated NADPH-dependent ubiquinone reductase against hydrogen peroxide toxicity.

Protective effect of the cellular ubiquinone (UQ) reducing system linked to cytosolic NADPH-dependent ubiquinone reductase (NADPH-UQ reductase) against hydrogen peroxide (H2O2)-induced lipid peroxidation was investigated using UQ and control hepatocytes freshly isolated from rats injected with UQ-10 and the vehicles 14 d in advance, respectively. The UQ hepatocytes had higher levels of ubiquinol (UQH2)-10 content and NADPH-UQ reductase activity than the control hepatocytes but did not differ in other antioxidant factors from the latter cells. The UQ hepatocytes exhibited higher cell viability and lower release of lactate dehydrogenase than the control hepatocytes when they were exposed to H2O2 of up to 100 mM for 1 h at 37 degrees C. Furthermore, the formation of thiobarbituric acid reactive substances (TBARS) by H2O2 was almost completely inhibited in the UQ hepatocytes. Decreases in UQH2 and alpha-tocopherol contents and NADPH-UQ reductase activity by H2O2 exposure were observed in both types of the hepatocytes, but those levels in the UQ hepatocytes after the exposure were still higher than in the control hepatocytes. The decreases in ascorbic acid, reduced glutathione and protein thiol contents and DT-diaphorase activity by H2O2 were not different between in the two types of hepatocytes. Antioxidant enzyme activities of catalase, superoxide dismutase, glutathione peroxidase, glutathione S-transferase and glutathione reductase in the hepatocytes were not inhibited by H2O2. From these results, it was concluded that the cellular UQ reducing system linked to cytosolic NADPH-UQ reductase functions mainly as an antioxidant defense for cellular membranes.

Primary T-cell lymphoma of the duodenum: report of a case.

A case of primary non-Hodgkin's T-cell lymphoma of the duodenum is presented. A 41-year-old man was hospitalized in 1984 complaining of abdominal distention and vomiting. Hypotonic duodenography showed an encircling filling defect in the second portion of the duodenum, and a biopsy specimen revealed features of malignancy suggestive of either undifferentiated carcinoma or malignant lymphoma. Radical surgery (pancreaticoduodenectomy) was performed, after which chemotherapy was administered. A histological evaluation of the duodenal tumor showed it to be non-Hodgkin's lymphoma. It was a diffuse, large-cell type, which immunohistochemically suggested it to be of T-cell origin. Currently the patient is doing well, with no evidence of disease recurrence 13 years after surgery.

Sevoflurane anaesthesia causes a transient decrease in aquaporin-2 and impairment of urine concentration.

Sevoflurane anaesthesia is occasionally associated with polyuria, but the exact mechanism of this phenomenon has not been clarified. Aquaporin-2 (AQP2) is an arginine vasopressin (AVP)-regulated water channel protein localized to the apical region of renal collecting duct cells and is involved in the regulation of water permeability. To elucidate the effect of sevoflurane anaesthesia on urine concentration and AQP2, we have compared serum and urinary concentrations of AVP, AQP2 and osmolar changes during sevoflurane and propofol anaesthesia. General anaesthesia was induced with sevoflurane or propofol in 30 patients for a variety of major surgical procedures. Blood and urine samples were obtained from patients at baseline, and 90 and 180 min after induction of anaesthesia. AVP and AQP2 concentrations were measured by radioimmunoassay. In both groups, plasma and urinary concentrations of AVP increased similarly during anaesthesia although plasma osmolality remained unchanged. Although urinary AQP2 excretion in the propofol group increased together with changes in plasma and urinary AVP, urinary AQP2 was significantly lower at 90 min in the sevoflurane group. Urine osmolality in the sevoflurane group also showed a transient but significant decrease in parallel with suppression of AQP2. Our data suggest that sevoflurane anaesthesia transiently produced an impaired AQP2 response to an increase in intrinsic AVP.

Pure red cell aplasia and myasthenia gravis with thymoma: a case report and review of the literature.

A case of pure red cell aplasia (PRCA), myasthenia gravis (MG) and thymoma is reported. A 70-year-old woman presented with severe anemia. She had been diagnosed as having MG 8 years earlier and her symptoms were adequately controlled with ambenonium chloride. When she visited our hospital, her hematocrit was 13.7% with a hemoglobin concentration of 4.7 g/dl and her reticulocyte counts were persistently abnormal at 0.1%. Although both direct and indirect Coombs' tests were positive, there was no evidence of hemolysis. Routine screening tests for other etiologies of anemia were negative. Serological tests for anti-DNA and anti-acetylcholine receptor antibodies gave positive results. A bone marrow examination revealed severe erythroid hypoplasia. PRCA was diagnosed and the patient was treated with periodic transfusions. A lateral view chest roentgenogram and a computed tomography scan of the thorax showed the presence of an anterior mediastinal mass which was suspected to be thymoma. The patient underwent thymothymectomy and the tumor was diagnosed as a thymoma. Although the patient received no treatment for MG and PRCA after surgery, her hematological test results rapidly improved and she was discharged from the hospital on the 29th postoperative day. At that time, her hematocrit was 33.2%, her hemoglobin concentration was 10.0 g/dl, her peripheral reticulocyte level was 1.8% and her left partial ptosis had improved. She is doing well, 9 months after surgery. For a patient to remain in remission without treatment for PRCA and MG after thymothymectomy is extremely rare.

Free forearm flap reconstruction of the posterior tracheal wall invaded by esophageal carcinoma.

A patient with a locally advanced cervical esophageal carcinoma invading the trachea underwent total esophagopharyngolaryngectomy and resection of the posterior wall of the trachea. The esophagus was repaired with a gastric pull-up, and the posterior defect in the trachea was repaired with a free radial forearm flap, obtaining a satisfactory result.

Comparison of plasma lidocaine concentrations after injection of a fixed small volume in the stellate ganglion, the lumbar epidural space, or a single intercostal nerve.

UNLABELLED: We measured the plasma lidocaine concentrations after stellate ganglion block (SGB) and compared them with those after intercostal nerve block (ICNB) and epidural block (EB) using identical doses of lidocaine. Thirty patients undergoing SGB (n = 10), ICNB (n = 10), or EB (n = 10) in our pain clinic participated in this study. Six milliliters of 1% lidocaine was used for all nerve blocks. SGB was performed at the C6 transverse process, ICNB was performed on a single intercostal nerve, and epidural lidocaine was injected through the lumbar epidural catheter. After drug administration, venous blood samples were taken from an indwelling catheter in the arm every minute for the first 10 min and 15, 20, 30, 45, and 60 min thereafter. Plasma lidocaine concentrations were measured by using an enzyme immunoassay method. The SGB group showed significantly higher peak plasma lidocaine concentrations than other groups (SGB 1.65 +/- 0.21 microgram/mL, ICNB 0.89 +/- 0.12 microgram/mL, EB 0.91 +/- 0.19 microgram/mL; P < 0.01). The SGB group reached peak levels significantly faster than the other groups (SGB 3.4 +/- 1.0 min, ICNB 7.9 +/- 1.5 min, EB 6.9 +/- 0.7 min; P < 0.01). We conclude that the plasma lidocaine concentrations after SGB were higher than those after ICNB and EB when using small, equal doses of lidocaine. The high and rapid peak plasma lidocaine concentrations after SGB are probably related to the high vascularity of the injection site. IMPLICATIONS: Higher plasma concentrations of local anesthetics are reportedly obtained after multiple intercostal nerves blocks compared with those after other types of nerve blocks. Our results, however, showed that the peak plasma concentrations after stellate ganglion block were higher and faster than those after a single intercostal nerve block.

Absence of human papillomavirus-16 and -18 DNA and Epstein-Barr virus DNA in esophageal squamous cell carcinoma.

To elucidate the association of human papillomavirus (HPV) and Epstein-Barr virus (EBV) with carcinogenesis of the esophagus, 41 surgically resected specimens and 12 cell lines of esophageal squamous cell carcinoma were examined for the presence of HPV DNA and EBV DNA by polymerase chain reaction using primers for the E6 regions of HPV-16 and -18 and for the EBNA 1 region of EBV. We designed the reaction condition to amplify HPV and EBV DNA specifically and detected by gel electrophoresis. In ethidium bromide staining, no band was detected either for the HPV E6 region of for the EBV EBNA 1 gene in any of the surgically resected specimens and the cell lines, although the HPV sequence was detectable by Southern blot hybridization, which is a more sensitive detection method than staining; three out of 41 surgically resected specimens were positive for HPV-18 by Southern blot hybridization of polymerase chain reaction products. However, the number of viral genomes has been estimated as lower than 1 x 10(-3) copies per cell based on the intensity of the hybridization signals. Moreover, the DNA samples extracted from the corresponding non-cancerous esophageal mucosa were also positive for HPV-18, and the intensities of the hybridization signals were almost the same as those of the tumors. The results of our study indicate that HPV-16, HPV-18 and EBV are not generally associated with esophageal carcinogenesis.

Metastatic esophageal tumors from distant primary lesions: report of three esophagectomies and study of 1835 autopsy cases.

Three cases of esophagectomy for secondary esophageal carcinoma metastasized from the ovary, breast and lung are reported. Long-term survival, 14 and 4 years, after esophagectomy was achieved in two patients. The intervals between surgery for primary cancer and dysphagia onset in these two patients were 16 and 7 years, respectively. An aggressive surgical approach appears to be the therapeutic procedure of choice for metastatic esophageal carcinoma when the primary tumor growth rate is suspected to be slow. Autopsy data on 1835 cases revealed 112 (6.1%) had metastasis to the esophagus. The lung was the most common primary tumor-bearing organ and the diffusely infiltrative type was the most common esophageal tumor observed macroscopically which corresponded to the findings in our three patients. When an esophageal stricture with normal mucosa is encountered, a metastatic tumor must be taken into consideration.

Growth requirements of hyperthermophilic sulfur-dependent heterotrophic archaea isolated from a shallow submarine geothermal system with reference to their essential amino acids.

Three hyperthermophilic sulfur-dependent heterotrophs were isolated from a shallow submarine hydrothermal system at an inlet of Kodakara-jima island, Kagoshima, Japan. The isolates grew at 60 to 97 degrees C, with the optimum temperatures at 85 to 90 degrees C. Sensitivity to rifampin and the existence of ether lipids indicated that the isolates are hyperthermophilic archaea. Partial sequencing of the genes coding for 16S rRNA showed that the three isolates are closely related to the genus Thermococcus. They grew on proteinaceous mixtures, such as yeast extract, Casamino Acids, and purified proteins (e.g., casein and gelatin), but not on carbohydrates or organic acids as sole carbon and energy sources. Nine amino acids were essential for growth of isolate KS-1 (Thr, Leu, Ile, Val, Met, Phe, His, Tyr, and Arg). Isolate KS-2 required Lys in addition to the nine amino acids, and KS-8 required Lys instead of Tyr. In comparative studies, it was shown that Thermococcus celer DSM 2476 required 10 amino acids (Thr, Leu, Ile, Val, Met, Phe, Tyr, Trp, Lys, and Arg) while Pyrococcus furiosus DSM 3638 required only Ile and Val. The hyperthermophilic fermentative eubacterium Thermotoga neapolitana DSM 4359 did not require any amino acids for growth.

Esophageal carcinoma simultaneously associated with gastric carcinoma: analysis of clinicopathologic features and treatments.

Among 1,420 patients with thoracic esophageal carcinoma, 85 (6.1%) had synchronous gastric carcinoma. Seventy-two patients (84.7%) underwent esophagectomy. Their operative mortality and prognosis were similar to those without gastric carcinoma. Among them, 25 patients, of whom the majority had advanced gastric carcinoma, underwent transthoracic esophagectomy with total gastrectomy (group A); eight died of esophageal cancer and four of gastric cancer. Forty-six patients, of whom the majority had gastric carcinoma in an early stage, underwent esophagectomy and esophagogastric anastomosis following partial gastrectomy or local treatment for gastric carcinoma (group B). None of the group B patients had recurrent gastric carcinoma. The operative burden was larger in group A. The 5-year survival rate for groups A and B were 38.8% and 23.0%, respectively. Esophagectomy and esophagogastric anastomosis after limited treatment for gastric carcinoma is an adequate treatment for the majority. However, esophagectomy and total gastrectomy are recommended for patients with advanced gastric carcinoma.

Pathophysiologic significance of free and conjugated dopamines in congestive heart failure.

sulfoconjugated dopamine constitutes the major portion of circulating or excreted dopamine, but its physiologic significance is still unknown. To test whether conjugated dopamine serves as a source of free dopamine in response to acute stress, plasma concentrations of free and conjugated dopamine were measured during an acute exacerbation of heart failure. The plasma concentration of conjugated dopamine decreased significantly during the acute phase of heart failure, whereas that of free dopamine increased. The plasma concentration of free dopamine decreased, whereas the concentration of conjugated dopamine increased as heart failure improved. An infusion of dopamine increased the plasma concentration of conjugated dopamine, suggesting that at least part of the excess active dopamine was detoxified through conjugation. The results of these tests with both conjugated and free dopamine are interconvertible and indicate that conjugated dopamine can serve as a reservoir of active dopamine.

Comparison of the virulence of methicillin-resistant and methicillin-sensitive Staphylococcus aureus.

The virulence of methicillin-resistant Staphylococcus aureus (MRSA) was compared with that of methicillin-sensitive S. aureus (MSSA), using 13 MRSA and 7 MSSA strains isolated from clinical specimens. The infectivity and lethality of the two groups were examined as to the inoculum required to infect 50% of guinea pigs (ID50) and to kill 50% of mice (LD50), respectively. The mean ID50 [log10 colony forming units (CFU)] for MRSA strains was 7.1 +/- 0.60 standard deviation, which was 1.5 higher than that for MSSA strains (P < 0.001). The mean LD50 (log10 CFU) for MRSA strains was 9.0 +/- 0.42, being 1.1 higher than that for MSSA strains (P = 0.001). Pretreatment of mice with cyclophosphamide decreased the mean LD50 for MRSA strains more than that for MSSA strains, resulting in the difference in the mean LD50 being insignificant (P = 0.502). These results indicate that MRSA is less virulent than MSSA in normal hosts, but that they are equally virulent in immunocompromised hosts. The growth of MRSA strains was much slower than that of MSSA strains in the lag phase, although their growth rates were almost the same in the exponential growth phase, suggesting that the difference in virulence between them may be at least partly due to such a difference in growth.