Dioxin binding activities of polymorphic forms of mouse and human arylhydrocarbon receptors

The genetic difference in the susceptibility of mice to environmental toxicities induced by dioxin and related chemicals is governed by polymorphism of the arylhydrocarbon receptor (AhR) (Poland, A., and Knutson, C. (1982) Annu. Rev. Pharmacol. Toxicol. 22, 517-554). cDNA cloning of AhR cDNA from responder (C57BL/6) and non-responder (DBA/2J) mice allowed us to analyze the structure and function of these AhRs. Both of the AhRs, which were expressed in COS-7 cells transfected with their expression plasmids, showed a clear 9 S complex with 2,3,7,8-[3H]tetrachlorodibenzo-p-dioxin (TCDD) in a linear glycerol gradient centrifugation, consistent with the result of the endogenously expressed AhR in Hepa-1 cells. This result provides the first direct evidence that the cDNA-encoded protein binds the ligand specifically. Scatchard plot analysis revealed that the dissociation constant (Kd) of C57BL AhR for TCDD is 0.27 nM, while that of DBA AhR is elevated up to six times that high. Chimeric plasmids between the two cDNAs and site-directed mutagenesis revealed two critical alterations responsible for the reduced ligand binding activity: an Ala375 to Val alteration and an elongated carboxyl-terminal sequence due to a T to C mutation at the first letter of the termination codon of C57BL AhR. Two variants with reduced and intermediate ligand binding activity were also found in human AhRs with amino acid alterations equivalent to those of the DBA AhR. Importance of the amino acid at position 381 of human AhR (equivalent to position 375 of mouse AhR) in the ligand binding was confirmed by the fact that the mutation of Val381 to Asp completely abolished the ligand binding activity of human AhR.

Immunohistochemical studies on the intestinal nerve of Remak in the male chicken

A peroxidase anti-peroxidase method was used to investigate and compare the distribution of neuropeptide and catecholamine synthesizing enzyme immunoreactive (IR) ganglion cells and nerve fibres in the intestinal nerve of Remak (INR) of male chickens. In the INR there were three kinds of ganglion cells: tyrosine hydroxylase (TH)-, aromatic L-amino acid decarboxylase (AADC)- and phenylethanolamine-N-methyltransferase (PNMT)-IR cells; AADC- and PNMT-IR but TH-immunonegative cells; and ganglion cells being immunoreactive for methionine enkephalin (mENK)- and somatostatin (SOM). The first one was distributed throughout the INR. The second was restricted in the ileojejunal region, and the last was localized in the rectal region. Substance P- and vasoactive intestinal polypeptide-IR nerve fibres were distributed in common but variable in number around three kinds of ganglion cells. Then TH-IR cells were characterized by the distribution of many calcitonin gene related peptide- and a few cholecystokinin-IR fibres. mENK and SOM-IR cells, and TH-immunonegative cells were distinguished by the distribution of SOM- and galanin-IR fibres. In addition, TH-immunonegative cells were characterized by the distribution of mENK- and neuropeptide Y-IR nerve fibres which were very few in number. Fig. 21 summarizes the connections described in the present study.

Depression of cytotoxicity of nonparenchymal cells in the liver after surgery

BACKGROUND

The nonparenchymal cells (NPCs) of the liver have a strong cytotoxic activity. Our hypothesis is that their activity, which prevents metastases to the liver, may be impaired after operation.

METHODS

First, Sprague-Dawley rats underwent either a sham operation consisting of only a laparotomy (group L, n = 10), a laparotomy and resection of a portion of the small intestine (group R, n = 10) or no operation (group C, n = 10). After 2 days liver NPCs were isolated and divided into two fractions, large and small NPCs. The cytotoxicity of the liver NPCs and of the circulating blood mononuclear cells (BMC) was assessed. Second, we measured the growth of tumor metastases 14 days after the inoculation of a cell line (MRMT-1) into the portal vein of rats undergoing similar surgical stress (group Rm, n = 10 and group Lm, n = 10).

RESULTS

The natural killer cell activity (anti-YAC-1) of large NPCs was 38% in group R, which was significantly less (p < 0.002) than that in groups L (72%) and C (83%). Small NPCs showed reduced natural killer activity in groups R and L (26% and 35%, respectively) compared with that in group C (70%) (p < 0.02). The natural killer cell activity of BMCs was similar in each group, and the lymphokine-activated killer cell activity (by anti-EL4) did not change in either the NPCs or BMCs. In the second experiment the area of the tumors occupied in the liver in the group Rm rats was significantly greater compared with that in the group Lm rats (p < 0.01).

CONCLUSIONS

Surgical stress depressed the cytotoxic activity of liver NPCs and enhanced the growth of metastatic liver tumors. This suggests the possibility that perioperative immunotherapy might be clinically useful in the future to prevent liver metastases after gastrointestinal surgery.

Anti-oncogene product p53 binds DNA helicase

An oncogene product, p53, interacts with a simian virus 40-encoded T-antigen, which is an initiation protein for the viral DNA replication and also works as DNA helicase during elongation. Here we examine the interaction of p53 with cellular DNA helicase. A recombinant human wild type p53 fused with glutathione S-transferase was immobilized on glutathione-agarose as a ligand for affinity column. Hela cell extract was applied to the p53 column and the adsorbed proteins were eluted with buffers containing salt, 50% ethylene glycol, and glutathione. The ethylene glycol fraction contained a number of p53 binding proteins, and this fraction showed a DNA helicase activity measured by the displacement of DNA fragment from partially duplexed M13 DNA. The DNA helicase translocated in a 5'-to-3' direction on the single-stranded DNA using ATP as an energy source. The glutathione fraction that contained the p53 glutathione S-transferase fused protein also showed the same activity. The corresponding fractions from a control column carrying glutathione S-transferase showed only a trace amount of activity of DNA helicase. Therefore, the binding may be specific. Furthermore, an anti-p53 antibody column retained a p53-DNA helicase complex when the crude extracts of human placenta and of osteosarcoma cells were applied. These results indicate that p53 physically interacts with DNA helicase in vitro as well as in vivo.

[Evaluation of cerebral circulation and cerebrovascular CO2 reactivity with transcranial Doppler ultrasonography]

We examined the cerebrovascular CO2 reactivity (K) determined by measurements of the middle cerebral artery blood flow velocity (Vm) with transcranial Doppler ultrasonography (TCD) in 24 anesthetized patients. The relationship between Vm and mean arterial blood pressure (mBP) showed a linear regression in each constant level of PaCO2. The exponential curve with an exponent of 0.0399 mmHg-1 was found to be the best fit to the plotted data of Vm against PaCO2 during normotension of 90 mmHg. The following equation was used to evaluate K from the two flow values, because the calculated K value would be logically constant, i.e., an exponent of Vm/PaCO2 exponential curve: K (mmHg-1) = delta lnVm/delta PaCO2 = (lnVm(1) - lnVm(2)/(PaCO2(1) - PaCO2(2)). The validity of K values could be enhanced under conditions of the delta PaCO2 > or = 12.5 mmHg and the variation in arranged mBP < or = 30 mmHg. This methodology with TCD can be used to correlate changes in cerebral blood flow and provide much benefit for the evaluation of cerebrovascular CO2 reactivity.

[Protective effects of sesamol and its related compounds on carbon tetrachloride induced liver injury in rats]

Sesamol is a kind of antioxidant and exists in sesame oil. This paper describes the protective effect of sesamol against carbon tetrachloride (CCl4)-induced liver injury in rats. Sesamol had a significant effect in case of intraperitoneal, subcutaneous and oral administration. In order to examine the relationship between the chemical constitution of sesamol and its protective effect, the protective effects of 20 kinds of sesamol related compounds against liver injury induced by CCl4 were investigated in rats. Consequently, significant protective effects were found in methylenedioxybenzene, isosafrole, safrole, methylenedioxyaniline and methylenedioxyacetophenone. These five compounds had a methylenedioxy group had protective effects, it was considered that the protective effects of the methylenedioxy group were influenced by substituent groups on 4 position of methylenedioxy phenyl compounds. In addition, sesamol, methylenedioxybenzene and isosafrole showed significant protective effects against cholestasis induced by CCl4.

Muscle glycogen repletion and pre-exercise glycogen content: effect of carbohydrate loading in rats previously fed a high fat diet

We have recently reported that rates of muscle glycogen repletion during the early period of recovery were increased by carbohydrate (CHO) loading in rats previously fed a high fat diet. However, the reason for this remained unanswered. The purpose of this study was to examine whether an increase of glycogen utilization due to an elevated pre-exercise glycogen store would enhance rates of glycogen repletion in muscle. Despite an equal degree of glycogen depletion, the rates of glycogen repletion of soleus, red and white gastrocnemius muscles by postexercise administration of glucose (3.0 g.kg-1 body mass) and citrate (0.5 g.kg-1 body mass) were faster in the CHO loaded (3 days) rats than in the nonloaded rats, as a result of elevated pre-exercise glycogen content and consequently the greater glycogen utilization. The higher rate of muscle glycogen repletion may in part be explained by increased postexercise glycogen synthase activity.

Survival after surgery for cancer of the gallbladder

The records of 45 patients with carcinoma of the gallbladder who had undergone surgical resection at least 5 years previously were reviewed retrospectively to determine which factors influence long-term survival. Seventeen patients survived at least 5 years and 23 died from recurrence (five patients were excluded from analysis). Of the 17 long-term survivors 15 had tumours superficial to the subserosa that showed a non-infiltrative growth pattern. Those alive at 5 years were more likely than short-term survivors to have tumours that were papillary (P < 0.05) or well differentiated (P < 0.01) adenocarcinoma. Venous, lymphatic and perineural invasion was more common in short- than in long-term survivors (87 versus 29 per cent, P < 0.001). Patients with tumours limited to the muscularis and those with non-infiltrative subserosal involvement are likely to have better survival and may have a chance of cure after extended cholecystectomy.

Purification and characterization of two Ca(2+)-dependent lectins from coelomic plasma of sea cucumber, Stichopus japonicus

Two structurally distinct lectins were purified from the coelomic plasma of holothurian, Stichopus japonicus, by affinity chromatography on a porcine stomach mucin-conjugated agarose column, gel filtration on a Superose 6 column, and ion-exchange chromatography on a HiTrap Q-FPLC. The two lectins showed apparent molecular masses of about 400 kDa (SPL-1) and 60 kDa (SPL-2) on gel filtration, but about 17 kDa on SDS-PAGE under reducing conditions. Both lectins showed hemagglutination activity toward rabbit erythrocytes in the presence of Ca2+ ions. The N-terminal amino acid sequences were highly homologous to but distinct from those of a Ca(2+)-dependent (C-type) lectin named SJL-I purified from the same species. In addition to porcine stomach mucin, the hemagglutination activity of SPL-1 was strongly inhibited by uronic acids such as galacturonic acid, and glucuronic acid, while the activity of SPL-2 was inhibited by GalNAc and galactosides. Both lectins were adsorbed on clotted coelomocytes in the presence of Ca2+ but not in the presence of inhibitory sugars or EGTA, suggesting the presence of an endogenous carbohydrate ligand(s) for plasma C-type lectins in the clot. However, coelomocyte clotting occurred normally even in the presence of inhibitory sugars, but was strongly inhibited by synthetic GRGDSP peptide or EGTA, suggesting the participation of integrin but not the lectin-carbohydrate interaction in the clotting events.

[Adenovirus-induced kidney graft pyelonephritis following renal transplantation]

A 16-year-old female received a kidney transplantation from her mother 13 months before she suddenly noticed gross hematuria and painful micturition, and developed high fever with chills. The serum creatinine (S-Cr) level rose from 1.5 to 2.6 mg/dl, but there was no clinical sign of acute rejection. Despite the treatment with antibiotics and gamma-globulin, the the high fever and hematuria did not improve. The adenovirus antibody titer elevated from x8 to x1,024, while adenovirus was not isolated from the urine. On the 15th day of the disease, hematuria disappeared spontaneously and on the 19th day she became afebrile. The S-Cr level also was normalized spontaneously. Histological examination of the graft biopsy on the 14th day, showed severe tubulointerstitial nephritis localized in the renal medulla and full type intranuclear inclusions were revealed in tubular epithelial cells. From these findings, we diagnosed this case as adenovirus-induced kidney graft pyelonephritis associated with acute hemorrhagic cystitis.

Extent and location of cerebral infarcts on multiplanar MR images: correlation with distribution of perforating arteries on cerebral angiograms and on cadaveric microangiograms

The basal gray matter in the cerebrum is supplied by different anatomical groups of perforating arteries, including striate, thalamic, and choroidal arteries. In this pictorial essay we illustrate multiplanar MR imaging of infarctions in those regions and correlate their appearances with cerebral angiographic findings of the same patients when available. We also correlate the extent and location of infarctions on multiplanar MR images with the anatomical distributions of perforating arteries seen on microangiograms of unrelated cadavers. Information conveyed from this correlation will increase understanding of patterns of basal cerebral infarction shown on cross-sectional imaging.

Proliferating cell nuclear antigen and Ki-67 in lung carcinoma. Correlation with DNA flow cytometric analysis

BACKGROUND

To study the prognosis of patients with lung carcinomas, the efficacy of proliferating cell nuclear antigen (PCNA) in ensuring both the proliferative activity defined using Ki-67 labeling and the cell cycle data obtained using flow cytometry was determined.

METHODS

The authors used immunostaining to study frozen and paraffin embedded sections of 165 surgically resected lung carcinomas [squamous cell carcinoma, n = 84; adenocarcinoma, n = 62; large cell carcinoma, n = 15; small cell carcinoma, n = 4] for the presence of PCNA and Ki-67 antibodies. Also studied were two parameter flow cytometric analysis of fluorescein isothiocyanate conjugated PCNA/propidium iodide for 165 fresh frozen tissues. Clinicopathologic data (sex, age, tumor stage, survival period, histologic type, degree of cell differentiation, and cellularity) were evaluated using the Statistical Analysis System.

RESULTS

The percentages of PCNA positive cells per 1000 nuclei were 52% of squamous cell carcinoma; 49% in adenocarcinomas; 76% of large cell carcinoma; and 63% of small cell carcinoma. Positive PCNA staining was significantly correlated with stage, cellularity, and DNA index. Calculation of logistic regression coefficients indicated an association between overall survivals and tumor cellularity (P < 0.0003), percentage of cells stained with PCNA antibody (P < 0.02), DNA pattern (aneuploid versus diploid) (P < 0.009), DNA index (P < 0.009), and percentage of cells in S-phase (P < 0.04). Both cellularity (P = 0.03) and DNA (P = 0.08) retained its independent level of significance by multivariate analysis.

CONCLUSIONS

In addition to clinical stage and histologic differentiation, both cellularity and DNA content may help predict the course of lung carcinomas.

Ganglioside antigen of DU-PAN-2 in a human pancreatic cancer

DU-PAN-2 reactive gangliosides were isolated from the tumor of a patient with pancreatic cancer (duct cell carcinoma, moderately differentiated adenocarcinoma), having a negative Lewis blood phenotype, and were analyzed by means of TLC-immunostaining, enzyme-linked immunosorbent assay (ELISA), permethylation study, 1H NMR spectroscopy and fast atom bombardment mass spectrometry. The structures of the gangliosides were found to be NeuAc alpha 2-3Gal beta 1-3GlcNAc beta 1-3Gal beta 1-4Glc beta 1-1'Cer, containing normal and hydroxy fatty acids. By TLC-immunostaining and ELISA with chemically synthesized gangliosides, DU-PAN-2 was demonstrated to react strongly with IV3 alpha NeuAc-Lc4Cer, weakly with IV3 alpha NeuAc-nLc4Cer, and moderately with IV6 alpha NeuAc-Lc4Cer and IV6 alpha NeuAc-nLc4Cer. Thus it was concluded that the DU-PAN-2 reactive ganglioside in the tumor is IV3 alpha NeuAc-Lc4Cer and that DU-PAN-2 has a rather broad specificity.

[Surgical intervention to tuberculous pericarditis: a case report]

A 32-year-old man was hospitalized because of cardiac tamponade with the thickened visceral and parietal pericardial layers. Marked high level of adenosine deaminase activity (ADA) in pericardial fluid strongly suggested the diagnosis of tuberculous pericarditis, which was later assured by positive smear and culture of the pericardial fluid for Mycobacterium tuberculosis. Before rigid adhesion of the pericardial space was established, pericardiectomy was easily performed with satisfactory improvement of the hemodynamic status and physical symptoms of the patient. The present case suggests the efficacy of early surgical intervention to tuberculous pericarditis when it shows a sign of rapid progression to constrictive pericarditis. Furthermore, high ADA in pericardial fluid might be an useful diagnostic modality for tuberculous pericarditis.

Induction of metallothionein synthesis by bismuth in cultured vascular endothelial cells

Metallothionein synthesis induced by bismuth nitrate was characterized using a cell culture system. It was found that bismuth (1-10 microM) significantly increased the intracellular accumulation of metallothionein in bovine aortic endothelial cells without an exhibition of cytotoxicity and a change of either general protein synthesis or proliferative DNA synthesis after a 24-h incubation. A low increase in the metallothionein accumulation was observed in bovine aortic smooth muscle cells; however, porcine kidney epithelial LLC-PK1 cells, human Chang liver cells and two human hepatoma cell lines (HLF cells and Hep-G2 cells) did not respond to bismuth. Other cations including cobalt, lead and zinc at 10 microM failed to induce metallothionein in endothelial cells, although cadmium at 1 microM was a strong inducer. Bismuth accumulated highly in endothelial cells but very slightly in LLC-PK1 cells and Chang liver cells. The present data suggest that bismuth is a selective inducer of metallothionein of vascular endothelial cells and this cell type particularly responds to the cation.

Noninvasive quantitative evaluation of early atherosclerosis and the effect of monatepil, a new antihypertensive agent. An interim report

In two studies on the same group of patients we evaluated noninvasive methods of assessing atherosclerosis and determined the effect of the new calcium channel-blocking agent monatepil on the progression of early atherosclerosis in humans. Computed tomography (CT) of the lower abdominal aorta and ultrasonography of the carotid arteries were used as noninvasive methods to determine the extent of atherosclerosis. To evaluate the CT images, we developed a new medical image analysis program. This enabled aortic calcification volume (ACV) to be quantified using plain CT images, and aortic wall volume (AWV) and aortic wall and calcification volume (AWCV) to be quantified from contrast CT images. Interobserver coefficients of variation of ACV, AWV, and AWCV (n = 8) were 4.7, 2.4, and 5.0%, respectively. In the monatepil study, the effect of the drug on serum lipid profiles was evaluated. Preliminary results show that shortly after monatepil administration, total serum cholesterol levels decreased significantly from 253.8 +/- 35.6 to 244.8 +/- 38.6 mg/dL (P < .009) and triglyceride levels tended to decrease. A positive correlation between the change in total cholesterol and changes in mean platelet volume was found (P = .028). Fasting immunoreactive insulin levels decreased in the four patients in which they were determined. Although this is a preliminary study, results indicate that CT of the lower abdominal aorta in combination with our new analysis program may be a precise, reproducible means of assessing early atherosclerosis. We have also shown that monatepil significantly decreases total cholesterol levels. However, the long-term effects of monatepil on the progression of atherosclerosis remain to be determined.

Improvement of glucose tolerance by bezafibrate in non-obese patients with hyperlipidemia and impaired glucose tolerance

Glucose intolerance or diabetes mellitus, hyperlipidemia, obesity and hypertension may have a close interrelation based on insulin resistance. We selected 28 impaired glucose tolerance (IGT) patients with hyperlipidemia. The IGT patients demonstrated hypertriglyceridemia associated with hyperinsulinemia, a typical manifestation of insulin resistance. Administration of bezafibrate at 400 mg/day for 4 weeks to the IGT patients with hypertriglyceridemia resulted in an improvement of the plasma glucose level and insulin response to 75 g oral glucose loading associated with a concomitant decrease in non-esterified fatty acids. The ratio of the level of serum C-peptide to that of insulin after a 75 g oral glucose tolerance test (OGTT) was augmented after 4 weeks of bezafibrate administration. However, reduction of the cholesterol level with pravastatin did not alter these parameters. These results suggest that treatment to reduce the level of serum triglycerides, but not that of cholesterol, may have a beneficial effect for improving insulin resistance even in the non-obese subjects with IGT and decreasing the risk of coronary heart disease.

Glucose effectiveness in two subtypes within impaired glucose tolerance. A minimal model analysis

To clarify the event that is involved in the pathogenesis of impaired glucose tolerance (IGT), we studied 15 individuals with IGT and 15 subjects with normal tolerance using the minimal model approach. Our IGT subjects were characterized by normal insulin secretory responses to oral glucose and mild impairments in insulin sensitivity (SI) and glucose effectiveness (SG) at basal and zero insulin. Next, we classified our IGT subjects into two subpopulations: one with normal insulin sensitivity (SI: 0.92 +/- 0.11 x 10(-4) min-1.pmol/l-1 and the other with insulin resistance (SI:0.31 +/- 0.06 x 10(-4)min-1.pmol/l-1, P < 0.05). The populations did not differ with respect to body mass index and fasting plasma glucose level. Basal plasma insulin level was higher in the insulin-resistant group (84.8 +/- 23.3 pmol/l) than in the insulin-sensitive group (48.7 +/- 6.8 pmol/l), but the difference was not statistically significant. The absolute insulin secretory responses to oral glucose were significantly higher in the resistant group (83,205 +/- 17,787 pmol/l x min) than in the sensitive group (24,727 +/- 3,591 pmol/l x min, P < 0.01), whose absolute responses were similar to those of normal control subjects (24,576 +/- 2,767 pmol/l x min). No significant difference was observed in SG between the resistant (0.016 +/- 0.002 min-1) and sensitive (0.013 +/- 0.002 min-1, P > 0.05) type of IGT, but SG was significantly type of IGT, but SG was significantly decreased in both groups compared with normal control subjects (0.023 +/- 0.002 min-1, P < 0.05-0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

Nonkallikrein arginine endopeptidase in the human submaxillary gland: purification and characterization of the enzyme

The two major species of arginine endopeptidase present in the soluble fraction of human submaxillary gland are glandular kallikrein and another enzyme tentatively named nonkallikrein arginine endopeptidase. In this study, we purified the latter enzyme to homogeneity and examined its catalytic properties. The newly found enzyme was clearly distinguishable from human tissue kallikrein in its molecular nature, action toward various synthetic substrates, and kinin-generated activity. The specificity of the action of the enzyme was further investigated using various basic amino acid-containing peptides as model substrates. HPLC analysis of peptide fragments produced, followed by their amino acid analysis, revealed that the enzyme preferentially hydrolyzed the Arg-Arg or Arg-Lys bonds in dynorphins A 1-10, 1-9, and 1-8, beta-neoendorphin, adenorphin, and neurotensin.