Anaerobic oxidation of dissolved hydrogen sulfide in continuous culture of the phototrophic bacterium Prosthecochloris aestuarii

The anaerobic oxidation of dissolved H2S to elemental sulfur was studied at 23 degrees C and pH 6.5+/-0.3 in continuous culture of the phototrophic green sulfur bacterium Prosthecochloris aestuarii. The number of cells formed in the cultures was proportional to the amount of H2S oxidized, and the growth yield was independent of light intensity. The specific growth rate was significantly dependent on the dissolved H2S concentration and light intensity. The kinetic data were analyzed with a rate expression as a function of each rate-limiting factor. Under illumination by white fluorescent lamps, the specific oxidation rate of P. aestuarii reached a maximum of 2.02 x 10(-14) mol-H2S.h(-1).cell(-1) when the dissolved H2S concentration was 2.1 mM at 5000 lx. Simultaneous use of near infrared LED (light-emitting diode) and white fluorescent lamps provided a 35% increase in the maximum specific H2S oxidation rate.

Increased expression of cyclooxygenase-2 protein in rat urinary bladder tumors induced by N-butyl-N-(4-hydroxybutyl) nitrosamine

The anti-inflammatory drugs, aspirin and piroxicam, are known to possess chemopreventive potential against rat superficial urinary bladder carcinogenesis induced by N-butyl-N-(4-hydroxybutyl)nitrosamine (BBN). Recently, we found similar inhibitory effects with a selective cyclooxygenase (COX)-2 inhibitor, nimesulide. In order to clarify the inhibitory mechanisms, we have further studied the expression of COX-2 protein in urinary bladder tumors induced by BBN in Fischer 344 male rats. For comparison, papillomatosis caused by uracil-induced urolithiasis, and normal epithelial cells, were also investigated. Western blot analysis revealed COX-2 protein to be barely expressed in the normal epithelial cells, whereas it was increased 13-22-fold in varying sizes of urinary bladder tumors and 7-fold in papillomatosis. Immunohistochemically, COX-2 protein was diffusely expressed in transitional cell carcinomas and nodulo-papillary hyperplasia but weakly expressed only in basal cells in simple hyperplasia and normal-looking surrounding epithelia. In papillomatosis, it was moderately expressed only in endothelial cells in stroma. These results indicate that COX-2 plays important roles in the development of preneoplastic and neoplastic lesions in the rat urinary bladder, and therefore could be a good target for chemoprevention of superficial lesions.

GOOSECOID inhibits erythrocyte differentiation by competing with Rb for PU.1 binding in murine cells

Misexpression of the dorsal mesodermal patterning factor goosecoid on the ventral side of amphibian embryos results in inhibition of blood formation in early embryogenesis. To investigate the mechanism of this inhibition, we ectopically expressed goosecoid in erythroleukemia cells. While erythroid differentiation of these cells can be induced by activin, goosecoid expressing cells were unresponsive to activin. We demonstrate an in vitro interaction between the oncogene PU.1, an ets family transcription factor thought to play a role in erythropoiesis, and the goosecoid protein (GSC). Interaction with PU.1 was specific as GSC did not bind to the ets family members, Fli-1 or Ets-2. The ability of goosecoid expressing erythroleukemia cells to differentiate in response to activin was rescued by coexpression of the GSC-binding N-terminal portion of PU.1. The N-terminal portion of PU.1 was co-immunoprecipitated with anti-GSC antibodies as well. The N-terminal domain of PU.1 is the region recognized by the retinoblastoma protein (Rb), a tumor suppressor gene presumably involved in erythroid differentiation. We show that GSC competitively inhibits binding of Rb to PU.1. Our data suggest that the suppression of blood formation by GSC could, at least in part, be mediated by binding to PU.1.

Creatinine clearance as a substitute for the glomerular filtration rate in the assessment of glomerular hemodynamics

A method for the clinical assessment of glomerular hemodynamics has been published previously. We here examined whether, when using this method, renal creatinine clearance (Ccr) can be substituted for the glomerular filtration rate (GFR). The study subjects comprised 57 inpatients from Osaka City General Hospital: 30 with type 2 diabetes mellitus and 27 with chronic glomerulonephritis. During the 2-wk study, patients received a high-salt diet for 1 wk and a low-salt diet for 1 wk. Urinary sodium excretion and systemic blood pressure were measured daily. The renal plasma flow, Ccr, and plasma total protein concentration were also evaluated simultaneously on the last day of the high-salt diet. The GFR was also calculated from the fractional renal accumulation of 99mTc-diethylenetriaminepentaacetic acid (DTPA). Glomerular hemodynamics, represented by the glomerular capillary hydraulic pressure and the resistance of afferent and efferent arterioles, were calculated using the renal clearance, the plasma total protein concentration, and the pressure-natriuresis relationship. Values for renal hemodynamics with the Ccr-derived GFR were compared with those from the 99mTc-DTPA-derived GFR. Ccr values of 53 to 169 ml/min correlated with the 99mTc-DTPA-derived clearance of 39 to 179 ml/min (n=57, r=.71, p<.001). Values for the glomerular pressure and the resistances of afferent and efferent arterioles calculated using the Ccr-derived GFR correlated significantly with those calculated using the 99mTc-DTPA-derived GFR (r=.99, p<.001 and r=.99, p<.001, respectively). These results indicate that the Ccr is an accurate representation of the GFR for use in glomerular hemodynamic analysis of the pressure-natriuresis relationship.

Enhanced expression of Tie2, its ligand angiopoietin-1, vascular endothelial growth factor, and CD31 in human non-small cell lung carcinomas

Expression of angiogenesis-associated genes was compared in 32 primary non-small cell lung carcinoma samples (14 adenocarcinomas, 17 squamous cell carcinomas, and 1 large cell carcinoma) and paired adjacent noncancerous lung tissues using a multiprobe RNase protection assay. Levels of Tie2, angiopoietin (Ang)-1, vascular endothelial growth factor (VEGF), and CD31 mRNAs were higher in cancers than in adjacent noncancerous tissues, in contrast to the fms-like tyrosine kinase (Flt)-1, Flt-4, Tie1, thrombin receptor, endoglin, and VEGF-C, for which no differences were evident. Overexpression did not seem to differ with histological type and pathological stage. Significant positive correlations were found between mRNA expression of Ang-1 and those of Tie2 and CD31, and that of VEGF and those of Flt-1 and CD31. These findings suggest that Ang-1 and VEGF are important angiogenic factors in human non-small cell lung carcinomas.

Carcinogenicity of heterocyclic amines for the pancreatic duct epithelium in hamsters

Effects of eight heterocyclic amines (HCAs) on pancreatic duct carcinogenesis were investigated in a rapid production model in hamsters. N-Nitrosobis(2-oxopropyl)amine (BOP) was given to effect initiation, followed by augmentation pressure consisting of four daily i.p. injections of 500 mg/kg DL-ethionine, a choline-deficient (CD) diet, a single i.p. injection of 800 mg/kg L-methionine and a s.c. injection of 20 mg/kg BOP. After two cycles of augmentation pressure, the HCAs 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP), 2-amino-3,8-dimethylimidazo[4,5-f]quinoxaline (MeIQx), 2-amino-3-methylimidazo[4,5-f]quinoline (IQ), 3-amino-1,4-dimethyl-5H-pyrido[4,3-b]indole (Trp-P-1), 3-amino-1-methyl-5H-pyrido[4,3-b]indole (Trp-P-2), 2-amino-9H-pyrido[2,3-b]indole (AalphaC), 2-amino-3-methyl-9H-pyrido[2,3-b]indole (MeAalphaC) or 2-amino-3,4,8-trimethylimidazo[4,5-f]quinoxaline [4,8-DiMeIQx) were administered in the diet for 50 or 70 days. The numbers of pancreatic ductal hyperplasias (H) and a total lesions including, atypical hyperplasia (AH), carcinomas in situ (CIS) and invasive carcinomas, were increased in hamsters given the diet containing 0.02% Trp-P-1 for 50 days. This result was confirmed and extended by the finding of increased numbers of invasive carcinomas in hamsters given 0.02% Trp-P-1 for 70 days. The number and incidence of invasive carcinomas were also elevated in hamsters given the diet containing 0.06% 4,8-DiMeIQx for 50 days. These results suggest a possible involvement of Trp-P-1 and 4,8-DiMeIQx in pancreatic duct carcinogenesis.

Enhancement by recombinant human bone morphogenetic protein-2 of bone formation by means of porous hydroxyapatite in mandibular bone defects

Hydroxyapatite is osteoconductive and can maintain an original biocompatible form. It is useful, in the reconstruction of bone defects, to enhance the osteoconduction of hydroxyapatite with an osteogenic protein. The aim of this study was to evaluate the bone formation in surgically created defects of rabbit mandibles by a combination of recombinant human bone morphogenetic protein-2 (rhBMP-2), with porous hydroxyapatite and atelopeptide type I collagen used as the carrier for rhBMP-2. A 10-microg rhBMP-2-implanted group (n = 15) and a control group (n = 15), in which only atelopeptide type I collagen and porous hydroxyapatite were implanted, were histologically examined 3, 7, and 21 days after implantation. The alkaline phosphatase activity was also quantitatively analyzed. No new bone formation was observed in either the tested or the control group after 3 days. At 7 days, immature bone tissue was observed in some pores of the rhBMP-2implanted group, while in the control group, immature mesenchymal cells were observed. At 21 days, trabecular bone lined some pore walls. In the central portion, the bone marrow, including angioid tissue, was observed. New trabecular bone formation was observed on portions of the external surface of the hydroxyapatite disk. On the other hand, the control group showed infiltration of immature mesenchymal cells into some pores. Marginal bone formation was found in the pores close to the surface of the disk which opposed mandibular bone. The control group showed a slow, small increase in alkaline phosphatase activity in this study, while the experimental group showed a marked increase at 21 days. This increase was significantly higher in the tested group than in the control group at both 7 and 21 days. The findings indicate that rhBMP-2 accelerated bone formation by osteoconduction from porous hydroxyapatite. The combination of rhBMP-2, atelopeptide type I collagen, and porous hydroxyapatite is suggested to be advantageous for clinical application in reconstructing mandibular bone defects.

Hypomethylation of CpG sites and c-myc gene overexpression in hepatocellular carcinomas, but not hyperplastic nodules, induced by a choline-deficient L-amino acid-defined diet in rats

We have investigated aberrant methylation of CpG nucleotides (CpG sites) and gene expression of c-myc during hepatocarcinogenesis induced by a choline-deficient, L-amino acid-defined (CDAA) diet in rats. Male Fischer 344 rats, 6 weeks old, were continuously given a CDAA diet for 50 and 75 weeks and then killed. Macroscopically detectable nodules, which were histologically confirmed to be hyperplastic nodules (HNs) or well-differentiated hepatocellular carcinomas (HCCs), were dissected free from the surrounding tissue. Normal control liver was obtained from 6-week-old rats. Methylation of CpG sites of the c-myc gene was investigated in bisulfite-treated DNA isolated from normal liver, HNs and HCCs. All 33 cytosines in the 5'-upstream region of the c-myc gene were fully methylated in control liver and the 4 HNs. In contrast, these cytosines were completely unmethylated in 5 HCCs. Examination of the c-myc expression by reverse transcription-polymerase chain reaction (RT-PCR) analysis also showed a marked increase as compared to the low levels in normal livers and HNs. These results suggest that hypomethylation of the c-myc gene might play a critical role in malignant transformation from HN to HCC during CDAA diet-induced hepatocarcinogenesis in rats.

Different frequencies and patterns of beta-catenin mutations in hepatocellular carcinomas induced by N-nitrosodiethylamine and a choline-deficient L-amino acid-defined diet in rats

To allow a study of beta-catenin mutations in hepatocellular carcinomas (HCCs) induced by exogenous and endogenous carcinogens, we induced tumors in male Fischer 344 rats with N-nitrosodiethylamine and a choline-deficient L-amino acid-defined diet. Administration of the former was followed by partial hepatectomy with colchicine to induce cell cycle disturbance and a selection pressure regimen (K. Ohashi et al., Cancer Res., 56: 3474-3479, 1996; M. Tsutsumi et al., Jpn. J. Cancer Res., 87: 5-9, 1996). HCCs were obtained after 42 weeks. With continuous choline-deficient L-amino acid-defined feeding, tumors were sampled after 75 weeks. Total RNA was extracted from individual lesions and mutations in the glycogen synthase kinase-3beta phosphorylation consensus motif of beta-catenin were investigated by reverse transcriptase-PCR-single-strand conformation polymorphism analysis followed by nucleotide sequencing. Changes were detected in 5 of 11 HCCs induced by the exogenous carcinogen. The observed shifts of C:G-->G:C or C:G-->A:T at codon 33 and G:C-->T:A transversions at codon 34 were associated with beta-catenin protein accumulation and confirmed by Western blot analysis. Only 2 of 15 HCCs induced in the endogenous carcinogenesis regimen demonstrated mutations, those being transitions of C:G-->T:A at codon 41 without amino acid alteration. These results suggest that different genetic pathways underlie exogenous and endogenous liver carcinogenesis in rats.

Potent bivalent thrombin inhibitors: replacement of the scissile peptide bond at P(1)-P(1)' with arginyl ketomethylene isosteres

We have designed highly potent synthetic bivalent thrombin inhibitors, which consist of an active site blocking segment, a fibrinogen recognition exosite blocking segment, and a linker connecting these segments. The bivalent inhibitors bind to the active site and the fibrinogen recognition exosite simultaneously. As a result, the inhibitors showed much higher affinity for thrombin than the individual blocking segments. Various arginyl ketomethylene isosteres ArgPsi[CO-CH(2)-X]P(1)' were incorporated into the bivalent inhibitors as P(1)-P(1)' segment to eliminate the scissile bond. The P(1)' residue is a natural or unnatural amino acid; specifically, the incorporation of mercaptoacetic acid exhibited superiority in synthesis and affinity for thrombin. Inhibitor 16, (D-cyclohexylalanine)-Pro-ArgPsi[CO-CH(2)-S]Gly-(Gly)(4)-Asp-Tyr-G lu- Pro-Ile-Pro-Glu-Glu-Tyr-cyclohexylalanine-(D-Glu)-OH, showed the lowest K(i) value of 3.5 +/- 0.5 x 10(-13) M, which is comparable to that (K(i) = 2.3 x 10(-13) M) of recombinant hirudin. Consequently we successfully reduced the size of the inhibitor from approximately 7 kDa of recombinant hirudin to approximately 2 kDa without losing the affinity.

Computational fluid dynamics analysis to establish the design process of a centrifugal blood pump: second report

To establish an efficient design process for centrifugal blood pumps, the results of computational fluid dynamics (CFD) analysis were compared to the results of flow visualization tests and hemolysis tests, using the Nikkiso centrifugal blood pump. CFD analysis revealed that the radial gap greatly affected the shear stress in the outlet diffuser. The hemolysis study also indicated a similar tendency. To see the flow behind the impeller, we conducted a comparative study between models with and without washout holes using the CFD technique. CFD analysis indicated that flow and pressure distributions behind the impeller were different between both models, and a particle was observed to remain longer behind the impeller in the model without washout holes. In the future, CFD analysis could be a useful tool for developing blood pumps in comparison to flow visualization tests and hemolysis tests.

[Clinical experience with gelatin-resorcine-formol glue for repair of postinfarction ventricular septal rupture]

We report a surgical technique for treatment of postinfarction ventricular septal rupture (VSR). An 82-year-old woman underwent successful surgical repair of a VSR two days after suffering anterior myocardial infarction. After repair of the VSR with a Dacron patch, the left ventriculotomy was closed with mattress sutures over felt strips using the gelatin-resorcine-formol glue to reinforce the left ventricular wall. The patient was doing well four months after surgery.

Flow visualization study to improve hemocompatibility of a centrifugal blood pump

A correlation study was conducted among quantitative flow visualization analysis, computational fluid dynamic analysis, and hemolysis tests regarding the flow in a centrifugal blood pump to prevent hemolysis. Particular attention was paid to the effect of the impeller/casing gap widths on the flow in the volute and in the outlet. Flow vector maps were obtained for 250% scaled-up models with various geometries, using an argon ion laser light sheet, a high speed video camera, and particle tracking velocimetry. In terms of the results, in the small radial gap model, high shear occurred near the inside wall of the outlet and stagnation near the outside wall of the outlet whereas the standard model maintained smooth flow and low shear. The small radial gap model showed a lower head and greater hemolysis than the standard model. This head decrease could be partly restored by relocating the outlet position; however, the hemolysis level hardly decreased. From these results, it was found that the small radial gap itself is important. It was also confirmed by detailed flow visualization and simple laminar shear analysis near the wall that the small radial gap caused a wider high shear layer (110-120 microm) than the standard model (approximately 80 microm). In the small radial gap model, the high shear layer in the outlet (approximately 50 microm) is much narrower than that in the volute. Flow visualization together with the aid of computational fluid dynamic analysis would be useful to eliminate the causes of hemolysis.

Glomerular hypertension as one cause of albuminuria in type II diabetic patients

AIMS/HYPOTHESIS

Results from animal models of glomerular hypertension have suggested that this disorder is one cause of albuminuria in diabetic nephropathy. We evaluated this hypothesis clinically.

METHODS

The subjects were 20 patients with Type II (non-insulin-dependent) diabetes mellitus but without uraemia or hypertension: 8 had normoalbuminuria and 12 had albuminuria (> or = 20 micrograms/min). In the 2-week study, patients were on a diet with ordinary amounts of sodium for 1 week and on a sodium-restricted diet for 1 week. Urinary excretion of sodium and albumin and the systemic blood pressure were measured daily. Intrarenal haemodynamics, in terms of the glomerular pressure and resistance of afferent and efferent arterioles, were calculated from renal clearance, the plasma total protein concentration, and the pressure-natriuresis relation. In 8 of the 12 patients with albuminuria, an angiotensin-converting enzyme inhibitor, cilazapril, was given orally (2 mg/day) and the 2-week study was repeated.

RESULTS

In patients with albuminuria, resistance of efferent arterioles and the glomerular pressure were higher than in patients with normoalbuminuria (glomerular pressure, 53 +/- 5 vs 43 +/- 5 mmHg, means +/- SD, p < 0.001). Urinary excretion of albumin correlated (n = 20, r = 0.675, p < 0.001) with the glomerular pressure but not with systemic pressure. The increased glomerular pressure and the albuminuria were decreased by cilazapril but systemic pressure was not.

CONCLUSIONS/INTERPRETATION

These findings are consistent with the hypothesis that glomerular hypertension is present in Type II diabetic patients with early nephropathy and can cause albuminuria.

Development of design methods for a centrifugal blood pump with a fluid dynamic approach: results in hemolysis tests

The purpose of this study was to examine the relationship between local flow conditions and the hemolysis level by integrating hemolysis tests, flow visualization, and computational fluid dynamics to establish practical design criteria for centrifugal blood pumps with lower levels of hemolysis. The Nikkiso centrifugal blood pump was used as a standard model, and pumps with different values of 3 geometrical parameters were tested. The studied parameters were the radial gap between the outer edge of the impeller vane and the casing wall, the position of the outlet port, and the discharge angle of the impeller vane. The effect of a narrow radial gap on hemolysis was consistent with no evidence that the outlet port position or the vane discharge angle affected blood trauma in so far as the Nikkiso centrifugal blood pump was concerned. The radial gap should be considered as a design parameter of a centrifugal blood pump to reduce blood trauma.

Cloning of differentially expressed genes in highly and low metastatic rat osteosarcomas by a modified cDNA-AFLP method

To identify differentially expressed genes between highly and low metastatic rat transplantable osteosarcomas, we applied a modified AFLP (amplified fragment length polymorphisms) method for cDNA subtraction. The specific point of our modification is selective amplification using suppression PCR technique after restriction enzyme cutting. Our cDNA-AFLP gave high reproducibility (about 95%) in mRNA patterns and enabled us to clone four dominantly expressed genes in a highly metastatic tumor line. Three showed homology with known genes, encoding Ki-67, a proliferation-associated effective marker of malignancy, type IV collagen alpha-3, a major component of basement membrane, and KIAA77 for which the function is unknown. Although one fragment showed no database homology, we revealed a derivation from the rat homologue of the Drosophila melanogaster diaphanous gene (Dia) by cloning of longer cDNA. Dia genes, known to affect actin filament formation, are downstream effectors of Rho small GTPase. The results suggest that alterations in the expression of cytoskeletal protein, basement membrane elements, and proliferative markers may be important for metastasis of osteosarcomas.

[A longitudinal study of hand-mouth contacts of pre-term infants]

The developmental change of spontaneous hand movements were investigated longitudinally in 5 low-risk pre-term infants. The observation period was divided into three: 33-40, 41-52 and 53-60 weeks in order of gestational age. Both hand-mouth contacts (H-M-C) and hand-face contacts (H-F-C) were frequent in the 33-40-week period, and decreased drastically in the 41-48 week period. In the 53-60-week period, the number of H-F-C remained at a low level, while H-M-C increased again to the level of the first period. Furthermore, the mouth was open as the hand came into contact with it as frequently in the 33-40-week period as in the 53-60-week period. These findings suggest that H-M-C are neurologically distinct from H-F-C, and that the H-M-C before 41 weeks and after 50 weeks share some common components of this neurological mechanism.

Expression of matrix metalloproteinase 2 (MMP-2), membrane-type 1 MMP and tissue inhibitor of metalloproteinase 2 and activation of proMMP-2 in pancreatic duct adenocarcinomas in hamsters treated with N-nitrosobis(2-oxopropyl)amine

In order to assess the significance of changes in metalloproteinase activity in pancreatic carcinogenesis, the expression of matrix metalloproteinases 2 and 9 (MMP-2 and MMP-9, respectively), tissue inhibitor of metalloproteinase-1 (TIMP-1) and TIMP-2, and membrane-type 1 MMP (MT1-MMP) and MT2-MMP in ductal lesions in a rapid-production model for pancreatic duct carcinomas (PCs) in hamsters initiated with N-nitrosobis(2-oxopropyl)amine (BOP) and in subcutaneous transplantable tumors of hamster pancreatic duct carcinoma (HPDs) was investigated. Northern analysis revealed MMP-2, MMP-9, TIMP-2 and MT1-MMP mRNAs to be overexpressed in PCs. Immunohistochemically, elevated levels of MMP-2 were apparent in early duct epithelial hyperplasias and staining increased from atypical hyperplasias to carcinomas. Gelatin zymography demonstrated clear activation of proMMP-2 but not proMMP-9 in both of primary and HPD tumors, the MT1-MMP mRNA level and proMMP-2 activation being significantly correlated (r = 0.893, P < 0.001). In our rapid production model, 0.1 and 0.2% OPB-3206, an inhibitor of MMPs, given in the diet after two cycles of augmentation pressures for 48 days decreased the incidence and number of carcinomas. Gelatin zymography demonstrated that OPB-3206 inhibited activation of proMMP-2 in pancreatic cancer tissues. These results indicate that overexpression of MMP-2, TIMP-2 and MT1-MMP, and cell surface activation of proMMP-2 by MT1-MMP, are involved in the development of PCs, and that MMP-2 expression at the protein level appears in the early phase of pancreatic duct carcinogenesis. OPB-3206 may be a candidate chemopreventive agent for pancreatic ductal adenocarcinomas.

[Coronary bypass surgery within thirty days of acute inferior myocardial infarction]

Between April 1988 and November 1998, 82 patients underwent isolated coronary artery bypass grafting within 30 days of acute myocardial infarction. The infarct-related artery was the proximal right coronary artery (27 patients; group 1) and the left coronary artery (55 patients; group 2). In group 2 the infarct-related artery was the left main coronary artery (8 patients), the left anterior descending coronary artery (33 patients), and the left circumflex coronary artery (14 patients). There was no difference between groups 1 and 2 with regard to sex, age (65 +/- 9 vs 66 +/- 10, respectively), presence of diabetes, renal insufficiency, previous myocardial infarction, and preoperative use of an intraaortic balloon pump (67% vs 71%, respectively). Compared with group 2, group 1 patients more often had three-vessel or left main disease (93% vs 65%, respectively; p = 0.018), a higher number of bypass grafts (3.0 +/- 0.8 vs 2.5 +/- 0.7, respectively; p = 0.014), and a greater incidence of postoperative complete atrioventricular (AV) block (30% vs 6%, respectively; p = 0.005). The hospital mortality rate for patients who underwent surgery within 48 hours after acute myocardial infarction did not differ between groups 1 and 2 (22% vs 18%, respectively). However, patients in both groups who underwent surgery between 48 hours and 30 days after infarction had significantly different mortality rates (22% vs 0%, respectively; p = 0.037). Patients with postoperative complete AV block had high mortality rates of 38% in group 1 and 67% in group 2. We conclude that patients who undergo coronary bypass surgery within 30 days of acute inferior myocardial infarction have a high incidence of postoperative complete AV block, which result in increased mortality.

Carbohydrate-dependent hemolytic activity of the conjugate composed of a C-type lectin, CEL-I, and an amphiphilic alpha-helical peptide, 4(3)-beta Ala2

A lectin-cationic peptide conjugate, 4(3)-CEL-I, was prepared from an invertebrate C-type lectin, CEL-I, and an amphiphilic alpha-helical peptide, 4(3)-beta Ala2 [Ac-(Leu-Ala-Arg-Leu)3-beta Ala2]. When 4(3)-CEL-I was incubated with rabbit erythrocytes, hemolysis was observed, especially at basic pH. Inhibition experiment using some carbohydrates suggested that hemolytic activity of 4(3)-CEL-I was caused by the interaction between 4(3)-beta Ala2 portion in the conjugate and the lipid bilayer after binding to the carbohydrate chains on the cell surface by the lectin activity of CEL-I.

Genetic properties for the suppression of development of putative preneoplastic glutathione S-transferase placental form-positive foci in the liver of carcinogen-resistant DRH strain rats

The post-initiation stage of hepatocarcinogenesis was investigated in carcinogen-resistant inbred DRH rats and the parental strain, carcinogen-sensitive Donryu rats. Male rats at 5 weeks of age from both strains were treated with N-nitrosodiethylamine (200 mg/kg i.p.) followed by feeding with a diet containing 3'-methyl-4-dimethylaminoazobenzene (3'-Me-DAB) from 2 weeks later and were then subjected to partial hepatectomy at 1 week later. At 8 weeks after the start of treatment, the mean area occupied by glutathione S-transferase placental form (GST-P)-positive lesions was about 30% in Donryu rats but less than 4% in DRH rats despite the presence of comparable numbers of foci in the livers of both strains. These observations suggested that clonal expansion of GST-P-positive foci in DRH rat liver was significantly suppressed under these conditions. Furthermore, this genetic property was dominantly inherited in the F1 rats by crosses of DRH and carcinogen-sensitive inbred F344 rats; that is, the induction of GST-P mRNA in the livers of F344 x DRH F1 rats was dominantly suppressed after administration of 3'-Me-DAB for 8 weeks as compared with parental F344 rats under the same conditions. We compared the intrinsic properties related to growth potential of liver cells between adult DRH and Donryu rats. DRH rat liver showed retarded and/or reduced DNA synthesis after partial hepatectomy or a single i.v. injection of lead nitrate and lower activity of telomerase induced by 3'-Me-DAB administration for 1 week, as compared with the Donryu rat liver. The intrinsic properties observed in this study may be related, at least in part, to the low incidence of liver tumors induced by hepatocarcinogens in DRH rats.

Expression of vascular endothelial growth factor and its receptors during lung carcinogenesis by N-nitrosobis(2-hydroxypropyl)amine in rats

The expression of vascular endothelial growth factor (VEGF) and its receptors (VEGFRs), VEGFR-1/Flt-1 and VEGFR-2/Flk-1, was investigated by immunohistochemical and northern blot analysis during lung carcinogenesis by N-nitrosobis(2-hydroxypropyl)amine (BHP) in male Wistar rats. After BHP was given in the drinking water for 12 wk, the rats were maintained without further treatment until they were killed at 20-28 wk. Immunohistochemical studies revealed VEGF expression in almost all malignancies, the reaction being strongly positive in most adenocarcinomas (15 of 18; 83.3%) and squamous cell carcinomas (four of five; 80.0%), but less so in a total of 120 adenomas and 136 alveolar hyperplasias. In addition, VEGF mRNA and VEGFR mRNAs were found to be overexpressed in most adenocarcinomas and squamous cell carcinomas as well as in one to three of the five adenomas tested. The results indicated that VEGF and VEGFRs play important roles in the acquisition of malignant potential by preneoplastic lung lesions induced by BHP in rats. Moreover, overexpression of VEGF was related to upregulation of VEGFR-1/Flt-1 and VEGFR-2/Flk-1 expression in malignant and premalignant lung lesions.

Expression of vascular endothelial growth factor and its receptors during lung carcinogenesis by N-nitrosobis(2-hydroxypropyl)amine in rats

The expression of vascular endothelial growth factor (VEGF) and its receptors (VEGFRs), VEGFR-1/Flt-1 and VEGFR-2/Flk-1, was investigated by immunohistochemical and northern blot analysis during lung carcinogenesis by N-nitrosobis(2-hydroxypropyl)amine (BHP) in male Wistar rats. After BHP was given in the drinking water for 12 wk, the rats were maintained without further treatment until they were killed at 20-28 wk. Immunohistochemical studies revealed VEGF expression in almost all malignancies, the reaction being strongly positive in most adenocarcinomas (15 of 18; 83.3%) and squamous cell carcinomas (four of five; 80.0%), but less so in a total of 120 adenomas and 136 alveolar hyperplasias. In addition, VEGF mRNA and VEGFR mRNAs were found to be overexpressed in most adenocarcinomas and squamous cell carcinomas as well as in one to three of the five adenomas tested. The results indicated that VEGF and VEGFRs play important roles in the acquisition of malignant potential by preneoplastic lung lesions induced by BHP in rats. Moreover, overexpression of VEGF was related to upregulation of VEGFR-1/Flt-1 and VEGFR-2/Flk-1 expression in malignant and premalignant lung lesions.

Ehlers-Danlos syndrome associated with multiple spinal meningeal cysts--case report

A 40-year-old female with Ehlers-Danlos syndrome was admitted because of a large pelvic mass. Radiological examination revealed multiple spinal meningeal cysts. The first operation through a laminectomy revealed that the cysts originated from dilated dural sleeves containing nerve roots. Packing of dilated sleeves was inadequate. Finally the cysts were oversewed through a laparotomy. The cysts were reduced, but the postoperative course was complicated by poor wound healing and diffuse muscle atrophy. Ehlers-Danlos syndrome associated with spinal cysts may be best treated by endoscopic surgery.

Primary leiomyosarcoma of the left atrium

A 69-year-old woman with symptoms of congestive heart failure had a left atrial leiomyosarcoma, an extremely rare cardiac tumor, which obstructed the mitral valve and pulmonary veins. Surgical resection was performed, but no other adjuvant therapy was administered because the patient refused it. Recurrence of the tumor occurred soon after surgery and the patient died 81 days postoperatively.

Two-stage repair for aortic regurgitation complicated by severe coarctation of the thoracoabdominal aorta due to Takayasu's arteritis

Takayasu's arteritis is a rare inflammatory aortoarteritis of unknown etiology and causes stenoocclusive disease of the aorta and its branches as well as aortic regurgitation. A surgical case of Takayasu's arteritis is presented. A 56-year-old female exhibited aortic regurgitation complicated by severe coarctation of the thoracoabdominal aorta due to Takayasu's arteritis. In this case, a 2-staged repair, consisting of an axillofemoral bypass and an aortic valve replacement, was successfully performed.

Distribution of Tsc2 protein in various normal rat tissues and renal tumours of Tsc2 mutant (Eker) rat detected by immunohistochemistry

Alterations in the rat tuberous sclerosis gene (Tsc2) are responsible for the hereditary renal carcinomas (RCs) of Eker rat. We examined protein distribution in various normal rat tissues and the Eker RCs by immunohistochemistry. Tsc2 protein is expressed in the mammary ducts, salivary glands, gastric glands, parathyroid, small and large intestine, ovary and uterus. Specific expression of Tsc2 protein is found in the B cells of pancreatic islets and in the smooth muscle of lung veins. Interestingly, in the RCs of Eker rat, Tsc2 protein was detectable with some variation in reactivity.

Distribution of AP-2 subtypes in the adult mouse brain

In the mammalian central nervous system (CNS), transcription factor activator protein 2 (AP-2) is one of the critical regulatory factors for neural gene expression and neural development. As AP-2 has diverged into several subtypes, i.e. AP-2alpha, -2beta, and 2.2, we investigated the distribution of the AP-2 subtypes in the adult mouse brain by in situ hybridization using subtype-specific probes. Though AP-2 was essentially expressed in most regions of the brain, the hippocampus and cerebellum Purkinje cells exhibited a relatively high concentration of transcripts of any of the AP-2 subtypes. Among AP-2alpha variants, the expression of variant 1 was considerably lower than that of variant 3. Hence, the expression pattern of AP-2alpha variant 3 is suggested to represent the major gene expression of AP-2alpha. On the other hand, the expression of AP-2beta messenger RNA (mRNA) was higher than that of AP-2alpha in many regions. Especially, the olfactory bulb, hippocampus, cerebellum, and cerebral cortex contained an abundance of these mRNAs. Different from those of AP-2alpha, AP-2beta mRNAs were detected in considerable amounts in the glanular cells as well as in Purkinje cells. AP-2.2 gene expression was weak throughout the brain. Consequently, we found that various AP-2 subtypes and variants were expressed in a similar distribution pattern with each having its own specific intensity but that their precise distribution profiles were not exactly the same. In the mature brain, AP-2 is thought to regulate neural gene expression through specific and redundant association with a target gene.

Overexpression of matrix metalloproteinase (MMP)-9 correlates with metastatic potency of spontaneous and 4-hydroxyaminoquinoline 1-oxide (4-HAQO)-induced transplantable osteosarcomas in rats

In the present experiment, the expression of matrix metalloproteinase (MMP)-2 and MMP-9, key proteins in the MMP family, and the tissue inhibitors of metalloproteinase (TIMP)-1 and TIMP-2, antagonistic proteins against MMP-2 and MMP-9, respectively, were investigated by Northern blot analysis in rat transplantable osteosarcomas with high and low metastatic potencies. Two transplantable osteosarcomas, one induced with the carcinogen, 4-hydroxyaminoquinoline 1-oxide (4-HAQO) (COS, chemical carcinogen-induced osteosarcoma), and the other, a spontaneous lesion (SOS, spontaneous osteosarcoma), were repeatedly transplanted from lung nodules to generate lines with high metastatic potency, C-SLM (chemical carcinogen-induced osteosarcoma, selected lung metastatic lesions) and S-SLM (spontaneous osteosarcoma, selected lung metastatic lesions), respectively. MMP-9 was overexpressed in both S-SLM and C-SLM, and TIMP-2 in the case of S-SLM. Neither MMP-2 nor TIMP-1 was overexpressed in either of the transplantable osteosarcomas with high metastatic potentials. The active form MMP-9, studied by zymography, increased in S-SLM and C-SLM but not in SOS and COS. MMP-9 mRNA expression was highly correlated with the gelatinolytic activity of active form MMP-9 (r = 0.85, P < 0.0001) and with the activation ratio of MMP-9 (r = 0.83, P < 0.0001). However, the active form MMP-2 was not detectable in all cases. These results suggest that overexpression of MMP-9 mRNA is one of the essential factors in the acquisition of metastatic potential in rat transplantable osteosarcomas.

Transcriptional regulation of mouse type 1 inositol 1,4,5-trisphosphate receptor gene by NeuroD-related factor

The type 1 inositol 1,4,5-trisphosphate receptor (IP3R1) is a Ca2+ channel protein that is expressed abundantly in the CNS, such as in the cerebellar Purkinje cells and hippocampus. We previously demonstrated that the box-I element, which is located -334 relative to the transcription initiation site of the mouse IP3R1 gene and includes an E-box consensus sequence, is involved in the up-regulation of such IP3R1 gene expression. Furthermore, the previous study also indicated that some CNS-related basic helix-loop-helix (bHLH) factors bind to the box-I and activate IP3R1 gene expression. In this study, we demonstrated that one of the CNS-related bHLH factors, neuronal differentiation factor (NeuroD)-related factor (NDRF), specifically bound to the box-I sequence with a ubiquitously expressed bHLH protein, E47, and activated IP3R1 gene expression. In situ hybridization of adult mouse brain revealed that IP3R1 and NDRF mRNA were co-expressed in many subsets of neurons, highly in Purkinje cells and hippocampus and moderately in cerebral cortex, olfactory bulb, and caudate putamen. Furthermore, the spatiotemporal expression patterns of these two genes resembled one another throughout postnatal development of the mouse CNS. From these results, we suggest that NDRF is involved in the tissue-specific regulation of IP3R1 gene expression in the CNS.

Activation of the mouse inositol 1,4,5-trisphosphate receptor type 1 promoter by AP-2

Inositol 1,4,5-trisphosphate receptor (IP3R) functions as a Ca2+ channel that increases the intracellular Ca2+ upon binding to inositol trisphosphates. IP3R is expressed ubiquitously and consists of a multigene family. Since the type 1 IP3R (IP3R1) is highly expressed in the cerebellar Purkinje cells and moderately in hippocampus in the mammalian central nervous system (CNS), it is regarded as a neural member of this gene family. In this work, we investigated transcriptional regulation of the mouse ip3r1 gene. A DNaseI footprinting assay demonstrated that a sequence from -95 to -75, designated as box-II, was a binding site for a cerebellum-enriched factor. A consensus sequence for AP-2 was located in box-II. An electrophoretic mobility shift assay with anti-AP-2 antibody revealed that AP-2 is capable of binding to box-II. Deletion analysis of box-II showed that flanking sequences beside the box-II motif were required for the stable binding. We demonstrated by transient luciferase assay that exogenously expressed AP-2 activated box-II-dependent transcription. Moreover, we showed that endogenous AP-2 induced by retinoic acid also activated transcription via box-II in P19 cells. In-situ hybridization of the mouse brain revealed that AP-2 was predominantly expressed in the cerebellar Purkinje cells and hippocampal CA1 region, where IP3R1 is also highly expressed. From these observations, AP-2 binding to box-II is thought to be responsible for IP3R1 gene regulation in the CNS.

Overexpression of midkine in lung tumors induced by N-nitrosobis(2-hydroxypropyl)amine in rats and its increase with progression

The expression of midkine (MK) in lung tumors induced by N-nitrosobis(2-hydroxypropyl)amine (BHP) in rats was examined. The animals were administered 2000 p.p.m. of BHP in their drinking water for 12 weeks, then maintained without further treatment until being killed 20-28 weeks after the beginning of the experiment. MK mRNA expression of adenocarcinomas and squamous cell carcinomas assessed by means of the reverse transcriptase-polymerase chain reaction and northern blot analysis was significantly higher than in rat embryonic tissues (positive controls) and contrasted strongly with the lack in normal lungs. MK protein was detected immunohistochemically in 58.3% of alveolar hyperplasias, 92.3% of adenomas and 100% of adenocarcinomas and squamous cell carcinomas. The extent of staining significantly increased along with malignant progression in adenomatous (pre-)neoplastic lesions and tended to become more pronounced with malignant progression in squamous lesions. The results suggest that MK may play some essential roles in the development and progression of lung tumors induced by BHP in rats.

Inhibition of spontaneous rat osteosarcoma lung metastasis by 3S-[4-(N-hydroxyamino)-2R-isobutylsuccinyl]amino-1-methoxy-3,4-dihydroc arbostyril, a novel matrix metalloproteinase inhibitor

In the present experiment, we examined the effects of OPB-3206, 3S-[4-(N-hydroxyamino)-2R-isobutylsuccinyl]amino-1-methoxy-3,4- dihydrocarbostyril, a novel metalloproteinase inhibitor, on the growth and metastasis of transplantable osteosarcomas (spontaneous osteosarcoma, selected lung metastatic lesions; S-SLM), which were previously established in rats. OPB-3206 inhibited the activities of interstitial collagenase, gelatinases A and B, and stromelysin in vitro. After oral administration to rats, its serum concentration peaked at 40 min and the drug was no longer detectable at 8 h. When OPB-3206 was orally administered at 0%, 0.1% and 0.4% in the diet for 4 weeks, starting 7 days after subcutaneous transplantation of osteosarcomas to male Fischer 344 rats, numbers of lung metastatic nodules were significantly reduced by the highest dose, while the growth of subcutaneous tumors was not affected. Zymographic analysis showed the presence of pro matrix metalloproteinase (proMMP)-2, proMMP-9 and MMP-9 activities in S-SLM. In animals fed 0.4% OPB-3206, the activity of proMMP-9 was increased, but that for MMP-9 had become undetectable. The results thus suggest that OPB-3206 selectively inhibits lung metastasis of rat transplantable osteosarcomas by inhibiting MMP-9 activation.

New evidence that the Tyr-157 and Tyr-159 residues of staphylococcal exfoliative toxin B are essential for its toxicity

To determine the active site of exfoliative toxin B (sETB) of Staphylococcus aureus, the etb gene was cloned from an S. aureus SU strain obtained from a patient with impetigo. We prepared a frame shift mutant protein from a recombinant plasmid with a BglII linker inserted into the Tyr-155 codon of the ETB gene (pETB/BglIIL). The recombinant mutant protein (ETB/BglIIL) obtained from Escherichia coli containing pETB/BgIIIL showed no toxicity in neonatal mice and no agglutination activity. The 20-kDa ETB/BglIIL contained 185 amino acid residues. Site-directed mutagenesis was used to introduce mutations at either Tyr-155, Tyr-157, Tyr-159, or Tyr-162. Substitution of any of the Tyr residues decreased exfoliative activity compared with that of native sETB (4,000 EU/ml). Substitution of Tyr-155 with a Phe (ETBYN155) decreased activity 5-fold (800 EU/ml). Substitution of Tyr-157 with Leu (ETB/Y157) decreased activity 80-fold (50 EU/ml) and decreased agglutination titer 5-fold compared with that of native sETB (400,000). Substitution of Tyr-159 with Leu (ETB/Y159)decreased activity 4-fold (1,000 EU/ml). When both Tyr-157 and Tyr-159 were mutated (ETB/Y157-159), both toxicity and antigenicity were completely lost. On an immunodiffusion test, ETBNY157 showed a faint precipitation line, but ETB/BglIIL and ETB/Y157-159 had no activity, showing that the Tyr-157 and Tyr-159 residues are essential for the toxicity and antigenicity of ETB.

Cephalometric abnormalities in non-obese and obese patients with obstructive sleep apnoea

The aim of this work was to comprehensively evaluate the cephalometric features in Japanese patients with obstructive sleep apnoea (OSA) and to elucidate the relationship between cephalometric variables and severity of apnoea. Forty-eight cephalometric variables were measured in 37 healthy males and 114 male OSA patients, who were classed into 54 non-obese (body mass index (BMI) <27 kg x m(-2), apnoea-hypopnoea index (AHI)=25.3+/-16.1 events x h(-1)) and 60 obese (BMI > or = 27 kg x m(-2), AHI=45.6+/-28.0 events h(-1)) groups. Diagnostic polysomnography was carried out in all of the OSA patients and in 19 of the normal controls. The non-obese OSA patients showed several cephalometric defects compared with their BMI-matched normal controls: 1) decreased facial A-P distance at cranial base, maxilla and mandible levels and decreased bony pharynx width; 2) enlarged tongue and inferior shift of the tongue volume; 3) enlarged soft palate; 4) inferiorly positioned hyoid bone; and 5) decreased upper airway width at four different levels. More extensive and severe soft tissue abnormalities with a few defects in craniofacial bony structures were found in the obese OSA group. For the non-obese OSA group, the stepwise regression model on AHI was significant with two bony structure variables as determinants: anterior cranial base length (S-N) and mandibular length (Me-Go). Although the regression model retained only linear distance between anterior vertebra and hyoid bone (H-VL) as an explainable determinant for AHI in the obese OSA group, H-VL was significantly correlated with soft tissue measurements such as overall tongue area (Ton), inferior tongue area (Ton2) and pharyngeal airway length (PNS-V). In conclusion, Japanese obstructive sleep apnoea patients have a series of cephalometric abnormalities similar to those described in Caucasian patients, and that the aetiology of obstructive sleep apnoea in obese patients may be different from that in non-obese patients. In obese patients, upper airway soft tissue enlargement may play a more important role in the development of obstructive sleep apnoea, whereas in non-obese patients, bony structure discrepancies may be the dominant contributing factors for obstructive sleep apnoea.

Single treatment with cisplatin or UFT, but not their combination treatment enhances the metastatic capacity of mouse fibrosarcoma cells

To elucidate the roles of chemotherapeutic agents in tumor progression, we examined whether cis-diamminedichloroplatinum (II) (cisplatin) and UFT would promote malignant progression of a weakly tumorigenic and poorly metastatic fibrosarcoma cell line OR-32SK in vivo. C57BL/6 mice, transplanted with QR32SK, were treated with either cisplatin or UFT alone and in combination. After treatment with or without cisplatin and/or UFT, we established in vitro culture cell lines from the tumors arising in the mice on day 21 and then i.v. injected the established cell lines into syngeneic mice. As a result, the cell lines established from cisplatin-treated mice and UFT-treated mice had significantly higher metastatic capacity in lung compared to the ones from control untreated mice (64 and 65%, respectively, versus 26.7%). The cell lines established from the mice with the combination therapy showed lower lung metastasis (11%) than the ones from control untreated mice. Furthermore, we found the incidences of these experimental metastases were closely related with in vitro chemotactic activities and the production of MMP-9 of the cultured cell lines. These results indicate that cisplatin and UFT as a single agent promote the chemotactic activities and the production of MMP-9 in non-metastatic fibrosarcoma cells, resulting in the conversion to highly metastatic ones, and that cisplatin and UFT in combination failed to promote the chemotactic activities and the conversion. These results suggest that the combination therapy with cisplatin and UFT is useful in preventing the emergence of more malignant tumor cells after chemotherapy.

Delay in administration of CDDP until completion of AGM-1470 treatment enhances antimetastatic and antitumor effects

The efficacy of cis-diammine dichloroplatinum (CDDP) therapy in combination with continuous administration of angiogenesis inhibitor o-(chloroacetyl-carbamoyl) fumagillol (AGM-1470) was evaluated experimentally using a transplantable rat osteosarcoma line previously established in our laboratory. AGM-1470 (2.5 mg/kg body weight/week) was administered by Alzet osmotic pumps for 2 weeks starting from 7 days after tumor inplantation and CDDP (1.25 mg/kg) was given on days 21 and 24. The number of lung metastatic nodules was counted and the wet weights of the primary tumors were measured 5 weeks after tumor inplantation. Values with administration of CDDP 3 days after discontinuation of AGM-1470 were significantly lower than when the two agents were coadministered (P < 0.05). This animal model should facilitate optimization of the timing of combination therapy.

Inflammatory cell-mediated tumour progression and minisatellite mutation correlate with the decrease of antioxidative enzymes in murine fibrosarcoma cells

We isolated six clones of weakly tumorigenic fibrosarcoma (QR) from the tumorigenic clone BMT-11 cl-9. The QR clones were unable to grow in normal C57BL/6 mice when injected s.c. (1x10(5) cells). However, they formed aggressive tumours upon co-implantation with a 'foreign body', i.e. a gelatin sponge, and the rate of tumour take ranged from 8% to 58% among QR clones. The enhanced tumorigenicity was due to host cell-mediated reaction to the gelatin sponge (inflammation). Immunoblot analysis and enzyme activity assay revealed a significant inverse correlation between the frequencies of tumour formation by QR clones and the levels of manganese superoxide dismutase (Mn-SOD, P<0.005) and glutathione peroxidase (GPchi, P<0.01) in the respective tumour clones. Electron spin resonance (ESR) revealed that superoxide-scavenging ability of cell lysates of the QR clone with high level of Mn-SOD was significantly higher than that with low level of the antioxidative enzyme in the presence of potassium cyanide, an inhibitor for copper-zinc superoxide dismutase (CuZn-SOD) (P<0.001). Minisatellite mutation (MSM) induced by the inflammatory cells in tumour cells were investigated by DNA fingerprint analysis after QR clones had been co-cultured with gelatin-sponge-reactive cells. The MSM rate was significantly higher in the subclones with low levels of Mn-SOD and GPchi (P<0.05) than in the subclones with high levels of both enzymes. The MSM of the subclones with low levels of both enzymes was inhibited in the presence of mannitol, a hydroxyl radical scavenger. The content of 8-hydroxydeoxyguanosine (8-OHdG) by which the cellular DNA damage caused by active oxygen species can be assessed was significantly low in the tumours arising from the QR clone with high levels of Mn-SOD and GPchi even if the clone had been co-implanted with gelatin sponge, compared with the arising tumour from the QR clone with low levels of those antioxidative enzymes (P<0.001). In contrast, CuZn-SOD and catalase levels in the six QR clones did not have any correlation with tumour progression parameters. These results suggest that tumour progression is accelerated by inflammation-induced active oxygen species particularly accompanied with declined levels of intracellular antioxidative enzymes in tumour cells.

Comparison of recombinant and purified human bone morphogenetic protein

Clinically, it would be more convenient to use recombinant than purified preparations of bone morphogenetic protein (BMP). Recently, recombinant human BMP (rhBMP) has attracted the attention of many investigators, but it has not been fully characterized. We examined the bone-inducing activity of rhBMP-2 and compared it with that of purified BMP derived from human bone matrix (phBMP). Two, 10, or 50 microg of rhBMP-2 or phBMP was mixed with 3 mg of atelopeptide type I collagen (carrier), and specimens were implanted in the calf muscles of Wistar rats (n=5 in each group). Four weeks later, new bone had formed in all the rhBMP-2- and phBMP-implanted muscles and was visible radiographically and histologically. The quantitative analysis indicated that the activity of rhBMP-2 was less than one tenth that of phBMP. It is necessary to find out why rhBMP-2 has fewer activities than phBMP.

[ASO as a risk factor of emergency CABG]

The presence of lower extremity arterial occlusive disease (arteriosus sclerosis obliterance of lower extremity) is an important risk factor for patients undergoing emergency coronary artery bypass operations. Those patients had higher mortality and morbidity rates related to the complications of intraaortic balloon pumps (IABP). If lower extremity ischemia is observed, rapid procedures such as removal of the IABP with or without thrombectomy and femorofemoral crossover interposition of a graft should be performed.

[Effects of coronary artery bypass surgery on the stunned and hibernating myocardium in the cases with depressed left ventricular function]

Chronic left ventricular (LV) dysfunction may result from irreversible damage (cell death), stunned myocardium (ST), or hibernating myocardium (HB). However, both of ST and HB are expected to be reversible. In this report, the effects of coronary artery bypass grafting on the regions of ST and HB were evaluated in 37 patients with less than 40% of LV ejection fraction. The patients were divided into two groups. Group I consisted of the patients whose postoperative LV ejection fraction rose by more than 10% compared to the preoperative value. Group II included the remaining patients with no significant improvement. After successful revascularization, 61% of HB changed to ST and 52% of ST to normal in group I. These changes were significant in comparison with group II because 48% of HB and 83% of ST in group II remained unchanged. Immediate or rapid recovery of HB hardly occurred in both of the groups. To recover normal function, HB may pass through a stage of ST on reperfusion. On the other hand, it is difficult to determine whether HB and ST with no significant changes after reperfusion are irreversibly damaged or reversible and take time to return to normal.

A case-control study on risk factors for pancreatic diseases in Kerala, India

BACKGROUND/AIMS

We simultaneously conducted case-control studies, in Kerala of South India, on chronic calcific pancreatitis of the tropics (CCPT), pancreatic ductal adenocarcinoma (PDA) with CCPT, and PDA alone to assess similarity of and difference between their risk factors.

METHODOLOGY

Cases with one of these diseases were identified at the Trivandrum Medical College (TMC) Hospital, in Kerala, from 1994 to 1996. Controls were selected from healthy hospital visitors of the TMC Hospital by individual age (within +/- 3 years) and sex-matched with the index case. Odds ratios and their 95% confidence intervals for potential risk factors were calculated.

RESULTS

Frequent consumption of cassava was positively associated with the risk of PDA with CCPT. Heavy cigarette smoking and drinking large amounts of coffee and/or tea everyday were positively related to the risk of PDA alone. Frequent consumption of vegetables and/or fruits was correlated to the decreased risk of PDA alone.

CONCLUSIONS

Risk factors as well as preventive factors seem to be different between PDA with CCPT and PDA alone. Further study is necessary, especially to clarify the prognostic factors which would induce pancreatic malignancy in patients with CCPT.

Application of three dimensional angiography for diagnosis of patients and intravascular surgery. Part 1

SUMMARY

We examined newly developed three-dimensional angiography to understand the anatomy for surgery and for intravascular surgery in order to decide when treatment should be stopped. The subjects were 23 patients chosen randomly (angiography, 22). The diagnoses in these patients included aneurysm (5), arteriovenous malformation (6), meningioma, glioma, vascular tumours of the brain and the neck (5), and vascular diseases (6) including carotid artery stenosis, Moya-Moya disease, middle cerebral artery occlusion, and megadolico-ectasia (6). The new technique was used for intravascular surgery in six cases, which allowed the neck of the aneurysm and the bifurcation to be revealed. This method is useful for determining whether another coil should be inserted. In patients with basilar top aneurysm using this technique during coil embolization the intra-aneurysmal blood flow disappeared because complete embolization was performed. This technique was more useful during coil embolization, especially to decide the timing of withdrawal in intravascular surgery compared with conventional DSA.

Mechanistic analysis and chemoprevention of pancreatic carcinogenesis

Thirteen presentations given at a workshop held in November 1997, under the sponsorship of The Princess Takamatsu Cancer Research Fund in Nara, Japan, are summarized. Topics include studies of initiation, promotion, and chemoprevention in animal models of pancreatic carcinogenesis, molecular and histopathologic studies of human carcinomas, and epidemiologic studies. A recurring focus was to explore ways that knowledge of molecular mechanisms of carcinogenesis and molecular abnormalities in carcinomas can guide approaches for prevention and treatment of pancreatic cancer.

Specific induction of hepatocellular adenomas by transplacental administration of ENU in the tsc2 gene mutant (Eker) rat

Eker rats develop dominantly inherited renal carcinomas (RCs), with hereditary mutation, and following somatic mutation (Knudson's second hit) at tuberous sclerosis gene (Tsc2). We document the effect of transplacental administration of N-ethyl-N-nitrosourea to Eker (Eker/+) and non-Eker (+/+) rats (same genetic background). Although we observed no difference in the number of preneoplastic GST-P positive foci between Eker and non-Eker rats, interestingly we observed the specific development of hepatocellular adenomas only in Eker rats. The Tsc2 gene mutation might thus influence the phenotype of preneoplastic initiated hepatocytes.

Inhibition of early-phase exogenous and endogenous liver carcinogenesis in transgenic rats harboring a rat glutathione S-transferase placental form gene

Hepatocarcinogenesis initiated with N-nitrosodiethylamine (DEN) and that initiated by feeding of a choline-deficient, L-amino acid-defined (CDAA) diet were compared in transgenic male Wistar rats harboring a rat glutathione S-transferase placental form (GST-P) gene (GST-P-Tg rats) and non-transgenic (N-Tg) rats. Eight-week-old GST-P-Tg and N-Tg rats were administered DEN intraperitoneally at 100 mg/kg body weight, subjected to a selection procedure with 2-acetylaminofluorene and CCl4, and killed at the end of weeks 5 and 12. Other groups were fed the CDAA diet for 12 weeks and killed. Five weeks after the DEN treatment, numbers and sizes of gamma-glutamyltransferase (GGT)- or GST-P-positive lesions and 8-hydroxyguanine (8-OHG) levels in the livers were significantly less in GST-P-Tg rats than in N-Tg rats. The lesion numbers were unchanged between the ends of weeks 5 and 12 in GST-P-Tg rats, but decreased in N-Tg rats. The lesion sizes were increased in GST-P-Tg rats, but unchanged in N-Tg rats. While the proliferating cell nuclear antigen labeling indices (PCNA L.I.) in and surrounding the lesions were decreased, more prominently in GST-P-Tg rats than in N-Tg rats, the 8-OHG levels were also decreased but similarly in both cases. After 12 weeks on the CDAA diet, the lesion incidences, numbers and sizes, 8-OHG levels, PCNA L.I. in and surrounding the lesions, and liver injury were significantly less in GST-P-Tg rats than in N-Tg rats. These results indicate that insertion of a rat GST-P transgene alters the early phase of exogenous and endogenous rat hepatocarcinogenesis, presumably due to enhanced detoxification by GST-P expressed both transiently during the initiation and chronically in the altered hepatocyte populations.

Generation of metastatic variants of Eker renal carcinoma cell lines for experimental investigation of renal cancer metastasis

We and others have demonstrated that a mutation in Tsc2 is the rate-limiting step for renal carcinogenesis in the Eker rat model. Although inactivation of Tsc2 results in development of renal tumors, it is not sufficient for metastatic renal cell carcinomas (RCs) in the Eker rat. To investigate the additional genetic event(s) necessary for cancer metastasis, we have established highly metastatic S-Lk9d-SLM cell lines from a non-metastatic RC cell line (Lk9dL) by co-implantation with a foreign body (gelatin sponge). Since these cell lines were remarkably different in metastatic performance (all and none, respectively) despite having the same genetic background, they should be useful experimental tools to investigate metastasis-promoting events in renal carcinogenesis.