E2A and HEB activate the pre-TCR alpha promoter during immature T cell development

The pre-TCRalpha (pTalpha) is exclusively expressed in immature thymocytes and constitutes the pre-TCR complex with TCRbeta, which regulates early T cell differentiation. Despite the recent identification of the pTalpha enhancer, the contribution of the promoter region, the direct DNA-protein interaction, and the regulation of such interaction along with T cell development have not been investigated. We analyzed the pTalpha promoter region and identified the critical elements for transcription of the pTalpha gene. The pTalpha promoter was found to contain two consecutive E-box elements that are critical for pTalpha transcription. The E-box elements in the promoter region formed the specific DNA-protein complex that was exclusively observed in immature thymocytes, not in mature thymocytes and T cells. The E proteins in this complex were identified as E2A and HeLa E-box binding protein (HEB), and overexpression of E2A and HEB resulted in activation of the pTalpha promoter. The binding complex in the consecutive E-boxes in the pTalpha promoter changed along with T cell development, as a distinct DNA-binding complex was observed in mature T cells. Comparing the E-box regions in the enhancer and the promoter, those in the promoter appear to make a greater contribution to pTalpha gene transcription.

"Variable echo sign" (ultrasonographical alteration of echogenicity) in cavernous hepatic hemangioma

There are few reports describing cavernous hepatic hemangiomas with alteration of ultrasonographical imaging during examinations. We performed ultrasonographic examination of 64 cavernous hepatic hemangiomas and recognized 26 cases (41%) with an alteration of echogenicity during the examinations. We refer to this alteration of echogenicity of cavernous hepatic hemangioma as a "variable echo sign". We performed angiography of the cavernous hepatic hemangiomas with variable echo sign. Most of these imaging patterns showed mild or moderate pooling, suggesting that the alteration of echogenicity might be based on a slow blood flow exchange. We suggest that a variable echo sign is specific to ultrasonographic imaging with cavernous hepatic hemangioma and may be useful to differentiate cavernous hepatic hemangioma from other tumors.

Impact of hepatitis B and C virus infection on the clinical prognosis of alcoholic liver cirrhosis

To elucidate the rates of appearance of hepatocellular carcinoma (HCC) and the prognosis of alcoholic liver cirrhosis upon infection with hepatitis virus, we retrospectively studied 190 consecutive patients. The patients were divided into three groups based on whether they were exposed either to hepatitis B virus (HBV), hepatitis C virus (HCV) or not. The cumulative survival rate of the alcoholic liver cirrhosis patients with hepatitis B surface antigen (HBsAg) was significantly lower than that in those with hepatitis C antibody (anti-HCV). Most alcoholic liver cirrhosis patients without hepatitis virus infection died of liver failure, gastrointestinal (G1) bleeding, or other diseases. However, alcoholic liver cirrhosis patients with anti-HCV tended to die of HCC. The cumulative HCC appearance rate in alcoholic liver cirrhosis patients without HBsAg or anti-HCV was 7% at the end of the fifth year after the diagnosis of cirrhosis and 15% at the end of the tenth year. However; the HCC appearance rate was about 20% at the end of the fifth year after the diagnosis of cirrhosis and about 50% at the end of the tenth year in both alcohol drinkers with HBsAg or anti-HCV. These data suggest that hepatitis virus infection may modify the prognosis for alcoholic liver cirrhosis patients, especially in the development of carcinogenesis.

Comparison of screening methods for hepatocellular carcinomas in patients with cirrhosis

To determine the most suitable screening methods for hepatocellular carcinomas (HCCs), we investigated 45 cases with HCCs. Ultrasonography, computed tomography (CT) scan and measurement of alpha-fetoprotein (AFP) were regularly performed. Thirty-two cases (72%) were detected initially by ultrasonography. Fourteen out of 23 cases (61%) with tumors 20 mm or less in diameter and 11 out of 12 cases (91%) with 21-30 mm tumors were detected initially by.ultrasonography. For the initial detection of tumors sized 20 mm or less, the mean interval of ultrasonography was 3.54 months, unlike the 5.67 months for tumors sized over 21 mm. There was no significant difference between tumor size and measurement interval in AFP levels or CT scan examinations. From these results, we suggest that a suitable screening schedule would be every three months by ultrasonography.

Splenectomy enhances liver regeneration through tumor necrosis factor (TNF)-alpha following dimethylnitrosamine-induced cirrhotic rat model

BACKGROUND/AIMS

We demonstrated that partial splenic embolization for hematological disorders in cirrhotic patients also improved liver function. Therefore, we investigated the mechanism of the beneficial effects of splenectomy on a rat cirrhotic model.

METHODOLOGY

1) Rats were administered DMN (dimethylnitrosamine) after splenectomy (splenectomized DMN rats) or a sham operation (DMN rats). 2) After completion of DMN administration, a tumor necrosis factor-alpha inhibitor (E3330) was administered on the same day as the splenectomy. Histological examination and cytokine expressions were analyzed.

RESULTS

The splenectomy apparently reduced liver damage. This may be partially due to the enhancement of liver regeneration since the proliferating cell nuclear antigen labeling index in the DMN-treated liver was significantly increased by splenectomy. Tumor necrosis factor-alpha was down-regulated in the DMN rats, whereas its expression was preserved in the splenectomized DMN rats. There were no apparent differences in the number of Kupffer cells between the splenectomized DMN and the DMN rats, suggesting that the down-regulation of tumor necrosis factor-alpha may contribute to the reduction of Kupffer cells' function. In addition, a tumor necrosis factor-alpha production inhibitor (E3330) significantly reduced the proliferating cell nuclear antigen labeling index after splenectomy.

CONCLUSIONS

Splenectomy, in this model, may promote liver regeneration by preserving Kupffer cell function, especially the secretion of tumor necrosis factor-alpha.

A novel strategy for organ allografts using sublethal (7 Gy) irradiation followed by injection of donor bone marrow cells via portal vein

A new strategy for organ allografts that does not require recourse to immunosuppressants is established in mice. The strategy includes sublethal (7 Gy) irradiation followed by the injection of donor bone marrow cells (BMCs) via the portal vein (P.V.) and organ allografts 1 day after irradiation. Irradiation doses (< or =7 Gy) are found to allow the recipients to survive without the need to reconstitute the BMCs, as the recipient hematolymphoid cells can gradually recover. One hundred percent of recipients irradiated with 7 Gy followed by either P.V. or i.v. injection of donor BMCs accept organ allografts (the skin, pancreas, and adrenal glands) for more than 1 year. However, organ allograft survival rates decrease when irradiation doses are reduced; the skin graft survival rate of mice treated with 6.5 Gy and P.V. injection of BMCs is 79%, whereas that of mice treated with 6.5 Gy and i.v. injection is 50%, indicating that the P.V. injection of BMCs induces persistent tolerance more effectively than the i.v. injection. H-2 typing reveals that almost all the hematolymphoid cells (>98%) in the peripheral blood and hematolymphoid organs are donor-derived even 1 year after the treatment (7 Gy and P.V.). The T cells are tolerant to both donor-type and host-type MHC determinants. The major mechanism underlying the persistent tolerance induced by this strategy seems to be because of clonal deletion. This simple and safe strategy would be of great advantage for human organ transplantation.

[A case of Gerstmann-Sträussler-Scheinker syndrome (GSS) with late onset--a haplotype analysis of Glu219Lys polymorphism in PrP gene]

We report a 74-year-old man with late onset Gerstmann-Sträussler-Scheinker syndrome (GSS). In this family, 3 out of 6 siblings and his father developed cerebellar ataxia and mental deterioration in their fifth decades. He complained of unsteady walking and tingling pain in the legs at the age of 70. Neurological examination revealed moderate truncal ataxia, mild limb ataxia, ataxic speech, sensory impairment, paresthesia and areflexia in the lower extremities. CSF examination showed elevated CSF and 14-3-3 proteins with a normal cell count. EEG and brain MRI demonstrated no abnormality. Somatosensory evoked potential (SEP) study showed delayed N13-N20 interpeak latencies in the upper extremities and delayed N20 at 12th thoracic spinous process, indicating dysfunction of the posterior roots or columns of the spinal cord including the dorsal horns and proximal peripheral nerve. Analysis of the prion protein gene demonstrated a Pro102Leu amino acid substitution, which is compatible with classical GSS. Haplotype analysis of the PrP gene identified a Glu219Lys polymorphism on another allele. Recently, it was confirmed that protein X, which accelerates the conversion of the normal type of PrP (PrPC) into a pathological type of PrP (PrPSc), binds to the 219th amino acid residue of PrP. Therefore, the 219Lys polymorphism theoretically inhibited formation of PrPSc and may thus have delayed the onset of the disease in this patient.

Binding rate constant of Tc-99m DTPA galactosyl human serum albumin measured by quantitative dynamic SPECT--clinical evaluation as a total and regional liver function test

To evaluate the clinical utility of a new method with dynamic single photon emission computed tomography (SPECT) and scatter and attenuation compensation to estimate both total and regional liver function quantitatively. Five controls, 20 patients with chronic liver disease, and 2 patients with Budd-Chiari syndrome were studied. Dynamic liver SPECT data were acquired during 20 minutes after injection of Technetium (Tc)-99m diethylenetriaminepentaacetic acid (DTPA) galactosyl human serum albumin (GSA) with scatter and attenuation compensation. The binding rate constant of Tc-99m GSA (Ku) was derived quantitatively from the Patlak plot based on kinetic models for GSA receptor binding. The mean Ku was obtained by dividing the Ku value (total Ku) by the liver volume. Both total and mean Ku were significantly lower in patients with chronic liver disease than in controls (302 +/- 112 vs. 523 +/- 78 ml/min; p < 0.001, 0.26 +/- 0.11 vs. 0.43 +/- 0.03 ml/min/cm3; p < 0.001). In the patient group, both total and mean Ku were significantly correlated with the results of conventional liver function tests and the histological severity of chronic liver disease. In 2 patients with Budd-Chiari syndrome, the mean Ku was lower in the right lobe, where the hepatic veins were occluded, than in the left lobe, where draining veins were patent. In conclusion, this method is a reliable diagnostic technique for estimating total and regional liver function.

Bronchial artery aneurysm treated with percutaneous transluminal coil embolization

We present a case with asymptomatic mediastinal bronchial artery aneurysm at the origin of the left bronchial artery. This bronchial artery aneurysm was successfully treated with percutaneous transluminal coil embolization. Complete embolization of the feeding artery and tributaries from the aneurysm is the key to successful isolation of a large bronchial artery aneurysm from the circulation. Percutaneous transluminal embolization is one of the treatment options for a patient with asymptomatic, incidentally-identified bronchial artery aneurysm.

Analysis of mutational effects of a polyhydroxybutyrate (PHB) polymerase on bacterial PHB accumulation using an in vivo assay system

Polymerase is a central enzyme involved in the biosynthesis of polyhydroxybutyrate (PHB), a well-known bacterial biodegradable polyester. In this study, we have established an in vivo assay system to analyze mutational effects of Ralstonia eutropha polymerase (termed PhbC(Re)) on the level of PHB accumulation in recombinant strains of Escherichia coli. This in vitro evolution system consists of a polymerase chain reaction-mediated random mutagenesis and two assay procedures, a plate assay using a PHB-staining dye and a high-pressure liquid chromatographic assay based on the converting reaction from PHB to crotonic acid. The distribution pattern of the PHB accumulation level of the mutant population using 378 clones arbitrarily selected, suggested that the present level of PhbC(Re) is high and well-optimized. It is noteworthy that many of the amino acid substitutions affecting the PHB accumulation occurred in the conserved positions or regions within an 'alpha/beta hydrolase fold' which is commonly found among hydrolytic enzymes. From a good correlation with the level of PHB accumulation, an activity estimation of the PhbC(Re) would be efficiently achieved by monitoring the level of PHB accumulation using the in vivo assay system established here.

[Study of neoadjuvant chemotherapy for invasive bladder cancer with MEC (methotrexate, epirubicin, cisplatin) therapy]

Eighteen patients with locally invasive bladder cancer were treated with 1 or 2 cycles of neoadjuvant chemotherapy consisting of methotrexate, epirubicin and cisplatin (MEC). All patients underwent radical cystectomy and pelvic lymph node dissection. Down-staging was observed in twelve (complete pathological response in 3 and partial pathological response in 9) patients (response rate were 67%). Four of the 18 patients died of disease and all of them had not achieved down-staging. Multivariate analysis revealed nodal status to be the only independent predictor. With regard to side effects, gastrointestinal symptoms and myelo-suppression were observed in almost all patients. Thrombocytopenia was observed in 13 patients (72%) including 7 patients who showed symptoms over grade 3. Gastro-intestinal symptoms and leukocytopenia disappeared with granisetron and granulocyte colony stimulating factor. There were no treatment-related deaths in this study. These results indicate that MEC therapy was safely performed and showed a high response rate in patients with locally invasive bladder cancer.

Prospective study of laparoscopic findings with regard to the development of hepatocellular carcinoma in patients with hepatitis C virus-associated cirrhosis

BACKGROUND

The laparoscopic findings of hepatocarcinogenesis are not well defined. The purpose of this prospective study was to evaluate the predictive value of laparoscopic findings with regard to the development of hepatocellular carcinoma (HCC) in patients with hepatitis C virus (HCV)-associated cirrhosis.

METHODS

One hundred nineteen patients with HCV-associated cirrhosis who underwent laparoscopy were enrolled in this study. Ten laparoscopic variables, including degree of development and size of regenerating nodules, irregularity of regenerating nodules, and size of both hepatic lobes, were measured. The predictive value of each finding for the development of HCC was investigated by using univariate and multivariate analyses.

RESULTS

HCC developed in a total of 42 of the 119 patients (35.3%) during a mean follow-up period of 62.9 months. The degree of regenerating nodules, the presence of irregular regenerative nodules, and atrophic right lobe were significant predictive factors for HCC with univariate analysis. In particular, 67.1% of patients with irregular regenerative nodules had HCC develop within 5 years. Multivariate analysis revealed that irregular regenerative nodules (relative risk 6.32, p = 0.012), the degree of regenerative nodules (relative risk 4.78, p = 0.029), and atrophic right lobe (relative risk 3.87, p = 0.048) were independent predictive factors.

CONCLUSIONS

Morphologic observation of the liver surface by laparoscopy is important and provides information on factors that are statistically significant early predictors of the development of HCC.

[Clinicopathological study of influential factors on prognosis in patients with renal cell carcinoma]

Between January 1986 and August 1996, 120 patients were diagnosed with renal cell carcinoma (RCC) at Kanagawa Cancer Center. In this study, we analyzed these patients in view of the clinicopathological factors, which affect the prognosis of these patients with univariate and multivariate analysis using Cox's proportional hazard model. Of these 120 patients, 40 patients (33%) died of RCC during this period. The cause specific survival rate was 65% after 5 years and 57% after 10 years. Univariate analysis showed some factors, performance status, symptoms, tumor size, histological grade, local invasion (pT), venous involvement (pV), lung metastasis, lymph-node metastasis, and bone metastasis, affected the prognosis. Furthermore, multivariate analysis using Cox's proportional hazard model showed that performance status, pT, pV, lung metastasis, lymphnode metastasis, and bone metastasis independently affected the prognosis. In summary, TMN factors and performance status importantly affect the prognosis of RCC patients.

Natural course of cavernous hepatic hemangioma

Cavernous hepatic hemangiomas are benign liver tumors and present as incidental findings on sonographic examinations, but little is known concerning their natural course. Therefore, we performed a clinical and imaging follow-up of 64 cases of cavernous hepatic hemangioma in 50 patients during an average 18.8 month period. One case presented a symptom of slightly right upper quadrant pain and two cases showed thrombocytopenia. In one of the thrombocytopenia cases, cavernous hepatic hemangioma was resected because of Kasabach-Merrit syndrome. No case increased in size during follow-up, but one case decreased and disappeared. These results suggested that prolonged clinical and imaging follow-up of cavernous hepatic hemangiomas may be needed.

Crystal structure of Bacillus stearothermophilus alpha-amylase: possible factors determining the thermostability

The crystal structure of a thermostable alpha-amylase from Bacillus stearothermophilus (BSTA) has been determined at 2.0 A resolution. The main-chain fold is almost identical to that of the known crystal structure of Bacillus licheniformis alpha-amylase (BLA). BLA is known to be more stable than BSTA. A structural comparison between the crystal structures of BSTA and BLA showed significant differences that may account for the difference in their thermostabilities, as follows. (i) The two-residue insertion in BSTA, Ile181-Gly182, pushes away the spatially contacting region including Asp207, which corresponds to Ca(2+)-coordinating Asp204 in BLA. As a result, Asp207 cannot coordinate the Ca(2+). (ii) BSTA contains nine fewer hydrogen bonds than BLA, which costs about 12 kcal/mol. This tendency is prominent in the (beta/alpha)(8)-barrel, where 10 fewer hydrogen bonds were observed in BSTA. BLA forms a denser hydrogen bond network in the inter-helical region, which may stabilize alpha-helices in the barrel. (iii) A few small voids observed in the alpha-helical region of the (beta/alpha)(8)-barrel in BSTA decrease inter-helical compactness and hydrophobic interactions. (iv) The solvent-accessible surface area of charged residues in BLA is about two times larger than that in BSTA.