70 FIBROBLAST GROWTH FACTOR 4 PROMOTES THE DEVELOPMENT OF SOMATIC CELL NUCLEAR TRANSFER EMBRYOS IN MICE

Somatic cell nuclear transfer (SCNT) embryos can develop during the preimplantation period; however, most of these die after implantation period. A transcription factor, Cdx2, promotes differentiation of extraembryonic tissues and appears to be involved in the segregation of inner cell mass (ICM) and trophectoderm (TE) in preimplantation embryos. So far, we have demonstrated that the expression of Cdx2 in mouse SCNT embryos is delayed and its expression level is significantly lower than that in intracytoplasmic sperm injection (ICSI) embryos. Moreover, the ectopic expression of Oct-3/4 was observed in the TE tissues of SCNT blastocysts, but not in ICSI blastocysts. Fibroblast growth factor (FGF) receptor 2 (FGFR2) is specifically expressed in 8-cell to morula-stage embryos and trophectoderm (TE) and is essential for implantation; however, FGFR2 expression in SCNT embryos significantly decreases compared with IVF embryos. Therefore, it is likely that abnormality of differentiation that is controlled in development of pre-implantation in SCNT embryos leads to a rapid decrease of subsequent developmental ability. Then, we investigated the effects of FGF4 on development of SCNT embryos. Mouse SCNT embryos were produced according to the method reported previously (Wakayama et al. 1998). B6D2F1 and B6C3F1 female mice were used for the collection of recipient oocytes and donor cells, respectively. Data were analyzed by Student’s t-test. First, the timing to start adding FGF4 was decided by FGFR2 expression time about 54 h after cell injection and treated for 3, 6, 12, 24, and 42 h thereafter. In the case of FGF4 concentration at 25 ng mL-1 with treating time of 6 h from the 4- to 8-cell stages, SCNT embryos significantly promoted the development to morula and blastocyst stages (91 and 45%, respectively) compared with IVF embryos (80 and 30%, respectively; P < 0.05). However, longer treatment of 42 h with FGF4 made their morphology considerably worse. Then, concentrations of FGF4 at 5, 25, 50, 250, and 500 ng mL-1 with treating time of 6 h was examined. In case of FGF4 concentration at 25 and 50 ng mL-1, SCNT embryos significantly promoted the development to morula and blastocyst stages (P < 0.05). Immunohistochemical analysis showed segregation of the expression of Oct-3/4 and Cdx2 in ICM and TE, respectively, in FGF4-treated SCNT embryos, unlike in the case of nontreated SCNT embryos, which showed an ectopic expression of Oct-3/4 in TE tissues. Furthermore, after the transplantation of SCNT embryos treated with FGF4 at 50 ng mL-1 and the treating time of 6 h to recipient mice, most of the transferred embryos implanted and cloned mice were successfully produced as well as nontreated SCNT embryos. Therefore, FGF4 facilitates the development of SCNT embryos especially to the morula and blastocyst stages. This work was supported by a Grant-in-Aid for Scientific Research from the Japan Society for the Promotion of Science.

Correlation between Histopathological Diagnosis and Real-Time Tissue Elastography Scores

Background“Hardness” is important characteristics of carcinoma. Recent invention of Real-time Tissue Elastography (EG) has made scaling the hardness possible. At 31st SABCS, we reported that B-mode ultrasound(US)+mammography(MMG)+EG demonstrated high sensitivity even for the malignancy of the mass-forming lesions of 1.1 cm or smaller in diameter. This results suggested that possibility of a mass-forming lesion being malignant is ignorable low when it is judged as “not malignant” by this combined method. In this study, we verified correlation between EG score and histopathological diagnosis.Method416 patients with mass-forming and non-mass-forming breast lesions (118 malignant, 298 benign) whose tissues were diagnosed by histopathologically from October 2007 to March 2009 were studied. The hardness was scored on a scale 1 to 5 on Tsukuba elasticity scoring system.ResultsIn mass-forming breast lesions, the mean overall score of malignant diseases was 4.1 (invasive carcinoma 4.3, noninvasive carcinoma 3.5), and the mean overall score of benign diseases was 2.4, and thus scores of malignant diseases were significantly high (&lt; 0.0001). On the other hand, in non-mass-forming breast lesions, the mean overall score of malignant diseases was 2.3 (invasive carcinoma 2.5, noninvasive carcinoma 2.4), and the mean overall score of benign diseases was 2.0, and thus no differences were seen between them. Furthermore, for examination by mass-forming lesions combined with non-mass-forming lesions the mean score of noninvasive carcinomas was 2.5.ConclusionIt was found that in mass-forming lesions, high scores suggest invasive carcinoma and low scores suggest benign diseases. However, as in non-mass-forming lesions, both invasive and noninvasive carcinomas almost show no high EG scores, it appeared necessary to look into invasive examinations such as biopsy for the diagnosis of non-mass-forming lesions.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 5026.

Conversion from mycophenolate mofetil to mizoribine for patients with positive polyomavirus type BK in urine

It is known that administration of mycophenolate mofetile (MMF) is associated with BK virus (BKV) nephropathy in renal transplant recipients. To determine any inhibitory effect of mizoribine for BKV, seven patients with positive BKV in their urine who took MMF as immunosuppressive therapy were evaluated after MMF was changed to mizoribine. Baseline BKV DNA in urine, which ranged from 2.2 x 10(2) to 5.5 x 10(6) copies per milliliter, decreased in all cases (mean = 1.9 x 10(-1) times; median 2.8 x 10(-3) times). Four cases turned negative within 6 months and one within 12 months. No acute rejection or deterioration of graft function occurred during the administration of mizoribine. An inhibitory effect of mizoribine on BKV was suggested.

11C-acetate PET in the evaluation of brain glioma: comparison with 11C-methionine and 18F-FDG-PET

PURPOSE

The aim of the study is to retrospectively investigate the usefulness of 11C-acetate (ACE)-positron emission tomography (PET) for evaluation of brain glioma, in comparison with 11C-methionine (MET) and 2-deoxy-2-18F-fluoro-D-glucose (FDG).

PROCEDURES

Fifteen patients with brain glioma referred to initial diagnosis were examined with ACE, MET, and FDG-PET. Five patients had low-grade gliomas (grade II), three had anaplastic astrocytomas (grade III), and seven had glioblastomas (grade IV). PET results were evaluated by visual and semiquantitative analysis. For semiquantitative analysis, the standardized uptake value (SUV) and tumor to contralateral normal gray matter (T/N) ratio were calculated. The sensitivity for detection of high-grade gliomas was calculated using visual analysis.

RESULTS

Sensitivities of ACE, MET, and FDG were 90%, 100%, and 40%, respectively. ACE and MET T/N ratios were significantly higher than that of FDG. ACE and FDG SUV in high-grade gliomas were significantly higher than that in low-grade gliomas. No significant differences were observed using MET.

CONCLUSIONS

ACE PET is a potentially useful radiotracer for detecting brain gliomas and differentiating high-grade gliomas.

Short-term plasticity of central benzodiazepine receptors in status epilepticus: case report

(123)I-iomazenil SPECT is of value in determining an epileptogenic focus, however, transient uptake change has been rarely reported in epileptic disorders. A 78-year-old woman diagnosed as status epilepticus (SE) showed transient reduction in (123)I-iomazenil uptake within the epileptic foci on SPECT images during a couple of weeks. It suggests a seizure-related 'short-term' plasticity in the central benzodiazepine receptors and dynamic change in the regulatory mechanisms of inhibitory neurotransmitter system within the epileptic foci in patients with SE.

Tumour budding at invasive margins and outcome in colorectal cancer

OBJECTIVE

Tumour budding, defined as small clusters of undifferentiated cancer cells at invasive margins, has been shown to reflect biologic aggressiveness of colorectal cancers. We therefore examined the prognostic significance of tumour budding in patients with colorectal carcinoma, particularly focusing on comparisons with other clinicopathological findings.

METHOD

Tumour budding was investigated in surgically resected specimens from 159 patients with colorectal carcinoma. With haematoxylin and eosin stained slides containing the entire invasive margin, the degree of tumour budding was classified into three grades: mild, <1/3 of the entire invasive margin; moderate, 1/3-2/3; marked, >2/3.

RESULTS

Mild tumour budding was found in 54 (34%) cases, moderate in 59 (37%) cases and marked in 46 (29%) cases. The degree of budding was linked with poor tumour differentiation, lymph node metastasis and advanced TNM stage (P < 0.001). In univariate analysis, patients with marked tumour budding [5-year cancer-related survival (CRS)/recurrence-free survival (RFS), 39%/53%] had significantly worse survival [CRS, hazard ratio (HR), 4.561; 95% confidence interval (CI), 2.265-9.184; P < 0.001; RFS, HR, 3.240; 95% CI, 1.430-7.342; P = 0.005] than those with mild (5-year CRS/RFS, 80%/82%) or moderate (63%/66%) budding. In the Cox regression model, marked tumour budding (HR, 3.137; 95% CI, 1.517-6.487; P = 0.002) and advanced tumour stage (stage III, HR, 3.226; 95% CI, 1.475-7.053; P = 0.003; stage IV, HR, 24.443; 95% CI, 10.843-55.100; P < 0.001) proved to be an independent predictor of short CRS.

CONCLUSION

Tumour budding is a practical and significant histological index for identification of high malignant potential and poor outcome in patients with colorectal carcinoma.

Oncolytic virotherapy with an HSV amplicon vector expressing granulocyte–macrophage colony-stimulating factor using the replication-competent HSV type 1 mutant HF10 as a helper virus

Direct viral infection of solid tumors can cause tumor cell death, but these techniques offer the opportunity to express exogenous factors to enhance the antitumor response. We investigated the antitumor effects of a herpes simplex virus (HSV) amplicon expressing mouse granulocyte-macrophage colony-stimulating factor (mGM-CSF) using the replication-competent HSV type 1 mutant HF10 as a helper virus. HF10-packaged mGM-CSF-expressing amplicon (mGM-CSF amplicon) was used to infect subcutaneously inoculated murine colorectal tumor cells (CT26 cells) and the antitumor effects were compared to tumors treated with only HF10. The mGM-CSF amplicon efficiently replicated in CT26 cells with similar oncolytic activity to HF10 in vitro. However, when mice subcutaneously inoculated with CT26 cells were intratumorally injected with HF10 or mGM-CSF amplicon, greater tumor regression was seen in mGM-CSF amplicon-treated animals. Furthermore, mGM-CSF amplicon treatment prolonged mouse survival. Immunohistochemical analysis revealed increased inflammatory cell infiltration in the solid tumor in the mGM-CSF amplicon-treated animals. These results suggest that expression of GM-CSF enhances the antitumor effects of HF10, and HF10-packaged GM-CSF-expressing amplicon is a promising agent for the treatment of subcutaneous tumors.

Extracranial carotid plaque is increasing in Japanese ischemic stroke patients

OBJECTIVE

The objectives of this study were to investigate the prevalence of extracranial carotid plaque and the association between risk factors and carotid plaque in Japanese patients with ischemic stroke.

METHODS

We consecutively recruited patients with ischemic stroke admitted to our hospital from January 2000 to September 2002. Neurologic signs and a brain magnetic resonance imaging diagnosed ischemic stroke. All subjects underwent a carotid ultrasonography. Multiple logistic regression analysis was used to determine the risk factors that independently contributed to the presence of carotid plaques.

RESULTS

Carotid plaques were identified in 76.2% of the patients and bilateral plaques were found in 58.2%. These lesions were more frequent in comparison with previous Japanese reports. The risk factors that independently contributed to the presence of extracranial carotid plaques were hypertension, age, smoking and past history of ischemic stroke.

CONCLUSIONS

This study demonstrates that extracranial carotid plaque is increasing in Japanese patients with ischemic stroke.

Enhanced efficacy of herpes simplex virus mutant HF10 combined with paclitaxel in peritoneal cancer dissemination models

BACKGROUND/AIMS

Oncolytic viral therapy is used worldwide. Many genetically engineered viruses have been evaluated for their potential as a new therapeutic agent for cancer. HF10, herpes simplex virus (HSV) type-1 clone, has remarkable anti-tumor effects, based on our previous research. In this study, we investigated the ability of HF10 to infect and lyse murine colon cancer cells, CT26, in vitro, and tested its efficacy in an immuno-competent animal model of colorectal cancer. Further, we attempted to evaluate HF10/paclitaxel combination therapy.

METHODOLOGY

In vitro, viral replication and cytotoxicity of HF10 against CT26 was observed. In vivo, BALB/c mice harboring carcinomatous peritonitis of CT26 cells were treated with HF10, paclitaxel or HF10 combined with paclitaxel.

RESULTS

HF10 is effective for peritoneal dissemination without ascites. The combination of HF10 and paclitaxel prolonged survival of mice bearing carcinomatous dissemination of CT26 compared with the controls, HF10 alone and paclitaxel alone. Paclitaxel did not suppress viral replication and cytotoxicity of HF10.

CONCLUSIONS

These results indicate that the combination of HF10 and paclitaxel had a remarkable effect as a cancer therapy and this method is applicable to almost all advanced cancers. This new combination therapy is a potentially epoch-making cancer therapy.

Suitability of a US3-inactivated HSV mutant (L1BR1) as an oncolytic virus for pancreatic cancer therapy

Recently, the use of oncolytic viruses against cancer has attracted considerable attention. We studied the potential of the US3 locus-deficient herpes simplex virus (HSV), L1BR1, for oncolytic virus therapy. Its high specificity and potency indicate that L1BR1 is a promising candidate as a new oncolytic virus against pancreatic cancer. Moreover, the virus exhibited the unique characteristic of increasing apoptosis when used in combination with anticancer drugs. We assessed the feasibility of using the US3 locus-deficient HSV named L1BR1 as a new replication-competent oncolytic virus for the treatment of pancreatic cancer. The US3 locus of HSV has been shown to be a key gene in producing a multifunctional protein kinase that inhibits apoptosis induced by viral infections, chemicals and ultraviolet (UV) light. L1BR1 has been reported to be more than 10 000-fold less virulent than the parental virus in mice. In this study, we examined the tumor specificity and oncolytic effect of this attenuated replication-competent virus, L1BR1, in pancreatic cancers derived from SW1990, Capan2 and Bxpc-3cells compared with the parent virus and other well-known oncolytic herpes viruses (R3616 and hrR3). We also studied the efficacy of L1BR1 for the induction of apoptosis as an attribute of this virus in combination with the anticancer drugs 5FU and cisplatin. The combined treatment of the pancreatic cancer cells with L1BR1 and these anticancer drugs enhanced apoptosis significantly. More importantly, L1BR1 showed the lowest replication capacity in normal human hepatocytes, but the highest tumor-reducing effect in vivo among the oncolytic herpes viruses tested. In addition, L1BR1 significantly increased the induction of apoptosis of cancer cells when treated in combination with anticancer drugs although the parental virus inhibited the induction of apoptosis. These results suggest that L1BR1 is promising as a new anticancer oncolytic virus.

Clinical Experiment of Mutant Herpes Simplex Virus HF10 Therapy for Cancer

We reviewed our clinical trial using mutant herpes simplex virus "HF10". We have evaluated the safety and effect of HF10 against recurrent breast cancer since 2003 and also applied HF10 to non-resectable pancreatic cancer since 2005. An oncolytic herpes simplex virus type 1, mutant HF10, has been isolated and evaluated for anti-tumor efficacy in syngeneic immunocompetent mouse models. From long time before clinical trial, we have found that the mutant virus can have remarkable potential to effectively treat cancer in experimental studies using animals, and that all of the surviving mice acquire resistance to rechallenge of the tumor cells. A number of studies have shown that HF10 is effective and safe for use in localized or peritoneally disseminated malignant tumors of non-neuronal origin in animals. Pilot studies using HF10 have been initiated in patients with metastatic breast cancer. For each patient, 0.5 ml HF10 diluents at various doses were injected into test nodule, and 0.5 ml sterile saline was injected into a second nodule. All patients were monitored for local and systemic adverse effects, and the nodules were excised 14 days after viral injection for histopathological studies. All patients tolerated the clinical trial well. While no adverse effects occurred, there was cancer cell death and 30-100% regression histopathologically in recurrent breast cancer. As mentioned above, intratumoral injection of mutant herpes simplex virus HF10 for recurrent metastatic breast cancer was safe and effective. Also a trial for non-resectable pancreatic cancer being carried out on the basis of the above result has proved to be innocuous and has been in progress to assess the clinical benefit and enhance the potentiality of HF10 against cancer.

Significance of fluorodeoxyglucose PET imaging in the diagnosis of malignancies in patients with biliary stricture

AIM

This study was performed to evaluate the significance of positron emission tomography using fluorodeoxyglucose (FDG-PET) in diagnosing malignancy in patients with biliary stricture by comparing the sensitivity and specificity of FDG-PET with those of CT scans and cytological examination of the bile.

METHODS

Thirty patients who underwent FDG-PET for differential diagnosis of the disease causing biliary stricture were included in this study. The sites of the strictures were as follows: in the intrahepatic bile duct in five patients, in the peripheral extrahepatic bile duct in 17 patients, and in the distal extrahepatic bile duct in eight patients. The sensitivity and specificity (%) of FDG-PET in diagnosing malignancies were evaluated and compared with those of CT scans and cytological examination using obtained bile. Final diagnoses were based on surgical or biopsy findings. Data was collected and analysed in a retrospective fashion.

RESULTS

Malignant diseases were diagnosed in 21 patients, as follows: cholangiocarcinoma including Klatskin tumour in 10 patients, gallbladder cancer in eight, duodenal and ampulla cancer in two, and pancreatic cancer in one. In diagnosing malignancy in patients with biliary stricture, overall sensitivity and specificity were 85.7 (18/21) and 55.6 (5/9), respectively, for CT, 64.7 (11/17) and 100 (7/7), respectively, for cytological examination of the bile, and 90.5 (19/21) and 77.8 (7/9), respectively, for FDG-PET.

CONCLUSIONS

In diagnosing malignant diseases in patients with biliary stricture, FDG-PET was superior to CT examination in both sensitivity and specificity, and superior to cytological examination of the bile in sensitivity. However, in patients with inflammatory disease, such as primary sclerosing cholangitis and cholecystitis, false positive rates were found. Therefore, a multidisciplinary diagnostic approach using FDG-PET in conjunction with conventional modalities seems essential to a precise differential diagnosis.

Orthopedic symptoms in pustular bacterid (pustulosis palmaris et plantaris): Tietze's syndrome and arthritis of manubriosternal joint due to focal infection

Painful orthopedic symptoms in the sternal area, such as arthritis of the manubriosternal and sternoclavicular joint or Tietze's syndrome, were found in 14 of 132 cases of pustulosis palmaris et plantaris. The majority of the pustulosis palmaris et plantaris patients with orthopedic symptoms had skin eruptions not only on the palms and soles, but also on the backs of the hands and feet, the arms, the legs and the trunk. Such cases were usually accompanied by elevation of the erythrocyte sedimentation rate, leucocytosis, changes in serum globulin, and also pyrexia at the time of exacerbation. The skin and orthopedic symptoms often worsened after acute exacerbation of the focal infection, and occasionally responded to tonsillectomy or chemotherapy with antibiotics, which is suggestive of the probable cause of the bacterid.

Bioconversion studies in cultured cells of Corydalis species

Structural analysis of the metabolites of dopamine and salsolinol in cultured cells of Corydalis species was carried out using the combination of LC-MS and LC-NMR techniques. Metabolic pathways were clarified without the need to isolate the individual metabolites.

In vitro and in vivo analysis of human herpesvirus-6 U90 protein expression

In order to establish a reliable method for the detection of human herpesvirus-6 (HHV-6) B antigens in peripheral blood mononuclear cells (PBMCs) collected from HHV-6 infected patients, we created a polyclonal antibody against the HHV-6 B U90 protein (IEA/ex3) and used it to examine the expression of this protein in virus-infected cells and patients' PBMCs. This antibody reacted with 170 and 195 kDa proteins in HHV-6 B-infected cord blood mononuclear cells. The IEA/ex3 antigen was detected in cord blood mononuclear cells at 6 hr post-infection, and the number of infected cells reached its maximum at 48 hr post-infection. The antigen stained in a punctate pattern and partially localized to the promyelocytic leukemia (PML) protein body. We also examined 60 PBMC samples from 60 febrile children (3-19 months old) and detected IEA/ex3 antigen in the PBMCs by laser-scanning microscopy. HHV-6 was isolated from 31 of the 60 samples. The sensitivity and specificity of the antigen detection were 84% (26/31) and 97% (28/29), respectively, in the samples with virus detected. The mean number of antigen-positive PBMCs was 409/10(6) cells in 20 samples with viral isolation. A significant correlation (r = 0.566; P = 0.008) was observed between the viral load and number of antigen-positive cells. Although IEA/ex3 antigen was detected by laser-scanning microscopy in PBMCs (without cultivation) collected from six patients with isolated virus, it was detected in only one sample by conventional fluorescence microscopy. Increasing the intensity by cultivation (24 hr) resulted in a higher detection rate (5/6) even by conventional fluorescence microscopy, which is available in most hospital laboratories.

Relapse of neonatal herpes simplex virus infection

BACKGROUND

Neonatal herpes simplex virus (HSV) infection is a severe disease with high mortality and morbidity. Recurrence of skin vesicles is common.

OBJECTIVE

To determine the features of relapse and identify the factors related to relapse.

DESIGN

Thirty two surviving patients with neonatal herpes virus infections were enrolled. All patients received acyclovir treatment. Clinical and virological data were analysed and compared between relapsed and non-relapsed cases.

RESULTS

Thirteen (41%) had either local skin or central nervous system relapse between 4 and 63 days after completing the initial antiviral treatment. Nine patients exhibited local skin relapses, and four developed central nervous system relapses. In one skin and two central nervous system relapse cases, neurological impairment later developed. Type 2 virus infection was significantly related to relapse (odds ratio 10.4, 95% confidence interval 1.1 to 99.0). Patients with relapse had worse outcomes than those without relapse.

CONCLUSION

Neonates with HSV type 2 infections have a greater risk of relapse. Relapsed patients have poorer prognoses.

Comparative whole-body 201Tl and bone scintigraphies for the detection of bone marrow involvement in multiple myeloma

The objectives of this study were to investigate the role of whole-body 201Tl-chloride scintigraphy in comparison with bone scintigraphy in the detection of bone marrow involvement in patients with multiple myeloma and to assess the follow-up evaluation using 201Tl-chloride. Twenty-one patients with untreated multiple myeloma were evaluated. 201Tl-chloride images were acquired 10 min (early) and 2 h (delayed) after the injection of 111 MBq 201Tl-chloride. Bone images were acquired 3 h after the intravenous injection of 740 MBq 99mTc-hydroxymethylene diphosphonate (HMDP). The 201Tl-chloride scan patterns were classified as normal, diffuse (presence of bone marrow), focal (localized areas of uptake) and diffuse+focal. The bone scan patterns were classified as normal and abnormal. Eight of the 21 patients also underwent 201Tl-chloride scintigraphy after chemotherapy for the evaluation of the therapeutic response. On the early 201Tl-chloride image, two patients showed a normal, 13 a diffuse, two a focal and four a diffuse + focal pattern. On the delayed 201Tl-chloride image, nine patients showed a normal, six a diffuse, four a focal and two a diffuse + focal pattern. Bone scintigraphy showed an abnormal accumulation in only five of the 21 patients. Of the eight patients who underwent follow-up 201Tl-chloride studies, the abnormal diffuse pattern was changed to a normal pattern on post-treatment scintigraphy in three, and the degree of abnormal 201Tl-chloride accumulation decreased in comparison with the pre-treatment scan in three. These six patients were considered to be in clinical remission. In the two remaining patients, the degree of abnormal 201Tl-chloride accumulation increased in comparison with the pre-treatment scan, and they were considered to be in clinical progression. 201Tl-chloride scintigraphy is a non-invasive tool, which may be more useful than bone scintigraphy for the diagnosis of multiple myeloma, and may be helpful in the follow-up of multiple myeloma.

99mTc galactosyl human serum albumin liver dynamic SPET for pre-operative assessment of hepatectomy in relation to percutaneous transhepatic portal embolization

We have devised an original predictive residual index (PRI) using 99mTc diethylenetriaminepentaacetic acid galactosyl human serum albumin (99mTc-GSA) liver dynamic SPET for the pre-operative assessment of hepatectomy, including the prediction of residual liver function before hepatectomy. The aim of this study was to evaluate the usefulness of the PRI by using 99mTc-GSA liver dynamic SPET before and after percutaneous transhepatic portal embolization (PTPE) to induce compensatory hypertrophy of the remnant lobe, and to compare the results with the prognosis after hepatectomy. The subjects included eight patients with cholangiocellular carcinoma, five with gallbladder cancer, four with hepatocellular carcinoma and three with metastatic liver cancer. 99mTc-GSA liver dynamic SPET was performed immediately before and 2 weeks after PTPE. Dynamic SPET with 35 continuous rotations was performed to obtain the k-value according to the accumulation curve in each voxel (0.54 cm x 0.54 cm x 1.08 cm) of the liver immediately after a bolus injection of 185 MBq 99mTc-GSA. Each rotation consisted of 180 degrees turn in 64 steps in a 64 x 64 matrix. The acquisition time of each rotation was 35 s. We devised an original PRI by combining the k-value with functional liver volume which were measured by liver dynamic SPET. Hepatectomy was performed following the second SPET. The correlation between the PRI and post-operative patient prognosis was investigated retrospectively. The functional liver volume of the remnant lobe and the PRI significantly increased after PTPE compared with respective values before PTPE (P<0.005 and P<0.0001, respectively). Regarding the relationship between the PRI and the clinical course following surgery, post-operative complications were observed in only two patients. The PRI values of these two patients were 0.323 and 0.394. When the PRI was above 0.400, no patient had symptoms of hepatic failure. The results of this study suggest that, when the PRI value is above 0.400, there is a low probability of hepatic failure after hepatectomy. We conclude that the PRI devised in this study is useful in the pre-operative assessment of hepatectomy after PTPE.

Oncolytic viral therapy using a spontaneously generated herpes simplex virus type 1 variant for disseminated peritoneal tumor in immunocompetent mice

The present study demonstrates that a clonal derivative (HF10) of HSV-1 strain HF effectively treated disseminated peritoneal neoplasm in an immunocompetent animal model and that all of survived mice acquired resistance to rechallenge with tumor cells. The survival time of mice treated with HF10 was longer than that of mice treated with hrR3, indicating that the oncolytic effect of HF10 was more potent than that of hrR3 in this animal model. HF10 induces syncytia formation in vitro, whereas hrR3 forms rounded CPE. The sequential administration of HF10 gave a long term survival of more than 90 days after tumor injection, with no signs of disease, in 8 of the 9 treated mice. The results suggest that treatment of disseminated peritoneal tumor with HF10 induces a specific antitumor immune response. Genomic structure determination showed that HF10 has a deletion of 3.9-kilobase pair (kbp) in the right end of UL and UL/IRL junction, resulting in the loss of UL 56 expression. A 2.3 kbp deletion and extensive rearrangement were also observed in the left end of the genome.

Carrier-dependent specificity of antibodies to a conserved peptide determinant of gp120

Amino acid residues 421-436 constitute a comparatively conserved determinant of gp120 that participates in the binding of host cell CD4 receptors by HIV-1. We compared the immunogenicity of synthetic Cys-gp120 (421-436) conjugated to KLH via the N terminal Cys residue (KLH-I) and gp120 (421-436) extended at its N terminus with a 15 residue tetanus toxoid T cell epitope (T-I) in non-autoimmune mice (BALB/cstrain) and Fas-defective autoimmune mice (MRL/lpr strain). Both immunogens elicited high titer Abs detected as the binding to gp120 (421-436) conjugated to bovine serum albumin (BSA-I) immobilized in ELISA plates. Abs from KLH-I immunized mice displayed binding to full-length gp120 but the Abs from T-I immunized mice did not. Proteins unrelated in sequence to gp120 did not bind the Abs. Soluble I and T-I failed to compete with immobilized BSA-I for binding to anti-KLH-I Abs, whereas these peptides inhibited anti-T-I Ab binding by BSA-I (rank potency order: BSA-I > T-I >> I). These results indicate the influence of the carrier protein on the specificity of Abs to synthetic I. Low level BSA-I and gp120 binding Abs were detected in sera from non-immunized MRL/lpr mice. Similar Ab binding titers and specificity profiles were evident in MRL/lpr and BALB/c mice following immunization with KLH-I and T-I, indicating that pre-existing immunity to gp120 in the former strain does not influence the magnitude or specificity of the Ab response.

X-ray structure of mercerized cellulose II at 1 a resolution

A revised crystal structure for mercerized cellulose based on high-resolution synchrotron X-ray data collected from ramie fibers is reported (space group P2(1), a = 8.10(3) A, b = 9.03(3) A, c = 10.31(5) A, gamma = 117.10(5) degrees; 751 reflections in 304 composite spots; theta < 21.11 degrees; lambda = 0.7208 A; LALS refinement with d > 1.5 A, R' ' = 0.16; SHELX97 refinement with d > 1 A, R = 0.21). As with regenerated cellulose the crystal structure consists of antiparallel chains with different conformations but with the hydroxymethyl groups of both chains near the gt position. However, the conformation of the hydroxymethyl group of the center chain in the structure reported here differs significantly from the conformation in regenerated cellulose. This may be related to a large observed difference in the amount of hydroxymethyl group disorder: approximately 30% for regenerated cellulose and approximately 10% for mercerized cellulose.

Expression of tegument protein pp65 of human cytomegalovirus (CMV) and its application to the analysis of viral-specific cellular immunity in CMV-infected individuals

Investigations into human cytomegalovirus (CMV)-specific cellular immunity are important to better understand and manage CMV infections. CMV phosphoprotein pp65 is thought to be a major antigen for CMV-specific cellular immunity. We newly synthesized protein pp65 with a baculovirus expression system and purified it via metal affinity chromatography in a soluble form. The recombinant protein pp65 was antigenic in an enzyme immuno-linked assay for pp65-specific IgG in sera from 196 children. Traditional lymphoproliferation assays have shown that pp65 protein promotes specific lymphoproliferation in CMV-seropositive donors. Using an intracellular cytokine detection system, we showed that this recombinant protein stimulated CD4-positive T cells to express interferon-gamma. The results of these assays using protein pp65 were comparable with the use of CMV whole antigen. pp65- and CMV-specific cellular immunity, and CMV DNA load were also compared in four recipients of unrelated cord blood transplantation. The delay in re-constitution in CMV-specific cellular immunity was associated with reactivation of CMV. These results indicated that the recombinant protein pp65 can be used to study specific immunity in CMV infections.

99mTc-MIBI and 201Tl SPET in the detection of recurrent brain tumours after radiation therapy

The purpose of this study was to evaluate whether Tc-hexakis-2-methoxyisobutylisonitrile ( Tc-MIBI) or Tl single photon emission tomography (SPET) could detect recurrent tumours in patients with previous radiation therapy for brain tumours. Dual SPET with Tc-MIBI and Tl was performed in 21 patients suspected of having recurrent brain tumours. SPET images were acquired 15 min (early) and 2 h (delayed) after injection. The ratio of the average counts for the region of interest in the lesion area and its mirror image in normal brain tissue was obtained. Early and delayed ratios were calculated. On the basis of histological and/or clinical findings, the final diagnosis was considered as recurrent tumours in 15 patients and radiation necrosis in six. Both ratios using Tc-MIBI and Tl were significantly higher in recurrent tumours than in radiation necrosis. Based on a cut-off of 5.89 of the early ratio using Tc-MIBI to distinguish between recurrent tumours and radiation necrosis, the accuracy was 90%. Based on a cut-off of 6.77 of the delayed ratio using Tc-MIBI, the accuracy was 86%. The corresponding values using cut-offs of 2.40 and 1.85 with Tl were 90% and 86%, respectively. However, within recurrent tumours, both ratios for Tc-MIBI were significantly higher than those for Tl. Early Tc-MIBI SPET may be especially useful for the detection of recurrent tumours in patients who have previously undergone radiation therapy for brain tumours.

Critical involvement of CD40 in protection against herpes simplex virus infection in a murine model of genital herpes

We studied the requirement for CD40+ cells in the resolution of vaginal infection with avirulent herpes simplex virus type I (HSV-1) in vivo using CD40-deficient mice, which were susceptible to infection with avirulent HSV-1. Compared with wild-type mice, CD40-deficient mice could not eliminate HSV-1 virus effectively from the vaginal mucosa and produced lower amounts of interleukin-12 and interferon-gamma. These results show that the induction and activation of CD40+ cells are important for HSV prevention, facilitating the activation of T cells to induce an efficient HSV clearance from the vaginal mucosa and to prevent lethal illness due to HSV infection.

Comparison of 201 Tl- with 67 Ga single photon emission tomography in the diagnosis of head and neck cancer recurrence

The purpose of this study was to evaluate the usefulness of 201Tl single photon emission tomography (SPET) in comparison with 67Ga SPET for distinguishing recurrent tumours in patients previously treated for head and neck cancer. A total of 37 patients with suspicion of recurrent cancer were investigated. SPET images with 201Tl were acquired 10min (early) and 3h (delayed) and SPET images with 67Ga were acquired 72h, after injection. The visual and semiquantitative (T/N ratio) analysis were performed. On visual analysis, results from early 201Tl SPET were the same as those from delayed 201Tl SPET. The sensitivity, specificity and accuracy of the diagnosis of local recurrence using 201Tl SPET were all 100%. The three values using 201Tl SPET for neck lymph node metastases were 73%, 100% and 91%. The corresponding values using 67Ga SPET for local recurrence were 57%, 100% and 89%, respectively, and those using 67Ga SPET for neck lymph node metastases 55%, 100% and 84%, respectively. In the semiquantitative analysis, there was a statistically higher T/N ratio obtained using 201Tl when compared with 67Ga. 201Tl early SPET, especially, has the potential to replace 67Ga SPET in the follow-up of patients with head and neck cancer.

The US2 gene product of herpes simplex virus type 2 interacts with cytokeratin 18

In order to clarify the biological role of US2 gene product of herpes simplex virus type 2 (HSV-2), a HeLa cDNA library was screened in the yeast two-hybrid system using US2 protein as bait, and several interacting proteins were identified, including cytokeratin 18. US2 protein was co-immunoprecipitated with cytokeratin 18 from HSV-2 infected cell lysates. Analysis of infected orA431 cells by immunofluorescence showed that US2 protein gave filamentous or dot-like cytoplasmic staining pattern, and that it co-localized with cytokeratin 18. When US2 protein was expressed alone, it co-localized with cytokeratin 18. To define the domain interacting with cytokeratin 18, deletion mutant proteins were constructed and cells transfected with mutants were analyzed by indirect immunofluorescence. These results suggest that the N-terminal half of the US2 protein, especially the region containing amino acids 42-77, is important for interaction with cytokeratin 18.

Fungal flora on board the Mir-Space Station, identification by morphological features and ribosomal DNA sequences

This report is on the morphological and molecular biological identification, using 18S- and ITS1-rDNA sequences, of the "space fungi" isolated on board the Russian Mir-Space Station as the major constituents of the fungal flora. The six fungal strains were isolated from air by using an air sampler or from condensation. Strains were identified as Penicillium chrysogenum, Aspergillus versicolor, or Penicillium sp. by both methods. The species of space fungi were common saprophytic fungi in our living environment, potential pathogens, and allergens. This study concluded that the environment on board the space station Mir allows the growth of potentially pathogenic fungi as true in residential areas on the earth. Therefore, to prevent infection or other health disorders caused by these fungi, easy and reliable methods should be established to survey the fungal flora in a space station.

Comparative evaluation of 99mTc-MIBI and 99mTc-HMDP scintimammography for the diagnosis of breast cancer and its axillary metastases

The purpose of the present study was to compare scintimammography using technetium-99m hexakis 2-methoxyisobutylisonitrile (MIBI) with that using 99mTc-hydroxymethylene diphosphonate (HMDP) in the detection of breast cancer and its axillary lesions. The study population comprised 50 consecutive females with breast cancer who were scheduled for surgery. All patients underwent scintimammography with 99mTc-MIBI and 99mTc-HMDP. The images were acquired 5 min (early) and 2 h (delayed) after injection of each radiopharmaceutical. Regions of interest were placed over the breast tumour (T), the axillary lesion (A) and the normal ipsilateral breast tissue (N). The two count ratios were calculated, i.e. the tumour to normal breast tissue ratio (T/N) and the axillary lymph node to normal breast tissue ratio (A/N). For the breast tumours, using 99mTc-MIBI the positive rate was 86% (43/50) for the early and 72% (36/50) for the delayed images. The corresponding values using 99mTc-HMDP were 72% (36/50) and 40% (20/50), respectively. Histopathological examination revealed metastatic lymph node involvement in 22 patients. For the axillary lesions, using 99mTc-MIBI the positive rate was 72.7% (16/22) for the early and 54.5% (12/22) for the delayed images. Using 99mTc-HMDP, the positive rate was only 18.2% (4/22) for the early and 4.5% (1/22) for the delayed images. Using 99mTc-MIBI, the mean T/N (+/- SD) ratios on early and delayed images were 2.69 +/- 1.64 and 2.03 +/- 1.16, respectively, and the mean A/N (+/- SD) ratios on early and delayed images were 2.20 +/- 1.23 and 1.80 +/- 1.20, respectively. The corresponding values using 99mTc-HMDP were 1.77 +/- 0.91, 1.42 +/- 0.72, 1.27 +/- 0.63 and 1.08 +/- 0.25, respectively. The T/N and A/N ratios on the early and delayed 99mTc-MIBI images were both significantly higher than those obtained using 99mTc-HMDP. 99mTc-MIBI scintimammography is more sensitive than 99mTc-HMDP scintimammography for the detection of breast cancer and its axillary lymph node metastases.

The US11 gene product of herpes simplex virus has intercellular trafficking activity

The US11 gene product of herpes simplex virus is an abundant virion structural protein with RNA-binding regulatory activity. Its carboxyl-terminal half consists of tandem tripeptide repeats of the sequence RXP. We demonstrate that the US11 protein has intercellular trafficking activity and accumulates in the nucleolus when singly expressed in cultured cells, and that the RXP repeats are responsible for this activity. These same properties were also observed in cells expressing a fusion protein linking US11 to the green fluorescent protein. Furthermore, exogenous US11 protein was internalized by cells at 4 degrees C, which suggests that US11 protein uptake occurs primarily through an energy-independent pathway.

Abundance of unconventional CD8(+) natural killer T cells in the large intestine

Natural killer T (NKT) cells are mainly present in the liver and thymus, and the majority of these T cells express either a CD4(+) or a double-negative (DN) CD4(-)8(-) phenotype. In the present study, we examined whether such NKT cells were present in the intestine. NKT cells were rare in all sites of the small intestine, including an intraepithelial site. However, a considerable number of NKT cells were found at an intraepithelial site in the large intestine. This result was confirmed by both immunofluorescence and immunohistochemistry. In contrast to conventional NKT cells, NKT cells in the large intestine were CD8(+) or DN CD4(-)8(-). In the case of conventional NKT cells, their existence is known to depend on non-classical MHC class I-like antigens (i. e. CD1d) but not on classical MHC class I antigens. However, the NKT cells in the large intestine were independent of the presence of both CD1d and classical MHC class I antigens. These results were obtained using knockout mice lacking the corresponding genes and molecules. NKT cells in the large intestine were mainly alpha betaTCR(+) (> 75 %) but did not use an invariant chain of Valpha14Jalpha281, which is preferentially used by conventional NKT cells. These NKT cells did not bias the TCR-Vbeta usage toward Vbeta8. These findings suggest that the large intestine is a site in which unconventional NKT cells carrying the CD8(+) phenotype (or DN CD4(-)8(-)) are abundant and that these cells are independent of MHC and MHC-like antigens.

Herpes simplex virus encodes a virion-associated protein which promotes long cellular processes in over-expressing cells

BACKGROUND

Herpes simplex virus (HSV) possesses a number of accessory genes which are dispensable for replication in cell culture. A previous study showed that the UL21 gene product of HSV type 1 is a virion component that is not necessary for viral replication. The function of the gene product remains unknown.

RESULTS

We found that the HSV-1 UL21 gene product, a capsid-associated tegument protein with an apparent molecular mass of 62 kDa, promotes the outgrowth of long cellular processes when it is over-expressed in non-neural cells. The UL21 protein co-localizes and physically associates with microtubules in the long processes. Analysis using mutant proteins implicates a proline-rich region in promotion of the processes.

CONCLUSIONS

The results suggest that the UL21 protein, like tau and other MAPs, promotes the process by directly or indirectly interacting with microtubules and facilitates the intracellular transport of the virus.

[Characterization of cryoglobulin, M protein, low molecular weight IgM in a patient with chronic hepatitis C and type II mixed cryoglobulinemia]

The common extrahepatic manifestation of hepatitis C virus(HCV) infection is mixed cryoglobulinemia. We have analyzed serum cryoglobulin, IgM and various antibody activities from a patient with chronic hepatitis C and type II cryoglobulinemia. Cryoprecipitates were consisted of polyclonal IgG and monoclonal IgM-kappa with rheumatoid factor activity. About 20% of total IgM was found to be low molecular weight IgM by gel-filtration and SDS-PAGE. The anti-streptolysin O(ASO) activity measured by Latex agglutination method was found to be markedly elevated despite normal activity by Rantz-Randell method. The patient's serum has revealed to react against bovine gamma globulin, which crosslinked streptolysin O to Latex particles, in a nonspecific manner. Phenotypic analysis of the surface markers on abnormal lymphoid cells from peripheral blood and bone marrow showed monoclonal expansion of B-cell lineage by flow cytometry. The patient was treated with interferon-alpha, which resulted in an improvement of liver dysfunction, decreased amounts of cryoglobulin and IgM. It was concluded that the patient has suffered from lymphoproliferative disorder, namely HCV infection-associated primary macroglobulinemia.

Effect of the deletion of US2 and US3 from herpes simplex virus type 2 on immune responses in the murine vagina following intravaginal infection

We investigated the effects of US2 and US3 deficiencies of herpes simplex virus type 2 (HSV-2) on host immunity in a murine model of genital herpes infection. Viral clearance from the vaginal mucosa was more rapid in mice infected with a US3-deficient mutant L1BR1 as compared with a wild-type 186 or YY2 (US2-deficient mutant) infection, although there was no significant difference among them in initial growth in the early stage of infection. Flow cytometric studies revealed that the number of vaginal mononuclear cells in L1BR1-infected mice was significantly greater than that in 186- or YY2-infected mice. Dendritic cells, macrophages and T cells were induced more rapidly and in greater numbers within the vaginas of L1BR1-infected mice. Moreover, the levels of IL-12 and IFN-gamma increased in L1BR1-infected mice over levels in 186-infected mice. These results indicate that a US3 deficiency alters the induction of the host immune response; therefore, the inactivation of US3 may be a promising strategy in the development of novel vaccines for genital herpes.

Hydrosilylation of carbonyl compounds using a PhSeSiMe(3)/Bu(3)SnH/AIBN system

[reaction: see text] When carbonyl compounds were allowed to react with phenyl trimethylsilyl selenide and tributylstannyl hydride in the presence of a catalytic amount of AIBN as a radical initiator, the hydrosilylation of the carbonyl compounds efficiently proceeded to give the corresponding silyl ethers in moderate to good yields.

Change of antimicrobial susceptibility of group B streptococci over 15 years in Japan

We compared antimicrobial susceptibility patterns of 206 group B streptococcal (GBS) strains isolated from pregnant women and six from neonates/infants with invasive infection during the two periods 1985-1986 and 1999-2000. All strains in both periods were susceptible to the penicillins, cephalosporins and carbapenem tested. Seven (3%) isolates were resistant to erythromycin and three (1%) were resistant to clindamycin. There were no significant differences between the two study periods in the incidence of GBS resistant to the 14 antibiotics tested. These results showed that penicillins are still the first choice to prevent vertical transmission of GBS in Japan.

Investigation of varicella-zoster virus DNA in lymphocyte subpopulations by quantitative PCR assay

To investigate the nature of viremia during the acute phase of varicella, we studied the viral load in nine otherwise healthy children with varicella. Plasma and peripheral blood mononuclear cells (PBMC) were obtained, then PBMC were divided into CD4+T, CD8+T, and B lymphocytes and monocyte/macrophage fractions. The viral DNA in each component was quantified using a real-time quantitative polymerase chain reaction assay. Varicella-zoster virus (VZV) DNA was detected in plasma, PBMC and all subpopulations. The amount of viral DNA was similar in each PBMC subpopulation, suggesting that each lymphocyte fraction and monocytes carry similar amounts of VZV DNA during viremia.

Tl-201 chloride and Tc-99m MIBI accumulation in lung adenocarcinoma in patients with and without distant metastases

PURPOSE

The relation between Tl-201 chloride accumulation by the tumor and its distant metastatic potential were evaluated in patients with lung adenocarcinoma and compared with the same parameters achieved using Tc-99m MIBI.

METHODS

Fifty-six patients with primary lung adenocarcinoma were examined before therapy was begun. They were classified according to the radiologic findings and pathologic diagnosis into two groups: distant metastases and no distant metastases. All patients underwent dual-isotope imaging with Tl-201 chloride and Tc-99m MIBI. Regions of interest were placed over the tumor uptake (T) and contralateral normal lung tissue (N) areas on one transverse view with clearly defined lesions, and the T:N ratio and retention index were calculated.

RESULTS

The early and delayed T:N ratios and retention index using Tl-201 chloride SPECT in the distant-metastases group were significantly greater (P < 0.001 to P < 0.05) than were those in the no-distant-metastases group. There was no significant correlation between the T:N ratio and retention index and distant metastatic potential using Tc-99m MIBI SPECT.

CONCLUSION

Tl-201 chloride SPECT may be more effective than Tc-99m MIBI SPECT for evaluating the distant metastatic potential of primary lung adenocarcinoma.

CT assessment of subtypes of pulmonary emphysema in smokers

OBJECTIVE

To determine the incidence of subtypes of pulmonary emphysema (PE) identified by CT imaging in male patients who have a significant smoking history.

PATIENTS AND SETTING

We reviewed 945 subjects (619 men and 326 women) who had undergone CT scanning. However, only the data for male subjects were analyzed due to there being too few female subjects. The male subjects were divided into the following two age groups: group A (age, </= 50 years) and group B (> 50 years). There were two subtypes of PE found: centrilobular emphysema (CLE) and paraseptal emphysema (PSE). Based on these subtypes, PE was divided into the following three categories: I (CLE or CLE-predominant); II (CLE and PSE of equal extent); and III (PSE or PSE-predominant).

RESULTS

PE was found in 270 of 516 male smokers (10 of 38 female smokers had PE). Among male subjects, in age group A there were 53 subjects with some degree of PE (category I, 12 subjects [22.6%]; category II, 7 subjects [13.2%]; and category III, 34 subjects [64.2%]). Among men in age group B, there were 217 subjects with some degree of PE (category I, 109 subjects [50.2%]; category II, 23 subjects [10.6%]; and category III, 85 subjects [39.2%]).

CONCLUSION

In age group A, men < 50 years of age who were in category III (PSE or PSE-predominant PE) predominated (34 of 53 subjects; 64.2%). In age group B, men > 50 years of age who were in category I (CLE or CLE-predominant PE) predominated (109 of 217 subjects; 50.2%).

99mTc-MIBI SPECT in small cell lung cancer patients before chemotherapy and after unresponsive chemotherapy

We evaluated the accumulation of 99mTc-MIBI in small cell lung cancer patients before chemotherapy and after unresponsive chemotherapy. The pre-chemotherapeutic group included 22 newly diagnosed patients. These patients underwent a 99mTc-MIBI SPECT study before starting chemotherapy. After chemotherapy, based on changes in tumor size, three different patterns of response (complete remission: CR, partial remission: PR and no change: NC) were defined. The post-chemotherapeutic group included 11 patients after chemotherapy who did not respond to chemotherapy. These patients underwent a 99mTc-MIBI SPECT study after completion of chemotherapy. SPECT images were acquired 15 min (early) and 2 hr (delayed) after injection of 99mTc-MIBI. With a region of interest technique, the early ratio, delayed ratio and retention index were calculated. Early and delayed ratios in pre-chemotherapeutic patients were significantly higher than those in post-chemotherapeutic patients. There were no significant differences between the pre-chemotherapeutic and post-chemotherapeutic patients in the retention index. In the pre-chemotherapeutic patients, early and delayed ratios for the CR and PR groups were significantly higher than those for the NC group. There were no significant differences in the retention index with respect to the tumor response. 99mTc-MIBI might be useful for evaluating the tumor chemosensitivity in patients with small cell lung cancer.

Molecular characterization of hepatitis C virus genotype 2a from the entire sequences of four isolates

Genotype 2a hepatitis C virus (HCV) has different characteristics from genotype 1b, such as responsiveness to interferon therapy. Such type-specific characteristics appear to be due to differences in the HCV genome sequence. The complete sequences of genotype 2a HCV genome isolated from four patients with chronic hepatitis C were determined, and nucleotide and deduced amino acid sequences were compared within genotype 2a, as well as between genotype 2a and 1b. Whereas the amino acid sequence similarity of the core region was highest within genotype 1b, the NS3 and NS4B regions of exhibited greater similarity than the core region in genotype 2a. The serine protease and helicase motifs in the NS3 region were well conserved in genotype 2a to the same degree as in genotype 1b. However, the putative secondary structure of 2a isolates was significantly different from that of the 1b isolates. Analysis of amino acid similarity between genotypes 2a and 1b revealed the lowest degree of similarity in the E1 region, followed by the NS2 and NS5A region. Sequences of genotype 2a in the interferon-sensitivity determining region (ISDR) located in the NS5A region had a deletion of four amino acids compared with that of genotype 1b. When the ISDR of the genotype 2a was aligned for maximal similarity, it exhibited similarity of only 52.5-55.0% when compared with that of HCV-J, which belongs to genotype 1b. These findings for the entire sequences of genotype 2a isolates will contribute to virological studies of HCV.

Phosphonate ester probes for proteolytic antibodies

The reactivity of phosphonate ester probes with several available proteolytic antibody (Ab) fragments was characterized. Irreversible, active site-directed inhibition of the peptidase activity was evident. Stable phosphonate diester-Ab adducts were resolved by column chromatography and denaturing electrophoresis. Biotinylated phosphonate esters were applied for chemical capture of phage particles displaying Fv and light chain repertoires. Selected Ab fragments displayed enriched catalytic activity inhibitable by the selection reagent. Somewhat unexpectedly, a phosphonate monoester also formed stable adducts with the Abs. Improved catalytic activity of phage Abs selected by monoester binding was evident. Turnover values (kcat) for a selected Fv construct and a light chain against their preferred model peptide substrates were 0.5 and 0.2 min(-1), respectively, and the corresponding Michaelis-Menten constants (Km) were 10 and 8 microm. The covalent reactivity of Abs with phosphonate esters suggests their ability to recapitulate the catalytic mechanism utilized by classical serine proteases.