Studies of severe acute respiratory syndrome coronavirus pathology in human cases and animal models

During the severe acute respiratory syndrome (SARS) outbreak of 2003, approximately 10% of SARS patients developed progressive respiratory failure and died. Since then, several animal models have been established to study SARS coronavirus, with the aim of developing new antiviral agents and vaccines. This short review describes the pathologic features of SARS in relation to their clinical presentation in human cases. It also looks at animal susceptibility after experimental infection, animal models of SARS, and the pathogenesis of this disease. It seems that adaptation of the virus within the host animal and the subsequent abnormal immune responses may be key factors in the pathogenesis of this new and fatal respiratory disease. The proteases produced in the lung during inflammation could also play an important role for exacerbation of SARS in animals.

Multicenter phase II study of FOLFOX for metastatic colorectal cancer (mCRC) in Japan; SWIFT-1 and 2 study

BACKGROUND/AIMS

This study assessed the efficacy and toxicity of the FOLFOX4 (SWIFT1) and mFOLFOX6 (SWIFT2) regimens in Japanese patients with metastatic colorectal cancer (mCRC).

METHODOLOGY

Patients with mCRC were required to have ECOG performance status of 0 to 1, and to have adequate organ function. Two multicenter Phase II studies (SWIFT1/SWIFT2) were conducted in chemotherapy naive patients with mCRC.

RESULTS

112 patients were enrolled in these studies (SWIFT1: 54 patients / SWIFT2: 58 patients). The disease sites for each study were the colon in 27 patients and 28 patients, and the rectum in 27 patients and 30 patients, respectively. All patients received a median of 8 courses. After a median follow-up period of 35 months, 54 patients and 58 patients were evaluable in the respective studies, and the overall response rate was 50.0% (CR:31 PR:53). The response rate according to the sites of metastasis were as follows: liver, 54.1% (46/85); lung, 17.4% (4/23); and lymph node, 23.3% (7/30). Grade 3/4 neutropenia occurred in 14 patients (12.5%), while Grade 3/4 non-hematological toxicities were observed in 16 patients (31.0%) and Grade 3 neurotoxicity was observed in 6patients (5.4%) and 5 patients (4.5%), respectively.

CONCLUSIONS

FOLFOX4 (SWIFT1) and mFOLFOX6 (SWIFT2) regimens complying with the international standard dosage and schedule can also be administered safely and effectively in Japan.

Ligand shape emerges in solvent dipole ordering region at ligand binding site of protein

Solvent dipole ordering (SDO), introduced by Higo et al. (Proteins Struct Funct Genet 2000, 40, 193), is an entity that captures an aspect of hydration structure. We have studied SDO in the ligand binding site of two proteins (FK506 binding protein and dihydrofolate reductase) and found that the high SDO regions overlap significantly with the 3D structures of known inhibitors bound to the proteins. Thus, the SDO region might be used to predict the preferred molecular shape of ligands that bind to a protein. Based on this finding, we propose a novel docking procedure using model molecules that mimic the shape of the SDO region. To prove the validity of thisapproach, we performed a redocking experiment for p38 mitogen-activated protein kinase ligands using model molecules for search queries; we succeeded in identifying the binding conformations and binding modes of known inhibitors.

Chemometric alternatives for resolution of classical analytical problems Spectrophotometric determination of lanthanide mixtures

The simultaneous determination of lanthanide family elements is one of the greatest problems in analytical chemistry, due to the close similarity of their chemical properties. Spectrophotometric methods are generally of limited use, due to the various mutual spectral interferences involved. By using multivariate calibration methods (partial least-squares regression, PLSR), it was possible to obtain a model that adjusts itself perfectly to the values of the mixture concentrations used in the calibration. The model used absorption spectra in the 290-800 nm range for a set of 20 different mixtures of Ce, Pr, Nd and Sm, and made possible the determination of Ce, Pr and Nd concentrations of a commercial rare-earth product, with significantly greater precision than the conventional univariate calibration method. Determination of the Sm concentrations was not possible, since its concentration was below the concentrations used in the model definition.

Multicenter phase II trial of combination chemotherapy with weekly paclitaxel and 5-fluorouracil for the treatment of advanced or recurrent gastric carcinoma

The aim of this study was to investigate the efficacy and safety of combination chemotherapy with weekly paclitaxel and 5-fluorouracil (5-FU) as first-line treatment in patients with advanced or recurrent gastric carcinoma. A total of 65 patients were treated with the following regimen, administered every 28 days; 5-FU 600 mg/m2 by 24-hour continuous infusion from days 1 through 5, and weekly paclitaxel 80 mg/m2 by 3-hour intravenous infusion on days 8, 14, and 21. A total of 272 cycles were conducted with a median of 4 (2-13) cycles per case. Out of 57 patients with measurable disease by RECIST criteria, there were 2 complete responses (3.5%), 20 partial responses (35.1%) and 25 cases with stable disease (43.9%). The overall response rate was 38.6% (95%CI: 26.0-51.2%). The median survival time and 1-year survival rates were 329 days and 47.4%, respectively. Both hematologic and non-hematologic toxicities were well tolerated.

Expression of sapovirus virus-like particles in mammalian cells

Sapovirus (SaV) is an etiological agent of acute gastroenteritis in human and swine. SaV can be divided into five genogroups, GI to GV. Virus-like particles (VLPs) morphologically similar to native SaV have been expressed for GI, GII, GIII and GV strains in insect cells, although only low expression levels were observed for GII strains. In this study, we report the successful expression of SaV GII VLPs using cultured mammalian COS-7 and 293T cells. Our results demonstrated that this mammalian expression system was able to express and form SaV VLPs.

Species-specific expression of microsomal prostaglandin E synthase-1 and cyclooxygenases in male monkey reproductive organs

We investigated the tissue distribution and cellular localization of microsomal PGE synthase-1 (mPGES-1) and cyclooxygenase (COX)-1 and -2 in male monkey reproductive organs. Western blotting revealed that monkey mPGES-1 was expressed most intensely in the seminal vesicles, moderately in the testis, and weakly in the epididymis and vas deferens. The tissue distribution profile was quite different from those profiles for rats, rabbits, and pigs, e.g., rat mPGES-1 was the most abundant in the vas deferens, and the rabbit and pig enzymes, in the testis. Immunohistochemical staining with mouse monoclonal anti-human mPGES-1 antibody revealed that monkey mPGES-1 was localized in spermatogonia, Sertoli cells, and primary spermatocytes of testis and in epithelial cells of the epididymis, vas deferens, and seminal vesicles. In monkeys, COX-1 was localized in epithelial cells of the epididymis and vas deferens, whereas COX-2 was dominantly found in epithelial cells of the seminal vesicles.

Cross-reactivity among sapovirus recombinant capsid proteins

Sapovirus (SaV), a member of the genus Sapovirus in the family Caliciviridae, is an agent of human and porcine gastroenteritis. SaV strains are divided into five genogroups (GI-GV) based on their capsid (VP1) sequences. Human SaV strains are noncultivable, but expression of the recombinant capsid protein (rVP1) in a baculovirus expression system results in the self-assembly of virus-like particles (VLPs) that are morphologically similar to native SaV. In this study, rVP1 constructs of SaV GI, GII, and GV strains were expressed in a baculovirus expression system. The structures of the GI, GII, and GV VLPs, with diameters of 41-48 nm, were morphologically similar to those of native SaV. However a fraction of GV VLPs were smaller, with diameters of 26-31 nm and spikes on the outline. This is the first report of GII and GV VLP formation and the first identification of small VLPs. To examine the cross-reactivities among GI, GII, and GV rVP1, hyperimmune rabbit antisera were raised against Escherichia coli-expressed GI, GII, and GV N- and C-terminal VP1. Western blotting showed the GI antisera cross-reacted with GV rVP1 but not GII rVP1; GII antisera cross-reacted weakly with GI rVP1 but did not cross-react with GV rVP1; and GV antisera reacted only with GV rVP1. Also, hyperimmune rabbit and guinea pig antisera raised against purified GI VLPs were used to examine the cross-reactivities among GI, GII, and GV VLPs by an antigen enzyme-linked immunosorbent assay (ELISA). The ELISA showed that the GI VLPs were antigenically distinct from GII and GV VLPs.

[Bentall operation for a 90-year-old man with root aneurysm; report of a case]

Open heart surgery in nonagenarians is not common. We reported a successful Bentall operation in a 90-year-old man with aortic root aneurysm and aortic regurgitation. He has lived healthfully and independently without a big problem. He was referred to our hospital for acute heart failure. The aortic root enlarged as a diameter of 60 mm and moderate aortic regurgitation were recognized by echocardiography and aortogram. We excised the aneurysm, implanted a composite graft, directly attached the coronary arteries to the aortic graft (Carrel patch technique), and made the distal anastomosis to the divided aorta. Postoperative course was uneventful. To our knowledge, this is the first successful case of Bentall operation for nonagenarians in Japan. If selective criteria identifying risks and benefits for individual patients is applied, the nonagenarian can safely undergo cardiac surgery.

Domain structures of chlorophyllide a oxygenase of green plants and Prochlorothrix hollandica in relation to catalytic functions

Chlorophyll b is a photosynthetic antenna pigment found in prochlorophytes and chlorophytes. In chlorophytes, its biosynthesis regulates the photosynthetic antenna size. Chlorophyll b is synthesized from chlorophyll a in a two-step oxygenation reaction by chlorophyllide a oxygenase (CAO). In this study, we first identified the entire sequence of a prochlorophyte CAO gene from Prochlorothrix hollandica to compare it with those from chlorophytes, and we examined the catalytic activity of the gene product. Southern blot analysis showed that the CAO gene is presented in one copy in the P. hollandica genome. The P. hollandica CAO gene (PhCAO) has a coding capacity for 367 amino acids, which is much smaller than that of Arabidopsis thaliana (537 amino acids) and Oryza sativa (542 amino acids) CAO genes. In spite of the small size, PhCAO catalyzed the formation of chlorophyll b. By comparing these sequences, we classified the land-plant sequences into four parts: the N-terminal sequence predicted to be a transit peptide, the successive conserved sequence unique in land plants (A-domain, 134 amino acids), a less-conserved sequence (B-domain, 30 amino acids) and the C-terminal conserved sequence common in chlorophytes and prochlorophytes (C-domain, 337 to 344 amino acids). We demonstrated that the C-domain is sufficient for catalytic activity by transforming the cyanobacterium Synechocystis sp. PCC6803 with the C-domain from A. thaliana. In this paper, the role of the A-domain is discussed in relation to the formation of light-harvesting chlorophyll a/b-protein complexes in land plants.

Turbidity current in a circular settling tank

This paper deals with turbidity currents in a circular settling tank. A mathematical model with a k-epsilon turbulence model has been developed. Using this mathematical model, the following unique properties of turbidity currents in a circular settling tank are demonstrated: turbulence induced by the turbidity currents remains after most sediment particles have settled down. This residual turbulent diffusivity has a serious effect on the settling of finer particles. This phenomenon is a very important result in this study. Especially, in the case of a smaller densimetric Froude number, which is a stronger density effect, this residual turbulence effect increases, and also decreases the removal ratio in the downstream with low concentration. Generally, the bottom density current enhances the sediment transport near the tank bottom, while the bottom shear gives reversal influence. When the settling velocity is high, the settling ends under the developing stage both of the turbidity current and of the bottom boundary layer. On the contrary, if the settling velocity is low, the sediment travels a long distance, where the boundary layer is built up, resulting in the reduction of sediment transport near the tank bottom. The overall properties of the density-affected settling tank are also investigated in terms of the removal ratio.

Neurovirulence of Sabin 1-derived polioviruses isolated from an immunodeficient patient with prolonged viral excretion

We have analysed the neurovirulence of Sabin 1-derived isolates which persisted more than nine years in an immunodeficient patient in the U.S.A. Samples were collected from stool specimens at days 11 (St1), 23 (St2), 48 (St3), 126 (St5), and 200 (St7) after the onset of paralysis. Critical nucleotides associated with the reversion of virulence were examined. All the isolates had the substitutions at nucleotide positions 480 (G to A) in the 5'-non-coding region (NCR), 2438 (A to U) in VP3, 2795 (A to G) in VP1, and 6203 (C to U) in 3D. Serially diluted samples were injected intracerebrally to transgenic mice harbouring the human poliovirus receptor gene. Samples St2, 3, 5 and 7 showed typical virulent characters in transgenic mice, whereas the sample ST1 showed intermediate neurovirulence. It seemed that there were two variant viruses providing for a major (M) and a minor (m) populations. After disappearance of the m-variant, samples obtained at the later stages showed neurovirulence almost equivalent to that of the Mahoney strain. Thus, the Sabin 1 strain evolved towards full neuropathogenicity after long-term replication in humans by accumulating mutations. Therefore, OPV-vaccination of immunodeficient persons should be avoided.

Gelatin-specific cellular immune responses persist for more than 3 years after priming with gelatin containing DTaP vaccine

BACKGROUND

Gelatin-specific cell-mediated immunity develops in subjects inoculated with gelatin containing DTaP vaccine. However, it is not yet known whether such established sensitization to gelatin disappears or persists with time.

OBJECTIVE

The aim of this study was to follow the patients with gelatin sensitization elicited by DTaP vaccination for their lymphocyte responsiveness and IgE, IgG antibody specific to gelatin over several years and to compare the activities with those at the time of enrollment into the study.

METHODS

We studied 28 subjects who developed positive lymphocyte proliferation test (LPT) after receiving gelatin containing DTaP vaccine and eight subjects who had a negative LPT after inoculation of non-gelatin DTaP. Determination of IgE, IgG antibodies and specific lymphoproliferative response directed against gelatin were performed at enrollment and on follow up.

RESULTS

None of the subjects had antibody to gelatin at enrollment and none developed gelatin IgE or IgG during follow-up. There was no significant difference in the SIs of the subjects receiving gelatin DTaP (P = 0.150, 95% CI, -0.198-0.032), whereas lymphocyte activity to gelatin increased between enrollment and follow-up in the subjects with non-gelatin DTaP (P = 0.011, 95% CI, 0.063-0.338).

CONCLUSION

Gelatin-specific lymphocyte activity persists at comparable levels for more than 3 years in subjects who acquire a positive LPT response to gelatin after receiving primary DTaP vaccine containing gelatin. Furthermore, five out of eight subjects initially with negative LPT to gelatin have been shown to acquire specific LPT with time.

Unique alignment and texture of biological apatite crystallites in typical calcified tissues analyzed by microbeam X-ray diffractometer system

Preferential orientation of biological apatite (Ap) crystallites in typical calcified tissues of rabbit ulna, rabbit skull, and monkey dentulous mandible was investigated using a microbeam X-ray diffractometer, with a beam spot of 100 microm in diameter, to clarify relationship between the Ap orientation and mechanical function. Preferential alignment of the c-axis of the biological Ap was evaluated by the relative intensity between (002) and (310) diffraction peaks. Preferential alignment of biological Ap in each calcified tissue varied depending on the shape and stress condition in vivo; that is, the c-axes of biological Ap in the rabbit ulna and the rabbit skull bone were preferentially observed as a one-dimensional orientation along the longitudinal axis and a two-dimensional orientation along the surface, respectively. Precise analysis of the preferential alignment along the skull surface showed an elliptical distribution of the c-axis of biological Ap elongating along the suture inside the skull surface of both lamina exterior and interior. The c-axis of biological Ap in a monkey dentulous mandible basically aligned along the mesiodistal direction in the flat bone, but this alignment changed along the normal direction to the flat bone surface parallel to the biting direction near the tooth, due to the force of mastication. It was concluded that the microscale measurement of biological Ap texture is one of the useful new methods for evaluating mechanical function and stress distribution in vivo in calcified tissues.

Comparative study of incadronate and elcatonin in patients with malignancy-associated hypercalcaemia

The clinical usefulness of incadronate was compared with elcatonin in 26 patients with malignancy-associated hypercalcaemia. Data from 21 and 24 patients could be used to assess efficacy and safety, respectively. Eleven patients were given a single 10-mg intravenous infusion of incadronate and 10 received twice-daily intramuscular injections of 40 IU of elcatonin for 7 consecutive days. After treatment, corrected serum calcium levels decreased significantly in both groups. The anti-hypercalcaemic effect of elcatonin was characterized by its rapid onset, with serum calcium levels reduced 1 day after administration. In contrast, the anti-hypercalcaemic effect of incadronate was more sustained but only became apparent a few days after infusion. Evaluation of symptoms revealed significantly greater improvement rates in the incadronate group compared with the elcatonin group. Adverse drug reactions were observed in three patients in the incadronate group, i.e. mild and transient fever in two cases and exacerbation of disturbance of consciousness in one case. These findings suggest that incadronate produces more marked and sustained hypocalcaemic effects than elcatonin, and that co-administration of these two drugs may yield both rapid and sustained control of malignancy-associated hypercalcaemia.

Effect of basic fibroblast growth factor on insulin secretion from microencapsulated pancreatic islets: an in vitro study

Microencapsulation of pancreatic islets represents a potentially effective method to prevent graft rejection in allotransplantation or xenotransplantation without the need of immunosuppression. Adequate insulin secretion and glucose responsiveness of microencapsulated pancreatic islets has been regarded as a prerequisite for successful transplantation. The microencapsulated pancreatic islets were respectively cultured in bFGF+ RPMI-1640 medium (bFGF+) or bFGF- RPMI-1640 medium (bFGF-) for 21 days. The functional activities of microencapsulated pancreatic islets were assessed by measuring basal insulin secretion and stimulated insulin release at different time points. The results revealed that microencapsulated pancreatic islets in the presence of bFGF demonstrated an increase in basal insulin secretion. Furthermore, microencapsulated pancreatic islets in the presence of bFGF demonstrated a marked stimulated insulin release and relative stability of stimulation indices (SI). The results in the perifusion study showed that microencapsulated pancreatic islets in the presence of bFGF maintained good glucose responsiveness over the course of culture period as well. These results indicate that bFGF has a beneficial effect on insulin secretion from microencapsulated pancreatic islets during in vitro culture. New strategies for preserving and improving function of microencapsulated pancreatic islets prior to transplantation may be developed by application of growth factors or other factors.