Roles of the PARP Inhibitor in BRCA1 and BRCA2 Pathogenic Mutated Metastatic Prostate Cancer: Direct Functions and Modification of the Tumor Microenvironment

Cancer cells frequently exhibit defects in DNA damage repair (DDR), leading to genomic instability. Mutations in DDR genes or epigenetic alterations leading to the downregulation of DDR genes can result in increased dependency on other DDR pathways. Therefore, DDR pathways could be a treatment target for various cancers. In fact, polyadenosine diphosphatase ribose polymerase (PARP) inhibitors, such as olaparib (Lynparza^®), have shown remarkable therapeutic efficacy against BRCA1/2-mutant cancers through synthetic lethality. Recent genomic analytical advancements have revealed that BRCA1/BRCA2 pathogenic variants are the most frequent mutations among DDR genes in prostate cancer. Currently, the PROfound randomized controlled trial is investigating the efficacy of a PARP inhibitor, olaparib (Lynparza^®), in patients with metastatic castration-resistant prostate cancer (mCRPC). The efficacy of the drug is promising, especially in patients with BRCA1/BRCA2 pathogenic variants, even if they are in the advanced stage of the disease. However, olaparib (Lynparza^®) is not effective in all BRCA1/2 mutant prostate cancer patients and inactivation of DDR genes elicits genomic instability, leading to alterations in multiple genes, which eventually leads to drug resistance. In this review, we summarize PARP inhibitors' basic and clinical mechanisms of action against prostate cancer cells and discuss their effects on the tumor microenvironment.

Prostate fibroblasts enhance androgen receptor splice variant 7 expression in prostate cancer cells

BACKGROUND

Androgen receptor splice variant (AR-V) expression has been associated with prostate cancer (PCa) progression to castration-resistant PCa during androgen deprivation therapy, which reduces androgen production and inhibits androgen action in PCa cells. However, the mechanisms whereby aberrant AR-V expression is increased in PCa are still largely unknown. Fibroblasts in tumor stroma influence PCa initiation and aggressiveness, and which may play a crucial role in eliciting genetic changes during malignant transformation in human prostate epithelium. Here, our aim was to determine whether prostate fibroblasts in tumor stroma induce aberrant AR-V7 expression in PCa cells under low androgen concentration.

METHODS

We performed in vitro experiments using androgen-sensitive, AR-positive PCa cell lines (LNCaP and 22Rv1 cells), commercially available prostate stromal cells (PrSC), and primary cultured prostate fibroblasts (pcPrF) from PCa specimens collected from biopsies of patients with advanced PCa. PCa cells were cocultured with each of the three fibroblast lines (PrSC, pcPrF-M37, and pcPrF-M48).

RESULTS

The proliferation under low androgen concentration of LNCaP and 22Rv1 cells cocultured with PrSC, pcPrF-M37, or pcPrF-M48 was significantly increased compared to that of PCa cells cultured alone. Androgen receptor-full length (AR-FL) protein expression was increased in LNCaP and 22Rv1 cells cocultured with PrSC, pcPrF-M37, or pcPrF-M48. AR-V7 protein expression was increased in 22Rv1 cells cocultured with PrSC, pcPrF-M37, or pcPrF-M48. Under low androgen concentration, AR-V7 protein expression was slightly detected in LNCaP cells cocultured with PrSC or pcPrF-M37. Cytokine array analysis revealed that monocyte chemotactic protein-1 (MCP-1) and interleukin-8 (IL-8) levels in the conditioned medium of 22Rv1 cells cocultured with PrSC, pcPrF-M37, or pcPrF-M48 were increased under low androgen concentration. High IL-8 concentration (30 ng/ml) resulted in significantly increased protein expression of AR-FL, AR-V7, and phospho-NF-κB p65 in 22Rv1 cells. In contrast, IL-8 antibody (1 µg/ml) decreased AR-V7 protein expression in 22Rv1 cells cocultured with PrSC, pcPrF-M37, or pcPrF-M48.

CONCLUSIONS

pcPrF from PCa specimens increase the expression of aberrant AR-V7 in PCa cells. IL-8 may be a target for preventing the expression of aberrant AR-Vs in PCa.

Succinate dehydrogenase B-deficient renal cell carcinoma with a germline variant in a Japanese patient: a case report

Succinate dehydrogenase (SDH)-deficient renal cell carcinoma (RCC) is a rare renal cancer. A 75-year-old Japanese female presented with gross hematuria. Computed tomography revealed two tumors in the left kidney, which were resected. Immunohistochemistry indicated negative staining for the B subunit of SDH (SDHB) in the resected specimen, leading to a final diagnosis of SDHB-deficient RCC. Genetic testing for SDHB showed a RCC germline variant in exon 6 (NM_003000.3:c.642 G > C) that was previously reported but associated with a novel phenotype (i.e., RCC). Twenty-six years prior, her daughter, who was 25 years old at the time, had undergone radical nephrectomy for a pathologic diagnosis of renal oncocytoma of the right kidney; SDHB immunostaining of her daughter's tumor was also negative retrospectively. We confirmed that her daughter carried the germline variant in SDHB exon 6, similar to the patient. The patient had no evidence of disease progression at 15 months after surgery.

The GP Score, a Simplified Formula (Bioptic Gleason Score Times Prostate Specific Antigen) as a Predictor for Biochemical Failure after Prostatectomy in Prostate Cancer

Objectives

We used a new GP score (Gleason score multiplied by prostate-specific antigen) without the T stage as a predictive value for biochemical failure (BCF) after prostatectomy.

Materials and Methods

We assessed 459 prostate cancer patients who underwent prostatectomies at our institution. Three sub-groups were defined in terms of D'Amico classification risk (low, intermediate, and high) and Gleason score (low, < 50; intermediate, 50-100; and high GP score, > 100). Risk factors for BCF were evaluated by multivariate analysis with a Cox hazard model. A log-rank test was used to compare the BCF rate in the 2 groups.

Results

There was nosignificant difference in the non-BCF rate between the lowrisk and low GP score subgroups or the intermediate risk andintermediate GP score subgroups. In contrast, the non-BCFrate of the high GP score subgroup (42.1%) was significantlylower than that of the high-risk subgroup (66.1%, log-rankp = 0.008). Based on multivariate analysis, a high GP score(p = 0.001; HR 3.78; 95%CI 1.95-7.35) was a significant independent risk factor for BCF after prostatectomy.

Conclusion

The GP score, consisting of two absolute numbers, may be a valuable predictive factor for BCF after prostatectomy, especially in the high-risk failure group.

Bending properties of stainless steel dynamic compression plates and limited contact dynamic compression plates

The equivalent bending stiffness and bending strength of the stainless steel DCP and stainless steel LC-DCP were compared. Three plates, of each size, were tested destructively in ‘four point bending’. All of the LC-DCP were significantly less stiff and less strong than the comparable size DCP, with the exception of the 4.5 mm narrow LC-DCP which was significantly stronger and more stiff than the 4.5 mm narrow DCP (p <.01). The design advantages of the LC-DCP are ease and versatility of plate application and improved cortical blood flow which one assumes promotes fracture healing. Also, the lower recorded stiffness of the LC-DCP may be advantageous in that it decreases the stress protection of the plated bone. Since optimal strength and stiffness of bone plates are currently unknown, the clinical relevance of the decreased strength and stiffness of the LC-DCP has yet to be determined.

Stainless steel LC-DCP and DCP of various sizes were tested in four point bending to ascertain equivalent bending stiffness and bending strength of each type of plate. The LC-DCP were consistently less stiff and strong than their DCP counterparts (p <.01) with the exception of the 4.5 mm Narrow LC-DCP which was stronger and more stiff than the 4.5 mm Narrow DCP. In general, as plate size increased. the difference between the two plate designs decreased. If it can be shown that there is not any detrimental effect on fracture healing, the design features of the LC-DCP make it a desirable choice for most fracture applications.

Very high-risk prostate cancer: stratification by outcomes of radiotherapy and long-term androgen deprivation therapy

AIM

The definition of very high-risk (VHR) prostate cancer is currently based on the study of radical prostatectomy. We aimed to identify a suitable definition for VHR group following external beam radiation therapy (EBRT) and long-term androgen-deprivation therapy (ADT).

METHODS

This retrospective study included 356 high-risk patients treated with EBRT and long-term ADT. A median follow-up time was 68 months. At first, associations of previously described prognostic factors with biochemical disease-free survival (bDFS), clinical relapse-free survival (cRFS) and prostate cancer-specific survival (CSS) were examined. Second, the combination of significant adverse factors in the first analysis served as VHR test definitions. For each factor, a Cox proportional hazards model was used to calculate their hazard ratios for bDFS and cRFS. The logrank test was used to evaluate the association between each factor and CSS.

RESULTS

Primary Gleason pattern 5, T4 and ≥ 5 or 4 cores with Gleason score 8-10 were risk factors associated with bDFS, cRFS and CSS. Eleven VHR test definitions composed of these adverse factors were associated significantly with bDFS, cRFS and CSS. The final definition was described by primary Gleason pattern 5 or T4 or ≥ 4 cores with Gleason score 8-10 because of the largest sample size of 38% among 11 test definitions. bDFS, cRFS and CSS of the VHR group were significantly lower compared with other high-risk patients (P < 0.001, P < 0.001 and P = 0.015, respectively).

CONCLUSION

These VHR criteria were best fitted following EBRT with long-term ADT.

The relationship between lip-closing force and dental arch morphology in patient with Angle Class I malocclusion

Dental arch morphology and tooth position are affected by lip-closing force (LCF). This study aimed to quantitatively evaluate the relationships between the horizontal or vertical balance of the LCF generated during maximum voluntary pursing-like movements and dental arch length (DAL) or width (DAW) or the lingual inclination of the upper or lower 1st molars (LIUM, LILM) in patients with Angle Class I malocclusion. Sixteen subjects with Angle Class I malocclusion (median age: 23·4 ± 5·9 years) who had never undergone orthodontic treatment were randomly selected. LCF was measured in eight directions during maximum voluntary pursing-like lip-closing movements. Dental arch models were scanned and analysed to obtain DAW, DAL, LIUM and LILM measurements. Mandibular deviation was measured on posteroanterior cephalograms. A significant negative correlation was detected between maxillary DAL and upper LCF. Maxillary DAL, DAW and the DAL/DAW ratio displayed significant negative correlations with total LCF and upper LCF. However, no significant correlations were detected between any mandibular dental arch morphological parameter and LCF. The difference in the LIUM between the deviation and non-deviation sides exhibited a significant positive correlation with the difference in upper LCF between the deviation and non-deviation sides and was significantly negatively correlated with the difference in lower LCF between the deviation and non-deviation sides. These results suggest that upper LCF is related to maxillary DAL, and the horizontal balance of the LCF of the upper and lower lips is related to the LIUM during pursing-like lip-closing movements in patients with Angle Class I malocclusion.

Clinical Effect of Switching from a Luteinizing Hormone-Releasing Hormone Agonist to an Antagonist in Patients with Castration-Resistant Prostate Cancer and Serum Testosterone Level ≥ 20 ng/dl

INTRODUCTION

The efficacy of conversion from a luteinizing hormone-releasing hormone agonist to an antagonist was evaluated prospectively in patients with castration-resistant prostate cancer.

MATERIALS AND METHODS

From October 2012 to December 2014, 8 cases with a serum testosterone level ≥ 20 ng/dl during following androgen deprivation therapy were enrolled and received degarelix monthly. The primary end-pointgoal was to determine the effective prostate-specific antigen response rate. The secondary end-pointgoal was to assess the proportion of cases with a decrease in serum testosterone level to < 20 ng/ml.

RESULTS

One patient achieved a complete response, with a prostate-specific antigen level of 0.02 ng/ml at the nadirend of the study. The effective response rate was 25.0% (2/8), and the proportion of cases with prostate-specific antigen decline was 62.5% (5/8). In 5/8 cases (5/8, 62.5%), serum testosterone levels declined to < 20 ng/dl.

CONCLUSION

Switching to a luteinizing hormone-releasing hormone antagonist in patients with testosterone levels ≥ 20 ng/dl may be an option in sequential androgen deprivation therapy for some patients.

Note: Application of CR-39 plastic nuclear track detectors for quality assurance of mixed oxide fuel pellets

A CR-39 plastic nuclear track detector was used for quality assurance of mixed oxide fuel pellets for next-generation nuclear power plants. Plutonium (Pu) spot sizes and concentrations in the pellets are significant parameters for safe use in the plants. We developed an automatic Pu detection system based on dense α-radiation tracks in the CR-39 detectors. This system would greatly improve image processing time and measurement accuracy, and will be a powerful tool for rapid pellet quality assurance screening.

Operational test of micro-oven for 48Ca beam

In order to supply a high-intensity and stable (48)Ca beam from the RIKEN 18-GHz electron cyclotron resonance ion source, we are conducting operational tests of a micro-oven. A mixture of CaO and Al powders is placed into the crucible of the micro-oven and heated to produce metallic calcium by a reductive reaction. The successful production of a calcium beam was confirmed. In addition, we reduced the material consumption rate by using a so-called "hot liner," and we enhanced the beam intensity by applying a negative voltage bias to the micro-oven, the effect of which is similar to the effect of a "biased disk."

Genetic analysis of novel avian A(H7N9) influenza viruses isolated from patients in China, February to April 2013

Novel influenza viruses of the H7N9 subtype have infected 33 and killed nine people in China as of 10 April 2013. Their haemagglutinin (HA) and neuraminidase genes probably originated from Eurasian avian influenza viruses; the remaining genes are closely related to avian H9N2 influenza viruses. Several characteristic amino acid changes in HA and the PB2 RNA polymerase subunit probably facilitate binding to human-type receptors and efficient replication in mammals, respectively, highlighting the pandemic potential of the novel viruses.

Genetic analysis of novel avian A(H7N9) influenza viruses isolated from patients in China, February to April 2013

Novel influenza viruses of the H7N9 subtype have infected 33 and killed nine people in China as of 10 April 2013. Their haemagglutinin (HA) and neuraminidase genes probably originated from Eurasian avian influenza viruses; the remaining genes are closely related to avian H9N2 influenza viruses. Several characteristic amino acid changes in HA and the PB2 RNA polymerase subunit probably facilitate binding to human-type receptors and efficient replication in mammals, respectively, highlighting the pandemic potential of the novel viruses.

Development-dependent expression of calreticulin in the brain and other tissues of the Japanese monkey, Macaca fuscata

BACKGROUND

Calreticulin (CRT) is a molecular chaperone localized to endoplasmic reticulum lumen. The protein is involved in the correct folding of glycoproteins and its cellular level changes depending on various physiologic conditions.

METHODS

To clarify the Crt level in various tissues of the Japanese monkey during postnatal development, an enzyme-linked immunosorbent assay system that we have established was applied.

RESULTS AND CONCLUSIONS

Calreticulin is distributed ubiquitously in various tissues. Its level in the heart, lung, liver, spleen, and kidney was high in newborns and decreased in juveniles and adults. In various cerebral areas, Crt was present in the gray matter but scarcely found in the white matter. The Crt levels in the cerebral areas were low in newborns and increased in juveniles and adults. These distribution and developmental changes in Crt might be correlated with the quality control of glycoproteins that are synthesized in respective tissues.

Molecular cloning and gene expression of endoplasmic reticulum stress proteins in Japanese monkey, Macaca fuscata

BACKGROUND

Immunoglobulin heavy-chain binding protein (BiP), calreticulin (Crt), and protein disulfide isomerase (PDI), are major resident endoplasmic reticulum (ER) stress proteins which are involved in diverse roles relating to successful folding, assembly, intracellular localization, and degradation of other proteins.

METHODS

In this study, we molecular cloned cDNAs for BiP, Crt, and PDI from Japanese monkey (Macaca fuscata), and analyzed tissue-specific expression of respective genes.

RESULTS AND CONCLUSIONS

The lengths of protein-coding regions of these cDNAs for BiP, Crt and PDI are 1965, 1254, and 1533 bp, respectively. Each protein has a signal peptide and a KDEL motif in N- and C-terminal parts respectively, showing its intracellular localization to be the lumen of the ER. These stress proteins are highly conserved, showing that their similarities among mammals are more than 90% in the level of amino acid. The expression of the genes for stress proteins differed among the monkey tissues examined. BiP and PDI gene expression was predominant in secretory tissues such as liver and kidney, and brain tissues. But Crt gene expressed rather ubiquitously in a variety of tissues.

Effect of vascularity on canine distracted tibial callus consolidation

In the consolidation period of distraction osteogenesis, mineralization occurs before corticalization. We hypothesized that the increased rate of bone mineral density correlates to the density of vascularity in the callus. We unilaterally lengthened the tibia in eight adult beagles. After a waiting period of 7 days, tibiae were lengthened for 30 days. After a consolidation period of an additional 60 days, all animals were euthanized. Just before euthanasia, blood vessels were perfused with 50% w/v barium sulfate solution, and soft radiographs of the distracted callus and the control tibiae were taken. Bone mineral density of the regenerated bones was measured preoperatively by quantitative computed tomography on Days 37, 68, and 98. Increases of the percent bone mineral density (from Day 37 to Day 98 and from Day 68 to Day 98) correlated with the blood vessel volume density ratios on Day 98. Our results suggest that preservation of the higher density of blood vessels in the consolidation period could lead to the better mineralization of the distracted callus.

Cleavage activity of the sapovirus 3C-like protease in Escherichia coli

We recently determined the ORF1 cleavage map of Mc10, a human sapovirus (SaV) strain, as follows: NH2-p11-p28-p35(NTPase)-p32-p14(VPg)-p70(Pro-Pol)-p60(VP1)-COOH. This cleavage was dependent on the viral encoded 3C-like protease. To identify the cleavage site of SaV ORF1, putative p70 (Pro-Pol) and p14-p70 (VPg-Pro-Pol) were expressed as N-terminal GST and C-terminal 6 x His-tag fusion proteins in Escherichia coli, and the expressed products were analyzed by SDS-PAGE and Western blotting. Our results indicated that the efficient proteolytic cleavage occurred between p14 (VPg) and p70 (Pro-Pol), and N-terminal amino acid sequencing revealed that the cleavage site was between E(1055) and A(1056). In contrast, the p70 (Pro-Pol) was not further cleaved. We also found that SaV protease cleaved the Q/G site within the rhinovirus 3C protease recognition site. Site-directed mutagenesis in a conserved GDCG motif of the protease completely abolished these proteolytic activities. This is the first report to identify the cleavage site of the SaV ORF1 polyprotein.

Visual results and complications of temporal incision phacoemulsification performed with the non-dominant left hand by junior ophthalmologists

AIMS

To assess the results of temporal incision phacoemulsification and aspiration performed with dominant and non-dominant hand of ophthalmology trainees.

METHODS

Retrospective analysis were made of 203 surgeries with dominant hand and 207 with non-dominant by five trainees at two institutions. Trainees sat at the patient's head, manipulating instruments with the dominant right hand for the right eye, and the non-dominant left hand for the left eye.

RESULTS

Vitreous loss occurred in 12 (5.9%) of 203 dominant operated eyes and seven (3.4%) of 207 non-dominant operated eyes. The rate of endothelial cell loss was 6.1% (9.8%) in dominant and 7.4% (12.4%) in non-dominant. Mean ultrasound time were 1.81 (0.70) minutes in dominant and 1.78 (0.78) minutes in non-dominant. One trainee showed statistically significant excesses in incidence of vitreous loss in dominant operated eyes (8.7%, p=0.0270), and one showed statistically significant prolongation of the operation in nondominant operated eyes (26.3 minutes, p=0.0315). In all other trainees, all parameters had no difference in both sides.

CONCLUSIONS

Ophthalmology trainees could successfully learn the technique with both hands. The authors consider that the skill of the non-dominant hand may be knowledge based and that surgeons avoid mistakes by mental efforts.

Yersinia pseudotuberculosis infection in breeding monkeys: detection and analysis of strain diversity by PCR

In the last three decades, several monkeys reared in outdoor/indoor-outdoor breeding colonies and cages of the Primate Research Institute, Kyoto University, died of yersiniosis caused by Yersinia pseudotuberculosis, necessitating introduction of a method to detect the bacteria rapidly and thus allow preventive measures to be undertaken. A rapid nested polymerase chain reaction (PCR) method for identification of Y. pseudotuberculosis in fecal samples and a random amplified polymorphic DNA (RAPD)-PCR approach for distinguishing between bacterial strains were therefore developed. Yersinia pseudotuberculosis isolates from monkey specimens were found to be classifiable into several types. To determine the source of infection, hundreds of fecal samples of wild rats, pigeons, and sparrows were collected from around the breeding colonies and cages, and subjected to PCR analyses. Yersinia pseudotuberculosis was detected in 1.7% of the fecal samples of wild rats. The DNA fingerprints of the bacteria revealed by RAPD-PCR were the same as that of one strain isolated from macaques, suggesting the wild rat to be a possible source of infection.

Novel mutations in the a3 subunit of vacuolar H(+)-adenosine triphosphatase in a Japanese patient with infantile malignant osteopetrosis

A case of infantile malignant osteopetrosis is described. The patient died from respiratory hemorrhage at 7 months of age despite treatment that included high doses of active vitamin D and administration of interferon-gamma. A postmortem examination revealed the presence of many osteoclasts in the bone, which lacked ruffled borders. This observation was consistent with the histology of bone reported in Atp6i-knockout mice, which lack the gene encoding the a3 subunit of vacuolar-type H(+)-adenosine triphosphatase (ATPase). Sequence analysis of the TCIRG1 gene encoding the a3 subunit revealed two novel mutations: a deletion/insertion mutation in exon 9 and a T-to-C transition at the splice donor site of intron 19. The former mutation caused a frame shift and premature stop codon. The latter was associated with abnormal splicing, which was confirmed by sequencing the products amplified by reverse transcription-polymerase chain reaction (RT-PCR), using total RNA from the liver specimen as template. Although several mutations in the TCIRG1 gene in infantile malignant osteopetrosis have been reported in other populations, this is the first case of a Japanese patient with a mutation identified in this gene. These results support the important role of the subunit in the function of the proton pump.

Pepsinogens, progastricsins, and prochymosins: structure, function, evolution, and development

Five types of zymogens of pepsins, gastric digestive proteinases, are known: pepsinogens A, B, and F, progastricsin, and prochymosin. The amino acid and/or nucleotide sequences of more than 50 pepsinogens other than pepsinogen B have been determined to date. Phylogenetic analyses based on these sequences indicate that progastricsin diverged first followed by prochymosin, and that pepsinogens A and F are most closely related. Tertiary structures, clarified by X-ray crystallography, are commonly bilobal with a large active-site cleft between the lobes. Two aspartates in the center of the cleft, Asp32 and Asp215, function as catalytic residues, and thus pepsinogens are classified as aspartic proteinases. Conversion of pepsinogens to pepsins proceeds autocatalytically at acidic pH by two different pathways, a one-step pathway to release the intact activation segment directly, and a stepwise pathway through a pseudo-pepsin(s). The active-site cleft is large enough to accommodate at least seven residues of a substrate, thus forming S4 through S'3 subsites. Hydrophobic and aromatic amino acids are preferred at the P1 and P'1 positions. Interactions at additional subsites are important in some cases, for example with cleavage of kappa-casein by chymosin. Two potent naturally occurring inhibitors are known: pepstatin, a pentapeptide from Streptomyces, and a unique proteinous inhibitor from Ascaris. Pepsinogen genes comprise nine exons and may be multiple, especially for pepsinogen A. The latter and progastricsin predominate in adult animals, while pepsinogen F and prochymosin are the main forms in the fetus/infant. The switching of gene expression from fetal/infant to adult-type pepsinogens during postnatal development is noteworthy, being regulated by several factors, including steroid hormones.

Cross-sectional survey on risk factors for insomnia in Japanese female hospital nurses working rapidly rotating shift systems

A cross-sectional survey was carried out for the purpose of examining the association of work stress with insomnia among nurses working rotating shift systems. A self-administered questionnaire on sleep and mental health was distributed to 875 nurses at five hospitals in Japan. Out of the data from 785 (89.7%) respondents, those from 555 women engaged in rapidly and irregularly rotating shift systems as full-time nurses were examined. The prevalence of insomnia (29.2%) was three to four times higher than that in the general population. Among the insomniacs, 23% were current users of medically prescribed hypnotics. Multiple logistic analysis revealed that being 24 or less years old, working three or less night shifts per month, having six or less non-working days per month, receiving less support from colleagues and superiors, and taking care of severely ill patients were independent risk factors for insomnia. The number of hours of a night shift was found not associated with insomnia, taking the above variables into account. These results suggest that at least three factors, i.e., 1) young nurses not adapted to shiftwork, 2) the nurses requiring to remedy sleep deficits on non-working days, and 3) the work stress partly characteristic of nurses, have an adverse influence on their sleep.

Evaluation of immunoglobulin G and its subclasses in aplastic anemia

We selected 31 patients with aplastic anemia to measure their total immunoglobulin (Ig) G and IgG subclasses and compared the results obtained with those obtained in the normal control group (n=461). Patients with aplastic anemia were classified into three subgroups according to severity: mild subgroup (n=14), moderate subgroup (n=12) and severe subgroup (n=5). The decrease in total IgG was recognized in all these three subgroups (p<0.001). Although IgG1 decreased in severe subgroup (p<0.01), it showed no significant difference in mild and moderate subgroups. The decrease in IgG2 and IgG3 was observed in all these three subgroups (p<0.001 and p<0.01, respectively). Although IgG4 decreased in mild subgroup (p<0.05), it showed no significant difference in moderate and severe subgroups. We speculated that the measurement of IgG subclasses was useful in understanding the pathophysiology of humoral immunity in aplastic anemia.

Mental health of scientific researchers. I. Characteristics of job stress among scientific researchers working at a research park in Japan

In order to clarify the characteristics of job stress in scientific researchers, a self-administered questionnaire survey for 16,330 workers was carried out at Tsukuba Research Park City, Japan. The data of 7,063 (43%) workers aged 20-59 years old were analyzed, and the characteristics of job stress in 3,290 scientific researchers were compared with those of 1,799 technicians and 1,849 clerks. The researchers perceived higher quantitative and qualitative workload, greater job control (job decision latitude), and greater reward from work, than did the other two job groups. In addition, young male researchers received a large amount of support from their coworkers, while middle-aged male researchers perceived difficulty in personal relationships with their coworkers. From the viewpoints of the demand-control-support model and the effort-reward imbalance model, the researchers, particularly men, were typically occupied in active jobs, and the large amount of effort required for their work seemed to be balanced by greater reward from work. Compared with male researchers, however, female researchers perceived lesser job demand, lesser job control, and lesser reward from work. The working environment of female researchers may be related to the so-called career stress of working women. The mental health status of these scientific researchers should be examined directly in a future study.

Autopsy case of lymphoplasmacytic lymphoma with a large submucosal tumor in the stomach

An autopsy case of lymphoplasmacytic lymphoma with a large submucosal tumor in the stomach is presented. The patient was a 77-year-old woman with gastric lymphoma associated with Waldenstrom's macroglobulinemia of IgM-lambda type. Diagnosis was initially mucosa-associated lymphoid tissue (MALT) lymphoma of the stomach, because gastric biopsy specimens showed epitheliotropic proliferation (lymphoepithelial lesion) of the lymphoma cells. Postmortem examination revealed a large gastric lymphoma with metastatic foci in the esophagus, larynx, trachea, lungs, spleen and lymph nodes. The bone marrow was also involved. Lymphoma cells consisted of small lymphocytoid cells occasionally admixed with blast-like large cells and a large number of plasmacytoid or plasma cells. Centrocyte-like cells were not found. Lymphoepithelial lesions were not conspicuous in autopsy specimens. Immunohistochemically, lymphoma cells reacted with CD20, CD45, CD79a, anti-IgM, anti-lambda protein and anti-BCL-2, but not with CD5, CD10, CD23 or CD38. Based on these findings, the revised diagnosis of the present case was lymphoplasmacytic lymphoma, and it highlighted the differential diagnostic problem from marginal zone B-cell lymphoma of MALT type.

Phylogenetic position of Eulipotyphla inferred from the cDNA sequences of pepsinogens A and C

Although to date the phylogenetic position of the provisional order Eulipotyphla has been assessed by various molecular markers, it has not been conclusively clarified due to low statistical supporting values and inconsistent results. To clarify the phylogenetic position of Eulipotyphla, we cloned cDNAs for pepsinogens A and C from five mammalian species belonging to four different orders and determined their nucleotide sequences. Molecular phylogenetic analysis based on the 1st and 2nd codon positions of the protein-coding region of cDNA sequences strongly supported the close relationship between Eulipotyphla and Chiroptera. Carnivora was found to be a sister group to these two orders. The monophyly of the order Rodentia and that of the cohort Glires (Rodentia and Lagomorpha) was also shown by the present phylogenetic trees of pepsinogens.

Results of vitrectomy performed at the time of phacoemulsification complicated by intravitreal lens fragments

AIM

To evaluate outcome of vitrectomy performed at the time of phacoemulsification complicated by intravitreal lens material.

METHODS

Clinical records associated with consecutive 8536 phacoemulsification procedures were reviewed retrospectively.

RESULTS

17 (0.20%) eyes had a posterior capsule rupture with retained lens material in the vitreous cavity that required vitrectomy. Final visual acuity was 0.5 or better in 14 eyes (82%) and 0.4 to 0.1 in three eyes (18%). Retinal detachment occurred in one eye during vitrectomy and two after the surgery. Cystoid macular oedema was observed in two eyes and none developed glaucoma. The corneal endothelial cell loss was 5.7% (SD 6.8 %) (n=15) at 3-6 months postoperatively.

CONCLUSIONS

Combined vitrectomy and intraocular lens implantation at the time of phacoemulsification complicated by intravitreal lens material is an option to be considered to reduce the risk of postoperative complications including secondary glaucoma and corneal endothelial cell damage.

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.

Down-regulation of translation driven by hepatitis C virus internal ribosomal entry site by the 3' untranslated region of RNA

The genome of hepatitis C virus (HCV) is a single-stranded RNA of positive polarity that has a poly(U/C) tract followed by a highly conserved 98-nt sequence, termed the X region, in the 3' untranslated region (UTR). To investigate the effect of the 3'UTR on the HCV translation that depends on the internal ribosomal entry site (IRES), we prepared a deletion HCV RNA, MA delta, that lacked the RNA region from nt 1286 to 8785. A series of MA delta RNAs that differ in the primary structure of their 3'UTR, were generated and examined for their translation efficiencies in reticulocyte lysates. Deletion of the poly(U/C) tract and/or stem-loop structure (SL) 3 region of 3'X resulted in enhancement of the translation efficiency. Translation of MA delta RNA was inhibited by the addition of recombinant polypyrimidine tract-binding protein (PTB). A similar inhibition by PTB, however, was observed when an RNA lacking the poly(U/C) tract or SL3 region was used. The inhibitory effect by PTB was not obvious for MA delta (1041) RNA composed of nt 1 to 1041 but MA delta (8928) RNA composed of nt 1 to 1285 and nt 8786 to 8928. These results suggest that the observed down-regulation of HCV translation by the 3'UTR is mediated by some host factor(s) other than PTB, and that a PTB site for inhibition resides in the coding sequence of nt 1042 to 8928 of MA delta RNA.

Ribosomal protein S5 interacts with the internal ribosomal entry site of hepatitis C virus

Translational initiation of hepatitis C virus (HCV) genome RNA occurs via its highly structured 5' noncoding region called the internal ribosome entry site (IRES). Recent studies indicate that HCV IRES and 40 S ribosomal subunit form a stable binary complex that is believed to be important for the subsequent assembly of the 48 S initiation complex. Ribosomal protein (rp) S9 has been suggested as the prime candidate protein for binding of the HCV IRES to the 40 S subunit. RpS9 has a molecular mass of approximately 25 kDa in UV cross-linking experiments. In the present study, we examined the approximately 25-kDa proteins of the 40 S ribosome that form complexes with the HCV IRES upon UV cross-linking. Immunoprecipitation with specific antibodies against two 25-kDa 40 S proteins, rpS5 and rpS9, clearly identified rpS5 as the protein bound to the IRES. Thus, our results support rpS5 as the critical element in positioning the HCV RNA on the 40 S ribosomal subunit during translation initiation.

Estimated sleep debt and work stress in Japanese white-collar workers

Sleep debt on weekdays in Japanese white-collar workers, estimated using a questionnaire, was associated with age, overtime, and self-rated workload.

[Inhibition of HCFU absorption after resection for gastric cancer--application of hydroxyaluminium gel]

HCFU (carmofur; Mifurol) is an 5-FU analog. The maximum blood concentration of HCFU in HCFU fraction (Cmax) after gastric resection was higher than before resection. Hot sensation and pollakiuria, characteristic side effects of HCFU, are dependent on concentration of HCFU fraction in blood. Therefore, it is considered that the frequency of occurrence of side effects after gastric resection is high. For that reason, we thought that if absorption of HCFU could be reduced, fewer side effects would result. We focused on the fact that drugs which include aluminium gel may decrease absorption in combined drugs, and thought it would be possible to delay absorption in HCFU by using them. We studied the HCFU concentration in the HCFU fraction and 5-FU concentration in blood, respectively, in two cases: 1) single oral administration of HCFU 100 mg and 2) coadministration with hydroxyaluminium gel (ALG) 10 ml in the whole or partial resection of gastric cancers for 8 patients. We found that the concentration of HCFU in the HCFU fraction 2 hours after its administration decreased significantly: 3.24 +/- 1.78 (single administration), 1.37 +/- 0.91 (coadministration with ALG) (p = 0.023). HCFU concentration in the HCFU fraction seemed to decrease for coadministration with ALG in the area under the time-blood concentration curve (AUG) (p = 0.071). The 5-FU concentration did not seem to decrease in either case. From these results, the coadministration of HCFU with ALG seems to be effective for the inhibition of adverse drug reaction after the resection of gastric cancers.

Sympathetic predominance in young male white-collar workers with mild to moderate hypertension

In order to investigate the difference in diurnal variation of autonomic control between young male mild to moderate hypertensive and normotensive white-collar workers, we accessed heart rate variability with ambulatory blood pressure for over 24 hours including work and sleep periods. Both mean systolic and diastolic blood pressures (SBP and DBP) were significantly (p<0.01) higher in hypertensives (HT, n=11) than normotensives (NT, n=11) in all phases, whereas heart rate was not different between them in any phase. Blood pressures during work period (on-duty) were significantly higher than those during non-work period (off-duty) in both NT and HT. High frequency (HF; 0.15-0.40 Hz) power showed a circadian pattern in phase with the sleep-wake cycle. Both HF and low frequency (LF; 0.05-0.15 Hz) powers in HT were significantly lower than that in NT during the sleep period (p<0.05). LF/HF ratio showed a circadian pattern that was almost opposite of the pattern in HF power. Twenty-four-hour average LF/HF in HT was higher than that in NT (p<0.05). Especially during on-duty, LF/HF in HT was significantly higher than in NT (p<0.05). The increase of SBP and LF/HF from off-duty period to on-duty period (deltaSBP and deltaLF/HF) showed significant positive correlation (r=0.67, P<0.05) in HT group, suggesting that the SBP elevation during on-duty in HT may be coupled with sympathetic activation. These results suggest that HT showed significantly reduced parasympathetic control during sleep and an increased sympathetic activity especially during on-duty as compared with NT. Our findings imply that persistence of sympathodominant states together with reduced vagal activity in young mild to moderate hypertensive workers may be related to future cardiovascular disorders.

Histopathology of viremia-associated ana-aki-byo in combination with Aeromonas hydrophila in color carp Cyprinus carpio in Japan

A disease in which 'viremia-associated ana-aki-byo' is combined with an Aeromonas hydrophila infection currently occurs and is highly transmissible in color carp Cyprinus carpio in Japan. In the present study, to determine the interrelation between a corona-like virus and A. hydrophila, we conducted transmission trials by cohabiting naturally diseased carp with healthy carp with skin that had been slightly damaged artificially. Experimentally exposed fish successfully replicated the combination of a corona-like viral viremia and A. hydrophila infection. Diseased carp displayed scale-sac edema, ascites and exophthalmus adding to the formation of skin ulcers. In addition to pathological changes due to the corona-like virus infection, various changes due to the A. hydrophila infection occurred. Anasarcous skin lesions exhibited a separated epidermis, expanded scale-sacs, and an edematous dermis accompanied by hemorrhage and necrosis. The underlying lateral musculature was edematous and possessed markedly atrophied muscle fibers. Hepatocytes were either atrophied or swollen and had a granular appearance. Renal tubular cells showed vacuolar degeneration, cloudy swelling, necrosis and destruction. Hemosiderin deposition occurred within macrophages in the spleen and hematopoietic tissue, and within hepatocytes. Cardiac muscle fibers exhibited degeneration and necrosis accompanied by hemorrhage in the myocardium of heart. These changes appeared to be induced by bacterial toxins because bacterial cells did not directly invade these affected tissues.

Interaction of poly(rC)-binding protein 2 with the 5'-terminal stem loop of the hepatitis C-virus genome

The 5' noncoding region (NCR) of hepatitis C virus (HCV) contains an internal ribosome entry site for translation initiation. Cellular proteins (e.g. La, polypyrimidine tract-binding protein, and p25) that interact with HCV 5' NCR have been implicated in facilitating efficient internal initiation. The 5' NCR may also contain RNA structures and specific RNA sequences that interact with cellular proteins to promote RNA replication. UV crosslinking experiments revealed a 43-kDa cellular protein (p43) also interacts with the HCV 5' NCR. Further UV crosslinking experiments with deletion mutants of HCV 5' NCR demonstrated that p43 bound specifically to the 5'-terminal stem-loop of the HCV 5' NCR. Achromobactor proteinase I digests, competition experiments, and immunoprecipitation confirmed that p43 was identical to human poly(rC)-binding protein 2 (PCBP2). We prepared a PCBP2-immunodepleted rabbit reticulocyte lysate with an anti-PCBP2 antibody. Translation activity promoted by the HCV internal ribosome-entry site was the same in PCBP2-depleted lysates as in mock-depleted lysates. In conclusion, PCBP2 specifically interacted with the 5' terminus of HCV genome but had no effect on HCV translation. We speculate that PCBP2's interaction with HCV 5' NCR may be involved in the replication-initiation complex of HCV.

Multiplicities and some enzymatic characteristics of ape pepsinogens and pepsins

Pepsinogen levels in ape stomachs were comparable to those in macaques and significantly higher than those in the stomachs of other mammals, including carnivores and ruminants. The occurrence of multiple forms of pepsinogens was remarkable. Nine, sixteen, eight, and fourteen pepsinogens were purified or partially purified from the gastric mucosa of a gibbon, orang-utan, gorilla, and chimpanzee, respectively. Most of these were type-A pepsinogens, and only one type-C pepsinogen was identified in each ape. The two types could be readily distinguished by staining for proteolytic activity on polyacrylamide gel electrophoresis (PAGE) in the presence/absence of pepstatin. Type-A pepsinogens were further divided into two subtypes. One subtype, constituting a major group of pepsinogens in apes, exhibited high hemoglobin-digestive activity. The other subtype was specified by a relatively high content of Lys and low hemoglobin-digestive activity. It is likely that pepsinogen-A genes have been duplicated several times as hominoids, including humans, evolved in the primate lineage. The presence of multiple pepsinogens in apes might be advantageous in the efficient digestion of a wide variety of foods.

Distribution of the 4F2 light chain, LAT1, in the mouse brain

LAT1 (the 4F2-light chain 1) is a component of the CD98 surface antigen which participates in multiple functions including amino acid transport, cell survival, cell fusion and integrin activation. We examined the distribution of LAT1 in the mouse brain using immunohistochemistry. LAT1 was expressed on the microvessels, the subfornical organ, the subcommissural organ, ventromedial nucleus of the hypothalamus, subgranular zone of the dentate gyrus, ependymal layer of the lateral ventricles, and the olfactory bulb. LAT1-positive cells incorporated bromodeoxyuridine in the latter three regions where neurogenesis occurs in adult mouse brain, indicating that LAT1 is involved in neuronal cell proliferation, as well as in amino acid transport in these regions.