Hepatic and renal expression of senescence marker protein-30 and its biological significance

A novel rat hepatic protein was detected and isolated, the amount of which is down-regulated in an androgen-independent manner with ageing. This protein was designated as senescence marker protein-30 (SMP30). Senescence marker protein-30 turned out to be identical to a hepatic calcium-binding protein called regucalcin (RC). This review gives an overview of SMP30 in its structure, expression and possible physiological function(s). A hypothetical role of SMP30 in ageing and calcium homeostasis is also discussed.     

CMV viraemia demonstrated in the serum of a patient with cytomegalovirus pneumonia

Summary. We attempted to demonstrate the expression of cytomegalovirus (CMV) particles in the serum of an acute lymphocytic leukaemia patient with CMV pneumonia. The serum sample was applied to an affinity column coupled with human monoclonal antibody C2 3 which recognizes the envelope glycoproteins of CMV virus and neutralizes the viral activity. The DNA obtained from each fraction was amplified by double polymerase chain reaction (PCR) and analysed by gel electrophoresis. Bands were clearly observed in the eluted fraction. These results strongly suggest that CMV particles exist in the sera of patients with CMV pneumonia.     

Erosion of a penile prosthesis due to an indwelling urethral catheter as a late complication

A case of erosion of a penile prosthesis caused by indwelling of a catheter in the urethra is reported. A 73-year-old man had maintained sexual intercourse with penile prostheses (Jonas prosthesis, 19 cm) for 11 years without any complications until he developed cerebral infarction. One month after starting an indwelling urethral catheter in a neurosurgery clinic, the left-side penile prosthesis eroded from the area of the fossa navicularis, and was immediately removed. This type of complication is not unusual in patients with a neurogenic bladder. However, it is not well recognized in patients who suddenly develop a neurogenic bladder following a long-term uneventful period after the implantation of penile prostheses. Therefore, urologists should inform patients who receive this type of treatment that erosion of the prosthesis may develop when they need an indwelling urethral catheter as a late complication.     

Sagittal spinal alignment in patients with Legg-Calve-Perthes disease

BACKGROUND: Legg-Calve-Perthes disease (LCPD) is an avascular necrosis of the capital femoral epiphysis in children. Several studies found a pathophysiological relationship between LCPD and juvenile Scheuermann's kyphosis, suggesting an abnormal spinal condition related to osteochondrogenesis. In the present study sagittal spinal alignment of the patients with LCPD was analyzed to examine associated spinal involvement. METHODS: A standing lateral radiograph of the spine was evaluated in 78 patients who had a history of LCPD. Various parameters of sagittal spinal alignment, including thoracic kyphosis (TK), lumbar lordosis (LL), sacral inclination (SI), apex of thoracic kyphosis (TK-apex) and lumbar lordosis (LL-apex), and sagittal balance (SB; positive SB values represent a sagittal balance in front of the sacrum) were measured and compared between the patients with and without vertebral abnormalities. RESULTS: Compared to previously published normative data, relatively decreased LL was evident in LCPD. Most of the patients (65%) had negative SB, which was correlated with decreased SI, more proximal TK-apex, and more distal LL-apex. Vertebral abnormalities including end-plate irregularities and wedging vertebrae were observed in 20 patients. Decreased SI, more distal LL-apex, and more negative SB were remarkable in the patients with vertebral abnormalities. CONCLUSIONS: The patients tended to stand in greater negative sagittal balance associated with decreased LL. The characteristic sagittal alignment was prominent especially in the patients with vertebral abnormalities. Wedging vertebrae, probably due to growth disturbance of the vertebral bodies, could result in decreased LL, which leads to posterior pelvic tilt and posterior shift of sagittal balance.     

Medically and economically appropriate follow-up schedule for prostate cancer patients after radical prostatectomy

BACKGROUND: Our goal was to determine the optimal frequency and method of follow-up after radical prostatectomy to minimize medical cost without adversely affecting patients. METHODS: Two hundred and twenty-one patients who underwent a radical prostatectomy with or without adjuvant androgen deprivation from 1989 to 1999 were selected for the study. Eighty percent of the patients received postoperative androgen deprivation. Tumor recurrence was strictly defined as detectable serum prostate specific antigen (PSA) and/or clinical findings such as local tumor detection or bone metastasis. Thirty of 221 patients experienced tumor recurrence. Risk of tumor recurrence, procedures for detection of recurrence, and PSA doubling time after biochemical failure were analyzed. RESULTS: None of the 30 patients who were examined showed definitive local recurrence or metastatic sites on the imaging study at the time of initial PSA detection, and there were no observed recurrences in the absence of detectable serum PSA. In patients who showed elevated PSA within 12 months after radical prostatectomy, PSA levels rapidly increased with doubling times ranging from 1.2 to 13.7 months. Excluding those patients, the doubling time of PSA levels ranged from 2.8 to 31.5 months. CONCLUSIONS: Prostate specific antigen screening is sufficient to detect treatment failure after radical prostatectomy, irrespective of adjuvant hormone therapy. Based on the calculated doubling time, the longest advisable interval between checks of PSA levels is estimated to be four months within the first year after radical prostatectomy, and biannually or annually thereafter. Continuously elevated PSA levels or clinical symptoms indicate surveys for local recurrences and distant metastases.     

A Novel Missense Mutation Causing a G487R Substitution in the S2–S3 Loop of Human ether‐à‐go‐go‐Related Gene Channel

hERG(G487R) Channel . Introduction: Mutations of human ether‐à‐go‐go‐related gene (hERG), which encodes a cardiac K⁺ channel responsible for the acceleration of the repolarizing phase of an action potential and the prevention of premature action potential regeneration, often cause severe arrhythmic disorders. We found a novel missense mutation of hERG that results in a G487R substitution in the S2–S3 loop of the channel subunit [hERG(G487R)] from a family and determined whether this mutant gene could induce an abnormality in channel function. Methods and Results: We made whole‐cell voltage‐clamp recordings from HEK‐293T cells transfected with wild‐type hERG [hERG(WT)], hERG(G487R), or both. We measured hERG channel‐mediated current as the “tail” of a depolarization‐elicited current. The current density of the tail current and its voltage‐ and time‐dependences were not different among all the cell groups. The time‐courses of deactivation, inactivation, and recovery from inactivation and their voltage‐dependences were not different among all the cell groups. Furthermore, we performed immunocytochemical analysis using an anti‐hERG subunit antibody. The ratio of the immunoreactivity of the plasma membrane to that of the cytoplasm was not different between cells transfected with hERG(WT), hERG(G487R), or both. Conclusion: hERG(G487R) can produce functional channels with normal gating kinetics and cell‐surface expression efficiency with or without the aid of hERG(WT). Therefore, neither the heterozygous nor homozygous inheritance of hERG(G487R) is thought to cause severe cardiac disorders. hERG(G487R) would be a candidate for a rare variant or polymorphism of hERG with an amino acid substitution in the unusual region of the channel subunit. (J Cardiovasc Electrophysiol, Vol. 23, pp. 1246–1253, November 2012)     

Susceptibility of experimental autoimmune hepatitis in transgenic mice overexpressing the c-H-ras gene

Results from a recent study of ours have demonstrated the significant role of the wild-type ras gene in the development of hepatocellular carcinoma in rasH2 mice having prototype human c-H- ras genes. Chronic cell death and regeneration have been considered to work as co-carcinogens with wild-type ras gene overexpression in this model. To elucidate a role of gene overexpression in the occurrence of chronic inflammation, we tried to induce inflammation in the liver of rasH2 mice by immunizing them with the supernatant of a freshly prepared syngenic liver homogenate. Immunization resulted in a dense inflammatory infiltrate in the portal tract and focal necrosis with spots of fatty or foamy degeneration in the transgenic mouse liver; however, these observations were less frequently observed in non-transgenic mouse liver. Monocytes, granulocytes and plasma cell infiltration were observed in the livers of transgenic mice. An immunohistochemical study showed that CD3-positive lymphocytes also infiltrated the liver. The inflammatory infiltrate was still present in the transgenic liver 24 weeks after the last injection, but little infiltrate was observed at the same time in non-transgenic mice. No hepatic tumours could be produced over the 6 months duration of the study and the results are only preliminary. However, these results do suggest that overexpression of wild-type ras is partially responsible for the occurrence of autoimmune chronic hepatitis.     

A comparative study of nucleolar organizer region, proliferating cell nuclear antigen and epidermal growth factor receptor staining in colon tumours

Several studies have reported that proliferating cell nuclear antigen (PCNA), nucleolar organizer regions (NOR) and epidermal growth factor receptor (EGF-R) are cellular proliferation parameters in malignant tumours. However, the correlation of EGF-R with PCNA and NOR has not been reported in colon tumours. To clarify this, we investigated the correlation of the expression of EGF-R with PCNA and NOR in colonic epithelial tumours. Using immunohistochemical staining and one-step silver staining techniques, the expressions of EGF-R-, PCNA- and NOR-associated protein were studied in paraffin sections from five normal mucosae, 10 adenomas with mild atypia, 16 adenomas with moderate atypia, 32 adenomas with severe atypia including carcinoma in situ and 47 with invasive colon carcinomas. Significant differences were found among the respective degrees of atypia in Ag-NOR counts, PCNA labelling index (LI), and the expression of EGF-R. However, there were no significant differences among the Ag-NOR counts of the severe atypia and invasive carcinoma. There was a significant positive correlation between Ag-NOR counts and PCNA LI (P<0.001). The Ag-NOR counts and PCNA LI in EGF-R-positive cases were higher than in EGF-R-negative cases (P<0.001). These results indicate that each of the parameters increased significantly with the increase in atypia and the progression of cancer. Epidermal growth factor receptor provokes an exacerbation of protein synthesis and the cell cycle in colonic epithelial tumours.     

Studies on peptides

A decapeptide corresponding to the entire amino acid sequence of neurokinin A, a porcine spinal cord peptide, was synthesized in a conventional manner using protecting groups removable by 1 M TFMSA-thioanisole in TFA. The HS-CH₂CH₂CO group was introduced onto the synthetic neurokinin A by reaction of 3-(S-acetyl-thiopropionyl)-thiazolidine-2-thione, followed by deacetylation with hydroxylamine. 2,4-Dinitrophenyl-p-(β-nitrovinyl)-benzoate trapped the above HS-CH₂CH₂CO-neurokinin A derivative in acidic media, then BSA in basic media in nearly quantitative yield. A similar decapeptide, neurokinin B, was also synthesized and conjugated onto BSA using an alternative SH-introducing reagent, 3-(S-p-methoxybenzyl-thiopropionyl)-thiazolidine-2-thione, and the above heterobifunctional conjugating reagent.