The bisphosphonate pamidronate on the surface of titanium stimulates bone formation around tibial implants in rats

Many materials with differing surfaces have been developed for clinical implant therapy in dentistry and orthopedics. We analyzed the quantity of new bone formed in vivo around calcium-immobilized titanium implants with surfaces modified using pamidronate (PAM), a nitrogen-containing bisphosphonate (N-BP), implants of pure titanium, and titanium implants immobilized with calcium ions. New bone formation was visualized using fluorescent labeling (calcein blue and alizarin complexone) with intravenous injection at 1 and 3 weeks after implantation. After 4 weeks, undecalcified sections were prepared, and new bone formation around the implants was examined by morphometry using confocal laser scanning microscopy images. After 1 week, more new bone formed around the PAM-immobilized implant than around the calcium-immobilized and pure titanium implants. This was also seen with the new bone formation after 3 weeks. After 4 weeks, significantly more new bones were formed around the BP-immobilized implant than around the calcium ion-implanted and pure titanium implants. The new N-BP-modified titanium surface stimulates new bone formation around the implant, which might contribute to the success of implant therapy.     

Intracerebroventricular administration of NPY stimulates resistin gene expression in mice

Resistin is thought to cause insulin resistance and link obesity to type 2 diabetes mellitus. However, little is known about the effects of neuropeptide Y (NPY) on resistin gene expression in white adipose tissue (WAT). Resistin gene expression was determined by northern blot analysis in food-deprived mice after NPY administration. Administered NPY (1 nmol/mouse) significantly increased resistin mRNA expression in WAT by 72% compared with artificial cerebrospinal fluid treated controls. These observations indicate that NPY might have a role in regulating resistin gene expression in WAT and that the novel brain-fat axis might be involved in the pathogenesis of obesity and related diseases.     

Ultrastructural localization of laminin-5 (gamma2 chain) in the rat peri-implant oral mucosa around a titanium-dental implant by immuno-electron microscopy

Laminin-5 (Ln-5) is an important molecule associated with epithelial cell adhesion and migration. In the gingiva around the tooth, Ln-5 localizes within basement membranes between the junctional epithelium (JE) and the tooth or connective tissue. Recently, we reported that in the oral mucosa around a dental implant, Ln-5 is expressed within the basement membranes at the implant-peri-implant epithelium (PIE) interface, and at the PIE-connective tissue interface. However, the ultrastructural localization of Ln-5 within or along the PIE has not yet been reported. Therefore, peri-implant oral mucosa was treated with anti-Ln-5 (gamma2 chain) antibody and examined using immuno-electron microscopy. Ln-5 was localized in the cells of the innermost-third layer and basal layer of the PIE. A 100-nm-wide Ln-5-positive internal basal lamina (basement membrane) and hemidesmosomes as adhesion structures were formed at the apical portion of the implant-PIE interface. However, at the upper-middle portion of the interface, these adhesion structures were not observed. Furthermore, at the PIE-connective tissue interface, the Ln-5-positive external basal lamina (basement membrane) and hemidesmosomes were partially deficient. Judging from these findings, we concluded that Ln-5 contributes to the attachment of the PIE to the titanium surface, and that PIE attached to titanium at the apical portion of the dental implant-PIE interface.     

Transforming growth factor-beta1 gene polymorphism modifies the histological and clinical manifestations in Japanese patients with IgA nephropathy

Transforming growth factor (TGF)-beta1, a multifunctional cytokine, which regulates proliferation and differentiation of a variety of cell types, has the central role in the development and progression of renal injury in both animal models and human. Although it has been suggested that genetic variations in the TGF-beta1 gene are associated with the activity of the gene product, their clinical significance in glomerular disease is unknown. We investigated whether the polymorphisms of C-509T and T869C in TGF-beta1 account for interindividual variation in manifestations of IgA nephropathy (IgAN) using 626 Japanese subjects including 329 patients with histologically proven IgAN and 297 healthy controls with normal urinalysis. The frequencies of genotypes, alleles, and major haplotypes were similar between the patients and controls. The C-509T and T869C polymorphisms were in tight linkage disequilibrium, and the major haplotypes were C-C and T-T, which accounted for more than 95% of the total. In patients with -509CC and in those with the 869CC, urinary protein excretion was higher than in those with other genotypes, whereas no difference in other clinical manifestations was noted. Moreover, patients with -509CC and those with 869CC genotypes presented with a significant higher score of mesangial cell proliferation than in those with other genotypes. These results suggest that TGF-beta1 gene polymorphisms are specifically associated with heavy proteinuria and mesangial cell proliferation in Japanese patients with IgAN, although they do not confer susceptibility to this disease.     

Pneumocystis carinii carriage in immunocompromised patients with and without human immunodeficiency virus infection

Eighty-one bronchoalveolar lavage (BAL) specimens obtained from 26 HIV-infected, 45 non-HIV immunosuppressed and 10 immunocompetent patients with primary pulmonary diseases were analysed for the presence of Pneumocystis carinii by staining and by P. carinii 5S rDNA determined by PCR. P. carinii was observed by staining of BAL specimens from HIV-infected patients significantly more frequently than those from immunocompromised hosts without HIV infection (57.7% versus 20.0%, respectively). P. carinii 5S rDNA was detected by PCR assay in seven (26.9%) HIV-infected individuals, which was significantly more frequent than for four (8.9%) immunosuppressed patients without HIV infection, for whom staining was negative. None of these patients developed P. carinii pneumonia (PCP) within the follow-up period. BAL specimens from 10 immunocompetent patients with pulmonary disorders were negative for PCP by both staining and PCR assay.     

Depletion of mitochondrial DNA in HIV-1-infected patients and its amelioration by antiretroviral therapy

Mitochondrial DNA (mtDNA) of peripheral blood mononuclear cells (PBMCs) collected from Human immunodeficiency virus 1 (HIV-1)-infected patients and healthy controls were measured longitudinally using real-time polymerase chain reaction to evaluate the effects of antiretroviral agents on mtDNA synthesis in vivo and to assess the value of monitoring mtDNA in PBMCs to predict adverse events amongst these patients. MtDNA levels in PBMCs were significantly decreased in treatment-naive HIV-1-infected patients compared with healthy people. MtDNA levels were not only significantly correlated with CD4(+) T-cell count, but also inversely correlated with HIV-1 viral load. MtDNA levels in untreated patients and healthy controls were stable during the period of observation. On the other hand, amongst patients treated with regimens containing AZT/3TC or d4T/3TC, mtDNA increased during treatment and recovered to levels comparable to healthy controls. In contrast, mtDNA decreased immediately after the initiation of an AZT/ddC-containing regimen. We did not find a correlation between mtDNA levels and changes in clinical parameters. There was no significant difference in mtDNA levels between patients with and those without lipoatrophy. Furthermore, there was no obvious difference in mtDNA levels amongst those patients exhibiting signs and symptoms of peripheral neuropathy. In conclusion, the decrease in mtDNA levels in PBMCs amongst HIV-1-infected patients and its amelioration by antiretroviral therapy may suggest the influence of direct effects on mitochondria or mtDNA by HIV-1 infection. Further investigations are needed to elucidate the mechanisms contributing to decreased mtDNA and the value of mtDNA measurement in the care of HIV-1-infected individuals.     

Werner helicase relocates into nuclear foci in response to DNA damaging agents and co-localizes with RPA and Rad51

BACKGROUND: Werner syndrome (WS) is an autosomal recessive disorder with many features of premature ageing. Cells derived from WS patients show genomic instability, aberrations in the S-phase and sensitivity to genotoxic agents. The gene responsible for WS (WRN) encodes a DNA helicase belonging to the RecQ helicase family. Although biochemical studies showed that the gene product of WRN (WRNp) interacts with proteins that participate in DNA metabolism, its precise biological function remains unclear. RESULTS: Using immunocytochemistry, we found that WRNp forms distinct nuclear foci in response to DNA damaging agents, including camptothecin (CPT), etoposide, 4-nitroquinolin-N-oxide and bleomycin. The presence of aphidicolin inhibited CPT-induced WRNp foci strongly but not bleomycin-induced foci. These WRNp foci overlapped with the foci of replication protein A (RPA) almost entirely and with the foci of Rad51 partially, implicating cooperative functions of these proteins in response to DNA damage. We also found that WRNp foci partially co-localize with sites of 5-bromo-2'-deoxy-uridine incorporation. CONCLUSIONS: These findings suggest that WRNp form nuclear foci in response to aberrant DNA structures, including DNA double-strand breaks and stalled replication forks. We propose that WRNp takes part in the homologous recombinational repair and in the processing of stalled replication forks.     

Prevalence of asthma in adults in Menda town rural-mountain area in Japan]

Several reports have suggested that the prevalence of asthma in adults is currently increasing. However, recent prevalence of asthma has not reported in Japan, especially in rural-mountain areas. To investigate the prevalence of asthma in adults in Japan, we conducted clinical epidemiological research on 5066 inhabitants of Menda town, in a rural-mountain area of Japan. The study population comprised 98.7% of adults in the town, including senior high school students whose age were more than 15 years old. The prevalence of asthma among adults was 3.6%. The ratio of prevalence in males to prevalence in females was 1.44. Peaks prevalences were observed in the age ranges of 15-19 and > 70 years old in males, and 15-19, 40-49 and > 70 years old in females.     

New method to determine oxygen cost for contractility

We developed a new method to determine the oxygen cost for myocardial contractility and applied it to epinephrine in the excised cross-circulated dog heart. We utilized the relation between myocardial oxygen consumption (VO2) and the systolic pressure-volume area (PVA) which represents the total mechanical energy generated by contraction. We first obtained a reference VO2-PVA relation in a baseline contractile state. Then, the end-diastolic and stroke volumes were fixed constant and a global index of ventricular contractility, Emax, was enhanced by infusing epinephrine. The VO2-PVA data point was shifted linearly right-upward with the increases in Emax. From the slopes of both the reference VO2-PVA relation line and the regression line of VO2 on PVA during the gradually increased Emax, we calculated the oxygen cost for contractility, i.e., the ratio of the elevation of the VO2-PVA relation to enhanced Emax in each heart. The ratio was 0.00095 +/- 0.00013 ml O2.ml.mmHg-1.beat-1.100 g LV-2. The result indicates that the oxygen cost for contractility can be reliably and efficiently determined by this new method.