Residual stress associated with crystalline phase transformation of 3-6 mol% yttria-stabilized zirconia ceramics induced by mechanical surface treatments

Monolithic dental prostheses made of 3-6 mol% yttria-stabilized zirconia (3-6YSZ) have gained popularity owing to their improved material properties and semi-automated fabrication processes. In this study, we aimed to evaluate the influence of mechanical surface treatments, such as polishing, grinding, and sandblasting, on the residual stress of 3-6YSZ used for monolithic prostheses in association with crystalline phase transformation. Plate specimens were prepared from five dental zirconia blocks: Aadva Zirconia ST (3YSZ), Aadva Zirconia NT (6YSZ), Katana HT (4YSZ), Katana STML (5YSZ), and Katana UTML (6YSZ). The specimens were either polished using 1, 3, or 9 μm diamond suspensions, ground using 15, 35, or 55 μm diamond discs, or sandblasted at 0.2, 0.3, or 0.4 MPa. The residual stress, crystalline phase, and hardness were analyzed using the cosα method, X-ray diffraction (XRD), and Vickers hardness test, respectively. Additionally, we analyzed the residual stress on the surfaces of monolithic zirconia crowns (MZCs) made of 4YSZ, 5YSZ, and 6YSZ, which were processed using clinically relevant procedures, including manual grinding, followed by polishing using a dental electric motor on the external surface, and sandblasting on the internal surface. Residual stress analysis demonstrated that grinding and sandblasting, particularly the latter, resulted in the generation of compressive residual stress on the surfaces of the plate specimens. XRD revealed that the ground and sandblasted specimens contained a larger amount of the rhombohedral phase than that of the polished specimens, which may be a cause of the residual stress. Sandblasting significantly increased the Vickers hardness compared to polishing, which may possibly be due to the generation of compressive residual stress. In the case of MZCs, compressive residual stress was detected not only on the sandblasted surface, but also on the polished surface. The difference in the residual stress between the plate and crown specimens may be related to the force applied during the automated and manual grinding and polishing procedures. Further studies are required to elucidate the effects of the compressive residual stress on the clinical performance of MZCs.

Putative Mechanisms Underlying the Beneficial Effects of Polyphenols in Murine Models of Metabolic Disorders in Relation to Gut Microbiota

The beneficial effects of polyphenols on metabolic disorders have been extensively reported. The interaction of these compounds with the gut microbiota has been the focus of recent studies. In this review, we explored the fundamental mechanisms underlying the beneficial effects of polyphenols in relation to the gut microbiota in murine models of metabolic disorders. We analyzed the effects of polyphenols on three murine models of metabolic disorders, namely, models of a high-fat diet (HFD)-induced metabolic disorder, dextran sulfate sodium (DSS)-induced colitis, and a metabolic disorder not associated with HFD or DSS. Regardless of the model, polyphenols ameliorated the effects of metabolic disorders by alleviating intestinal oxidative stress, improving inflammatory status, and improving intestinal barrier function, as well as by modulating gut microbiota, for example, by increasing the abundance of short-chain fatty acid-producing bacteria. Consequently, polyphenols reduce circulating lipopolysaccharide levels, thereby improving inflammatory status and alleviating oxidative imbalance at the lesion sites. In conclusion, polyphenols likely act by regulating intestinal functions, including the gut microbiota, and may be a safe and suitable therapeutic agent for various metabolic disorders.

Impact of adhesive primer and light-curing on polymerization kinetics of self-adhesive resin cement in association with free radical reaction

This study analyzed the impact of adhesive primer and light-curing on the polymerization kinetics of urethane dimethacrylate-based self-adhesive resin cement combined with free radical reaction. Specimens were prepared by mixing the cement paste with or without adhesive primer. Subsequently, specimens were light-cured or set without light-curing. The degree of conversion (DC), Vickers hardness (Hv), and free radical concentrations were repeatedly measured up to 168 h after the curing initiation. Irrespective of the curing procedures, DC, Hv, and free radical concentration rapidly increased during the initial 30 min of curing. The specimens cured with adhesive primer and/or light-curing generally showed higher values of DC, Hv, and radical concentration than those set by chemical curing alone, especially during the initial polymerization phase. Kinetic analysis using a linear mixed model revealed that the adhesive primer had a higher coefficient estimate than light-curing, indicating that the former had a higher impact on the polymerization. Additionally, the adhesive primer alleviated the Hv reduction caused by water and air during the initial polymerization phase, although light-curing hardly prevented the polymerization inhibition. Therefore, we suggest that application of adhesive primer is beneficial to achieve higher degree of conversion and better mechanical properties of self-adhesive resin cements by enhancing free radical reactions.

Influence of crystalline phase transformation induced by airborne-particle abrasion and low-temperature degradation on mechanical properties of dental zirconia ceramics stabilized with over 5 mol% yttria

Monolithic dental prostheses fabricated from 5 mol% yttria-stabilized zirconia (5YZ) have been developed to improve the translucency of conventional 3 mol% yttria-stabilized zirconia. In this study, we aimed to evaluate the influence of airborne-particle abrasion (APA) and low-temperature degradation (LTD) on the mechanical properties of 5YZ in association with the crystalline phase transformation. In total, 120 disc-shaped specimens of two brands of 5YZ (Lava Esthetic and Katana UTML) were prepared. The specimens were divided into four groups (n = 15 for each group): (i) control, (ii) APA, (iii) LTD, and (iv) APA + LTD groups. APA was performed with 50 μm alumina particles, and LTD was induced by autoclaving at 134 °C for 50 h. The biaxial flexural strength of the specimens was assessed using a piston-on-three-ball test according to ISO 6872:2015, and Vickers hardness was determined using a microhardness tester. The crystalline phase was analyzed by the Rietveld refinement of X-ray diffraction patterns. APA significantly increased the flexural strength of the Lava Esthetic specimens, whereas LTD hardly affected the strength of both materials. APA and APA + LTD significantly increased the Vickers hardness of both materials. According to Rietveld analysis, the pseudocubic phase was predominant in both materials, i.e., 66 mass% and 81 mass% in the Lava Esthetic and Katana UTML specimens, respectively. APA induced the rhombohedral phase at approximately 37 mass% in both materials, while LTD induced the monoclinic phase at 2.8 mass% in the Lava Esthetic specimens and 0.9 mass% in the Katana UTML specimens. APA + LTD weakly affected the amount of the rhombohedral phase but slightly increased the amount of the monoclinic phase. These findings suggest that APA may improve the mechanical properties of 5YZ, particularly hardness, via the generation of the rhombohedral phase. In contrast, the influence of LTD on the mechanical and microstructural properties of 5YZ was limited.

Reactions of dental pulp to hydrogen peroxide photolysis-based antimicrobial chemotherapy under ultraviolet-A irradiation in rats

Hydrogen peroxide photolysis-based antimicrobial chemotherapy that utilizes ultraviolet-A irradiation (UVA-H₂O₂ photolysis) has been previously proposed as a method of treatment of cariogenic biofilm. Therefore, in the present study, we aimed to assess time-dependent reactions in the dental pulp of rats after UVA-H₂O₂ photolysis. Maxillary first molars were treated. UVA irradiation (wavelength: 365 nm) with 3 wt% H₂O₂ was performed for 90 s at a radiant emittance of 500-2000 mW/cm² on the rats for 3 consecutive days or only 1 day. The animals were sacrificed at Days 1, 3, 7, and 21 after the treatment for the histological evaluation of inflammatory cells and immunohistochemistry of heat shock protein (HSP)-25, a marker of odontoblasts. Tertiary dentin formation was evaluated at Day 21 by histomorphometry and micro-CT analysis. UVA-H₂O₂ photolysis elicited little infiltration of inflammatory cells, but disturbances in the odontoblast layer and/or presence of localized degenerative tissue were observed on Day 3. This condition was followed by a healing process that was characterized by the reappearance of HSP-25 positive odontoblast-like cells at Day 7 and tertiary dentin formation at Day 21. The amount of tertiary dentin formed was dependent on the intensity of treatment; repeated UVA irradiations of H₂O₂ at 2000 mW/cm² resulted in the largest amount of tertiary dentin formation at the pulp horn regions. Our findings suggest that UVA-H₂O₂ photolysis treatment can be used to treat dental caries clinically because the post-treatment inflammatory reaction was minimal and tertiary dentin formation was substantial, which may prove effective in protecting dental pulp from external irritants. As a cautionary consideration, the radiant emittance of the UVA irradiation should be carefully optimized before clinical application.

Mechanical and microstructural properties of ultra-translucent dental zirconia ceramic stabilized with 5 mol% yttria

Monolithic dental prostheses fabricated from 3 mol.% yttria-stabilized zirconia (3YZ) are becoming increasingly popular. Recently, 5 mol.% yttria-stabilized zirconia (5YZ) which significantly improves the translucency of 3YZ has been prepared. However, its mechanical and microstructural properties, especially those affected by low-temperature degradation (LTD), have not been fully elucidated yet. The objective of the present study was to establish the relationship between the flexural strength of 5YZ with or without autoclave-induced LTD and its microstructural properties. For this purpose, a total of 320 bar-shaped specimens were cut from 5YZ and 3YZ blocks, and half of the specimens in each group were autoclaved at 134 °C for 50 h. Their flexural strengths were determined by conducting three-point bending tests, and the obtained results were analyzed by the Weibull statistical method. Grain sizes and crystalline structures of the specimens were analyzed by scanning electron microscopy (SEM) and X-ray diffraction, respectively. Additionally, the LTD-induced phase transformation was examined by Raman microscopy and cross-sectional surface analysis. The characteristic strengths of 5YZ and 3YZ were approximately 620 and 950 MPa, respectively, and 5YZ was found to be more resistant to LTD in terms of phase transformation than 3YZ. However, a low amount of the monoclinic phase was detected even in 5YZ after 50 h of autoclaving, which significantly decreased its flexural strength and reliability. The results of SEM analysis revealed that 5YZ was composed of two distinct regions: a dominant matrix with large grains (median size: 0.8 μm) and scattered areas with small grains (median size: 0.4 μm). Phase transformation analysis and fractography data indicated that the small-grain region was strongly affected by LTD and likely represented a fracture origin. The described properties should be considered during the clinical application of monolithic 5YZ dental prostheses.

A novel pathway for the photooxidation of catechin in relation to its prooxidative activity

In the present study, we evaluated the prooxidative mode of action of photoirradiated (+)-catechin at 400 nm in relation to reactive oxygen species generation and its possible application to disinfection. Photoirradiation of (+)-catechin at a concentration of 1 mg/mL yielded not only hydrogen peroxide (H2O2) but hydroxyl radical (·OH) in a total amount of approximately 20 μM in 10 min. As a result, photoirradiated catechin killed Staphylococcus aureus, and a > 5-log reduction in viable bacteria counts was observed within 20 min. Liquid chromatography-high-resolution-electrospray ionization-mass spectrometry showed that photoirradiation decreased the (+)-catechin peak (molecular formula C15H14O6) whilst it increased two peaks of a substance with the molecular formula C15H12O6 with increasing irradiation time. Nuclear magnetic resonance analysis revealed that the two C15H12O6 peaks were allocated to intramolecular cyclization products that are enantiomers of each other. These results suggest that photoirradiation induces oxidation of (+)-catechin resulting in the reduction of oxygen to generate H2O2. This H2O2 is then homolytically cleaved to ·OH, and alongside this process, (+)-catechin is finally converted to two intramolecular cyclization products that are different from the quinone structure of the B ring, as proposed previously for the autoxidation and enzymatic oxidation of catechins.

Association Between the Fertile Period and Live Birth Post-Kidney Transplantation: A Retrospective Single-Center Cohort Study

BACKGROUND

Despite restoration of fertility after kidney transplantation, the benefit is limited in female kidney recipients. Our objective is to determine the reasons for this discrepancy.

METHODS

We evaluated 315 women who underwent kidney transplantation from 1983 to 2015 (a median of age at transplantation [10th-90th percentile] of 32 years [7-55 years]); 230 recipients between the ages of 15 to 49 years old as of March 2016 were observed.

RESULTS

We experienced 10 abortions and 21 live births from our 23 recipients and 2 abortions and 7 live births in 7 recipients from other transplant center. The live birth rate was 8.9 per 1000 female transplant recipients of childbearing age. Seven recipients received either treatments of artificial insemination or in vitro fertilization. Average age at pregnancy was 33.2 ± 3.2 years old, and the fertile period post-transplantation was longer in recipients with live births than those without live births (14.1 ± 7.1 vs 9.9 ± 7.3 years, P < .05). In 42.9% of recipients with live birth, pregnancy-induced hypertension was observed in the last trimester. The gestational age and the average birth weight were 32.8 ± 5.0 months and 2184 ± 632 g, respectively. During follow-up of 14.5 years, there was one case of graft loss, which is a rate of 2.5 per 1000 female recipients.

CONCLUSION

Although pregnancy complications are often observed in kidney recipients, graft survival is less influenced by pregnancy. Importantly, kidney disease at childbearing age disrupts pregnancy even after kidney transplantation.

Pharmacokinetic Profile of Twice- and Once-daily Tacrolimus in Pediatric Kidney Transplant Recipients

BACKGROUND

The aim of this study was to assess the differences in pharmacokinetic (PK) profiles after the 1:1 ratio-based conversion from a twice-daily to a once-daily tacrolimus formulation (TD-TAC and OD-TAC, respectively) in pediatric recipients of kidney transplants.

METHODS

TD-TAC was initially administered to 29 pediatric patients who underwent kidney transplantations between April 2010 and September 2015 and were then subsequently switched to OD-TAC. The switch dose ratio was 1:1, and the 24-hour complete PK parameter assessment was performed before and after the regimen was changed from TD-TAC to OD-TAC.

RESULTS

The mean total daily dose at baseline was 5.5 ± 2.9 mg (0.18 ± 0.10 mg/kg body weight). Consecutive PK studies revealed no significant difference in the mean time to achieve maximum concentrations and the area under the concentration-time curve from 0 to 24 hours (AUC_0-24) of both drug formulations. However, the mean trough concentration (C_min) and the maximum concentration of OD-TAC were 22% and 6% lower and higher, respectively, than those of TD-TAC. Therefore, a better correlation was observed between the AUC_0-24 and C_min of OD-TAC than between those of TD-TAC.

CONCLUSIONS

After the change from TD-TAC to OD-TAC, the AUC_0-24 values were equivalent despite a 22% reduction in C_min. C_min may therefore be an excellent predictor in the therapeutic drug monitoring of OD-TAC because of its superior correlation with AUC_0-24.

Similar Anemic Control Between Chronic Kidney Diseases in Patients With and Without Transplantation on Entry to Dialysis

BACKGROUND

Transplant recipients are supposedly in a more anemic, catabolic, and even inflammatory state at re-entering hemodialysis due to chronic rejection. The goal of this study was to clarify how transplant recipients can re-enter dialysis safely by focusing on control of anemia.

METHODS

From 2012 to 2014, a total of 29 transplant recipients re-entered hemodialysis because of chronic rejection (ie, the chronic kidney disease with transplant [CKDT] group). At the same time, in 2014, a total of 30 patients with chronic kidney disease without transplantation entered dialysis as the control group (ie, the CKD group). CKDT recipients (mean ± standard deviation age, 41.9 ± 11.8 years; 18 male subjects, 10 female subjects; frequency of diabetes, 10%; duration of graft survival, 12.5 ± 4.3 years) were younger and fewer had diabetes compared with the CKD group (age, 53.2 ± 10.5 years; 21 male subjects, 9 female subjects; frequency of diabetes, 36%). Patient characteristics at entering dialysis in both groups were analyzed according to retrospective chart review.

RESULTS

At entering dialysis, there were no significant differences between the CKD and CKDT groups in terms of the following: dose of darbepoetin; concentrations of hemoglobin, albumin, and C-reactive protein; cardiothoracic ratio; blood urea nitrogen and creatinine levels; estimated glomerular filtration rate; initial ultrafiltration; and duration of hospitalization for initiation of dialysis. The only difference between groups was mean weight at entry to dialysis (CKDT group, 58.5 ± 15.1 kg; CKD group, 67.1 ± 14.8 kg; P = .03). The darbepoetin dose per kilogram of weight did not differ between groups (CKDT, 2.28 ± 2.03 μg/kg; CKD, 2.12 ± 1.6 μg/kg; P = .95) in the final month before entry to dialysis.

CONCLUSIONS

Safe re-initiation of dialysis is important for recipient survival. Although anemia is supposedly higher in transplant recipients due to immunosuppression, this single-center analysis found no difference in anemia in CKD with or without transplantation, caused by good use of erythropoietin-stimulating agents in both groups.

Regimen of Tacrolimus-Based Immunosuppression With Basiliximab, Mycophenolate Mofetil, and Low-Dose Steroid Reduces Acute Rejection in Kidney Transplants

BACKGROUND

Acute rejection is a major problem in kidney transplantation. To reduce its likelihood, we investigated the efficacy and safety of an immunosuppressive regimen including tacrolimus, basiliximab, mycophenolate mofetil, and low-dose steroids.

METHODS

Fifty-seven patients, including 14 pediatric patients, were enrolled in this study. The mean age at the time of transplantation was 33.5 years, and the mean observation period was 8.2 months. The mean trough concentrations of FK at 1, 6, and 12 months posttransplant were 10.2, 6.6, and 6.0 ng/mL, respectively.

RESULTS

All recipients survived without graft loss. The cumulative incidence of acute rejection in adults was 2.3% and 8.4% at 6 and 12 months posttransplant, respectively. Of the adverse events, 11 recipients (19.3%) were positive for CMV antigenemia or had CMV infections. Four recipients (7.0%) exhibited mild hyperglycemia.

CONCLUSIONS

Our immunosuppressive regimen demonstrated favorable results, reducing the incidence of acute rejection without causing severe adverse events, especially in adults.

Current status of ABO-incompatible kidney transplantation in children

This article reviews the current status of ABO-incompatible kidney transplantation in the pediatric population. ABO blood type incompatibility between a donor and recipient was generally considered a contraindication to kidney transplantation because of the associated high risk for hyperacute rejection. However, due to a severe shortage of suitable cadaveric allografts, much effort has been made over the last decade to investigate whether successful and effective kidney transplantation is possible across the ABO blood group barrier. At present, ABO-incompatible kidney transplantation has been shown to be a valid alternative even for children with end stage renal disease. In this review, we will discuss protocols available for successfully performing ABO-incompatible kidney transplantation in children: (1) pre-transplant extracorporeal immunomodulation with removal of pre-existing anti-A and/or anti-B antibodies; (2) immunosuppressive therapy and anti-rejection therapy; (3) splenectomy and the associated infectious complication in asplenic children. Also, we will speculate regarding the mechanisms underlying accommodation following transplantation.

A prospective trial of steroid withdrawal after renal transplantation in children: results obtained 1990 and 2002

Ten-year graft survival rate was 89% after immunosuppressive therapy with cyclosporine, methylprednisolone, and mizoribine in pediatric renal transplant recipients enrolled in our multicenter study. Adrenocorticosteroids, which cause growth retardation, were reduced by administration on alternate days in 67% and withdrawn in 23% of recipients. Acute rejection episodes occurred in 30% of patients after withdrawal of steroids. Graft function returned to prerejection levels after treatment with high-dose methylprednisolone. Catch-up growth occurred after alternate day administration and steroid withdrawal. Twenty-eight of 94 patients reached the final height of 156 cm in boys and 145 cm in girls, because of the gradually reduced growth rate. Management of growth retardation before transplantation, especially in patients with congenital renal diseases, and early reduction of the steroid dose after transplantation will increase the final height of children with chronic renal failure.

ABO-incompatible living-donor kidney transplantation in children

BACKGROUND

Due to a severe shortage of suitable cadaveric allografts for children awaiting kidney transplants, we have performed a series of ABO-incompatible living kidney transplantations (LKT) at our institution.

METHODS

Between July 1989 and March 2000, 16 pediatric patients (3 female, 13 male) underwent ABO-incompatible LKT. The mean age at transplantation was 10.9+/-4.3 years (range 5.1-15.0 years). The donor to recipient ABO blood antigen incompatibility was as follows: A1-->O, 5 patients; B-->O, 6 patients; A1B-->B, 2 patients; and A1B -->B, A1-->B, or B-->A1, 1 patient each. The median pretransplantation anti-A1 titers of eight A-incompatible recipients were 1:128 (IgM, range 1:16 to 1:512) and 1:32 (IgG, range 1:2 to 1:128). Median anti-B titers of seven B-incompatible recipients were 1:32 (IgM, range 1:4 to 1:128) and 1:8 (IgG, range 1:2 to 1:64). All patients received three or four sessions of plasmapheresis (PP) and/or immunoadsorption (IA) to remove the anti-A and/or anti-B antibodies before transplantation. Immunosuppression initially consisted of cyclosporine, methylprednisolone, cyclophosphamide, and antilymphocyte globulin. Splenectomy was performed on all recipients at the time of transplantation.

RESULTS

The patients were followed for 6 to 122 months with a mean follow-up of 63 months. All 16 recipients who underwent ABO-incompatible LKT achieved a pretransplant isoagglutinin titer less than 1:8 with 3-4 sessions of PP/IA treatment. Of 16 patients, 10 patients had rebound increase in their IgM and/or IgG anti-A/B titers to greater than 1:64 or predepletion levels within 10 days posttransplantation. In addition, nine patients developed renal dysfunction in association with the rebound increase in their anti-A/B. One patient lost his graft because of uncontrolled delayed hyperacute rejection, whereas eight other recipients recovered completely with pulse steroids and PP/IA therapy. After the third week posttransplant, there was no correlation between the occurrence of AR and their isoagglutinin titers. Moreover, no antibody-mediated rejection was observed, even in recipients with continued high titer anti-A and/or anti-B antibodies. Patient survival is 100% to date. The actuarial 1-year and 5-year graft survival rates are 87% and 85%, respectively. No fatal infectious complications occurred despite the combination of splenectomy and immunosuppressive drugs.

CONCLUSIONS

We have demonstrated that with adequate pre- and posttransplant management, successful kidney transplantation across the ABO barrier is possible in the pediatric population. "Accommodation" of the allografts occurred within 2 weeks of transplantation. Subsequently, the long-term graft outcome of ABO-incompatible LKT was comparable to that of ABO-compatible LKT.

[The usefulness of two-step tuberculin skin testing in nosocomial infection cases]

The usefulness of the two-step tuberculin skin test in the preceding year for the contact investigation was reported, when a pulmonary tuberculosis patient was discovered in our hospital. Four persons showed stronger reaction than the results in two-step tuberculin skin test in the preceding year after nosocomial infection. One of them was diagnosed as pulmonary tuberculosis by chest radiograph, and antituberculosis chemotherapy was started. Other three started chemoprophylaxis. The chemoprophylaxis subjects might increase 4, if basic value of tuberculin reaction had not been available by two-step tuberculin skin test in the previous year. We could identify persons in whom tuberculin reaction became stronger by comparing the test results after exposure with the result of two-step tuberculin skin test in the preceding year. It is considered that two-step tuberculin skin test is very useful to efficiently execute the protective measure.

[Clinical evaluation of patients with pulmonary tuberculosis during the past 10 years in our hospital]

The background of patients who died of active pulmonary tuberculosis during 10 year's period (1989 to 1998). Of 973 tuberculosis patients, 76 patients died, of which 56 died of non-tuberculosis, and 20 died of tuberculosis. A total of 12 patients died within 3 months after being hospitalized. The period from hospitalization to death was significantly shorter in tuberculosis patients with independent gait failure, original treatment, without tuberculosis medical history, and no drug resistance. We considered that in tuberculosis death, severe tuberculosis itself is the cause of early death, and recurrence and drug resistance patients are the most serious problems in later deaths.

Invasive pulmonary aspergillosis with thrombosis in the left atrium

We report a female patient with left atrial wall invasion from pulmonary aspergillosis. She had been treated for diabetes mellitus. Pulmonary aspergillosis extended to the left atrial wall via the left pulmonary vein and formed a polypoid lesion in the left atrium. The polypoid lesion was composed of thrombus, and the thrombus increased in size to become large, and it showed invagination into the mitral valve during diastole. We considered that the thrombus was formed on the injured endocardium. Severe invasive aspergillosis thus could occur in a mild systemic immunocompromised host.

[Desensitization therapy for allergic reactions of antituberculous drugs--evaluation of desensitization therapy according to the guideline of the Japanese Society for Tuberculosis]

We prospectively evaluated the effectiveness of desensitization therapy for cases showing side-effects to antituberculous drugs (Isoniazid and Rifampicin) according to the guideline proposed by the Treatment Committee of the Japanese Society for Tuberculosis. Nineteen patients (23-88 years old, male 9, female 10) who had experienced adverse effects after receiving antituberculous drugs and underwent desensitization therapy between August 1998 and March 2000 were studied. Underlying diseases were 14 cases of pulmonary tuberculosis, 2 cases of cervical tuberculous lymphadenitis, 1 case of pulmonary atypical mycobacteriosis, 1 case of pulmonary tuberculosis and tuberculous pleuritis, 1 case of pulmonary tuberculosis and tuberculous lymphadenitis. The regimens of treatment for tuberculosis were INH + RFP + EB in 8 cases, INH + RFP + EB + PZA in 7 cases, INH + RFP + SM in 2 cases, INH + RFP + SM + PZA in 1 case, and INH + RFP in 1 case. Adverse reactions were 8 cases of eruption, 7 cases of drug fever, 3 cases of drug fever and eruption, and 1 case of drug fever and cervical lymphadenopathy. The causative drugs suggested from DLST or the clinical course were RFP in 17 cases and INH in 8 cases. The clinical effect of desensitization therapy for these antituberculous drugs was good in 14 out of the 17 cases (82%) for RFP, and in 6 out of 8 cases (75%) for INH. The effectiveness rate of the present desensitization therapy according to the guideline of the Japanese Society for Tuberculosis was almost equal to that of previous desensitization therapy, and the clinical results were almost same in present and previous studies despite the different methods of administration of the antituberculous drugs.

Inflammatory pseudotumor of the bladder in neonates

Inflammatory pseudotumors of the bladder are rare in children. We describe a 7-day-old male neonate with inflammatory pseudotumor of the bladder. He presented with a 3-day history of macroscopic hematuria. Ultrasonography, computed tomography and cystoscopy showed an intravesical mass arising from the right lateral wall. Pathologic findings obtained by open excision revealed that the tumor had spindle-shaped cells without significant atypia infiltrating into submucosal fibrous tissue. There has been no evidence of recurrent tumor 12 months post-operatively. To our knowledge our case is the first presentation in a neonate among the reported pediatric cases.

[Desensitization therapy for antituberculous drugs]

We retrospectively evaluated the effectiveness of desensitization therapy for antituberculous drugs (Rifampicin and Isoniazid) in 28 cases (29 episodes) with adverse reactions to these drugs. Desensitization therapy for RFP was performed in 23 cases (24 episodes) with administration of a first dose of 1-150 mg and a final dose of 300-450 mg for 1-29 days. The success rate of this therapy was 79% (19 of 24 episodes). Desensitization therapy for INH was performed in 12 cases with administration of a first dose of 2.5-100 mg and a final dose of 200-400 mg for 3-25 days. The success rate of this therapy was 83% (10 of 12 cases). Based on a comparative study of cases between successful and unsuccessful desensitization to RFP and INH it was concluded that there were no significant differences with regard to allergic history, adverse effects and their periods of appearance, the first dose and final dose of administration and the interval of administration, starting periods of the desensitization therapy and the periods of appearance of adverse effects due to this therapy. We evaluated desensitization therapy for two antituberculous drugs (RFP and INH) for tuberculous patients for whom the use of such drugs was restricted because of adverse effects, and we found it is a useful treatment, showing a high rate of success (80%).

[Two-step tuberculin skin testing in our hospital employees]

To evaluate the baseline values of tuberculin reaction, two-step tuberculin skin testing was carried out in 365 employees of our hospital. We defined strongly response group when the size of erythema showed more than 30 mm or who showed strongly positive reaction. Two-step tuberculin skin testing was carried out in 165 hospital employees excluding those who were defined as the strongly response group in the first testing. 80 hospital employees (48.5%) became strongly response group by the second tuberculin skin testing. Altogether, 76.7% of all employees were strongly response group either by the first time or the second tuberculin skin testing. The size of erythema and that of induration showed 13.2 +/- 12.6 mm (mean +/- SD), 6.9 +/- 9.2 mm increase, respectively, in the two-step tuberculin skin testing, so-called Booster phenomenon. We could not know the true tuberculin reaction status by the single tuberculin skin testing. Therefore, two-step tuberculin skin testing is important as one of an infection prevention countermeasures in the hospital workers.

A giant urinoma in a neonate without obstructive uropathy

We report a neonate with a giant urinoma and renal failure. A 7-day-old boy had a giant abdominal mass of 6.5 cm x 8 cm in the right quadrant, gastroesophageal reflux, and renal failure caused by the compression from the mass. Radiological observations revealed a multiseptated cyst and neither kidney could be detected. To relieve these symptoms percutaneous drainage was performed. The contents of the fluid were similar to the patient's urine. The symptoms were improved by the drainage, and we found the left kidney to be absent and the right kidney small. Four prenatal ultrasound scans detected no cystic lesions in his abdomen. Neonatal urinomas are commonly complicated by obstructive uropathy, such as posterior urethral valves or ureteropelvic junction obstruction. These obstructive uropathies were ruled out by retrograde pyelography and voiding cystourethrography. A severely dilated upper pole of a double collecting system was also ruled out by intravenous pyelography and direct observation of the kidney during an open biopsy. The cause of the urinoma is still uncertain, but trauma during delivery and the dysplastic right kidney may be involved.

[Erdheim-Chester disease presenting with pulmonary lesion]

A 49-year-old man first visited our hospital in 1991 for further examination of abnormal pulmonary shadows. A chest radiograph and computed tomographic (CT) scan showed diffuse reticular shadows in both lung fields. The findings from a transbronchial lung biopsy specimen were not conclusive. Although there was little change in the abnormal pulmonary shadows, the patient's lung functions gradually deteriorated, indicating an obstructive defect. The patient was admitted in 1998 with the chief complaint of increasing dyspnea on exertion. A thoracoscopic lung biopsy specimen revealed proliferation of histiocytes with fibrosis in the pleura and perivascular interstitium. Immunohistochemically, the histiocytic cells were CD68-positive, alpha 1-antichymotripsin-positive, S100 protein-negative, and CD1a-negative. A bone scintigram and magnetic resonance images showed symmetrical diametaphyseal bone lesions in the distal femurs and the proximal tibiae; however, the epiphyses were spared. These findings were consistent with Erdheim-Chester disease. This is the first reported case of Erdheim-Chester disease with pulmonary involvement in Japan.

Congenital vesicovaginal fistula

Congenital vesicovaginal fistula is a very rare entity, the etiology of which has not been clearly elucidated because pathologic features have not been mentioned in previous reports. The case of a 4-year-old girl having incontinence resulting from a congenital vesicovaginal fistula joining with the left ectopic ureter from the hypoplastic kidney is described. This is thought to be the first presentation of congenital vesicovaginal fistula joining with ectopic ureter. A microscopic examination revealed the fistula consisting of transitional cell epithelium, suggesting an abnormal fusion of the ureteral bud and caudal end of the müllerian duct with the urogenital sinus.

Sjögren's syndrome with primary biliary cirrhosis, complicated by transverse myelitis and malignant lymphoma

A 53-year-old woman with Sjögren's syndrome (SS) and primary biliary cirrhosis (PBC) complicated by transverse myelitis (TM) and malignant lymphoma (ML) is reported. TM has been described only in seven cases of primary SS, including three with PBC and four without PBC. The features of SS associated with PBC and complicated by TM were less typical compared with those seen in SS without PBC complicated by TM. This case is the first report of a case with SS, PBC, TM and ML. SS in association with PBC is, in general, overlooked, but such cases must be investigated with great caution for extraglandular complications.

Comparative antimicrobial activities of the newly synthesized quinolone WQ-3034, levofloxacin, sparfloxacin, and ciprofloxacin against Mycobacterium tuberculosis and Mycobacterium avium complex

WQ-3034 is a newly synthesized acidic fluoroquinolone. We assessed its in vitro activity against Mycobacterium tuberculosis and M. avium complex using levofloxacin (LVFX), ciprofloxacin (CPFX), sparfloxacin (SPFX), and KRM-1648 (KRM) as reference drugs. The MICs of these agents were determined by the agar dilution method with 7H11 medium. The MICs at which 50 and 90% of the test strains were inhibited (MIC(50)s, and MIC(90)s, respectively) for the test quinolones for rifampin (RMP)-susceptible M. tuberculosis strains were in the order SPFX < LVFX SPFX >/= LVFX > WQ-3034 > CPFX. The efficacies of all quinolones against intracellular M. tuberculosis organisms were significantly lower in A-549 cells than in MM6-Mphis. WQ-3034 at the MIC caused more marked growth inhibition of intramacrophage M. tuberculosis than did LVFX. These findings indicate that the in vitro anti-M. tuberculosis activity of WQ-3034 is greater than that of CPFX and is comparable to that of LVFX.

[Limited-form Wegener's granulomatosis without anti-neutrophil cytoplasmic antibody]

A 78-year-old woman was admitted because of dry cough and weight loss. A computed tomographic (CT) scan of the thorax showed multiple masses in both lungs with and without cavitation. No other organ lesions were detected. The patient was seronegative for antineutrophil cytoplasmic antibody (ANCA) and a routine sputum culture was normal. Because specimens from transbronchial and CT-guided transluminal lung biopsies disclosed non-specific granuloma with necrosis, an excisional biopsy of the mass by video-assisted thoracoscopic surgery was performed. The specimens contained geographic basophilic necrosis with palisading histiocytes, giant cells, and neutrophils. A limited form of Wegener's granulomatosis was diagnosed on the basis of the clinical and pathological features and effects of treatment.

[Refluxing megaureter in infancy--the significance of differentiation from primary high grade VUR]

BACKGROUND

Recent advance of perinatal ultrasound screening and/or physician's awareness of renal damage from recurrent pyelonephritis has brought about the increasing number of infants with primary vesicoureteral reflux (VUR) including refluxing megaureter which should be conceptually differentiated from simple high grade VUR. We evaluated the clinical outcome of infants diagnosed with refluxing megaureter.

PATIENTS AND METHODS

We retrospectively reviewed the clinical records of 15 infants (17 ureters) diagnosed as refluxing megaureter (max caliber > or = 10 mm) at our institution from 1988 to 1997. We compared the clinical outcome of refluxing megaureter with that of high grade VUR. (Results) Patients were 13 boys and 2 girls. Megaureter was unilateral in 13 patients and bilateral in 2. Fourteen infants (93.3%) presented with febrile urinary tract infection (UTI). The diameter of megaureter was 10-21 mm (average: 13.6 +/- 4.0 mm) at excretory urogram. Nine of 15 infants (60.0%) had breakthrough urinary infection. Its incidence was significantly higher than that of high grade VUR (21.3%) (p = 0.02). In 13 cases surgical treatments were performed, however 2 cases (max caliber: 16 mm, 21 mm) by Politano-Leadbetter or Paquin procedure required re-ureteroneocystostomy by Psoas-hitch procedure because of persistent reflux and recurrent UTI. On the other hand no patient required re-ureteroneocystostomy in high grade VUR.

CONCLUSION

It is important to differentiate refluxing megaureter from high grade VUR due to high incidence of breakthrough UTI. Ureteral remodeling and/or Psoas-hitch procedure are strongly recommended for adequate length of submucosal tunnel in refluxing megaureter.

Renal cell carcinoma in children: experience at a single institution in Japan

PURPOSE

We analyzed the presentation, treatment and survival of 4 children with renal cell carcinoma.

MATERIALS AND METHODS

We retrospectively reviewed the pathological and hospital records of 4 Japanese children diagnosed with renal cell carcinoma at our hospital from 1970 to 1998.

RESULTS

In the 1 boy and 3 girls with an average age of 8 years 7 months at diagnosis the most common presenting complaints were gross hematuria in 75% and a palpable abdominal mass in 50%. Computerized tomography revealed characteristic calcification within the tumor in 3 of the 4 patients (75%). In the remaining case the lesion had high density areas with microcalcification, as confirmed by histopathological study. In 2 patients with regional lymph node metastasis calcification was also observed in the metastatic lesions. Disease was stages I to III in 1, 1 and 2 patients, respectively. All patients underwent transabdominal nephrectomy with regional lymphadenectomy. One patient with stage I disease had multiple metastases 15 months later and died of disease 55 months postoperatively. However, the remaining 3 patients received adjuvant interferon therapy and they are without evidence of recurrence a mean of 51.3 months postoperatively.

CONCLUSIONS

Calcification within the tumor and/or metastatic lesions or high density areas in the tumor on screening computerized tomography are characteristic findings suggestive of pediatric renal cell carcinoma. Adjuvant therapy with interferon may provide some benefit in select pediatric patients. Further studies of a larger number of pediatric renal cell carcinoma cases may be necessary to establish the optimal diagnostic and therapeutic regimen.

Bronchocentric granulomatosis due to Aspergillus terreus in an immunocompetent and non-asthmatic woman

This is the first report of bronchocentric granulomatosis due to Aspergillus terreus in a healthy and non-asthmatic 74-year-old Japanese woman. Following identification of the fungus, oral itraconazole therapy was begun after intrabronchial infusion of amphotericin B. No recurrence has occurred after treatment for 24 months. We should consider the possibility of bronchocentric granulomatosis including Aspergillus terreus, when an intrabronchial lesion is found even in a healthy and non-asthmatic person. Oral itraconazole after intrabronchial infusion of amphotericin B seems to be effective in such cases.

[The present status and the task of nosocomial tuberculosis infection in Japan]

The present study aimed to assess the status of preventive measures for nosocomial tuberculosis infection and the incidence of tuberculosis among hospital workers in Japan. Data were collected using two types of questionnaires submitted to 333 hospitals with tuberculosis beds and 247 hospitals without tuberculosis beds. The incidence of tuberculosis among hospital workers was assessed for the period from 1992 to 1996. Handling of the tuberculin test and BCG vaccination at the time of employment was inadequate. Environmental management of the workplace in laboratories and tuberculosis wards was also in adequent. Regarding the incidence of tuberculosis among hospital workers, nurses at hospitals with tuberculosis beds had the highest incidence especially those in their twenties to thirties. Considering these findings, improvement of the prevention of tuberculosis infection in hospitals is important.

Intrabronchial Aspergillus nidulans infection in an immunocompetent man

We describe the first report of intrabronchial Aspergillus nidulans infection in an immunocompetent patient, which fit the description of bronchocentric granulomatosis. The patient had a history of accidental aspiration of light grade oil. Fiberoptic bronchoscopy revealed that the right B4aii alpha was obstructed. Endobronchial biopsy specimens contained fungal hyphae. The fungus was confirmed to be Aspergillus nidulans by culture. We suspected that aspiration of light grade oil had injured the bronchial mucosa, after which airborne Aspergillus nidulans had entered the lesion and multiplied. Intrabronchial fungal infection can occur in a healthy person without immunologic abnormalities, if a bronchial lesion provides an entry portal.

Hemorrhagic enteritis associated with Clostridium perfringens type A in a dog

A female Shetland sheep dog died suddenly with hemorrhagic diarrhea and vomitting, and was examined pathologically and microbiologically. Gross pathological change was restricted to the intestinal tract. The intestine contained watery, blood-stained fluid. Histopathologically, the principal intestinal lesion was superficial mucosal hemorrhagic necrosis at the jejunoileum. Many Gram-positive bacilli were found adhering to the necrotic mucosal surface in parts of the intestinal tract. Clostridium perfringens in pure culture were isolated from jejunal contents by anaerobic culture. These results suggested that the typical lesion of this case coincided with canine hemorrhagic enteritis and enterotoxemia due to C. perfringens infection could be the cause of sudden death.

Determination of potassium flux activity of viable human erythrocytes by measuring the release-influx ratio

A simple and convenient method to determine the K+-flux activity of viable human erythrocytes was developed. Erythrocyte suspensions were incubated at 4 degrees C for 24 h to induce K+-release (deltaKr) and then at 37 degrees C for 3 h to influx K+ into erythrocytes (deltaKi). A straight-line relationship between K+ release-influx ratio and ouabain-induced K+-efflux from erythrocytes indicated that deltaKi/deltaKr ratio or the K+-flux activity was reflected predominantly by Na+/K+-exchanging ATPase activity. Using this method, K+-flux activity of erythrocytes in the young and the aged subjects was measured. The mean deltaKi/deltaKr ratio of the aged subjects was decreased significantly. This method of measuring deltaKi/deltaKr ratio is useful for the evaluation of K+-flux activity of viable erythrocytes.

[Clinical analysis of foreign patients with tuberculosis found in Chugoku-Shikoku area]

In this study, we investigated 45 foreign patients who had been diagnosed as having tuberculosis in Chugoku-Shikoku area during the past 12 years. Regarding regional characteristics, in Hiroshima prefecture an epidemic of tuberculosis was experienced among patients coming from South America, but antituberculous therapy was performed for 87% of the patients because of the high coverage of the health insurance scheme. But in Okayama prefecture, most of the patients were female and came from Asian countries, such as, the Philippines. Antituberculous therapy was not performed for nine patients because of no coverage of the health insurance scheme. In the other prefectures, only a few cases of tuberculosis were experienced, but in Yamaguchi prefecture two of three foreign patients were multidrug-resistant tuberculosis.

[Clinical study on cystinuria in children--the stone management and the prevention of calculi recurrence]

BACKGROUND

Cystinuria is an autosomal recessive disorder, and primary manifestation is the repeated formation of cystine calculi. Little information is available regarding clinical course of pediatric cystinuria having followed into adulthood. We report our experience with the management and the clinical course on cystinuria in children, who have been followed up for relatively long time.

MATERIALS AND METHODS

We retrospectively reviewed the records of all pediatric patients with cystinuria in whom urolithiasis was treated from 1970 to 1996.

RESULTS

A total of 15 pediatric patients with cystine calculi (9 boys, 6 girls) were treated in our hospital. Average age at diagnosis was 3 years 4 months old. Mean follow-up was 104 months. Stone location was upper urinary tract in 11 cases, bladder in 3 cases and both upper urinary tract and bladder in 1 case. Medical treatments including hydration, urine alkalization and dissolution therapy were performed in all patients. In three cases whose urinary cystine level ranged from 138 to 326 mg/gCr, cystine calculi were disappeared by medical therapy alone. In one of 3 cases vesicoureteral reflux was identified. Side effects were noticed in 30.0% of patients with tiopronin and in 85.7% of those with D-penicillamine, especially in 1 case with tiopronin nephrotic syndrome being noticed. Surgical procedures were performed in 13 patients (lithotomy: 17 calculi, endourology: 7 calculi and ESWL: 7 calculi). The stone free rate was 100% with lithotomy, 80 to 100% with endourology and 43% with ESWL at an average of 5.9 procedures. No complications were recognized after the surgical treatments. The stone events of 15 patients ranged from 0 to 1.5 (average 0.55). In all six patients followed up over the age of 20 years, stone recurrences were observed exclusively between 17 and 20 years of age.

CONCLUSION

Dissolution therapy is more effective for cystinuric patients in whom urinary cystine excretion is less than 330 mg/gCr. For those cases with low urinary cystine level it is necessary to evaluate structural abnormalities of the urinary tract to avoid stone recurrence. ESWL and endourology should be tried for pediatric cystinuria except for neonates and infants, considering its safety. The patients and their parents must have adequate knowledge about the disease itself and its management. Prevention of cystine calculi recurrences depends on patient compliance to the therapeutic regimens necessitating close follow up according to the clinical conditions, especially for those in pubertic or postpubertic age.

Evaluation of two commercial diagnostic kits for Mycobacterium tuberculosis completely based on bacterial DNA and rRNA amplification for direct detection of tubercle bacilli in sputum specimens

The Roche Amplicor Mycobacterium Tuberculosis Kit (Amplicor PCR) and Gen-Probe Amplified Mycobacterium Tuberculosis Direct Test (MTD) were compared for efficiency in the direct detection of tubercle bacilli in sputum specimens. In total, 72 sputum specimens obtained from patients with active tuberculosis were examined with the Amplicor PCR and MTD kits. Of the 72 test specimens, 45 and 41 samples were positive by the Amplicor PCR and MTD methods, respectively. These values were larger than those obtained by the culture method (Septi-Chek) and acid-fast bacilli-smear test, yielding 37 and 20 positive results, respectively, and the sensitivities were as follows: smear, 39.2%; culture, 72.5%; Amplicor PCR, 88.2%; MTD, 80.4%. Amplicor PCR was similarly or somewhat more sensitive in direct detection of M. tuberculosis in sputum samples from patients with clinically active tuberculosis than was MTD.

Indirect recognition of porcine xenoantigens by human CD4+ T cell clones

BACKGROUND

Human T-cell response against xenogeneic antigens may occur either by direct recognition of antigens on xenogeneic antigen-presenting cells (APCs) or by an indirect pathway mediated by autologous APCs.

METHODS

The proliferative response of human CD4+ T cells to porcine aortic endothelial cells (PAECs) was measured. From these T-cell lines, eight CD4+ T-cell clones were obtained by limiting dilution.

RESULTS

CD4+ T cells, in the absence of monocytes, proliferated in response to PAECs only after swine leukocyte antigen (SLA) class II molecules were induced on PAECs. The proliferation was significantly better when autologous human monocytes were added back as APCs. All of the eight CD4+ T-cell clones demonstrated specific proliferative response when stimulator PAECs, but not PAECs of other porcine origins, were preincubated with autologous human APCs before addition of these clones. These results indicated that the clones are recognizing porcine xenoantigens presented by self-APCs. The proliferative response of CD4+ T-cell clones was blocked by antibodies directed against human leukocyte antigen class II and human CD4, but not by anti-SLA class II monoclonal antibodies. A marked inhibition in proliferation was also noted when human APCs were incubated with chloroquine before addition to the cultures, indicating that xenoantigens had to be processed in order to be recognized by the clones.

CONCLUSIONS

Human CD4+ T cells can recognize xenoantigens by either a direct or indirect pathway. The CD4+ T-cell clones developed against SLA class II-negative PAECs recognized strain-specific porcine xenoantigens indirectly.

[The diagnostic value of thoracoscopic examinations in tuberculous pleurisy]

We evaluated the diagnostic value of thoracoscopic examinations in eleven patients who had pleural effusion and were diagnosed as tuberculous pleurisy. The characteristic white or yellowish-white micronodules were observed by thoracoscopy in eight patients and all their biopsied tissue were compatible with tuberculosis. We had some cases which were not determined as tuberculous pleurisy from bacteriological examinations and were determined only from the thoracoscopic findings.

[A clinicopathological study of 218 patients with bladder carcinoma treated by radical cystectomy]

Between 1986 and 1995, 218 patients with primary carcinoma of the bladder were treated with radical cystectomy at our hospitals. Clinicopathological specimens and the relative value of prognostic factors were analyzed with both the univariate and multivariate method. Univariate analysis indicated that age, sex, pathological tumor stage, grade, vessel involvement, tumor infiltrating type and positive nodes were predictive of poor cancer-specific survival. Multivariate analysis demonstrated that female patients were predictive of poor cancer-specific survival. As for the risk ratio, the prognostic factors in lymphatics involvement and tumor infiltrating type were 2.77 and 2.47, respectively.

A prospective trial of steroid cessation after renal transplantation in pediatric patients treated with cyclosporine and mizoribine

We conducted a multi-center prospective study to evaluate the safety and efficacy of steroid withdrawal after renal transplantation in children. In 52 children (51 living-related donor transplants and 1 cadaver donor transplant), immunosuppressive therapy was started with cyclosporine (CyA), mizoribine (MZ), methylprednisolone (MPL) and anti-lymphocyte globulin. Administration of MPL was reduced to alternate days more than 6 months after transplantation, and attempts were made to withdraw it. Acute rejection was noted in 19 patients (36.5%) by 1 month after transplantation. The whole-blood CyA trough level using monoclonal antibody was 175.0+/-17.0 ng/ml in patients who developed acute rejection and 282.0+/-25.3 ng/ml in those who did not show acute rejection (p<0.01). During the 37 attempts at alternate-day MPL administration, clinical acute rejection was observed in only 1 patient and chronic rejection in 3. During 10 attempts to withdraw MPL, acute rejection was noted in 3 patients, but graft function recovered to the pre-rejection level after treatment of the acute rejection. At the last observation, graft function was lost in 3 patients, 22 were receiving MPL on alternate days, and MPL had been withdrawn from 7 for a mean period of 16.7 months. The survival rate of the patients and the grafts was 100% and 94% after an average follow-up period of 4 years. Evaluation of growth showed catch-up growth in all patients during the withdrawal period.