Use of collagen sponge incorporating transforming growth factor-beta1 to promote bone repair in skull defects in rabbits.

The objective of this study was to evaluate the potential of collagen sponge incorporating transforming growth factor-beta1 (TGF-beta1) to enhance bone repair. The collagen sponge was prepared by freeze-drying aqueous foamed collagen solution. Thermal cross-linking was performed in a vacuum at 140 degrees C for periods ranging from 1 to 48 h to prepare a number of fine collagen sponges. When collagen sponges incorporating 125I-labeled TGF-beta1 were placed in phosphate-buffered saline (PBS) solution at 37 degrees C, a small amount of TGF-beta1 was released for the first hour, but no further release was observed thereafter, irrespective of the amount of cross-linking time the sponges had received. Collagen sponges incorporating 125I-labeled TGF-beta1 or simply labeled with 125I were implanted into the skin on the backs of mice. The radioactivity of the 125I-labeled TGF-beta1 in the collagen sponges decreased with time; the amount of TGF-beta1 remaining dependent on the cross-linking time. The in vivo retention of TGF-beta1 was longer in those sponges that had been subjected to longer cross-linking times. The in vivo release profile of the TGF-beta1 was matched with the degradation profile of the sponges. Scanning electron microscopic observation revealed no difference in structure among sponges subjected to different cross-linking times. The TGF-beta1 immobilized in the sponges was probably released in vivo as a result of sponge biodegradation because TGF-beta1 release did not occur in in vitro conditions in which sponges did not degrade. We applied collagen sponges incorporating 0.1 microg of TGF-beta1 to skull defects in rabbits in stress-unloaded bone situations. Six weeks later, the skull defects were covered by newly formed bone, in marked contrast to the results obtained with a TGF-beta1 free empty collagen sponge and 0.1 microg of free TGF-beta1. We concluded that the collagen sponges were able to release biologically active TGF-beta1 and were a promising material for bone repair.     

Inhibition of cellular DNA synthesis in hamster kidney cells infected with western equine encephalitis virus

Summary Infection of BHK cells with western equine encephalitis (WEE) virus resulted in rapid inhibition of cellular DNA synthesis. The rate of inhibition of DNA synthesis depended on the multiplicity of infection, and was closely related to virus replication. Cellular DNA synthesis was not inhibited in infected BHK cells that had been irradiated with ultraviolet radiation. These results indicated that a functional viral genome was required for the inhibition of DNA synthesis by WEE virus. The sharp decrease in thymidine incorporation into the acid-insoluble fraction was not due to a change in the intracellular pool of the acid-soluble fraction. Sedimentation analysis in alkaline sucrose gradients was used to show that cellular DNA was not degraded during WEE virus infection. DNA polymerase activity in infected cells was not significantly reduced.With 4 Figures     

Comparison of standard and hand-assisted laparoscopic radical nephrectomy for renal cell carcinoma.

A laparoscopic radical nephrectomy (LRN) for renal cancer can be performed using two methods, hand-assisted laparoscopic surgery (HALS) and standard laparoscopic surgery (SLS). This institute initially used HALS to perform all radical nephrectomy, but gradually shifted to SLS. This study compared the two methods of radical nephrectomy: HALS vs. SLS, which were performed at a single institute. From March 1999 to November 2006, a total 129 patients with pathologically confirmed renal cell carcinoma underwent LRN, including 73 patients with the HALS and 56 patients with SLS. The median operative time was 264 minutes, and median estimated blood loss was 200 ml in the HALS group, respectively. The median operative time and median estimated blood loss in the SLS were 215 minutes and 100 ml, respectively. There was no significant difference in either the operative time or estimated blood loss between HALS and SLS. The median time to both postoperative oral intake and ambulation in the SLS were 1 day. Neither of these events after SLS was significantly shorter than that after HALS. The 4-year disease-free and overall survival rates in the HALS patients were 97.5% and 98.2%, respectively. Both the 4-year disease-free and overall survival rates in the SLS patients were 100%. Since no significant differences were observed between the two operative methods (SLS and HALS) regarding the operative data, postoperative course and oncological outcome, the surgical method for LRN can be selected according to characteristics of each surgical method.     

Elemental distributions and microtensile bond strength of the adhesive interface to normal and caries-affected dentin

The aim of this study was to evaluate the microtensile bond strength (microTBS) and the elemental contents of the adhesive interface created to normal versus caries-affected dentin. Extracted human molars with coronal carious lesions were used in this study. A self-etching primer/adhesive system (Clearfil Protect Bond) was applied to flat dentin surfaces with normal and caries-affected dentin according to the manufacturer's instructions. After 24 h water storage, the bonded specimens were cross-sectioned and subjected to a microTBS test and electron probe microanalysis for the elemental distributions [calcium (Ca), phosphorus (P), magnesium (Mg), and nitrogen (N)] of the resin-dentin interface after gold sputter-coating. The microTBS to caries-affected dentin was lower than that of normal dentin. The demineralized zone of the caries-affected dentin-resin interface was thicker than that of normal dentin (approximately 3 microm thick in normal dentin; 8 microm thick in caries-affected dentin), and Ca and P in both types of dentin gradually increased from the interface to the underlying dentin. The caries-affected dentin had lost most of its Mg content. The distributions of the minerals, Ca, P, and Mg, at the adhesive interface to caries-affected dentin were different from normal dentin. Moreover, a N peak, which was considered to be the collagen-rich zone resulting from incomplete resin infiltration of exposed collagen, was observed to be thicker within the demineralized zone of caries-affected dentin compared with normal dentin.     

Appearance of the LAT protein at an early stage of B-cell development and its possible role

The linker protein LAT is expressed mainly in T and natural killer (NK) cells. LAT-deficient mice have an arrest of intrathymic T-cell development at the CD4+ CD8+ stage and lack mature T cells in the periphery. However, no gross abnormality in development and function of the B and NK cells has been described. Here we report that LAT is expressed in mouse progenitor B (pro-B) and precursor B (pre-B) cells, but not in immature or mature B cells. LAT in pre-B cells becomes tyrosine phosphorylated upon cross-linking of the pre-B-cell receptor (pre-BCR) by anti- micro antibody. Incubation of 1xN/2b (mouse pre-B-cell line) cells or bone marrow cells from microMT/ microMT mice, which lack B cells after the small pre-B-cell stage, with anti-Ig beta antibody resulted in the downregulation of LAT expression. Transgenic mice which expressed LAT protein in B-lineage cells showed an increased proportion of pro- and large pre-B cells in the bone marrow and a remarkable reduction in the numbers of mature B cells in peripheral lymphoid tissues. Collectively, the present results indicate that LAT is expressed in the cells at the early stages of B-lineage development, but is absent in immature and mature B cells. LAT may play a crucial role in the negative regulation of B-cell development at the transition from pre-B to mature B-cell stages, and signal(s) via the pre-BCR may extinguish LAT expression, thus allowing pre-B-cell differentiation towards the mature B-cell stage.     

Can random bladder biopsies be eliminated after bacillus Calmette–Guérin therapy against carcinoma in situ?

Purpose

Intravesical bacillus Calmette–Guérin (BCG) is the standard of care for bladder carcinoma in situ (CIS). The response to BCG therapy against CIS is generally assessed by random bladder biopsy (RBB). In this study, we examined the necessity of routine RBB after BCG therapy.

Methods

We retrospectively identified 102 patients who were initially diagnosed with CIS with or without papillary tumor and received subsequent 6–8-week BCG therapy. Thereafter, all patients underwent voiding cytology analysis, cystoscopy, and RBB to evaluate the effects of BCG therapy. We evaluated the association between clinical parameters (voiding cytology and cystoscopy findings) and the final pathological results by RBB specimens.

Results

According to the pathological results of RBB, 30 (29%) patients had BCG-unresponsive disease (remaining urothelial carcinoma was confirmed pathologically) and 20 were diagnosed with CIS. Positive/suspicious voiding cytology and positive cystoscopy findings were well observed in patients who had BCG-unresponsive disease compared with their counterparts (p?=?0.116, and p?<?0.001, respectively). The sensitivity (Sen.), specificity (Spe.), positive predictive value (PPV), and negative predictive value (NPV) of voiding cytology were 50%, 68%, 39%, and 77%, respectively. The values for cystoscopy findings were as follows: Sen.: 87%, Spe.: 57%, PPV: 46%, and NPV: 91%. The values for their combination (having either of them) were as follows: Sen.: 100%, Spe.: 44%, PPV: 43%, and NPV: 100%.

Conclusion

RBB after BCG therapy for patients with negative voiding cytology and negative cystoscopy may be omitted because their risk of BCG-unresponsive disease is significantly low (NPV: 100%).

     

Bullous pemphigoid in patients receiving peritoneal dialysis: a case series and a literature survey

Bullous pemphigoid (BP) is an autoimmune subepidermal blistering disease. Although several cases of BP in end-stage renal disease patients receiving peritoneal dialysis (PD) or hemodialysis have been reported, the incidence of BP in these patients remains unknown. We recently experienced three PD patients diagnosed with BP. The skin injury was likely to be a trigger of BP in all the three PD patients. Nifedipine and icodextrin exposures were possible factors directly or indirectly affecting the onset of BP, because they were common in the three cases. We also report that the incidence of BP in PD patients was 3/478.3 person-years in a single-center 10-year study. This case series with a literature survey describes that the skin and tissue injuries are potential triggers responsible for the onset of BP in dialysis patients and that the incidence of BP in these patients seems to be much higher than that in the general population.     

Comparison of reliability,validity and responsiveness of the Japanese Orthopaedic Association Shoulder 36 Ver. 1.3 among different diagnoses of shoulder lesions

BackgroundShoulder 36 (Sh-36) is an original quality of life measure for shoulder lesions with high reliability and validity; however, in some cases, especially in those with a Bankart lesion, we observed no improvement in Sh-36 during the postoperative follow-up. Sh-36 may be less effective for a certain shoulder lesion. This study aimed to compare the reliability, validity, and responsiveness of Sh-36 among different representative diagnoses of shoulder lesions.MethodsSh-36 and the Disability of the Arm, Shoulder and Hand (DASH) were measured in 192 patients with a Bankart lesion (Bankart group), rotator cuff tear (Cuff group), and SLAP lesion (SLAP group) who underwent arthroscopic surgery. Both measures were evaluated before surgery, and at 3, 6, 9, 12, 18, and 24 months postoperatively, and reliability, validity, and responsiveness of Sh-36 and the DASH were compared among the three groups.ResultsSignificant postoperative improvement was observed in the three groups (p < 0.0001) within 9 months. No marked improvement was observed after 9 months in the Bankart and SLAP groups due to the ceiling effect; however, most domains of Sh-36 increased continuously in the Cuff group during the whole follow-up period. Reliability and construct validity were sufficient in all the groups. The longitudinal validity was sufficient in most domains for the three groups; however, the standardized response mean in the Bankart group was lower than that in other two groups, indicating low responsiveness in this group because of the ceiling effect.ConclusionsSh-36 was a valid and reliable instrument in patients who have undergone arthroscopic shoulder surgery, especially for patient with a rotator cuff tear with high responsiveness. However, Sh-36 had lower standard response mean representing lower responsiveness in the Bankart group due to the ceiling effect and may not be ideal for longitudinal follow-up in patients with a Bankart lesion.