BRCT domain of DNA polymerase μ has DNA-binding activity and promotes the DNA polymerization activity

DNA polymerase μ (pol μ) catalyzes nonhomologous end-joining in DNA double-stranded break repair. Pol μ consists of an amino-terminal BRCA1 carboxyl-terminal homology (BRCT) domain and a pol β-like region, which contains the catalytic site. By DNA cellulose column chromatography, using full-length pol μ and five different deletion mutants, we found that the amino-terminal region has double-stranded DNA (dsDNA)-binding activity. Pol μ without BRCT domain reduces the DNA polymerization activity when compared to full-length pol μ. Observation by atomic force microscopy showed that full-length pol μ binds to the ends and middle part of dsDNA. Pol μ lacking the amino-terminal region or with a mutation within the BRCT domain bound only to DNA ends, whereas the amino-terminal region with the BRCT domain bound to both the ends and the middle part of dsDNA (mpdDNA). Terminal deoxynucleotidyltransferase, which, like pol μ, belongs to the X family DNA polymerases, also bound to mpdDNA through its amino-terminal region.     

Impact of postgraduate education on physician practice for community-acquired pneumonia

Background Clinical practice guidelines on community‐acquired pneumonia (CAP) are widely recognized by hospitals in Japan; however, little is known about the effect of postgraduate education on physicians' adherence to the guidelines or on patient outcomes. Method We conducted a chart review of inpatient CAP cases at a single teaching hospital in Japan from 2003 to 2005, during which the educational programme for residents was gradually reinforced by the introduction of multifaceted education and training in the management of infectious diseases. To assess the effects of this educational programme, we measured process indicators such as usage of diagnostic tests, choice of antibiotics, and clinical outcomes, including length of antibiotic treatment, length of stay, and mortality. Results Several improvements were observed after educational intervention: (1) more frequent blood, sputum cultures, and Gram stain tests; (2) less frequent use of broad‐spectrum antibiotics as the initial empiric therapy (from 50% to 12%) and on hospital day 5 (from 66.7% to 10%); and (3) median length of stay was shorter after intervention (16.5 days to 13 days). Conclusions Our findings suggest that multifaceted educational intervention for residents focused on diagnostic efforts, including Gram stain and cultures, choice of antibiotics with the appropriate spectrum, and de‐escalation of antibiotics, can increase adherence to CAP guidelines as well as improve clinical outcomes.     

Molecular cloning and characterization of a novel human papillomavirus, HPV 126, isolated from a flat wart-like lesion with intracytoplasmic inclusion bodies and a peculiar distribution of Ki-67 and p53

Infection with certain human papillomavirus types induces warts with specific macroscopic and microscopic features. We observed multiple flat wart-like lesions on the chest, neck and extremities of an adult T-cell leukemia patient. Histologically, atypical intracytoplasmic inclusion bodies currently known to be pathognomonic for genus gamma or mu papillomaviruses were disclosed in some cells of the epidermis showing histological features compatible with flat warts. In the present study, a novel human papillomavirus was identified and its whole genome, 7326 bp in length, was cloned and characterized. Phylogenetic analysis showed the virus designated as HPV126 to be a novel type of genus gamma papillomavirus. Strikingly, Ki-67 and p53 expression was found to be increased in all layers of the epidermis except for horny layer, contrasting to expression restricted to the basal and lower spinous layers in ordinary flat warts.     

Spatiotemporal dynamics of intracellular calcium in the middle cerebral artery isolated from stroke-prone spontaneously hypertensive rats

The spatiotemporal dynamics of intracellular calcium within the middle cerebral artery (MCA) isolated from stroke-prone spontaneously hypertensive rats (SHR-SP) were investigated using real-time confocal laser microscopy. At 3 months of age (prestroke), rhythmical changes in the [Ca(2+)](i) during the tonic phase were found to precede vasomotion following application of 5-HT, but not other stimuli. These responses were not observed at 1 month of age; moreover, the MCA lost both responses post-stroke (5 months of age). When [Ca(2+)](i) was analysed in arteriolar smooth muscle cells, rhythmical changes in [Ca(2+)](i) occurred during the same cycle. Thus, these processes were synchronized. The synchronized rhythmical changes in [Ca(2+)](i) were abolished following application of 100 nM ketanserin and 10 μM nicardipine. Treatment with 60 nM charybdotoxin and 10 μM cyclopiazonic acid also significantly reduced rhythmical elevations in [Ca(2+)](i). In addition, rhythmical changes in [Ca(2+)](i) became unsynchronized following treatment with 100 μM carbenoxolone, a gap junction blocker. Connexin 45 mRNA and protein expression were both elevated in the MCA of SHR-SP. Taken together, these findings suggest that rhythmical changes in [Ca(2+)](i) of the MCA are dependent upon the 5-HT(2) receptor-mediated release of calcium from intracellular stores which, in turn, activates voltage-dependent calcium channels to enable an influx of calcium into smooth muscle cells. Subsequently, charybdotoxin-sensitive potassium channels are activated and provide a negative feedback pathway to regulate [Ca(2+)](i). Moreover, the co-ordinated synchronization of rhythmical changes in [Ca(2+)](i) across smooth muscle cells was found to be dependent upon gap junctions.     

The second therapeutic trial for children with hematological malignancies who relapsed after their first allogeneic SCT: Long-term outcomes

Nishikawa T, Inagaki J, Nagatoshi Y, Fukano R, Nakashima K, Ito N, Sawa D, Kawano Y, Okamura J. The second therapeutic trial for children with hematological malignancies who relapsed after their first allogeneic SCT: Long‐term outcomes. Abstract: The impact of a second all‐SCT on the long‐term outcomes of children who relapse after allo‐SCT has been unclear. We retrospectively analyzed the long‐term outcomes of different salvage treatments for such children. Sixty‐six children with hematological malignancies (40 ALL, 22 AML, three MDS, and one CML) who relapsed after a first allo‐SCT received either a second allo‐SCT (n = 16) or CTx and/or DLI (n = 50). The median follow‐up for all children was 9.1 yr. The five‐yr OS after relapse was significantly better in patients who underwent a second allo‐SCT (42.9%) than in patients treated with CTx and/or DLI (11.8%) (p < 0.05). However, this advantage diminished with increasing time. The eight‐yr OS for these groups of patients were 21.4% and 11.8%, respectively (p = n.s.). Among the 16 patients who received a second allo‐SCT, two died more than five yr after the second allo‐SCT. A second allo‐SCT can therefore lead to a prolonged OS in patients who relapse after allo‐SCT. However, a second allo‐SCT should be selected carefully. This is because the mortality rate is still high, even when there is an extensive duration of time following the second allo‐SCT.     

New method of assessing pinch function in children with anomalies of the hands

We designed a method for the evaluation of pinch function in children that uses a tape measure, which is suitable in size and weight for the infant's hand. Our aim was to investigate the value of the tape measure in the evaluation of pinch function in children. Thirty-two hands of 27 children with congenital anomalies that we operated on in our hospital were included. The assessment of pinch function was made using a tape measure. The criteria were evaluated as follows: grasp = 1; push button = 2; pinch the end of the measuring tape = 3; pull out tape by side pinch = 4; and pull out tape by pulp pinch = 5. We assessed the relation between the scoring by tape measure and parents' preoperative assessment. We also examined the relations between the increase in score evaluated by the tape measure method and parents' assessment of postoperative improvement in pinch function. The mean preoperative score by the tape measure assessment of pinch function in the unimpaired group according to the parents' evaluation was significantly higher than that in the impaired group. Preoperative evaluation using the tape measure method correlated with the parents' evaluation. The increase in score in the "remarkably improved" group was significantly higher than that of those in the "no change" and "improved" groups. The tape measure method reflected the parents' evaluation, and could be a useful test for the evaluation of pinch function in children.     

Observer variation study of the assessment and diagnosis of incidental colonic FDG uptake

Purpose

The aim of this study was to evaluate the interpretations of incidental colonic 18F-FDG uptake made by 10 experienced readers and to more clearly identify the pattern of suspicious colonic FDG uptake. The potential contributions of delayed FDG-PET scanning and of immune fecal occult blood testing (FOBT) in making a diagnosis were also analyzed.

Materials and methods

Visual interpretations by 10 readers were made for 147 FDG uptake sites from 126 PET scans (cancer, 38 sites; adenoma, 43 sites; and no abnormality, 66 sites) with colonic FDG uptake. Assessments for the early FDG-PET images were (1) FDG uptake pattern, (2) FDG uptake degree, and (3) likelihood of malignancy. For the delayed images, the assessments were (1) change in the FDG uptake position, (2) change in FDG uptake degree, and (3) likelihood of malignancy. The results of FOBT were analyzed independently of the visual interpretations.

Results

Interobserver agreement (κ) was 0.501 for assessing FDG uptake patterns, while agreement on assessing changes in uptake degree and changes in uptake position between early and delayed imaging were low (κ = 0.213–0.229). Logistic regression analysis indicated that ‘FDG uptake patterns’ and ‘FDG uptake degree’ were significantly related to decide on the suspicion of malignancy (p < 0.001) and the final result (p < 0.001). “Small localized” and “large irregular localized” types had a high probability of a lesion regardless of either (1) FDG uptake degree or (2) variation in the uptake between the early and the delayed image. The delayed image decreased false-positive cases for some FDG uptake patterns, but it had little impact on distinguishing clearly between “cancer or adenoma” and “normal”. The addition of FOBT had little impact on the diagnosis.

Conclusion

There was highest agreement among readers with respect to the recognition of specified colonic FDG uptake patterns, and this pattern recognition had the most influence on the diagnosis. “Small localized” and “large irregular localized” types had a high probability of a lesion. The addition of delayed imaging and of FOBT results to the early imaging did not have much impact on the diagnosis.     

Life-threatening risk factors and the role of intestinal transplantation in patients with intestinal failure

Purpose

We elucidated the life-threatening risk factors for intestinal failure (IF) and characterized the role of intestinal transplantation (ITx) in affected patients.

Methods

We conducted a retrospective review of 38 patients with short bowel (SB) and 19 with motility disorders (MD). The SB patients were divided into three categories according to the length of their residual small bowel and the presence of the ileocecal valve. The four disease subcategories were grouped into two categories: low-risk category (mild and moderated SB) and high-risk category (extensive SB and MD). The age at the introduction of parenteral nutrition (PN) was <1 year in 50 patients (infant group, IG) and 1–15 years in 7 patients (pediatric group, PG).

Results

Enteral autonomy was rarely achieved in the high-risk category (p < 0.0001). IG was associated with a higher incidence of developing intestinal failure-associated liver disease (IFALD) (p = 0.004). Eight patients died, due to IFALD in four, sepsis in three and acute heart failure in one. Twenty-eight patients (49 %) are currently alive without PN, including four after ITx.

Conclusion

The treatment of high-risk IF is still challenging. Inclusion of ITx in appropriate timing, along with aggressive medical, nutritional and surgical management, may reduce advanced morbidity and mortality of high-risk IF.