Devastating complication of negative pressure wound therapy after deep inferior epigastric perforator free flap surgery: A case report

BACKGROUND

Thermal injuries on free transferred or replanted tissues resulting from loss of sensibility are an infrequent occurrence. They require immediate and appropriate management before they progress to an irreversible condition. Although negative pressure wound therapy (NPWT) can prevent wound progression by increasing microcirculation, the inappropriate application of NPWT on complication-threatened transferred and replanted tissues can induce an adverse effect.

CASE SUMMARY

A 48-year-old woman who underwent immediate breast reconstruction with a deep inferior epigastric artery perforator free flap. While applying a heating pad directly to the flap site, she sustained a deep second to third-degree contact burn over 30% of the transferred flap on postoperative 7 d. As the necrotic changes had progressed, we applied an NPWT dressing over the burned area after en-bloc debridement of the transferred tissues on postoperative 21 d. After 4 d of NPWT application, the exposed fatty tissues of the flap changed to dry and brown-colored necrotic tissues. Upon further debridement, we noted that the wound gradually reached total necrosis with a collapsed vascular pedicle of deep inferior epigastric artery.

CONCLUSION

Although NPWT has been shown to be successful for treating various wound types, the significant risk of NPWT application in short-lasting reconstructed flap wounds after thermal injury should be reminded.

[Meta-analysis of laparoscopic versus open surgery for palliative resection of the primary tumor in stage IV colorectal cancer]

Objective: To systematically evaluate the safety and efficacy of laparoscopic versus open surgery for palliative resection of the primary tumor in stage IV colorectal cancer. Methods: The databases of CNKI, Wanfang, VIP, PubMed, EMBASE and Cochrane Library were searched to retrieve randomized controlled trials (RCT) or clinical controlled trials (CCT) comparing laparoscopic surgery with open surgery for palliative resection of the primary tumor in stage IV colorectal cancer published from January 1991 to May 2019. Chinese search terms included "colorectum/colon/rectum" , "cancer/malignant tumor" , "laparoscopy" , "metastasis" , " IV" ; English search terms included "laparoscop*" , "colo*" , "rect*" , "cancer/tumor/carcinoma/neoplasm" , " IV" , "metasta*" . Inclusion criteria: (1) RCT or CCT, with or without allocation concealment or blinding; (2) patients with stage IV colorectal cancer that was diagnosed preoperatively and would receive resection of the primary tumor; (3) the primary tumor that was palliatively resected by laparoscopic or open procedure. Exclusion criteria: (1) no valid data available in the literature; (2) single study sample size ≤20; (3) subjects with colorectal benign disease; (4) metastatic resection or lymph node dissection was performed intraoperatively in an attempt to perform radical surgery; (5) duplicate publication of the literature. Two researchers independently evaluated the quality of the included studies. In case of disagreement, the evaluation was performed by discussion or a third researcher was invited to participate. The data were extracted from the included studies, and the Cochrane Collaboration RevMan 5.1.0 version software was used for this meta-analysis. Results: Four CCTs with a total of 864 patients were included in this study, including 216 patients in the laparoscopic group and 648 patients in the open group. Compared with the open group, except for longer operation time (WMD=37.60, 95% CI: 26.11 to 49.08, P<0.05), laparoscopic group had less intraoperative blood loss (WMD=-74.89, 95% CI: -144.78 to -5.00, P<0.05), earlier first flatus and food intake after surgery (WMD=-1.00, 95% CI: -1.12 to -0.87, P<0.05; WMD=-1.61, 95%CI: -2.16 to -1.06, P<0.05), shorter hospital stay (WMD=-2.01, 95% CI: -2.21 to -1.80, P<0.05) and lower morbidity of postoperative complication (OR=0.52, 95% CI: 0.35 to 0.77, P<0.05). However, no significant differences were found in time to start postoperative chemotherapy, postoperative chemotherapy rate, and mortality (P > all 0.05). Conclusion: Laparoscopic surgery for palliative resection of the primary tumor is safe and feasible to enhance recovery after surgery by promoting postoperative bowel function recovery, shortening hospital stay and reducing postoperative complication in stage IV colorectal cancer.

Identification of a novel RIG-I isoform and its truncating variant in Japanese eel, Anguilla japonica

Retinoic acid-inducible gene-I (RIG-I) is a cytoplasmic viral RNA sensor that triggers the production of type I interferons (IFNs) and proinflammatory cytokines during viral infection. RIG-I gene has been identified previously in Japanese eel, Anguilla japonica. In the present study, we have characterized a novel isoform of RIG-I (designated as AjRIG-Ib) and its truncated variant (AjRIG-Ibv). The AjRIG-Ib encodes 940 amino acids (aa) consisting of two N-terminal caspase activation and recruitment domains (CARDs), a DEX(D/H) box RNA helicase domain, and a C-terminal regulatory domain (CTD). The AjRIG-Ibv encodes a protein of 843 aa, that shares similar structural organization with AjRIG-Ib, but lacking CTD. The gene expression analyses showed that AjRIG-Ib and AjRIG-Ibv were detectable in all tissues/organs examined, and AjRIG-Ib was the predominant form. The mRNA level of AjRIG-Ibv was upregulated rapidly at 8 h after the Poly I:C injection, and the significant increase of AjRIG-Ib was observed at 16 and 24 h post-injection (hpi). Laser confocal microscopy showed that AjRIG-Ib and AjRIG-Ibv were both located in cytoplasm. In addition, the overexpression of AjRIG-Ib or AjRIG-Ibv led to the increased activity of IFN promoter in transient transfection assay. Taken together, our results indicated that AjRIG-Ib and AjRIG-Ibv may play cooperative or somewhat complementary roles in coordinating the antiviral response in fish.

Temporal augmentation with calvarial onlay graft during pterional craniotomy for prevention of temporal hollowing

Background

Atrophy of muscle and fat often contributes to temporal hollowing after pterional craniotomy. However, the main cause is from the bony defect. Several methods to prevent temporal hollowing have been introduced, all with specific limitations. Autologous bone grafts are most ideal for cranial defect reconstruction. The authors investigated the effectiveness of bony defect coverage and temporal augmentation using pterional craniotomy bone flap.

Methods

This study was conducted in 100 patients who underwent brain tumor excision through pterional approach from 2015 to 2016. Group 1 underwent pterional craniotomy with temporal augmentation and group 2 without temporal augmentation. In group 1, after splitting the calvarial bone at the diploic space, the inner table was used for covering the bone defect and as an onlay graft for temporal augmentation. The outcome is evaluated by computed tomography at 1-year follow-up.

Results

The mean operative time for temporal augmentation was 45 minutes. The mean follow-up was 12 months. The ratio of temporal thickness of operated side to non-operated side was 0.99 in group 1 and 0.44 in group 2, which was statistically different. The mean visual analogue scale score was 1.77 in group 1 and 6.85 in group 2.

Conclusion

This study demonstrated a surgical technique using autologous bone graft for successfully preventing the temporal hollowing and improved patient satisfaction.

Myxoid Solitary Fibrous Tumor on the Scalp

Myxoid solitary fibrous tumor (SFT) is very rare soft tissue neoplasm. It is microscopically composed of spindle cells which is individually separated by delicate band of collagen fibers. And this tumor cells are immunohisto-chemistrically highlighted by CD34. Myxoid SFT has indolent clinical course and a good prognosis, so it is important to make a diagnosis because of its morphological similarities to myxoid spindle cell neoplasms that have different prognoses and treatment. We report the case of a 20-year-old female with a myxoid SFT found in the left temporo-parietal scalp. This case report appears to be the first reported scalp occurrence of this rare tumor.

[Comparison of intensified myeloablative conditioning regime without antithymocytic globulin (ATG) with myeloablative conditioning regime for single-unit unrelated umbilical cord blood transplantation in hematological malignancies]

OBJECTIVE

To campare the effect and tolerance beween intensified myeloablative conditioning regime (IMCR) without antithymocyte globulin (ATG) and myeloablative conditioning regime (MCR) for single-unit unrelated umbilical cord blood transplantation (sUCBT) in hematological malignancies.

METHODS

The clinical data of 190 patients with hematological malignancies undergoing sUCBT between April 2000 and December 2013 at Department of Hematology, Anhui Provincial Hospital were retrospectively analyzed, of whom 156 received IMCR without ATG (IMCR group), including 79 patient receiving total body irradiation (TBI)/cytosine arabinoside (Ara-C)/cyclophosphamide (CY) regime, 47 receiving fludarabine (Flu)/busulfan (Bu)/CY regime, and 30 receiving Ara-C/Bu/CY regime, and all of the 156 received a combination of cyclosporine A (CsA) and mycophelonate mofetil (MMF) for the prophylaxis of graft-versus-host disease (GVHD); the remaining 34 patients received MCR (MCR group), 30 patients receiving Bu/CY regime, and 4 receiving TBI/CY regime, all using CsA/MMF±ATG or methotrexate (MTX) for the prophylaxis of GVHD. The two groups were compared in disease status at the time of transplantation, characteristics of graft, transplantation effect, and transplantation-related complications.

RESULTS

There were no statistically significant differences between the two groups in gender, disease type, human leukocyte antigen match, ABO blood type match, and disease status at the time of transplantation (all P>0.05). The median age and body weight at transplantation in the IMCR group were significantly higher than those in the MCR group (13 years vs 9 years, P=0.003; 44 kg vs 26 kg, P=0.000). The median doses of infused total nucleated cells (×10(7)/kg) and CD34(+) cells (×10(5)/kg) in the IMCR group were significantly lower than in the MCR group (3.87 vs 4.99, P=0.002; 2.00 vs 3.17, P=0.000). The cumulative incidence of myeloid engraftment on the 42th day and platelet engraftment on the 120th day in the IMCR group were remarkably higher than in the MCR group [96.33%(95%CI: 96.27%-96.39%)vs 82.30%(95%CI: 80.67%-83.93%), P=0.000; 86.44%(95%CI: 86.28%-86.60%)vs 51.17%(95%CI: 49.02%-53.32%), P=0.002]. There were no statistically significant differences in the incidences of grade Ⅱ to Ⅳ acute GVHD, grade Ⅲ to Ⅳ acute GVHD, and 2-year chronic GVHD(P=0.482, 0.928, 0.579). The incidence of pre-engraftment syndrome in the IMCR group was higher than in the MCR group(82.70% vs 47.06%, P=0.000). And 180-day transplantation-related mortality (TRM) in the IMCR group was lower than that in the MCR group [20.50%(95%CI: 20.28%-20.71%)vs 42.20% (95%CI: 41.32%-45.09%), P=0.004]. Up to October 2015, with a median follow-up of 44.2(22.7-188.9)months, the estimated 3-year overall survival and disease-free survival in the IMCR group were both significantly higher than those in the MCR group (62.90% vs 34.10%, P=0.000; 58.60% vs 34.10%, P=0.001).

CONCLUSION

IMCR without ATG may improve the engraftment without increasing complications, reduce early transplantation-related mortality, and improve survival.

[Pathogens and clinical characteristics of bacterial infection in hematology department between 2010 and 2014]

OBJECTIVE

To analyze the characteristics of distribution and drug resistance of bacterial infection in several different parts of hematology department inpatients of Anhui Provincial Hospital from January 2010 to December 2014, including patients who had received hematopoietic stem cell transplantation (HSCT).

METHODS

Anti-microbial susceptibility test was done by Kirby-Bauer method and automated systems and the data were analysed by WHONET 5.6 software.

RESULTS

A total of 3 312 copies of inspection samples were analyzed, including 2 716 (82%) blood samples and other 596 specimens (18%). 634 bacterial strains were isolated from 3 312 samples (19.14%) including 488 samples (76.97%) from blood culture. 427 (67.35%) bacterial strains were gram-negative, and the other 207 (32.65%) were gram-positive. Escherichia coli, Klebsiella pneumoniae and Pseudomonas aeruginosa were most common gram-negative bacterial and the resistant rates to imipenem were 0.8%, 11.8% and 3.3%, respectively. Detection rates of Extended-spectrum beta-lactamases in Escherichia coli and Klebsiella pneumoniae were 83.9% and 75.0%, respectively. At the same time, Coagulase negative Staphylococcus, Streptococcus and Enterococcus were most common kinds of gram-positive bacteria. Methicillin-resistant coagulase negative staphylococcus accounted for 65.9% antibiotic resistance. No vancomycin and/or linezolid and/or tigecycline resistant strains of Staphylococcus spp. and Enterococcus spp. were found in those patients.

CONCLUSION

Patients with hematology diseases had a higher risk of bacterial infections, mainly caused by Gram-negative bacteria. There are different distributions of bacterial in different wards.

Optimal central venous pressure during the neohepatic phase to decrease peak portal vein flow velocity for the prevention of portal hyperperfusion in patients undergoing living donor liver transplantation

BACKGROUND

The association between intraoperative systemic hemodynamic status and preventing portal hyperperfusion, which induces shear stress on the sinusoidal endothelial cells of liver grafts, resulting in poor graft function in live-donor recipients, has not been identified. This study evaluates the effects of systemic hemodynamic parameters (SHPs) during the neohepatic phase on changes in hepatic hemodynamic parameters (HHPs) between the neohepatic phase and the 1st postoperative day.

METHODS

Thirty-eight patients undergoing living donor liver transplantation (LDLT) were enrolled in this study. HHPs (flow velocities of portal vein and hepatic artery) were measured immediately after hepatic artery and bile duct reconstruction and on the first postoperative day. SHPs (mean arterial pressure, central venous pressure [CVP], cardiac index, stroke volume variation, stroke volume index, systemic vascular resistance index, and central venous oxygen saturation) were recorded and averaged for 5 minutes after the measurement of HHPs. The relationships between the SHPs and HHPs were assessed using linear or quadratic regression analysis.

RESULTS

Peak portal vein flow velocity (PVV) decreased on the 1st postoperative day in 24 patients (63%). There was an inverted-U relationship between CVP and the percentage change in PVV (R(2) = 0.241, P = .008). According to the quadratic regression model, the PVV maximally decreased at a CVP of 7.8 mm Hg. No significant correlations were found between the other SHPs and HHPs.

CONCLUSIONS

Maintaining CVP (approximately 8 mm Hg) during the neohepatic phase was clinically beneficial in decreasing PVV to prevent portal hyperperfusion in the early postoperative period of LDLT.

Transfacial Surgical Approaches to Secure Wide Exposure of the Skull Base

Background

Treatment of skull base tumors is challenging due to limited access and presence of important neurovascular structures nearby. The success of a complete tumor resection depends on the extent of tumor exposure and secure field of view. While these tumors are often removed by transcranial endoscopic access, transfacial approach is sometimes required depending on the location and size of the tumor. This study describes various transfacial approaches in patients undergoing skull base tumor resection.

Methods

From March to November 2013, 15 patients underwent skull base tumor resection via transfacial accesses at a tertiary institution. Data were reviewed for patient demographics, type of access used, completeness of tumor resection, surgical outcome, and postoperative complications.

Results

Two clivus tumor patients underwent transmaxillary approach; three tuberculum- sellae and suprasellar-hypothalamus tumor patients underwent transbasal approach; three clinoid and retrobulbar intraconal orbital tumor patients underwent orbitozygomatic approach; and seven petroclival-area, pons, cavernous sinus, and lateral-sphenoid-wing tumor patients underwent zygomatic approach. In all cases, the upper and lower margins of the tumor were visible. Complete tumor removal consisted of 10 cases, and partial tumor removal in 5. There were no immediate major complications observed for the transfacial portion of the operations. The overall cosmetic results were satisfactory.

Conclusion

Plastic surgeons can use various transfacial approaches according to the location and size of skull base tumors to secure a sufficient field of view for neurosurgeons.

Fourteen successful consecutive cases of ABO-incompatible living donor liver transplantation: new simplified intravenous immunoglobulin protocol without local infusion therapy

Since various innovative strategies including local infusion therapy and rituximab have been introduced, the survivals and outcomes of recipients in ABO-incompatible (ABO-I) living donor liver transplantation (LDLT) have remarkably improved. Thus, ABO-I LDLT can be a feasible therapeutic option for the patient with end-stage liver disease if an ABO-compatible donor is not available. Although most ABO-I protocols are based on rituximab, plasma exchange, and local infusion therapy, treatment strategies have been changing according to a center's preference or their results. Nonetheless, the consensus of the ABO-I LDLT protocol remains undetermined. Herein, we present our experience with new simple ABO-I LDLT protocol and the excellent results for 14 patients from January 2011 to May 2013. All patients were administrated a single dose of rituximab over 7 days before transplantation followed by plasma exchange to lower anti-ABO antibody titer ≤32. The basic immunosuppression protocol consisted of tacrolimus and steroids with mycophenolate mofetil starting 3 days before transplantation. Splenectomy was not performed routinely and local infusion therapy was not applied at the postoperative period. Instead, the patients received intravenous immunoglobulin (IVIG) after LDLT on days 1, 3, and 5. Neither antibody-mediated rejection nor biliary stricture were encountered in the patients, with a mean follow-up of 16.27 ± 9.4 months. This new simplified ABO-I LDLT protocol seems to prevent antibody-mediated rejection and could be considered as the safe and effective modality to overcome the ABO blood-type barrier in LDLT.

Importance of Accurate Diagnosis in Pyoderma Gangrenosum

Pyoderma gangrenosum is a rare inflammatory reactive dermatosis marked by painful cutaneous ulcers. Diagnosis of pyoderma gangrenosum is usually made based on past medical history and after the exclusion of other possible diseases based on the clinical manifestations of the lesion. Diseases that show rapid progression to necrosis and that should not be misdiagnosed as pyoderma gangrenosum include malignant neoplasms and necrotizing fasciitis. Immunosuppressive agents such as steroids and cyclosporine are considered first-line therapy. Surgical removal of the necrotic tissues is contraindicated, as it may further induce immune reaction and promote ulcer to enlarge. Here, we present a case to encourage plastic surgeons to consider pyodermagangrenosum in the differential diagnosis of idiopathic ulcers. Satisfactory outcomes for patients with pyodermagangrenosum may be expected when using steroids and immunosuppressive agents during the early stage of the disease.

Application of Digital Infrared Thermographic Imaging (DITI) in the Monitoring of Change of Skin Temperature about Vascular Supply of Lower Abdominal Axial Flap in the Rabbit

MethodsEight male New Zealand white rabbits with average weight of 3kg were used. A 10 x 10 cm unipedicled fasciocutaneous island flap was elevated based on the left superficial inferior epigastric vessel. The surface temperatures on designed flap were checked with DITI for 24 hours after the operation. On 14th day after the operation, the surviving area was measured and compared with DITI image which was taken on 24 hours after the operation using digital analysis software ImageJ. Statistical analysis was evaluated by paired T-test ResultsOn DITI image 24 hours after the flap elevation, distal portion of the flap showed remarkable color change. The average percentage and the standard deviation of the survival area of the flap which is predicted by DITI and the average percentage and the standard deviation of the survival area of the flap which was actually measured 2 weeks after flap elevation were 55.3 (16.6), 56.2 (18.0), respectively. This shows no significant difference between the two. ObjectivesMonitoring viability of flap is important. The flap survival depends on the vascularity of the flap, on which the skin temperature depends. The authors applied digital infrared thermographic imaging (DITI) for monitoring the vascular supply of the flap and for the prediction of the prognosis of the flap survival. MethodsEight male New Zealand white rabbits with average weight of 3kg were used. A 10 x 10 cm unipedicled fasciocutaneous island flap was elevated based on the left superficial inferior epigastric vessel. The surface temperatures on designed flap were checked with DITI for 24 hours after the operation. On 14th day after the operation, the surviving area was measured and compared with DITI image which was taken on 24 hours after the operation using digital analysis software ImageJ. Statistical analysis was evaluated by paired T-test ResultsOn DITI image 24 hours after the flap elevation, distal portion of the flap showed remarkable color change. The average percentage and the standard deviation of the survival area of the flap which is predicted by DITI and the average percentage and the standard deviation of the survival area of the flap which was actually measured 2 weeks after flap elevation were 55.3 (16.6), 56.2 (18.0), respectively. This shows no significant difference between the two. ConclusionsThis study shows that DITI system could be used in evaluation of flap vascularity with ease, quickness and safety for patient and flap. Thus, it could be used clinically for the prediction of flap survival.

Effects of a Topical Angiotensin-Converting Enzyme Inhibitor and a Selective COX-2 Inhibitor on the Prevention of Hypertrophic Scarring in the Skin of a Rabbit Ear

 Angiotensin-converting enzyme (ACE) inhibitors have been reported to inhibit fibrogenesis, and cyclooxygenase-2 (COX-2) inhibitors, to reduce scarring by reducing the initial inflammation. The authors reasoned that the topical application of these 2 agents may have a complementary effect on scar reduction.

METHODS

Captopril (ACE inhibitor), celecoxib (COX-2 inhibitor), or a combination of captopril and celecoxib were topically applied to a skin wound in a rabbit ear, and investigated for the effects on scar formation.

RESULTS

The level of scar elevation decreased in the captopril group and the level of infiltration of inflammatory cells decreased in the celecoxib group. In the group where a combination of the 2 drugs was used, the level of scar elevation decreased the most, and collagen deposition and organization returned to normal most rapidly. Celecoxib was found to inhibit the initial inflammation in the ear wound of the rabbit, and captopril inhibited scar elevation.

CONCLUSION

Clinical application of these drugs will require further studies with regard to adverse events and their absorptivity as topical agents. However, these findings suggest that the combined topical administration of an ACE inhibitor and COX-2 inhibitor to a skin wound could be an effective treatment for the prevention of hypertrophic scarring. .

Chest wall reconstruction with a lateral thoracic artery perforator propeller flap for a radiation ulcer on the anterior chest

A lateral thoracic artery perforator propeller flap is advantageous because it does not require microvascular anastomosis, only rarely involves donor-site morbidity and provides sufficient blood flow. Moreover, by rotating the flap, remote tissues with less radiation-induced damage can be used at the site of the defect. In this article, we report the use of a lateral thoracic artery perforator propeller flap to treat a radiation ulcer.

Acute insulin resistance following surgical trauma in rats

OBJECTIVE

To unravel the possible mechanism of acute posttraumatic insulin resistance in rats.

METHODS

Resection of small intestine was performed to establish the surgical trauma model. The blood glucose and serum insulin level were detected and the HOMA index was calculated. The Hyperinsulinemic-euglycemic clamp was performed to investigate the glucose disposal rate by peripheral tissue. The content and phosphorylation state of IRS-1, p85 of PI3-K and PKB/Akt in skeletal muscle were measured respectively. Finally, the [3H] labeled glucose uptake experiment was carried out.

RESULTS

The blood glucose elevated significantly after resection of small intestine in rats. The level of serum insulin decreased during the first 30 min after operation but elevated in the following time. The HOMA-IR in trauma group was significantly greater than control group; however the HOMA-β in trauma group was less than control group. The glucose disposal rate was decreased 49% after operation. The p-IRS-1(Ser307) was significantly enhanced 95% after trauma while the p-IRS-1 (Tyr612) was attenuated by 38%. The phosphorylation of its downstream target, p-PKB/Akt(Ser473) was attenuated by 48%. Accordingly, the glucose uptaken by skeletal muscle was significantly decreased in trauma group.

CONCLUSION

We demonstrated the posttraumatic insulin resistance occurred soon after surgical trauma in rats. The level of insulin was relatively insufficient because of the decreased sensitivity in peripheral tissue. Trauma induced Ser phosphorylation instead of Tyr phosphorylation eliminated the ability of IRS-1 to activate downstream effector molecules such as PKB/Akt and resulted in severe impairment of insulin signal transduction and glucose transport in skeletal muscle.

Molecular cloning and characterization of the STAT gene in Hyphantria cunea haemocytes

A new insect member of the signal transducer and activator of transcription (STAT) family of transcription factors, Hyphantria cunea STAT (HcSTAT), was cloned from the lepidopteran H. cunea. The domain involved in DNA interaction and the Src homology 2 (SH2) domain were well conserved. During all developmental stages, the gene was expressed at a low level in the haemocytes, fat body cells, midgut, epidermis and Malpighian tubules. The haemocytes and Malpighian tubules showed transcriptional activation of HcSTAT upon Gram-negative and Gram-positive bacterial challenges. These challenges increased the induction and nuclear translocation of the HcSTAT protein that recognizes a STAT target site in H. cunea haemocytes. In vivo treatment with sodium orthovanadate translocated HcSTAT to the haemocyte nucleus. This study shows the involvement of the haemocyte Janus kinase/STAT pathway after microbial infection in lepidopteran insects.

Homologous expression and quantitative analysis of T3SS-dependent secretion of TAP-tagged XoAvrBs2 in Xanthomonas oryzae pv. oryzae induced by rice leaf extract

Xanthomonas oryzae pv. oryzae (Xoo) produces a putative effector, XoAvrBs2. We expressed XoAvrBs2 homologously in Xoo with a TAP-tag at the C-terminus to enable quantitative analysis of protein expression and secretion. Addition of rice leaf extracts from both Xoo-sensitive and Xoo-resistant rice cultivars to the Xoo cells induced expression of the XoAvrBs2 gene at the transcriptional and translational levels, and also stimulated a remarkable amount of XoAvrBs2 secretion into the medium. In a T3SS-defective Xoo mutant strain, secretion of the TAPtagged XoAvrBs2 was blocked. Thus, we elucidated the transcriptional and translational expressions of the XoAvrBs2 gene in Xoo was induced in vitro by the interaction with rice and the induced secretion of XoAvrBs2 was T3SSdependent. It is the first report to measure the homologous expression and secretion of XoAvrBs2 in vitro by rice leaf extract. Our system for the quantitative analysis of effector protein expression and secretion could be generally used for the study of host-pathogen interactions.

A new approach to the treatment of nasal bone fracture: radiologic classification of nasal bone fractures and its clinical application

PURPOSE

A radiologic examination is required in the treatment of nasal bone fracture to determine the fracture condition. Thus, there is an increasing need for radiologic classification of nasal bone fractures that can be applied to clinical practice.

MATERIALS AND METHODS

Computed tomography was performed in 125 patients with nasal bone fractures to determine which axial view best showed the entire nasal view. The obtained axial view was then used as a reference for classification. The length from the top to the base of the nasal bone was divided into upper, middle, and lower levels, after which the fracture location was determined. If the fracture spanned the boundaries of these levels, it was classified as the total level. Subsequently, the fracture was subclassified based on the fracture direction and pattern and the concurrent fracture.

RESULTS

Radiologic examination of patients with nasal bone fracture showed that nasal bone fracture was frequently found at the total, middle, upper, and lower levels, in that order. Nasal bone fractures at the upper level showed lower frequencies of complication and reoperation than the fractures at the other levels, whereas nasal bone fractures at the total level showed the highest frequencies of complication and reoperation.

CONCLUSION

Radiologic classification can be useful for preoperative and postoperative evaluations of nasal bone fractures and can be helpful in understanding such fractures because it can efficiently predict the prognosis of a fracture.

A new approach to the treatment of nasal bone fracture: the clinical usefulness of closed reduction using a C-arm

Closed reduction is commonly conducted for the treatment of a nasal bone fracture unless a concurrent fracture or a severe nasal septum fracture is observed. As the reduction, however, is not conducted through the direct gross observation of the fracture site, it is difficult to obtain a good result from it. Accordingly, a supplementary process is required. Closed reduction with a C-arm was conducted within the period from March 2009 to January 2010 on 50 patients with nasal bone fractures, to treat these fractures or to evaluate the postoperative conditions of such. The usefulness of the C-arm was evaluated by comparing the aforementioned closed reduction with a C-arm with the closed reduction without a C-arm that was conducted on 64 patients with nasal bone fractures within the period from January 2008 to February 2009. The complication morbidity and re-operation rate were significantly lower in the patient group with closed reduction with a C-arm, and the radiologic examination also showed a significant difference. If closed reduction is conducted on patients with nasal bone fractures using a C-arm, an accurate result can be obtained by observing the fractured bone indirectly with continuous imaging during the operation, and the operation result can be immediately assessed in the operating room, thereby reducing the frequencies of complications and re-operation.

Benefit and pitfalls of newborn hearing screening

The importance of universal newborn hearing screening (UNHS) in identifying hearing-impaired infants as early as possible is already well recognized. Transient evoked otoacoustic emissions (TEOAE) have been established as a reliable method for UNHS in full term infants. This is a cross sectional study between April 2003--December 2005. Thirteen thousand five hundred and ninety eight (13,598) newborns were screened for hearing loss with portable otoacoustic emission (OAE) before discharge. The initial coverage rate during the 3 years study period was 85.9% (13,598) with 89.2% (3762), 79.0% (4480) and 90.3% (5356) for 2003, 2004 and 2005 respectively. The mean age when hearing loss was diagnosed using ABR were 3.56 months old, 3.08 months old, and 2.25 months old and 3.01 months old for 2003, 2004, 2005 respectively and it was statistically significant. The defaulter rate at the third stage during the 3 years study period was 35% (21), 15.2% (7) and 18.2% (2) for 2003, 2004 and 2005 respectively. This study showed significant improvement in initial referral rate, coverage rate and age of diagnosis. However, we need to improve on high defaulter rates.

Functional changes in a novel uracil-DNA glycosylase determined by mutational analyses

Uracil-DNA glycosylase (UDG) is a ubiquitous enzyme found in bacteria and eukaryotes, which removes uracil residues from DNA strands. Methanococcus jannaschii UDG (MjUDG), a novel monofunctional glycosylase, contains a helix-hairpin-helix (HhH) motif and Gly/Pro rich loop (GPD region), which is important for catalytic activity; it shares these features with other glycosylases such as endonuclease III. First, to examine the role of two conserved amino acid residues (Asp150 and Tyr152) in the HhH-GPD region of MjUDG, mutant MjUDG proteins were constructed, in which Asp 150 was replaced with either Glu or Trp (D150E and D150W), Tyr152 was replaced with either Glu or Asn (Y152E and Y152N). Mutant D150W completely lacked DNA glycosylase activity, whereas D150E displayed reduced activity of about 70% of the wild type value. However, the mutants Y152E and Y152N retained unchanged levels of UDG activity. We also replaced Glu132 in the HhH motif with a lysine residue equivalent to Lys120 in endonuclease III. This mutation converted the enzyme into a bifunctional glycosylase/AP lyase capable of both removing uracil at a glycosylic bond and cleaving the phosphodiester backbone at an AP site. Mutant E132K catalyzes a beta-elimination reaction at the AP site via uracil excision and forms a Schiff base intermediate in the form of a protein-DNA complex.

Comparative analysis of two attacin genes from Hyphantria cunea

A full-length clone corresponding to attacin was isolated from a cDNA library made from fat body of immunized Hyphantria cunea larvae. This newly isolated attacin B shows characteristics different from those previously reported for attacin A. The two attacin cDNAs encode precursor proteins of 233 and 248 amino acid residues, respectively. The two attacins show 45.9% identity at the amino acid level, and 35.2% identity at the nucleotide level. Attacins A and B of H. cunea show significant identities with the attacins of Lepidoptera. Attacin B is a typical glycine-rich protein, while attacin A is leucine-rich. Attacin B is expressed from last instar larvae to adult, while attacin A showed stage-specific expression during the prepupal and pupal stages. Attacins A and B are predicted to have different secondary structure in that attacin A has no tendency to form helices but attacin B contains a substantial number of helices. Attacin A is induced at a trace level in infected larvae, while attacin B is strongly induced against Gram-positive and negative bacteria, fungi, and viruses. The attacin B transcripts were detected in fat body, epidermis and hemocytes after injection with Escherichia coli, Citrobacter freundii, or Candida albicans, but not in the midgut and Malpighian tubule. Recombinant attacin A showed no antibacterial activity, while recombinant attacin B showed strong antibacterial activity in proportion to the amount of the protein injected.

Liver transplantation for hepatocellular carcinoma with bile duct thrombi

In a few cases of hepatocellular carcinoma (HCC), jaundice results from obstructive causes, including tumor invasion or thrombi in the bile duct. We have reported herein our experience with liver transplantation (OLT) for HCC cares showing bile duct thrombi (BDT). From September 1996 to August 2004, 140 adult patients underwent OLT for HCC at our center. Four patients (2.9%) who had OLT performed for HCC had BDT and were included in this study. The patients were all men of mean age 57.0 years. The initial total bilirubin levels were in the range of 2.0 to 30.5 mg/dL. The sizes of the tumors ranged from 2.0 cm to 3.0 cm in diameter, all were single lesions. The median follow-up period was 20.6 months (range: 17.6 to 28.1 months). The only case in which the BDT was identified intraoperatively died 20 months after OLT due to multiple intrahepatic recurrences. The other three patients were alive, showing no evidence of recurrence at the end of follow-up. Although a series of four is too small to reach any conclusion, we suggest that OLT may be a treatment option for HCC with BDT in selected cases.

Safety of donors with fatty liver in liver transplantation

Steatotic liver graft transplantation affect donor safety as well as recipient survival. We investigated safety of donors according to the extent of fatty change. We retrospectively reviewed donors who underwent right hepatectomy from September 1999 to April 2005, dividing them into three groups according to degree of macrovesicular fatty change upon intraoperative liver biopsy. Group 1 included patients with macrovesicular steatosis of 0 approximately 9%: group 2, 10 approximately 19% and group 3, at least 20%. Two hundred forty-five donors were enrolled with a male to female ratio of 2.02:1 and mean age of 31.8 years. There were 163 donors in group 1, 75 in group 2, and seven in group 3. There was no statistically significant difference in body mass index, operative time, blood loss, postoperative peak serum bilirubin, and aspartate transaminase levels among groups 1, 2, and 3. Overall complication rate, including reoperation, biliary stricture, wound infection, ileus, transfusion, bile leak and fluid collection were not different between the groups. Postoperative hospital stay was also not different. Peak alanine transaminase level was different between each group, and prothrombin time between group 1 and 3, but days until return to normal levels in all measured laboratory parameters were not different. Residual liver volume percent was significantly smaller among group 1 compared to others. In conclusion, fatty livers with less than 30% macrovesicular steatosis may be good donor candidates without significant complications as long as sufficient residual liver volume is left for the donor.

Prognosis After Liver Transplantation Predicted by Preoperative MELD Score

The model for end-stage liver disease (MELD) has been an excellent predictor of 3-month mortality among cirrhotic patients awaiting orthotopic liver transplantation (OLT). The aim of this study was to evaluate whether the preoperative MELD score predicts short-term prognosis after OLT. We enrolled 98 adult liver transplant patients performed at our center from January 2001 to December 2002. In univariate analysis of risk factors for death within 3 and 6 months after liver transplantation, serum total bilirubin, creatinine, MELD score, hyponatremia with ascites, Child-Turcotte-Pugh (CTP) score were statistically significant parameters (P < .05). By logistic regression, none of the risk factors were subjected to multivariate analysis showed statistical significance. The odds ratios of the MELD score, hyponatremia with ascites, CTP score within 3 months were 0.997, 1.151, and 0.726 with 95% confidence intervals of [0.899, 1.105], [0.102, 12.959], and [0.389, 1.352], respectively. The odds ratio of MELD score, hyponatremia with ascites, CTP score within 6 months were 0.996, 0.914, and 0.764, with 95% confidence intervals of [0.901, 1.102], [0.089, 9.369], and [0.417, 1.401], respectively. Although MELD score has been a good predictor of short-term prognosis before OLT, MELD did not show an influence on the short-term prognosis after liver transplantation in this study.

Outcome of Patients With Recurrent Hepatocellular Carcinoma in Liver Transplantation

Liver transplantation (OLT) is the treatment of choice for patients with hepatic cirrhosis related hepatocellular carcinoma (HCC). Among 156 liver transplant patients for HCC from June 1996 to February 2005, 23 had recurrent HCC. To evaluate risk factors that affect early recurrence of HCC after OLT, we divided the 23 patients into two groups: early (< or =12 months) and late (>12 months) recurrences. Among them, 15 patients were dead and eight alive patients had been followed to 31 July 2005. The most common recurrence site was the grafted liver (n = 15), next was bone (n = 11), lung (n = 8), lymph node (n = 6), brain (n = 4), skin (n = 2), adrenal gland (n = 1). There were no significant differences between the two groups in age or tumor size, number of tumors, cell differentiation, alpha-feto protein levels, tumor staging, number of patients within Milan criteria, steroid pulse therapy, infectious diseases, and immunostaining of tumor. In our study, there were no risk factors that predict early tumor recurrence. We noticed that more patients in the early recurrence group were excluded by Milan criteria due to a more progressed tumor staging with higher mean levels of serum alpha-feto protein.

Outcomes of Hepatitis B Virus Recurrence After Liver Transplantation

The introduction of high doses of hepatitis B immune globulin (HBIG) and lamivudine for liver transplantation (OLT) prophylaxis has reduced the risk of hepatitis B recurrence and improved the survival of patients transplanted for hepatitis B virus (HBV)-related liver disease. But, posttransplant prophylaxis strategies to treat the recurrence of HBV have not yet been standardized. We analyzed 23 patients with HBV recurrence among 340 HBV-associated liver transplants performed from September 1996 to April 2004 (6.7%). Nine patients underwent deceased donor OLT and 14, living donor OLT. Mean follow-up was 37 months. Seroconversion after recurrence was observed in 6 of 23 patients (26%). Mean time to HBV recurrence tended to be shorter among the seroconversion (+) patients compared to seroconversion (-) patients (10 months vs 19.7 months; P = .062). Seroconversion rate after HBIG and lamivudine combination therapy for patients with HBV recurrence was 37.5% and time to seroconversion after HBV recurrence was 1.7 months. Seroconversion was best achieved when the pretransplant HBV DNA level was high and HBeAg was positive. Also, seroconversion rate was increased when HBV DNA level was low and the alanine transferase level high at the time of recurrence and when the time to recurrence after transplantation was short. Seroconversion after HBV recurrence, which was observed in 26%, may be increased in selected cases. Accordingly, aggressive treatment should be undertaken after HBV recurrence.

Self-reported prevalence and risk factors of asthma among Korean adolescents: 5-year follow-up study, 1995-2000

OBJECTIVES

The International Study of Asthma and Allergies in Childhood (ISAAC) questionnaires have shown that the prevalence of childhood asthma is increasing worldwide. Although Asian countries used to have lower prevalence rates of allergic disease than Western countries, this prevalence is increasing in several Asian countries. To determine whether the prevalence of childhood asthma is changing in Korean adolescents, we compared findings from nationwide cross-sectional surveys in 1995 and 2000 on populations of middle-school children using the Korean version of the ISAAC questionnaire.

METHODS

We developed Korean versions of the ISAAC written (WQ) and video (AVQ) questionnaires for allergic diseases. In 1995, the enrolled population consisted of 15,481 children, ages 12-15, and encompassing all three grades in middle school, selected from 34 schools across the nation; the response rate was 97.3%. In 2000, 15,894 children were selected from 31 of the same schools, and the response rate was 96.4%. The SAS system version 8.0 was utilized for all statistical analyses.

RESULTS

The WQ showed that the lifetime and 12-month prevalence of wheeze did not change from 1995 to 2000. While the 12-month prevalence rates of sleep disturbed by wheezing and night cough increased, the rates of severe attack of wheezing and exercise-induced wheeze did not change, over this period of time. The lifetime prevalence of asthma diagnosis, however, increased significantly, from 2.7% in 1995 to 5.3% in 2000, as did the 12-month prevalence of asthma treatment, from 1.0% in 1995 to 1.9% in 2000. The AVQ also showed increases in the lifetime and 12-month prevalence rates of wheeze at rest, exercise-induced wheeze, nocturnal wheeze, nocturnal cough, and severe wheeze over this period of time. These were especially because of significant increases in the Provincial cities of Korea. Interestingly, the 12-month prevalence of wheeze was consistently high in Cheju with low air pollution indices, whereas this rate was low in Ulsan and Ansan with very high air pollution indices. Risk factor analysis showed that body mass index (BMI), passive smoking, and living with a dog or cat, but not air pollution, were associated with higher risk of wheeze.

CONCLUSIONS

In the 5-year period from 1995 to 2000, the prevalence of asthma symptoms has increased in Korean adolescents, much of it because of increases in Provincial Centers. BMI, passive smoking, and living with a dog or cat are important risk factors. Environmental factors other than air pollution may be associated with increases in asthma, especially in Provincial Centers.

Temporal aspects of excitation-contraction coupling in airway smooth muscle

In airway smooth muscle (ASM), ACh induces propagating intracellular Ca2+ concentration ([Ca2+]i) oscillations (5-30 Hz). We hypothesized that, in ASM, coupling of elevations and reductions in [Ca2+]i to force generation and relaxation (excitation-contraction coupling) is slower than ACh-induced [Ca2+]i oscillations, leading to stable force generation. When we used real-time confocal imaging, the delay between elevated [Ca2+]i and contraction in intact porcine ASM cells was found to be approximately 450 ms. In beta-escin-permeabilized ASM strips, photolytic release of caged Ca2+ resulted in force generation after approximately 800 ms. When calmodulin (CaM) was added, this delay was shortened to approximately 500 ms. In the presence of exogenous CaM and 100 microM Ca2+, photolytic release of caged ATP led to force generation after approximately 80 ms. These results indicated significant delays due to CaM mobilization and Ca2+-CaM activation of myosin light chain kinase but much shorter delays introduced by myosin light chain kinase-induced phosphorylation of the regulatory myosin light chain MLC20 and cross-bridge recruitment. This was confirmed by prior thiophosphorylation of MLC20, in which force generation occurred approximately 50 ms after photolytic release of caged ATP, approximating the delay introduced by cross-bridge recruitment alone. The time required to reach maximum steady-state force was >15 s. Rapid chelation of [Ca2+]i after photolytic release of caged diazo-2 resulted in relaxation after a delay of approximately 1.2 s and 50% reduction in force after approximately 57 s. We conclude that in ASM cells agonist-induced [Ca2+]i oscillations are temporally and spatially integrated during excitation-contraction coupling, resulting in stable force production.

Mutational effects on thermostable superoxide dismutase from Aquifex pyrophilus: understanding the molecular basis of protein thermostability

We designed two mutants of superoxide dismutase (SOD), one is thermostable and the other is thermolabile, which provide valuable insight to identify amino acid residues essential for the thermostability of the SOD from Aquifex pyrophilus (ApSOD). The mutant K12A, in which Lys12 was replaced by Ala, had increased thermostability compared to that of the wild type. The T(1/2) value of K12A was 210 min and that of the wild type was 175 min at 95 degrees C. However, the thermostability of the mutant E41A, which has a T(1/2) value of 25 min at 95 degrees C, was significantly decreased compared to the wild type of ApSOD. To explain the enhanced thermostability of K12A and thermolabile E41A on the structural basis, the crystal structures of the two SOD mutants have been determined. The results have clearly shown the general significance of hydrogen bonds and ion-pair network in the thermostability of proteins.

Biochemical characterization of a novel hypoxanthine/xanthine dNTP pyrophosphatase from Methanococcus jannaschii

A novel dNTP pyrophosphatase, Mj0226 from Methanococcus jannaschii, which catalyzes the hydrolysis of nucleoside triphosphates to the monophosphate and PPi, has been characterized. Mj0226 protein catalyzes hydrolysis of two major substrates, dITP and XTP, suggesting that the 6-keto group of hypoxanthine and xanthine is critical for interaction with the protein. Under optimal reaction conditions the k(ca)(t) /K(m) value for these substrates was approximately 10 000 times that with dATP. Neither endonuclease nor 3'-exonuclease activities were detected in this protein. Interestingly, dITP was efficiently inserted opposite a dC residue in a DNA template and four dNTPs were also incorporated opposite a hypoxanthine residue in template DNA by DNA polymerase I. Two protein homologs of Mj0226 from Escherichia coli and Archaeoglobus fulgidus were also cloned and purified. These have catalytic activities similar to Mj0226 protein under optimal conditions. The implications of these results have significance in understanding how homologous proteins, including Mj0226, act biologically in many organisms. It seems likely that Mj0226 and its homologs have a major role in preventing mutations caused by incorporation of dITP and XTP formed spontaneously in the nucleotide pool into DNA. This report is the first identification and functional characterization of an enzyme hydrolyzing non-canonical nucleotides, dITP and XTP.

Repair activities of 8-oxoguanine DNA glycosylase from Archaeoglobus fulgidus, a hyperthermophilic archaeon

Oxidative DNA damage is caused by reactive oxygen species formed in cells as by products of aerobic metabolism or of oxidative stress. The 8-oxoguanine (8-oxoG) DNA glycosylase from Archaeoglobus fulgidus (Afogg), which excises an oxidatively-damaged form of guanine, was overproduced in Escherichia coli, purified and characterized. A. fulgidus is a sulfate-reducing archaeon, which grows at between 60 and 95 degrees C, with an optimum growth at 83 degrees C. The Afogg enzyme has both DNA glycosylase and apurinic/apyrimidinic (AP) lyase activities, with the latter proceeding through a Schiff base intermediate. As expected for a protein from a hyperthermophilic organism, the enzyme activity is optimal near pH 8.5 and 60 degrees C, denaturing at 80 degrees C, and is thermally stable at high levels of salt (500mM). The Afogg protein efficiently cleaves oligomers containing 8-oxoG:C and 8-oxoG:G base pairs, and is less effective on oligomers containing 8-oxoG:T and 8-oxoG:A mispairs. While the catalytic action mechanism of Afogg protein is likely similar to the human Ogg1 (hOgg1), the DNA recognition mechanism and the basis for 8-oxoG substrate specificity of Afogg differ from that of hOgg.

Molecular cloning and characterization of thermostable DNA ligase from Aquifex pyrophilus, a hyperthermophilic bacterium

A DNA ligase gene from the hyperthermophilic bacterium Aquifex pyrophilus (Ap) was cloned and sequenced. An open reading frame of 2,157 bp that codes for a 82-kDa protein showed 40%-60% homology with a series of NAD+-dependent DNA ligases from different organisms. The recombinant enzyme Ap DNA ligase expressed in Escherichia coli was purified to homogeneity and characterized. The activity of Ap DNA ligase gradually increased in proportion to the concentration of monovalent salt up to 200 mM NaCl, 150 mM KCl, 200 mM NH4Cl, and 350 mM potassium glutamate. The optimum temperature and pH of Ap DNA ligase were greater than 65 degrees C and 8.0-8.6, respectively, for nick-closing activity. More than 75% of the ligation activity was retained after incubation at 95 degrees C for 60 min, whereas the half-lives of Thermus aquaticus and Escherichia coli DNA ligases at 95 degrees C were < or =15 min and 5 min, respectively. Thermostable Ap DNA ligase was applied to repeat expansion detection (RED) and could be a useful enzyme in DNA diagnostics.

Mutational analyses of Aquifex pyrophilus DNA ligase define essential domains for self-adenylation and DNA binding activity

We constructed nine deletion mutants of NAD+-dependent DNA ligase from Aquifex pyrophilus to characterize the functional domains. All of DNA ligase deletion mutants were analyzed in biochemical assays for NAD+-dependent self-adenylation, DNA binding, and nick-closing activity. Although the mutant lsub1 (91-362) included the active site lysine (KxDG), self-adenylation was not shown. However, the mutants lsub6 (1-362), lsub7 (1-516), and lsub9 (1-635) showed the same adenylation activity as that of wild type. The lsub5 (91-719), which has the C-terminal domain (487-719) as to lsub4 (91-486), showed minimal adenylation activity. These results suggest that the presence of N-terminal 90 residues is essential for the formation of an enzyme-AMP complex, while C-terminal domain (487-719) appears to play a minimal role in adenylation. It was found that the presence of C-terminal domain (487-719) is indispensable for DNA binding activity of lsub5 (91-719). The mutant lsub9 (1-635) showed reduced DNA binding activity compared to that of wild type, suggesting the contribution of the domain (636-719) for the DNA binding activity. Thus, we concluded that the N-terminal 90 residues and C-terminal domain (487-719) of NAD+-dependent DNA ligase from A. pyrophilus are mutually indispensable for binding of DNA substrate.

Mast cell chymase expression and mast cell phenotypes in human rejected kidneys

BACKGROUND

Mast cells (MCs) are known to participate in various types of chronic disease, but their role in chronic renal rejection is poorly understood. Recently, distinct phenotypes of MCs have been described in humans by the demonstration of one protease, chymase. Hence, we questioned whether chymase in MCs could play a role in the pathogenesis of renal rejection in humans.

METHODS

We investigated MC chymase expression and MC phenotypes, using immunohistochemical single- and double-staining techniques, in nephrectomy (N = 13) and biopsy (N = 8) specimens of human rejected kidneys. Tissue chymase levels were determined by enzymatic assay for chymase activity. We also examined the association between MC chymase expression and the degree of interstitial fibrosis in these renal allografts.

RESULTS

Based on chymase positivity, rejected kidneys were divided into two groups, a chymase-negative [Chy(-)] group and a chymase-positive [Chy(+)] group. Quantitative analysis showed that the number of chymase-positive MCs and tissue chymase levels were significantly higher in the Chy(+) group than in the Chy(-) group. Furthermore, the interstitial fibrotic area in the Chy(+) group was significantly larger than that in the Chy(-) group. Immunodouble staining analysis also demonstrated that a new MC phenotype, positive for chymase but negative for tryptase, was present in the human rejected kidney.

CONCLUSIONS

These results show that increased expression of chymase in MCs is related to the severity of interstitial fibrosis in human rejected kidneys.

Ion exchange and fixation of rare-earth cation into expandable tetrasilicic fluorine mica

Rare-earth cation (Nd3+) are incorporated into the interlayer spaces between the silicate layers of synthetic fluorine mica, Na0.665Mg2.68(Si3.98)Al0.02F1.98, by conventional ion exchange reaction. Subsequent migration of the interlayer cations upon calcination into the vacant octahedra of 2:1 layers is followed by powder X-ray diffraction, diffuse-reflectance UV spectroscopy, and X-ray absorption spectroscopy as a function of calcination temperature. It is found from the spectroscopic analyses that the interlayer cations start to migrate into the octahedral vacant sites from 400 degrees C through the hexagonal siloxane ring of the tetrahedral silicate layers. According to the Nd L(III)-edge XANES spectra, the normalized absorption intensity gradually decreases while the FWHM increases with temperature, suggesting that the bonding character of rare-earth cations and silicate lattices evolves from ionic to covalent as the calcination temperature increases.

XAFS study of copper species stabilized in the interlayer space of layered perovskite oxides

New intercalation compounds with Cu2+ ions in the interlayer of layered perovskite oxides, OA(1-x)Ca(2-x)La(x)Nb3O10) (OA = n-octylammonium ion, 0 < or = x < 1), have been prepared by ion-exchange reaction, and characterized by means of XRD and XAS. For the detail elucidation of the fine structure of the Cu K-edge XANES spectra, polarized XAS was applied for the [Cu(en)2]2+ and Cu2+ ions intercalated to the single crystal. According to the XANES and EXAFS spectra measured at Cu K-edge, copper ions are four coordinated. In addition, XANES spectra have shown that the charge transfer from host layer to intercalated ions influences on the chemical state of copper ion.

Local structure analysis of Ti species stabilized in ion exchangeable layer solids by x-ray absorption spectroscopy

Nano-sized titanium dioxides are incorporated into the interlayer spaces of ion-exchangeable layered perovskites, H(1-x)Ca2(x)La(x)Nb3O10 (x=0.0-0.75), by replacing the interlayer protons with positively charged TiO2 nano-sol particles or basic titanium glycolate complex (titanatrane). Powder X-ray diffraction analysis. UV-Vis absorption spectroscopy, thermogravimetric analysis, and N2 adsorption-desorption isotherm measurements show that quantum sized TiO2 particles are stabilized in between perovskite lattices to form micropores (S(BET) = 37-110 m2/g). X-ray absorption spectroscopy at the Ti K-edge was used for investigating the local environment around Ti atoms constituting the interlayer pillars. According to the XANES spectra, the 'as-pillared' Ti species have the same local environments with those of precursory species, which subsequently converted into TiO2 clusters with rutile and anatase-like local structures when TiO2 nano-sol particles and titanatrane are used as pillaring species. respectively. It is also found that the local environment of TiO2 remains almost constant irrespective of the layer charge density, while the TiO2 pillar content and the microporosity increase with the latter.

Reserve capacity for ATP consumption during isometric contraction in human skeletal muscle fibers

Maximum velocity of the actomyosin ATPase reaction (V(max) ATPase) and ATP consumption rate during maximum isometric activation (ATP(iso)) were determined in human vastus lateralis (VL) muscle fibers expressing different myosin heavy chain (MHC) isoforms. We hypothesized that the reserve capacity for ATP consumption [1 -- (ratio of ATP(iso) to V(max) ATPase)] varies across VL muscle fibers expressing different MHC isoforms. Biopsies were obtained from 12 subjects (10 men and 2 women; age 21--66 yr). A quantitative histochemical procedure was used to measure V(max) ATPase. In permeabilized fibers, ATP(iso) was measured using an NADH-linked fluorometric procedure. The reserve capacity for ATP consumption was lower for fibers coexpressing MHC(2X) and MHC(2A) compared with fibers singularly expressing MHC(2A) and MHC(slow) (39 vs. 52 and 56%, respectively). Tension cost (ratio of ATP(iso) to generated force) also varied with fiber type, being highest in fibers coexpressing MHC(2X) and MHC(2A). We conclude that fiber-type differences in the reserve capacity for ATP consumption and tension cost reflect functional differences such as susceptibility to fatigue.

The incidence and clinical characteristics of symptomatic propylthiouracil-induced hepatic injury in patients with hyperthyroidism: a single-center retrospective study

OBJECTIVES

Although symptomatic propylthiouracil (PTU)-induced hepatic injury is known to be rare, there have been few reports about its exact incidence in patients with hyperthyroidism. We tried to evaluate its incidence in a single center and its clinical course.

METHODS

Medical records of 912 hyperthyroid patients who had been diagnosed between March 1990 and December 1998 were reviewed about clinical characteristics, management, and laboratory findings. Symptomatic PTU-induced hepatic injury was defined as the development of jaundice or hepatitis symptoms with at least a 3-times elevation of liver function tests (LFT) without other causes.

RESULTS

Four hundred ninety-seven patients (age 42.6 +/- 10.7 yr, male/female 140/357) were included. Clinically overt hepatitis developed in six patients (1.2%; age, 43.7 +/- 14.8 yr; male:female ratio, 3:3) between 12 and 49 days after PTU administration. Jaundice and itching developed in five patients, fever in two, rash in two, and arthralgia in one. Bilirubin, ALT, and ALP increased in five, four, and six patients, respectively (293 +/- 288 micromol/L, 143 +/- 111 U/L, and 265 +/- 81 U/L; normal, < 117 U/L). The type of hepatic injury was cholestatic in three, hepatocellular in one, and mixed in two patients. None resulted from viral hepatitis. There were no statistical differences in age, sex, PTU dose, or T4 and T3 levels at initial diagnosis between patients with and without hepatic injury. LFT normalized in all patients between 16 and 145 (72.8 +/- 46.4) days after the PTU withdrawal.

CONCLUSIONS

Symptomatic hepatic injury develops usually within the first few months of PTU administration with rare frequency, but its clinical course is relatively benign once the drug is withdrawn. However, it may be difficult to predict its development, so all patients should be monitored for rise in LFTs at regular intervals, especially during the early period.

Molecular interactions between Anopheles stephensi midgut cells and Plasmodium berghei: the time bomb theory of ookinete invasion of mosquitoes

We present a detailed analysis of the interactions between Anopheles stephensi midgut epithelial cells and Plasmodium berghei ookinetes during invasion of the mosquito by the parasite. In this mosquito, P. berghei ookinetes invade polarized columnar epithelial cells with microvilli, which do not express high levels of vesicular ATPase. The invaded cells are damaged, protrude towards the midgut lumen and suffer other characteristic changes, including induction of nitric oxide synthase (NOS) expression, a substantial loss of microvilli and genomic DNA fragmentation. Our results indicate that the parasite inflicts extensive damage leading to subsequent death of the invaded cell. Ookinetes were found to be remarkably plastic, to secrete a subtilisin-like serine protease and the GPI-anchored surface protein Pbs21 into the cytoplasm of invaded cells, and to be capable of extensive lateral movement between cells. The epithelial damage inflicted is repaired efficiently by an actin purse-string-mediated restitution mechanism, which allows the epithelium to 'bud off' the damaged cells without losing its integrity. A new model, the time bomb theory of ookinete invasion, is proposed and its implications are discussed.

Autoimmune hepatitis in a patient with myasthenia gravis and thymoma--a report on the first case in Korea

Myasthenia gravis is an autoimmune disease that results from an antibody-mediated reaction and occurs with thymoma in 15% of patients. It is very rarely associated with autoimmune hepatitis. Four cases of myasthenia gravis with autoimmune hepatitis have been reported in the world. We recently experienced a case of 30-year-old man with myasthenia gravis associated with thymoma and autoimmune hepatitis. This condition is the first case that has not been reported previously in Korea. We report this rare condition along with a brief review of the literature.

Mosquito immune responses and malaria transmission: lessons from insect model systems and implications for vertebrate innate immunity and vaccine development

The introduction of novel biochemical, genetic, molecular and cell biology tools to the study of insect immunity has generated an information explosion in recent years. Due to the biodiversity of insects, complementary model systems have been developed. The conceptual framework built based on these systems is used to discuss our current understanding of mosquito immune responses and their implications for malaria transmission. The areas of insect and vertebrate innate immunity are merging as new information confirms the remarkable extent of the evolutionary conservation, at a molecular level, in the signaling pathways mediating these responses in such distant species. Our current understanding of the molecular language that allows the vertebrate innate immune system to identify parasites, such as malaria, and direct the acquired immune system to mount a protective immune response is very limited. Insect vectors of parasitic diseases, such as mosquitoes, could represent excellent models to understand the molecular responses of epithelial cells to parasite invasion. This information could broaden our understanding of vertebrate responses to parasitic infection and could have extensive implications for anti-malarial vaccine development.

[Urethral injury with unusual clinical course: a case report]

A 20-year-old men fell from a ladder in 1995, striking his perineum strongly, and macroscopic hematuria with painful urination lasted for several days. Subsequently, swelling of the perineum on urination continued to occur. However, he did not seek medical treatment until July 1997, when he consulted our medical institution. A diverticulum-like change was found in the bulbous urethra on urethrocystography, and a tear in the same position on urethroscopy. On September 22, 1997, surgery was performed after constructing a cystostomy, the tear was located using a urethroscope, and closed through a perineal approach. At 14 days after surgery, there was extra-urethral leakage of contrast media on voiding cystourethrography, and at 28 days after surgery, the findings showed improvement. Since then, he has been free of the preoperative symptoms.

Induction of mosquito hemolymph proteins in response to immune challenge and wounding

The rapid induction of proteins in the hemolymph of the mosquito, Anopheles gambiae, was examined after wounding or injection of immune elicitors (Escherichia coli, lipopolysaccharide, laminarin, zymosan). One-dimensional gel electrophoresis revealed at least six hemolymph polypeptides >25 kDa that consistently appeared after any breech of the cuticle. All of these polypeptides appeared in the hemolymph within 30 min and reached a maximum concentration after approx. 6 h. No proteins were specifically induced by bacteria or bacterial or fungal cell wall products, however two constitutively expressed proteins were repressed by these injections. Patterns of hemolymph proteins were further analyzed by two-dimensional electrophoresis. Seven spots were enhanced or induced 2 h after injection in four replicate experiments. An additional two spots demonstrated some variability between replicates, but were generally responsive to injection. These rapidly induced polypeptides are candidates for regulating and initiating the mosquito's responses to pathogens and wounding.

Structure-based identification of a novel NTPase from Methanococcus jannaschii

Almost half of the entire set of predicted genomic products from Methanococcus jannaschii are classified as functionally unknown hypothetical proteins. We present a structure-based identification of the biochemical function of a protein with an as yet unknown function from a M. jannaschii gene, Mj0226. The crystal structure of Mj0226 protein determined at 2.2 A resolution reveals that the protein is a homodimer and each monomer folds into an elongated alpha/beta structure of a new fold family. Comparisons of Mj0226 protein with protein structures in the database, however, indicate that one part of the protein is homologous to some of the nucleotide-binding proteins. Biochemical analysis shows that Mj0226 protein is a novel nucleotide triphosphatase that can efficiently hydrolyze nonstandard nucleotides such as XTP to XMP or ITP to IMP, but not the standard nucleotides, in the presence of Mg2+ or Mn2+ ions.