MoRBP9 Encoding a Ran-Binding Protein Microtubule-Organizing Center Is Required for Asexual Reproduction and Infection in the Rice Blast Pathogen Magnaporthe oryzae

Like many fungal pathogens, the conidium and appressorium play key roles during polycyclic dissemination and infection of Magnaporthe oryzae. Ran-binding protein microtubule-organizing center (RanBPM) is a highly conserved nucleocytoplasmic protein. In animalia, RanBPM has been implicated in apoptosis, cell morphology, and transcription. However, the functional roles of RanBPM, encoded by MGG_00753 (named MoRBP9) in M. oryzae, have not been elucidated. Here, the deletion mutant ΔMorbp9 for MoRBP9 was generated via homologous recombination to investigate the functions of this gene. The ΔMorbp9 exhibited normal conidial germination and vegetative growth but dramatically reduced conidiation compared with the wild type, suggesting that MoRBP9 is involved in conidial production. ΔMorbp9 conidia failed to produce appressoria on hydrophobic surfaces, whereas ΔMorbp9 still developed aberrantly shaped appressorium-like structures at hyphal tips on the same surface, suggesting that MoRBP9 is involved in the morphology of appressorium-like structures from hyphal tips and is critical for development of appressorium from germ tubes. Taken together, our results indicated that MoRBP9 played a pleiotropic role in polycyclic dissemination and infection-related morphogenesis of M. oryzae.

Dual-graft adult living donor liver transplantation with ABO-incompatible graft: short-term and long-term outcomes

ABO-incompatible (ABOi) dual-graft (DG) adult living donor liver transplantation (ALDLT) is not commonly performed due to its inherently intricate surgical technique and immunological complexity. Therefore, data are lacking on the short- and long-term clinical outcomes of ABOi DG ALDLT. We performed a retrospective study by reviewing the medical records of patients who underwent ABOi DG ALDLT between 2008 and 2014. Additionally, computed tomography volumetric analysis was conducted to assess the graft regeneration rate. The mean age of a total of 28 recipients was 50.2 ± 8.5 years, and the mean model for end-stage liver disease score was 12.2 ± 4.6. The 1-, 3-, and 5-year patient survival rate was 96.4% during the mean follow-up period of 57.0 ± 22.4 months. The 1-, 3-, and 5-year graft survival rate was 96.4%, 94.2%, and 92.0%, respectively, and no significant differences were observed between ABO-compatible (ABOc) and ABOi grafts (P = .145). The biliary complication rate showed no significant difference (P = .195) between ABOc and ABOi grafts. Regeneration rates of ABOi grafts were not significantly different from those of ABOc grafts. DG ALDLT with ABOi and ABOc graft combination seems to be a feasible option for expanding the donor pool without additional donor risks.

Antagonistic Evaluation of Chromobacterium sp. JH7 for Biological Control of Ginseng Root Rot Caused by Cylindrocarpon destructans

Cylindrocarpon destructans is an ascomycete soil-borne pathogen that causes ginseng root rot. To identify effective biocontrol agents, we isolated several bacteria from ginseng cultivation soil and evaluated their antifungal activity. Among the isolated bacteria, one isolate (named JH7) was selected for its high antibiotic activity and was further examined for antagonism against fungal pathogens. Strain JH7 was identified as a Chromobacterium sp. using phylogenetic analysis based on 16S rRNA gene sequences. This strain was shown to produce antimicrobial molecules, including chitinases and proteases, but not cellulases. Additionally, the ability of JH7 to produce siderophore and solubilize insoluble phosphate supports its antagonistic and beneficial traits for plant growth. The JH7 strain suppressed the conidiation, conidial germination, and chlamydospore formation of C. destructans. Furthermore, the JH7 strain inhibited other plant pathogenic fungi. Thus, it provides a basis for developing a biocontrol agent for ginseng cultivation.

Living Donor Liver Transplantation for Patients Older Than Age 70 Years: A Single-Center Experience

Over the past two decades, the age of liver transplantation (LT) recipients has been increasing. We reviewed our experience with LT for patients aged ≥70 years (range: 70-78 years) and investigated the feasibility of performing LT, especially living donor LT (LDLT), for older patients. We retrospectively reviewed the medical records of 25 patients (15 LDLT recipients, 10 deceased donor LT recipients) aged ≥70 years who underwent LT from January 2000 to April 2016. Their perioperative morbidity rate was 28.0%, and the in-hospital mortality rate was 16.0%; these results were comparable to those of matched patients in their 60s (n = 73; morbidity, p = 0.726; mortality, p = 0.816). For patients in their 70s, the 1- and 5-year patient survival rates were 84.0% and 69.8%, and the 1- and 5-year graft survival rates were 83.5% and 75.1%, respectively. Comparisons of patient and graft survival rates between matched patients in their 60s and 70s showed no statistically significant differences (patient survival, p = 0.372; graft survival, p = 0.183). Our experience suggests that patients aged ≥70 years should not be excluded from LT, or even LDLT, based solely on age and implies that careful selection of recipients and donors as well as meticulous surgical technique are necessary for successful results.

Survival Benefit of Early Cancer Detection Through Regular Endoscopic Screening for De Novo Gastric and Colorectal Cancers in Korean Liver Transplant Recipients

BACKGROUND

De novo malignancy is not uncommon after liver transplantation (LT). Gastric cancer is one of the most common malignancies in both the Korean general population and LT recipients, and colorectal cancer prevalence is gradually increasing.

METHODS

Among 3690 adult recipients who underwent LT from January 1999 and December 2013, the screening patterns and prognosis of 26 cases of gastric cancer and 22 cases of colorectal cancer were analyzed.

RESULTS

For gastric cancer, the mean patient age was 54.6 ± 6.2 years at LT and 59.5 ± 6.7 years at cancer diagnosis, with a post-transplant interval of 60.2 ± 29.8 months. Patients were divided into regular (n = 18) and non-regular (n = 8) screening groups, with early cancer found in 14 and 0 patients; their 2-year survival rates after cancer diagnosis were 93.1% and 33.3% (P = .006), respectively. Endoscopic resection was successfully performed in 8 patients, all in the regular screening group. For colorectal cancer, the mean patient age was 53.3 ± 6.1 years at LT and 58.1 ± 6.7 years at cancer diagnosis, with a post-transplant interval of 54.3 ± 38.0 months. Patients were divided into regular (n = 19) and non-regular (n = 3) screening groups, with early cancer found in 12 and 0 patients; their 2-year survival rates after cancer diagnosis of 92.3% and 33.3% (P = .003), respectively. Endoscopic resection was successfully performed in 6 patients, all in the regular screening group.

CONCLUSIONS

LT recipients are strongly advised to undergo regular screening studies for various de novo malignancies, especially cancers common in the general population. Regular endoscopic screening contributes to the timely detection of gastric and colorectal cancers, improving post-treatment survival outcomes.

Donor Safety and Recipient Liver Function After Right-Lobe Liver Transplantation From Living Donors With Gilbert Syndrome

BACKGROUND

Donor safety is the most important aspect in living-donor liver transplantation (LDLT). Gilbert syndrome is an autosomal recessive condition that is a common cause of isolated unconjugated hyperbilirubinemia, and its prevalence is not negligibly low in the general population. This study intended to assess donor safety and recipient liver function after LDLT with the use of right liver grafts from living donors with Gilbert syndrome.

METHODS

Among 2,140 right liver transplantations performed from January 2002 to December 20113 at our institution, we identified 12 living donors (0.6%) who showed a preoperative serum total bilirubin level of ≥2 mg/dL. These donors were clinically diagnosed with Gilbert syndrome. The clinical outcomes of these donors and their recipients were analyzed retrospectively.

RESULTS

The mean donor age was 24.6 ± 7.1 years, and 11 donors were male. All subjects met the preoperative evaluation conditions for right liver donation except for the level of unconjugated hyperbilirubinemia. The mean serum total bilirubin level of the donors was 2.23 ± 0.20 mg/dL before and 1.79 ± 0.61 mg/dL 1 year after right liver donation. The preoperative donor direct bilirubin level was 0.43 ± 0.19 mg/dL. The preoperative indocyanine green retention rate at 15 minutes was 8.2 ± 2.8%. All donors and recipients recovered uneventfully and were alive at the time of writing. The recipient serum total bilirubin level was 1.29 ± 0.47 mg/dL 1 year after LDLT.

CONCLUSIONS

We suggest that LDLT with living donors with Gilbert syndrome can be safely performed, but that a meticulous preoperative evaluation is vital to maximize donor safety.

Impact of co-existent thyroiditis on clinical outcome in papillary thyroid carcinoma with high preoperative serum antithyroglobulin antibody: a retrospective cohort study

OBJECTIVES

The aim of this study was to investigate the impact of co-existent chronic lymphocytic thyroiditis (CLT) on changes in serum antithyroglobulin antibody (TgAb) and clinical outcome in papillary thyroid carcinoma (PTC) patients with high preoperative serum TgAb.

DESIGN

A retrospective cohort study.

SETTING

University teaching hospital.

PARTICIPANTS

Thirty-seven PTC patients with high preoperative serum TgAb level (≥100 U/mL) were evaluated. All patients underwent total thyroidectomy followed by high-dose I-131 ablation.

MAIN OUTCOME MEASURES

Per cent changes of TgAb between pre-treatment and post-treatment, and disease-free survival were calculated.

RESULTS

Twenty-two patients (59.5%) had co-existent CLT, and seven had residual/recurrent tumours. There was a higher proportion of females among the patients with CLT compared to those without CLT (95.5% versus 66.7%; P = 0.0306). There were trends towards more aggressive pathologies, such as tumour size, extrathyroidal extension, surgical margin and lymph node stage, in PTC without CLT than in that with co-existent CLT. Pre-treatment and post-treatment TgAb were all higher in PTC with co-existent CLT. But, per cent changes of TgAb between pre-treatment and post-treatment were no significant difference between PTC with and without CLT (P < 0.05). Patients with co-existent CLT showed a significantly lower residual/recurrent tumour rate than those without CLT (4.5% versus 40%; P = 0.0113).

CONCLUSION

Residual/recurrent tumour rate was lower in PTC patients with co-existent CLT than in those without CLT.

Liver transplantation in Korea: past, present, and future

PURPOSE

This study reviewed the past and present status of liver transplantation (LT) and outlooks for the future of LT in Korea.

METHOD

The first LT in Korea was successfully performed using a deceased donor graft in 1988. Pediatric and adult living donor liver transplantations (LDLTs) were initiated in 1994 and 1997, respectively. From 1988 to 2013, 10,581 LTs were performed at 40 centers, whereas LDLT accounted for 76.5% of all LTs.

RESULTS

In the early 1990s, the deceased organ donation rate was less than 1.5 per million population (PMP) per year, but it increased to 5 PMP beginning in 2008. Despite the increasing number of deceased donor liver transplantations (DDLTs), high prevalence of hepatitis B virus (HBV)-induced cirrhosis and hepatocellular carcinoma (HCC) has provoked persistent performance of adult LDLT with technical advancement including middle hepatic vein (MHV) reconstruction of right lobe graft and dual graft LDLT with 1 nationwide donor mortality.

CONCLUSION

The number of LTs in Korea in 2010 was 23.2 PMP (1042 LTs/45 million population), lower than 23.5 PMP of Spain, but higher than 20 PMP of the United States. However, future LT numbers may decrease because of lowering the HBV carrier rate (neonatal HBV universal vaccination began in 1992), new potent anti-HBV agents, and lowest birth rate (1.22 children per family) with a decrease of potential live donors.

Safety and usefulness of warm dissection technique during liver graft retrieval from deceased donors

BACKGROUND

For deceased-donor liver graft retrieval, the warm dissection technique of hilar dissection before perfusion had been the standard procedure in the early period of liver transplantation. Thereafter, the cold dissection technique of in situ flushing and hilar dissection after perfusion has been preferred in many transplantation centers for rapid procurement of multiple organs. This study intended to assess the safety and usefulness of the warm dissection technique used in deceased-donor liver transplantation.

METHODS

This study analyzed a single surgeon's experience of the warm dissection technique for 165 cases of liver graft retrieval, regarding the prolongation of retrieval operation time, retrieval-associated graft injury, and recipient outcomes.

RESULTS

An additional 20 to 40 minutes was required for warm dissection. The incidence of retrieval-associated graft injury was 13 (7.9%), in which hepatic parenchymal injury was detected in 7 (capsular tear in 6 and subcapsular hematoma in 1) and vascular injury in 6 (celiac axis injury in 5 and common hepatic artery injury in 1). There was no other episode of injury at the branch artery, vena cava, portal vein, and bile duct. There was no significant difference of 1-year graft survival rates between liver grafts with and without graft injury (83% vs 83.3%, P = .73).

CONCLUSIONS

When the vital signs of deceased donor are stable, the warm dissection technique may be helpful to decrease the cold ischemic preservation time because the risk of graft injury is acceptably low and it provides more time for recipient preparation, thus giving potential advantages for marginal liver grafts.

A pilot study on the safety and efficacy of generic mycophenolate agent as conversion maintenance therapy in stable liver transplant recipients

PURPOSE

The patent covering mycophenolate mofetil (MMF) in Korea has expired and, thus, several generic MMF agents are now commercially available. The supply of Cellcept (Roche Korea) was interrupted at the end of 2011, so it was inevitable that a generic MMF would be used instead. During this period, we performed a prospective pilot study to examine the safety and efficacy of a generic mycophenolate agent (Myconol: Hanmi Pharmaceutical, Seoul Korea) for use as conversion maintenance therapy in stable liver transplantation (OLT) recipients.

METHODS

OLT recipients, who were treated with MMF on an outpatient basis from January 2012 to March 2012, attended follow-up interviews conducted. The patients had undergone OLT ≥ 2 years before the study, had tolerated Cellcept, and showed stable liver function. Fifty-three patients were followed up for more than 3 months after conversion to the same dose of Myconol.

RESULTS

After conversion to Myconol, 6 patients (11.3%) experienced new side effects, which disappeared when they reverted to Cellcept (n = 5) or stopped taking Myconol medication (n = 1). The side effects associated with Myconol included gastrointestinal symptoms (indigestion and diarrhea; n = 3), skin eruptions (n = 1), pruritus (n = 1), and insomnia (n = 1). The mean mycophenolic acid levels were 1.71 ± 0.88 μg/mL for Cellcept and 1.83 ± 0.91 μg/mL for Myconol, which showed a strong correlation (r(2) = 0.92, P < .001).

CONCLUSIONS

Myconol showed similar pharmacokinetics to those of Celcept, but a small proportion of patients experienced agent-specific side effects; therefore, patients should be closely monitored when taking Myconol. Also, further studies, with a greater number of patients, are required to identify the full spectrum of drug-associated side effects.

Phospho-Rb (Ser780) as a biomarker in patients with cervical lymph node metastases from an unknown primary tumour: a retrospective cohort study

OBJECTIVES

Cervical lymph node metastases from an unknown primary tumour are a heterogeneous disease entity with various clinical features. There are many controversies regarding treatment methods and treatment response predictions. Therefore, we examined the prognostic significance of biomarkers in patients with cervical metastasis of unknown primary tumour.

DESIGN

A molecular study of retrospective cohorts.

SETTING

University teaching hospital.

MAIN OUTCOME MEASURES

Metastatic cervical lymph nodes of 36 patients with cervical unknown primary metastasis of squamous cell carcinoma were assessed by in situ hybridisation for human papillomavirus and immunohistochemistry for p16, retinoblastoma protein (phospho-Ser780), hypoxia-inducible factor-1α, glucose transporter 1 and carbonic anhydrase 9 expression. Clinicopathological factors and biomarkers were analysed for their associations with disease-free survival and overall survival.

RESULTS

Univariate analysis showed that nodal extracapsular spread was associated with poor overall survival (P = 0.049), nodal-positive retinoblastoma protein staining were significantly associated with poor outcomes of both disease-free survival (P = 0.035) and overall survival (P = 0.019), Multivariate analysis revealed that nodal positivity of retinoblastoma protein and nodal extracapsular spread were the significant predictors of overall survival (P = 0.049, hazard ratio = 6.21, 95% confidence interval = 1.01-38.35 and P = 0.037, hazard ratio = 4.34, 95% confidence interval = 1.09-17.21, respectively).

CONCLUSION

The retinoblastoma protein expression of metastatic lymph nodes represents an independent prognostic indicator in patients with cervical metastasis of unknown primary tumour.

Toward more than 400 liver transplantations a year at a single center

BACKGROUND

For the first time at Asan Medical Center (AMC) we performed more than 400 liver transplantations (LTs) per year in 2011, despite same number of living donor liver transplantations (LDLTs).

METHODS

Our OLT program was started in 1992, but not activated well due to the scarcity of deceased donor organs. Since adult LDLTs using a left lobe and then a right lobe were successfully performed in 1997, we have developed several innovative techniques and approaches for adult LDLT, for example, modified right-lobe graft reconstructing middle hepatic branches in 1998, dual graft LDLT using 2 left lobes in 2000; new criteria for hepatocellular carcinoma (HCC); as well as ABO-incompatible LDLT, the first in the world. As a result, the number of LDLTs has increased rapidly but reached a plateau recently. Nationwide efforts to promote deceased donation increased the number of deceased donor liver transplantation (DDLT).

RESULTS

We have performed 317 LDLTs per year in 2010 and 2011, respectively. The number of LTs reached 403 in 2011. This large number was possible due to a remarkable increase of DDLTs from 50 in 2010 to 86 in 2011. Seventy-nine patients (68.1%) among 116 patients (28.8%) required an urgent LT receiving a DDLT. LT for HCC or ABO-mismatch comprised 50.3% (n = 150) or 8.7% (n = 35), respectively. In-hospital mortality rate in 2011 was 4.7%.

CONCLUSIONS

The increased LTs number at AMC was aided by the nationwide campaign.

Utility of quantitative 18 F-fluorodeoxyglucose uptake measurement to identify occult tonsillar carcinoma in patients with cervical metastasis of unknown primary tumours: a retrospective case-control study

OBJECTIVES

Due to relatively high (18) F-fluorodeoxyglucose accumulation in the tonsillar region, the detection of occult tonsillar cancers by (18) F-fluorodeoxyglucose positron emission tomography/computerised tomography remains controversial. Therefore, we assessed the usefulness of quantitative tonsil (18) F-fluorodeoxyglucose uptake in identifying occult tonsillar squamous cell carcinoma.

DESIGN

A case-control study of retrospective cohorts.

SETTING

University Teaching Hospital.

MAIN OUTCOME MEASURES

We assessed all patients diagnosed with tonsillar cancers or cervical lymph node metastasis of unknown primary tumours between 2005 and 2010 who underwent (18) F-fluorodeoxyglucose positron emission tomography/computerised tomography. The subjects were grouped into A (apparent early pT-stage tonsillar squamous cell carcinoma; n = 27), B (occult tonsillar squamous cell carcinoma, primary tumours were found by surgery; n = 21), C (cervical metastasis of unknown primary tumour, primary tumours were not found by surgery and for follow-up; n = 16) and D (33 healthy controls). Tonsillar maximum standardised uptake values were bilaterally measured and compared between groups.

RESULTS

The sensitivity and specificity of qualitative assessment of (18) F-fluorodeoxyglucose positron emission tomography/computerised tomography for detection of occult tonsillar cancers were 67% and 69%, respectively. Mean maximum standardised uptake values of tonsils with cancer were 11.19 ± 5.46 in group A and 8.12 ± 4.52 in group B, which were significantly higher than that of group C (4.62 ± 1.76) or group D (4.57 ± 1.62) (P < 0.01). The mean maximum standardised uptake value differences of groups A (6.35) and B (3.11) were significantly greater than those of groups C (0.32) and D (0.59) (P < 0.01). Similarly, the mean maximum standardised uptake value ratios of groups A (2.47) and B (1.73) were significantly greater than those of groups C (1.06) and D (1.16) (P < 0.01).

CONCLUSION

(18) F-fluorodeoxyglucose positron emission tomography/computerised tomography with tonsil SUVmax measurement is useful to identify occult tonsillar squamous cell carcinoma.

Standardization of modified right lobe grafts to minimize vascular outflow complications for adult living donor liver transplantation

BACKGROUND

After >2000 adult living donor liver transplants (LDLTs), we observed minimization of the complication rate using case-by-case modification of venous outflow reconstruction in right liver graft (RLG), standardization seeking intend to provide a hemodynamic- based, regeneration-compliant hepatic outflow reconstruction.

METHODS

We retrospectively examined 100 consecutive adult LDLT using modified RLG before and after application of RLG standardization to compare the 6-month incidences of vascular outflow complications.

RESULT

The right hepatic vein stenting rate for first 6 months was 5% in the customized group and 1% in the standardized group (P=.212). The middle hepatic vein stenting rate for first 6 months was 9% in the customized group and 4% in the standardized group (P=.373). The inferior right hepatic vein stenting rate for first 6 months was 12.8% in the customized group and 7.1% in the standardized group (P=.472). The overall 6-month patient survival rate was 94% in the customized group and 95% in the standardized group (P=.867). The overall incidence of significant RLG venous outflow complications was 19% in the customized group and 8% in the standardized group (P=.023).

CONCLUSION

Standardization as a universal graft model seemed to be more effective and feasible than conventional graft customization requiring individualized case-by-case modification.

De novo malignancies after liver transplantation: incidence comparison with the Korean cancer registry

PURPOSE

De novo malignancy is not uncommon after liver transplantation (OLT). We have compared the incidence of novo malignancy following OLT with those among the general Korean population.

METHODS

Between January 1998 and December 2008, 1952 adult OLT were performed, including 1714 living donor and 238 deceased donor grafts whose medical records were retrospectively reviewed.

RESULTS

Among the 1952 patients, 44 (2.3%) showed de novo malignancies after a mean posttransplant period of 41 months. Among the 14 types of malignancy the most frequent was stomach cancer (n = 11; 25.0%), colorectal cancer (n = 9; 20.5%), breast cancer (n = 4; 9.1%), and thyroid cancer (n = 3; 6.8%). These patients underwent aggressive treatment, including surgery, chemotherapy, and radiotherapy, except for one patient with an aggressive primary liver cancer. Over a mean follow-up of 45 months after diagnosis of de novo malignancy, 13 patients (29.5%) died; the overall 3-year patient survival rate was 67.5%. The relative risk of malignancy following OLT was 7.7-fold higher in men and 7.3-fold higher in women than the Korean general population.

CONCLUSIONS

OLT recipients must be checked periodically for de novo malignancy throughout their lives, especially for cancers common in the general population.

Peritransplant monitoring of immune cell function in adult living donor liver transplantation

PURPOSE

We evaluated the clinical utility of peritransplant in vitro assays of immune cell function in adult living donor liver transplant (LDLT) recipients.

METHODS

In particular, we measured immune cell function, using the ImmuKnow assay, in 107 adult LDLT recipients and 200 potential living liver donors (control group) admitted to our center between July 2008 and January 2009.

RESULTS

In the control group, the mean proportion of T-helper/inducer cells was 36.8% ± 8.2%. The degree of immune response was strong in 12%, moderate in 77%, and low in 11%. In the study group, the degree of immune response within the first month was strong in 4.6%, moderate in 38.2%, and low in 57.2%, thus significantly lower than in the control group (P < .001). ImmuKnow results and tacrolimus levels did not show a significant correlation (r(2) = .002, P = .392). Although six patients showed biopsy-proven acute cellular rejection, none showed a strong immune response. Patients with overt infection showed a lower immune response.

CONCLUSIONS

These results indicate that peritransplant assessment of immune response using the ImmuKnow assay does not reliably predict the occurrence of acute rejection. Additional studies are necessary to accurately assess the clinical utility of immune response monitoring.

The evaluation of rhytidectomy flap healing after CO2 laser resurfacing in a pig model

OBJECTIVE

This study was conducted to determine when it becomes safe to perform laser resurfacing after rhytidectomy flap elevation.

STUDY DESIGN

Eighty-four sites on 12 domestic Yorkshire pigs were selected; 4 x 10-cm skin flaps were elevated in 72 of the 84 sites and shortened 10%. The 12 remaining sites (controls) were treated with laser resurfacing alone. Laser resurfacing was also performed at days 0, 7, 14, 21, and 28 after closing the skin flaps. The healing time for the laser-resurfaced sites without flap elevation were compared to that of the skin flaps treated with the laser at days 0, 7, 14, 21, and 28. Twelve "skin flap" controls were elevated, shortened 10%, and closed without laser treatment. Resurfacing was performed using 2 passes with the Sharplan Silk Touch CO(2) laser.

RESULTS

The average healing time for the skin flaps treated with the laser at day 0 was 23.9 days. All of these flaps showed skin slough with delayed healing followed by scar formation. The areas treated with the laser alone (controls), and the subsequent skin flaps treated with the laser postoperatively at days 7, 14, 21, and 28 days completely re-epithelialized in an average of 7.8, 8.1, 7.3, 7.4, and 7.3 days, respectively. There were no statistically significant differences in healing time between the controls and flaps treated with the laser on or after 7 days (P > 0.05). However, there were statistically significant differences in healing time between the laser-treated skin flaps at day 0 and the controls, between the laser-treated flaps on day 0 and day 7, and between the laser-treated flaps on day 0 and day 14 (P < 0.001). Because there was little difference in healing time after 14 days, only the healing times for laser-treated skin flaps up to 14 days were compared using paired t tests.

CONCLUSIONS

From our observations using a pig model, we conclude that skin flaps may be safely laser resurfaced about 1 week postoperatively. On the other hand, simultaneous flap elevation and laser resurfacing results in delayed healing with subsequent scar formation.

Merkel cell carcinoma of the lower lip: a case report and histopathologic study

Merkel cell carcinoma of the lower lip is a rare clinical entity. It is generally thought to be more aggressive than the more common skin cancers of the lips and oral cavity. The literature reveals that delayed diagnoses and poor survival are common among patients with these malignancies. Recommended treatment is surgical excision with wide margins and treatment of cervical metastases with either surgery or radiotherapy or both. Unlike other malignant neoplasms, the occurrence of Merkel cell carcinoma in a relatively older population makes comorbid conditions a key factor in treatment planning.

The role of nitric oxide as an effector of macrophage-mediated cytotoxicity against Trichomonas vaginalis

The purpose of this study is to determine whether nitric oxide is involved in the extracellular killing of Trichomonas vaginalis by mouse (BALB/c) peritoneal macrophages and RAW264.7 cells activated with LPS or rIFN-gamma and also to observe the effects of various chemicals which affect the production of reactive nitrogen intermediates (RNI) in the cytotoxicity against T. vaginalis. The cytotoxicity was measured by counting the release of [3H]-thymidine from labelled protozoa and NO2- was assayed by Griess reaction. NG-monomethyl-L-arginine (L-NMMA), NG-nitro-L-arginine methyl ester (NAME) and arginase inhibited cytotoxicity to T. vaginalis and nitrite production by activated mouse perioneal macrophages and RAW 264.7 cells. The addition of excess L-arginine competitively restored trichomonacidal activity of macrophages. Exogenous addition of FeSO4 inhibited cytotoxicity to T. vaginalis and nitric products of macrophages. From above results, it is assumed that nitric oxide plays an important role in the host defense mechanism of macrophages against T. vaginalis.