Sooyun Chang

Use of the delta neutrophil index as a prognostic factor of mortality in patients with spontaneous bacterial peritonitis: implications of a simple and useful marker.

Background Spontaneous bacterial peritonitis (SBP) is a common and life-threatening infection in patients with advanced cirrhosis. The prognostic value of a novel marker, the delta neutrophil index (DNI), was investigated relative to mortality in patients with SBP. Materials & Methods Seventy-five patients with SBP were studied from April 2010 to May 2012. DNI at initial diagnosis of SBP was determined and compared with 30-day mortality rates. Results Of the patients, 87.7% were men, and the median age of all patients was 59.0 yrs. The area under the receiver-operating characteristic (ROC) curve of DNI for 30-day mortality was 0.701 (95% confidence interval [CI], 0.553–0.849; p = 0.009), which was higher than that of C-reactive protein (0.640, 95% CI, 0.494–0.786; p = 0.076) or the model for end-stage liver disease score (0.592, 95% CI, 0.436–0.748; p = 0.235). From the ROC curve, with the sum of sensitivity and specificity, the cutoff value of DNI was determined to be 5.7%. In the high-DNI group (DNI ≥5.7%), septic shock and 30-day mortality were more prevalent compared with the low-DNI group (84.2% vs. 48.2%, p = 0.007; 57.9% vs. 14.3%, p<0.001, respectively). Patients with an elevated DNI had a higher risk of 30-day mortality compared with those with a low DNI (4.225, 95% CI, 1.631–10.949; p = 0.003). Conclusion A higher DNI at the time of SBP diagnosis is an independent predictor of 30-day mortality in patients with SBP.

Efficacy of Sorafenib Monotherapy versus Sorafenib-Based Loco-Regional Treatments in Advanced Hepatocellular Carcinoma

Background Although sorafenib is accepted as the standard of care in advanced hepatocellular carcinoma (HCC), its therapeutic benefit is marginal. Here, we aimed to compare the efficacy and safety of sorafenib monotherapy (S-M) and sorafenib-based loco-regional treatments (S-LRTs) in advanced HCC. Methods From 2007 to 2012, 290 patients with advanced HCC (Barcelona Clinic Liver Cancer stage C) with S-M (n = 226) or S-LRTs (n = 64) were reviewed retrospectively. Survival outcomes and treatment-related toxicities between two groups were analyzed. Results Variables related to tumor burden and liver function were similar between the groups (all P > 0.05). Within the entire population, the S-LRTs group had both longer median overall survival (OS) (8.5 vs 5.5 months, P = 0.001) and progression-free survival (PFS) (5.3 vs 3.0 months, P = 0.002) than the S-M group. Furthermore, the S-LRTs group had longer Os than the S-M group in a subgroup with neither extrahepatic spread (EHS) nor regional nodal involvement (RNI) (18.0 vs 7.8 months, P = 0.019) and in a subgroup with EHS and/or RNI (8.3 vs 4.8 months, P = 0.028). In addition, the S-LRTs group had longer PFS than the S-M group in the subgroup with neither EHS nor RNI (9.6 vs 3.2 months, P = 0.027). Treatment Related toxicity was similar between two groups. Conclusion Combined use of sorafenib and LRTs may provide better treatment outcomes without significantly increasing treatment-related toxicities, even in patients with EHS and/or RNI. Therefore, addition of active LRTs might be considered, if feasible.

Esophageal Involvement of Pemphigus Vulgaris Associated with Upper Gastrointestinal Bleeding

Esophageal involvement of pemphigus vulgaris is rare, and when present, the most common presenting symptoms reported in the medical literature are odynophagia and dysphagia. Here, we present two cases of pemphigus vulgaris presenting with upper gastrointestinal hemorrhage because of esophageal involvement of the disease. In case 1, a 41-year-old female patient with a prior diagnosis of pemphigus vulgaris presented with hematemesis. Esophagogastroduodenoscopy showed diffuse mucosal exfoliation and oozing bleeding of the oropharynx and esophagus. The patient recovered after the administration of high-dose corticosteroids and immunosuppressants. In case 2, a 30-year-old female patient with known pemphigus vulgaris also presented with hematemesis, showing similar endoscopic findings to the first case. She also responded to the same treatment. Esophageal involvement of pemphigus vulgaris responds to high-dose corticosteroids and immunosuppressants. Thus, in patients with pemphigus vulgaris with signs or symptoms of upper gastrointestinal bleeding, an early endoscopy for the evaluation of esophageal involvement is beneficial.

A Clinical Significance of Assessing Cytomegalovirus Infection Status in Patients With Ulcerative Colitis

Cytomegalovirus (CMV) is a pathogen implicated in a diverse spectrum of diseases, depending on the immune status of the host. CMV usually leads to asymptomatic infection in immunocompetent individuals, but may cause serious morbidity and mortality in immunocompromised patients.1,2 CMV is also considered to be the most common viral pathogen involved in IBD. CMV infection is frequently detected using colonic mucosal biopsy in severe cases of UC or CD, but its clinical significance is still controversial. CMV may be the cause of severe colitis flares, or may play the role of an innocent bystander.3,4 Recently, noninvasive diagnostic methods such as the serum CMV PCR and CMV antigenemia assay have received a lot of clinical interest owing to the difficulty in diagnosing CMV colitis. In a retrospective study by Kim et al., among 229 moderate-to-severe UC patients, 83 patients (36.2%) had CMV colitis, and the sensitivity and specificity of the CMV antigenemia assay were found to be 47.0% and 81.7%, respectively.5 Jang et al. also reported similar results in 149 patients with suspected CMV gastrointestinal disease, with the sensitivity and specificity of the CMV antigenemia assay being 54% and 88%, respectively.6 These results indicate that even though the CMV antigenemia assay could not replace endoscopic biopsy owing to its comparatively low sensitivity, it may still be helpful in diagnosing CMV colitis in some cases because of its high specificity.5 Although CMV infection has been reported as a risk factor for poor outcomes in two prospective multicenter studies by the IBD Study Group of the Korean Association for the Study for Intestinal Diseases,7,8 there is little data concerning the relationship between CMV antigenemia assay results and clinical outcomes. In the present study,9 the authors retrospectively evaluted the usefulness of the CMV antigenemia assay in predicting clinical prognosis in UC patients in a single academic center. Of 146 patients hospitalized for an exacerbation of moderate-to-severe UC, 43 patients who had undergone the CMV antigenemia assay at the time of admission were included. Twelve of the patients had CMV antigenemia, and 8 (66.7%) were diagnosed with CMV colitis by endoscopic biopsy. Of the 31 patients with negative CMV antigenemia assay results, 4 (12.9%) had CMV colitis. CMV antigenemia was significantly associated with CMV colitis (P=0.001). The sensitivity and specificity of the CMV antigenemia assay for CMV colitis were 66.7% and 87.1%, respectively. Regarding the clinical course, there was a significant association between CMV antigenemia and refractoriness to corticosteroid therapy (P=0.002). Eleven of 12 (91.7%) patients in the CMV antigenemia-positive group, and 12 of 31 (38.7%) patients in the CMV antigenemia-negative group had refractoriness. In addition, the titer of the antigenemia assay showed a tendency to be higher in patients with steroid-refractory UC than in those with the steroid-responsive UC (P=0.058). Multivariate analysis revealed that steroid refractoriness was significantly increased in CMV antigenemia-positive patients (adjusted OR, 7.73; P=0.030), and in patients with a shorter duration of UC (adjusted OR, 0.99; P=0.025). However, there was no significant difference in the colectomy rate between the positive group (33.3%) and the negative group (22.6%, P=0.467). In conclusion, the CMV antigenemia assay showed low sensitivity but high specificity for detecting CMV colitis and predicting steroid-refractory UC. There are some limitations to the present study. Selection bias may have been introduced when performing the CMV antigenemia assay, which could have influenced the results by leading to higher chances of testing CMV antigenemia in severe patients. Whether and when to examine for CMV colitis is generally decided by the attending physician, the severity of the disease, and/or steroid refractoriness. In future studies, it would be beneficial to establish certain objective criteria for the CMV antigenemia assay, and to determine the optimal timing for blood sampling. Furthermore, the sample size was small, and the analysis was retrospective and based on medical charts, which makes it difficult to draw a concrete conclusion based on these results alone. However, the present study clearly shows that CMV antigenemia is an independent predictive factor for steroid refractoriness in moderate-to-severe cases of UC. Corticosteroid therapy is currently a significant tool in the management of acute exacerbation of UC. Moreover, a history of CMV has been shown to be predictive of nonresponse to infliximab.10 CMV testing would be useful to predict the response to steroids earlier in the treatment course. Therefore, testing for CMV should be routinely performed before corticosteroid or infliximab therapies in acute, severe cases of UC. However, a positive antigenemia test result is not sufficient to confirm a diagnosis of CMV colitis in cases of UC. It is generally accepted that sigmoidoscopy should be performed to both evaluate the disease status itself and determine if CMV infection is involved. Given that CMV antigenemia testing has a relatively high specificity as revealed by several studies, and that immunohistochemical staining of CMV takes 3-5 days before providing final results, the CMV antigenemia assay should be considered as a preliminary test in acute, severe cases of UC.

Heat Exchanger Method (HEM) grown GaAs single crystals and their homogeneity

GaAs single crystals, 32 mm in diameter and 32 mm in length, were grown by the heat exchanger method (HEM). A 〈111〉 seed crystal was used with helium gas for the heat exchanger. The optimum conditions for single crystal growth were determined to be growth time of 8.5 h, growth rate less than 4 mm/h and a helium flow rate smaller than 23.6 l/min. The Hall effect was measured by the Van der Pauw method about the radial and axial directions. From this measurement the homogeneity was known, and the Hall mobility and carrier concentration at room temperature were found to be 4580 cm2/V·s and 3.5×1016 cm-3, respectively. An EPD measurement was made to investigate the crystal quality. The value was 2×103 cm-2 at the center, but increased toward the edge to a value of 1×104 cm-2.

Photoluminescence studies on ZnRich Hg1−xZnxTe single crystals and composition determination

The Zn-rich Hg1−xZnxTe single crystals, i.e., 0.6 < x < 1, were grown by travelling heater method. Photoluminescence studies on the localized intrinsic exciton have been done and an empirical formula determining the composition x in Zn-rich Hg1−xZnxTe is derived subsequently.