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This paper proposes a low latency incremental redundancy hybrid ARQ (IR-HARQ) scheme for the wireless local area network (WLAN) system. The proposed scheme adopt the rate compatible low-density parity-check (RC-LDPC) code based on IEEE802.11n LDPC codes and ensure backward compatibility with WLAN devices by using the current WLAN control frame. Additionally, it enables to minimize the retransmission latency by selection of an optimal retransmission data length based on the mutual information (MI). Through computer simulations, it has confirmed that the proposed scheme can reduce the required SNR by 2.6 dB to achieve a system throughput of 15 Mbps compared with the retransmission scheme of the current WLAN system.

Objective:Toevaluatethesignificance ofpreoperativeclinicopathologicalfactors,includingserumcarcinoembryonicantigen(CEA),aswellas postoperative clinicopathological factors in T1-2N1M0 patients with non-small cell lung cancer who underwent curative pulmonary resection. Methods: Twenty T1N1M0 disease patients and 25 T2N1M0 patients underwent standard surgical procedures between September 1996 and December 2005, and were found to have non-small lung cancer. As prognostic factors, we retrospectively investigated age, sex, Brinkman index, histologic type, primary site, tumor diameter, clinical T factor, clinical N factor, pathological T factor, preoperative serum CEA levels, surgical procedure, visceral pleural involvement, and the status of lymph node involvement (level and number). Results: The overall 5-year survival rate of all patientswas59.6%.In univariateanalysis,survivalwasrelatedto age(

The aim of this study was to evaluate our personal experience with video-assisted thoracoscopic lobectomy and compare survival between this procedure and conventional lobectomy via open thoracotomy in patients with clinical stage IA non-small cell lung carcinoma. Between May 1997 and December 2004, 140 patients with clinical stage IA non-small cell lung carcinoma had either VATS lobectomy (VATS group, 84 patients) or standard lobectomy via open thoracotomy (open group, 56 patients) performed in our hospital. We compared overall survival, disease-free survival and recurrence between the two groups. The overall survival rate five years after surgery was 72% in the open group and 82% in the VATS group. There were no significant differences in the overall survival rate between the two groups. The disease-free survival rate five years after surgery was 68% in the open group and 80% in the VATS group. There were no significant differences in the disease-free survival rate between the two groups. Five patients in the open group developed distant recurrence, whereas one patient developed regional recurrence. In the VATS group six patients developed distant recurrence, whereas one patient developed regional recurrence. We consider VATS lobectomy to be one of the therapeutic options in patients with clinical stage IA non-small cell lung carcinoma.

The psychological effects of surgery have received little attention in patients with lung cancer, so it is unclear how much psychological support is required by these patients. This study was done to assess the mental state of patients with lung cancer before and after surgery and to determine their need for psychological care.A group of 165 patients with lung cancer scheduled for surgical treatment were included in this study. They were asked to complete the Profile of Mood States questionnaire before surgery and on discharge after completion of treatment. The data on mood from the questionnaires were analyzed.Tension-anxiety improved significantly after surgery, whereas the fatigue score increased significantly. The scores for depression-dejection and confusion were elevated before surgery and were unchanged afterward.Patients with lung cancer were depressed before surgery and remained depressed after their operations, although postoperative tension-anxiety diminished. These results indicate that lung cancer patients need psychological support to alleviate depression during the perioperative period.

Background: This study endeavored to clarify the location, frequency, and prognostic value of metastatic lymph nodes in the mediastinum among patients with left upper lung cancer who underwent complete dissection of the superior mediastinal lymph node through a median sternotomy. Methods: Forty-four patients with left upper lobe cancer underwent extended radical mediastinal nodal dissection (ERD), all of whom were analyzed in this retrospective study. The group comprised 12 females and 32 males, with ages ranging from 28 to 70 years (median age, 60 years). Mediastinal nodal status was assessed according to the systems of Mountain/Dresler 7 and Naruke 8. The clinicopathological records of each patient were examined for prognostic factors, including age, sex, histology, tumor size, c-N number, preoperative serum CEA level, metastatic stations and distribution of metastatic nodes according to Naruke’s system 8. The superior mediastinal lymph nodes which cannotbedissectedthrougha leftthoracotomy(bilateral#1and#2,#3,right#3a,andright#4accordingtoNaruke’smap8 weredefinedasextrasuperior mediastinal nodes for left lung cancer (ESMD). Results: Fourteen patients had one or more metastases to mediastinal lymph nodes, among whom the most common metastatic station was the aortic nodes: 71.4% had metastasis to #5 or #6 (57.1% to #5 and 50% to #6). The next mostcommonmetastatic station wasthe left tracheobronchialnodes (42.8%).Metastasis to the ESMDoccurredin 7 of the 44study subjects (16%), representing a 50% rate of occurrence (7/14) among those with mediastinal nodal involvement. Univariate analysis found that CN factor and aortic nodal involvement (#5, #6) were significant predictive factors for ESMD metastasis. Multivariate analysis determined that only aortic nodal involvement was significant (p = 0.008). Furthermore, ESMD metastasis was rare (5.8%) in the absence of aortic node metastasis. The overall survival rate at 5 years was 50% among the patients without ESMD metastasis. However, the survival rate was 32% at 3 years and 0% at 5 years among the seven patients with ESMD metastasis. Conclusions: The aortic lymph node is the most common site of metastasis from left upper lobe cancer. Multivariate analysis demonstrated that aortic nodal involvement was a significant predictive factor for ESMD metastasis. Based upon the rates of metastasis and the post-operative prognosis in our study patients, dissection of aortic nodes and left tracheobronchial nodes may be important for patients with left upper lobe cancer. Whether ESMD dissection has a beneficial effect on prognosis remains controversial.

Objective: We worked to devise a new way to prevent postoperative persistent air leaks in high-risk pulmonary surgery patients. Methods: From November 1993 to June 2002, 60 patients with difficult to control intraoperative pulmonary air leakage were treated using bioabsorbable polyglycolide felt patches soaked in fibrin glue to cover the leakage site. Results: After application, the felt patch adhered tightly to the lung surface without peeling off, enabling good leakage closure with only 2 ml of fibrin glue used. Air leakage was controlled successfully in 52 (86.7%) of the 60. Four of the 8 patients in whom this method failed to stop air leakage also developed mild pyothorax, with 2 requiring a second operation by video-assisted thoracic surgery. Leakage was eventually controlled in all patients, with no postoperative deaths relating to air leakage. Conclusions: Fibrin-glue-soaked bioabsorbable felt patches effectively seal intraoperative intractable air leaks. Felt patch use may increase the risk of postoperative infection. It should be considered for use on patients with fistulas that cannot be controlled by direct closure or otherwise intraoperatively and who may potentially develop uncontrollable air leakage postoperatively.

Legionella spp are well recognized as one of the etiologic factor in pneumonia, but it is difficult to distinguish the clinical features of Legionella infection from pneumonia due to other causes. The objective of the present study was to examine the clinical characteristics of community-acquired Legionella pneumonia in elderly patients. We reviewed the clinical, laboratory and radiographic findings in 8 patients diagnosed as having pneumonia caused by Legionella. The diagnosis was confirmed by the presence of urinary antigen, bacterial culture, polymerase chain reaction (PCR) and serum antibody. There were 6 men and 2 women, whose ages ranged from 76 to 85 years. All patients had fever and hypoxia, four patients had respiratory symptoms. The initial chest X-ray findings were varied--consolidation, ground glass opacity, pleural effusion and linear shadow. Urinary antigen was positive in 4 patients, bacterial culture in 2, PCR on the sputum in 3 and serum antibody in 2 patients. As pneumonia caused by Legionella often becomes life-threatening, especially in elderly people, it is imperative to diagnose it at the initial stage. In this study, urinary antigen proved to be the most useful diagnostic means. However, it is important to confirm the diagnosis through plural examinations.

Background We tried to clarify whether the histologic subtypes and the size of the solid component of an adenocarcinoma are more important predictive factors for invasiveness or prognosis than is total tumor size, even in lung adenocarcinomas that were 2 cm or smaller. Methods Between 1996 and December 2005, after standard surgical treatment, 82 patients were diagnosed as having adenocarcinoma with a maximum diameter of 2 cm or less. The group comprised 37 females and 45 males, with ages ranging from 41 to 80 years (median, 64). The clinicopathologic records of the patients were examined with regard to age, sex, nodal status, tumor size (largest diameter of the total tumor as well as the largest diameter without the bronchioloalveolar carcinoma [BAC] component [solid component]), serum carcinoembryonic antigen level, and histologic type. These variables were analyzed as risk factors for vascular or lymphatic invasion, lymph node metastasis, and prognosis. Histologic subtype was classified into two groups: mixed BAC (mixed adenocarcinoma with BAC) and minimal or non-BAC (tumors with little or no BAC component). Results Histologic subtype was a significant predictive factor both for invasiveness (vascular or lymph vessels) and lymph node metastasis, in both univariate and multivariate analysis. Tumor diameter was not a significant factor in either univariate or multivariate analysis (p = 0.28, 0.15, respectively). However, diameter excluding the BAC component was a significant factor for invasiveness in mixed BAC type (p = 0.035), whereas total diameter was not significant (p = 0.28). Finally, histologic subtype and lymph node metastasis were significant prognostic factors for survival in both univariate (p = 0.03, 0.05, respectively) and multivariate (p = 0.04, 0.05, respectively) analyses. The 5-year survival rate was 94.4% (94.1% for pN0) for the mixed BAC type and 71.4% (78.7% for pN0) for the minimal or non-BAC type (p = 0.009; p = 0.04 for pN0 nodes). Conclusions Small adenocarcinomas can be classified into two categories. The first category is a minimal or non-BAC adenocarcinoma that shows aggressive biological behavior. The second category is a mixed BAC, which demonstrates less invasive or aggressive biological behavior than the minimal or non-BAC type, with the degree of invasiveness being associated with the size of the non-BAC component.

BACKGROUND Many histologic classifications of thymic epithelial tumors have been reported to date, but to the authors' knowledge, none of them closely reflect the clinical behavior or prognosis of the tumor. Therefore, it is necessary to establish a biologic marker for thymic epithelial tumors. Variants of CD44 may be important in promoting tumor progression and metastasis. Accordingly, the expression of CD44 isoforms in thymic epithelial neoplasms was investigated using immunohistochemistry to assess their possible value as prognostic indicators. METHODS Expression of CD44v6 in thymic epithelial tumors was investigated with immunohistochemistry using consecutive surgical specimens resected from 108 patients between 1983 and 2002 at Juntendo University Hospital in Tokyo, Japan. RESULTS Among the 108 thymic epithelial tumors, 70 were negative for CD44v6, 20 were weakly positive, and 18 were strongly positive. The status of CD44v6 expression (negative vs. weakly plus strongly positive) was found to be correlated with the tumor stage according to the Masaoka staging system (noninvasive vs. invasive tumors) (P = 0.0214). When patients with tumors that were negative and weakly positive for CD44v6 expression were combined, the 5-year, 10-year, and 15-year recurrence-free survival rates were 98.2%, 95.9%, and 86.1%, respectively, whereas the corresponding rates for patients with strongly positive tumors were 73.5%, 73.5%, and 55.1%, respectively. Therefore, these two groups demonstrated a significant difference with regard to recurrence-free survival (P = 0.0172). CONCLUSIONS CD44v6 expression in thymic epithelial neoplasms demonstrated a significant difference based on the World Health Organization classification, the Masaoka stage (invasive vs. noninvasive tumors), and recurrence, if an appropriate cutoff value was chosen in each case. This suggests that CD44v6 can be used as a marker that reflects the stage of thymic tumors. Cancer 2005. © 2005 American Cancer Society.