Masazumi Maeda

Thirty-day operative mortality for thoracotomy in lung cancer

OBJECTIVE The 30-day operative mortality for thoracotomy in lung cancer is described herein. METHODS From January 1994 through December 1994, the Japanese Association for Chest Surgery surveyed the number of thoracotomies for lung cancer by operative procedure, age, and operative mortality. The operative mortality was defined as death within 30 days of operation. RESULTS The total number of operations was 7099. The overall 30-day operative mortality was 1.3%. By operative procedure, the mortalities were 3.2% for pneumonectomy, 1.2% for lobectomy, and 0.8% for a lesser operation, which showed a significant difference between pneumonectomy and lobectomy (p < 0.01). The mortality by age was 0.4% for patients younger than 60 years, 1.3% for those aged 60 to 69, 2.0% for those aged 70 to 79, and 2.2% for those aged 80 or older, which showed significant differences between the less than 60-year and 60- to 69-year-old groups, and between the 60- and 69-year-old and 70- and 79-year-old groups (p < 0.01 and p = 0.047, respectively). Pneumonia and respiratory failure caused most deaths (51.6%). CONCLUSIONS The operative mortality in Japan for thoracotomy in lung cancer was satisfactorily low. The results of this study on a large population could serve as a standard when discussing the operative outcome of lung cancer.

Functional indications for bullectomy of giant bulla.

Nineteen patients with giant bulla were followed for more than 1 year after bullectomy. They were divided into two groups according to their postoperative symptoms. Group 1 consisted of 16 patients who had no problems in their postoperative clinical course, while Group 2 included 3 patients who complained of severe dyspnea at 5 to 6 years of follow-up. Prior to operation, the forced expiratory volume in 1 sec over vital capacity (FEV1%) was 66.8 +/- in Group 1 and 27.6 +/- 5.4% in Group 2. Differences in preoperative and postoperative FEV1% were statistically significant within Group 1 and between the two groups. Postoperative FEV1% (Y) correlated significantly with preoperative FEV1% (X) (Y = 0.74X + 25.4; r = 0.836; p less than 0.001). Thus, we were able to predict the postoperative FEV1% from the preoperative value. Regional ventilation over volume was computed from the washout curve of xenon 133 after reaching equilibrium with rebreathing in a closed circuit (V/V dynamic). Group 2 had significantly lower regional ventilation over volume in all regions, both before and even after bullectomy, compared with normal subjects or Group 1 patients. Preoperative V/V dynamic was below 0.5 in all regions of Group 2. Furthermore, postoperative V/V dynamic (Y) correlated significantly with preoperative V/V dynamic (X) in the upper region (Y = 0.46X + 0.40; r = 0.638; p less than 0.02) and in the lower region (Y = 0.72X + 0.33; r = 0.869; p less than 0.001). We conclude that functional indications of bullectomy for giant bulla are that FEV1% should be greater than 40%, and that regional V/V dynamic should be greater than 0.5. On the other hand, symptomatic and functional improvement following bullectomy was reduced in patients whose FEV1% was less than 35% in whose V/V dynamic was remarkably disturbed in all regions of the involved hemithorax.

Human papillomavirus not found in squamous and large cell lung carcinomas by polymerase chain reaction.

BACKGROUND: Human papillomavirus (HPV) has been identified not only in anogenital carcinomas, but also in malignancies of other organs, including bronchogenic carcinomas. Previous studies reporting detection of these viruses in lung cancers used mainly in situ hybridization. The authors applied the polymerase chain reaction (PCR) for investigating the occurrence of HPV in bronchial neoplasms. METHODS: Formalin fixed, paraffin embedded tissues of 40 squamous and 7 large cell lung cancers were examined. PCR was done with consensus primers, capable of detecting HPV 6, 11, 16, 18, 31, 33, 52b, and 58. RESULTS: None of the 47 samples contained any of the examined HPV types. CONCLUSIONS: Because the squamous and large cell cancer cases were found not to be associated with HPV infection, this study does not support the potential role of these viruses in the development of lung cancers.

Effectiveness of planar image and single photon emission tomography of thallium-201 compared with gallium-67 in patients with primary lung cancer

A comparative study of planar images and single photon emission tomography (SPET) of thallium-201 chloride and gallium-67 citrate was performed in 38 patients with proven primary lung cancer to detect the primary lung tumour and to establish the presence of metastasis in the lung hilum and mediastinum. The findings of planar images and SPET were compared with the pathological findings after thoracotomy. It was shown that 201Tl studies were superior to 67Ga studies for evaluation of the primary lesion and lymph node metastases.

Operative Approaches for Left-Sided Carinoplasty

Carinoplasty was performed in 42 patients: 7 with wedge pneumonectomy, 15 with sleeve pneumonectomy, 14 with one-stoma-type carinal reconstruction, 5 with montage-type carinal reconstruction, and 1 other. Diagnoses in the 42 patients consisted of lung cancer in 31 (73.8%), tuberculous stenosis in 10 (23.8%), and tracheobronchial injury in 1 (2.4%). The thoracotomy was on the right side for lung cancer in 77.4% and on the left side for tuberculous stenosis in 80.0% (p < 0.01). Left-sided carinoplasty was performed in 14 patients using four approaches: midline thoracotomy in 1, left thoracotomy in 10, midline sternotomy and left thoracotomy in 2, and bilateral thoracotomies in 1. Left wedge or sleeve pneumonectomy, without right thoracotomy, could be done by midline sternotomy and left thoracotomy but with limited tracheal resection. Left one-stoma-type carinoplasty was undertaken, sacrificing one lobe, as an alternative to pneumonectomy, where an approach drawing the carina down to an aortopulmonary window was considered to be preferable to the drawing-up approach.

Study on the ratio of lymphocytes to epithelial cells in thymoma.

In order to quantify the lymphocyte to epithelial cell ratio (L/E ratio) of the thymoma, actual counting was performed. The L/E ratio was investigated in 25 specimens of 22 cases (22 initial tumors and 3 recurrent tumors). L/E ratios ranged from 0.27 to 4.10, and the mean value was 1.93 ± 0.21. The mean L/E ratio of histologically malignant group was lower than that of the benign group. In the three recurrent cases, L/E ratios of the recurred tumor decreased in all cases. It was concluded that the epithelial element increases with the advance of the tumor.

A study on optimal temperature for isolated lung preservation

Fifty-two heart-lung blocks (grafts) of New Zealand white rabbits were used for determining optimal temperature in lung preservation. Grafts were inflated with room air and preserved by simple surface cooling at arbitrarily determined temperatures for 18 hours. Graft function was assessed by nonrecirculated perfusion with autologous blood. Segmented regression models between functional parameters and preservation temperature (T) were applied for determining optimal temperature. Graft ability was also assessed from the point of view of pulmonary circulation by indocyanine green dilution rate of effluent and histological distribution of carbon particles. Significant segmented regression curves and lines between parameters of effluent oxygen tension (PO2) and wet-dry weight ratio (W/D), and T were obtained as follows: PO2 = 150/(1 + 3208.1[e-1.17T]), p less than 0.01; PO2 = -13.8T + 222.6, p less than 0.05; W/D = 5.0 + 1.5/(1 + 0.0028[e0.94T]), p less than 0.01; W/D = 0.075T + 4.52, p less than 0.05. Optimal temperature for lung preservation by topical cooling was calculated as 8 degrees to 9 degrees C from each intersecting point of regression equations. Analysis of regression curves suggested that the most common hypothermic ischemic injury during preservation by topical cooling is pulmonary vascular obstruction, which might be induced at temperatures lower than the critical temperature of 6 degrees to 7 degrees C. Indocyanine green dilution rate and histological findings supported the results of graft functional parameters.

Ansa-recurrent nerve anastomosis for vocal cord paralysis due to mediastinal lesions.

Recurrent laryngeal or vagus nerve injuries in the mediastinum are repaired rarely because of technical difficulties. Impairment in phonation is especially severe in patients with respiratory dysfunction. We performed a simple and less invasive reconstruction, ansa cervicalis-recurrent laryngeal nerve anastomosis in the neck, to improve phonation in 2 patients. Although the reinnervated vocal cord did not regain normal movement, both of the patients obtained excellent improvement in phonation.

Postoperative chemo–endocrine treatment with mitomycin C, tamoxifen, and UFT is effective for patients with premenopausal estrogen receptor–positive stage II breast cancer

The effectiveness of combining mitomycin C (MMC), tamoxifen (TAM), and 1-(2-tetrahydrofuryl)-5-fluorouracil (tegafur) was evident in patients with estrogen receptor-positive (ER+) breast cancers. UFT, an oral preparation of tegafur and uracil at a molar ratio of 1:4, was reported to have higher antitumor effects than tegafur alone for patients with breast cancer. Therefore, the combined chemotherapy of MMC, TAM and UFT may possibly be effective for breast cancer.From 1988 to 1991, we studied the effects of postoperative adjuvant therapy for Japanese women with stage II breast cancer, all seen at 71 institutions in western areas of Japan. Five hundred and ninety four patients with stage II primary breast cancer who had undergone curative surgery, including total mastectomy and axillary lymph node dissection, were enrolled. On the day of surgery, each patient was given 13 mg/m2 of MMC intravenously. Patients with ER+ tumors were then assigned to group A or group B. Group A received 30 mg/day of TAM given orally from postoperative 2 weeks, for 2 years. Group B was additionally given an oral dose of 300 mg/day of UFT for 2 years, given concomitantly with 30 mg/day of TAM. Patients with ER− tumors were assigned to group C or group D. Group C were prescribed 300 mg/day of UFT, orally, from postoperative 2 weeks for 2 years, and group D were additionally given an oral dose of 30 mg/day of TAM together with 300 mg/day of UFT.There were no differences among the groups regarding prognostic factors or doses of MMC and TAM in ER+ patients and MMC and UFT in ER− patients. Toxicity rates for leukopenia, anorexia, and nausea/vomiting were higher in group B than in group A patients. There were no statistical differences in the overall survival and disease–free survival times between groups A and B, or groups C and D, for all eligible cases. In a retrospective subgroup analysis using Bonferronis adjustments, the additional effect of UFT on the combined treatment of MMC and TAM lengthened the disease-free survival time for patients with premenopausal ER+ cancers (corrected P value by Bonferronis adjustments <0.05). Multivariate analysis showed that effects of the combined treatment of MMC, TAM, and UFT was significantly related to the menopausal status (P<0.0 1).Our findings show that postoperative ingestion of MMC, TAM, and UFT was effective for patients with premenopausal ER+ stage II breast cancer.

Analysis of the Phospholipase C Gene of Clostridium perfringens KZ1340 Isolated from Antarctic Soil

Clostridium perfringens KZ1340 isolated from Antarctic soil was first classified as Clostridium plagarum and later as a lecithinase‐negative variant of C. perfringens. Although the strain produced no detectable lecithinase (phospholipase C, PLC) activity in the culture supernatant, it was shown by Southern blot hybridization to possess a PLC‐encoding gene (plc). To determine the cause of the PLC deficiency, we cloned and sequenced the plc gene from KZ1340. The deduced amino acid sequence consists of 398 amino acid residues, coinciding with those of the plc genes previously determined. Tyrosine was substituted for histidine at amino acid position 148, which is thought to bind a zinc ion essential for PLC activity. Northern blot analysis revealed that KZ1340 expressed the plc gene at an extremely low level. Furthermore, the plc gene cloned from C. perfringens strain 13 into a plasmid was expressed weakly in KZ1340, compared to that in strain 13. This indicates that the former strain represses plc gene expression in trans. When a phylogenetic tree of plc genes was constructed, the KZ1340 plc gene formed a monophyletic branch along with those of various other C. perfringens strains, supporting the classification of the strain as a variant of C. perfringens.