CT-based deep learning enables early postoperative recurrence prediction for intrahepatic cholangiocarcinoma

Preoperatively accurate evaluation of risk for early postoperative recurrence contributes to maximizing the therapeutic success for intrahepatic cholangiocarcinoma (iCCA) patients. This study aimed to investigate the potential of deep learning (DL) algorithms for predicting postoperative early recurrence through the use of preoperative images. We collected the dataset, including preoperative plain computed tomography (CT) images, from 41 patients undergoing curative surgery for iCCA at multiple institutions. We built a CT patch-based predictive model using a residual convolutional neural network and used fivefold cross-validation. The prediction accuracy of the model was analyzed. We defined early recurrence as recurrence within a year after surgical resection. Of the 41 patients, early recurrence was observed in 20 (48.8%). A total of 71,081 patches were extracted from the entire segmented tumor area of each patient. The average accuracy of the ResNet model for predicting early recurrence was 98.2% for the training dataset. In the validation dataset, the average sensitivity, specificity, and accuracy were 97.8%, 94.0%, and 96.5%, respectively. Furthermore, the area under the receiver operating characteristic curve was 0.994. Our CT-based DL model exhibited high predictive performance in projecting postoperative early recurrence, proposing a novel insight into iCCA management.

[A Case of Ectopic Pheochromocytoma between the Abdominal Aorta and Inferior Vena Cava]

We report a case of ectopic pheochromocytoma which is relatively rare. A 50-year-old man was found to have an abdominal tumor on a medical examination, and contrast-enhanced computed tomography showed a retroperitoneal tumor between the abdominal aorta and the inferior vena cava. As a result of close examinations, an ectopic pheochromocytoma was suspected. He was asymptomatic and suspected infiltrating into great vessels, but possibility of a malignant neoplasm could not be ruled out for the tumor had a tendency to enlarge, the resection of the tumor was performed. During the operation, the invasion of the tumor into the great vessels was denied and the tumor was completely resected. Large fluctuation of the blood pressure was not observed during the operation. Histopathological evaluations of the resected specimen revealed the ectopic pheochromocytoma. A pheochromocytoma was newly defined as a tumor with malignant potential for metastasis in all cases by the WHO classification published in 2017. He was diagnosed as moderately malignant by GAPP score, therefore the careful follow-up was considered necessary in the future.

[A Case of Metastatic Breast Cancer with BRCA1 Mutation after Breast Reconstruction and Pregnancy]

We present the case of a 31-year-old woman with a chief complaint of a left breast mass. The patient visited our department for an evaluation of this left breast mass. Left breast cancer(cT1cN0M0, cStage Ⅰ, triple negative type)was diagnosed, and left partial mastectomy and sentinel node biopsy were performed. Although the pStage was the same prior to surgery, a BRCA1 mutation was identified on genetic testing. After administration of postoperative adjuvant chemotherapy (epirubicin, cyclophosphamide, and paclitaxel), consorted mastectomy, tissue expander insertion, and breast reconstruction with silicone implant were performed. Spontaneous pregnancy occurred 1 year and 10 months after the first operation. She had an uneventful delivery with a normal course of labor 2 years and 6 months after the surgery. Two years and 11 months after the first operation, she visited our institution with complaints of headache, dizziness, and difficulty eating. Upon assessment, brain, lung, liver, and bone metastases were identified on contrast-enhanced computed tomography. Concentrated glycerin and fructose, steroid administration, and whole-brain irradiation improved the symptoms due to cerebral edema. Thereafter, olaparib was started, and treatment was continued while maintaining partial response(PR).

No significant association between stable iodine intake and thyroid dysfunction in children after the Fukushima Nuclear Disaster: an observational study

PURPOSE

Stable iodine prophylaxis helps prevent childhood thyroid cancer in nuclear emergencies; however, there is limited information on its effect on thyroid function. This study aimed to examine thyroid function and autoimmunity among children and adolescents that took stable iodine after the Fukushima Nuclear Disaster.

METHODS

For this observational study, data were obtained from children and adolescents that underwent thyroid cancer screening at Hirata Central Hospital from April 2012 to March 2018. Participant characteristics, including possible hypothyroidism and hyperthyroidism, were compared between the prophylaxis and no-prophylaxis groups. Multivariable logistic regression models were used to assess for possible hypothyroidism, autoantibodies positive, and hyperthyroidism.

RESULTS

A total of 1,225 participants with stable iodine prophylaxis and 3,946 without prophylaxis were enrolled. Of those participants, blood samples were available for 144 and 1,201 participants in the prophylaxis and no-prophylaxis groups, respectively. There were 17 (11.8%) and 146 cases (12.2%) of possible hypothyroidism or autoantibodies positive cases in the prophylaxis and no-prophylaxis groups, respectively, and there were no cases and 3 cases (0.2%) of possible hyperthyroidism in those two groups, respectively. Multivariable analysis for possible hypothyroidism revealed no association between stable iodine intake and possible hypothyroidism or autoantibodies positive [odds ratio 0.716 (95% confidence interval 0.399-1.284)] (p = 0.262). We did not perform multivariable analysis for hyperthyroidism due to the limited number of cases.

CONCLUSION

Significant adverse effects of stable iodine intake on thyroid function were not observed among children and adolescents 7 years after the Fukushima Nuclear Disaster.

[Two Cases in Which Simultaneous Laparoscopic Surgery and Breast Cancer Surgery Using a Head-Mounted Monitor Were Useful]

Herein, we report on how we were able to reduce the operation time by simultaneously performing laparoscopic surgery and breast cancer surgery using a head-mounted monitor(HMS-3000MT, Sony corporation). Case 1: 60s, female. A 5.5 cm leiomyoma was found in the central thoracic esophagus, and a 1 cm breast cancer was found in the C region of the left mammary gland. Subtotal esophagectomy with right thoracotomy and laparoscopy and a left partial mastectomy were performed. For the abdominal surgery, HMS-3000MT was used under hand-assisted laparoscopy, and a left partial mastectomy was performed concurrently. Operation time was 367 minutes(simultaneous surgery for 56 minutes). Esophagus: leiomyoma, 50×45 mm; and mammary gland: 16×15 mm, pTis(DCIS), pN0(sn), cM0, and pStage 0. Case 2: 70s, female. A 3 cm sized GIST was found on the posterior wall of the middle gastric body, and a breast cancer of 1.3 cm was also found in the B region of the right mammary gland. Using HMS-3000MT, laparoscopic local resection of the stomach and right total glandectomy were performed concurrently. Operation time was 114 minutes(simultaneous surgery for 58 minutes). Stomach: GIST, 25×22 mm, and modified Flecher classification low risk; and mammary gland: invasive ductal carcinoma, 15×15 mm, pT1c, pN0(sn), cM0, and pStage Ⅰ. Conclusion: In 2 fields of surgery, simultaneous surgery using HMS-3000MT was considered to be a useful method to shorten the operation time.

[A Case of Laparoscopic Distal Gastrectomy for Gastric Cancer with an Adachi Type Ⅵ Group 24 Vascular Anomaly]

We report a case of successful laparoscopic distal gastrectomy for gastric cancer with an Adachi type Ⅵ group 24 vascular anomaly. A male in his 60s exhibited a type 0-Ⅱa plus Ⅱc lesion at the lesser curvature of the gastric angle by esophagogastroduodenoscopy and was diagnosed with tub2. He was referred to us for surgical treatment. The clinical diagnosis was cT1bN0M0, and cStage Ⅰ. Preoperative multidetector-row computed tomography(MDCT)showed an Adachi type Ⅵ group 24 vascular anomaly. At laparoscopic surgery, we dissected No. 8a lymph nodes with exposure of the surface of the portal vein because the common hepatic artery was absent. The left gastric artery and splenic artery formed a common trunk. As there are various kinds of vascular anomalies of the celiac artery branch, we must understand the arterial running pattern prior to gastric surgery. This technique is more useful in laparoscopic surgeries where tactile sensation is limited. To prevent perioperative and postoperative complications, we must recognize the anomaly pattern prior to surgery using MDCT.

Underestimation of COVID-19 cases in Japan: an analysis of RT-PCR testing for COVID-19 among 47 prefectures in Japan

BACKGROUND

Under the unique Japanese policy to restrict reverse transcriptase-polymerase chain reaction (RT-PCR) testing against severe acute respiratory syndrome coronavirus 2, a nationwide number of its confirmed cases and mortality remains to be low. Yet the information is lacking on geographical differences of these measures and their associated factors.

AIM

Evaluation of prefecture-based geographical differences and associated predictors for the incidence and number of RT-PCR tests for coronavirus disease 2019 (COVID-19).

DESIGN

Cross-sectional study using regression and correlation analysis.

METHODS

We retrieved domestic laboratory-confirmed cases, deaths and the number of RT-PCR testing for COVID-19 from 15 January to 6 April 2020 in 47 prefectures in Japan, using publicly available data by the Ministry of Health, Labour and Welfare. We did descriptive analyses of these three measures and identified significant predictors for the incidence and RT-PCR testing through multiple regression analyses and correlates with the number of deaths through correlation analysis.

RESULTS

The median prefectural-level incidence and number of RT-PCR testing per 100 000 population were 1.14 and 38.6, respectively. Multiple regression analyses revealed that significant predictors for the incidence were prefectural-level population (P < 0.001) and the number of RT-PCR testing (P = 0.03); and those for RT-PCR testing were the incidence (P = 0.025), available beds (P = 0.045) and cluster infections (P = 0.034).

CONCLUSION

Considering bidirectional association between the incidence and RT-PCR testing, there may have been an underdiagnosed population for the infection. The restraint policy for RT-PCR testing should be revisited to meet the increasing demand under the COVID-19 epidemic.

[A Case in Which Trastuzumab Combined Chemotherapy Was Effective for Recurrence of Post-Operative Gastric Cancer with Partial HER2 Overexpression]

We report a case in which recurrent partial HER2-positive gastric cancer showed complete clinical response to capecitabine (Cape)/oxaliplatin(L-OHP/OX)(CapeOX)plus trastuzumab(Tmab)combined chemotherapy for 32months. A 65-yearold man underwent distal gastrectomy, D2 lymph node dissection, and Roux-en-Y reconstruction for type 2 gastric cancer of the prepyloric anterior wall in December 2014. Pathological stage was as follows: L, ant, Type 2, 32×22 mm, tub1>tub2> por1, pT2(MP), int>med, INF c>a, Ly1a, V0, pN0, cM0, cH0, cP0, pCY0, pStage I B, pPM0(60mm), pDM0(75mm), pR0. Immunostaining of the tumor indicated overexpression of the HER2 gene in more than 10% of the well differentiated tubular adenocarcinoma(tub1). Nineteen months post-surgery, pancreatic head lymph node metastasis was diagnosed, and we started CapeOX plus Tmab combined chemotherapy. After 19 courses, the metastatic lymph node reduced its size until we could not detect it on CT. We continued treatment for 45 courses(about 32 months). During the courses, there were adverse events such as peripheral neuropathy(Grade 3, CTCAE v5.0), which required interruption of L-OHP, and oral mucosal ulcer (Grade 2).

[A Case of Pancreatic Acinar Cell Carcinoma in a Young Woman without Recurrence after Systemic Chemotherapy Using S-1]

A 26-year-old woman underwent laparoscopic-assisted distal pancreatectomy and splenectomy for a tumor in the tail of the pancreas. Although the preoperative diagnosis was a solid pseudopapillary tumor, pathological tissue examination revealed that the tumor was a pancreatic acinar cell carcinoma. She was treated with S-1 chemotherapy for 6 months without severe side effects, and no recurrence was detected on several imaging inspections. Acinar cell carcinoma of the pancreas is a rare tumor in young patients, and there are few reports of treatment with postoperative chemotherapy.

[A Case of Laparoscopic Resection for Locally Advanced Primary Rectal Cancer after Neoadjuvant Chemotherapy]

We treateda 70-year-oldfemale patient with locally advancedrectal cancer accompaniedby metastases to other organs. Three courses of S-1 plus oxaliplatin(SOX)therapy were administered as neoadjuvant chemotherapy(NAC), andthe cancer was subsequently treatedwith laparoscopic rectal resection. She hadvisiteda physician with a chief complaint of melena. A type 2 tumor located in the rectum Rb was found during the lower gastrointestinal endoscopy, which was diagnosed as an adenocarcinoma by biopsy. Vaginal invasion andlymph node metastasis were observedon CT andMRI. After 3 courses of SOX therapy(NAC), her condition was categorized as SD. Laparoscopic rectal amputation(D3)combinedwith resection of the ovary, uterus, and vagina was performed. On histopathological examination, the tumor was an adenocarcinoma, muc> tub2, ypT4b(AI, vaginal wall), int, INF b, ly1, v2, EX(-), PN1a, grade 1, pPM0, pDM0, pRM0 and pStage Ⅲa. The histological analysis demonstrated that the therapeutic effect of chemotherapy was grade 1a. Laparoscopic surgery, which is a relatively safe procedure, may be useful after NAC for an R0 resection.

Development of the micro pixel chamber based on MEMS technology

Micro pixel chambers (μ-PIC) are gaseous two-dimensional imaging detectors originally manufactured using printed circuit board (PCB) technology. They are used in MeV gamma-ray astronomy, medicalimaging, neutron imaging, the search for dark matter, and dose monitoring. The position resolution of the present μ-PIC is approximately 120 μm (RMS), however some applications require a fine position resolution of less than 100 μm. To this end, we have started to develop a μ-PIC based on micro electro mechanical system (MEMS) technology, which provides better manufacturing accuracy than PCB technology. Our simulation predicted the gains of MEMS μ-PICs to be twice those of PCB μ-PICs at the same anode voltage. We manufactured two MEMS μ-PICs and tested them to study their behavior. In these experiments, we successfully operated the fabricatedMEMS μ-PICs and we achieved a maximum gain of approximately 7×103 and collected their energy spectra under irradiation of X-rays from 55Fe. However, the measured gains of the MEMS μ-PICs were less than half of the values predicted in the simulations. We postulated that the gains of the MEMS μ-PICs are diminished by the effect of the silicon used as a semiconducting substrate.

Abstract P3-10-14: Breast cancer provider delay after the 2011 triple disaster in Fukushima, Japan

Introduction

Timely diagnosis and treatment is an indispensable part of breast cancer management. Delay of this process, also known as provider delay, can result in a deteriorated prognosis of affected patients. Although it has been suggested that disasters can impact cancer care and extend provider delay, there is little information available on long-term trends of breast cancer provider delay in post-disaster settings.

So-so district of Fukushima prefecture, Japan, experienced an earthquake, tsunami and the Fukushima Daiichi Nuclear Power Plant Accident in 2011. So-so district has areas falling within the mandatory, voluntary and non-evacuation ordered zones. Due to a long-term shortage of medical staff and closure of medical institutions post-disaster, patients with breast cancer may have experienced longer provider delay in this area.

Objectives

To compare provider delay of breast cancer patients and elucidate contributing factors to delay pre- and post-disaster, in an area severely affected by Japan's 2011 triple disaster.

Methods

We retrospectively investigated data of newly diagnosed breast cancer patients who undertook first medical consultation at the two main cancer centers in the non-evacuation ordered zone of So-so district from 2005 to 2016. Sociodemographic and clinical information was collected from medical records. The main outcome measure was median (days) from first medical consultation to start of breast cancer-specific treatment, pre- and post-disaster, using Mann-Whitney U test. Multivariate linear regression was then conducted to identify any factors which contributed to extended provider delay before and after the disaster.

Results

A total of 157 pre-disaster patients and 121 post-disaster patients were included in the study. There was no significant difference in the interval of median days of first medical consultation to start of first treatment pre- and post-disaster (40 vs. 39, p=0.82). Although diagnosis was made in a shorter interval post-disaster compared to pre-disaster (11 vs. 14, p=0.01) with significantly smaller median number of biopsies (1 vs. 1, p=0.001), this post-disaster improvement in diagnostic process was offset by deferred start of treatment after diagnosis (26 vs. 22, p=0.008). Among the pre-disaster patients, cancer detection by breast cancer screening program (p&lt;0.001), being engaged in full-time job (p&lt;0.042), and number of biopsies before diagnosis (p=0.005) contributed to longer provider delay in multivariate regression. However, consultation from other medical providers (p=0.03) was the only factor which significantly contributed to extended delay post-disaster, after controlling for multiple variables.

Conclusion

There was no significant increase in provider delay among breast cancer patients post-disaster. However, a median interval of 39 days from first medical consultation to start of treatment is much longer than other high-income countries, and shows much room for improvement in future.Introduction

Timely diagnosis and treatment is an indispensable part of breast cancer management. Delay of this process, also known as provider delay, can result in a deteriorated prognosis of affected patients. Although it has been suggested that disasters can impact cancer care and extend provider delay, there is little information available on long-term trends of breast cancer provider delay in post-disaster settings.

So-so district of Fukushima prefecture, Japan, experienced an earthquake, tsunami and the Fukushima Daiichi Nuclear Power Plant Accident in 2011. So-so district has areas falling within the mandatory, voluntary and non-evacuation ordered zones. Due to a long-term shortage of medical staff and closure of medical institutions post-disaster, patients with breast cancer may have experienced longer provider delay in this area.

Objectives

To compare provider delay of breast cancer patients and elucidate contributing factors to delay pre- and post-disaster, in an area severely affected by Japan's 2011 triple disaster.

Methods

We retrospectively investigated data of newly diagnosed breast cancer patients who undertook first medical consultation at the two main cancer centers in the non-evacuation ordered zone of So-so district from 2005 to 2016. Sociodemographic and clinical information was collected from medical records. The main outcome measure was median (days) from first medical consultation to start of breast cancer-specific treatment, pre- and post-disaster, using Mann-Whitney U test. Multivariate linear regression was then conducted to identify any factors which contributed to extended provider delay before and after the disaster.

Results

A total of 157 pre-disaster patients and 121 post-disaster patients were included in the study. There was no significant difference in the interval of median days of first medical consultation to start of first treatment pre- and post-disaster (40 vs. 39, p=0.82). Although diagnosis was made in a shorter interval post-disaster compared to pre-disaster (11 vs. 14, p=0.01) with significantly smaller median number of biopsies (1 vs. 1, p=0.001), this post-disaster improvement in diagnostic process was offset by deferred start of treatment after diagnosis (26 vs. 22, p=0.008). Among the pre-disaster patients, cancer detection by breast cancer screening program (p&lt;0.001), being engaged in full-time job (p&lt;0.042), and number of biopsies before diagnosis (p=0.005) contributed to longer provider delay in multivariate regression. However, consultation from other medical providers (p=0.03) was the only factor which significantly contributed to extended delay post-disaster, after controlling for multiple variables.

Conclusion

There was no significant increase in provider delay among breast cancer patients post-disaster. However, a median interval of 39 days from first medical consultation to start of treatment is much longer than other high-income countries, and shows much room for improvement in future.

Citation Format: Ozaki A, Leppold C, Tsubokura M, Sawano T, Tsukada M, Ohira H. Breast cancer provider delay after the 2011 triple disaster in Fukushima, Japan [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P3-10-14.

Fatty acid synthase-positive hepatocytes and subsequent steatosis in rat livers by irinotecan

Using a rat model, we investigated factors contributing to the pathogenesis of irinotecan-associated fatty liver disease. Male Sprague-Dawley rats were administered 200 mg/kg irinotecan by intraperitoneal injection on days 1–4, but not on days 5–7. This schedule was repeated 3 times. Rats were sacrificed 4, 18 and 25 days after the last injection, and liver steatosis was evaluated by hematoxylin and eosin (H&E) staining, microarray analysis and immunohistochemistry. Panacinar intrahepatocyte vacuoles were absent on days 4 and 25, but present on day 18, and this alteration was more prominent around the bile ducts than the central veins. Microarray analysis showed that the expression of genes involved in the synthesis of cholesterol and fatty acids was upregulated on day 4. Immunohistochemistry detected fatty acid synthase (Fasn)-strongly positive hepatocytes as well as the activation of liver progenitor cells on day 4, whereas intracellular vacuoles were evident in carbonic anhydrase 3 (CA3)-positive hepatocytes on day 18. Thus, irinotecan-induced liver steatosis was preceded by Fasn-strongly-positive hepatocytes and liver progenitor cell activation. The magnitude of the decrease in the number of Fasn-strongly positive hepatocytes between days 4 and 18 was similar to that of the increase in the number of CA3-positive hepatocytes accompanying vacuoles.

Video-assisted thoracoscopic transdiaphragmatic liver resection for malignant tumors located in the posterosuperior segments

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Background: Laparoscopic liver resection has recently become more common. However, it is difficult to resect laparoscopically the liver tumor located in the posterosuperior segments (IVa, VII and VIII), especillay for patients with liver cirrhosis. Compared to laparoscopy, gaining access to tumors in the dome of the liver may be more easily obtained via thoracoscopy.Therefore, we describe the technique and outcome of a video-assisted thoracoscopic transdiaphragmatic liver resection in patients with a malignant tumor of the liver. Methods: Five female patients underwent video-assisted thoracoscopic transdiaphragmatic partial hepatectomy. The tumors were located at segment VIII in 4 patients and segment VII in 1. Three patients were preoparatively diagnosed with hepatocellular carcinoma, and two were metastatic tumor of the colorectal cancer. Underlying cirrhosis was staged as Child-Pugh B in 2 cases and Child-Pugh A in 1. Thoracoscopic transdiaphragmatic partial hepatic resection was chosen due to the tumor’s location and impaired liver function. The patient was placed in an oblique position with her left side on the table. The ports were placed around the tumor at three levels, the ninth (3cm mini-thoracotomy), the seventh (two ports, 5mm and 12mm), and the fifth (12mm) intercostals spaces. Using thoracoscopic ultrasonography, the portion of the diaphragm located just above the tumor was cut and opened using electric cautery. The partial liver resection was performed using coagulating shears and electric cautery. Results: No conversion to laparotomy occurred. The median blood loss was 200 g (20-500g), and median operating time was 220 min (135-347 min). There were no perioperative deaths, and no patients underwent reoperation. Conclusions: Thoracoscopic hepatic resection can be safely performed in patients with subdiaphragmatic tumors, especially with cirrhosis or previous upper abdominal surgery.

[A case of syndrome of inappropriate antidiuretic hormone secretion in a patient with esophageal carcinoma possibly induced by cisplatin in neoadjuvant chemotherapy]

A 60 -year-old man complained of dysphagia and was admitted to our hospital for adjuvant chemotherapy under a diagnosis of esophageal carcinoma(squamous cell carcinoma[SCC], Stage II ). He was treated with cisplatin(CDDP)and 5- fluorouracil(5-FU). On the fifth day after administration, he experienced mild disorientation, and early morning on the sixth day, he showed impaired consciousness. Laboratory studies revealed a serum sodium level of 111mEq/L and a serum chloride level of 73mEq/L. The findings of computed tomography and magnetic resonance imaging of the head were unremarkable. Other laboratory studies revealed a plasma vasopressin level of 19.2 pg/mL, a plasma osmolality of 219mOsm/kg, a serum creatinine level of 0.61mg/dL, a serum cortisol level of 27.1 mg/dL, a urine osmolality of 665mOsm/kg, and a urine sodium level of 157.1mEq/L. There were no signs of dehydration, and so the patient was diagnosed with syndrome of inappropriate antidiuretic hormone secretion(SIADH). We discontinued chemotherapy and initiated fluid restriction and sodium supplementation. After this treatment, the patient's consciousness progressively improved. On the fifth day of treatment, laboratory studies revealed a serum sodium level of 138mEq/L and a serum chloride level of 98mEq/L, indicating recovery from hyponatremia.

[A case of cancer in the dilated jejunal pouch after total gastrectomy]

We report a case of cancer in the dilated jejunal pouch after total gastrectomy, in which we resected the jejunal pouch. The patient was a man in his 60s and had a history of total gastrectomy with jejunal pouch ρ-interposition for mucosa-associated lymphoid tissue (MALT) lymphoma in 1994. In late July 2012, he presented to the emergency department with a protracted ileus-like symptom and was admitted to the gastroenterological department after the diagnosis of a dilated jejunal pouch. He was managed conservatively; however, the same symptom recurred. Examinations showed a duodenal carcinoma and cancer in the jejunal pouch; therefore, he was referred for digestive surgery in early August. Endoscopic mucosal resection( EMR) was performed on the duodenal carcinoma, and we resected the jejunal pouch with Roux-en-Y reconstruction for the jejunal cancer. He recovered from postoperative wound infection and was discharged 15 days after the second operation.

Lectin-like receptor Ly49s3 on dendritic cells contributes to the differentiation of regulatory T cells in the rat thymus

Naturally occurring regulatory T cells (nTregs), important for immune regulation and the maintenance of self-tolerance, develop in the thymus. The Hirosaki hairless rat (HHR), derived from the Sprague-Dawley rat (SDR), was shown to have decreased peripheral lymphocyte number, small thymus, and leukocyte infiltration in its dermis. In the HHR thymus, the medulla was underdeveloped and nTreg number was decreased. Array comparative genome hybridization revealed the deletion of an NK cell lectin-like receptor gene, Ly49s3, detecting MHC class I molecules on target cells, in the chromosome 4q42 region in HHRs. The gene was expressed in thymic conventional dendritic cells (cDCs) in SDRs, but not in HHRs. When CD4-single-positive or CD4(+)CD8(-)CD25(-) thymocytes were cultured with thymic cDCs, the expression of nTreg marker genes was lower when these cells were from HHRs than from SDRs, suggesting that HHR cDCs are deficient in the ability to induce and maintain nTreg differentiation. Expression of the genes was recovered when Ly49s3 was expressed on HHR thymic cDCs. Expression levels of MHC class II genes, presumably from cDCs, were parallel to those of nTreg marker genes in mixed-cell cultures. However, in the presence of an anti-MHC class I Ab, blocking interaction between Ly49s3 and MHC class I molecules, the expression of the former genes was upregulated, whereas the latter was downregulated. These results suggest that Ly49s3 contributes to nTreg regulation along with MHC class II molecules, whose effects alone are insufficient, and loss of Ly49s3 from thymic cDCs is the reason for the nTreg deficiency in HHRs.

Late-onset chylothorax after pulmonary resection for lung cancer

Chylothorax is a relatively rare complication of thoracic surgery. Most instances of chylothorax after pulmonary resection are diagnosed within 3 days after surgery. Hence, late-onset chylothorax is rare. A 68-year-old woman underwent right lower lobectomy and mediastinal dissection for lung cancer. After discharge, the patient developed a dry cough, and chest radiography more than 3 months after surgery revealed a right-sided pleural effusion occupying more than half of the right hemithorax, which we diagnosed as late-onset chylothorax. Treatment comprised chest drainage, subcutaneous octreotide, and pleurodesis by injecting a preparation of OK-432. Follow-up chest radiography confirmed no reaccumulation of fluid. Three months later no recurrence of pleural effusion was detected. We report a rare case of postoperative late-onset chylothorax that proved difficult to treat.

Whole genome sequencing of meticillin-resistant Staphylococcus aureus

BACKGROUND

Staphylococcus aureus is one of the major causes of community-acquired and hospital-acquired infections. It produces numerous toxins including superantigens that cause unique disease entities such as toxic-shock syndrome and staphylococcal scarlet fever, and has acquired resistance to practically all antibiotics. Whole genome analysis is a necessary step towards future development of countermeasures against this organism.

METHODS

Whole genome sequences of two related S aureus strains (N315 and Mu50) were determined by shot-gun random sequencing. N315 is a meticillin-resistant S aureus (MRSA) strain isolated in 1982, and Mu50 is an MRSA strain with vancomycin resistance isolated in 1997. The open reading frames were identified by use of GAMBLER and GLIMMER programs, and annotation of each was done with a BLAST homology search, motif analysis, and protein localisation prediction.

FINDINGS

The Staphylococcus genome was composed of a complex mixture of genes, many of which seem to have been acquired by lateral gene transfer. Most of the antibiotic resistance genes were carried either by plasmids or by mobile genetic elements including a unique resistance island. Three classes of new pathogenicity islands were identified in the genome: a toxic-shock-syndrome toxin island family, exotoxin islands, and enterotoxin islands. In the latter two pathogenicity islands, clusters of exotoxin and enterotoxin genes were found closely linked with other gene clusters encoding putative pathogenic factors. The analysis also identified 70 candidates for new virulence factors.

INTERPRETATION

The remarkable ability of S aureus to acquire useful genes from various organisms was revealed through the observation of genome complexity and evidence of lateral gene transfer. Repeated duplication of genes encoding superantigens explains why S aureus is capable of infecting humans of diverse genetic backgrounds, eliciting severe immune reactions. Investigation of many newly identified gene products, including the 70 putative virulence factors, will greatly improve our understanding of the biology of staphylococci and the processes of infectious diseases caused by S aureus.

Hepatic coma recovered after interventional obliteration for ileocecal-inferior vena cava shunt--report of one case

We performed interventional angiography (IVA) in a patient with liver cirrhosis (LC) and hepatoma (HCC) who experienced repeated attacks of unconsciousness due to hyperammonemia caused by ileocecal-inferior vena cava (IC-IVC) shunt and succeeded in the treatment. We report the results below. The patient, 53-year-old male, underwent endoscopic injection sclerotherapy for esophageal varix due to LC followed by splenectomy for pancytopenia in 1986. He made good progress. However intraarterial anticancer therapy was conducted for HCC in 1994. From that time hepatic coma began to appear and its frequency gradually increased. Hepatic coma occurred once every 3 weeks from June 1996. He was thus admitted to our hospital. Hematobiochemical testes showed that ammonia level was 297 mcg/dl. Albumin 2.8d/dl, and Total-Bilirubin 10.78 mg/dl. Arterioportography from superior mesenteric artery showed most of portal blood flowed away from the liver though the ileocolic vein to IVC. We decided to conduct IVA for treatment. Specially, a 6Fr balloon catheter was inserted from the right inguinal region into a shunt to the portal vein though IVC by the Seldinger technique. The balloon was inflated in the shunt to close the shunt. Six ml of 5% ethanolamime oleate with iopamidol was injected because retrograde angiography showed that iopamidol was flowed out via testicular vein to IVC. The balloon catheter was retained for 24 hours. Angiography, conducted from the catheter again 24 hours later, showed that the shunt was occluded, blood ammonia level was 71 mcg/dl after occlusion. Hepatic coma was not observed after treatment. We encountered a very rare case who repeated hepatic comas due to IC-IVC shunt and recovered dramatically after IVA.

An improved endoscopic variceal ligation for esophageal and solitary gastric varices--three-O-band-shooter

We have reported a 16.0 mm long new type of instrument with the inner diameter of inner cylinder of 10.3 mm for endoscopic variceal ligation which could shoot 3 elastic O bands continuously in short period of time without removing the endoscope. The suction volume of new instrument is larger than that of the Stiegmann's ligator. We performed endoscopic variceal ligation (EVL) in 17 cases of the esophageal varix and 8 cases of the solitary gastric varix. EVL was performed as prophylaxis as all the cases. The esophageal varices were eliminated in all the cases after ulcer formation. The procedure was performed one time in 15 cases and two times in the remaining 2 cases. Three patients died one to hepatic failure during the follow-up period between 4 and 16 months. Six and twelve months cumulative recurrence rates were 30% and 48% respectively. On the other hand all the gastric varices disappeared after one sitting of the treatment. There was one variceal recurrence during the follow-up period. Computed tomography and/or arterioportography performed before had showed patent gastro-renal shunt in five cases. No change in the shunt was observed after the treatment. No serious complications due to EVL was encountered in all the cases. Therefore, it is thought that this method can be used for the treatment of not only esophageal varices but also gastric varices.

Mitochondrial DNA mutations associated with the 11778 mutation in Leber's disease

To clarify the characteristics of possible synergestic mitochondrial DNA (mtDNA) mutations associated with Leber's hereditary optic neuropathy (LHON), we analyzed the entire nucleotide sequences of mitochondrial genome of two Japanese patients from independent pedigrees harboring the 11778 mtDNA mutation, and compared their sequences with those of 47 disease and 6 normal controls. We have detected several unique mutations in the mtDNA in addition to the 11778 mutation. Two nucleotide substitutions, an A-to-G transition at position 856 in the 12S rRNA gene and an A-to-G transition at 14692 in the T psi C loop of the tRNA(Glu) gene, occurred at highly conserved sites among various species. These mutations in combination with the 11778 mutation might synergetically contribute to the pathogenesis of LHON.

[The efficacy and side effects of chemotherapy for primary lung cancer with cisplatin and etoposide]

We treated 34 primary lung cancer patients with chemotherapy of cisplatin and etoposide. There were 2 cases of CR (15%) and 8 cases of PR (61%) out of 13 cases of small cell lung cancer. No case of CR and one case of PR (5%) were obtained out of 21 cases of non-small cell cancer. Side effects were leukopenia, increase of BUN and creatinine, angina pectoris, supraventricular premature contraction, and renal failure. WBC reached nadir on day 15 on average. When we repeated this regimen, we encountered 3 cases of acute myocardial infarction, and it was useful for small cell lung cancer.

[CDDP-containing combination chemotherapy for advanced lung cancer]

The effect and toxicities of Cis-containing combination chemotherapy were tested in 28 patients with primary lung cancer. All patients were treated with 80 mg/m2 Cisplatinum on the first day and 750 mg ftorafur p.o. every day. In addition to these drugs, patients with squamous cell cancer were treated with continuous subcutaneous infusion of 4 mg/m2 Peplomycin for 5 days and one shot i.v. of 4 mg MMC. Patients with adeno- and large cell cancer were treated with 30 mg/m2 Adriamycin and 4 mg MMC, while patients with small cell cancer were given 150 mg/m2 VP-16 p.o. for 5 days. The following results were obtained. Of 22 evaluable patients, overall response rate was 50%. In each histologic type, response rate was 50% (5/10) for squamous cell carcinoma 50% (4/8) for adenocarcinoma 33% (1/3) for large cell carcinoma and 100% (1/1) for small cell carcinoma. No CR was obtained in this series. Main side effects due to Cisplatinum were nausea, vomiting, loss of appetite, mild leukopenia and thrombocytopenia, mild elevation of serum creatinine and BUN and alopecia, all of which were transient. Interstitial pneumonitis was observed in 40% of patients with squamous cell cancer. Two patients with adenocarcinoma died within 3 weeks after treatment due to embolism of the abdominal aorta and myocardial infarction probably caused by treatment with Adriamycin.