Learning to stop: a unifying principle for legged locomotion in varying environments

Evolutionary studies have unequivocally proven the transition of living organisms from water to land. Consequently, it can be deduced that locomotion strategies must have evolved from one environment to the other. However, the mechanism by which this transition happened and its implications on bio-mechanical studies and robotics research have not been explored in detail. This paper presents a unifying control strategy for locomotion in varying environments based on the principle of 'learning to stop'. Using a common reinforcement learning framework, deep deterministic policy gradient, we show that our proposed learning strategy facilitates a fast and safe methodology for transferring learned controllers from the facile water environment to the harsh land environment. Our results not only propose a plausible mechanism for safe and quick transition of locomotion strategies from a water to land environment but also provide a novel alternative for safer and faster training of robots.

An anthropomorphic soft skeleton hand exploiting conditional models for piano playing

The development of robotic manipulators and hands that show dexterity, adaptability, and subtle behavior comparable to human hands is an unsolved research challenge. In this article, we considered the passive dynamics of mechanically complex systems, such as a skeleton hand, as an approach to improving adaptability, dexterity, and richness of behavioral diversity of such robotic manipulators. With the use of state-of-the-art multimaterial three-dimensional printing technologies, it is possible to design and construct complex passive structures, namely, a complex anthropomorphic skeleton hand that shows anisotropic mechanical stiffness. We introduce a concept, termed the “conditional model,” that exploits the anisotropic stiffness of complex soft-rigid hybrid systems. In this approach, the physical configuration, environment conditions, and conditional actuation (applied actuation) resulted in an observable conditional model, allowing joint actuation through passivity-based dynamic interactions. The conditional model approach allowed the physical configuration and actuation to be altered, enabling a single skeleton hand to perform three different phrases of piano music with varying styles and forms and facilitating improved dynamic behaviors and interactions with the piano over those achievable with a rigid end effector.

Goal-directed multimodal locomotion through coupling between mechanical and attractor selection dynamics

One of the most significant challenges in bio-inspired robotics is how to realize and take advantage of multimodal locomotion, which may help robots perform a variety of tasks adaptively in different environments. In order to address the challenge properly, it is important to notice that locomotion dynamics are the result of interactions between a particular internal control structure, the mechanical dynamics and the environment. From this perspective, this paper presents an approach to enable a robot to take advantage of its multiple locomotion modes by coupling the mechanical dynamics of the robot with an internal control structure known as an attractor selection model. The robot used is a curved-beam hopping robot; this robot, despite its simple actuation method, possesses rich and complex mechanical dynamics that are dependent on its interactions with the environment. Through dynamical coupling, we will show how this robot performs goal-directed locomotion by gracefully shifting between different locomotion modes regulated by sensory input, the robot's mechanical dynamics and an internally generated perturbation. The efficacy of the approach is validated and discussed based on the simulation and on real-world experiments.

Shift of hepatitis E virus RNA from hepatocytes to biliary epithelial cells during acute infection of rhesus monkey

Hepatitis E virus (HEV) has been considered to be the major cause of enterically transmitted non-A, non-B hepatitis in developing countries. However, little is known about viral replication and localization in the liver. The aim of this study was to examine the distribution of HEV-infected cells in experimentally infected animals. Seven captured wild rhesus monkeys were inoculated intravenously with faecal extract derived from a Myanmar strain of HEV. Animals were killed at different time-points of clinical illness: during early infection, during prehepatitis with viral-like particles in bile, during acute hepatitis and during convalescence. Intrahepatic localization of HEV was analysed using non-isotopic thymine dimer in situ hybridization (NITDISH). Both plus and minus strands of HEV RNA were found in hepatocytes during the early infection period. Staining in the submembranous cytoplasmic region of hepatocytes was observed. In the prehepatitis period, both plus and minus strand HEV RNAs appeared in the canalicular side of isolated bile epithelial cells. Subsequently, HEV RNA became universally distributed in the cytoplasm of medium-size bile epithelial cells. After recovery, HEV RNA disappeared.

Chronic Japanese schistosomiasis and hepatocellular carcinoma: ten years of follow-up in Yamanashi Prefecture, Japan

In a preliminary study carried out in the study area we found that 19.1% (173/907) of patients with chronic liver disease and 51% (35/68) of hepatocellular carcinoma cases were infected with Japanese schistosomiasis. Analysis of data from 571 autopsies revealed a similarly high incidence of schistosomiasis among cases of hepatoma and other liver diseases. A prospective case-control study conducted over 10 years showed that hepatoma developed in 5.4% (26/484) of chronic schistosomiasis cases and in 7.5% (23/307) of patients with chronic liver disease (hepatitis, cirrhosis, etc). The difference was not statistically significant (P = 0.228). A high incidence of hepatitis C virus (HCV) antibody (HCVAb) was found in the schistosomiasis group (36.5%; 95% CI = 44.9-28.1%) and in the chronic liver disease group (56.0%), 39% of whom had chronic hepatitis (P = 0.028). Various factors that might have contributed to the development of hepatoma and schistosomiasis were investigated, but no evidence of a significant correlation between schistosomiasis and hepatoma was found. The high incidence of HCVAb was considered to have been responsible for the development of hepatocellular carcinoma in chronic schistosomiasis patients. The role of HBV infection in the development of hepatoma in schistosomiasis patients was not confirmed after an assay for HCVAb was included in the study.

Genotyping of the CYP1A1 and GSTM1 genes in esophageal carcinoma patients with special reference to smoking

BACKGROUND

Aromatic hydrocarbons, including benzol[a]pyrene, in tobacco smoke first require metabolic activation by phase I enzymes, cytochrome P450s (CYP450s), and then are subjected to detoxification by phase II enzymes, the glutathione-S-transferases. A high risk lung carcinoma group has been reported to have specific polymorphisms of the cytochrome P450 (CYP1A1) gene and the glutathione-S-transferase (GSTM1) gene. In this study, the authors investigated whether such genotypes were also risk factors for esophageal carcinoma.

METHODS

Subjects were comprised of 89 esophageal carcinoma patients and 137 noncancer controls. Forty-nine of the patients and 60 of the control subjects were smokers. Genotypic studies of both CYP1A1 and GSTM1 were performed in the cancer tissues of all 89 patients. Genotypes of peripheral blood leukocytes taken from the control subjects were also determined. Genotypes of the CYP1A1 and GSTM1 genes were determined by the polymerase chain reaction.

RESULTS

Patients who were heavy smokers with the genotypes Val/Val (V/V) for CYPIAI and the combined genotype of V/V for CYP1A1 and GSTM1- were a statistically high risk group compared with control subjects (P < 0.01, chi-square = 10.6 vs. P < 0.01, chi-square = 11.0). The association of V/V for CYPIAI with a smoking index > or = 600 in esophageal carcinoma patients was estimated at 6.63 (95% confidence interval [CI], 1.86-23.7). The association of combined genotypes of V/V of CYP1A1 and GSTM1 with a smoking index > or = 600 in esophageal carcinoma patients was estimated at 12.7 (95% CI, 1.97-81.8)

CONCLUSIONS

Specific genotypes of the CYP1A1 and GSTM1- genes are related to the incidence of esophageal carcinoma, especially in heavy smokers.

Genotyping of the CYP1A1 and GSTM1 genes in esophageal carcinoma patients with special reference to smoking

BACKGROUND

Aromatic hydrocarbons, including benzol[a]pyrene, in tobacco smoke first require metabolic activation by phase I enzymes, cytochrome P450s (CYP450s), and then are subjected to detoxification by phase II enzymes, the glutathione-S-transferases. A high risk lung carcinoma group has been reported to have specific polymorphisms of the cytochrome P450 (CYP1A1) gene and the glutathione-S-transferase (GSTM1) gene. In this study, the authors investigated whether such genotypes were also risk factors for esophageal carcinoma.

METHODS

Subjects were comprised of 89 esophageal carcinoma patients and 137 noncancer controls. Forty-nine of the patients and 60 of the control subjects were smokers. Genotypic studies of both CYP1A1 and GSTM1 were performed in the cancer tissues of all 89 patients. Genotypes of peripheral blood leukocytes taken from the control subjects were also determined. Genotypes of the CYP1A1 and GSTM1 genes were determined by the polymerase chain reaction.

RESULTS

Patients who were heavy smokers with the genotypes Val/Val (V/V) for CYPIAI and the combined genotype of V/V for CYP1A1 and GSTM1- were a statistically high risk group compared with control subjects (P < 0.01, chi-square = 10.6 vs. P < 0.01, chi-square = 11.0). The association of V/V for CYPIAI with a smoking index > or = 600 in esophageal carcinoma patients was estimated at 6.63 (95% confidence interval [CI], 1.86-23.7). The association of combined genotypes of V/V of CYP1A1 and GSTM1 with a smoking index > or = 600 in esophageal carcinoma patients was estimated at 12.7 (95% CI, 1.97-81.8)

CONCLUSIONS

Specific genotypes of the CYP1A1 and GSTM1- genes are related to the incidence of esophageal carcinoma, especially in heavy smokers.

Genotyping of the CYP1A1 and GSTM1 genes in esophageal carcinoma patients with special reference to smoking

BACKGROUND

Aromatic hydrocarbons, including benzol[a]pyrene, in tobacco smoke first require metabolic activation by phase I enzymes, cytochrome P450s (CYP450s), and then are subjected to detoxification by phase II enzymes, the glutathione-S-transferases. A high risk lung carcinoma group has been reported to have specific polymorphisms of the cytochrome P450 (CYP1A1) gene and the glutathione-S-transferase (GSTM1) gene. In this study, the authors investigated whether such genotypes were also risk factors for esophageal carcinoma.

METHODS

Subjects were comprised of 89 esophageal carcinoma patients and 137 noncancer controls. Forty-nine of the patients and 60 of the control subjects were smokers. Genotypic studies of both CYP1A1 and GSTM1 were performed in the cancer tissues of all 89 patients. Genotypes of peripheral blood leukocytes taken from the control subjects were also determined. Genotypes of the CYP1A1 and GSTM1 genes were determined by the polymerase chain reaction.

RESULTS

Patients who were heavy smokers with the genotypes Val/Val (V/V) for CYPIAI and the combined genotype of V/V for CYP1A1 and GSTM1- were a statistically high risk group compared with control subjects (P < 0.01, chi-square = 10.6 vs. P < 0.01, chi-square = 11.0). The association of V/V for CYPIAI with a smoking index > or = 600 in esophageal carcinoma patients was estimated at 6.63 (95% confidence interval [CI], 1.86-23.7). The association of combined genotypes of V/V of CYP1A1 and GSTM1 with a smoking index > or = 600 in esophageal carcinoma patients was estimated at 12.7 (95% CI, 1.97-81.8)

CONCLUSIONS

Specific genotypes of the CYP1A1 and GSTM1- genes are related to the incidence of esophageal carcinoma, especially in heavy smokers.

Rupture of lens cataract: a novel hereditary recessive cataract model in the mouse

The RLC is a new mouse model of hereditary cataract. In this mutant, opacity of lens developed spontaneously at 35-60 days of age. The initial histological change was irregular swelling, condensation, degeneration and fragmentation of lens fibers in the deep cortex, leading to rupture of the lens capsule at the posterior pole at 45-100 days of age. Following rupture, the lens nucleus dislocated behind the lens or occasionally in the anterior chamber. Both eyes were affected. Genetic analysis indicated that the mutation was dictated by a single autosomal recessive gene with complete penetrance. Homozygotes of either sex developed cataract with rupture of lens capsule. We named the responsible gene as rupture of lens cataract (rlc) and the mouse strain as RLC. Neither allelism nor linkage was found between rlc and nct, another recessive gene in Nakano cataract mice. The rlc mutation is now fixed in a inbred background since the RLC has been maintained over 20 inbred generations in the laboratory. Although no direct homologous disease of this unusual cataract is found in human, this mutant will provide a valuable tool to investigate the mechanism involved in maintainance of lens.

Immunohistochemical studies of vascular volume and proliferative activity in squamous cell carcinoma of the esophagus

For immunohistochemical investigation and clarification of the relationship between the vascular volume in esophageal carcinoma and the proliferative activity of its tumor cells, we examined surgical specimens of squamous cell carcinoma (SCC) of the esophagus from 15 patients. The vascular volume was evaluated by immunostaining for platelet-endothelial cell adhesion molecule-1 with monoclonal antibody JC70, and the proliferative activity of the carcinoma cells was evaluated by immunostaining for proliferating cell nuclear antigen (PCNA) with antibody 19A2. The ratio of the vascular area to the tumor area and the labeling index (LI) for PCNA in the carcinoma cells was then calculated. The antibody JC70 was useful for immunohistochemically detecting blood microvessels in esophageal carcinoma. The vascular volume, expressed as the ratio mentioned above, was higher in well- and moderately differentiated SCCs than in poorly differentiated SCC (P < 0.01), and the PCNA LI did not depend on the degree of differentiation. However, there was a significantly inverse relationship between the ratio of the vascular area to that of carcinoma and the PCNA LI of the carcinoma cells (P < 0.01). These findings show that angiogenesis is greater in esophageal carcinomas with little proliferative activity.

Expression of cytochrome P450s and glutathione S-transferases in human esophagus with squamous-cell carcinomas

In order to clarify the expression of cytochrome P450 and glutathione S-transferase in human esophagus, 41 samples of human esophagus with squamous-cell carcinoma were investigated by immunoblot analysis and enzyme assays. Cytochrome P450 1A2/1 was clearly expressed in microsomes, and the amount in samples with tumorous tissue was significantly greater than that in samples without tumourous tissues or in liver; cytochrome P450 2B6 and 3A4/3 were expressed polymorphically. Aryl hydrocarbon hydroxylase activity was detected in microsomes and was greater in samples from smokers than non-smokers. Patients who both smoked and drank alcohol, however, had activity similar to that of patients without these habits. Glutathione S-transferase M1 and A1/2 protein existed polymorphically in cytosol, and glutathione S-transferase P1-1 was detected in all samples. The frequency of expression of the glutathione S-transferase A1/2 protein was greater in patients with M1 protein than in those without; no difference in the expression was seen for glutathione S-transferase P1-1. Neither smoking nor drinking influenced the expression or activity of glutathione S-transferase. Our data support the idea that some carcinogens can be directly activated or inactivated in human esophageal epithelium.

Clinicopathologic characteristics and postoperative outcome in Japanese and Chinese patients with thoracic esophageal cancer

We evaluated the clinicopathologic findings and surgical results of 140 patients with thoracic esophageal cancer treated at Shinshu University, Japan (Shinshu group), and compared them with those from 1164 patients treated at Hebei Medical College, China (Hebei group) to determine if the two groups showed any differences. The Shinshu group had significantly higher incidences of elderly patients (>70 years of age), male patients, and tumors located at the lower esophagus (p < 0.01). In the Hebei group, although the depth of tumor invasion was more advanced, the incidence of nodal metastasis was significantly lower (p < 0.01). Operative death and postoperative complications were more frequent in the Shinshu group. Comparison of the postoperative survival curves revealed significantly longer survival of patients with pT2 or pT3 tumor in the Hebei group (p < 0.01), but there were no significant differences between the two groups when the lesions were classified by pTNM stage. This study demonstrated several differences between the patients in the two areas in regard to the clinicopathologic characteristics of thoracic esophageal cancer. The most important characteristic of the esophageal cancer in the Hebei group appears to be the low incidence of nodal metastasis.

Assessment of proliferative activity of glandular cells in hyperfunctioning parathyroid gland using flow cytometric and immunohistochemical methods

The proliferative activity of epithelial cells in hyperfunctioning parathyroid glands was estimated by flow cytometric and immunohistochemical procedures. A total of 30 parathyroid glands, 29 hyperfunctioning glands, and 1 normal gland were studied. The pathology of the 29 glands was determined to be hyperplasia in 19 and adenoma in 10. The S-phase cell population was expressed in terms of the S-phase fraction (%SPF) calculated from the histogram by DNA flow cytometry and in terms of the BrdU immunostaining labeling index (BrdU LI). Cells in all stages of the cell cycle were studied by Ki-67 immunostaining and expressed in terms of the labeling index (Ki-67 LI). Both BrdU LI and Ki-67 LI values were low, ranging from 0% to 0.58% and from 0.21% to 2.62%, respectively. The BrdU LIs were lower than the Ki-67 LIs, ranging from one-sixth to one-twelfth of the values depending on the disease. There were significant correlations between the two indices (p < 0.001). The %SPF determined by flow cytometry was consistently higher than both the BrdU LI and the Ki-67 LI. This discrepancy cannot be explained precisely, and further improvements are required for the flow cytometric analysis of %SPF. The cell cycle study by BrdU and Ki-67 immunohistochemistry suggested that the glandular cells of the hyperfunctioning parathyroid were characterized by low proliferative activity. No evidence of rapid cell turnover rate assumed from the flow cytometric study could be observed in the hyperfunctioning parathyroid gland.

The influence of excess body weight on the surgical treatment of patients with gastric cancer

Sixty-two overweight gastric cancer patients were compared with 201 normal-weight patients to clarify the influences of excessive weight on the surgical treatment of gastric cancer. The frequencies of hypertension and diabetes mellitus were significantly higher in the overweight group (P < 0.01), but no pathologic differences in the resected tumor were found between the two groups. The operative times were longer (P < 0.01) and the number of lymph nodes extirpated and examined was smaller (P < 0.01) in the overweight group. The incidence of postoperative complications was not higher in the overweight group. The postoperative survival rate of patients with nodal metastasis was statistically lower in the overweight group (P < 0.05). Regarding the causes of death in patients with nodal metastasis, 61.1% of overweight patients and 43.8% of normal-weight patients died of recurrence of gastric cancer. In conclusion, surgical treatment of overweight patients with gastric cancer was found to be technically more difficult and the prognosis of such patients with nodal metastasis may thus be worse than that of their normal-weight counterparts.

[Immunohistochemical expression of sialyl-Lewis antigens in lung cancer]

We investigated the immunohistochemical expression of three carbohydrate antigens, sialyl-Lewisa, sialyl-Lewisx and sialyl-Lewisx-i, in human lung cancer tissues using monoclonal antibodies, 2D3, SNH3 and FH6, respectively, and compared the expression rate of these three antigens with clinical and pathologic findings. The expression rate of all the three antigens in adenocarcinoma was higher than that in squamous cell carcinoma and that of sialyl-Lewisx was highest in adenocarcinoma. Sialyl-Lewisx antigen was expressed in all cases of positive nodal metastasis or postoperative distant metastasis in adenocarcinoma. In squamous cell carcinoma, however, there was no relationship between the expression rate of sialyl-Lewisx antigen and nodal or distant metastasis. These results suggest that expression of sialyl-Lewisx antigen in adenocarcinoma of the lung may be correlated with nodal or distant metastasis.

Management of tracheal wall resection for thyroid carcinoma by tracheocutaneous fenestration and delayed closure using auricular cartilage

BACKGROUND

In the case of advanced thyroid carcinoma invading the trachea, surgical procedures for tracheal resection are selected in relation to the degree of invasion. We created a tracheocutaneous fenestration that was later closed with a free auricular cartilage autograft. We present a simple and effective method for permanent closure of tracheostoma.

METHODS

The surgical procedure for delayed closure consists of three steps: (1) preparing the hinge flap with additional undermining of the subcutaneous layer and the strap muscles; (2) removing a portion of the conchal cartilage from the auricle, which is easily performed with a semicircular skin incision along the anthelix of the ear; and (3) placing the conchal cartilage with its convex surface upward just over the sutured hinge flap layer.

RESULTS

Under local anesthesia, we successfully employed this reconstructive procedure for 5 patients. Unfortunately, however, in one patient, we had to reopen the closed tracheocutaneous fenestration on the second postoperative day because of an acute problem that was independent of the closure surgery. Four patients remain in satisfactory condition for more than 2 years since the closure of tracheostoma.

CONCLUSIONS

The auricular cartilage free graft is a relatively simple procedure which supplies tracheal wall skeletal support for the permanent closure of the tracheocutaneous fenestration.

Management of chylothorax after pulmonary resection

BACKGROUND

Conservative management with intrapleural drainage and total parenteral nutrition (TPN) has been the first choice of treatment for postoperative chylothorax. With this approach, however, it usually takes several weeks for the chylothorax to resolve and it is sometimes unsuccessful. In this study, we reviewed seven patients who had chylothorax develop after pulmonary resection for primary carcinoma of the lung.

STUDY DESIGN

The patients were treated according to a "one-week trial" that consisted of one week of observation with intrapleural drainage and maximum parenteral nutritional support followed by operative intervention if the effect of the conservative therapy was not adequate. When the chylous leak was decreased to less than 100 mL/day or less than 15 percent of the maximum daily drainage volume after the "one-week trial," the conservative management was continued for two more weeks. After observation for three weeks, oral intake was begun and a final evaluation of the treatment was made.

RESULTS

One patient did not consent to the "one-week trial" and underwent operative treatment on the third postoperative day. Two patients had chylous leaks less than 100 mL/day or less than 15 percent of the maximum daily chylous leak after one week observation. Conservative management with TPN was continued in these patients for two more weeks and operation was performed in one on the 20th day and in the other on the 22nd postoperative day. The remaining four patients underwent operative treatment on the seventh or eighth postoperative day. All of the operations for chylothorax were successful, and chest tubes were removed promptly. These results show that operative management of chylothorax was reliable and safe. The "one-week trial," however, offered few advantages in determining the therapeutic strategy for postoperative chylothorax.

Histopathological features of atrophic thyroiditis with blocking type-TSH binding inhibitor immunoglobulins

To investigate the histopathological features of atrophic thyroiditis (AT) with blocking type-TSH binding inhibitor immunoglobulins (TBII), the present morphological observations were carried out employing additional immunohistochemical procedures. Moreover, these were compared with examples of goitrous Hashimoto's thyroiditis showing negative TBII (HT). There exist apparent differences between AT and HT. In particular, significant follicular atrophy with epithelial flattening including decreased positive staining of the follicular epithelial cells for thyroglobulin in AT was characteristically observed. These results suggest that the mechanism for the development of hypothyroidism in AT with blocking type-TBII might be due to suppression of thyroid cell function through the inhibition of endogenous TSH stimulation by the blocking antibody with subsequent epithelial degenerative destruction.

Frequent natural killer cell abnormality in children in an area highly contaminated by the Chernobyl accident

Since January 1991, we have been performing thyroid surveys and hematologic and immunologic screening on children in Chechersk, Belarus, a city situated in one of the areas most seriously contaminated with high levels of radionuclides after the Chernobyl accident. Ten children selected from 713 children because of goiter did not show a decrease in humoral immunity or in the number and function of T cells. By contrast, natural killer (NK) cell activity against K562 cells was depressed in 4 of these 10 children. The clinical and laboratory findings indicated that previously reported diseases with NK cell dysfunction could be excluded. A comparative analysis of NK cell activity in children from areas with and without high 137Cs levels revealed a high frequency of abnormal NK cell activity only in children from the area contaminated by radioactive fallout. In addition, there was no correlation between NK cell activity and NK cell number as percentage in the children from the area with high 137Cs levels. Neither activity nor number of NK cells was correlated with the body content of 137Cs. Thus, the frequent abnormality of NK cell function may not have been due to actual internal exposure to the long-lived radionuclide.

The safe and complete removal of a carotid body tumor with elements suggestive of a malignant potential by employing an intraluminal shunt: report of a case

The carotid body tumor is a relatively rare neoplasm arising from the intercarotid paraganglions. We report herein the case of a patient with a Shamblin group 2 type carotid body tumor for which safe and successful removal was facilitated by the insertion of an intraluminal shunt. The patient was a 54-year-old man who presented with a spherical elastic mass, 4.8 x 3.7 cm in size, on the right anterior aspect of his neck, which was diagnosed as a carotid body tumor by diagnostic imaging. Because the tumor was suspected to be malignant based on the operative findings, which included invasive adhesion to the carotid artery, an intraluminal shunt was inserted, allowing for safe and complete removal. Histologically, this tumor showed malignant potential with sporadic mitoses and incomplete capsular invasion. Thus, it is recommended that an intraluminal shunt be employed for the removal of a carotid body tumor when it is found to be tightly adherent to the carotid artery during the operation.

Thyroid abnormalities among children in the contaminated area related to the Chernobyl accident

Gradual increases of various radiation-related diseases including thyroid cancer following the Chernobyl accident have been recently reported. We have carried out systematic thyroid surveys in school children aged 10-15 years in the highly contaminated area and compared the results with a similar survey in a nonaffected neighboring area as a control. Systematic examinations of the thyroid gland were performed in 888 schoolchildren (408 males and 480 females) in the districts of Chechelsk city with 5 to over 40 Ci/km2 of radiation level for 137Cs. In the control area (Bobruisk city), 521 children with the same age range (229 males and 292 females) were examined. Thyroid surveys were carried out as follows: palpation, ultrasonography, blood examinations of thyroid function, and measurements of daily urinary excretion of iodine. Certain thyroid abnormalities were observed in the high radioactive fallout area more frequently than in the control region. In particular, the prevalence of multiple micronodular lesions in diffuse goiter in the contaminated area was significantly higher than in the control area. However, endemic goiter due to iodine deficiency was present in both districts. The environment factor of iodine deficiency might have resulted in the early occurrence of ultrasonographic thyroid abnormalities attributed to radioactive contamination.

Evaluation of imaging examination for hepatic invasion of carcinoma of the gallbladder and postoperative patient outcome

BACKGROUND

Hepatic invasion is an important factor in the selection of an operative procedure for patients with carcinoma of the gallbladder. Imaging modalities to detect the hepatic invasion were evaluated for accuracy, and postoperative patient outcome was analyzed.

STUDY DESIGN

Thirty-six patients who were treated for carcinoma of the gallbladder at our institution between 1984 and 1993 were studied. The imaging results of ultrasonography (US), computed tomography, and angiography were compared with histologic findings regarding intrahepatic invasion of the carcinoma.

RESULTS

Histologic examination of the operative specimens removed from 21 patients revealed that the detection of hepatic invasion with preoperative US was superior to that with the other two modalities. The preoperative US showed a diagnostic value that was almost the same as that of the intraoperative US. The postoperative patient outcome was not satisfactory, although extended radical operation was performed using image guidance in the 21 patients. The patients died as a result of nodal recurrence rather than hepatic recurrence.

CONCLUSIONS

Preoperative US should be performed initially for detecting hepatic invasion from carcinoma of the gallbladder and can be substituted for intraoperative US. Considering the operative treatment for patients with carcinoma of the gallbladder, lymph node dissection is as important as the extent of hepatectomy.

Preoperative intraperitoneal chemotherapy for gastric cancer, with special reference to delayed peritoneal complications

Preoperative intraperitoneal (IP) chemotherapy was performed in 23 patients with gastric malignancies to inhibit peritoneal recurrence. Cis-diamminedichloroplatinum (CDDP) and mitomycin C (MMC) were administered intraperitoneally 3 days prior to surgery, at which time a very viscid peritoneum and mucinous intraperitoneal fluid were found in 100% and 83% of the patients, respectively. Inflammatory changes were microscopically observed in the subserosal layer of the resected stomachs and in the intraperitoneal fluid, but degenerative changes characteristic of cancer cells could not be seen. The 3-year survival rate of the stage III patients was 55.6%, and peritoneal recurrence was found in three of six patients with recurrence. Extensive adhesions were found in eight patients (34.8%) as a delayed peritoneal complication, and chronic bowel obstruction resulting from the adhesion developed in five patients (21.7%). Thus, we conclude that the administration of this IP chemotherapy demonstrated no definite antitumor effects or survival benefits, but was frequently associated with delayed peritoneal complications.

Lower esophageal sphincter pressure after subtotal gastrectomy and postoperative reflux esophagitis

Although reflux esophagitis after subtotal gastrectomy has been noticed by surgeons, the mechanism of its development is obscure. This study was undertaken with the aim of clarifying the role of the lower esophageal sphincter in the development of this abnormality. Manometric studies were carried out on 42 patients with gastric cancer, and on 19 with cholelithiasis. The lower esophageal sphincter pressure was measured using a catheter tip pressure transducer and a rapid pull-through technique, and the results presented as the mean of three measurements. The technical error of this experiment was estimated to be within 2 mmHg by a study of the cholecystectomy patients. After gastrectomy, the lower esophageal pressure decreased in 17 patients, increased in 4 and remained unchanged in 21. A more pronounced decrease in the lower esophageal sphincter pressure was found after Billroth II. Clinical evaluation of the 42 patients revealed symptoms of postgastrectomy regurgitation in 10. Preoperatively, these 10 had lower values of the lower esophageal sphincter pressure followed by a more marked postoperative decrease, as compared with the patients with no regurgitation symptoms. Oral administration of a test meal revealed regurgitation after subtotal gastrectomy. This study suggests that a low value of the pre-operative lower esophageal sphincter pressure, a marked decrease in the pressure after gastrectomy, and Billroth II anastomosis, may be factors that predispose to regurgitation.

Protective effect of the thromboxane A2 receptor antagonist ONO 3708 on ischemia-reperfusion injury in the dog liver

BACKGROUND

Prostaglandins are widely known to have cytoprotective effects in a variety of conditions. Thromboxane A2 has the opposite effect of prostaglandins. In this study the effects of the thromboxane A2 receptor antagonist ONO 3708 on ischemia and subsequent reperfusion in the dog liver was evaluated.

METHODS

Mongrel dogs weighing from 10 to 15 kg were divided into three groups: a control group, a group with induced liver ischemia and subsequent reperfusion, and a group that received ONO 3708 and then underwent induced liver ischemia and subsequent reperfusion. Liver ischemia was induced by the Pringle procedure for 60 minutes. The concentrations of total free amino acids, aromatic amino acids, and branched-chain amino acids in blood taken from the portal and hepatic veins were examined before and after the Pringle procedure in the latter two groups and at the corresponding points in the control group.

RESULTS

Disturbances in amino acid metabolism in the liver occurred 5 minutes after the declamping in the ischemic group, and prostaglandin I2 and thromboxane A2 levels and lipid peroxide production, were increased. In contrast, hepatic amino acid metabolism was unchanged, and prostaglandin I2 and thromboxane A2, and lipid peroxide production, were normalized in the group that was treated with ONO 3708.

CONCLUSIONS

ONO 3708 appears to protects hepatic tissue from ischemia-reperfusion injury through free-radical scavenging, by increasing prostaglandin I2 levels, and by decreasing thromboxane A2 production.

[Combination neoadjuvant therapy with continuous intra-arterial CDDP infusion and radiotherapy for locally advanced breast cancer]

Neoadjuvant therapy combined with intra-arterial continuous infusion of CDDP and external radiation was evaluated in a patient with locally advanced breast cancer. Although only MR was observed on the primary tumor, PR was found in several metastatic lymph nodes and daughter nodules. All tumor markers elevated before treatment decreased to normal ranges only by this therapy, and histological damage was also recognized remarkably with a high concentration of free Pt (8.89 micrograms/g) in cancer tissues. Since no severe side effects appeared during the present therapy, extended radical mastectomy with wide skin resection could be performed following additional intra-arterial chemotherapy using 5-FU, epi-ADM and MMC. From this experience, it was suggested that CDDP was an useful drug in the chemotherapy for breast cancer.

Prostaglandin E1 protects liver from ischemic damage

Studies were carried out to investigate the effects of prostaglandin E1 (PGE1) pretreatment on normothermic liver ischemia. Mixed-breed dogs were divided into three groups: a control group, a group with induced liver ischemia, and a group pretreated with PGE1 followed by induced liver ischemia. Liver ischemia was induced by the Pringle procedure for 60 min. PGE1 was administered intravenously to some dogs at a dose of 0.5 microgram/kg/min for 30 min prior to the Pringle procedure. Sham operations were performed without induction of liver ischemia in control animals. Insulin, glucagon, and glucose metabolic clearance rates were examined before and after the Pringle procedure in the control and experimental groups. Insulin and glucose metabolic clearance rates decreased 5 min after declamping in the ischemic group, while the glucagon metabolism was not affected, and lipid peroxide production increased. In contrast, hepatic insulin metabolism improved, and lipid peroxide production normalized in the ischemic group which was pretreated with PGE1. This study suggests that PGE1 prevents hepatic metabolic disturbances due to warm ischemia and subsequent reperfusion.

Accentuated temporal line on the frontal skull radiograph: a sign of hyperparathyroidism

PURPOSE

To determine the importance of a temporal line (the marginal line for the attachment of the temporal muscle to the skull) that is accentuated on frontal skull radiographs of hyperparathyroid patients owing to subligamentous bone resorption under the temporal muscle.

MATERIALS AND METHODS

Radiographs from skeletal surveys of 134 surgically treated patients with primary (n = 102) or secondary (n = 32) hyperparathyroidism (HPT) and frontal skull radiographs of 63 age-matched control patients were reviewed.

RESULTS

An accentuated temporal line was the most frequent finding (29.4% of cases) in primary HPT, followed by subperiosteal bone resorption in the hand (8.6%), salt-and-pepper appearance of the skull (3.5%), and rugger-jersey spine (1.1%). In secondary HPT, an accentuated temporal line became less obvious as subperiosteal bone resorption advanced. This finding was not seen in the control group.

CONCLUSION

An accentuated temporal line is another radiographic indication of bone resorption in HPT.

Significance of values of thyrotropin binding inhibitor immunoglobulins and appearance of intrathyroidal lymphocytes at subtotal thyroidectomy for Graves' disease

This study was undertaken to investigate whether thyrotropin binding inhibitor immunoglobulins (TBII) values at and after subtotal thyroidectomy correlated with the outcome or the histologic grade applied to the appearance of intrathyroidal lymphocytes at the time of surgical treatment. In addition, the main reason for the study was to determine whether or not it was possible to predict the outcome after the operation by the data obtained. There was no relation between the TBII results and the grade of the appearance of intrathyroidal lymphocytes at the time of operation or the TBII postoperative results (whether positive or negative) and the final outcome. However, it was of interest that patients with a recurrence of hyperthyroidism had the TBII values of more than 50 percent at the time of surgical treatment, and also manifested continuously positive TBII values after the operation. They also had moderate grades of lymphocytic infiltration and lymph follicle formation in the surgical specimen. It seemed impossible to predict the outcome of each instance in accordance with TBII values and the grade of the appearance of intrathyroidal lymphocytes at the time of the operation. However, it might be possible to predict at least the recurrence of hyperthyroidism by the consideration of changes of TBII values postoperatively.

Frequent loss of heterozygosity in the region including BRCA1 on chromosome 17q in squamous cell carcinomas of the esophagus

Ninety-four esophageal squamous cell carcinomas were examined for loss of heterozygosity at several loci on the long arm of chromosome 17 (17q), using restriction fragment length polymorphism markers. Loss of heterozygosity was observed in 56 (62%) of 91 tumors that were informative with at least one marker. Comparison of these results with clinicopathological data indicated that the losses on chromosome 17q had occurred at an early stage of carcinogenesis. Detailed deletion mapping in these tumors revealed that the region commonly deleted was within the segment between loci defined by two markers at chromosomal band 17q21.3.

Calcium regulating hormones and bone mineral content in patients after subtotal gastrectomy

Twenty-nine men who had undergone Billroth I gastrectomy and 19 men who had undergone Billroth II gastrectomy were studied to examine the changes in their calcium regulating hormones and bone mineral content following surgery. The serum calcium and phosphate concentrations in the patients with Billroth I and Billroth II were normal. The Billroth II group had an elevated level of serum alkaline phosphatase and reduced bone mineral content. The 24,25(OH)2D concentration was reduced (P < 0.01) and 25(OH)D and 1,25(OH)2D concentrations were increased (P < 0.01, P < 0.05, respectively) in the Billroth II group. It was suggested by our study that the Billroth II patients had a reduced bone mineral content and an elevated 1,25(OH)2D concentration. Therefore, the pathophysiology of postgastrectomy bone metabolic disease is not due to vitamin D deficiency, but may instead be due to reduced calcium absorption in the intestine.

[Ultrasonography in the diagnosis of malignant lymphoma of the thyroid]

Malignant lymphoma of the thyroid was rare condition and it was difficult to make a diagnosis of malignant lymphoma preoperatively. Both ultrasonographic appearance and diagnostic significance of ultrasonography in malignant lymphoma of the thyroid were investigated in this study. Ultrasonography of 10 patients with malignant lymphoma of the thyroid was analyzed. Only 3 cases of 10 were diagnosed as malignant lymphoma by ultrasonography. Five cases were misdiagnosed as thyroid carcinoma, 1 as adenomatous goiter accompanied by cystic degeneration and 1 as chronic thyroiditis. Nine cases were nodular type i.e. limited extremely hypoechoic mass as contrasted with surrounding thyroid tissue, occupying asymmetrically in the thyroid gland. One case was diffuse type i.e. diffused hypoechoic area without surrounding residual thyroid tissue. The tumor size of the 2 cases in which no accumulation was observed in the 67Ga scintigram was 2 cm or less. By ultrasonography of these 2 cases, one case was diagnosed as malignant lymphoma and the other as thyroid carcinoma. Ultrasonography can be regarded to be very significant method as a screening test to make a diagnosis of malignant tumor for nodular type, especially small sized malignant lymphoma of the thyroid.

Effects of parathyroid hormone on pancreatic exocrine secretion

The role of parathyroid hormone (PTH) and calcium on pancreatic exocrine secretion were observed using sham-operated and parathyroidectomized dogs. First, exocrine secretion of the pancreas stimulated with secretin and cholecystokinin octapeptide (CCK-8) was examined in vivo 3 weeks after parathyroidectomy. Secondly, perfusion experiments of isolated pancreas in the sham-operated and parathyroidectomized dogs were examined. In one experiment, volume of pancreatic juice and bicarbonate output, but not amylase output, was decreased in the parathyroidectomized dogs compared with those in the sham-operated dogs; no participation of calcium in exocrine secretion was revealed. In another experiment, high doses of PTH evoked increases of pancreatic juice and bicarbonate output without changing amylase output; as before, no participation of calcium in the exocrine secretion was observed. We conclude that (a) PTH increases volume of pancreatic juice and bicarbonate output, and (b) pancreatic exocrine secretion is modified by direct effect of PTH, and the pancreatic ductular cells, not the acinar cells, are the target for PTH.

Isolated pulmonary valve endocarditis without cardiac anomaly in an infant

A patient with isolated pulmonary valve infective endocarditis without congenital heart disease was diagnosed at an early stage. Simple valvulectomy without replacement was successfully performed during the active stage of infection.

Comparative study between molecular hybridization and electron microscopy for the detection of hepatitis E virus

The study describes a comparison between molecular hybridization using a non-radiolabeled, thymine-thymine (TT) dimerized synthetic oligonucleotide complementary DNA probe and electron microscopy for the detection of hepatitis E virus genome in bile. Spot hybridization with the TT dimerized probe was found to be more sensitive and specific compared to electron microscopy.

Newly designed tissue adhesion prevention technology based on photocurable mucopolysaccharides. In vivo evaluation

Tissue adhesion after surgery occasionally causes serious complications. The authors have been developing photocurable mucopolysaccharides for a tissue adhesion prevention material that meets requirements such as nonadherent surface characteristics, biocompatibility, biodegradability in accordance with the wound healing rate, and nontoxicity. Mucopolysaccharides (hyaluronic acid and chondroitin sulfate) partially derived with photoreactive groups, such as cinnamate or thymine, were subjected to ultraviolet (UV) irradiation to produce water insoluble gels via intermolecular photodimerization of photoreactive groups. Photocured films that covered injured liver surfaces of rats were implanted for as long as 4 weeks and histologically evaluated. In vivo performance, including tissue adhesion prevention, biodegradability, and mechanical flexibility of the films, was found to be controlled by the type of mucopolysaccharides, the type of photoreactive groups, and their degrees of substitution (DS). Photocured films with lower DS, which had high water swellability and flexibility, prevented tissue adhesion and exhibited enhanced biodegradability. As an increase in DS occurred, tissue adhesion prevention, biodegradability, and mechanical flexibility were reduced. Control of the biodegradation rate was feasible. Minimum inflammatory reaction was noticed.

An in vitro endothelialized compliant vascular graft minimizes anastomotic hyperplasia

The authors developed a hybrid vascular graft consisting of three components: a polyurethane (PU) graft (internal diameter = 3 mm; length: 5 cm) with a compliance similar to that of natural arteries; an artificial basement membrane composed of a complex gel of Type I collagen and dermatan sulfate; and an autogenous endothelial cell (EC) monolayer constructed before implantation. As a continuation of their previous study that focused on antithrombogenicity for as long as 1 month after implantation, the authors evaluated the antihyperplastic characteristics of their hybrid vascular graft for longer implantation periods. The hybrid grafts were implanted bilaterally into carotid arteries of dogs without anticoagulant or anti-platelet agents. The implantation period ranged from 6 to 26 weeks. The overall patency rate observed in this study was 70%. Histologic evaluation of grafts revealed that luminal surfaces of the arteries and grafts joined uniformly and smoothly. The mean initimal thickness of grafts was approximately 80 microns at 12 weeks; there was no statistically significant difference in the thickness between portions of the graft. Little additional increase was observed at 26 weeks. The intimal thickness of adjacent arteries was small. Thus, anastomotic hyperplasia was considered minimized. These encouraging results were explained in terms of synergistic activities of the compliant PU graft and durable EC monolayer as follows. The PU graft, which was fabricated to have the same compliance as that of natural arteries, minimized the compliance mismatch at the anastomoses.(ABSTRACT TRUNCATED AT 250 WORDS)

Enhanced sensitivity of pancreatic cells to cholecystokinin octapeptide in obstructive jaundice

Exocrine function of the pancreas in obstructive jaundice was examined using dogs. Jaundice induced by choledochal ligation over 3 weeks showed pancreatic hypersecretion in response to cholecystokinin octapeptide (CCK-8) stimulation. To clarify the mechanism of pancreatic hypersecretion in obstructive jaundice, three experiments were undertaken. In a perfusion experiment performed on isolated pancreas, hypersecretion in obstructive jaundice was observed in response to CCK-8 stimulation. An incubation experiment showed an increase in secretion in response to CCK-8 stimulation in a dose-dependent manner, producing a greater increase in dogs with obstructive jaundice than in controls, despite the fact that basal secretion in both groups was the same. This would suggest that at least one of the mechanisms of pancreatic hypersecretion in obstructive jaundice may be related to the degree of sensitivity of acinar cells to CCK-8. In morphological observation of acinar cells by electron microscopy, the average number of zymogen granules and total granular area per unit of cytoplasm in both groups before and after stimulation with CCK-8 were compared. There was no difference between the groups before stimulation. Following stimulation, values for the control group decreased but appeared to increase in the jaundiced pancreas. These results strongly suggest that pancreatic acinar cells in obstructive jaundice may retain their secretory potential after stimulation for 60 min, though the potential in nonjaundiced pancreatic acinar cells may decrease after stimulation.

Development of a hierarchically structured hybrid vascular graft biomimicking natural arteries

A hierarchically structured hybrid vascular graft, resembling the layered structure of the intima and the media of a natural artery, is expected to exhibit structural stability and function similar to those of an artery. Two models of hybrid vascular grafts were constructed on knitted Dacron grafts (internal diameter, 4 mm; length, 6 cm; Golaski Laboratories, Inc., Philadelphia, PA) in vitro. The model I graft consisted of only an endothelial cell (EC) monolayer, and the model II graft was hierarchically structured with an EC monolayer and smooth muscle cell (SMC) multilayers embedded in a mixed gel of type I collagen and dermatan sulfate. Both models were implanted bilaterally in carotid arteries of 11 dogs for up to 12 weeks without anticoagulant. All grafts were patent after the implantation. There was a marked difference in the formation of the neomedia between the two models at 2 weeks: only a collagenous layer was observed beneath the EC monolayer in model I grafts, whereas the reconstructed neomedia consisting of proliferating SMCs and extracellular matrix was observed in model II grafts. In model I grafts at 2 weeks, the luminal surface with a wavelike form, along with crimps of the vascular graft, was almost endothelialized, but EC orientation was disorganized at the troughs of the crimps. Leukocyte adhesion on ECs and migration into their interstices were observed in some areas. Such events were infrequent in model II grafts at 2 weeks. Model II grafts at 12 weeks had an integrated neomedia comparable to that of a natural artery: SMCs exhibited dense accumulation and circumferential orientation.(ABSTRACT TRUNCATED AT 250 WORDS)

[A case of postpartum silent thyroiditis misapprehended as malignant lymphoma of the thyroid]

A case of postpartum silent thyroiditis misapprehended as malignant lymphoma of the thyroid is reported. The patient was a 30-year-old female who had received irradiation therapy to the neck for malignant lymphoma 9 years ago. She was referred to our department owing to a struma accompanying rapid aggravation of chronic thyroiditis after delivery. The mechanism of this case was possible to be explained by immune rebound theory. It was difficult to make differential diagnosis of this case from malignant lymphoma of the thyroid clinically and cytologically when immune rebound phenomena with invasion of lymphocyte and appearance of lymph follicle were the strongest. Immune state of the patients with chronic thyroiditis accompanied by morphological change should be taken into consideration in the process of making diagnosis of malignant lymphoma of the thyroid.

Proliferative activity of human thyroid tumors evaluated by proliferating cell nuclear antigen/cyclin immunohistochemical studies

BACKGROUND

To clarify the proliferative activity of human thyroid tumors, the labeling index of various thyroid tumors was evaluated by proliferating cell nuclear antigen (PCNA)/cyclin immunostaining.

METHODS

Surgically removed thyroid carcinoma, adenoma, adenomatous goiter, normal thyroid, and breast carcinoma were used for the study. Small pieces of tissue from the surgical materials were fixed in Methacarn solution (methanol-chloroform-acetic acid = 6:3:1) (Wako junyaku Co., Osaka, Japan) and embedded in paraffin. Sections were stained with PCNA/cyclin monoclonal antibody.

RESULTS

The reaction product for PCNA/cyclin was observed mainly on nuclei. The ratio of the PCNA/cyclin-positive nuclei to the total number of nuclei was compared among the tumors. Ratios of PCNA/cyclin-positive nuclei were 4.9% in well-differentiated papillary carcinoma of the thyroid, 4.6% in poorly differentiated papillary carcinoma of the thyroid, 3.6% in thyroid follicular carcinoma, 1.9% in adenomatous goiter, 2.0% in thyroid follicular adenoma, and 0.6% in normal thyroid tissues.

CONCLUSIONS

It was shown in this study that the ratio of PCNA/cyclin-positive nuclei reflects the relative clinical behavior of thyroid tumors.

Clinical evaluation of upper mediastinal dissection for differentiated thyroid carcinoma

BACKGROUND

An extensive upper mediastinal dissection in advanced differentiated thyroid carcinoma is occasionally required. This investigation was undertaken to clarify the indications for mediastinal lymph node dissection and the route of upper mediastinal metastases.

METHODS

Twenty-one patients with differentiated thyroid cancer, who underwent their first radical operations with mediastinal dissection through a partial midline sternotomy, were enrolled in this study. Of 21 patients, 10 (48%) were found to have mediastinal lymph node metastases.

RESULTS

The tumor size in the group with metastatic disease was much bigger than that in the group without metastatic disease. Histologic type and age were similar between the two groups. The extent of cervical lymph node metastases was more significant in the group with metastatic disease; in particular, all 10 patients showed more than two metastatic nodes along the internal jugular vein of the tumor-free side.

CONCLUSIONS

This study indicates that metastases to the internal jugular chain on the side contralateral to the primary tumor would be an extremely important factor for indication of extensive upper mediastinal lymph node dissection after median partial sternotomy in patients with differentiated thyroid carcinoma.

Closure of a perineal sinus connected with the small bowel developing after radical surgery for rectal carcinoma: a report of the operative procedures used in two cases

A technique for closure of a perineal sinus connected with the small bowel is described herein. One patient who underwent Miles' operation and another who underwent total pelvic exenteration for rectal carcinoma developed a perineal sinus through which a large amount of intestinal fluid was discharged. The pelvic orifice of the sinus was successfully closed in both patients using a right rectus abdominis muscle flap. In one patient, the muscle flap was reflected with the peritoneal surface inside and fixed to the pelvic floor covering the pelvic orifice of the sinus. In the other patient, the flap was isolated without the attached peritoneum and the peritoneal side of the flap covered with omentum.

Extended total gastrectomy for carcinoma of the cardia

Eighty-five patients with gastric carcinoma developing at or involving the cardia were operated on under a newly established principle to prevent a cancer-positive proximal margin. The choice of operative procedure, standard total gastrectomy or extended total gastrectomy, was determined by the degree of proximal extension of carcinoma as confirmed by preoperative examinations. The cancer-positive rate was decreased in this manner to 1.2% from the 13.8% of the controls operated on before the principle was established. Extended total gastrectomy without sternotomy should be used more frequently than that with sternotomy because of the technical advantages. Survival rates of the 85 patients were 48.3% at three years and 30.4% at five years after the operation, and were not significantly different from the controls. As post-operative survival rate is influenced by factors other than transmural extension of the tumor, this study should prompt us to focus on the problem of the proximal surgical margin in surgery for carcinoma of the gastric cardia.