Specificity of co-promoting effects of caffeine on thyroid carcinogenesis in rats pretreated with N-bis(2-hydroxypropyl)nitrosamine

The specificity of copromotion effects of caffeine with known goitrogenic factors on thyroid carcinogenesis was examined in rats pretreated with N-bis(2-hydroxypropyl)nitrosamine (DHPN). Male F344 rats were divided into 8 groups, each consisting of 10 animals, and received a single sc injection of 2,800 mg/kg DHPN. From one week after the DHPN initiation, they were given basal diet, iodine deficiency (ID) diet, 500 ppm phenobarbital (PB) solution or 1,000 ppm sulfadimethoxine (SDM) solution with or without 1,500 ppm caffeine feeding for 12 weeks. The caffeine, PB, SDM, and ID treatments significantly (p < 0.05 or 0.01) increased the relative thyroid weights, and the increases with PB or ID were further (p < 0.05 or 0.01) enhanced in combination with caffeine. SDM drastically promoted thyroid carcinogenesis in association with increased serum TSH levels regardless of the caffeine treatment. Thyroid follicular carcinomas and adenomas were more frequently observed in the additional caffeine groups than in the ID alone groups. The incidence and multiplicity of focal thyroid follicular hyperplasias in the ID-treated groups were significantly (p < 0.05 and 0.01) elevated in the case of combination with caffeine. Increases in serum TSH levels with PB or ID were also further enhanced in combination with caffeine. Serum thyroid hormone levels were significantly (p < 0.01) decreased by SDM but significantly (p < 0.05 or 0.01) increased by caffeine, PB or ID. Our results clearly indicate that dietary caffeine at a high dose of 1,500 ppm interacts with ID, but neither SDM nor PB, to promote rat thyroid carcinogenesis although the combined caffeine + PB treatment somewhat affected thyroid weights as well as thyroid hormone levels.     

Analysis of mRNA with microsomal fractionation using a SAGE-based DNA microarray system facilitates identification of the genes encoding secretory proteins

In the regulation of host defense responses such as inflammation and immunity, the secretory proteins, including membrane proteins, play central roles. Although many secretory proteins have been identified by using methods such as differential display, random screening, or the signal sequence trap method, each method suffers from poor reproducibility, low sensitivity, or time-consuming or laborious work. Therefore, the strategy for facilitating the selection of the genes encoding the secretory proteins is desired. In this paper, we describe a system for isolating the genes encoding secretory proteins by analyzing mRNAs with microsomal fractionation on serial analysis of gene expression (SAGE)-based DNA microarray system. This system succeeded in discriminating the genes encoding secretory proteins from ones encoding nonsecretory proteins with 80% accuracy. We applied this system to human T lymphocytes. As a result, we were able to identify the genes that are not only encoding secretory proteins but also expressing selectively in a specific subset of T lymphocytes. The SAGE-based DNA microarray system is a promising system to identify the genes encoding specific secretory proteins.     

T-cell variant of classical Hodgkin's lymphoma with nodal and cutaneous manifestations demonstrated by single-cell polymerase chain reaction

The atypical cells of CD30(+) cutaneous lymphoproliferative disorders (CD30CLD) are commonly of T-cell origin and frequently have a similar morphology as Hodgkin or Reed-Sternberg cells of Hodgkin's lymphoma (HL). HL is one of the tumors associated with CD30CLD. Although most studies support a B-cell derivation of the tumor cells in HL, recently a few cases of classical HL with T-cell genotype have been reported. We report a patient who presented with CD30CLD whose lymph nodes showed classical HL of mixed cellularity subtype at presentation. By single-cell PCR, the same clonal gene rearrangements of the T cell receptor-beta gene locus could be assigned to the CD30(+) and CD15(+) cells of both skin and lymph node. In a lymph node biopsy specimen taken in relapse after several courses of chemotherapy, the CD30(+) tumor cells were abundant. The T cell-derived tumor cells displayed aberrant expression of the Pax-5 gene in all specimens. A common clonal origin of both CD30CLD and HL of the lymph node in the patient presented here suggests that HL with T-cell genotype exists in association with CD30CLD as well as in sporadic cases and may share clonal origin with the skin tumor.     

The PPARgamma ligand, 15-Deoxy-Delta12,14-PGJ2, regulates apoptosis-related protein expression in cholangio cell carcinoma cells

PPARgamma is known to induce apoptosis in malignant tumor cells, but the mechanism of this induction is not well understood. We investigated induction of apoptosis with 15-Deoxy-Delta12,14-prostaglandin J2 (15d-PGJ2), a PPARgamma ligand, in cholangio cell carcinoma (CCC) cells (RBE, ETK-1 or HuCCT-1). Apoptosis was induced in RBE and ETK-1 cells with 15d-PGJ2, but not in HuCCT-1 cells, although PPARgamma was expressed in all CCC cells. Apoptosis-related proteins were also expressed, including FLIP, bclx, Apaf-1 and XIAP, but expression levels differed among the three cell lines. RBE cells treated with 15d-PGJ2 showed caspase activation, and it appeared that PPARgamma-induced apoptosis was dependent on caspase activation. However, neither ETK-1 nor HuCCT-1 cells showed significant activation of caspase-8 or -3 with 15d-PGJ2 treatment, raising the possibility of a caspase-independent apoptosis induction pathway. XIAP was down-regulated by 15d-PGJ2 in all three CCC cell lines. Therefore, 15d-PGJ2 induces apoptosis in CCC cells via caspase-dependent or independent pathways. 15d-PGJ2 may also induce down-regulation of XIAP and may promote caspase cascade activation through TNF-family receptor signaling pathways.     

Physiological characterization of the renal-sympathetic reflex in rabbits

In urethane-anesthetized and vagotomized rabbits, electrical stimulation of the afferent renal nerve (RN) elicited reflex changes in renal nerve activity (RNA) and arterial pressure (AP). The responses were attributable mostly to excitation of nonmyelinated afferent fibers, although, in about 30% of the animals, they were contributed slightly by myelinated afferents. In about 70% of rabbits, the peristimulus time histogram (PTH) of RNA following stimulation of the RN consisted of a long-lasting inhibitory (I) component occasionally accompanied, during its recovery phase, by a transient excitatory (E) component. In these animals, tetanic stimulation of the RN resulted in a depressor response, either alone or, if an E component was present in the PTH, followed by a slight pressor response. In the remaining rabbits, the PTH was composed exclusively of an E component and tetanic stimulation caused a pressor response. Stimulation of the RN evoked reflex changes in cardiac sympathetic discharges comparable to that of RNA, whereas the change in cervical sympathetic discharges was much smaller. The sympathetic response remained intact after a total transection of the rostral medulla near the ponto-medullary junction; the I component was even augmented. However, it usually disappeared following a transection at the high cervical cord. Bilateral lesions of the nucl. tractus solitarius (NTS) near the obex failed to appreciably affect the response. Among chemical and mechanical stimuli examined, nociceptive stimulation of the kidney elicited a sympathetic response comparable to that following nerve stimulation. In conclusion, the renal-sympathetic reflex in rabbits (1) originates predominantly from nonmyelinated afferent renal fibers activated effectively by nociceptive stimulation applied to the kidney; (2) depends critically on medullary structures other than the NTS; and (3) evokes changes of the same temporal pattern but of nonuniform magnitude in sympathetic discharges to different organs.     

Participation of ventrolateral medullary neurons in the renal-sympathetic reflex in rabbits

In an effort to locate medullary structures that mediate the renal-sympathetic reflex, the effect, on the excitatory (E) and inhibitory (I) components of that reflex, of certain drugs applied to the ventral surface of the medulla was investigated in urethane-anesthetized and vagotomized rabbits. Application of bicuculline, a GABA receptor antagonist, selectively abolished the I component of the renal-sympathetic reflex as well as the sympathoinhibition elicited by stimulation of the aortic nerve. The E component, on the other hand, was specifically eliminated by kynurenic acid, a glutamate receptor antagonist. Strychnine or atropine sulfate did not affect either reflex appreciably. Subsequently, within the region of the ventrolateral medulla (VLM) subjacent to the site of drug applications, we searched for neurons which responded to stimulation of the renal nerve and/or the aortic nerve. Of 68 responsive VLM neurons found, 50 (73.5%) responded to stimulation of both nerves. Of the 50 neurons, 40 were tested for their antidromic activation to stimulation of the spinal cord. Twenty-four neurons (60%) were antidromically activated. Responses of these reticulospinal neurons to stimulation of the renal nerve preceded that of renal nerve activity (RNA) by about 100 ms. All the antidromically activated, VLM neurons which responded to stimulation of the renal nerve also responded to stimulation of the aortic nerve. In conclusion, the renal-sympathetic reflex appears to be mediated by the same pool of bulbospinal neurons in the ventrolateral medulla that mediates the arterial baroreceptor reflex, and the E and I components of that reflex can be selectively abolished by pharmacological intervention of the subjacent ventral surface of the medulla.     

Pathological Aspects of Radiofrequency Catheter Ablation of the Canine Atrioventricular Node and Bundle of His

Radiofrequency catheter ablation of the atrioventricular (AV) node or bundle of His was performed in 12 adult mongrel dogs. The aim was to create chronic incomplete AV block (first- and second-degree AV block) and to examine the histopathology of the ablated lesions. However, the late electrophysiological results (2 4 weeks follow up) were various: normal in 2 dogs, mild PR prolongation (< 50%) in 2 dogs, first-degree AV block (PR prolongation a 50%) in 2 dogs, second degree AV block in 2 dogs, complete AV block in 4 dogs. The maximally ablated area (%) of the atrioventricular conduction system in serial histologic sections from dogs with these conditions was 69%, 75%, 89.5%, 95% and 99.5%, respectively. The number of intact conduction cells at the maximally ablated site varied from 6 to 30 in the four cases of incomplete AV block. The mean ablated volume (%) of either the AV node or penetrating His bundle correlated roughly with the degree of AV block. The ablated lesions were well demarcated and almost replaced by dense fibrous tissue at 4 weeks. Interruption (3 dogs) or thinning (1 dog) of the endocardial elastic lamellae was detected, in association with endocardial thickening (mean 913 μm). Endocardial thrombi were found in 3 dogs (2 fresh, 1 organized). We conclude that radiofrequency catheter ablation does not cause severe complicated lesions. Several possible conditions for creating chronic incomplete AV block are discussed. Acta Pathol Jpn 41: 487–498, 1991.     

Inhibitory effects of adhesion oligopeptides on the invasion of squamous carcinoma cells with special reference to implication of αv integrins

We studied invasion-related adhesion events in vitro using three squamous carcinoma cell lines (HSC-3, poorly differentiated type; OSC-19, well-differentiated type; and KB cells, undifferentiated type). An in vitro invasion assay through matrigel in the transwell chamber revealed that HSC-3 cells were most invasive, OSC-19 cells moderately invasive and KB cells least invasive. Inhibition assay of invasion using synthetic peptides RGD, RGDV, RGDS, RGDT, IKVAV and YIGSR, showed that invasion of the three cell lines was significantly inhibited by RGDV. There were other peptides that inhibited invasion significantly including IKVAV for HSC-3, and RGDS and YIGSR for OSC-19. HSC-3 cells and OSC-19 cells adhered to fibronectin, laminin, vitronectin, and type IV collagen, and KB cells did not adhere to laminin but did to fibronectin, vitronectin and collagen type IV. Pretreatment of cells with RGDV peptide in the attachment assay reduced the ability of these cells to bind to vitronectin and fibronectin more efficiently than pretreatment with RGDS. Anti-v antibodies inhibited adhesion of HSC-3, OSC-19 and KB cells to vitronectin, but anti-1 antibodies did not inhibit adhesion. Immunofluorescent microscopic examinations showed that all cell lines were positive for anti-5 and anti-v antibodies, and only HSC-3 cells were positive for anti-3 antibody. 51 was not clearly demonstrated in any of the cell lines. RGDV was the most effective inhibitor of squamous cell carcinoma invasion among the synthetic oligopeptides used in this experiment, and it is suggested that it affects v3-and/or v5-mediated carcinoma cell invasion.Abbreviations BSA bovine serum albumin - MEM Eagle's minimal essential medium - MTT 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide - PBS phosphatebuffered saline - FITC fluorescein isothiocyanate This work supported in part by a grant from the Osaka Cancer Research Foundation     

Increased expression of angiogenin in hepatocellular carcinoma in correlation with tumor vascularity.

PURPOSE: Neovascularization is known to be one of the major characteristics of human hepatocellular carcinoma (HCC). Angiogenin (ANG), originally discovered in a human colon cancer cell line, is a liver-derived polypeptide that shows strong angiogenic activity in vivo. However, the role of ANG on the development of HCC remains unknown. The present study was designed to examine the implication of ANG in the neovascularization of human HCC. EXPERIMENTAL DESIGN: Forty-one HCC patients who had undergone conventional celiac angiography were used in this study. ANG protein expression and microvessel density (MVD) in HCC specimens obtained by liver biopsy or surgical resection were examined by immunohistochemistry, and the levels were quantified by the KS-400 image analyzing system. ANG mRNA expression in liver tissues was evaluated by in situ hybridization. Serum ANG concentrations were measured by an ELISA. Survival rates were calculated using the Kaplan-Meier method. RESULTS: Immunohistochemistry and in situ hybridization showed greater increments of ANG protein expression and mRNA expression, respectively, in HCC tissues than in the surrounding nontumorous tissues. MVD within tumorous tissues increased according to dedifferentiation of the histological grade of HCC, showing a significant correlation (r = 0.877, P = 0.0009) with ANG expression levels. Mean +/- SD serum ANG levels of healthy subjects and chronic hepatitis (CH) patients were 362.3 +/- 84.1 ng/ml and 331.9 +/- 133.8 ng/ml, respectively, with no significant difference. Serum ANG levels of liver cirrhosis patients (242.4 +/- 126.9 ng/ml) were lower than those of healthy subjects or CH patients and decreased as the fibrosis grade advanced. In HCC patients, despite the cirrhotic background, serum ANG levels increased as the tumor vascularity increased (197.8 +/- 64.9 ng/ml for hypovascular, 326.7 +/- 148.6 ng/ml for hypervascular, and 405.0 +/- 121.3 ng/ml for very hypervascular), in good accordance with histological grading, and significantly decreased (P = 0.015) after successful treatment with transcatheter arterial embolization or percutaneous ethanol injection. HCC patients were conventionally divided into two groups according to the serum level of ANG, those with values higher than the mean level (332.9 +/- 143.8 ng/ml) and those with values lower than the mean,; the 5-year survival rate of the latter group was determined to be significantly higher than that in the former group. CONCLUSIONS: These results suggest that ANG is one of the neovascularization defining factors of HCC. Thus, measuring serum ANG may assist in monitoring the disease, and targeting ANG may provide a new strategy for treating advanced HCC.     

Sleep survey of medical residents at a National University Hospital]

In order to ascertain the workload and lifestyle of medical residents prior to the introduction of a new medical resident training system, 102 residents at a national university hospital were monitored for four consecutive weeks to ascertain their life habits. Valid responses were obtained from 76% of the respondents for a total of 2,722 person days. It was found that the average length of sleep was 5.7 h on weekdays and 6.8 h on weekends. Of the 102 residents, 40% slept less than six hours a night and 17% slept less than five hours a night. The time spent sleeping was particularly short among surgical residents. Given that lack of sleep not only affects the health of the residents negatively, but also compromises the safety of medical care that they provide, the new medical residency training system will need to monitor and analyze the wellbeing, including sleep patterns, of medical residents.