Epstein-Barr Virus Lytic Reactivation Induces IgG4 Production by Host B Lymphocytes in Graves' Disease Patients and Controls: A Subset of Graves' Disease Is an IgG4-Related Disease-Like Condition

Immunoglobulin (Ig) G4-related disease (IgG4-RD) is a newly recognized systemic fibroinflammatory disease with characteristic histological findings and high serum IgG4 levels. Epstein–Barr virus (EBV) is a persistent herpesvirus in B lymphocytes, and we previously reported EBV reactivation-induced Ig production. We showed that EBV reactivation induced the production of thyrotropin receptor antibodies, the causative antibodies of Graves' disease. In the present study, we investigated whether EBV reactivation induced IgG4 production and if EBV-positive B cells or IgG4-positive plasma cells are present in the thyroid tissues of Graves' disease patients with lymphoplasmacytic infiltration. EBV-encoded small RNA1 (EBER1) in situ hybridization and immunohistochemistry for IgG and IgG4 were performed on seven resected thyroid tissues with lymphoplasmacytic infiltration collected from the thyroids of 11 Graves' disease patients. We then cultured the lymphocytes of 13 Graves' disease patients and 14 controls and induced EBV reactivation to measure IgG4 levels in culture fluids. We detected EBER1-positive cells and IgG4-positive plasma cells in the same area of thyroid tissues. EBV-reactivated cells with IgG4 on their surface were observed in culture cells, and IgG4 production was detected in culture fluids. The IgG4/IgG percentage was higher than that in normal serum level. A subset of Graves' disease is an IgG4-RD-like condition, not an IgG4-RD. EBV reactivation stimulates IgG4 production, which may result in high serum IgG4 levels and promote IgG4-positive plasma cell infiltration. EBER1 needs to be examined when an increase in IgG4-positive plasma cell numbers is noted.

Aberrant expression of AID and AID activators of NF-κB and PAX5 is irrelevant to EBV-associated gastric cancers, but is associated with carcinogenesis in certain EBV-non-associated gastric cancers

Epstein-Barr virus-associated gastric carcinoma (EBVaGC) is a distinct subtype of gastric cancer characterized by clinicopathological features including lymphoepithelioma-like histology. Aberrant expression of activation-induced cytidine deaminase (AID) as a genomic modulator was demonstrated through pathogen-related nuclear factor κB (NF-κB) signaling in Helicobacter pylori-associated gastric cancer. To elucidate whether or not AID expression is relevant to carcinogenesis in EBVaGC, immunohistochemical expression of AID and AID-regulatory factors between EBVaGC and EBV-non-associated gastric carcinoma (GC) were evaluated, each using 15 cases of GC with lymphoid stroma (GCLS) and other types of GC. Aberrant expression of AID, NF-κB and paired box 5 (PAX5) were significantly decreased in EBVaGC (0/11, 1/11 and 1/11) compared with in EBV-non-associated GC (7/19, 12/19 and 11/19) (P=0.025, 0.005 and 0.01, respectively); however, no significant difference in c-Myb proto-oncogene expression was identified. AID expression was also decreased in EBV-associated GCLS (0/10) compared with in EBV-non-associated GCLS (3/5). Unexpectedly, decreased expression of NF-κB and PAX5 was observed in GCLS (1/15 and 2/15) compared with in GC without LS (12/15 and 10/15) (P<0.001 and P=0.003, respectively). Decreased AID expression observed in EBVaGC is consistent with the reported molecular characterization of hypermethylation and rare somatic gene mutation in EBVaGC. Only PAX5 was identified to be significantly associated with venous invasion (P=0.022). The results of the present study suggest that pathogen-induced AID expression may be irrelevant to carcinogenesis of EBVaGC, whereas it contributes to carcinogenesis in certain types of EBV-non-associated GC.

Epstein-Barr Virus Lytic Reactivation Activates B Cells Polyclonally and Induces Activation-Induced Cytidine Deaminase Expression: A Mechanism Underlying Autoimmunity and Its Contribution to Graves' Disease

Graves' disease is an autoimmune disease that results in and is the most common cause of hyperthyroidism, and the reactivation of persisting Epstein–Barr virus (EBV) in B lymphocytes induces the differentiation of host B cells into plasma cells. We previously reported that some EBV-infected B cells had thyrotropin receptor antibodies (TRAbs) as surface immunoglobulins (Igs), and EBV reactivation induced these TRAb+EBV+ cells to produce TRAbs. EBV reactivation induces Ig production from host B cells. The purpose of the present study was to examine total Ig productions from B cell culture fluids and to detect activation-induced cytidine deaminase (AID), nuclear factor kappa B (NF-κB), and EBV latent membrane protein (LMP) 1 in culture B cells during EBV reactivation induction and then we discussed the mechanisms of EBV reactivation-induced Ig production in relation to autoimmunity. We showed that the EBV reactivation induces the production of every isotype of Ig and suggested that the Ig production was catalyzed by AID through LMP1 and NF-κB. The results that the amount of IgM was significantly larger compared with IgG suggested the polyclonal B cell activation due to LMP1. We proposed the pathway of EBV reactivation induced Ig production; B cells newly infected with EBV are activated by polyclonal B cell activation and produce Igs through plasma cell differentiation induced by EBV reactivation. LMP1-induced AID enabled B cells to undergo class-switch recombination to produce every isotype of Ig. According to this mechanism, EBV rescues autoreactive B cells to produce autoantibodies, which contribute to the development and exacerbation of autoimmune diseases.

Presence of Epstein-Barr virus-infected B lymphocytes with thyrotropin receptor antibodies on their surface in Graves' disease patients and in healthy individuals

Graves' disease is an autoimmune hyperthyroidism caused by thyrotropin receptor antibodies (TRAbs). Because Epstein-Barr virus (EBV) persists in B cells and is occasionally reactivated, we hypothesized that EBV contributes to TRAbs production in Graves' disease patients by stimulating the TRAbs-producing B cells. In order for EBV to stimulate antibody-producing cells, EBV must be present in those cells but that have not yet been observed. We examined whether EBV-infected (EBV(+)) B cells with TRAbs on their surface (TRAbs(+)) as membrane immunoglobulin were present in peripheral blood of Graves' disease patients. We analyzed cultured or non-cultured peripheral blood mononuclear cells (PBMCs) from 13 patients and 11 healthy controls by flow-cytometry and confocal laser microscopy, and confirmed all cultured PBMCs from 8 patients really had TRAbs(+) EBV(+) double positive cells. We unexpectedly detected TRAbs(+) cells in all healthy controls, and TRAbs(+) EBV(+) double positive cells in all cultured PBMC from eight healthy controls. The frequency of TRAbs(+) cells in cultured PBMCs was significantly higher in patients than in controls (p = 0.021). In this study, we indicated the presence of EBV-infected B lymphocytes with TRAbs on their surface, a possible player of the production of excessive TRAbs, the causative autoantibody for Graves' disease. This is a basic evidence for our hypothesis that EBV contributes to TRAbs production in Graves' disease patients. Our results further suggest that healthy controls have the potential for TRAbs production. This gives us an important insight into the pathogenesis of Graves' disease.

EBNA-2 -deleted Epstein-Barr virus from P3HR-1 can infect rabbits with lower efficiency than prototype Epstein-Barr virus from B95-8

OBJECTIVES

To clarify characteristics on rabbit in vivo infection with type 2 EBV nuclear antigen (EBNA-2)-deleted Epstein-Barr virus (P3HR-1-EBV) and compare infectious efficacy of P3HR-1-EBV with previously reported prototype type 1 EBV from B95-8.

METHODS

Twelve Japanese White rabbits were inoculated with P3HR-1-EBV via intranasal or intravenous routes and autopsied on day 70-84.

RESULTS

In only 2 of 12 P3HR-1-EBV-inoculated rabbits, EBV-DNA was detected in peripheral blood mononuclear cells (PBMCs). BamHI M rightward reading frame (BMRF)-1, EBNA-1 and BamHI Z leftward reading frame (BZLF)-1-mRNA were intermittently expressed in PBMCs. In 1 infected rabbit with continuous detection of EBV-DNA in PBMCs, many EBER-1-positive lymphocytes were observed in germinal centers and/or marginal zones in some follicles of the appendix, and for the first time a lymphocyte with EBER-1 expression infiltrating in the squamous cell layer of the tonsils was found. The other rabbit with a transient detection of EBV-DNA in PBMCs had no EBER-1-positive lymphocytes in the tissues examined. Few EBER-1-positive lymphocytes were detected in some rabbits without detection of EBV-DNA in PBMCs.

CONCLUSIONS

P3HR-1-EBV showed less efficient infection in rabbits than EBV from the B95-8 cell line. However, a P3HR-1-EBV-inoculated animal model is meaningful because this is the first study of EBNA-2 function on in vivo EBV infection and it demonstrated the in vivo infectivity with lytic-type infection by EBNA-2-deleted EBV.

Is there any circadian variation consequence on acute case fatality of stroke? Takashima Stroke Registry, Japan (1990-2003)

BACKGROUND

Circadian periodicity in the onset of stroke has been reported. However, it is unclear whether this variation affects the acute stroke case fatality. Time of the day variation in stroke case fatality was examined using population-based stroke registration data.

METHODS

Stroke event data were acquired from the Takashima Stroke Registry, which covers a stable population of approximately 55,000 in Takashima County in central Japan. During the period of 1990-2003, there were 1080 (549 men and 531 women) cases with classifiable stroke onset time. Stroke incidence was categorized as occurring at night (midnight-6 a.m.), morning (6 a.m.-noon), afternoon (noon-6 p.m.), and evening (6 p.m.-midnight). The 28-day case fatality rates and 95% confidence intervals (95% CI) were calculated by gender, age, and stroke subtype across the time blocks. After adjusting for gender, age at onset, and stroke severity at onset, the hazard ratios for fatal strokes in evening, night, and morning were calculated, with afternoon serving as the reference.

RESULTS

For all strokes, the 28-day case fatality rate was 23.3% (95% CI:19.4-27.6) for morning onset, 16.9% (95% CI:13.1-21.6) for afternoon onset, 18.3% (95% CI:13.6-24.1) for evening onset, and 21.0% (95% CI:15.0-28.5) for the night onset stroke. The case fatality for strokes during the morning was higher than the case fatality for strokes during afternoon. This fatality risk excess for morning strokes persisted even after adjusting for age, gender, and stroke severity on onset in multivariate analysis.

CONCLUSION

In the examination of circadian variation of stroke case fatality, 28-day case fatality rate tended to be higher for the morning strokes.

The influence of Epstein-Barr virus reactivation in patients with Graves' disease

In Graves' disease, the IgG class autoantibody against thyrotropin receptor (TRAb) is produced excessively and induces hyperthyroidism. Epstein-Barr virus (EBV) is one of the human herpesviruses that persists for life, mainly in B lymphocytes, and is occasionally reactivated. Therefore, EBV may affect the antibody production of B lymphocytes that would normally produce TRAb. The purpose of the present study was to evaluate the association of EBV reactivation with the etiology of Graves' disease. Serum levels of EBV antibodies and IgE were determined by ELISA. TRAb levels were determined by radioreceptor assay. We performed in-situ hybridization (ISH) of EBV-encoded small RNA (EBER)1 on the thyroid tissue of one of our patients. In Graves' disease patients with TRAb levels ≥ 10%, EA antibody levels, which indicate EBV reactivation, were moderately but significantly correlated with the levels of TRAb, and weakly but significantly correlated with IgE. EBER1-ISH revealed that one of our patients had EBV-infected lymphocytes infiltrating the thyroid gland. EBV reactivation may stimulate antibody-producing B lymphocytes predisposed to make TRAb, and this may contribute to or exacerbate the disease.

In vitro Epstein-Barr virus infection model of rabbit lymphocytes from peripheral blood or spleen

Most humans become lifelong carriers of Epstein-Barr virus (EBV) by adulthood. Primary EBV infection in adolescents causes infectious mononucleosis. EBV infection is associated with various diseases, neoplasms and hematological disorders. Recently, we reported that EBV can infect rabbits by intravenous, intranasal and/or peroral inoculation, which caused primary EBV infection in rabbits with heterogeneous host reactions. Some rabbits showed chronic and lifelong EBV infection with hemophagocytosis. In this study, to reveal detailed mechanisms in rabbit EBV infection, an in vitro investigation was performed. We elucidated that: (1) EBV can infect rabbit peripheral blood mononuclear cells and splenic lymphocytes in vitro, because EBV gene expressions were confirmed. (2) It is highly likely that the B cell is the main target cell of rabbit EBV infection and is immortalized similar to humans. (3) CD8+ T cells increased in the rabbit in vivo model after EBV inoculation, whereas an increase of B cells occurred after their transient decrease. These data suggest that EBV-infected B cells were proliferated, while CD8+ T cells increased to recognize and kill them. This system may explain the paths of rabbit EBV infection and host reaction, simulating human EBV infection. In vitro studies will be helpful to reveal the pathogenesis of rabbit EBV infection and EBV-associated diseases.

Epstein-Barr virus can infect rabbits by the intranasal or peroral route: an animal model for natural primary EBV infection in humans

Epstein-Barr virus (EBV) is spread universally in humans, and it causes infectious mononucleosis and sometimes induces serious EBV-associated disease. The detailed mechanism of primary infection in humans has remained unclear, because it is difficult to examine the dynamics of EBV in vivo. In this study, a natural EBV-infection rabbit model by intranasal or peroral inoculation is described. Ten male rabbits were examined for EBV-DNA or mRNA expression and anti-EBV antibodies in blood. Four of 10 rabbits showed the evidence of EBV infection; detection of EBV-DNA or EBV-related genes mRNA in peripheral blood mononuclear cells, increased EBV antibodies in the plasma, and the presence of lymphocytes expressing EBER1 and EBV-related gene proteins in the lymphoid tissues of a rabbit. Three of four infected rabbits were detected transiently EBV-DNA and/or mRNA of EBV-related genes such as EBNA1, EBNA2, BZLF1, and EA in blood, while in one of four, EBV-DNA and/or mRNA were detected for more than 200 days after viral inoculation. The level of EA-IgG increased and its level was maintained in all infected rabbits, whereas those of VCA-IgM and VCA-IgG increased transiently, and EBNA-IgG was not elevated. Pathological examination of a rabbit infected transiently revealed some scattered lymphocytes expressing EBER1, LMP1, and EBNA2 in the spleen and lymph nodes. EA expression was also observed in the spleen. These findings suggest that EBV can infect the rabbit by the intranasal or peroral route, and that this rabbit model is useful for examining the pathophysiology of natural primary EBV infection in humans.

Trend of Stroke Incidence in a Japanese Population: Takashima Stroke Registry, 1990-2001

Background

In Japan, stroke mortality and incidence started to decline during the 1960s. The recent unfavourably diverging trends in risk factors make it uncertain whether the decline will continue. Few comprehensive stroke registries of long research duration exist in Japan to illustrate the trends in stroke incidence.

Objective

We examined 12-year stroke registration data to evaluate the current trend in a Japanese population.

Methods

Data were obtained from the Takashima Stroke Registry, covering approximately 55000 residents of Takashima County in central Japan. We calculated the age-adjusted stroke incidence rates (/100 000 person-years) and 95% confidence intervals for 1990–1992, 1993–1995, 1996–1998, and 1999–2001. We applied the direct method to adjust for the age distribution among the four periods. The incidence time trend was determined by calculating the average annual change across the study years using negative binomial regression analysis.

Results

There were 1453 (men: 771 and women: 682) registered first-ever stroke cases during 1990–2001. The diagnosis was established by neuro-imaging in 93·6% of the cases. The average age was 69·4 years in men and 74·2 years in women. The age-adjusted incidence rates of stroke across the four observation periods were 143·1 (confidence interval: 127·4-158·8) in 1990–1992, 147·4 (confidence interval: 131·9–162·8) in 1993–1995, 120·4 (confidence interval: 106·7–134·0) in 1996–1998, and 122·9 (confidence interval: 109·6–136·2) in 1999–2001. The stroke incidence across the study years showed an insignificant time trend, with an average annual change of −0·33% (confidence interval: −2·44 to 1·78) per year. Similar trends were observed for both men and women and stroke subtypes.

Conclusions

The previously reported declining trend in stroke incidence may have levelled off or slowed down considerably in the Japanese population.

An animal model of intrinsic dental erosion caused by gastro-oesophageal reflux disease

OBJECTIVES

To explore the association between dental erosion and gastro-oesophageal reflux disease (GORD), we used an animal model of GORD.

MATERIALS AND METHODS

We performed an operation to force gastro-duodenal contents reflux in male Wistar rats, and examined the teeth in the reflux rats at 15 or 30 weeks postoperatively. Dental erosion was evaluated based on a slightly modified index from a previous report. Estimation of pH was employed in the oesophageal and gastric contents.

RESULTS

Macroscopically, dental erosion was only detected in the reflux rats. Histopathologically, dentin exposure was detected in three of the seven cases after 30 weeks. Alveolar bone destruction and osteomyelitis were also noted in severe cases. The pH of the oesophageal and stomach contents was 6.93 +/- 0.15 and 3.7 +/- 0.39, respectively.

CONCLUSIONS

We confirmed the relationship between dental erosion and GORD. First step of dental erosion caused by GORD is the loss of surface enamel induced by regurgitation of an acidic liquid and acidic gas. Subsequently, further destruction of dental hard tissues and tooth supporting structure is accelerated by mixed juice with gastric and duodenal contents. The reflux animal model is a useful tool to examine the mechanism of dental erosion in GORD.

PGE2 signal via EP2 receptors evoked by a selective agonist enhances regeneration of injured articular cartilage

OBJECTIVE

The effect of the prostaglandin E2 (PGE2) signal through prostaglandin E receptor 2 (EP2) receptors on the repair of injured articular cartilage was investigated using a selective agonist for EP2.

METHODS

Chondral and osteochondral defects were prepared on the rabbit femoral concave in both knee joints, and gelatin containing polylactic-co-glycolic acid microspheres conjugated with or without the EP2 agonist was placed nearby. Animals were sacrificed at 4 or 12 weeks post-operation, and regenerated cartilage tissues and subchondral structure remodeling were evaluated by histological scoring. The quality of regenerated tissues was also evaluated by the immunohistochemical staining of EP2, type II collagen, and proliferating cell nuclear antigen (PCNA). As an evaluation of side effects, the inflammatory reaction of the synovial membrane was analyzed based on histology and the mRNA expression of matrix metalloproteinase3 (MMP3), tissue inhibitor of metalloproteinase 3 (TIMP3), and interleukin-1 beta (IL-1 beta). Also, the activity of MMP3 and the amount of tumor necrosis factor-alpha (TNF-alpha) and C-reactive protein in joint fluid were measured.

RESULTS

In both models, the EP2 agonist enhanced the regeneration of the type II collagen-positive tissues containing EP2- and PCNA-positive chondrocytes, and the histological scale of regenerated tissue and subchondral bone was better than that of on the control side, particularly at 12 weeks post-operation. No inflammatory reaction in the synovial membrane was observed, and no induction of pro-inflammatory cytokines was found in joint fluid.

CONCLUSION

Selective stimulation of the PGE2 signal through EP2 receptors by a specific agonist promoted regeneration of cartilage tissues with a physiological osteochondral boundary, suggesting the potential usefulness of this small molecule for the treatment of injured articular cartilages.

Intratumoural heterogeneity of intestinal expression reflects environmental induction and progression-related loss of induction in undifferentiated-type gastric carcinomas

AIMS

Gene expression in tumours is regulated by environmental as well as genetic/epigenetic factors. This study assessed the environmental factors in intestinal expression of gastric cancers.

METHODS AND RESULTS

We immunohistochemically examined intratumoural heterogeneity in the expression of Cdx2, MUC2, MUC5AC and MUC6 in 39 intramucosal and 49 extramucosally invasive undifferentiated-type gastric carcinomas (UGCs), consisting of signet ring cell carcinomas showing a layered structure (LS) in the mucosa and dedifferentiated tubular adenocarcinomas without LS and with minor tubular components (TC). The LS retains mucosal vertical polarity with superficial MUC5AC expression. Loss of this polarity was independent of intestinal expression and associated with extramucosal invasion. In LS(+) UGCs, intestinal expression was enhanced as the size of mucosal spread increased and was significantly reduced with deeper extramucosal invasion, whereas, in LS(-)/TC(+) UGCs, intestinal expression was frequent and predominant in the mucosa and was insignificantly reduced with deeper extramucosal invasion.

CONCLUSIONS

In LS(+) UGCs, intestinal expression showed dynamic alteration probably by environmental induction and progression-related loss of induction, whereas it was relatively stable in LS(-)/TC(+) UGCs. Thus, intestinal expression in UGCs is not useful as a marker of tumour progression because it is also affected by environmental factors and genetic lineage.

A new animal model for primary and persistent Epstein-Barr virus infection: human EBV-infected rabbit characteristics determined using sequential imaging and pathological analysis

Most adults have persistent Epstein-Barr virus (EBV)-infection. Adolescents and young adults with primary EBV-infection frequently develop infectious mononucleosis. Latent EBV-infection is associated with various diseases, neoplasms, and hematological disorders. In vivo animal models of human EBV infection, such as non-human primates, have had limited success. A new rabbit model for primary human EBV-infection is described in this study. Seven male rabbits inoculated intravenously with EBV were sequentially imaged by ultrasonography and computed tomography, and examined for anti-EBV-VCA titer and EBV-DNA levels in blood. Six rabbits demonstrated transient splenomegaly, increased anti-EBV-VCA titers and/or EBV-DNA in blood. Transient infiltration of some EBER1-positive lymphocytes was observed in biopsied liver tissues. After splenomegaly, two rabbits tested continuously negative, two alternatively positive and negative, and one consistently positive EBV detection in blood for 470 days. One tested negative for both EBV DNA and splenomegaly. On the 14th day, mild to moderate numbers of EBER1-positive lymphocytes expressing LMP1, EBNA2, or ZEBRA infiltrated mainly in enlarged white pulps of two splenectomized materials. These cells included both B and T cells. EBV clonality analysis revealed an oligoclonal pattern. These indicate that EBV-inoculated rabbits exhibiting heterogenous host reactions are a good model for primary and persistent human EBV infection.

A non-acromegalic case of multiple endocrine neoplasia type 1 accompanied by a growth hormone-releasing hormone-producing pancreatic tumor

Cases of acromegaly due to GHRHproducing pancreatic endocrine tumors have been reported. Here we present a case of a 31-yr-old nonacromegalic man with hyperparathyroidism and elevated serum IGF-I with normal serum GH levels. Serum GH was not suppressed below 1 ng/ml by the glucose tolerance test and increased in response to TR H and GHRH administration. Magnetic resonance imaging (MRI) revealed pituitary hyperplasia and an abdominal computed tomography (CT ) scan showed a tumor in the pancreatic tail. Plasma concentration of GHRH was elevated. Based on these clinical data, multiple endocrine neoplasia (MEN) type 1 was suspected. Three enlarged parathyroid glands were removed and a distal pancreatectomy was performed. Pathological examination of the parathyroid glands and pancreatic tumor showed nodular hyperplasia and a well-differentiated endocrine tumor, respectively, both compatible with MEN features. Immunohistochemistry revealed positive immunoreactivity for GHRH, SS , insulin, glucagon, chromogranin A, and pancreatic polypeptide in the pancreatic tumor. After pancreatic surgery, elevated levels of GHRH and IGF-I were normalized and pituitary hyperplasia definitely decreased in size. In cases of pituitary hyperplasia with elevated IGF-I, ectopic GHRH syndrome must be considered even if physical features of acromegaly are absent. It is also important to measure plasma GHRH concentrations in order to give a diagnosis.

New antibody immobilization method via functional liposome layer for specific protein assays

A specific protein assay system based on functional liposome-modified gold electrodes has been demonstrated. To fabricate such assay system, a liposome layer was initially grown on top of a gold layer. The liposome layer contained two kinds of functional molecules: biotin molecules for the binding sites of streptavidin and N-(10,12-pentacosadiynoic)-acetylferrocene molecules for the facile redox probe in electrochemical detections. Then, streptavidin was attached on the functional liposme-modified layer using the interaction of streptavidin-sbiotin complex. On the streptavidin-attached surface, antibody molecules, anti-human serum albumin antibodies could be immobilized without any secondary antibodies. AFM imaging of the streptavidin-attached liposome surface revealed a uniform distribution of closely packed streptavidin molecules. In situ quartz-crystal microbalance and electrochemical measurements demonstrated that the wanted antibody-antigen reactions should occur with high specificity and selectivity. Our specific antibody assay system, based on a functional liposome modified electrode, can be developed further to yield sophisticated structures for numerous protein chips and immunoassay sensors.

Enhanced vagal modulation and exercise induced ischaemia of the inferoposterior myocardium

OBJECTIVE

To determine whether the Bezold-Jarisch reflex or enhancement of vagal nerves, which are preferentially distributed in the inferoposterior myocardium, results from exercise induced ischaemia in this region.

METHODS

On the basis of exercise myocardial scintigraphy and coronary angiography, 145 patients were classified as follows: group I, 34 patients with inferoposterior ischaemia; group A, 32 with anterior ischaemia; and control, 79 without ischaemia. The relation between ischaemic areas and ECG leads with ST segment changes and vagal modulation assessed by heart rate variability (HRV) (high frequency (HF) component (0.15-0.40 Hz) and coefficient of HF component variance (CCVHF), which is the square root of HF divided by mean RR interval) were assessed.

RESULTS

The rate of ST segment depression in any lead did not differ between group I and group A. HF and CCV(HF) were similar before exercise but higher in group I than in group A and the control group after exercise (mean (SEM) HF: 94 (17) ms2, 41 (7) ms2, and 45 (6) ms2, respectively, p = 0.021; CCV(HF): 1.18 (0.09)%, 0.81 (0.07)%, and 0.89 (0.05)%, p = 0.0053). Furthermore, the percentage change in CCV(HF) before and after exercise was higher in group I than in group A or controls (mean (SEM) 22 (10)%, -24 (4)%, and -21 (3)%, p < 0.0001). The optimal cut off for diagnosis of inferoposterior ischaemia was -5% with a sensitivity of 74%, specificity 75%, and accuracy 75%.

CONCLUSIONS

Vagal modulation as assessed by HRV analysis was enhanced in association with exercise induced inferoposterior ischaemia. Exercise ECG testing combined with HRV analysis would increase accuracy in the diagnosis of ischaemic areas in selected patients with angina pectoris.

Characterization of novel squamous cell carcinoma antigen-related molecules in mice

The squamous cell carcinoma antigen 1 (SCCA1) and SCCA2 are unique serpins that can inhibit cysteine proteinases. SQN-5, their mouse ortholog, has already been identified, and its inhibitory property has been characterized; however, its biological role has remained undefined. Furthermore, no other mouse homolog of SQN-5 has been known. We characterize three mouse members of SCCA-related molecules including SQN-5 in this article. Serpinb3a (SQN-5) and Serpinb3b, but not Serpinb3c, were functional, inhibiting both serine and cysteine proteinases with different inhibitory profiles due to the difference of two amino acids in their reactive site loops. Serpinb3a was ubiquitously expressed in most tissues, whereas expression of Serpinb3b was limited to keratinocytes. Keratinocytes secreted both SCCA-related proteins, Serpinb3a and Serpinb3b. These results indicate that Serpinb3a and Serpinb3b may play different roles by inhibiting intrinsic or extrinsic proteinases with different expression distributions and different inhibitory profiles.

Usefulness of switching to cabergoline from other dopamine agonists in patients with advanced Parkinson?s disease

Problems associated with long-term treatment of advanced Parkinson's disease (PD) include motor complications and psychotic and autonomic symptoms. We switched patients from bromocriptine (BR) or pergolide (PER) to cabergoline (CB) therapy and investigated CB's usefulness in alleviating such problems. Subjects were 30 patients (mean age 68.2 years; 13 receiving BR, 17 PER) with PD complicated by effects of long-term treatment but in whom their dose of dopamine (DA) agonist was contraindicated due to adverse reactions. Patients were switched to CB over a 2-4-week period. Hoehn-Yahr and Unified Parkinson Disease Rating Scale (UPDRS) I-IV "on" and "off" scores improved in both the BR and PER groups. CB was not discontinued due to adverse reactions in any patient. In conclusion, switching to CB is useful in patients in whom it is problematic to increase their dose of DA agonist due to motor complications or psychotic symptoms of advanced PD.

Probing feature selectivity of neurons in primary visual cortex with natural stimuli

One way to characterize neural feature selectivity is to model the response probability as a nonlinear function of the output of a set of linear filters applied to incoming signals. Traditionally these linear filters are measured by probing neurons with correlated Gaussian noise ensembles and calculating correlation functions between incoming signals and neural responses. It is also important to derive these filters in response to natural stimuli, which have been shown to have strongly non-Gaussian spatiotemporal correlations. An information-theoretic method has been proposed recently for reconstructing neural filters using natural stimuli in which one looks for filters whose convolution with the stimulus ensemble accounts for the maximal possible part of the overall information carried the sequence of neural responses. Here we give a first-time demonstration of this method on real neural data, and compare responses of neurons in cat primary visual cortex driven with natural stimuli, noise ensembles, and moving gratings. We show that the information-theoretic method achieves the same quality of filter reconstruction for natural stimuli as that of well-established white-noise methods. Major parameters of neural filters derived from noise ensembles and natural stimuli, as well as from moving gratings are consistent with one another. We find that application of the reverse correlation method to natural stimuli ensembles leads to significant distortions in filters for a majority of studied cells with non-zero reverse-correlation filter.

Cell kinetic study on histogenesis of Barrett's esophagus using rat reflux model

BACKGROUND

To elucidate the histogenesis of Barrett's esophagus and esophageal adenocarcinoma, we designed a duodeno-gastric reflux model in which normal stomach function and normal nutritional status are retained.

METHODS

Male Wistar rats were used in the experiment. The esophago-gastric junction was side-to-side anastomosed to a loop of jejunum about 3 cm distal to Treitz's ligament. The animals were not exposed to any known carcinogens during the experiment. Sequential morphological changes were studied for up to 50 weeks after surgery. Serial sections were made and stained with hematoxylin and eosin (H&E). In addition, immunohistochemical staining for bromodeoxyuridine (BrdU) was performed along with histochemical staining for mucins using paradoxical concanavalin A (ConA), galactose oxidase Schiff (GOS), and high-iron diamine-alcian blue (HID-AB).

RESULTS

Severe esophagitis with squamous cell hyperplasia was noted in all animals after surgery. At week 20 after surgery, glandular metaplastic cells positive for ConA first appeared within the basal cell layer of esophageal squamous cell epithelium, and then GOS-positive cells and HID-AB goblet cells appeared. This is a characteristic of the specialized columnar epithelium of Barrett's esophagus. We detected esophageal adenocarcinomas in 1 out of 8 subjects at week 40 and in 3 out of 8 subjects at week 50 after surgery.

CONCLUSIONS

Reflux of duodenal contents causes specialized columnar epithelium of Barrett's esophagus and esophageal adenocarcinoma. As part of the sequence of events leading to the development of Barrett's esophagus, pyloric-foveolar metaplasia was observed followed by the appearance of intestinal goblet cells. The pyloric-foveolar metaplasia appears to be associated with chronic mucosal damage and regeneration. This multiplastic cell lineage is referred to as 'gut-regenerative cell lineage' (GRCL).

Prostate cancer cell growth is modulated by adipocyte-cancer cell interaction

OBJECTIVE

To assess whether adipocytes (mesenchymal stromal cells thought to affect the proliferation and differentiation of epithelial cells) affect the behaviour of prostate cancer cells in vitro, as prostate cancer metastasizes to the bone, which is an adipocyte-rich environment.

MATERIALS AND METHODS

The human bone-metastatic prostate carcinoma cell line PC3 was cultured with or without adipocytes in a three-dimensional collagen gel matrix. Histological and immunohistochemical assays were used to evaluate the proliferation and differentiation of PC3 cells. The cytokine expression of this culture assembly was also examined by reverse transcription-polymerase chain reaction (RT-PCR).

RESULTS

The proliferation and differentiation of cancer cells were clearly changed on co-culture with adipocytes compared with the control cultures. The mean (range) bromodeoxyuridine (BrdU) indices estimated (according to uptake) to evaluate the growth of the cultured cells were 36.3 (8.55)% in the co-culture and 26.95 (10.50) in the control (P < 0.02). PC3 cells in co-culture formed larger clusters than in the control, at 16.0 (11.0) vs 14.0 (10.0), respectively (P < 0.01). Cancer cells also showed pleomorphism, varying from cuboidal to spindle-shaped. The expressions of vascular endothelial and platelet-derived growth factor were greater in co-culture than in the control.

CONCLUSION

These findings suggest that adipocytes modulate the growth, morphology and cytokine expression of prostate cancer cells. This specific mesenchymal stromal cell type is important in the biological behaviour of prostate cancer cells.

Clonal analysis of esophageal squamous cell carcinoma with intraepithelial components

OBJECTIVE

In tumors of the upper aerodigestive tract, field carcinogenesis is a prevailing concept which suggests that such tumors are commonly of multiclonal origin.

METHODS

To test this possibility, we applied a PCR-based clonality assay utilizing the polymorphic locus of the human androgen receptor gene (HUMARA) in female patients with esophageal squamous cell carcinomas (SCCs). DNA was extracted from small pieces of tissues microdissected from multiple points of intraepithelial and invasive parts of each tumor and the adjacent epithelia in 12 cases. The HUMARA locus was PCR amplified with or without prior digestion with Hpa II. PCR products were analyzed by a genetic analyzer and polyacrylamide gel electrophoresis followed by silver staining.

RESULTS

In each of 8 informative cases, the pattern of X chromosome inactivation of the major cell population in each sample was common among the samples from the invasive part and among those samples, if any, from the intraepithelial part, and was concordant between the intraepithelial and invasive parts in 5 cases and discordant in 1 case. Out of the samples of adjacent epithelia, a monoclonal pattern was demonstrated in 8 basal cell hyperplasias and 3 dysplasias, of which 2 and 1, respectively, showed inactivation patterns discordant with those of the concomitant cancers.

CONCLUSION

Esophageal SCCs may often be preceded or accompanied by multiclonal precancerous lesions, and may develop through the outgrowth of single or less commonly multiple dominant clones.

Bromodeoxyuridine induces p53-dependent and -independent cell cycle arrests in human gastric carcinoma cell lines

OBJECTIVES

This study was designed to clarify the effects of bromodeoxyuridine (BrdU) on cell cycle progression and induction of apoptosis, and to demonstrate the role of P53 in these processes.

METHODS

We continuously exposed four human gastric carcinoma cell lines with different P53 status (P53 wild-type AGS and MKN-45, P53-mutated MKN-28 and P53-deleted KATO-III) to BrdU in asynchronous and synchronous culture conditions, and analyzed DNA histograms of apoptotic and nonapoptotic cells determined by static DNA cytofluorometry.

RESULTS

Continuous exposure to 20 microM BrdU after synchronization with hydroxyurea resulted in S phase delay and G1 arrest in MKN-45 and an increase of apoptosis in the first S/G(2) phase in AGS and MKN-45. In the second S phase, a delay of 3-6 h was observed in all the four cell lines. In asynchronous cultures, continuous exposures to 20 and 200 microM BrdU for 72 h or more caused growth suppression with G(1) and G(2) arrests, respectively, in all the cell lines.

CONCLUSIONS

These data suggested that the BrdU-induced growth suppression of the cell lines examined was mainly caused by cell cycle arrest rather than cell death, and that the cell cycle arrests in the first S and G(1) phases (elicited by BrdU in the single DNA strand) and those in the second S, G(2) and G(1) phases (elicited by BrdU in the double DNA strands) were mediated by p53-dependent and -independent pathways, respectively.

Bladder cancer cell implantation in reconstructed bladder in vitro: a model of tumour recurrence

OBJECTIVE

To evaluate the involvement of umbrella cells in tumour adhesion and growth, by examining whether human urinary bladder carcinoma cells (HUBCC) can grow on reconstructed urinary bladder mucosa in vitro, as the implantation of tumour cells after resection is thought to be a cause of bladder tumour recurrence.

MATERIALS AND METHODS

Normal transitional epithelial cells isolated from porcine bladder were cultured on reconstructed lamina propria using fibroblasts in type I collagen gel. The urothelium thus reconstructed was artificially injured either by a scalpel or by dilute acid, after which transitional epithelial cells began to grow in a stratified fashion within a few days of culture. A HUBCC line (HT-1197) was seeded onto this impaired mucosa to determine whether the cells could become implanted. Cultured cells on the reconstructed mucosa were evaluated by histological observation of vertical paraffin sections.

RESULTS

The inoculated transitional epithelial cells grew in a stratified fashion and closely resembled urothelium in vivo. The superficial cells that were in contact with the medium solution differentiated into umbrella cells. HUBCC were unable to adhere to reconstructed mucosa which had not been injured, but these cells could adhere to and become implanted on the reconstructed mucosa after it had been injured either by a scalpel or by dilute acid. After acid injury, only the surface-covering cells were removed sporadically, while the lower epithelial cell layer remained intact. The bladder cancer cells adhered to and proliferated within these stripped regions.

CONCLUSION

These results suggest that the urothelium, especially umbrella cells, seems to be important in preventing the adhesion and growth of urinary bladder tumour cells.

An autopsy case of hemilaterally dominant and systematic/extensive border zone infarction: sequela of preceding atherosclerotic obstruction of one common carotid artery followed by repeated episodes of systemic hypotension

A 68-year-old man was admitted to St Marianna University Hospital on account of loss of consciousness with left hemiplegia. During the hospital recovery course with a rehabilitation procedure, the patient's blood pressure was very unstable, fluctuating between high (210/110 mmHg) and low (110/70 mmHg) values accompanied by a fainting sensation. A second stroke of left hemiplegia took place 1 month later. Afterwards, his condition worsened to tetraplegia with dysarthria. Three months later, lung cancer with multiple metastasis including his left neck was found and he died from adynamic ileus 6 months after the onset of the present illness. Autopsy revealed nearly complete atheromatous obstruction and more than 50% stenosis, respectively, of his right common and internal/external carotid arteries. His intracranial arterial trunks and main branches were all patent with localized atherosclerosis of only moderate degree. The pathology of the brain existed predominantly in the right hemisphere in the border zone area between the anterior and middle cerebral arteries systematically with numerous disseminated foci of complete or incomplete necrosis, white matter and gray matter being involved independently. Involvement of centrum semiovale white matter is more extensive and intensive than that of gray matter. Of the gray matter, cerebral cortex as well as striatum, periventricular (the third ventricle) gray and cerebellar cortex was involved. The specific characteristic topography and distribution of the lesions together with their histopathology are described in detail with illustration. It is concluded that this case represents an outstanding example of hemodynamic cerebral circulatory insufficiency doubly caused by hemilateral carotid artery stenosis and repeated episodes of systemic hypotension.

Chronic central infusion of ghrelin increases hypothalamic neuropeptide Y and Agouti-related protein mRNA levels and body weight in rats

Ghrelin, an endogenous ligand for the growth hormone secretagogue receptor (GHS-R), was originally purified from the rat stomach. Like the synthetic growth hormone secretagogues (GHSs), ghrelin specifically releases growth hormone (GH) after intravenous administration. Also consistent with the central actions of GHSs, ghrelin-immunoreactive cells were shown to be located in the hypothalamic arcuate nucleus as well as the stomach. Recently, we showed that a single central administration of ghrelin increased food intake and hypothalamic agouti-related protein (AGRP) gene expression in rodents, and the orexigenic effect of this peptide seems to be independent of its GH-releasing activity. However, the effect of chronic infusion of ghrelin on food consumption and body weight and their possible mechanisms have not been elucidated. In this study, we determined the effects of chronic intracerebroventricular treatment with ghrelin on metabolic factors and on neuropeptide genes that are expressed in hypothalamic neurons that have been previously shown to express the GHS-R and to regulate food consumption. Chronic central administration of rat ghrelin (1 microg/rat every 12 h for 72 h) significantly increased food intake and body weight. However, it did not affect plasma insulin, glucose, leptin, or GH concentrations. We also found that chronic central administration of ghrelin increased both neuropeptide Y (NPY) mRNA levels (151.0 +/- 10.1% of saline-treated controls; P < 0.05) and AGRP mRNA levels (160.0 +/- 22.5% of saline-treated controls; P < 0.05) in the arcuate nucleus. Thus, the primary hypothalamic targets of ghrelin are NPY/AGRP-containing neurons, and ghrelin is a newly discovered orexigenic peptide in the brain and stomach.

[Assessment of myocardial fatty acid metabolism in patients with angina pectoris and diabetes mellitus using 123I-BMIPP myocardial scintigraphy]

PURPOSE

We studied the effect of myocardial ischemia and diabetes mellitus (DM) on the myocardial fatty acid metabolism using 123I-BMIPP myocardial scintigraphy.

METHODS

We performed 123I-BMIPP myocardial scintigraphy in 50 patients with myocardial ischemia and without DM (AP), in 30 patients with myocardial ischemia and DM (AP + DM), 12 patients with DM and without myocardial ischemia (DM), and in 10 normal subjects (N). Myocardial uptake rate of 123I-BMIPP was obtained using the time activity curve. Myocardial washout rate of 123I-BMIPP was calculated using the polar images of early and delayed SPECT images.

RESULTS

Myocardial uptake rate of 123I-BMIPP (%) were AP: 4.9 +/- 0.6, AP + DM: 5.5 +/- 0.5, DM 5.7 +/- 0.5 and N: 5.0 +/- 0.4. 123I-BMIPP myocardial uptake rate was increased in AP + DM and DM. 123I-BMIPP myocardial washout rate (%) were AP: 30.2 +/- 4.3, AP + DM: 24.5 +/- 3.9, DM: 16.1 +/- 2.8 and N: 19.4 +/- 3.2. 123I-BMIPP myocardial washout rate was increased in AP and AP + DM. 123I-BMIPP myocardial washout rate was increased particularly in patients with multi-vessels disease. 123I-BMIPP myocardial washout rate was decreased in DM.

CONCLUSION

The present study suggested that diabetes mellitus increased myocardial fatty acid uptake and decreased myocardial fatty acid washout, and that myocardial ischemia increased myocardial fatty acid washout.

MUC gene expression and histogenesis of adenocarcinoma of the stomach

To elucidate the histogenesis of adenocarcinomas of the stomach, we examined MUC gene expression in gland-forming intramucosal neoplastic lesions. Eighty tumors were histopathologically assigned to 1 of the following 3 groups based upon the Vienna classification: group A (low-grade adenoma/dysplasia), group B (high-grade adenoma/dysplasia) and group C (intramucosal carcinoma). Immunohistochemic staining was performed with monoclonal antibodies against MUC2 (goblet cell mucin), MUC5AC (gastric-foveolar mucin), MUC6 (pyloric-gland mucin) and CD10 (brush border). Ki-67 staining was also carried out. An obvious difference existed in MUC gene expression between lesions in group A and those in groups B and C. The majority of group A lesions strongly expressed intestinal markers in which proliferating cell zones were formed but generally expressed no gastric markers, whereas more than 50% of groups B and C tumors expressed gastric markers. These findings suggest that group A lesions are of a stable intestinal phenotype, whereas those in groups B and C are phenotypically and genotypically unstable, indicating that the adenoma-carcinoma sequence is not a major pathway, but instead that adenocarcinomas arise de novo.

Dye sensitization of nanocrystalline titanium dioxide with square planar platinum(II) diimine dithiolate complexes

A series of platinum-based sensitizers of the general type Pt(NN)(SS), where NN is 4,4'-dicarboxy-2,2'-bipyridine (dcbpy) or 4,7-dicarboxy-1,10-phenanthroline (dcphen) and SS is ethyl-2-cyano-3,3-dimercaptoacrylate (ecda), quinoxaline-2,3-dithiolate (qdt), 1,2-benzenedithiolate (bdt), or 3,4-toluenedithiolate (tdt), that have various ground-state oxidation potentials has been synthesized and anchored to nanocrystalline titanium dioxide electrodes for light-to-electricity conversion in regenerative photoelectrochemical cells with an I(-)/I(-)(3) acetonitrile electrolyte. The intense mixed-Pt/dithiolate-to-diimine charge-transfer absorption bands in this series could be tuned from 440 to 580 nm by choosing appropriate dithiolate ligands, and the highest occupied molecular orbitals varied by more than 500 mV. Spectrophotometric titration of the Pt(dcphen)(bdt) complex exhibits a ground-state pK(a) value of 3.2 +/- 0.1, which can be assigned to the protonation of the carboxylate group of the dcphen ligand. Binding of Pt(dcbpy)(qdt) to porous nanostructured TiO(2) films was analyzed using the Langmuir adsorption isotherm model, yielding an adsorption equilibrium constant of 4 x 10(5) M(-1). The amount of dye adsorbed at the surface of TiO(2) films was 9.5 x 10(-8) mol/cm(2), which is ca. 50% lower than the full monolayer coverage. The resulting complexes efficiently sensitized TiO(2) over a notably broad spectral range and showed an open-circuit potential of ca. 600 mV with an impressive fill factor of > 0.70, making them attractive candidates for solar energy conversion applications. The visible spectra of the 3,4-toluenedithiol-based sensitizers showed an enhanced red response, but the lower photocurrent efficiency observed for these sensitizers stems in part from a sluggish halide oxidation rate and a fast recombination of injected electrons with the oxidized dye.