Nicorandil, a hybrid between nitrate and ATP-sensitive potassium channel opener, preconditions human heart to ischemia during percutaneous transluminal coronary angioplasty

The human heart progressively becomes more tolerant to ischemia after repeated balloon inflations during percutaneous transluminal coronary angioplasty (PTCA). The present study investigated whether nicorandil, a hybrid between nitrate and an ATP-sensitive potassium channel opener, affects this ischemic preconditioning. Sixteen patients with stable angina pectoris caused by left anterior descending artery lesions were subjected to 2 balloon inflations of 2-min duration with a 3-min reperfusion period. Seven of these patients served as the control group and in the remaining 9 patients, nicorandil was administered intravenously (6 mg/h) throughout the PTCA procedure (nicorandil group). The lactate extraction ratio (LER) was obtained at 30 s after each ischemic event (LERpost-1 and LERpost-2) in both groups. In the control group, LERpost-1 was more negative than LERpost-2 (-185.7+/-74.2 vs -98.0+/-37.3%, p<0.01). The ratio of the sum of the ST elevation in the precordial leads during the second inflation (sumST-2, 0.94+/-0.66 mV) to that during the first inflation (sumST-1, 1.43+/-1.17 mV) was 0.72+/-0.16 in the control group, which was less than the ratio in the nicorandil group (1.06+/-0.13, p<0.01). Nicorandil abolished the difference between the 2 ischemic events (LERpost-1, -45.1+/-41.6 vs LERpost-2, -43.5+/-51.1%; sumST-1, 1.38+/-0.80 vs sumST-2, 1.46+/-0.90 mV). LER was less negative in the nicorandil group than that in the control group (LERpost-1, -45.1+/-41.6 vs -185.7+/-74.2%, p<0.01; LERpost-2, -43.5+/-51.1 vs -98.0+/-37.3%, p<0.05). Thus, nicorandil improved lactate metabolism during PTCA without significantly influencing ST-elevation. In conclusion, intravenous pre-administration of nicorandil appears to precondition the human heart during PTCA.

Prognostic significance of neuroendocrine differentiation, proliferation activity and androgen receptor expression in prostate cancer

Androgen, acting via the androgen receptor (AR), is associated with the development and progression of prostate cancer. Anti-androgen therapy is widely used to manage prostate cancer. However, the conversion of the tumor from a hormone-sensitive to a hormone-insensitive status causes such therapy to fail. Several mechanisms have now been put forward for this conversion, including neuroendocrine (NE) differentiation of the tumor cells. In this study, we evaluated the prognostic significance of tumor-cell proliferation activity, NE differentiation and AR expression. Formalin-fixed, paraffin-embedded sections were prepared from 42 patients with adenocarcinoma of the prostate. Using antibodies to AR, the Ki-67 antigen (MIB-1), chromogranin A and synaptophysin, immunohistochemical expression of AR, tumor proliferation activity and NE differentiation were analyzed. Our study revealed that AR expression was significantly lower in adenocarcinoma (52.2 +/- 27.1%) than in non-tumorous prostate tissue (68.3 +/- 18.3%; P < 0.001). NE differentiation was found in 50% of the tumors, which was correlated with the Gleason score (P < 0.05). An univariate analysis revealed a significant correlation between progression-free survival with both AR expression (P < 0.01) and proliferation activity (P < 0.001). NE differentiation was not a prognostic factor in this study.

Thymidine phosphorylase expression correlates with tumor differentiation and Bcl-2 in invasive breast cancer

BACKGROUND

Angiogenesis plays an important role in the growth and metastasis of solid tumors. Several angiogenic factors have been identified, and thymidine phosphorylase (TP) is thought to be one such factor. To date, little information is available on the relationship between TP and other clinicopathological variables.

METHODS

Formalin-fixed, paraffin-embedded materials from 116 primary breast carcinomas were used. The expression of TP, estrogen receptor, Bcl-2, Bax, p53, c-erbB-2 and MIB-1 was examined by immunohistochemical methods.

RESULTS

Nuclear and/or cytoplasmic TP expression was observed in the neoplastic cells, and accentuation of TP was often present at the infiltrating tumor edge and intraductal spread region. Tumor cell TP expression was significantly inversely correlated with histological grade (p< 0.05) and positively correlated with Bcl-2 expression, but no association with other tumor variables was found.

CONCLUSIONS

TP is associated with Bcl-2 expression and tumor differentiation in breast cancer. TP may be a new prognostic parameter for breast cancer.

Hypermethylation does not account for the frequent loss of the retinoic acid receptor beta2 in breast carcinoma

Hypermethylation of the retinoic acid receptor (RAR) beta2 has been detected in breast cancer cell lines and is known to repress the level of RAR beta2 transcription. RAR beta2 mRNA loss has often been detected in breast cancer tumors, whether promoter region methylation of the RAR beta2 gene accounts for its loss is still unknown. We examined the methylation status of RAR beta2 in breast tumors; 21 out of 50 (42%) breast tumors showed RAR beta2 hypermethylation. RT-PCR analysis showed a complete loss of RAR beta2 mRNA expression in 15 out of 43 (35%) breast tumors. No correlation between the hypermethylation and RAR beta2 loss was found, suggesting that hypermethylation is not fully responsible for the loss of expression of the RAR beta2 gene during breast tumorigenesis.

Novel polymorphisms of prostate-specific antigen (PSA) gene associated with PSA mRNA expression in breast cancer

A growing body of evidence suggests that prostate-specific antigen (PSA) is a novel prognostic factor for breast cancer. The molecular mechanism of variant PSA expression in breast cancer has remained poorly understood in spite of intensive research. Previous studies have shown that the coding region of the PSA gene is not a target for mutations in prostate cancer and breast cancer. The purpose of this study was to analyze genetic variations in the promoter region of the PSA gene, and to detect whether such variations are correlated with PSA mRNA expression in breast tumors. We identified two polymorphisms in the proximal promoter region of the PSA gene. These polymorphisms are located at positions -252 (G or A) and -205 (A or AA), and generate three genotypes. The genotypes were associated with PSA mRNA expression. Our findings suggest that these polymorphisms identified in the proximal promoter region may affect the transcriptional activity of PSA.

Ca2+ signaling via the neuronal calcium sensor-1 regulates associative learning and memory in C. elegans

On a radial temperature gradient, C. elegans worms migrate, after conditioning with food, toward their cultivation temperature and move along this isotherm. This experience-dependent behavior is called isothermal tracking (IT). Here we show that the neuron-specific calcium sensor-1 (NCS-1) is essential for optimal IT. ncs-1 knockout animals show major defects in IT behavior, although their chemotactic, locomotor, and thermal avoidance behaviors are normal. The knockout phenotype can be rescued by reintroducing wild-type NCS-1 into the AIY interneuron, a key component of the thermotaxis network. A loss-of-function form of NCS-1 incapable of binding calcium does not restore IT, whereas NCS-1 overexpression enhances IT performance levels, accelerates learning (faster acquisition), and produces a memory with slower extinction. Thus, proper calcium signaling via NCS-1 defines a novel pathway essential for associative learning and memory.

Frequent loss of heterozygosity at 1p36.3 and p73 abnormality in parathyroid adenomas

Although 1p is one of the most common loci showing loss of heterozygosity (LOH) in primary parathyroid adenoma, fine mapping has not been previously examined. In this study, we analyzed LOH in 32 primary parathyroid adenomas using five microsatellite markers at 1p36 (proximal-D1S507-D1S450-D1S2893-D1S468-D1S243-distal). All cases were heterozygous for at least one marker. The frequency of LOH varied from 41.2% (D1S468) to 7.1% (D1S507) among the different markers. LOH was detected consistently in a group of nine adenomas (28.1%, 9/32). A single region (7 cM) showing a consistent LOH at 1p36.3 was obtained that was flanked distally by D1S468 and proximally by D1S2893. Because the p73 gene is localized within this region and acts as a tumor suppressor gene, we examined the possible involvement of p73 in the development of parathyroid tumor. Allelic loss of p73 was identified in four adenomas (25%, 4/16 informative cases) that were all from the group of the nine adenomas with LOH, but somatic mutation was not detected in the remaining allele. At the StyI polymorphism of Exon 2, four of the six adenomas with LOH at 1p36 were heterozygous and expressed the GC allele. Of the six heterozygous adenomas without LOH, 4 showed biallelic and 2 monoallelic expressions (GC allele). All adenomas mainly expressed the p73alpha isoform. p73 protein was observed in five of the six adenomas with LOH and in two of the six adenomas without LOH. There were no differences in p73 protein levels between the samples with and without LOH. In conclusion, a candidate gene for parathyroid tumorigenesis is present within a 7-cM region at 1p36.3, however p73 is unlikely to be the target of the LOH at 1p36.3.

Urinary 8-oxo-7, 8-dihydro-2'-deoxyguanosine and biopyrrins levels among construction workers with asbestos exposure history

It has been suggested that oxidative stress is associated with the cancers caused by asbestos. Since construction workers are sometimes exposed to low levels of asbestos, we investigated whether oxidative stress was elevated in construction workers who had been exposed to low levels of asbestos. The subjects were 48 Japanese construction workers. The defined asbestos-exposed group consisted of subjects who had the history of suspected exposure to asbestos and were diagnosed to have irregular opacities or pleural plaques. We measured the amount of 8-oxo-7, 8-dihydro-2'-deoxyguanosine (8-oxodG) and biopyyrins in the urine of the subjects. The results showed that 8-oxodG and biopyyrins levels in the defined asbestos-exposed group were higher, although they were not statistically significant, than those in the control group. In addition, the urinary 8-oxodG levels tended to correlate positively with the duration of suspected exposure to asbestos. These results suggest that even low-level asbestos exposure may induce oxidative stress and that the resulting's the oxidative stress might be related to lung cancer in construction workers.

Upregulated expression of Iba1 molecules in the central nervous system of mice in response to neurovirulent influenza A virus infection

The present study deals with the expression of Iba1 molecules, a novel EF-hand Ca2+-binding protein, in the brain after stereotaxic introduction of the neurovirulent WSN strain of influenza A virus into the olfactory bulb of C57BL/6 mice. The virus selectively targeted the paraventricular and anterior olfactory nuclei. Infected neurons appeared as early as at day 3 post infection and degenerated and vanished by day 12. The Iba1 molecule was normally expressed in resting microglia. The overexpression of the Iba1 in microglial cells was detected at day 3 post infection, culminating at day 7 with a morphological activation. Iba1-immunopositive macrophages outnumbered microglia in the paraventricular and anterior olfactory nuclei, where the infected neurons had degenerated. Macrophages totally disappeared by day 12, and the Iba1-expression in microglia was reduced to a normal level by day 35. Lack of perforin predisposed the mice to long-term virus infection of the brain, leading to the prolonged Iba1-overexpression. These results show that the Iba1 is upregulated in the mouse brain in response to influenza virus infection and may play significant roles in the regulation of some immunological and pathophysiological functions of microglia during virus infection.

Aberrant expression of cyclin D1 in pulmonary proliferative lesions induced by high doses of urethane in transgenic mice carrying the human prototype c-H-ras gene

In our previous study, when rasH2 mice and non-transgenic (non-Tg) littermates were injected intraperitoneally with 1,000 mg/kg of urethane once or three times at two-day intervals, the incidence of lung proliferative lesions in rasH2 mice given triple doses of urethane was significantly increased, compared to that in rasH2 mice given a single dose of urethane, and the mutation frequency of the transgene in lung tumors in rasH2 mice given triple doses was lower than that in rasH2 mice given a single dose of urethane. In the present study, differential immunohistochemical expressions of Cyclin D1 and PCNA, that lead to abnormal cell proliferation and tumor development due to uncontrolled G1-S transition in the cell cycle, as well as p53 tumor suppressor gene in pulmonary proliferative lesions obtained from our previous study were investigated. Over-expression of Cyclin D1 in hyperplasias in rasH2 mice given triple doses was significantly increased, compared to that in the single-injection group, but no significant differences in Cyclin D1 between the single and triple injection groups were observed in hyperplasias in non-Tg mice or lung tumors in either rasH2 or non-Tg mice. There were no differences in the PCNA labeling index of hyperplasias in rasH2 or non-Tg mice between the triple-injection and single-injection groups, while the PCNA labeling index tended to be increased in the tumor, compared with that in hyperplasias. There was neither mutation of p53 nor an increase in immunoreactivity of wild type p53 in these proliferative lesions. These results suggest that cyclin D1 over-expression in alveolar/bronchiolar hyperplasias in rasH2 mice in the triple-injection group is not only indicative of a high cell proliferation rate but also of an important role in the process of malignant transformation.

Clinical features of fulminant hepatitis in Nagasaki Prefecture, Japan

OBJECTIVE

Fulminant hepatitis is a rare but fatal disease. In the present study, we examined the changes in etiology and prognosis of fulminant hepatitis in Nagasaki Prefecture, Japan between 1980 to 1999.

METHODS

Eighty-one patients with fulminant hepatitis admitted to our hospitals from 1980 to 1999 were examined with respect to the etiology and prognosis.

RESULTS

Fulminant hepatitis was due to hepatitis A virus in 2 (12%) cases, hepatitis B virus in 18 (22%) cases, unknown etiology in 50 (62%) cases, and drug-induced in 11(14%) cases. The number of cases in the first half of the study (1980-1989) was 47 and that of the latter half (1990-1999) was 34 cases. The incidence of fulminant hepatitis type B also decreased from 14 cases (30%) to 4 cases (12%) during these periods. The overall survival rate of fulminant hepatitis was 32%; it was equal in fulminant hepatitis type B, fulminant hepatitis of unknown etiology and fulminant drug-induced hepatitis. The survival rate of fulminant hepatitis type A was 100%, though only two cases were identified. Retrospectively, the survival rate in patients with a pre-encephalopathy period of < or = 10 days and aged < or = 39 years was significantly higher than in patients > or = 40 years of age (p<0.01). There was no difference between the two age groups when pre-encephalopathy period was > or = 11 days.

CONCLUSIONS

The incidence of fulminant hepatitis especially that of fulminant hepatitis type B in Nagasaki Prefecture has decreased in recent years. The survival rate is significantly higher in younger patients with a short pre-encephalopathy period.

Novel polymorphisms in prostate specific antigen gene and its association with prostate cancer

Prostate-specific antigen (PSA) is now used widely for the diagnosis and monitoring of patients with prostate cancer. The PSA gene is a target of the androgen receptor (AR) which interacts with androgen response elements (AREs) in the PSA gene promoter. Recently, we identified two novel polymorphisms in the PSA promoter ARE2 region in breast cancer. We hypothesized that some genetic variations might also exist in the AREs of prostate cancer, and that feature might correlate with cancer development and/or progression. To test this hypothesis, three AREs of the PSA gene promoter were characterized for 47 prostate cancer cases and 105 controls from the Japanese population. We demonstrated the presence of two polymorphisms at positions -252 (G or A) and -205 (A or AA), which were the same as those we have found in breast cancer. Interestingly, the -252 A was linked with the presence of -205 AA, and the -252 G was always linked with the presence of -205 A. Therefore, only A-AA and G-A (-252--205) alleles were present in the Japanese population. The proportion of patients who were either heterozygotes or homozygotes for the A-AA allele was not significantly different from that observed among 105 individuals without cancer (p = 0.726). However, comparing with G-A allele homozygotes, prostate cancer patients carrying at least 1 A-AA alleles tended to exhibit high serum PSA levels (p = 0.0002), poor differentiation (p = 0.0149) and advanced clinical stage (p = 0.0077). These results suggest that the novel polymorphisms identified in the PSA gene promoter may affect transcriptional activity of the PSA gene, and an excess of PSA production may enhance rapid progression of prostate cancer.

Biallelic inactivation of retinoic acid receptor beta2 gene by epigenetic change in breast cancer

A growing body of evidence supports the hypotheses that retinoic acid receptor beta2 (RAR beta2) is a tumor suppressor gene. Although the loss of RAR beta2 expression has been reported in many malignant tumors, including breast cancer, the molecular mechanism is still poorly understood. We hypothesized that loss of RAR beta2 activity could result from multiple factors, including epigenetic modification and loss of heterozygosity (LOH). Using methylation-specific polymerase chain reaction and LOH analysis, we found that biallelic inactivation via epigenetic changes of both maternal and paternal alleles, or epigenetic modification of one allele combined with genetic loss of the remaining allele, could completely suppress RAR beta2 expression in breast cancer. Thus, it is possible that substantial numbers of human cancers arise through suppressor gene silencing via epigenetic mechanisms that inactivate both alleles. Because of this, chromatin-remodeling drugs may provide a novel strategy for cancer prevention and treatment.

Radiation-induced senescence-like growth arrest requires TP53 function but not telomere shortening

Suzuki, K., Mori, I., Nakayama, Y., Miyakoda, M., Kodama, S. and Watanabe, M. Radiation-Induced Senescence-like Growth Arrest Requires TP53 Function but not Telomere Shortening. Normal human diploid cells irradiated with X rays showed permanent cell cycle arrest and exhibited senescence-like phenotypes including the expression of senescence-associated beta-galactosidase (SA-beta-gal). X irradiation caused persistent phosphorylation of TP53 at Ser 15 and accumulation of the TP53 protein, followed by the induction of CDKN1A (also known as p21(Waf1/Cip1)) and CDKN2A (also known as p16), preceded the expression of SA-beta-gal. NCI-H1299 human lung carcinoma cells, in which no TP53 protein was expressed, were irradiated with X rays with or without the exogenous expression of TP53 gene. Although induction of TP53 protein alone could induce SA-beta-gal expression, the frequency of SA-beta-gal-positive cells was significantly increased when TP53-induced H1299 cells were exposed to X rays. The mean terminal restriction fragment length in normal human cells was approximately 12 kb and did not change in SA-beta-gal-positive cells. These results indicate that ionizing radiation induces senescence-like growth arrest that is dependent on TP53 function but independent of telomere shortening. Our findings suggest that cells harboring irreparable DNA damage are programmed to undergo premature senescence to maintain the integrity of the genome.

Culture condition-dependent senescence-like growth arrest and immortalization in rodent embryo cells

Culture Condition-Dependent Senescence-Like Growth Arrest and Immortalization in Rodent Embryo Cells. We investigated the telomerase activity, telomere length, and replicative life span of cells from human embryos and rodent embryos (mouse, rat and Syrian hamster). We used two culture conditions for rodent embryo cells whereby the cells were plated at a density of 2 x 10(5) into a 25-cm(2) flask and subcultured every 3 days or every 10 days. We found that nearly 100% of the cultures of rodent embryo cells become immortal when they are subcultured using the 10-day culture protocol. These rodent embryo cells retain telomerase activity and long telomeres (19-50 kb) in the long-term cultures, whereas human embryo cells rapidly deplete telomerase activity associated with significant shortening of telomeres, and then they senesce. In contrast to the results from 10-day cultures, we found that some mouse cell cultures and most Syrian hamster cell cultures arrest cell growth after 13 and 29 population doublings, respectively, while retaining substantial levels of telomerase activity and experiencing no significant loss of telomeres when the cells were subcultured using the 3-day culture protocol. This growth arrest is phenotypically indistinguishable from cellular senescence. The present results suggest that in rodent cells the onset of senescence-like arrest can be activated without repression of telomerase, and that this activation pathway can be bypassed easily under certain culture conditions, such as the 10-day culture protocol.

[Comparison of nerve conduction studies between conventional and lumbrical/interossei recording methods in diabetics]

Median nerve conduction studies were performed by conventional and lumbrical/interossei recording methods. The former is composed of recordings of compound muscle action potential from abductor pollicis brevis (APB) and sensory nerve action potential from second digit (D) after wrist stimulation. In the latter the recording electrode was placed lateral to the midpoint of the 3rd metacarpal bone, and recorded compound muscle action potential from the 2nd lumbrical (2 L) and sensory nerve action potential from the digital nerve (N) after wrist stimulation. Subjects were 57 healthy individuals and 97 patients with diabetes mellitus. Particularly in diabetic patients values of coefficient of correlation between each measurement were high enough; i.e., r = 0.91 between latencies to 2 L and APB, r = 0.55 between amplitudes of 2 L and APB, r = 0.86 between amplitudes of N and D. Corresponding measurements by conventional method and lumbrical/interossei method were identical in the values of coefficient of correlation between measurements. The characteristics of lumbrical/interossei method are to be able to record compound muscle action potentials and nerve action potential from the same electrode. In this study values obtained by lumbrical/interossei method showed identical correlation between measurements to the corresponding ones by conventional method. In conclusion recordings of APB and D by conventional method can be replaced with the recordings of 2 L and N by lumbrical/interossei method in the evaluation of diabetic neuropathies.

Re-analysis of clinical features of 89 patients with autoimmune hepatitis using the revised scoring system proposed by the International Autoimmune Hepatitis Group

OBJECTIVE

The diagnostic criteria of autoimmune hepatitis (AIH) were recently modified by the International Autoimmune Hepatitis Group. This study was performed to assess the impact of the revised scoring system on the diagnosis of AIH.

PATIENTS AND METHODS

We re-analyzed the clinical features of 89 patients diagnosed as AIH in Nagasaki Prefecture, Japan, using the revised scoring system, and compared the scores and final diagnosis with our previously published results using the original system.

RESULTS

Of the 89 patients with AIH, 40 (45%) were classified using the new system as "definite" AIH, 41 (46%) as "probable" AIH, and 8 (9%) patients were categorized as "others". Of these, 37 (42%), 35 (39%), and 4 (4%) patients who were classified as "definite", "probable", and "others" by the original system remained in the same category by the revised system, respectively. However, 3, 4, and 6 patients were re-categorized as "definite" from "probable", "others" from "probable", and "probable" from "definite", respectively. The difference in aggregate scores between the above two systems ranged from -5 to +2. The main contributing factors to the changes in aggregate AIH score were "other autoimmune disease(s)" and "interface hepatitis without lobular involvement and bridging necrosis on liver histology". However, the main contributing factors to the demotions from "definite" to "probable" and form "probable" to "others" were those related to the characteristics of biliary diseases, i.e., antimitochondrial antibody positive, biliary changes in liver histology, and alkaline phosphatase: aspartate aminotransferase ratio between 1.5 and 3.0. Moreover, two patients who had no histological evidence of AIH were both re-categorized as "others" from "probable" AIH.

CONCLUSION

Our results indicated that the diagnosis, whether based on the revised or original system, was the same in the majority of AIH patients, but the revised scoring system excluded cases who had features suggestive of biliary diseases from "definite" AIH, and also confirmed that a diagnosis of "definite" AIH should not be made without liver histology.

Overexpression of p27 protein in human breast cancer correlates with in vitro resistance to doxorubicin and mitomycin C

BACKGROUND

The cycle regulatory protein p27, an inhibitor of cyclin-dependent kinase (CDK), has been attributed a role in resistance to cancer chemotherapy. However, the predictive value of p27 for chemosensitivity of breast cancer is still unclear. We therefore analyzed the in vitro chemosensitivity to a series of anticancer agents in fresh breast cancer specimens and correlated it with the respective expression levels of p27.

MATERIALS AND METHODS

The expression of p27 protein was examined immunohistochemically in 119 patients with primary breast cancer. The in vitro chemosensitivity was assessed by the histoculture drug response assay (HDRA) using mitomycin C (MMC), 5-fluorouracil (5-Fu), Doxorubicin (DXR), cisplatin (CDDP) and cyclophosphamide (CPA).

RESULTS

Fifty-six (47%) of the 119 patients demonstrated p27 overexpression. The susceptibility of DXR and MMC in tumors with high p27 expression was significantly higher than that in tumors with low p27 expression.

CONCLUSION

Immunohistochemical results regarding p27 might be therapeutically useful as an indicator of response to DXR and/or MMC based adjuvant chemotherapy for breast cancer.

Apoptotic neurodegeneration induced by influenza A virus infection in the mouse brain

Neurodegeneration in the brain induced by the WSN strain of influenza A virus was investigated after stereotaxic introduction into the olfactory bulb of C57BL/6 mice. Immunohistochemistry detected WSN virus-infected neurons in the anterior olfactory nucleus as early as day 3 postinfection. Thereafter, they became shrunken and showed loss of neurite-immunolabeling and chromatin condensation. Infected neurons died by day 12, degenerating into multiple small granular bodies. The terminal deoxynucleotidyltransferase-mediated dUTP nick end-labeling method demonstrated DNA fragmentation in infected neurons at day 7 and also in such granular bodies at day 12. In perforin-deficient mice, the appearance of virally induced apoptotic neurodegeneration was delayed and virus infection continued for a longer period of 35 days postinfection. These findings indicate that perforin-mediated neuroapoptosis appears significant in exterminating the intracellular pathogen at an early stage of infection.

Active allele loss of the androgen receptor gene contributes to loss of androgen receptor expression in female breast cancers

Given the importance of androgen and androgen receptor (AR) in the control of female breast growth and the potential association with female breast cancer, we evaluated the AR expression in 114 female breast cancers and further analyzed why AR expression was lost. Immunohistochemical analysis revealed that 14.1% (17/114) of the tumors lost the AR expression completely. To unravel the molecular mechanism for AR expression loss, we first analyzed the somatic mutations in exons 2 through 8 of the AR gene by PCR-SSCP, but no mutation was detected. As the CAG repeats within exon 1 are also microsatellite markers, we then analyzed whether allelic loss was present. Interestingly, 11 of the 17 AR-negative tumors were heterozygous and 9 of them showed allelic loss. The lost allele was further demonstrated to be the active one by X-chromosome inactivation analysis. To confirm the immunohistochemical results, Northern and Western blot hybridization was performed and neither AR mRNA nor protein was detected in these AR-negative tumors. Loss of the active AR allele was strongly correlated with the AR expression loss (P = 0.0005). We conclude that AR expression loss is attributed to the active allele loss of AR gene in female breast cancers. Our finding may be also crucial in predicting and influencing the response of breast cancer to endocrine therapy.

Application of hydrostatic pressure facilitates ex vivo adenovirus gene transfer into rabbit aortas

We investigated whether application of hydrostatic pressure facilitates ex vivo adenovirus gene transfer into rabbit aortas. Assay of beta-galactosidase activity was performed in the aortas subjected to adenovirus encoding LacZ gene (Ad-LacZ) transfer. Application of hydrostatic pressure at 8 atmospheres during Ad-LacZ gene transfer (10(10) pfu/mL, 10 min) to aortic segments resulted in an approximately 4.5-fold increase in transgene efficiency. X-Gal staining showed predominant beta-galactosidase activity in the endothelial and the adventitial cells in the aorta subjected to pressure-supported Ad-LacZ gene transfer. Then we examined the effect of heme oxygenase-1 (HO-1), which catabolizes heme to carbon monoxide and biliverdin, by transferring adenovirus encoding HO-1 (Ad-HO-1) into rabbit aortas using this pressurization system. The Ad-HO-1-infected aortic segment showed a significantly decreased contractile response to phenylephrine compared to the Ad-LacZ-infected aortic segment. Pressure-supported adenovirus gene transfer may increase the feasibility of exploiting intraoperative adenovirus-mediated gene transfer.

The senescence-accelerated mouse shows aging-related defects in cellular but not humoral immunity against influenza virus infection

The senescence-accelerated mouse (SAM) strain P1, which has a short life span, was adopted as a murine model for an investigation of the pathogenesis of viral infection in elderly adults. After intranasal inoculation with influenza A virus, the SAM-P1 mice showed a higher rate of mortality, with prolonged virus growth in the lungs. The increased susceptibility was associated with impaired activity of both NK cells and virus-specific cytotoxic T lymphocytes. The production of interferon-gamma and interleukin-12 was significantly restrained, which suggests a partial deficiency of the T helper (Th) 1 cells. In contrast, the immunologic activity of the Th2 cells appeared to be functionally normal, judging from the release of large amounts of interleukin-4 followed by production of appropriate amounts of influenza virus-specific antibody. It is suggested that the elicitation of cellular immunity is an important and effective procedure for protecting the elderly from influenza virus infection.

Heme oxygenase-1 is upregulated in the rat heart in response to chronic administration of angiotensin II

Heme oxygenase (HO) is a heme-catabolizing enzyme that converts heme into biliverdin, iron, and carbon monoxide. HO-1, an inducible form of HO, is thought to act as an endogenous antioxidant defense mechanism. To determine whether chronic administration of angiotensin II affects HO-1 expression in the heart, expression and localization of HO-1 were investigated in the heart of rats receiving angiotensin II infusion (0.7 mg. kg(-1). day(-1)) via osmotic minipump for up to 7 days. Angiotensin II induced formation of granulation tissue, characterized by myofibroblast proliferation, fibrous deposition, and inflammatory cell migration. Angiotensin II also upregulated cardiac HO-1 expression. Immunohistochemistry revealed that HO-1 was intensively expressed in the granulation tissue. The selective AT(1)-receptor antagonist, losartan, completely, but hydralazine only partially, suppressed angiotensin II-induced granulation tissue formation and HO-1 upregulation. Chronic norepinephrine infusion (2.8 mg. kg(-1). day(-1)) did not induce granulation tissue formation or HO-1 upregulation. Our data suggest that angiotensin II upregulates cardiac HO-1 expression in the newly formed inflammatory lesion, which may represent an adaptive response to angiotensin II-induced cardiac damage.

Egg-adapted replication-restricted virus protects mice against lethal influenza

Infection of mice with the egg-adapted (EA) strain of influenza virus was studied as a murine model of human live attenuated virus vaccine. The growth and spread of the EA virus in the mouse lungs were restricted, and only small inflammatory changes were detected in the respiratory tracts. Deletion and substitutions of amino acids were found in the hemagglutinin molecule of the EA virus, which were attributable to the reduced envelope fusion activity in virus multiplication cycles. Intranasal inoculation of mice with the EA virus induced specific IgG and IgA antibody production together with a specific cytotoxic T lymphocyte response. Immunized mice showed a distinct resistance to subsequent lethal challenge with the virulent influenza virus. These results indicate that the mutant virus loaded with a growth restriction in the respiratory tract is an appropriate candidate for a live attenuated vaccine.

[Feasibility study of SPECT quantification using CdTe semiconductor detector]

Quantification of SPECT using CdTe semiconductors as a detector head in nuclear medicine equipment was investigated. A prototype of semiconductor detectors with an effective field-of-view as small as 2.54 cm x 5.08 cm was constructed, and a cylindrical phantom containing four spherical phantoms with capacities 71, 56, 42, and 15 ml, was used. Water was placed in three of these spherical phantoms (71, 56, and 42 ml), and 8.362 MBq of 99mTc was poured into the remaining 15 ml phantom. In the outer cylindrical phantom, 925 MBq (6200 ml) of 99mTc was placed. A Toshiba LEHR (Low Energy High Resolution) collimator was attached to the semiconductor detectors, and SPECT acquisition with a rotation radius 132 mm was performed. It was found that in the data thus acquired using the semiconductor detector, the amount of scattered gamma-rays decreased by 33% as compared to data acquired using NaI(Tl) scintillators under the same condition. Moreover, when attenuation correction was applied to SPECT data from the CdTe semiconductor detector, the measurement accuracy of radioactivity improved by 16% as compared to SPECT data from NaI(Tl) scintillators with the same acquisition and post-correction conditions. Finally, the CdTe detector data with only attenuation correction was found to have almost the same grade of accuracy as NaI scintillator data with both attenuation and TEW scatter corrections.