Masked prosthetic graft to sigmoid colon fistula diagnosed by 18-fluorodeoxyglucose positron emission tomography.

The diagnosis of low grade prosthetic graft infection or aorto-enteric fistula is difficult using conventional radiographic imaging modalities. We report a case of aorto-enteric fistula to the sigmoid colon diagnosed by the new technique of 18-fluorodeoxyglucose positron emission tomography.

Benign variations and incidental abnormalities of myocardial FDG uptake in the fasting state as encountered during routine oncology positron emission tomography studies.

Increased 18fluoro-2-deoxyglucose (FDG) uptake in the myocardium is frequently observed while performing clinical positron emission tomography (PET) body scans for oncology under fasting conditions. This article reviews the normal variations and abnormal appearances of myocardial FDG accumulation which are likely to be encountered in the routine PET studies. Knowledge about the myocardial glucose metabolism and specific abnormalities are indispensable in the interpretation of myocardial FDG uptake.

Glucose utilization in the inferior cerebellar vermis and ocular myoclonus.

In a patient with symptomatic ocular myoclonus, the authors observed the regional cerebral metabolic rate of glucose use (rCMRGlu) before and after successful treatment with clonazepam. Even after the symptoms resolved, the rCMRGlu in the hypertrophic olive increased persistently, whereas that in the inferior cerebellar vermis contralateral to the hypertrophic olive decreased. The inferior cerebellar vermis, belonging to the vestibulocerebellar system, may be associated with the generation of symptomatic ocular myoclonus.

Microalbuminuria and deterioration of renal function after elective repair of infrarenal abdominal aortic aneurysm.

AIMS: Renal dysfunction affects the prognosis of patients after aortic surgery. However, the factors associated with the postoperative deterioration of renal function has not been clarified precisely. METHOD: We prospectively examined renal function in 80 patients (age: 73 +/- 7 years, 66 males) who required the elective repair of infrarenal abdominal aortic aneurysm (AAA). Serum creatinine (Scr) was measured. 24-h-creatinine clearance (Ccr) and urinary albumin excretion (UAE) were determined. Renal volume and mean renal length were calculated using the data obtained by ultrasonography. 48 patients showed normal UAE (< 30 mg/day), and 24 had microalbuminuria (30-300 mg/day) and 8 had overt proteinuria (> 300 mg/day). Scr were 0.9 +/- 0.4, 1.0 +/- 0.3 and 2.1 +/- 1.3 mg/dl, respectively. RESULTS: On Day 5 after surgery, 12 patients (15%) showed deterioration of renal function as defined either by an increase in Scr (> or = 0.5 mg/dl) or by a decrease in Ccr > or =20%). The acute deterioration of renal function was related to mean renal volume, mean renal length, duration of operation and the use of antibiotics. At Month 12 after surgery, Scr increased in the overt proteinuria group. The deterioration of renal function at Month 12 was found in 8 patients (10%) with microalbuminuria or overt proteinuria, and related to preoperative Ccr, UAE, mean renal volume, mean renal length, smoking status and blood pressure. CONCLUSION: We conclude that the deterioration of renal function occurred in considerable number of patients with AAA after elective operation on acute and chronic phase, although the development of end-stage renal failure is rare. Factors related to the acute and late deterioration appears to be different. UAE and renal size should be measured, even if Scr is in normal range at preoperative observation.

Radionuclide imaging metabolic activity of brown adipose tissue in a patient with pheochromocytoma.

We describe a patient with extra-adrenal pheochromocytoma and high plasma norepinephrine levels. Radionuclide images of this patient obtained using (18)F-fluorodeoxyglucose and (123)I-metaiodobenzylguanidine revealed bilateral tracer accumulation in the shoulder and lower neck. The regions of radiotracer uptake corresponded to the location of human brown adipose tissue (BAT). Excessive sympathetic stimulation by high circulating catecholamine concentrations augmented the metabolic activity and tracer uptake in the BAT. This study showed that radionuclide imaging can noninvasively visualize human BAT in terms of metabolic and functional activity.

Transgenic mice expressing the human C99 terminal fragment of betaAPP: effects on cytochrome oxidase activity in skeletal muscle and brain.

In order to furnish a combined model of relevance to human inclusion-body myopathy and Alzheimer's disease, transgenic mice expressing human betaAPP-C99 in skeletal muscle and brain under the control of the cytomegalovirus/beta-actin promoter were produced (Tg13592). These transgenic mice develop Abeta deposits in muscles but not in brain. Cell metabolic activity was analyzed in brain regions and muscle by cytochrome oxidase (CO) histochemistry, the terminal enzyme of the electron transport chain. By comparison to age-matched controls of the C57BL/6 strain, CO activity was selectively increased in dark skeletal muscle fibers of Tg13592 mice. In addition, only increases in CO activity were obtained in those brain regions where a significant difference appeared. The CO activity of Tg13592 mice was elevated in several thalamic nuclei, including laterodorsal, ventromedial, and midline as well as submedial, intralaminar, and reticular. In contrast, the groups did not differ in most cortical regions, except for prefrontal, secondary motor, and auditory cortices, and in most brainstem regions, except for cerebellar (fastigial and interpositus) nuclei and related areas (red and lateral vestibular nuclei). No variation in cell density and surface area appeared in conjunction with these enzymatic alterations. The overproduction of betaAPP-C99 fragments in brain without (amyloidosis did not appear to affect the metabolic activity of structures particularly vulnerable in Alzheimer's disease.

Transgenic mice overexpressing both amyloid beta-protein and perlecan in pancreatic acinar cells.

Heparan sulfate proteoglycans such as perlecan are thought to facilitate amyloid fibril formation. Tg3695 mice overexpress perlecan core protein in many tissues including the brain and pancreas. Tg13592 mice overexpress the signal plus 99-amino acid carboxyl terminal sequences (C99) of amyloid beta-protein precursor in multiple tissues and develop amyloid deposits in the pancreas. To investigate a role of perlecan in beta-amyloidosis, we established doubly transgenic mice by crossing the two lines of transgenic mice. The expression levels of the two transgenes remained unchanged in the brain and pancreas and the doubly transgenic mice did not develop amyloid deposits in the brain up to 19-months of age. Amyloid load detected by thioflavine S in the pancreas of the doubly transgenic mice was not significantly different from that in the transgenic littermates expressing only C99. Amyloid load in the pancreas increased during aging. We found a positive correlation between the Abeta-immunoreactive (non-fibrillar and fibrillar) and thioflavine S-positive (fibrillar) Abeta deposits in the single (C99) but not doubly transgenic mice. Our results suggest that perlecan does not independently influence amyloid formation in the pancreas of the transgenic mice and that there may be other factors that may modulate amyloid formation together with perlecan.

Apoptosis in human oral squamous cell carcinomas is induced by 15-deoxy-delta 12,14-prostaglandin J2 but not by troglitazone.

15-deoxy-Delta(12,14)-prostaglandin J(2) (15-d-PGJ(2)) and troglitazone have been shown to induce apoptosis in several carcinoma cell lines. However, apoptotic signaling pathways of these agents are poorly understood. We tested the hypothesis that peroxisome proliferator-activated receptor-gamma ligands such as these two agents will induce caspase-mediated apoptosis in human oral squamous cell carcinomas (SCC). Treatment of these cell lines with 15-d-PGJ(2) or troglitazone decreased cell viability in a time- and dose-dependent manner. 15-d-PGJ(2), but not troglitazone, induced apoptosis, and this effect was time-dependent. Exposure of cells to 20 micro M of 15-d-PGJ(2) initiated early cytochrome c release, followed by late caspase activation. Furthermore, co-treatment with caspase inhibitors such as Z-VAD-FMK or Z-DEVD-FMK of oral SCC cells that had been treated with 20 micro M of 15-d-PGJ(2) blocked apoptosis. Our study demonstrates that treatment with 15-d-PGJ(2), but not troglitazone, induces apoptosis in human SCC cell lines, and 15-d-PGJ(2) appears to work through cytochrome c release and caspase activation.

Analysis of c-myc DNA amplification in non-small cell lung carcinoma in comparison with small cell lung carcinoma using polymerase chain reaction.

Previous studies of c-mvc DNA amplification in lung cancer have focused primarily on analysis of small cell carcinoma or its tumor cell lines. There are few data about c-myc DNA amplification in histological types of lung cancer other than small cell carcinoma. Therefore the present study was conducted to investigate c-myc oncogene amplification in non-small cell lung carcinoma. We studied 46 lung tumor specimens for c-myc DNA amplification (15 adenocarcinomas, 15 squamous cell carcinomas, 6 large cell carcinomas, and 10 small cell carcinomas). Polymerase chain reaction, digoxigenin DNA labeling, and electrophoresis were utilized to investigate the c-myc copy number in the lung tumor specimens. The c-myc copy number of non-small cell carcinoma ranged from 1.5 to more than 20.0 in adenocarcinoma and squamous cell carcinoma, and from 6.0 to 12.0 in large cell carcinoma. That of small cell carcinoma ranged from 1.8 to 12.0. The c-myc copy number of non-small cell carcinoma was significantly higher than that of small cell carcinoma (Wilcoxon rank sum test, Z=2.06 P=0.040). However, the differences in c-myc copy number among these four histological types were not statistically significant. Amplification of c-myc (more than 4 copies) was observed not only in small cell carcinoma but also in nonsmall cell carcinoma at similarly high frequency (12/15 in adenocarcinoma and squamous cell carcinoma, 6/6 in large cell carcinoma, and 9/10 in small cell carcinoma).

Production of hydrogen peroxide and methionine sulfoxide by epigallocatechin gallate and antioxidants.

Epigallocatechin gallate (EGCG) induced apoptosis-associated characteristics in human oral tumor cell lines more efficiently than ascorbates, gallic acid, vitamin K, flavonoids or steroidal saponins. Since catalase partially inhibited the cytotoxic activity of EGCG, the possible involvement of hydrogen peroxide (H2O2) in cell death induction was investigated, using TCPO chemiluminescence method. Production of H2O2 by EGCG, sodium ascorbate, gallic acid or catechin reached a maximum level within 30 minutes, and was increased up to a plateau level above pH 8. Under optimal conditions, 1 mM EGCG was converted to 1 mM H2O2. At neutral pH, EGCG produced the highest amount of H2O2, followed by gallic acid, sodium ascorbate and catechin. EGCG produced methionine sulfoxide from methionine in the culture medium, while the methionine oxidation by EGCG was significantly reduced in the presence of serum. ESR spectroscopy showed that EGCG, gallic acid and sodium ascorbate, but not catechin, produced radicals under alkaline condition and that all these compounds scavenged superoxide anion, produced by hypoxanthine-xanthine oxidase reaction. EGCG also effectively scavenged the ascorbate and gallate radicals, more efficiently than other compounds. These data suggest that the apoptosis induction by EGCG may be mediated by H2O2 produced in the culture medium.

Synergistic effect of CGS16949A and 5-fluorouracil on a human breast cancer cell line.

The effects of the aromatase inhibitor, CGS16949A, and the fluoropyrimidine, 5-fluorouracil (5-FU), on cell cycle distribution and growth were studied using FACS analysis and MTT assay in the human breast cancer cell line, SK-BR-3. CGS16949A induced an increase in the G0-G1 fraction on SK-BR-3 cells, and the growth inhibition rate of the combination of both (65.7 +/- 3.0%) was significantly higher than 10 nM CGS16949A (37.9 +/- 6.9%) or 100 microg/ml 5-FU (45.6 +/- 4.5%); p < 0.01). Administering 5-FU after preincubation with CGS16949A significantly increased the combined cytotoxic efficacy, suggesting that clinical therapy using this combined therapy may be more efficient.

Overproduction of perlecan core protein in cultured cells and transgenic mice.

Heparan sulphate proteoglycan (HSPG) and amyloid P component are the only macromolecules consistently associated with all varieties of amyloid, irrespective of the type of amyloid protein, suggesting that HSPG may play a pathogenetic role in amyloid formation through a common mechanism. In the case of Alzheimer's disease (AD), HSPG, such as perlecan, co-accumulates with amyloid-beta protein (Abeta), a main constituent of amyloid plaques, and paired helical filaments (PHFs). Additionally, in vitro, HSPG accelerates both Abeta fibril and PHF formation and protects Abeta from degradation. Therefore, this study first established lines of P19 mouse embryonic carcinoma cells stably carrying an expression vector encoding the complete perlecan core protein (approximately 400 kD). In the cell lysates, overexpressed perlecan was identified as an approximately 400 kD protein without glycosaminoglycan side-chains, while in the media, secreted perlecan was mostly glycosylated, suggesting that the secretion and glycosylation of perlecan are coupled. Next, transgenic mice were produced using the same expression vector. Marked perlecan overexpression occurred in the cytoplasm of multiple tissues including the brain, heart, kidney, and pancreas, without a discernible increase of perlecan in extracellular matrices. The transgenic mice up to 18 months of age did not develop amyloid or AD-like pathology in the brain or elsewhere, based on histochemical and immunohistochemical analyses. Thus, overproduction of perlecan core protein is insufficient to lead to amyloidosis and AD-like pathology.

Changes in perfusion and fatty acid metabolism of rat heart with autoimmune myocarditis.

To elucidate the change in perfusion and aerobic metabolism in myocarditis, tissue counting and dual tracer ex vivo autoradiography with Tl-201 and a free fatty acid analog, I-123- or I-125-labeled (p-iodophenyl)-methyl-pentadecanoic acid (BMIPP), were performed in rats with myocarditis induced by immunization with cardiac myosin. Inflammatory damage was classified histologically. At the acute stage (2-4 weeks after the antigen-injection), total heart uptakes of Tl and BMIPP and the ratio (BMIPP/Tl) were significantly reduced in myocarditis rats (N = 15) compared with the controls (N = 12). Myocardial distribution of Tl and BMIPP was not homogeneous. Relative uptake of Tl and BMIPP (N = 9, 128 regions) was gradually decreased with the extent of inflammation, and the regional BMIPP/Tl was smaller than the control. At the subacute stage (7 weeks after the antigen-injection), total Tl uptake in myocarditis rats (N = 5) recovered to the control level (N = 4), but that of BMIPP was still significantly lower than the control. BMIPP/Tl was still significantly lower in myocarditis. Myocardial distribution of Tl and BMIPP recovered to be more homogeneous. Relative uptake of Tl and BMIPP (N = 6, 78 regions) still gradually but significantly decreased with the extent of inflammation. Regional BMIPP/Tl was still depressed in myocarditis. These results indicate that myocardial perfusion and aerobic metabolism were discrepant and heterogeneously suppressed with severe inflammation during the acute stages, but the difference decreases with time. Examination with Tl-201 and BMIPP may provide information about the severity of myocarditis.

Heterodimerization of Bcl-2 and Bcl-X(L) with Bax and Bad in colorectal cancer.

The rate of cell loss owing to apoptosis is mediated by competitive dimerization with selective pairs of cell death antagonists (Bcl-2, Bcl-X(L)) and agonists (Bax, Bad). The aim of this study was to investigate which Bcl-2 family dimers had a critical factor in colorectal cancer. We analyzed the expression of Bcl-2, Bcl-X(L), Bax, and Bad in normal-appearing mucosa and colorectal tumor tissues by Western blotting after immunoprecipitation. Compared with the ratio of Bax-Bcl-2/total Bax in normal mucosa, the ratio was significantly reduced in tumors (p = 0.02). In this series, the low ratio of Bad-Bcl-2/total Bcl-2 was associated with advanced tumor stages (p = 0.02). A reduced heterodimerization of Bax with Bcl-2 may contribute to the development of colorectal cancer. The heterodimerization of Bad with Bcl-2 may be repressed in advanced tumor tissues, and may contribute to tumor growth in colorectal cancer.

Accumulation of amyloid-beta protein in exocrine glands of transgenic mice overexpressing a carboxyl terminal portion of amyloid protein precursor.

Amyloid-beta protein (Abeta) and its precursor (betaPP) play important roles in the pathogenesis of Alzheimer disease and inclusion-body myositis. In humans, Abeta deposits are found in brain, skeletal muscle, and skin. Therefore, we have investigated possible Abeta deposits in multiple tissues of two transgenic mouse lines overexpressing the signal plus Abeta-bearing 99-amino acid carboxyl terminal sequences of betaPP under the control of a cytomegalovirus enhancer/beta-actin promoter. One of the lines developed Abeta-immunoreactive intracellular deposits consistently in the pancreas and lacrimal gland, and occasionally in gastric, DeSteno's, and lingual glands. Although the Abeta deposits increased during ageing and degenerative changes of the tissues were observed, little or no extracellular Abeta deposits were observed up to the age of 25 months. These lines of transgenic mice are useful for studying the molecular mechanisms of development and clearance of intracellular Abeta deposits.

The effect of an oral administration of Lactobacillus casei strain shirota on azoxymethane-induced colonic aberrant crypt foci and colon cancer in the rat.

The preventive effect of oral administration of viable Lactobacillus casei strain Shirota (LcS) on azoxymethane (AOM)-induced colonic aberrant crypt foci (ACF) and colon cancers in the rat was investigated. The study consisted of two experiments; in a short-term experiment (Exp-I), the inhibitory effect of 8- and 12-week treatments with LcS. Forty rats each received weekly a subcutaneous injection of AOM at a dose of 15 mg/kg of body weight for 5 weeks. Eight and twelve weeks after the start of the carcinogen treatment, each subgroup of rats were sacrificed, and the colon and the mesenteric lymph nodes (MLN) were removed. The number of ACFs and the surface marker of lymphocytes derived from the MLN were investigated. The large ACF (those comprising four or more aberrant crypts per focus) had significantly decreased in the rats which had consumed the LcS diet. And oral administration of viable LcS significantly recovered CD8 positive lymphocytes to the levels in the control group. In a long-term experiment (Exp-II), 30 rats each received weekly a subcutaneous injection of AOM at a dose of 7. 4 mg/kg of body weight for 10 weeks. Twenty-five weeks after the start of the carcinogen treatment, each subgroup of rats were sacrificed, and the colon were removed. The number and incidence of colon cancers were investigated. The number of rats with colon cancers and the number of colon cancers per rat, were significantly decreased in the rats which had consumed the LcS diet. LcS inhibited chemically-induced colon carcinogenesis in the rat. CD8 positive T lymphocytes may play a key role in the preventive effect against colon carcinogenesis.