Enhanced Production of Nitric Oxide Leads to ATP Collapse in the Retinas of Otsuka Long-Evans Tokushima Fatty Rats, a Model of Human Diabetes.

PURPOSE: We determined nitric oxide (NO) production via inducible NO synthase (iNOS) by hyperglycemia using the retina of Otsuka Long-Evans Tokushima Fatty rats (OLETF rats), and investigated the relationship between ATP contents and NO production in the retinas of OLETF rats. METHODS: Long-Evans Tokushima Otsuka rats (LETO rats, normal rats) and OLETF rats (model rat for diabetes mellitus) aged 60 weeks of age were used. Plasma glucose (Glu) levels were determined using an Accutrend GCT System, and NO levels were measured by the microdialysis method as nitrite ([Formula: see text]). Cytochrome c oxidase (CCO) activity was measured using a Mitochondrial Isolation Kit and Cytochrome c Oxidase Assay Kit, and ATP levels were determined using a Sigma ATP Bioluminescent Assay Kit and a luminometer AB-2200. RESULTS: [Formula: see text] levels in the retinas of OLETF rats were significantly higher than in LETO rats, and the [Formula: see text] levels in the retinas of 60-week-old OLETF rats increased with increasing Glu. CCO activity in the retinas of OLETF rats showed no significant difference from that in LETO rats; however, ATP levels in the retinas of OLETF rats were significantly lower than those in LETO rats. The oral administration of aminoguanidine or disulfiram, an iNOS inhibitor, attenuated the decrease in ATP levels in the retinas of 60-week-old OELTF rats. CONCLUSION: The present study demonstrates that NO production via iNOS in the retinas of 60-week-old OLETF rats is caused by hyperglycemia, and that NO causes a decrease in ATP contents in the retinas of 60-week-old OELTF rats. It is possible that the low ATP contents caused by NO may affect the normal functioning of the retina in OLETF rats.

Pathological fracture due to vertebral osteonecrosis associated with pancreatitis.

A 50-year-old man with a history of alcohol-induced pancreatitis was admitted to a hospital with swelling and pain of the right ankle, and fever, and was suspected to have osteomyelitis. Radiographs of the fingers, ankles, and feet, in which pain and swelling were present, revealed multiple pathological fractures. The histological examination of the tissue sample in the right radius showed sequestrated fat necrosis. Bacterial culture test remained negative. Based on the findings mentioned above, a diagnosis of intraosseous fat necrosis associated with pancreatitis was made. Treatments proven to be effective in the literature for pancreatitis were started. Symptoms of the bones and joints gradually improved. However, pancreatitis relapsed, triggered by drinking, 4 months after discharge. He had complaints of back pain without any history of trauma. Radiographs showed fractures of the entire vertebral body from the 12th thoracic to 5th lumbar vertebrae. What was interesting about the present case was that, after the pathological fractures of the extremities were completely resolved, osteonecrosis relapsed as pancreatitis deteriorated, resulting in pancreatic cyst rupture into the intrathoracic cavity and vertebrae, differing from the previous lesions that were affected. There are very few cases of pathological fracture induced by pancreatitis that affect the vertebrae.

[Case of primary hepatic neuroendocrine carcinoma diagnosed by needle biopsy].

The patient was a 55-year-old man with a large hepatic tumor measuring 12 × 12 cm in the left lobe. To obtain the histological diagnosis, the target liver biopsy was performed. Histologically, the tumor revealed as a neuroendocrine carcinoma. After the diagnosis, he received the chemotherapy (CTX) with etoposide and cisplatin. Serum levels of NSE and the tumor size were decreased after the first course of CTX. We here report a case of primary hepatic neuroendocrine carcinoma treated with CTX following the diagnosis by the needle biopsy.

Poorly differentiated endocrine carcinoma of the pancreas responded to gemcitabine: Case report.

Poorly differentiated endocrine carcinoma (PDEC) of the pancreas is a rare and aggressive tumor. First-line treatment is commonly a combination of etoposide and cisplatin, but there is no consensus regarding further treatment recommendations. In this report, we describe a case of pancreatic PDEC treated with gemcitabine as third-line chemotherapy. A 62-year-old man with pancreatic PDEC was administered etoposide plus cisplatin as first-line treatment; he then received irinotecan for tumor relapse. However, because irinotecan induced ileus in this patient, we chose gemcitabine as third-line chemotherapy. After two cycles of gemcitabine (1000 mg/m(2) on days 1, 8 and 15 every 4 wk), a partial tumor response was noted by computed tomography (approximately 68% reduction in tumor size). Our patient survived for 15 mo after diagnosis. This is a rare case of unresectable pancreatic PDEC, which showed a partial response to gemcitabine after the failure of two other regimens. Gemcitabine could be an effective treatment option for pancreatic PDEC that is resistant to other treatments.

Tumor necrosis factor-alpha inhibits chondrogenic differentiation of synovial fibroblasts through p38 mitogen activating protein kinase pathways.

We previously reported that synovial fibroblast-like cells (SFs) can be differentiated into chondrocytes through activin receptor-like kinase (ALK) 3 activation. The aim of this study was to clarify the effect and signaling pathways of tumor necrosis factor (TNF)-alpha on the chondrogenic differentiation of SFs. Primary SFs from patients with rheumatoid arthritis (RA) were treated with recombinant human bone morphogenetic protein-2 or transduced with a constitutively active mutant of the ALK3 gene (ALK3CA) with or without TNF-alpha, and then cultured in pellets. Expression of chondrocyte-specific genes was analyzed by real-time polymerase chain reaction or by histological analysis. Inhibitors of mitogen-activating protein kinase (MAPK) pathways or adenovirus vectors carrying a dominant-negative mutant of the IkappaB kinase 2 gene (AxIKK2DN) were used to analyze the signaling pathways of TNF-alpha. Expression of chondrocyte-specific genes was induced in SFs either by rhBMP-2 treatment or by ALK3CA transduction, which was strongly suppressed by TNF-alpha treatment. TNF-alpha markedly increased the p38 MAPK pathways in SFs, and inhibition of p38 MAPK activation partially restored the inhibitory effect of TNF-alpha on the chondrogenic differentiation of SFs. Combination therapy BMP-2 and anti-TNF-alpha agents especially targeting p38 MAPK might be a good approach to stimulating neochondrogenesis in the damaged joints in RA.

Tumor necrosis factor-α inhibits chondrogenic differentiation of synovial fibroblasts through p38 mitogen activating protein kinase pathways.

We previously reported that synovial fibroblast-like cells (SFs) can be differentiated into chondrocytes through activin receptor-like kinase (ALK) 3 activation. The aim of this study was to clarify the effect and signaling pathways of tumor necrosis factor (TNF)-α on the chondrogenic differentiation of SFs. Primary SFs from patients with rheumatoid arthritis (RA) were treated with recombinant human bone morphogenetic protein-2 or transduced with a constitutively active mutant of the ALK3 gene (ALK3CA) with or without TNF-α, and then cultured in pellets. Expression of chondrocyte-specific genes was analyzed by real-time polymerase chain reaction or by histological analysis. Inhibitors of mitogen-activating protein kinase (MAPK) pathways or adenovirus vectors carrying a dominant-negative mutant of the IκB kinase 2 gene (AxIKK2DN) were used to analyze the signaling pathways of TNF-α. Expression of chondrocyte-specific genes was induced in SFs either by rhBMP-2 treatment or by ALK3CA transduction, which was strongly suppressed by TNF-α treatment. TNF-α markedly increased the p38 MAPK pathways in SFs, and inhibition of p38 MAPK activation partially restored the inhibitory effect of TNF-α on the chondrogenic differentiation of SFs. Combination therapy BMP-2 and anti-TNF-α agents especially targeting p38 MAPK might be a good approach to stimulating neochondrogenesis in the damaged joints in RA.