Spontaneous isolated dissection of the superior mesenteric artery and aneurysm formation resulting from segmental arterial mediolysis: a case report.

BACKGROUND: Spontaneous isolated dissection of the superior mesenteric artery (SMA) can lead to bowel ischemia, aneurysm rupture, or even death. Studies have suggested that mechanical or hemodynamic stress on the vascular wall of the SMA may be a contributor, but its pathogenesis is unclear. CASE PRESENTATION: A 57-year-old Japanese man with a history of untreated hypertension and hyperuricemia was admitted to our hospital with the sudden onset of severe epigastric pain. Laboratory findings showed elevated white blood cell count and C-reactive protein, and contrast-enhanced computed tomography (CT) of the abdomen demonstrated arterial dissection with luminal stenosis and aneurysm formation at the distal portion of the SMA after the branching of the jejunal artery, and intravenous nicardipine was administered. The patient's epigastric pain resolved spontaneously but recurred on day 6 of his hospital stay. Contrast-enhanced abdominal CT revealed an enlarged aneurysm with wall thinning. Because of the risk of aneurysm rupture, the decision was made to perform aneurysmectomy and bowel resection on day 6. Histologic examinations revealed two separate dissecting lesions: one latent and the other resulting in aneurysm formation. Both lesions showed characteristics of segmental arterial mediolysis (SAM) with lack of arterial media, absence of internal and external elastic laminae and intimal proliferation. CONCLUSIONS: Histologic findings in the present case suggest that mechanical or hemodynamic stress on the vascular wall and SAM-related vascular vulnerability may concomitantly contribute to the onset of isolated SMA dissection.

A phase II study of weekly paclitaxel and doxifluridine combination chemotherapy for advanced/recurrent gastric cancer.

BACKGROUND: Paclitaxel and doxifluridine (5'-DFUR) have distinct mechanisms of action and toxicity profiles. This study evaluated the antitumor activity and toxicities of combination chemotherapy with these drugs in patients with advanced/recurrent gastric cancer (AGC). PATIENTS AND METHODS: Patients with histologically confirmed AGC, which was either unresectable or metastatic, were included in this study. The treatment consisted of 80 mg/m² paclitaxel given i.v. on days 1, 8, and 15 every 4 weeks, and 533 mg/m² doxifluridine given orally on days 1-5 every week. RESULTS: One hundred and four patients were evaluated for toxicity and 93 patients were evaluated for a therapeutic response. The overall response rate was 33.3% (1st line: 41.7%, 2nd line: 25.0%), including a complete remission in two patients, a partial remission in 29, stable disease in 39, progressive disease in 17; the response was not evaluable in six patients. The median overall survival was 287 days. Commonly observed grade 3/4 adverse events were leukopenia (13.5%), anorexia (3.8%), fatigue (3.8%) and diarrhea (2.9%). CONCLUSION: Paclitaxel and doxifluridine combination chemotherapy is a well-tolerated and convenient treatment regimen that can be given on an outpatient basis with promising efficacy for AGC.

The effects of a cyclooxygenase-2 inhibitor, FK3311, on total hepatic ischemia-reperfusion injury of the rat.

BACKGROUND/AIMS: This study was designed to investigate the effects of a selective cyclooxygenase-2 inhibitor, FK3311, on warm ischemia-reperfusion injury of the rat liver. METHODOLOGY: Male Sprague-Dawley rats were used in this experimental study. Total hepatic ischemia was induced with a clamping portal triad. The animals were divided into two groups: the control group and the FK group, in which FK3311 (FK, 1.0 mg/kg) was administered via the penile vein. The serum levels of aspartate aminotransferase (AST), alanine aminotransferase (ALT), and lactate dehydrogenase (LDH) were measured 2 h after reperfusion, while those of thromboxane (Tx) B2 and 6-ketoprostaglandin (PG) F1alpha (stable metabolites of TxA2 and PGI2) were measured 30 min after reperfusion. The liver tissue blood flow was measured at preischemia, end-ischemia, and 30, 60, 90, and 120 min after reperfusion. The liver tissues obtained from animals at 2h after reperfusion were excised for histopathology. RESULTS: The serum levels of AST, ALT, and LDH were significantly lower in the FK group than in the control group. Similarly, in the FK group, the serum levels of TxB2 were significantly lower than in the control group. By contrast, the 6-keto-PG F1a levels were not significantly reduced. The liver tissue blood flow at 120 min after reperfusion was significantly higher in the FK group than in the control group. The histopathological study showed that hepatic tissue damage was milder in the FK group than in the control group. CONCLUSIONS: FK has protective effects on hepatic ischemia-reperfusion injury stemming from the marked inhibition of TxA2.

[A retrospective study of irinotecan plus fluorouracil and l-leucovorin chemotherapy for advanced and metastatic colorectal cancer].

We have treated 14 advanced and metastatic colorectal cancers with irinotecan (CPT-11) plus fluorouracil (5-FU) and l-leucovorin (l-LV) combination chemotherapy. The 14 patients consisted of 8 males and 6 females with a mean age of 65 years. We diagnosed adenocarcinoma of the colon in 10 patients and of the rectum in 4 patients. Four patients had liver metastases, five had lung metastases, and one had both, while one had lung and lymph node metastases, two had lymph node metastases and one had a local recurrence. The chemotherapy consisted of CPT-11 100 mg/m(2) div, as a 150-minute infusion, simultaneously l-LV 10 mg/m(2) div, as a 30-minute infusion, followed by 5-FU 500 mg/m(2) iv, as a bolus injection. This treatment was administered weekly for 2 weeks followed by a 2-week rest period and repeated every 4 weeks. All patients received this regimen as first-line chemotherapy. All patients were evaluated for efficacy 1 CR, 2 PR, 9 SD, and 2 PD. The overall response rate was 21.4% with a median time to progression of 8.1 months and a median survival time of 18.6 months. Grade 3 nausea, diarrhea and the suppression of white blood cells were seen in 3 patients, respectively. All other adverse reactions were mild (grade 1 or 2). Except for one patient,residual patients were able to receive the systemic chemotherapy on schedule. CPT-11/5-FU/l-LV combination chemotherapy appears to be effective first-line chemotherapy for advanced and metastatic colorectal cancer.

The role of mitogen-activated protein kinases and the participation of intestinal congestion in total hepatic ischemia-reperfusion injury.

BACKGROUND/AIMS: The mitogen-activated protein kinase (MAPK) pathways are comprised of key regulatory proteins that control the cellular responses to both proliferation and stress signals. This study was performed to examine the degree of liver damage and MAPK activation induced by ischemia of varying durations, and the association between intestinal congestion and liver dysfunction after hepatic ischemia-reperfusion injury. METHODOLOGY: Male Sprague-Dawley rats were divided into five groups: sham-operated controls (no hepatic ischemia); 15, 30, or 45 min of total hepatic ischemia; or 45 min of total hepatic ischemia with a portosystemic shunt. Serum levels of aspartate aminotransferase, alanine aminotransferase, lactate dehydrogenase, interleukin-1beta and tumor necrosis factor-alpha, as well as liver tissue blood flow were measured. Liver was also sampled for MAPK analysis and histopathological examination. RESULTS: Total hepatic ischemia for over 30 min, with intestinal congestion, caused severe liver damage and an inflammatory cytokine response. A portosystemic shunt attenuated ischemia-reperfusion injury and inhibited inflammatory cytokine expression. Extracellular signal-regulated kinase was markedly phosphorylated in all groups other than the sham-operated group. p38 MAPK and c-Jun N-terminal kinase were highly phosphorylated in all groups receiving 30 min or more of ischemia. CONCLUSIONS: Prolonged warm total hepatic ischemia-reperfusion injury is associated with small intestinal congestion; a portosystemic shunt reduces liver damage by inhibiting inflammatory cytokine expression. MAPKs are markedly phosphorylated after reperfusion.

A dual inhibitor of TNF-alpha and IL-1 mitigates liver and kidney dysfunction and improves survival in rat endotoxemia.

BACKGROUND/AIMS: Endotoxin shock induces multiple organ dysfunction syndromes that are associated with a substantial increase in mortality. In this study, we evaluated the effect of FR167653, a potent suppressant of tumor necrosis factor-alpha (TNF-alpha) and interleukin-1 (IL-1) production, on lipopolysaccharide (LPS)-induced liver and kidney injury and lethality in rats. METHODOLOGY: Male Sprague-Dawley rats weighing from 200 to 270g received an injection of LPS. The FR group received an infusion of FR167653 at 0.2 mg/kg/hr, commencing 30 min prior to the LPS injection and continuing for 5.5 hr, while the control group received an infusion of a vehicle in the same fashion. Separate groups of animals were used for the survival study (n=5 each), and for blood sampling (n=5 each group, each time point). RESULTS: The FR group showed a significantly better survival rate'than the control group. Serum levels of GOT, Cr, and BUN were significantly lower in the FR group than in the control group. The elevation of TNF-alpha and IL-1beta at 2 hr after LPS administration was significantly lower in the FR group than in the control group. CONCLUSIONS: FR167653 administration is effective in decreasing serum TNF-alpha and IL-1beta levels and associated injury to liver and kidney caused by LPS-induced endotoxemia, as well as decreasing mortality.

A combination phase I study of weekly paclitaxel and doxifluridine in advanced gastric cancer patients.

BACKGROUND: Preclinical studies have shown that paclitaxel and doxifluridine can act synergistically without overlapping toxicity for the treatment of advanced gastric cancer. The objectives of this study were to determine the maximum tolerated dose (MTD), the dose-limiting toxicity and the recommended Phase II dose for this drug combination. PATIENTS AND METHODS: Patients with histologically confirmed gastric cancer were eligible for the study. The paclitaxel dose (days 1, 8, 15) was augmented with a fixed dose of for treatments (1-3). doxifluridine (533 mg/m2, 5 days/week) on a 28-day cycle. RESULTS: Eighteen patients were enrolled. The MTD was not reached until the highest dose level. One patient had Grade 3 myelosuppression. The responses of the 13 suitable patients included 1 complete response and 5 partial responses. CONCLUSION: Although the MTD level could not be definitively which is a established, upon consideration of the lengthy administration time and the effectiveness, the recommended Phase II dose of paclitaxel was concluded to be 80 mg/m2 in combination with doxifluridine at 533 mg/m2.

P38 mitogen-activated protein kinase inhibition attenuates ischemia-reperfusion injury of the rat liver.

BACKGROUND: Several studies have implicated the mitogen-activated protein kinase (MAPK) signal pathway in non-hepatic organ ischemia-reperfusion injury. However, the role of p38 MAPK in hepatic ischemia-reperfusion injury remains unclear. This study investigated the role of p38 MAPK in hepatic ischemia-reperfusion injury. METHODS: Male Sprague-Dawley rats were divided into 4 groups (sham, FR-only, control, and FR-treated groups). The animals in the control and FR-treated groups were subjected to 30 minutes of warm ischemia with congestion of the gut. The FR-only and FR-treated groups received FR167653 (FR), which is a novel p38 MAPK inhibitor. The serum levels of aspartate transaminase, alanine transaminase, lactate dehydrogenase, tumor necrosis factor-alpha (TNF-alpha), and interleukin-1beta (IL-1beta) were measured (each, n = 6). Liver tissue blood flow was measured at pre-ischemia, end-ischemia, and 30, 60, 90, and 120 minutes after reperfusion (each, n = 4). The liver tissues in the control and FR-treated groups were excised for p38 MAPK and c-Jun N-terminal kinase (JNK) analyses and histopathology (each, n = 4). RESULTS: Serum levels of aspartate transaminase, alanine transaminase, lactate dehydrogenase, TNF-alpha, and IL-1beta were significantly lower in the FR-treated group than in the control group, and liver tissue blood flow was significantly higher in the FR-treated group than in the control group. Histopathologically, tissue damage was milder in the FR-treated group than in the control group. Both p38 MAPK and JNK were markedly phosphorylated after 30 minutes of reperfusion, and FR inhibited the phosphorylation of p38 MAPK without affecting the JNK. CONCLUSIONS: FR decreased serum TNF-alpha and IL-1beta levels and liver injury associated with the inhibition of p38 MAPK activation. These results suggest that inhibiting the activation of p38 MAPK may attenuate warm ischemia-reperfusion injury of the liver.