Activation of stress signaling pathways by the end product of lipid peroxidation. 4-hydroxy-2-nonenal is a potential inducer of intracellular peroxide production

In the present study, we studied the signal transduction mechanism that is involved in the expression of c-Jun protein evident after exposure of rat liver epithelial RL34 cells to the major end product of oxidized fatty acid metabolism, 4-hydroxy-2-nonenal (HNE). HNE treatment of the cells resulted in depletion of intracellular glutathione (GSH) and in the formation of protein-bound HNE in plasma membrane. In addition, HNE strongly induced intracellular peroxide production, suggesting that HNE exerted oxidative stress on the cells. Potent expression of c-Jun occurred within 30 min of HNE treatment, which was accompanied by a time-dependent increase in activator protein-1 (AP-1) DNA binding activity. We found that HNE caused an immediate increase in tyrosine phosphorylation in RL34 cells. In addition, HNE strongly induced phosphorylation of c-Jun N-terminal kinases (JNK) and p38 mitogen-activated protein kinases and also moderately induced phosphorylation of extracellular signal-regulated kinases. The phosphorylation of JNK was accompanied by a rapid and transient increase in JNK and p38 activities, whereas changes in the activity of extracellular signal-regulated kinase were scarcely observed. GSH depletion by L-buthionine-S, R-sulfoximine, a specific inhibitor of GSH biosynthesis, only slightly enhanced peroxide production and JNK activation, suggesting that HNE exerted these effects independent of GSH depletion. This and the findings that (i) HNE strongly induced intracellular peroxide production, (ii) HNE-induced JNK activation was inhibited by pretreatment of the cells with a thiol antioxidant, N-acetylcysteine, and (iii) H2O2 significantly activated JNK support the hypothesis that pro-oxidants play a crucial role in the HNE-induced activation of stress signaling pathways. In addition, we found that, among the inhibitors of tyrosine kinases, cyclooxygenase, and Ca2+ influx, only quercetin exerted a significant inhibitory effect on HNE-induced JNK activation. In light of the JNK-dependent induction of c-jun transcription and the AP-1-induced transcription of xenobiotic-metabolizing enzymes, these data may show a potential critical role for JNK in the induction of a cellular defense program against toxic products generated from lipid peroxidation.

Resection of triple synchronous cancers: a case report

We herein present a case of synchronous triple cancer, which was successfully resected in a curative manner. These cancers consisted of primary duodenal, pancreatic and lung cancers, which were diagnosed in an asymptomatic 74 year-old male, who was referred to our department on December 14, 1996. On admission, his laboratory data showed no abnormality, including tumor markers (CEA 1.0, CA 19-9 1.0, AFP 8.1 U/ml), but he did show an impaired pulmonary function (FEV1.0: 57%). Upper gastrointestinal endoscopy showed a smooth surfaced duodenal tumor measuring 4 cm in size. The second tumor was found at the head of the pancreas by computed tomography (CT), showing a hypervascular mass measuring 3.0 cm, along with neighboring multiple cysts. In endoscopic retrograde cholangiopancreatography (ERCP), marked mucous secretion was observed through the papilla, while a filling defect was found in the dilated pancreatic duct. In a routine chest X-ray, a third tumor, which measured 1.5 cm in diameter, was recognized in the right upper lobe of the lung, and a moderately differentiated squamous cell carcinoma was also detected by a percutaneous CT guided biopsy. The pancreatic and duodenal tumors were surgically resected by a pancreatoduodenectomy (Stage I) in January 1997 and, 5 months later, a lung tumor underwent partial resection (Stage I). This patient tolerated these surgical procedures well and presently leads a normal, healthy life after discharge. In summary, a successful resection of synchronous triple cancers, which has never been previously reported in this specific combination, is described.

Alteration of mosaic methylation of the repeat unit of the human ribosomal RNA genes in lung cancer

We have investigated the methylation status of the repeat unit of the human ribosomal RNA genes in lung cancer. Using a Southern blot analysis approach we have determined that the non-transcribed region of these genes was generally heavily methylated, while the transcribed region was not methylated in either tumor or normal DNA. Our study also revealed that, in one tumor, the boundary of mosaic methylation of the repeat unit was not distinct. In the same tumor, both the non-transcribed ribosomal spacer region and the L1 interspersed repeat sequences became partially demethylated. In tumor cells, the methylation status of DNA can be altered, but the methylation of subtelomeric repeats was found to be maintained. These results suggest that the mosaic methylation of the repeat unit is not necessarily maintained in tumor DNA, while subtelomeric repeats escape tumor-specific wave of demethylation.

The isolation of CpG islands from human chromosomal regions 11q13 and Xp22 by segregation of partlymelted molecules

We isolated fragments containing parts of CpG islands from human chromosomal regions chosen for expected differences in gene density by segregation of partly melted molecules. Restriction fragments of P1 bacteriophage clones covering a region of 11q13 and those of cosmid clones derived from Xp22 were recovered from bands in denaturing gradient gels that were retained following prolonged exposure to electric field. Forty-five independent fragments derived from 11q13 and five from Xp22 were isolated. Nucleotide sequence analysis revealed that 11 of the 45 fragments from 11q13 contained CpG islands including four derived from known genes in 11q13. None of the five fragments derived from Xp22 resembled CpG islands. The number of CpG island fragments obtained was consistent with the expectation based on the number of Not I restriction endonuclease sites present at these regions. Adjustment of parameters in our quasi-theoretical approach to the rate of fragment dissociation improves the discrimination between retention and non-retention. The results support probable identification of CpG island fragments by their reduced rate of strand dissociation when retarded in a denaturing gradient gel.

Revision of ventriculo-peritoneal shunt under laparoscopic guidance in patients with hydrocephalus

Ventriculo-peritoneal (V-P) shunt is a common treatment for hydrocephalus. However, shunt insufficiency due to obstruction, dislocation, and detachment of the peritoneal tube is frequently encountered. We designed a new technique in which the peritoneal tube is inserted into a target site of the abdominal cavity under laparoscopic guidance. We operated on 9 patients with hydrocephalus using this technique. Shunt insufficiency of the peritoneal tube had been observed in all patients, and 7 patients had undergone repeated revision of the peritoneal tube before this procedure. Our laparoscopic-assisted method ensured tube insertion into the appropriate site, and minimized the abdominal wound and postoperative adhesions. This method also made it possible to differentiate abdominal pain induced by shunt failure from pain caused by other diseases, including appendicitis. In conclusion, we consider this new technique for V-P shunt performed under laparoscopic guidance to be very useful.

[Significance of percutaneous endoscopic gastrostomy (PEG) in home medical care]

In recent years, reflecting our aging society, the importance of home medical care has been recognized in view of medical economic and patients' needs. We are actively responding to this trend by positioning home medical care as a "new comprehensive medical care" and by organizing home medical care team. Percutaneous endoscopic gastrostomy (PEG) was developed by Ponsky et al. in 1980. While it has been widespread in Europe and America, it has not been much used in Japan yet. PEG does not require complicated hand skills. It is less invasive and sufficiently applicable to severe cases. Also, since the nursing management is easy, it can be carried out at home. It is an enteral feeding method with superb features as described earlier, in view of home medical care that attaches importance to the quality of life (QOL). In this research, we investigated hand skills for PEG and problems with PEG nutrition. Also, we referred to new possibilities for PEG in home medical care. The success of home medical care will depend on the introduction of PEG, which plays a key role in home medical care.

Detection of DNA abnormalities by arbitrarily primed PCR fingerprinting: allelic losses in chromosome 10q in lung cancers

DNA fingerprinting using arbitrarily primed PCR (AP-PCR) is useful for detecting cancer-specific DNA aberrations without targeting any particular genes or knowing any nucleotide sequences in advance. AP-PCR fingerprinting is an efficient method for finding loss of anonymous chromosomal regions in cancers. We analyzed DNA from 44 human non-small cell lung cancers by fingerprinting using a single primer and found a loss of signal intensity in a DNA fragment amplified from chromosome 10 (fragment F) in 15 tumors. The detailed location of the fragment F locus on chromosome 10q was determined by PCR-based analysis of radiation hybrid panels using a sequence-tagged site established for the fragment. In 12 of the 15 tumors, loss of the signal detected by AP-PCR fingerprinting was in agreement with the results obtained by analysis of allelic imbalances using 7 polymorphic CA-microsatellite DNA markers for loci around the fragment F locus (p=0.0009). We conclude that a hitherto unknown suppressor gene for lung cancer resides at 10q in the vicinity of fragment F.

Evaluation of cerebral perfusion from bypass arteries using selective intraarterial microsphere tracer after vascular reconstructive surgery

BACKGROUND AND PURPOSE

To detect areas of cerebral perfusion from bypass arteries after vascular reconstruction, we administered selective intraarterial microsphere tracer into the external carotid arteries and determined (via single-photon emission computed tomography [IA-SPECT]) whether the distribution of radiotracer matched the arteriographic distribution of contrast material as shown on external carotid angiograms.

METHODS

We compared the extent of regional distribution of tracer after external carotid artery injection of 20 to 40 MBq of 99mTc-HMPAO or 99mTc-ECD with that of contrast medium on the external carotid angiograms in 582 cortical regions in 12 patients with atherosclerotic occlusive disease and in 18 patients with moyamoya disease.

RESULTS

Marked accumulation of tracer was found only in the expected, specific, newly developed areas of cerebral perfusion from bypass arteries. The regional distribution of tracer corresponded to that of contrast medium in 523 regions (90%) and did not correspond in 59 regions (10%). Significant overestimation of the distribution of contrast material relative to that of tracer was observed in the patients with moyamoya disease.

CONCLUSION

SPECT showed slightly different distribution of tracer from that predicted by conventional angiography. IA-SPECT should enhance the analysis of newly developed areas of cerebral perfusion from the bypass arteries.

Perforation due to metastatic tumors of the ileocecal region

We reviewed our department's medical records between April 1986 and April 1994 to identify patients who showed acute abdominal symptoms requiring surgical treatment due to metastatic tumors of the small intestine. In group A, seven patients (30%) were treated for acute peritonitis, and all were found to have an intestinal perforation due to hematogenous metastases (group A). In group B, 16 patients (70%) were treated for an intestinal obstruction, and all were found to have disseminated tumors of the small intestine (group B). In group A all tumors were isolated and located exclusively in the ileocecal region, whereas all tumors in group B showed peritoneal dissemination, with no predominant anatomic localization. In general, the intestinal tumors in group A originated from cancers of the upper aerodigestive tract, whereas those in group B originated from advanced cancers in the abdominal cavity. The tumors were significantly smaller and the period between the onset of symptoms from the original malignancy and the onset of abdominal symptoms (perforation or obstruction) was significantly shorter in group A. In conclusion, intestinal metastases located in the ileocecal region have unique clinicopathologic features and so should be recognized as a distinct disease entity. Therefore when patients with a known upper aerodigestive malignancy exhibit acute abdominal symptoms, intestinal metastasis to the ileocecal region, necrotic changes, and perforation should be considered in the differential diagnosis.

Increase in histamine production by inflammatory exudate in the chronic phase of allergic inflammation in rats

In the air pouch-type allergic inflammation in rats, we reported that a sustained histamine production in the late phase is induced by a cytokine-like factor, named histamine-production-increasing factor (HPIF) (1). Recently, we found another type of histamine-production-increasing factor in the pouch fluid at the chronic phase of air pouch-type allergic inflammation. Although it did not increase histamine production by itself, it enhanced the HPIF-induced histamine production by rat bone marrow cells. It also increased GM-CSF-induced histamine production. The activity of this factor increased time-dependently from 3 to 7 days after the antigen challenge. Injection of the 5 day pouch fluid sample containing this factor into the pouch 4 h after the antigen challenge increased histamine contents in the pouch fluid at 24 h, indicating that this factor enhances HPIF-induced histamine production in vivo. Biochemical analysis of the 5 day pouch fluid sample indicated that this factor is a heat-labile and trypsin-sensitive protein of which pI value and molecular weight are 7-8 and about 100 kDa, respectively.

Combined hepatocellular and cholangiocellular carcinoma in a non-cirrhotic liver

Combined hepatocellular (HCC) and cholangiocellular carcinoma (CCC) (mixed carcinoma) is a rare subtype of primary hepatic carcinoma. We report a case of mixed carcinoma that developed in a non-cirrhotic liver, in a patient who was serologically negative for both hepatitis B and C viruses. A 65-year-old Japanese woman with a 25-year history of chronic rheumatoid arthritis had been treated with steroids and anti-inflammatory drugs, and was diagnosed by ultrasonography with an asymptomatic solitary tumor in the right lobe of the liver. On computed tomography scan and hepatic arteriography, the tumor was well enhanced by contrast medium in the early phase. Based on the findings of elevated serum alpha-feto protein (AFP, 245 ng/ml) and normal carcino-embryonic antigen (CEA, 2.6 ng/ml) levels, a preoperative diagnosis of hepatocellular carcinoma was made. Right lobectomy of the liver was performed on January 7, 1997. Histological examination showed that the resected tumor consisted of combined CCC cells and HCC cells in an intermingled form, with CCC being far more dominant than HCC. The tumor was therefore determined to be a combined carcinoma, subclassified as intermingled type. This case appears to indicate that mixed type carcinoma developed in a non-cirrhotic liver, with CCC being dominant; such a finding is extremely unusual, based on previously published reports.

Identification of histamine-production-increasing factor produced by stimulated RBL-2H3 rat basophilic leukemia cells as granulocyte-macrophage colony-stimulating factor

When RBL-2H3 rat basophilic leukemia cells were stimulated by antigen or the Ca2+ ionophore A23187, the activity to increase histamine production by rat bone marrow cells in the conditioned medium increased time-dependently. To characterize the histamine-production-increasing factor (HPIF) produced by RBL-2H3 cells, the conditioned medium was collected 8 h after stimulation by A23187, and the factor was purified by three-step chromatography, the specific activity being increased by 9000-fold. The partial amino acid sequence of the peptide obtained by S. aureus V8 protease digestion was identical to the internal amino acid sequence of rat granulocyte-macrophage colony-stimulating factor (GM-CSF). In addition, GM-CSF mRNA levels in RBL-2H3 cells were increased by A23187 with a peak at 4 h. Furthermore, recombinant rat GM-CSF increased histamine production by rat bone marrow cells. These findings suggested that HPIF produced by the stimulated RBL-2H3 cells is GM-CSF. Possible significant roles of HPIF at the late phase of allergic inflammation are discussed.

[Effect of hyaluronidase on porcine pancreatic elastase-induced lung injury]

The present study was conducted to investigate the effects of hyaluronidase on elastase-induced lung injury in rats. Male Wistar rats were divided into 4 groups: 1) Control group, single tracheal instillation of 0.3 ml saline; 2) PPE group, single tracheal instillation of 120 micrograms porcine pancreatic elastase (PPE); 3) HD group, intravenous injection of 240 mg/kg hyaluronidase (HD); and 4) HE + PPE group, intravenous injection of HD before single tracheal instillation of PPE. Cellular component and protein concentration in bronchoalveolar lavage fluid (BALF), myeloperoxidase (MPO) activity and hyaluronan content in lungs were examined 24 hours after treatment. After 8 weeks of treatment, hyaluronan content in the lungs and physiological parameters such as total lung capacity (TLC), functional residual capacity (FRC) and static compliance (Cst) were examined. The number of BALF nucleated cells in the HD + PPE group 6 h after treatment, and lung MPO activity in the HD group after 1 h and 3 h. were both higher than the corresponding measurements in the PPE group. After 6 h of treatment, the number of BALF nucleated cells in the HD + PPE group was significantly higher than in the HD group. The BALF albumin concentrations in the HD + PPE and HD groups were also significantly higher than in the control group. After 8 weeks of treatment, the measurements of TLC and Cst indicated greater emphysematous changes in the HD + PPE group. These results suggest that decreased interstitial HA accelerates acute inflammation and emphysematous changes in elastase-induced lung injury.