Microsatellite instability in precancerous lesions and adenocarcinomas of the stomach

BACKGROUND

It is generally known that replication errors (RERs) at microsatellite loci detected in human malignancies reflect a genetic instability that is caused by abnormalities of DNA mismatch repair system and underlie human carcinogenesis. The authors analyzed RERs in precancerous lesions and adenocarcinomas of the stomach to learn when genetic instability occurs in stomach carcinogenesis. In addition, the authors examined genetic instability occurs in stomach carcinogenesis. In addition, the authors examined genetic alterations of the p53 and adenomatous polyposis coli (APC) genes to investigate the correlation between genetic instability and genetic alterations in these tumor suppressor genes.

METHODS

The authors examined microsatellite assay at 9 microsatellite loci in 24 sporadic gastric cancers, 12 gastric adenomas, and 9 intestinal metaplasia mucosae of the stomach from patients with gastric cancers using fresh frozen or formalin fixed and paraffin embedded samples paired with normal mucosae. They also screened loss of heterozygosity (LOH) of the p53 and APC genes by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) analysis.

RESULTS

In total, the RER(+) phenotypes were observed in 8 of 24 (33%) gastric cancers, 5 of 12 (42%) gastric adenomas, and 3 of 9 (33%) intestinal metaplasia mucosae of the stomach. Histology, RERs were detected in 3 of 9 (33%) well differentiated adenocarcinomas, 2 of 11 (18%) poorly differentiated adenocarcinomas, and 3 of 4 (75%) scirrhous type gastric cancers respectively. Several cases showed RERs at many microsatellite loci simultaneously. Some RER(+) phenotypes had genetic alterations of the p53 or APC genes detected by LOH using PCR-RFLP analysis. However, no significant correlation was found between RER(+) phenotypes and LOH in these genes.

CONCLUSIONS

The frequency of RERs in detected gastric cancers were almost the same when compared with previously reported data. Interestingly, RERs were detected in greater than 30% of precancerous lesions, suggesting that genetic instability is an early somatic event of multistep stomach carcinogenesis. It also suggests that the adenoma-carcinoma sequence does exist in stomach carcinogenesis, especially in well differentiated adenocarcinomas. Moreover, alterations in the p53 and APC genes detected by PCR-RFLP analysis did not correlate with RER(+) phenotypes.

Calnexin: its molecular cloning and expression in the liver of the frog, Rana rugosa

A 2.2-kb cDNA clone encoding the endoplasmic reticulum (ER) resident protein, calnexin (CLX), was isolated from the frog Rana rugosa liver cDNA library and sequenced. The sequence encoded 622 amino acids and was 77% similar to mammalian CLXs and 56% to mouse CLX-t. In the phylogenetic tree, mouse CLX-t was clearly diverged from other CLXs including frog. The amino acid sequence of CLX showed regions similar to those in frog calreticulin (CLT), although CLX, but not CLT, contained a histidine-rich region at the NH2-terminus. CLX gene expression was observed only in the liver among various tissues examined. Additionally, its expression was strong in the liver in 2-month post-metamorphosis frogs, but very weak in adults. The results suggest that the CLX gene is expressed in a tissue- and stage-dependent manner in the frog, R. rugosa, and that CLX is widely distributed in eukaryotic organisms.

[A case of multiple pulmonary leiomyomatous hamartoma]

A 45-year-old woman with multiple pulmonary leiomyomatous hamartoma was reported. Multiple round shadows were observed in the chest X-ray film of mass examination. Retrospectively chest X-ray films revealed an increase in size and number of pulmonary nodules in three years. Metastatic pulmonary tumors were suspected. Primary site was unclear. Calcified myoma uteri was recognized. The pathological diagnosis under diagnostic thoracotomy was multiple leiomyomatous hamartoma. After ten months of medical castration using superactive analogue of LHRH (buserelin) by intranasal spray, chest X-ray film showed a slight decrease in size of nodular shadows in the right middle lung field.

[A case of benign multiple neurilemmomas in the mediastinum and the chest wall]

A 55-year-old female was admitted to our hospital because of the increase in the size of a left posterior mediastinal tumor after 5 years of observation. The patient also had a chest wall tumor on her left back which had 20 year's history. CT findings suggested the mediastinal tumor and the chest wall tumor were connected through the 4th intercostal space. Pathological specimen obtained by a needle biopsy of the chest wall tumor showed neurilemmoma-like lesion, but malignancy could not be ruled out. With a left posterolateral thoracotomy we removed the mediastinal tumor measuring 3 x 2.5 x 2.5 cm and the extra-thoracic chest wall tumor measuring 7 x 3.5 x 3.5 cm. Intra-operative findings showed these tumors arising from the 4 th intercostal nerve separately had no relevancy. Histological examination of both tumors revealed benign neurilemmoma. Postoperative clinical course was uneventful.

Detection of Proteus mirabilis urease gene in urinary calculi by polymerase chain reaction

BACKGROUND

Urea-splitting microorganisms cannot always be detected by stone or urine culture in patients with infection stones. Detection of genetic elements within the calculi by the polymerase chain reaction (PCR) may be a useful alternative. In this study, we assessed the usefulness of the PCR method in detecting the urease gene specific to Proteus mirabilis in urinary calculi.

METHODS

Thirty-eight metabolic stones (calcium oxalate and/or calcium phosphate, uric acid, or cystine) and 49 struvite stones were examined. The PCR was applied with DNA extracted by boiling pulverized stone pieces.

RESULTS

Of the 87 stones, PCR demonstrated the presence of the P. mirabilis urease elements ureC1 and ureC2 in 17, all of which were struvite. Stone culture and urine culture had been performed in 22 and 46 struvite stone cases, respectively, and the PCR was positive in all of the 10 culture-positive calculi and also in two calculi from which P. mirabilis was not isolated.

CONCLUSION

PCR was reliable and convenient for detecting P. mirabilis in desiccated struvite calculi. Study to detect other species such as Ureaplasma or Corynebacterium would be useful in elucidating the role of bacterial infection in the formation of these stones.

Detecting herpesvirus DNA in uveitis using the polymerase chain reaction

BACKGROUND

Herpesviruses are involved in the pathogenesis of many ocular diseases including keratitis, iridocyclitis, and acute retinal necrosis syndrome. The rapid and accurate diagnosis of herpetic infections has become increasingly important with the rising incidence of immunosuppressive diseases. The purpose of this study was to evaluate the use of the polymerase chain reaction (PCR) to detect herpesvirus DNA in uveitis patients.

METHODS

Aqueous samples were aspirated from 11 patients with active uveitis of suspected viral origin. Using PCR, masked samples were assayed for herpes simplex virus (HSV), varicella zoster virus (VZV), and cytomegalovirus (CMV) to assist in supporting the clinical diagnosis of viral aetiology. Masked controls included 10 aqueous humour specimens from normal patients undergoing cataract surgery and specimens from seven patients diagnosed with active non-viral uveitis--Behçet's disease, sarcoidosis, Fuchs' heterochromic iridocyclitis, or Harada's disease.

RESULTS

Ten of 11 cases clinically diagnosed as being of possible viral aetiology yielded aqueous PCR positive for a herpesvirus. Eight patients were PCR positive for amplified HSV DNA, of whom two had acute retinal necrosis, one had corneal endotheliitis, and five had recurrent iridocyclitis. VZV DNA was detected in one case of iridocyclitis, and CMV DNA in one case of chorioretinitis. Successful therapy was based on the PCR results. Ten normal aqueous specimens and the seven uveitis samples from cases not suspected of a viral aetiology were PCR negative for HSV, VZV, and CMV.

CONCLUSION

These results demonstrate that detecting herpesvirus DNA in the aqueous humour is useful to support a clinical diagnosis of viral uveitis.

Hepatic hemodynamics in a patient with nodular regenerative hyperplasia

Nodular regenerative hyperplasia of the liver is an uncommon condition. Approximately 50% of these patients develop portal hypertension. Few previous reports document the site of increased resistance to blood flow within the liver in this disorder. We measured Doppler waveform patterns of the right hepatic vein by pulsed Doppler ultrasonography and portal, wedged hepatic, and free hepatic venous pressure by intravenous catheter before and after splenectomy in a 47-yr-old woman with nodular regenerative hyperplasia who presented with portal hypertension and pancytopenia. Nodular regenerative hyperplasia was histologically confirmed. Pre- and postoperative measures indicated a marked difference between wedged hepatic venous pressure and free hepatic venous pressure, whereas there was little difference between portal venous pressure and wedged hepatic venous pressure. Doppler waveform patterns of the right hepatic vein showed an unclear pulsatile flow pattern with a decreasing reversed phase. The above data suggest that portal hypertension in nodular regenerative hyperplasia is primarily sinusoidal, similar to that seen with cirrhosis.

Immunohistochemical expression of the c-kit proto-oncogene product in human malignant and non-malignant breast tissues

The immunohistochemical expression of c-kit proto-oncogene product in 57 breast cancer tissues was studied using anti-c-kit proto-oncogene product antibody in comparison with 20 normal breast tissues and 58 benign breast tumours. In normal breast tissues, the c-kit proto-oncogene product was strongly expressed on cell membrane and/or cytoplasm of alveolar and ductal cells. The immunoreactive score (IRS) of c-kit proto-oncogene product in normal mammary epithelia was 6.22 +/- 2.11 (mean +/- s.d.). In benign breast diseases, the c-kit proto-oncogene product was detected heterogeneously with a reduced IRS (3.33 +/- 2.44). In breast cancer tissues, the expression of the immunoreactive c-kit proto-oncogene product was often deleted and the average IRS was significantly reduced compared to those of normal breast tissues or benign breast diseases tissues. Among benign diseases, the average IRS of intraductal papilloma was significantly reduced (1.34 +/- 1.70) and the staining intensity and pattern were found to be similar to those seen in breast cancer. The results in this study suggested that the c-kit proto-oncogene product is correlated with the growth control or the differentiation of normal breast epithelium. Also, the loss of the expression of this protein may indicate the change of the signal transduction in relation to malignant transformation in human mammary epithelium.

Giant basal cell carcinoma associated with systemic amyloidosis

A large basal cell carcinoma, 39 x 26 cm in size, is presented as second in size only to the largest basal cell carcinoma documented (40 x 30 cm), reported by Beck and co-workers (1). A 61-year-old Japanese male visited our clinic with a huge ulcerating tumor on the back. He had hidden the tumor for the previous 30 years. The tumor was histologically confirmed as basal cell carcinoma. The condition was associated with anemia, hypoproteinemia, and dyspnea, and with systemic amyloidosis in the skin, in the lymph nodes, and in the intestinal canal. On admission, the tumor had metastasized to the regional lymph nodes, and, about two years after the first operation, there were metastases to bone and lung, leading to death due to respiratory failure.

Inhibition of leukotriene synthesis by azelastine

BACKGROUND

Azelastine, oxatomide, and ketotifen are used for patients with allergic diseases. These drugs inhibit the release of chemical mediators including the leukotrienes; however, the mechanism involved is unclear.

OBJECTIVE

To clarify the mechanism of inhibition, we investigated the effects of three drugs on the function of phospholipase A2, 5-lipoxygenase, leukotriene C4 synthase, and leukotriene A4 hydrolase, which are all catabolic enzymes involved in synthesizing leukotriene C4 and leukotriene B4 in rat basophilic leukemia (RBL)-1 cells.

METHODS AND RESULTS

The production of leukotriene C4 and leukotriene B4 was measured by high performance liquid chromatography (HPLC). All three drugs inhibited the production of leukotriene C4 and leukotriene B4 when cells were stimulated with A23187. All three drugs also inhibited the A23187-stimulated release of 3H-arachidonic acid from membrane phospholipids. Azelastine inhibited the production of leukotriene C4, but not leukotriene B4, when either arachidonic acid or leukotriene A4 free acid was used as the substrate in our cell free system. Oxatomide and ketotifen did not inhibit the synthesis of either leukotriene C4 or leukotriene B4 in the same cell free study.

CONCLUSION

Results indicated that oxatomide and ketotifen inhibit the production of leukotriene C4 and leukotriene B4 by inhibiting phospholipase A2 activity, whereas, azelastine inhibits the leukotriene C4 production by inhibiting phospholipase A2 and leukotriene C4 synthase.

Active transport activities of free B-6 vitamers in various yeast strains

Active transport activities of free B-6 vitamers in 35 strains of 8 genera of yeast were measured by isocratic reverse-phase HPLC. Many but not all strains transported pyridoxamine and/or pyridoxine. The active transport activities in some yeast strains tested were completely inhibited by amiloride (0.5 mM). In contrast to cells so far studied, yeast cells showed a novel character in metabolism of accumulated B-6 vitamers: the phosphorylation of the free B-6 vitamers was regulated at a low level. There was no apparent correlation between the presence of the active transport activity in yeasts and the requirement of vitamin B-6 for their growth.

Prolongation of lung xenograft survival in rats with a short course of deoxyspergualin and cyclosporin A

The efficacy of 15-deoxyspergualin (DSG), cyclosporin A (CyA), and splenectomy--alone or in combination--in prolonging the survival of concordant lung xenotransplants was studied in the hamster-to-rat model. In the untreated group, rejection occurred within 3 days, with an elevation of lymphocytotoxic antibody titers. The rejected lung revealed that ED1 + cells were more prevalent than MRC OX8 + cells in the perivascular infiltrates. In the DSG group, the antibody response was suppressed and median survival increased to 7.5 days. The rejected lungs demonstrated a highly significant depression in ED1 + cellular infiltration and a moderate MRC OX8 + cellular infiltration. When maintenance CyA was combined with a short course of DSG, survival dramatically increased to beyond 100 days. There were no deposits of IgM, IgG, or C3 or of any cell infiltrate in the grafts of two animals sacrificed 107 and 119 days post-transplantation. We conclude that initial treatment with DSG combined with continuous CyA can suppress acute rejection in the hamster-to-rat lung xenograft model, resulting in long-term graft survival.

Inhibition by dexamethasone of the lipopolysaccharide-induced increase in IL-6 mRNA abundance and IL-6 production in human polymorphonuclear leukocytes

Interleukin-6 (IL-6) is a key inflammatory cytokine that is produced by various cell types including polymorphonuclear leukocytes (PMNs). However, the pathophysiological roles of IL-6 produced by human PMNs are unclear. Bacterial lipopolysaccharide (LPS) induced marked increase in IL-6 production, determined by enzyme-linked immunosorbent assay, and IL-6 mRNA abundance determined by reverse transcription-polymerase chain reaction analysis, in purified human PMNs. Both effects of LPS were inhibited in a dose-dependent manner by dexamethasone (10(-6) to 10(-8) M). IL-6 receptor mRNA was constitutively present in PMNs and its abundance was not affected by either LPS or dexamethasone. These results indicate that PMNs are an important source of IL-6 in acute inflammatory reactions, and that the anti-inflammatory actions of dexamethasone is attributable in part to inhibition of IL-6 production by these cells. The constitutive presence of IL-6 receptor mRNA in PMNs suggests that IL-6 may exert pathophysiological effects on these cells.

A splice variant of the c-met proto-oncogene is the predominant population expressed in human gastric mucosa and carcinoma

Difference in the expression of the c-met protooncogene transcription variants in human gastric mucosa and cancer was studied by deoxynucleotide sequencing and cloning-restriction fragment length assay of the PCR products amplified with the specific primer set to membrane proximal extracellular domain of the c-met c-DNA. Fight gastric cancer cell lines, five gastric carcinoma tissues as well as their corresponding non-neoplastic gastric mucosas had the 54 bp- form splice variant of the c-met which encodes mature 190 kDa alpha beta heterodimeric protein as the major transcript population and 54 bp+ form variant which encodes 170 kDa protein, which is distinct from the met precursor protein, could not be detected. These results indicate that 190 kDa alpha beta heterodimeric protein encoded by major 54 bp- form c-met transcript mainly mediates the effect of HGF/SF in the stomach.

Relationship between sonographic endometrial thickness and progestin-induced withdrawal bleeding

OBJECTIVE

To determine whether the response to the progestin challenge test can be predicted from the endometrial thickness measured sonographically.

METHODS

Progestin challenge tests were performed on 44 women with secondary amenorrhea, each of whom also had her endometrial thickness measured by transvaginal ultrasonography and her serum estradiol (E2) levels determined. The relationships between the response to the challenge test, endometrial thickness, and serum E2 levels were studied, as well as whether the presence or absence of withdrawal bleeding could be predicted from the endometrial thickness and serum E2 levels.

RESULTS

The endometrium was significantly thicker in 32 women who had withdrawal bleeding (10.3 +/-4.1 mm) than in the 12 who did not bleed (5.0 +/- 1.3 mm) (P < .001). The serum E2 level was also significantly higher in the positive group: 45.3 +/- 19.4 versus 18.6 +/- 8.0 pg/mL (P < .001). Endometrial thickness of 6.0 mm or more predicted the occurrence of withdrawal bleeding with an accuracy of 95.5%. Endometrial thickness was superior to the serum E2 level in predicting withdrawal bleeding.

CONCLUSION

Progestin-induced withdrawal bleeding can be predicted from the endometrial thickness measured sonographically.

Microsatellite instability in precancerous lesions and adenocarcinomas of the stomach

BACKGROUND

It is generally known that replication errors (RERs) at microsatellite loci detected in human malignancies reflect a genetic instability that is caused by abnormalities of DNA mismatch repair system and underlie human carcinogenesis. The authors analyzed RERs in precancerous lesions and adenocarcinomas of the stomach to learn when genetic instability occurs in stomach carcinogenesis. In addition, the authors examined genetic instability occurs in stomach carcinogenesis. In addition, the authors examined genetic alterations of the p53 and adenomatous polyposis coli (APC) genes to investigate the correlation between genetic instability and genetic alterations in these tumor suppressor genes.

METHODS

The authors examined microsatellite assay at 9 microsatellite loci in 24 sporadic gastric cancers, 12 gastric adenomas, and 9 intestinal metaplasia mucosae of the stomach from patients with gastric cancers using fresh frozen or formalin fixed and paraffin embedded samples paired with normal mucosae. They also screened loss of heterozygosity (LOH) of the p53 and APC genes by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) analysis.

RESULTS

In total, the RER(+) phenotypes were observed in 8 of 24 (33%) gastric cancers, 5 of 12 (42%) gastric adenomas, and 3 of 9 (33%) intestinal metaplasia mucosae of the stomach. Histology, RERs were detected in 3 of 9 (33%) well differentiated adenocarcinomas, 2 of 11 (18%) poorly differentiated adenocarcinomas, and 3 of 4 (75%) scirrhous type gastric cancers respectively. Several cases showed RERs at many microsatellite loci simultaneously. Some RER(+) phenotypes had genetic alterations of the p53 or APC genes detected by LOH using PCR-RFLP analysis. However, no significant correlation was found between RER(+) phenotypes and LOH in these genes.

CONCLUSIONS

The frequency of RERs in detected gastric cancers were almost the same when compared with previously reported data. Interestingly, RERs were detected in greater than 30% of precancerous lesions, suggesting that genetic instability is an early somatic event of multistep stomach carcinogenesis. It also suggests that the adenoma-carcinoma sequence does exist in stomach carcinogenesis, especially in well differentiated adenocarcinomas. Moreover, alterations in the p53 and APC genes detected by PCR-RFLP analysis did not correlate with RER(+) phenotypes.

[Serum CA 19-9 levels in rheumatic diseases with interstitial pneumonia]

Serum CA 19-9 (2-3 sialyl Le(a)) is a marker of malignant disorder such as pancreas or gall bladder cancers. It has been reported that sera from patients with interstitial pneumonia show elevated level of CA 19-9. To investigate the relationship between the elevation of serum CA 19-9 (sCA 19-9) and the presence of pulmonary fibrosis, we examined the level of sCA 19-9 in sera from patients with rheumatic diseases with or without interstitial pneumonia (IP). The sCA 19-9 level was determined by enzyme-linked immunosorbent assay (ELISA). Fourteen sera of 129 (10.9%) patients with rheumatic diseases without malignant disorders were positive for sCA 19-9 when normal range was determined as less than 100 U/ml (mean +/- 5 SD), and 26.7% of sera from poly/dermatomyositis (PM/DM) and 11.8% of systemic sclerosis (PSS) were positive for CA 19-9. Whereas only 8.0% of rheumatoid arthritis (RA) was positive. Twelve (28.6%) of 42 rheumatic patients with IP showed positive levels for sCA 19-9 (mean 142.5 +/- 363.0 U/ml), whereas only two (2.3%) of 87 without IP were positive (mean 33.9 +/- 65.8 U/ml; p < 0.05). The correlation between the level of sCA 19-9 and pulmonary diffusing capacity (%DLCO) revealed an inverse correlation in 32 rheumatic patients with IP (r = -0.43, p < 0.05). Furthermore, the elevated sCA 19-9 levels decreased after treatment with corticosteroid and/or cyclophosphamide or cyclosporin A. Therefore, elevation of the level of sCA 19-9 seems to be involved in the pathogenesis of IP and sCA 19-9 will be a useful parameter for IP. It has been reported that the CA 19-9 is produced from the bronchial glands and suggested that during chronic fibrotic process of the lung, the metaplastic change of the bronchial glandular cells occur and the cells produce CA 19-9.