Generation of intestinal T cells from progenitors residing in gut cryptopatches

Cryptopatches (CPs) are part of the murine intestinal immune compartment. Cells isolated from CPs of the small intestine that were c-kit positive (c-kit+) but lineage markers negative (Lin-) gave rise to T cell receptor (TCR) alphabeta and TCR gammadelta intestinal intraepithelial T cells after in vivo transfer or tissue engraftment into severe combined immunodeficient mice. In contrast, cells from Peyer's patches and mesenteric lymph nodes, which belong in the same intestinal immune compartment but lack c-kit+Lin- cells, failed to do so. These findings and results of electron microscopic analysis provide evidence of a local intestinal T cell precursor that develops in the CPs.

Chronic inflammation and susceptibility to bacterial infections in mice lacking the polypeptide (p)105 precursor (NF-kappaB1) but expressing p50

The polypeptide (p)50 molecule, a subunit of nuclear factor (NF)-kappaB, is produced after proteolytic processing of the p105 precursor (NF-kappaB1). Although the p105 precursor has been postulated to play a role in the regulation of the Rel/NF-kappaB activity, its physiological relevance remains unclear. To investigate that, we generated mutant mice lacking the COOH terminal half of the p105 precursor, but expressing the p50 product (p105-/-). These mutant mice displayed an inflammatory phenotype composed of lymphocytic infiltration in lungs and liver, and an increased susceptibility to opportunistic infections. Enlargement of multiple lymph nodes, splenomegaly due to erythrocytic extramedullary hematopoiesis, and lymphoid hyperplasia were also observed in p105-/- mice. Cytokine production in p105-/- macrophages was severely impaired, whereas proliferative responses of p105-/- B cells were increased. T cell functions were only moderately impaired in mutant mice. Loss of p105 also led to enhanced constitutive p50 homodimer and inducible NF-kappaB activities in unstimulated and stimulated cells, respectively. As several genes regulated by Rel/NF-kappaB were upregulated in p105-/- thymus but downregulated in p105-/- macrophages, the enhanced p50 homodimers appear to function as transcriptional activators or repressors, depending on the cell type. Thus, the p105 precursor is indispensable in the control of p50 activity, and lack of the precursor has distinct effects on different cells.

Adenocarcinoma arising in the retrorectal space: report of a case

We herein present an extremely rare case of adenocarcinoma of unknown origin arising in the retrorectal space. The imaging and endoscopic findings misled us to preoperatively diagnose a "submucosal tumor." This histological findings were highly suggestive of adenocarcinoma, and its unexpected early and aggressive recurrence required thorough investigation on the true cell type and its origin. Both radiochemotherapy findings and conclusive findings of immunohistochemical staining finally revealed this tumor to be an ordinary adenocarcinoma. It was impossible to identify its origin histologically, because this case was so advanced that it had already replaced the entire entity with adenocarcinoma without leaving any clues as to its former nature. We thus assumed this tumor to be an adenocarcinoma of unknown origin arising in the retrorectal space.

Simultaneous observation of capillary nets and tenascin in intestinal villi

BACKGROUND

In order to reveal the biological role of capillaries in a tissue, it is desirable to study the three-dimensional distribution of capillary nets in relation to tissue architecture. However, the simultaneous observation of the three-dimensional distribution of these nets and other substances has been rarely performed to date. In the present study, we have developed a novel method for investigating the three-dimensional distribution of capillary nets simultaneously with that of extracellular matrix components, such as tenascin, using the confocal laser scanning microscope.

METHODS

Adult male mice were perfused with TRITC-labelled gelatin. After perfusion, the intestine was irrigated with chilled fixative containing paraformaldehyde and picric acid, dissected, and returned to the same fixative. The intestine was further sectioned and indirectly immunostained for tenascin using an FITC-labelled antibody.

RESULTS

The three-dimensional distribution of capillary nets and tenascin in villi was simultaneously observed on stereo pairs of pseudo-colored and superimposed images. Tenascin was distributed at the basement membrane zone and in the underlying connective tissue but absent in some regions where capillary nets were running just beneath the epithelium. Substances other than tenascin also can be examined in correlation with capillary nets.

CONCLUSIONS

This method will be useful for investigating the biological role of capillary nets.

Retrovirus-mediated gene therapy for human hepatocellular carcinoma transplanted in athymic mice

Gene therapy using a retrovirus vector carrying herpes simplex virus thymidine kinase gene under the control of the 0.3-kb human alpha-fetoprotein (AFP) gene promoter (LNAF0.3TK virus) in combination with ganciclovir (GCV) treatment was performed in athymic mice harboring AFP-producing HuH-7 human hepatoma cells. GCV treatment resulted in pronounced growth inhibition of the virus-infected HuH-7 xenograft in mice, but did not affect growth of the parental xenograft. These results indicate that the AFP gene promoter sequence allows enough therapeutic gene expression to induce the GCV-mediated cytotoxicity in vivo in AFP-producing human hepatoma cells.

[Lymphocyte chemotactic factor in tuberculous pleural effusion]

To evaluate whether lymphocyte chemotactic factor is involved in the accumulation of lymphocytes in tuberculous pleurisy, we measured lymphocyte chemotactic activity in tuberculous pleural effusions, and compared with that in malignant pleural effusions and transudate. The lymphocyte chemotactic activity was measured in vitro with chemotactic chamber. The cells suspended in the culture medium was added to the upper well and the effusions, normal human serum (NHS), or culture medium were placed below nitrocellulose filter. The lymphocyte migration was quantified by counting the number of cells migrating beyond a distance of 70 microns from top of the filter in 5 selected fields. The chemotactic activity of the effusions was expressed as a percentage of the control migration in the culture medium. When we used the freshly isolated peripheral blood lymphocytes as responding cells, the chemotactic activity was 176.0 +/- 41.3% in tuberculous effusions, 115.1 +/- 53.8% in malignant effusions, 87.1 +/- 16.1% in transudate, and 113.3 +/- 24.2% in NHS, respectively. The activity of tuberculous effusions was significantly higher than that of transudate and NHS. When we used PHA-activated lymphocytes, the activity was 284.4 +/- 159.3% in tuberculous effusions, 123.1 +/- 77.6% in malignant effusions, 75.8 +/- 10.3% in transudate, and 52.6 +/- 10.1% in NHS, respectively. The activity of tuberculous effusions was significantly higher than that of malignant effusions, transudate and NHS. The chemotactic activity of tuberculous effusions to PHA-activated lymphocytes was significantly higher than that to freshly isolated lymphocytes. The activity was specific for T lymphocytes, and showed both chemotaxis and chemokinesis by checkerboard analysis. Gel filtration performed with Sephacryl S-200 revealed that the chemotactic activities in a tuberculous fluid had three peaks located in the regions between blue dextran and immunoglobulin G, near to human albumin and cytochrome c marker. The most potent activity was found at the region near human albumin. Lymphocyte chemotactic factor in tuberculous effusion may stimulate the migration of T lymphocytes, especially the activated T lymphocytes to the pleural spaces.

Differential distribution of actin and cytokeratin in isolated full-length rabbit renal tubules

The distribution of basal actin bundles and cytokeratin intermediate filaments in the rabbit kidney was examined along isolated renal tubules by confocal laser microscopy. Perfusion of collagenase and subsequent manipulation of kidney tissues yielded well preserved renal tubules free of connective tissue components often extending from glomeruli to collecting tubules. Such isolated renal tubules were fluorescently stained with phalloidin and with anti-cytokeratin antibody and then observed as whole-mount preparations by confocal laser microscopy. Epithelial cells of Bowman's capsules showed conspicuous actin bundles which were arranged parallel to each other in individual cells. In proximal ducts, thick actin bundles were seen running in the basal regions of epithelial cells perpendicular to the tubule axis. Basal actin bundles in proximal tubules appeared to be somewhat thinner and run more irregularly in more distal parts of the tubule. Thin limbs of Henle's loop showed bright but very short rod or dot-like stainings of actin, while in thick limbs, there were thick and short actin bundles. In distal tubules basal actin bundles were somewhat longer than those in thick limbs of Henle's loop. In the collecting ducts in the renal cortex, a few short actin bundles as well as dotty or patchy stainings were shown in the basal region. In both whole-mount preparations and cryostat sections, cytokeratin immunoreactivities were almost exclusively detected in epithelial cells of Henle's loops and collecting ducts but poorly in proximal and distal tubules. Epithelial cells of Henle's loops showed dense networks of cytokeratin immunoreactivities throughout the cytoplasm, whereas cell boundaries were immunostained in collecting ducts. The actin and cytokeratin distribution in such isolated renal tubules was confirmed by immunofluorescence of cryostat sections and by thin-section electron microscopy. The observations that actin and intermediate filaments varied in distribution in different segments of renal tubules are interesting in view of the segmental differentiation of renal tubule functions.

Detection of deoxyribonuclease I in a hormone-secretory pathway of pituitary cells in humans and rats

High levels of deoxyribonuclease I (DNase I) were detected in the cytoplasm of hormone-secreting cells in anterior and intermediate lobes of human and rat pituitary glands. Tissue homogenate fractions of anterior and intermediate pituitary lobes showed strong DNase I-specific enzymatic activity. Immunofluorescence, with several specific antibodies against human and rat DNase I, indicated strong immunoreactivity in the cytoplasm of hormone-secreting cells within the gland. In situ hybridization demonstrated high levels of DNase I mRNA in the cells. By immunoelectron microscopy, immunogold particles were found in the rough endoplasmic reticulum, Golgi apparatus and secretory granules. Exocytotic secretory granules were also immunopositive. These results indicate that endocrine cells in the pituitary gland synthesize and secrete DNase I together with their respective pituitary hormones.

Curved chest tube for drainage of malignant pleural effusion

Thoracentesis with a chest tube insertion and drainage of large pleural effusion is widely performed in patients with malignant lung diseases. One potential problem with a conventional chest tube placement is occasional incomplete evacuation of effusion owing to inappropriate position of the tip where the drainage holes opened. We have developed a curved chest tube and evaluated the position of tip placement just after the placement and before removal on plain chest X-ray in 20 patients with massive pleural effusions due to lung cancer. In 15 of the 20 patients, the tip of the tube was successfully positioned at the paravertebral gutter in posterobasal with higher drainage efficacy compared with other patients whose tube tips happened to be positioned at other sites. There were no significant complications. This study suggested that the curved chest tube would be safe and useful in completing drainage of pleural effusion.

Calcium mobilization evoked by amyloid beta-protein involves inositol 1,4,5-triphosphate production in human platelets

We examined the effects of amyloid beta-protein (A beta) on Ca2+ mobilization in human platelets. The addition of A beta fragments 25-35 (A beta 25-35) gradually increased the cytoplasmic free Ca2+ concentration ([Ca2+]i). After the maximum response, [Ca2+]i decreased and then reached a sustained, higher level of [Ca2+]i. Similar effects were also observed with A beta 1-40, whereas 1-28 , 12-28 and 31-35 did not affect the Ca2+ response. In the absence of extracellular Ca2+, A beta 25-35 caused a transient increase in [Ca2+]i, which returned to the resting level. U73122, a phospholipase C inhibitor, completely abolished Ca2+ mobilization induced by thrombin and A beta 25-35. Furthermore, A beta enhanced the production of inositol 1,4,5-trisphosphate (IP3) in platelets. These findings suggest that Ca2+ mobilization induced by A beta 25-35 is due to phospholipase C activation and IP3 production.

Radioligand binding characteristics of the endothelin receptor in the rabbit iris

We previously suggested the presence of functionally atypical endothelin (ET) A receptors in the rabbit iris sphincter. Here, we further characterized the ET receptor by a radioligand-receptor binding study utilizing a membrane fraction of the rabbit iris. In addition, we functionally confirm the presence of an atypical ET(A) receptor in the iris dilator similar to that in the iris sphincter. In binding experiments, [125I]ET-1 was completely displaced by ET-3 in a biphasic fashion, but only partially by BQ-123 and ET(B) ligands. In the presence of RES-701, ET-3 and sarafotoxin (SRTX)-b completely displaced [125I]ET-1 in a monophasic fashion, but with shallow slopes. Moreover, ET-1, ET-3 and SRTX-b completely displaced [3H]BQ-123 with IC50 values of 0.8, 81 and 4.4 nM, respectively, but with slopes of ET-3 and SRTX-b being again shallow. In iris dilator muscles, ET-3 showed lower and SRTX-b showed higher contractile activities than ET-1. SRTX-c was inactive. BQ-123 more preferentially antagonized ET-3 and SRTX-b than ET-1, with the Schild plot slope of SRTX-b being shallow. Thus, functional experiments suggested the presence of atypical ET(A) receptors in the iris dilator similar to the iris sphincter. However, the binding experiments suggested the presence of rather typical ET(A)- and ET(B)-like receptors. Therefore, we apparently failed to show ET binding sites corresponding to functionally atypical ET(A) receptors.

[Necrosis of the hepatocellular carcinoma nodule can aggravate metastasis]

Since the stroma of hepatocellular carcinoma is composed of sinusoid-like structures, cancer cells are readily released from the primary tumor with possible injurious consequences. A 63-year-old woman with hepatocellular carcinoma underwent percutaneous ethanol injection therapy. During this treatment, tumor thrombus developed in the right hepatic vein. Partial hepatic resection was performed. Six months later, multiple nodules appeared in the lung fields. Partial necrosis may have allowed the release of cancer cells from the primary tumor. Perioperative therapy should have an effect on intrahepatic micrometastases, because removal of the main tumor can be done surgically.

Analysis of long-term survivors after platinum containing chemotherapy in advanced non-small cell lung cancer

Among 195 patients with locally advanced or metastatic non-small cell lung cancer(NSCLC), we evaluated the characteristics of two-year survivors. All the patients with stage IIIA-IV disease received platinum containing combination chemotherapy at Tsukuba University Hospital between 1985 and 1996. Fourteen patients (7.2%) and 7 patients (3.6%) survived for more than 2 and 3 years, respectively. Ten of the 14 responded to initial chemotherapy, and 9 patients received additional treatment such as thoracic irradiation and/or surgical resection. Three of the 14 patients survived more than 5 years disease free, one of them survived more than 10 years. From the results uni- and multivariate analyses of these patients, early stage of the disease, low number of metastatic site, without associated lung disease were confirmed as significant determinants of survival. This study revealed that a small proportion of patients with advanced NSCLC might be potentially curable with appropriate treatment.

Antioxidative and superoxide scavenging activities of retrochalcones in Glycyrrhiza inflata

Licochalcone A, B, C, D and echinatin, retrochalcones isolated from the roots of Glycyrrhiza inflata (licorice), along with an ordinary chalcone isoliquiritigenin, were assessed for their inhibitory activities on lipid peroxidation in various systems and radical scavenging activity. Among those tested, licochalcones B and D strongly inhibited superoxide anion production in the xanthine/xanthine oxidase system. These two compounds also showed potent scavenging activity on DPPH radical. Microsomal lipid peroxidation induced by Fe(III)-ADP/NAPDH was inhibited almost completely by 3 micrograms/ml of licochalcones B and D. Mitochondrial lipid peroxidation induced by Fe(III)-ADP/NADH was more sensitive to these retrochalcones; almost complete inhibition was observed at 10 micrograms/ml of all retrochalcones tested. Licochalcones B and D scavenged superoxide anion in microsome. Furthermore, these retrochalcones protected red cells against oxidative hemolysis. These phenolic compounds were shown to be effective to protect biological systems against various oxidative stresses.

Analysis of colchicine-induced chromosomal aberrations in embryos obtained from XO mice

A high incidence of chromosomal anomalies has been observed in the offspring of our XO mouse colony. However, the reason(s) are unknown. We hypothesized that XO dams might be more susceptible to certain chromosomal mutagens. Therefore, we assessed whether the oocytes of XO mice are more susceptible to colchicine. Pregnant XO and XX mice were intraperitoneally (i.p.) injected with colchicine, 0.2 mg/kg, 6 h after mating (between resumption of meiosis II and extrusion of the second polar body). Contrary to our expectation, the incidence of chromosomal anomalies induced by colchicine exposure did not differ between XX and XO dams. These findings suggest that the chromosomal stability of the oocytes from XO mice may not be affected by colchicine exposure at the stage of extrusion of the second polar body. The effects of chromosomal imbalance inherent in XO mice on chemical susceptibilities should be further investigated.

[Laparoscopic surgery for early gastric cancer--its advantages and pitfalls]

We have successfully established two different laparoscopic procedures for early gastric cancer since March 1992, which are laparoscopic wedge resection of the stomach using a lesion-lifting method and laparoscopic intragastric mucosal resection. The indication is as follows; (A) mucosal cancer, (B) < 25 mm, if the lesion is elevated type, (C) < 15 mm and Ul (-), if the lesion is depressive type. The advantages of these methods are; 1) minimally invasiveness, 2) sufficient surgical margin, 3) feasibility of detailed histology, 4) feasivility of perigastric lymph node dissection. In contrast, there are several problems to be solved, which are; 1) preoperative diagnostic accuracy of the depth of cancer invasion, 2) possibility of reoperation because of sm invasion or lymphatic or venous invasion in final histology, 3) possibility of postoperative stenosis after laparoscopic intragastric mucosal resection for the lesion near the cardia, 4) incidence of metachronous multiple gastric cancer. In conclusion, if the indication is properly selected, these laparoscopic procedures are curative and minimally invasive treatment for early gastric cancer.

[A case of advanced gastric cancer with virchow's metastasis responding remarkably to combination chemotherapy of low-dose CDDP and 5-FU]

The patient was a 72-year-old female who had Stage IVb advanced gastric cancer with Virchow's and paraaortic lymph node metastases. She was considered nonresectable and placed on neoadjuvant chemotherapy consisting of low-dose CDDP and 5-FU. After 1 course of administration, Virchow's metastasis disappeared, and the tumor was remarkably reduced in size. However, this chemotherapy was interrupted by toxicity of grade 3 appetite loss, nausea and vomiting, so that total gastrectomy and splenectomy were performed, which were non-curative operation because of paraaortic lymph node metastases. Histopathological examination of the section of the primary tumor revealed that cancer cells had almost disappeared, and only a few atypical cells remained in the granulation tissue. Eleven months after the surgery, there has been no progression of Virchow's and paraaortic lymph node metastases. Combination chemotherapy of low-dose CDDP and 5-FU appears useful as an inductive approach to advanced gastric cancer.

Combined effects of TNP-470 and taxol in human non-small cell lung cancer cell lines

The effects of TNP-470, one of the promising antiangiogenic agents and taxol when combined were evaluated in two human cultured cell lines derived from non-small cell lung cancer(NSCLC). Cytotoxicity was determined using a tetrazolium salt(MTT) assay. The inhibitory effects of TNP-470 on cell proliferation were dose related and the 50% inhibitory concentration on these cell lines were 50.0 to 62.5 microM. Evaluation of drug interactions with isobologram and the combination index values showed that sequential exposure to taxol followed by TNP-470 produced synergistic effects in these cell lines tested. Our findings suggest that such an angiocytotoxic chemotherapy might be promising for the treatment of NSCLC.

Lung cancer cell line producing cytokeratin 19 fragment and sialyl Lewis X-i antigen

A new human lung large cell carcinoma cell line producing cytokeratin 19 fragment(CYFRA) and sialyl Lewis X-i antigen(SLX), designated TKB-13, was established from a patent in our laboratory. The cell line grew in a monolayer and had a polygonal epitheloid appearance in phase-contrast microscopy. The doubling time of TKB-13 cells was approximately 32 hours in Dulbecco's minimal essential medium with 5% fetal bovine serum. TKB-13 cells could be transplanted to nude mice and the histological characteristics were the same as those of resected tissue from the primary site. Positive reactions for CYFRA and for SLX were seen within the cytoplasm of TKB-13 cells by immunocytochemical staining. Both CYFRA and SLX were detected in the culture supernatant. Our results suggested that TKB-13 cell line is available for experimental studies on the biological behavior of non-small cell lung cancer.

Suppressed production of nitric oxide as a cause of irregular constriction of gastric venules induced by thermal injury in rats

Microcirculatory disturbance is a crucial step in development of gastric mucosal lesions. In this study we investigated the influence of nitric oxide (NO) on the irregular constriction of gastric venules observed in rats subjected to thermal injury. Male Wistar rats were anesthetized and a 30% full skin thickness dorsal burn was inflicted. Microvascular images in the submucosal layer and basal region of the gastric mucosa were obtained through an intravital microscope. Distribution of constitutive-type nitric oxide synthase (cNOS) was observed by the immunofluorescence method. Venule walls were basically smooth in the control group (no injury), whereas irregular constrictions tended to be observed in the 5-h group (5 h after thermal injury). Venule diameter was significantly smaller in the 5-h group. In the control group, cNOS-associated fluorescence was found on the venule endothelium, whereas it was almost negligible after thermal injury. A NO donor, 3-morpholinosydnonimine hydrochloride, simultaneously diminished the thermal injury-associated venule constriction and irregularity of venule walls. Therefore, the present study suggests that venule constriction, which is observed 5 h after thermal injury, is related to decreased NO production by endothelial cNOS and is a cause of irregularity of the venule walls.

Optical Kerr coefficient measurement in coiled high-birefringent fibers

The optical Kerr effect in coiled high-birefringent fibers was measured based on a double-beam polarimetric method. A Q-switched Nd:YAG laser, operating at 1.064 mum (FWHM of 80 ns at 1 kHz), was used as the pump beam and a cw 0.633-mum He-Ne laser was used as the probe beam with its polarization fixed at 45 degrees with respect to the birefringent axis whereas orientation of the linearly polarized pump light varied. The phase shifts induced by an intense pump beam in a short bow-tie high-birefringent fiber were determined for different fiber lengths coiled into 15- and 30-cm-diameter drums. It was found that the induced phase shift changes drastically with the state of polarization of the pump light. A strong dependence of the phase shift on orientations of linear pump polarization is attributed to differential losses of eigenmodes peculiar to birefringent axes. Therefore, optical Kerr coefficients remain unchanged regardless of the dependence of the nonlinear response of the coiled high-birefringent fibers on pump polarization.

Interleukin 7 transgenic mice develop chronic colitis with decreased interleukin 7 protein accumulation in the colonic mucosa

We have demonstrated that intestinal epithelial cells produce interleukin 7 (IL-7), and IL-7 serves as a potent regulatory factor for proliferation of intestinal mucosal lymphocytes expressing functional IL-7 receptor. To clarify the mechanism by which locally produced IL-7 regulates the mucosal lymphocytes, we investigated IL-7 transgenic mice. Here we report that transgenic mice expressing murine IL-7 cDNA driver by the SRalpha promoter developed chronic colitis in concert with the expression of SRalpha/IL-7 transgene in the colonic mucosa. IL-7 transgenic but not littermate mice developed chronic colitis at 4-12 wk of age, with histopathological similarity to ulcerative colitis in humans. Southern blot hybridization and competitive PCR demonstrated that the expression of IL-7 messenger RNA was increased in the colonic mucosal lymphocytes but not in the colonic epithelial cells. IL-7 protein accumulation was decreased in the goblet cell-depleted colonic epithelium in the transgenic mice. Immunohistochemical and cytokine production analysis showed that lymphoid infiltrates in the lamina propria were dominated by T helper cell type 1 CD4+ T cells. Flow cytometric analysis demonstrated that CD4+ intraepithelial T cells were increased, but T cell receptor gamma/delta T cells and CD8alpha/alpha cells were not increased in the area of chronic inflammation. Increased IL-7 receptor expression in mucosal lymphocytes was demonstrated in the transgenic mice. These findings suggest that chronic inflammation in the colonic mucosa may be mediated by dysregulation of colonic epithelial cell-derived IL-7, and this murine model of chronic colitis may contribute to the understanding of the pathogenesis of human inflammatory bowel disease.