Intestinal intraepithelial T lymphocytes. Our T cell horizons are expanding

The alimentary tract is an essential structure for the ingesting of nutrients from the outside, and even most primitive animals have a straight tract that runs from the mouth to the anus. We come into contact with the outside world through our skin and mucous membranes. The surface area of the enteric mucous membrane, which absorbs nutrients, is enlarge through its ciliary structure, and the enteric cavity creates by far the largest external world that we come into contact with. For instance, the enteric mucosal surface of the human gastrointestinal tract covered by a single layer of epithelial cells corresponds to the size of one-and-a-half tennis courts, and the innumerable number of epithelial cells covering this mucous surface are entirely replaced by new epithelial cells in the space of just several days. Simultaneously, the fact that 60-70% of peripheral lymphocytes are congregating in the gastrointestinal tract supports the notion that the enteric mucous membrane represents an extremely dangerous locale, where numerous harmless/precarious external antigens come in through the wide array of food we injest on a daily basis, and the literally infinite amounts of normal intestinal flora intermingled from time to time with life-threatening microbes surge across. Surprisingly, approximately one out of the five cells in the intestinal epithelium are lymphocytes, most of which are ill-defined T cells having unusual, but distinctive characteristics and situated apparently so close to external antigens in the entire body. This article deals with the information that has been accumulated mainly in the past decade concerning the development, phenotypes, and possible function of these yet unacknowledged mucosal T cells that lurk in the anatomical front of the intestine.

Selectivity of muscarinic agonists including (+/-)-aceclidine and antimuscarinics on the human intraocular muscles

The average EC50 value and the maximum response of carbachol on the human circular ciliary muscle obtained within 24 h of postmortem hypoxia was 517 nmol/l and 135 mg, respectively. These values for carbachol did not differ significantly from that of the longitudinal ciliary muscle. However, when tested at 1 mumol/l of carbachol, the peak response of the longitudinal muscle occurred at 59 sec vs 173 sec for that of the circular muscle of 70 year old donors. The relative potency of the muscarinic agonists on the circular muscle was oxotremorine-M, 1 > carbachol, 1/4 > pilocarpine, 1/19 > aceclidine, 1/132. The relative order of potency of agonists was similar for the longitudinal muscle. Only pilocarpine and aceclidine were partial agonists which produced 80-85% of the maximum response. When compared with the EC50 values of aceclidine on the iris sphincter and the longitudinal ciliary muscles, the agonist potency was only 1/28 for the latter tissue. Implications of these findings in relation to the use of these agonists in glaucoma are discussed. The pKB values of muscarinic antagonists on the circular ciliary muscle were: atropine, 8.8; cyclopentolate, 7.8; tropicamide, 7.4; P.F. HHSiD, 7.0; pirenzepine, 6.4; and methoctramine, 5.7. Nearly equal pKB values of each antagonist were obtained for the longitudinal ciliary muscle and iris sphincter. Based on the affinity constants of various competitive antagonists, the human iris as well as ciliary muscles may contain M3, M2 or M4 subtypes of muscarinic receptors.

Relation of interferon therapy and hepatocellular carcinoma in patients with chronic hepatitis C. Osaka Hepatocellular Carcinoma Prevention Study Group

BACKGROUND

The effect of interferon therapy on the incidence of hepatocellular carcinoma in chronic hepatitis C is poorly defined.

OBJECTIVE

To compare the incidence of hepatocellular carcinoma in interferon-treated patients with chronic hepatitis C to that of historical controls and to examine whether response to therapy is related to incidence of hepatocellular carcinoma in patients with chronic hepatitis C.

DESIGN

Retrospective cohort study.

SETTING

One university hospital and seven university-affiliated hospitals.

PATIENTS

419 consecutive patients with chronic hepatitis C who started interferon therapy between January 1992 and December 1993 (interferon group) and 144 patients with chronic hepatitis C who had liver biopsy between January 1986 and December 1989 and did not receive interferon (controls).

INTERVENTION

Patients in the interferon group received human lymphoblastoid interferon, recombinant interferon-alpha2a, or recombinant interferon-alpha2b for 6 months.

MEASUREMENTS

The end point was development of hepatocellular carcinoma on abdominal ultrasonography or computed tomography. Sustained response was defined as persistent normalization of alanine aminotransferase (ALT) levels during interferon therapy and follow-up. Relapse was defined as a normal serum ALT level at the end of treatment with an increase to an abnormal level after cessation of treatment. Nonresponse included all other ALT patterns.

RESULTS

Median follow-up in the interferon and control groups was 47.6 and 46.8 months, respectively. During follow-up, hepatocellular carcinoma was found in 28 interferon-treated patients and 19 controls. Cox proportional hazards regression analysis that included all patients revealed that interferon therapy (P=0.041), older age (P=0.003), greater histologic activity (P=0.029), and higher histologic stage (P=0.049) were independent factors associated with the development of hepatocellular carcinoma. The risk ratios for development of hepatocellular carcinoma in patients with sustained response, relapse, and nonresponse were 0.06 (95% CI, 0.01 to 0.46), 0.51 (CI, 0.20 to 1.27), and 0.95 (CI, 0.48 to 1.84), respectively, compared with controls.

CONCLUSIONS

The incidence of hepatocellular carcinoma was lower in patients with sustained response to interferon therapy than historical controls and nonresponders. Interferon therapy may decrease the risk for hepatocellular carcinoma in patients with chronic hepatitis C.

Detection of deoxyribonuclease I along the secretory pathway in Paneth cells of human small intestine

The expression and distribution of deoxyribonuclease I (DNase I) in human duodenum, jejunum and ileum were examined by DNase I activity assay and the reverse transcriptase-polymerase chain reaction (RT-PCR), immunofluorescence, in situ hybridization, and immunocytochemical ultrastructural analyses. High levels of DNase I were detected in the cytoplasm of Paneth cells in human small intestine. A tissue homogenate fraction rich in Paneth cells showed strong DNase I-specific enzymatic activity. Immunofluorescence analysis using several specific anti-human DNase I antibodies showed very strong immunoreactivity in the cytoplasm of every Paneth cell. In situ hybridization demonstrated high levels of DNase I mRNA in Paneth cells. Immunogold electron microscopy revealed gold particles localized along the secretory pathway, with the exocrine secretory granules mostly labeled. Our findings strongly suggest that Paneth cells synthesize and secrete DNase I into the intestinal lumen.

Factors affecting image acquisition during scanning laser polarimetry

BACKGROUND AND OBJECTIVE

To illustrate artifacts that may be encountered during measurement of the peripapillary retinal nerve fiber layer (RNFL) using scanning laser polarimetry (SLP).

PATIENTS AND METHODS

A total of 426 patients with a variety of ocular diagnoses underwent RNFL measurements using SLP from June 1996 to April 1997. Scanning was performed by two operators whose reproducibility of measurements had been previously validated. Images were selected to illustrate clinical features that adversely affected measurement of the thickness of the RNFL.

RESULTS

Image acquisition was difficult in eyes with corneal grafts or edema, keratic precipitates, anterior uveitis, posterior subcapsular cataract, vitreous opacity, peripapillary atrophy, posterior staphyloma, and high axial myopia. These scans resulted in poor clinical correlation with visual field tests and optic nerve examination, poor reproducibility of images, and unreadable images.

CONCLUSION

Anterior and posterior segment pathologies, particularly those localized to the cornea and lens, may produce spurious RNFL measurements and should be carefully considered prior to clinical decision making.

Predictive value of preoperative serum sialyl Lewis X-i antigen levels in non-small cell lung cancer

BACKGROUND AND STUDY OBJECTIVE

Serum sialyl Lewis X-i antigen has been shown to be one of the most specific markers for monitoring non-small cell lung cancer(NSCLC). We evaluated the correlation between serum levels of sialyl Lewis X-i antigen and mediastinal lymph node involvement in NSCLC patients.

METHODS

One hundred patients with untreated NSCLC were included in this study. All the patients received surgical treatment and the lymph nodes were evaluated pathologically. Pretreatment sera from these patients examined for the levels of sialyl Lewis X-i antigen, using a radioimmunoassay.

RESULTS

Serum levels of sialyl Lewis X-i antigen levels in patients with N2 were higher than those of N0-1(p = 0.0049). According to the receiver characteristic curve analysis, the recommended cut-off level of the antigen between N0-1 patients and N2 patients was 38.0 U/ml.

CONCLUSION

Measurement of serum levels of sialyl Lewis X-i antigen might provide preoperative information in patients with NSCLC.

Effect of additives on refolding of a denatured protein

Denatured lysozyme was refolded by a dilution method. The refolding yield depended greatly on the lysozyme concentration in the refolding mixture. When the concentration of denatured lysozyme was 0.02 g/L, the refolding yield was as high as 60%. However, when the concentration of denatured lysozyme was 0.2 g/L, the refolding yield was as low as 10% due to the formation of aggregates. To prevent the formation of aggregates and to increase the refolding yield at a low cost, inexpensive additives were screened. The addition of acetone, acetoamide, or urea derivatives was very effective for improving the refolding yield. To clarify why the addition of acetoamide in the refolding mixture improved the refolding yield at the high lysozyme concentration, the time courses of the concentration and the average diameter of the aggregates in the refolding mixture were monitored by the dynamic light scattering method. The experimental results showed that acetoamide played a role in preventing the formation and growth of aggregates and secondary aggregation between the lysozyme aggregates.

Scar tissue distribution on palates and its relation to maxillary dental arch form

OBJECTIVE

This study investigated the relationship between maxillary dental arch form and distribution of postsurgical scar tissue on previously denuded bone in isolated cleft palate patients.

METHOD

The palatal blood flow of 21 Japanese isolated cleft palate patients (6 males, 15 females) was examined by laser doppler flowmetry to determine the scar tissue areas. All had undergone pushback operations for palatal repair at around 18 months of age. Tissue blood flow was examined at a time ranging from 11 years, 5 months to 19 years, 9 months of age. To evaluate the maxillary dental arch form, dental casts obtained at the start of orthodontic treatment (a mean age of 8 years, 4 months) were analyzed.

RESULTS/CONCLUSIONS

Scar tissue distribution in the 21 cases was classified into five types. Characteristic features in the maxillary dental arch form were found in each of the five types according to the extent of the scar tissue. It was evident that the severity of the maxillary dental arch constriction was closely related to the scar tissue distribution on palates.

High Fas ligand expression on lymphocytes in lesions of ulcerative colitis

BACKGROUND

The pathogenesis of ulcerative colitis is unclear, but cytotoxic T lymphocytes infiltrating the mucosa have been implicated in mucosal damage. The Fas ligand (FasL), expressed on cytotoxic T lymphocytes, induces apoptosis in cells expressing Fas.

AIM

To analyse FasL expression in affected colonic mucosa to ascertain Fas-FasL interaction in ulcerative colitis.

METHODS

FasL mRNA was quantified in colonic mucosal specimens from healthy subjects and patients with ulcerative colitis or Crohn's disease, using the competitive reverse transcription polymerase chain reaction. FasL mRNA localisation was determined by in situ hybridisation. Expression of Fas in colonic mucosa was analysed immunohistochemically. Phenotypes of lamina propria lymphocytes that expressed FasL were analysed by flow cytometry.

RESULTS

FasL mRNA was strongly expressed in active ulcerative colitis lesions, but not in those associated with active Crohn's disease or active proctitis-type ulcerative colitis. In situ hybridisation showed that FasL mRNA expression occurred in mononuclear cells infiltrating lesions. Fas was expressed in epithelial cells in ulcerative colitis and Crohn's disease, and in normal subjects. Cytometry showed that FasL was expressed in CD3 lymphocytes infiltrating the lamina propria in active lesions.

CONCLUSIONS

FasL is expressed in CD3 lymphocytes infiltrating into ulcerative colitis but not Crohn's disease lesions, suggesting that Fas-FasL induced apoptosis participates in the mucosal damage of ulcerative colitis.

Patterns of pancreatic metastasis from lung cancer

BACKGROUND

Metastatic involvement of the pancrease is not an uncommon autopsy finding, however, pancreatic metastasis is an infrequent clinical condition and the pattern of the metastases have not been studied. We conducted a retrospective study in order to evaluate the pattern of the metastasis from lung cancer.

PATIENTS

From 1976 to 1997, 26 patients with pancreatic metastasis were identified by searching the medical records of 850 patients with lung cancer.

RESULTS

The usual pattern of pancreatic metastasis involved a solitary nodule in 19 patients (73.1%); multiple nodules in 3(11.5%), and diffuse swelling in 4(15.4%). Nineteen(73.1%) and 18(69.2%) of 26 patients had liver and adrenal gland metastases, respectively.

CONCLUSIONS

Pancreatic metastasis represents a common site of extrathoracic spread of disease for the small number of patients with advanced lung cancer, especially in small cell lung cancer. The usual pattern of the metastasis is a solitary nodule. In order to diagnose exactly, abdominal CT scan would be helpful in such metastasis.

Cytotoxic enhancement of low dose-rate irradiation in human lung cancer cells by mild hyperthermia

PURPOSE

The aim of this study was to investigate the cell killing induced by low dose-rate irradiation (LDRI) simultaneously combined with long duration mild hyperthermia in LK87 human lung cancer cells. Cell cycle alteration due to this combined treatment was also observed.

MATERIALS AND METHODS

Human lung adenocarcinoma cells, LK87, were treated with concurrent LDRI (50 cGy/hr) and mild hyperthermia (38 to 42 degrees C). Cell survival was estimated by clonogenic assay. Flow cytometry was performed with FACScan. The treatments were simultaneously performed for up to 48 hr (24 Gy).

RESULTS

Survival curves of mild hyperthermia alone revealed development of chronic thermotolerance up to 48 hr, whereas LDRI plus hyperthermia caused an exponential decrease in survival. The LDRI cytotoxicities were enhanced by mild hyperthermia over a non-lethal temperature range. The Do values calculated from dose response curves at 37, 38, 39, 40, 41 41.5 and 42 degrees C were 6.55, 5.25, 4.24, 3.99, 3.46, 1.83 and 0.70 Gy, respectively. Cell cycle analysis demonstrated a remarkable G2 and a mild G1 block for LDRI alone, but only a G1 block was observed for LDRI combined with 41 degrees C hyperthermia.

CONCLUSION

The LDRI cytotoxicity was enhanced by long duration mild temperature hyperthermia. The suppression of chronic thermotolerance was considered to be a mechanism involved in this sensitization.

Diagnosis of squamous cell carcinoma arising from mature cystic teratoma of the ovary

BACKGROUND

The prognoses of patients with squamous cell carcinoma of the ovary are quite poor. However, preoperative diagnosis is difficult due to the rarity of this tumor and its similarity to mature cystic teratoma (MCT). The objective of this study was to assess the value of tumor markers and clinical characteristics in making a differential diagnosis between MCT and squamous cell carcinoma arising from MCT.

METHODS

Between September 1979 and June 1996, 37 patients with ovarian squamous cell carcinoma arising from MCT were treated by the Tokai Ovarian Tumor Study Group. The authors evaluated tumor markers, tumor size, and age as parameters for differentiation between MCT and squamous cell carcinoma arising from MCT. Diagnostic efficiency was calculated as the sensitivity multiplied by the specificity.

RESULTS

There were significant differences (P < or = 0.0002) in age, tumor size, and levels of squamous cell carcinoma antigen (SCC), CA125, and CEA, as well as a significant difference (P < or = 0.0396) in the CA19-9 level between MCT and squamous cell carcinoma arising from MCT. Diagnostic efficiency was highest for SCC (63.0%), followed by CA125 (50.7%). Receiver operating characteristic (ROC) curves demonstrated that CEA was the best screening marker for squamous cell carcinoma arising from MCT, whereas age and tumor size were better markers than CA125 or CA19-9. The optimal cutoff values for age and tumor size were 45 years and 99 mm, respectively, according to ROC analysis.

CONCLUSIONS

These findings demonstrate that age and tumor size are important factors in making a differential diagnosis. In addition, SCC and CEA levels should be measured in patients age 45 years or older who have an MCT-like ovarian tumor larger than 99 mm in greatest dimension.

Anti-Helicobacter pylori agents. 2. Structure activity relationships in a new series of 2-alkylguanidino-4-furylthiazoles

SAR for antimicrobial activity against H. pylori was investigated in a new series of 2-alkylguanidino-4-furylthiazoles. Of the compounds obtained, cyclohexylmethyl and ethoxyethyl derivatives were identified as a novel class of anti-H. pylori agents which possessed potent and selective antimicrobial activity against H. pylori. These compounds also showed gastric antisecretory activity.

Collagen production by cultured human retinal pigment epithelial cells

We investigated extracellular matrix produced by human retinal pigment epithelial cells (RPE) in vitro using electron microscopy and enzyme linked immunosorbent assay (ELISA). The thickness of the matrix under the cell layer was about 30 microns after 360 days of culture. It consisted mainly of fibrous and granular components. Type IV and V collagen were detected but type I and III were not detected by ELISA. It appeared that RPE can secrete type IV and V collagen and form a thick membrane which may cause proliferative vitreoretinopathy (PVR) by contraction. Control of RPE proliferation and secretion of extracellular matrix is indispensable for prevention of PVR.

Diagnosis of squamous cell carcinoma arising from mature cystic teratoma of the ovary

BACKGROUND

The prognoses of patients with squamous cell carcinoma of the ovary are quite poor. However, preoperative diagnosis is difficult due to the rarity of this tumor and its similarity to mature cystic teratoma (MCT). The objective of this study was to assess the value of tumor markers and clinical characteristics in making a differential diagnosis between MCT and squamous cell carcinoma arising from MCT.

METHODS

Between September 1979 and June 1996, 37 patients with ovarian squamous cell carcinoma arising from MCT were treated by the Tokai Ovarian Tumor Study Group. The authors evaluated tumor markers, tumor size, and age as parameters for differentiation between MCT and squamous cell carcinoma arising from MCT. Diagnostic efficiency was calculated as the sensitivity multiplied by the specificity.

RESULTS

There were significant differences (P < or = 0.0002) in age, tumor size, and levels of squamous cell carcinoma antigen (SCC), CA125, and CEA, as well as a significant difference (P < or = 0.0396) in the CA19-9 level between MCT and squamous cell carcinoma arising from MCT. Diagnostic efficiency was highest for SCC (63.0%), followed by CA125 (50.7%). Receiver operating characteristic (ROC) curves demonstrated that CEA was the best screening marker for squamous cell carcinoma arising from MCT, whereas age and tumor size were better markers than CA125 or CA19-9. The optimal cutoff values for age and tumor size were 45 years and 99 mm, respectively, according to ROC analysis.

CONCLUSIONS

These findings demonstrate that age and tumor size are important factors in making a differential diagnosis. In addition, SCC and CEA levels should be measured in patients age 45 years or older who have an MCT-like ovarian tumor larger than 99 mm in greatest dimension.

Ultrastructural observations of astrocyte end-feet in the rat central nervous system

Astrocytic end-feet in the rat CNS were studied by thin section electron microscopy. Astrocyte processes that enclose neuronal elements extended to blood vessels and the pia mater, where the processes expanded to form end-feet or glial limiting membranes. At the end-feet, cell junctions such as gap junctions and desmosome-like junctions were formed between the astrocyte processes. The end-foot plasma membrane facing the basal lamina was undercoated with electron-dense, layered materials, with an internal substructure of filamentous networks, with which bundles of glial filaments (GFs) appeared to be closely associated via fine filamentous structures, often showing a hemi-desmosome-like appearance. In specimens treated with Triton X-100, the internal substructure of the undercoat was better visualized and the association with GFs was well preserved. At the end-feet, some unique tubular structures were found in spatial relationship to the plasmalemmal undercoat. Plectin visualized by immunofluorescence was localized to astrocytes and their processes, especially at the end-feet facing the pia mater. Immunoelectron microscopy located plectin on fine filamentous structures lying between GFs and the plasmalemmal undercoat. These observations suggest that plasmalemmal undercoats at the astrocyte end feet may serve as attachment sites of GFs to the plasma membrane and that plectin may be involved in such attachment.

Establishment and characterization of melanoma cell line derived from malignant melanoma of human uterine cervix

A cell line designated HOMM (human Okuno Malignant Melanoma) was established from the uterine cervical malignant melanoma of a 65-year-old Japanese woman. The cell line has grown well and serial passages were successively carried out 32 times within 19 months. The monolayer cultured cells revealed anaplastic and pleomorphic features, and grew in multilayers. They had long cell protrusions and many dark brown pigments. Immunocytochemical stain revealed that S-100 protein existed in the cytoplasm. Electron micrographs also revealed that they had a number of pre-melanosomes and melanosomes in the cytoplasm. All cultured cells were triploid, the modal chromosome number was 68 and the marker chromosomes were presented. The cells were transplanted into an immune-suppressed hamster's cheek pouch and produced a malignant melanoma resembled original tumor.

Correlated confocal and intermediate voltage electron microscopy imaging of the same cells using sequential fluorescence labeling, fixation, and critical point dehydration

Confocal laser scanning microscopy (CLSM) and intermediate voltage transmission electron microscopy (IVEM) each has its own particular advantages. CLSM can examine living cells, but is particularly useful when applied to cells that have been lightly fixed, permeabilized, and stained with fluorescent-labeled antibodies for localization of specific molecular species at the resolution of the light microscope while still in the hydrated state. IVEM provides much higher resolution images, but requires more drastic preparation procedures, including dehydration. This paper presents methods for combining these complementary approaches to examine exactly the same cells sequentially by CLSM and IVEM. Cells are grown in culture on sterile formvar films spread over gold index grids on cover glasses, which are mounted on larger cover glasses or microscope slides with spacers to prevent compression of the cells. Light and epifluorescence microscopy, and CLSM are performed concentrating on cells in grid openings. Then the grids are fixed with aldehydes followed by OsO4, dehydrated and critical point dried (CPD) from liquid CO2. Immediately following CPD, the grids are ready for examination in the IVEM. Low magnification (300-600x) survey images allow correlation of the IVEM images with the light microscopic images. In higher power images, structures that are fluorescent labeled can be related to corresponding regions in the IVEM images.

Plasma D-dimer level in patients with colorectal cancer: its role as a tumor marker

The purpose of this study was to explore the relationship between the preoperative plasma D-dimer (DD) levels and the tumor pathology of colorectal cancer. The plasma DD levels were measured preoperatively in 108 patients with colorectal cancer, and then were correlated with the tumor pathology and stage. The diagnostic value of the DD levels for the tumor stage was then compared with that of the preoperative carcinoembryonic antigen (CEA) levels. The preoperative DD levels were higher in patients with either a large-sized tumor or a tumor showing deep wall penetration. Lymph-node metastasis, lymphatic invasion, hepatic metastasis, and peritoneal dissemination were all associated with higher DD levels. A stepwise increase in the median DD level was found with the tumor stage. The preoperative DD levels also significantly correlated with CEA levels. When a cutoff value of 0.6 microg/ml was used in the DD assay, the sensitivity and specificity for Dukes C or D cancer were 67.2% and 64.0%, and those for Dukes D cancer were 91.3% and 57.6%, respectively. Although the DD assay was less specific, its diagnostic value in the preoperative staging of colorectal cancer was comparable to that of the CEA assay. The measurement of the preoperative DD level is thus considered to be useful for the preoperative staging of colorectal cancer.

Functional morphology of serially linked skeletal muscle fibers

In the skeletal muscle fiber organization of many vertebrate muscles, serial arrangements or linkages of muscle fibers along the muscle or fascicle are commonly found. These serially linked muscle fibers employ distinct junctional morphologies from muscle to muscle. Notable are the end-to-end linkages of muscle fibers through tendinous intersections (TIs), where many fibers end onto a continuous connective tissue plate with folded terminations similar to myotendinous junctions. Besides this end-to-end linkage, overlapping linkages or arrangements occur among nonspanning fibers terminating intrafascicularly. These nonspanning fibers bear tapering terminations with direct cell-cell (myomuscular) junctions or without any specialized junctions. Despite their overlapping linkages or tapering profiles, nonspanning fibers maintain a uniform sarcomere length along the linked fibers, suggesting that the overlapping-linked nonspanning fibers are equivalent to the end-to-end linked fibers in their mechanical capacity. However, the junctional compliance could differ in their extracellular elastic components and their organization at junctional sites, e.g., direct mechanical (myomuscular) junctions vs. indirect linkages through connective tissue. Increasing evidence suggests that the elastic components, including muscle fibers as well as connective tissues, are more critical than previously thought for the mode and/or the efficiency of tension transmission among serially arranged fibers and thus for the mechanical properties of the muscle.

Angiocytotoxic therapy in human non-small cell lung cancer cell lines--advantage of combined effects of TNP-470 and SN-38

The combined effects of TNP-470, a promising antiangiogenic agent, and SN-38, a camptothecin derivative, were evaluated in four human cultured cell lines derived from non-small cell lung cancer (NSCLC). Cytotoxicity experiments were determined by using a tetrazolium salt (MTT) assay. The inhibitory effects of TNP-470 on cell proliferation were dose related and the 50% inhibitory concentrations on these cell lines were 47.3-139.8 microM. Evaluation of drug interactions with isobologram and the combination index values showed that sequential exposure to SN-38 followed by TNP-470 produced synergistic effects in the four cell lines tested. Our findings suggest that such an angiocytotoxic chemotherapy might be promising for the treatment of NSCLC.

Three-dimensional analysis of the developing pituitary gland in the mouse

Prenatal development of the mouse pituitary gland was analyzed in three-dimensions by using confocal laser-scanning microscopy. In any wholemount preparation of the fetal pituitary gland from day 10 to day 18, immunofluorescence of laminin was observed in the deeper regions of the organ and demarcated the boundary of the epithelial tissue from the surrounding mesenchyme. Three-dimensional capillary networks in the fetal pituitary gland at day 13, day 15, and day 18 were visualized clearly by perfusing the blood vessels with an fluorescein isothiocyanate-labelled gelatin solution. During days 12-14, cellular plates protruded from the anterior wall of the pituitary anlage and extended toward the base of the infundibulum. At the same time, the mesenchyme situated among the cellular plates separated from the surrounding mesenchyme except at the anteroventral portion of the anlage. In a posterior wall of the anlage, intercellular depositions of laminin were found among the epithelial cells, some of which reached the laminin sheet in the basement membrane of the anlage. From days 15-18, the pituitary gland enlarged, and the mesenchyme spread radially from the median anteroventral portion to the lateral, posterior, and dorsal regions and finally expanded throughout the entire organ. At the periphery, the mesenchyme in the pituitary gland connected with that surrounding the capsule. Laminin was still found in the intercellular spaces between the epithelial cells, and most of the intercellular depositions of laminin were combined with the laminin sheet in the epithelial basement membrane. An abundance of vessels entered the organ from its anteroventral portion, spread, and connected with one another throughout the gland, similar to the distribution of mesenchyme. Intercellular laminin would induce the polarization of the contacting epithelial cells, resulting in rearrangement of the epithelial cells. The mesenchyme might spread in the pituitary gland, providing the intercellular laminin a foothold, in order to cleave the epithelial cell mass into lobules. The development of capillary nets in the adenohypophysis corresponded well with that of the mesenchyme. Because laminin localizes mainly in the basement membrane in the fetal organs, immunostaining of laminin clearly indicates the boundary between epithelial tissue and the mesenchyme. Three-dimensional observation of laminin in wholemount preparation is very useful for studying morphogenesis.