Id2 gene-targeted crosstalk between Wnt and retinoid signaling regulates proliferation in human keratinocytes.

We investigated the effect of all-trans-retinoic acid (atRA) on proliferation in several human skin cell lines and found that antiproliferative potency of atRA correlated with the endogenous activity of canonical Wnt signaling. In HaCaT keratinocytes, we found that atRA significantly suppressed the expression of Id2, a member of the inhibitor of differentiation family of transcription factors that regulate cell growth and differentiation. However, no apparent change in the expression of other Wnt targets, like c-Myc or cyclin D1, was observed. Retinoid-induced Id2 gene suppression was associated with decreased levels of histone H3 and H4 acetylation and histone H3 Lys-4 methylation, and with recruitment of the LSD1 demethylase at the Wnt-response element (WRE) (TCF/LEF-binding site), in the Id2 gene promoter. None of such changes was detected at the WRE of c-Myc and cyclin D1 gene promoters. Inhibition of Id2 by short interfering RNA (siRNA) had a similar effect on the proliferation of HaCaT cells as exposure to atRA, whereas anti-beta-catenin siRNA significantly inhibited its antiproliferative effect. These data suggest that downregulation of Id2 gene expression through transcriptional convergence between Wnt and retinoid signaling pathways underlies the antiproliferative effect of retinoids in keratinocytes, and provide evidence of gene-targeted crosstalk between signaling pathways.

Inhibition of human chondrosarcoma cell growth via apoptosis by peroxisome proliferator-activated receptor-gamma.

A rare immunohistochemical study using 28 surgical sections of human chondrosarcoma revealed that 67.9% of tumour cells had weak (10-40%) or strong (>40%) positive immunoreaction for peroxisome proliferator-activated receptor-gamma. The expression of peroxisome proliferator-activated receptor-gamma mRNA and protein in human chondrosarcoma cell line OUMS-27 was also determined by reverse transcription-polymerase chain reaction and immunocytochemistry, respectively. Furthermore, the effects of peroxisome proliferator-activated receptor-gamma ligands on cell proliferation and survival were investigated in OUMS-27 cells. Pioglitazone, a selective ligand for peroxisome proliferator-activated receptor-gamma, and 15-deoxy-Delta(12,14)-prostaglandin J(2) (15d-PGJ(2)), a putative endogenous ligand for peroxisome proliferator-activated receptor-gamma, inhibited the proliferation of OUMS-27 cells in a dose-dependent manner. The mechanism of cytotoxic effects of 15d-PGJ(2) was via apoptosis as shown by DNA fragmentation using TUNEL stain and DNA ladder formation, and by ultrastructural analysis using transmission electron microscopy. Flow-cytometric analysis using annexin-V-fluorescein and propidium iodide detected the early change of apoptosis, as well as necrosis of OUMS-27 cells at 4 h after co-incubation with 15d-PGJ(2). These results suggest that peroxisome proliferator-activated receptor-gamma may play a significant role in the pathogenesis of chondrosarcoma, and peroxisome proliferator-activated receptor-gamma ligands, especially 15d-PGJ(2), may be of therapeutic value in the treatment of human chondrosarcoma.

Alteration of a single amino acid in peroxisome proliferator-activated receptor-alpha (PPAR alpha) generates a PPAR delta phenotype.

Three pharmacologically important nuclear receptors, the peroxisome proliferator-activated receptors (PPARs alpha, gamma, and delta), mediate key transcriptional responses involved in lipid homeostasis. The PPAR alpha and gamma subtypes are well conserved from Xenopus to man, but the beta/delta subtypes display substantial species variations in both structure and ligand activation profiles. Characterization of the avian cognates revealed a close relationship between chick (c) alpha and gamma subtypes to their mammalian counterparts, whereas the third chicken subtype was intermediate to Xenopus (x) beta and mammalian delta, establishing that beta and delta are orthologs. Like xPPAR beta, cPPAR beta responded efficiently to hypolipidemic compounds that fail to activate the human counterpart. This provided the opportunity to address the pharmacological problem as to how drug selectivity is achieved and the more global evolutionary question as to the minimal changes needed to generate a new class of receptor. X-ray crystallography and chimeric analyses combined with site-directed mutagenesis of avian and mammalian cognates revealed that a Met to Val change at residue 417 was sufficient to switch the human and chick phenotype. These results establish that the genetic drive to evolve a novel and functionally selectable receptor can be modulated by a single amino acid change and suggest how nuclear receptors can accommodate natural variation in species physiology.

Autoimmune hemolytic anemia in allergic granulomatous angitis (Churg-Strauss syndrome).

We describe a patient with allergic granulomatous angitis who developed autoimmune hemolytic anemia (AIHA). A 44-year-old male had been suffering from bronchial asthma. On admission, laboratory tests revealed the presence of severe eosinophilia (21,500/microliters), elevation of total immunoglobulin E (IgE), high lactic dehydrogenase (LDH) and low haptoglobin levels, in addition to moderate reticulocytosis. During admission, the patient showed almost simultaneous occurrence of vasculitis in the extremities, severe hemolysis and exacerbation of asthma in relation to the progression of eosinophilia. Both IgM and IgG autoantibodies were considered to be responsible for hemolysis. Interestingly, serum levels of interleukin-4 (IL-4) and IL-5 were increased in association with eosinophilia and increased IgE production. These findings suggest that the AIHA in this patient is mediated or enhanced at least partly by high IL-4 and IL-5 production. Although AIHA in this syndrome is very rare, it should be considered as a clinical manifestation.

[MR imaging of compressive cervical myelopathy after surgery--high signal intensity of the spinal cord on T2 weighted images].

We reviewed the MR images of 32 patients with cervical myelopathy, showing lesions of high signal intensity in the spinal cord on the sagittal T2 weighted images (T2WI) after surgery: 16 with OPLL; 9 with spondylosis; 4 with disc herniation and 3 with trauma. All images were obtained on a superconducting 1.5 Tesla system. The lesions were classified into five groups, according to the shape and grade of signal intensity on the sagittal T2WI: (I) oval-shaped lesion of signal intensity less brighter than CSF with blurred margin, (II) longitudinal linear-shaped lesion of signal intensity similar to CSF, (III) spindle-shaped lesion of signal intensity similar to CSF, (IV) round-shaped lesion of signal intensity similar to CSF and (V) mixed-types lesions which consisted of group I and II. The present study was summarized as follows: 1) Oval-shaped lesions were seen in the cases of disc herniation and spondylosis with relatively short duration of the symptom, presumptively with relatively short duration of the symptom, presumptively indicative of edema. 2) Most cases of OPLL and spondylosis showed linear-shaped lesions, suggesting necrosis and/or cavitations of the central gray matter. 3) One case of spondylosis developed a spindle-shaped lesion, implicating syringomyelia. 4) Round-shaped lesions were seen in the cases of spinal trauma, suggesting posttraumatic cyst. 5) In a case of mixed-typed lesion examined pre- and postoperatively, only an oval-shaped lesion decreased in size after surgery.

[CT-guided biopsy of thoracic mass lesions followed by fast stain technique].

We performed CT-guided needle biopsy of 92 thoracic mass lesions using a Rotex-II screw needle. Fast stain technique was performed for an immediate evaluation of the specimen in the last 39 procedures. The overall accuracy of malignancy was 93.2%, and the correct histological typing was obtained in 82.8% of malignancy proven at surgery or autopsy. The method enabled histopathological diagnosis of thoracic lesions, which could not obtained by other diagnostic modalities including fiberoptic bronchoscopy or fluoroscopy-guided biopsy. The true positive rate increased up 10.2% to 91.3% by introducing fast stain technique. A close cooperation between radiologists and cytopathologists was essential for performing this CT-guided biopsy procedure followed by fast stain technique.

[MR imaging for lung cancer in evaluating local invasion; referring to CT and surgical-histological basis].

The diagnostic potentiality of MR imaging for lung cancer was researched in 17 patients in evaluating local invasions based on surgical-histological evidence. Comparative reviewing with CT was also performed. MR imaging appeared to have an ability unique to portray malignant invasions somewhere such as in the hili or apices. On the other hand, there were also some diagnostic limitations of MR imaging in delineating the localized invasive changes. On the way of working up lung cancer, CT still may stand at the first choice as a radiographic staging procedure which provides the more detailed anatomic-pathologic informations. We consider that MR imaging is mandatory when CT and/or other modalities could'not obtain efficient results.

[CT of hypersensitivity pneumonitis].

High resolution computed tomography (CT) was applied to seven patients with hypersensitivity pneumonitis clinically confirmed. The CT findings include; (1) granular pattern with acino-centric distribution, (2) increase in density of haziness in the lung fields, (3) multiform high density areas, and (4) "subpleural curvilinear shadow" localized posteriorly. Of these findings, which severally varied degree during clinical course, the haziness showed the most remarkable fluctuation. It was especially of interest that the relapsed haziness distributed quite in the same regions. High resolution CT may be an effective adjuvant tool for hypersensitivity pneumonitis when applied to the opportune evaluation through the clinical course.

Immune status in two brothers with Omenn's syndrome: no discernible chimerism on FACS analysis using a monoclonal antibody specific for a maternally restricted HLA antigen.

Sequential immunologic examinations, including lymph node biopsies, in two brothers with clinical characteristics of Omenn's syndrome are presented in this study. Although the number of circulating T cells with mature phenotype (OKT3+, TCR1+) was within normal range, the lymphocyte proliferative response to mitogens was poor. Examinations of the lymph nodes revealed marked lymphoid depletion associated with eosinophilic infiltration and reticular cell proliferation. Over the clinical course of 5 months, circulating T cells also mostly disappeared. Thymic hypoplasia was noted at autopsy. Although intrauterine graft-versus host disease (GVHD) has been hypothesized as being the pathogenetic mechanism in this syndrome, maternal lymphocytes circulating in these patients were not identified either by karyotype and HLA typing or by highly sensitive FACS analysis and immunohistochemical studies using a monoclonal antibody, HLA-A9, specific for a maternally restricted HLA antigen, Aw24. In conclusion, the familial occurrence and the absence of maternal chimerism might be the essential features of Omenn's syndrome which should be differentiated from fetal GVHD.

[DS-bronchial arteriography; demonstration of metastasized lymphnodes of lung cancer--with special reference to the primary effect in BAI].

We analysed the 44 DS-Bronchial arteriograms (DSBAG) of lung cancer with an attention to the demonstration of metastasized mediastinal lymphnodes. The stain of lymphnode is well demonstrated in the pericarinal region, such as station #7, #R4 along the course of bronchial arteries. The swollen nodes with stains on DSBAG show the good reduction rates (37.5%) after BAI that is analogous to the primary lesion (38.9%), in contrast to the nodes without stains (24.5%). DSBAG with excellent contrast resolution contributes to the BAI as verifying the infused area.

[High resolution computed tomography of diffuse interstitial pneumonia during treatment].

HRCT was carried out in twenty patients with diffuse interstitial pneumonia: 13 cases of IIP, 3 of BOOP, 2 of drug-induced pneumonia, 1 of rheumatoid lung and acute interstitial pneumonia of unknown origin. With special attention to inflammatory activity, the patients underwent HRCT periodically during the treatment. Correlative investigation between HRCT image and grade of accumulation in 67Ga scintigraphy was also performed. Response to steroid therapy was clearly reflected on HRCT image, that was shown as decreasing pulmonary density or thinning of honeycomb wall. HRCT is considered to be useful in assessing the activity of diffuse interstitial pneumonia.

Effects of somatostatin deficiency on cell distribution within the Langerhans islets.

Insulin, glucagon and somatostatin (SLI) in the pancreas and the gastrointestinal tissue of rats were measured following a high (300 mg/kg) or low (150 mg/kg) dose of cysteamine, given intermittently for 14 days. In addition, the effect of prolonged cysteamine-induced depletion of pancreatic SLI upon the cell distribution within the Langerhans islets was compared with that of chronic insulin-deficient rats produced by streptozotocin. The high or low dose of cysteamine reduced pancreatic SLI to 8.3% and gastrointestinal SLI to 5.6% of control levels without duodenal ulcer. The high dose of cysteamine also reduced pancreatic insulin to 37% of controls without hyperglycemia. No change in the glucagon concentration was observed. In SLI-deficient rats, distribution of A and B cells was similar to that of controls, even though D cells were rarely seen. In insulin-deficient rats, however, the number of A and D cells per islet area increased with a concomitant decrease in B cells. Intermittent administration of a low dose of cysteamine, thus, appears to be useful to produce a chronic SLI-deficient rat. However, a high dose of cysteamine is not a specific depletor of pancreatic SLI. Although insulin may be important to maintain normal cell distribution within the islets, pancreatic SLI may not have such a role.