Downregulation of microRNA-126 in endothelial progenitor cells from diabetes patients, impairs their functional properties, via target gene Spred-1

Diabetes mellitus (DM) adversely affects the number and function of circulating endothelial progenitor cells (EPCs). Consequently, there is also a reduction in the repair mechanism of these cells, which is a critical and initiating factor in the development of diabetic vascular disease. The aim of the present study was to analyze miR expression profiles in EPCs from patients with DM and choose the most significantly regulated miR to study its possible role on EPC dysfunction and elucidate its mechanism of action. EPCs were collected from subjects with Type II DM and non-diabetic control subjects. Total RNA was harvested from EPCs, and a total of 5 candidate miRNAs were identified by microarray screening and were quantified by TaqMan real-time PCR. Lentiviral vectors expressing miR-126 and miR-126 inhibitor (anti-miR-126) were transfected into EPCs, and the EPC colony-forming capacity, proliferation activity, migratory activity, differentiation capacity, and apoptotic susceptibility were determined and Western Blotting and mRNA real-time PCR analyses were performed. To study the mechanisms, lentiviral vectors expressing Spred-1 and a short interfering RNA (siRNA) targeting Spred-1 were prepared. Five miRs were aberrantly downregulated in EPCs from DM patients. These miRs included miR-126, miR-21, miR-27a, miR-27b and miR-130a. Anti-miR-126 inhibited EPC proliferation, migration, and enhanced apoptosis. Restored miR-126 expression in EPCs from DM promoted EPC proliferation, migration, and inhibited EPC apoptosis ability. Despite this, miR-126 had no effect on EPC differentiation. miR-126 overexpression significantly downregulated Spred-1 in EPCs. The knockdown of Spred-1 expression in EPCs from DM promoted proliferation, migration, and inhibited apoptosis of the cells. The signal pathway of miR-126 effecting on EPCs is partially mediated through Ras/ERK/VEGF and PI3K/Akt/eNOS regulation. This study provides the first evidence that miR-126 is downregulated in EPCs from diabetic patients, and impairs EPCs-mediated function via its target, Spred-1, and through Ras/ERK/VEGF and PI3K/Akt/eNOS signal pathway.

Identification and characterization of the Oct4 extended transcriptional regulatory region in Guanzhong dairy goat

The octamer-binding transcription factor 4 gene (Oct4) plays a critical role in maintaining pluripotency during early mammalian embryonic development and self-renewal of embryonic stem (ES) cells. In this study, we cloned the Oct4 cDNA and 2.8-kb regulatory region upstream of the start codon in Guanzhong dairy goat ( Capra hircus ). The comparative sequence analysis of Oct4 cDNA showed that it was highly conserved among six mammalian species. The goat Oct4 5' regulatory regions were homologous to the corresponding regions of Oct4 in other species and were functional in directing the expression of luciferase in mouse P19 embryonic carcinoma cells and mouse J1 ES cells. Furthermore, the methylation levels in the goat Oct4 minimal promoter and proximal enhancer in the fetal genital ridge were lower than those in the heart. Additionally, two processed pseudogenes that shared high homology with goat Oct4 cDNA were identified and characterized.

Magnetic resonance imaging contrast agent: cRGD-ferric oxide nanometer particle and its role in the diagnosis of tumor

To construct tumor-targeted nanometer particles as a negative magnetic resonance imaging (MRI) contrast agent. Ultra-small superparamagnetic iron oxide (USPIO) nanometer particles were prepared by one-step chemical precipitation. The covalent bond between cyclic RGD (cRGD) containing an Arg-Gly-Asp sequence targeting integrin-alphavbeta3, and USPIO was conducted by chemical crosslinking. The physico-chemical property of cRGD-USPIO was detected. Prussian blue staining was applied to detect the specific binding capacity of cRGD-USPIO and USPIO to human pulmonary adenocarcinoma A549 cells and human umbilical vein endothelial cells. Subsequently, A549 xenografts in nude mice were established, and intravenous injections of USPIO and cRGD-USPIO into the vena caudalis were performed. The enhancement of cRGD-USPIO against tumor MRI signal was evaluated. The mean hydrodynamic diameter of cRGD-USPIO was 43.97 +/- 10.10 nm and the size of the ferric oxide core was 5-10 nm. The specific saturation magnetization was 59.94 A x m2 x Kg(-1). The cell conjugation assay results indicated that the positive staining of the cRGD-USPIO group was significantly enhanced. The in vivo MRI diagnosis indicated that the cRGD-USPIO tumor signal was significantly reduced compared to that of the USPIO group (P < 0.01). The targeted superparamagnetic iron oxide nanometer particle can be a novel MRI negative contrast agent for more specific tumor early diagnosis.

[Quantitative analysis of telomerase reverse transcriptase gene expression in goat reprogramming cells]

Currently, animal somatic cell reprogramming into the induced pluripotent stem cell (iPS) is one of the hottest research target in the field of cell biology. We focused on the analysis of telomerase reverse transcriptase (TERT) gene expression during goat somatic fibroblasts reprogramming, and investigated the relationship between the expression of TERT and the pluripotency of reprogrammed cells. RNA samples of fetal tissues isolated from Guanzhong milk goat fetus, and the induced goat reprogramming cell clones were used to determine the relative expression levels of TERT by the real-time RT-PCR method. Goat embryonic fibroblasts (GEF) collected from the Guanzhong milk goat with normal karyotype were induced by 4 transcription factors to become reprogramming cells. The expression of TERT in reprogramming cells was detected by Real-time RT-PCR. The results showed that the expression of TERT in testis tissue was higher than that in epithelial tissues (P < 0.01). The expression level of TERT was higher in AP staining positive cells than that in AP staining negative cells (P < 0.01). This result indicated that TERT activity played an important role in cell reprogramming.

Enhanced antitumor effect of novel dual-targeted paclitaxel liposomes

A novel dual-targeted peptide containing an alpha V integrins specific ligand and a neuropilin-1 specific motif was developed which showed an increased specific targeting affinity to tumors. Active dual-targeted liposomes were then produced with this peptide and exhibited greater binding activity than single-targeted liposomes in vitro. Paclitaxel entrapped in this formulation greatly increased the uptake of paclitaxel in the targeting cells and significantly suppressed the growth of HUVEC and A549 cells compared with general paclitaxel injections (Taxol) and single-targeted paclitaxel liposomes. The treatment of tumor xenograft models with dual-targeted paclitaxel liposomes also resulted in better tumor growth inhibition than any other treatment groups. Therefore, the dual-targeted paclitaxel liposomes prepared in the present study might be a more promising drug for cancer treatment. Furthermore, the dual-targeting approach may produce synergistic effects that can be applied in the development of new targeted drug delivery systems.

Impact of obstructive sleep apnoea on clinical characteristics and outcomes in patients with acute coronary syndrome following percutaneous coronary intervention

This study tested whether obstructive sleep apnoea syndrome (OSAS) influenced clinical characteristics and outcomes after successful percutaneous coronary intervention (PCI) in 123 consecutive patients with acute coronary syndrome (ACS). Patients with an apnoea-hypopnea index (AHI) >or= 5 were considered as having OSAS. Carotid ultrasonography and echocardiography were performed, and C-reactive protein (CRP) and fibrinogen were measured. Co-existence of ACS and OSAS occurred in 76 patients (61.8%) and patients with OSAS had a greater interventricular septum thickness (IVST) and higher levels of CRP than non-OSAS patients. In an elderly subpopulation (>or= 75 years of age), two-vessel disease was significantly more common and fibrinogen levels were significantly higher in OSAS than non-OSAS patients. Carotid intima-media thickness (IMT) correlated with the AHI in ACS patients. In elderly ACS patients, IMT, Gensini score and fibrinogen correlated with AHI. Patients were followed up for 1 year for major adverse cardiac events (MACEs) and no significant difference in major MACEs was found after this period between OASAS and non-OSAS patients. This study indicates that OSAS is associated with inflammation and increased IVST in ACS patients after successful PCI and, in elderly ACS patients, also with CAD severity and enhanced blood coagulability.

Evidence of spin glass dynamics in dilute LiHoxY1-xF4

ac susceptibility measurements are presented on the dilute, dipolar coupled, Ising magnet LiHoxY1-xF4 for a concentration x=0.045. The frequency and temperature dependences of the susceptibility show characteristic glassy relaxation. The absorption spectrum is found to broaden with decreasing temperature suggesting that the material is behaving as a spin glass and not as an exotic spin liquid as was previously observed. A dynamical scaling analysis suggests a spin glass transition temperature of 43+/-2 mK with an exponent znu=7.8+/-0.2.

Methods for isolating circulating epithelial cells and criteria for their classification as carcinoma cells

Novel assay methods developed for the isolation and characterization of circulating tumor cells (CTC) of epithelial origin offer the potential of markers for the non-invasive gathering of clinical information relevant to the diagnosis, evolution and treatment of carcinoma. Of the numerous techniques currently used to analyze CTC, slide-based assays are perhaps the most common. While traditional combined immunocytochemical/brightfield microscopy systems continue to be the most frequently employed, fluorescence-based analysis is gaining in importance. This is partly because fluorescence microscopy analysis of slide-mounted CTC can provide simultaneously cytogenetic as well as morphologic and multiple phenotypic information. In particular, fluorescence microscopy analysis of slide-mounted CTC can accurately determine genetic changes at the chromosomal level in patients with recurrent disease. More importantly, by identifying genetic aberrations in CTC, it becomes possible to choose those patients most likely to benefit from a given treatment. The potential of this technique has already been demonstrated by employing fluorescence in situ hybridization (FISH) methods to measure expression of the HER2/neu gene in tissue from patients with breast carcinoma for the specific purpose of identifying those patients most likely to respond to Trastuzumab targeted therapy. Here, we review the major methodologies used in the preparation and analysis of the slide-based assays.

Cerebral blood flow response to a hypoxic-ischemic insult differs in neonatal and juvenile rats

To compare the cerebral blood flow (CBF) response to a transient episode of hypoxia-ischemia producing damage in neonatal and juvenile rats. One- and four-week-old rats were subjected to unilateral carotid artery occlusion plus hypoxia (8% oxygen). Perfusion MR images were acquired either in sham controls or in hypoxic-ischemic rats before, during, 1 h and 24 h after hypoxia-ischemia. At 24 h post hypoxia-ischemia, T2 maps and histology were used to assess damage. In sham controls, CBF increased twofold between the age of one and four weeks. Reductions in CBF ipsilateral to the occlusion occurred during hypoxia-ischemia followed by a substantial recovery at 1 h post in both age groups. However, contralaterally, hyperemia occurred during hypoxia-ischemia in four-week but not one-week-old rats. Similarly, hyperemia occurred ipsilaterally at 24 h post hypoxia-ischemia in four-week but not one-week-olds, corresponding to the distribution of elevations in T2. Despite CBF differences, extensive cell death occurred ipsilaterally in both age groups. The CBF responses to hypoxia-ischemia and reperfusion differ depending on postnatal age, with hyperemia occurring in juvenile but not neonatal rats. The results suggest a greater CBF responsiveness and differential relationship between post-ischemic vascular perfusion and tissue injury in older compared with immature animals.

Morphologie und funktionelle Anatomie des wachsenden Thorax

Morphogenesis of most thoracic organs and structures is not finished with birth but perpetuates in postnatal life. The postnatal growth is partly associated with enormous changes in structure, morphology, and function. Our study presents an overview of morphological, topological and functional peculiarities of thoracic anatomy during infancy, childhood and adolescence. It focuses on the development of the mammary gland, osseous structures of the chest wall, thymus, heart, and lungs. Most of the presented data are based on post-mortem studies. Measurements and numerical data are mainly included for illustration of growth-associated changes.

Renal and vascular oxidative stress and salt-sensitivity of arterial pressure

Oxidative stress occurs in a tissue or in the whole body when the total oxidant production exceeds the antioxidant capacity. Recent studies in human essential hypertension indicate that free radical production is increased and antioxidant levels are decreased, and more than one-half of these hypertensives have a salt-sensitive type of hypertension with progressive renal damage. Increased oxidative stress may also play a critical role in animal models of salt-sensitive hypertension. The stroke-prone spontaneously hypertensive rats (SHRSP) exhibits salt-sensitivity, vascular release of superoxide is increased, and total plasma antioxidant capacity is decreased. The superoxide release in the SHRSP rats inactivates nitric oxide, and superoxide dismutase (SOD) administration returns the bioactive nitric oxide levels to normal. The deoxycorticosterone acetate (DOCA)-salt hypertensive rat is salt-sensitive, aortic superoxide production is increased, and renal inflammation is significant. Treatment of the DOCA-salt rats with apocynin, an NADPH oxidase inhibitor, decreased aortic superoxide production and decreased arterial pressure. The Dahl salt-sensitive (S) rat has increased mesenteric microvascular and renal superoxide production and increased plasma levels of H2O2. The renal protein expression of SOD is decreased in the kidney of Dahl S rats, and long-term administration of Tempol, a superoxide mimetic, significantly decreased arterial pressure and renal damage. In conclusion, both human hypertension and experimental models of salt-sensitive hypertension have increased superoxide release, decreased antioxidant capacity and elevated renal damage.

American ginseng transcriptionally activates p21 mRNA in breast cancer cell lines

American ginseng (AG) has been demonstrated to inhibit breast cancer cell growth in vitro. p21 protein, a universal cell cycle inhibitor, binds cyclin-CDK complexes, an important mechanism in cell cycle regulation. The purpose of this investigation was to determine if AG induces p21 gene expression in hormone sensitive (MCF-7) and insensitive (MDA-MB-231) breast cancer cell lines. Cells grown in steroid stripped medium (SSM) were treated with AG, 17-beta-estradiol (E2), genistein or cycloheximide (CHX). Northern blot analyses were performed using human p21Cip1 and 36B4 cDNA probes. Cell lines were transiently transfected with select mouse p21 CAT reporter constructs, including those lacking a p53 binding site. Cell cycle analyses was performed by FACScan. The results revealed that AG induced p21 mRNA expression in MCF-7 and MDA-MB-231 cells (p=0.0004; p < or =0.0001, respectively). Neither E2 nor genistein alter p21 mRNA expression. CHX, a protein synthesis inhibitor, did not block p21 mRNA expression induced by AG, indicating that p21 is induced as an immediate early gene. AG activated p21 reporter constructs in transfected cells, independent of p53 binding sites. The cell cycle proliferative phase was significantly decreased by AG and increased by E2 (p < or =0.0001). AG may inhibit breast cancer cell growth by transcriptional activation of the p21 gene, independent of p53.

[Establishment of detection test for hepatitis C virus antigen]

OBJECTIVE

To establish the enzyme linking immunosorbent assay (ELISA) test with the specific monoclonal antibody (McAb) for detecting the hepatitis C virus (HCV) antigen so as to study the possibility of HCV antigen detection from plasma and serum samples.

METHODS

Among the McAbs against HCV core and NS3 region, several kinds of combination models were analyzed to choose the optimal one. 348 samples from volunteer donors were tested by this test to calculate the cutoff value. 371 samples, among which 146 samples were positive to anti-HCV and 225 ones were negative to anti-HCV, were screened. The antigen positive samples were confirmed by HCV nested PCR.

RESULTS

The model of detection test was constructed with the C39,C7-6 as capture McAb and C39,C7-57 as HRP Conjugated McAb. This test could detect the C7 antigen to 5 ng/ml, and its cutoff value was determined as the average value of negative control by adding 0.25. Eleven of 146 samples positive to anti-HCV and 16 of 225 ones negative to anti-HCV were positive to HCV antigen. Among these 27 antigen positive samples, there were 23 positive to HCV RNA by PCR detection.

CONCLUSIONS

With this HCV antigen detection test, some of samples positive to HCV antigen can be found from plasma positive to and negative to anti-HCV and be confirmed by PCR. It is shown that it is possible to detect HCV antigen directly from plasma samples and it is important for HCV basic research and for control of transmission of HCV.

Role of abnormal nitric oxide systems in salt-sensitive hypertension

A large percentage of human hypertensive patients are salt sensitive, referring to the dependence of hypertension on sodium intake, but the cause of the salt sensitivity is not known. Although several mechanisms may contribute to salt-sensitive hypertension, the nitric oxide (NO) system appears to play a major role. Studies in humans and Dahl salt-sensitive (S) rats indicate that NO production is decreased during hypertension. Intravenous L-arginine infusion in Dahl S rats increases NO production and prevents salt-sensitive hypertension. In the Dahl salt-resistant (R) rat, NO production by both inducible NO synthase (iNOS) and neuronal NOS (nNOS) help to prevent salt-sensitive hypertension. Experimental evidence is summarized, indicating that the Dahl S rat has a deficient production of NO by nNOS, although NO production by iNOS appears to moderately decrease salt sensitivity. Other evidence about the importance of NO in salt-sensitive hypertension is reviewed, including the role of the renal NO system.

Transient vs. prolonged histone hyperacetylation: effects on colon cancer cell growth, differentiation, and apoptosis

The role of histone hyperacetylation in regard to growth, differentiation, and apoptosis in colon cancer cells was assessed in an in vitro model system. HT-29 cells were grown in +/-10% fetal bovine serum with either 5 mM sodium butyrate or 0.3 microM trichostatin A [single dose (T) or 3 doses 8 h apart (TR)] for 24 h. Serum-starved HT-29 cells were further treated with epidermal growth factor or insulin-like growth factor I for an additional 24 h. Apoptosis was quantified with propidium iodide and characterized by electron microscopy. Northern blot analyses were performed with cDNA probes specific for intestinal alkaline phosphatase, Na-K-2Cl cotransporter, the cell cycle inhibitor p21, and the actin control. Flow cytometric analysis revealed a time-dependent growth suppression along with early induction of p21 mRNA in the butyrate, T, and TR groups. Histone hyperacetylation, assessed by acid-urea-triton gel electrophoresis, was transient in the T group but persisted for up to 24 h in the butyrate and TR groups. Induction of apoptosis, growth factor unresponsiveness, and differentiation occurred in the butyrate- and TR-treated cells but not those treated with a single dose of trichostatin A. Thus transient hyperacetylation of histones is sufficient to induce p21 expression and produce cellular growth arrest, but prolonged histone hyperacetylation is required for induction of the programs of differentiation, apoptosis, and growth factor unresponsiveness.

Thyroid hormone and the d-type cyclins interact in regulating enterocyte gene transcription

Thyroid hormone (T3) is an important regulator of gut mucosal development and differentiation, inducing intestinal alkaline phosphatase (IAP) and repressing lactase gene transcription. In contrast, cyclin D1 (CD1) appears to be a growth promoter in the gut, functioning to maintain the undifferentiated state. The present studies were designed to examine the effects of CD1 on T3 action within intestinal epithelia. Caco-2 cells were maintained in hypothyroid medium and transiently transfected with either rat lactase (3.0 kb) or human IAP (2.4 kb) luciferase (Luc) reporter plasmids. Cotransfections were carried out using two T3 receptor (TR) isoforms, TR"-1 and TR$-1, as well as plasmids expressing CD1, CD3, CA, or CB1. Cells were then treated +/- 10 nmol/L T3 for 24 hours and luciferase activity was determined. With T3 treatment, IAP-Luc activity was induced (TR"-1 = eightfold, TR$-1 = ninefold), but these effects were dramatically inhibited (> 50%) by CD1 and CD3. In contrast, CA and CB1 did not alter T3-mediated IAP gene activation. The ability of CD1 and CD3 to inhibit T3 action was also tested in the context of the lactase gene, which is negatively regulated by T3. As expected, lactase reporter gene activity was repressed by T3 treatment in the case of both receptor isoforms, TR"-1 = 30% and TR$-1 = 40%. In contrast to its effects on the IAP gene, CD1 did not inhibit T3-mediated changes in lactase reporter gene activity. The D-type cyclins (CD1 and CD3), but not CA or CB1, specifically inhibit T3-mediated activation of the IAP gene. In contrast, the D-type cyclins do not inhibit T3-mediated repression of the lactase gene. These studies have identified a novel molecular interaction that exists between the pathways of growth and differentiation within intestinal epithelia.

Management of tongue cancer in the patient who is systemically immunosuppressed: a preliminary report

OBJECTIVE

Renal transplantation is being improved, and life expectancy for patients with transplanted kidneys is being prolonged, but the incidence of malignant tumors in other body organs or tissues is increasing progressively. We investigated effective clinical plans for treating lingual cancer in persons who are long-term renal transplant recipients.

STUDY DESIGN

The group included 3 cases of lingual cancer after renal transplantation. All were men. The mean age was 47.5 years (range, 40 to 55). The lingual cancer occurred a mean of 9 years after renal transplantation. The lesions of two patients were in the left lingual margins; the other patient had multiple bilateral lesions. All diagnoses were confirmed microscopically to be squamous cell carcinomas stage I to II.

RESULTS

The doses of immunosuppressive agents were decreased, and two patients accepted surgery, chemotherapy, and radiotherapy. The third patient died 1 year after the cancer was diagnosed because of metastases. The other 2 patients had regular follow-up for 2 to 3 years and did not have either local recurrence or metastasis.

CONCLUSION

Patients who have lingual cancer develop after renal transplantation have received long-term immunosuppressive therapy. We suggest the following clinical protocol: (1) Besides regular evaluation after renal transplantation, physical examination and biopsy of suspicious oral lesions are necessary because of the possibility of postrenal malignancy. (2) Surgery, along with chemotherapy and radiotherapy, is the main treatment of lingual cancer after renal transplantation. (3) The lingual tumor should be comprehensively treated despite the poor immune state of the body, or tumor recurrence can accelerate and metastases can occur. (4) Treating cancer thoroughly and maintaining the function of the transplanted kidney can decrease the patient's immune status. We should continue to observe and to report the patients' protocol, even if the patients' clinical follow-up periods are limited.

Mechanisms of salt-sensitive hypertension: role of inducible nitric oxide synthase

The goal of this study was to determine the role of inducible nitric oxide synthase (iNOS) in the arterial pressure, renal hemodynamic, renal excretory, and hormonal changes that occur in Dahl/Rapp salt-resistant (R) and salt-sensitive (S) rats during changes in Na intake. Thirty-two R and S rats, equipped with indwelling arterial and venous catheters, were subjected to low (0.87 mmol/day) or high (20.6 mmol/day) Na intake, and selective iNOS inhibition was achieved with intravenous aminoguanidine (AG, 12.3 mg. kg(-1). h(-1)). After 5 days of AG, mean arterial pressure increased to 121 +/- 3% control in the R-high Na AG rats compared with 98 +/- 1% control (P < 0.05) in the R-high Na alone rats, and S-high Na rats increased their arterial pressure to 123 +/- 3% control compared with 110 +/- 2% control (P < 0.05) in S-high Na alone rats. AG caused no significant changes in renal hemodynamics, urinary Na or H(2)O excretion, plasma renin activity, or cerebellar Ca-dependent NOS activity. The data suggest that nitric oxide produced by iNOS normally helps to prevent salt-sensitive hypertension in the Dahl R rat and decreases salt sensitivity in the Dahl S rat.

Intimal hyperplasia of the infant parasellar carotid artery: a potential developmental factor in atherosclerosis and SIDS

Intimal cushions that project into the lumen of arteries are precursors of atherosclerotic plaque formation. The "carotid siphon, " although frequently affected by atherosclerosis, was never analyzed for the occurrence of neonatal intimal hyperplasia. This study provides a topographic and morphometric analysis of intimal cushions in the parasellar internal carotid artery (pICA) of the human infant. A total of 35 specimens were studied in detail, using both standard histological techniques and a new method of computer-aided 3D reconstruction. Intimal hyperplasia occurred at 3 characteristic locations of the pICA: (1) the convex side of the posterior knee (C5 cushion), (2) the bottom of the horizontal segment (C4 cushion), and (3) the concave side of the anterior knee (C3 cushion). The extension of the cushions and the degrees to which they occluded the vessel lumens were measured. The complex shape of the pICA required 3D computer models for exact topographical descriptions and precise measurements. Our results suggest that the occurrence and degree of intimal hyperplasia are related to shape changes of the pICA during postnatal development. We predict that individuals who retain the relatively straight course of the fetal pICA throughout their lives are less prone to develop atherosclerotic lesions at this portion of the carotid artery. A possible contribution of neonatal intimal cushions to the origin of sudden infant death syndrome is discussed.

Short-chain fatty acids and thyroid hormone interact in regulating enterocyte gene transcription

BACKGROUND

Enterocyte differentiation is known to be regulated by a variety of extracellular compounds, among which are triiodothyronine (T3) and the short-chain fatty acids (SCFAs). Because several SCFAs are known to induce histone hyperacetylation, and T3 action has been recently linked to chromatin structure, we sought to investigate the interplay between SCFAs and T3 in regard to the enterocyte differentiation marker, intestinal alkaline phosphatase (IAP).

METHODS

Caco-2 cells were transiently transfected with a reporter construct containing 2.4 kb of the human IAP gene 5' flanking region (IAP2.4CAT). Cotransfections were carried out with and without thyroid hormone receptor-1 (TR beta-1) or histone deacetylase-1 (HDAC-1) expression plasmids. Cells were treated with 5 mmol/L SCFAs (propionic, butyric, valeric, or caproic acids as propionate, butyrate, valerate, or caproate, respectively), with and without 10 nmol/L T3. Reporter gene activity was measured and the level of histone acetylation assessed by means of acid-urea-triton (AUT) gel assays.

RESULTS

TR beta-1 cotransfection caused a marked decrease in IAP reporter gene activity, which is consistent with the well-known phenomenon of ligand independent repression (LIR), whereas T3 treatment reversed the LIR and caused further reporter gene activation. Treatment with SCFAs similarly resulted in a complete blockage of LIR, and, in fact, turned the TR beta-1 into a transcriptional activator, even in the absence of T3. Concomitant treatment with T3 and butyric acid produced an additive effect on IAP transactivation. In contrast, cotransfection with HDAC-1 attenuated the effects of SCFAs on IAP gene activation. AUT gel studies demonstrated histone hyperacetylation in response to SCFA treatment.

CONCLUSION

One or more DNA cis-elements in the human IAP gene mediate ligand independent repression by the TR beta-1, an effect that can be entirely reversed by those SCFAs that induce histone hyperacetylation. In addition T3 and SCFAs can act in concert to induce IAP gene transcription, demonstrating an important link between triiodothyronine and histone hyperacetylation in regard to enterocyte-specific gene expression.

A novel Sp1-related cis element involved in intestinal alkaline phosphatase gene transcription

We have used sodium butyrate-treated HT-29 cells as an in vitro model system to study the molecular mechanisms underlying intestinal alkaline phosphatase (IAP) gene activation. Transient transfection assays using human IAP-CAT reporter genes along with DNase I footprinting were used to localize a critical cis element (IF-III) corresponding to the sequence 5'-GACTGGGCGGGGTCAAGATGGA-3'. Deletion of the IF-III element resulted in a dramatic reduction in reporter gene activity, and IF-III was shown to function in the context of a heterologous (SV40) promoter in a cell type-specific manner, further supporting its functional role in IAP transactivation. Electrophoretic mobility shift assays revealed that IF-III binds Sp1 and Sp3, but these factors comprise only a portion of the total nuclear binding and appear to mediate only a small portion of its transcriptional activity. IF-III does not correspond to any previously characterized regulatory region from other intestine-specific genes. We have thus identified a novel, Sp1-related cis-regulatory element in the human IAP gene that appears to play a role in its transcriptional activation during differentiation in vitro.

Role of neuronal nitric oxide synthase in Dahl salt-sensitive hypertension

The goal of this study was to determine the role of neuronal nitric oxide synthase (nNOS) in the arterial pressure, renal hemodynamic, and renal excretory changes that occur in Dahl salt-resistant (DR) and salt-sensitive (DS) rats during changes in Na intake. Fifty-three DR and DS rats/Rapp strain of 7 to 8 weeks of age with indwelling arterial and venous catheters were subjected to low (0.87 mmol/d) or high (20.6 mmol/d) Na intake beginning 2 days before the start of the control period. Measurements were made during a 5-day control period followed by a 5-day period of nNOS inhibition with intravenous 7-nitroindazole (7NI, 1.67 mg. kg-1. h-1) or vehicle infusion. After 5 days of 7NI, mean arterial pressure increased to 120+/-6% control in the DR-high Na, 7NI rats compared with 98+/-1% control (P<0.05) in the DR-high Na alone rats. After 5 days of 7NI, DS-high Na rats, which had a control arterial pressure 31 mm Hg higher than the comparable DR rats, increased their arterial pressure to 114+/-3% control, which was not significantly different from the DS-high Na alone pressure of 110+/-2% control. No significant changes occurred in glomerular filtration rate, effective renal plasma flow, urinary Na excretion, or urine volume because of 7NI. However, plasma renin activity decreased significantly in DR and DS rats on low Na intake with 7NI infusion. The data demonstrate that the highly salt-resistant DR rat became salt-sensitive during nNOS inhibition with 7NI. However, the arterial pressure of the DS rat was not affected by 7NI. This suggests that nitric oxide produced by nNOS in the DR rat normally helps to prevent salt-sensitive hypertension and that low functional levels of nNOS in the DS rat may contribute to its salt-sensitivity.

[The application of intracoronary stenting to type B and C lesions of coronary arteries]

Intracoronary stenting was introduced to 4 lesions due to coronary arterial dissections and to 2 lesions owing to elastic recoil of coronary arteries and stent placement was directly performed in 6 complex coronary lesions after 12 target lesions from 7 patients with Types B and C lesions of coronary arteries had been pre-dilated with balloon. Coronary angiography showed that dissections and recoils had disappeared. Target lesions were well dilated and blood flow was well improved in all cases, one patient was complicated with hemorrhage which was cured quickly. During the follow-up period of 1 to 24 months, another case had recurrence of angina after 2 months of stenting which could be controlled with anti-angina agents. These indicate that intracoronary stenting had good therapeutic effect and is considered as a safe, fast and effective method in dealing with acute complications of coronary artery after routine PTCA.

p21(WAF1) is required for butyrate-mediated growth inhibition of human colon cancer cells

A diet high in fiber is associated with a decreased incidence and growth of colon cancers. Butyrate, a four-carbon short-chain fatty acid product of fiber fermentation within the colon, appears to mediate these salutary effects. We sought to determine the molecular mechanism by which butyrate mediates growth inhibition of colonic cancer cells and thereby to elucidate the molecular link between a high-fiber diet and the arrest of colon carcinogenesis. We show that concomitant with growth arrest, butyrate induces p21 mRNA expression in an immediate-early fashion, through transactivation of a promoter cis-element(s) located within 1.4 kb of the transcriptional start site, independent of p53 binding. Studies using the specific histone hyperacetylating agent, trichostatin A, and histone deacetylase 1 indicate that growth arrest and p21 induction occur through a mechanism involving histone hyperacetylation. We show the critical importance of p21 in butyrate-mediated growth arrest by first confirming that stable overexpression of the p21 gene is able to cause growth arrest in the human colon carcinoma cell line, HT-29. Furthermore, using p21-deleted HCT116 human colon carcinoma cells, we provide convincing evidence that p21 is required for growth arrest to occur in response to histone hyperacetylation, but not for serum starvation nor postconfluent growth. Thus, p21 appears to be a critical effector of butyrate-induced growth arrest in colonic cancer cells, and may be an important molecular link between a high-fiber diet and the prevention of colon carcinogenesis.

Na-K-2Cl cotransporter gene expression and function during enterocyte differentiation. Modulation of Cl- secretory capacity by butyrate

The basolateral Na-K-2Cl cotransporter (NKCC1) is a key component of the intestinal crypt cell secretory apparatus. Its fate during the transition to absorptive enterocyte and the potential impact of its altered expression on secretory output have not been addressed. In this report, NKCC1 mRNA was found to be expressed in rat jejunal crypt but not villus cells. Butyrate treatment of intestinal epithelial HT29 cells induced a differentiation pattern that recapitulated the rat intestinal crypt-villus axis, with NKCC1 mRNA levels decreasing in a time- and dose-dependent fashion in parallel with upregulation of apical brush-border markers. Butyrate but not acetate or proprionate decreased basal and cAMP-stimulated bumetanide-sensitive K+ (86Rb) uptake in both HT29 cells and the Cl--secreting T84 line. Butyrate markedly decreased transepithelial Cl- secretion in confluent T84 monolayers without effect on cAMP-regulated apical Cl- efflux. We conclude that NKCC1 regulation during enterocyte differentiation occurs at the level of gene expression, and that selective downregulation of NKCC1 gene expression and function by butyrate leads to a profound decrease in transepithelial Cl- secretion. These data emphasize the importance of NKCC1 in determining epithelial secretory capacity and suggest the possibility of modulation of the enterocytic transport phenotype as therapy for diarrheal disorders.

[Expression of oncogene ras product p21 protein in the tissues of penis cancer and its surrounding tissues]

OBJECTIVE

To explore the clinical significance of expression of oncogene ras product p21 protein in the tissues of penis cancer and its surrounding tissues.

METHOD

Oncogene ras product p21 protein in 32 cases of penis cancer, 32 cases of para-carcinoma tissues and in 16 cases of normal penis tissues were detected by immunohistochemical ABC method.

RESULT

p21 protein expressed in 28 cases of penis cancer and 8 cases of para-carcinoma tissues, but it did not express in 16 cases of normal penis. Expression of p21 protein was related to pathological grading and clinical stage i. e, expression of p21 protein enhanced with the increasing of grading and stage. The positive cases of p21 protein expression in para-carcinoma tissue had worse impact on the prognosis of early recurrence and metastasis.

CONCLUSION

p21 protein could be used as predictor of malignant potential and prognosis of penis cancer.

A new episcopic method for rapid 3-D reconstruction: applications in anatomy and embryology

The topographic relations of complex structures and the morphogenesis of organ systems can only be fully understood in their three-dimensional context. Three-dimensional (3-D) reconstruction of physically sectioned specimens has become an indispensable tool in modern anatomical and embryological research. Teaching also makes increasingly use of 3-D representations, in particular in the case of embryonic systems that undergo complicated transformations of form and shape. At present no cheap and simple technique is available that generates accurate 3-D models of sectioned objects. In this study we describe a novel technique that rapidly provides faithful 3-D models of sectioned specimens. The images are captured directly from the cutting surface of the embedding block after each sectioning and "on block" staining step. Automatic image processing generates a stack of binary images of the specimen contour. Binary images of internal structures are obtained both by automatic segmentation and manual tracing. Since these image series are inherently aligned, they can be reconstructed three-dimensionally without time-consuming alignment procedures. The quality and the flexibility of the method are demonstrated by reconstructing three kinds of specimens of different histological composition and staining contrast: a 4 mm mouse embryo together with several of its inner organs, a cavernous sinus region of a human infant, and a segment of a human carotid artery. Very short processing times and the faithful representation of complex structural arrangements recommend this technique for routine use in morphological research and for creating embryologic teaching models or 3-D embryonic staging series.

[Application of diode laser in the operation of retinal diseases]

OBJECTIVES

To evaluate the effects of diode laser photocoagulation applied on 43 cases of various kinds of fundus diseases with media opacity and on 40 cases during vitreo-retinal surgery.

METHODS

Indirect ophthalmoscope laser photocoagulator was used for fundus diseases, and endolaser used during surgery.

RESULTS

Vision was improved in 24.7% of the eyes, and was unchanged in 62.9% of the eyes. The neovascularization in proliferative diabetic retinopathy regressed in 78.3% of the eyes. All the retinal holes were closed.

CONCLUSIONS

Diode laser can be used for treatment of some retinal diseases and in the operation. Good results can be obtained in the eyes with some extent of media opacity. No obvious side-effect was observed.

Transcriptional activation of the human villin gene during enterocyte differentiation

Enterocyte differentiation occurs along the crypt-villus axis and is generally thought to involve the transcriptional activation of cell-specific genes, among which is the brush-border structural protein villin. We have examined the molecular mechanisms of villin induction using both in vivo and in vitro systems. Total RNA was purified from rat tissues or cultured cells by the guanidinium thiocyanate method and Northern blot analyses carried out using radiolabeled complementary DNA probes specific for villin or the actin control. Transient transfection (calcium/phosphate method) assays were performed using a luciferase reporter gene containing 2 kb of the human villin gene 5'-flanking region. We have found that the villin mRNA was expressed at high levels in the small intestine, to a lesser degree in the colon, and was not detected in the brain or liver. In HT-29 cells, villin mRNA levels increased 2.5-fold (P<0.001) after 24 hours of sodium butyrate treatment, consistent with the process of enterocyte differentiation. Similarly, villin gene expression was induced in Caco-2 cells during postconfluence differentiation. Transient transfection assays demonstrated marked reporter gene activation (fourfold, P<0.001) in response to sodium butyrate in HT-29 cells, but no activation in the liver cell line HepG2. The effects of sodium butyrate were dose dependent, reaching a maximum at a concentration of 5 mmol/L. We conclude that a 2 kb region of the human villin gene is able to mediate its transcriptional activation during HT-29 cell differentiation. This DNA regulatory region appears to function in a cell type-specific (gut) manner.

[Isolation of human herpes virus 6 from peripheral blood of renal transplant recipients]

One strain of the viruses was isolated from preipheral blood lymphocytes (PBL) of a renal transplant recipient. PBL isolated from blood samples were cocultured with the PHA actived cord blood lymphocytes (CBL). Two of twelve recipient's samples found cytopathic effect after 10 to 14 days. Examination of ultrathin-sections of the virus infected cells by electron microscope showed herpes-like virus particles. Detection of indirect immunofluorescences with McAbs against HHV-6 was positive in the infected cells.

[Clinical observation on juvenile-children type of Coats' disease]

OBJECTIVES

To observe the clinical features and the effects of management of juvenile-children type of Coats' disease and to approach the classification of the disease.

METHODS

Fundus was examined and fundus fluorescein angiography (FFA) was made. Laser photocoagulation and cryotherapy were used for treatment.

RESULTS

Compared to adult type of Coats' disease, this type was characterized by early onset, severe macular lesion, rapid progression and poor visual prognosis. The vision in 75.0% of eyes was unchanged, and in 19.2% of eyes was improved after treatment.

CONCLUSIONS

Visual damage is more severe in this type. Early examination and early treatment are the key points to decrease visual deterioration. The classification of the disease is helpful in understanding the disease.

[Determination of chrysophanol in semen Cassiae by HPLC]

A HPLC method for the determination of chrysophanol in Semen Cassiae was investigated. The result showed that this method was simple, specific and accurate. The recovery was 99.0% and relative standard deviation was 1.8%. The method is useful for the quality control of this medicinal meaterial.

Thyroid hormone and the gut: selective transcriptional activation of a villus-enterocyte marker

BACKGROUND

Thyroid hormone (T3) is an important regulator of gut mucosal growth, differentiation, and barrier function, but its mechanism of action in the gastrointestinal tract is largely unknown. The present studies were carried out to define the molecular mechanisms by which T3 alters gut gene expression.

METHODS

In vivo: Adult, male, Sprague-Dawley rats were given three daily injections (intraperitoneal) of either saline solution or 30 micrograms/kg triiodothyronine. Small intestinal tissues were harvested, and Northern blot analyses were performed by using specific radiolabeled cDNA probes. In vitro: HT-29 cells were transfected with reporter plasmids and treated with or without T3, and chloramphenicol acetyltransferase activity was measured.

RESULTS

The T3-induced changes in enterocyte gene expression occurred in villus enterocytes and not in crypt cells and were independent of food intake. Northern analyses with an intron-specific probe revealed that the T3 induction in intestinal alkaline phosphatase (IAP) expression occurs at the level of transcription. Transient transfection assays revealed no T3-induced changes under basal conditions but marked increases (sixfold, p < 0.001) when a T3-receptor (TR beta-1) plasmid was cotransfected. Furthermore, T3 was found to induce greater IAP reporter gene activity in differentiated (+ sodium butyrate) compared with undifferentiated HT-29 cells.

CONCLUSIONS

T3 induces IAP expression at the level of gene transcription. Both in vivo and in vitro, IAP transcriptional activation occurs to a greater extent in differentiated enterocytes than in undifferentiated crypt cells. Transactivation of the IAP gene by T3 is mediated via a DNA cis-element(s) located within the 2.4 kb segment present in the reporter gene.

Cellular growth state differentially regulates enterocyte gene expression in butyrate-treated HT-29 cells

Enterocyte differentiation occurs at the crypt-villus junction through the transcriptional activation of cell-specific genes, including the brush-border enzyme intestinal alkaline phosphatase (IAP) and the microvillar structural protein, villin. Based upon previous in vivo studies demonstrating that IAP and villin are differentially affected by alterations in epithelial growth state, we examined the regulation of these two genes in an in vitro model of enterocyte differentiation. HT-29 cells were maintained in DMEM + 10% FCS and treated with sodium butyrate to induce enterocyte differentiation. Cell count and [3H]thymidine measurements confirm that sodium butyrate causes a marked decrease in cellular growth state, consistent with the differentiation process. Northern blot analyses revealed time- and dose-dependent increases (P < 0.001) in steady-state IAP and villin mRNA levels. The increases in both IAP and villin expression were dependent upon the presence of one or more newly synthesized proteins. Post-confluence and serum starvation were used to cause cell cycle withdrawal prior to the differentiation process. As predicted from our previous in vivo data, villin expression was unaffected by changes in cellular growth state, whereas IAP expression was dramatically diminished under hypoproliferative conditions. We conclude that early withdrawal from the cell cycle alters the course of enterocyte differentiation, specifically decreasing IAP expression.

Small bowel adaptation: counterregulatory effects of epidermal growth factor and somatostatin on the program of early gene expression

BACKGROUND

Small intestinal crypt cell proliferation is essential to the normal renewal of the epithelium, as well as the adaptive responses that follow resection or injury. The present studies were designed to elucidate the molecular mechanisms by which epidermal growth factor (EGF) and somatostatin interact to regulate crypt cell proliferation.

METHODS

Rat crypt (IEC-6) cells were maintained in Dulbecco's modified Eagle's medium plus 10% fetal calf serum and treated with EGF (10 or 100 ng/ml) or somatostatin (0.5 microgram/ml). Cell counts were done to examine the effects on cellular growth, and Northern blot analyses were carried out by using complementary DNA probes corresponding to various protooncogenes.

RESULTS

EGF caused a 41% increase in cellular growth, an effect that was almost completely blocked by pretreatment (30 minutes) with somatostatin. EGF led to dramatic increases in c-fos (greater than 20-fold), c-jun (2-fold), and jun B (3-fold) gene expression at 30 minutes, consistent with the previously characterized immediate-early gene response in IEC-6 cells. Somatostatin alone had no effects on protooncogene levels, but pretreatment with somatostatin resulted in a marked inhibition (80%, p < 0.001 in all cases) of the EGF-induced increases in protooncogene expression.

CONCLUSIONS

Somatostatin inhibits the EGF-induced protooncogene expression in IEC-6 cells. The somatostatin inhibition of immediate-early gene expression lends support to its role as a negative growth regulator in intestinal epithelia and indicates that its effect occur at an upstream site in the cellular growth response.

Pattern of rat intestinal brush-border enzyme gene expression changes with epithelial growth state

Enterocyte growth and differentiation occur simultaneously within the epithelium, but little is known regarding any relationship between these two processes. Four rat models of small intestinal epithelial hypo- and hyperplasia (neonatal ontogeny, fasting/refeeding, hypo-/hyperthyroidism, and bombesin treatment) were used to study the regulation of enterocyte gene expression in relation to epithelial growth state. Mucosal scrapings, as well as crypt and villus cell populations, were subjected to Northern blot analyses using radiolabeled cDNA probes corresponding to lactase, intestinal alkaline phosphatase, villin, ornithine decarboxylase (ODC), and the actin control. In all four models, the hypoplastic (atrophic) condition is characterized by high levels of lactase and low levels of the 3.0-kb intestinal alkaline phosphatase mRNA, whereas under hyperplastic conditions this pattern is reversed. The changes in intestinal alkaline phosphatase and lactase are qualitatively similar along the longitudinal axis of the intestine and are proportional to the degree of hyperplasia, as verified by ODC mRNA levels. Furthermore, the crypt-villus axis of differentiation is maintained regardless of epithelial growth state. In conclusion, the pattern of brush-border enzyme gene expression changes as a function of epithelial growth state, indicating a previously unrecognized degree of plasticity to the state of enterocyte differentiation.

[A new method for qualitative determination of astragaloside]

A multi-function column has been devised for qualitative determination of astragaloside in Yuanheng-yitai Chutang Tablets. The result of experiment shows that the method is convenient fast and stable.