GSTP1 promoter hypermethylation during breast cancer development

Abstract #5042

Background. Promoter hypermethylation in precursor lesions of the breast cancer may be biomarkers of cancer risk and targets for cancer chemoprevention. GSTP1 is inactivated by promotor hypermethylation in invasive breast cancers. However, little is known about epigenetic silencing of GSTP1 gene by promoter hypermethylation in precursor lesions.
 Method. To determine the significance of GSTP1 promoter hypermethylation in breast carcinogenesis, methylation status of GSTP1 gene was studied by nested methylation-specific PCR and GSTP1 expression was studied by immunohistochemistry in invasive ductal carcinoma (IDC), ductal carcinoma in situ (DCIS), usual ductal hyperplasia (UDH) and normal breast tissue.
 Results. GSTP1 promoter hypermethylation was detected in 4/24 (16.7%) of UDH, 18/49 (36.7%) of DCIS, and 14/36 (38.9%) of IDC. No hypermethylation was detected in normal breast tissues. GSTP1 promoter hypermethylation was found to be progressively elevated during breast carcinogenesis (P < 0.01). GSTP1 promoter hypermethylation was associated with loss of GSTP1 expression (P < 0.01 for UDH, P < 0.001 for DCIS and IDC).
 Conclusion. Our results suggest that GSTP1 promoter hypermethylation is an early event in breast carcinogenesis and appears to functionally silence GSTP1 expression. GSTP1 promoter hypermethylation in the precursor lesions of breast cancer may be used as a target for cancer chemoprevention.

Citation Information: Cancer Res 2009;69(2 Suppl):Abstract nr 5042.

Induction of cell cycle arrest and apoptosis in breast cancer cells by troglitazone, a peroxisome proliferator-activated receptor-gamma (PPAR-γ) ligand

Abstract #5034

Background: Peroxisome proliferator-activated receptor-gamma(PPAR-γ) ligands inhibit cell proliferation and induce apoptosis in cancer cells. And, it is reported that PPAR-γ ligands could serve as negative regulators of breast cancer development and progression, but their mechanism is still unknown. Here we wished to determine whether the PPAR-γ ligand induces cell cycle arrest and apoptosis of MDA-MB-231(ERα-negative) and MCF-7(ERα-positive) breast cancer cell.
 Methods: The effect of PPAR-γ ligands on the cell viability of breast cancer cells was determined using mitochondrial tetrazolium(MTT) assay. The cell cycle distribution and apoptosis induction were evaluated by using the flow cytometry. The expression of apoptosis-related proteins were measured with Western blot analysis. Statistical analysis was performed using Student's t test, and p<0.05 was considered significant.
 Results: The treatment of MDA-MB-231 cell with PPAR-γ ligand, troglitazone was shown to induce cell cycle G1 arrest and induction of apoptosis. Moreover, troglitazone treatment, applied in a dose-dependent manner, caused a marked decrease in phosphorylated retinoblastoma(pRb), cyclin D1, D2, D3, cyclin dependent kinase(Cdk) 2, 4, and 6 expression as well as a significant increase in Cdk inhibitor, p21 and p27. Troglitazone showed antiproliferative effect on MCF-7 cell with tamoxifen, respectively and synergically. Troglitazone and tamoxifen could induce G1 arrest and apoptosis of MCF-7 cell, through upregulation of Bax and downregulation of Bcl-2 and cyclin D1.
 Conclusion: PPAR-γ ligand, troglitazone induces cell cycle arrest and apoptosis of MDA-MB-231 cell and increases the sensitivity of anti-hormonal therapy in MCF-7 cell. These results suggest that troglitazone has anticancer effect on both ERα-negative and positive breast cancer cells.

Citation Information: Cancer Res 2009;69(2 Suppl):Abstract nr 5034.

Characterization of the Drosophila melanogaster retinin gene encoding a cornea-specific protein

Two-dimensional analysis of head extracts from Drosophila melanogaster identified the four eye-specific protein spots corresponding to the retinin protein. The retinin protein spots were specifically stained with phosphoprotein-specific dye, suggesting that the retinin protein undergoes post-translational modification by phosphorylation. Northern blot analysis showed that the retinin gene begins to be expressed during the late stage of puparium formation during development. Analysis of the N-terminal sequence and expression of the retinin gene in S2 suggest that retinin is a secretory protein. Transgenic flies with knockdown expression of the retinin gene by RNA interference (RNAi) were established. However, no significant phenotypic changes in eye structure or phototransduction were observed in the transgenic flies. Western blot analysis and immunohistochemical studies of D. melanogaster eyes suggest that retinin is a cornea-specific protein.

Measurement of OH radical CT for inactivating Cryptosporidium parvum using photo/ferrioxalate and photo/TiO2 systems

AIM

This study investigates the inactivation of Cryptosporidium parvum using the OH radical and reports the OH radical CT (OH radical concentration x contact time) values for C. parvum inactivation.

METHODS AND RESULTS

Although a wealth of information has demonstrated the efficacy of the microbial inactivation activity of the OH radical, no studies have performed a quantitative estimation of the OH radical for C. parvum inactivation. The CT value of the OH radical required for 2 log C. parvum inactivation was measured with two OH radical-generating systems, photo/ferrioxalate and photo/TiO2. The OH radical was approx. 10(4)-10(7)-fold more effective for microbial inactivation than other popular chemical disinfectants such as ozone, chlorine dioxide and free chlorine.

CONCLUSIONS

The OH radical appears to be suitable for microbial inactivation with a calculated CT value required for 2 log C. parvum inactivation of 9.3 x 10(-5) mg min l(-1).

SIGNIFICANCE AND IMPACT OF THE STUDY

This study is the first report of an investigation on the role of the OH radical in the photo/ferrioxalate and photo/TiO2 systems and on the OH radical CT required for C. parvum inactivation.

Neuroimaging of cognitive disability in schizophrenia: search for a pathophysiological mechanism

This article reviews how functional neuroimaging research of cognitive dysfunction in schizophrenia has resulted in a progression of influential pathophysiological models of the disorder. The review begins with discussion of the 'hypofrontality' model, moving from resting studies examining anterior to posterior gradients of cerebral blood flow (CBF), to cognitive activation studies employing the Wisconsin Card Sorting Test, and current functional magnetic resonance imaging (fMRI) studies of working memory and cognitive control utilizing parametric task designs and event-related procedures. A similar progression is described for development of the temporal lobe model of schizophrenia, moving from research on the temporal cortex and language processing to the hippocampal formation and long-term memory (LTM). These LTM studies found that hippocampal dysfunction was often accompanied by disrupted prefrontal function, supporting a hybrid model of impaired fronto-temporal connectivity. Developments in image analysis procedures are described that allow assessment of these distributed network models. However, given limitations in temporal and spatial resolution, current methods do not provide 'real-time' imaging of network activity, making arrival at a definitive pathophysiologic mechanism difficult. Dorsolateral prefrontal cortex (DLPFC) dysfunction and disrupted fronto-temporal integration appear to be equally viable current models. The article concludes with a discussion of how fMRI can help facilitate development of novel psychosocial and pharmacological interventions designed to improve cognition and functional outcome in patients with schizophrenia.

BAY 43–9006 (sorafenib-BAY) alters proliferation pathways and mutant specific-PCR (MS-PCR) improves detection of BRAF mutations in metastatic melanoma (MM)

8542

Background: Approximately 60% of melanomas carry BRAF mutations (mut). BAY is a multi-kinase inhibitor that inhibits the BRAF pathway. A phase II trial of BAY in MM is being conducted to: 1) determine if treatment (tx) with BAY can alter proliferation as measured by cyclin D1, Ki-67 and ERK, 2) assess for differential anti-tumor responses and 3) to assess a newly developed fluorescent-based PCR assay to detect mutant BRAF. Methods: Eligibility criteria: Biopsy (bx)-accessible, untreated MM. Measurable disease (RECIST). Stratification of tumor BRAF status determined by routine PCR sequencing for codon 600 mut prior to tx and fluorescent MS-PCR sequencing for confirmation. MS-PCR specifically amplified the M-BRAF allele without amplifying the wild-type (WT)allele. Tx: BAY 400 mg po BID D1–28 q4w. Repeat bx on Day 28. Bx assessed for Ki-67, cyclin-D1 and ERK. Serum collagen cryptic epitopes were measured serially. Re-imaging was done every 2 cycles and pts treated until POD. Results: 29 pts (9-M1a, 8-M1b, 12-M1c) enrolled. 26 wild type (WT) and 3 mutant (M) BRAF by routine PCR. Due to the low yield of mut on routine PCR, MS-PCR was done. 6 mutants were detected in the first 16 pts with MS-PCR compared to 2 with routine sequencing. Median age: 68 (range 22–91). 8 pts with LDH ≥ 1.5 × nl. Tox: Gr I-diarrhea(7), alopecia(4), rash(6), mucositis(4), nausea(4), pain(4), hand-foot(2); Gr II- HTN(4), fatigue(2),mucositis(1), rash(3), pain(3), hand-foot(2); Gr III-hand-foot(1), rash(1), fatigue(1) and intestinal perforation(1). Responses: 12 NE (2 WD, 8 early POD, 1 tox, 1 too early); M BRAF- 1 PR (lymph nodes and large SQ arm masses) and 2 PD; WT BRAF- 1 PR, 7 POD after 2 cycles, 6 SD. Matched paired biopsies demonstrated down regulation of tumor ki-67, erk and cyclin-D1. Collagen cryptic epitopes correlated with tumor responses. Conclusions: MM patients with tumors that were molecularly characterized for BRAF mutational status were entered on this single agent BAY trial and responses were seen in both M and WT arms. Down-regulation of Ki-67, cyclin D1 and ERK was demonstrated and MS-PCR improved the sensitivity to detect BRAF mut. Supported by NCI N01-CM17103 and TRI.

No significant financial relationships to disclose.

Quantitative evaluation and application of Cryptosporidium parvum inactivation with ozone treatment

Despite a wealth of studies concerning the factors affecting the inactivation of Cryptosporidium parvum on ozone disinfection, practical approaches for predicting the inactivation level on ozone treatment system and determining the required ozone dose or contact time to achieve the required inactivation level remain unclear. When modified version of the "Delayed Chick-Watson model" was applied, the results show that Cryptosporidium parvum inactivation was well fitted with one unique line as "CTlag" and "inactivation slope" for several water parameters and water types. Thus, this study suggests quantitative methodology for predicting the Cryptosporidium parvum inactivation level with observation for the contact time of ozone and Cryptosporidium parvum and ozone residual.

Characterisation of pore structures in nanoporous materials for advanced bionanotechnology

Porous materials are potential candidates for applications in various fields, such as bionanotechnology, gas separation, catalysts and micro-electronics. In particular, their applications in bionanotechnology include biosensors, biomedical implants and microdevices, biosupporters, bio-encapsules, biomolecule separations and biomedical therapy. All these bionanotechnology applications utilise the shape, size and size distribution of pores in porous materials. Therefore the controlled creation of pores with desired shape, size and size distribution is most important in the development of nanoporous materials. Accordingly, the accurate evaluation of pore structure is necessary in the development of nanoporous materials and their applications. This article reviews recent developments in analytical techniques to characterise the pore structures of nanoporous materials.

Transport of target anions, chromate (Cr (VI)), arsenate (As (V)), and perchlorate (ClO4-), through RO, NF, and UF membranes

Rejection and transport of chromate (Cr (VI)), arsenate (As (V)), and perchlorate (ClO4-) by and through reverse osmosis, nanofiltration, and ultrafiltration were found to be affected by solution pH and ionic strength. In this study, the rejection of these target ionic contaminants increased with increasing pH at the same conductivity (ionic strength) for the tested membranes, regardless of salt type. General trends showed that the rejection followed the order: CaCl2 < KCl < or = K2SO4, at the same pH and conductivity condition. The rejection also significantly decreased as conductivity was increased regardless of the salt type. These results support the notion that a more negative surface charge due to increasing pH and/or decreasing ionic strength (conductivity) enhances rejection; lower molecular weight cut-off also enhances rejection. Measured values of hindered diffusion coefficient through the membrane pores (Dp) for the target contaminants significantly decreased as pH was increased, regardless of salt type at the same conductivity. At the same pH and conductivity, the Dp of the target contaminants follows the order: CaCl2 > KCl > K2SO4, in the presence of different types of salts. The Dp of the target contaminants significantly increased as conductivity was increased regardless of the salt type. The rejection data were modeled by application of a non-equilibrium thermodynamic model. The rejection model has five transport parameters: the molecular transport coefficient (omega), osmotic pressure gradient (deltaII), molecular reflection coefficient (sigma), the average bulk fluid interfacial concentration between the feed and permeate side (C(avg)), and the solvent flux (Jv). The transport parameters were determined by independent measurements (and calculation with minimum assumptions.) Measurements and predictions of the target contaminant transport were in good agreement.

Influence of mass transfer on the ozonation of wastewater from the glass fiber industry

The mass transfer rate (kLa) is one of the most important parameters in the ozonation of wastewater, because it frequently constitutes the rate-determining step. This study investigated the influence of kLa on the ozonation of glass fiber wastewater using a high-performance jet loop reactor (HJLR), which is well known for its high mass transfer property, and compared the results of this investigation with those obtained using the bubble column reactor. It was found that the higher kLa achieved by increasing the energy input did not lead to higher ozonation efficiency, since the reaction involving the OH radical was greatly hindered at the low pH produced as a result of ozonation. By maintaining the pH at a value greater than 8.0, the higher kLa in the HJLR reactor contributed to increasing not only the TOC removal of wastewater, but also the ozone consumption efficiency, as expressed by the specific ozone consumption. The specific ozone consumption in the HJLR reactor (7.1 g ozone/ g TOC) was 20% better than that in the bubble column reactor.

Ozonation characteristics of bisphenol A in water

Ozonation characteristics of bisphenol A were investigated as a function of gaseous ozone dose, initial concentration of bisphenol A, pH, radical scavenger (tert-butanol), and radical initiator (hydrogen peroxide). The ozonation led to a complete removal of bisphenol A in water within a certain period of time. The overall rate of the ozonation linearly increased with the ozone dose. The stoichiometry in the ozonation of bisphenol A was found to be 1.5 - 1.8 mole of ozone per mole of bisphenol A. The direct reaction rate constants were 1.3 x 10(4) M(-1)s(-1) for bisphenol A (at pH = 2) and 1.6 x 10(9) M(-1)s(-1) for dissociated bisphenol A (at pH = 12). Bisphenol A degraded via the direct reaction with molecular ozone in the pH range from 2 to 12. Degradation by OH radical was minor even at pH = 12. The overall degradation rate in heterogeneous conditions was independent of pH as it was limited by ozone mass transfer rate. Use of hydrogen peroxide did not alter the main degradation route and the molecular ozone remained a principal oxidant as a substantial portion of the OH radical is scavenged by hydrogen peroxide. Effective ozone mass transfer may appear essential to enhance the ozonation kinetics of bisphenol A.

The evaluation of a density current experiment as a verification tool of a secondary clarifier model

The prediction of the spatial and temporal flow regime is important for the efficient design and operation of the settling tank. The impact of the gravity current has been investigated by the temperature difference or artificial glass particles. This experimental study is designed to obtain the steady state of stratified flow with the consideration of the heavy density flow. Two different approaches were performed at lab scale considering the hydraulic similarity. One is the investigation of a heavy density current of saline water intrusion. The characteristics of the internal hydraulics are monitored using Particle Image Velocimetry (PIV). As a result of the saline intrusion, the internal flow established a continual density stratification of 3-layers in steady state. The other is the movement of activated sludge from a sewage treatment plant. The video image is captured to analyze the behavior of activated sludge in the settling tank. The experiments with various inlet baffle conditions suggest that the hydraulic characteristics of the two experiments are significantly different. As the distance between the baffle and inlet point was decreased, significant strength of saline density currents in the bottom layer was observed. However, the strength of the velocity in the bottom density currents appeared to be the opposite in the case of the activated sludge. The reason for the slower density current in the bottom layer is associated with the compressibility of activated sludge characteristics.

Ultrasonographic observation of intestinal mobility of dogs after acupunctural stimulation on acupoints ST-36 and BL-27

objectives of this study were to observe normal peristalsis and mixing (or segmental movements) and to evaluate an acupuncture stimulation (ST-36 and BL-27) on the intestinal (duodenum) motility in normal dogs using duplex Doppler sonography. Fifteen healthy Beagle dogs were used for this experiment after the administration of warm saline and pellet feeding. The duodenal motility was examined using duplex Doppler sonography. Six hours after the pellet feeding, an electroacupuncture stimulation at ST-36 and BL-27 was applied and the duodenal motility was examined using duplex Doppler sonography pre-stimulation, during the stimulation and post-stimulation. After saline and pellet administration, the duplex Doppler sonograms showed 3 types of peristalsis and a mixing type (or segmental movement) of duodenum motility. In the peristalsis types, most yielded high-amplitude signals which had one high peak (type-1), two high peaks (type-2), and three high peaks (type-3) and lasted more than 1.3 seconds. Mixing type of duodenum motility had weak signals and were lasted more than 1.5 seconds. Among the peristalsis types, the type 1 and type 2 were predominant and the type 3 was rarely observed. The frequency of intestinal motility stimulated by ST-36 acupoint was increased during the acupuncture stimulation (20% increase compared to the basal value) and decreased (7% decrease compared to the basal value) after stimulation. The frequency of intestinal motility stimulated by BL-27 acupoint was decreased during the acupuncture stimulation (31% decrease compared to the basal value) and increased (18% increase compared to the basal value) after stimulation. There was a significant increase between the value found in during and the post-stimulation tests. We conclude that duplex Doppler studies permit a graphic visualization of intestinal movements which can be qualitatively and quantitatively analyzed using this technique, it is possible to evaluate the gastrointestinal motility after an acupuncture

A new reverse PET chemosensor and its chelatoselective aromatic cadmiation

[reaction: see text]. A new fluorescent chemosensor, anthryl tetra acid, was synthesized and showed large fluorescence quenching effects in 100% aqueous solution with metal ions via photoinduced electron transfer (PET). Chelatoselective fluorescence perturbation was observed with Cd(II) and resulted from electrophilic aromatic cadmiation.

Promoter analysis of the Drosophila melanogaster gene encoding the pterin 4alpha-carbinolamine dehydratase

Pterin-4alpha-carbinolamine dehydratase (PCD) is a key enzyme in the regeneration pathway of tetrahydrobiopterin. Previously, we isolated and reported the Drosophila melanogaster gene encoding PCD. In the present study, we isolated and characterized the Drosophila virilis gene encoding PCD. The Drosophila virilis PCD gene has two introns and an open reading frame to encode a protein of 101 amino acids. The amino acid sequence of Drosophila virilis PCD shows a 83% homology to that of the Drosophila melanogaster PCD protein. From the alignment of the nucleotide sequence in the 5'-flanking region of the Drosophila melanogaster and Drosophila virilis PCD genes, we found four conserved sequences. Using a transient transfection assay, we showed that one of the conserved sequences (-127 to approximately -115) is critical for expression, also the minimal promoter region between -127 and +51 is necessary for the efficient expression of Drosophila melanogaster PCD.

Therapeutic effect of hyaluronic acid on experimental osteoarthrosis of ovine temporomandibular joint

A symptomatic relief by hyaluronic acid (HA, MW: 3.5 x 10(6)), which is synthesized by Streptococcus spp, was investigated in experimental ovine osteoarthrosis. Bilateral osteoarthrosis (OA) of the temporo-mandibular joints (TMJs) was induced by perforating discs and by scrapping subchondral condylar surface. HA was intra-articularly injected into the left joints of 6 sheep on 7, 10, 14, 17 and 21 days after the operation and physiological saline as the control was injected into the contralateral (right) joints on the same day. Three sheep were killed at I month post-operation (MPO) and the remaining three sheep were killed at 3 MPO. Various responses such as proliferation of fibrous tissue, denudation, erosion, osteophyte formation, subcortical cyst formation and ankylosis were observed radiographically and histopathologically. The treatment of HA ameliorated the degenerative changes and lowered the osteoarthrotic score in the left joints at I MPO (9.96 vs 5.81) and 3 MPO (10.86 vs 5.29) compared to the right joints. These results indicate that a repeated intra-articular injection of HA inhibits the progression of OA in ovine TMJs by inducing the development of articular cartilage and by reducing the proliferation of fibrotic tissue.

Evaluation of urinary continence and voiding function: early results in men with neo-urethral modification of the Hautmann orthotopic neobladder

PURPOSE

At our institution we use the Hautmann orthotopic bladder replacement with a chimney and neo-urethral modification. A neo-urethral tube allows tension-free intestino-urethral anastomosis, thus providing application of this procedure for patients who may otherwise not qualify due to the inability of the small bowel to reach the urethra. However, this neo-urethral tube may also enhance continence by providing significant intra-abdominal urethral length. Conversely, such a modification may be associated with a higher degree of urinary retention. Early evaluation and reporting on the results of this procedure appear warranted.

MATERIALS AND METHODS

From April 1996 to March 2000, 14 consecutive male patients underwent cystoprostatectomy and urinary reconstruction with Hautmann repair using chimney and neo-urethral modifications. We performed a retrospective analysis of urinary function and continence with data obtained from patient questionnaires completed preoperatively and at each postoperative office visit. The examining physician chart notes were reviewed for information about urinary retention. The American Urological Association symptom score and voiding bother index were used to assess urinary function and bother, respectively. Urinary continence was defined as the complete absence of any form of urinary leakage protection.

RESULTS

Of the 14 patients 12 were completely continent day and night, with a median followup of 17 months. There were 2 patients who wore pads less than 7 months after surgery. Improvement of urinary continence appeared to continue up to 12 months postoperatively. Despite this encouraging effect, when our data were compared to the published literature, we noted a somewhat increased incidence of patients requiring clean intermittent catheterization to manage significant post-void urinary residuals. We had no patients with urethro-intestinal strictures who required clean intermittent catheterization.

CONCLUSIONS

The neo-urethral tube modification appears to have a significant and favorable impact on urinary continence while seeming to be associated with a trend towards an increased rate of chronic urinary retention. Longer followup will be required to determine whether this higher rate of chronic urinary retention will remain stable or change with time.

Changes of aortic dimensions as evidence of cardiac pump mechanism during cardiopulmonary resuscitation in humans

The mechanism of forward blood flow during cardiopulmonary resuscitation (CPR) remains controversial. We hypothesized that, if the heart acts as a pump, the proximal descending thoracic aorta would be distended during compression by forward blood flow, and would be constricted or remained unchanged if blood flow is generated by increased intrathoracic pressure. Fourteen patients with nontraumatic cardiac arrest underwent transesophageal echocardiography to verify changes in the descending thoracic aorta during standard manual CPR. The aortic dimensions, including cross-sectional area and diameter at the end of compression and relaxation, were measured proximal to, and at the maximal compression site of the descending thoracic aorta. At the maximal compression site, deformation of the descending thoracic aorta was observed during compression in all patients and the ratio of maximal to minimal diameter of the aorta (deformation ratio) decreased during compression compared with relaxation (0.58+/-0.15 vs. 0.81+/-0.11, P=0.001). This suggests eccentric compression of the descending thoracic aorta by external chest compression. The deformation ratio of the descending thoracic aorta proximal to the maximal compression site remained unchanged during compression and relaxation (1.0+/-0.88 vs. 1.0+/-0.9, P=0.345). The cross-sectional area of the descending thoracic aorta proximal to the maximal compression site increased 15% on average during compression compared with relaxation in 12 of 14 patients. In conclusion, deformation of the aorta at the maximal compression site and increase in the cross-sectional area of the proximal aorta suggests that cardiac pumping is the dominant mechanism in generating forward blood flow during CPR in humans.

Syndrome of painful legs and moving toes: a case study

Painful legs and moving toes syndrome is characterized by spontaneous causalgic pain in the lower extremities associated with peculiar involuntary movements of the lower extremities, especially the toes and feet. The pain is diffuse, intractable, aching, and deep. The movements consist of persistent writhing movements in the digits that cannot be limited voluntarily. The syndrome has been observed after a variety of abnormalities affecting the posterior nerve roots, the spinal ganglia, and the peripheral nerves. This article reviews commonly reported findings and current concepts in the etiology and management of this condition.

Inequality in America: the contribution of health centers in reducing and eliminating disparities in access to care

Reducing and eliminating health status disparities by providing access to appropriate health care is a goal of the nation's health care delivery system. This article reviews the literature that demonstrates a relationship between access to appropriate health care and reductions in health status disparities. Using comprehensive site-level data, patient surveys, and medical record reviews, the authors present an evaluation of the ability of health centers to provide such access. Access to a regular and usual source of care alone can mitigate health status disparities. The safety net health center network has reduced racial/ethnic, income, and insurance status disparities in access to primary care and important preventive screening procedures. In addition, the network has reduced low birth weight disparities for African American infants. Evidence suggests that health centers are successful in reducing and eliminating health access disparities by establishing themselves as their patients' usual and regular source of care. This relationship portends well for reducing and eliminating health status disparities.

Promoter analysis of the Drosophila melanogaster gene encoding transcription elongation factor TFIIS

The promoter region of the Drosophila melanogaster TFIIS gene was characterized by transient expression assay. Serial deletion analysis of the promoter region showed that the promoter region between -112 and +113 is required for the efficient expression of the D. melanogaster TFIIS gene. The results also suggest that the DNA fragments between -112 and -54 and between +94 and +113 contain the vital elements for the expression. The importance of these fragments was further substantiated by the findings that the sequences in these fragments of the D. melanogaster TFIIS gene are conserved in the 5'-flanking regions of the Drosophila virilis TFIIS gene. The comparison of the nucleotide sequences in the 5'-flanking region of the D. melanogaster and D. virilis TFIIS genes revealed that the three regions, -85--59, +76-+126, and the vicinity of the transcription initiation site of the D. melanogaster TFIIS gene, are conserved. It is very interesting that the long downstream DNA between +76 and +126 is highly conserved with 90% identities between the two species. The downstream promoter region between +94 and +113 of the D. melanogaster TFIIS gene was further analyzed by transient expression and band mobility shift assays. The results obtained suggest that the region between +94 and +113 is probably recognized by nuclear factors and that the sequence (+98)AGTAAACAACAT(+109) seems to make a great contribution to promoter activity of the D. melanogaster TFIIS gene.

Application of pulsed Doppler ultrasound for the evaluation of small intestinal motility in dogs

The purpose of this study was to verify whether small intestinal peristalsis could be observed and quantitatively assessed using pulsed-Doppler ultrasound. Pulsed-Doppler ultrasound was used to evaluate small intestinal peristalsis after a meal in ten normal dogs and ten sedated dogs. The small intestinal peristalses were measured 0, 1, 3, 6, 9, 12, and 24 hours after a 24-hour fast and after feeding. The number of small intestinal peristalsis were 0.133/min, 0.100/min, 0.033/min, 0.167/min, 0.070/min, 0.067/min, and 0.100/min in the fasted dogs, and 1.667/ min, 0.933/min, 1.133/min, 1.234/min, 1.933/min, 1.533/ min, and 0.533/min in fed dogs, respectively. In the dogs sedated with xylazine HCl, the number of small intestinal peristalsis was significantly reduced (p<0.01). However, in the dogs treated with ketamine HCl and acepromazine, the number of small intestinal peristalsis remained unchanged. Therefore, it can be concluded that pulsed-Doppler ultrasound allows graphic visualization of the intestinal movements, which can be subjected to qualitative and quantitative analysis, and may be suitable for a non-invasive study of small intestinal motility.

Effect of dopamine on excretory urographic image quality and the prevention of contrast-induced nephropathy in dogs

The effect of low dose dopamine on the excretory urographic image quality and contrast media-induced nephropathy in normal dogs (experiment 1) and the dogs with decreased renal function (experiment 2) were assessed. In experiment 2, decreased renal function was induced by gentamicin overdose. In each experiment, animals were divided into 3 groups. In group 1, only contrast medium (iohexol) was administered. In group 2, contrast medium plus intravenous fluid (0.9% saline) were administered. And in group 3, contrast medium plus intravenous fluid and low dose dopamine were administered. Investigated parameters included intrarenal resistive index (RI), serum BUN and creatinine concentrations, contrast medium elimination time and radiographic image quality. In experiment 1, RI of group I increased at 80 min after contrast medium administration (p<0.05), but RI of group 3 decreased at 48 and 72 hr (p<0.05). Serum BUN concentration of group 1 was higher than that of group 2 and 3 (p<0.05); in radiographic examination, contrast medium elimination time decreased in group 2 and 3, but image quality of group 2 was inferior to that of group 3. In experiment 2, image quality of group 3 only provided adequate visualization of renal structures. The formula of contrast medium plus low dose dopamine was found to provide good nephrogram and pyelogram image quality without supplemental contrast medium, and to protect renal tubules from prolonged exposure to concentrated contrast medium.