Gene expression profiling of responses to dimethylarsinic acid in female F344 rat urothelium

Gene expression profiling has been shown to be useful for identifying underlying mechanisms of toxicity, determining patterns of biological response, and elucidating candidate markers of exposure and response. Inorganic arsenic (iAs) is a human carcinogen and epidemiologic evidence implicates it in the development of urinary bladder cancer. Dimethylarsinic acid (DMA), the major excreted metabolite of iAs in humans, is a known rat bladder carcinogen. To examine the changes associated with DMA exposure, microarray analysis of the urothelium was performed in female F344 rats exposed to non-toxic and toxic doses of DMA in their drinking water for 28 days. A novel method for isolating predominantly urothelial cells was developed. Gene expression profiling of the urothelium using a custom 2-dye spotted array revealed that DMA treatment modulated the expression of transcripts of genes that regulate apoptosis, cell cycle regulation and the oxidative stress response. Expression of genes mapping to pathways involved in cancer control processes were also altered after DMA exposure. Morphological data suggested a dose dependent increase in cellular toxicity. Significant changes in differential gene expression were present after all treatments event at doses where standard toxicological responses were not detectable. The greatest perturbation in gene expression was present in rats after treatment with 40 ppm DMA. Doses which produced no histologic or ultrastructural evidence of toxicity (non-toxic) could be differentiated from toxic doses based on the expression of a subset of genes, which control cell signaling and the stress response. These reported changes in gene expression show similarities between the mechanisms of action of DMA in vivo and those previously described for iAs in vitro. These data illustrate the utility of transcriptional profiling and its potential in predicting key mechanistic pathways involved in toxicity and as a time efficient tool to inform the mode of action analysis in risk assessment.

Does Donor Cardiopulmonary Resuscitation Time Affect Outcome in Uncontrolled Non–Heart-Beating Donor Renal Transplants?

Uncontrolled non-heart-beating donors offer the opportunity to significantly expand the potential pool of kidney donors but are associated with a variable duration of cardiopulmonary resuscitation (CPR), where cardiac output is only 30% to 40% of normal. We were concerned that prolonged CPR would adversely affect the function of transplanted kidneys. In our series of 46 uncontrolled donors the mean duration of CPR was 60 minutes, which also represents a realistic cutoff point for CPR duration. Taking a cutoff point of 60 minutes, we found no differences in kidney discard rates following viability assessment, primary nonfunction rate, or duration of delayed graft function. We therefore conclude that if formal viability assessment is performed, kidneys may be retrieved from uncontrolled non-heart-beating donors irrespective of duration of CPR.

SEP-class genes in Populus tremuloides and their likely role in reproductive survival of poplar trees

One of the most important processes to the survival of a species is its ability to reproduce. In plants, SEPALLATA-class MADS-box genes have been found to control the development of the inner whorls of flowers. However, while much is known about floral development in herbaceous plants, similar systems in woody trees remain poorly understood. Populus tremuloides (trembling aspen) is a widespread North American tree having important economic value, and its floral development differs from that of well-studied species in that the flowers have only two whorls and are truly unisexual. Sequence based analyses indicate that PTM3 (Populus tremuloides MADS-box 3), and a duplicate gene PTM4, are related to the SEPALLATA1-and 2-class of MADS-box genes. Another gene, PTM6, is related to SEP3, and each of these genes has a counterpart in the poplar genomic database along with additional members of the A, B, C, D, and E-classes of MADS-box genes. PTM3/4 and 6 are expressed in all stages of male and female aspen floral development. However, PTM3/4 is also expressed in the terminal buds, young leaves, and young stems. In situ RNA localization identified PTM3/4 and 6 transcripts predominantly in the inner, sexual whorl, within developing ovules of female flowers and anther primordia of male flowers. Tree researchers often use heterologous systems to help study tree floral development due to the long juvenile periods found in most trees. We found that the participation of PTM3/4 in floral development is supported by transgenic experiments in both P. tremuloides and heterologous systems such as tobacco and Arabidopsis. However, phenotypic artifacts were observed in the heterologous systems. Together the results suggest a role for poplar SEP-class genes in reproductive viability.

Camptothecin analogs with enhanced activity against human breast cancer cells. II. Impact of the tumor pH gradient

Human breast tumors often exist in an acidic and hypoxic microenvironment, which can promote resistance to radiation and chemotherapies. A tumor-selective pH gradient arises in these tumors which favors uptake and retention of drugs like camptothecin that are weak acids. We evaluated the effect of alkyl substitutions at the 7 position in seven CPTs with varying groups at the 10 position on modulation by acidic extracellular pH in three human breast cancer cell lines. Growth inhibition was assessed by propidium iodide staining of nucleic acids in human breast cancer cells cultured at either extracellular pH 6.8 or 7.4 that were (1) hormone-sensitive (MCF-7/wt), (2) hormone insensitive (MDA-MB-231), or (3) alkylator-resistant (MCF-7/4-hc). Over 10-fold pH modulation was observed in 7-halomethyl analogs of methylenedioxy-CPT and in 7-alkyl analogs of 10-amino-CPT. Of 39 analogs tested, the overall pattern of activity across breast tumor cell lines was similar with some notable exceptions. For example, 7-propyl-10-amino-CPT was modulated 16- to 20-fold by acidic extracellular pH in the MCF-7 cell lines, but only 6-fold in MDA-MB-231 cells. One mechanism that can contribute to pH modulation is enhanced cellular drug uptake and retention. In MCF-7/wt cells, uptake of 10-amino-CPT increased 4-fold, while retention increased over 10-fold at acidic extracellular pH. In addition, gene expression analysis of MCF-7/wt cells indicated that expression of a number of genes changed under acidic culture conditions, including down-regulation of the CPT efflux protein pump breast cancer resistance protein (BCRP). Interestingly, expression of topoisomerase I, the molecular target of CPT, was not affected by acidic growth conditions. These results highlight the importance of maintaining key features of tumor physiology in cell culture models used to study cancer biology and to discover and develop new anticancer drugs. While several substitutions at the 7 and 10 positions enhance potency, 7-halomethyl and 10-amino CPT analogs show selective activity at the acidic pH common to the microenvironment of most solid tumors.

Indoor airborne fungal spores and home characteristics in asthmatic children from Edirne region of Turkey

BACKGROUND

The contribution of indoor fungal exposure to childhood asthma is not completely clear.

OBJECTIVE

To investigate airborne fungal flora within the homes of asthmatic and control children, and to assess the influence of housing characteristics regarding indoor fungi.

METHODS

Forty-seven atopic asthmatic and 23 nonatopic control children were studied. Allergen sensitivity was determined by skin prick tests. A thorough assessment, using a questionnaire and inspection surveys, was carried out. Home visits were made between October 2000 and February 2001. Samples of airborne fungal spores were collected from four rooms by the "open Petri dish" method. Indoor temperature and humidity were measured.

RESULTS

The total indoor fungal colony counts from the living rooms and bedrooms were significantly higher in the asthma group than in controls (p = .012 and p = .003, respectively). The most commonly isolated genus was Cladosporium. Twelve of the asthmatic patients (25.53 %) were found to be sensitive to fungal allergens. The factors found to be associated with indoor fungal growth in logistic regression were visible fungal patches in the bathrooms [(odds ratio (OR) = 5.75; 95 % CI 1.19 to 27.70)], and the age of the house [OR = 4.24; 95 % CI 1.34 to 13.45]. Total fungal colony numbers did not correlate with indoor temperature or humidity.

CONCLUSION

Fungal colony numbers were higher in the homes of asthmatic children than in those of controls. Therefore, indoor fungal exposure may contribute to childhood asthma. Bathrooms were the main source of fungal propagules. Old houses were more prone to fungal growth.

The transcriptional profile of the kidney in Tsc2 heterozygous mutant Long Evans (Eker) rats compared to wild-type

Hereditary renal cell carcinoma (RCC) in Eker rats results from an inherited insertional mutation in the Tsc2 tumor suppressor gene and provides a valuable experimental model to characterize the function of the Tsc2 gene product, tuberin in vivo. The Tsc2 mutation predisposes the Eker rat to develop renal tumors at an early age. The exact mechanism of Tsc2 mediated tumor suppression is not known, however, there is evidence that it is most likely mediated by changes in cell cycle regulation via the PI3K/Akt pathway. The present study was designed to identify if gene expression was different in Tsc2 heterozygous mutant rat kidney compared to wild-type and if any of those differences are associated with tumorigenesis. cDNA microarray analysis of the untreated Tsc2 (+/-) mutant Long Evans (Eker) rat was compared to the Tsc2 (+/+) wild-type Long Evans rat to search for patterns that might be indicative of the intrinsic role of Tsc2. Of 4395 genes queried, 3.2% were significantly altered in kidneys from heterozygous mutant rats, of which 110 (76%) were up-regulated and 34 (24%) were down-regulated relative to the wild-type. The genes with altered expression belonged to the functional categories of cell cycle regulation, cell proliferation, cell adhesion and endocytosis. Many of these genes appear to be directly or indirectly regulated by the PI3K/Akt pathway. In addition to the PI3K/Akt pathway, other signaling pathways were also differentially expressed in Tsc2 mutant Eker rat kidneys compared to wild-type rats. The gene expression profiles of the Tsc2 heterozygous mutant and wild-type animals highlights new pathways for investigation that may be associated with the tumorigenic activity of tuberin loss and correlate with the enhanced susceptibility of the Tsc2 mutant animal's tendency to develop renal cell carcinoma.

Laparoscopic lateral pancreaticojejunostomy: our experience of 17 cases

BACKGROUND

Although lateral pancreaticojejunostomy (LPJ) is one of the most commonly performed procedures for the management of chronic obstructive pancreatitis, it is seldom performed laparoscopically. We report our experience of 17 consecutive laparoscopic LPJ (lap LPJ) and their outcome.

METHODS

Seventeen patients (nine male and eight female) with ages ranging between 16 and 48 years underwent lap LPJ by a single surgical team. The most common presenting symptoms were abdominal pain and weight loss.

RESULTS

The mean operating times for lap LPJ and lap LPJ with one or more additional procedures were 277 min and 377 min, respectively. The mean hospital stay was 5.2 days. Conversion to laparotomy was required in four patients. There were no deaths and the overall complication rate was 11.8%. On follow-up, ranging from 3 months to 1 year, 82.3% of the patients were pain-free.

CONCLUSIONS

Lateral pancreaticojejunostomy is the surgical procedure of choice for the management of chronic obstructive pancreatitis. The same procedure can be performed laparoscopically; although it is technically demanding, the results are excellent. However, the procedure is still in the early phase of feasibility owing to the limited number of cases reported in the world literature.

Mapping the range and scope of emergency nurse practitioner services in the Northern and Yorkshire Region: a telephone survey

OBJECTIVE

To map the range and scope of emergency nurse practitioner (ENP) services in the Northern and Yorkshire Region as part one of a three phased study investigating the developing role of the ENP on a multi-professional context.

METHODS

A telephone survey was conducted in the 48 hospital trusts within the region. Semi-structured interviews were arranged with the senior nurses responsible for accident and emergency services in responding departments. Data collection entailed completion of a form comprising 14 open-ended questions designed to elicit information about the range and scope of ENP services (as defined by the Royal College of Nursing). Data were analysed using descriptive statistics.

RESULTS

Interviews were conducted at 35 (73%) of the sites, 22 (63%) of which had an ENP service as defined above. Wide variation was found in the range of services in relation to: hours/days of availability; age range and sources of referrals of patients accessing the service; clinical caseloads of ENPs and the referral pathways to other services.

CONCLUSION

The findings from the survey highlight the organic, context specific nature of ENP role developments in response to national government initiatives, professional agendas, and local service needs.

Early results of a non-heartbeating donor (NHBD) programme with machine perfusion

Freeman Hospital, Newcastle upon Tyne restarted their non-heartbeating donor (NHBD) programme in September 1998 using machine perfusion, due to early poor results with conventional cold storage (45% graft survival, phase II). Since then, 15 NHBD kidneys have been transplanted. The retrieval protocol consisted of in situ perfusion with a double balloon triple lumen cannula in Maastricht category II male donors age range 13-59 years. Mean primary warm ischaemic time was 24.8 min (range 10-44). All kidneys were machine perfused through a locally developed perfusion system. The viability was assessed by serial measurements of total GST (maximum acceptable limit of 200 units/l) and intrarenal vascular resistance (IRVR) was recorded. Fifteen of the 22 kidneys (68.62%) were transplanted. Delayed graft function (DGF) was seen in ten recipients (66.6%), two kidneys had immediate function (IF), one organ was exported, two recipients died of unrelated causes and a further seven kidneys were discarded (two had high tGST, two were infected and three had poor flow characteristics). In phase III, a success rate of 91.7% was thus achieved, which was better than the phase II period (P = 0.027, Fisher 2-tail test). Machine perfusion has been successfully introduced in phase III to the Newcastle NHBD programme and facilitates viability assessment of NHBD kidneys.

The trouble with kidneys derived from the non heart-beating donor: a single center 10-year experience

BACKGROUND

The demand for renal transplantation has increasingly outstripped the supply of donor organs especially over the past 10 years. Although related and unrelated live donation is being promoted as one option for increasing the donor pool, it is unlikely that this will in itself be able to bridge the gap. Non-heart beating donors (NHBD) can provide an alternative supply of organs, which should substantially increase the donor pool.

METHODS

In Newcastle, NHBD kidneys have been used for transplantation for a period of 10 years. In the early period (1988-1993) excellent results were obtained (90.5% success); however, these donors were controlled NHBD, Maastricht category III. In the second phase (1994-1998) increasing numbers of donors were obtained from the Accident and Emergency Department unit. These were failed resuscitation for cardiac arrest (category II). The rates of success in this period were poor (45.5% success) and the program was halted. The third phase of the program used machine perfusion of the kidneys and glutathione S transferase enzyme analysis to assess viability.

RESULTS

Using such approaches renal transplants from largely category II donors produced a success rate of 92.3% which was significantly better than the phase II period of the program (P=0.023, Fisher two-tail test).

CONCLUSION

Machine perfusion and viability assessment of NHB kidneys in phase III of the program has increased our donor pool as well as improved the graft survival. This is particularly relevant for the use of the category II NHB donor where the incidence of primary nonfunction was high, illustrated by phase II where machine perfusion/viability assessment was not used.

Diagnosis of carotid sinus hypersensitivity in older adults: carotid sinus massage in the upright position is essential

OBJECTIVE

To assess the diagnostic value of supine and upright carotid sinus massage in elderly patients.

DESIGN

Prospective controlled cohort study.

SETTING

Three inner city accident and emergency departments and a dedicated syncope facility.

PATIENTS

1375 consecutive patients aged > 55 years presenting with unexplained syncope and drop attacks; 25 healthy controls.

INTERVENTIONS

Bilateral supine carotid sinus massage, repeated in the 70 degrees head up tilt position if the initial supine test was not diagnostic of cardioinhibitory and mixed carotid sinus hypersensitivity.

MAIN OUTCOME MEASURES

Diagnosis of cardioinhibitory or mixed carotid sinus hypersensitivity; clinical characteristics of supine v upright positive groups.

RESULTS

226 patients were excluded for contraindications to carotid sinus massage. Of 1149 patients undergoing massage, 223 (19%) had cardioinhibitory or mixed carotid sinus hypersensitivity; 70 (31%) of these had a positive response to massage with head up tilt following negative supine massage (95% confidence interval, 25.3% to 37.5%). None of the healthy controls showed carotid sinus hypersensitivity on erect or supine massage. The initially positive supine test had 74% specificity and 100% sensitivity; these were both 100% for the upright positive test. The clinical characteristics of the supine v upright positive subgroups were similar.

CONCLUSIONS

The diagnosis of carotid sinus hypersensitivity amenable to treatment by pacing may be missed in one third of cases if only supine massage is performed. Massage should be done routinely in the head up tilt position if the initial supine test is negative.

Fungal metabolites from Aspergillus niger AN27 related to plant growth promotion

Two metabolites have been isolated from Aspergillus niger AN27, a biocontrol agent, and identified as 2-carboxymethyl 3-n-hexyl maleic acid (compound 1) and 2-methylene-3-hexylbutanedioic acid (compound 2). Their biological activities related to crop growth promotion have been assayed. Both the compounds increased germination and improved crop vigour. Compound 1 was more effective for increase in germination and shoot length, whereas compound 2 had relatively greater role in increasing the root length and biomass of cauliflower seedlings.