Impact of Clostridium difficile colitis on 5-year health outcomes in patients with ulcerative colitis.

BACKGROUND: Clostridium difficile colitis (CDC) is associated with an increased short-term mortality risk in hospitalised ulcerative colitis (UC) patients. We sought to determine whether CDC also impacts long-term risks of adverse health events in this population. AIM: To determine whether CDC also impacts long-term risks of adverse health events in this population. METHODS: A population-based retrospective cohort study was conducted of UC patients hospitalised in Ontario, Canada between 2002 and 2008. Patients with and without CDC were compared on the rates of adverse health events. The primary outcomes were the 5-year adjusted risks of colectomy and death. RESULTS: Among 181 patients with CDC and 1835 patients without CDC, the 5-year cumulative colectomy rates were 44% and 33% (P = 0.0052) and the 5-year cumulative mortality rates were 27% and 14% (P < 0.0001) respectively. CDC was associated with a higher adjusted 5-year risk of mortality [adjusted hazard ratio (aHR) 2.40, 95% CI 1.37-4.20], but not of colectomy (aHR 1.18, 95% CI 0.90-1.54). CDC impacted mortality risk both during index hospitalisation (adjusted odds ratio 8.90, 95% CI 2.80-28.3) as well as over 5 years following hospital discharge among patients who recovered from their acute illness (aHR 2.41, 95% CI 1.37-4.22). Colectomy risk was not influenced by CDC in this cohort. CONCLUSION: Clostridium difficile colitis is associated with increased short-term and long-term mortality risks among hospitalised ulcerative colitis patients. As colectomy risk is not similarly impacted by Clostridium difficile colitis, factors predictive of death among C. difficile-infected ulcerative colitis patients require elucidation.

Stable biopassive insulation synthesized by initiated chemical vapor deposition of poly(1,3,5-trivinyltrimethylcyclotrisiloxane).

The permanent implantation of electronic probes capable of recording neural activity patterns requires long-term electrical insulation of these devices by biopassive coatings. In this work, the material properties and neural cell compatibility of a novel polymeric material, poly(trivinyltrimethylcyclotrisiloxane) (poly(V3D3)), are demonstrated to be suitable for application as permanently bioimplanted electrically insulating films. The poly(V3D3) polymeric films are synthesized by initiated chemical vapor deposition (iCVD), allowing for conformal and flexible encapsulation of fine wires. The poly(V3D3) also exhibits high adhesive strength to silicon substrates, a common material of manufacture for neural probes. The poly(V3D3) films were found to be insoluble in both polar and nonpolar solvents, consistent with their highly cross-linked structure. The films are pinhole-free and extremely smooth, having a root-mean-square (rms) roughness of 0.4 nm. The material possesses a bulk resistivity of 4 x 1015 Ohm-cm exceeding that of Parylene-C, the material currently used to insulate neurally implanted devices. The iCVD poly(V3D3) films are hydrolytically stable and are demonstrated to maintain their electrical properties under physiological soak conditions, and constant electrical bias, for more than 2 years. In addition, biocompatibility studies with PC12 neurons demonstrate that this material is noncytotoxic and does not influence cell proliferation.

Detection of a novel familial deletion of four genes between BP1 and BP2 of the Prader-Willi/Angelman syndrome critical region by oligo-array CGH in a child with neurological disorder and speech impairment.

Two common classes of deletions are described in the literature in individuals with Prader-Willi/Angelman syndrome (PWS/AS): one between breakpoint 1 (BP1) to BP3 and the other between BP2 to BP3 of the PWS/AS critical region on chromosome 15q11-->q13. We present here a novel observation of an approximately 253-kb deletion between BP1 and BP2 on 15q11.2, in a 3(1/2)-year-old boy, who was referred to us with a clinical suspicion of having Angelman syndrome and presenting with mental retardation, neurological disorder, developmental delay and speech impairment. Karyotype and FISH results were found to be normal. The microdeletion between BP1 and BP2 includes four genes - NIPA1, NIPA2, CYFIP1 and TUBGCP5 which was detected by a high-resolution oligonucleotide array-CGH that was further validated by a Multiplex Ligation-dependent Probe Amplification (MLPA) assay. The same deletion was observed in the father who presented with similar but relatively milder clinical features as compared to the affected son. Methylation studies by methylation-specific MLPA (MS-MLPA) of the SNRPN imprinting center (IC) showed a normal imprinting pattern, both in the patient and the father. To our knowledge a microdeletion limited only to the BP1-BP2 region has not yet been reported. The familial genetic alteration together with the striking clinical presentation in this study are interesting, but from our single case study it is difficult to suggest if the deletion is causative of some of the abnormal features or if it is a normal variant. The study however further strengthens the fact that genome-wide analysis by array CGH in individuals with developmental delay and mental retardation is very useful in detecting such hidden interstitial chromosomal rearrangements.

Physicians' approaches to the use of gastroprotective strategies in low-risk non-steroidal anti-inflammatory drug users.

BACKGROUND: Many doctors unnecessarily prescribe gastroprotective strategies to non-steroidal anti-inflammatory drugs users at low risk of non-steroidal anti-inflammatory drug-related gastrointestinal complications. AIM: To identify factors that predict the overuse of gastroprotective strategies in low-risk non-steroidal anti-inflammatory drug users. METHODS: We distributed a questionnaire to family doctors and general internists consisting of a clinical vignette describing a low-risk hypothetical patient with osteoarthritis who was a candidate for non-steroidal anti-inflammatory drug therapy. Respondents were asked whether they would prescribe this patient a gastroprotective strategy and to estimate the annual risk of that patient developing a gastrointestinal complication with non-steroidal anti-inflammatory drug use. Respondents inappropriately recommending a gastroprotective strategy were compared with respondents who opted not to use gastroprotection. RESULTS: We received 340 responses (response rate of 28.3%), of which 278 supplied analysable data. Thirty-five percent of respondents inappropriately recommended a gastroprotective strategy for the low-risk subject. Inappropriate prescribers were significantly more likely to overestimate the risk of gastrointestinal complications with traditional non-steroidal anti-inflammatory drugs and this was strongly predictive of gastroprotective strategy recommendation in logistic regression. CONCLUSIONS: Many doctors inappropriately recommend gastroprotective strategies in low-risk non-steroidal anti-inflammatory drug users. Improving doctors' awareness of non-steroidal anti-inflammatory drug-associated gastrointestinal risks may lead to a decrease in inappropriate utilization of gastroprotective strategies in low-risk patients.

Hydrogels as potential probes for investigating the mechanism of lenticular presbyopia.

PURPOSE: To synthesize and characterize hydrogels with viscoelastic properties comparable to those of the natural lens. METHODS: Hydrogels were synthesized in water by free-radical polymerization of the monomer poly(ethyleneglycol)-monomethacrylate. Three different molecular weights of poly(ethyleneglycol)-dimethacrylates were used as crosslinkers. For each crosslinker used, five different monomer-to-crosslinker weight ratios were utilized while the total mass of the reactants was kept constant. In another series, the concentration of the reactants was varied while the weight ratio of monomer to crosslinker was kept constant at 95 : 5. The percent optical transmission, equilibrium water content, moduli (elastic, shear, storage, and loss), and retardation time constant of the hydrogels were determined. In addition, endocapsular polymerization was performed in the capsular bag of porcine eyes. RESULTS: The hydrogels examined exhibited the following ranges for viscoelastic properties: elastic modulus, 1.33-2.37 x 10(4) Pa; shear modulus, 3.35-6.72 x 10(3) Pa; storage modulus, 1.65-6.24 x 10(4) Pa. For any given hydrogel, raising its crosslinker's weight ratio increased its moduli and decreased its equilibrium water content and optical transmission. For any given monomer-to-crosslinker weight ratio, increasing the molecular weight of the crosslinker reversed these trends. Reactant concentrations increased the elastic modulus and decreased the equilibrium water content. The hydrogels formed ex vivo (in the evacuated capsular bag of porcine eyes) allowed for the clear and undistorted viewing of objects. CONCLUSIONS: Hydrogels that exhibit physical and mechanical properties comparable to those of the natural lens were successfully identified, synthesized, and characterized, and the feasibility of endocapsular polymerization was demonstrated.

Sphingosine generation, cytochrome c release, and activation of caspase-7 in doxorubicin-induced apoptosis of MCF7 breast adenocarcinoma cells.

Treatment of human breast carcinoma MCF7 cells with doxorubicin, one of the most active antineoplastic agents used in clinical oncology, induces apoptosis and leads to increases in sphingosine levels. The transient generation of this sphingolipid mediator preceded cytochrome c release from the mitochondria and activation of the executioner caspase-7 in MCF7 cells which do not express caspase-3. Bcl-x(L) overexpression did not affect sphingosine generation whereas it reduced apoptosis triggered by doxorubicin and completely blocked apoptosis triggered by sphingosine. Exogenous sphingosine-induced apoptosis was also accompanied by cytochrome c release and activation of caspase-7 in a Bcl-x(L)-sensitive manner. Furthermore, neither doxorubicin nor sphingosine treatment affected expression of Fas ligand or induced activation of the apical caspase-8, indicating a Fas/Fas ligand-independent mechanism. Our results suggest that a further metabolite of ceramide, sphingosine, may also be involved in mitochondria-mediated apoptotic signaling induced by doxorubicin in human breast cancer cells.

Laser capture microdissection-guided fluorescence in situ hybridization and flow cytometric cell cycle analysis of purified nuclei from paraffin sections.

Laser capture microdissection (LCM) has recently been identified as a quick, simple, and effective method by which microdissection of complex tissue specimens for molecular analysis can be routinely performed. Assessment of gene copy number by fluorescence in situ hybridization (FISH) is useful for the analysis of molecular genetic alterations in cancer. Unfortunately, the application of FISH to paraffin sections of tumor specimens is fraught with technical difficulty and potential artifacts. Our results demonstrate that LCM-microdissected nuclei are suitable for FISH gene copy analysis. Amplification of genes in cancer specimens can be detected as easily in LCM-prepared nuclei as in fresh nuclei from cancer tissue specimens. Furthermore, contamination of tumor specimens by normal cells can make interpretation of flow cytometric cell cycle analysis difficult. Our results show that LCM-microdissected nuclei can also be used for flow cytometric cell cycle and ploidy analysis. LCM/FISH offers the advantages of multicolor FISH in a morphologically defined cell population, without the technical problems of FISH performed on paraffin sections. This technique should further simplify the methodology required to perform copy number analysis of tumor suppressor or protooncogenes in archived cancer specimens. The use of LCM specimens will also improve the specificity and simplify the interpretation of flow cytometric cell cycle and ploidy analysis of breast cancer specimens.

Chromosomal localization and genomic organization of the human retinal rod Na-Ca+K exchanger.

The retinal rod Na-Ca+K exchanger is a unique calcium extrusion protein found only in the outer segments of retinal rod photoreceptors. Rod Na-Ca+K exchanger cDNA (NCKX1) has been cloned from bovine and human retinas. Here, we have used fluorescent in situ hybridization and radiation hybrid mapping to localize the human NCKX1 gene to chromosome 15q22. We have determined the genomic organization of human rod NCKX1 and found one intron in the 5' untranslated region and eight introns within the coding region.

Hyperthermic induction of premature chromosome condensation in human lymphocytes.

Hyperthermic induction of chromosomal aberrations was examined in human lymphocytes. For this purpose, whole blood cultures were exposed to an elevated temperature (43 degrees C) at the 46th h of culture initiation, followed by 24 h of recovery. Detailed chromosomal analysis showed significantly higher levels of aberrations as compared to control cultures of the same individuals. These aberrations include breaks, gaps of both chromosome and chromatid type, aneuploidy and high levels of polyploidy. The interesting observation was the occurrence of S-phase premature chromosome condensation (PCC). The S-phase PCC observed here could be due to asynchronous nuclei induced by hyperthermia. A possible interpretation for the occurrence of asynchronous nuclei leading to the induction of S-phase PCC is discussed.

Sporadic occurrence of nondeletion Prader-Willi syndrome in two cases: a female with maternal uniparental disomy and a male with complex chromosomal rearrangement.

We report here two cases of nondeletion Prader-Willi syndrome (PWS). Case 1 is a 9-yr-old female patient with classical features of the syndrome and cytogenetically normal chromosome 15. DNA analysis using polymorphic probes for Prader-Willi Critical Region (PWCR) showed absence of paternal alleles while maternal uniparental isodisomy (UPisoD) was confirmed. This is the first report of nondeletion PWS with uniparental disomy (UPD) in the population of Kuwait. The second case with Prader-Willi syndrome-like features had normal chromosome 15 but showed familial complex chromosomal rearrangement (CCR) involving chromosomes 13, 19, and 20 inherited from his mother. No paternal deletion or UPD disomy was observed after DNA molecular analysis. This is a case of "atypical" PWS with no cytogenetic or molecular abnormality for PWCR. The two cases represent two different mechanisms associated with nondeletion PWS.

Multiple drug resistance in Candida albicans.

By functional complementation of a PDR 5 (pleiotropic drug resistance) null mutant of S. cerevisiae, we have recently cloned and sequenced a multidrug resistance gene CDR 1 (Candida Drug Resistance). Transformation by CDR 1 of a PDR 5 disrupted host hypersensitive to cycloheximide and chloramphenicol resulted in resistance to these as well as other unrelated drugs. The nucleotide sequence of CDR 1 revealed that, like PDR 5, it encodes a putative membrane pump belonging to the ABC superfamily. CDR 1 encodes a protein of 169.9 kDa whose predicted structural organisation is characterised by two homologous halves, each comprising a hydrophobic region, with a set of six transmembrane stretches, preceded by a hydrophilic binding fold. We now have evidence to suggest that there are several PDR homologues present in C. albicans which display multidrug resistance and a collateral sensitivity pattern different from PDR 5 and CDR 1. The functions of such genes and their products in the overall physiology of C. albicans is not yet established.

Solid and cystic papillary neoplasm of pancreas--a report of seven cases.

OBJECTIVE: To study the clinico-pathological features of patients with solid and cystic papillary neoplasm of the pancreas. METHODS: The clinico-pathological features of solid and cystic papillary neoplasm of the pancreas were studied in seven fully documented and confirmed cases presented during the last seven years. RESULTS: All the patients were women with a median age of 18 years (range 12-40). Four presented with epigastric pain and three had a painless abdominal lump. The median duration of symptoms prior to presentation was 3 months (range 1-6). The tumor size ranged from 6-16 cm (mean 10 cm). Preoperative diagnosis was established by fine needle aspiration cytology in three patients. All the seven underwent resection. Pericapsular adhesions were found in two patients. All the patients were free of disease on follow-up ranging from 3-60 months (median 16 mo). CONCLUSION: Occurrence in young females, solid and cystic areas on imaging, resectability in spite of large size, and good prognosis are the important features of this tumor.

Crystallization and preliminary X-ray diffraction analysis of crystals of Thermoascus aurantiacus xylanase.

Crystals suitable for high resolution X-ray diffraction analysis have been grown of the 29,774-Da protein, xylanase (1,-4-beta-xylan xylanohydrolase EC 3.2.1.8) from the thermophilic fungus Thermoascus aurantiacus. This protein, an endoxylanase demonstrates the hydrolysis of beta-(1-4)-D-xylose linkage in xylans and crystallizes as monoclinic pinacoids in the presence of ammonium sulphate buffered at pH 6.5, and also with neutral polyethylene glycol 6000. The crystals belong to space group P2(1) and have cell dimensions, a = 41.2 A, b = 67.76 A, c = 51.8 A; beta = 113.2 degrees.

Trisomy 18q: 46,XX,-10,+der(10) t(10;18) (p15;q12) pat: a case report.

A 2-month-old female with intrauterine and postnatal growth retardation, multiple congenital anomalies, absent right kidney, congenital heart disease was investigated. Her karyotype revealed, 46,XX,-10,+der(10), t(10;18) (p15;q12) pat. The child died at 2 months 2 weeks. This is the third case of trisomy 18q resulting from translocation of chromosome 10 and 18.

The primary structure of xylanase from Thermoascus aurantiacus.

The amino acid sequence of xylanase isolated from the culture medium of Thermoascus aurantiacus was determined. It had 269 amino acid residues with an alpha-N-acetyl group at the amino terminus. The structure of blocked N-terminal 11 amino acid tryptic peptide except for acetylalanine was determined by sequence analysis of peptides derived from partial acid hydrolysis and from thermolysin digestion. The blocked N-terminal amino acid was determined as N-acetylalanine by electron ionization mass spectrometry. The sequence comparison of xylanase from T. aurantiacus with the xylanases of alkalophilic Bacillus sp C-125 and Cryptococcus albidus showed 40% similarity. Xylanase from T. aurantiacus had up to 15% similarity with the other two xylanases known. All the five xylanases showed a higher degree of similarity at the level of secondary structure.

Unusual splenic metastasis from oesophageal cancer.

The most common visceral metastasis from oesophageal carcinomas are lungs and liver. A case of splenic metastasis from a squamous carcinoma of oesophagus is reported. To our knowledge, splenic metastasis without any nodal disease has not been described previously. The pattern of reported metastasis is summarised.