952 resultados para dichloromethane substitution


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Glanzmann's thrombasthenia (GT) arises from a qualitative or quantitative defect in the GPIIb-IIIa complex (integrin alphaIIbbeta3), the mediator of platelet aggregation. We describe a patient in whom clinical and laboratory findings typical of type I GT were found together with a second pathology involving neurological and other complications symptomatic of tuberous sclerosis. Analysis of platelet proteins by Western blotting revealed trace amounts of normally migrating GPIIb and equally small amounts of GPIIIa of slightly slower than normal migration. Flow cytometry confirmed a much decreased binding to platelets of monoclonal antibodies to GPIIb, GPIIIa or GPIIb-IIIa, and an antibody to the alphav subunit also showed decreased binding. Nonradioactive PCR single-strand conformation polymorphism analysis followed by direct sequencing of PCR-amplified DNA fragments showed a homozygous point mutation (T to C) at nucleotide 1722 of GPIIIa cDNA and which led to a Cys542-->Arg substitution in the GPIIIa protein. The mutation gave rise to a HinP1 I restriction site in exon 11 of the GPIIIa gene and allele-specific restriction enzyme analysis of family members confirmed that a single mutated allele was inherited from each parent. This amino acid substitution presumably changes the capacity for disulphide bond formation within the cysteine-rich core region of GPIIIa and its study will provide new information on GPIIb-IIIa and alphavbeta3 structure and biosynthesis.

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PURPOSE: In male patients with ileal bladder substitute we ascertained the likelihood of spontaneous voiding failure, the corrective procedures required and the eventual outcomes. MATERIALS AND METHODS: Following cystectomy and ileal bladder substitution for urothelial cancer between April 1985 and September 2002 male patients were identified and analyzed from the prospective departmental database. Four patients underwent ileum conduit conversion following urethral recurrence or pouch necrosis and were excluded from study. Funnel-shaped outlets were avoided during bladder substitute surgery after the first 4 patients with this configuration experienced voiding failure and required corrective procedures. Only patients with a minimum 5-year followup were assessed for voiding failure, corrective procedures and final outcomes. RESULTS: Of 354 patients with a median age of 65 years (range 36 to 84) treated with bladder substitute 180 (51%) were alive at 5 years. All 180 of these patients spontaneously voided within 3 months of surgery. During this 5-year observation period 22 (12%) patients experienced voiding problems requiring de-obstructive procedures. Following intervention 177 (98%) patients were spontaneously voiding by 5 years. Of 237 patients 77 (32%) were alive at 10 years. Of these 77 patients followed for another 5 years 10 (13%) had similar voiding problems requiring de-obstructive procedures. Subsequently 74 (96%) were voiding spontaneously by 10 years. CONCLUSIONS: Patients often fail to void spontaneously after ileal bladder substitution. However, if a funnel-shaped outlet is avoided and de-obstructive surgery is appropriately implemented, excellent long-term results are seen with spontaneous voiding and clean intermittent catheterization can be avoided.

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OBJECTIVES: The aim of the study was to investigate the influence of continued injecting drug use, enrolment in an opiate substitution treatment programme (OSTP), or cessation of injecting drug use on the uptake and course of antiretroviral therapy (ART). Design A prospective observational study of all participants in the Swiss HIV Cohort Study followed between 1997 and 2006 was carried out. METHODS: We distinguished four groups of former or current injecting drug users (IDUs): (i) abstinent former IDUs; (ii) persons in OSTPs without concomitant injecting drug use; (iii) persons in OSTPs with concomitant injecting drug use; (vi) current IDUs. These groups were compared with a group of patients who had never been IDUs. Factors related to ART uptake and virological endpoints were analysed using logistic generalized estimating equations. RESULTS: We followed 8660 participants for 48 477 person-years; 29.7% were in the IDU HIV transmission group. The likelihood of being on ART at biannual visits was lower among individuals in OSTPs with concomitant injecting drug use [odds ratio (OR) 0.79; 95% confidence interval (CI) 0.71-0.89] and current IDUs (OR 0.80; 95% CI 0.67-0.96), compared with those who had never been IDUs (reference), abstinent former IDUs (OR 1.13; 95% CI 1.02-1.25) and individuals in OSTPs without injecting drug use (OR 1.18; 95% CI 1.06-1.31). The likelihood of suppressed viral replication on ART was similar among those who had never been IDUs, abstinent former IDUs and individuals in an OSTP without injecting drug use, and lower among those in OSTPs with concomitant drug use (OR 0.82; 95% CI 0.72-0.93) and current IDUs (OR 0.81; 0.65-1.00). Adherence to ART was decreased among persons with continued injecting drug use, and correlated with virological outcome. CONCLUSIONS: Uptake of and virological response to ART were improved among abstinent former IDUs and persons in OSTPs without concomitant injecting drug use, compared with persons with continued injecting drug use.

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Acetylation and formylation of 3-phenyl-cycl[3.2.2]azine derivatives, in the presence of Lewis acids, have been Investigated. It has been found that the orientation of substitution in 2-carbomethoxy- 3-phenyl-cycl[3.2.2]azine for these two reactions, under Identical conditions, is different.

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The use of bowel segments as bladder substitutes may result in chronic, impaired vitamin D and calcium metabolism, and ultimately in bone demineralization.

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Thirty-two multiparous Holstein cows were used to investigate the effects of chromium-l-methionine (Cr-Met) supplementation and dietary grain source on performance and lactation during the periparturient period. Cows were fed a total mixed ration consisting of either a barley-based diet (BBD) or a corn-based diet (CBD) from 21 d before anticipated calving through 28 d after calving. The Cr-Met was supplemented at dosages of 0 or 0.08 mg of Cr/kg of metabolic body weight. The study was designed as a randomized complete block design with 2 (Cr-Met levels) x 2 (grain sources) factorial arrangement. There was no Cr effect on prepartum dry matter intake (DMI) or postpartum DMI, body weight (BW), net energy balance, and whole tract apparent digestibility of nutrients. Prepartum DMI as a percentage of BW tended to increase with Cr-Met. Supplemental Cr-Met tended to increase milk yield whereas milk protein percentage decreased. Pre- and postpartum DMI, BW, net energy balance, milk yield, and milk composition were not affected by substituting ground barley with ground corn. The addition of Cr-Met increased prepartum DMI and tended to increase postpartum DMI of the BBD but not the CBD. The change in prepartum DMI was smaller when the BBD was supplemented with Cr-Met but remained unchanged when the CBD was supplemented with Cr-Met. Yields of crude protein and total solids in milk and prepartum digestibility of DM and organic matter tended to increase when Cr-Met was added to the BBD but remained unchanged when added to the CBD. Periparturient cows failed to respond to the grain source of the diet, whereas they showed greater response in milk yield to diets supplemented with Cr-Met. In conclusion, the present results demonstrate that the beneficial effect of Cr-Met supplementation during the periparturient period to improve feed intake may depend on the grain source of the diet.

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OBJECTIVE To evaluate the etiology and treatment of bilateral hydronephrosis not responding to bladder substitute drainage after ileal bladder substitution using an afferent isoperistaltic tubular segment. MATERIALS AND METHODS A retrospective analysis was performed of a consecutive series of 739 patients who had undergone bladder substitution from April 1985 to August 2012. RESULTS Of the 739 ileal bladder substitute patients, 10 (1.4%) developed bilateral hydronephrosis unresponsive to complete bladder substitute drainage. The etiology was stenosis of the afferent isoperistaltic tubular segment. The median interval to presentation was 131 months (range 45-192). The incidence of afferent tubular segment stenosis was significantly higher in the 61 ileal bladder substitute patients with recurrent urinary tract infection (9 [15%]) than in the 678 without recurrent urinary tract infection (1 [0.15%]; P <.001). Urine cultures revealed mixed infections (34%), Escherichia coli (18%), Staphylococcus aureus (13%), enterococci (11%), Candida (8%), Klebsiella (8%), and others (8%). Seven patients underwent 10 endourologic interventions, only 1 of which was successful (10%). After failed endourologic treatment, 7 open surgical revisions with resection of the stricture were performed, with all 7 (100%) successful. CONCLUSION Bilateral dilation of the upper urinary tract after ileal orthotopic bladder substitution unresponsive to complete bladder substitute drainage is likely to be caused by stenosis of the afferent isoperistaltic tubular segment. The stenosis occurs almost exclusively in patients with long-lasting, recurrent urinary tract infection and can develop many years after the ileal bladder substitution. Minimally invasive endourologic treatment is usually unsuccessful; however, open surgical revision offers excellent results.

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This paper develops a process model of how and why complementarity and substitution form over time between contractual and relational governance in the context of information systems outsourcing. Our analysis identifies four distinct process patterns that explain this formation as the outcome of interaction processes between key elements of both contractual and relational governance. These patterns unveil the dynamic nature of complementarity and substitution. In particular, we show that the relationship between contractual and relational governance oscillates between complementarity and substitution. Those oscillations are triggered mainly by three types of contextual events (goal fuzziness, goal conflict, and goal misalignment). Surprisingly, substitution of informal control did not occur as an immediate reaction to external events but emerged as a consequence of preceding complementarity. Thus, our study challenges the prevailing view of an either/or dichotomy of complementarity and substitution by showing that they are causally connected over time.

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As pituitary function depends on the integrity of the hypothalamic-pituitary axis, any defect in the development and organogenesis of this gland may account for a form of combined pituitary hormone deficiency (CPHD). A mutation in a novel, tissue-specific, paired-like homeodomain transcription factor, termed Prophet of Pit-1 (PROP1), has been identified as causing the Ames dwarf (df) mouse phenotype, and thereafter, different PROP1 gene alterations have been found in humans with CPHD. We report on the follow-up of two consanguineous families (n = 12), with five subjects affected with CPHD (three males and two females) caused by the same nucleotide C to T transition, resulting in the substitution of Arg-->Cys in PROP1 at codon 120. Importantly, there is a variability of phenotype, even among patients with the same mutation. The age at diagnosis was dependent on the severity of symptoms, ranging from 9 months to 8 yr. Although in one patient TSH deficiency was the first symptom of the disorder, all patients became symptomatic by exhibiting severe growth retardation and failure to thrive, which was mainly caused by GH deficiency (n = 4). The secretion of the pituitary-derived hormones (GH, PRL, TSH, LH, and FSH) declined gradually with age, following a different pattern in each individual; therefore, the deficiencies developed over a variable period of time. All of the subjects entered puberty spontaneously, and the two females also experienced menarche and periods before a replacement therapy was necessary.

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Electronic tuning effects of substituents at the 4- and 8-positions of benzothiadiazole (BTD) within the fused tetrathiafulvalene–BTD donor–acceptor dyad have been studied. The electron acceptor strength of BTD is greatly increased by replacing Br with CN groups, extending the optical absorption of the small dyad into the near-IR region and importantly, the charge transport can be switched from p-type to ambipolar behaviour.