Prognostic markers in pT3 bladder cancer: A study from the international bladder cancer tissue microarray project

PurposeWe evaluated the prognostic value of 10 putative tumor markers by immunohistochemistry in a large multi-institutional cohort of patients with locally advanced urothelial cancer of the bladder (UCB) with the aim to validate their clinical value and to harmonize protocols for their evaluation.Materials and MethodsPrimary tumor specimens from 576 patients with pathologic (p)T3 UCB were collected from 24 institutions in North America and Europe. Three replicate 0.6-mm core diameter samples were collected for the construction of a tissue microarray (TMA). Immunohistochemistry (IHC) for 10 previously described tumor markers was performed and scored at 3 laboratories independently according to a standardized protocol. Associations between marker positivity and freedom from recurrence (FFR) or overall survival (OS) were analyzed separately for each individual laboratory using Cox regression analysis.ResultsThe overall agreement of the IHC scoring among laboratories was poor. Correlation among the 3 laboratories varied across the 10 markers. There was generally a lack of association between the individual markers and FFR or OS. The number of altered cell cycle regulators (p53, Rb, and p21) was associated with increased risk of cancer recurrence (P < 0.032). There was no clear pattern in the relationship between the percentage of markers altered in an 8-marker panel and FFR or OS.ConclusionsThis large international TMA of locally advanced (pT3) UCB suggests that altered expression of p53, Rb, and p21 is associated with worse outcome. However this study also highlights limitations in the reproducibility of IHC even in the most expert hands.     

Comparison of static and dynamic models of maternal immunization to prevent infant pertussis in Brazil

BackgroundThis paper compares cost-effectiveness results from two models of maternal immunization to prevent pertussis in infants in Brazil, one static, one dynamic, to explore when static models are adequate for public health decisions and when the extra effort required by dynamic models is worthwhile.MethodsWe defined two scenarios to explore key differences between static and dynamic models, herd immunity and time horizon. Scenario 1 evaluates the incremental cost/DALY of maternal acellular pertussis (aP) immunization as routine infant vaccination coverage ranges from low/moderate up to, and above, the threshold at which herd immunity begins to eliminate pertussis. Scenario 2 compares cost-effectiveness estimates over the models’ different time horizons. Maternal vaccine prices of $9.55/dose (base case) and $1/dose were evaluated.ResultsThe dynamic model shows that maternal immunization could be cost-saving as well as life-saving at low levels of infant vaccination coverage. When infant coverage reaches the threshold range (90–95%), it is expensive: the dynamic model estimates that maternal immunization costs $2 million/DALY at infant coverage > 95% and maternal vaccine price of $9.55/dose; at $1/dose, cost/DALY is $200,000. By contrast, the static model estimates costs/DALY only modestly higher at high than at low infant coverage. When the models’ estimates over their different time horizons are compared at infant coverage < 90–95%, their projections fall in the same range.ConclusionsStatic models may serve to explore an intervention’s cost-effectiveness against infectious disease: the direction and principal drivers of change were the same in both models. When, however, an intervention too small to have significant herd immunity effects itself, such as maternal aP immunization, takes place against a background of vaccination in the rest of the population, a dynamic model is crucial to accurate estimates of cost-effectiveness. This finding is particularly important in the context of widely varying routine infant vaccination rates globally.Clinical Trial registryClinical Trial registry name and registration number: Not applicable.     

Cost-effectiveness of maternal pertussis immunization: Implications of a dynamic transmission model for low- and middle-income countries

ObjectiveThis study evaluates the cost-effectiveness of maternal acellular pertussis (aP) immunization in low- and middle-income countries using a dynamic transmission model.MethodsWe developed a dynamic transmission model to simulate the impact of infant vaccination with whole-cell pertussis (wP) vaccine with and without maternal aP immunization. The model was calibrated to Brazilian surveillance data and then used to project health outcomes and costs under alternative strategies in Brazil, and, after adjusting model parameter values to reflect their conditions, in Nigeria and Bangladesh. The primary measure of cost-effectiveness is incremental cost (2014 USD) per disability-adjusted life-year (DALY).ResultsThe dynamic model shows that maternal aP immunization would be cost-effective in Brazil, a middle-income country, under the base-case assumptions, but would be very expensive at infant vaccination coverage in and above the threshold range necessary to eliminate the disease (90–95%). At 2007 infant coverage (DTP1 90%, DTP3 61% at 1 year of age), maternal immunization would cost < $4,000 per DALY averted. At high infant coverage, such as Brazil in 1996 (DTP1 94%, DTP3 74% at 1 year), cost/DALY increases to $1.27 million. When the model’s time horizon was extended from 2030 to 2100, cost/DALY increased under both infant coverage levels, but more steeply with high coverage. The results were moderately sensitive to discount rate, maternal vaccine price, and maternal aP coverage and were robust using the 100 best-fitting parameter sets. Scenarios representing low-income countries showed that maternal aP immunization could be cost-saving in countries with low infant coverage, such as Nigeria, but very expensive in countries, such as Bangladesh, with high infant coverage.ConclusionA dynamic model, which captures the herd immunity benefits of pertussis vaccination, shows that, in low- and middle-income countries, maternal aP immunization is cost-effective when infant vaccination coverage is moderate, even cost-saving when it is low, but not cost-effective when coverage levels pass 90–95%.     

Transmission of SARS-CoV-2 before and after symptom onset: impact of nonpharmaceutical interventions in China

Nonpharmaceutical interventions, such as contact tracing and quarantine, have been the primary means of controlling the spread of SARS-CoV-2; however, it remains uncertain which interventions are most effective at reducing transmission at the population level. Using serial interval data from before and after the rollout of nonpharmaceutical interventions in China, we estimate that the relative frequency of presymptomatic transmission increased from 34% before the rollout to 71% afterward. The shift toward earlier transmission indicates a disproportionate reduction in transmission post-symptom onset. We estimate that, following the rollout of nonpharmaceutical interventions, transmission post-symptom onset was reduced by 82% whereas presymptomatic transmission decreased by only 16%. The observation that only one-third of transmission was presymptomatic at baseline, combined with the finding that NPIs reduced presymptomatic transmission by less than 20%, suggests that the overall impact of NPIs was driven in large part by reductions in transmission following symptom onset. This implies that interventions which limit opportunities for transmission in the later stages of infection, such as contact tracing and isolation, are particularly important for control of SARS-CoV-2. Interventions which specifically reduce opportunities for presymptomatic transmission, such as quarantine of asymptomatic contacts, are likely to have smaller, but non-negligible, effects on overall transmission.

     

Peroxisome biogenesis occurs in late dorsal-anterior structures in the development of Xenopus laevis.

Metabolism and development are two important processes not often examined in the same context. The focus of the present study is the expression of specific peroxisomal genes, the subsequent biogenesis of peroxisomes, and their potential role in the metabolism associated with the development of Xenopus laevis embryos. The temporal and expression patterns of six peroxisomal genes (PEX5, ACO, PEX19, PMP70, PEX16, and catalase) were elucidated using RT-PCR. Functionally related peroxisomal genes exhibited similar expression patterns with their RNA levels elevated relatively late during embryogenesis. Using immunohistochemistry PMP70 and catalase protein was localized largely to dorsal-anterior structures. Peroxisomal function was assayed with peroxisomal targeted-GFP, which when microinjected, revealed peroxisomes in dorsal-anterior structures at stage 45. A requirement for peroxisomal function appears to be present only late in development as organogenesis is finishing, yolk stores are depleted, and ingestion commences.     

Induction of follicular growth and production of a normal hormonal milieu in spite of using a constant low dose of luteinizing hormone in women with hypogonadotrophic hypogonadism

This study was designed to examine ovarian performance, i.e.follicular growth, normal steroidogenesis and luteal phase function,following the administration of multiple increasing doses ofhuman follicle stimulating hormone (FSH) with a constant lowdose of luteinizing hormone (LH) in women with isolated hypogonadotrophichypogonadism. Human meno–pausal gonadotrophin (HMG) wasused in the first treatment cycle, starting with 150 IU of LHand 150 IU of FSH per day, for 7 days. The dose was increaseddaily with 75 IU of LH and 75 IU of FSH for another 7 days ifno response was detected by serial ultrasound measurements andserumoestradiol determinations. In the second treatment cycle,a constant dose of 75 IU of LH (using HMG) was administeredper day and up to 150 IU of FSH (using urofollitrophin) wassupplemented. If no response was detected after 7 days of treatment,the dose of FSH was increased. For the final stage of ovulationinduction, human chorionic gonadotrophin (HCG) was administeredin the presence of at least one follicle >17 mm in diameterbut with no more than three follicles >16mm in diameter.To verify the adequacy of the luteal phase, a pharmacokinetic/pharmacodynamicstudy of -HCG, oestradiol and progesterone was performed followingthe second treatment cycle only. Ovarian stimulation using aconstant dose of 75 IU of LH and increasing doses of FSH upto 225 IU, resulted in normal follicular growth and hormonalmilieu. Both women showed normal luteal phase oestradiol andprogesterone production and both women conceived following thesecond treatment cycle     

The Qualitative and Quantitative Analysis of Chlorpropamide Polymorphic Mixtures by Near-Infrared Fourier Transform Raman Spectroscopy

We analyzed binary mixtures of polymorphs A and B of chlorpropamide ((l-[4-chlorobenzenesulphonyl]-3-propyl urea)) by near-infrared Fourier transform Raman spectroscopy (FTRS). The individual polymorphs were prepared and characterized by differential scanning calorimetry (DSC), Fourier transform infrared (FT-IR) microscopy, and physical appearance. The FTR spectra of the two polymorphs showed distinct differences which result from "crystal splitting effects. A series of 13 different mixtures of polymorph A and B was prepared by geometric mixing and their FTR spectra statistically analysed by factor analysis programming. Predictions of the A/B polymorphic composition of mixtures were made and compared with the theoretical values. The results demonstrate that FTRS combined with factor analysis programming may be successfully applied to the in situ monitoring of the A/B polymorphic nature of a chlorpropamide sample.     

Enhancement of the response to purinergic agonists in P2Y1 transfected 1321N1 cells by antagonists suramin and PPADS

1. We have previously shown that both suramin and pyridoxal-phosphate-6-azophenyl-2′, 4′ disulphonic acid (PPADS) act as antagonists at transfected P2Y₁ receptors. Here we show that under certain experimental conditions these two P2 antagonists can enhance the response to agonists acting at these receptors.
2. The expression of either P2Y₁ or P2Y₂ receptors in 1321N1 human astrocytoma cells results, on a change of medium, in an elevation of basal (no added agonist) accumulation of [³H]-inositol(poly)phosphates([³H]-InsP_x) compared to cells not expressing these receptors. This elevation is much greater in P2Y₁ transfectants than in P2Y₂ transfectants.
3. Both PPADS and suramin reduced this basal level of [³H]-InsP_x accumulation in the P2Y₁ expressing cells.
4. When a protocol was used which required changing the culture medium, antagonists were added at a concentration which reduced the basal accumulation by about 50%, there was a significant stimulation in response to increasing concentrations of 2-methylthioadenosine 5′-triphosphate (2MeSATP), in the absence of antagonists there was no significant effect of the agonist.
5. However, when 2MeSATP was added in the absence of a change of medium and with no antagonist present, there was a several fold increase in [³H]-InsP_x accumulation. These results show that a release of endogenous agonist activity (possibly ATP/ADP) from the P2Y₁ expressing cells can create conditions in which a response to an agonist such as 2MeSATP can only be seen in the presence of a competitive antagonist.

     

Interactions between imidazoline compounds and sulphonylureas in the regulation of insulin secretion

1. Imidazoline α₂-antagonist drugs such as efaroxan have been shown to increase the insulin secretory response to sulphonylureas from rat pancreatic B-cells. We have investigated whether this reflects binding to an islet imidazoline receptor or whether α₂-adrenoceptor antagonism is involved.
2. Administration of (±)-efaroxan or glibenclamide to Wistar rats was associated with a transient increase in plasma insulin. When both drugs were administered together, the resultant increase in insulin levels was much greater than that obtained with either drug alone.
3. Use of the resolved enantiomers of efaroxan revealed that the ability of the compound to enhance the insulin secretory response to glibenclamide resided only in the α₂-selective-(+)-enantiomer; the imidazoline receptor-selective-(−)-enantiomer was ineffective.
4. In vitro, (+)-efaroxan increased the insulin secretory response to glibenclamide in rat freshly isolated and cultured islets of Langerhans, whereas (−)-efaroxan was inactive. By contrast, (+)-efaroxan did not potentiate glucose-induced insulin secretion but (−)-efaroxan induced a marked increase in insulin secretion from islets incubated in the presence of 6 mM glucose.
5. Incubation of rat islets under conditions designed to minimize the extent of α₂-adrenoceptor signalling (by receptor blockade with phenoxybenzamine; receptor down-regulation or treatment with pertussis toxin) abolished the capacity of (+)-and (±)-efaroxan to enhance the insulin secretory response to glibenclamide. However, these manoeuvres did not alter the ability of (±)-efaroxan to potentiate glucose-induced insulin secretion.
6. The results indicate that the enantiomers of efaroxan exert differential effects on insulin secretion which may result from binding to effector sites having opposite stereoselectivity. Binding of (−)-efaroxan (presumably to imidazoline receptors) results in potentiation of glucose-induced insulin secretion, whereas interaction of (+)-efaroxan with a second site leads to selective enhancement of sulphonylurea-induced insulin release.

     

Atrial Fibrillation in the Elderly: A Review

Atrial fibrillation is the most common cardiac arrhythmia in the elderly. It is associated with significant morbidity and mortality due to hemodynamic and cardioembolic complications. The incidence of stroke in elderly patients is 5 times higher than in patients in sinus rhythm. Atrial fibrillation should be actively treated in the elderly. Treatment should be directed toward the correction of reversible factors, control of ventricular response rate, restoration and maintenance of sinus rhythm, and prevention of cardioembolic events. Treatment of atrial fibrillation in the elderly should be individualized with careful regard for risk-benefit ratio.