Aspectos da biologia reprodutiva de Boa constrictor constrictor: um estudo histológico dos testículos nos períodos reprodutivos de quiescência e máxima atividade

RESUMO As serpentes pertencem ao segundo maior grupo dentro dos répteis, podendo apresentar sazonalidade quanto à espermatogênese, com produção descontínua ou contínua. O presente trabalho tem como objetivo caracterizar aspectos da biologia reprodutiva de Boa constrictor constrictor com base nos achados histológicos dos testículos nos períodos de máxima atividade (período de gametogênese) e quiescência. Os testículos de dois espécimes de Boa c. constrictor (7767 e 11752) foram cortados a uma espessura de 3μm em micrótomo, corados com azul de toluidina 1%, fotodocumentados e descritos. A presença de espermatozoides na luz do túbulo seminífero no indivíduo 7767 indica um período de máxima gametogênese, enquanto o lúmen dos túbulos seminíferos pouco evidentes, sem a presença de espermatozoides e de células gaméticas em divisão, caracteriza o indivíduo 11752 em período quiescente. Mediante os achados histológicos descritos no presente estudo, concluiu-se que Boa c. constrictor apresenta sazonalidade em relação à gametogênese, sendo esse padrão de sazonalidade associado ao período de cópulas relatado em literatura característico de serpentes com padrão pré-nupcial.

P6326Which results of the cardiopulmonary exercise test deserve greatest attention to establish the prognosis in heart failure?

Background and aim

Limitation of exercise tolerance is one of the cardinal manifestations of heart failure (HF). Cardiopulmonary exercise testing (CPET) provides a thorough assessment of exercise integrative physiology involving the pulmonary, muscular, and oxidative cellular systems. We aimed to identify which data collected during a CPET shows the best prognostic performance with respect to predicting mortality or the need for heart transplantation (HT).

Methods

Single-centre retrospective cohort study of consecutive HF patients performing a CPET for functional and prognostic HF evaluation from October 1996 till May 2018. Left ventricular ejection fraction was not an exclusion criterion. A Cox model was fit with time to death or heart transplantation (whichever recorded first within 5 years) as the dependent variable and CPET parameters as the independent variables. Both unadjusted and adjusted covariate Cox regressions were performed. ROC curve analysis was used to determine whether the significant variables, as a model, could reliably predict the study endpoint.

Results

The study population consisted of 513 patients, median age 58 (IQ 16) years, and 74.9% male. The majority had reduced ejection fraction (75.4%), and the most common HF aetiology was ischemic heart disease (55.8%). During the 5-years follow up, 126 patients died and 60 underwent heart transplantation. In unadjusted Cox regression, nearly all CPET variables were significantly associated with the study endpoint. After covariate adjustment, with prior exclusion of redundant variables, three measures remained associated with the study endpoint: peak VO2 consumption (hazard ratio [HR] 0.85; 95% confidence interval [CI], 0.81–0.90); VE/VCO2 slope (HR 1.02; 95% CI, 1.00–1.02); presence of oscillatory ventilatory pattern (HR 3.73; 95% CI, 2.43–5.72). As a model, these 3 variables showed a strong discriminatory ability (c-statistic 0.87; 95% CI, 0.83–0.90) (see figure) for the study endpoint.

Figure 1

Conclusion

When using the CPET for prognostic stratification of HF patients, the presence of an oscillatory ventilatory pattern, the peak VO2 and the VE/VCO2 slope are the most important tools on which clinicians should focus.

P5423Exercise oscillatory ventilation improves the performance of prognosis scores currently used for heart failure

Background and aim

Several prognostic risk scores are available for heart failure with reduced ejection fraction (HFrEF), and are used, together with other criteria, to help decide the ideal timing for listing candidates for a heart transplant. The detection of an oscillatory ventilatory pattern (OVP) during cardiopulmonary exercise testing (CPET) has been associated with more advanced HF and a worse prognosis, but was not considered in the development of all the current risk scores. We evaluated whether OVP adds significant prognostic information to four contemporary HF scores.

Methods

Single-centre retrospective cohort study of consecutive HFrEF patients undergoing CPET for functional and prognostic assessment from October 1996 till May 2018. The Heart Failure Survival Score (HFSS), Seattle Heart Failure Model (SHFM), Meta-analysis Global Group in Chronic Heart Failure (MAGGIC) and Metabolic Exercise Cardiac Kidney Index (MECKI) were obtained in each patient. Cox model was fit with time to death or urgent transplant (whichever came first within 2 years) as the dependent variable and OVP and respective HF score as the independent variables. We further assessed the added discriminative power by performing ROC curve comparisons.

Results

We studied 387 patients, median age 58 (IQR 49; 65) years, and 77% were male. The most common HFrEF aetiology was ischemic heart disease (54%). Median peak oxygen consumption was 15,7 mL/kg/min (IQR 12,8; 20,0). OVP was present in 150 (39%) patients. Over the 2-year follow-up period, 48 patients died, and 52 underwent heart transplantation (of which 25 were urgent). HFSS showed the weakest (c-statistic 0,625; 95% [CI] 0,54–0,71) and MECKI score the strongest (c-statistic 0,819; 95% [CI] 0,76–0,88) discriminatory ability. Contrasting with NTproBNP value, the presence of OVP predicted the study endpoint independently of the HF prognosis score used (see table). Adding the occurrence of OVP to the HFSS and the MAGGIC scores significantly improved their prognostic performance (see Table).

Conclusion

An OVP is a common finding in HFrEF patients undergoing CPET, and adds prognostic information to contemporary HF prognosis scores. Systematic evaluation of this easily available criterion may assist the decision on the appropriate timing for heart transplantation listing.

Abstract P6-18-16: Ribociclib (RIBO) + letrozole (LET) in older patients with hormone receptor-positive (HR+), human epidermal growth factor receptor-2–negative (HER2–) advanced breast cancer (ABC): Preliminary subgroup results from the phase 3b CompLEEment-1 trial

Background: The cyclin-dependent kinase (CDK)4/6 inhibitor RIBO is approved in combination with an aromatase inhibitor (AI) for HR+, HER2– ABC in postmenopausal women with no prior therapy for ABC, based on the MONALEESA-2 trial (Hortobagyi et al. NEJM 2016). Although a high proportion of patients with HR+, HER2– ABC are >65 years of age, older patients are often under-represented in clinical trials. Furthermore, treatment decisions may be complicated by comorbidities, functional status, and concurrent medications. Here, we report early safety results for patients ≥65 years of age enrolled in CompLEEment-1, an open-label, phase 3b trial evaluating RIBO+LET as first-line endocrine-based therapy in an expanded patient population.

Methods: Patients with HR+, HER2– ABC, ≤1 line of prior chemotherapy (CT), and no prior endocrine therapy for ABC received RIBO (600 mg/day, 3 weeks on/1 week off) + LET (2.5 mg/day); men and premenopausal women received concomitant goserelin (3.6-mg subcutaneous implant every 28 days). The primary outcome was safety and tolerability. A pre-planned interim analysis was conducted ˜15 months after first patient first visit.

Results: Of the first 1,008 patients enrolled who completed 56 days of follow-up or discontinued before the data cut-off date, 377 were ≥65 years of age. Of these, 157 (41.6%) were 65-<70 years, 107 (28.4%) were 70-<75 years, and 113 (30%) were ≥75 years. The majority of patients (94.4%) had an Eastern Cooperative Oncology Group performance status ≤1; 33.2% presented with stage IV disease at diagnosis; 9 patients were male. The most common sites of metastasis were bone (70.0%), lung (44.8%), and lymph nodes (29.7%). The most common all-grade adverse events (AEs) were neutropenia (58.4%), nausea (31.8%), and fatigue (24.1%). The most common grade 3/4 AEs were neutropenia (37.7%) and alanine aminotransferase increase (4.2%). QT prolongation events were mild (majority grade 1/2) and occurred in 6.1% of patients (0.5% grade 3/4). Dose reduction or interruption due to AEs occurred in 54.5% of patients; 6.9% of patients had AEs leading to treatment discontinuation. In the overall patient population, the most frequent grade 3/4 AEs were neutropenia (42.8%), leukopenia (3.4%), and increased alanine aminotransferase (2.9%); QT prolongation occurred in 5.4% of patients (0.5% grade 3/4).

Conclusions: Initial safety results from CompLEEment-1, from the first 56 days of follow-up, demonstrate the tolerability of RIBO+LET in older patients, consistent with the overall patient population. NCT02941926.

Citation Format: Ring A, Borstnar S, Ferreira A, Azim HA, Cottu P, Lu J, Martin M, Zamagni C, Beck JT, Zhou K, Wu J, Menon L, De Laurentiis M. Ribociclib (RIBO) + letrozole (LET) in older patients with hormone receptor-positive (HR+), human epidermal growth factor receptor-2–negative (HER2–) advanced breast cancer (ABC): Preliminary subgroup results from the phase 3b CompLEEment-1 trial [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P6-18-16.

Abstract P1-15-19: Carboplatin-addition in neoadjuvant treatment of women with triple negative breast cancer (TNBC): Prognostic value in real-world patients

Background

The addition of carboplatin to an anthracycline/taxane-based chemotherapy(CT) in neoadjuvant setting has been suggested to improve pathological complete response(pCR) in TNBC. However, the impact of pCR in prognosis is unknown. We aim to study the value and feasibility of the addition of carboplatin in neoadjuvant setting.

Methods

Demographic and clinical data of TNBC patients treated with neoadjuvant CT in a comprehensive cancer center between 2010-2018 were retrospectively collected. Two cohorts were defined: one treated with Carboplatin/Paclitaxel followed by dose-dense Doxorrubicin/Cyclophosphamide(CP-AC) and other with AC followed by Docetaxel(AC-D). Median follow-up time was 3.1 and 6.9 years, respectively. pCR was defined as absence of residual invasive tumor in breast/axilla. Survival analysis using Kaplan-Meier method and Cox proportional-hazards model were applied. Statistical significance was set at p<0.05.

Results

One-hundred and sixty patients were enrolled: 78 CP-AC and 38 AC-D. Groups were balanced regarding patients and tumor characteristics with exception of pre-menopausal status, more frequent in CP-AC(68% vs 47%;p=.04). Age at diagnosis was 47(28-76)years, the majority had ECOG 0(92%) ductal carcinomas(82%), clinicalT2/3 stages(76%), grade 3(81%) with lymph node involvement(N+)(57%). 14% had Inflammatory breast cancer(IBC)(CP-AC 14%;AC-D 13%; p=.9).

Neutropenia was the most prevalent adverse event(G3/4: CP-AC 61%;AC-D 16%;p=.02), 12% and 16% of febrile neutropenia(p=.8). G3/4 thrombocytopenia occurred only in CP-AC(6%). Hypersensitivity reactions were more prevalent in CP-AC(19% vs 2.7%;p=.02), majority to paclitaxel, all G1/2. Hospital admission occurred in 12%(CP-AC 13%;AC-D 9%; p=.8). There were no treatment-related deaths. Treatment schedule was complete in 89%(CP-AC 87%;AC-D 92%;p=.5), with 20% dose reductions(CP-AC 25%;AC-D 11%;p=0.9).

pCR was achieved in 42%(CP-AC 50%;AC-D 28%;p=.03). 1- and 3-year disease-free survival(DFS) was 94%/85% for CP-AC and 72%/58% for AC-D(p=.3). Risk of recurrence was higher in IBC(HR 25.1;CI95% 7.7-81.3;p<.0001), N+ disease(HR 3.6;CI95% 1.2-10.5;p=.02) and non-pCR(HR 10.9;CI95% 2.3-52.3,p=.003). N+ disease was associated with higher recurrence only in AC-D(HR 11.7;CI95% 1.3-104;p=.03).

Cancer-related deaths were 20%(CP-AC 10%;AC-D 40%;p=.001). 1- and 2-year overall survival (OS) was 99%/95% for CP-AC and 70%/61% for AC-D(p=.06). N+ disease was associated with higher risk of death in AC-D(HR 6.3;CI95% 1.1-24.6;p=.04). Risk of death was independently associated with IBC(HR 4.1;CI95% 2.1-18.7; p=.001) but not with N+ disease(HR 2.7;CI95% 0.8-9.5;p=.13) or pCR(HR 4.1;CI95% 0.9-19.7;p=.08) although pCR was statistically significant in univariate analysis (1- and 2-year OS 97% vs 92% and 94% vs 86% for pCR and non-PCR;p=.003).

Conclusions

Carboplatin addition clearly increased pCR with a trend to DFS and OS benefit. This regimen was associated with more, nevertheless manageable, adverse events with most of the patients able to tolerate and complete the full-dose regimen. Though we did not find a subgroup of patients that benefit with carboplatin regimen, we should consider avoiding AC-D at least in N+ disease.

Citation Format: Coelho S, Abreu MH, Sales C, Lopes AR, Sousa MF, Couto R, Pousa I, Ferreira A, Ferreira M, Vieira C, Leal C, Castro F, Sousa S, Pereira D. Carboplatin-addition in neoadjuvant treatment of women with triple negative breast cancer (TNBC): Prognostic value in real-world patients [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P1-15-19.

The α2 isoform Na,K-ATPase modulates contraction of rat mesenteric small artery via cSrc-dependent Ca2+ sensitization

AIMS

The Na,K-ATPase is involved in a large number of regulatory activities including cSrc-dependent signalling. Upon inhibition of the Na,K-ATPase with ouabain, cSrc activation is shown to occur in many cell types. This study tests the hypothesis that acute potentiation of agonist-induced contraction by ouabain is mediated through Na,K-ATPase-cSrc signalling-dependent sensitization of vascular smooth muscle cells to Ca²⁺ .

METHODS

Agonist-induced rat mesenteric small artery contraction was examined in vitro under isometric conditions and in vivo in anaesthetized rats. Arterial wall tension and [Ca²⁺ ]_i in vascular smooth muscle cells were measured simultaneously. Changes in cSrc and myosin phosphatase targeting protein 1 (MYPT1) phosphorylation were analysed by Western blot. Protein expression was examined with immunohistochemistry. The α1 and α2 isoforms of the Na,K-ATPase were transiently downregulated by siRNA transfection in vivo.

RESULTS

Ten micromolar ouabain, but not digoxin, potentiated contraction to noradrenaline. This effect was not endothelium-dependent. Ouabain sensitized smooth muscle cells to Ca²⁺ , and this was associated with increased phosphorylation of cSrc and MYPT1. Inhibition of tyrosine kinase by genistein, PP2 or pNaKtide abolished the potentiating effect of ouabain on arterial contraction and Ca²⁺ sensitization. Downregulation of the Na,K-ATPase α2 isoform made arterial contraction insensitive to ouabain and tyrosine kinase inhibition.

CONCLUSION

Data suggest that micromolar ouabain potentiates agonist-induced contraction of rat mesenteric small artery via Na,K-ATPase-dependent cSrc activation, which increases Ca²⁺ sensitization of vascular smooth muscle cells by MYPT1 phosphorylation. This mechanism may be critical for acute control of vascular tone.