Clinical features and response to immune combinations in patients with renal cell carcinoma and sarcomatoid de-differentiation (ARON-1 study).

Metastatic renal cell carcinoma (mRCC) carrying sarcomatoid features (sRCC) has aggressive biology and poor prognosis. First-line immunotherapy (IO)-based combinations have improved the outcome of clear cell RCC patients, including that of sRCC. Real-world data confirming the adequate first-line management of sRCC is largely lacking. We investigated the clinical features and the outcome of sRCC patients treated with IO-based combinations within the ARON-1 study population (NCT05287464). The primary objective was to define the incidence and baseline clinical characteristics of sRCC compared with non-sRCC patients. The secondary objective was to describe the outcome of sRCC patients based on type of first-line treatment (IO + IO vs. IO + tyrosin kinase inhibitor [TKI]). We identified 1362 mRCC patients with IMDC intermediate or poor risk, 226 sRCC and 1136 non-sRCC. These two subgroups did not differ in terms of baseline characteristics. The median overall survival (OS) was 26.8 months (95%CI 21.6-44.2) in sRCC and 35.3 months (95%CI 30.2-40.4) in non-sRCC patients (p = .013). The median progression-free survival (PFS) was longer in non-sRCC patients compared to sRCC (14.5 vs. 12.3 months, p = .064). In patients treated with first-line IO + TKI the median OS was 34.4 months compared to 26.4 months of those who received IO + IO (p = .729). The median PFS was 12.4 months with IO + TKI and 12.3 months with IO + IO (p = .606). In conclusion, we confirm that sRCC are aggressive tumors with poor prognosis. IO-based combinations improve survival outcomes of sRCC patients, regardless from the type of strategy (IO + IO versus IO + TKI) adopted.

Real-world effectiveness of pembrolizumab as first-line therapy for cisplatin-ineligible patients with advanced urothelial carcinoma: the ARON-2 study.

BACKGROUND: The advent of immune-checkpoint inhibitors has challenged previous treatment paradigms for advanced urothelial carcinoma (UC) in the post-platinum setting as well as in the first-line setting for cisplatin-ineligible patients. In this study, we investigated the effectiveness of pembrolizumab as first-line treatment for cisplatin-ineligible UC. METHODS: Data from patients aged ≥ 18 years with cisplatin-ineligible UC and receiving first-line pembrolizumab from January 1st 2017 to September 1st 2022 were collected. Cisplatin ineligibility was defined according to the Galsky criteria. Thirty-three Institutions from 18 countries were involved in the ARON-2 study. RESULTS: Our analysis included 162 patients. The median follow-up time was 18.9 months (95%CI 15.3-76.9). In the overall study population, the median OS was 15.8 months (95%CI 11.3-32.4). The median OS was significantly longer in males versus females while no statistically significant differences were observed between patients aged < 65y versus ≥ 65y and between smokers and non-smokers. According to Recist 1.1 criteria, 26 patients (16%) experienced CR, 32 (20%) PR, 39 (24%) SD and 55 (34%) PD. CONCLUSIONS: Our data confirm the role of pembrolizumab as first-line therapy for cisplatin-unfit patients. Further studies investigating the biological and immunological characteristics of UC patients are warranted in order to optimize the outcome of patients receiving immunotherapy in this setting.

Pembrolizumab in patients with advanced upper tract urothelial carcinoma: a real-world study from ARON-2 project.

Upper tract urothelial carcinoma (UTUC) accounts for the 5-10% of all urothelial carcinomas (UCs). In this analysis, we reported the real-world data from the ARON-2 study (NCT05290038) on the efficacy of pembrolizumab in patients with UTUC who recurred or progressed after platinum-based chemotherapy. Medical records of patients with metastatic UTUC treated with pembrolizumab as second-line therapy were reviewed from 34 institutions in 14 countries. Patients were assessed for overall survival (OS), progression-free survival (PFS), and overall response rate (ORR). Univariate and multivariate analyses were used to explore the association of variables of interest with OS and PFS. 235 patients were included in our analysis. Median OS was 8.6 months (95% CI 6.6-12.1), the 1 year OS rate was 43% while the 2 years OS rate 29%. The median PFS was 5.1 months (95% CI 3.9-6.9); 46% of patients were alive at 6 months, 34% at 12 months and 25% at 24 months. According to RECIST 1.1, 18 patients (8%) experienced complete response (CR), 57 (24%) partial response (PR), 44 (19%) stable disease (SD), and 116 (49%) progressive disease (PD), with an ORR of 32%. Our study confirms the effectiveness of pembrolizumab in patients pretreated with a platinum-based combination, irrespective of their sensitivity to the first-line treatment and of their histology. In addition, we emphasized the limited benefit of the treatment with pembrolizumab in patients with hepatic metastases and poor ECOG performance status.

Real-World Impact of Upfront Cytoreductive Nephrectomy in Metastatic Non-Clear Cell Renal Cell Carcinoma Treated with First-Line Immunotherapy Combinations or Tyrosine Kinase Inhibitors (A Sub-Analysis from the ARON-1 Retrospective Study).

BACKGROUND: About 20% of patients with renal cell carcinoma present with non-clear cell histology (nccRCC), encompassing various histological types. While surgery remains pivotal for localized-stage nccRCC, the role of cytoreductive nephrectomy (CN) in metastatic nccRCC is contentious. Limited data exist on the role of CN in metastatic nccRCC under current standard of care. OBJECTIVE: This retrospective study focused on the impact of upfront CN on metastatic nccRCC outcomes with first-line immune checkpoint inhibitor (IO) combinations or tyrosine kinase inhibitor (TKI) monotherapy. METHODS: The study included 221 patients with nccRCC and synchronous metastatic disease, treated with IO combinations or TKI monotherapy in the first line. Baseline clinical characteristics, systemic therapy, and treatment outcomes were analyzed. The primary objective was to assess clinical outcomes, including progression-free survival (PFS) and overall survival (OS). Statistical analysis involved the Fisher exact test, Pearson's correlation coefficient, analysis of variance, Kaplan-Meier method, log-rank test, and univariate/multivariate Cox proportional hazard regression models. RESULTS: Median OS for patients undergoing upfront CN was 36.8 (95% confidence interval [CI] 24.9-71.3) versus 20.8 (95% CI 12.6-24.8) months for those without CN (p = 0.005). Upfront CN was significantly associated with OS in the multivariate Cox regression analysis (hazard ratio 0.47 [95% CI 0.31-0.72], p < 0.001). In patients without CN, the median OS and PFS was 24.5 (95% CI 18.1-40.5) and 13.0 months (95% CI 6.6-23.5) for patients treated with IO+TKI versus 7.5 (95% CI 4.3-22.4) and 4.9 months (95% CI 3.0-8.1) for those receiving the IO+IO combination (p = 0.059 and p = 0.032, respectively). CONCLUSIONS: Our study demonstrates the survival benefits of upfront CN compared with systemic therapy without CN. The study suggests that the use of IO+TKI combination or, eventually, TKI monotherapy might be a better choice than IO+IO combination for patients who are not candidates for CN regardless of IO eligibility. Prospective trials are needed to validate these findings and refine the role of CN in current mRCC management.

A Systematic Review and Meta-Analysis of the Role of Immune Checkpoint Inhibitors (ICI) as Adjuvant Treatment for Localized High-Risk Muscle-Invasive Urothelial Carcinoma (MIUC).

Nivolumab, a PD-1 ICI has been recently approved for the adjuvant treatment of high-risk MIUC patients. However, conflicting data from another randomized controlled trial (RCT) with atezolizumab makes the benefit of this treatment uncertain. We performed a systematic review and study-level meta-analysis to evaluate the benefit in terms of disease-free survival (DFS) with ICI adjuvant treatment for patients with high-risk MIUC. Considering the Preferred Reporting Items for Systematic Review statement, a systematic search was performed in PUBMED/MEDLINE, Scopus and EMBASE up to October 30, 2021. The statistical analysis was performed by RevMan 5.4 software in intention-to-treat (ITT) population and in predetermined subgroups. Two RCTRCT, with a total of 1518 patients, met the inclusion criteria. Systemic immunotherapy was atezolizumab for 406 patients and nivolumab for 353 patients. In the ITT population there was a nonsignificant benefit with the systemic adjuvant immunotherapy (HR:0.79, 95% CI 0.62-1.00; z = 2.00) but with high heterogeneity (I2 = 65%). Regarding the subgroups, there was no benefit in PD-L1 negative (HR:0.81, 95% CI 0.70-1.00; z = 1.96, I2 = 0%) and in non-neoadjuvant chemotherapy (HR:0.95, 95% CI 0.78-1.15; z = 0.56, I2 = 0%). Adjuvant treatment with ICI to patients with high-risk MIUC reveals a nonsignificant impact in DFS. The lack of clinical benefit was demonstrated in all subgroups. These data reinforce the need for a careful selection of patients before offering this approach in daily practice.

Statins and renal cell carcinoma: Antitumor activity and influence on cancer risk and survival.

Statins are commonly prescribed to reduce plasma cholesterol levels and risk of cardiovascular events and mortality. Statin exposure may have cancer-preventive properties in some solid tumors, including Renal Cell Carcinoma (RCC). Emerging evidences show that statins can inhibit RCC cell growth by inducing cell cycle arrest and apoptosis in a dose- and time-dependent manner. In addition, statins inhibit the phosphorylation of AKT, mammalian target of rapamycin (mTOR), and ERK leading to reduced motility of RCC cells. Interestingly, the potential impact of concomitant statin intake has been recently evaluated in RCC patients treated by targeted therapy or immunotherapy. In this review, we illustrate the most recent data on the preclinical activity of statins in Renal Cell Carcinoma models and discuss the impact of their use on the prevention and survival of patients affected by this tumor.

Osteoprotegerin blocks bone cancer-induced skeletal destruction, skeletal pain and pain-related neurochemical reorganization of the spinal cord.

Bone cancer pain is common among cancer patients and can have a devastating effect on their quality of life. A chief problem in designing new therapies for bone cancer pain is that it is unclear what mechanisms drive this distinct pain condition. Here we show that osteoprotegerin, a secreted 'decoy' receptor that inhibits osteoclast activity, also blocks behaviors indicative of pain in mice with bone cancer. A substantial part of the actions of osteoprotegerin seems to result from inhibition of tumor-induced bone destruction that in turn inhibits the neurochemical changes in the spinal cord that are thought to be involved in the generation and maintenance of cancer pain. These results demonstrate that excessive tumor-induced bone destruction is involved in the generation of bone cancer pain and that osteoprotegerin may provide an effective treatment for this common human condition.

The role of 68Gallium-prostate-specific membrane antigen positron emission tomography on staging of high-risk localized prostate cancer: for all high-risk patients or would it be better to select them?

BACKGROUND: According to pathologico-clinical features, patients diagnosed with localized prostate cancer (PCa) are stratified into distinct risk groups (low-risk, intermediate-risk or high-risk). Data have demonstrated that 68Gallium-prostate-specific membrane antigen positron emission tomography (68Ga-PSMA PET/CT) is superior to conventional radiological exams (CT or MRI and bone scintigraphy) in the primary staging of high-risk localized PCa. However, it is still unknown if in a population of high-risk PCa, there would be a subgroup of patients with a higher probability of identifying metastatic disease by the 68Ga-PSMA PET/CT. MATERIALS AND METHODS: Data from patients with localized PCa who underwent 68GA-PSMA PET/CT for primary staging from four institutions were retrospectively collected. We selected patients with at least one D'Amico classification risk factor (International Society of Urological Pathology ≥ IV and/or prostate-specific antigen > 20 ng/ml). To detect an association between extent of disease and number of risk factors as well as International Society of Urological Pathology prostate cancer grade, contingency tables were used, and Fisher Exact Test was performed. RESULTS: Between 2016 and 2020, 60 patients underwent a 68GA-PSMA PET/CT for primary staging of high-risk localized PCa. Regarding the number of risk factors, 37 patients (62%) had one risk factor, and 23 (38%) had two risk factors. In the subgroup of patients with metastatic disease (n = 22), those with two risk factors had higher incidence of metastatic disease, and it was statistically significant (p = 0.011). CONCLUSION: This retrospective analysis demonstrated that 68GA-PSMA PET/CT was able to identify advanced disease in more than one-third of patients with high-risk disease especially those with two adverse risk factors.

Erdafitinib treatment in Brazilian patients with metastatic urothelial carcinoma (mUC): real-world evidence from an Expanded Access Program.

BACKGROUND: Erdafitinib is the first targeted therapy approved for the treatment of patients with metastatic urothelial carcinoma (mUC). Approval was based on a phase II single-arm trial that demonstrated significant activity of erdafitinib in patients with tumors harboring FGFR2/3 alterations. In Brazil, an Expanded Access Program (EAP) provided patients with early access to erdafitinib prior to market authorization. The current report describes characteristics and outcomes of patients with mUC on erdafitinib therapy. METHODS: Patients with mUC that failed first- and second-line systemic therapies were screened for FGFR2/3 alterations in primary or metastatic tumor tissues. Patients with FGFR2/3 alterations were selected to receive erdafitinib at the standard dosing schedule and were followed prospectively to evaluate the efficacy and safety outcomes. RESULTS: From 19 April 2019, through 13 March 2020, 47 patients with mUC from 10 Brazilian centers were tested for FGFR2/3 alterations. Alterations in FGFR2/3 were found in 12 patients (25.5%) and all of them were eligible for the EAP. Four patients (33%) had partial response, while two patients (17%) had stable disease. Progressive disease, the best response, was observed in five patients (42%). At a median follow-up of 16.2 months, the median time to treatment failure (TTF) was 2.8 months. When considering only patients with objective response, the median TTF was 5.3 months. Adverse events (AEs) were reported for any grade and grade 3 or higher in 10 patients (83%) and 5 patients (42%), respectively. The most common AE was hyperphosphatemia. CONCLUSION: This first real-world evidence report of heavily treated patients with mUC confirms the efficacy and safety of erdafitinib in a disease setting with a lack of treatment options.

First-line Treatment of Metastatic Renal Cell Carcinoma in the Immuno-oncology Era: Systematic Review and Network Meta-analysis.

Combination treatments with immuno-oncology (IO) agents and IO agents plus a vascular endothelial growth factor receptor tyrosine kinase inhibitor (VEGFR-TKI) have been approved for first-line treatment of patients with metastatic renal cell carcinoma (mRCC). No direct comparisons have been performed among these treatment options. We performed a systematic review and network meta-analysis to compare and rank the available regimens for first-line treatment in terms of survival benefit and efficacy. In accordance with the Preferred Reporting Items for Systematic Review statement, a systematic search of reported studies was performed in MEDLINE, the Cochrane Central Register of Controlled Trials, and EMBASE up to May 31, 2019. Network meta-analysis models were adjusted using the Bayesian method. Four randomized clinical trials, with a total of 3758 patients, met the inclusion criteria. Considering systemic therapy, 1880 patients had received sunitinib and 550, 432, 442, and 454 patients had received ipilimumab plus nivolumab (ipi + nivo), pembrolizumab plus axitinib (pembro + axi), avelumab plus axitinib (avelu + axi), and atezolizumab plus bevacizumab (atezo + bev). No difference was found in overall survival between ipi + nivo and pembro + axi for the intention to treat population (hazard ratio [HR], 1.34; 95% credible interval [CrI], 0.92-1.97). No difference was found in progression-free survival among the treatments. The overall response rate (ORR) was superior with pembro + axi and avelu + axi compared with the ORR with the other treatments (atezo + bev vs. pembro + axi: HR, 0.66; 95% CrI, 0.52-0.84; ipi + nivo vs. pembro + axi: HR, 0.73; 95% CrI, 0.59-0.90; atezo + bev vs. avelu + axi: HR, 0.55; 95% CrI, 0.43-0.71; avelu + axi vs. ipi + nivo: HR, 1.66; 95% CrI, 1.31-2.12), with no differences across them (HR, 1.21; 95% CrI, 0.95-1.53). In the present indirect comparison, for an intention to treat population, we found no survival differences between pembro + axi and ipi + nivo. All treatments showed better progression-free survival compared with sunitinib that was similar among them. The combination of an IO agent (pembrolizumab or avelumab) and axitinib seemed to be the most effective therapy for the ORR.

Osteoprotegerin diminishes advanced bone cancer pain.

Bone cancer pain most commonly occurs when tumors originating in breast, prostate, or lung metastasize to long bones, spinal vertebrae, and/or pelvis. Primary and metastatic cancers involving bone account for approximately 400,000 new cancer cases per year in the United States alone, and >70% of patients with advanced breast or prostate cancer have skeletal metastases. Whereas pain resulting from bone cancer can dramatically impact an individual's quality of life, very little is known about the mechanisms that generate and maintain this pain. To begin to define the mechanisms that give rise to advanced bone cancer pain, osteolytic 2472 sarcoma cells or media were injected into the intramedullary space of the femur of C3H/HeJ mice, and the injection hole was sealed using dental amalgam, confining the tumor cells to the bone. Twelve days after injection of 2472 tumor cells, animals showed advanced tumor-induced bone destruction of the injected femur, bone cancer pain, and a stereotypic set of neurochemical changes in the spinal cord dorsal horn that receives sensory inputs from the affected femur. Administration of osteoprotegerin, a naturally secreted decoy receptor that inhibits osteoclast maturation and activity and induces osteoclast apoptosis, or vehicle was begun at 12 days, when significant bone destruction had already occurred, and administration was continued daily until day 21. Ongoing pain behaviors, movement-evoked pain behaviors, and bone destruction were assessed on days 10, 12, 14, 17, and 21. The neurochemistry of the spinal cord was evaluated at days 12 and 21. Results indicated that osteoprotegerin treatment halted further bone destruction, reduced ongoing and movement-evoked pain, and reversed several aspects of the neurochemical reorganization of the spinal cord. Thus, even in advanced stages of bone cancer, ongoing osteoclast activity appears to be involved in the generation and maintenance of ongoing and movement-evoked pain. Blockade of ongoing osteoclast activity appears to have the potential to reduce bone cancer pain in patients with advanced tumor-induced bone destruction.

Determination of ochratoxin A in green coffee by immunoaffinity column cleanup and liquid chomatography: collaborative study.

A collaborative study was conducted to evaluate a method using immunoaffinity column cleanup with liquid chromatography (LC) for the determination of ochratoxin A (OTA) in green coffee at levels that could be included in possible future regulations of the European Union. The test portion was extracted with methanol-3% aqueous sodium hydrogen carbonate solution (50 + 50, v/v). The extract was filtered, and the filtrate was diluted with phosphate-buffered saline and applied to an immunoaffinity column containing antibodies specific for OTA. After washing, the toxin was eluted from the column with methanol and quantified by LC with fluorescence detection. Pairs of 4 homogeneous noncontaminated and naturally contaminated materials (mean levels of < 0.12, 2.44, 5.15, and 13.46 ng/g) and blank samples (< 0.12 ng/g) for spiking were sent to 20 participant laboratories from 8 countries. The materials were analyzed according to the method description and all difficulties encountered in the analysis were reported. Statistical analysis was carried out according to the Harmonized Protocol of the International Union of Pure and Applied Chemistry. The relative standard deviation for repeatability (RSDr) ranged from 7.42 to 20.94%, and the relative standard deviation for reproducibility (RSDR) ranged from 16.34 to 29.17%. The method showed acceptable within-laboratory and between-laboratories precision for green coffee materials, as evidenced by HorRat values of < or = 0.85, at the studied range, for spiked and naturally contaminated materials. The mean recovery was 92.8% for green coffee material spiked with OTA at a level of 4.82 ng/g.

Murine models of inflammatory, neuropathic and cancer pain each generates a unique set of neurochemical changes in the spinal cord and sensory neurons.

The aim of this investigation was to determine whether murine models of inflammatory, neuropathic and cancer pain are each characterized by a unique set of neurochemical changes in the spinal cord and sensory neurons. All models were generated in C3H/HeJ mice and hyperalgesia and allodynia behaviorally characterized. A variety of neurochemical markers that have been implicated in the generation and maintenance of chronic pain were then examined in spinal cord and primary afferent neurons.Three days after injection of complete Freund's adjuvant into the hindpaw (a model of persistent inflammatory pain) increases in substance P, calcitonin gene-related peptide, protein kinase C gamma, and substance P receptor were observed in the spinal cord. Following sciatic nerve transection or L5 spinal nerve ligation (a model of persistent neuropathic pain) significant decreases in substance P and calcitonin gene-related peptide and increases in galanin and neuropeptide Y were observed in both primary afferent neurons and the spinal cord. In contrast, in a model of cancer pain induced by injection of osteolytic sarcoma cells into the femur, there were no detectable changes in any of these markers in either primary afferent neurons or the spinal cord. However, in this cancer-pain model, changes including massive astrocyte hypertrophy without neuronal loss, increase in the neuronal expression of c-Fos, and increase in the number of dynorphin-immunoreactive neurons were observed in the spinal cord, ipsilateral to the limb with cancer. These results indicate that a unique set of neurochemical changes occur with inflammatory, neuropathic and cancer pain in C3H/HeJ mice and further suggest that cancer induces a unique persistent pain state. Determining whether these neurochemical changes are involved in the generation and maintenance of each type of persistent pain may provide insight into the mechanisms that underlie each of these pain states.

Origins of skeletal pain: sensory and sympathetic innervation of the mouse femur.

Although skeletal pain plays a major role in reducing the quality of life in patients suffering from osteoarthritis, Paget's disease, sickle cell anemia and bone cancer, little is known about the mechanisms that generate and maintain this pain. To define the peripheral fibers involved in transmitting and modulating skeletal pain, we used immunohistochemistry with antigen retrieval, confocal microscopy and three-dimensional image reconstruction of the bone to examine the sensory and sympathetic innervation of mineralized bone, bone marrow and periosteum of the normal mouse femur. Thinly myelinated and unmyelinated peptidergic sensory fibers were labeled with antibodies raised against calcitonin gene-related peptide (CGRP) and the unmyelinated, non-peptidergic sensory fibers were labeled with the isolectin B4 (Bandeira simplicifolia). Myelinated sensory fibers were labeled with an antibody raised against 200-kDa neurofilament H (clone RT-97). Sympathetic fibers were labeled with an antibody raised against tyrosine hydroxylase. CGRP, RT-97, and tyrosine hydroxylase immunoreactive fibers, but not isolectin B4 positive fibers, were present throughout the bone marrow, mineralized bone and the periosteum. While the periosteum is the most densely innervated tissue, when the total volume of each tissue is considered, the bone marrow receives the greatest total number of sensory and sympathetic fibers followed by mineralized bone and then periosteum. Understanding the sensory and sympathetic innervation of bone should provide a better understanding of the mechanisms that drive bone pain and aid in developing therapeutic strategies for treating skeletal pain.

Childhood vitamin A status and the risk of otitis media.

BACKGROUND: It has been suggested that vitamin A deficiency may predispose to otitis media. METHODS: We conducted a prospective, observational study of 200 children, ages 3 to 5 years, on the island of Saipan in the Commonwealth of the Northern Mariana Islands. Baseline measurements of serum retinol concentrations were obtained from the children, and incidence of otitis media was determined during the following year by review of medical records. The sera were also tested for concentration of other carotenoids (beta-carotene, alpha-carotene, lutein and zeaxanthin, beta-cryptoxanthin, lycopene), and alpha-tocopherol and baseline concentrations of these compounds were also examined for relationship to incidence of otitis media. RESULTS: Serum retinol concentrations of the children ranged from 13 to 58 microg/dl. Episodes of otitis media occurred in 22% of children during the follow-up period. Children with low serum retinol concentrations did not have an excess of episodes of otitis media (chi square for trend, 0.438; P = 0.508 for children grouped by serum retinol concentration; mean serum retinol concentrations were 29.1 and 28.6 microg/dl, respectively, for children who had and did not have a subsequent episode of otitis media). Controlling for potential confounding variables (duration of breast feeding, smoking in the household, illness or live virus vaccination in the 2 weeks before serum collection, day-care attendance) did not substantially alter this finding. Baseline serum concentrations of the other carotenoids and alpha-tocopherol also demonstrated no relation to incidence of otitis media. CONCLUSION: In the range of serum vitamin concentrations found in this population, the status of vitamin A and related compounds in children appeared to have no effect on the incidence of otitis media.

[Cardiac memory in patients with permanent artificial pacemakers]. / Memória cardíaca em pacientes com marcapasso artificial definitivo.

PURPOSE: To correlate the direction of QRS complex of paced beats and postpacing T wave, in patients with artificial pacemaker. METHODS: Thirty five patients with spontaneous rhythm obtained by chest wall stimulation or by programmability of the automatic interval. It was correlated in all patients, the direction forces of QRS complexes of paced beats and postpacing T waves in all 12 ECG leads. It was considered as a cardiac memory phenomenon when QRS complexes of paced beats and postpacing T waves had the same polarity. The phenomenon was correlated with the 12 ECG leads and with specific variables like spontaneous rhythm, QRS complex duration, type and modality of artificial stimulation and chronicity of the implant. RESULTS: The artificial QRS complexes and spontaneous T waves had the same direction in 5 or more leads of the frontal plane in 77% of the patients and in 50% of the patients in the horizontal plane. In patients with supraventricular command, this correlation was found in 82% of the patients and in 50% of the patients with idioventricular rhythm. Regardless of the type of spontaneous command, the phenomenon was better observed with normal intraventricular conduction. It was not found correlation between type, modality of stimulation and chronicity of the implant and cardiac memory. It was better observed in aVF, D2, D3 and V3, V4. CONCLUSION: The phenomenon of cardiac memory in patients with artificial pacemaker is very frequent. The most important factor to develop the phenomenon seem to be a normal pattern of ventricular activation.

Immunohistochemical evidence for myofibroblast-like cells associated with liver injury induced by aflatoxin B1 in rainbow trout (Oncorhynchus mykiss).

In mammalian species, profibrogenic cells are activated to become myofibroblasts in response to liver damage. Few studies have examined hepatic myofibroblasts and their role in liver damage in teleosts. The aim of the present study was to investigate the involvement of myofibroblast-like cells in rainbow trout (Oncorhynchus mykiss) with hepatic damage induced by aflatoxin B1 (AFB1). Histopathological and immunohistochemical analyses characterized alterations in the liver stroma during the carcinogenic process. Anti-human α-smooth muscle actin (SMA) and anti-human desmin primary antibodies were used in immunohistochemistry. Only the anti-SMA reagent labelled cells in trout liver. In the livers of control fish, only smooth muscle in blood vessels and around bile ducts was labelled. In the livers from AFB1-treated fish, SMA-positive cells were present in the stroma surrounding neoplastic lesions and in areas of desmoplastic reaction. These observations indicate that in teleosts, as in mammals, the myofibroblast-like cell is involved in fibrosis associated with liver injury. Chronic liver injury induced in trout by aflatoxin may provide a useful model system for study of the evolution of such mechanisms.

Cimento de aluminato de cálcio: uso em defeitos ósseos induzidos em fêmur de coelhos / Calcium aluminate cement: used in bone defects induced in the femur of rabbits

Avaliou-se o comportamento do cimento de aluminato de cálcio em defeitos ósseos induzidos experimentalmente em fêmur de 12 coelhos Nova Zelândia Branco, distribuídos em três grupos experimentais, correspondentes aos tempos de observação pós-operatória de 15 (G15), 30 (G30) e 60 (G60) dias. Realizaram-se avaliações clínico-cirúrgicas, radiográficas e histológicas, a fim de se observar o potencial osteoindutor e osteocondutor do biomaterial no defeito ósseo, e se houve osteointegração. O cimento de aluminato de cálcio, na formulação utilizada, mostrou-se biocompatível, porém não atuou como osteocondutor ou osteoindutor.

The patterns of the calcium aluminate cement in bone defects experimentally induced in the femur of 12 New Zealand White rabbits were evaluated. The animals were distributed in three experimental groups, corresponding to postoperative observation periods of 15 (G15), 30 (G30) and 60 (G60) days. Clinical, surgical, radiographic and histological appraisals were made to observe the osteoinductor and osteoconductor potential of the biological material, as well as the bone integration. The calcium aluminate cement formulation was biocompatible, but has not acted as a osteoconductor or osteoinductor.

Imbibition, desiccation and mechanical deformations of zein pills in relation to their porosity.

This paper deals with the interaction between zein (the main protein component of corn grain) and water. It induces macroscopic properties changes and may allow for the understanding of the basis of zein endosperm structure: vitreous endosperm is compact and floury endosperm is porous, giving the endosperm its hard and soft textures, respectively. In that aim porous pills made by compaction of zein powder submitted to different hydration/dehydration processes have been prepared and studied. In particular, imbibition measurements of a pure-water drop deposited onto a zein pill were performed. Also, desiccation of a zein pill previously imbibed induces strong mechanical stresses leading to crack formation and/or large deformations.