Abdominal Transplant Surgeons: The Lack of Female Surgeons and People From Underrepresented Racial and Ethnic Minority Groups in Academic and Clinical Leadership.

OBJECTIVES: The demographic disparities among surgeons in academic leadership positions is well documented. We aimed to characterize the present demographic details of abdominal transplant surgeons who have achieved academic and clinical leadership positions. MATERIALS AND METHODS: We reviewed the 2022-2023 American Society of Transplant Surgeons membership registry to identify 1007 active abdominal transplant surgeons. Demographic details (academic and clinical titles) were collected and analyzed using the chi-square test, the Fisher exact test, and t tests. Multinomial logistic regressions were conducted. RESULTS: Female surgeons (P < .001) and surgeons from racial-ethnic minorities (P = .027) were more likely to be assistants or associates rather than full professors. White male surgeons were more likely to be full professors than were White female (P < .001), Asian female (P = .008), and Asian male surgeons (P = .005). There were no Black female surgeons who were full professors. The frequency of full professorship increased with surgeon age (P < .001). Male surgeons were more likely to hold no academic titles (P < .001). Female surgeons were less likely to be chief of transplant(P = .025), chief of livertransplant (P = .001), chief of pancreas transplant (P = .037), or chair of surgery (P = .087, significance at 10%). Chief of kidney transplant was the most common clinical position held by a surgeon from a racial or ethnic minority group. Female surgeons were more likely to hold no clinical titles (P = .001). CONCLUSIONS: The underrepresentation of women and people from racial and ethnic minority groups in academic and clinical leadership positions in the field of abdominal transplant surgery remains evident. White male physicians are more likely to obtain full professorship, and they comprise most of the clinical leadership positions overall. A continued push for representative leadership is needed.

The effects of Phycocyanobilin on experimental arthritis involve the reduction in nociception and synovial neutrophil infiltration, inhibition of cytokine production, and modulation of the neuronal proteome.

Introduction: The antinociceptive and pharmacological activities of C-Phycocyanin (C-PC) and Phycocyanobilin (PCB) in the context of inflammatory arthritis remain unexplored so far. In the present study, we aimed to assess the protective actions of these compounds in an experimental mice model that replicates key aspects of human rheumatoid arthritis. Methods: Antigen-induced arthritis (AIA) was established by intradermal injection of methylated bovine serum albumin in C57BL/6 mice, and one hour before the antigen challenge, either C-PC (2, 4, or 8 mg/kg) or PCB (0.1 or 1 mg/kg) were administered intraperitoneally. Proteome profiling was also conducted on glutamate-exposed SH-SY5Y neuronal cells to evaluate the PCB impact on this key signaling pathway associated with nociceptive neuronal sensitization. Results and discussion: C-PC and PCB notably ameliorated hypernociception, synovial neutrophil infiltration, myeloperoxidase activity, and the periarticular cytokine concentration of IFN-γ, TNF-α, IL-17A, and IL-4 dose-dependently in AIA mice. In addition, 1 mg/kg PCB downregulated the gene expression for T-bet, RORγ, and IFN-γ in the popliteal lymph nodes, accompanied by a significant reduction in the pathological arthritic index of AIA mice. Noteworthy, neuronal proteome analysis revealed that PCB modulated biological processes such as pain, inflammation, and glutamatergic transmission, all of which are involved in arthritic pathology. Conclusions: These findings demonstrate the remarkable efficacy of PCB in alleviating the nociception and inflammation in the AIA mice model and shed new light on mechanisms underlying the PCB modulation of the neuronal proteome. This research work opens a new avenue to explore the translational potential of PCB in developing a therapeutic strategy for inflammation and pain in rheumatoid arthritis.

SARS-CoV-2: theoretical analysis of the proposed algorithms to the enhancement and segmentation of high-resolution microscopy images-Part II.

Today is a reality that the novel coronavirus SARS-Cov-2 has become a global pandemic. For this reason, the study of real microscopic images of this coronavirus is of great importance, as it allows us to carry out a more precise research on it. However, as we pointed out in a former paper as reported by Roberto Rodríguez (SARS-CoV-2: Enhancement and Segmentation of High-Resolution Microscopy Images. Part I", Sent to Signal, Image and Video Processing Video Processing, Springer, New York, 2020), many times these microscopic images present some blurring problems, which are always susceptible to be improved. The aim of this work is to carry out a theoretical analysis of the proposed algorithms to enhancement and segmentation of these microscopic images, which is important for the design and development of future algorithms before new epidemics.

The microglial NLRP3 inflammasome is involved in human SARS-CoV-2 cerebral pathogenicity: A report of three post-mortem cases.

We herein report, by using confocal immunofluorescence, the colocalization of the SARS-CoV-2 nucleocapsid within neurons, astrocytes, oligodendrocytes and microglia in three deceased COVID-19 cases, of between 78 and 85 years of age at death. The viral nucleocapsid was detected together with its ACE2 cell entry receptor, as well as the NLRP3 inflammasome in cerebral cortical tissues. It is noteworthy that NLRP3 was colocalized with CD68 + macrophages in the brain and lung of the deceased, suggesting the critical role of this type of inflammasome in SARS-CoV-2 lesions of the nervous system/lungs and supporting its potential role as a therapeutic target.

SARS-CoV-2: preliminary study of infected human nasopharyngeal tissue by high resolution microscopy.

BACKGROUND: The novel coronavirus SARS-CoV-2 is the etiological agent of COVID-19. This virus has become one of the most dangerous in recent times with a very high rate of transmission. At present, several publications show the typical crown-shape of the novel coronavirus grown in cell cultures. However, an integral ultramicroscopy study done directly from clinical specimens has not been published. METHODS: Nasopharyngeal swabs were collected from 12 Cuban individuals, six asymptomatic and RT-PCR negative (negative control) and six others from a COVID-19 symptomatic and RT-PCR positive for SARS CoV-2. Samples were treated with an aldehyde solution and processed by scanning electron microscopy (SEM), confocal microscopy (CM) and, atomic force microscopy. Improvement and segmentation of coronavirus images were performed by a novel mathematical image enhancement algorithm. RESULTS: The images of the negative control sample showed the characteristic healthy microvilli morphology at the apical region of the nasal epithelial cells. As expected, they do not display virus-like structures. The images of the positive sample showed characteristic coronavirus-like particles and evident destruction of microvilli. In some regions, virions budding through the cell membrane were observed. Microvilli destruction could explain the anosmia reported by some patients. Virus-particles emerging from the cell-surface with a variable size ranging from 80 to 400 nm were observed by SEM. Viral antigen was identified in the apical cells zone by CM. CONCLUSIONS: The integral microscopy study showed that SARS-CoV-2 has a similar image to SARS-CoV. The application of several high-resolution microscopy techniques to nasopharyngeal samples awaits future use.

SARS-CoV-2: enhancement and segmentation of high-resolution microscopy images-Part I.

Possibly, and due to poor eating habits and unhealthy lifestyle, many viruses are transmitted to human people. Such is the case, of the novel coronavirus SARS-Cov-2, which has expanded of exponential way, practically, to whole world population. For this reason, the enhancement of real microscopic images of this coronavirus is of great importance. Of this way, one can highlight the S-spikes and visualizing those areas that show a high density, which are related to active zones of viral germination and major spread of the virus. The SARS-Cov-2 images were captured from nasopharyngeal samples of Cuban symptomatic individuals (RT-PCR positives for SARS-CoV-2) and processed via scanning electron microscopy. However, many times these microscopic images present some blurring problems, and the S-spikes do not look well defined. Therefore, the aim of this work is to propose new computational methods to carry out enhancement and segmentation of SARS-Cov-2 high-resolution microscopic images. The proposed strategy obtained very satisfactory results, and we validated its performance, together with specialist physicians, on a set of 1005 images. Due to the importance of the obtained results, this first work will be addressed to the application of the proposed algorithm. A second paper will deeply analyze the theory related to these algorithms.

Insights into the Interaction between the Monophagous Tephritid Fly Anastrepha acris and its Highly Toxic Host Hippomane mancinella (Euphorbiaceae).

Despite their enormous economic importance and the fact that there are almost 5000 tephritid (Diptera) species, fruit fly - host plant interactions are poorly understood from a chemical perspective. We analyzed the interactions among Anastrepha acris (a little studied monophagous tephritid) and its highly toxic host plant Hippomane mancinella from chemical, ecological and experimental perspectives, and also searched for toxicants from H. mancinella in the larval-pupal endoparasitoid Doryctobracon areolatus. We identified 18 phenolic compounds from H. mancinella pulp belonging to different chemical groups including phenylpropanoids, flavonoids, chalcones and coumarins. No traces of Hippomanin A were detected in larvae, pupae or A. acris adults, or in D. areolatus adults, implying that A. acris larvae can metabolize this toxicant, that as a result does not reach the third trophic level. We tested the "behavioral preference - lack of larval specialization-hypothesis" via feeding experiments with a larval rearing medium containing H. mancinella fruit (skin + pulp or pulp alone). The high toxicity of H. mancinella was confirmed as only two (out of 2520 in three experiments) A. ludens larvae (a polyphagous pest species that preferentially feeds on plants within the Rutaceae) survived without reaching the adult stage when fed on media containing H. mancinella, whereas A. acris larvae developed well and produced healthy adults. Together, these findings open a window of opportunity to study the detoxification mechanisms used by tephritid fruit flies.

Ultrastructural and biochemical basis for hepatitis C virus morphogenesis.

Chronic infection with HCV is a leading cause of cirrhosis, hepatocellular carcinoma and liver failure. One of the least understood steps in the HCV life cycle is the morphogenesis of new viral particles. HCV infection alters the lipid metabolism and generates a variety of microenvironments in the cell cytoplasm that protect viral proteins and RNA promoting viral replication and assembly. Lipid droplets (LDs) have been proposed to link viral RNA synthesis and virion assembly by physically associating these viral processes. HCV assembly, envelopment, and maturation have been shown to take place at specialized detergent-resistant membranes in the ER, rich in cholesterol and sphingolipids, supporting the synthesis of luminal LDs-containing ApoE. HCV assembly involves a regulated allocation of viral and host factors to viral assembly sites. Then, virus budding takes place through encapsidation of the HCV genome and viral envelopment in the ER. Interaction of ApoE with envelope proteins supports the viral particle acquisition of lipids and maturation. HCV secretion has been suggested to entail the ion channel activity of viral p7, several components of the classical trafficking and autophagy pathways, ESCRT, and exosome-mediated export of viral RNA. Here, we review the most recent advances in virus morphogenesis and the interplay between viral and host factors required for the formation of HCV virions.

Arresting progressive atherosclerosis by immunization with an anti-glycosaminoglycan monoclonal antibody in apolipoprotein E-deficient mice.

Atherogenesis is associated with the early retention of low-density lipoproteins (LDL) in the arterial intima by interaction with glycosaminoglycan (GAG)-side chains of proteoglycans. Retained LDL undergo reactive oxygen species-mediated oxidation. Oxidized LDL trigger oxidative stress (OS) and inflammation, contributing to atherosclerosis development. Recently, we reported the preventive anti-atherogenic properties of the chimeric mouse/human monoclonal antibody (mAb) chP3R99-LALA, which were related to the induction of anti-chondroitin sulfate antibody response able to inhibit chondroitin sulfate dependent LDL-enhanced oxidation. In the present work, we aimed at further investigating the impact of chP3R99-LALA mAb vaccination on progressive atherosclerosis in apolipoprotein E-deficient mice (apoE(-/-)) fed with a high-fat high-cholesterol diet receiving 5 doses (50 µg) of the antibody subcutaneously, when ~5% of the aortic area was covered by lesions. Therapeutic immunization with chP3R99-LALA mAb halted atherosclerotic lesions progression. In addition, aortic OS was modulated, as shown by a significant (p<0.05) reduction of lipid and protein oxidation, preservation of antioxidant enzymes activity and reduced glutathione, together with a decrease of nitric oxide levels. chP3R99-LALA mAb immunization also regulated aortic NF-κB activation, diminishing the proinflammatory IL1-ß and TNF-α gene expression as well as the infiltration of macrophages into the arterial wall. The therapeutic immunization of apoE(-/-) with progressive atheromas and persistent hypercholesterolemia using chP3R99-LALA mAb arrested further development of lesions, accompanied by a decrease of aortic OS and NF-κB-regulated pro-inflammatory cytokine gene expression. These results contribute to broaden the potential use of this anti-GAG antibody-based immunotherapy as a novel approach to target atherosclerosis at different phases of progression.

Candida albicans adherence to denture base material: chemical disinfection and the effect of acquired salivary pellicle formation.

PURPOSE: The aim of this study was to evaluate the effect of 1% sodium hypochlorite (H1%) and 4% chlorhexidine gluconate (CG4%) on the adhesion of Candida albicans to denture base acrylic resins, as well as to verify the effect of the acquired salivary pellicle (ASP) formation on this process. MATERIALS AND METHODS: A total of 300 acrylic specimens were immersed in distilled water (control) (n = 100), H1% (n = 100), or CG4% (n = 100) for 30 days. Twenty specimens were used in each experimental period (0, 1, 7, 15, 30 days). At the end of disinfection testing periods, 10 specimens of each group were exposed to human whole saliva to simulate ASP formation, and then all specimens were incubated with C. albicans ATTC 90028. Microorganism adhesion was analyzed by fluorescence microscopy, after staining with Acridine orange. RESULTS: In the 30(th) disinfection cycle in relation to baseline, the H1% or CG4%, without ASP formation, reduced the C. albicans adhesion by approximately 80%; however, with ASP, this reduction after disinfection with H1% was higher (88%). The presence of ASP resulted in higher reduction of adhered fungal cells in comparison to resin without ASP, at the 1(st) H1% or CG4% disinfection cycle, as well as at 30(th) H1% disinfection cycles. CONCLUSIONS: Our results suggest that the presence of saliva might influence the adhesion of C. albicans and improve the effectiveness of methods to reduce fungal adhesion.

Efficacy of commercial traps and food odor attractants for mass trapping of Anastrepha ludens (Diptera: Tephritidae).

One of the most important factors for the success of a mass trapping strategy to control a fruit fly involves the selection of an effective trap-lure combination. Because different species of fruit flies respond differently to the physical characteristics of a trap and to bait volatiles, the evaluation of commercial traps and lures that have proved useful against other tephtrids is necessary to determine their efficacy for mass trapping of Anastrepha ludens (Loew) (Diptera: Tephritidae). Under caged conditions, a commercial hemispherical trap with lateral holes (Maxitrap Plus) proved more attractive to A. ludens (both sexes) than five other commercial traps that were all baited with hydrolyzed protein. Among these traps, bottom invaginated traps and traps with invaginated lateral holes constructed with transparent cylinders had the best physical retention properties. When evaluated under field conditions, the lure was critical for the efficacy of the trap, and one of the traps that performed poorly in attraction and retention cage tests (MS2) resulted as one of the most effective traps when baited with CeraTrap lure. Considering the use of different trap models under field conditions, CeraTrap liquid bait was more effective in A. ludens capture than Biolure dry synthetic bait, but both lures were not replaced during the entire course of the experiment. The percentage of captured females was also slightly higher using CeraTrap lure (67.2%) than using Biolure baits (54.5-58.8%). In field tests, 75-81% of females were mated and no significant differences were observed among trap-lure combinations. Trap selectivity against nontarget adult lacewings also differed among trap-lure combinations.

Antiatherosclerotic effect of an antibody that binds to extracellular matrix glycosaminoglycans.

OBJECTIVE: Subendothelial retention of proatherogenic lipoproteins by proteoglycans is critical in atherosclerosis. The aim of this study was to characterize the recognition and antiatherogenic properties of a chimeric monoclonal antibody (mAb) that reacts with sulfated molecules. METHODS AND RESULTS: chP3R99 mAb recognized sulfated glycosaminoglycans, mainly chondroitin sulfate (CS), by ELISA. This mAb blocked ≈70% of low-density lipoprotein (LDL)-CS association and ≈80% of LDL oxidation in vitro, and when intravenously injected to Sprague-Dawley rats (n=6, 1 mg/animal), it inhibited LDL (4 mg/kg intraperitoneally, 1 hour later) retention and oxidation in the artery wall. Moreover, subcutaneous immunization of New Zealand White rabbits (n=19) with chP3R99 mAb (100 µg, 3 doses at weekly intervals) prevented Lipofundin-induced atherosclerosis (2 mL/kg, 8 days) with a 22-fold reduction in the intima-media ratio (P<0.01). Histopathologic and ultrastructural studies showed no intimal alterations or slight thickening, with preserved junctions between endothelial cells and scarce collagen fibers and glycosaminoglycans. In addition, immunization with chP3R99 mAb suppressed macrophage infiltration in aorta and preserved redox status. The atheroprotective effect was associated with the induction of anti-CS antibodies in chP3R99-immunized rabbits, capable of blocking CS-LDL binding and LDL oxidation. CONCLUSION: These results support the use of anti-sulfated glycosaminoglycan antibody-based immunotherapy as a potential tool to prevent atherosclerosis.

Effect of repeated immersion solution cycles on the color stability of denture tooth acrylic resins

OBJECTIVE: Chemical solutions have been widely used for disinfection of dentures, but their effect on color stability of denture tooth acrylic resins after repeated procedures is still unclear. The aim of this in vitro study was to evaluate whether repeated cycles of chemical disinfectants affected the color stability of two denture tooth acrylic resins. MATERIAL AND METHODS: Sixty disc-shaped specimens (40 mm x 3 mm) were fabricated from two different brands (Artiplus and Trilux) of denture tooth acrylic resin. The specimens from each brand (n=30) were randomly divided into 6 groups (n=5) and immersed in the following solutions: distilled water (control group) and 5 disinfecting solutions (1 percent sodium hypochlorite, 2 percent sodium hypochlorite, 5.25 percent sodium hypochlorite, 2 percent glutaraldehyde, and 4 percent chlorhexidine gluconate). Tooth color measurements were made by spectrophotometry. Before disinfection, the initial color of each tooth was recorded. Further color measurements were determined after subjecting the specimens to 7, 21, 30, 45, 60, and 90 immersion cycles in each tested solution. Color differences (ΔE*) were determined using the CIE L*a*b* color system. Data were analyzed using two-way repeated measures analysis of variance (ANOVA) followed by Tukey tests. The significance level was set at 5 percent. RESULTS: There were statistically significant differences in ΔE* among the 5 disinfectants and water during the 90 cycles of immersion for both denture tooth acrylic resins. Distilled water promoted the greatest color change in both denture tooth acrylic resins, nevertheless none of tested disinfectants promoted ΔE* values higher than 1.0 on these acrylic materials during the 90 cycles of disinfection. CONCLUSIONS: Repeated immersion cycles in disinfecting solutions alter ΔE* values, however these values do not compromise the color of the tested denture tooth acrylic resins because they are imperceptible to the human eye.

Microscopical analysis of Candida albicans biofilms on heat-polymerised acrylic resin after chlorhexidine gluconate and sodium hypochlorite treatments.

The ability of Candida albicans to form biofilms on denture surfaces is a significant cofactor in the pathogenesis of denture stomatitis. In this study, we applied a differential staining approach and scanning electron microscopy (SEM) to analyse the effect of sodium hypochlorite and chlorhexidine gluconate on the viability, removal and morphology of C. albicans forming biofilms on denture acrylic using an in vitro model. Immediately after treatment, to distinguish live from dead C. albicans cells in the remaining biofilms, the specimens were stained differentially and analysed by confocal scanning laser microscopy. Moreover, morphological alterations of fungal cells were investigated using scanning electron microscopy. All disinfectant solutions killed all remaining fungal cells on the specimens. Interestingly, 4% chlorhexidine did not remove these cells from the acrylic resin surface whereas sodium hypochlorite solutions (1% and 2%) provided almost complete biofilm removal. Furthermore, treating the specimens with sodium hypochlorite induced cell morphology alterations, as seen in the residual fungal cells. Finally, according to our findings, it can be suggested that sodium hypochlorite solutions are the first choice as denture cleanser when compared with 4% chlorhexidine because those solutions not only killed C. albicans biofilms but also removed them from the heat-polymerised acrylic resin.

Effect of repeated immersion solution cycles on the color stability of denture tooth acrylic resins.

OBJECTIVE: Chemical solutions have been widely used for disinfection of dentures, but their effect on color stability of denture tooth acrylic resins after repeated procedures is still unclear. The aim of this in vitro study was to evaluate whether repeated cycles of chemical disinfectants affected the color stability of two denture tooth acrylic resins. MATERIAL AND METHODS: Sixty disc-shaped specimens (40 mm x 3 mm) were fabricated from two different brands (Artiplus and Trilux) of denture tooth acrylic resin. The specimens from each brand (n=30) were randomly divided into 6 groups (n=5) and immersed in the following solutions: distilled water (control group) and 5 disinfecting solutions (1% sodium hypochlorite, 2% sodium hypochlorite, 5.25% sodium hypochlorite, 2% glutaraldehyde, and 4% chlorhexidine gluconate). Tooth color measurements were made by spectrophotometry. Before disinfection, the initial color of each tooth was recorded. Further color measurements were determined after subjecting the specimens to 7, 21, 30, 45, 60, and 90 immersion cycles in each tested solution. Color differences (ΔE*) were determined using the CIE L*a*b* color system. Data were analyzed using two-way repeated measures analysis of variance (ANOVA) followed by Tukey tests. The significance level was set at 5%. RESULTS: There were statistically significant differences in ΔE* among the 5 disinfectants and water during the 90 cycles of immersion for both denture tooth acrylic resins. Distilled water promoted the greatest color change in both denture tooth acrylic resins, nevertheless none of tested disinfectants promoted ΔE* values higher than 1.0 on these acrylic materials during the 90 cycles of disinfection. CONCLUSIONS: Repeated immersion cycles in disinfecting solutions alter ΔE* values, however these values do not compromise the color of the tested denture tooth acrylic resins because they are imperceptible to the human eye.

Effect of repeated cycles of chemical disinfection on the roughness and hardness of hard reline acrylic resins.

OBJECTIVE: The aim of this study was to assess the effect of repeated cycles of five chemical disinfectant solutions on the roughness and hardness of three hard chairside reliners. METHODS: A total of 180 circular specimens (30 mm x 6 mm) were fabricated using three hard chairside reliners (Jet; n = 60, Kooliner; n = 60, Tokuyama Rebase II Fast; n = 60), which were immersed in deionised water (control), and five disinfectant solutions (1%, 2%, 5.25% sodium hypochlorite; 2% glutaraldehyde; 4% chlorhexidine gluconate). They were tested for Knoop hardness (KHN) and surface roughness (microm), before and after 30 simulated disinfecting cycles. Data was analysed by the factorial scheme (6 x 2), two-way analysis of variance (anova), followed by Tukey's test. RESULTS: For Jet (from 18.74 to 13.86 KHN), Kooliner (from 14.09 to 8.72 KHN), Tokuyama (from 12.57 to 8.28 KHN) a significant decrease in hardness was observed irrespective of the solution used on all materials. For Jet (from 0.09 to 0.11 microm) there was a statistically significant increase in roughness. Kooliner (from 0.36 to 0.26 microm) presented a statistically significant decrease in roughness and Tokuyama (from 0.15 to 0.11 microm) presented no statistically significant difference after 30 days. CONCLUSIONS: This study showed that all disinfectant solutions promoted a statistically significant decrease in hardness, whereas with roughness, the materials tested showed a statistically significant increase, except for Tokuyama. Although statistically significant values were registered, these results could not be considered clinically significant.

Complicaciones y evolución natural de la comunicación interventricular: estudio de 177 casos / Complications and natural evolution of interventricular communication: study of 177 cases

Se estudiaron 177 casos que padecían de CIV sintomáticos, Ingresados en el ICCCV en el período comprendido desde 1970 a 1981, ambos inclusive, se analizaron las complicaciones más frecuentes presentadas por los mismos, que fueron: bronconeumonía, neumopatías a repetición e ICC y se hace incapié en que si bien el número de casos que presentaron HTP y cierre espontaneo del defecto, no está acorde con otros autores, posiblemente se deba a las características de la muestra. por ;último se presentan 5 casos de endocarditis bacteriana y un caso de estenosis pulmonar infundibular desarrollada secundariamente.

Complicaciones y evolución natural de la comunicación interventricular: estudio de 177 casos / Complications and natural evolution of interventricular communication: study of 177 cases

Se estudiaron 177 casos que padecían de CIV sintomáticos, Ingresados en el ICCCV en el período comprendido desde 1970 a 1981, ambos inclusive, se analizaron las complicaciones más frecuentes presentadas por los mismos, que fueron: bronconeumonía, neumopatías a repetición e ICC y se hace incapié en que si bien el número de casos que presentaron HTP y cierre espontaneo del defecto, no está acorde con otros autores, posiblemente se deba a las características de la muestra. por ;último se presentan 5 casos de endocarditis bacteriana y un caso de estenosis pulmonar infundibular desarrollada secundariamente.