Anatomical and physiological adaptation of the scrotal artery with muscular reinforcement in the middle layer and connective reinforcement of the adventitia.

The histology of blood vessels shows they are structured in three layers or tunics: tunica intima, which includes the internal limiting lamina with high elastin content; tunica media of smooth muscles fibers of circular disposition, which includes the external limiting lamina; and tunica adventitia of connective tissue. The vascular system is essential in regulating body temperature, especially in the scrotum and testis. This study aimed to analyze the histology of the scrotal arteries and their possible relationship to testicular temperature homeostasis. This study used scrotal samples from human adults, anonymized and obtained from the University of Chile's teaching bank. The control group corresponds to an arteriole of muscle tissue. The results show that the middle layer of the scrotal artery is made up of smooth muscle fibers distributed in two layers: a longitudinal inner sublayer and a circular outer sublayer, different from the findings in muscle tissue arteries, with a single, circularly arranged muscle layer. This arrangement could be related to testicular temperature homeostasis by reducing the temperature of the testis and seminiferous tubules. The results described in this work suggest that these anatomical adaptations may be very significant in the face of the constant increase in global temperature. Further and better research is required to understand the mechanisms of thermoregulation in human reproduction and the histological particularities of the tissues that form the scrotum. RESEARCH HIGHLIGHTS: The human scrotal artery has a histological composition adapted for regulation of testicular temperature. The muscular double middle layer of the scrotal artery retains intravascular temperature.

Qualitative and quantitative characteristics of the passive compartment underneath the myocardial bridge comprising the blood vessel adventitia and the perivascular connective tissue / Características cualitativas y cuantitativas del compartimento pasivo debajo del puente miocárdico que comprende la adventicia del vaso sanguíneo y el tejido conectivo perivascular

SUMMARY: Myocardial bridges are inborn anomalies frequently found in authopsies. Although tipically clinically silent, they are occasionally associated with severe clinical manifestations, e.g. myocardial ischemia or even sudden death. The pathophysiology and risk factors for these manifestations have not yet been completely elucidated. The connective tissue underneath the bridge has been considered as one of the factors the symptoms depend on. Thus, the aim of this research was to determine the histological characteristics of the connective tissue lying underneath the myocardial bridge and to contribute to a better understanding of the protective effects this passive compartment might have in prevention of severe clinical manifestations of myocardial bridging. The study was carried out on twenty hearts with myocardial bridges. Length of the bridge was determined using a precise electronic caliper. Sections of the myocardial bridges with the underlying connective tissue were obtained and prepared for qualitative and quantitative analysis. The connective tissue underneath the bridges was composed of adipose tissue and loose connective tissue in different ratios. The tissue underneath thin bridges was predominantly composed of adipose tissue, while loose connective tissue was the dominant component under thick bridges. The myocardial bridges had an average thickness of 0,98 ± 0.44 mm and an average length of 15,25±5,65 mm. We found a strong positive correlation between the myocardial bridge thickness and length (r = 0,860, p = 0,0001). The thickness of the passive connective tissue compartment under the myocardial bridges was 0,58±0,22 mm, and there was no correlation between this parameter and the myocardial bridge thickness (r = -0,011; p = 0,963). In the clinical evaluation of patients with these anomalies it is necessary to take into account independently the myocardial bridge thickness and length on one side and the thickness of the connective tissue lying underneath it on the other.

Los puentes miocárdicos son anomalías congénitas que se encuentran con frecuencia en las autopsias. Aunque típicamente éstos son clínicamente silenciosos, ocasionalmente se asocian con manifestaciones clínicas graves, como isquemia miocárdica o incluso muerte súbita. La fisiopatología y los factores de riesgo de estas manifestaciones aún no se han dilucidado por completo. El tejido conectivo debajo del puente se ha considerado como uno de los factores de los que dependen los síntomas. Por lo tanto, el objetivo de esta investigación fue determinar las características histológicas del tejido conectivo que se encuentra debajo del puente miocárdico y contribuir a una mejor comprensión de los efectos protectores que este compartimento pasivo podría tener en la prevención de manifestaciones clínicas graves de puente miocárdico. El estudio se llevó a cabo en veinte corazones con puentes miocárdicos. La longitud del puente se determinó utilizando un calibrador electrónico preciso. Se obtuvieron secciones de los puentes miocárdicos con el tejido conjuntivo subyacente y se prepararon para análisis cualitativo y cuantitativo. El tejido conectivo debajo de los puentes estaba compuesto de tejido adiposo y tejido conectivo laxo en diferentes proporciones. El tejido debajo de los puentes delgados estaba predominantemente compuesto de tejido adiposo, mientras que el tejido conectivo laxo era el componente dominante debajo de los puentes gruesos. Los puentes de miocardio tenían un espesor promedio de 0,98 ± 0,44 mm y una longitud promedio de 15,25 ± 5,65 mm. Encontramos una fuerte correlación positiva entre el grosor y la longitud del puente miocárdico (r = 0,860, p = 0,0001). El grosor del compartimiento de tejido conectivo pasivo debajo de los puentes miocárdicos era de 0,58±0,22 mm, y no hubo correlación entre este parámetro y el grosor del puente miocárdico (r = -0,011; p = 0,963). En la evaluación clínica de pacientes con estas anomalías es necesario tener en consideración de forma independiente el grosor y la longitud del puente de miocardio por un lado y el grosor del tejido conectivo que se encuentra debajo del mismo por el otro.

Adventitial Collagen Cross-Linking by Glutaraldehyde Reinforcing Human Saphenous Vein - Implication for Coronary Artery Bypass Grafting.

INTRODUCTION: A weak venous wall is one of the major reasons contributing to vein graft failure after coronary artery bypass grafting (CABG). We investigated whether adventitial collagen cross-linking by glutaraldehyde reinforces venous wall, preserving the endothelium of veins during high-pressure distention. METHODS: Human saphenous veins (SVs) were collected from 40 patients undergoing CABG, and adventitia cross-linking was performed with 0.3% glutaraldehyde for five minutes. The cross-linked SVs were accessed by biodegradation assay, immunofluorescent staining, and tensile test. Native SVs and cross-linked SVs from another 20 patients received the 200 mmHg pressure distention for two minutes. Pressure-induced injury of SVs were accessed by immunohistochemistry and electron microscopy. RESULTS: Time to digestion was 97±13 minutes for native SVs and 720±0 minutes for cross-linked SVs (P<0.05). After adventitial cross-linking, the collagen I fibres of the vein remarkably presented with compact and nonporous arrangement. In the high-stretch region (stretch ratio 1.4-1.8), the Young's elastic modulus of stress-stretch ratio curve in cross-linked SVs was larger than that in native SVs (13.88 vs. 5.83, P<0.05). The cross-linked SVs had a lower extent of endothelial denudation without fibre fracture during high-pressure distension than native SVs. Comparing with the non-cross-linked SVs, the percentage of endothelial nitric oxide synthase staining length on the endothelium of cross-linked SVs was significantly preserved after high-pressure distension (85.2% vs. 64.7%, P<0.05). CONCLUSION: Adventitial collagen cross-linking by glutaraldehyde reinforced venous wall by increasing stiffness and decreasing extensibility of SVs and mitigated the endothelial damage under high-pressure distension.

Multiscale simulations suggest a protective role of neo-adventitia in abdominal aortic aneurysms.

Abdominal aortic aneurysms (AAAs) are a dangerous cardiovascular disease, the pathogenesis of which is not yet fully understood. In the present work a recent mechanopathological theory, which correlates AAA progression with microstructural and mechanical alterations in the tissue, is investigated using multiscale models. The goal is to combine these changes, within the framework of mechanobiology, with possible mechanical cues that are sensed by vascular cells along the AAA pathogenesis. Particular attention is paid to the formation of a 'neo-adventitia' on the abluminal side of the aortic wall, which is characterized by a highly random (isotropic) distribution of collagen fibers. Macro- and micro-scale results suggest that the formation of an AAA, as expected, perturbs the micromechanical state of the aortic tissue and triggers a growth and remodeling (G&R) reaction by mechanosensing cells such as fibroblasts. This G&R then leads to the formation of a thick neo-adventitia that appears to bring the micromechanical state of the tissue closer to the original homeostatic level. In this context, this new layer could act like a protective sheath, similar to the tunica adventitia in healthy aortas. This potential 'attempt at healing' by vascular cells would have important implications on the stability of the AAA wall and thus on the risk of rupture. STATEMENT OF SIGNIFICANCE: Current clinical criteria for risk assessment in AAAs are still empirical, as the causes and mechanisms of the disease are not yet fully understood. The strength of the arterial tissue is closely related to its microstructure, which in turn is remodeled by mechanosensing cells in the course of the disease. In this study, multiscale simulations show a possible connection between mechanical cues at the microscopic level and collagen G&R in AAA tissue. It should be emphasized that these micromechanical cues cannot be visualized in vivo. Therefore, the results presented here will help to advance our current understanding of the disease and motivate future experimental studies, with important implications for AAA risk assessment.

Anatomical relationship between mitral valve annulus and circumflex artery and its surgical implications.

BACKGROUND: Performing surgical procedures around the mitral valve (MV) annulus can cause iatrogenic lesions on the circumflex artery (Cx). The risk of this iatrogenesis comes from the proximity between this vessel and the MV annulus. OBJECTIVE: To evaluate the relation between the MV annulus and the Cx at different spots of its path and highlight the risks of its damage. METHODS: Fifty cadaveric adult human hearts were studied. Each heart was categorized depending on coronary dominance, and Cx was classified in type 1 (Cx giving off only the left posterior ventricular artery) and type 2 (Cx reaching the crux cordis and giving off the posterior interventricular branch). Three reference spots were chosen: A- when Cx begins to run across the coronary sulcus; B- immediately before the left posterior ventricular artery emerges and C- in the midpoint of the two previous points; to measure the diameter of the Cx and the MV annulus. Values of P<0.05 were considered significant. RESULTS: A total of 43 (86%) hearts were classified in type 1. These hearts showed that the diameter of the Cx in spot A is bigger than in the B and C spots (P=0.001). The 7 hearts (14%) classified in type 2 did not exhibit a difference in the diameter of the Cx in the A, B and C spots (NS). Also, the thickness of the fibrous annulus, in type 1 and type 2 hearts were not different between the three spots (NS). CONCLUSION: The present study showed that the diameter of the Cx varies depending on the heart type. This knowledge might improve the success rate of cardiac surgeries and decrease the rates of iatrogenic Cx lesions.

Morphological description of smell glands in Cyclopes didactylus.

A macroscopic and microscopic study of the mandibular organ of the silky anteater (Cyclopes didactylus) was carried out. The organ extends from below the zygomatic bone line to the middle of the mandible body, between the skin and the masseter muscle, on both sides of the animal. It has an average length of 11.7 mm and a width of 6.3 mm. In the mesoscopic analysis, it was observed that the organ presents in yellowish color due to the high amount of sebaceous content. In the histological analysis, the mandibular organ was observed to be composed of innumerable alveoli of the specialized sebaceous gland, surrounded by a layer of adventitia tunica. Scanning electron microscopy (SEM), revealed an apparent alveolar division with what appeared to be a sulcus at its center. The information here presented regarding the constitution and location of this structure has not been previously explored for other species and differs with respect to other descriptions for anteaters. Based on the present study, it is suggested that the mandibular organ is involved in social interaction in this species.

Hydrogen peroxide and nitric oxide induce anticontractile effect of perivascular adipose tissue via renin angiotensin system activation.

The perivascular adipose tissue (PVAT) is located around the adventitia, composed primarily by adipocytes, stromal cells, leukocytes, fibroblasts and capillaries. It is well described that PVAT is an important modulator of the vascular tone being considered a biologically active tissue, releasing both vasoconstrictor and vasodilators factors. The literature shows that the anti-contractile effect induced by PVAT may be due to activation of the renin-angiotensin system (RAS). AIM: Investigate whether the renin-angiotensin system participates in the effect exerted by perivascular adipose tissue on the vascular tone. METHODS AND RESULTS: For this study we used thoracic aorta from Balb/c mice and performed vascular reactivity, nitric oxide and hydrogen peroxide quantification using selective probes and fluorescence microscopy, immunofluorescence to locate receptors and enzymes involved in this response. Our results demonstrated that perivascular adipose tissue induces an anti-contractile effect in endothelium-independent manner and involves Mas and AT2 receptors participation with subsequent PI3K/Akt pathway activation. This pathway culminated with nitric oxide and hydrogen peroxide production by neuronal nitric oxide synthase, being hydrogen peroxide most relevant for the anti-contractile effect of perivascular adipose tissue. CONCLUSION: For the first time in the literature, our results show the presence of Mas and AT2 receptors, as well as, nitric oxide synthase on perivascular adipose tissue. Furthermore, our results show the involvement of Mas and AT2 receptors and consequently nitric oxide synthase activation in the anti-contractile effect exerted by perivascular adipose tissue.

Histological characterization of umbilical cord in alpaca (Vicugna pacos).

The histomorphometric features of umbilical cord constituents in seven foetuses of alpaca (Vicugna pacos) from Cerro de Pasco, Department, Peru, were determined. Sections of 2-5 cm of umbilical cord were fixed in 10% neutral buffered formalin and processed for light microscopy. Standard histological slides stained with haematoxylin and eosin, Masson's trichrome and Van Gieson's trichrome were obtained. Histologically, common features of umbilical artery and vein were observed as well as mucous connective tissue, some cell features that compound this tissue constituted by cells presented features of myofibroblasts. Among most important findings that were observed, the lumen of umbilical vein was obliterated into star-shaped form with the thinner umbilical artery wall; the smooth muscles and fibroblast were comparatively more in number in umbilical artery than that of umbilical vein, and the tunica media was larger in dimension than the tunica adventitia in umbilical vein. Conclusively, this histological study features an observation of the umbilical cord of alpaca foetuses and shows the similarity between them and those of other mammal species, including dromedaries and South American camelids.

Enfermedad quística de la adventicia, arteria poplítea / Cystic disease of the adventitial layer of the popliteal artery

La enfermedad quística de la adventicia es una rara alteración de las arterias periféricas, caracterizada por la acumulación de contenido mucoso en la adventicia del vaso. Tiene predilección por la arteria poplítea, donde se localiza en cerca de 85 % de los casos. La mayoría de los afectados son hombres entre los 40 y los 50 años de edad, que presentan claudicación intermitente de inicio brusco y rápida progresión, sin evidencia de enfermedad ateroesclerótica. Se describe el caso un hombre de 57 años de edad en el que se diagnosticó esta entidad, con énfasis en las imágenes diagnósticas y el abordaje quirúrgico

Cystic adventitial disease is a rare vascular disorder of the peripheral arteries characterized by the collection of a mucinous substance inside the adventitia of the vessel. It has a predilection for the popliteal artery, being this localization about 85% of cases. Most of those affected are male between 40 to 50 years old, presenting with intermittent claudication of sudden onset and rapid progression without evidence of atherosclerotic disease. We describe the case of a 57 years old male who was diagnosed with this entity, with emphasis on the diagnostic imaging and surgical approach

Stromal-vascular fraction content and adipose stem cell behavior are altered in morbid obese and post bariatric surgery ex-obese women.

INTRODUCTION: Subcutaneous adipose tissue is an interesting source of autologous stem cells with a fundamental role in the pathophysiology of obesity, metabolic syndromes and insulin resistance. We hypothesize that obesity could alter the stromal-vascular fraction (SVF) and adipose stem cell (ASCs) functions, which could compromise its regenerative behavior. Furthermore, we aimed to evaluate whether ASCs derived from post bariatric surgery ex-obese women maintain their functions in a similar fashion as do those from individuals who have never been obese. METHODS: The SVF of subcutaneous adipose tissue from control (n = 6, body mass index - BMI - 27.5 ± 0.5 kg/m(2)), obese (n = 12, BMI 46.2 ± 5.1 kg/m(2)) and post bariatric surgery ex-obese (n = 7, initial BMI 47.8 ± 1.3 kg/m(2); final BMI 28.1 ± 1.1 kg/m(2)) women were isolated and evaluated by flow cytometry. ASCs were tested for lipid accumulation by perilipin, adipose differentiation-related protein (ADRP) and Oil Red O staining after adipogenic stimulus. The cytokines secreted by the ASCs and after lipid accumulation induction were also evaluated. RESULTS: The subcutaneous adipose tissue of obese and post bariatric surgery ex-obese women was enriched in pericytes (p = 0.0345). The number of supra-adventitial cells was not altered in the obese patients, but it was highly enriched in the post bariatric surgery ex-obese women (p = 0.0099). The ASCs of the post bariatric surgery ex-obese patients secreted more MCP-1 (monocyte chemoattractant protein-1; p = 0.0078). After lipid accumulation induction, the ASCs of the patients in all groups secreted less IL-6 than the ASCs with no adipogenic stimulus (p < 0.0001). Obese ASCs with lipid accumulation secreted the highest amount of IL-6 (p < 0.001) whereas the ASCs from the controls secreted the highest amount of adiponectin (p < 0.0001). The ASCs from the post bariatric surgery ex-obese patients showed the highest levels of lipid accumulation whereas those from the obese women had the lowest levels (p < 0.0001). CONCLUSIONS: SVF content and ASC behavior are altered in the subcutaneous adipose tissue of morbid obese women; these changes are not completely restored after bariatric surgery-induced weight loss. The cellular alterations described in this study could affect the regenerative effects of adipose stem cells. Further investigations are required to avoid jeopardizing the development of autologous stem cell-based therapies.

Adventitial alterations are the main features in pulmonary artery remodeling due to long-term chronic intermittent hypobaric hypoxia in rats.

Long-term chronic intermittent exposure to altitude hypoxia is a labor phenomenon requiring further research. Using a rat model, we examined whether this type of exposure differed from chronic exposure in terms of pulmonary artery remodeling and other features. Rats were subjected to chronic hypoxia (CH, n = 9) and long-term intermittent hypoxia (CIH2x2; 2 days of hypoxia/2 days of normoxia, n = 10) in a chamber (428 Torr, 4,600 m of altitude) for 46 days and compared to rats under normoxia (NX, n = 10). Body weight, hematocrit, and right ventricle ratio were measured. Pulmonary artery remodeling was assessed using confocal microscopy of tissues stained with a nuclear dye (DAPI) and CD11b antibody. Both hypoxic conditions exhibited increased hematocrit and hypertrophy of the right ventricle, tunica adventitia, and tunica media, with no changes in lumen size. The medial hypertrophy area (larger in CH) depicted a significant increase in smooth muscle cell number. Additionally, CIH2x2 increased the adventitial hypertrophy area, with an increased cellularity and a larger prevalence of clustered inflammatory cells. In conclusion, CIH2x2 elicits milder effects on pulmonary artery medial layer muscularization and subsequent right ventricular hypertrophy than CH. However, CIH2x2 induces greater and characteristic alterations of the adventitial layer.

Doença cística adventicial da artéria poplítea: causa infrequente de claudicação intermitente / Cystic adventitial disease of the popliteal artery: an infrequent cause of intermittent claudication

A claudicação intermitente está frequentemente associada à doença aterosclerótica, mas diagnósticos diferenciais devem ser pesquisados em pacientes sem fatores de risco tradicionais. A doença cística adventicial, de etiologia incerta, acomete em maior proporção a artéria poplítea e, eventualmente, apresenta-se como claudicação intermitente. Apresentamos um caso da doença e seu manejo cirúrgico, e discutimos a etiopatogenia, os aspectos diagnósticos e terapêuticos da enfermidade.

Intermittent claudication is frequently associated with atherosclerotic disease, but differential diagnosis must be sought in patients with no traditional risk factors. Cystic adventitial disease, of unknown etiology, most frequently affects the popliteal artery, and occasionally presents as intermittent claudication. We report a case of this disease and the surgical treatment, and discuss some aspects related to etiopathogenesis, diagnosis and treatment of this condition.

In vitro propagation of Vriesea reitzii, a native epiphyte bromeliad from the Atlantic rainforest / Propagação in vitro de Vriesea reitzii, uma bromélia epífita nativa da Mata Atlântica

The induction of nodular culture (NC) and the subsequent development of microshoots of V. reitzii are considered an in vitro propagation model-system with high regenerative performance. Current research analyzed the determinant factors of the in vitro morphogenesis control of bromeliads. Seeds excised from mature capsules were grown on medium MS basic (MSB), liquid or gelled, supplemented or not with -naphthaleneacetic acid (NAA), 6-benzilaminopurine (BAP) or thidiazuron (TDZ). The regeneration and elongation of microshoots were evaluated from NC sub-cultivated on MSB medium on liquid culture medium supplemented with different concentrations of indolyl-3-acetic acid (IAA) and gibberellic acid (GA3). Plant growth regulators (PGR) supplemented into the medium MSB inhibited the germination of the seeds and induced NC in the second week of growth. The induced NC on MSB medium with NAA (4 µM) and sub-cultivated on MSB medium with NAA (2 µM) plus N6(2-isopentenyl) adenine (2-iP) (2 µM) showed granular texture and high rate of proliferation. NC sub-culture in MSB medium with IAA (4 µM) provided a higher average number of microshoots (1,478 shoots g-1 of NC). Shoots over 3.0 cm resulted in more than 95% ex vitro survival.(AU)

A indução de culturas nodulares (CNs) e subsequente desenvolvimento de microbrotos de V. reitzii configuraram-se em um sistema de alta performance regenerativa in vitro. No presente trabalho foram estudados os fatores determinantes do controle da morfogênese in vitro das CNs. Sementes excisadas de cápsulas maduras foram cultivadas em meio básico MS (MSB) líquido ou geleificado e suplementado ou não com ácido naftalenoacético (ANA), 6-benzilaminopurina (BAP) ou thidiazuron (TDZ). A partir das CNs subcultivadas em meio MSB, foi avaliada a regeneração e o alongamento de microbrotos em meio de cultura líquido suplementado com diferentes concentrações de ácido indolil-3-acético (AIA) combinados com ácido giberélico (AG3). A suplementação de fitorreguladores ao meio MSB inibiram a germinação das sementes e promoveram a indução de CNs na segunda semana de cultivo. As CNs induzidas em meio MSB suplementado com ANA (4 M) e subcultivadas em meio MSB suplementado com ANA (2 M) mais N6 (2-isopentenil) adenina (2-iP) (2 M) apresentaram textura granular e alta taxa de proliferação. O cultivo destas CNs em meio MSB suplementado com AIA (4 M) resultou no maior número médio de microbrotos (1.478 brotos g-1 de CN). Brotos maiores de 3,0 cm resultaram em mais de 95% de sobrevivência em ambiente ex vitro.(AU)

Cystic adventitial disease of the popliteal artery: an infrequent cause of intermittent claudication.

Intermittent claudication is frequently associated with atherosclerotic disease, but differential diagnosis must be sought in patients with no traditional risk factors. Cystic adventitial disease, of unknown etiology, most frequently affects the popliteal artery, and occasionally presents as intermittent claudication. We report a case of this disease and the surgical treatment, and discuss some aspects related to etiopathogenesis, diagnosis and treatment of this condition.

Genetic epidemiology and genome-wide linkage analysis of carotid artery ultrasound traits in multigenerational African ancestry families.

OBJECTIVE: Intima-media thickness, adventitial diameter and lumen diameter are indicators of cardiovascular disease risk. The influence of genetic factors on these measures in African ancestry populations is not well defined. Therefore, we estimated heritability and performed genome-wide linkage analysis of carotid ultrasound traits in 7 multigenerational families of African ancestry. METHODS: A total of 395 individuals (7 pedigrees; mean family size = 56; 2392 relative pairs) aged ≥18 years had a common carotid artery ultrasound scan. Statistical analyses were conducted using pedigree-based maximum likelihood methods. RESULTS: Significant covariates included age, sex, body mass index or height and waist, and systolic blood pressure. Residual heritabilities ranged from 0.35 ± 0.10 to 0.64 ± 0.12 (P < 0.0001). We identified a novel quantitative trait locus for adventitial and lumen diameters on chromosome 11 (max LOD = 4.09, 133 cm). CONCLUSION: Further fine mapping of this region may identify specific mutations predisposing to subclinical vascular disease among African ancestry individuals.

Correlation of bacterial coinfection versus matrix metalloproteinase 9 and tissue inhibitor of metalloproteinase 1 expression in aortic aneurysm and atherosclerosis.

BACKGROUND: We searched for any relationship between Chlamydophila pneumoniae, Mycoplasma pneumoniae, matrix metalloproteinase 9 (MMP-9), and tissue inhibitor of metalloproteinase 1 (TIMP-1) in aneurysmatic atherosclerotic lesions, and whether this relationship differed from that in atherosclerotic nonaneurysmatic lesions. METHODS: Twenty-eight tissue samples paired by age and sex were grouped as follows: group 1 included 14 nonaneurysmal atherosclerotic fragments obtained from abdominal aortas collected from necropsies; group 2 included 14 aneurysmatic atherosclerotic aortic fragments obtained from patients during corrective surgery. Immunohistochemistry reactions were evaluated for C pneumoniae, M pneumoniae, MMP-9, and TIMP-1 antigens. Both groups were compared using the Mann-Whitney test, and the correlations among variables were obtained using the Spearman correlation test. P ≤ 0.05 was considered statistically significant. RESULTS: C pneumoniae and M pneumoniae antigens were detected in 100% of cases. A higher amount of C pneumoniae (P = 0.005), M pneumoniae (P = 0.002), and MMP-9 (P = 0.021) was found in adventitia of group 2 with aneurysm. A positive correlation was found in the aneurysm group, as follows: intima C pneumoniae versus adventitia thickness (r = 0.70; P = 0.01), media C pneumoniae versus adventitia C pneumoniae (r = 0.75; P = 0.002), intima C pneumoniae versus media C pneumoniae (r = 0.8; P = 0.00), and adventitia C pneumoniae versus intima M pneumoniae (r = 0.54; P = 0.05); negative correlations were as follows: adventitia thickness and adventitia M pneumoniae (r = -0.65; P = 0.01), media MMP-9 and media thickness (r = -0.55; P = 0.04), TIMP-1 media versus adventitia C pneumoniae (r = -0.86; P = 0.00), and TIMP-1 media versus M pneumoniae intima (r = -0.67; P = 0.03). Nonaneurysmal atherosclerotic group 1 results are as follows: adventitia C pneumoniae versus TIMP-1 media (r = 0.75; P = 0.01) and media C pneumoniae and adventitia C pneumoniae (r = 0.59; P = 0.03). CONCLUSIONS: The present work favors a role for coinfection of both M pneumoniae and C pneumoniae in the development of aortic atherosclerotic aneurysm, with increased adventitial inflammation, inhibition of TIMP-1 activity, and increased collagen degradation.

The adventitia layer modulates the arterial wall elastic response to intra-aortic counterpulsation: in vivo studies.

There is a relationship between the intra-aortic balloon pumping (IABP) benefits and the dynamic behavior of muscular arteries, which is associated with induced changes on the vessel walls through an endothelial-dependent mechanism. The arterial wall elastic behavior is influenced by adventitial function; however, no studies were performed in order to elucidate if this layer plays a role in the changes determined by IABP. Our aim was to quantify acute IABP effects on the mechanical properties of muscular arteries in induced acute heart failure (AHF), before and after adventitia removal. Pressure and diameter were recorded in the iliac arteries (IA) of sheep (n = 7), before and during 1:2 IABP: (i) in control state (CS) with intact IA, (ii) in CS after IA adventitia removal, and (iii) in de-adventitialized IA after AHF. Conduit function, compliance and arterial distensibility were calculated in each state. During CS, IABP resulted in intact IA dilatation and in an increase in conduit function, compliance and distensibility; adventitial removal determined an increase of arterial stiffness with respect to the CS, which decreased when IABP was used; the increase in arterial stiffness observed after adventitia removal was also detected in AHF state; IABP improves conduit function and arterial stiffness in de-adventitialized arteries, both before and during AHF. However, the improvement in these properties was lower than in intact arteries. Before and after AHF induction, the improvements of conduit function and arterial distensibility determined by IABP in intact IA were significantly reduced after adventitia removal. Adventitial layer integrity would be necessary to maximize IABP-related beneficial effects on arterial system properties.

Estrutura, ultraestrutura e morfometria da veia cava de paca (Cuniculus paca Linnaeus, 1766) criada em cativeiro / Structure, ultrastructure and morphometry of the Vena cava in the paca (Cuniculus paca Linnaeus, 1766) raised in captivity

A paca (Cuniculus paca) é o segundo maior roedor da fauna brasileira. Apresenta carne de excelente qualidade, o que incentiva a criação comercial. Além disso, este animal pode tornar-se uma opção válida em experimentação embora poucas sejam as informações detalhadas sobre sua morfologia. Assim, objetivou-se descrever a morfologia, morfometria e ultraestrutura de segmentos das porções cranial e caudal da veia cava de quatro pacas (Cuniculus paca) adultas excedentes do plantel do Setor de Animais Silvestres do Departamento de Zootecnia da FCAV-Unesp. Os segmentos venosos foram analisados à microscopia de luz e à microscopia eletrônica de varredura. Foram mensuradas as espessuras do complexo formado pelas túnicas íntima e média, além da túnica adventícia e analisou-se os resultados pela estatística descritiva, teste "T" pareado (p<0,05). Em relação à espessura das túnicas estudadas, comprovou-se que os valores da espessura das túnicas íntima, média e adventícia, para todos os animais, foram significativamente maiores no segmento cranial. As camadas das paredes dos vasos apresentaram variações entre si quanto à estrutura e espessura, supostamente devido a uma adaptação à exigência funcional.(AU)

The paca (Cuniculus paca) is the second largest rodent of the Brazilian fauna. The excellent meat quality of this specie encourages the development of their commercial production. Moreover, this animal can become a viable alternative for animal experimentation although there exists scarce detailed information concerning their morphology. Therefore the purpose of this study is to describe the morphology, morphometry and ultrastructure in segments of the cranial and caudal portions of vena cava in four adult males and females of Cuniculus paca from the squad of Wild Animals Sector of Animal Science Department of FCAV-Unesp. Parts of the segments were examined by light microscopy and part by scanning electron microscopy. Thickness measures of the tunica intima and media complex and tunica adventitia of the vena cava were taken and analyzed using "T" test (p<0.05). In vena cava the thickness values of the intima, media and adventitia, for all animals, were significantly higher in the cranial segment. The layers of the vessel walls showed variations in structure and thickness, presumably due to an adaptation to functional demand.(AU)