Volume calculation of rats' organs and its application in the validation of the volume relation between the abdominal cavity and the hernial sac in incisional hernias with "loss of abdominal domain"

Impact of passive smoking on renal vascular morphology

Objective

To determine whether passive smoking causes morphological and structural changes in the arcuate arteries of rats exposed for 7 to 28 days.

Methods

Wistar rats aged eight weeks and weighing 260g on average were allocated to a Control or a Smoker Group. Groups were further divided into 4 groups containing 5 animals each. Morphological-functional analysis of the right kidneys was carried out after 7 and 28 days of exposure to the smoke of 40 cigarettes per day. Cigarettes were burned at set times using automated cigarette-burning equipment (“Smoking Machine” - SM-MC-01). At the end of each exposure period, the kidneys were dissected and submitted to histological processing for morphological and quantitative analysis.

Results

Exposure to cigarette smoke for 7 days led to a decrease in inner vascular diameter. Decreased thickness of the vascular tunica media was observed after exposure for 28 days. Increased thickness of the tunica adventitia, increased total vascular wall thickness, increased total vascular diameter and qualitative increase in collagen deposition were observed. Vascular volume increased after 28 days of exposure.

Conclusion

Passive smoking has a negative impact on renal vasculature.

A simplified method to evaluate the loss of domain

PURPOSE

The treatment of giant incisional hernia (IH) with loss of domain (LOD, IHLD) is considerably challenging due to technical difficulties and subsequent post-operative complications. These post-operative risks may be anticipated by calculating the abdominal cavity (AC) volume (ACV) and the IH volume (IHV) on the preoperative CT-scans, using the AC and IH dimensions (Tanaka's method) or using tridimensional volumetry (Sabbagh's method). These techniques are often time-consuming and require specific softwares. The aim of the present study was to develop a simple method to rapidly obtain the LOD-ratio on the preoperative CT-Scan.

METHODS

The CT-scans (n = 89) of patients with IHLD were retrospectively studied. Several ratios were calculated using different parameters of the AC and the IH, including width, height and depth, the areas (axial and sagittal ellipse, as well as freehand sagittal surface areas) and these were compared with the reference methods of Sabbagh et al. and Tanaka et al. RESULTS: The LOD ratios calculated from the two reference methods gave similar results (ICC = 0.82, p < 0.0001). The new "R-ratios" (Reims-ratios) obtained from the IH and AC surface areas measured using the "freehand ROI" tool on sagittal view or roughly evaluated by an ellipse on axial view showed excellent correlation with both reference ratios (all ICC ≥ 0.71, p < 0.0001).

CONCLUSION

The LOD ratio may be quickly obtained by drawing two circles on the pre-operative CT scan ("R ratios") and available on the webpage https://romeo.univ-reims.fr/Rratio/ . This will certainly help surgeons to routinely anticipate the post-operative complications before IHLD repair.

Morphofunctional study on the effects of passive smoking in kidneys of rats

Objective

To analyze whether passive inhalation of cigarette smoke causes morphological, structural, and functional changes in kidneys of rats.

Methods

Wistar rats, aged eight weeks, weighing on average 260g, were divided into Control Group and Smoking Group. Each group was subdivided into four groups of ten animals for morphofunctional analysis, in a period of seven and 28 days. The Smoking Group was exposed to smoke of 40 cigarettes per day, at certain times and in automated equipment for cigarette burning, called smoking machine (SM-MC-01). After the exposure period, urine and blood samples were collected for the functional analyses, and the kidneys were dissected and submitted to histological procedures for morphoquantitative analyses.

Results

After exposure of animals of the Smoking Group, the following were observed: lower weight gain; lower water and feed intake; decreased renal weight, diameter, and volume; reduction in cortical thickness and glomerular volume density; decrease in glomerular and capsular diameter; increase in mesangial density; decreased urine volume; increased levels of glucose, serum creatinine and microalbuminuria; decreased urinary creatinine levels and creatinine clearance rate.

Conclusion

Passive smoking negatively influences renal morphology and glomerular filtration rate, with effects similar to those described in the literature regarding active smoking.

Modulation of stress and immune response by Amblyomin-X results in tumor cell death in a horse melanoma model

We have investigated Amblyomin-X-treated horse melanomas to better understand its mode of action through transcriptome analysis and the in vivo model. Amblyomin-X is a Kunitz-type homologous protein that selectively leads to the death of tumor cells via ER stress and apoptosis, currently under investigation as a new drug candidate for cancer treatment. Melanomas are immunogenic tumors, and a better understanding of the immune responses is warranted. Equine melanomas are spontaneous and not so aggressive as human melanomas are, as this study shows that the in vivo treatment of encapsulated horse melanoma tumors led to a significant reduction in the tumor size or even the complete disappearance of the tumor mass through intratumoral injections of Amblyomin-X. Transcriptome analysis identified ER- and mitochondria-stress, modulation of the innate immune system, apoptosis, and possibly immunogenic cell death activation. Interactome analysis showed that Amblyomin-X potentially interacts with key elements found in transcriptomics. Taken together, Amblyomin-X modulated the tumor immune microenvironment in different ways, at least contributing to induce tumor cell death.

STEM CELLS HEMATOPOIETIC NICHES AND INFLAMMATORY RESPONSE TO DIFFERENT SYNTHETIC PROSTHESIS IMPLANTED IN RAT WITH INCISIONAL HERNIAS

Background:

Extramedullary hematopoiesis depends on complex pathophysiological mechanisms linked to hematopoietic stem cells and the proteins considered mediators of the inflammation. The identification of hematopoietic cells outside bone marrow in the adult is an occurrence that can occasionally follows the inflammatory response, was considered a secondary occurrence, but current biomolecular studies have changed that concept.

Aim:

Describe the presence of clusters of precursor cells of platelets (megakaryocytes), and cells of the inflammatory response in the abdominal wall and spleen of rats with experimentally induced incisional hernias and repaired with different synthetic prostheses.

Methods:

Twenty-five rats with incisional hernias previously performed, were divided into groups of five animals each: Group 1, repair of the hernia defect without prosthetic implant; Group 2, repair with polypropylene prosthesis; Group 3, repair using polypropylene with low weight; Group 4, the use of polypropylene and polyglecaprone prosthesis; Group 5, of polypropylene and polyglactin prosthesis. All prostheses were cut in rhombus format with area 2,625 cm². The animals were reoperated after 10 days, the abdominal walls were removed with the viscera attached to them and the material was processed for histological study.

Results:

Megakaryocyte niches in the abdominal wall and spleen, occasionally removed together with the adhesions produced in animals with implantation of prostheses and significant inflammatory reaction.

Conclusion:

The intense inflammatory reaction due to the prostheses with polypropylene in their composition was disproportionate to the expected response, indicating that further studies should be accomplished including immunophenotyping evaluation and specific panels of monoclonal antibodies to better understand the findings.

A survey of Angiostrongylus species in definitive hosts in Queensland

Despite the recent sporadic reports of angiostrongyliasis in humans, dogs and wildlife in eastern Australia there has been no systematic study to explore the epidemiology of Angiostrongylus spp. in definitive and intermediate hosts in the region. Little is known about the epidemiology of Angiostrongylus species in the definitive host in southeast Queensland, since the only survey conducted in this region was performed in the late 1960s. In this study, free-living populations of Rattus spp. were sampled and examined for the presence of adult and larval Angiostrongylus in the lungs, and of larvae in faeces. The prevalence of infection with Angiostrongylus spp. was 16.5% in Rattus spp. trapped in urban Brisbane and surrounds. This prevalence is much higher than estimates of earlier studies. This highlights the possible risk of zoonotic infection in children, dogs and wildlife in this region and indicates the necessity for public awareness as well as more detailed epidemiological studies on this parasite in eastern Australia.

Critical analysis of experimental model for study of adhesions after incisional hernias induced in rats' and repair of abdominal wall with different biomaterials

BACKGROUND

Adhesions induced by biomaterials experimentally implanted in the abdominal cavity are basically studied by primary repair of different abdominal wall defects or by the correction of incisional hernias previously performed with no precise definition of the most appropriate model.

AIM

To describe the adhesions which occur after the development of incisional hernias, before the prosthesis implantation, in an experimental model to study the changes induced by different meshes.

METHODS

Incisional hernias were performed in 10 rats with hernia orifices of standardized dimensions, obtained by the median incision of the abdominal wall and eversion of the defect edges. Ten days after the procedure adhesions of abdominal structures were found when hernias were repaired with different meshes.

RESULTS

The results showed hernia sac well defined in all rats ten days after the initial procedure. Adhesions of the greater omentum occurred in five animals of which two also showed adhesions of small bowel loops besides the omentum, and another two showed liver adhesions as well as the greater omentum, numbers with statistical significance by Student's t test (p<0.05).

CONCLUSION

Although it reproduces the real clinical situation, the choice of experimental model of incisional hernia repair previously induced implies important adhesions, with possible repercussions in the evaluation of the second operation, when different implants of synthetic materials are used.