A rat model of acute kidney injury through systemic hypoperfusion evaluated by micro-US, color and PW-Doppler.

AIM: To create an animal model of acute renal ischemia induced by systemic hypoperfusion, controllable and reproducible to study, in real time, hemorrhagic shock changes with micro-imaging. ANIMALS AND METHODS: Hemorrhagic shock was induced in rats activating a syringe pump setup to remove 1 mL/min of blood, through the femoral artery catheter. The withdrawal was continued until the mean arterial pressure (MAP) dropped to 25-30 mmHg. For the next 60 min, the MAP was maintained at a constant pressure value, by automatic pump infusion and withdrawal. Micro-ultrasound imaging was performed using the Vevo 2100 system with the MS250 transducer (13-24 MHz). Renal size, morphology and echogenicity were evaluated in B-mode. Renal blood flow was evaluated using color and PW-Doppler. RESULTS: After 1 h of ischemia, B-mode images documented slight changes in kidney echogenicity. Color and PW-Doppler analysis showed a reduction in renal blood flow in kidneys during the hypoperfusion with a progressive and significant change from baseline values of resistive index (RI). At the histological evaluation, 60 min of hypoperfusion resulted in ischemic changes in the kidneys. CONCLUSIONS: The results of this experimental study encourage the use of the described model to study acute renal ischemia trough severe hypoperfusion. The histological data confirmed that the model was able to produce injury in renal parenchyma. It can be used to assess acute ischemic damage not only in the kidney but also in other organs by using all available dedicated small animals imaging techniques.

Time- and segment-related changes of postresected intestine: a 4-dimensional model of intestinal adaptation.

OBJECTIVES: The aim of the present study was to investigate the segment- and time-related changes in rat short bowel syndrome and construct a 4-dimensional (4D) geometrical model of intestinal adaptation. METHODS: Sprague-Dawley rats were divided into 3 groups: 2-day, 7-day, and 15-day postresection groups in which 75% of the jejunoileum was removed. Histological and morphometrical parameters in the remaining proximal to distal intestinal segments, from the jejunum to the distal colon, were comparatively evaluated in the groups. The data were used to construct a 4D geometric model in which villi were considered as cylinders, and their surface area was expressed as cylinder lateral area. RESULTS: Major adaptive changes were observed in the ileum consisting of an increase in both the diameter of base and the height of villi. A parallel reduction in their number/mm was observed. The resulting ileal architecture was characterized by a limited number of large villi. An opposite pattern was observed in the jejunum whose postresection structure consisted of an increased number of villi. No changes were observed in the colon. Postresection restructuring was early and faster in the ileum than in the jejunum resulting in an increase in absorptive area of 81.5% and 22.5% in the ileum and jejunum, respectively. CONCLUSIONS: Postresection adaptation is intestinal segment-specific because all of the major changes occur in the ileum rather than in the jejunum. Sparing ileal segments during resection may improve the outcome of patients undergoing extensive intestinal resection. Our 4D model can be used to test interventions aimed at optimizing postresection intestinal adaptation.

The Safety Profile of COVID-19 Vaccines in Patients Diagnosed with Multiple Sclerosis: A Retrospective Observational Study.

In the current COVID-19 pandemic, patients diagnosed with multiple sclerosis (MS) are considered to be one of the highest priority categories, being recognized as extremely vulnerable people. For this reason, mRNA-based COVID-19 vaccines are strongly recommended for these patients. Despite encouraging results on the efficacy and safety profile of mRNA-based COVID-19 vaccines, to date, in frail populations, including patients diagnosed with MS, this information is rather limited. We carried out a retrospective observational study with the aim to evaluate the safety profile of mRNA-based COVID-19 vaccines by retrieving real-life data of MS patients who were treated and vaccinated at the Multiple Sclerosis Center of the Hospital A.O.R.N. A. Cardarelli. Three-hundred and ten medical records of MS patients who received the first dose of the mRNA-based COVID-19 vaccine were retrieved (63% female; mean age: 45.9 years). Of these patients, 288 also received the second dose. All patients received the Pfizer-BioNTech vaccine. Relapsing-Remitting Multiple Sclerosis (RRSM) was the most common form of MS. The Expanded Disability Status Scale (EDSS) values were <3.0 in 70% of patients. The majority of patients received a Disease Modifying Therapy (DMT) during the study period, mainly interferon beta 1-a, dimethyl fumarate, and natalizumab and fingolimod. Overall, 913 AEFIs were identified, of which 539 were after the first dose of the vaccine and 374 after the second dose. The majority of these AEFIs were classified as short-term since they occurred within the first 72 h. The most common identified adverse events were pain at injection site, flu-like symptoms, and headache. Fever was reported more frequently after the second dose than after the first dose. SARS-CoV-2 infection occurred in 3 patients after the first dose. Using historical data of previous years (2017−2020), the relapses' rate during 2021 was found to be lower. Lastly, the results of the multivariable analysis that assessed factors associated with the occurrence of AEFIs revealed a statistical significance for age, sex, and therapy with ocrelizumab (p < 0.05). In conclusion, our results indicated that Pfizer-BioNTech vaccine was safe for MS patients, being associated with AEFIs already detected in the general population. Larger observational studies with longer follow-up and epidemiological studies are strongly needed.

A longitudinal study on BIO14.6 hamsters with dilated cardiomyopathy: micro-echocardiographic evaluation.

BACKGROUND: In recent years, several new technologies for small-animal imaging have been developed. In particular, the use of ultrasound in animal imaging has focused on the investigation of accessible biological structures such as the heart, of which it provides a morphological and functional assessment. The purpose of this study was to investigate the role of micro-ultrasonography (µ-US) in a longitudinal study on BIO14.6 cardiomyopathic hamsters treated with gene therapy. METHODS: Thirty hamsters were divided into three groups (n = 10): Group I, untreated BIO 14.6 hamsters; Group II, BIO 14.6 hamsters treated with gene therapy; Group III, untreated wild type (WT) hamsters. All hamsters underwent serial µ-US sessions and were sacrificed at predetermined time points. RESULTS: µ-US revealed: in Group I, progressive dilation of the left ventricle with a change in heart morphology from an elliptical to a more spherical shape, altered configuration of the mitral valve and subvalvular apparatus, and severe reduction in ejection fraction; in Group II, mild decrease in contractile function and ejection fraction; in Group III, normal cardiac chamber morphology and function. There was a negative correlation between the percentage of fibrosis observed at histology and the ejection fraction obtained on µ-echocardiography (Spearman r: -0.839; p < 0.001). CONCLUSIONS: Although histological examination remains indispensable for a conclusive diagnosis, high-frequency µ-echocardiography, thanks to the high spatial and contrast resolution, can be considered sufficient for monitoring therapeutic efficacy and/or the progression of dilated cardiomyopathy, providing an alternative tool for repeatable and noninvasive evaluation.

Long-term absence of porcine endogenous retrovirus infection in chronically immunosuppressed patients after treatment with the porcine cell-based Academic Medical Center bioartificial liver.

BACKGROUND: Clinical use of porcine cell-based bioartificial liver (BAL) support in acute liver failure as bridging therapy for liver transplantation exposes the patient to the risk of transmission of porcine endogenous retroviruses (PERVs) to human. This risk may be enhanced when patients receive liver transplant and are subsequently immunosuppressed. As further follow-up of previously reported patients (Di Nicuolo et al. 2005), an assessment of PERV infection was made in the same patient population pharmacologically immunosuppressed for several years after BAL treatment and in healthcare workers (HCWs) involved in the clinical trial at that time. METHODS: Plasma and peripheral blood mononuclear cells (PBMCs) from eight patients treated with the Academic Medical Center-BAL (AMC-BAL), who survived to transplant, and 13 HCWs, who were involved in the trial, were assessed to detect PERV infection. A novel quantitative real-time polymerase chain reaction assay has been used. RESULTS: Eight patients who received a liver transplant after AMC-BAL treatment are still alive under long-term pharmacological immunosuppression. The current clinical follow-up ranges from 5.6 to 8.7 yr after BAL treatment. A new q-real-time PCR assay has been developed and validated to detect PERV infection. The limit of quantification of PERV DNA was ≥ 5 copies per 1 × 10(5) PBMCs. The linear dynamic range was from 5 × 10(0) to 5 × 10(6) copies. In both patients and HCWs, neither PERV DNA in PBMCs nor PERV RNA in plasma and PBMC samples have been found. CONCLUSION: Up to 8.7 yr after exposure to treatment with porcine liver cell-based BAL, no PERV infection has been found in long-term immunosuppressed patients and in HCWs by a new highly sensitive and specific q-real-time PCR assay.

Laparoscopic Injection of Tissue Adhesives for Inguinal Hernia Repair in a Rabbit Model: Results of an Experimental Comparative Study with the Standard Laparoscopic Inguinal Hernia Repair.

Background: The injection of tissue adhesives has been proposed as an alternative to standard laparoscopic inguinal hernia repair but no evidence is available in the pediatric population. This study aimed to evaluate safety, efficacy, and feasibility of injection of tissue adhesives for inguinal hernia repair in a rabbit model. Materials and Methods: Thirty-six New Zealand White male rabbits underwent laparoscopic inguinal hernia repair. In each animal, the hernia defect was repaired using glue on the right side and purse-string suture on the left side. The animals were divided in 3 groups, each 1 of 12 animals, according to the glue used: Glubran 2® (cyanoacrylate), Histoacryl® (cyanoacrylate), and BioGlue® (bovine serum albumin-based). For each group, 6 animals were sacrificed at 7 days postoperatively, and 6 animals at 90 days postoperatively. Histopathological exam of testis and spermatic bundle was performed. Results: The hernia defect was successfully closed on both sides in all cases. The injection of glue was faster than suture repair (P = .001). Postoperative complications (epiploon-parietal adhesions, spermatic vessel ectasia, and hydrocele) rate was significantly higher on the right side compared to the left side at both short- and long-term follow-up (P = .001). Furthermore, a lower maturity of testicles treated by adhesive compared with suture was histologically demonstrated at both short- and long-term follow-up (P = .001). Conclusions: The present experimental study confirmed the feasibility and efficacy of inguinal hernia repair by injection of tissue adhesive. However, several critical issues emerged about the safety of this technique. The use of glue was associated with higher incidence of postoperative complications and significant decrease of testicular maturity compared with standard suture repair. Based upon these preliminary results, repair using suture remains the standard of care for inguinal hernia in children. Further experimental studies are needed to assess the safety of injection of tissue adhesives for pediatric inguinal hernia repair.

International microsurgery simulation society (IMSS) consensus statement on the minimum standards for a basic microsurgery course, requirements for a microsurgical anastomosis global rating scale and minimum thresholds for training.

INTRODUCTION: Microsurgery is a surgical technique that uses optical magnification as well as specific instruments to address necessary reconstructive procedures in different medical specialties. The apprenticeship of this technique requires overcoming a steep learning curve. There is a need for standardization of the training criteria in microsurgery. The International Microsurgery Simulation Society (IMSS) was born in 2011, since then its main objective has been to connect the main international specialists and educators of this sub-specialty to share and discuss the ethical and scientific basis of preclinical microsurgery teaching. METHODS: In order to achieve a consensus on the minimum standards for the organization of basic microsurgery training courses, the requirements for a microsurgical anastomosis global rating scale and minimum thresholds for training, a total of nineteen independent global experts participated in a formal consultative consensus development program. The agreement criteria for each statement was established when consensus of 65-100% was reached. RESULTS: There have been established six recommendations concerning minimum standards for a basic microsurgery course, one recommendation in relation to minimum thresholds for training and four recommendations regarding the global rating scale as gold standard for a microsurgical anastomosis assessment. The eleven defined recommendations reached the agreement threshold of 65-100%. CONCLUSIONS: The development of this consensus sets the minimum recommended requirements for conducting basic microsurgery training courses, as well as suggestions for objective assessment of the learning curve and skills of trainees.

A sequence of flaps and dissection exercises in the living model to improve the learning curve for perforator flap surgery.

INTRODUCTION: The training to learn how to perform perforator flaps requires practice on a living model to optimize dissection and to evaluate outcome. The purpose of this study was to describe a training model that optimizes the use of animals in order to perform the maximum number of exercises per animal. MATERIAL AND METHODS: The sequence has been planned and practiced by the first and last author, recorded perfected and implemented in a two-day surgical course. The sequence was then evaluated by the trainers and the trainees by means of a questionnaire. RESULTS: All students were able to complete the sequence of exercises before the end of the second day except two (8/10) who could not complete one exercise each. The students considered the Deep Superior Epigastric Artery Perforator flap the most difficult to perform, being the most technically demanding. The sequence of exercises was judged either easily reproducible or reproducible by all the students. Two students suggested to postpone the DSEAP flap to the second day, after some training, to optimize the experience with the most challenging and rewarding flap. CONCLUSIONS: The training sequence proposed offers a wide range of exercises and allows four trainees, divided in two teams, to work and learn on the same animal. They can perform a wide range of flaps and also harvest the internal mammary vessels. The living model allows for evaluation of the quality of the surgical performance, judged by the difficulties and complications encountered during dissection, and finally through the feedback of flap perfusion.

Training Models in Pediatric Minimally Invasive Surgery: Rabbit Model Versus Porcine Model: A Comparative Study.

AIM: The porcine model is the most widely used animal model for laparoscopic training. However, in pediatric surgery, an experimental setting with smaller animals could improve the training conditions. We compared the efficiency of a rabbit model versus the porcine model for training in pediatric minimally invasive surgery (MIS). MATERIALS AND METHODS: At the training center of Cardarelli Hospital in Naples, Italy, 10 young pediatric surgeons underwent training sessions on rabbit and porcine models under the supervision of five experienced tutors. The results of four laparoscopic techniques (inguinal hernia repair, varicocelectomy [basic procedures], nephrectomy, and fundoplication [advanced procedures]) were evaluated in regard to mean operative time, intraoperative complications, and surgical performances. Results were analyzed using Fisher's exact test and Student's t test. RESULTS: Practitioners were significantly more confident in the rabbit model compared with the pig model, especially for advanced procedures (P = .03). The overall surgical performance score (ranging from 0 [unacceptable] to 10 [excellent]) was significantly higher in the rabbit model compared with the pig model (8.1 versus 6.0; P = .01). The most significant scoring differences between the surgical performances of the trainees in the two models were reported in regard to dissection, suturing and knot-tying, tissue handling, and handling of instruments. In addition, the length of surgery for advanced procedures was statistically shorter in the rabbit model compared with the pig model (P = .01). We found that only the performances of those who started on the pig had a significantly higher improvement when transitioning to the rabbit compared with those who started on the rabbit (P = .01). Of the trainees, 90% preferred the rabbit model to the pig model. CONCLUSIONS: On the basis of our preliminary results, rabbits are preferred over pigs as the training model in pediatric MIS. In the rabbit model it is possible to perform more procedures and perform them more easily compared with the porcine model. The rabbit model provides a comfortable approach to technical training in basic and advanced laparoscopic procedures.

Induction of VX2 para-renal carcinoma in rabbits: generation of animal model for loco-regional treatments of solid tumors.

BACKGROUND: Animal models of para-renal cancer can provide useful information for the evaluation of tumor response to loco-regional therapy experiments in solid tumors. The aim of our study was to establish a rabbit para-renal cancer model using locally implanted VX2 tumors. METHODS: In order to generate a rabbit model of para-renal cancer, we established four hind limb donor rabbits by using frozen VX2 tumor samples. Following inoculation, rabbits were monitored for appetite and signs of pain. Viable tumors appeared as palpable nodules within 2 weeks of inoculation. Tumor growth was confirmed in all rabbits by high-resolution ultrasound analysis and histology. Once tumor growth was established, hind limb tumors extraction was used for tumor line propagation and para-renal tumor creation. Twenty-one rabbit models bearing para-renal cancer were established by implanting VX2 tumor into the para-renal capsula. Tumors developed into discreet 2-3 cm nodules within 1-3 weeks of implantation. Serial renal ultrasonography follow-up, starting 1 week after tumor implantation, was performed. Two weeks after tumor implantation, rabbits were euthanized and tumors and other organs were collected for histopathology. RESULTS: Tumor growth after VX2 tumor fragment implantation was confirmed in all rabbits by high-resolution ultrasound (US) imaging examinations of the para-renal regions and was measured with digital caliper. The para-renal injection of VX2 tumor fragments, achieved tumor growth in 100% of cases. All data were confirmed by histological analysis. CONCLUSIONS: We generated for the first time, a model of para-renal cancer by surgical tumor implantation of VX2 frozen tumor fragments into rabbit's para-renal region. This method minimizes the development of metastases and the use of non-necrotic tumors and will optimize the evaluation of tumor response to loco-regional therapy experiments.

Acute arterial mesenteric ischemia and reperfusion: macroscopic and MRI findings, preliminary report.

AIM: To explore the physiopathology and magnetic resonance imaging (MRI) findings in an animal model of acute arterial mesenteric ischemia (AAMI) with and without reperfusion. METHODS: In this study, 8 adult Sprague-Dawley rats underwent superior mesenteric artery (SMA) ligation and were then randomly divided in two groups of 4. In group I, the ischemia was maintained for 8 h. In group II, 1-h after SMA occlusion, the ligation was removed by cutting the thread fixed on the back of the animal, and reperfusion was monitored for 8 h. MRI was performed using a 7-T system. RESULTS: We found that, in the case of AAMI without reperfusion, spastic reflex ileus, hypotonic reflex ileus, free abdominal fluid and bowel wall thinning are present from the second hour, and bowel wall hyperintensity in T2-W sequences are present from the fourth hour. The reperfusion model shows the presence of early bowel wall hyperintensity in T2-W sequences after 1 h and bowel wall thickening from the second hour. CONCLUSION: Our study has shown that MRI can assess pathological changes that occur in the small bowel and distinguish between the presence and absence of reperfusion after induced acute arterial ischemia.

Biliverdin protects against liver ischemia reperfusion injury in swine.

Ischemia reperfusion injury (IRI) in organ transplantation remains a serious and unsolved problem. Organs that undergo significant damage during IRI, function less well immediately after reperfusion and tend to have more problems at later times when rejection can occur. Biliverdin has emerged as an agent that potently suppress IRI in rodent models. Since the use of biliverdin is being developed as a potential therapeutic modality for humans, we tested the efficacy for its effects on IRI of the liver in swine, an accepted and relevant pre-clinical animal model. Administration of biliverdin resulted in rapid appearance of bilirubin in the serum and significantly suppressed IRI-induced liver dysfunction as measured by multiple parameters including urea and ammonia clearance, neutrophil infiltration and tissue histopathology including hepatocyte cell death. Taken together, our findings, in a large animal model, provide strong support for the continued evaluation of biliverdin as a potential therapeutic in the clinical setting of transplantation of the liver and perhaps other organs.

Magnetic resonance imaging: a new tool for diagnosis of acute ischemic colitis?

AIM: To define the evolution of ischemic lesions with 7T magnetic resonance imaging (7T-MRI) in an animal model of acute colonic ischemia. METHODS: Adult Sprague-Dawley rats were divided into two groups. Group I underwent inferior mesenteric artery (IMA) ligation followed by macroscopic observations and histological analysis. In group II, 7T-MRI was performed before and after IMA ligation and followed by histological analysis. RESULTS: Morphological alterations started to develop 1 h after IMA ligation, when pale areas became evident in the splenic flexure mesentery and progressively worsened up to 8 h thereafter, when the mesentery was less pale, and the splenic flexure loop appeared very dark. The 7T-MRI results reflected these alterations, showing a hyperintense signal in both the intraperitoneal space and the colonic loop wall 1 h after IMA ligation; the latter progressively increased to demonstrate a reduction in the colonic loop lumen at 6 h. Eight hours after IMA ligation, MRI showed a persistent colonic mural hyperintensity associated with a reduction in peritoneal free fluid. The 7T-MRI findings were correlated with histological alterations, varying from an attenuated epithelium with glandular apex lesions at 1 h to coagulative necrosis and loss of the surface epithelium detected 8 h after IMA ligation. CONCLUSION: MRI may be used as a substitute for invasive procedures in diagnosing and grading acute ischemic colitis, allowing for the early identification of pathological findings.

Promotion of behavioural change in people with hypertension: an intervention study.

OBJECTIVE: To assess the efficacy of a comprehensive motivational approach in reducing blood pressure in Italian patients with hypertension. METHOD: Two hundred and ninety-two first visit patients with hypertension without diabetes and dyslipidemia and with BMI < 28 were enrolled. One hundred and forty-two were randomly assigned to a Control group (C) and 150 to an Intervention group (I). A ten-multiple-choice questionnaire was developed to evaluate the effect of the intervention on lifestyle modification. Patients were given the questionnaire, had their BP measured and drug therapy registered before educational intervention and 12 months later. Group I patients participated in the focus group and in the role play 2 and 4 months, respectively, after recruitment. Group C patients received the oral information. MAIN OUTCOME MEASURE: Blood pressure values and lifestyle modification. An intention to treat analysis was undertaken. Analysis was performed using SPSS version 15.0. RESULTS: Of the 150 group I patients, 58 participated in both focus group and role play, 30 participated only in focus group and the remaining 62 never participated. After 12 months, there was a significant reduction of BP for group I (P < 0.001) and a significant reduction only for systolic BP in group C (P = 0.01). Diastolic BP and systolic BP decreased more markedly in group I than in group C, with P < 0.001 for both. We found a significant improvement of lifestyle modification after 12 months of follow-up concerning some aspects in both groups. CONCLUSION: Our findings show that a motivational approach is a powerful tool for achieving better blood pressure control and is an essential skill for all healthcare professionals.

Electrolitholysis--from basic research to the formulation of a new therapeutic method.

OBJECTIVE: An electrochemical method, based on anodic oxidation and/or protolysis, has been developed with the aim of extending it to the dissolution of urinary stones. The method has been named electrolitholysis, or ELLYS. An ex vivo experimental trial has been performed to check the current intensity needed to obtain the dissolution of stones without lesions to tissues. A new therapeutic method has been conceived based on these preliminary findings. MATERIALS AND METHODS: An ex vivo experimental trial has been performed on twelve bladders surgically removed from pigs and placed in an experimental model resembling possible vital organs; the electrolytic dissolution of natural urinary stones was then performed in these bladders. RESULTS: The ex vivo trial showed that the method is safe and reliable if the current intensity is maintained at < or =30 mA. CONCLUSIONS: A new therapy based on a new concept has been conceived which can be delivered percutaneously through an electrified spiral stent implanted several days into renal cavities and connected with a power supplier (battery) attached to the patient's flank.

Scanning for mutations of the ryanodine receptor (RYR1) gene by denaturing HPLC: detection of three novel malignant hyperthermia alleles.

BACKGROUND: Malignant hyperthermia (MH) is a fatal autosomal dominant pharmacogenetic disorder characterized by skeletal muscle hypertonicity that causes a sudden increase in body temperature after exposure to common anesthetic agents. The disease is genetically heterogeneous, with mutations in the gene encoding the skeletal muscle ryanodine receptor (RYR1) at 19q13.1 accounting for up to 80% of the cases. To date, at least 42 RYR1 mutations have been described that cause MH and/or central core disease. Because the RYR1 gene is huge, containing 106 exons, molecular tests have focused on the regions that are more frequently mutated. Thus the causative defect has been identified in only a fraction of families as linked to chromosome 19q, whereas in others it remains undetected. METHODS: We used denaturing HPLC (DHPLC) to analyze the RYR1 gene. We set up conditions to scan the 27 exons to identify both known and unknown mutations in critical regions of the protein. For each exon, we analyzed members from 52 families with positive in vitro contracture test results, but without preliminary selection by linkage analysis. RESULTS: We identified seven different mutations in 11 MH families. Among them, three were novel MH alleles: Arg44Cys, Arg533Cys, and Val2117Leu. CONCLUSION: Because of its sensitivity and speed, DHPLC could be the method of choice for the detection of unknown mutations in the RYR1 gene.