Right ventricular rupture due to recurrent mediastinal infection with a closed chest.

Right ventricular (RV) rupture in cases of mediastinitis following cardiac surgery is a rare and dangerous complication. Bleeding from the right ventricle occurs mainly after sternal reopening, due to either iatrogenic manipulation (wire removal, lesions due to wiring maneuvers) or mechanical shearing forces, producing direct injury. We present a case of RV wall perforation due to infection in a recurrent postoperative mediastinitis with a closed chest. The current literature on treatment of postoperative mediastinitis is also reviewed.

Surgical treatment of hamstring injuries and disorders – the clinical spectrum from chronic tendinopathy to complete rupture

Hamstring muscle injuries and tendon disorders are common, especially in sports. They can be severe and difficult to treat, often resulting in impaired athletic performance and long rehabilitation times. Previous studies considering treatment of these problems are scarce. The current study was designed to investigate the effect of surgery on different types of hamstring muscle injuries and on proximal hamstring tendinopathy. In addition, we wanted to study the typical histopathological findings relating to proximal hamstring tendinopathy. In the study of complete (all three muscles torn) proximal hamstring avulsions (41 patients), our results showed that early operative treatment gives significantly better results than late surgery, and is therefore recommended. Despite this, considerable improvement of symptoms could also be achieved in chronic cases. In the study of partial (one or two muscles torn) proximal hamstring tears (47 patients), we observed that these injuries can cause significant functional deficit and impaired performance in athletes. The main finding was that after surgical repair most of the patients were able to return to their pre-injury level of sports. In the study of distal hamstring tears (18 patients), the results showed that surgical treatment had a good effect in the majority of these cases. In proximal hamstring tendinopathy, the main problem is pain which limits sports. In this study (90 patients), we found that after unsuccessful conservative treatment, surgery was a good treatment option resulting in full return to sports in most cases. In tendinopathic hamstring tendons, the morphological changes of tendinosis were largely identical to those previously described in other common (e.g. Achilles and patellar) tendinopathies. In chronic proximal hamstring avulsions, and also in reoperations, a large defect between distally retracted tendons and the ischial tuberosity may occasionally prevent anatomic reinsertion. We have described a reconstruction method using fascia lata autograft augmentation to be used in these most challenging repairs. This technique was utilized in the treatment of five patients, with encouraging results.

DWI and complex brain network analysis predicts vascular cognitive impairment in spontaneous hypertensive rats undergoing executive function tests

The identification of biomarkers of vascular cognitive impairment is urgent for its early diagnosis. The aim of this study was to detect and monitor changes in brain structure and connectivity, and to correlate them with the decline in executive function. We examined the feasibility of early diagnostic magnetic resonance imaging (MRI) to predict cognitive impairment before onset in an animal model of chronic hypertension: Spontaneously Hypertensive Rats. Cognitive performance was tested in an operant conditioning paradigm that evaluated learning, memory, and behavioral flexibility skills. Behavioral tests were coupled with longitudinal diffusion weighted imaging acquired with 126 diffusion gradient directions and 0.3 mm(3) isometric resolution at 10, 14, 18, 22, 26, and 40 weeks after birth. Diffusion weighted imaging was analyzed in two different ways, by regional characterization of diffusion tensor imaging (DTI) indices, and by assessing changes in structural brain network organization based on Q-Ball tractography. Already at the first evaluated times, DTI scalar maps revealed significant differences in many regions, suggesting loss of integrity in white and gray matter of spontaneously hypertensive rats when compared to normotensive control rats. In addition, graph theory analysis of the structural brain network demonstrated a significant decrease of hierarchical modularity, global and local efficacy, with predictive value as shown by regional three-fold cross validation study. Moreover, these decreases were significantly correlated with the behavioral performance deficits observed at subsequent time points, suggesting that the diffusion weighted imaging and connectivity studies can unravel neuroimaging alterations even overt signs of cognitive impairment become apparent.

Investigating the spontaneous formation of SDS micelle in aqueous solution using a coarse-grained force field

A 1µs Molecular Dynamic simulation was performed with a realistic model system of Sodium Dodecyl Sulfate (SDS) micelles in aqueous solution, comprising of 360 DS-, 360 Na+ and 90000 water particles. After 300 ns three different micellar shapes and sizes 41, 68 and 95 monomers, were observed. The process led to stabilization in the total number of SDS clusters and an increase in the micellar radius to 2.23 nm, in agreement with experimental results. An important conclusion, is be aware that simulations employed in one aggregate, should be considered as a constraint. Size and shape distribution must be analyzed.

Physicochemical properties of lecithin-based nanoemulsions obtained by spontaneous emulsification or high-pressure homogenization

Nanoemulsions composed of a medium-chain triglyceride oil core stabilized by rapeseed or sunflower lecithins were prepared by spontaneous emulsification and high-pressure homogenization. These nanoemulsions are compared with formulations stabilized by egg lecithin. Nanoemulsions obtained by high-pressure homogenization display larger droplet size (230 to 440 nm) compared with those obtained by spontaneous emulsification (190 to 310 nm). The zeta potentials of the emulsions were negative and below -25 mV. Zeta potential inversion occurred between pH 3.0 and 4.0. The results demonstrate the feasibility of preparing lipid emulsions comprising rapeseed or sunflower lecithins by spontaneous emulsification and high-pressure homogenization.

AVOIDING FIRST-YEAR UNIVERSITY CHEMISTRY TEXTBOOKS’ MISREPRESENTATIONS IN THE TEACHING OF SPONTANEOUS REACTIONS

This paper summarizes the misrepresentations related to Gibbs energy in general chemistry textbooks. These misrepresentations arise from a problem in the terminology textbooks use. Thus, after reviewing the proper definition of each of the terms analyzed, we present two problems to exemplify the correct treatment of the quantities involved, which may help in the discussion and clarification of the misleading conventions and assumptions reported in this study.

Perfuração espontânea de ducto hepático comum

Perforation of common bile duct (CBD) is usually associated with invasive procedures. Spontaneous perforation is rare, and more often described in neonates. We report a case of a spontaneous perforation of CBD in an adult with a family history of cholelithiasis, but with no calculus found during exploration of the biliary tree. The patient was successfully treated by cholecystectomy and T - tube drainage of the CBD.

Abdome agudo: ruptura espontânea de bexiga como um importante diagnóstico diferencial

A case of spontaneous perforation of the bladder in a diabetic female patient is reported. It is a rare clinical condition, that should be suspected in patients with a past history of radiotherapy to the pelvis, enterocystoplasty and those suspected of having a tumor in the bladder. A general surgeon should be aware of this possibility in the differential diagnosis of an acute abdomen.

Síndrome de Boerhaave: relato de caso

Spontaneous esophageal rupture carries high morbidity and mortality. The main prognostic factor is early diagnosis, before 12 hours, and appropriate treatment. This is a case report of a 41-years-old man with late esophageal rupture diagnosis treated successfully with transmediatinal esophagectomy and esophageal-gastric tube cervical anastomosis.

Obstetric outcomes in the second birth of women with a previous caesarean delivery: a retrospective cohort study from Peru

PURPOSE: To examine obstetric outcomes in the second birth of women who had undergone a previous cesarean delivery. METHODS: This was a large hospital-based retrospective cohort study. We included pregnant women who had a previous delivery (vaginal or cesarean) attending their second birth from 2001 to 2009. Main inclusion criteria were singleton pregnancies and delivery between a gestation of 24 and 41 weeks. Two cohorts were selected, being women with a previous cesarean delivery (n=7,215) and those with a vaginal one (n=23,720). Both groups were compared and logistic regression was performed to adjust for confounding variables. The obstetric outcomes included uterine rupture, placenta previa, and placental-related complications such as placental abruption, preeclampsia, and spontaneous preterm delivery. RESULTS: Women with previous cesarean delivery were more likely to have adverse outcomes such as uterine rupture (OR=12.4, 95%CI 6.8-22.3), placental abruption (OR=1.4, 95%CI 1.1-2.1), preeclampsia (OR=1.4, 95%CI 1.2-1.6), and spontaneous preterm delivery (OR=1.4, 95%CI 1.1-1.7). CONCLUSIONS: Individuals with previous cesarean section have adverse obstetric outcomes in the subsequent pregnancy, including uterine rupture, and placental-related disorders such as preeclampsia, spontaneous preterm delivery, and placental abruption.

Do induced twin pregnancies influence the obstetric and neonatal results of multiple births born before 32 weeks? Comparison to spontaneous gestation

PURPOSE: To compare obstetric outcomes of induced preterm twin births (under 32 weeks gestation) with those spontaneously conceived. METHODS: Prospective study of twin pregnancies (25 induced and 157 spontaneously conceived) developed over a period of 16 years in a tertiary obstetric center. Demographic factors, obstetric complications, gestational age at delivery, mode of delivery, birth weight and immediate newborn outcome were compared. RESULTS: The analysis of obstetrical complications concerning urinary or other infections, hypertensive disorders of pregnancy, gestational diabetes, fetal malformations, intrauterine fetal death, intrauterine growth restriction and intrauterine discordant growth reveal no significant statistical differences between the two groups. First trimester bleeding was higher in the induced group (24 versus 8.3%, p=0.029). The cesarean delivery rate was 52.2% in spontaneous gestations and 64% in induced gestations. Gestational age at delivery, birth weight, Apgar scores at first and fifth minutes, admissions to Neonatal Intensive Care Unit and puerperal complications show no statistically significant differences between the two groups. These results were independent of chorionicity and induction method. CONCLUSION: The mode of conception did not influence obstetric and neonatal outcomes. Although induced pregnancies have higher risk of first trimester bleeding, significant differences were not observed regarding other obstetric and puerperal complications and neonatal results.

Spontaneous poisoning by larvae of Perreyia flavipes (Pergidae) in sheep

From a flock of 175 Texel sheep 25 animals died after consumption of a sawfly larvae subsequently identified as Perreyia flavipes. The disease occurred in June-July 2006 on a farm located in the county of Encruzilhada do Sul, Rio Grande do Sul, Brazil. Although there were 11 cattle in the same paddock, none of them was affected. High numbers of compact masses containing up to 150 larvae were scattered in the paddock where the animals were grazing. Most affected sheep showed severe apathy during 24-36 h before death, but weakness, muscular tremors and depression were also observed. Necropsy was performed on six sheep and the main macroscopic lesions were hemorrhages in the subcutaneous tissues, endocardium, gallbladder wall, and abomasal mucosa. In all animals was found hydrothorax, hydropericardium, ascites, and mild jaundice. Edema in the abomasal folds, mesentery, perirenal tissues, and gallbladder wall were also seen. The livers were yellowish with disseminated pinpoint hemorrhages in the parenchyma and had an enhanced lobular pattern. Perreyia flavipes larval body fragments and heads were found in the forestomach contents of the six sheep. Feces were scant, dry and formed balls coated by mucus and streaks of blood. Similar contents were also present at the end of the cecum. Prominent microscopic lesions included severe and diffuse periacinar or massive necrosis of hepatocytes associated with multifocal random hemorrhages. Diffuse necrosis of lymphoid follicles in lymph nodes and Peyer's patches, lymphoid depletion and necrosis in germinative centers of the spleen, and diffuse vacuolization in the renal tubular epithelia were also seen.

Spontaneous coffee senna poisoning in cattle: report on 16 outbreaks

Sixteen outbreaks of Senna occidentalis (coffee senna) that occurred in cattle in the state of Rio Grande do Sul, Brazil, were reviewed. The great majority (75%) of the outbreaks occurred in adult cattle at pasture during the autumn and winter months with 50% in May, evidencing a striking seasonality. Mortality rates varied from 4.2% to 55.2% and cattle died 2 days up to 2 weeks after showing clinical signs that included dry feces (occasionally diarrhea), muscle weakness, reluctance to move, tachypnea, instability of the hind limbs with dragging of the toes, tremors in muscles of the thighs, neck, and head, ear dropping, sternal recumbency, lateral recumbency and death. Myoglobinuria characterized by a dark red or black discolored urine was a consistent finding in cattle affected at pasture but not in those poisoned by ration contaminated with coffee senna beans. Creatine phosphokinase serum activity was marked ly elevated. Main gross changes observed in 23 necropsies involved skeletal muscles of the hind limbs. These changes consisted of varying degrees of paleness of muscle groups. Subepicardial and subendocardial hemorrhages were present in the hearts of all affected cattle. Histologically a segmental degenerative myopathy of striated muscles was present in every case and had a multifocal polyphasic or monophasic character. Myocardial (3/23), hepatic (3/13), renal (3/10), and splenic (1/6) microscopic lesions were observed occasionally. Myocardial lesions were mild and consisted of vacuolation of cardiomyocytes or focal fibrosis. Hepatic changes consisted of diffuse hepatocelular vacuolation, cytosegrosomes within hepatocytes, and individual hepatocellular necrosis. Kidneys had vacuolar degeneration of tubular epithelium associated with acidophilic casts (proteinosis) within tubular lumina. In the spleen there was marked necrosis of lymphocytes of the white pulp. No histological changes were found in the brains of 13 affected cattle. The data of this study suggest that coffee senna poisoning is an important cause of death in cattle in southern Brazil.