Infectious agents in coronary atheromas: a possible role in the pathogenesis of plaque rupture and acute myocardial infarction

In this review we report our recent findings of histopathological features of plaque instability and the association with Mycoplasma pneumoniae (MP) and Chlamydia pneumoniae (CP) infection, studying thrombosed coronary artery segments (CAS) of patients who died due to acute myocardial infarction. Vulnerable plaques are known to be associated with fat atheromas and inflammation of the plaque. Here we demonstrated that vulnerability is also related with focal positive vessel remodeling that maintains relatively well preserved lumen even in the presence of large atheromatous plaques. This phenomena may explain why the cinecoronariography may not detect large and dangerous vulnerable plaques. Greater amount of these bacteria in vulnerable plaques is associated with adventitial inflammation and positive vessel remodeling: the mean numbers of lymphocytes were significantly higher in adventitia than in the plaque, good direct correlation was obtained between numbers of CD20 B cells and numbers of CP infected cells in adventitia, and between % area of MP-DNA in the plaque and cross sectional area of the vessel, suggesting a cause-effect relationship. Mycoplasma is a bacterium that needs cholesterol for proliferation and may increase virulence of other infectious agents. In conclusion, co-infection by Mycoplasma pneumoniae and Chlamydia pneumoniae may represent an important co-factor for plaque instability, leading to coronary plaque thrombosis and acute myocardial infarction, since larger amount of these bacteria strongly correlated with histological signs of more vulnerability of the plaque. The search of CMV and Helicobacter pilori in these tissues resulted negative.

Isokinetic assessment of the flexor-extensor balance of the knee in athletes with total rupture of the anterior cruciate ligament

The purpose of this study was to assess the flexor-extensor group of muscles of the knee in young athletes diagnosed with a total rupture of the anterior cruciate ligament (ACL). Eighteen knees of 18 athletes (14 men and 4 women) with an average age of 21.6 years (range 16-32 years) were assessed with a Cybex 6000 model isokinetic apparatus. The average interval between occurrence of the injury and assessment was 10.2 months (range 2 - 48 months). There was an associated meniscal injury in eight of the knees. Athletes with any other kind of associated injury, limitation, or blockage of the movement of the joint, significant pain during the exam, or interval between injury and exam of less than two months were excluded from the study. The parameters studied were the peak torque-velocity and flexor-extensor relationships at the constant angular velocities of 60°/sec and 240°/sec. Previous warming-up was done by means of an ergometric bicycle and adaptation with 3 submaximal repetitions. The contra-lateral side, which presented no injury, was used as control. Peak torque (PT) at the constant velocity of 60°/sec was greater than that at 240°/sec for knees with and without injuries. However, there was no significant difference between the injured and uninjured sides at 60°/sec or at 240°/sec. The average value for the flexor-extensor relationship at 60°/sec on the injured was 60% (( 6), compared to 57% (( 10) on the contra-lateral side. At 240°/sec, the average value was 75% ((10) on the injured side, and 65% ((12) on the contra-lateral side. In conclusion, despite the complete rupture of the ACL of one knee, the average values for the flexor-extensor relationship were similar on the injured and uninjured sides at the velocity of 60°/sec. As the velocity increased, an increase in the values for the flexor-extensor relationship of the knee also occurred, indicating a tendency of the performance of the flexor muscle group to approach that of the extensor muscle group, and this tendency was more pronounced on the side of the injury.

Treatment of delayed rupture of the left ventricle after mitral valve replacement

Rupture of the left ventricle following mitral valve replacement is a catastrophic complication with deadly consequences. We report here the case of a 75-year-old man who underwent elective mitral valve replacement for severe mitral regurgitation. Delayed type 1 rupture of the left ventricle developed 3 hours postoperatively in the intensive care unit. A salvaging maneuver was used, which gained time, allowing reoperation and successful intraventricular repair.

Spontaneous rupture of a right atrial angiosarcoma and cardiac tamponade

Primary cardiac angiosarcoma is a rare disease of difficult diagnosis and poor prognosis frequently associated with recurring hemopericardium. We report the case of a 30-year-old female with a right atrial angiosarcoma and spontaneous rupture to the pericardial cavity, who was diagnosed during an emergency exploratory thoracotomy, whose indication was cardiac tamponade. This is the 8th case reported in the literature. Clinical findings are discussed and a literature review is provided.

Spontaneous rupture of ovarian cystadenocarcinoma: pre- and post-rupture computed tomography evaluation

AbstractEpithelial ovarian tumors are the most common malignant ovarian neoplasms and, in most cases, eventual rupture of such tumors is associated with a surgical procedure. The authors report the case of a 54-year-old woman who presented with spontaneous rupture of ovarian cystadenocarcinoma documented by computed tomography, both before and after the event. In such cases, a post-rupture staging tends to be less favorable, compromising the prognosis.

Spontaneous rupture of renal angiomyolipoma during pregnancy

Renal angiomyolipoma is a benign tumor, composed of adipocytes, smooth muscle cells and blood vessels. The association with pregnancy is rare and related with an increased risk of complications, including rupture with massive retroperitoneal hemorrhage. The follow-up is controversial because of the lack of known cases, but the priorities are: timely diagnosis in urgent cases and a conservative treatment when possible. The mode of delivery is not consensual and should be individualized to each case. We report a case of a pregnant woman with 18 weeks of gestation admitted in the emergency room with an acute right low back pain with no other symptoms. The diagnosis of rupture of renal angiomyolipoma was established by ultrasound and, due to hemodinamically stability, conservative treatment with imaging and clinical monitoring was chosen. At 35 weeks of gestation, it was performed elective cesarean section without complications for both mother and fetus.

Serial superficial digital flexor tendon biopsies for diagnosing and monitoring collagenase-induced tendonitis in horses

The purpose of this investigation was to demonstrate the feasibility of a biopsy technique by performing serial evaluations of tissue samples of the forelimb superficial digital flexor tendon (SDFT) in healthy horses and in horses subjected to superficial digital flexor tendonitis induction. Eight adult horses were evaluated in two different phases (P), control (P1) and tendonitis-induced (P2). At P1, the horses were subjected to five SDFT biopsies of the left forelimb, with 24 hours (h) of interval. Clinical and ultrasonographic (US) examinations were performed immediately before the tendonitis induction, 24 and 48 h after the procedure. The biopsied tendon tissues were analyzed through histology. P2 evaluations were carried out three months later, when the same horses were subjected to tendonitis induction by injection of bacterial collagenase into the right forelimb SDFT. P2 clinical and US evaluations, and SDFT biopsies were performed before, and after injury induction at the following time intervals: after 24, 48, 72 and 96 h, and after 15, 30, 60, 90, 120 and 150 days. The biopsy technique has proven to be easy and quick to perform and yielded good tendon samples for histological evaluation. At P1 the horses did not show signs of localised inflammation, pain or lameness, neither SDFT US alterations after biopsies, showing that the biopsy procedure per se did not risk tendon integrity. Therefore, this procedure is feasible for routine tendon histological evaluations. The P2 findings demonstrate a relation between the US and histology evaluations concerning induced tendonitis evolution. However, the clinical signs of tendonitis poorly reflected the microscopic tissue condition, indicating that clinical presentation is not a reliable parameter for monitoring injury development. The presented method of biopsying SDFT tissue in horses enables the serial collection of material for histological analysis causing no clinical signs and tendon damage seen by US images. Therefore, this technique allows tendonitis to be monitored and can be considered an excellent tool in protocols for evaluating SDFT injury.

Effect of an aqueous extract of Phaseolus vulgaris on the properties of tail tendon collagen of rats with streptozotocin-induced diabetes

Changes in the structural and functional properties of collagen caused by advanced glycation might be of importance for the etiology of late complications in diabetes. The present study was undertaken to investigate the influence of oral administration of aqueous pod extract (200 mg/kg body weight) of Phaseolus vulgaris, an indigenous plant used in Ayurvedic Medicine in India, on collagen content and characteristics in the tail tendon of streptozotocin-diabetic rats. In diabetic rats, collagen content (117.01 ± 6.84 mg/100 mg tissue) as well as its degree of cross-linking was increased, as shown by increased extent of glycation (21.70 ± 0.90 µg glucose/mg collagen), collagen-linked fluorescence (52.8 ± 3.0 AU/µmol hydroxyproline), shrinkage temperature (71.50 ± 2.50ºC) and decreased acid (1.878 ± 0.062 mg hydroxyproline/100 mg tissue) and pepsin solubility (1.77 ± 0.080 mg hydroxyproline/100 mg tissue). The alpha/ß ratio of acid- (1.69) and pepsin-soluble (2.00) collagen was significantly decreased in streptozotocin-diabetic rats. Administration of P. vulgaris for 45 days to streptozotocin-diabetic rats significantly reduced the accumulation and cross-linking of collagen. The effect of P. vulgaris was compared with that of glibenclamide, a reference drug administered to streptozotocin-diabetic rats at the dose of 600 µg/kg body weight for 45 days by gavage. The effects of P. vulgaris (collagen content, 64.18 ± 1.97; extent of glycation, 12.00 ± 0.53; collagen-linked fluorescence, 33.6 ± 1.9; shrinkage temperature, 57.0 ± 1.0; extent of cross-linking - acid-soluble collagen, 2.572 ± 0.080, and pepsin-soluble collagen, 2.28 ± 0.112) were comparable with those of glibenclamide (collagen content, 71.5 ± 2.04; extent of glycation, 13.00 ± 0.60; collagen-linked fluorescence, 38.9 ± 2.0; shrinkage temperature, 59.0 ± 1.5; extent of cross-linking - acid-soluble collagen, 2.463 ± 0.078, and pepsin-soluble collagen, 2.17 ± 0.104). In conclusion, administration of P. vulgaris pods had a positive influence on the content of collagen and its properties in streptozotocin-diabetic rats.

ABO System: molecular mimicry of Ascaris lumbricoides

A. lumbricoides has been associated to the ABO System by various authors. The objective was to detect ABO System epitopes in A. lumbricoides of groups O, A, B and AB patients. 28 adult parasites were obtained from children to be used as assay material. The patients ABO blood groups were determined. Extracts of A. lumbricoides [AE] were prepared by surgical remotion of the cuticle and refrigerated mechanical rupture. Agglutination Inhibition (AI) and Hemoagglutination Kinetics (HK) tests were used with the [AE]. Of the 28 [AE], eight belonged to O group patients, 15 to A group, three to B group and the remaining two to AB children. The AI Test showed A epitopes in two [AE] of group A patients and B epitopes in two [AE] of group B patients. The HK Test showed B antigenic determiners in two [AE] of group B patients and in two [AE] of group AB patients as well as A antigenic determiners in one [AE] of A group patient. Of the 28 [AE] studied in both tests B epitopes were detected in all [AE] from B and AB patients and A epitopes in three of the 15 [AE] of group A patients. The experiments carried out suggest that A. lumbricoides might absorb A and B antigens from the host, and/or modify the cuticular carbohydrates expression as a kind of antigenic mimicry.

Rat hepatocyte invasion by Listeria monocytogenes and analysis of TNF-alpha role in apoptosis

Listeria monocytogenes, etiological agent of severe human foodborne infection, uses sophisticated mechanisms of entry into host cytoplasm and manipulation of the cellular cytoskeleton, resulting in cell death. The host cells and bacteria interaction may result in cytokine production as Tumor Necrosis Factor (TNF) alpha. Hepatocytes have potential to produce pro-inflammatory cytokines as TNF-alpha when invaded by bacteria. In the present work we showed the behavior of hepatocytes invaded by L. monocytogenes by microscopic analysis, determination of TNF-alpha production by bioassay and analysis of the apoptosis through TUNEL technique. The presence of bacterium, in ratios that ranged from 5 to 50,000 bacteria per cell, induced the rupture of cellular monolayers. We observed the presence of internalized bacteria in the first hour of incubation by electronic microscopy. The levels of TNF-alpha increased from first hour of incubation to sixth hour, ranging from 0 to 3749 pg/mL. After seven and eight hours of incubation non-significant TNF-alpha levels decrease occurred, indicating possible saturation of cellular receptors. Thus, the quantity of TNF-alpha produced by hepatocytes was dependent of the incubation time, as well as of the proportion between bacteria and cells. The apoptosis rate increased in direct form with the incubation time (1 h to 8 + 24 h), ranging from 0 to 43%, as well as with the bacteria : cells ratio. These results show the ability of hepatocyte invasion by non-hemolytic L. monocytogenes, and the main consequences of this phenomenon were the release of TNF-alpha by hepatocytes and the induction of apoptosis. We speculate that hepatocytes use apoptosis induced by TNF-alpha for release bacteria to extracellular medium. This phenomenon may facilitate the bacteria destruction by the immune system.

Kinetics of the cercaria-schistosomulum transformation in vivo

Sitice most studies on the cercaria-schistosomulum transformation have been carried out in vitro, the authors used the inoculation ofcercariae into the peritoneal cavity of mice tofollow the steps involved in this progressive adaptation of cercarie to the vertebmte host. The main conclusions were: 1. Most cercariae reach the schistosomular stage between 90-120 min after intraperitoneal inoculation. 2. Changes usuallystart with detachment of the tail followed by loss, rupture or changes of the glycocalix. 3. After 120 min most larvae loss their tails and present water sensitivity. 4. Acetabular grands depletion usually does not occur in cercaria-shistosomulum changes in the peritoneal cavity of mice. These steps differ in some way from those described in the kinetics of the in vitro observations performed by other investigators, and is more like those described in the penetration in the skin of living vertebrates.

Revisiting the concept of hepatosplenic schistosomiasis and its challenges using traditional and new tools

Different aspects of hepatosplenic schistosomiasis are revisited here. Manson's schistosomiasis causes periportal fibrosis and portal hypertension in approximately 6% of infected subjects, usually with preservation of their hepatic function. The assessment of liver involvement is of major importance in determining the prognosis and risk of complications from schistosomiasis, such as upper digestive bleeding secondary to variceal rupture. For many years, the diagnosis of hepatosplenic schistosomiasis and liver fibrosis was made by abdominal palpation and the finding of liver and/or spleen enlargement. However, there is no consensus regarding the clinical parameters of the liver and spleen to be considered in this physical evaluation. For the last three decades, abdominal ultrasound (US) has become the best imaging technique to evaluate liver fibrosis caused by schistosomiasis mansoni. However, US is a subjective procedure and is therefore examiner-dependent. Magnetic resonance imaging (MRI) findings have provided valuable information in addition to ultrasound and clinical examination. The combination of a comprehensive history and physical examination, basic laboratory tests (a stool examination for Schistosoma mansoni eggs and a blood cell count), biomarkers for liver fibrosis/portal hypertension and imaging methods seem to offer the best approach for evaluating patients with this disease. In situations where research is involved or in patients with severe disease, MRI may be considered.

Experimental determination of bone cortex holding power of orthopedic screw

Cylindrical specimens of bone measuring 15 mm in diameter were obtained from the lateral cortical layer of 10 pairs of femurs and tibias. A central hole 3.2 mm in diameter was drilled in each specimen. The hole was tapped, and a 4.5 mm cortical bone screw was inserted from the outer surface. The montage was submitted to push-out testing up to a complete strip of the bone threads. The cortical thickness and rupture load were measured, and the shear stress was calculated. The results were grouped according to the bone segment from which the specimen was obtained. The results showed that bone cortex screw holding power is dependent on the bone site. Additionally, the diaphyseal cortical bone tissue is both quantitatively and qualitatively more resistant to screw extraction than the metaphyseal tissue.

Friedreich's ataxia: clinical and molecular study of 25 Brazilian cases

INTRODUCTION: Friedreich's ataxia is a neurodegenerative disorder whose clinical diagnostic criteria for typical cases basically include: a) early age of onset (< 20 or 25 years), b) autosomal recessive inheritance, c) progressive ataxia of limbs and gait, and d) absence of lower limb tendon reflexes. METHODS: We studied the frequency and the size of expanded GAA and their influence on neurologic findings, age at onset, and disease progression in 25 Brazilian patients with clinical diagnosis of Friedreich's ataxia - 19 typical and 6 atypical - using a long-range PCR test. RESULTS: Abnormalities in cerebellar signs, in electrocardiography, and pes cavus occurred more frequently in typical cases; however, plantar response and speech were more frequently normal in this group when the both typical and atypical cases were compared. Homozygous GAA expansion repeats were detected in 17 cases (68%) - all typical cases. In 8 patients (32%) (6 atypical and 2 typical), no expansion was observed, ruling out the diagnosis of Friedreich's ataxia. In cases with GAA expansions, foot deformity, cardiac abnormalities, and some neurologic findings occurred more frequently; however, abnormalities in cranial nerves and in tomographic findings were detected less frequently than in patients without GAA expansions. DISCUSSION: Molecular analysis was imperative for the diagnosis of Friedreich's ataxia, not only for typical cases but also for atypical ones. There was no genotype-phenotype correlation. Diagnosis based only on clinical findings is limited; however, it aids in better screening for suspected cases that should be tested. Evaluation for vitamin E deficiency is recommended, especially in cases without GAA expansion.

Screening for abdominal aortic aneurysms

OBJECTIVE AND METHODS: Screening for abdominal aortic aneurysms may be useful to decrease mortality related to rupture. We conducted a study to assess the prevalence of abdominal aortic aneurysms in southern Brazil and to define risk factors associated with high prevalence of this disorder. The screening was conducted using abdominal ultrasound. Three groups were studied: Group 1 - cardiology clinic patients; Group 2 - individuals with severe ischemic disease and previous coronary surgery, or important lesions on cardiac catheterism; Group 3 - individuals without cardiac disease selected from the general population. All individuals were male and older than 54 years of age. The ultrasonographic diagnosis of aneurysm was based on an anteroposterior abdominal aorta diameter of 3 cm, or on an abdominal aorta diameter 0.5 cm greater than that of the supra-renal aorta. RESULTS: A total of 2.281 people were screened for abdominal aortic aneurysms in all groups: Group 1 - 768 individuals, Group 2 - 501 individuals, and Group 3 - 1012 individuals. The prevalence of aneurysms was 4.3%, 6.8% and 1.7%, respectively. Age and cigarette smoking were significantly associated with increased prevalence of aneurysms, as was the diagnosis of peripheral artery disease. DISCUSSION: We concluded that screening may be an important tool to prevent the mortality associated with abdominal aortic aneurysms surgery. Additionally, the cost of screening can be decreased if only individuals presenting significant risk factors, such as coronary and peripheral artery disease, smokers and relatives of aneurysm patients, are examined.