The biological control of Ancylostoma spp. dog infective larvae by Duddingtonia flagrans in a soil microcosm.

Experiments to evaluate the potential ability of the nematode-trapping fungus Duddingtonia flagrans (Isolate CG768) to prey on the Ancylostoma spp. dog infective larvae (L(3)) in pasteurized soil were performed through several laboratory assays. A microcosm approach was used with increasing fungal concentrations in an inoculum of a chlamydospore water suspension. The highest fungal concentrations provide a more consistent larval reduction than the lowest concentrations, but no difference was observed from 10,000 to 25,000 chlamydospores per grain of soil. When using D. flagrans in a water suspension, in white rice and in milled maize, there were reductions in the larval population of 72.0%, 78.4% and 79.4%, respectively, but there was no difference between white rice and milled maize (p<0.05). To evaluate the nematode control by D. flagrans inoculated in milled maize at 10,000 chlamydospores per grain of soil under greenhouse conditions, observations were performed at 10, 15, 20, 25 and 30 days after inoculation and the percent reduction in the larval population was 61.4%, 73.2%, 70.8%, 64.5% and 57%, respectively (p<0.05). There was an inverse relationship between the number of L(3) recovered from the soil and the total days of exposure to the fungus (p<0.05). These results showed that D. flagrans could present some potential to be used as a non-chemotherapeutic alternative for regulation of Ancylostoma spp. populations in the environment.

Predation of Ancylostoma spp. dog infective larvae by nematophagous fungi in different conidial concentrations.

In the present work, it was evaluated the in vitro effect of 12 isolates from the fungal species Arthrobotrys, Duddingtonia, Nematoctonus and Monacrosporium genera in different conidial concentrations on the capture of Ancylostoma spp. dog infective larvae (L(3)), on 2% water-agar medium at 25 degrees C, at the end of a period of 7 days. The concentrations used for each nematophagous fungus were 1000, 5000, 10,000, 15,000 and 20,000conidia/Petri dish plated with 1000 Ancylostoma spp. L(3). All nematode-trapping fungi isolates tested reduced the averages of the uncaptured Ancylostoma spp. L(3) recovered, with the increase of the fungal inoculum concentration, in comparison to the fungus-free control (p<0.05). The adhesive network producing species were better predators than the constricting ring or adhesive knob producing species. Duddingtonia flagrans (Isolate CG768) was the most effective, reducing the averages of the uncaptured Ancylostoma spp. L(3) recovered in 92.8%, 96.3%, 97.5%, 98.3% and 98.9%, respectively in five fungal inoculum concentrations established. Other effective nematophagous fungi were Arthrobotrys robusta (Isolate I31), which reduced the averages of the uncaptured Ancylostoma spp. L(3) recovered in 85.4%, 88.3%, 90.7%, 92.5% and 95.2%, and Arthrobotrys oligospora (Isolate A183), with reductions of 66.6%, 79.8%, 86.8%, 89.5% and 90.8%, respectively for both, in the five fungal inoculum concentrations established. No difference was found between Isolates A183 and I31 in the conidial concentrations of 15,000/Petri dish. Nematoctonus robustus (Isolate D1) and Arthrobotrys bronchophaga (Isolate AB) had the smallest percentages of reduction among the tested isolates and showed the lowest predacious activity. The Isolates CG768, I31 and A183 were considered potential biological control agents of Ancylostoma spp. dog free-living stages, being directly influenced by the fungal inoculum concentration.

Potential definition of the time of death from autolytic myocardial cells: a morphometric study.

Morphometric methods and transmission electron microscopy were used to quantify modifications occurring in the mitochondria of dog myocardium during the first four hours of autolysis. Myocardial fragments were obtained from the outer free wall of the left ventricle, during anesthesia (control-zero) and at 15, 45, 120, and 240 min after cardiac arrest, maintaining the heart "in situ" at 22 degrees C. During the 240 min of autolysis, the main parameters evaluated showed: (a) a decrease in the number of mitochondria from 0.31 to 0.12 per micron 3 of cytoplasm. The decrease over the first 45 min reached 50% of the initial value; (b) an increase in mitochondrial volume, three times greater after the first 45 min (from 0.92 to 2.68 micron 3) and four times greater after 240 min (from 0.92 to 3.79 micron 3); (c) an increase in mitochondrial outer membrane surface area from 5.51 to 12.54 micron 2; (d) an increase in the surface area of individual mitochondria inner membrane and cristae from 27.60 to 56.96 micron 2. The progressive nature of the alterations and the difference in the numerically expressed values allow correlation with the time of somatic death. The authors emphasize the need for further studies in order to complement the present study.

Distribution of hyaluronan and dermatan/chondroitin sulfate proteoglycans in human aortic dissection.

Aortic dissections (AD) are characterized by the separation of the artery into two sheets, possibly due to fragility of the vessel wall. A mucoid histological pattern, imparted to the tissues mainly by hyaluronan and proteoglycans, can be seen in "cysts" and, in chronic cases, in a band of repair tissue. We studied the localization of hyaluronan, versican, decorin and biglycan in situ in aortas of 21 patients with recent AD, 8 with chronic AD and in 15 control cases. None of these substances was increased in the areas of mucoid "cysts" that possibly contain anomalous material. Similar distributions were seen in normal and dissected aortas: versican and hyaluronan were more prominent in the external half of the medial layer where the dissection usually occurs. Since these molecules play a role in resistance to compression, disorders not detected by our method may be involved in aortic dissection. Hyaluronan was seen adjacent to fibrin at the dissection tear, probably as an early wound repair phenomenon. Biglycan, hyaluronan and mostly versican are seen during advanced repairing. The mucoid deposits may represent various compounds which reflect different disorders in vascular biology.

Myocardial protection in the occlusion/reperfusion dog model: the role of ischemic necrosis vs reperfusion injury.

The present study was designed to assess the possibility of maximizing the effects of reperfusion by the association of the calcium channel blocker, verapamil and the iron chelator deferoxamine, to delay necrosis and avoid reperfusion injury. Sixty-four mongrel dogs (15 +/- 1.1 (SD) kg) were successfully subjected to 24 h of reperfusion following 90-min occlusion of the left anterior coronary artery. ECG and arterial pressure were monitored. The risk area (RA; % left ventricle (LV)) was determined by the infusion of Evans blue into the aortic root and the area of necrosis (AN; %RA) by triphenyltetrazolium chloride staining. Myocardial preservation was defined as %RA not necrosed calculated as (RA-AN)/RA x 100. RA was similar in all dogs, i.e., 33 +/- 2% LV (SD). There were no differences in arterial pressure, heart rate or double product among groups. Myocardial preservation was 60 +/- 13% RA in 9 control dogs submitted to reperfusion only (group C), and 58 +/- 18% RA in 17 dogs treated with deferoxamine (500 mg, iv), 30 min before reperfusion (group DF). Verapamil (0.2 mg/kg, iv) was given alone 15 min after occlusion to 15 dogs (group VP), followed by prereperfusion deferoxamine to 16 dogs (group VP+DF) and in two doses after occlusion and 15 min before reperfusion in 7 dogs (group VP+VP). Myocardial preservation was greater in the latter groups when compared to controls, namely 76 +/- 13% RA in group VP, 74 +/- 11% in group VP+DF and 73 +/- 9% in group VP+VP (P = 0.04 vs group C, ANOVA). The data suggest that the mechanism underlying this beneficial effect is mainly related to the retardation of necrosis progression. O2 free radicals or Ca(2+)-induced reperfusion injury do not play a major role.

Myocardial protection in the occlusion/reperfusion dog model: the role of ischemic necrosis vs reperfusion injury

The present study was designed to assess the possbility of maximizing the effects of reperfusion by the association of the calcium channel blocker, verapamil and the iron chelator deferoxamine, to delay necrosis and avoid reperfusion injury. Sixty-four mongrel dogs (15 ñ 1.1 (SD)Kg) were successfully subjected to 24 h of reperfusion following 90-min occlusion of the left anterior coronary artery. ECG and arterial presure were monitored. The risk area (RA; percent left ventricle (LV)) was determined by the infusion of Evans blue into the aortic root and the area of necrosis (AN; per cent RA) by triphenyltetrazolium chloride staining. Myocardial presevation was defined as per cent RA not necrosed calculated as (RA - AN)/RA x 100.RA was similar in all dogs, i.e., 33 ñ 2 per cent LV (SD). There were no differences in arterial pressure, heart rate or double product among groups. Myocardial preservation was 60 ñ 13 per cent RA in 9 control dogs submitted to reperfusion only (group C), and 58 ñ 18 per cent RA in 17 dogs treated with deferoxamine (500 mg, iv), 30 min before reperfusion (group DF). Verapamil (0.2 mg/Kg, iv) was given alone 15 min after occlusion to 15 dogs (group VP), followed by prereperfusion deferoxamine to 16 dogs (goup VP + DF) and in two doses after occlusion and 15 min before reperfusion in 7 dogs (group VP + VP). Myocardial preservation was greater in the latter groups when compared to controls, namely 76 ñ 13 per cent RA in group VP, 74 ñ 11 per cent in group VP + DF and 73 ñ 9 per cent in group VP + VP (P = 0.04 vs group C., ANOVA). The data suggest that mechanism underlying this beneficial effect is mainly related to the retardation of nectosis progression. O2 free radicals or Ca2+-induced reperfusion injury do not play a major role

[Analysis of the composition and spatial disposition of atherosclerotic plaques localized in epicardial coronary artery bifurcations in adults]. / Análise da composição e disposição espacial de placas ateroscleróticas localizadas em bifurcações das artérias coronárias epicárdicas de adultos.

PURPOSE: To analyze macro and microscopic features of atherosclerotic plaques located in bifurcation of coronary arteries, defining their spatial disposition in those sites. METHODS: We studied 38 bifurcations of coronary arteries of patients whose cause of death was related to coronary artery disease. Histologic sections of 0.5mm were sequentially made from the main artery to the secondary branches. They were stained with hematoxilin-eosin technique. Histological analysis evaluated: a) morphologic composition of the plaques, b) degree of obstruction and c) plaque's disposition. RESULTS: a) Plaque's composition: fibrolipid plaques constituted 80% of the cases and mingled focal atrophy of the media at the base of the plaque in 61% with spots of total destruction and rupture of the elastic layers in 30%; b) degree of obstruction: ranged from 20% to 95%, with average 60 +/- 28%; c) disposition of plaques: we verified morphologic variation along the plaque, most of them (71%) being eccentric at bifurcation and not reaching the beginning of flow divider walls. CONCLUSION: Atherosclerotic plaques located in bifurcation of coronary arteries of adults are often fibrolipid plaques, eccentric, and their spatial disposition on those sites spare the beginning of the inner walls, reaching the outer walls.

[Myocardial infarction: comparison of anatomo-pathological findings from hearts with and without severe coronary atherosclerosis in 194 necropsy cases]. / Infarto do miocárdio: comparação dos achados anátomo-patológicos em corações com e sem aterosclerose coronária grave em 194 casos de necrópsia.

PURPOSE: To compare morphological features of myocardial infarction (MI) from patients with any epicardial coronary artery narrowed at some point more than 70% (severe coronary atherosclerosis--SCA) with those from patients with either no coronary atherosclerosis or only mild (less than 70%) atherosclerosis. METHODS: Necropsy findings from 194 patients who died due to MI, 174 patients with and 20 without SCA. Ages ranged from 21 to 82 (mean 60) years. RESULTS: Mean age was 60 years in the cases with SCA and 56 in the case without it; nevertheless, age distribution was different (p = 0.023), due to the existence of more patients under age 40 in the group without SCA. There was no significant difference concerning sex (31.0% of female patients in the group with SCA and 35.0% in the other group, p = 0.718), mean heart weight (500 g and 506 g), distribution of cases according to time of evolution of MI in recent only, old only or both (cases with SCA--36.2%, 28.2% and 35.6%; cases without SCA--45.0% and 20%; p = 0.666), left ventricular wall committed by the MI (p = 0.715), incidence of hemorrhagic infarction (with SCA--8.6%; without SCA--15.0%; p = 0.406), left ventricular rupture (with SCa--5.17%, without SCA--10.0%; p = 0.719) and left ventricular aneurysms (with SCA--12.1%, without SCA--15.0%; p = 0.316). An association was found between coronary atherosclerosis and recent (p = 0.046) and recanalized (p less than 0.001) thrombosis, but absent when only recent thrombosis and non-operated cases with recent MI were considered (p = 0.091). CONCLUSION: Necropsy of fatal cases of MI were not significantly different in the presence or absence of severe atherosclerotic narrowing (greater than 70%) of epicardial coronary arteries, suggesting that this factor does not modify the natural history of MI.

Evidence for superoxide radical-dependent coronary vasospasm after angioplasty in intact dogs.

BACKGROUND: Active oxygen species can influence vascular tone and platelet activation through a variety of mechanisms. This study assessed the role of the superoxide anion, the hydroxyl radical, and hydrogen peroxide in vasoconstriction and mural thrombosis after coronary artery angioplasty in intact dogs. METHODS AND RESULTS: Injury was induced by inflation of a balloon catheter 50 +/- 6% above baseline arterial diameter; dogs were followed for 2 hours before death. Epicardial coronary diameters at arteriography and extent of thrombus deposition at serial histological sections were analyzed in controls (n = 20) and in dogs pretreated with superoxide dismutase (SOD, a superoxide radical scavenger, n = 10); other dogs were pretreated with the hydrogen peroxide scavenger catalase (n = 8), the iron chelator deferoxamine (n = 6), or the hydroxyl radical scavenger 1,3-dimethyl-2-thiourea (n = 9). Angioplasty-induced injury was similar among groups. After angioplasty, control dogs exhibited localized and persistent vessel constriction, which was maximal at the initial 5 minutes (28.9 +/- 6.3% diameter decrease versus baseline). Corresponding arterial diameters of SOD-treated dogs were 24-69% larger (95% confidence interval, p less than 0.001) than controls at 5 minutes and, on average, 32% larger than controls thereafter (p less than 0.01). Vasoconstriction was not prevented by the other treatments. The SOD dose used accounted for inhibition of zymosan-stimulated blood cytochrome c reduction versus baseline (7 +/- 3 versus 30 +/- 6 nmol/min/10(6) cells, respectively, p = 0.003); such inhibition occurred in no other group. Prevalence of mural thrombosis was similar among all groups, but large thrombi (greater than 15% of lumen area) were absent in SOD-treated dogs, contrary to control group (p = 0.028); other groups were similar to control. In the absence of injury, SOD alone induced no change in coronary diameter, coronary blood flow, or platelet aggregation. CONCLUSIONS: These data provide evidence implicating the superoxide radical in the genesis of vasoconstriction after coronary angioplasty in vivo. Such effects seem to be independent of its conversion to hydroxyl radicals and availability of hydrogen peroxide or catalytic iron complexes.

[Differences between men and women in fatal cases of myocardial infarction: study of 200 necropsies]. / Diferenças entre homens e mulheres em casos fatais de infarto do miocárdio. Estudo de 200 necrópsias.

PURPOSE: To compare morphological characteristics from myocardial infarction (IM) in men and women in 200 consecutive necropsies. MATERIAL AND METHODS: Necropsy heart findings from 62 female cases compared with those from 138 male cases, from patients who died from transmural myocardial infarction. Age ranged from 21 to 82 (mean 60) years. RESULTS: Concerning the coronary arteries, the number of 3 major (right, left anterior descending and left circumflex) epicardial coronary arteries narrowed at some point greater than 70% in cross-sectional area by atherosclerotic plaque was not significantly different; on the other hand, there were more severe lesions in the left main coronary artery in men (10.33%) than in women (1.64%) (p = 0.050). 33.33% of men and 43.55% of women had only recent myocardial infarction (1 month or less); 33.33% of men and 14.52% of women had only old myocardial infarction (more than 1 month); 33.33% of men and 41.94% of women had both recent and old myocardial infarction. 12.90% of women and 2.17% of men showed rupture of the left ventricle (p = 0.0220). 15.22% of men and 6.45% of women had left ventricular aneurysms (p = 0.830). CONCLUSION: There are more deaths during the acute phase of MI, in the first infarction and from rupture of the left ventricle in female patients; in men, there are more deaths occurring in chronic phases of the disease and with previous myocardial infarction; and more severe narrowing from the left main coronary artery.

Bizarre nuclei of myocardial fibers in an infant with dilated cardiomyopathy. Light, electron-microscopic, and immunoperoxidase studies of a necropsy case.

The authors present the case of a 9-month-old child with clinical dilated cardiomyopathy that at necropsy showed myocardial cells with volumous, bizarre, and pleomorphic nuclei. These nuclear alterations were also found in other tissues. The myocardial ultrastructural studies revealed degenerative cytoplasmatic changes, nuclear membrane invaginations forming tubules, vesicles, and cytoplasmatic pseudoinclusions, and intranuclear vermicelar bodies, which all suggest virus-induced lesions. Although the ultrastructural studies and immunoperoxidase tests for virus identification were negative, the authors believe that a virus is most probably the agent of these alterations. This case seems to be the first reported on dilated cardiomyopathy with bizarre nuclear alterations in the myocardial fibers having strong evidence pointing to viral etiology.

[Cardiac thrombosis and embolism in patients having died of chronic Chagas cardiopathy]. / Trombose cardíaca e embolia em pacientes falecidos de cardiopatia chagásica crônica.

The authors studied the files of 111 patients (mean age 47.5 years) with chronic Chagas' disease and severe heart failure who had died between 1978 and 1984; they were 72 men and 39 women. Eighty-one patients (73%) had cardiac thrombosis, 65 times (53%) in right chambers and 56 times (46%) in left ones. Sixty-seven patients (60%) had thromboembolic episodes, 41 (65%) to the lungs, 23 (38%) to other organs (target organs: the kidneys in 21 cases, spleen in four, brain in two, abdominal aorta in one, mesenteric artery in one and iliac artery in one). Right chamber thrombosis occurred 65 times, 35 (53%) with pulmonary thromboembolism. Left chamber thrombosis occurred 56 times, 24 (42%) with systemic thromboembolism. A total of 41 patients had pulmonary thromboembolism, only six (14%) without right chamber thrombosis; of 26 patients with systemic thromboembolism, only two (7%) did not have left chamber thrombosis. The authors concluded that the incidence of thrombosis and thromboembolism was high in the group studied, and that there was a relationship between chamber thrombosis and systemic or pulmonary thromboembolism.

[Comparison of histologic changes in Chagas' cardiomyopathy and dilated cardiomyopathy]. / Comparação entre alterações histológicas da miocardiopatia da doença de Chagas e cardiomiopatia dilatada.

In this study the histopathologic features of Chagas' disease and idiopathic dilated cardiomyopathy were compared in 38 patients with congestive heart failure, classes II or III. Biopsy specimens were obtained with the Stanford model needle for right ventricle. Twenty-two patients presented non-chagasic dilated cardiomyopathy, and 16 were carriers of Chagas' disease. Twenty-three were male and 15 were female; their ages varied 18 and 49 years (mean 35.5). Fibrosis was slightly more frequently and intense in Chagas' disease than in dilated cardiomyopathy. Myocarditis aspect also was more frequent in Chagas' disease than in dilated cardiomyopathy (62.4% vs. 50%), with all cases showing a chronic form; acute myocarditis was observed only in dilated myocardiopathy. These differences, however, did not reach statistical significance. In conclusion, the presence of fibrosis, hypertrophy and moderate to severe degrees of chronic inflammatory infiltrate are suggestive of but not pathognomonic of Chagas' disease. On the other hand, dilated myocardiopathies are more frequently associated with less fibrosis or hypertrophy and the presence of mild degree of inflammatory infiltrate. The arrangement of this inflammatory infiltrate tends to be diffuse in dilated cardiomyopathy and in chagasic myocarditis it is multifocal, very similar to the histopathological aspect found in myocardial rejections episodes of transplanted hearts.

Balloon-induced endothelial denudation promotes deep injury of the arterial wall.

To investigate the cellular reactions to arterial injuries and the influence of a cholesterol-rich diet, 18 rabbits underwent endothelial denudation of the abdominal aorta with a balloon catheter. Fourteen animals were fed a 2% cholesterol diet and 4 were fed normal rabbit chow for 8 weeks. In the cholesterol-fed group, 6 animals had only the expected intimal lesions; however, 8 animals exhibited different degrees of balloon-induced medial layer injury, with fibrous healing. Similarly, in the control rabbits, 1 had intimal lesions and 3 had both intimal and medial layer lesions. We conclude that removal of the endothelium with a balloon catheter promotes arterial wall injury deeper than expected. This unexpected result could influence the effect of interventions usually employed in experimental atherosclerosis.

Balloon-induced endothelial denudation promotes deep injury of the arterial wall

To investigate the cellular reactions to arterial injuries and the influence of a cholesterol-rich diet, 18 rabbits underwent endothelial denudation of the abdominal aorta with a balloon catheter. Fourteen animals were fed a 2% cholesterol diet and 4 were fed normal rabbit chow for 8 weeks. In the cholesterolfed group, 6 animals had only the expected intimal lesions; however, 8 animals exhibited different degrees of balloon=induced medial layer injury, with fibrous healing. Similarly, in the control rabbits, 1 had intimal lesions and 3 had both intimal and medial layer lesions. We conclude that removal of the endothelium with a balloon catheter prometes arterial wall injury deeper than expected. This unexpected result could influence the effect of interventions usually employed in experimental atherosclerosis

Mucus-producing adenopapillary carcinoma of minor salivary gland origin with signet ring cells and intracytoplasmic lumina. A light and electron microscopic study.

A histological and subcellular study of a mucus-producing adenopapillary carcinoma of a minor salivary gland is presented. The tumor was located on the buccal mucosa of a 36-year-old white man. Microscopic examination showed that the tumor was an invasive papillary growth with numerous signet-ring cells and mucous production. When viewed under the electron microscope, the tumor exhibited clusters of cells showing intracellular lumina and finely dispersed chromatin.

The role of active myocarditis in the development of heart failure in chronic Chagas' disease: a study based on endomyocardial biopsies.

The authors analyze the presence of active myocarditis in endomyocardial biopsies from 38 patients with chronic Chagas' disease diagnosed serologically. The patients were divided into three clinical groups of increasing severity. Group I: 13 patients with normal electrocardiograms, normal chest x-rays, and no symptoms; Group II: 13 patients with abnormal electrocardiograms and no cardiomegaly; and Group III: 12 patients with abnormal electrocardiograms, cardiomegaly and heart failure. In order to diagnose myocarditis activity, two sets of criteria were used: one mainly observing histopathologic aspects of inflammatory cells aggressing cardiac fibers; and the other counting the mean number of lymphocytes per high power microscopic field. The results of both methods showed a higher incidence of active myocarditis in the clinical group with heart failure. The present report clearly shows the important role played by activity of myocarditis in the development of heart failure in chronic Chagas' disease. Therefore, the possibility of using drugs to control early stages of the activity of the inflammatory process is suggested. On the other hand, endomyocardial biopsy (EMB) seems to be an adequate method to evaluate the intensity of the cardiac inflammatory process in Chagas' heart disease.