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At least 1,099 records · Page 61Linked to original sources
PubMed1982

Acute vitamin D2 (ergocalciferol) toxicosis in horses: case report and experimental studies.

Acute accidental vitamin D2 (ergocalciferol) toxicosis was diagnosed in a 6-month-old foal with extensive lesions of soft tissue mineralization. In an experimental study, three 18-month-old horses were given ergocalciferol per os at a rate of 9,300, 22,200, or 47,200 IU/kg of body weight/day for 21 days. Clinical signs or lesions were not seen in horses given the low and intermediate doses, whereas the horse receiving the highest dose developed clinical signs and lesions similar to those noted in the foal. Signs included depression, loss of appetite, weakness, limb stiffness with impaired mobility, and cessation of growth or weight loss. Gross and histologic lesions of mineralization of various soft tissues, especially of the endocardium and wall of large blood vessels, were seen in the foal and the horse given the high dose. Marked, persistent, hyperphosphatemia (7.0 to 13.0 mg of P/dl of serum) developed in each horse. The horse given the intermediate dose remained normocalcemic. Horses given the low and high doses became hypercalcemic (13.6 to 14.5 mg of Ca/dl of serum), but serum calcium concentrations varied from day to day and both horses were normocalcemic at necropsy (12.4 to 12.7 mg of Ca/dl of serum). Distal metacarpal bone ash concentrations of calcium, phosphorus, and magnesium of the foal were mg/g of bone ash) 400.5, 180.5, and 5.30, respectively. In the horses, treatment with ergocalciferol also had no significant effect on serum magnesium (1.88 to 2.18 mg/dl of serum) or distal metacarpal bone ash concentrations of calcium (352.5 to 362.5 mg/g of bone ash), phosphorus (182.5 to 184.0 mg/g of bone ash), or magnesium (5.48 to 6.02 mg/g of bone ash).

Animals↗
PubMed1981

[Changes in the heart in the carcinoid syndrome].

An observation of carcinoid syndrome in a woman of 47 suffering from malignant carcinoid of the ileum with metastases into the liver and right ovary is described. The clinical picture included diarrhea, heat waves, bronchospasms, hypertension, hyperserotoninemia, affection of the mitral valve and left atrium. "Carcinoid plaques" in the endocardium formed due to excessive proliferation under the influence of serotonin and kinins of polypotent subendothelial cells followed by their differentiation into fibroblast-like and smooth-muscle elements and production of basophilic interstitial substance. The receding rheumatic affection of the mitral valve may be the cause of the predominant involvement of the left part of the heart.

Autopsy↗
PubMed1978

Infective endocarditis: a review. I. Incidence, etiology, pathology and clinical features.

In this paper demographic characteristics, etiology, pathology and clinical features of infective endocarditis are reviewed simultaneous presentation of the data from our series of 50 cases with infective endocarditis. The peak incidence of infective endocarditis is between 11 and 15 years. Both sexes are equally affected. Patients with congenital or acquired heart disease tend to have hemodynamic trauma to the endocardium and vascular endothelium. These sites form the nidus for circulating bacteria of either spontaneous origin or the result of any oro-dental, genitourinary or other surgery or procedures and produce vegetations characteristic of infective endocarditis. The location of the vegetation is dependent upon the predisposing cardiac lesion. Embolic phenomenon is another cardinal feature of endocarditis and may occur in any organ system. Although a large variety of microbes have been known to cause endocarditis, streptococci and staphylococci remain the most frequent offenders. Clinical diagnosis of infective endocarditis is difficult because of the insidious onset and varied clinical features. A high degree of suspicion is essential for early diagnosis. Any patient with known heart disease and unexplained fever should be suspect for endocarditis. Splenomegaly, petechiae and embolic phenomena support this diagnosis. New or changing murmurs, splinter hemorrhages, Osler's nodes. Janeway's lesions and Roth's spots may be present. Elevated sedimentation rate, microscopic hematuria, leukocytosis with a shift-to-the-left and anemia may further support the diagnosis. Congenital or acquired heart disease and fever are all that will be present in many cases. Only isolation of the causative agent from the blood can confirm the diagnosis.

Adolescent↗
PubMed1980

Pathology of experimental radiation pancarditis. I. Observation on radiation-induced heart injuries following a single dose of x-ray irradiation to rabbit heart with special reference to its pathogenesis.

Radiation-induced heart injuries were morphologically studied by using the rabbits irradiated with a single dose of 3,000R (group I) or 300R of X-ray group II) from 1 hour until 6 months. There was no essential difference in the lesions of the hearts from group I and that of group II. Acute epicarditis was found as early as 1 hour after irradiation and it became maximum in severity at 1-2 days. In the myocardium, there were degeneration and resolution of the myocardial cell, various architectural changes of mitochondria, and disorganization of the intercalated disc. Polymorphonuclear cell infiltration and endothelial injuries of the capillaries occurred in the interstitial tissue. In addition, endocarditis with or without thrombus formation was often found. Acute inflammation was seen in the myocardium of group II rather later than that of group I, but it disappeared earlier. In the later stage, fibrosis finally occurred in the epicardium and endocardium. Glycoprotein degeneration of the muscle cells and fibrosis appeared in the myocardium. The pathogenesis of radiation pancarditis is thought to be dependent not only on the disturbance of microcirculation caused by endothelial cell damage of the capillaries, but also on alterations of the myocardial mitochondria as a result of direct injury.

Animals↗
PubMed1980

Observations on endocardial lesions in pigs.

The heart valves and mural endocardium of 1000 sows, aged one to six years, and of 500 pigs, aged six months, were examined at the time of slaughter in an abattoir. Abnormalities were found in 9.8 per cent of sows and 1.2 per cent of the six-months-old pigs. The principal lesions encountered were atrial ridges and plaques, thickened valves, cystic valves and nonvegetative endocarditis; their histological features are described. The majority of the abnormalities were found on the left side of the heart.

Animals↗
PubMed1978

[Changes caused by ultrasound in the isolated rat heart and in the rat heart in situ].

1. The morphological alterations of rat hearts were investigated on isolated and on in situ organs after exposure to ultrasound. The ultrasonic waves, at 850 kHz frequency, were administered for 2 to 4 minutes with an energy of 2 to 4 watts/cm2. 2. In the exposed area, the pathological modifications are occurring in four successive steps. At the initial stage, the myocardial cells swell, at the second one one they contract and still later they show cleared spots and breakage lines, which may lead to fragmentation of the fibres. At the fourth stage the cells undergo a granular, mottling and vacuolar degeneration. 3. The epicardium demonstrates spotted blebs and swollen areas. It sometimes disintegrates or disappears, and can also cover some bleedings. Similar changes are found in the endocardium. 4. The alterations of the connective and endothelial cells correspond to those of the myocardial cells. Where the latter are swollen or contracted, the blood vessels are enlarged. In the regions with fragmented or degenerated muscle cells they are frequently necrotic. 5. In the wall of the left ventricle, the ventral part demonstrate more alterations than the dorsal one. However an exception is made by the tissues immediately next to border zones. Cellular and tissular damages augmented by increase in exposure period or energy.

Animals↗
PubMed1994

[Diagnosis of endomyocardial fibrosis with endomyocardial biopsy].

Ten cases of endomyocardial fibrosis (EMF) were diagnosed with angiocardiography in showing a huge right atrium' tricuspid regurgitation and obliteration of right ventricular apex. The diagnosis was confirmed in 9 of them pathologically after right ventricular endomyocardial biopsy (EMB) in showing striking thickening of endocardium with presence of fibrosis. The remaining case was not confirmed with EMB. It is concluded that EMB is a quite useful method in the diagnosis of EMF. The cause of misdiagnosis in the tenth case was discussed.

Adolescent↗
PubMed1994

[Electron canon computed tomography. Technique and clinical applications in cardiac imaging].

Electron Beam CT (EBCT) was initially devoted to both dynamic and morphological cardiac studies. ECG gated slices acquired in 100 milliseconds produce cardiac images without motion artefacts. Intracavitary tumors and thrombus are clearly detected and EBCT contributes to the stagging and follow-up of masses. Exploration of congenital abnormalities such as pulmonary atresia can be performed even in newborns. EBCT allows the diagnosis of tiny modifications of coronary arteries, endocardium or pericardium. EBCT offers a new modality of cardiac imaging which gives complementary informations to other modalities.

Coronary Disease↗
PubMedDate not supplied

Grade 2 cellular heart rejection: does it exist?

According to the International Society for Heart and Lung Transplantation, a single focus of lymphocytic infiltration associated with myocyte injury in a cardiac allograft endomyocardial biopsy is focal moderate cellular rejection (Grade 2). We reviewed 115 endomyocardial biopsy specimens that were completely negative (n = 17), had a Quilty A (n = 17) or Quilty B (n = 46) lesion, or had a lesion fulfilling the criteria of grade 2 rejection (n = 35). By studying step sections (mean = 18) or sections stained for elastic tissue and collagen, we showed continuity of the focus of grade 2 rejection with the endocardium in 32 of 35 cases; these results justify reclassification of these foci as Quilty B lesions, which are defined as endocardial infiltrates that encroach on the underlying myocardium and that may be associated with myocyte injury but are not generally considered to represent acute rejection. Immunohistochemical staining for T and B lymphocytes and histiocytes showed similar patterns in deeper zones of Quilty B lesions and lesions initially regarded as grade 2 rejection. Normal hemodynamics were observed with 16 of 17 completely negative biopsy specimens, 16 of 17 Quilty A biopsy specimens, 46 of 46 Quilty B biopsy specimens, and 35 of 35 grade 2 rejection biopsy specimens. No grade 2 rejection was treated; only 1 biopsy specimen progressed to grade 3A rejection in a subsequent biopsy 2 months later. Most, if not all, cases of grade 2 cellular rejection can be shown to be Quilty B lesions, are not associated with hemodynamic abnormalities, and do not require augmented immunosuppression.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1994

Morphological change in myocardium in goat recovered from profound left ventricular failure with cardiac assist device.

With left ventricular assist device (LVAD) pumping, goats having induced-heart-failure were salvaged. LVAD was weaned off when the heart seemed to recover, and animals were kept alive for about 1 month after the pump removal. After termination of the experiments, infarction area was 10 to 50% of the left ventricular wall including the septum. The longer pumping period against severe infarction resulted in the thinner wall thickness of normal myocardial area. The myocyte diameter (Dm) was microscopically measured in 3 layers: sub-epicardium, middle myocardium and sub-endocardium. Subendocardial Dm was largest, and followed by Dm in middle myocardium, and then Dm in subepicardium. These results coincided with results obtained from a control-heart experiment except that Dm in the normal area of recovered hearts was thicker. The relation between Dm and left ventricular external mechanical work computed from left ventricular pressure-volume relation showed an adaptive control mechanism of myocardium.

Animals↗
PubMed1975

Nonuniform subendocardial fiber orientation in the normal macaque left ventricle.

Fiber-angle changes in tangential planes through the heart wall are described in two macaque left ventricles at four equatorial and three near-apical sites. At each site, starting at a strongly negative angle at the epicardium, the fibers swing circumferentially short of midwall and continue their progressive climb to positive angles. Angles depart from the steady climb in the subendocardial region, and beyond the endocardium a wide scatter of fiber angles persist into the free trabeculae, the profuseness of which motivated this study. An interface is described histologically, coinciding with the fiber-angle deviations in the subendocardial sections, which divides the compact region of the wall from the trabeculated region. A dual function is postulated for the mural portion of the trabeculated region of the heart wall.

Animals↗
PubMed1975

Decreased myocardial fibrinolytic activity following temporary ischaemia and reperfusion.

The effect of temporary myocardial ischaemia (x 52 mins) and reperfusion (x 23 hrs 8 mins) on myocardial tissue fibrinolysis and 125I fibrinogen incorporation into fibrin was investigated in nine baboons. Fibrinolytic activity was reduced by 54% in the endocardium of the ischaemic reperfused myocardium and the 125I fibrinogen activity was elevated by 480%. The reduction in myocardial fibrinolytic activity following ischaemia and reperfusion may be due to endothelial damage.

Animals↗
PubMed1975

[Endocardial resection: surgical treatment of constrictive fibrous endocarditis].

A new operation, the resection of the endocardium, is proposed in the case of fibrous constrictive endocarditis. I performed this operation in 1971, for the first time, with good results. I operated on two other patients with success in 1973 and 1975. The results I have obtained indicate that this new technique is possibly the answer to a disease which otherwise ultimately results in death.

Adolescent↗
PubMed1994

[Biomechanical pump as a cardiac assist and replacement system--the trend of research and development].

The trend of research and development of biomechanical pump (BMP) reviewed and two BMPs were presented. One was the BMP, consisting of a skeletal muscle ventricle, lined with a bioartificial endocardium. It consisted of a structural matrix made of a polyurethane porous membrane, fragmented blood vessels and collagen gel. In vitro and in vivo construction showed that this could provide biocompatibility. Another BMP is the system actuated by in situ latissimus dorsi muscle (LDM). Bellows were mounted on the back of the pump. The force of LDM contraction was transmitted through cables to the bellows resulting in blood ejection. To assist the pump filling and LDM re-extension, an additional force was incorporated to the pump. The prototype system showed good performance.

Animals↗
PubMed1994

Scanning electron microscopy study of endocardial regeneration in bovine pericardial patch-grafts implanted in the canine heart.

The pattern of endocardial regeneration was studied in bovine parietal pericardial patch-grafts implanted in canine hearts. The grafts consisted of fibrous tissue without a cellular lining. They were implanted with either the thoracic or the cardiac surface facing the lumen of the canine ventricle to evaluate the effect on endocardial regeneration. The grafts were retrieved 7, 21, 45 and 60 days after implantation and were examined using scanning electron microscopy. At 7 days, both the thoracic and the cardiac aspect exhibited connective tissue fibers, focally covered by fibrin, platelets and blood cells. The cardiac aspect showed finer and more highly intermingled filamentous fibers than the thoracic aspect. At 21-60 days, the thoracic surface displayed a continuous network of connective fibers with a few blood cells and isolated groups of spindle-shaped cells resembling fibroblasts. At 21-60 days, the cardiac surface showed a diffuse growth of cells on the connective fiber substratum. Regenerating cells first lined the periphery of the grafts (21 days) and then proliferated towards the centrum (45-60 days). These cells varied in size and shape, were mostly closely packed, exhibited numerous microvilli or longer cytoplasmic projections, and resembled regenerating endothelial cells and mature endocardial cells. The topographic arrangement of the new lining cells suggests that they were the result of a per continuitatem regeneration (endothelial re-endothelialization) and that they they originated from the healthy endocardium of the host surrounding the implantation site. The arrangement of the connective fibers, finer on the cardiac than on the thoracic aspect, probably facilitated the development of a cellular lining.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1993

[An experimental study of catheter ablation using microwave energy via coaxial electrode catheter].

The purpose of this study was to examine the efficacy, arrhythmogenicity, and the size of ablated lesions of catheter ablation with microwave energy. Microwave energy generated by a device with a frequency of 2450 MHz, was delivered via a bipolar electrode coaxial catheter with an electrode ball tip. Microwave ablation was applied (50 watts for 15-150 sec.) on the left ventricular endocardium in 6 dogs. No ventricular arrhythmia occurred during ablation in any of the dogs when microwave catheter ablation was applied for less than 45 sec. However, when the duration of microwave catheter ablation was longer than 45-60 sec, ventricular premature contractions were observed in all 6 dogs. When ablation time was set for a longer time, the dogs developed nonsustained ventricular tachycardias. Nevertheless, ventricular arrhythmias after ablation did not occur in all dogs. Ventricular programmed stimulation after ablation did not induce ventricular tachycardia in any of the dogs. When ablation time lasted more than 120 sec, the coagulation layer was extended to the epicardium in all 6 dogs. The results of this study suggest that microwave ablation is feasible for the treatment of tachyarrhythmias from a deep focus of the ventricular myocardium.

Animals↗
PubMed1977

Intraoperative mapping of atrial activation before, during, and after the Mustard operation.

Thirty-eight patients with transposition of the great arteries underwent intraoperative mapping of atrial epicardium and endocardium during various stages of the operative procedure. The purpose was to determine the electrophysiological basis of the postoperative supraventricular arrhythmias associated with this operation. Comparisons were made between atrial activation patterns and times before and after each of the following stages: (1) cannulation, (2) atriotomy, (3) excision of atrial septum and coronary sinus, and (4) placement of intra-atrial baffle. The first stage produced no significant changes in atrial activation times or patterns but did demonstrate a shift of the functional pacemaker to the sulcus terminalis in 8 of 14 patients studied. Longitudinal atriotomy did not significantly lengthen atrial activation. Transverse atriotomy did not alter activation times of the His bundle but did significantly change patterns of epicardial and endocardial activation. Excision of the septum and coronary sinus always produced block in the posterior crista terminalis, and placement of a baffle worsened this block. Four patients developed nodal rhythm on the operating table and had both a posterior crista terminalis block and anterior septal block. Suggestions for modification in the surgical techniques were advanced to help prevent rhythm disturbances in paitients undergoing transvenous correction of transposition of the great arteries.

Arrhythmias, Cardiac↗
PubMedDate not supplied

[Effects of midazolam on the delivery and consumption of myocardial oxygen in the postoperative period of children undergoing heart surgery].

INTRODUCTION: The aim of this study was to evaluate the effect of midazolam on the variables which determine myocardial oxygen delivery and consumption relationship (endocardiac viability index) in children undergoing cardiac surgery under extracorporal circulation. METHODS: The study was carried out in 15 children to whom a doses of midazolam of 0.2 mg/kg was given in immediate postoperative period upon hemodynamic stabilization. The determinations were performed prior to administration of the drug, at 5, 15, and 30 minutes thereafter. The variables analyzed were mean systemic blood pressure, mean diastolic pressure in aorta, mean pressure in the left auriculum, diastolic-systolic time relation, arterial blood O2 content and index of endocardiac viability. RESULTS: The following variables were modified with respect to the basal contributing to an improvement in the endocardiac viability index. Mean aortic diastolic pressure decreased 10.05% at 5 min and 6.17% at 15 min (p < 0.05, p < 0.005); mean systemic arterial pressure decreased 10.64% at 5 min and 6.9% at 15 min (p < 0.05, p < 0.005); the mean pressure in the left auriculum decreased 6.28% at 5 and 8.32% at 15 min (p < 0.05); the diastolic-systolic time relation increased 24.04% at 5 min (p < 0.05, p < 0.005). The index of delivery and consumption of endocardiac oxygen increased 23.4% at 5 min (p < 0.05). CONCLUSIONS: The intravenous administration of midazolam to children at doses of 0.2 mg/kg during the postoperative period of cardiac surgery produced an improvement in the delivery and consumption of oxygen to endocardium at 5 minutes of its administration.

Anesthesia Recovery Period↗