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Biomedical subjects

B Winkler

Publications and source records attributed to B Winkler.

At least 73 records · Page 4Linked to original sources
PubMed1984

Pitfalls in the diagnosis of endometrial neoplasia.

One hundred consecutive cases of hyperplasia of the endometrium were referred to the Sloane Hospital for Women. The referral diagnoses and consultation diagnoses were compared for the purpose of analyzing common diagnostic problems in interpretation of endometrial hyperplasias and the use of diagnostic terminology as it applies to prognosis and therapy. The consultation diagnosis was a down grade of the original diagnosis in 69% of the reviewed cases. The most common endometrial pathology misinterpreted as hyperplasia was endometrial polyps, followed by the endometrial metaplasias, and architectural distortion caused by necrosis and mechanical artifact. In 14% of the referral diagnoses, the use of terminology was vague, with such terms as endometrial, epithelial, or glandular hyperplasia, and did not communicate the prognostic intent of the referring pathologist to the consulting physician. The careful use of endometrial diagnostic terms accompanied by a statement of the system of classification used and its corresponding clinical intent is suggested.

Adenocarcinoma↗
PubMed1984

Chlamydial endometritis. A histological and immunohistochemical analysis.

A series of 90 endometrial biopsies and curettings originally diagnosed as chronic endometritis were reviewed and histological findings of plasma cells, lymphoid infiltrate, stromal necrosis, acute inflammation, lymphoid follicles, and epithelial atypia were correlated with the demonstration of chlamydial antigens by the immunoperoxidase technique. Chlamydial antigens were localized within endometrial epithelial cells in four cases. Although these four cases represented only 4% of the total number, chlamydial immunoperoxidase positivity was best discriminated by the severity of the inflammation and the presence of an acute inflammatory infiltrate. Among cases of severe endometritis 22% were chlamydia-positive, and in those cases with an associated acute inflammatory infiltrate, 57% were positive. A high index of suspicion of chlamydial infection should exist when severe endometritis is diagnosed in patients with clinical histories of post-abortal state, pelvic inflammatory disease, secondary infertility or menometrorrhagia, and chronic pelvic pain.

Adult↗
PubMed1982

The effects of global ischemia and reperfusion on human myocardium: quantitative evaluation by electron microscopic morphometry.

During open-heart operation, myocardial biopsies were taken from 31 patients undergoing aortic valve replacement during total cardiopulmonary bypass. The first needle biopsy was taken before induction of cardiac arrest (Kirsch cardioplegia), the second at the end of global ischemia, and the third during the reperfusion period. Teh tissue was investigated by electron microscopy, in both a qualitative and a quantitative manner (morphometry). Ultrastructural morphometry revealed cellular and especially mitochondrial swelling that occurred during the reperfusion phase, but not after ischemia alone. On the basis of morphological measurements, this study shows the occurrence of postischemic cellular and mitochondrial edema that possibly might be avoided by the use of improved techniques of myocardial protection during operation.

Aortic Valve↗
PubMed1981

Changes in blood-flow in the bones after osteotomy and osteosynthesis.

The blood-flow can be measured with the method of "tracer microspheres". In 15 adult shepherd-dog bastards the blood-flow in the bones of the posterior extremity was determined. The blood-flow in callous bone is 6 times higher than in cortical bone. The values for blood-flow are decreasing from the proximal to the distal end, in cortical as well as in callous bone. In 10 of the 15 dogs the blood-flow was determined after manipulation of the bone. If the medullary cavity of the tibia was evacuated the blood-flow of the corticalis in the bone shaft diminished; it was reduced 3 times more than after removal of the periost. If an osteotomy was performed in the middle of the shaft, the blood-flow was more reduced distally than proximally. In the corticalis of the shaft the blood-flow of the proximal fragment drops only when an osteosynthesis is performed. In extended oblique fractures the upper ends of the fragments--proximally as well as distally--are endangered by a reduction of the blood-flow.

Animals↗
PubMed1981

Thickening of the posterior wall of the bronchus intermedius. A sign on lateral radiographs of congestive heart failure, lymph node enlargement, and neoplastic infiltration.

The posterior wall of the bronchus intermedius (PWBI) is outlined on most lateral chest radiographs by air in the lumen and in adjacent lung. In a prospective review over a 19-month interval, the authors found 36 patients whose PWBI was thick, defined as thickness greater than the normal upper limit of 3.0 mm (33 patients) or as increase of 1.5 mm in thickness compared with control radiographs (three patients). Uniform thickening was found in 23 patients as a sign of congestive heart failure. Nine subjects with neoplastic thickening of the PWBI demonstrated either uniform (six patients) or lobulated (three patients) enlargement. Two patients with sarcoidosis showed lobulated thickening of the PWBI. Inspection of lateral chest radiographs for thickening of the PWBI may be helpful in establishing bronchial involvement by edema, neoplasm, or enlarged lymph nodes.

Aged↗
PubMed1980

Ultrastructural evaluation of the effects of global ischemia and reperfusion on human myocardium.

During open-heart surgery, myocardial biopsies were taken from 31 patients undergoing aortic valve replacement on total cardiopulmonary bypass. The first needle biopsy was taken before the induction of cardiac arrest (Kirsch cardioplegia), the second at the end of global ischemia, and the third during the reperfusion period. The tissue was investigated by electron microscopy using a semiquantitative scoring system for changes in both myocytes and blood vessels. Mitochondrial volume and surface density were determined by morphometry. Reversible ischemic injury of moderate to severe degree occurred in cardiac cells and in small blood vessels. On reperfusion, signs of damage regressed earlier in myocardial than in vascular tissue. Morphometry revealed significant mitochondrial swelling during the reperfusion phase, but this was not present after ischemia alone. It is concluded that Kirsch cardioplegia as applied here, is unable to protect the heart from ischemic cellular damage.

Biopsy↗
PubMed1977

Role of cardiac contractility in hypertrophy from chronic volume loading.

In an experimental model of chronic cardiac volume overloading, ie chronic A-V block, evaluations of cardiac function were performed during the phase of the development of hypertrophy (one and two weeks of A-V block) and at stable hypertrophy (ten weeks of A-V block). During a time period of ten weeks of volume overload left ventricular muscle mass increased to 1.41 of normal hearts. Cardiac performance measured from cardiac index, stroke volume, and left ventricular ejection fraction was not depressed at any evaluated state of hypertrophy. Normal cardiac performance was also demonstrated when the heart was stressed by high ventricular pacing rates. The contractile state of the intact heart was expressed as the velocity of the isometric left ventricular pressure rise (dP/dt) at comparable loading conditions. Increased dP/dtmax at a stage before stable hypertrophy was reached, even when preload is normalised by ventricular pacing (70/min) implies that the volume overloaded heart during the development of hypertrophy mobilises part of its contractile reserve. It is assumed that increased contractility is a functional cause of an increase in oxygen demand; and that an adequate energy availability is covered by the enlargement of the mitochondrial mass. At stable hypertrophy when the contractile material has also increased, a new steady state is reached and an again normal contractility indicates an also stable dynamic situation.

Animals↗
PubMed1976

Quantification of collateral resistance in acute and chronic experimental coronary occlusion in the dog.

The resistance to coronary blood flow in various parts of the myocardium was studied with the tracer microspheres technique before and immediately after an acute coronary occlusion and several weeks after a more slowly occurring coronary occlusion by Ameroid constrictor. All experiments were carried out in the isolated, metabolically supported, empty, beating dog heart at maximal coronary vasodilation induced with adenosine. Coronary resistance of the normal empty beating heart at maximal coronary vasodilation was 0.20 mm mm Hg/(ml/min) per 100 g of tissue (subepicardium) and 0.16 mm Hg/(ml/min) per 100 g of tissue (subendocardium). After acute coronary occlusion the perfusion of the subtended myocardium was maintained at a much lower level by way of collateral vessels, which showed a resistance to flow of 3.52 mm Hg/(ml/min) per 100 g. If coronary artery occlusion proceeded more slowly the collateral vessels became more functional and myocardial infarction was avoided. During collateral enlargement collateral resistance fell from 3.52 to 0.22 mm Hg/(ml/min) per 100 g within a period of 8 weeks after implantation of the constricting device. The degree of compensation by collaterals for the loss of the occluded native coronary artery was 33% of its former conductance.

Acute Disease↗
PubMed1975

[Contraction disorders of the left ventricle in ischemic heart disease. Studies using atrial stimulation].

Sixty-one patients with suspected ischemic heart disease (IHD) have been investigated by atrial stimulation (AST). Group A patients had normal coronarograms and served as controls. Group B patients had pathological conronarograms (at least 50% stenosis in one of the 3 vessels) and normal ventriculograms. Group C patients had pathological coronarograms and ventricular aneurysms. During AST, group C patients exhibited lower dp/dt max and dp/dt min as well as higher left ventricular end-diastolic pressure (LVEDP) and/or mean pulmonary artery pressure (MPAP) than groups A and B. Group B differed from group A only by increased MPAP during AST. When compared to controls, contractility in group C was reduced even at rest. AST offers an excellent means of diagnosing IHD if heart rates of 140/min and above are used. An abnormal increase in MPAP serves as the simplest parameter for IHD. Elevated MPAP at rest prompts suspicion of ventricular aneurysm. It is possible to deduce a quanitative estimate of contracitility by correlating dp/dt max to LVEDP. A hyperbolic relation results.

Adult↗
PubMed1975

Influence of perfusion pressure and heart rate on local myocardial flow in the collateralized heart with chronic coronary occlusion.

We studied the influence of controlled changes in perfusion pressure and heart rate on the regional distribution of myocardial flow in normal dogs and in dogs with multiple chronic coronary artery occlusions but without infarctions. Local myocardial blood flow was determined with the tracer microsphere technique. By stepwise altering of systemic blood pressure during maximal vasodilation classical pressure flow relations were obtained. One week after complete chronic occlusion a functionally and anatomically well-defined compartmentation of blood flow was found. The dilatory reserve is clearly compromised not only in the collateral-dependent myocardium but also in the apparently normal myocardium which delivers collateral flow. An "arterio-arterial shunting" mechanism is shown to exist. Several months after coronary occlusion, regional mycoardial flow is still nonhomogeneous. Although the coronary dilatory capacity of the collateralized myocardium is nearly normal, that of the normal myocardium is found to be higher than normal. Vessel growth in both areas is discussed as being responsible for this phenomenon. Right ventricular pacing during maximal vasodilation produces a flow decrease to the endocardial muscle layers in normal dogs, while the epicardial flow is unchanged. One week after complete chronic coronary occlusion pacing during maximal vasocilation reduces the dilatory capacity in the collateralized areas to such an extent that the supplementary increase in myocardial oxygen demand will induce ischemia because of the compromised oxygen supply.

Animals↗
PubMed1975

Frequency potentiation and postextrasystolic potentiation in patients with and without coronary arterial disease.

Frequency potentiation and postextrasystolic potentiation of myocardial contractility were induced in 17 patients found not to have cardiac disease (group 1) and in 10 patients with coronary arterial disease (group 2). Atrial stimulation was performed starting at a rate of 110/min and going up to 200/min (frequency potentiation). Single, premature ventricular beats with decreasing coupling intervals were induced every fifteenth beat during basal atrial stimulation at 125/min, after which compensatory pauses were provided (posts used an an index of contractility. With increasing heart rate dp/dt max was augmented equally, in both groups of patients, by frequency increases and premature beats (the coupling interval of the extrasystole being expressed as heart rate). dp/dt min and left ventricular systolic pressure remained unchanged while left ventricular end-diastolic pressure decreased in both groups of patients with the two forms of potentiation It was concluded that both these forms of potentiation have the same augmenting effect on myocardial contractility. Shortening the coupling intervals of premature beats caused a decreased in left ventricular end-diastolic pressure, suggesting that the Frank-Starling mechanism was not involved in postextrasystolic potentiation. Patients with coronary arterial disease had lower values of dp/dt max, dp/dt min, and higher values of left ventricular end-diastolic pressure during rest and stimulation procedures, while the systolic pressures equalled those in the control group. Though individual case values from the healthy and diseased hearts might be similar, it was only under the stress of potentiation that the true state of contractility was made apparent. Impairment of dp/dt min was not found without an impairment of dp/dt max in the presence of myocardial ischaemia.

Adolescent↗