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At least 1,603 records · Page 89Linked to original sources
PubMed1997

A calculation of the forces acting on the human acetabulum during walking. Based On in vivo force measurements, kinematic analysis and morphometry.

Information about the loading of the human acetabulum during walking is necessary for a functional understanding of the morphology of the pelvic girdle and the hip joint as well as for the optimization of endoprosthetic therapy in osteoarthritis. For this purpose, experimental data of the forces acting on the femur in walking taken from the literature [Bergmann et al.: J. Biomech. 1993;26: 969-990] were combined with our own kinematic and morphometric data, to transform the force vectors from the femoral into a pelvic and an acetabular frame. During the walking cycle, the resultant force vector takes a rather constant course relative to the pelvis and its orientation seems to be highly regulated to act within a small range of angles. Only small deviations occur from the angles against the vertical which the resultant peak force forms in the frontal plane (F = 11 degrees, medially orientated) and in the sagittal plane (S = 5 degrees, ventrally orientated). The experimental results form the basis for a model of the incongruous hip joint as an elastic joint, the femoral head being centered between compliant elements.

Acetabulum↗
PubMed1978

[Morphometry and histology of the eye of Callimico goeldii (Thomas 1904, callimiconidae primates) (author's transl)].

The histologic anatomy of the eye of Callimico goeldii is described and histometric data are communicated. The retina is treated with special attention. The eye of Callimico features all characteristics of a visual organ adapted to diurnal activity as is known from many higher primates and man. The well-differentiated Fovea centralis and the numerical relations of the three retinal neurons, which are clearly reduced from the periphery towards the center of the retina, indicate a particularly high degree of centralization ("Zentralisationsstufe" sensu Rohen). Similar numerical relations are found in the taxonomically related families Cebidae and Callithrichidae. A high degree of centralization is understood to facilitate a good visual resolution. The eyelid apparatus is differentiated like in other higher primates. The eye muscles contain extraordinarily many nervous-muscular entities that are interpreted to serve as nervous regulatory functions. The histologic results relate well with certain behavioral phenomena of this species.

Animals↗
PubMed1981

Arterial morphometry in neonatal and infant spontaneously hypertensive rats.

Media/lumen area ratios and density of arteries and arterioles were obtained from tail sections of newborn and 2-week-old spontaneously hypertensive rats (SHR) and normotensive Wistar Kyoto rats (WKY) on prenatal/postnatal high salt diets or standard salt diets. Fixation was by a solution which caused minimal contraction and no differences in contractile response between SHR and WKY. Standard salt SHR of both ages demonstrated significantly greater media/lumen ratios in intermediate size arterioles but not in smaller or larger arterial categories. Prenatal high salt caused significant medial thickening in 49- to 58- micrometer arterioles of newborn SHR. Maintenance on high salt to 2 weeks caused significant medial thickening i SHR arterioles of 19-38 micrometer outside diameter. High salt significantly increased the density of terminal arterioles in 2-week SHR.

Aging↗
PubMed1992

Glomerular morphometry of adriamycin-induced focal and segmental glomerulosclerosis in the rat.

The present paper presents a morphometric study of the evolution of the glomerulus in Adriamycin-induced focal and segmental glomerulosclerosis in the rat over 32 weeks. The morphometric parameters studied generally varied significantly when the groups treated with Adriamycin were compared with controls. Glomerular area and perimeter showed an irregular pattern and finally ended up with values similar to those of the control group. Glomerular capillary tuft area and perimeter were always significantly greater in Adriamycin-treated groups than in controls. The mesangial area of treated animals increased over the study period in comparison with that of controls. While the total number of cells in the glomerular capillary tuft had an irregular pattern, the proportion of cells in relation to glomerular capillary tuft area was significantly lower in treated animals than in controls.

Animals↗
PubMed1995

Glomerular morphometry of twenty-three biopsied patients with IgA nephropathy.

The aim of the present study was the process of an easy method for quantitative evaluation of the alterations of the mesangial matrix, cellularity and urinary space in IgA glomerulonephritis (IgA-GN) by the image analysis technique. A Vidas (Kontron-Zeiss) image analyzer was employed for the morphometric study of renal biopsies from 23 patients with IgA-GN. The following parameters were assessed: mesangial matrix index, expressed as the ratio between mesangial area and total glomerular area x 100; mesangial cellularity index, considered as the ratio between the total number of nuclei contained in the glomerulus and the overall glomerular area in mm2 x 10(4); urinary space/glomerular area ratio. The morphometric results compared to the respective values observed in normal glomeruli indicate an increase in the overall area of glomeruli with IgA-GN and, conversely, a decrease in the total area occupied by the urinary space (p = 0.0001). It can therefore be concluded that the morphometric determination of the morphologic abnormalities occurring in the renal glomerulus with IgA-GN is an extremely useful method to describe the characteristics of this pathologic condition with a rapid and less laborious approach.

Adult↗
PubMed1987

Morphometry of the second trimester fetal brain. Comparison of ultrasonographic and post-mortem findings.

With the increasing use of ultrasound examination in the antenatal period the lack of morphological correlates has become a problem. This study was carried out in order to correct this deficiency. An antenatal real-time ultrasound scan of the fetal head was performed and measurements of the biparietal diameter, occipitofrontal diameter, head circumference and cerebral ventricle-to-hemisphere ratio were undertaken in 103 fetuses at 13-24 weeks gestation. After prostaglandin termination of pregnancy, the fetal brains were perfused in situ through the right carotid artery with 10% formal saline. Horizontal slices of the fetal head were cut, photographs were obtained and measurements of the same parameters as in the ultrasound examination were undertaken. There is a significant correlation (p less than 0.001) between the ultrasonographic and post-mortem measurements of all parameters. Also several anatomical structures of the fetal brain are now confidently identified in the antenatal ultrasound scan, using the anatomical preparations for comparison.

Brain↗
PubMed1994

Histopathological aspects of pelviscopic hysterectomy. Investigation of histological giant sections and morphometry to confirm a new application of minimally invasive surgery.

The present study attempts to confirm the effectiveness of a new method of pelviscopic hysterectomy which maintains the pelvic floor integrity comparable to that in a supracervical uterus amputation. A major advantage of this procedure is that the central portion of the cervix and transformation zone is punched out using a special resection tool for the purpose of removing any potential source of cancer. Thirty-four specimens resected by pelviscopic hysterectomy were investigated using histological giant and serial sections. Morphometrical analysis was performed using MOP-AMO2 (Kontron Instruments). The transitional zone and cervical glands were excised completely with an average security distance of 1.5 cm to the resection margins. No mesonephric remnants were found which might serve as a possible source of adenocarcinoma. Our study confirms that the application of this new technique of pelviscopic hysterectomy is not limited by the development of stump carcinoma while also possessing the additional advantage of maintaining pelvic floor integrity.

Adult↗
PubMed1991

Technical procedures and software for magnification-corrected morphometry of optic disk photography.

In order to obtain a new diagnostic tool for the early diagnosis of glaucoma, we developed a method based on computerized analysis of the optic disk, cup and neuroretinal rim areas. A fundus camera, a personal computer and a graphic tablet are employed. Suitable software was developed for calculating the areas (disk, cup and rim) providing an index, the rim/disk ratio. The method revealed high repeatability and reproducibility. The simplicity and speed of the procedure make this test suitable for routine clinical use in the early diagnosis of glaucoma.

Glaucoma↗
PubMedDate not supplied

Microscopic morphometry of abdominal aorta from men in New Orleans and Guatemala.

Morphometric light microscope measurements were made on 154 abdominal aortas from 77 Guatemalan Indian-white (ladinos) men and from 77 new Orleans white men, aged 15 to 54 years. In each case, means were derived from 12 points measured independently. A progressive increase in intimal lipid with increasing age was observed in men from both countries. Extracellular intimal lipid was consistently higher in men from New Orleans than in those from Guatemala, although not always significantly so. Intimal thickness followed a similar pattern to intimal lipid regarding age and geographic location. Foam cells and leukocytes (mainly monocytes) did not follow a consistent pattern. The smooth muscle cell count was the only variable that was significantly greater in New Orleans men than in Guatemalans aged 15 to 34 years. Morphometric microscopic measurements were significantly correlated with unaided visual estimates of atherosclerotic lesions and with chemical determinations of lipid fractions in the arterial intima. All three methods, gross grading, microscopy, and chemistry, agree in revealing little or nor measureable difference between new Orleans men and Guatemalans younger than 35 years, but an accelerated divergence of the populations over age 35.

Adolescent↗
PubMedDate not supplied

Morphometry of air-drying-induced arteriosclerosis in rat carotid artery. Effect of air-flow rate.

Arteriosclerosis in the Wistar rat carotid artery was induced by air drying of the endothelium, a procedure that caused media necrosis. We describe a number of technical modifications that facilitate the procedure and minimize damage to the vessel wall (i.e., media necrosis). A morphometric study of vessel wall changes induced by endothelial denudation at various air-flow rates showed that necrosis of the inner medial layer and lesion size and position were constant at all flow rates used (greater than or equal to 28 ml/min). The extent of necrosis of the outer medial layers, the endothelial repair, and the shape of the lesions varied with the air-flow rate used. Since at an air-flow rate of 28 ml/min medial necrosis was minimal and myointimal lesion development was as extensive as at higher flow rates, we consider this air-flow rate to be optimal for this model of experimental arteriosclerosis. We hypothesize that the shape of the myointimal lesion is determined by the timespan of endothelial denudation and by the availability of smooth muscle cells in necrotic and normal media. Furthermore, the proliferation of the smooth muscle cells and their migration into the intima is probably dominant over the repopulation of the media by these cells.

Air Movements↗
PubMed1989

Primary pulmonary hypertension. Vascular structure, morphometry, and responsiveness to vasodilator agents.

The use of pharmacologic agents in the treatment of pulmonary hypertension has not proved to be uniformly successful or predictable. One possible reason for the vagaries in response is that the pulmonary vascular lesions are not consistent. We examined the relation between the structure of the pulmonary resistance vessels in unexplained (primary) pulmonary hypertension and the response to pulmonary vasodilators. Our study involved 19 patients with clinically unexplained pulmonary hypertension (mean pressure, 59 +/- 14 mm Hg). After characterizing them clinically and performing control hemodynamic measurements, we determined the acute effects of a series of vasodilator agents that have different mechanisms of action. In 16 patients, lung biopsy material was related to the hemodynamic studies; in nine patients, including six who had undergone open lung biopsy, the hemodynamic studies were related to the pathologic changes found at autopsy. Histologic specimens from all 19 patients were evaluated qualitatively and sorted into three subsets of hypertensive pulmonary arteriopathy: medial hypertrophy (with minimal intimal proliferation), arteriopathy with plexiform lesions (associated predominantly with concentric laminar intimal proliferation and fibrosis), and arteriopathy with microthrombotic lesions (associated predominantly with eccentric intimal proliferation and fibrosis). The 16 lung biopsies were also quantitated by morphometric techniques. Using a decrease in calculated pulmonary vascular resistance of more than 30% accompanied by a decrease in mean pulmonary arterial pressure of at least 10% to define vasodilation, only four patients were responders. The patients varied considerably in their responses to different vasodilator agents. Patients with similar clinical and hemodynamic profiles differed considerably with respect to the nature of their pulmonary vascular obstructive lesions and their responses to vasodilator agents. Qualitative histologic examination of lung tissue did not provide a basis for predicting how individual patients would respond to vasodilator agents. However, quantitative morphologic analysis of the initial open lung biopsy specimens did prove helpful in predicting acute responsiveness to vasodilator agents and the subsequent clinical course of these patients with unexplained (primary) pulmonary hypertension. An intimal area of more than 18% of the vascular cross-sectional area had an 85% predictive value for identifying the patients who did poorly during the first 36 months of follow-up.

Adolescent↗
PubMed1992

Morphometry of human coronary capillaries during normal growth and the effect of age in left ventricular pressure-overload hypertrophy.

BACKGROUND: In adults, acquired pressure-overload left ventricular hypertrophy can result in myocardial ischemia, which may be due in part to insufficient capillary growth during development of hypertrophy. The coronary microvascular response to congenital pressure-overload hypertrophy in children has not been previously characterized. METHODS AND RESULTS: Average capillary density and heterogeneity of capillary spacing were measured in 63 postmortem human hearts with left ventricular hypertrophy and control hearts without heart disease. Pathology specimens were chosen that had left ventricular hypertrophy caused by 1) congenital isolated aortic valve stenosis in infants less than 1 year old at death, children 9-14 years old, and adults 15-30 years old; 2) congenital isolated coarctation of the aorta in adults 15-39 years old; and 3) acquired aortic stenosis in adults 51-86 years old. Major findings of the study were: 1) Human left ventricular capillary density and heterogeneity of capillary spacing are similar to other mammalian species. 2) Capillary density is higher in infants (3,315 +/- 85 capillaries per square millimeter), decreases with increasing heart weight during normal growth in early childhood (children, 2,388 +/- 75 capillaries per square millimeter, p less than 0.05), and thereafter remains relatively constant. 3) Capillary density with left ventricular hypertrophy is dependent on the age of onset. Congenital aortic stenosis and coarctation are characterized by an increase in capillary supply proportional to myocyte volume, maintaining capillary density similar to control hearts. Adults with acquired aortic stenosis have decreased capillary density (1,671 +/- 66 capillaries per square millimeter, p less than 0.01 versus control). CONCLUSIONS: Pressure-overload left ventricular hypertrophy in children demonstrates proportional capillary angiogenesis, whereas in adults, hypertrophy appears to be associated with failure of compensatory angiogenesis.

Adolescent↗
PubMed1978

Morphometry of the small pulmonary arteries in man.

From a resin cast of a normal pulmonary arterial tree, the diameter, length, and number of branches in each order were determined for arteries from 25 to 300 micrometer in diameter. Histological sections 120-micrometer thick were cut from a normal human lung in which the pulmonary artery had been injected with a mixture of ink and gelatin. Similar measurements were made on arteries from 10 to 70 micrometer in diameter, and the mode of origin of the capillaries was studied. The data thus obtained were found to correspond reasonably well to values previously estimated by extrapolation from data for arteries of 100 micrometer or more in diameter. The branching rules apply down to arteries of about 10-15 micrometer in diameter, the estimated number of which is 73 million. Distal to these vessels, capillaries arise either directly from small arteries or indirectly via precapillaries which are given off in great numbers and diverse patterns from the small arteries

Capillaries↗
PubMed1983

Morphometry of exercise-induced right ventricular hypertrophy in the rat.

In our morphometric study of the effects of exercise on the heart, male Wistar-Kyoto rats at 5 weeks of age were subjected daily to a moderate treadmill running program that lasted for 7 weeks. The heart responded to physical conditioning by different magnitudes of tissue growth of the right (22%) and left (7%) ventricular myocardium, the latter change not statistically significant. The increase in right ventricular volume was associated with a 25% enlargement of ventricular area, a 26% average lengthening of the myocytes, and no change in sarcomere length and in ventricular midwall thickness. Exercise produced significant alterations in the quantitative parameters of the microvasculature of the right ventricle, but no appreciable changes in the left ventricle. Right ventricular hypertrophy was characterized by an absolute 44% growth of the endothelial luminal surface brought about through a 16% increase in capillary numerical density, and a 41% augmentation of the total length of the capillary network. Maximum diffusion distance from the capillary wall to the mitochondria of myocytes decreased 10% as a result of capillary proliferation and the lack of lateral expansion of myocyte cross-sectional area. Evaluation of the subcellular constituents of myocytes showed no change in the mitochondria:myofibrils volume ratio, indicating a growth of these components proportional to each other and to the growth of the myocyte population as a whole. It was concluded that, as a result of running exercise, right ventricular growth is analogous to eccentric hypertrophy in which the structural adaptations of the capillary bed can be expected to improve the diffusion and transport of oxygen within the tissue.

Animals↗
PubMed1986

Morphometry of canine coronary arteries, arterioles, and capillaries during hypertension and left ventricular hypertrophy.

The mechanisms responsible for the increase in minimal coronary vascular resistance per unit mass of myocardium in animals with chronic hypertension and left ventricular hypertrophy remain unidentified. Because increases in wall thickness of resistance vessels in some vascular beds in response to hypertension may decrease luminal diameter, we hypothesized that similar changes may occur in the coronary vasculature. To test this hypothesis, we performed hemodynamic and morphometric studies on eight dogs with renovascular hypertension (one kidney, one clip) of 6 weeks' duration, and in six normotensive dogs. Hypertension evoked a 27% increase in left ventricular mass and was associated with a 67% increase in left ventricular minimal coronary vascular resistance per 100 g calculated from coronary perfusion measured with microspheres during adenosine infusion. The vasculature was fixed via perfusion of glutaraldehyde and tissue samples from the left ventricle were embedded in Epon. Wall:lumen ratios, determined by light microscopy, of coronary arteries and arterioles were similar in hypertensive and normotensive dogs. Lumen diameters of large epicardial arteries (greater than 640 microns) of hypertensive dogs increased significantly so that wall:lumen ratios were normal despite an increased medial thickness. Ultrastructural analysis, however, showed an enhancement of the relative extracellular compartment of the tunica media of large coronary arteries of hypertensive dogs: 36.4 +/- 3.4% vs. 26.5 +/- 1.6% (mean +/- SEM). Capillary numerical density and surface area (surface area:tissue volume) were significantly lower in the endomyocardium, while capillary volume density (volume:tissue volume) was lower in the midmyocardium and endomyocardium of hypertensive dogs compared to normotensives.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗