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PubMed1988

Distribution of insulin-like growth factor II receptor immunoreactivity in rat tissues.

Antibodies specific for the insulin-like growth factor II (IGF-II) receptor were used to study its distribution in a number of rat tissues and cell lines in order to determine which cells might be responsive to local or circulating IGF-II. In cultured 18-54,SF and B104 neuroblastoma cells, plasma membrane and cytoplasmic staining corresponding to Golgi apparatus could be seen, consistent with the glycoprotein nature of this receptor. Antibody binding was also seen in the central nervous system, confined primarily to the choroid plexus, and the vascular and ependymal elements. Some staining was seen in the parenchyma of the brain, in addition to binding around nerve sheaths and axon bundles. There were high levels of immunoreactivity in all three lobes of the pituitary, including vascular and cellular elements. In liver, highest levels of immunoreactivity occurred in the sinusoidal cells. In lung, IGF-II receptor immunostaining was seen in the alveoli and around the bronchioles. Staining in kidney was observed in glomeruli, tubules, and Bowman's capsules. Lower levels of immunostaining were seen in skeletal muscle, located primarily around the muscle sheaths. Localization of IGF-II receptor to cells of known function in different tissues will help elucidate the role of this ligand-receptor system in regulating growth and metabolism.

Animals↗
PubMed1992

The pathologic changes in the conduction system beyond the age of ninety.

The conduction systems of two women who were 92 and 91 years of age, respectively, were examined by serial section. The first patient had sick sinus syndrome for more than 20 years, and the second patient had intermittent complete AV block that alternated with normal sinus rhythm for 12 years before her death. Both patients had severe coronary artery disease and had pacemakers and were doing well. The conduction systems in both revealed fatty metamorphosis in the approaches to the SA and AV nodes, the SA node, the AV node, and the atria with fibrotic changes in the ventricular septum, the AV bundle, and the bundle branches. Patient 1 had normal SA nodal artery and patient 2 had extensive vascularization of the AV node. As the heart ages, fatty replacement of the atria affect the SA and AV nodes, and fibrotic changes of the ventricular septum affect the AV bundle and the bundle branches. Adequate collateral anastomosis to the conduction system may prevent the development of permanent complete AV block in the elderly.

Aged↗
PubMed2000

A cytoskeletal basis for wood formation in angiosperm trees: the involvement of microfilaments.

The cortical microfilament (MF) component of the cytoskeleton within axial elements of the secondary vascular system of the angiosperm tree, Aesculus hippocastanum L. (horse-chestnut) was studied using transmission electron microscopy of ultrathin sections and indirect immunofluorescence microscopy of actin in thick sections. As seen by electron microscopy, MF bundles have a net axial orientation within fusiform cambial cells and their secondary vascular derivatives (i.e. in the axial xylem and phloem parenchyma, xylem fibres, vessel and sieve elements, and companion cells). Immunofluorescence studies, however, reveal that this axial orientation can be more accurately described as a helix of extremely high pitch; it is a persistent feature of all axial secondary vascular elements during their development. Helical MF arrays are the only arrangement seen in secondary phloem cells. However, in addition to helices, other MF arrays are seen in secondary xylem cells. For example, fibres possess ellipses of MFs associated with simple-pit formation, and vessel elements possess circular arrays of MFs that associate with the developing inter-vessel bordered pits, ray-vessel contact pits, and with the perforation plate. Linear MF arrays are seen co-oriented with the developing tertiary wall-thickenings in vessel elements. The possible roles of MFs during the cytodifferentiation of secondary vascular cells is discussed, and compared with that of microtubules.

Actin Cytoskeleton↗
PubMed2007

Arthroscopic single-bundle reconstruction of posterior cruciate ligament with quadrupled hamstring tendon.

OBJECTIVE: To evaluate the technique and outcome of arthroscopic single-bundle reconstruction of posterior cruciate ligament (PCL) with quadrupled hamstring tendon. METHODS: From April 2001 to October 2004, 49 knees with PCL tears in 49 patients were verified with arthroscope in this department. Of them, 13 were combined with anterior cruciate ligament tears, 14 with disruptions of the posterolateral corner, 6 with ruptures of the posteromedial corner and medial collateral ligament, 9 with lateral meniscus tears, 5 with medial meniscus tears and 2 with popliteal vascular tears. All the damaged PCLs were reconstructed with single-bundle of autogenous quadrupled hamstring tendons under arthroscope. Biodegradable interference screws or blunt titanium interference screws were used for direct anatomic fixation of the reconstructed ligament. RESULTS: After operation, no severe complications occurred at early stage in the 49 patients. All of them were followed up for 10-52 months with an average of 22.0 months+/-10.7 months. Lysholm score was remarkably improved from 30-60 (mean: 47.96+/-8.16) preoperatively to 70-95 (mean: 89.08+/-6.10) at the last postoperative follow-up (P less than 0.01). Furthermore, there was a significant improvement in International Knee Documentation Committee (IKDC) score from abnormal (Grade C) in 10 knees and severely abnormal (Grade D) in 39 preoperatively to normal (Grade A) in 20, nearly normal (Grade B) in 24 and abnormal in 5 at the last follow-up. Of the 49 patients, 40 returned to the same activity level as before and 9 were under the level. CONCLUSIONS: Single-bundle reconstruction of PCL with quadrupled hamstring tendons has the advantage of minimal trauma in surgery and satisfactory outcome.

Adolescent↗
PubMed1982

F-actin in conifer roots.

The distribution of F-actin in the complex tissues of a higher plant organ has been visualized by fluorescence labeling the roots of the conifers Chamaecyparis obtusa and Pseudotsuga menziesii with F-actin-specific fluorescent dye-conjugated phallicidin. F-actin is present in the parenchymatous cells of the vascular tissue. Some vascular parenchyma cells possess larger numbers of F-actin-containing structures (microfilament bundles) than are known to exist in any other higher plant cell. Tissue type appears to be an important determinant of the presence or absence of F-actin in a cell. For example, in contrast to vascular cells, cortical cells show no indication of fluorescence labeling of F-actin after incubation with fluorescent phallicidin. Cytoplasmic streaming is seen only in vascular cells and in a pattern that reflects the intracellular distribution of F-actin.

Journal Article↗
PubMed1986

Pulmonary artery endothelial abnormalities in patients with congenital heart defects and pulmonary hypertension. A correlation of light with scanning electron microscopy and transmission electron microscopy.

Scanning electron microscopy and transmission electron microscopy were applied to lung biopsy specimens from patients with congenital heart defects, and pulmonary artery endothelium was analyzed for alterations in surface characteristics and intracytoplasmic composition which might reflect abnormal function. The patients were divided into four groups distinguished by increasing severity of pulmonary vascular changes on light microscopy graded both morphometrically and by the Heath-Edwards classification; group 1, normal vasculature or only abnormal extension of muscle into peripheral arteries; group 2, medial hypertrophy; group 3, medial hypertrophy +/- decreased artery number + intimal hyperplasia; group 4, decreased artery number + occlusive intimal hyperplasia. On scanning electron microscopy, the pulmonary artery endothelial surface in group 1 patients was "crinkled" or "corduroy-like", i.e., composed of narrow, even ridges; in groups 2 and 3, it was "cable-like", i.e., comprised of deep intertwined ridges; in group 4 it was "chenille" in texture, i.e., high ridges alternated with low, uneven, and twisted ones. There was significant increased density of surface microvilli in groups 2 and 3 patients when compared to groups 1 and 4 (p less than 0.05 for each comparison). On transmission electron microscopy pulmonary artery endothelial cells in groups 2 and 3 patients were also characterized by a significant increase in the volume density of rough endoplasmic reticulum (p less than 0.01) and microfilament bundles (p less than 0.05). The coarse endothelial surface characteristics associated with pulmonary vascular changes may result in abnormal interaction with blood elements and release of vasoactive substances. The increased microvilli, rough endoplasmic reticulum, and microfilament bundles in patients with moderate but not advanced arterial changes suggest a phase where increased endothelial metabolic function and alterations in the cytoskeleton may also contribute to heightened pulmonary vascular reactivity.

Actin Cytoskeleton↗
PubMed2000

Histologic analysis of prefabricated, vascularized bone grafts: an experimental study in rabbits.

PURPOSE: The purpose of this study was to investigate the cellular quality of prefabricated bone grafts. MATERIALS AND METHODS: Small pieces of iliac bone were placed around the neurovascular bundle on the dorsal aspect of the ear of 11 one-month-old baby rabbits to create a prefabricated vascularized graft. In five animals, the prefabricated bone grafts were harvested for histologic examination 12 months later. In a second group of 6 rabbits, the prefabricated bone grafts, with the neurovascular bundle as a pedicle, were transferred after 30 days to a defect created by removing 1 cm of the midportion of zygoma on the right side of the face. The transferred bone was removed for histologic examination 11 months later. RESULTS: In both groups, microscopic examination showed the presence of a rich, vascular network and similar histologic characteristics to those of normal iliac bone. CONCLUSION: The findings support the concept that prefabricated bone grafts are a potentially useful source for bony reconstruction.

Animals↗
PubMed2004

Feline lymphangiosarcoma--definitive identification using a lymphatic vascular marker.

Three cases of feline exudative dermatitis associated with lymphangiosarcoma are described. The animals, an 11-year-old, neutered male and two 10-year-old, neutered female short hair European cats, presented with a 2-month history of transparent liquid oozing from the skin of the groin and caudal abdomen. On physical examination the neutered male cat and one of the females were slightly depressed and showed loss of weight. Skin lesions were similar in all cats and characterized by the presence of alopecia and moist dermatitis in the ventral abdomen, groin and inner thigh. The hair at the periphery appeared matted by the fluid. In all three cases, histopathological examination of skin biopsies from the abdomen identified poorly defined neoplasia involving dermis and subcutis, characterized by proliferation of spindle cells aligned along pre-existing collagen bundles. The dissection of collagen bundles gave rise to irregular shaped anastomosing, often blind-ending vascular channels and trabeculae. Vascular spaces were mostly optically empty. These histological features were strongly suggestive of lymphangiosarcoma. Neoplastic cells were positive for the blood vascular marker Von Willebrand factor, and a lymphatic vascular marker LYVE-1 (Lymphatic Vessel Endothelial receptor - 1), demonstrating the mixed vascular origin of the tumour. Ultrastructural findings confirmed the final diagnosis of lymphangiosarcoma.

Abdomen↗
PubMed1985

Bundling of actin filaments by aorta caldesmon is not related to its regulatory function.

Ca2+-sensitive thin filaments from vascular smooth muscle were disassembled into their constituent proteins, actin, tropomyosin and caldesmon. Caldesmon bound to both actin and to actin-tropomyosin and inhibited actin-tropomyosin activation of skeletal muscle myosin MgATPase. It also promoted the aggregation of actin or actin-tropomyosin into parallel aligned bundles. Quantitative electron microscopy measurements showed that with 1.1 microM actin-tropomyosin, 1.6 +/- 0.5% (n = 3) of the filaments were in bundles. At 0.073 microM, caldesmon inhibited MgATPase activity by 50%, whereas bundling was 3.0 +/- 1.3% (n = 4). At 0.37 microM caldesmon, MgATPase inhibition was 83% while 28.1 +/- 6.9% (n = 4) of filaments were in bundles. Experiments at 4.4 microM in which MgATPase and bundling were measured in the same samples gave similar results. Small bundles of 2-3 filaments showed the most frequent occurrence at 1.1 microM actin. At 4.4 microM actin the most common bundle size was 3-5 filaments, with the occasional occurrence of large bundles consisting of up to 120 filaments. The incidence of bundling was the same in the presence and absence of tropomyosin. Thus caldesmon can induce the formation of actin bundles but this property bears no relationship to its inhibition of MgATPase activity.

Actins↗
PubMed1984

Actin filaments in contracting preretinal membranes.

In 14 patients, preretinal membranes, causing retinal traction and severe visual impairment, were removed by vitrectomy and evaluated by light and electron microscopy using myosin subfragment-1 to stain actin filaments. Eight membranes were of vascular origin, six of nonvascular origin. All but one contained bundles of oriented actin filaments within a number of their nonvascular stroma cells, suggesting that the contractile protein action may have been involved in their clinically observed contraction.

Actins↗
PubMedDate not supplied

Angiomyolipoma of the nasal cavity: case report and review of the literature.

An unusual localization of intranasal angiomyolipoma is described in an adult male patient with no signs of tuberous sclerosis. The lesion was composed of mature fat cells, vascular spaces with lack of elastic tissue, and presence of bundles of mature smooth muscle cells. Antibodies to intermediate filaments revealed presence of vimentin and absence of desmin in both smooth muscle bundles and in vessel walls. A review of the literature has shown that this is only the third reported case of the angiomyolipoma of the nasal cavity, and some important differences between this entity and renal angiomyolipoma are described.

Angiomyolipoma↗
PubMed1991

Microfibril-microvessel connections in the rabbit eye: correlative confocal and electron microscopy.

The connections between elastic tissue and microvessels (arterioles, capillaries, and venules) in the rabbit eye were examined by light and electron microscopy. In particular, confocal scanning laser microscopy of tissue stained with orcein and examined by fluorescence using a rhodamine filter was correlated with electron microscopic observations. The goal was an analysis of the way in which elastic tissue of the uvea (i.e., choroid, ciliary body, and iris) and the optic nerve of the eye connect to the microvessels in these structures. Confocal microscopy revealed these connections advantageously and showed how they link the elastic tissue meshwork in the perivascular tissue spaces with the wall of the blood vessels. Electron microscopy showed that the connections consist of bundles of 10-12 nm diameter microfilaments that insert into vascular basement membranes. These connections may contribute to the vascular response to changes in blood pressure or intraocular pressure in the eye.

Animals↗
PubMed1993

The effects of forebrain multiple lesions on the pressor response induced by bilateral carotid occlusion in conscious rats.

In the present study, the effects of electrolytic lesions of the anteroventral third ventricle (AV3V) region and of the medial forebrain bundle (MFB) on the pressor response induced by bilateral carotid occlusion (BCO) in conscious intact and aortic baroreceptor-denervated (AD) rats were investigated. In intact control rats, BCO during 60 s produced a pressor response that could be divided into an early response (ER = 50 +/- 3 mmHg) that reachs a peak during the first 20 s and a sustained late response (LR), smaller than ER (32 +/- 2 mmHg), observed during the last 30 s. In intact-innervated rats, AV3V lesion (2 days) reduced ER (22 +/- 3 mmHg) and LR (16 +/- 2 mmHg), whereas the bilateral MFB lesions (6 days) mainly reduced LR (9 +/- 1 mmHg). Rats with simultaneous lesion of both the AV3V region and the MFB showed additional reduction of the ER (15 +/- 3 mmHg), but not LR (11 +/- 1 mmHg) when compared to the effect of MFB lesions alone. Compared to the AV3V lesion alone, LR but not ER was reduced in rats with a double lesion. In sham-lesioned rats, AD induced a significant increase in the pressor response to BCO (ER = 75 +/- 4 mmHg and LR = 65 +/- 3 mmHg) when compared to intact controls.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed2005

Digital cushions in horses comprise coarse connective tissue, myxoid tissue, and cartilage but only little unilocular fat tissue.

Digital cushions were studied in horses with particular reference to vascularization, tissue constituents and matrix components. The cushions mainly resembled a network of coarse collagen bundles. The areas inbetween the bundles were replenished with loosely woven interstitial connective tissue, myxoid tissue, and fibrocartilage. Expected masses of fat lobules were missing: only solitary adipocytes or small groups of adipocytes were seen. Vascular supply to the cushions was remarkably poor. The mucinous myxoid matrix largely consisted of hyaluronan with little sulphated glycosaminoglycans. Myxoid cells were stellate or ramified in shape and showed a tendency to store glycogen and lipid droplets. Myxoid cells reacted for vimentin and stained for S-100 protein. Moreover, myxoid cells often reacted for neuron specific enolase and glial fibrillary acidic protein. Myxoid tissue continuously transformed into loosely organized interstitial connective tissue with fibroblasts, which remained unreactive when tested for neuroectodermal markers. Myxoid tissue also was not clearly demarcated against irregularly interspersed islets of fibrocartilage or hyaline cartilage. Chondrocytes did not stain for neuron specific enolase but reactivity for S-100 protein and glial fibrillary acidic protein was noted in peripheral regions of fibrocartilage. Single or grouped unilocular fat cells were rarely placed into myxoid areas. Unilocular fat cells stained for vimentin, S-100 protein, and occasionally for glial fibrillary acidic protein but not for neuron specific enolase. Continuous transformation of myxoid tissue into cartilage together with corresponding reactivity for neuroectodermal marker proteins of myxoid cells and peripherally located chondrocytes suggest close relationship between myxoid cells and chondrocytes. The same criteria indicate relationship between myxoid cells and adipocytes. Coarse connective tissue, myxoid tissue, fibrous cartilage, and fat cells are functionally combined to absorb mechanical shock in the horse digital cushions.

Adipose Tissue↗
PubMed1993

The role of pacing modality in determining long-term survival in the sick sinus syndrome.

OBJECTIVE: To determine whether the atrial-based pacing modalities ("physiologic pacing") improve survival when compared with single-chamber ventricular pacing in patients with the sick sinus syndrome. DESIGN: Retrospective, nonrandomized study. SETTING: A tertiary care teaching hospital. PATIENTS: A total of 507 patients with a mean age of 66 years who received an initial pacemaker for the sick sinus syndrome between January 1980 and December 1989. Pacing modes were ventricular (22%), atrial (4%), and dual-chamber (74%). MEASUREMENTS: Total and cardiovascular mortality rates. Mean follow-up was 66 months. RESULTS: Independent predictors of total mortality by the Cox proportional hazards model were 1) New York Heart Association functional class (hazard ratio = 1.67/class; 95% Cl, 1.31 to 2.11); 2) age (hazard ratio = 1.62/12-year increment; Cl, 1.28 to 2.05); 3) peripheral vascular disease (hazard ratio = 2.21; Cl, 1.42 to 3.42); 4) bundle branch block (hazard ratio = 2.04; Cl, 1.33 to 3.13); 5) coronary artery disease (hazard ratio = 1.66; Cl, 1.15 to 2.39); and 6) valvular heart disease (hazard ratio = 1.71; Cl, 1.08 to 2.69). The same variables were independent predictors of cardiovascular mortality, with cerebrovascular disease reaching borderline statistical significance (hazard ratio = 1.69; Cl, 1.00 to 2.86). Using univariate analysis, single-chamber ventricular pacing had more than 40% increased risk for both total and cardiovascular death, but the difference was of borderline statistical significance (total mortality: P = 0.053; hazard ratio = 1.43; Cl, 0.99 to 2.07; cardiovascular mortality: P = 0.15; hazard ratio = 1.41; Cl = 0.87 to 2.29). CONCLUSIONS: Because the role of the ventricular pacing mode as a long-term predictor of total and cardiovascular mortality remains inconclusive, a large, randomized study is necessary to confirm whether physiologic pacing provides a substantial reduction in mortality when compared with ventricular pacing.

Aged↗
PubMed2006

Cyclooxygenase 2 expression in vessels and nerves in reversal reaction leprosy.

Tissue expression of cyclooxygenase (COX)2, an inducible enzyme synthesizing eicosanoids in inflammation, was studied in reversal reaction (RR) leprosy in comparison with nonreactionary leprosy. COX2 was consistently expressed in cells of the mononuclear-macrophage lineage across the leprosy spectrum. Only in RR, the following two additional sites showed COX2 expression in the dermis and subcutis: 1) microvessels and 2) nerve bundles and isolated nerve fibers. The same sites also express vascular endothelial growth factor (VEGF). This is in keeping with experimental models relating VEGF to COX2 expression, with VEGF enhancing prostaglandin production through COX2 stimulation and prostaglandin synthase expression. We postulate that selective COX2 inhibitors, which are currently used in several inflammatory conditions, could be considered for RR treatment to reduce acute symptoms caused by tissue edema and possibly prevent long-term nerve damage, the main complication of RR.

Blood Vessels↗
PubMed1991

Contribution of vascular network transformation of the heart to the pathogenesis of ischaemic heart disease. Qualitative changes in myocardial angioarchitectonics.

Based on the idea of segmental arterial vascularization of the heart as well as qualitative assessment of angio- and microangiograms, transformations of intramyocardial vascularization induced by atherosclerotic lesions of the extramyocardial coronary arteries have been presented. Using various angiographic methods, vascularization was evaluated in 58 cases of acute and chronic ischaemic heart disease. Attention was paid to transformations of spatial structure of the vascular network and it was found that some morphological forms of ischaemic heart disease are characterized by a progressive remodelling of the peripheral vascular bed microangioarchitectonics which seems to be of major importance for exacerbation pathomechanisms. Two group of angiographic changes in the ischaemic myocardium have been distinguished, which consisted in disturbances of the segmental pattern of myocardial vascularization and disturbances of the intrasegmental structure of the arterial bundles and capillary vessels.

Adult↗
PubMed1985

[Results of the intracardiac repair of tetralogy of Fallot and interventricular communication before the age of 2 years].

The post-operative review of 81 patients operated for a large interventricular communication before the age of two years reveals excellent results: the mean age at operation was 7 months, extracorporeal circulation was performed in 25 patients for a mean duration of 77 minutes and profound hypothermia to 18 degrees C was induced in 56 patients. The atrial approach was used in 30% of cases. The mean follow-up period is 26 months. There was one case of complete bundle branch block, which was subsequently fitted with a pacemaker, 7 cases of bifascicular branch block and a right bundle branch block in the majority of cases. The pulmonary vascular resistance was virtually normal (a mean of 3.2 U.m-2 prior to the operation and a mean of 1.9 U.m-2 after the operation). The left ventricular volume, which was markedly increased in all patients preoperatively, returned to normal with maintenance of a normal ejection fraction. The neuro-psychomotor behaviour was abnormal in 13 of the 63 patients tested. These abnormalities are not related to the correction procedure, but to pre-existing pathology (small birth weight). 52 patients from a series of 63 cases operated for tetralogy of Fallot before the age of 2 years (median age 12 months) were also reviewed. Extracorporeal circulation lasting a mean of 115 minutes was performed in 31 patients, cardiac arrest under profound hypothermia was induced in the other cases, for a mean duration of 61 minutes. The mean follow-up period was 29 months.(ABSTRACT TRUNCATED AT 250 WORDS)

Birth Weight↗