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PubMed1978

Scanning electron microscopy of human ossicles.

Human middle ear ossicles removed from cadavers and during surgical procedures have been examined with scanning electron microscope (SEM). Two kinds of bone tissue compose ossicles: periosteal and endochrondral bone. Periosteal bone occurs in the form of external covering on the ossicles. In the middle of the ossicles there is endochrondral bone which shows various spatial arrangement of collagen bundles. Lamellar bone occurs also in this bone around vascular channels but rarely in the form of typical osteons. Surface appearance of periosteal, coarse-fibred bone and lamellar, fine-fibred bone is almost the same. Lamellar bone is composed of coarse collagen bundles arranged tightly in the rows. The space between the rows is filled by fine fibres which link the coarse bundles.

Ear Ossicles↗
PubMed2006

[Prevascularisation strategies in tissue engineering].

INTRODUCTION: Experiments on animals have underlined the importance of vascularisation for biointegration and functionality of any given tissue engineering device. The aim of this investigation was to dissect the angiogenetic process in the frame of axial neovascularisation of a xenogenic solid matrix. The ultimate goal of this series of studies is the application of cells onto a prevascularised matrix, with the ambition to enhance cell survival after transplantation in vivo. MATERIALS AND METHODS: We performed a study in the rat with different vascular configurations in an isolation chamber. A disc-formed biogenic hard matrix (9 x 5 mm) was encased into an isolation chamber made of Teflon. In group 1, an arteriovenous fistula (AV loop) between the femoral vessels was microsurgically constructed and was placed around the matrix (n = 15). In group 2, the vascular carrier had the form of an arteriovenous ligated pedicle (n = 15). Evaluation intervals were two, four and eight weeks after implantation. The modes of evaluation included histology, scanning electron microscopy of corrosion casts as well as intravital micro-magnetic resonance imaging (MRI). RESULTS: The arteriovenous loop as vascular carrier revealed a higher capacity for angiogenesis over the bundle configuration. The neo-fibrovascular tissue displayed minimal inflammatory elements but dense vascularisation. Scanning electron microscopy demonstrated a vivid angiogenesis with rapid evolution of the vascular bead into mature, hierarchically organised network. Micro-MRI could be used for serial investigation in terms of flow measurements and detection of thrombosis. DISCUSSION: The presence of a vascular bed prior to cell transplantation might protect against hypoxia-induced cellular death, especially at central portions of the matrix, and therefore ensure physiological function of the device. The generation of vascularised bioartificial tissue substitutes might offer new modalities of surgical reconstruction for use in reparative medicine.

Animals↗
PubMed2004

The major histopathologic characteristics in the vulvar vestibulitis syndrome.

OBJECTIVE: In order to better understand the etiology of the vulvar vestibulitis syndrome, we examined the histopathologic parameters in vestibular mucosa, and compared the findings in specimens obtained from women with vulvar vestibulitis with those obtained from the control group. STUDY DESIGN: Specimens of vestibulitis were obtained from 24 patients, undergoing circumferential vestibulectomy under general anesthesia due to the symptoms and signs consistent with vulvar vestibulitis. Control specimens were obtained from 16 women, without symptoms or signs of vulvar vestibulitis, undergoing reconstructive introital surgery due to roomy vagina, rectocele or painful episiotomy. All vestibular tissue specimens were examined for intensity of inflammation, extension of inflammatory cells into the epithelium, vascular proliferation, the presence of mast cells and proliferation of peripheral nerve bundles. RESULTS: No significant difference was found regarding the degree of inflammation, the extension of inflammatory cells into the epithelium, the vascular proliferation and the presence of mast cells while comparing the study and the control groups. The only histopathologic feature, differentiating the patients with vulvar vestibulitis from the control group, was the proliferation of peripheral nerve bundles found in 19 out of 24 (79.1%) specimens expressing vestibulitis and in none of 16 control specimens (p < 0.0001). CONCLUSION: Our results, therefore, support the existence of peripheral nerve hyperplasia in vestibular tissue obtained from patients with vulvar vestibulitis, and exclude the role of active inflammation or mast cells as probable etiologies for the vulvar vestibulitis syndrome.

Adult↗
PubMed1994

Neurogenic vasodilation in rabbit hindlimb mediated by tachykinins and nitric oxide.

We investigated the role of nitric oxide (NO) in the mediation of nerve stimulation-induced vasodilation in skeletal muscle. Hindlimb blood flow and vascular resistance were measured in pentobarbital-anesthetized, paralyzed, and guanethidine-treated rabbits. Centrifugal electrical stimulation of the sciatic nerve bundle induced reproducible, frequency-, voltage-, and pulse duration-dependent decrements in vascular resistance. The tachykinin antagonist CP-96,345 (1 mg/kg intravenously, i.v.) attenuated the vasodilation induced by intraarterially (i.a.) administered substance P but not by adenosine. Furthermore, CP-96,345 attenuated the decrease in vascular resistance in response to nerve stimulation, from 22.9 +/- 3.2 to 4.5 +/- 4.1% of control resting resistance (p < 0.005), without affecting basal vascular resistance. An inhibitor of NO formation, N omega-nitro-L-arginine methyl ester (L-NAME, 30 mg/kg i.v.), increased vascular resistance from 6.1 +/- 0.5 to 9.1 +/- 1.2 resistance units (p < 0.05) and significantly attenuated the vascular response to i.a. administered substance P but not adenosine. Finally, nerve stimulation-induced reduction in vascular resistance was attenuated by L-NAME, from 22.6 +/- 2.7 to 7.0 +/- 1.0% of control (p < 0.001). These findings suggest that tachykinins and NO are involved in mediation of vasodilation in response to the present type of nerve stimulation. The data are consistent with the hypothesis that NO is produced subsequent to neural release of tachykinin-type transmitter(s).

Animals↗
PubMed2006

Insular involvement in brain infarction increases risk for cardiac arrhythmia and death.

OBJECTIVE: Brain injuries may induce cardiac dysrhythmias and sudden cardiac death. METHODS: We analyzed 12-lead electrocardiograms of 493 consecutive patients with brain infarction (BI) proved by an magnetic resonance imaging and 493 control subjects matched for age, sex, and center. Insular involvement (insula (+/-)) was assessed by two independent readings of the magnetic resonance imaging scans. Cases were followed for 5 years. RESULTS: Acute BI was independently associated with heart rate (< or = 64 beats/min), abnormal repolarization, atrial fibrillation, and ventricular and supraventricular ectopic beats. Lower heart rate in BI patients was due to an interaction with smoking (p for interaction = 0.004). Insula(+) group was significantly associated with abnormal repolarization with no interaction with infarct side. Atrial fibrillation by history was also more frequent in the insula(+) than in the insula(-) group (p = 0.07). After adjustment for age, sex, cardiovascular history, and handicap at admission, right insula(+) BI was significantly associated with 2-year all-cause death (hazard ratio, 2.11; 95% confidence interval, 1.27-3.52) and with vascular death (hazard ratio, 2.00; 95% confidence interval, 1.00-3.93). In multivariate analysis including age, sex, cardiovascular history, handicap at admission, and lesion side, increased QTc interval and left bundle branch block were independent predictors of all-cause and vascular mortality at 2 years in right insula(+) patients. INTERPRETATION: These findings support the notion that right insular involvement may lead to electrocardiographic abnormalities with potential prognostic implications. This could be important for optimal care in patients with right insular infarct.

Adult↗
PubMed1983

A hypothesis of osmotic endothelial injury. A pathogenetic mechanism in central pontine myelinolysis.

Central pontine myelinolysis (CPM) is a demyelinative disorder of unknown origin. Recent clinical and experimental studies have indicated an association of CPM with a rise in the serum sodium level. I propose that the rapid rise in the serum sodium level causes an osmotic injury to the endothelium resulting in the release of myelinotoxic factors and/or the production of vasogenic edema. The latter factors may lead to demyelination. The patient at risk, viz, a chronically ill, alcoholic, cirrhotic person, may be the one least able to generate protective cerebral mechanisms against the osmotic stress. The location of lesions may be explained by a suitable anatomic arrangement consisting of an extensive admixture of gray and white matter; thus, myelinotoxic factors derived from the richly vascular gray are able to interact with adjacent bundles of myelin-containing white matter.

Biomechanical Phenomena↗
PubMed1983

Ophthalmoscopic findings in Leber's hereditary optic neuropathy. II. The fundus findings in the affected family members.

Eighteen men and four women had Leber's disease. Fundus photographs obtained in three cases showed the following: Peripapillary microangiopathy, present from the beginning, slowly increased during the presymptomatic stage. At the end of the presymptomatic stage, the nerve fiber layer became swollen. During the acute stage, retinal vessels on and around the disc were dilated, tortuous, and telangiectatic. Nerve fiber layer hemorrhages occurred in two eyes. As atrophy appeared first in the papillomacular bundle and then in the remaining retina, the vascular bed involuted, leaving a capillary-poor retina with attenuated arterioles and a pale optic disc. The final degree of atrophy varied. Fifteen of the affected persons were blind with severe optic atrophy, but in seven optic atrophy was only partial, causing less visual handicap. Our results suggest that Leber's disease is primarily an intraocular, not a retrobulbar, optic neuropathy. It should be redesignated as Leber's hereditary neuroretinopathy.

Adolescent↗
PubMed1991

A possible mechanism of mechanoreception in Ruffini endings in the periodontal ligament of hamster incisors.

The topographical relationship between Ruffini endings and the surrounding collagen fibers in the periodontal ligament of hamster incisors was investigated by means of both immunohistochemistry for neurofilament protein (NFP) and electron microscopy. Periodontal Ruffini endings, a type of stretch receptor, were present exclusively in the alveolar half of the periodontal ligament. Their axon terminals were densely and regularly associated with transverse collagen fibers, possibly forming a mechanoreceptive complex. Since blood sinuses with frequent anastomoses extended throughout the alveolus-related part, the densely innervated collagen bundles were separated from each other by the vascular spaces. Electron microscopic observation of specimens stained with tannic acid revealed a linkage between the axon terminals of the Ruffini endings and the surrounding collagen filaments. The axon terminals were enveloped by multiple layers of the basal lamina, which were penetrated by collagen filaments. The irregularly arranged collagen filaments were sandwiched between electron-dense laminae of the multilayered basal lamina. The possible mechanism of mechanoreception by the periodontal Ruffini endings is discussed on the basis of the immunohistochemical and ultrastructural findings.

Animals↗
PubMed2002

Supracondylar missile fractures of the femur.

We present the results of the surgical treatment of 50 supracondylar missile fractures of the femur in 48 patients wounded in the territory of the former Yugoslavia in the period June 1991-October 1995. The injuries were caused by bullets in 28 (58.3%) patients and by fragments of mines or other explosive devices in 20 (41.7%) patients. In nine (18.0%) missile supracondylar fractures there were associated fractures of articular surfaces in the knee-joint. Neurovascular bundle injuries were present in 19 (38.0%) and vascular injuries alone in 17 (34.0%) limbs. Bone fragments were stabilized by external fixation in 43 (86.0%) and by plaster of Paris in five (10.0%) limbs. Primary reconstruction of large blood vessel was necessary in 16 (32.0%) limbs. In total eight (16.0%) above knee amputations were done. Coverage of soft tissue defects was required in 19 (38.0%) limbs. Early and late postoperative complications occurred in 26 (52.0%) limbs. Additional surgical procedures were necessary in 15 patients. Definitive results showed a large number of limb shortenings, nerve paralyses and contractures of the knee-joint.

Adult↗
PubMed1976

Acute ultrastructural changes in the middle cerebral artery due to the injury and ischemia of surgical clamping.

Ultrastructural changes in the zone of clamping of the middle cerebral artery of the squirrel monkey are described after application of a surgical clip. The experimental model utilized has been widely applied to the study of cerebral ischemia and possibly has relevance to clamps applied to the cerebral vessels during neurosurgical treatment of patients with cerebrovascular disorders. The earliest changes within the arterial wall were found in the smooth muscle (media) and accompanying fasciculi of nerves. Changes within the nerve bundles were sufficiently advances following 4 hours of vascular clipping to suggest temporary or permanent impairment of neurogenic innervation of the cerebral vessels distal to the trunk of the vessel clipped.

Animals↗
PubMed2001

Histologic analysis of the tibial bone tunnel after anterior cruciate ligament reconstruction using solvent-dried and gamma-irradiated fascia lata allograft.

Anterior cruciate ligament (ACL) reconstruction using free tendon graft requires biologic fixation in the bone tunnel. This report describes the intratunnel histology retrieved from a 47-year-old woman who underwent high tibial osteotomy 17 months after ACL reconstruction using a hybrid graft (a solvent-dried and gamma-irradiated fascia lata allograft as a core wrapped with iliotibial autograft). The patient underwent revision because of pain resulting from osteoarthrotic change, and the graft appeared to be taut and healthy on second-look arthroscopy. The sample was taken from the site of the metaphyseal osteotomy site. Histologic examination of the samples was performed with a light microscope (H&E and Masson trichrome stain). Biologic fixation of the graft to the bone was evident from observation of collagen fiber continuities, resembling Sharpey fibers. Integration of the autograft and allograft seemed to have occurred; the junction between the allograft and the autograft could not be determined. However, there was a difference in ligamentization depending on location. In the peripheral region of the graft (the autograft region), the collagen fibers showed a distinct crimped pattern; the fibroblasts were arranged regularly along the major axis of the collagen fiber bundle. In the central part of the graft (the allograft region), remodeling seemed to be delayed. There were acellular, bubbly or myxoid degeneration areas in which the fiber bundles were less oriented and there was increased vascularity.

Anterior Cruciate Ligament↗
PubMed1985

Laser treatment for retinal vascular diseases.

To obtain a clinically adequate laser lesion one must adjust four variables, namely treatment spot size, duration of application, wavelength, and power. The intensity of the necessary reaction will depend upon the type of disease and lesion being treated. When retinal vascular diseases are treated using the laser, the pattern of laser lesions is determined by the morphology, type, and distribution of the retinal vascular disease. This pattern varies from focal and multifocal direct treatment to ablative techniques from one to four quadrants and maximally four quadrants and treatment within the temporal retinal vascular arcades usually avoiding treatment within the papillomacular bundle.

Aneurysm↗
PubMed1980

[Etiology and morphogenesis of the socalled bronchial arterioma (author's transl)].

Angiomatoid vascular convolusions may develop during the intrapulmonic course of the bronchial artery. The angiomatoid convolusions are arranged segmentally along the longitudinal axis of a bronchus. Histopathologic examinations of 26 cases reveal that the angiomatous lesions form from branches of the bronchial artery, arterial bronchopulmonic connections and their arteriovenous anastomoses, as well as from branches of the pulmonary artery and vein. Common morphologic findings include marked tortuosity with branching, variable lumens, stenosing intimal scars, thrombotic occlusions, pronounced longitudinal muscle bundles and focal necrosis of the vessel wall. Such vascular formations, usually confined to one lung segment, may arise from inborn malformations in this vascular area. Such cases are to be called angioma arteriovenosum racemosum (5 cases from our material). In 21 observations however they have developed secondarily following primary inflammatory, stenosing or deforming diseases of the bronchus, the peribronchial tissues and the surrounding lung tissues. In such cases the angiomatoid changes are the consequence of local stress on blood vessels, blood flow and blood presssure; they do not develop on the basis of a congenital bronchial or vascular dysplasia. We propose the term secondary angiomatoid vascular convolusions in a scarred, deformed bronchial wall or peribronchial tissue. Pulmonary hypertension does not accompany the angiomatoid lesion and their clinical significance lies in dangerous hemorrhages into the bronchial tree.

Adult↗
PubMed2006

Effects of isoflavones from red clover (Trifolium pratense) on skin changes induced by ovariectomy in rats.

Estrogens have a profound influence on skin. The relative hypoestrogenism that accompanies menopause exacerbates the deleterious effects of both intrinsic and environmental aging. Estrogens improve skin in many ways. Among these, they increase collagen content, skin thickness and improve skin moisture. There is evidence that diets with high levels of phytoestrogenic isoflavones are associated with a low incidence of menopausal symptoms and osteoporosis. Plant extracts such as red clover, which contain high levels of isoflavones, have been used to reduce menopausal symptoms and have been shown to reduce bone loss in healthy women. In this study to investigate the effects of red clover isoflavones on skin aging, the histology of the skin, skin thickness and the amount of total collagen determined by a colorimetric method, were studied in ovariectomized rats after treatment for 14 weeks with a red clover extract standardized to contain 11% isoflavones determined by HPLC. In ovariectomized rats the thickness and keratinization of the epidermis were reduced; glands were less in number and vascularity was poor; the distribution and morphology of the collagen bundles and elastic fibers were altered. Whereas the skin of the ovariectomized rats treated with red clover isoflavones (20 and 40 mg of total isoflavones daily for 14 weeks) appeared well organized with a normal epidermis with uniform thickness and regular keratinization; vascularity, collagen and elastic fibers were well developed. The amount of collagen significantly increased in the treated group in comparison with the control group. These findings suggest that red clover isoflavones are effective in reducing skin aging induced by estrogen deprivation.

Animals↗
PubMed2000

The arrangement of the trabecular bone in the vestibular surface of the human fetus mandible. A scanning electron microscopy study.

The characteristics of trabecular bone in human fetuses at seven to nine months of intra-uterine life were studied in the vestibular surface of the mental and body portions of the mandible. In the mental portion, many circular trabeculae joined by "bridges" were observed in the alveolar region (AR). In the 8-month old fetus are trabeculae with tortuous disposition in the medium region (MR). Oblique trabeculae with superior and inferior dispositions defining a triangular area (future mental fossae) are verified in 9-month old fetuses. Trabeculae circularly disposed and vascular foramina are present close to the apex of this area. In the basilar region (BR) some trabeculae obliquely oriented are observed disposed near to the mandibular symphysis. The longitudinal bundles of collagen fibers assume an antero-posterior direction. At 9-month age the vascular foramina range from 6 to 20 microns and the osteocyte lacunae ranging from 1 to 4 microns diameter, are present in mandibles from all ages examined. In the body portion the presence of circular trabeculae joined by "bridges" is the main characteristic of the AR. In the MR most of the trabeculae are circular and the longitudinal trabeculae of this region assume an antero-posterior direction. The laminar, antero-posterior and juxtaposed trabeculae lying parallel to mandible base are a characteristic of the BR. The bundles of collagen fibers exhibit the same pattern of the trabeculae. The vascular foramina of the BR are smaller than that of the precedent regions. In the body portion of the mandible from all ages examined the osteocyte lacunae range from 1 to 4 microns in diameter.

Female↗
PubMed2003

Aggressive giant fibroepithelial lesion with unusual vascular stroma--a case report.

The stroma of fibroadenoma and phyllodes tumor usually consists of fibroblastic proliferation. Rarely the stroma contains bundles of smooth muscle. Pseudoangiomatous hyperplasia of the mammary stroma has been described in fibroadenomas. However, true benign vascular stroma has not been reported. We report a case of a 34-year-old Chinese woman who presented with a large mass occupying the entire left breast. Left mastectomy was performed and showed a large, well-circumscribed, lobulated, rubbery-firm tumor measuring 13 x 10 x 6 cm. Microscopic examination revealed a fibroepithelial tumor formed by an organoid pattern of ductal structures with a very striking stromal appearance composed of extensive vascular proliferation and that demonstrated strong immunoreactivity for CD31, CD34, and Factor VIII. Ultrastructural examination revealed intercellular junctions, basal lamina, pinocytotic vesicles, and Weibel-Palade bodies in the cells lining the vascular spaces, confirming their endothelial nature. These findings rule out the diagnosis of pseudoangiomatous hyperplasia. The patient developed local recurrence a year later, and the resection showed malignant phyllodes tumor with ductal carcinoma in situ. The extensive vascular stroma noted in the primary tumor may have played a role in the malignant transformation of the epithelial and stromal components in this tumor.

Adult↗
PubMed1984

Microvascular architecture of the pampiniform plexus-testicular artery system in the rat: a scanning electron microscope study of corrosion casts.

The vascular architecture of the rat pampiniform plexus was studied by scanning electron microscopy of vascular corrosion casts. The plexus consists of a thick bundle of many anastomosing veins that entirely and closely surround the convoluted segments of the testicular artery. This specially developed close contact of the pampiniform plexus with the testicular artery may allow heat exchange between the plexus and the artery to maintain the cooled condition of the testis. The epididymal arteries are also closely surrounded by the networks of the epididymal veins. It is likely that heat exchange may operate even between these epididymal vessels. The ductus deferens is provided with no vascular channels for such heat exchange. A loose or coarse capillary network is always observed between the testicular artery and the pampiniform plexus. This network is supplied by the epididymal arteries and drains into the pampiniform plexus.

Animals↗
PubMed1978

Echocardiographic assessment of pulmonary arterial pressure in children with complete right bundle branch block.

The time interval between tricuspid valve closure and pulmonary valve opening, termed the isovolumic contraction time of the right ventricle, was evaluated echographically in 38 normal children and within 24 hours of cardiac catheterization in 53 children with congenital heart disease and normal conduction as assessed with the electrocardiogram. In the 53 patients with congenital heart disease, isovolumic contraction time was strongly influenced by right ventricular afterload, as defined by pulmonary arterial end-diastolic pressure (r = 0.87). It was possible to utilize isovolumic contraction time to separate patients with normal or elevated values for pulmonary arterial end-diastolic pressure. Similar correlations were demonstrated between isovolumic contraction time and mean pulmonary arterial pressure and calculated pulmonary vascular resistance. Evaluation of 15 children with complete right bundle branch block revealed values for isovolumic contraction time that did not significantly differ from those of patients with similar pulmonary arterial end-diastolic pressure but no conduction abnormalities. These findings indicate that serial echographic evaluation of the interval from tricuspid valve closure to pulmonary valve opening can give an accurate reproducible assessment of right ventricular afterload in many children with congenital heart disease and complete right bundle branch block

Adolescent↗