Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “vascular bundle”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 1,099 records · Page 61Linked to original sources
PubMed2004

Characterization of a lignified secondary phloem fibre-deficient mutant of jute (Corchorus capsularis).

BACKGROUND AND AIMS: High lignin content of lignocellulose jute fibre does not favour its utilization in making finer fabrics and other value-added products. To aid the development of low-lignin jute fibre, this study aimed to identify a phloem fibre mutant with reduced lignin. METHODS: An x-ray-induced mutant line (CMU) of jute (Corchorus capsularis) was morphologically evaluated and the accession (CMU 013) with the most undulated phenotype was compared with its normal parent (JRC 212) for its growth, secondary fibre development and lignification of the fibre cell wall. KEY RESULTS: The normal and mutant plants showed similar leaf photosynthetic rates. The mutant grew more slowly, had shorter internodes and yielded much less fibre after retting. The fibre of the mutant contained 50 % less lignin but comparatively more cellulose than that of the normal type. Differentiation of primary and secondary vascular tissues throughout the CMU 013 stem was regular but it did not have secondary phloem fibre bundles as in JRC 212. Instead, a few thin-walled, less lignified fibre cells formed uni- or biseriate radial rows within the phloem wedges of the middle stem. The lower and earliest developed part of the mutant stem had no lignified fibre cells. This developmental deficiency in lignification of fibre cells was correlated to a similar deficiency in phenylalanine ammonia lyase activity, but not peroxidase activity, in the bark tissue along the stem axis. In spite of severe reduction in lignin synthesis in the phloem cells this mutant functioned normally and bred true. CONCLUSIONS: In view of the observations made, the mutant is designated as deficient lignified phloem fibre (dlpf). This mutant may be utilized to engineer low-lignin jute fibre strains and may also serve as a model to study the positional information that coordinates secondary wall thickening of fibre cells.

Corchorus↗
PubMed2002

Three-dimensional mapping of sensory innervation with substance p in porcine bronchial mucosa: comparison with human airways.

In asthma, neurogenic inflammation in bronchial airways may occur though the release of neuropeptides from C fibers via an axon reflex. Structural evidence for this neural pathway was sought in the pig and in humans by three-dimensional mapping of substance P-immunoreactive (SP-IR) nerves in whole mounts of mucosa using immunofluorescent staining and confocal microscopy. To show continuity, nerves were traced with 1,1'-didodecyl-3,3,3',3'-tetramethyl indocarbocyanine perchlorate from their epithelial endings through the mucosa. The pan-neuronal marker protein gene product 9.5 revealed an extensive apical and basal plexus of nerves in the epithelium; 94% of these were varicose SP-IR fibers. Apical SP-IR fibers had a length density of 88 mm/mm(2). Varicose apical processes followed closely around the circumference of goblet cells. Calcitonin gene-related peptide was colocalized with SP-IR in varicosites. The epithelial fibers converged into bundles as they entered the lamina propria where lateral branches ran along arterioles, often contiguous with the vascular smooth muscle. 1,1'-didodecyl-3,3,3',3'-tetramethyl indocarbocyanine perchlorate tracing showed that they projected to the epithelium. SP-IR fibers were rare near postcapillary venules. In human bronchial epithelium, protein gene product 9.5 revealed a similar apical and basal plexus of varicose fibers that weakly stained for SP-IR. Thus, a continuous sensory nerve pathway from the epithelium to arterioles provides structural support for a local axon reflex.

Adult↗
PubMed1978

Haemangiosarcoma of the pulmonary valve presenting as a pulmonary stenosis. A case report.

Intractable congestive cardiac failure, unexplained arrhythmias, changes in the cardiac silhouette and murmurs which change with position are all features which should arouse suspicion of a cardiac tumour. A case of intracardiac haemangiosarcoma of endothelial origin is discussed. The tumour presented as a pulmonary stenosis and extended into the right ventricular myocardium, causing a right bundle-branch block. At first the tumour seemed to be restricted to the endothelium of the pulmonary vascular bed, but it later infiltrated the interstitium and bronchi, cuasing dyspnoea and haemoptysis. After surgical removal of the tumour and reconstruction of the pulmonary outflow tract, the patient was free of symptoms for 14 months. However, rapid tumour growth in the pulmonary arterial system, lung interstitium and right ventricle subsequently recurred. Deep radiotherapy did not cause the tumour to regress.

Female↗
PubMed1978

[Visual field defects and fluorescein angiography in acute anterior ischemic optic neuropathy (author's transl)].

Typical visual field defects were found in 86 acute anterior ischemic optic neuropathies occurring in 71 patients. These field defects suggest a separate vascular supply of the upper and lower half of the disc and of the maculo-papillar bundle. A sub-division into four sectors can be inferred in the upper half of the disc. Fluorescein angiography showed sectorial differences of the capillary filling and leakage in some cases. This pattern was however poorly correlated with the localisation of the field defects.

Adult↗
PubMed1999

Intravascular and diffuse dermal reactive angioendotheliomatosis secondary to iatrogenic arteriovenous fistulas.

Reactive angioendotheliomatosis is a rare benign process that has been mainly described in patients with systemic infections, such as subacute bacterial endocarditis or tuberculosis, and in association with intravascular deposition of cryoproteins. Histopathologically, it is characterized by a proliferation of endothelial cells within vascular lumina resulting in the obliteration of the involved vessels. Another rare variant of reactive angioendotheliomatosis has been described in the lower extremities of patients with severe peripheral vascular atherosclerotic disease. It consists of violaceous and purpuric plaques histopathologically characterized by diffuse proliferation of endothelial cells interstitially arranged between collagen bundles of the reticular dermis. This second variant has been named diffuse dermal reactive angioendotheliomatosis. We report two patients with reactive cutaneous angioendotheliomatosis appearing distally to arteriovenous fistulas used for hemodialysis because of chronic renal failure. The first patient showed intravascular reactive angioendotheliomatosis, while the second one had purpuric plaques that were characterized histopathologically by diffuse dermal angioendotheliomatosis. Both patients showed an arteriovenous "steal" syndrome with distal ischemia, and it is possible that a local increase of vascular endothelial growth factor, as is the case in hypoxia situations, induces the endothelial proliferation. To the best of our knowledge, cutaneous reactive angioendotheliomatosis has not been previously described in association with arteriovenous shunts.

Aged↗
PubMed1998

Endothelial changes in muscle and skin biopsies in patients with CADASIL.

Cerebral autosomal dominant arteriopathy with subcortical infarcts and leucoencephalopathy (CADASIL) is characterized by the deposition of granular osmiophilic material in association with vascular smooth muscle cells in many different organs. However, the cause of the subsequent destruction of smooth muscle cells that are surrounded by granular osmiophilic material is unclear. In the present study, the ultrastructural changes that occur in endothelial cells in CADASIL have been evaluated by examining blood vessels in six skin biopsies and seven muscle biopsies belonging to three different CADASIL pedigrees. The appearances have been compared with five skin biopsies and five muscle biopsies from age-matched controls without vascular disease. The most striking features observed in vessels in the skin of CADASIL patients were attenuation of endothelial cells and increased density of endothelial cytoplasm, accompanied by the presence of compact bundles of microfilaments within the cytoplasm of endothelial cells. Endothelial cells in muscle biopsies from CADASIL patients, on the other hand, were swollen until destruction of tight junctions were observed. These findings suggest that impaired permeability of vascular endothelium may play a role in the destruction of vascular smooth muscle cells in CADASIL. Furthermore, the results of this study suggest that further fine structural investigation of blood vessel endothelium and underlying smooth muscle may lead to a better understanding of the pathophysiology of CADASIL.

Adult↗
PubMedDate not supplied

Highly oriented, tubular hybrid vascular tissue for a low pressure circulatory system.

A hierarchically structured hybrid vascular tissue was prepared from vascular cells and collagen. First a hybrid medial tissue was prepared by pouring a cold mixed solution of bovine aortic smooth muscle cells (SMCs) and Type I collagen into a tubular glass mold composed of a mandrel and a sheath (inner diameter, 1.5 mm; outer diameter, 7 mm; length, 7 cm). An SMC incorporating collagenous gel was formed with incubation at 37 degrees C. After the sheath of the mold was removed, the resulting fragile tissue cultured in the medium shrank in a time dependent manner to form an opaque, dense tissue. Seeding at a higher cell density and a lower concentration of collagen resulted in rapid and prominent shrinkage. Morphologic investigation showed that with time, bipolarly elongated SMCs and collagen fiber bundles became positioned around the mandrel. When the mandrel was removed, a tubular hybrid medial tissue was formed. A hybrid vascular tissue with a hierarchical structure was constructed by seeding endothelial cells onto the inner surface of the hybrid medial tissue. Prepared tissues tolerated luminal pressures as great as 100 mmHg and mechanical stress applied during the anastomotic procedure. This method allowed the authors to prepare hybrid medial tissues of predetermined size (specifically inner diameter, wall thickness, and length) and mechanical property, which all depend on the mold design, SMC seeding density, initial collagen concentration, and incubation period. Hybrid vascular tissues may provide physiologic functions such as antithrombogenicity and regulation of vasomotor tone when implanted into a venous system.

Animals↗
PubMed2001

[Prefabrication of vascularized bone flap using bone morphogenetic protein (BMP)].

The purpose of this study was to produce newly vascularized bone, and to form the bone into the desired shape. Silicone molds given the shape of a cylinder were used to deliver collagen sheets impregnated with or without rhBMP-2. The superficial inferior epigastric neurovascular bundle in a Wistar rat was identified and sandwiched between the silicone molds. The molds containing collagen sheets impregnated with 10 micrograms of rhBMP-2 were used for the experimental purpose, and those without rhBMP-2 were used as a control. In some of the experimental molds, the neurovascular bundle was ligated at both proximal and distal sites of the molds. After 2 and 4 weeks operation, bone formation was detected macroscopically, radiologically, and histologically. As a result, newly formed bone was observed in all experimental sites without the ligation, and the shape of the bone was exactly the same shape as the silicone mold. Newly formed bone was supplied by the superficial inferior epigastric artery, whereas newly formed bone was not observed in the control and the ligated flaps. Newly vascularized and shaped bone was created by applying an osteoinductive factor to a neurovascular bundle. This study demonstrates that this experimental model could be a therapeutically potential approach for effective bone reconstruction.

Animals↗
PubMed1985

[Atypical compression of the humeral axial artery treated by surgical arteriolysis].

A 28-year-old man with atypical humeral artery compression presented clinical signs and results of Doppler tests suggestive of a cervicothoracic outlet syndrome: dysesthesie disorders and pain in left upper limb on active abduction. Murmurs over the vascular pathways were not elicited on clinical examination. Pulses were palpable in the upper limbs at rest but were abolished during abduction and external rotation. Data were confirmed by velocimetric studies, and dynamic arteriography showed absence of compression at the cervicothoracic outlet but its presence at the humeral head level. Axillohumeral surgical exploration provided evidence of compression of the nerve-vessel bundle, which was stretched within its sheath over the head of humerus. Incision of the fibrous sheath and freeing of the artery restored distal vascular pulsatility during abduction movements. This clinical pseudosyndrome of the cervicothoracic outlet appears to result from a rare cause of compression situated distal to this anatomic zone, and to respond to simple treatment.

Adult↗
PubMed1993

PCR localization of angiotensin II receptor and angiotensinogen mRNAs in rat kidney.

Recent studies revealed that angiotensin II (Ang II) interacts with two pharmacologically different subtypes of cell surface receptors. Type I Ang II (AT1) receptor is characterized by signal transduction mediated through G protein and phospholipase C. In this study, the micro-localization of mRNAs coding for AT1 receptor and angiotensinogen was carried out in the rat kidney, using an assay of reverse transcription and polymerase chain reaction (RT-PCR) in individual microdissected renal tubule segments along the nephron, glomeruli, vasa recta bundle, and arcuate arteries. Large signals for AT1 receptor were detected in the glomerulus, proximal convoluted tubule (PCT), proximal straight tubule (PST), cortical collecting duct, and vascular system. Small signals were also seen in medullary thick ascending limb, outer medullary collecting duct, and inner medullary collecting duct (IMCD). Angiotensinogen mRNA is expressed largely in PCT, PST, and a small amount in glomerulus and vasa recta. Our data demonstrate that Ang II could be produced locally in proximal tubule and vasa recta bundle, and that the AT1 receptor was widely distributed not only in the glomerulus and vessels but also in tubules from PCT to IMCD.

Angiotensin II↗
PubMed1988

The heart after surgery for congenital heart disease.

The pathology of the heart following surgical correction for congenital cardiac defects has not been fully explored. This study is based on valvar aortic stenosis, atrioventricular septal defect, complete transposition of the great arteries, and Fallot's tetralogy. Emphasis has been put on preexistent gross pathology, with histological verification, and postoperative complications. Among patients with aortic valve stenosis preexistent anomalies dominated (left ventricular hypoplasia, mitral valve abnormalities, left ventricular endocardial fibroelastosis). The findings suggest that the cases represent an extreme within a spectrum and could explain the late postoperative dismal results in patients suffering from congenital left heart obstruction. In patients with atrioventricular septal defects the important pathology related predominantly to the operative procedure (injury to the atrioventricular bundle, patch dehiscence at the site of the atrioventricular node, inadequate repair of the left atrioventricular valve leaflets) and to pulmonary obstructive vascular disease. In complete transposition of the great arteries, with or without ventricular septal defects, technical problems dominated. Obstruction of the systemic and pulmonic venous pathways, atrial dysrhythmia, and tricuspid valve injury were the most serious complications following Mustard's procedure. The Rastelli-type procedure was complicated by degeneration and calcification of the porcine valve and crowding of the left ventricle. The arterial switch was complicated by abnormal origin and course of the left circumflex artery, which led to kinking and myocardial infarction. In Fallot's tetralogy surgical complications (injury to the atrioventricular bundle and the tricuspid valve) were the most important. The study discloses that the heart after surgery for congenital heart disease cannot be considered without taking preexistent pathology into account. Careful preoperative investigations are mandatory, since most anomalies could have been detected and, hence, might have changed the operative result.

Adolescent↗
PubMed1985

The cerebellopontine angle and internal auditory canal: neurovascular anatomy on gas CT cisternograms.

We reviewed 103 normal gas CT cisternograms to delineate the appearance of normal neurovascular structures in the cerebellopontine angle (CPA) and internal auditory canal (IAC). Cranial nerves VII and VIII were identified in the CPA in 97% of cases, either separately (53%) or as a bundle (44%). Intracanalicular branches of the VIIIth cranial nerve were identified in 20% of cases, and cranial nerve V was visualized in the CPA in 14%. The characteristic vascular loop, usually the anterior inferior cerebellar artery, was visible in 35% of cases, and, in 22% of visualized cases, was in an intracanalicular location. The internal auditory artery was questionably visualized in one case. In 10% of cases, greater than 66% of the IAC was occupied by the neurovascular bundle. Familiarity with the normal anatomy and variants seen on gas CT cisternograms is necessary to prevent false-positive interpretations.

Cerebellopontine Angle↗
PubMed1991

Histopathologic changes in snoring and obstructive sleep apnea syndrome.

The pathophysiologic events that lead to the loss of airway compensation in obstructive sleep apnea (OSA) are poorly understood. The development of airway instability may be secondary to changes in neurologic control, airway morphology, or both. To identify potential histopathologic features of pharyngeal tissues that may contribute to OSA, transverse sections of the distal soft palate and uvula were qualitatively compared using light and electron microscopy from 4 severe apneics (greater than 50 apnea/hour), 4 severe snorers (less than 20 apnea/hour), and 4 nonsnorers. Light microscopy of both apneics and snorers revealed mucous gland hypertrophy with ductal dilation and focal squamous metaplasia, disruption of muscle bundles by infiltrating mucous glands, focal atrophy of muscle fibers, and extensive edema of the lamina propria with vascular dilation. Severe snorers did not differ qualitatively from apneics in the characteristic changes found; however, some snorers had less extensive changes. No distinctive histopathologic findings could be associated with the development of apnea. Electron microscopy of severe apneics identified frequent focal degeneration of myelinated nerve fibers and axons. The finding of similar histopathologic changes in apneics and severe snorers supports previous speculation of a common etiology not directly related to apnea, such as vibratory trauma to pharyngeal tissues. Degenerative changes in peripheral nerves, identified on electron microscopy, however, may contribute to airway instability and the development of obstructive apnea by impairing pharyngeal reflexes.

Atrophy↗
PubMed2002

Hemangiosarcoma of the third eyelid in a cat.

A case of hemangiosarcoma of the third eyelid in a 15-year-old Domestic Short-haired cat is reported. A small red mass protruding from the anterior surface of the third eyelid in the left eye was present. Only mild bilateral conjunctivitis and nuclear sclerosis were revealed on initial ophthalmic examination. After anti-inflammatory treatment, surgery and cryotherapy were performed. On histopathologic examination the mass was located just beneath the conjunctival epithelium, suggesting that the conjunctiva was the tissue of origin. The tumor showed high cellularity and was composed of pleomorphic spindle and polygonal cells arranged in interlacing bundles and solid sheets. The presence of slit-like spaces between tumor cells containing erythrocytes demonstrated the vascular differentiation. Mitotic activity was moderate, but atypical mitoses were detected. The surgical area healed uneventfully and after 7 months there was no recurrence. To the authors' knowledge, this is the first report of conjunctival hemangiosarcoma of the third eyelid in a cat.

Animals↗
PubMed2000

Intravesical adipose tissue: a quantitative study of its presence and location with implications for therapy and prognosis.

Accurate pathologic staging of carcinomas of the urinary bladder involves assessment of invasion by the tumor into the bladder wall and beyond into perivesical soft tissue. The presence of tumor within perivesical soft tissue implies pathologic stage pT3 (AJCC/UICC system, 1997). In traditional textbooks of histology, anatomy, pathology, and in the literature, other than a single case report and a brief reference in another paper, there is no information on the presence of adipose tissue in the lamina propria or muscularis propria of the urinary bladder. Nine hundred forty-three sections from 139 cystectomy specimens were evaluated for the presence, location, and quantity of adipose tissue within the lamina propria and muscularis propria. The histology of the perivesical soft tissues and the nature of its delineation from muscularis propria were also analyzed. Adipose tissue was seen within the lamina propria in 53% (74 of 139) of cystectomies and in 17.6% (166 of 943) of the examined sections. It was located predominantly in the deep lamina propria (at or below the muscularis mucosae) in 81.1% (60 of 74) of the cystectomies and in 91% (151 of 166) of the sections. Within the lamina propria it was predominantly seen as small localized aggregates in 92% (153 of 166) of sections. All cases showed adipose tissue within the muscularis propria. Adipose tissue was identified within the superficial (inner) muscularis propria in 54% (512 of 943) of sections and was predominantly in small aggregates in 80.5% (412 of 512) of sections. It was in moderate to abundant quantities within the deep (outer) muscularis propria in 60.7% (572 of 943) of sections. The perivesical soft tissue was almost exclusively composed of adipose tissue with variable vascularity. Delineation of the perivesical adipose tissue from the deep (outer) muscularis propria was typically indistinct because muscle bundles of the latter haphazardly merged with the perivesical adipose tissue. Based on these findings, we conclude that adipose tissue is frequently present in the lamina propria and muscularis propria of the urinary bladder wall, and is usually scant in the former location and frequently abundant in the latter. Awareness of the high frequency of adipose tissue within the urinary bladder wall has prognostic and therapeutic implications. In transurethral resection of bladder tumor (TURBT) specimens, misinterpretation of tumor infiltrating adipose tissue within lamina propria (pT1) as perivesical soft tissue involvement (pT3) may potentially result in unwarranted aggressive management. Substaging of muscle invasive tumors should be performed in cystectomy specimens only, because the junction of muscularis propria and the perivesical adipose tissue is typically ill-defined. Muscularis propria adipose tissue in TURBT specimens may be erroneously assumed to be perivesical adipose tissue, potentially leading to overstaging of the primary tumor.

Adipose Tissue↗
PubMed1996

Management of facial contour deformities with deepithelialized lateral intercostal free flap.

Ten cases suffering from facial contour deformities caused by loss of subcutaneous tissue are presented. Three cases had hemifacial microsomia, 3 had postmaxillectomy collapsed cheek, while the remaining 4 patients had Romberg's disease. All cases were treated by the insertion of a deepithelialized, revascularized lateral intercostal flap. The flaps used had dimensions ranging from 9 cm x 6 cm to 12 cm x 14 cm. The vascular pedicle of the flap is the lateral cutaneous branch of one of the lower four posterior intercostal bundles (usually the tenth or the eleventh). The flap is designed to have the pedicle in its center, thus allowing defattening of the edges at the primary surgery and minimizing the need for secondary debulking. Nine flaps were successful and one failed. All successful flaps gave a permanent and satisfactory correction of the deformity. The difficulties and advantages of the flap are presented.

Adolescent↗
PubMed2000

Prefabricated temporalis fascia pedicled flap for previously skin-grafted contracted eye socket.

The use of free skin, mucous membrane, or dermis-fat grafts in eye socket reconstruction proved to be unsatisfactory in long-term follow-up because of the progressive contraction of the socket. For achieving eye socket expansion of proper size and shape and a good vascularized lining that can last despite eventual fibrosis, a prefabricated temporalis fascia flap pedicled on the superficial temporal bundle is described in this report. In this technique, a split-thickness skin graft is applied over the termporalis fascia to create a sort of prefabricated flap, on which the proper dimensions of the socket can be fabricated on the grafted temporalis fascia. This study was conducted on 17 patients who had previously undergone eye socket reconstruction with skin graft after posttraumatic enucleation. All patients presented with a contracted eye socket, which manifested clinically by extrusion and migration of the ocular prosthesis. The procedure was performed in two stages. The purpose of prefabrication was to provide the proper shape and size of the newly created socket after release of skin-graft contracture to get a proper fit of the prosthesis, because the flap is thin and can be shaped well. The follow-up period ranged between 1 and 5 years, and the results were good.

Adult↗
PubMed1997

Folliculosebaceous cystic hamartoma with a neural component: an immunohistochemical study.

We present a case of follicular cystic hamartoma, a distinctive cutaneous malformation characterized by marked overgrowth of folliculosebaceous units accompanied by appreciable mesenchymal alterations, including fibroplasia, increased vascular components, and numerous adipocytes. A conspicuous feature of our case is an aggregation of thick trespassing nerve bundles in the deep portion of the neoplasm. An immunohistochemical study revealed the nerve bundles were immunoreactive for the general neuronal marker protein gene product 9.5. The nerves, however, stained negatively with antibodies against neuropeptides such as calcitonin gene-related peptide, substance P, vasoactive intestinal polypeptide, and neuropeptide Y, all of which are known to be contained in normal cutaneous nerves. The presence of these aberrant nerve bundles devoid of the normal expression of neuropeptides supports the concept that folliculosebaceous cystic hamartoma is a true, tumor-like malformation characterized by abnormal overgrowth of normal components of the skin.

Biomarkers↗