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At least 1,027 records · Page 57Linked to original sources
PubMed1999

Wound healing following injury to vascular smooth muscle cell cultures is modulated by culture under hypergravity.

Anticipated hazards for crewmembers in future long-term space flights may result in a variety of injuries including fractures, deep punctures or cuts. The microgravity environment of space may complicate the wound healing process. Myofibroblasts have been proposed to play a role in wound contraction; these cells develop from tissue fibroblasts sue fibroblasts develop numerous features found in vascular smooth muscle cells (SMC), ultrastructural features, expression of alpha-SM actin and microfilament bundles. These changes have been shown to be inducible by TGF beta 1. Previous studies have also shown that TGF beta 1 is capable of initiating and regulating critical events in bone fracture, soft tissue, dermal wound healing. Several studies have suggested that bFGF may also be involved in the wound healing process, and that the interactions of bFGF with TGF beta 1 control the overall repair of a wounded tissue. The formation (angiogenesis) and/or repair of blood vessels is also essential for wound healing. Both TGF beta 1 and bFGF have been shown to affect both angiogenesis and vascular injury repair. However, the response of cells following injury, in a microgravity or hypergravity (HG) environment has not been evaluated. We assessed the influence of HG (centrifugation at 6G) and clinostat rotation at 30 rpm (CR) on the response of SMC to a denudation injury. We also examined the possible involvement of c-myc, c-fos and TGF beta 1 in meeting the response of SMC to wounding.

Animals↗
PubMedDate not supplied

Lipofibromatous hamartoma of the median nerve associated with macrodactyly and port-wine stains.

Lipofibromatous hamartoma of the nerve is a very uncommon congenital tumor. An association between this condition and vascular malformations is not well known. We present an 11-year-old girl with a lipofibromatous hamartoma of the right median nerve with macrodactyly. She had small red macules on her right neck, chest, and arm, which were diagnosed clinically as port-wine stains. The specimens of the enlarged nerves showed fibrous and fatty growth surrounding the nerve bundles and proliferation of the small veins. We suggest that this disorder can be accompanied by a vascular malformation.

Child↗
PubMed1993

Mucoid vasculopathy: vascular lesions in an autopsy study.

Mucoid vasculopathy is a unique, idiopathic, vascular entity observed in autopsy material at the Sree Chitra Tirunal Institute for Medical Sciences and Technology, Trivandrum, India. The vascular lesions are the most prominent manifestation of a pathologic condition characterized by a generalized mucopolysaccharidosis of connective tissues found, for example, within nerve bundles in the adventitia of blood vessels and in the interstitium of such organs as the heart, lung, and kidney. Tissue deposits are accompanied by a mastocytosis. The pathology of vascular lesions observed in 44% of 131 autopsies is described. In this group, mucoid vasculopathy occurred more commonly in young males of lower socioeconomic status. Both arteries and veins are affected, particularly muscular arteries. They present a uniform concentric thickening of the intima and media, causing an apparent reduction in luminal diameter. Significant histological features include (a) large quantities of glycosaminoglycans accompanied by smooth muscle hyperplasia in the intima and media and (b) degenerative changes with mineralization of the internal elastic lamina of arteries and of mucoid material in the media. Except for the mucoid arteriopathy described in popliteal vessels in cases of idiopathic peripheral gangrene from Central Africa, which mucoid vasculopathy resembles somewhat, the latter condition is not exactly comparable to any other known vascular or connective tissue disorder.

Adolescent↗
PubMed2002

Nerve fiber layer splaying at vascular crossings.

PURPOSE: To examine the anatomic relationships of retinal blood vessels to the nerve fiber layer. METHODS: Retinal flat preparations from monkey and cat were stained with methylene blue dye and examined by light microscopy. RESULTS: A focal transition in nerve fiber bundle patterns occurs just above major retinal blood vessels. Bundles abandon a compact form and splay open just as they reach a major blood vessel. Maximum separation of axon fascicles occurs immediately above the blood vessel and the bundles reform after the crossing of the blood vessel is complete. In so doing, nerve fiber bundles temporarily thin and broaden, assuming the shape of an inverted hull. In contrast, at the retinal periphery, minor blood vessels and axon fascicles have no special relationship to each other. CONCLUSIONS: At major blood vessel crossings, a focal alteration in nerve fiber bundle anatomy takes place under which local deformability may be enhanced. This adaptation probably lessens the risk of injury to ganglion cell axons from vascular compression. In addition, deflection of the nerve fiber pathway obviates the need for major blood vessels to bend or kink to achieve a crossing, thus avoiding turbulent flow.

Animals↗
PubMed1976

De subitaneis mortibus. XIX. On the cause of sudden death in pheochromocytoma, with special reference to the pulmonary arteries, the cardiac conduction system, and the aggregation of platelets.

Pheochromocytoma may cause sudden and unexpected death. In this study of three fatal cases of pheochromocytoma the small pulmonary arteries were narrowed by a variety of chronic and acute processes which included medial hypertrophy and fibrosis, endothelial proliferation and fibrosis, and endothelial cellular edema; within the sinus node, atrioventricular (A-V) node and His bundle of all three cases there was focal degeneration and fibrosis similar to that also observed throughout the ventricular myocardium; and in addition to the focal narrowing of many small coronary arteries produced by medial hypertrophy, intimal fibrosis, and fibromuscular dysplasia, there were also focal aggregations of platelets clogging the lumen and occasionally mixed with a varying amount of fibrin. In patients known to have pheochromocytoma it may be necessary to direct new attention to the possibility of abnormal pulmonary vascular resistance, instability of normal cardiac rhythm, and perhaps difficulty in restoring it when disordered and to the effects of platelet aggregations, both causing acute obstruction and possibly contributing to the pathogenesis of chronic vascular disease.

Adrenal Gland Neoplasms↗
PubMed2003

The biceps femoris short head muscle flap: an experimental anatomical study.

The vascular communication between the heads of the biceps femoris muscle has been established after 25 cadaveric dissections. Perfusions of dye through the long or the short head consistently showed 1-2 anastomotic bundles. Outflow of dye opposite to the site of the perfused head was remarkable in most cases. Intramuscular dissections disclosed broad and well structured vascular networks in all short heads, but this was not true for all long heads. Our observations suggest that the anastomotic vessels alone might support the short head which, when released from its profunda femoris vessels, is adequate to cover lateral knee defects. Depending on the level of the anastomotic vessels, the proximal or the distal part of the short head should be used. A pedicled flap may be used as well, whereas transsection of the biceps tendon offers additional mobility.

Dissection↗
PubMed1995

Scanning electron microscopic observations of nerves in the guinea-pig gallbladder after an acetylcholinesterase histochemistry.

Three-dimensional structures of the nerves of the guinea-pig gallbladder, after histochemical demonstration of the acetylcholinesterase activity and HCl hydrolysis-collagenase digestion, were examined by scanning electron microscope. HCl-collagenase digestion facilitated easy identification of silver- and gold-intensified acetylcholinesterase-positive nerve fibers at a high accelerating voltage (25 kV), due to their strong reflection image. Ganglia were either triangular or ovoidal in shape. Dense para- and peri-vascular nerve fibers occurred around the cystic artery. There were a few intramuscular nerve fibers with varicosity-like structures among smooth muscle bundles. Dense branched and tapering nerve fibers with varicosities in the lamina propria mucosae were closely attached to epithelial cells. The acetylcholinesterase-positive fibers in the lamina propria and peri- and para-vascular nerves, and fewer positive fibers in the smooth muscle layer probably represent cholinergic nerves involved in the concentration of biliary compounds and lesser in the motor function of the smooth muscle.

Acetylcholinesterase↗
PubMed1990

[Nerve regeneration through vascularized muscle autograft].

Nerve regeneration through a vascularized muscle autograft was investigated in Sprague-Dawley rats. The electrophysiological evaluation, progressive ultrastructural observation and advanced image analysis system were employed to asses the nerve regeneration process at selected intervals postoperatively. The regenerating axons concentrated into bundles to establish 'Regenerating Nerve Units', in contact with the inner or outer surface of the muscle basement membrane. Regeneration through a vascularized muscle graft was equivalent to autogenous nerve graft. The feasible use of free muscle transfer or transplantation is also discussed. It is concluded that vascularized muscle graft can facilitate and guide the regeneration, especially in clinical repair of large gaps of a major nerve.

Animals↗
PubMed1998

Vascular leiomyoma of the mesentery in a dog.

A 4-year-old male, miniature Schnauzer dog showed two large masses in the mesentery at necropsy. Histological examination of both masses revealed plain smooth muscle tumour cells intermingled with thick-walled blood vessels. The bundles of tumour cells often extended from the periphery of the vessels. Mitotic figures were rare. From these findings, the tumour was diagnosed as a vascular leiomyoma (angiomyoma), previously unreported in animals. The term, vascular leiomyoma, was proposed to describe this tumour in order to avoid confusion with hamartomatous angiomyoma.

Actins↗
PubMed2004

Abnormal musculoaponeurotic tunnel in the arm: possible entrapment of the median nerve and brachial artery with high origin of nerve to pronator teres within the tunnel.

Median nerve and brachial artery in the arm are not usually overlapped by any structure. Connective tissue bands and muscular slips draping or enclosing this neurovascular bundle have been reported, however, which may produce clinical symptoms of nerve compression and vascular changes. We report an unusual musculoaponeurotic band that originates as the ligament of Struthers but terminates as the brachiofascialis muscle of Wood and in the process may have entrapped both the median nerve and brachial artery. The nerve to pronator teres originates from the median nerve within this tunnel. On histological examination the nerve was flattened and showed some perineurial thickening. In view of the flexor function of brachialis muscle, this anomalous musculoaponeurotic band may be considered a clinically important entity in the causation of idiopathic neurovasculopathy in the hand.

Brachial Artery↗
PubMed2000

Robust regeneration of CNS axons through a track depleted of CNS glia.

Transected CNS axons do not regenerate spontaneously but may do so if given an appropriate environment through which to grow. Since molecules associated with CNS macroglia are thought to be inhibitory to axon regeneration, we have tested the hypothesis that removing these cell types from an area of brain will leave an environment more permissive for axon regeneration. Adult rats received unilateral knife cuts of the nigrostriatal tract and ethidium bromide (EB) was used to create a lesion devoid of astrocytes, oligodendrocytes, intact myelin sheaths, and NG2 immunoreactive cells from the site of the knife cut to the ipsilateral striatum (a distance of 6 mm). The regenerative response and the EB lesion environment was examined with immunostaining and electron microscopy at different timepoints following surgery. We report that large numbers of dopaminergic nigral axons regenerated for over 4 mm through EB lesions. At 4 days postlesion dopaminergic sprouting was maximal and the axon growth front had reached the striatum, but there was no additional growth into the striatum after 7 days. Regenerating axons did not leave the EB lesion to form terminals in the striatum, there was no recovery of function, and the end of axon growth correlated with increasing glial immunoreactivity around the EB lesion. We conclude that the removal of CNS glia promotes robust axon regeneration but that this becomes limited by the reappearance of nonpermissive CNS glia. These results suggest, first, that control of the glial reaction is likely to be an important feature in brain repair and, second, that reports of axon regeneration must be interpreted with caution since extensive regeneration can occur simply as a result of a major glia-depleting lesion, rather than as the result of some other specific intervention.

Animals↗
PubMed1986

Congenital generalized multicentric myofibromatosis with orbital involvement.

We studied a rare case of congenital myofibromatosis of the orbit as part of a generalized multicentric disease in a 5-month-old boy. The ultrasonographic and computed tomographic findings were those of a low-reflective, firm, vascularized, lesion with heterogeneous internal structure. The histopathologic findings showed vascular channels with large polygonal cells and transition toward myofibroblasts with interwoven collagen fiber bundles.

Follow-Up Studies↗
PubMed2005

Recombinant human relaxin reduces hypoxic pulmonary hypertension in the rat.

The fibroproliferative changes in pulmonary artery (PA) remodeling are partially prevented by antifibrotic agents. Relaxin (Rlx), a hormone involved in loosening collagen bundles in ligaments during parturition, has antifibrotic and vasodilator properties that may prevent pulmonary vascular remodeling. In the hypoxia model of pulmonary hypertension, two doses of recombinant human relaxin (rhRlx 24 [high] or 5 [low] mg X 10(-2)/kg d(-1)) were administered subcutaneously continuously for 10d to hypoxic (10% O2) rats. At day 11, right ventricular pressure (Pa X 10(2)) was reduced by rhRlx in a dose-dependent manner (15 +/- 1* control; 28 +/- 1 hypoxia; 23 +/- 1* low; 20+/-1* high; n = 10-14/group, *P < 0.05 vs. hypoxia). High rhRlx ameliorated increased collagen accumulation (mug hydroxyproline/vessel) in main PAs (87 +/- 6) vs. untreated hypoxia (102 +/- 2) (n=5/group, P < 0.05). Infusion of rhRlx had no effect on air-breathing rats, and acute administration did not alter blood pressure in hypoxic rats. Fibroblasts cultured from rat PAs spontaneously expressed collagen and fibronectin, and treatment with TGF-beta increased secretion 26- and 25 X 10(-1)-fold, respectively. Addition of rhRlx to transforming growth factor-beta-stimulated fibroblasts inhibited collagen (37%) and fibronectin (38%) secretion vs. vehicle (n = 4 per group, both P < 0.05). We conclude that rhRlx inhibits the early fibroproliferative response in hypoxic pulmonary hypertension and the mechanism may be due in part to suppression of collagen synthesis.

Animals↗
PubMed2005

Lateral pedicle control during laparoscopic radical prostatectomy: refined technique.

OBJECTIVES: To report a technique of lateral pedicle control during laparoscopic radical prostatectomy that completely eliminates any form of electrocautery, ultrasonic thermal energy, clips, or bioadhesives. METHODS: The technique was used in 25 men undergoing nerve-sparing laparoscopic radical prostatectomy. Our antegrade technique involves transient control of the lateral prostate pedicles with an atraumatic vascular bulldog clamp. The pedicles were divided by precise cold cutting, and the neurovascular bundles (NVBs) were teased away with gentle blunt and sharp dissection. Hemostasis was secured with meticulous, superficial suturing of transected blood vessels with 4-0 Vicryl. Real-time transrectal ultrasound monitoring was performed preoperatively, during bulldog clamp application, and postoperatively. RESULTS: The mean bulldog clamp time for the right and left prostate pedicles was 11.1 and 11.2 minutes, respectively. Transrectal ultrasonography confirmed continued arterial blood flow within NVB during active bulldog clamping. Before clamping, during clamping, and after prostatectomy, the mean number of visible blood vessels within each NVB was 3.4, 2.2, and 2.1 (P <0.001 before versus during or after), and the mean resistive index of arterial blood flow was 0.86, 0.85, and 0.85, respectively. Positive surgical margins occurred in 1 patient (4%). Potency and continence data are awaited. CONCLUSIONS: We describe a technique of lateral pedicle ligation during laparoscopic radical prostatectomy using monitored cold cutting and delicate 4-0 hemostatic suturing that completely eliminates all electrocautery, ultrasound thermal energy, clips, and bioadhesives. Bulldog clamp placement on the lateral prostate pedicles did not interrupt blood flow within the NVB.

Hemostasis, Surgical↗
PubMed1980

Ultrastructure and successful keratoplasty of sclerocornea in Mietens' syndrome.

A 5-year-old boy with Mietens' syndrome had bilateral microsclerocornea, hypoplastic nose, bilaterally absent radii, elbow flexion contractures, absent left fibula, growth retardation, and normal intelligence. Both corneas measured 9.25 mm in diameter and showed diffuse anterior stromal opacification with focal nebular densities and extensive superficial vascularization. Penetrating keratoplasty in one eye remained clear and compact two years postoperatively and visual acuity improved. Histopathologically, vascularized collagenous tissue occupied the anterior one fourth of the corneal stroma and contained bundles of collagen fibrils 75 to 90 nm in diameter. Descemet's membrane showed abnormal anterior lamination.

Abnormalities, Multiple↗
PubMed2000

Myofibromas and myofibromatosis of the oral region: A clinicopathologic analysis of 79 cases.

The clinicopathologic features of 79 myofibromas or myofibromatoses of the oral and maxillofacial region were studied. The case studies were taken from the files of the Armed Forces Institute of Pathology. The tumors affected 44 males and 33 females (gender was unknown in 2 cases). The patients' ages at diagnosis ranged from birth to 84 years, with mean and median ages of 26.6 and 22 years, respectively. Four patients had infantile myofibromatosis; 2 had extraoral bone lesions and 2 had multiple subcutaneous tumors. In descending order, tumors involved the mandible, tongue, lips, cheek or buccal area, maxilla or palate, pterygomandibular raphae, floor of mouth, and submandibular gland. One third of the tumors affected the bones of the jaws; 12 were central and 15 were cortical or periosteal. All medullary tumors occurred in patients under age 18. On gross examination, the lesions were firm, homogeneous or whorled, white-grey fibrous masses that ranged in size from 0.5 to 5.0 cm. Microscopically, all tumors demonstrated a pattern of nodules or bundles of spindle cells separated by areas of greater cellularity and crescent-shaped vascular spaces. Distinct hemangiopericytoma-like areas were present in 22 cases. Despite apparent circumscription, the tumors commonly infiltrated and entrapped adjacent muscle, nerve, or salivary tissue. Immunohistochemically, 37 of 37 and 39 of 39 tumors stained positively for alpha-smooth muscle actin and muscle-specific actin, respectively, with the former eliciting a more intense reaction. Eight of 8 tumors were weakly positive for CD68, and one case stained focally with S-100 protein. No desmin staining was present in 36 tumors examined. Diagnostic interpretations by the pathologists seeking consultation were malignant or aggressive tumors in 31 cases and other benign conditions in 26. Nine were interpreted as myofibromatosis and 13 offered no interpretation. Thirty-two patients were alive and free of tumor an average of 42 months after initial diagnosis. Four patients had one recurrence each, and 2 had lesions recur twice. Myofibromas are relatively common soft tissue tumors of the maxillofacial region, which have been misinterpreted as malignant or aggressive lesions.

Adolescent↗
PubMed1993

Transforming growth factor-beta 1 induces alpha-smooth muscle actin expression in granulation tissue myofibroblasts and in quiescent and growing cultured fibroblasts.

Granulation tissue fibroblasts (myofibroblasts) develop several ultrastructural and biochemical features of smooth muscle (SM) cells, including the presence of microfilament bundles and the expression of alpha-SM actin, the actin isoform typical of vascular SM cells. Myofibroblasts have been proposed to play a role in wound contraction and in retractile phenomena observed during fibrotic diseases. We show here that the subcutaneous administration of transforming growth factor-beta 1 (TGF beta 1) to rats results in the formation of a granulation tissue in which alpha-SM actin expressing myofibroblasts are particularly abundant. Other cytokines and growth factors, such as platelet-derived growth factor and tumor necrosis factor-alpha, despite their profibrotic activity, do not induce alpha-SM actin in myofibroblasts. In situ hybridization with an alpha-SM actin probe shows a high level of alpha-SM actin mRNA expression in myofibroblasts of TGF beta 1-induced granulation tissue. Moreover, TGF beta 1 induces alpha-SM actin protein and mRNA expression in growing and quiescent cultured fibroblasts and preincubation of culture medium containing whole blood serum with neutralizing antibodies to TGF beta 1 results in a decrease of alpha-SM actin expression by fibroblasts in replicative and non-replicative conditions. These results suggest that TGF beta 1 plays an important role in myofibroblast differentiation during wound healing and fibrocontractive diseases by regulating the expression of alpha-SM actin in these cells.

Actins↗
PubMed1993

Solitary infantile myofibromatosis of bone. An immunohistochemical and ultrastructural study.

A rare case of solitary infantile myofibromatosis of bone in an 11-month-old boy is reported. Radiographically the lesion of parietal bone was round, well-circumscribed, and osteolytic with a sclerotic rim. Histologically the tumor was made up of nodules that were hyalinized or cellular and containing plump, spindle-shaped cells that were intermediate in appearance between fibroblasts and smooth-muscle cells, arranged in short bundles or whorls. Another typical feature was the presence of distended, cleft-shaped vascular spaces around the nodules. The microscopic features of this tumor were consistent with those of infantile myofibromatosis of other sites, such as the skin and deep soft tissue. The tumor cells showed immunoreactivities for vimentin and alpha-smooth muscle actin. Microfilaments with dense bodies were observed in the fibroblast-like tumor cells. In addition, many tumor cells stained for collagen type IV and were covered by incomplete external laminae, indicating infantile myofibromatosis has more advanced smooth-muscle differentiation than conventional fibromatosis.

Actins↗