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PubMedDate not supplied

Induction of human vascular endothelial stress fibres by fluid shear stress.

Endothelial cells of the arterial vascular system and the heart contain straight actin filament bundles, of which there are few, if any, in the venous endothelium. Since stress fibre-containing endothelial cells within the vascular system tend to be located at sites exposed to particularly high shear stress of blood flow, we have investigated, in an experimental rheological system (Fig. 1), the response of the endothelial actin filament skeleton to controlled levels of fluid shear stress. Here we report that endothelial stress fibres can be induced by a 3-h exposure of confluent monolayer cultures of human vascular endothelium to a fluid shear stress of 2 dynes cm-2, approximately the stress occurring in human arteries in vivo. Fourfold lower levels of shear stress that normally occur only in veins, had no significant effect on the endothelial actin filament system. The formation of endothelial stress fibres in response to critical levels of fluid shear stress is probably a functionally important mechanism that protects the endothelium from hydrodynamic injury and detachment.

Actinin↗
PubMed1988

The extracellular matrix composition of the monkey optic nerve head.

The presence and distribution of laminin, heparan sulfate proteoglycan and collagen types I, III and IV were immunohistologically determined in cynomolgus monkey optic nerve heads using the avidin-biotin-peroxidase complex technique. Collagen types I and III were detected within the collagenous plates of the scleral lamina cribrosa, in the septa and pia mater of the postlaminar optic nerve and in blood vessel walls in all regions of the optic nerve head. Collagen type IV, laminin and heparan sulfate proteoglycans were all localized to the margins of the collagenous laminar plates of the scleral lamina cribrosa and along the margins of the optic nerve septa and the pia mater. All three components also appeared beneath the blood vessel endothelium throughout the optic nerve head. Within the lamina cribrosa, collagen types I and III occupy the core of the scleral laminar plates and may provide structural support for optic nerve bundles exiting the eye. The distribution of collagen type IV, laminin and heparan sulfate proteoglycan corresponds to basement membranes from two sources: vascular endothelial cells and glial cells lining the axonal bundles. Abnormalities of these substances may influence optic nerve function and susceptibility to elevated intraocular pressure by altering their mechanical support functions within the nerve head, by interfering with axonal nutrition, or both.

Animals↗
PubMed2005

Effects of mitomycin C on glaucoma filtration capsules.

One of the leading causes of implantable device failure is build up of scar tissue on the device. Approaches to address this complication range from choosing device materials that prevent cell adhesion to treatment with potent antifibrotic medications such as mitomycin C. We examined the collagen matrix around aqueous shunt implants in rabbit eyes and found the filtration capsule formed around these devices is not composed of scar tissue. Rather collagen deposition is highly organized with collagen bundles oriented along stress axes. We also examined adjacent tissue deposition in mitomycin C treated animals and found decreased vascularization, condensed collagen in Tenon's capsule with more collagen bundles less well formed than those in the control eye of the same animal. The sclera was thicker under the plate than at the opposite side of the same eye. Structural and functional evaluation correlates with the clinical paradox that patients treated with mitomycin C have lower initial pressures with adjunct drug treatment but lower success rates than the control population after 18 months.

Animals↗
PubMed1978

Unilateral anorchism. Report of 11 cases with discussion of etiology and pathogenesis.

Eleven cases of unilateral anorchism are presented. The patients, aged two to thirty-nine years, were explored for cryptorchism but, though ducts could be identified operatively in most cases, there was doubt regarding the presence of the testis. These tissues, including the putative testes, were excised and pathologically the excurrent ducts, consisting of vas deferens with or without epididymis, were seen in all cases. No tunica albuginea or testicular parenchyma was identified and the structures, submitted as possibly testicular, were nonencapsulated, well-circumscribed, subserosal foci of highly vascularized fibrous tissue with few small nerves and smooth muscle bundles. Dystrophic calcific deposits were seen in 2 cases and microfoci of poorly developed Leydig cells in 2 cases. A vascular hypothesis is proposed for the etiology and pathogenesis of unilateral anorchism.

Adolescent↗
PubMed1993

Confocal microscopy and computer-assisted image reconstruction of astrocytes in the mammalian retina.

The distribution of astrocytes in the vascularized retina of pigs, rats and cats was investigated by confocal microscopy and computer-assisted image processing. In whole mounts, immunocytochemical identification was done by staining astrocytes for glial fibrillary acidic protein (GFAP), and blood vessels for alpha-smooth muscle actin or collagen IV. Double-staining was followed through consecutive optical sections and made it possible to precisely align the two markers in the inner retina. The resulting computer-assisted image reconstructions revealed asymmetric ensheathment of blood vessels by GFAP-positive fibres. The ultrastructural basis for this asymmetry, as studied by electron microscopy, was found to be different in pigs and cats. In the pig, astrocytes firmly ensheathed the vessel circumference, but glial filaments were much more abundant on the vitreal and lateral than on the scleral side. By contrast, in the cat astrocytes were generally confined to regions occupied by axonal bundles and constituted only part of the vascular glia limitans, else formed by Müller cells. Moreover, our observations unambiguously showed that individual astrocytes maintained simultaneous contact with axons and blood vessels and lined the vitreous body. The physical links provided by astrocytes suggest that they are able to function as central communicating elements between ganglion cells, the vasculature and the vitreous body.

Animals↗
PubMed1996

The revascularization interface in flap prefabrication: a quantitative and morphologic study of the relationship between carrier size and surviving area.

To make a quantitative assessment of the relationship between size of vascular carrier and surviving area in a prefabricated flap, vascular carriers composed of the superficial epigastric arteriovenous bundles and a surrounding fascial patch with varying sizes were transferred under a 7- x 7-cm bipedicled abdominal skin flap in a rat model. Seven days later, the abdominal flaps were raised as composite island flaps connected only by the superficial epigastric vascular pedicle, transferred, and then sutured back into place. Immediately after replacement, the degree of revascularization was assessed using quantitative skin fluorometry, after intravenous injection of sodium fluorescein. At 7 days after elevation as an island flap, the area of skin flap surviving was recorded and plotted on a map depicting the original flap surface. High levels of fluorescence appeared on the flap surface where the carrier was tacked underneath. The prefabricated island flaps survived with a circular shape up to approximately 4 times the radius of the vascular carrier. When the distance was converted into area, theoretically, an area 13 times the area of the vascular carrier survived, regardless of its size in this experimental model. Histologic examination revealed connections of fine capillaries between the carrier and flap.

Animals↗
PubMed2006

Autologous diaphragm reconstruction with the pedicled latissimus dorsi flap.

The latissimus dorsi (LD) muscle has been previously described to repair diaphragmatic defects, but as a "reverse" flap, relying on secondary blood supply from the perforating lumbar vessels rather than primary inflow from the dominant thoracodorsal artery. We report resection of a retroperitoneal synovial sarcoma, with reconstruction of the hemidiaphragm using the LD rotated on its primary neurovascular bundle. By using the dominant pedicle, the vascularity of the flap is improved, minimizing the chance of flap tip loss. Maintaining an intact nerve supply prevents atrophy. As the distal origin of the LD is broad and flat, it is ideally suited for diaphragm repair. A latissimus-sparing thoracotomy incision is required to enable this method of diaphragm reconstruction.

Abdominal Muscles↗
PubMed2000

Structurally preserved sphenophytes from the Triassic of Antarctica: reproductive remains of Spaciinodum.

Permineralized cones found organically attached to Spaciinodum collinsonii stems are described from the early Middle Triassic silicified flora from the Fremouw Formation of Antarctica, and the species diagnosis is emended to include the reproductive specimens. The apical cones are organized into internodal and leaf-bearing nodal regions. Nodal septations span the central pith and cortex, and thin fimbrils subdivide the internodal areas into smaller chambers. The vascular system consists of 31-33 continuous bundles that do not alternate in position between successive nodes and internodes. Simple sporangia are associated with the cortical chambers and occur in one whorl on the axis. Spores are small, lack elaters, and have no discernible ultrastructure preserved, and they are interpreted to be immature. The Antarctic cones are different in structure from typical cones of modern and fossil members of Equisetales; however, they share similarities with some morphologically aberrant cones of extant Equisetum and several Late Paleozoic and Mesozoic compression-impression fossils. Spaciinodum is now the most complete anatomically described Mesozoic sphenophyte.

Journal Article↗
PubMed1992

[Intramuscular hemangioma of the posterior wall of the pharynx. Diagnosis and differential diagnosis].

We report on the case of a seven-year old boy who developed an enlarged swelling of the oropharynx. Clinical examination revealed a well demarcated cystic tumour. Histopathologically the diagnosis of an intramuscular haemangioma could be made because of the multitude of vascular spaces filled with erythrocytes lying between bundles of smooth muscles. Such a lesion coming from the posterior wall of the oropharynx is not described in literature. In differential diagnosis the angiosarcoma and the arteriovenous aneurysm must have been involved since there were multiple arteries and veins lying close together in couples. Moreover the adenotomia carried out one and a half year earlier prompted us to think about the possibility of a traumatic arteriovenous fistula.

Arteries↗
PubMed2001

The anatomy of the septal perforating arteries in normal and congenitally malformed hearts.

BACKGROUND: Many cardiac operations involve incisions and sutures on or near the ventricular septum. These jeopardize the septal perforating arteries. Our aim was to provide guidelines for the surgeon to predict the site of these vessels. METHODS AND RESULTS: We dissected 50 hearts. In 16 of these we also conducted histologic examination of the area of the septum containing the atrioventricular node, the penetrating bundle (of His), and the branching atrioventricular bundle to elucidate the source of the vascular supply to these structures. The major perforating septal arteries arise from the superior interventricular artery or, in hearts with a rudimentary right ventricle, from the superior delimiting artery. The first is usually the largest. The location of this artery can be predicted relative to the position of the medial papillary muscle. In abnormal hearts, holes within the ventricular septum in the presence of a well-developed muscular outlet septum were found to deviate the path of the septal perforating arteries in a predictable manner. The triangular area bordered by the margin of the ventricular septal defect, the muscular outlet septum, and the medial papillary muscle is free of major perforating arteries. The histologic studies showed that the conduction tissues at the base of the ventricles tend to receive their blood supply from arteries arising from the inferior interventricular artery, except in double-inlet left ventricle, in which the arterial supply is from the right-sided delimiting artery. CONCLUSION: The location of the first superior septal perforating artery is predictable in many cases. Its course leaves a triangular area on the muscular ventricular septum that is free of major arteries.

Cadaver↗
PubMed2007

Rhabdomyomatous (mesenchymal) hamartoma of the tongue: report of a case.

A 12-year-old girl presented with three yellowish polypoid lesions in the lateral border of tongue since birth. Histological examination showed oral mucosa covered by squamous epithelium and an underlying vascularized fibrous stroma, containing small and short bundles of striated muscle, corresponding to a rhabdomyomatous hamartoma.

Child↗
PubMed2004

Implantation of immature neonatal cardiac cells into the wall of the aorta in rats: a novel model for studying morphological and functional development of heart cells in an extracardiac environment.

BACKGROUND: Morphological and functional development of implanted neonatal cardiac cells in the wall of the abdominal aorta in rats was investigated. METHODS AND RESULTS: Cardiomyocytes from neonatal Fischer rats (both sexes) or medium were injected into the wall of the abdominal aorta in female Fischer rats (n=22 in each group). Two or 6 weeks later, the grafted site was exposed and fixed for histological and immunohistological examination. Polymerase chain reaction analysis of the SRY gene to identify male cells was performed in the treated aortas. Seven of 10 cell-treated aortas but none of 10 medium-treated aortas showed spontaneous rhythmic beating at the grafted site after excision of the heart at 2 weeks. Polymerase chain reaction of the SRY gene was positive in 3 cell-treated aortas and none of 3 medium-treated aortas at 6 weeks. Hematoxylin-and-eosin staining showed viable grafts in 9 of 10 aortas at 2 weeks and 9 of 9 aortas at 6 weeks in the cell-treated group but in none of the aortas receiving medium. Neonatal cardiomyocytes in the graft formed compact, longitudinally oriented cardiac muscle bundles and had cross-striations and vascularization. Immunohistochemical staining for sarcomeric actin was positive in 4 of 10 aortas at 2 weeks and 9 of 9 aortas at 6 weeks in the cell group but in none of the aortas in the medium group. CONCLUSIONS: Grafted neonatal cardiomyocytes survive, differentiate, grow, develop a blood supply, and spontaneously contract within the wall of the aorta in rats.

Animals↗
PubMedDate not supplied

Kaposi's sarcoma of the glans penis in an immunocompetent patient.

We report a 39-year-old HIV negative man with a solitary reddish-brown papule located on the glans penis, which had developed 6 months previously. Histopathologic examination showed spindle-shaped cells scattered between collagen bundles and intermingled with small, pointed vascular-like spaces. Spindle-shaped cells stained positively for antiFactor VIII and anti-CD34 antibodies. Human herpes virus-8 DNA was detected in tumor tissue and in peripheral blood mononuclear cells. Based on clinicopathologic and molecular findings, the diagnosis of classic Kaposi's sarcoma was made. Two months after the initial observation, three additional papules developed on the glans penis. Histopathologic examination of one lesion confirmed the diagnosis of classic Kaposi's sarcoma. The remaining lesions were treated with electrodessication and curettage. After a follow-up period of 6 months no evidence of recurrence was observed. We report this case for the unusual localization of Kaposi's Sarcoma in a young, HIV-negative patient.

Adult↗
PubMedDate not supplied

Angioleiomyoma of the tongue.

A case of angioleiomyoma of the tongue is detailed. The patient sought treatment for a painless, rubbery mass of 10 years duration. The tumor was unusual, appearing bilobed, with the dorsal aspect whitish in color and a blue ventral component. Occasional episodes of numbness were noted. Biopsy of the lesion demonstrated bundles of smooth muscle cells surrounding numerous vascular spaces. The patient was lost to follow-up; as a result, a complete surgical excision of the tumor was not performed.

Actins↗
PubMed1993

[Preoperative diagnosis of unroofed coronary sinus: a case report].

A 54-year-old man was admitted to our hospital because of exertional dyspnea. A second heart sound with fixed splitting and a systolic ejection murmur along the left sternal border was audible. The chest roentgenogram showed increased pulmonary vascularity, and the electrocardiogram showed incomplete right bundle branch block. Two-dimensional echocardiography in the parasternal view demonstrated a partition defect between the left atrium and the coronary sinus. Furthermore, transesophageal echocardiography revealed a left-to-right shunt flow into the coronary sinus through the defect. At these points, the patient was diagnosed as having a partially unroofed mid-portion of the coronary sinus. Unroofed coronary sinus is a cardiac anomaly rarely diagnosed prior to surgical operation. Two-dimensional echocardiography, especially transesophageal echocardiography, is useful for the preoperative diagnosis of unroofed coronary sinus.

Coronary Vessel Anomalies↗
PubMed2001

Harmonic scalpel in laparoscopic colorectal surgery.

PURPOSE: With advances in laparoscopy, various hemostatic procedures have been advocated with variable results. Using currently available tools, some steps in laparoscopic colorectal surgery still represent technical challenges. Our aim was to investigate the feasibility and reliability of the Harmonic Scalpel in laparoscopic colorectal surgery. METHODS: In this nonrandomized prospective study, 34 consecutive patients (15 males; mean age, 46 (range, 24-80) years) underwent laparoscopic colorectal surgery for benign disease (27 patients) and colorectal cancer (7 patients). Dissection, hemostasis, coagulation, and division of several types of vascular pedicles were performed exclusively with the Harmonic Scalpel. The 10-mm-blade Harmonic Scalpel device was used at full power mode for all purposes through a 10-mm port. Coagulation of vascular pedicles was always achieved with the blades in the flat position. The large pedicles (inferior mesenteric, right and left colic, and ileocolic) were coagulated for 20 seconds in several locations along the length (1 cm) before final division. Smaller vascular pedicles were coagulated for ten seconds before division. When the vein and the artery of major pedicles were divided at their origin, either for malignancy or for technical reasons, they were dissected and coagulated separately. For more limited resection of the mesentery, as in the case of benign disease, vascular pedicles were coagulated together as a single bundle. Operative time, minor or major intraoperative or postoperative hemorrhage, need for conversion to laparotomy, bowel injury, and trocar complications were recorded. All anastomoses were checked on Day 8 by a diatrizoate sodium enema. RESULTS: There was no mortality. Mean operative time was 276 (range, 200-520) minutes. Neither minor nor uncontrollable hemorrhage occurred; no conversion to laparotomy and no vascular or bowel injury were recorded. There was one port-site hematoma. Neither hemoperitoneum, intraperitoneal hematoma, fistula, nor intra-abdominal abscess was observed. CONCLUSION: Coagulation and division of minor as well as major vascular pedicles in laparoscopic colorectal surgery with the Harmonic Scalpel" are technically easy, feasible, and reliable.

Adenocarcinoma↗
PubMed1995

Patterns of peptide-containing perivascular nerves in the circle of Willis: their absence in intracranial arteriovenous malformations.

Using standard immunohistochemical techniques and an improved procedure for whole-mount vascular preparations, the authors describe the pattern and density of innervation of calcitonin gene-related peptide (CGRP)-like, neuropeptide Y (NPY)-like and vasoactive intestinal polypeptide (VIP)-like immunoreactivity in major arteries of postmortem adult human circles of Willis. Calcitonin gene-related peptide-, NPY-, and VIP-LI exhibited a variety of varicose and nonvaricose single axons, and small and large perivascular nerve bundles. Although the density of innervation within each vascular segment was highly variable, the pattern of innervation for each neuropeptide observed was consistent throughout the circle of Willis. With the use of human and rat circles of Willis as positive control preparations, the lack of CGRP-LI, NPY-LI, and VIP-LI in vessel segments taken from five cases of intracranial arteriovenous malformations (AVMs) is also reported. It is concluded that adult human circles of Willis exhibit CGRP-LI, NPY-LI, and VIP-LI perivascular nerves. In addition, intracranial AVMs do not possess these peptide-containing nerves that, in animals, normally mediate neurogenic control in the cerebrovasculature. It is hypothesized that this lack of innervation, and hence neurotrophic influence, may contribute to the development of AVMs.

Adult↗