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At least 19 recordsLinked to original sources
PubMed1990

[Experimental study on the implantation of a vascular bundle into subcutaneous tissue for improving local blood supply].

This paper reports that the adjacent vascular bundle was transferred into tubed flap in order to investigate the course of the angiogenesis of the vascular bundle by method of microangiography, pathology, transparent tissue specimens and microvascular casts, and effect on blood supply by measuring blood flow and skin temperature. The studies gave us the following results: New capillaries of vascular bundle occurred at 2nd day after operation, and gradually increased in number and then formed rich bush-like vessels on the surface of vascular bundle. The time of the earliest anastomosis between the vessels of the implanted vascular bundle and the recipient site was four day postoperation. The early anastomosed vessels were a few capillaries and some of them were changed into vein-like or artery-like structure. Improving the blood circulation in tubed flap begins on five day postoperation. The anastomosed vessels between the vascular bundle and tubed flap tend to stabilize at 10 day postoperation. The higher pressure in small arteries of the vascular bundle may be one of the main factors that vascular bundle possesses potential ability in angiogenesis and improves the blood circulation.

Animals↗
PubMed1989

[Experimental study on secondary living bone graft--method of creating new donor by vascular bundle implantation to isolated bone].

The purpose of this study was to demonstrate the possibility of creating a new donor for a vascularized bone graft by a vascular bundle implantation to an isolated bone. Preliminary experiments on rats were performed preliminarily in order to investigate the revascularization of bone by a vascular bundle implantation and/or by implanting in muscular tissues (experiment-1). When a vascular bundle was implanted to the intramedullary cavity of an isolated bone and then the bone was implanted in muscular tissues, the isolated bone was more readily revascularized and revitalized than under other conditions. In experiment-2, the revascularized bone was transferred to the abdominal subcutaneous space on the vascular pedicle that was an implanted vascular bundle. Histologic and fluorochrome bone labeling studies showed that the revascularized bone was kept revitalized after the transfer. These results demonstrate that muscle and vascular bundle co-operated effectively in the revascularization of bone. Vascular bundle can also act as a pedicle for transferring the revascularized bone.

Animals↗
PubMed1977

Changes within vascular bundles of rodent kidneys caused by different diets.

Morphological effects caused by two different diets (low protein-high water intake, and high protein-restricted water) on the vascular bundles in the outer medullary zone of the kidney were studied in the laboratory white mouse and in the golden spiny mouse (Acomys russatus, Muridae). In both rodents, when on a low protein-high water intake diet, considerable interstitial substance was found between the vasa recta of the bundles. No interstitial substance was found in animals on high protein-low water intake diet; as a result the vasa recta of the vascular bundle adhered closely. The low protein-high water intake diet caused a marked diuresis, low urine osmolality and low urinary urea concentration. It is assumed that the increase in interstitial substance between the vasa recta of the vascular bundle lowers the efficiency of the counter current barrier system for urea in the kidney and, as a consequence, the medullary urea gradient and urine concentrating capacity decreases. In animals on a high protein diet, the closely juxtaposed vasa recta assure an efficient countercurrent exchange, leading to accumulation and maintenance of a large urea gradient in the medulla and maximal urine concentration. It is suggested that the amount of interstitial material between the vasa recta of the vascular bundle might serve as a modulating factor for the urea concentration in the kidney.

Animal Nutritional Physiological Phenomena↗
PubMed1991

Revascularization of avascular spongy bone and head of the femur in transplantation of vascular bundle (An experimental and clinical study).

Transplantation of a vascular bundle into an avascular spongiosa replant and the head of the femur after interruption of its blood supply was carried out in experiment (66 experiments on 34 dogs). The periods of observation reached 72 weeks. The mechanisms of revascularization of bones devoid of vessels and the results of morphometric analysis were investigated. It has been established that revascularization of a spongiosa replant sets in after 3 weeks and that of the femoral head after 12-16 weeks. Clinical observations (69 cases) were concerned with transplantation of a vascular bundle in the treatment of patients with aseptic osteonecrosis.

Adolescent↗
PubMed2026

Zea mays Drought-Overly Sensitive1/TUBA4 Is Wilty3, and Transcriptome Co-Expression Analysis of Shoot Meristem Mutant Tissues Reveals Wilty2/TUB6:Wi3 Interactions Associated With Stem Vascular Bundle Development.

Plant vasculature is essential for the transport of water, nutrients, and signaling molecules across organs, while also providing critical mechanical support for growth and development. Disruptions in vascular bundle formation can therefore lead to severe physiological and developmental defects. In maize, ethyl methanesulfonate (EMS)-induced dominant nonallelic Wilty mutants exhibit a pronounced wilting phenotype even under well-watered conditions, indicating underlying defects in vascular function. In this study, we characterized the Wi3 mutant, identified as ZmDrought-Overly-Sensitive1/DOS1, and compared it with the previously described Wi2 mutant to uncover shared mechanisms underlying their phenotypes. We provide evidence, by bulk segregant resequencing linkage disequilibrium of SNPs adjacent to the causal Wilty SNPs in respective ß- and α-tubulin genes, for the personal communication from Gerry Neuffer that Wi2/ß-tub6 provenance is from ACR-related stock, whereas Wi3/α-tub4 allele is from Mo17, not B73 as claimed by the authors who cloned Dos1. Histochemical staining and Fourier-transform infrared (FTIR) spectroscopy of vascular bundles in Wi3 indicated apparent alterations in cellulose and lignin content consistent with those observed in Wi2. Transcriptome analysis of shoot meristems further indicated that similar sets of genes and pathways are differentially expressed in both mutants, suggesting convergence on common biological pathways. Using bulk-segregant whole-genome resequencing, we identified alpha-tubulin4 (TUA4) as the causal gene in Wi3 (ZmDOS1), harboring a C-to-T substitution within the N-terminal GTPase-binding domain. This mutation results in a glutamic acid196-to-lysine substitution. Given that α- and β-tubulin subunits heterodimerize, and in many plants and animal mutant alleles are dominant-negative gains-of-function, we infer Wi2, Wi3, and likely Wi4, based on very similar FTIR biophysical difference spectra, may act as effectors of vascular bundle cell wall deposition, potentially involving vesicle trafficking as recently shown for asymmetric cell divisions in maize stomatal development. Together, these findings highlight the functional interdependence of tubulin subunits and provide a plausible mechanistic framework for the striking biophysical, transcriptomic, and phenotypic similarities observed between Wi2, Wi3/ZmDOS1, and Wi4 mutants.

bulk segregant analysis↗
PubMed1989

Vascular bundles and wickerworks in childhood brain tumors.

We reviewed 114 childhood brain tumors and brain sections from 30 children with no nervous system lesions to determine the incidence of vascular bundles (VB) and vascular wickerworks (VW). VB consist of a group of small blood vessels running parallel to each other. VW denote spiralling or twisting of two or more small blood vessels around one another, resembling vines. By light microscopy, VB cannot be differentiated from VW; both appear as a group of small blood vessels oriented in the same direction. VB and VW have been described in normal and abnormal brains at all ages, in association with aging, in neovascularization following necrosis, and in brain tumors. They occur rarely in normal brains, but are a common histological feature of cerebellar pilocytic astrocytomas in contrast to diencephalic pilocytic astrocytomas, anaplastic astrocytomas of cerebrum and cerebellum, and meningiomas.

Adolescent↗
PubMed1976

[Injuries of the thigh bone with a destruction of the neuro-vascular bundle].

From 1969 to 1971 the authors treated 1360 injured patients, eight of which suffered serious injuries of the thigh; fractured femur complicated by a severed Femoral Popliteal Artery, and lesions of the Sciatic Nerve. Six patients were injured at work, one in an automobile accident, and one was a gunshot victim. In approximately 1000 fractures one is complicated by an injured neurovascular bundle. The clinical picture of such a case is characteristic. The arteriograph is used only to locate the lesion. Reconstruction of the artery must be accomplished some eight to twelve hours following the injury. In all of the authors' cases, this was done one to eight hours following the trauma. After twelve hours, ischemic necrosis of the soft tissue (musculature) sets in requiring amputation. The remaining segment of the damaged artery is usually resected. In one case, a segment 8 cm. long was removed. Following the termino-terminal anastomosis, the injured extremity was placed in a flexed position whlich alleviated the tension on the sutures. The result of vein autographs are worse than those of the termino-terminal anastomoses. Thrombosis later begins to restrict blood flow through the reconstructed artery, but by this time, adequate collateral circulation has been established. The limb has thus been saved. Heparin is administrated immediately before and during the operation in a dosage of 5000 units per 500 ml. of physiological solution. Postoperatively, it is not used as it acts on the fibrin thrombi, and not on the thrombocyte thrombi which are formed postoperatively in the areas where the tunica intima has been damaged. Heparin is indicated in the prophylaxis of venous thrombosis. In these cases in which the femur was fractured, the question asked is whether to perform the osteosynthesis and anastomosis simultaneously, or to perform the former at a later time. The authors chose both methods for various reasons. Only a few cases permitted the authors to decide which approach would be better. Usually they performed a temporary fixation of the bone with Rusch's Pin, and sutured the artery. Four months later, a compressive osteosynthesis using an L-plate, was performed. In four cases, the Sciatic Nerve was injured, which, according to the circumstances was sutured either immediately, or 3 to 4 weeks later. In 3 patients, good functional results were obtained. Three cases resulted in a contracture of the knee, two of which also had residual Sciatic Paresis. One case resulted in permanent venous stasis (edema of the legs, and two cases results in amputation.

Adult↗
PubMed1975

The structural organization of the kidney of the desert rodent Psammomys obesus.

The architecture of the desert rodent Psammomys obesus has been studied by means of standard histologic procedures and by single nephron injections. As other rodent kidneys (rat, mouse), the Psammomys kidney consists of two types of nephrons, 66% short looped and 34% long looped nephrons. The cortex is composed of 4 to 5 layers of glomeruli, which lie closely put together, the glomeruli often touch each other. The superficial and the midcortical glomeruli give rise to short looped neophrons, the juxtamedullary to long looped nephrons. In the strongly developed medulla the inner stripe shows the most striking pattern. It consists of two distinct compartments, that of the giant vascular bundles and that of the interbundle regions. The giant vascular bundles consist of about 8 to 14% arterial vasa recta and 39 to 47% venous vasa recta; furthermore they include the thin descending limbs of the short loops of Henle which amount to 44 to 51% of the bundle structures. The tubules of the interbundle regions surround the bundles in a regular pattern. The inner zone is almost completely surrounded by the renal pelvis; the long broad papilla protrudes into the ureter. The thin descending limbs of short looped nephrons traverse the inner stripe inside the giant vascular bundles. Leaving the bundles they turn back within the inner stripe; their ascending limbs lie in the interbundle region. Both limbs of the long loops of Henle run in the interbundle region, together with the ascending limbs of the short loops and the collecting ducts. The long loops penetrate deeply the inner zone. Many bends are found near the tip of the papilla. The renal pelvis has a very specialized form. It penetrates the inner stripe with many complexely shaped extensions, which surround the giant vascular bundles. Large parts of the bundles with their thin walled structures are thus separated from the pelvic urine only by a single layer of cuboidal epithelium. The possible functional importance of the described specializations of the Psammomys kidney (giant vascular bundles, large inner zone, special shape of the renal pelvis) for the urine concentrating and urea recyclng mechanisms is discussed.

Animals↗
PubMed1991

[An experimental study to determine the most effective delay procedures on secondary vascularized skin island flaps].

Secondary vascularized flaps made from implanted vascular bundles in the subcutaneous tissues have dominant vascularities. Animal experiments were performed using white rabbits, two types of skin flaps were made on their backs. The first delay procedure was performed on the left side where the vascular bundle had been implanted with an elevation of distally based flap (size 2 cm x 7 cm). 28 out of 32, secondary vascularized skin island flaps survived either partially or completely in the first procedure. Moreover, the first delay method was observed to be efficacious in 15 out of 16 cases (p less than 0.01). The viability of vascular bundles of secondary vascularized flap was thus proved. The first stage of the second delay procedure was performed in bilateral side using the same procedure as the first delay. Two weeks later, two types of delay method were carried out. On the left side, a proximally based flap (size 2 cm x 7 cm) was made at the distal area of the first delay flap. On the right side, a bipedicled flap was made (size 2 cm x 14 cm). These flaps were elevated as secondary vascularized skin island flaps two weeks later. In all cases, the latter procedure produced a longer survival rate compared with the former (p less than 0.01). It was concluded experimentally that the most effective second delay procedure was the bipedicled flap method.

Animals↗
PubMed1985

Morphologic and functional evidence for oxygen deficiency in the isolated perfused rat kidney.

Morphologic and functional studies were undertaken in the isolated rat kidney, perfused with an albumin-Krebs-Henseleit solution, to which 5% human erythrocytes and/or various amino acids had been added. Perfused only with the albumin-Krebs-Henseleit solution, the kidneys displayed a characteristic pattern of cell necrosis after 2 hours of perfusion, which was confined to the interbundle region of the outer medulla and was not evident in either the cortex or the inner medulla. In the outer stripe only those proximal straight tubules (P3 segments) farthest from the vascular bundles were damaged. In the inner stripe only those thick ascending loops of Henle at the periphery of the vascular bundles escaped damage; all thick ascending loops of Henle lying farthest from the bundles were severely damaged. The number of damaged tubules increased toward the border to the inner medulla. Necroses in both segments, P3 and thick ascending loops of Henle, could be prevented by perfusion with the erythrocyte-albumin-Krebs-Henseleit solution but not by the addition of glutathione, in the absence of erythrocytes. Perfusion with the erythrocyte medium also significantly improved glomerular filtration rate and sodium and glucose reabsorption. It is concluded that, in the isolated, erythrocyte-free perfused kidney, the oxygen content of the "arterial" vasa recta in the vascular bundles is only sufficient to supply the tubules in the immediate surroundings. Countercurrent exchange in the vascular bundles between arterial and "venous" vasa recta progressively lowers the arterial oxygen content as the inner stripe of the outer medulla is approached and with it the number of tubules receiving an adequate oxygen supply.

Animals↗
PubMedDate not supplied

Urinary concentrating processes in vertebrates.

Avian and mammalian kidneys can produce a urine hyperosmotic to the blood by means of a renal countercurrent system. Birds are uricotelic; mammals are ureotelic. It is proposed that the inner medulla present in mammalian, but not in avian kidneys serves specifically to accumulate urea in the inner and outer medulla. Among mammalian kidneys the degree to which urea accumulates in the inner medulla is inversely related to the complexity of the vascular bundles (in the outer medulla) and the cortical urea recycling index. A model is proposed for urea recycling via the vascular bundles. The renal pelvis varies in size among mammals. Its relative size is unrelated to the type of vascular bundles, cortical recycling index; or urea accumulation in the inner medulla. Since urine refluxes into the renal pelvis during rising urine flow only, the function of the pelvis could be that of bringing the more dilute urine into contact with the outer medulla and underlying capillaries, thereby aiding in reducing the urea concentration in outer and inner medulla during rising urine flow. The size of the renal pelvis may be related to the volume of the inner medulla. Other factors may also be involved.

Animals↗