Minor Blood Vessels Research Articles

Hamster retractor muscle: A new preparation for intravital microscopy

The hamster retractor muscle is a long strap-shaped muscle which has its origin on the spinal processes of the last three thoracic vertebrae and inserts proximal to the blind end of the cheek pouch. The muscle is easily prepared without interruption of the nerve supply or major arterial supply by severing the tendon at the spine and ligating two minor blood vessels. The dimensions of the muscle region studied are typically 6 to 7 mm wide, 15 to 20 mm long, and less than 600 μm in thickness at the center in hamsters weighing 80 to 100 g. Microscopic observations are usually confined to the edge of the muscle where the thickness is less than 150 μm. Two small arteries supply the muscle region studied and branch four to five times before reaching the capillaries. A repetitive modular pattern consisting of an arteriole, capillaries, and a venule, occurs along the edge of the muscle. At the edge, all layers of capillaries are visible and blood generally flows in a concurrent pattern to the collecting venules located on either side of the arteriole. The relatively simple vascular arrangement of this new striated muscle preparation makes it an attractive vascular bed for mathematical modeling of microcirculatory mass transport experiments.

The Microcirculation of Irradiated Spontaneous Osteosarcoma in Dogs

From proceedings of the 2nd international conference of veterinary radiologists; Stockholm, Meden (1970). Of 13 dogs with spontaneous osteosarcoma, six were irradiated with a Caesatron. Three dogs received 1000, 2000, and 3000 rad respectively in a weekly dose of 1000 rad. Three dogs received the corresponding weekly dose in daily fractions. Microangiographic examination showed that the large doses caused obstructions of small blood vessels and obstructions and constrictions of the larger vessel. One thousand rad given in flve daily fractions caused no noticeable vascular changes. Two thousand and 3000 rad given as daily fractions caused slight changes in the minor blood vessels while the larger vessels remained open. (auth)

Second-order subtraction with simultaneous bilateral carotid, internal carotid injections.

Second-order subtraction technic in conjunction with simultaneous bilateral carotid angiography has definite advantages in comparing subtle changes in expansive processes. Displacement of minor blood vessels or variations in circulation time can be better appreciated. During the capillary phase, the brain can be seen with contrast loading. History Second-order subtraction was described in 1961 by Ziedses des Plantes (1) in his monograph. Little interest in this technic has been expressed in the American literature (2, 3). Simultaneous injections of both carotid arteries have not been widely advocated (4, 5). The fear of subintimal injections into both carotid arteries with resultant sudden, near total, reduction in blood supply to the cerebral cortex reduces the attractiveness of the procedure. Amundsen et al. (6), Saltzman (7, 9), and Gryspeerdt (8) have made extensive use of the cross compression test to get opacification of the opposite internal carotid artery system with no adverse reactions. Amundsen, by employing a percutaneous catheter technic, reported a complication rate of less than 0.3 per cent in 971 consecutive carotid angiograms. It is his routine to compress the opposite carotid artery to compare both middle cerebral arteries on the anteroposterior projection. Material Between January and July 1965, 25 patients were subjected to bilateral carotid angiography with simultaneous injection into both internal carotid arteries. This was followed by use of the subtraction technic of the roentgenograms. The simultaneous bilateral angiograms have been so helpful that the method has now been established as part of our routine projections. No adverse reactions related to the simultaneous injections have been recorded. Technic A percutaneous catheter technic for carotid angiography has been used at UCLA since 1961. The details of this procedure have been published elsewhere (10). In general, a 1 mm (O.D.) catheter is passed percutaneously by a modified Seldinger technic into the low common carotid artery. Under fluoroscopic control the tip of the catheter is maneuvered into the internal carotid and advanced for a distance of 3–5 cm. Since the carotid bulb tends to act as an arterial pressure stabilizer, injections made distal to the bulb will cause a slight rise in intra-arterial pressure. This slight rise produced better filling of the internal carotid system without the overlapping of the external carotid vessels. With a catheter in the internal carotid artery, forceful hand injections of 6 cc of contrast material can be made without fear of extravasation or intramural injection. First-Order Subtraction Subtraction requires taking a roentgenogram immediately prior to serial angiography. This radiograph is called the base film and contains no injected contrast material. A photographic contact print or diapositive is made of this base film, reversing the image relationships from black to white and vice versa.

Roentgen Diagnosis of Hemangioma of the Long Bones

THE present paper gives a description of a ease of hemangioma affecting the bones of the forearm which was diagnosed from a roentgenologic examination of the patient. In spite of the fact that there have been a number of roentgenograms published in the medical press of the world showing hemangiomas of long bones, none of the cases reported has been diagnosed on the strength of its roentgenograms, the diagnosis having been made either after an operation or a biopsy. Hemangioma is of very frequent occurrence. In the vast majority of the cases it is found to affect the skin and the subcutaneous tissue; less frequently it involves other soft tissues and viscera, such as the muscles, liver, spleen, and brain, but much more rarely does angioma affect the bones. Hemangioma should undoubtedly be regarded as a tumor or neoformation, for in this case we have not merely to deal with the enlargement of capillaries and minor blood vessels, but also with their neoformation and tumoral growth, as has been proved by the investigations conducted by Virchow and later by Ribbert. Beside, hemangioma is characterized by its infiltrating growth resulting in the atrophy and destruction of the surrounding tissues. In this respect, hemangioma resembles a malignant tumor. However, actually hemangioma belongs to the group of innocent tumors, for, as a rule, it produces no metastasis. It is true that we may observe multiple hemangiomas, but they cannot be regarded as being of a metastatic nature and should be considered as having originated from numerous foci disseminated throughout the organism. Two types of the tumor are distinguished—hemangioma simplex and angioma cavernosum—but there seems to be no essential difference between the two, except that in the latter variety the formation resembles a cavernous body. A section of the tumor reveals a sponge-like structure, consisting of porous connective tissue containing elastic fibers. The nuclei are lined with a layer of endothelium and filled with blood. Of all the bones of the skeleton, the vertebræ are most frequently affected with hemangioma; then come the bones of the skull, while the long bones are least frequently affected. According to Töpfer's data obtained by making a longitudinal section of the vertebral column in 2,154 cadavers, hemangioma of the spine was observed in 257 cases (11 per cent). Out of this number, the spinous processes were affected in four cases and the bodies of the vertebræ in three cases. It was noted that hemangioma affected most frequently the middle and the lower dorsal vertebræ. The size of the tumors varied between that of a pea and a formation completely filling the body of the vertebra. Not infrequently the bodies of several vertebræ were involved. The intervertebral cartilages remained intact.