M. S. Mahaley

Mechanics of the Human Common Carotid Artery in Vivo

The relationships between lateral intravascular pressure, vessel radius, and vessel length were evaluated in the common carotid artery in vivo in thirteen patients during treatment by surgery. Strain was measured in the wall of the carotid artery by means of an electrical caliper sutured to the vessel wall. Lateral intravascular pressure was measured directly with either an 18-gauge needle or a short polyethylene catheter connected to a Statham, P23Db, strain gauge. The results indicate that circumferential and longitudinal strains in the common carotid artery were both small. The mean systolic change in cross-sectional area was 2.10% (±SD 1.08) of the end diastolic area. In three patients a negative circumferential strain was produced by making the cross section of the vessel elliptical. During systole, longitudinal strain increased in four patients and decreased in six patients. The average change in vessel segment length during systole was approximately 1.0% of the end diastolic length.

Prevention of glioma induction in rats by simultaneous intracerebral inoculation of avian sarcoma virus plus bacillus calmette-guerin cell-wall preparation

Bacillus Calmette-Guerin cell-wall preparation was injected along with avian sarcoma virus in the brains of newborn Fischer 344 rats, and subsequent glioma induction was compared with rats injected with avian sarcoma virus alone. The percentage of glioma induction and survival were found to be directly related to avian sarcoma virus concentration (10(0), 10(-1), 10(-2), and 10(-3)). A significant reduction in glioma induction occurred when BCG cell-wall preparation was injected with 10(-2) ASV concentration. Above that concentration of ASV, the tumor induction was not significantly affected by bacillus Calmette-Guerin cell-wall preparation; below that concentration, the tumor induction was too low with avian sarcoma virus alone to evaluate an effect.

Approximation of total vascular space and its distribution in three sizes of blood vessels in rats by plastic casts.

To know where given amounts of blood might be, we need to know the potential vascular space and what the distribution among various sized vessels is. Methyl methacrylate was injected via the cannulated aorta into 4 rats, and vascular casts made. Polymerization caused 15 per cent shrinkage. The casts were separated into 3 compartments: 150 μ. and smaller, 150 to 600 μ., and 600 μ. and larger. Using the shrinkage, specific density, and weights of plastic, the “total vascular spaces” in cc./100 Gm. were found to be 8.9, 10.6, 11.1 and 11.1, respectively. The mean percentages for the 3 compartments were 10.4 in vessels 706 μ and larger, 6.7 in 188 to 706 μ., and 82.9 in vessels 188 μ. and smaller. Because the only observed distortions of the casts on the basis of comparisons with the in vivo vasculature of a number of organs were some noninjected capillaries and nonmaximally injected veins, the approximations of “total vascular space” are considered too low. The utility of methyl methacrylate casts for gravimetric determinations of volumes was demonstrated. The finding of over 80 per cent of the vascular space in vessels 188 μ. and smaller is relevant to the potential location of blood within the body.

The Effect of Isordil and Cyclospasmol on Vascular Spasm Induced in the Basilar Artery of the Cat

Vasospasm of the basilar artery of the cat was induced by subarachnoid bleeding and was observed by a transoral approach to the vessel. Intravenous Isordil (2 to 4 mg/kg) given following vasospasm produced vasodilatation with minimal arterial hypotension. Cyclospasmol, administered intravenously after vasospasm or orally prior to vasospasm, was ineffective in relieving or preventing basilar artery spasm.

Further physiological observations during induced basilar artery spasm in cats and dogs

Abstract In these experiments, it was determined that the previously described basilar artery spasm in the cat induced by direct exposure to blood or platelet fraction could be similarly produced in the dog. It was also found that spasmogenic platelet fraction was not deactivated by in vitro exposure to CSF for 24 hours, and that platelet fraction was active when injected intrathecally in vivo , thus expanding the significance of our earlier report of the spasmogenic properties of platelet fractions when irrigated directly upon the basilar artery of the cat.

Chromosomes and chromosomal progression of malignant human gliomas: theoretical and practical implications

We karyotyped 27 malignant human gliomas including 3 anaplastic astrocytomas (AA), 23 glioblastoma multiformes (GBM), and 1 gliosarcoma (GS) in direct preparation, short term culture, or both, and found that they could be grouped according to their karyotypic patterns. Six of these tumors (3 GBM) had normal stemlines or only lacked one sex chromosome (Group la). Two tumors (Group lb) lacked one sex chromosome but showed, in addition, numerical and structural deviations. Three tumors were near-tetraploid (Group II) and contained double minutes (DMs). The remaining 16 tumors (I AA, 14 GBM, 1 GS) had near-diploid stemlines (Group III), often with gains of No. 7, loss of No. 10, structural abnormalities of No. 9 and DMs. These different patterns could be reflecting activation and/or amplification of different oncogenes. Alternatively they could be reflecting induction by different agents. But quite apart from their theoretical significance these karyotypic patterns could prove useful as prognostic indicators. The observa-tion that near-diploid human gliomas double their chromosome complements as they establish in culture and as transplantable lines in nude mice suggests that the near-tetraploid tumors in Group II are at a later stage of karyotypic progression than the near-diploid tumors in Groups I and III. There is also a spectrum of stage of karyotypic progression within Groups I and III ranging from tumors with only simple numerical deviations to those with complex numerical and structural abberations. The present series is too small and therapeutic regimens of individual patients are too diverse to determine if stage of karyotypic progression is a useful prognostic indicator. Long term studies of a large group of patients will be necessary to define these relationships.

Characterization of Malignant Gliomas and Cerebrovascular Disease by Cerebral Dynamic Studies

A technique for analysis of dynamic radionuclide studies of the cerebral circulation is described. This technique permits objective classification of observed radionuclide distribution patterns. Variation in the time-to-peak activity, and in the maximum attained activity as determined by region-of-interest analysis of cerebral hemispheric activity, was defined for a normal population. Application of these normal values permits classification of observed hemispheric radionuclide distribution patterns in anaplastic gliomas and in occlusive cerebrovascular disease. Radionuclide activity in gliomas may be normal, decreased, or increased in the region of the tumor. In cerebrovascular occlusion, decreased activity, associated with a delay in time-to-peak activity, is frequently demonstrated in the affected hemisphere.

The use of externally monitored radioisotope techniques in the study of regional carotid blood flow under various experimental conditions

Summary o 1. The regional isotope flow curve obtained following intravascular injection of RISA is described. 2. In a model circulatory system, blood flow is proportional to the tangent of the angle formed by the intersection of the upsweep portion of the isotope curve with the horizontal baseline. 3. Changes in regional carotid blood flow associated with Crutchfield clamp occlusions, intracarotid injection of emboli, pentobarbital injection and intracranial injection of clots in dogs and monkeys are described. 4. The application of this technique in studying regional cerebral blood flow in various clinical situations is discussed.

Perfusion with fibrinolysin in experimental iliofemoral thromboembolism

Summary o 1. An experimental lesion is described resembling iliofemoral emboli seen clinically. 2. This lesion has resisted lysis by the methods employed, including regional perfusion with an intensely lytic perfusate.