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Presents the abstracts of papers presented at the Microcirculatory Society on April 10, 1966.

The article presents information on several meetings related to biosciences. An international conference on Microcirculation as Related to Shock was held at Boston University, Charles River Campus, from March 29 to April 1, 1967. The conference was chaired by George P. Fulton. Its purpose was to examine the involvement of small blood vessels as related to the shock problem with relevance to human beings. The twenty-eighth annual Biology Colloquium was held at Oregon State University on April 28-29, 1967. In the opening paper, titled "Energy Exchange Between Organism and Environment," David M. Gates described the nature of the organism's atmospheric environment. The annual meeting of the Society for Applied Spectroscopy will be held in Chicago, Illinois on May 13-17, 1968.

The present paper briefly discusses the behavior of capillaries in skeletal muscle during increased effort, and the factors affecting the capillary circulation. The number of capillaries is then discussed. The number of open capillaries May vary considerably; the relevant literature is reviewed. Personal experiments are described which indicate that formation of new capillaries is possible in very hypertrophic skeletal muscle. This has so far been regarded as doubtful and no reliable evidence to this effect has hitherto been presented. [ABSTRACT FROM AUTHOR]

Leg varices often show a peculiar and regular tortuosity, their course resembling the meander of river. The meanders of the great saphenous vein tend to start in certain regions, viz. at the levels of the union of a perforant with the superficial venous system. Knowledge of the underlying mechanism of such meandering of the veins is meagre, but as the course of such vessels seems to be approximations of sine-generated curves, the curves of minimum total loss of energy and hence induced by hemodynamic forces, a search for such a background may be rewarding. A morphologic study of early meanders and the neighboring vein compartments may yield valuable information about the hemodynamics involved. This paper reports an x-ray study of early meander formations of the great saphenous vein in the thigh and in the upper part of the lower leg. [ABSTRACT FROM AUTHOR]

The purpose of this paper is to illustrate some rarely encountered congenital or acquired pathologic modifications of the abdominal and thoracoabdominal aorta. The patients observed by us were treated surgically. The affections studied were (1) coarctation of the abdominal aorta (two cases), (2) multiple congenital segmentary stenosis of the abdominal aorta and (3) aneurysm of the thoracoabdominal aorta. [ABSTRACT FROM AUTHOR]

The arterial supply and venous drainage of the baroceptor areas of the cat and dog, and the human carotid sinus, are described from injected and cleared whole-mount preparations. There is an extremely rich vasa vasoral supply in these areas and a high venous to arterial ratio. The possibility that the vasa vasorum are modified to act as a ‘venous pump’ is discussed. This microcirculatory pattern appears to be specific to baroceptor areas. This was demonstrated by examination of the structure of the vessel wall and by staining baroceptor nerve endings. Species differences are described. The method allows satisfactory photography and the paper is illustrated by photomicrographs. [ABSTRACT FROM AUTHOR]

A brief critical review of prevailing theories on the etiology of varicose veins is given. It is emphasized that the subject of varicose veins needs drastic revision. In primary varicose veins valvular incompetence seems to be characteristic of the advanced stages of the disorder and, consequently, is of no etiologic significance. The author's investigations, reviewed in this paper, have introduced three new findings in the field of varicose veins: 1. Prolonged, excessive use of ethyl alcohol appears to con tribute to the development of varicose veins. 2. Generalized scantiness of body hair is characteristic of patients with primary varicose veins. 3. In patients with portal cirrhosis the incidence of varicose veins is high regardless of the presence or absence of ascites. It is suggested that extreme vasodilation caused by alcohol may be equivalent to the effect of arteriovenous fistulas in the development of varicose formations. The fact that varicose veins are frequently seen in those individuals who consume alcohol suggests the possibility of other exogenous or endogenous chemical substances as causative agents in varicose veins. [ABSTRACT FROM AUTHOR]

The theory of fluid flow in compliant tubes developed in a previous paper is applied to a catheter, and the results of various calculations are compared with experiment. When a parabola is used for the unknown velocity profile, the calculated gains are too high. Agreement is slightly improved by using more reasonable profiles. It is shown that there exists a functional relationship between the parameter gamma and the nondimensional parameter alpha(10) which gives reasonable agreements with all the experimental data considered. The theory of Womersley is applied to the catheter, and the calculated gains are larger than those observed experimentally. A form for the frictional force suggested by Lambossy is used in some further calculations.

The results reported in this paper indicate that dinitrophenol acts directly on the isolated heart, increasing its metabolic rate. It also produces heart failure associated with a low phosphocreatine content of the muscle but with no change in adenosine triphosphate, which may or may not be due to a relative hypoxia of the cardiac tissue. Experimental arterial hypoxaemia, if severe, produces a similar picture of heart failure with a decrease in phosphocreatine and no change in adenosine triphosphate. Ligation of the coronary arteries results in disappearance of the major part of the phosphocreatine within a few minutes regardless of whether or not ventricular fibrillation ensues; the adenosine triphosphate remains unchanged.

Hanna, Edgar E. (University of Minnesota, Minneapolis), and Dennis W. Watson. Host-parasite relationships among group A streptococci. III. Depression of reticuloendothelial function by streptococcal pyrogenic exotoxins. J. Bacteriol. 89:154-158. 1965.-Measurement of the rate of clearance of colloidal carbon from the circulating blood is an effective and simple technique for assessing the functional state of the reticuloendothelial system (RES) of experimental animals. This paper concerns a study of the RES function in rabbits after treatment with streptococcal pyrogenic exotoxins. Intravenous injection of 1.0 ml of the toxin produced by a strain of type 18, group A streptococcus caused a prolonged (at least 24 hr) depression of RES function. The activity at 48 hr after toxin injection was about equal to that in control animals. Repeated intravenous injections of the toxin abolished the initial depressing effect on RES function, but did not cause stimulation. In comparison, intravenous injection of equivalent doses of endotoxin prepared from Escherichia coli COO8 also caused an initial depression of RES function; however, in contrast with the effect of exotoxin, stimulation occurred as early as 24 hr and was about twice as active at 48 hr. The prolonged depression by streptococcal pyrogenic exotoxin is suggested as one means by which this toxin potentiates lethality and tissue damage by other toxins such as streptolysin O and endotoxins from gram-negative bacteria.

The article discusses blood-volume measurements of dog teeth. The paper compares the blood volumes obtained for extracted teeth with in situ teeth. The authors detail a number of procedures for the determination of blood volume, including freezing the teeth and jaw through direct application of liquid nitrogen.

Pulse trains were applied separately to each forefinger and to each hallux of 23 Ss to assess stimulus site effects on the relative amplitudes of skin conductance responses recorded concurrently from each palm and from each plantar surface. A binaurally presented tone was used as a non-lateralized stimulus. Analyses of the ratio of response amplitudes from contralateral recording sites indicated that for both the upper and lower extremities, responses from the volar surface of the stimulated extremity were augmented in amplitude. Responses from the volar surface of the extremity ipsilateral to the stimulus site were also augmented in amplitude, though less than when the stimulus and recording sites involved the same extremity. Analyses of the ratio of response amplitudes from the palmar and plantar surfaces on the same side of the body indicated that the specific effects of stimulation did not cross the body midline. The results were interpreted as indicating a regionally differentiated sympathetic outflow to the volar sweat glands that reflects the locus of cutaneous stimulation. [ABSTRACT FROM AUTHOR]

Bilateral differences in the diameter of the two pupils, anisocoria, has been associated with everything from beriberi to psychological trauma. The one common finding in most studies dealing with anisocoria is the increased psychophysiological variability of this population. A neurological model is proposed explaining both the anisocoric condition and increase in autonomic variability. The model suggests that deficiencies in the ascending bulbar inhibitory system reduce tonic control of the medial reticular activating system and may be implicated in the etiology of anisocoria. The portions of the nervous system implicated are those reported by Lacey (1967) to be involved in "directional fractionation." It is suggested that the anisocoric individual may provide a ready made "lesioned" sample with which to compare normal subjects. At the very least anisocoria represents another example of bilateral autonomic asymmetry. Possible research in this area is disussed. [ABSTRACT FROM AUTHOR]

1) In 37 lower extremities of 34 patients and in 14 extremities of 10 control subjects, calf blood flow was measured at rest and after ischaemic exercise by strain-gauge plethysmography. The pathological extremities were also studied by angiography and divided into four groups as follows: (1) atherosclerosis of patent arteries without occlusions. (2) proximal occlusions (femoral and/or popliteal only) (3) distal occlusions (calf arteries only), and (4) combined occlusions. 2) Rest flow in the patients was slightly but insignificantly lower than flow in the controls. Maximal flow, however, was definitely lower in the pathological group (P < 0.005). There was a linear correlation between rest and maximal flow in patients with proximal occlusions. 3) Maximal calf flow was significantly decreased in atherosclerosis of patent arteries without occlusions and in all types of occlusions. Moreover, atherosclerosis of patent arterial segments further decreased maximal blood flow in the presence of occlusions. 4) Maximal calf flow could neither he correlated with total length of occlusions in the affected extremity nor with maximal foot flow after body heating. 5) It is concluded that measurement of maximal calf blood flow is a useful procedure serving to recognize unapparent lesions and to test the progress of the disease as well as the effect of treatment in follow-up studies. [ABSTRACT FROM AUTHOR]

The hemostasis after occlusion of the superior mesenteric artery as well as after the reestablishment of the mesenteric circulation, with and without splenectomy, was studied in the dog. According to our results, during this intestinal ischemia, of 4 hours duration, the presence of an intestinal factor intervening in the mechanism of hemostasis was not revealed. [ABSTRACT FROM AUTHOR]

, , 343-348. Abnormally prolonged peripheral vasoconstriction has been detected prospectively by means of a toe temperature nomogram in 15 (11·5%) out of 131 patients following cardiopulmonary bypass. This state has been associated with a 53% incidence of hospital death, a detectable pathological cause in all cases, and in seven of the 15 cases it was the first or only evidence of a circulatory disorder. It is apparent that toe temperature monitoring after open-heart surgery gives early warning of a wide variety of potentially serious pathological processes, permitting effective treatment of the underlying cause before irreversible changes occur. It has become an indispensable part of routine postoperative care in our unit and is regarded as the simplest and most effective method of monitoring the circulation currently available. [ABSTRACT FROM PUBLISHER]

A study has been made into the effects of blood pressure on the spinal cord blood flow. Under conditions of normoxia and normocarbia a well-functioning autoregulation was present between 150-60 mmHg. Below 60 mmHg the flow decreased with reductions in pressure. In individual dogs, autoregulation was sometimes present to 40 mmHg. Under conditions of hypoxia or hypercarbia, autoregulation was absent or severely impaired. The results are discussed in relation to the cerebral circulation and to some aspects of experimental cord disease. [ABSTRACT FROM AUTHOR]

This article discusses the results of a research study conducted to determine the mechanics of the oral vasomotor reflex in cats. Particularly examined was the blood circulation response to the reflex and its physiological mechanisms in the oral soft tissue, including its temperature and latency period.

This section presents a list of books and papers about the diseases that affect the circulatory system.

A series of experiments was conducted to determine whether any physiological changes accompany the previously observed drop in impedance of the electrodeskin circuit during the administration of electric shock. Two concentric shock electrodes were modified by the addition of devices to measure the local temperature, blood volume, and blood pulse volume changes occurring directly under the electrode. Subjects were given a series of shocks through one of these electrodes, but not the other, while the physiological measures were recorded at both sites. No significant differences in temperature and blood volume measures occurred between shocked and unshocked electrodes. However, directly correlated with the drastic drop in impedance of the shocked circuit was a marked increase in blood pulse volume, inferred to be a manifestation of the axon reflex. The two related effects were shown to be highly localized at or near the shocked electrode, and also to be characteristic only of the passage of current through electrode-skin junctions. [ABSTRACT FROM AUTHOR]

Twenty-four patients with deceleration trauma and widened mediastinums have been studied for aortic laceration. Eight had laceration. Analysis of the chest films demonstrates that the findings of aortic laceration are those of mediastinal bleeding and are nonspecific. While deceleration trauma appears to be causative, a widened mediastinum with such trauma is not diagnostic of aortic laceration. Upright films often cannot be obtained and are not necessary. Serial chest films are contraindicated. Aortography is the definitive technique and should be performed if clinical suspicion of aortic laceration exists. Laceration of the thoracic aorta caused by rapid decleration injury is a surgical emergency. Less than 20% of these patients reach the emergency room alive and, of these, 90% will exsanguinate within four weeks, 25% within 24 hours. Therefore prompt diagnosis and surgery are imperative. The chest film findings of aortic laceration are nonspecific since any mediastinal bleeding can give the same radiographic appearance. Aortography must he performed to confirm this diagnosis. We have recently seen 24 patients with severe deceleration injuries all of whom had mediastinal abnormalities suggestive of aortic laceration. Eight actually had lacerations and these cases form the basis for this report. [ABSTRACT FROM AUTHOR]