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Biomedical subjects

D Julian

Publications and source records attributed to D Julian.

33 records · Page 2Linked to original sources
PubMed1992

Microvascular circulation of the small intestine in horses.

The microvascular anatomic features of the small intestine was described by correlating results of microangiography, light microscopy, gross studies, and scanning electron microscopy of vascular replicas in 14 horses. After heparinization, the horses were euthanatized, a length of jejunum was transected, and blood was flushed free of the circulation, using isotonic NaCl solution. In six horses, the circulatory system was perfused with a modified radiopaque medium and evaluated radiographically. These sections were then evaluated by standard histologic methods. Sections from 8 horses were perfused with 1 of 2 types of plastics and studied grossly or by scanning electron microscopy. The marginal arterial arcade gives rise to vessels that enter the jejunum at the mesenteric angle. These vessels penetrated either directly, by branching and entering on both sides of the mesenteric angle, or supplying only 1 side of the mesenteric angle. All these vessels continued in the submucosa branching extensively, forming a submucosal plexus. This submucosal plexus supplied the tunica muscularis, tunica serosa, and the mucosa. Vessels within the 2 muscle layers ran parallel to the muscle fibers and, consequently, perpendicular to each other. The arterial supply to the mucosa penetrated the muscularis mucosae and branched to supply 2 mucosal capillary networks. An eccentrically placed arteriole penetrated the base of the villus and spiralled to the tip where it "fountained" into a mesh-like capillary network, which descended peripherally in the villus to drain via 1 to 3, but most commonly 2 venules. Venules from adjacent villi united and drained via the submucosal veins.(ABSTRACT TRUNCATED AT 250 WORDS)

Angiography↗
PubMed1991

British Heart Foundation surveys (1987 and 1989) of United Kingdom treatment policies for acute myocardial infarction.

Consultant physicians and cardiologists were surveyed early in 1987 and 1989 to document the management policies for the treatment of acute myocardial infarction in United Kingdom hospitals and to assess the influence of major clinical trials on these policies. The response rate to both these surveys was high (84% (1178 physicians) in 1987 and 76% (982 physicians) in 1989). The percentage of physicians that reported using antiplatelet therapy "routinely" in acute myocardial infarction rose from 9% in 1987 to 84% in 1989 while those who reported using it "rarely or never" fell from 42% to 3%. Similarly, "routine" use of fibrinolytic therapy rose from 2% to 68%, and use "rarely or never" fell from 53% to 3%. This increase in the reported use of fibrinolytic therapy was accompanied by greater certainty about its efficacy and relative safety and by a general widening of the indications for its use. The use of other treatments in acute myocardial infarction (for example, the general use of anticoagulants, beta blockers, nitrates, calcium antagonists, or prophylactic antiarrhythmic agents) seemed to change little during this period, although the routine use of coronary angiography and oral anticoagulants after fibrinolytic therapy fell substantially between 1987 and 1989 (from 23% to 4%, and from 24% to 7% respectively). Fibrinolytic and antiplatelet therapy were accepted into the routine management of myocardial infarction during a relatively short period that coincided with the reporting of several positive controlled trial results. Clinical trials have rarely been seen to have had such a great impact on practice. In this case the rapid acceptance of the trial results may have been due to the consistency and reliability of the estimates of the size of the benefits (and risks) of therapy seen in these unusually large studies.

Adult↗
PubMed1991

Microvascular circulation of the cecum in horses.

The microvascular circulation of the cecum was studied in 15 adult horses, using microangiography and light microscopy combined with gross studies and scanning electron microscopy of vascular replicas. After heparinization, the horses were euthanatized and the cecum was transected at the cecocolic junction. Blood was flushed free of the circulation with isotonic NaCl and the cecal lumen was slightly distended. In 6 horses, the vascular system was injected with a modified radiopaque medium and evaluated radiographically. Sections evaluated radiographically were also prepared for histologic examination by standard methods. Eight horses were injected with 1 of 2 types of plastics and studied grossly or by scanning electron microscopy. In 1 additional horse, the lateral and medial arteries were injected with different colored plastic for gross studies. The lateral and medial cecal arteries appear to supply the respective areas of the cecum with minimal mixing of the 2 circulations. The major vascular supply to the cecal apex appeared to be through the medial cecal artery. Both the lateral and medial cecal arteries gave rise to cecal retia, which formed a mesh-like network around the respective veins. Vessels from these retia supplied the cecal tissue and the cecal lymph nodes. The continuation of the retia was through long terminal arteries that coursed around the circumference in the submucosa, forming an extensive submucosal plexus. This plexus supplied both the mucosa, and the tunica muscularis and serosa. Vessels within the longitudinal and circular muscle layers of the muscularis externa ran parallel to the muscle fibers, and consequently, perpendicular to each other.(ABSTRACT TRUNCATED AT 250 WORDS)

Angiography↗
PubMed1990

Effectiveness of intermittent pneumatic leg compression for preventing deep vein thrombosis after total hip replacement.

A randomized trial was performed in consecutive patients undergoing total hip replacement to evaluate the effectiveness of sequential intermittent calf and thigh compression for preventing venous thrombosis compared with a control group given no prophylaxis. Both groups underwent case finding for deep vein thrombosis using combined fibrinogen I 125 leg scanning, impedance plethysmography, and venography. Deep vein thrombosis by venography was present in 77 (49%) of 158 control patients compared with 36 (24%) of 152 patients given intermittent compression. Proximal vein thrombosis was present in 42 controls (27%) compared with 22 patients (14%) given intermittent compression. Combined impedance plethysmography and leg scanning was insensitive in this patient group (sensitivity, 46%); venography was required to detect more than half the patients with venous thrombosis. Sequential intermittent leg compression clinically and statistically significantly reduced the frequency of both proximal vein and calf vein thrombosis. Case finding resulted in early detection and treatment of patients with venous thrombosis.

Female↗
PubMed1989

Treatment for chronic CHD.

It seems likely that a number of medical and surgical treatments have had an impact on the overall mortality from ischaemic heart disease in recent years although there is comparatively little data upon which to base conclusions. The two forms of treatment which have been shown, in controlled trials, to reduce mortality are beta blockade after infarction and coronary artery bypass surgery in chronic ischaemic heart disease. It is of interest that these treatments seem to be most often applied in countries that have had the greatest fall in mortality, although it is not suggested that they have played more than a small role. It is likely that other influences on mortality have included the use of pacemakers and the avoidance of previously undesirable medical practices. Much more careful documentation of the use of treatments in different countries is highly desirable.

Adrenergic beta-Antagonists↗
PubMed1989

Prevention of deep vein thrombosis in potential neurosurgical patients. A randomized trial comparing graduated compression stockings alone or graduated compression stockings plus intermittent pneumatic compression with control.

In a randomized trial of neurosurgical patients, groups wearing graduated compression stockings alone (group 1) or graduated compression stockings plus intermittent pneumatic compression (IPC) (group 2) were compared with an untreated control group in the prevention of deep vein thrombosis (DVT). In both active treatment groups, the graduated compression stockings were continued for 14 days or until hospital discharge, if earlier. In group 2, IPC was continued for seven days. All patients underwent DVT surveillance with iodine 125-labeled fibrinogen leg scanning and impedance plethysmography. Venography was carried out if either test became abnormal. Deep vein thrombosis occurred in seven (8.8%) of 80 patients in group 1, in seven (9.0%) of 78 patients in group 2, and in 16 (19.8%) of 81 patients in the control group. The observed differences among these rates are statistically significant. The results of this study indicate that graduated compression stockings alone or in combination with IPC are effective methods of preventing DVT in neurosurgical patients.

Clinical Trials as Topic↗
PubMedDate not supplied

Thiosulfate elimination and permeability in a sulfide-adapted marine invertebrate.

Oxidation of hydrogen sulfide to thiosulfate is one of the best-characterized mechanisms by which animals adapted to sulfide minimize its toxicity, but the mechanism of thiosulfate elimination in these animals has remained unclear. In this study, we examined the accumulation and elimination of thiosulfate in the sulfide-adapted marine worm Urechis caupo. The coelomic fluid of U. caupo exposed to 50-100 micromol L-1 sulfide in hypoxic seawater (Po2 ca. 10 kPa) accumulated (mean+/-SD) 132+/-41 micromol L-1 thiosulfate after 2 h, reaching 227+/-113 micromol L-1 after an additional 4 h in aerated, sulfide-free seawater. In whole-animal thiosulfate clearance studies, the rate of thiosulfate elimination from the coelomic fluid followed a single exponential time course with a half-life of 6 h. The thiosulfate permeability coefficient of isolated preparations mounted in diffusion chambers was 7.6x10-5+/-7. 7x10-5 cm s-1 for the hindgut and 5.5x10-7+/-2.7x10-7 cm s-1 for the body wall. These rates were independent of the direction of net efflux (mucosal-to-serosal or serosal-to-mucosal). Using a simple mathematical model of U. caupo that incorporates the thiosulfate permeability coefficients, the thiosulfate half-life was calculated to be 23 h without hindgut ventilation but less than 1 h with normal hindgut ventilation. Based on this information, we propose that passive thiosulfate diffusion across the hindgut is adequate to explain the observed rates of thiosulfate elimination.

Adaptation, Physiological↗
PubMedDate not supplied

Intensive versus standard blood glucose awareness training (BGAT) with insulin-dependent diabetes: mechanisms and ancillary effects.

Insulin-dependent diabetes mellitus (IDDM) patients make critical daily self-care decisions on the basis of what they estimate their blood glucose (BG) levels to be. This study: a) replicated efficacy of Standard Blood Glucose Awareness Training (BGAT), b) evaluated the relative efficacy of an Intensive Blood Glucose Awareness Training (BGAT) to enhance patient accuracy of BG estimation, and c) evaluated the mechanisms and ancillary effects of BGAT. Thirty-nine subjects were randomly assigned to one of three groups. Compared with Control, both Standard and Intensive BGAT improved accuracy (p less than 0.001). Intensive BGAT post-treatment accuracy relative to Standard BGAT did not reach statistical significance (p = 0.177). Greater improvement in accuracy was associated with poorer pretreatment accuracy. Only Intensive BGAT improved metabolic control (glycosylated hemoglobin), and this improvement was associated with poorer pretreatment control. The effects of BGAT were highly specific, affecting only accuracy and metabolic control, and not affecting fear of hypoglycemia, diabetes knowledge, of frequency of blood glucose monitoring.

Adult↗
PubMedDate not supplied

The relationship between nonroutine use of insulin, food, and exercise and the occurrence of hypoglycemia in adults with IDDM and varying degrees of hypoglycemic awareness and metabolic control.

The purpose of this study was to determine objectively the relationships between changes in the usual amount of insulin injected, food eaten, and exercise performed, and the subsequent occurrence of low blood glucose (< 3.9 mM) in adults with IDDM and varying degrees of hypoglycemic awareness and metabolic control. Subjects used a handheld computer to record whether their most recent insulin, food, and exercise had been omitted or were greater than, less than, or about the same as usual following every measured blood glucose level of < 3.9 mM and > 5.6 mM. Responses for each self-management behavior were compared for the two blood glucose ranges. Food was omitted more frequently prior to a low glucose reading and exercise was omitted more frequently prior to a high glucose reading. More insulin, less food, and more exercise each were associated with low glucose levels. These findings underscore the importance of traditional diabetes education.

Adult↗