The clinical significance of blood viscosity in degenerative angiopathies]

During an examination of a group of 63 patients with chronic ischaemic heart disease and condition after myocardial infarction the viscosities measured with the help of a rotation viscosimeter lay clearly above the values of good reference persons. There were positive correlations of the blood viscosity to the haematocrit value, fibrinogen level, globulin content as well as to the total protein, total lipid and cholesterol level. In the transition to the logarithm of the viscosity the measure for the linear dependence with the exception of the total protein level became smaller. A formation of partial correlation coefficients by means of the exclusion of the haematocrit in every case resulted in increasing coefficients r for the investigated parameters of the lipid metabolism cholesterol, total lipids and triglycerides.     

The viscosity and viscoelasticity of blood in small diameter tubes.

Both steady and oscillatory flow of blood are studied in small rigid tubes having radii from 0.02 to 0.2 cm. This is done for rates of flow extending from higher values where nonlinear effects are evident down to very low values where the pressure to flow relations are linear. The data are analyzed using the parameters of Poiseuille theory for steady tube flow and of the linear, viscoelastic theory for oscillatory tube flow. In the low flow, linear region the apparent values of the steady flow viscosity and the oscillatory flow viscosity at 2 Hz are dependent upon the tube radius, this being in contraction with the assumptions of the theories. Another theoretical analysis is then made assuming that the blood in a boundary zone at the tube wall has modified viscous and viscoelastic properties. The measurements are in good agreement with this analysis. For low rates of flow, the steady flow is pluglike, the blood in the core moving as a solid. The pressure to flow relation is then controlled by the boundary zone for all tube radii. In this case of oscillatory flow, the core undergoes viscoelastic deformation and thus flow occurs in both the core and the boundary zone. For larger tubes, the boundary zone effects became insignificant. Under this condition the oscillatory pressure to flow relation may be used to obtain the viscoelasticity of the blood, free from the boundary layer artifacts which dominate the steady flow.     

The relationship between the blood and vein wall fibrinolytic activities in response to surgical trauma

The fibrinolytic response to surgical trauma was studied longitudinally in 7 pigs by measuring the fibrinolytic activity in the blood and vein wall simultaneously. The results indicated a marked suppression in fibrinolytic activity in the blood which was closely correlated with the activity in the vein wall. This correlation lends support to the hypothesis that the venous endothelium is the source of spontaneous fibrinolytic activity in the blood.     

Head trauma in hemophilia. A prospective study

Intracranial hemorrhage (ICH) remains a serious problem in hemophilia. Consecutive episodes of ICH or reports of head trauma were prospectively recorded in 140 patients with hemophilia seen during a two-year period. Forty of 48 consecutive episodes of ICH or trauma occurred in 37 patients with severe disease (less than 1% factor VIII or IX). Five injured patients had inhibitors to factor VIII. Two fatalities occurred following injury and one patient died following a spontaneous bleed. Injury in 40 instances warranted replacement therapy. No patient given coagulation factor within six hours of injury experienced ICH. The risk of ICH following head trauma (13% in this series) warrants aggressive use of coagulation factor replacement. Watchfulness in dealing with such patients and early therapy may be more necessary than often realized.     

The Elag-Koln automatic blood pressure recorder. A clinical appraisal.

The performance of an Elag-Koln semiautomatic blood pressure recorder was compared with the London School of Hygiene mercury sphygmomanometer in 24 subjects providing a wide range of blood pressure measurements. Readings with the two instruments correlated highly (for systole, r=0-99; for diastole phase 4, r=0-97; for diastole phase 5,r=0-98), and the slopes of the regressions did not differ significantly from unity. Elag-Koln measurements were higher for systole (mean difference 3-7 mmHg,P less than 0-001) and diastole phase 5 (mean difference 7-4 mmHg,P less than 0-001), but agreed closely with diastole phase 4 readings with the London School of Hygiene instrument. The Elag-Koln recorder tested was compact, easy to use, and had acceptable accuracy. This type of instrument deserves further testing to examine its suitability for general use.     

Evaluation of coagulase-negative staphylococci in blood cultures. A prospective clinical and microbiological study

Coagulase-negative staphylococci (CNS) are the commonest microorganisms in blood cultures, and sorting out patients with CNS septicemia from sample contamination a persistent problem. We prospectively evaluated 73 patients with CNS-positive blood cultures during 1 year and analysed the corresponding 122 isolates in order to determine the rate of septicemia and define the role of microbiological markers of identity such as plasmid profile for that purpose. Three patients had true septicemia, all of them with implanted foreign devices. The plasmid analysis, being the most reliable identity marker, had its greatest implication in reducing the intermediate group of patients clinically suspected of septicemia from 12 to 4. Strict clinical criteria and serial blood cultures are most important in sorting out patients with CNS septicemia from cases of sample contamination. In high risk patients--critically ill with implanted foreign devices--plasmid analysis or other reliable markers of identity are of great additional value.     

Reduction of blood viscosity following plasma exchange.

The effect of plasma exchange with plasma protein fraction on blood viscosity was determined in seven hyperlipoproteinaemic patients with coronary or peripheral vascular disease. This resulted in decreases in whole blood viscosity of 83% and 30% respectively at the lowest and highest shear rates studied, and decreases of 21% and 59% in plasma viscosity and fibrinogen. Serum cholesterol and triglyceride were reduced by 66% and 48% respectively. Sequential studies in two patients showed that blood viscosity returned to near-basal values by the 6th day. These findings suggest that plasma exchange may result in short-term enhancement of blood flow in vessels where low shear rates predominate.     

Fibrinogen, plasma viscosity and blood viscosity in obesity. Relationship with insulin resistance

Plasma viscosity (PV) and blood viscosity (BV) have been scarcely evaluated in morbid obese patients with no other concomitant cardiovascular risk factors. Contradictory results have been published regarding the influence of insulin resistance on these rheological parameters in obesity. In 67 severe or morbid obese patients without other cardiovascular risk factors (51 women and 11 men, aged 34+/-11 years), fibrinogen, PV and BV at native (nBV) and corrected 45% hematocrit (cBV) have been determined, and insulin resistance has been calculated with homeostasis model assessment (HOMA) index, in basal conditions and after a three month diet period. The same determinations were performed in 67 healthy volunteers (45 women, 22 men, aged 32+/-10 years) at baseline and three months later. When cases and controls were compared, obese patients showed higher fibrinogen levels (P<0.001), PV (P=0.050) and cBV (P=0.035), and showed a higher insulin resistance than the control group (P<0.001). Differences in PV were maintained after adjusting for BMI (P=0.001), but disappeared after adjusting for HOMA (P=0.391) fibrinogen (P=0.367) and LDL-chol (P=0.097). Differences between obese patients and the control group for cBV disappeared after adjusting for BMI (P=0.739), HOMA (P=0.744), fibrinogen (P=0.907), LDL-chol (P=0.283) and PV (P=0.112). The achieved weight loss (8.7+/-3.53%) was not accompanied by any changes in these rheological parameters (P>0.050). Obese patients show increased fibrinogen levels, PV and cBV. These rheological disturbances seem to be associated with insulin resistance and the metabolic syndrome, and do not seem to improve with moderate weight loss.     

新生儿脐带血TSH影响因素研究

目的 探讨新生儿脐带血TSH影响因素,为合理解释我国新生儿脐带血TSH向高值偏移提供依据。方法 在碘营养充足的人群中,对335例孕妇及其新生儿,用多元线性回归法分析了分娩过程各因素对新生儿脐带血TSH的影响。结果 分娩方式（β＝0.641)、产程（β＝0．136）、产次（β＝－0．707）、是否用催产素（β＝0．420）、Apgar评分（β＝－0．126）、是否患妊高征（β＝0．633）以及分娩月份（β＝－0．136）对新生儿脐带血TSH产有影响。结论 在碘营养充足情况下,分娩难易程度、分娩月份等非碘因素对TSH均有影响,建议以新生儿全血TSH指标评价碘缺乏病时,不腚使用脐带血,而应采集新生儿出生4－7d足跟血。     

Capillary blood viscosity in microcirculation

As known, at the arteriolar level there is the highest resistance to the flow due to the section and to the velocity with an average pressure fall of 50 mmHg (from 85 to 35 mmHg). This resistance is expressed in sec(-1) by the ratio W/2r. This ratio is very high with an average value of 332 sec(-1) and viscosity at this high shear-rate is negligible. At the capillary level the pressure fall is 11.5 mmHg but the vascular resistance W/2r is much lower, on average 32 sec(-1). We can say that if a resistance of 333 sec(-1) corresponds with a pressure fall of 50 mmHg, then a resistance of 32 sec(-1) should correspond with a pressure fall of 4.8 mmHg. The highest pressure fall is due to another kind of resistance which we can define as "Capillary Blood Viscosity" because it depends on the rheological and structural characteristics of the blood. Our instrument reproduces the structure of the capillary district in an experimental model and measures the General Blood Viscosity (GBV) and the Capillary Blood Viscosity (CBV) at the same shear-rate and in particular at the low shear-rate when in non-Newtonian fluids the highest increase in viscosity appears. Consequently, at the capillary, viscosity is dominant with respect to the other geometric and physical resistances. Moreover, the percentage ratio between the GBV and the CBV gives a physical measure of erythrocyte deformability. Knowing viscosity at shear-rate present in the circulatory system, we can obtain the size of RBCs aggregates in the different circulatory districts and their characteristics expressed like "aggregation bond". Changes in CBV are the only possibility in clinical practice to improve the circulatory flow in the capillary district because it is not sure that changes in the arteriolar section can improve the capillary flow or rather open arterio-venous anastomosis. Moreover, in the systemic circulation the aggregate size allows us to point out the phenomenon of cell adhesion because the presence of several receptors involves also the other blood cells. Finally the size and the stability of the RBCs aggregates can modify the endothelial thrombo-resistance.     

The spectrum of atrioventricular discordance. A clinical study.

The clinical, investigative, and surgical findings were reviewed in 47 patients with atrioventricular discordance who presented to the Brompton Hospital between January 1962 and June 1981. Although the unifying feature was the atria connecting to morphologically inappropriate ventricles, the hearts differed widely in other respects. In most cases there was the usual visceral and atrial arrangement, but six had a mirror image arrangement of the atria and viscera. Among those patients with usual atrial arrangement (solitus) the aorta was not always anterior and left sided, and ventricular "inversion" was not invariable. Only 35 of the 47 patients also had a discordant ventriculoarterial connexion, the majority of the remainder having a double outlet right ventricle. The specific diagnosis of atrioventricular discordance depended on echocardiographic and angiographic examination. The other investigations did not distinguish between different ventriculoarterial connexions and were not specific even for the presence of atrioventricular discordance. For those patients with the usual atrial arrangement the anticipated right heart border was present in only just over one third, and the reversal of Q wave progression in the precordial leads of the standard electrocardiogram was found in under a half. Many patients with atrioventricular discordance progressed normally to adult life. In 20 cases no surgery was performed. The results of total correction showed a mortality of 25% (three cases), including two deaths after a modified Fontan procedure for exceedingly complex associated lesions. The results of surgery in the survivors were excellent, and awareness of the disposition of the atrioventricular conduction tissue made it possible to avoid atrioventricular dissociation.     

The clinical relevance of plasma viscosity in Hodgkin's disease

The erythrocyte sedimentation rate has previously been identified as an important prognostic factor in Hodgkin's disease. The plasma viscosity has replaced the ESR measurement in many laboratories, but doubts exist about its clinical relevance. In this study plasma viscosity at presentation/diagnosis was studied in 107 patients with Hodgkin's disease. A multivariate analysis of factors influencing prognosis and relapse-free survival identified plasma viscosity and number of disease sites as being highly significant. The risk of relapse increases initially with a rise in plasma viscosity, but after a value of about 2.0 mPa.s no further increase in risk is observed. When all of the prognostic factors are made available to the proportional hazards model, treatment modality and plasma viscosity are selected as the best set for predicting time to first relapse. This study demonstrates that measurement of plasma viscosity at presentation is an important prognostic factor in Hodgkin's disease, in terms of predicting outcome or risk of relapse.     

Experimental and clinical study of influence of high-frequency electric surgical knives on healing of abdominal incision

AIM: To study the influence of high-frequency electric surgical knives on healing of abdominal incision. METHODS: Two hundred and forty white rats were divided into 100, 102, 105, and 108 groups and rat models of abdominal operation were induced by using electric surgical knives and common lancets respectively. Then they were respectively given hypodermic injections of normal saline and 0.2 mL quantitative mixture of Escherichia coll, Staphylococcus aureus and Pseudomonas aeruginosa at a concentration of 102, 105 and 108. On the basis of the animal experiment, 220 patients undergoing abdominal operations (above type II) were randomly allocated into one of following three groups: electric knife (EK, 93 cases), electro-coagulation (EC, 55 cases) and control (72 cases). High-frequency electric surgical knives were used to dissect abdominal tissues and electro-coagulation for hemostasis in EK group. Common lancets and electro-coagulation were applied in EC group. Common lancets and tieing silk suture were used in the controls. RESULTS: In all the groups except group 100, infection rate of incisional wounds made by electric surgical knives were remarkably higher than that with common lancets. Furthermore, there were significant differences in groups 102, 105, and 108(P < 0.05), but not in group 100(P > 0.05) between EK and EC groups. Clinical studies showed a delayed wound healing in 16 cases (17.20%) in EK, 11 cases (16.36%) in EC and 2 cases (2.86%) in the control groups. A significant difference between EK and the control groups (X2= 8.57, P < 0.01), and between EC and the control groups (X2= 5.66, P < 0.05) was observed, but not between EK and EC (X2= 0.017, P > 0.05). CONCLUSION: High-frequency electric knives may remarkably delay abdominal incision healing. Its application should be minimized so as to reduce the possibility of postoperative complications.     

The spectrum of atrioventricular discordance. A clinical study

The clinical, investigative, and surgical findings were reviewed in 47 patients with atrioventricular discordance who presented to the Brompton Hospital between January 1962 and June 1981. Although the unifying feature was the atria connecting to morphologically inappropriate ventricles, the hearts differed widely in other respects. In most cases there was the usual visceral and atrial arrangement, but six had a mirror image arrangement of the atria and viscera. Among those patients with usual atrial arrangement (solitus) the aorta was not always anterior and left sided, and ventricular "inversion" was not invariable. Only 35 of the 47 patients also had a discordant ventriculoarterial connexion, the majority of the remainder having a double outlet right ventricle. The specific diagnosis of atrioventricular discordance depended on echocardiographic and angiographic examination. The other investigations did not distinguish between different ventriculoarterial connexions and were not specific even for the presence of atrioventricular discordance. For those patients with the usual atrial arrangement the anticipated right heart border was present in only just over one third, and the reversal of Q wave progression in the precordial leads of the standard electrocardiogram was found in under a half. Many patients with atrioventricular discordance progressed normally to adult life. In 20 cases no surgery was performed. The results of total correction showed a mortality of 25% (three cases), including two deaths after a modified Fontan procedure for exceedingly complex associated lesions. The results of surgery in the survivors were excellent, and awareness of the disposition of the atrioventricular conduction tissue made it possible to avoid atrioventricular dissociation.