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Biomedical subjects

F Jung

Publications and source records attributed to F Jung.

At least 127 records · Page 7Linked to original sources
PubMed1991

Synthesis and structure-activity relationship of new cephalosporins with amino heterocycles at C-7. Dependence of the antibacterial spectrum and beta-lactamase stability on the pKa of the C-7 heterocycle.

Cephalosporins with new aminobenzimidazole and aminoimidazoline heterocycles at C-7 have been synthesized starting with versatile C-7 isocyanide dihalide synthons. The aminobenzimidazoles have a broad spectrum of antibacterial activity, including Gram-positive and Gram-negative organisms, but possess limited beta-lactamase stability. In contrast, the aminoimidazolines have a narrow spectrum of antibacterial activity, limited to Gram-negative strains only, but possess outstanding beta-lactamase stability. Structure-activity relationships are discussed in terms of their dependence on the pKa of the C-7 amino heterocycle, basic C-7 residues giving cephalosporins with exceptional beta-lactamase stability.

Bacteria↗
PubMed1991

Retinal microcirculation in patients with diabetes mellitus: dynamic and morphological analysis of perifoveal capillary network.

The new scanning laser technique allows one to quantify the retinal microcirculation. A digital image analysing system was used to study capillary blood flow velocities and morphological parameters of perifoveal intercapillary areas and foveal avascular zones in normal and diabetic subjects. Diabetic patients showed a significant reduction in capillary blood cell velocities in comparison with normal subjects. Perifoveal intercapillary areas and foveal avascular zones were significantly increased in all stages of diabetic retinopathy, and both parameters increased with progressing diabetic retinopathy. Significant changes in the perifoveal intercapillary areas were observed between normal subjects and patients with no retinopathy.

Adult↗
PubMed1991

[Variance, factors of influence and clinical relevance of plasma viscosity].

The problem of measuring plasma viscosity has been solved through the use of capillary and falling-ball viscosimeters which have a determination variance of less than 1%. On account of the influence of overeating, forced thirst, psychological and physical stress plasma viscosity should be determined in the morning; the patient should be fasting and well hydrated. Plasma viscosity is influenced by diseases with alterated plasma protein composition. An elevated viscosity also significantly increases the risk of developing an arterial occlusion. Since the physician can both decrease and increase plasma viscosity, it should be determined parallel to therapy. Accordingly, plasma viscosity is one of the most important rheological parameters.

Adult↗
PubMed1991

[Hyper- or isovolemic hemodilution in patients with stage II peripheral arterial occlusive disease].

The influence of hyper- and isovolaemic hemodilution using HES 200/0.5 6% (HES steril, Fresenius AG) on pain-free walking distance in patients with peripheral arterial occlusive disease stage II according to Fontaine was tested in a randomised investigation involving three groups. The increase in pain-free walking distance was significant both in the hypervolaemic and isovolaemic hemodilution group. The increase in both dilution groups did not differ but compared to a control group (infusion of Ringer lactate) it was significantly higher. Considerable changes concerning rheological parameters (decrease in haematocrit and plasma viscosity) were observed after isovolaemic hemodilution.

Adolescent↗
PubMed1991

[Hydroxyethyl starch-induced transient renal failure in preexisting glomerular damage].

Hemorheological therapy through hemodilution has been gaining importance for several years and been applied to an ever increasing degree in stationary as well as in ambulant treatment. While renal insufficiency without previously established nephropathy is known to be a side effect of dextrans, cases of HES-induced nephropathy have so far not been reported. Two cases are presented in which in the course of stationary hemodilution therapy with HES an acute deterioration of an already exiting nephropathy was noted. Possible pathophysiological causes for such a deterioration are most likely to be found in an increased permeability of the glomerular basal lamina. Hydroxyethyl starch molecules are filtered above the physiological renal threshold which increases the viscosity of the primary urine. This can be counteracted by increasing diuresis. This conclusion can be drawn from our own observations which proved that renal insufficiency can be avoided through sufficient fluid intake (approx. 3 liters/day). In patients with creatinine values above 1.5/dl and arterial hypertension the indication for hemodilution therapy must be analysed carefully. If hemodilution therapy proves to be necessary, sufficient fluid intake must be guaranteed. Retention parameters must be controlled every other day in the course of the therapy. As an alternative, the administration of gelatin preparations should be considered as it does not cause cumulation.

Acute Kidney Injury↗
PubMed1991

[Hemorheologic and circulatory effects of hemodilution with medium molecular weight hydroxyethyl starch in two concentrations (HAES 200/0.62 10% and 6%)].

This study was designed to investigate whether the positive effect occurring after infusion of a 10% hydroxyethyl starch solution 200.000/0.62 on cutaneous capillary blood flow could still be increased by using a 6% solution having a lower initial viscosity (HES 6% 200.000/0.62). A single blind study of 10 female volunteers was carried out to study the influence of a hypervolemic hemodilution using 500 ml of a 10% solution hydroxyethyl starch solution at first and that of 6% hydroxyethyl starch solution on macro- and microcirculation, transcutaneous oxygen partial pressure and blood fluidity. After hydroxyethyl starch infusion blood flow in the macro- and microvessels increased significantly. This increase occurred considerably earlier after administration of 6% solution than after infusion of 10% solution. Thus blood flow had already increased after 1 hour and continued to show a tendency of increase over about three hours. 6 hours after end of infusion blood flow had almost dropped to its initial value. The volume effect of the 6% solution immediately after infusion was less pronounced than that after infusion of the 10% solution, but it reached the value of the 10% solution at a later point in time. The course of the haematocrit reflected this process. Average decrease in haematocrit value compared to that following the 10% solution was not as pronounced at hour 3. After 6 hours the decreases were comparable. Similar observations were made of plasma viscosity and platelet aggregation. One hour after infusion plasma viscosity and erythrocyte aggregation had hardly changed but haematocrit had clearly dropped. Thus, blood viscosity at this point in time was essentially lowered.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1991

[Rheologic findings in patients with diabetic retinopathy].

The rheological parameters hematocrit, plasma viscosity, red blood cell aggregation and blood cell rigidity were measured in 256 adult-onset (type II) diabetics. The stage of diabetic retinopathy was graded by means of ophthalmoscopy and videofluorescein angiography. The mean values of hematocrit (men 45 +/- 5%, women 42 +/- 5%) and red blood cell rigidity (1.01 +/- 0.08) were equal to those in normal subjects. Plasma viscosity (1.40 +/- 0.10) mPas, normals: 1.24 +/- 0.05 mPas) and red blood cell aggregation (16.0 +/- 4.2, normals: 14.6 +/- 3.2) were increased over the values in normals. The groups with different stages of diabetic retinopathy showed no difference in all rheological parameters. Plasma viscosity and red blood cell aggregation were determined partly by the levels of the large plasma proteins. In the type II diabetics fibrinogen was the most markedly elevated large plasma protein (4.1 +/- 1.2 g/l, normals: 3.2 +/- 0.6 g/l). Significant correlations were found between plasma viscosity and fibrinogen (0.49); plasma viscosity and alpha-2-macroglobulin (0.33); red blood cell aggregation and alpha-2-macroglobulin (0.28); and red blood cell aggregation and immunoglobulin M (0.25). The elevation of red blood cell aggregation and plasma viscosity may be one of the reasons for disturbed microcirculation and fundus changes in diabetic retinopathy.

Adult↗
PubMed1991

[Conjunctival microcirculation and hemorheology in patients with venous occlusions of the retina].

Forty-two patients with branch vein or central retinal vein occlusion were enrolled in this randomized placebo-controlled study. We studied the influence of hemodilution therapy with hydroxyethyl-starch (HAES-steril) combined with pentoxifylline (Trental) for 6 months. In the bulbar conjunctiva, capillary red blood cell (RBC) velocities and vessel diameters and rheological parameters of hematocrit, erythrocyte aggregation and plasma viscosity were examined. In the hemodilution group we observed no changes in vessel diameter and a significant increase in RBC velocity after therapy. After 6 weeks the RBC velocity showed 30% higher values but there was no statistically significant difference. After hemodilution therapy hematocrit, erythrocyte aggregation and plasma viscosity were significantly different from those in the control group. After 6 weeks we observed significant differences only in erythrocyte aggregation. This examination verifies the positive influence of hemodilution therapy on microcirculation and hemorheology.

Adult↗
PubMed1991

Influence of garlic powder on cutaneous microcirculation. A randomized placebo-controlled double-blind cross-over study in apparently healthy subjects.

In a randomized placebo-controlled double-blind cross-over study it could be shown that 5 h after the administration of garlic powder (Kwai, Sapec; total dose of 900 mg garlic powder) a significant increase in capillary skin perfusion by 55% occurs in the healthy volunteers. Placebo did not cause any changes. The difference between the two study phases is also significant. The increased erythrocyte velocity results from vasodilation of precapillary arterioles which increases diameter of erythrocyte column by an average of 8.6%. Simultaneously inflow of interstitial fluidity accompanied by a significant decrease in haematocrit and plasma viscosity occurs (rheoregulation).

Adult↗
PubMed1991

Effect of garlic on thrombocyte aggregation, microcirculation, and other risk factors.

Significant positive effects could be achieved in a placebo-controlled double-blind study through the administration of 800 mg of garlic powder over a period of four weeks. Spontaneous thrombocyte aggregation disappeared, the microcirculation of the skin increased by 47.6% (from 0.63 +/- 0.13 to 0.93 +/- 0.22 mm/s), plasma viscosity decreased by 3.2% (from 1.25 +/- 0.34 to 1.21 +/- 0.43 mPas), diastolic blood pressure by 9.5% (from 74 +/- 9 to 67 +/- 5 mmHg), and blood glucose concentration by 11.6% (from 89.4 +/- 8.8 to 79.0 +/- 11.9 mg/dl). The vascular protection of garlic as atherosclerosis prevention by influencing the mentioned risk parameters for cardiovascular diseases must be pointed out. Especially interesting is the thrombocyte aggregation inhibiting effect. Thus, the application of garlic may be useful in case of acetylsalicyclic acid intolerance.

Adult↗
PubMed1990

Modern strategies for treatment of acute myocardial infarction: significance of haemostaseological and rheological findings.

In spite of equivalent clinical efficacy of various thrombolytic agents for the treatment of acute myocardial infarction there is evidence of different drug-depending influences on the haemostatic and fibrinolytic system. In the present study 40 patients with acute myocardial infarction have been investigated. 20 patients received 750,000 and 1.5 mio U streptokinase (SK), respectively, 10 patients 30 mg anisoylated plasminogen streptokinase activator complex (BRL 26921) and 10 patients a combination of 200,000 U urokinase (UK) and 4.5 mio U pro-urokinase (PUK) as a short-term intravenous treatment. Reperfusion of coronary arteries has been achieved in 70 to 100 percent. Major not fatal bleedings occurred in 2 patients. One patient died within 72 hours after beginning of the myocardial infarction. The longest duration of fibrinolytic activity was observed in the BRL 26921 group (half-disappearance time close to 2 h). It was significantly shorter in the SK groups showing a dose-dependency. Plasma concentration of fibrinogen dropped beyond normal levels following SK and BRL 26921, but not under UK/PUK. Plasma viscosity correlated with fibrinogen decrease and displayed a dose-depending relationship with the presence of SK. Haemorheological effects are suggested to be important for the clinical efficacy of thrombolytic therapy in myocardial infarction.

Anistreplase↗
PubMed1990

[Coincidence of hypertensive changes of the eye fundus and regulation disorders of peripheral microcirculation: I--Skin].

In cases of arterial hypertension, funduscopy is an established method of estimating systemic vascular lesions. In this study the relation between the extent of retinal vascular changes and dynamic processes in the microcirculation of the skin was investigated by nailfold capillaroscopy in 88 patients. With increasing vascular changes a progressive loss of vasodilator reserve and transcutaneous partial pressure was observed (no morphologic changes--fundus hypertonicus II--fundus hypertonicus III). It thus appears possible to evaluate the functional state of the macro- and microcirculation by funduscopy.

Adult↗
PubMed1990

[Coincidence of hypertensive fundus changes and regulatory disorders of peripheral microcirculation. II--Skeletal muscles].

In patients with hypertensive fundus changes considerable morphologic changes of the entire vascular system may be assumed. In the present study, the effects of these processes on the partial oxygen pressure of the skeletal musculature were investigated in 62 patients via a macro puncture electrode placed in the tibial muscle. The extent of fundus changes and the reduction in muscular partial oxygen pressure were found to be correlated. With advancing stages of fundus changes, blood flow measured in the common carotid artery decreased. Vascular changes which are clearly recognizable in the hypertensive fundus thus appear to be accompanied by a deterioration in partial oxygen pressure in muscular tissue and restriction of flow in the macrocirculation.

Aged↗
PubMed1990

Haemodilution with medium molecular weight hydroxyethyl starch in patients with peripheral arterial occlusive disease stage IIb.

The basic therapy of peripheral arterial occlusive disease stage IIb, according to Fontaine, is exercise. It should be determined whether a mild hypervolaemic haemodilution with hydroxyethyl starch or Ringer lactate can produce a further increase in walking distance. For this purpose, three groups of 25 patients each were formed. One group exercised three times weekly and the second group, in addition to exercise, underwent a mild hypervolaemic to isovolaemic dilution therapy with HES for a period of 6 weeks. In the final group the haematocrit was reduced to the same extent by venesections and volume substitution using Ringer lactate. The walking distance in the HES group increased from 216 m to 311 m (44%), in the Ringer lactate group from 214 m to 258 m (20%), and in the exercise group from 213 m to 242 m (14%). On comparison of the groups, the increase in pain-free walking distance in the HES group differs significantly (P less than 0.05) from that achieved in the other groups. It was demonstrated that haemodilution with HES in combination with exercise brings about a clinical effect three times that achieved by exercise alone. Venesection with subsequent administration of Ringer lactate and exercise is superior to exercise alone but markedly inferior to the combination therapy with HES.

Adult↗
PubMed1990

[The clinical rheological laboratory].

To quantify the fluidity of blood it is not suitable to measure whole blood viscosity as blood is no Newton's fluid. For this reason, it is necessary to measure characteristic blood flow parameters direct. This study presents methods of measurement for plasma viscosity, haematocrit, thrombocyte aggregation, erythrocyte rigidity, erythrocyte aggregation and leukocyte adhesivity.

Blood Viscosity↗
PubMed1990

[Error analysis, biological modification factors and variance of peri-ungual video-capillary microscopy].

Error analysis or the evaluation of the precision of microscopic measurements must distinguish between technical errors inherent in the measuring system, and biological variability. The technical error inherent in the overall system in the case of linear measurements is smaller than the lengths to be measured by 1 or 2 orders of magnitude. Thus, the erythrocyte column lengths can be correctly, reproducibly and linearly quantified over the entire measuring range. The biological influencing factors can largely be taken into account or excluded by suitable standardisation of the measuring process. Despite a considerable individual fluctuation in the erythrocyte velocity, there is, on average, no significant dependence of the measuring parameter within the daily profile or from day to day. Differences in capillary perfusion in the presence of diseases associated with microcirculatory disorders or a therapeutic influence on erythrocyte velocity can thus be reliably demonstrated.

Capillaries↗
PubMed1990

[Intra- and postoperative effect of different hydroxyethyl starch solutions on the flow properties of the blood and on the oxygen partial pressure of the conjunctiva].

During lumbar disc operation in the flexed prone position, a decrease in conjunctival pO2 can be observed although there is an increase in systemic blood flow after infusion of colloidal volume expanders. The regions of the body situated below the heart do not profit from the increase in systemic blood flow due to compression. The pO2 decreases more significantly after the infusion of a medium-molecular-weight solution with a more marked hemodynamic effect than after the infusion of low-molecular-weight hydroxyethyl starch. As the decrease in conjunctival pO2 is considerably less after low-molecular-weight hydroxyethyl starch, improved blood fluidity may be responsible for the increased tissue perfusion in the compressed area.

Adult↗