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Biomedical subjects

R Renner

Publications and source records attributed to R Renner.

At least 55 records · Page 3Linked to original sources
PubMed1997

Multicenter evaluation of the Micral-Test II test strip, an immunologic rapid test for the detection of microalbuminuria.

OBJECTIVE: To assess the performance of the Micral-Test II immunologic test strip for the detection of microalbuminuria, a multicenter evaluation in eight European study sites was performed. RESEARCH DESIGN AND METHODS: Using both the Micral-Test II test strip and the routine method for the determination of albumin concentration, we investigated 2,228 urine samples from diabetic patients. Additionally, interperson variability, color stability, and possible interfering factors (temperature, pH, leucocyturia, erythrocyturia, and drugs) were tested. RESULTS: For a cutoff concentration of 20 mg/l with respect to the routine methods, a sensitivity of 96.7% and a specificity of 71% were calculated for the Micral-Test II test strip. The negative predictive value was 0.95, and the positive predictive value was 0.78, with a prevalence of positive samples (laboratory method) of 52%. The interperson variability of color interpretation showed 93% concordant readings. The interference study showed an influence of oxytetracycline, leading to higher readings. There was no interference from pH. A sample temperature of < 10 degrees C led to lower readings. In the case of samples with massive leucocyturia and erythrocyturia that may delete the chromatographic process, waiting an additional 1-2 min is needed before reading. CONCLUSIONS: The results of the multicenter evaluation show that the Micral-Test II test strip permits an immediate and reliable semiquantitative determination of low albumin concentrations in urine samples with an almost user-independent color interpretation.

Albuminuria↗
PubMed1996

Abnormal axonal inward rectification in diabetic neuropathy.

An abnormal axonal membrane conductance might contribute to human diabetic neuropathy. To test this idea, we have compared the threshold changes produced by long-lasting (100-200 ms) de- and hyperpolarizing currents applied to median motor and sensory axons at the wrist in 63 diabetic patients with those from 50 normal controls and 27 amyotrophic lateral sclerosis (ALS) patients. Averages of the threshold electrotonus plots for motor and sensory axons of diabetic patients showed more subexcitability during, and slower recovery following, the application of hyperpolarizing currents. Such alterations have been previously found in isolated rat nerves after inhibition of axonal inward rectification by means of cesium ions. The abnormalities in diabetics were positively correlated with the age of patients and the presence of neuropathy. Threshold electrotonus seen in diabetes differed strongly from the effects of acute ischemia and were unlike changes recorded in ALS. The data indicate that an abnormal inward rectification of peripheral axons is associated with diabetic neuropathy. A better understanding of the neurobiology of this conductance might provide information about the pathophysiology of this disease.

Adult↗
PubMed1993

Postprandial blood glucose and its relation to diabetic gastroparesis--a comparison of two methods.

Delayed gastric emptying is known as an important organic cause for brittle diabetes. We proposed the interval from the start of a meal to the rise in blood glucose, defined as blood glucose latency (T BG) as an index for gastric emptying and a non-invasive test for diabetic gastropathy. In order to validate this test we compared it in 22 type 1 diabetic patients with an established scintigraphic method for the measurement of gastric half-emptying time (T1/2) and found the following correlation: T BG = 4.4 + 0.162 x T1/2; r 0.79, P < 0.001. We therefore suggest measuring the blood glucose latency as a simple non-invasive screening method.

Adult↗
PubMed1993

[Experience with the AO universal femoral intramedullary nail for management of femur shaft fractures].

57 fractures of the femoral shaft, treated with an AO femoral interlocking nail, have been analysed in a retrospective study. 40 nails have been implanted primarily, 17 as secondary procedures following different operations. In the group of primary nailing 35/40 reached a good or very good result, 8 of them however, following secondary operations. In the group of the secondary nailing, 9/17 patients had a good or a very good result. 3 pseudarthroses persisted. The AO femoral interlocking nail therefore appears to be an adequate implant for the treatment of femoral shaft fractures, but a precise implantation technique is a prerequisite for the successful outcome.

Bone Nails↗
PubMed1992

[Ultrasonographic findings in varicose phlebitis of the great saphenous vein. Evidence of thrombus growth and detachment with asymptomatic lung embolism].

In five women (mean age 58 [31-74] years) with clinically diagnosed varicose phlebitis of the long saphenous vein appositional thrombus growth was demonstrated by serial ultrasonography (B-mode compression and colour-coded duplex sonography). In one patient the appositional thrombus was found to be free-floating as far as the common femoral vein, but this was not seen by phlebography. During therapeutic heparinization there was ultrasonographic evidence of softening and partial liquefaction of thrombus material in a cranial direction. There were no clinical signs of pulmonary embolism, but pulmonary perfusion scintigraphy demonstrated perfusion deficit characteristic of emboli. Four of the five patients had a surgical crossectomy and partial saphenous vein resection. The congruence between ultrasonographic and macro- as well as micropathological findings demonstrates the great value of B-mode and duplex ultrasound examination in the area of the epifascial veins. Ultrasonography should be performed in every case of varicose phlebitis of the large veins to exclude the presence of apposition thrombi.

Adult↗
PubMed1990

[Insulin injection therapy of diabetes mellitus].

In general, insulin treatment of type I diabetes mellitus is difficult. Good long-term metabolic control can be achieved only in patients who have been well informed and trained in the use of intensive insulin regimens by experts. Today, insulin distribution is differentiated into basal and meal-adapted requirements, with the circadian rhythm of insulin needs receiving special consideration. In type II diabetics, the use of insulin is indicated only when all other therapeutic measures (diet, physical activity, oral antidiabetic drugs, lipid-lowering agents and substances delaying glucose resorption) have failed. The combined administration of sulfonylurea and insulin has a number of interesting aspects.

Blood Glucose↗
PubMed1990

Is resistance to ischaemia of motor axons in diabetic subjects due to membrane depolarization?

The reasons for the resistance to ischaemia of peripheral nerves in diabetics are not well understood. We have now explored whether axonal depolarization underlies this phenomenon, as has previously been proposed. Resistance to ischaemia was determined by the new method of "threshold tracking". This method revealed an increase in excitability of the peroneal nerve at the popliteal fossa during ischaemia, and a decrease in excitability in the post-ischaemic period. The extent of these alterations in 28 type 1 diabetics without peripheral neuropathy showed a strong correlation with the mean blood glucose concentrations during the last 24 h before examination. To test whether the ischaemic resistance was related to membrane potential, we also measured axonal superexcitability in 11 selected diabetics, since it has been shown that post-spike changes in excitability depend on membrane potential. Changes in excitability of the peroneal nerve were measured in the period between 10 and 30 msec following a conditioning supramaximal compound action potential. Under resting conditions, no differences in the post-spike superexcitability were found between controls and diabetics, despite striking differences in their responses to a 10-min pressure cuff. These observations indicate that membrane depolarization is not involved in the resistance to ischaemia of motor axons in diabetic subjects.

Action Potentials↗
PubMed1990

Analysis and processing of data in a hospital-based diabetes management system.

Both short-term care (blood glucose monitoring) and long-term care (clinical examinations) of diabetes generate an ample amount of data for each patient. Health care in hospitals has to provide services with respect to both demands. The quality of control depends on obtaining the right finding at the right time and taking the individually adequate measures. These repetitive activities follow to a certain extent standardized algorithms and computer-programs are able to support demands like this; however, up to now no attempts have been made to provide useful tools for this environment. DIALIN is a data-bank especially designed for the use in hospitals or outclinics and Camit is a diabetes management system for advanced evaluation of long-term blood glucose monitoring data. The expert-system DIACONS up to now determines diabetes type and adequate initial therapy from data of patients' history alone; it operates on the DIALIN-databank via SQL. DIALIN has proven to be a useful tool for data-processing in hospitals. Camit was well accepted by patients in a feasibility study. DIACONS has been tested with 83 diabetic patients to provide the correct diabetes-type and the proper initial regimen with a precision of 96% compared to the correspondence between two independent experts. The combination of all three systems is a step towards the Munich Medical Information system MAMIS.

Blood Glucose Self-Monitoring↗
PubMed1989

[Protracted blood sugar increase in type 1 diabetics after brief but exhausting muscular exercise].

In eight type I diabetics-three of them under intensified insulin therapy and five on continuous subcutaneous insulin infusion (CSII)-blood-glucose concentrations fell significantly during 20-minute isometric and dynamic muscle work at about 50% of individual maximal work capacity and subsequent intensive exercise of five minutes until exhaustion. However, 6 1/2 hours later blood-glucose levels (221 +/- 39 mg/dl after isometric exercise and 219 +/- 24 mg/dl after dynamic exercise) were clearly above the mean level measured at the same time of day on the three preceding days of 138 +/- 12 mg/dl (P less than 0.05). No hypoglycaemia occurred. This blood-sugar profile can be explained by a significant rise in cortisol and growth hormone and their long-lasting blood-sugar raising effect.

Adolescent↗
PubMed1988

[The early breakfast--an unknown pitfall in the treatment of type-I diabetes mellitus].

In 15 type I diabetics the mean postprandial rise in blood glucose levels, 90 min after breakfast at about 8 a.m. (the customary time for this meal in hospitals), was 62.2 +/- 34.3 mg/dl, but 90 min after a breakfast which had been put forward by about 1 1/2 hours it was only 2.6 +/- 18.6 mg/dl (P less than 0.001). Seven patients developed hypoglycaemia after the early breakfast, none after the late one. This finding suggests that, to avoid hypoglycaemia after an early breakfast, an additional small meal should be given at about 8:30 a.m. or the insulin content of the morning injection should be changed. The clear connection between the time of the morning insulin injection and the insulin action during the morning explains why, in uninstructed patients who--under their usual daily conditions of starting school or work--are forced to inject insulin early or to eat early, a state of hypoglycaemia may occur.

Adult↗
PubMed1986

[Comparison of the effects of protamine-bound NPH porcine insulin and NPH human insulin in type 1 and 2 diabetes].

Porcine and semisynthetic human insulin preparations (Nordisk) having the same content of regular insulin, same galenic characteristics and same degree of purity, were tested in type I, type IIa and type IIb diabetics. There was no difference as to the duration of action. This is contrary to some earlier reports stating that protamine-bound biosynthetic human insulin has a shorter duration of action than porcine preparations. The onset of the hypoglycaemic action in type IIa diabetics is significantly more rapid with isophane human insulin than with isophane pork insulin. The use of an insulin pump prior to testing the duration of action of intermediate insulin preparations appears to be superior to other methods.

Aged↗
PubMed1982

Glucose control in mobile type 1 (insulin-dependent) diabetic patients by means of a semi-automatic feedback controlled insulin infusion system.

A portable insulin dosing device (Siemens) was used together with a programmable pocket calculator and a glucose analyzer for short-term adaptation of continuous intravenous insulin infusion to blood glucose alterations. A special algorithm was developed which utilizes a given blood glucose value and the glucose rate of change obtained from two to four consecutive samples as input variables. In contrast to current techniques of feedback-regulation, which require continuous glucose monitoring, intermittent blood sampling allows greater mobility of patients. With the semi-automatic feedback system, euglycaemic control was obtained for 12-h periods in ten Type 1 (insulin-dependent) diabetic patients (maximum value 9.50 mmol/l, minimum value 2.83 mmol/l). Severe hypoglycaemia occurred in no case and additional control by glucose infusion appeared to be unnecessary. Light exercise after termination of insulin dose for standard meals led to glycaemic excursions with a rapid decrease (mean 1.08 +/- 0.09 mmol/l), followed by a rebound (0.59 +/- 0.07 mmol/l) in each patient. The amplitude of these excursions decreased with increasing distance from the peak of the meal dose. Comparison of feedback-control alone with feedback by glucose plus preprogrammed dose (4 U/h) at the onset of the test meal revealed lower post-prandial glucose levels (post-prandial maximum +/- SEM: 6.49 +/- 0.18 versus 7.71 +/- 0.79 mmol/l) and a lower infusion rate of insulin for the combined regimen (mean post-prandial maximum +/- SEM: 8.4 +/- 1.2 versus 12.0 +/- 0 IU/h). The system is useful for programming of portable infusion devices and studies based on euglycaemic control in unrestrained patients.

Adult↗