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Biomedical subjects

L Kerp

Publications and source records attributed to L Kerp.

11 recordsLinked to original sources

Is the reuse of needles for insulin injection systems associated with a higher risk of cutaneous complications?

Twenty diabetic patients participated in a study to assess if multiple use of needles for insulin injection systems (Pens) is safe under normal daily conditions. The previous mean duration of Pen therapy was 16.3 months. During this time, the 20 patients carried out altogether more than 33,000 injections without any sign of local infection despite needle reuse. Patients were told to use needles if possible for 1, 3, 6, 9, and 12 injections before bacteriological assessment. Bacteriological investigation of these needles showed no contamination, except with one needle used three times, which was colonized with coagulase negative Staphylococcus. In contrast, half of the needles' plastic ground points which touched the skin were contaminated. No signs of infection were observed at the injection sites throughout the study. We conclude that, based on the bacteriostatic effects of commercially formulated insulin and on the siliconisation of needles' surfaces, bacterial growth is sufficiently prevented. Therefore, we can recommend the reuse of pen needles as a simple, safe and cost-beneficial procedure.

Adult

Osmotic stress due to changes in plasma glucose and its regulation in IDDM patients.

Intravenous glucose tolerance tests (30 g, 5 min, constant rate) were performed in 8 IDDM patients and in 8 controls. The consequences of the osmotic pressure, induced by glucose, were investigated. Serum choline esterase was used as an endogenous marker of serum dilution. Five minutes after the end of infusion plasma glucose was raised by 182 +/- 12 mg.dl-1 in patients and by 189 +/- 6 mg.dl-1 in controls. Choline esterase values decreased by 6.6 +/- 0.8% and 6.3 +/- 1.0% respectively, P less than 0.01 each. Calculated water shifts into the extracellular space were 924 +/- 112 ml and 882 +/- 140 ml respectively. Fifteen minutes after the end of infusion glucose decreased by 32 +/- 1 mg.dl-1 in IDDM patients and by 57 +/- 2 mg-1 in controls. Serum choline esterase recovered by 2.6 +/- 0.2% and 2.7 +/- 0.2% respectively, P less than 0.01 each, indicating comparable water correction in spite of the slower fall of glucose in IDDM patients. Water correction was more rapid than glucose fall. Diuresis (46 +/- 4 ml versus 42 +/- 3 ml) or cellular uptake of serum solutes (electrolytes, amino acids, urea, creatinine) could not explain this. It is hypothesized that accumulation of free intracellular glucose reduces the osmotic gradient and facilitates cellular water re-uptake.

Adult

The pupillary light reflex. 1. Age-dependent and age-independent parameters in normal subjects.

A hundred and three normal subjects (14-75 years old) were examined with a modified infrared TV videopupillometer that had previously been developed. Maximal pupillary diameter (p less than 0.00001), pupillary diameter in percent of iris diameter (p less than 0.00001), maximal pupillary area (p less than 0.00001), latency time of the light reflex (p less than 0.00001), maximal contraction velocity (p less than 0.00002), contraction velocity at 1 s (p less than 0.00001) and dilatation velocity at 6 s (p less than 0.0001) are strongly age dependent. A statistical formula is given to allow the calculation of the exact percentile for every parameter. Parameters which are age independent if they are expressed in percent of the maximal pupillary area are contraction velocity at 1 s (r = 0.042, p = 0.68) and dilatation velocity at 6 s (r = -0.150, p = 0.13). They can be used if age-matched study groups are not available. Furthermore, it is shown that most parameters of the pupillary light reflex correlate significantly with each other. The highest correlations are found with the maximal pupillary area. Differences between sexes are not evident. It is thought that this infrared videopupillometry and the given data base are useful for further clinical studies to investigate the autonomic nervous system.

Adolescent

The pupillary light reflex. 2. Prevalence of pupillary autonomic neuropathy in diabetics using age-dependent and age-independent pupillary parameters.

Seventy-seven diabetics with a duration of the disease ranging from 2 to 55 years (average 18.5 years) were studied with infrared videopupillometry. The prevalence of diabetic autonomic neuropathy at the pupillary control system (pANP) was studied comparatively using several pupillary tests. The average prevalence using age-dependent parameters was 30.2% [maximal pupillary area: 22.1%, maximal contraction velocity: 24.7%, contraction velocity at 1 s (CV1): 28.6%, and dilation velocity at 6 s (DV6): 45.5%]. Comparing these percentages to prevalences of other diabetic late complications, e.g. retinopathy (49.4%), DV6 seems to be good for the diagnosis of pANP. If CV1 and DV6 are expressed in percent of the maximal pupillary area (CV1% and DV6%), they become age-independent. The average CV1% and DV6% of diabetics differ highly significantly from those of normals (CV1%: 58.6 +/- 14.5 vs. 64.1 +/- 6.4%, 2 p less than 0.005, and DV6%: 6.0 +/- 2.9 vs. 7.3 +/- 1.1%, 2 p less than 0.001). The average prevalence of pANP using these age-independent parameters was 25.4%. These data suggest that the prevalence of pANP, especially disorders of pupillary dilation (DV6), is high in long-standing diabetes. Furthermore, CV1% and DV6% have proved to be valid parameters in finding differences in the light reflex in non-age-matched study groups.

Adolescent

Lack of beta 2-adrenoceptor induced long-acting effect on glucose tolerance in type 2 diabetic patients.

The long-acting effect of a 10-min pulse infusion of the beta 2-adrenergic agonist fenoterol on oral glucose tolerance tests in controls and in normotensive patients with type 2 diabetes mellitus on diet was compared. During an oral glucose load starting 2 h after fenoterol control persons showed hyperglycemia (area: 25,950 +/- 467 vs. 22,650 +/- 410, P less than 0.01), hyperinsulinemia (area: 13,980 +/- 1050 vs. 8160 +/- 405, P less than 0.02) and a pronounced fall of serum potassium (area: 775 +/- 26 vs. 748 +/- 25, P less than 0.02). The patient group showed no late response to fenoterol: plasma glucose (area: 51,000 +/- 382 vs. 51,300 +/- 413, n.s.), serum insulin (area: 7215 +/- 233 vs. 8280 +/- 410, n.s.), serum potassium (area: 748 +/- 26 vs. 750 +/- 24, n.s.). The data show that there is a defect of the beta 2-adrenergic long-acting effect on glucose metabolism and on insulin release in type 2 diabetes mellitus.

Adult

The detection of single cells forming antibodies to defined epitopes on insulin.

A solid-phase immunoenzymatic technique was modified to permit the detection and enumeration of antibody-secreting cells recognizing the amino or carboxy terminal of the insulin B chain. The procedure involves coating well surfaces with avidin and binding insulins specifically labelled with biotin at the B1 or B30 residue. On day 15 after immunization with human insulin, 20 outbred NMRI mice had generated cells secreting anti-insulin antibodies. The recognition of B1- or B30-related epitopes differed between individuals, suggesting that there was genetic determination of the epitopes expressed early in the immune response. The method can be used to find strains of mice with a preferential immune response to defined areas on the surface of small peptide molecules. Such strains could then be used to produce specific monoclonal antibodies.

Animals

Synthesis of proinsulin and large glucagon immunoreactivity in isolated Langerhans islets from EMC-virus infected mice.

The protein synthesis in normal and in EMC-virus infected mouse islets of Langerhans was investigated. Mouse large glucagon immunoreactivity was determined by an immunoassay after chromatographic separation. It was characterized as a peptide of 16 000 MW with in intracellular half-life of 35-45 min. The proportional reduction of void volume proteins, large glucagon immunoreactivity and proinsulin synthesis after infection shows, that both alpha- and beta-cells are damaged by the virus. A reduction in the synthesis of the three protein fractions was already found 6 hrs after inoculation of the virus and remained nearly constant for 48 hrs. An almost complete breakdown of protein synthesis occurred 60 to 70 hrs after infection and was paralleled by the first light microscopic changes in the islets. The stimulation of proinsulin synthesis by glucose was preserved for 48 hrs after EMC-virus infection.

Animals