Lack of glucagon response in glucose counter-regulation in Type 1 (insulin-dependent) diabetics: Absence of recovery after prolonged optimal insulin therapy

Summary Mild hypoglycaemia was induced using an artificial pancreas in five normal subjects (from 5.00 ±0.15 to 2.83±0.15 mmol/l) by infusing 28 mU/m² per min soluble insulin for 60 min. Six Type 1 (insulin-dependent) diabetic patients were stabilized for 14h using an artificial pancreas. They were then rendered hypoglycaemic (from 4.94±0.09 to 2.89±0.11 mmol/l) by infusing 28mU/m² per min plus 16 ±3.8mU/min insulin for 60 min. Before the study, the diabetic patients were in optimal blood glucose control (mean blood glucose 6.72±0.11 mmol/l over the previous 14–20 days; HbA₁ 8.3±0.1%). During the insulin infusion test, blood glucose decrement was slower in the diabetic patients than in the control subjects. The blood glucose nadir was delayed in the diabetics until 75 min compared with 55 min in the control subjects. Blood glucose recovery rate in the diabetic subjects was severely impaired. In Type 1 diabetes, the counter-regulatory hormonal response to insulin induced hypoglycaemia is similar to that of non-diabetics, except for that of glucagon, the blunted response of which is not reversed by prolonged optimisation of blood glucose control. This impaired response of the A cell does not seem to be a consequence of insulin deficiency.     

The first case of locally acquired tick-borne Babesia microti infection in Canada

A child with a complicated medical history that included asplenia acquired an infection with Babesia microti in the summer of 2013 and had not travelled outside of Manitoba. Although the clinical findings were subtle, astute laboratory work helped to reach a preliminary identification of Babesia species, while reference laboratory testing confirmed the diagnosis. Blacklegged ticks (Ixodes scapularis) are known to transmit Borrelia burgdorferi and Anaplasma phagocytophilum in the province; however, the present case represents the first known instance of tick-borne B microti, both in Manitoba and in Canada. The expanding territory of the blacklegged tick increases the relevance of this emerging infection. Clinicians, laboratory medical practitioners and public health officials should be aware of B microti as a potential locally acquired infection in Canada.     

Prevalence of cerebral palsy in Slovenia: birth years 1981 to 1990

Changes in the prevalence of cerebral palsy (CP) in a population of Slovenian children born between 1981 and 1990 were determined. A population-based birth-cohort study was undertaken. Seven hundred and sixty-eight children with CP (aged 5 to 14 years) were identified from the National Cerebral Palsy Register in 1995. Spastic syndromes accounted for 84.8%. Of the 768 children studied, the total prevalence of CP per 1000 live births fell significantly from 3.3 in 1981 to 2.3 in 1990. This decreasing trend was observed in children born at <38 weeks of gestation and in those with a birthweight of <1500 g, but the prevalence of CP remained fairly constant in those born at ≥38 weeks of gestation and in those with a birthweight of ≥2500g. The results show that a statistically significant improvement in the survival rate of infants born in Slovenia between 1981 and 1990 was not accompanied by an increase in the prevalence of CP. Additionally, in the group of very-low-birthweight infants the prevalence of CP considerably decreased.     

The importance of non-invasive genetic analysis in the initial diagnostics of Alport syndrome in young patients

Alport syndrome is an important hereditary disorder characterized by nephritis and sometimes accompanied by impairment or loss of vision and hearing. The most common form of Alport syndrome is an X-linked dominant trait that has been associated with the gene COL4A5, one of the six types of IV collagen genes. More than 300 different mutations have been identified in the COL4A5 gene, and appear randomly along the whole gene. Three novel mutations, G198E, G3189D and G669R, were found in 5 young patients from 3 different Slovenian families. On the basis of the results of our study and the existing national register of Alport syndrome patients, we demonstrated that non-invasive methods, such as the genetic analysis of collagen genes, particularly in the case of young patients with undefined clinical features, may be of great importance and could diminish the need for invasive skin and renal biopsy. Our study showed the importance of molecular genetic data for the purpose of providing quick and precise diagnoses for affected family members and their offspring, particularly small children.M. lajpah and A. Megli contributed equally to this work     

Antithrombotic potential of new direct thrombin inhibitors built on the azaphenylalanine scaffold in two rat venous thrombosis models

The antithrombotic potential of new direct thrombin inhibitors built on the azaphenylalanine scaffold (LK-732, LK-639 and LK-731) and their amidoxime prodrugs (LK-658, LK-633 and LK-730) was studied in comparison to argatroban and nadroparin in two rat models of venous thrombosis, induced either by complete stasis combined with hypercoagulability (model 1) or by partial stasis combined with vessel injury (model 2). In initial experiments LK-732 was established as the most promising antithrombotic of the LK inhibitors and as such was further tested. In model 1, intravenous bolus administration of LK-732 produced a dose-dependent inhibition of thrombus formation with an ID50 value of 1.3 mg/kg. This ID50 value was approximately four times higher than the ID50 value of argatroban (0.3 mg/kg; p=0.011). However, in model 2, LK-732 and argatroban decreased thrombus weight by 50% at similar ID50 values (3.8 mg/kg vs 3.0 mg/kg, respectively; p=0.726). The ex vivo anticoagulant effect of LK-732 was substantially weaker compared to argatroban at doses that produced comparable antithrombotic effects. After subcutaneous administration, in vivo thrombus weight reduction of LK inhibitors (10 mg/kg) ranged between 22 to 48%. However, their oral antithrombotic effect at a dose of 30 mg/kg was rather low. LK amidoxime prodrugs failed to produce a substantial antithrombotic effect after subcutaneous (10 mg/kg) as well as after oral administration (30 mg/kg). In conclusion, thrombin inhibitors built on the azaphenylalanine scaffold represent a new group of intravenously effective antithrombotics. However, optimisation of the oral antithrombotic effect of amidoxime prodrug LK-658 of the lead inhibitor LK-732 is required for justifying further development of these inhibitors.     

Sensitivity of culture and polymerase chain reaction for the etiologic diagnosis of erythema migrans

Skin biopsy samples from 150 patients with typical cutaneous manifestation of Lyme borreliosis, erythema migrans, were cultivated for the presence of Borrelia burgdorferi sensu lato in modified Kelly Pettenkofer (MKP) medium and analysed with two different polymerase chain reactions using either flagellin or nested OspA primers. Cultivation was successful in 75 of 150 (50%) skin samples. Out of 70 strains that were typed using PFGE, B. afzelii was identified in 60 (86%), B. garinii in 10 (14%) specimens, while no B. burgdorferi sensu stricto strains were found. B. burgdorferi sensu lato DNA was detected with polymerase chain reaction in 28% and 61% of skin samples, using flagellin and nested OspA primers, respectively. Concordant results in all three procedures employed in the present study were found in 62 (41%) specimens: 25/150 (17%) were positive with all three methods and 37/150 (25%) samples were completely negative.