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Biomedical subjects

M G Bianchetti

Publications and source records attributed to M G Bianchetti.

At least 55 records · Page 3Linked to original sources
PubMed1999

Free and total circulating magnesium following glucagon injection in humans.

It has been postulated that parathormone, calcitonine, insulin and catecholamines are involved in extracellular magnesium homeostasis. Yet, there is still a rudimentary knowledge of the endocrine factors that control circulating magnesium homeostasis. The effects of exogenous glucagon injection on circulating total and ionized magnesium were investigated in 11 healthy humans (five females and six males, aged between 21 and 30, median 26 years). As compared with a control study, intravenous injection of a bolus of 1 mg of glucagon was associated with the expected raised glucose (at 5, 10, 20 and 30 min) and with decreased potassium (at 20 and 30 min) and inorganic phosphate (at 20 and 30 min) levels. Intravenous glucagon was not followed by significant changes in plasma total and ionized magnesium. Consequently, there is still little evidence for a glucagon-dependent control of the extracellular magnesium concentration after acute administration of glucagon.

Adult↗
PubMed1998

Amlodipine once-daily in systemic hypertension.

UNLABELLED: The calcium channel blocker nifedipine is widely used in children with systemic hypertension: however, because of the short duration of action, three to four daily doses of the standard preparation are required. Amlodipine once-daily, a calcium channel blocker structurally related to nifedipine with an excellent bioavailability and a long elimination half-time, has been shown to reduce blood pressure in adults. No information is available on the use of amlodipine in childhood. The effects of amlodipine once-daily (5 to 10 mg) were therefore assessed in 28 paediatric patients with hypertension. Amlodipine was withdrawn in five patients who experienced oedema and flushing. In the remaining 23 patients blood pressure was significantly reduced 3 weeks after amlodipine (on average by 7/5 mm Hg) and further decreased at 12 weeks (by 21/12 mm Hg). Heart rate and body weight were unchanged. In eight patients concomitantly treated with cyclosporine, the blood level of this agent was stable throughout the study, thus not requiring any dose adjustment. CONCLUSION: The study illustrates the antihypertensive properties of amlodipine once-daily in paediatric hypertension. Amlodipine appears particularly indicated in patients concomitantly treated with cyclosporine.

Adolescent↗
PubMed1998

Sedation with intravenous benzodiazepine and ketamine for renal biopsies.

"Lytic cocktail" is the customary sedation before percutaneous renal biopsy. Owing to deficient sedation and respiratory depression, this approach is no longer advised. The intravenous combination of a benzodiazepine plus ketamine, which has been found to be effective and safe in several conditions, was therefore used for 60 pediatric biopsies. In addition to pulse oximetry, a physician trained in airway management monitored the patient. The quality of sedation was acceptable (n = 7) or optimal (n = 53) in all cases. None of the patients required ventilation or intubation. A mild oxygen desaturation lasting 4 min or less was detected in 6 patients. None of the patients experienced major change in respiratory rate or blood pressure. The administration of ketamine and, in some cases, the biopsy puncture were associated with a mildly increased heart rate. In conclusion, a benzodiazepine plus ketamine provides effective deep sedation for renal biopsy in childhood.

Adolescent↗
PubMed1998

Acute encephalitis in Swiss children: aetiology and outcome.

Since published data on the course and prognosis of encephalitis in Central Europe is limited, we retrospectively evaluated 104 children with either acute strict sense encephalitis (n = 80) or acute cerebellar ataxia (n = 24) treated at the Department of Pediatrics, University of Bern, Switzerland, between 1980 and 1991. Of the 80 patients with strict sense encephalitis, four (5%) died acutely and 28 (36%) of 78 followed up had sequelae - eight patients with severe, six with moderate and 14 with mild sequelae. Young age and seizures were shown to correlate with poor outcome. Among the 24 patients with acute cerebellar ataxia, there was no fatal outcome and none developed severe residua, but six had mild and one had moderate sequelae. Initial cerebrospinal fluid white cell count was significantly higher in these children with sequelae compared with those without any sequelae after acute cerebellar ataxia.

Acute Disease↗
PubMed1998

Weekly versus biweekly lipid removal and effect of statins in severe hypercholesterolemia.

Lipid removal using a continuous-flow extracorporeal system is of proven efficacy in severe hypercholesterolemia. Because of the inconveniences and expenses of extracorporeal removal of lipids, the effects of two treatment intervals (weekly versus biweekly) were assessed in two adolescents with circulating cholesterol higher than 20.0 mmol/L. In both patients, circulating levels were largely lower on a weekly lipid removal interval when compared with a biweekly interval. A rapid reaccumulation of cholesterol was noted after lipid removal. Treatment with simvastatin decreased the rapid reappearance of total cholesterol noted during the first 2 days after lipid removal but without any major effect on the subsequent reaccumulation of cholesterol. Aggressive treatment of severe hypercholesterolemia with statins and especially with extracorporeal lipid removal is now possible and of proven efficacy. The minimal practical lipid removal treatment interval should be used.

Adolescent↗
PubMed1998

Free circulating magnesium and renal magnesium handling during acute metabolic acidosis in humans.

Ion-selective electrodes have been designed for determining the ionized concentration of magnesium in blood, the biologically active form of this ion. The effect of acute acidosis induced by ammonium loading on circulating and urinary magnesium was investigated in 11 volunteers. No changes in plasma total and ionized magnesium were noted following administration of ammonium chloride. On the contrary, administration of ammonium chloride increased the plasma free magnesium fraction and the urinary magnesium excretion. The study demonstrates that the hypermagnesiuria induced by acute acidosis is not caused by ionized hypermagnesemia and supports the theory that acidosis decreases the circulating magnesium fraction that is bound to proteins.

Acidosis↗
PubMed1998

Circulating ionized and total magnesium in end-stage kidney disease.

BACKGROUND: Circulating magnesium exists in the ionized state and in the undissociated form, either bound to albumin, or complexed to various anions. Until recently, only the measurement of total plasma magnesium has been possible. Now circulating ionized magnesium can be assessed as well. METHODS: Total and ionized plasma magnesium were determined in 43 patients on maintenance hemodialysis (dialysate composition: calcium 1.75 mmol/l, magnesium 0.75 mmol/l) before a dialysis session and in a group of 23 healthy subjects. RESULTS: The total (1.16 [1.03-1.31] versus 0.81 [0.78-0.89] mmol/l; median and interquartile range) and the ionized (0.71 [0.66-0.78] versus 0.54 [0.53-0.59] mmol/l) plasma magnesium levels were significantly higher (p < 0.01) and the ionized plasma magnesium fraction lower (0.61 [0.58-0.65] versus 0.67 [0.64-0.70]; p < 0.02) in patients than in controls. CONCLUSION: The determination of circulating ionized magnesium using selective electrodes is an attractive method to evaluate extracellular magnesium in kidney disease.

Adolescent↗
PubMed1998

Childhood insulin-dependent diabetes mellitus: initial presentation and management in the nineties.

Diabetes mellitus with onset during childhood usually presents as overt ketoacidemia. Pediatricians now inquire specifically about diabetes mellitus in children with nonspecific signs of illness and perform urinary dipstick testing. The present study was therefore performed to assess the possible influence of this strategy on the initial presentation and management of diabetes mellitus. The charts of 61 consecutive children with newly diagnosed diabetes mellitus (positive glucosuria and ketonuria and capillary glucose >14 mmol/l), who had been admitted between 1991 and 1996 at the Department of Pediatrics, University of Bern, Switzerland, were therefore reviewed. Twenty-six out of the 61 patients were nonacidemic (blood pH 7.36 or more). Children with and without acidemia did not differ with respect to age, history of polydipsia and polyuria, plasma glucose and circulating glycated hemoglobin A1c. The degree of dehydration and the amount of fluid required for its correction and the total insulin dosage were more prominent in the group of patients with acidemia. The study demonstrates that childhood diabetes mellitus is nowadays often recognized as nonacidemic hyperglycemia and that in these patients a reduced initial fluid repair and total insulin dosage is recommended.

Acids↗
PubMed1998

[Urinary tract infections in pediatric practice--which new aspects must be considered?].

The prevalence of urinary tract infections varies markedly with sex and age. They are caused mainly by colonic bacteria. Acute cystitis should be promptly treated either with cotrimoxazol or coamoxyclav to prevent its possible progression to pyelonephritis. In acute febrile infections suggestive of pyelonephritis, the initial use of broad-spectrum antibiotics capable to reaching significant tissue levels is advised, mostly amoxycillin with an aminoglycoside. A variety of functional voiding disorders including bladder instability, detrusor-sphincter dyscoordination, postponing syndrome or lazy bladder syndrome have been identified since the early 1970s, each with its own characteristics and clinical importance. Functional voiding disorders are nowadays a major cause of recurrent urinary tract infections in children. A careful investigation to confirm or exclude functional voiding disorders is warranted in children with recurrent urinary tract infections. Management will vary according to the type and severity of the dysfunction present.

Acute Disease↗
PubMed1997

[How is hemolytic-uremic syndrome in childhood acquired in Switzerland?].

Intestinal infections with shigatoxin-producing Escherichia coli or Shigella dysenteriae type I play a major role in the pathogenesis of the hemolytic-uremic syndrome in childhood. Escherichia coli has been repeatedly detected in the intestines of healthy cattle. Twenty-seven children with hemolytic-uremic syndrome were treated at our hospital between June 1990 and March 1997. Factors indicating a possible previous contact with bovine intestinal content were found in 18 out of the 27 patients: parents stockbreeders (n = 7), recent visit to a cowshed or contact with cowdung or manure (n = 5), residence in a rural cattle-breeding area (n = 5), or consumption of raw milk (n = 1). The factors mentioned were found in 5 out of 27 control patients (p < 0.01). Two children experienced hemolytic-uremic syndrome after a stay respectively in Egypt and Tunisia. Our results indicate an important source for acquisition of hemolytic-uremic syndrome in childhood. Observing simple hygienic rules such as washing of hands and pasteurization of milk is likely to have a positive influence on the incidence of this illness. There are also grounds to consider adding the hemolytic-uremic syndrome to the list of travel-related diseases.

Animals↗