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Biomedical subjects

A Raes

Publications and source records attributed to A Raes.

29 records · Page 2Linked to original sources
PubMed1997

Advantages of HCO3 solution with low sodium concentration over standard lactate solutions for acute peritoneal dialysis.

The aim of this study was to identify the advantages of a bicarbonate solution with a low sodium concentration. Twelve children (3 days-6 years) with acute renal failure (ARF), positive fluid balance, and lactate acidosis (> 40 mg/dL) were treated by automated peritoneal dialysis (APD) with frequent exchanges of small fill volumes of a hypertonic solution. For Day 1 we used PD1/PD4 Dianeal (3.86%) (Baxter). After 24 hours we switched to a HCO3 solution: 38 mmol/L, Na 128 mmol/L. As the control group, we studied retrospectively the last 12 children of the previous period who were treated with APD. The age distribution was 4 days to 4 years. No significant differences were found between the groups for serum creatinine, blood urea nitrogen, and fluid overload (Day 1 to Day 4). Although the values for lactate and Na were not different before the start of the study (Day 1) and after 24 hours of Dianeal (Day 2), they were significantly lower in the study group on Day 4 [HCO3 53 (23-83), Na 148 (137-136) mEq/L] than in the control group [lactate 148 (137-156), Na 154 (142-165) mEq/L]. A low sodium concentration results in higher sodium extraction, which is important for patients with fluid overload. Low sodium concentrations in APD are needed because the peritoneal membrane "sieves" the sodium during short dwells. HCO3 dialysis is a logical choice for patients with lactate acidosis, resulting in a significant lower serum lactate and increase of BE after 48 hours of treatment.

Acute Kidney Injury↗
PubMed1997

New perspectives for PD in acute renal failure related to new catheter techniques and introduction of APD.

Acute renal failure remains a major problem in pediatric intensive care unit (PICU) patients. Although in most handbooks peritoneal dialysis (PD) is still considered to be the first choice for children < 20 kg and there is some evidence that PD may preserve and/or favor recuperation of renal function, most PICU departments are using continuous veno-venous hemofiltration and dialysis or hemodialysis as treatment. The main reasons for this are workload for the PICU nurses, catheter problems, the risk of peritonitis, and limited ultrafiltration. In a retrospective study (1992-1995) in 46 patients (age 3 days to 14 years), automated PD (APD) was the initial treatment in 44 patients. Complications of the Seldinger-placed Cook (pleuropericard) catheter were limited: leakage (1/44); bleeding: n = 0; obstruction or dislocation: n = 4; peritonitis: n = 1 (Candida); ultrafiltration (UF) problems: n = 3. APD in children with acute renal function (ARF) is a good alternative for continuous veno-venous dialysis. Placement of a pigtail (Cook) catheter is a quick (10 min), safe procedure, with low leakage risk. This, together with the low manipulation rate, gives a low peritonitis rate. The use of the cycler makes frequent changes of small volumes possible, resulting in better clearance, good UF, no interference with hemodynamic or respiratory stability, and a reduced workload.

Acute Kidney Injury↗
PubMed1997

Membrano-bulbo-urethral junction stenosis. Posterior urethra obstruction due to extreme caliber disproportion in the male urethra.

OBJECTIVE: Based on 4 cases of infravesical obstruction due to extreme caliber disproportion between the posterior urethra and the penile urethra, a pathophysiological mechanism for this dynamic obstruction is given and endoscopic treatment is described. SUBJECTS: Four cases of membrano-bulbo-urethral junction (MBUJ) stenosis, seen between September 1995 and April 1996, are described. Two boys had previous successful valve resection but still showed extreme ballooning of the posterior urethra. The other 2 boys showed bladder instability on urodynamics and the male variant of the spinning top urethra on voiding cystourethrography (VCUG). RESULTS: All cases were successfully treated by endoscopic incision at the 12 o'clock position of the kink between the posterior and the penile urethra which is seen when the full bladder is expressed. Disproportion in the posterior urethra, seen on VCUG, together with bad urinary flow measured on uroflowmetry raise the suspicion of MBUJ stenosis. CONCLUSION: Although rarely seen, extreme caliber disproportion in the male urethra can cause obstruction. Ballooning of the posterior urethra, caused by urethral valves, bladder instability resisted by voluntary sphincter contraction or congenital posterior urethral dilatation, creates an obstructive kink in the urethra comparable to some obstructions in ureteropelvic junction stenosis. If suspicion of such a form of obstruction arises, cystoscopy during pressure on the full bladder is mandatory in order to see the obstruction, descending as a membrane from the vault of the urethra.

Adolescent↗
PubMed1996

N-methyl-D-aspartate receptor activation by guanidinosuccinate but not by methylguanidine: behavioural and electrophysiological evidence.

Levels of methylguanidine (MG) and guanidinosuccinate (GSA) are known to be highly increased in uraemic patients. In the present work, the effects of these uraemic guanidino compounds on the excitatory amino acid system were investigated in vivo and in vitro. It was found that convulsions induced by intracerebroventricular GSA injection in mice were antagonized by N-methyl-D-aspartate (NMDA) receptor blockade, whereas those induced by MG were not significantly altered. Application of GSA (between 25 and 10,000 microM) to mouse spinal cord neurones in primary dissociated cell cultures, evoked depolarizing, inward whole-cell currents in a dose-dependent fashion and with reversal potential at 0 mV; MG did not produce such effects. GSA-induced whole-cell currents were caused by NMDA receptor activation since NMDA receptor antagonists (2-amino-5-phosphonovalerate, Mg2+ and ketamine) blocked GSA-evoked whole-cell currents completely and reversibly, whereas co-application of a non-NMDA receptor antagonist (6-cyano-7-nitroquinoxaline-2,3-dione) did not affect GSA-induced current. Evoked field potentials in CA1 region of rat hippocampal slices were completely abolished by GSA, and this effect was antagonized by NMDA receptor blockade. All data were consistent with selective agonist action of GSA upon the NMDA-type glutamate receptor. In view of the results presented here, it should be examined whether NMDA receptors contribute to the neurological complications of renal failure through GSA-induced inappropriate or excessive activation of NMDA receptors.

Animals↗
PubMed1996

One hundred consecutive cystoscopic examinations in children: indications and results.

OBJECTIVE: To evaluate the place and value of cystoscopy in paediatric bladder dysfunction. METHODS: A retrospective analysis of files of 100 children who underwent cystoscopy. RESULTS: In 6 patients with neurogenic bladder dysfunction, cystoscopy was done for the diagnosis of secondary uropathy. In patients with uropathy, of the neonatal group of 6 patients 2 were seen for evaluation of disorders of sexual differentiation and 4 were seen for further diagnosis of neonatal hydronephrosis. In 21 children cystoscopy was part of the diagnostic and/or therapeutic workup for severe urinary-tract infection and in 5 patients for other uropathies. Sixty-two patients with non-neurogenic, non-uropathic bladder dysfunction were selected to undergo cystoscopy on the urodynamic findings. In boys, 36 had an obstruction and 12 had normal cystoscopy. In girls, 4 had an obstruction and 10 had a minimal meatal deformity. CONCLUSIONS: In children with neurogenic dysfunction, cystoscopy is only indicated in diagnosis and therapy of secondary uropathies. Cystoscopy is part of the diagnostic and therapeutic strategy in uropathy. In non-neurogenic, non-uropathic dysfunction urodynamic study allows the selection of patients who have minimal anatomic deformities that provoke the bladder dysfunction and for whom cystoscopy is indicated.

Adolescent↗
PubMed1996

Anticonvulsant activity of piperine on seizures induced by excitatory amino acid receptor agonists.

In traditional Chinese medicine, a mixture of radish and pepper is used to treat epilepsy. The presumptive effectiveness of this prescription might be due to the anticonvulsant actions of the principal component of pepper, the alkaloid piperine (CAS 94-62-2). The effects of piperine on convulsions induced in mice by agonists at different excitatory amino acid receptor subtypes were studied. Piperine was shown to significantly block convulsions induced by intracerebroventricular injection of threshold doses of kainate, but to have no or only slight effects on convulsions induced by L-glutamate, N-methyl-D-aspartate or guanidinosuccinate. Piperine suspensions, injected intraperitoneally, 1 h before injection of the threshold intracerebroventricular dose of kainate for the induction of clonic convulsions (1 nmol), blocked these convulsions with an ED50 (and 95% confidence interval) of 46 (25-86) mg/kg. Although piperine did block convulsions, induced by kainate, the compound does not appear to act as a kainate receptor antagonist. Whole-cell currents induced by the application of kainate to spinal cord cells in primary dissociated cultures were not affected by co-application of piperine.

Alkaloids↗
PubMed1995

Commercial television bladder dysfunction.

Bladderdysfunction seems to have an increasing frequency in infancy, and especially in children without obvious congenital organic or functional bladderdysfunction. The disorder seems is related with changes in our behaviour, that are stimulated by familial and social pseudo-reasons. Commercial interests and marketing play a major role. This leads to wrong dry-training, an exaggerated hygienic education, prudisheness, wrong toilet-posture, lack of time to void, post-poning, wrong drink- and void-pattern, wrong food-pattern and increasing constipation. Prevention is necessary by an adapted reeducation of parents ans society.

Adolescent↗
PubMed1995

Bladder function and non-neurogenic dysfunction in children: classification and terminology.

Urological function and dysfunction in children are different from function and dysfunction in adults. The dynamics of the urinary tract in children are more complex as development from simple reflex controlled infant bladder to mature bladder function takes place during the first five years of live. The most crucial event in this development is the maturation of the inhibition that takes place in the growing urinary tract. Apart from gaining neurological control over de lower urinary tract there is the physical growth of the bladder-sfincter unit. Otherwise in children there exist a large amount of structural organic congenital pathology of the lower urinary tract that can trouble the normal development. Finally there is the cognitive function that has no anatomical substrate in the lower urinary tract but which takes place in the central nervous system and which is influenced by training and which can play a major role in development of non structural functional dysfunction. In order to train a child adequately the anatomical structure needs to have undergone enough maturation. By training a child on a too early age one can help to develop non structural functional dysfunction. In a time where competition in dry-training is encouraged by commercial pressure and where parents have less time, so that they are urged to train their children dry, more and more non-structural functional dysfunction in children is seen. The most prominent symptom of maldevelopment of the urinary tract, be it structural or functional is urinary incontinence. It is the most common problem seen in the paediatric urology practice.(ABSTRACT TRUNCATED AT 250 WORDS)

Child↗
PubMed1993

Use-dependent block of the pacemaker current I(f) in rabbit sinoatrial node cells by zatebradine (UL-FS 49). On the mode of action of sinus node inhibitors.

BACKGROUND: Zatebradine (UL-FS 49) is a drug with a specific bradycardiac electrophysiological profile. It reduces heart rate by lengthening the duration of diastolic depolarization in the sinoatrial (SA) node. The ionic basis of this action, however, is not clarified. METHODS AND RESULTS: We used the whole-cell patch-clamp technique to study the effects of zatebradine on ionic currents underlying diastolic depolarization of isolated rabbit SA node cells. Low concentrations of zatebradine simultaneously reduced diastolic depolarization rate and the pacemaker current I(f). The drug blocked the pacemaker current, I(f), in a use-dependent manner without causing a shift of its activation curve. At hyperpolarized potentials, unblock of I(f) occurred. Clinically relevant concentrations of the drug have little effect on the L-type calcium current or delayed rectifier potassium current. CONCLUSIONS: This use-dependent block of the If channel can account for most of the pharmacological characteristics of zatebradine and is probably the mechanism of heart rate reduction caused by this agent. Thus, the sinus node inhibitor zatebradine belongs to a new class of "I(f) blockers" with possible advantages over currently available drugs for the treatment of ischemic heart disease.

Animals↗
PubMed1977

The pattern of food and mortality in Belgium.

Belgians have been gradually shifting from a low ratio of polyunsaturated/saturated fat in their food to a higher one with lower total fat and cholesterol. This has occurred predominantly in the north, where the most obvious change is a decrease in butter consumption and an increase in margarine consumption. The northerners have a four to five times smaller intake of butter than the southerners and nearly double the intake of margarine. Evidence gathered over the past ten years reveals in the north a decreasing serum-cholesterol and in the south a significantly higher serum-cholesterol, associated with higher coronary morbidity and mortality. Life expectancy of males in the north is 2-4 years higher at birth and 2-2 years higher at the age of 30. It is concluded that the food habits of a population can be changed, with great benefit.

Adult↗