Biomedical subjects
M Fischbach
Publications and source records attributed to M Fischbach.
[National French observation study of ceftriaxone treatment of acute pyelonephritis in children].
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Impact of fill volume changes on peritoneal dialysis tolerance and effectiveness in children.
In the last decade, it has became apparent that the prescribed fill volume (IPV) in children on peritoneal dialysis (PD) should be expressed per body surface area (BSA in square meters) to avoid a false perception of peritoneal hyperpermeability as determined during a peritoneal equilibration test [PET, dialysate-to-plasma (D/P) ratio]. Nevertheless, the optimal IPV in terms of both tolerance and effectiveness remains under discussion. An individual approach to IPV prescription might balance the measurement of the intraperitoneal pressure, the use of the mass transfer coefficient despite the D/P ratio, and a determination of the effective peritoneal area available for exchanges. Considering these parameters, we usually found the individual optimal fill volume to be less than 1400 mL/m2.
The optimal approach to peritoneal dialysis prescription in children.
OBJECTIVE: To describe the optimal approach to peritoneal dialysis (PD) prescription in children. DESIGN: Review of the available literature. RESULTS: Unlike the situation in adults, the main method used for PD in children is automated peritoneal dialysis (APD). The prone position, while resting, permits the dialysis prescription to use a higher fill volume (IPV), as in continuous ambulatory peritoneal dialysis (CAPD), and is also probably more effective than PD in an upright position. However, because APD is limited to 10 hours, the dialytic effectiveness of nocturnal APD should avoid two potential risks: (1) use of too high an IPV per exchange, inducing lymphatic reabsorption, a factor in unsuitable water and sodium balance [Fischbach M. Peritoneal dialysis prescription for neonates. Perit Dial Int. 1996; 16(Suppl):S52-4]; and (2) use of too short a dwell time per exchange, limiting the purification of creatinine and phosphate despite an apparently adequate urea purification (Malhotra C, Murota GH, Tzamaloukas AH. Creatinine clearance and urea clearance in PD: What to do in case of discrepancy. Perit Dial Int. 1997; 17:532-5).
A three generations family with blepharo-naso-facial malformations suggestive of Pashayan syndrome.
Blepharo-naso-facial syndrome, described by Pashayan et al. (10), is characterized by telecanthus, lateral displacement and stenosis of lacrimal puncta, bulky nose, mask-like facies, trapezoïdal upper lip, torsion dystonia and mental retardation. We report on a family with this rare malformation syndrome, confirming the existence of this syndrome and its dominant inheritance. The proband had a fleshy nose, a prominant nose bridge, an hypoplastic midface, telecanthus with temporal displacement of puncta, lacrimal excretory obstruction. CNS torsion dystonia, increased deep tendon reflexes, Babinski reflexes, poor coordination and joint laxity. The proband's mother, brother and maternal grandfather also showed manifestations of the syndrome. The proband and his brother had delayed developmental milestones. Hearing impairment was present in the proband, his mother and his grandfather but was absent in the proband's brother. The blepharonasofacial syndrome was described by Pashayan et al. (10) in four members of one family, two male and one female sib and their mother. Two other sibs were unaffected. Many of the features of the blepharo-facio-nasal syndrome also occur in other well known syndromes i.e. Waardenburg syndrome. The pedigrees of the family of Pashayan et al. (10) and of our family are compatible with Mendelian dominant inheritance, either autosomal or X-linked. X-linked dominant inheritance cannot be ruled out except by male-to-male transmission, which does not occur in these families. Pashayan et al. (10) suggested that an autosomal gene with variable expressivity appears more likely. More families are needed for defining the transmission of the condition and for mapping the gene involved in the blepharo-naso-facial syndrome.
Glucose-charged dialysate for children on hemodialysis: acute dialytic changes.
Glucose has been omitted from hemodialysates in the recent past. Currently, there is a tendency to include glucose in dialysates at physiological concentrations between 100 and 200 mg/dl (5.56-11.12 mmol/l). In adult patients, this induces, over the dialysis session, a significant uptake of glucose, with some benefits, i.e., avoidance of caloric loss, but also with some metabolic risks, i.e. decreased dialytic potassium removal secondary to an insulin-dependent intracellular potassium shift. We have performed a crossover study in five stable children (mean age 11.7 years) with normal fasting glucose on chronic bicarbonate hemodialysis. The dialysis prescription of 3-h sessions was changed only in terms of the glucose dialysate concentration, being either glucose free or containing 9.17 mmol/l (165 mg/dl) glucose; dialysates were potassium free. Twenty sessions were analyzed for each group by whole dialysate collection (glucose, potassium, phosphate) and serum concentration analysis during and post dialysis (glucose, potassium, phosphate, insulin). Glucose-free dialysis was associated with a patient net glucose loss of 113 +/- 12 mmol/session (nearly 20 g). Conversely, with the glucose-charged dialysate a small uptake of glucose was noted [13.8 +/- 2.1 mmol/session (nearly 2 g)]. At the end of the session, serum glucose was lower with the glucose-free dialysate (4.64 +/- 0.52 mmol/l) than the glucose-charged dialysate (6.11 +/- 0.92 mmol/l). Conversely, serum insulin was higher with the glucose-charged dialysate (38 +/- 17 mU/l) than the glucose-free dialysate (19 +/- 9 mU/l). There were no significant differences either for dialytic removal of potassium (70 vs. 73 mmol/session) or phosphate (20 vs. 22 mmol/session), with and without glucose dialysates. Our study, contrary to previously published data in adults, demonstrated that in children the use of a physiological concentration of glucose in the dialysate (165 mg/dl) avoids dialytic glucose loss without a significant decrease in dialytic potassium removal.
Effect of posture on intraperitoneal pressure and peritoneal permeability in children.
The posture of the patient influences both the intraperitoneal pressure (IPP) and the peritoneal permeability. We have studied the effects of the supine and the upright position in six children. Two peritoneal equilibration tests (PET) of 90-min dwell time each were performed consecutively, firstly in the supine position and then in the upright position. The same amount of dialysate was instilled (1,000 ml/m2; isotonic 1.36% dextrose) for each PET. Using the same filling volume, the IPP was significantly higher in the upright position (18.4 +/- 4.8 cm H2O) than in the supine position (8 +/- 2.4 cm H2O). The mean percentage IPP increase was 130% +/- 35%. The decline in glucose resorption rate from the dialysate during the PET was significantly lower in the upright position. Despite this greater relative loss of osmotic gradient in the upright than the supine position, no significant difference in net ultrafiltration was noted after 90 min of dwell. The peritoneal equilibration ratio during the PET was lower in the upright than the supine position for urea, creatinine, and phosphate. These results favor performing peritoneal dialysis in a supine position, both to increase dialysis efficiency and to reduce patient discomfort.
Impact of increased intraperitoneal fill volume on tolerance and dialysis effectiveness in children.
The known relationship between peritoneal fill volume (IVP) and dialysis efficiency favors the use of an optimal IVP to enhance peritoneal dialysis (PD). Therefore, we have studied the effects of an increased IVP in consecutive stages [800, 1400, and 2000 mL/m2 of body surface area (BSA), respectively] in 8 children on chronic PD (mean age: 9 years 6 months; range: 2-16 years). Each prescribed IVP was maintained for 60 minutes of dwell time, allowing a short peritoneal equilibration test. Tolerance was assessed clinically and by intraperitoneal pressure (IPP) measurements at the end of each dwell test. Determination of dialysate-to-plasma ratios, and calculation of mass transfer area coefficients (K0A) using the Henderson method for urea, creatinine, and phosphate, were used to assess the impact of an increased IVP on dialytic efficiency. Increasing IVP from 800 to 1400 and thereafter to 2000 mL/m2 induced an IPP increment, respectively, from 8.4 +/- 1.4 cm (of water) to 12.1 +/- 1.4 cm and thereafter to 18.3 +/- 1.4 cm, with a positive strong linear correlation (r = 0.92; P = 0.001; IPP = 1.46 +/- 8.17(-3) IVP). In the same manner increasing IVP induced K0A increments for urea of 10.6 +/- 1.2 mL/min per m2 to 15.3 +/- 1.6 mL/min per m2 and 17.1 +/- 1.9 mL/min per m2; for creatinine of 7.9 +/- 0.09 mL/min per m2 to 11.2 +/- 0.18 mL/min per m2, and 12.3 +/- 0.21 mL/min per m2; and for phosphate of 5.2 +/- 0.08 mL/min per m2 to 6.7 +/- 0.09 mL/min per m2 and 6.6 +/- 0.07 mL/min per m2, respectively. When K0A values were normalized to the values achieved at the IVP of 1400 mL/m2, the K0A gain obtained increasing IVP from 1400 to 2000 mL/m2 was only significant for urea, peaked for creatinine, and even slowly decreased for phosphate. Moreover, a fill volume over 1400 mL/m2, which appears to be the optimal volume in terms of dialysis efficiency, was only barely tolerated with clinical signs of discomfort and an increased IPP. Therefore, in our opinion, the maximal IVP in children over the age of 2 years should be nearly 1400 mL/m2, both in terms of abdominal tolerance and in terms of urea, creatinine, and phosphate peritoneal membrane purification capacities.
Musculoskeletal manifestations, pain, and quality of life in Persian Gulf War veterans referred for rheumatologic evaluation.
OBJECTIVE: Pain in the joints and other areas has been a frequent complaint among veterans of Operation Desert Storm who are experiencing unexplained illness. We characterized the rheumatic manifestations of a group of veterans of the Persian Gulf War who were referred to a rheumatology clinic. METHODS: Consecutive South Texas veterans of the Persian Gulf War who were referred for evaluation of rheumatic manifestations underwent a comprehensive evaluation of their musculoskeletal symptoms, pain, and health related quality of life. RESULTS: Of 928 veterans evaluated in a screening clinic for unexplained symptoms, 145 had rheumatic manifestations (15.6%) and were referred to a rheumatology clinic. The most common diagnosis was fibromyalgia, present in 49 patients (33.8%), followed by various soft tissue problems in 25 (17.2%), nonspecific arthralgias in 14 (9.6%), and clinical or radiographic osteoarthritis in 16 (11.0%). In 39 patients (26.9%), no symptoms were present at the time of the evaluation, a careful musculoskeletal examination and laboratory tests were normal, and no diagnosis was possible. Two patients had Reiter's syndrome. Four had a positive rheumatoid factor and 3 had antinuclear antibodies, but none of these had clinical evidence of rheumatoid arthritis or systemic lupus erythematosus. Pain was present in nearly all patients and was widely distributed, with no body area spared in this group of patients. The most frequent painful areas were the knees in > 65%, the lower back in > 60%, the shoulders in 50%, and the hands and wrists in 35%. Widespread body pain was present in 65.1% of the veterans. Average values of all 8 scales measured by the SF-36 health survey were below the 25th percentile of published national norms, with pain and the number of nonarticular rheumatic symptoms explaining most of the decreased health related quality of life in the veterans we evaluated. CONCLUSION: No specific rheumatic diagnosis is characteristic of Gulf War veterans with unexplained illness referred to a rheumatology clinic. However, pain is common and widespread in these patients, and their health related quality of life is poor. Further research is necessary to determine the cause of the symptoms of veterans of the Gulf War.
Phosphate end dialysis value: a misleading parameter of hemodialysis efficiency. French Society for Pediatric Nephrology.
Despite low end dialysis serum phosphate levels (Pe) the control of phosphate retention remains often unsatisfactory in dialyzed patients. In order to assess the value of Pe in dialyzed children as an indicator of dialytic phosphate removal, we studied serum phosphate kinetics over the period of dialysis and post dialysis and compared these with urea kinetics. A multicenter study was conducted in the 21 French pediatric hemodialysis units and included 144 children under 15 years of age. Blood urea and phosphate concentrations were measured at the beginning, at 45 min later, at the end of dialysis, and 30 min post dialysis. At 60 min and at 360 min post dialysis measurements were made only for a subgroup of 12 children. From the serum levels, reduction ratios for urea (URR) and phosphate (PRR) and post dialysis rebound for urea (PDUR) and phosphate (PDPR) were calculated. URR (over the dialysis session, 72% +/- 9%) was higher than PRR (47% +/- 12%). Moreover, urea removal continued throughout the dialysis period, while most of the reduction in phosphate occurred in the initial dialysis period. Post dialysis urea rebound was limited to the 60th min post dialysis, whereas post dialysis phosphate rebound occurred until the 360th min post dialysis; by this time the serum phosphate levels had almost reached the predialysis levels. In summary, serum phosphate kinetics over dialysis and post dialysis periods in children appear to be misleading for the quantification of phosphate removal, i.e., phosphate clearance is a poor indicator of dialytic phosphate removal.
[Peritoneal dialysis in children].
In the recent years, continuous peritoneal dialysis (PD) had a widespread development in children. This technique is available even in infants and is adapted to home care. If initially the prescription of PD was empirical, it has nowadays improved thanks to objective approaches: intraperitoneal dwell volume and tolerance assessment by intraperitoneal pressure measurement, dwell time determination in terms of dialysis adequacy, ie APEX time as ultrafiltration and low molecular purification times. Nevertheless children home dialysis is a daily challenge for the family and requires an active and long-lasting support from the medical and paramedical team.
[Superior sagittal sinus thrombosis and nephrotic syndrome: favorable outcome with low molecular weight heparin].
BACKGROUND: Nephrotic syndrome is known to be associated with thrombosis but rarely of cerebral vessels. CASE REPORT: A 3-year old child with steroid-dependent nephrotic syndrome was hospitalized for drowziness followed by a left hemiparesis. The CTscan showed a superior sagittal sinus thrombosis. The child completely recovered after treatment by low molecular weight heparin (LMWH). CONCLUSION: LMWH could be used for preventing and/or treating thrombosis associated with nephrotic syndrome. Nevertheless, controlled studies are necessary for assessing its efficacy and absence of risk in children.
A systematic review of the evidence for hypodermoclysis to treat dehydration in older people.
BACKGROUND: The purpose of the study was to evaluate the evidence supporting the use of hypodermoclysis (i.e., subcutaneous infusion of fluids) to treat dehydrated elderly patients, and to discuss clinical applications of this mode of therapy in the long-term care setting. METHOD: Articles reporting the use of hypodermoclysis were identified using a systematic MEDLINE search between January 1966 and May 1996. Articles were included in our sample if they contained original patient data that evaluated either the efficacy or adverse effects associated with the use of subcutaneous infusions to treat dehydration in adults, whether hyaluronidase was required to facilitate the absorption of subcutaneous fluid, or if potassium could be added to the solution. RESULTS: Eighteen articles met the inclusion criteria. Since we hypothesized that adverse effects associated with hypodermoclysis may have been related largely to the use of nonelectrolyte or hypertonic solutions, the studies were evaluated according to the type of fluid administered. Six hundred and eighty-five patients were described in 13 studies evaluating the efficacy and toxicity of subcutaneously administered fluid. Four studies evaluated hypodermoclysis using electrolyte-containing solutions in 25 patients. Two of these were randomized control trials (RCT) that compared hypodermoclysis to intravenous therapy. Both reported similar absorption of fluids. In the single RCT that evaluated adverse effects, 4 of 17 patients receiving hypodermoclysis reported minor side effects similar to those reported with intravenous therapy. Adverse effects were more severe when electrolyte-free or hypertonic solutions were evaluated. Of the 639 patients who may have received electrolyte-free solutions, 16 patients (2.5%) reported adverse effects, 8 of which were severe. Both patients reported to have received hypertonic solutions noted adverse effects, one of which was severe. The use of hyaluronidase to facilitate absorption was evaluated in 74 patients. These studies suggest that hyaluronidase improves the speed of fluid absorption but may not change the patient's comfort level. A single case report of 350 subcutaneous infusions in 67 patients investigated the administration of up to 34 mmol/L of potassium chloride (KCl) by hypodermoclysis. The only adverse reaction observed was discomfort at the infusion site. CONCLUSIONS: Hypodermoclysis can be used to most safely provide fluids when electrolyte-containing fluids are administered. Hypodermoclysis may have fallen into disuse because of reports of severe adverse reactions related to infusions of electrolyte-free or hypertonic solutions that would likely be considered inappropriate today. Whether or not hyaluronidase is required to promote subcutaneous fluid absorption remains unresolved. Limited evidence suggests that potassium chloride may, with caution, be safely added to subcutaneous infusions. The majority of the available studies evaluating hypodermoclysis are of poor quality. Because of the tremendous potential benefits of administering fluid subcutaneously, there is a need for good quality studies to evaluate the efficacy of hypodermoclysis.
Human Ig heavy chain CDR3 regions in adult bone marrow pre-B cells display an adult phenotype of diversity: evidence for structural selection of DH amino acid sequences.
Ig repertoires generated at various developmental stages differ markedly in diversity. It is well documented that Ig H chain genes in human fetal liver are limited with regard to N-regional diversity and use of diversity elements. It is unclear whether these characteristics persist in pre-B cell H chain genes of adult bone marrow. Using Ig H chain CDR3 fingerprinting and sequence analysis, we analyzed the diversity of Ig H chain third complementarity determining regions (HCDR3) in adult bone marrow pre-B and mature B lymphocytes. Pre-B cell HCDR3 sequences exhibited adult characteristics with respect to HCDR3 size, distribution of N regions and usage of diversity elements. This suggested that pre-B cells in adults are distinct from fetal B cell precursors with regard to Ig H chain diversification mechanisms. At the DNA sequence level, HCDR3 diversity in mature B cells was similar to that in pre-B cells. Pre-B HCDR3s, however, frequently contained a consecutive stretch of hydrophobic amino acids, which were rare in mature B cells. We propose that highly hydrophobic pre-B HCDR3s may be negatively selected on the basis of structural limitations imposed by the antigen binding site. At the same time, usage of hydrophilic HCDR3 sequences (thought to support HCDR3 loop formation) may be promoted by positive selection.
[Diurnal and nocturnal paroxysmal dyskinesia in young children: a new entity?].
Paroxysmal dyskinesias are intermittent attacks of involuntary hyperkinetics abnormal movements. Among paroxysmal dyskinesias were individualized three entities: paroxysmal kinesigenic choreoathetosis, paroxysmal choreoathetosis of Mount and Reback, hypnogenic paroxysmal dystonia. New classifications are based upon the circumstances of occurrence, the duration of attacks and their etiology. We report here two observations of idiopathic non familial paroxysmal dyskinesias in three-year-old children. Both were seen first in consultation for falls and nocturnal motor agitation. The attacks were paroxysmal jerky "puppet-like" movements lasting from 20 seconds to 15 minutes. They could occur during non REM sleep, during the day, at rest, after a sudden movement, or during prolonged exercise. Carbamazepine was inefficient. These cases were not classifiable according to the classical criteria and could constitute a new entity. Moreover, some sleep-EEG showed abnormal patterns (frontal rapid rhythms, central spikes in one case) and led us to discuss the pathophysiology of this episodic movements disorder, and its relation with frontal partial epilepsy.
Improved dialysis dose by optimizing intraperitoneal volume prescription thanks to intraperitoneal pressure measurements in children.
An optimal intraperitoneal volume (Vip) may be the most critical and least-used option to enhance higher clearances of small solutes. A higher Vip is more effective in increasing small solute clearances when compated to a lower Vip and more frequent exchanges. Additionally, a higher Vip generates minimal intraperitoneal pressure (Pip) in the supine position. Therefore, the highest tolerated Vip should be used at night while the child is sleeping in the supine position. Therefore, in 5 children, mean age 7 years, 4 months, on continuous cyclic peritoneal dialysis (CCPD) (Baxter HomeChoice), we tested the impact of Vip on tolerance (measured by Pip) measurements, and efficiency [assessed by daily Kt/Vurea and weekly creatinine clearance (Kcreatinine]. Basal Pip was determined for the usually prescribed Vip. Then Vip was increased during a morning outpatient study day, in 30-minute stages, stepping up to an increase of 25% of the basal Pip (upper limit 18 cm of water) level reached at the so-called optimized Vip used for the prescription of an optimal total dialysate volume for a 4-week period. The latest study week was compared to the prestudy week. The optimized Vip of 1230 +/- 70 mL/m2 was significantly higher than the basal Vip, 940 +/- 90 mL/m2. The dialysis dose improved both in terms of Kt/V urea from 0.23 +/- 0.02 to 0.29 +/- 0.03 and Kcreatinine from 60 +/- 5 to 76 +/- 9 L/1.73 m2/week. The supine position allowed the 25% Pip increment from 10.2 +/- 2.5 to 12.5 +/- 3.1 cm water, without any obvious clinical side effects.
Renal stones in nephropathic cystinosis treated with phosphocysteamine.
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Gitelman's syndrome is genetically distinct from other forms of Bartter's syndrome.
In the past the term Bartter's syndrome has been used to describe a spectrum of inherited renal tubular disorders with hypokalemic metabolic alkalosis and overlapping and additional clinical and biochemical features. Pathogenesis remained uncertain until recently Gitelman's syndrome, the hypokalemic-hypomagnesemic variant with hypocalciuria, was linked to the gene encoding the thiazide-sensitive Na-Cl-cotransporter (TSC) located on chromosome 16q. Various mutations in the TSC gene were identified in patients with Gitelman's syndrome. To clarify whether different forms of hypokalemic tubular disorders (HTD) represent variable phenotypes of a common genetic defect, we performed linkage analyses in 17 families with different symptoms of HTD with four highly polymorphic chromosome 16 DNA markers closely linked to the TSC gene. Linkage of Gitelman's syndrome to the TSC locus was confirmed in our families with a maximum two-point Lod score Z = 4.70 (theta = 0.001) for marker locus D16S526. Highly negative LOD scores were obtained at this locus in our families with classic Bartter's syndrome (Z = 9.89, theta = 0.001) and hyperprostaglandin E syndrome (Z = -11.24, theta = 0.001). Our data prove that Gitelman's syndrome is genetically distinct from classic Bartter's syndrome and hyperprostaglandin E syndrome. It remains unknown if classic Bartter's syndrome and hyperprostaglandin E syndrome are caused by a common genetic defect.