Biomedical subjects
Publications and source records attributed to P Petit.
We report a case of an incidentally diagnosed apparently isolated splenosis nodule located in the hepatorenal peritoneal recess. According to imaging features, this mass was a non-renal retroperitoneal tumor. In spite of the isolated location, the history of splenic rupture should have led to a heat-damaged red blood cell scintiscan and would thus have avoided percutaneous biopsy.
We present genotype-phenotype correlations in two patients with distal 10q deletion. A patient with a small terminal deletion presented mild mental retardation and behavioral difficulties with hyperactivity, whereas the patient with a larger deletion, had multiple congenital anomalies and moderate mental retardation. Our observation confirms the previous suggestion that larger deletions of distal chromosome 10q are associated with a more severe clinical presentation, whereas hyperactive behavior may be a specific feature of small terminal deletions of chromosome 10q26.
PURPOSE: Invasive haemodynamic monitoring during general anaesthesia in infants is usually limited to very high risk operations, such as cardiac surgery. Nevertheless, different surgical procedures and/or anaesthetic techniques justify additional monitoring for children, as for adults. The aim of this preliminary study was to evaluate the feasibility of using a new echo-Doppler device (Dynemo 3000) capable of measuring continuous aortic blood flow during general anaesthesia in infants. METHODS: Aortic blood flow (ABF) was measured with a small oesophageal probe designed for newborns and infants. The aortic flowmeter was connected with satellite devices to visualise the haemodynamic profile which included ABF, pre-ejection period (PEPi), left ventricular ejection time (LVETi), mean arterial pressure, heart rate, stroke volume and systemic vascular resistance. Twelve infants, aged 8-26 mo, undergoing surgery under general anaesthesia were successively included in the evaluation of this device. Isoflurane (1% end-expired concentration) was introduced to maintain anaesthesia after induction with halothane, midazolam, fentanyl and atracurium. RESULTS: Correct positioning of the probe was easily obtained in all cases and the recording quality was excellent, whatever the operative position. Recordings of haemodynamic data showed some myocardial depression from isoflurane: decreased ABF (indexed to body surface area) and lengthened PEP/LVET (2.24 +/- 0.53 L.min-1.m-2 and 0.32 +/- 0.05 respectively, before introduction of isoflurane and 1.71 +/ 0.53 L.min-1.m-2 (P = 0.027) and 0.39 +/- 0.06 (P = 0.007) with isoflurane). CONCLUSION: These preliminary results suggest that this continuous ABF echo-Doppler device may be valuable for peri anaesthetic monitoring in infants.
OBJECTIVE: To describe the imaging findings of vascularized fibular grafts (VFG) in large bone reconstruction in children and teenagers. DESIGN AND PATIENTS: Fifteen patients aged from 4 to 19 years underwent VFG for bone reconstruction for primary tumors involving bone in 13 cases and for chronic osteomyelitis in 2 cases. Lesions were located in the femur (6 cases), the tibia (6 cases), the humerus, the distal fibula and the ilium. Radiographic follow-up was performed in all patients, radionuclide studies in 12 patients and MRI in 8. RESULTS: Plain films showed a lamellated periosteal reaction on the VFG within 3 weeks following the procedure in all cases. Fusion of VFG and host bone occurred during the first 3 months. Radionuclide uptake of the VFG was seen in all cases but one. MRI showed cortical thickening and conservation of the high signal intensity of fatty marrow on T1-weighted sequences, and periosteal enhancement on dynamic post-contrast studies in all but one of the patients. CONCLUSION: Radionuclide studies and MRI show the periosteal enhancement and assess the viability of the VFG satisfactorily. However, we feel that plain films may be sufficient to ascertain this viability.
The mechanism(s) for the origin of jumping translocations (JTs) are unknown. To assess the possible involvement of telomeric sequences in the jumping process, metaphases of a patient with hydrops fetalis having a JT were analyzed for the presence of interstitial telomeres. Telomere DNA sequences were detected at the junction sites of the donor and the recipient chromosomes. Interstitial telomeric sequences have so far only been detected in JTs involving chromosome 15q in patients with Prader-Willi syndrome. Our finding of interstitial telomeric sequences in a JT with a chromosome different from chromosome arm 15q in a patient without Prader-Willi syndrome implies that telomere sequences may be common to all telomeric JTs. The possible role of telomeric sequences as a cause of the observed chromosomal mosaicism is discussed.
The correlation between haemodynamic and oxymetric parameters, and circulating cytokines has been little studied for the early phase of extensive burns. The aim of this prospective study was to evaluate survival, looking at variations in cardiac index (CI), oxygen delivery (DO2I) and consumption (VO2I) indexed to the body surface area (BSA), and circulating interleukin-6 (IL6) levels in the acute stage of major burns. Over a 12-month period, all patients admitted within 6 h of extensive thermal injury with total burn surface area (TBSA) of over 60 per cent, necessitating standardized resuscitation and mechanical ventilation, were included. Routine intensive care monitoring, including pulmonary and femoral artery catheters, was set up. During the first 3 days post-injury haemodynamic and oxymetric profiles were recorded every 6 h. Circulating IL6 samples were taken within 6 h of admission, then daily (at 24, 48 and 72 h). A comparison of the results in survivors (S) and non-survivors (NS) at those previously determined times was made. Ten consecutive patients were studied. Six patients survived (Age = 33 +/- 10 years; TBSA = 76 +/- 11 per cent) and four died (Age = 40 +/- 14 years; TBSA = 77 +/- 13 per cent). Similar initial hypovolemic profiles were found in both groups. From 24 h, a hyperdynamic status was observed which increased until 72 h. This hyperkinetic evolution was more marked in the survivors (CI: 4.6 +/- 2.0 for NS and 6.9 +/- 1.51 min-1 m-2 for S; SVRI: 2125 +/- 1288 for NS and 918 +/- 232 dyne s cm-5 m2 for S at 72 h). DO2I and VO2I were always higher in the survivors. DO2I and VO2I increased from admission to 72 h in the survivors whereas a significant drop in DO2I and VO2I occurred in the non-survivors at 48 h (DO2I:536 +/- 222 for NS and 1228 +/- 268 ml min-1 m-2 for S; VO2I:120 +/- 50 for NS and 251 +/- 56 ml min-1 m-2 for S (P < 0.01)). Plasma IL6 revealed abnormal values with consistent peaks at 24-48 h in the survivors (respectively 17,411 +/- 24,542 and 10,746 +/- 11,802 pg ml-1) and only moderate peaks in the non-survivors (865 +/- 652 and 912 +/- 485 pg ml-1). Finally, CI, DO2I, VO2I and circulating IL6 were always higher, and SVRI lower, in the survivors than in the non-survivors. The ability to increase DO2 and to optimize VO2 during the 'turning point' of 48 h seems to improve the prognosis of critically burned patients: the role of IL6 in this systemic inflammatory response is discussed.
1. Epidemiological and experimental data have shown that homocysteine may provoke vascular lesions and that moderate homocysteinaemia may constitute an independent risk factor for vascular disease. It is now documented that homocysteine damages human endothelial cells in culture, possibly by producing hydrogen peroxide in an oxygen-dependent reaction. 2. In this study, we have examined the direct effect of this sulphur amino acid on pancreatic vascular resistance. Experiments were performed on the vascular bed of the rat isolated pancreas perfused at constant pressure; thus, any change in pancreatic vascular resistance resulted in a change in the flow rate. D,L-Homocysteine perfused for one hour at three different concentrations (200 microM, 2 mM, 20 mM) did not induce any significant change in the flow rate per se. Homocysteine infusion for 30 min at a concentration of 200 microM or 2 mM abolished the endothelium-dependent vasodilatation induced by acetylcholine (0.05 microM), but did not modify adenosine (1.5 microM)-induced vasodilatation. 3. The effect of D,L-homocysteine (200 microM or 2 mM) cannot be ascribed to a direct antimuscarinic effect since 30 min pretreatment of rat ileum with these concentrations did not significantly change the contractile effect of increasing concentrations of acetylcholine (0.015-15 microM). 4. Preincubation of human umbilical vein endothelial cells with D,L-homocysteine (0.2-5.0 mM) had no significant effect on overall cell number or viability during 18 h of incubation; the endothelial cells exposed to concentrations up to 5 mM exhibited a spindle-shaped, whirled pattern. This pattern was reversed 48 h after the removal of homocysteine. A cytotoxic effect was seen after 18 h incubation in 10 mM D,L-homocysteine. 5. In conclusion, an acute infusion of homocysteine altered acetylcholine endothelium-induced vasodilation, whereas the adenosine vasodilatator effect was insensitive to the deleterious action of homocysteine in vitro.
All human X-linked genes known so far, except for the Xp/Yp pseudoautosomal genes, are conserved as a single linkage group on the murine X chromosome. We show that the interleukin-9 (IL-9) receptor gene (IL9R), which is located within the human Xq/Yq homology region, maps to the murine chromosome 11. The Xq/Yq pseudoautosomal region (Xq PAR) thus represents a second region on the human X chromosome which is not X linked in mice. Furthermore, we show that IL9R is absent on the Y of great apes. IL9R is thus exceptional among X/Y genes in that it is X linked in some mammals, but autosomal or pseudoautosomal in others. Genes located on the X and the Y generally escape X inactivation. An exception to this rule is SYBL1, a gene located in Xq PAR. SYBL1 is X inactivated and is inactive on the Y chromosome. In contrast, we show that IL9R expression does occur from the Y, the active and the inactive X chromosomes. This finding raises the question of how the transcriptional regulation of genes within Xq PAR occurs and how the X inactivation status of IL9R has evolved following the autosome to X and the X to X/Y translocation. The evolutionary analysis of the IL9R gene, which is located at 10 kb from the telomere, and its pseudogenes at several telomeres, also provides insight into the evolution of these loci and of subtelomeric regions in general.
Adenosine tri- and diphosphate (ATP and ADP) and their structural analogues stimulate insulin secretion from the isolated perfused rat pancreas, an effect mediated by P2Y-purinoceptor activation. Concerning the base moiety of the nucleotide, it was previously shown that purine but not pyrimidine nucleoside triphosphates were active and that substitution on purine C2 with the 2-methylthio group greatly enhanced the potency. In this study, we further analyze the consequences of ribose and polyphosphate chain modifications. Modifications in 2' and 3' position on the ribose led to a decrease in insulin response when bulky substitutions were made: indeed, 2'-deoxy ATP was similar in activity to ATP, whereas arylazido-aminopropionyl ATP (ANAPP3) was weakly effective and trinitrophenyl ATP (TNP-ATP) was inactive. Substitution on the gamma phosphorus of the triphosphate chain led to a decrease (gamma-anilide ATP) or no change (gamma-azido ATP) in potency; the replacement of the bridging oxygen between beta and gamma phosphorus by a peroxide group did not significantly change the activity, whereas substitution by a methylene group completely abolished stimulation of insulin secretion. As for the phosphorothioate analogues, adenosine-5'-O-(3-thiotriphosphate) (ATP gamma S) induced an insulin response similar to that produced by ATP, whereas adenosine-5'-O-(2-thiodiphosphate) (ADP beta S) was about 100-fold more potent than ATP, as previously shown. In conclusion, two structural features seem to have a strategic importance for increasing the insulin secretory activity of ATP analogues: substitution at the C2 position on the adenine ring of ATP and modifications of the polyphosphate chain at the level of the beta phosphorus.
We report a patient with Prader-Willi syndrome (PWS) and mosaicism for a de novo jumping translocation of distal chromosome 15q, resulting in partial trisomy for 15q24-qter. A maternal uniparental heterodisomy for chromosome 15 was present in all cells, defining the molecular basis for the PWS in this patient. The translocated distal 15q fragment was of paternal origin and was present as a jumping translocation, involving three different translocation partners, chromosomes 14q, 4q, and 16p. The recipient chromosomes appeared cytogenetically intact and interstitial telomere DNA sequences were present at the breakpoint junctions. This strongly suggests that the initial event leading to the translocation of distal 15q was a non-reciprocal translocation, with fusion between the 15q24 break-point and the telomeres of the recipient chromosomes. These observations are best explained by a partial zygotic trisomy rescue and comprise a previously undescribed mechanism leading to partial trisomy.
BACKGROUND: Models of sex therapy for sexual dysfunction in single men are available, but their value is not well established. This controlled study compared three approaches to the treatment of sexually dysfunctional single men. METHOD: Sixty-nine single men diagnosed as sexually dysfunctional were randomly assigned to treatments focusing on either their sexual dysfunction, their interpersonal problems, a combination of both or a waiting list; 51 completed treatment and 50 the one-year follow-up. Treatment was administered in small groups in 15 weekly sessions and four six-weekly sessions during the first six months of a year-long follow-up. RESULTS: No clinically meaningful change was observed during the waiting period. In contrast, a significant and equivalent improvement was observed in all treatment groups by the end of treatment. However, differences between them were in evidence at 6 and 12 months' follow-up. CONCLUSIONS: Both treatments paying attention to the patients' interpersonal difficulties resulted in significantly better outcomes overall than the approach that concentrated on problems in sexual functioning alone.
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The diagnosis of a metastatic kidney tumor arising in a 2-month infant is discussed between atypical mesoblastic nephroma and clear cell sarcoma. The precocity of distant metastases, their location in bone marrow, liver and thoracic soft tissues, and their association with myelofibrosis set up an original clinical presentation which seems to have never been described elsewhere. Treatment strategy with surgery of the primary followed by a polychemotherapy combining vincristin-etoposide-ifosfamide and the short term follow-up are reported.
Focal cartilaginous dysplasia is a rare condition associated with unilateral tibia vara in young children. The authors report 2 cases. In one patient spontaneous correction occurred at the age of 18 months. In the other case the patient's deformity persisted, and an osteotomy was performed at the age of 36 months. Through these 2 cases and 26 cases of the literature, the authors discuss the healing process and etiology. The most likely exploration is an abnormal development at the insertion of the pes anserinus inducing epiphysiodese like effect. In most cases, the growth plate of the proximal tibial appears to correct the deformity. Surgical correction is necessary after the age of 36 months, if the angular deformation is up to 30 degrees of varus.
We reexamined a moderately mentally retarded patient with mild dysmorphism previously described with de novo 47,XY, del(2)(p11;p21), +acefr. Using fluorescence in situ hybridization (FISH), we now confirm the chromosome 2 nature of the extra marker resulting from interstitial deletion of del(2)(p11;p21) as well the lack alpha satellite DNA pattern. The authors suggest that a reactivation process of a latent centromere may explain the origin of this stable extra marker.
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