Biomedical subjects
Publications and source records attributed to M Robert.
We report 3 cases of head and neck malignant fibrous histiocytoma (MFH). The first case is a xanthomatous subtype of the inferior lip with lymph node metastasis. The two others cases are storiform-pleomorphic MFM of the hypopharynx and Killian area. A summary of actual knowledges about this entity is reviewed.
Rejection continues to be a major cause of graft loss in small intestine transplantation (SIT). We have studied, by semiquantitative reverse transcriptase PCR (rtPCR), the intragraft expression of cytokines relevant to rejection in a rat model. Heterotopic SIT grafts were performed from Lewis x Brown Norway F1 donors into Lewis recipients. The isograft control was Lewis into Lewis. Five animals in each isograft and allograft group were sacrificed on POD 3, 5, 7, 8, 9, 10, 12, and 14. mRNA was isolated from portions of the terminal ileum and rtPCR performed to amplify message for interleukin-2 (IL-2), IL-2 receptor (IL-2R), interleukin-6 (IL-6), tumor necrosis factor alpha (TNF-alpha), and interferon gamma (IFN-gamma). Semiquantitative analysis was performed using 32P radionuclide incorporation and scintillation counting. The results were expressed as percent activity compared with beta-actin. Histologic correlation with cytokine expression was made. On POD 3 after SIT there was no evidence of rejection by histology and all cytokines studied showed no difference between the isograft and the allograft. On POD 5 the first evidence of mild rejection was seen on histology and IL-6, IFN-gamma, TNF-alpha showed a significant up regulation in the allograft that persisted through POD 14. mRNA for IL-2 was not significantly upregulated until POD 7 and persisted until POD 14. IL-2R was constitutively expressed in both isograft and allograft and was not a reliable predictor of rejection. Histologic rejection was moderately severe by POD 7 and severe between POD 8 and 14 correlating with the increasing expression of IL-6, IFN-gamma, and TNF-alpha. In summary, we have shown that increasing expression of mRNA for IL-6, IFN-gamma, and TNF-alpha not only correlated with severity of rejection but that upregulation began early when histologic evidence of rejection first occurred.
Membrane vesicles enriched in both ryanodine receptor and dihydropyridine receptor were obtained from rabbit skeletal muscle and solubilized with 3-[(3-cholamidopropyl)dimethylammonio]-1-propanesulfonate. Analysis of the sedimentation behavior of the solubilized proteins showed the existence of a population of alpha 1 subunits of the dihydropyridine receptor which cosedimented with the ryanodine receptor. Solubilized proteins were immunoprecipitated with antibodies directed against either the ryanodine receptor or the alpha 1, alpha 2, or beta subunits of the dihydropyridine receptor. Immunoprecipitated proteins were identified by Western blot analysis and by specific labeling with [3H]ryanodine or [3H]PN200-110. Immunoprecipitation of the solubilized proteins with antibodies directed against the dihydropyridine receptor led to the coimmunoprecipitation of the ryanodine receptor. Conversely, immunoprecipitation with antibodies directed against the ryanodine receptor led to an immune complex containing both receptors, but these antibodies were unable to precipitate purified dihydropyridine receptor. These results demonstrate that ryanodine receptor and dihydropyridine receptor are present in the triad membrane preparation in a complex which may play an important role in excitation-contraction coupling.
The placement of stents has been proposed as a possible modality to treat pancreatic diseases. Ductal changes observed on endoscopic retrograde cholangiopancreatography during stenting are believed to be reversible when the stents are removed. We describe a patient with normal anatomy on baseline pancreatograms who underwent endoscopic sphincterotomy, followed by stent placement for 9 months. Symptoms progressed, leading to a pancreaticoduodenectomy. Histologic evaluation of the head of the pancreas revealed more extensive inflammatory changes in the duct and parenchyma drained by the stent. This suggests that stent-induced changes noted on pancreatography correspond to parenchymal changes that may be severe and irreversible.
Anticholinergic adverse-effects in children treated with conventional doses of oxybutynine led us to measure plasma oxybutynine levels in children. 18 children, aged 5 to 13 y, who required treatment with oxybutynine chloride for daytime incontinence were studied. Plasma concentrations were measured on the fifth day of a course of treatment in which the dose was adapted to the child's body weight; the dose was given twice daily at 12-hour intervals. In 10 children aged between 5 and 8 y, the mean dose was 0.1 mg.kg-1. In 8 children aged between 10 and 13 years, the mean dose was 0.15 mg.kg-1. The highest concentration was usually found between 1 and 2 h after administration. The subsequent fall in concentration was rapid and after 6 h oxybutynine was no longer measurable in 14 of the children. The concentrations found were not different from those seen in adults given equivalent doses. The results show that plasma concentrations in children were not very different from those observed in adults if the dose were adapted to the body weight of the children. No special differences in paediatric use were revealed that might explain the particular adverse-effects. The results of the study argue against the dosage regimen proposed before these adverse events were detected. They strongly favour a dose adapted to the body weight of the child, with a 12-hour interval between doses.
Culture of keratinocytes on a noncoated porous synthetic membrane maintained at the air-liquid interface allows the establishment of a fibroblast/keratinocyte co-culture, without direct cell-cell contact between the two cellular layers. The influence of fibroblasts (proliferating, confluent or blocked by mitomycin C) on epidermization (i.e., expression of integrins and markers of epidermal differentiation) was studied by immunohistochemistry in two culture media. In the medium supplemented with FCS or Ultroser G and in the absence of fibroblasts, alpha 2, alpha 3, alpha 5 and alpha 6 subunits of integrins are expressed by the basal keratinocytes, except alpha 5 which does not appear with the medium supplemented with Ultroser G. During stratification, the alpha 3 subunit is the only one to persist on suprabasal cells and all the markers of epidermal differentiation studied (filaggrin, involucrin, transglutaminase, keratins K1/K10) are expressed at the 14th day of emerged culture. The presence of fibroblasts modifies the expression profile of integrins: when they are proliferative, the expression of alpha 2 and alpha 6 chains is delayed in the medium supplemented with FCS, and the alpha 6 chain is absent in the medium supplemented with Ultroser G; when they are confluent or blocked by mitomycin C, greater changes are observed only in the medium supplemented with Ultroser G and lead to inhibition or delay of the expression of alpha 2 and alpha 6.(ABSTRACT TRUNCATED AT 250 WORDS)
The present experiment studied horizontality representation among men and women performing the water-level task either in visual conditions (the subjects saw outlines of tilted containers in which they respectively drew or set the water line) or in partially and totally haptic conditions (respectively, the subjects both saw and felt or merely felt the contours of the containers cut out of metal plates, and positioned a rod on the underside of the plates to indicate the water line). It was expected that, as the visual components of the setting were replaced by haptic ones, a reduction of the typical gender difference in proficiency would ensue. It was found that men surpassed women under visual conditions, whereas both genders were equivalent in haptic conditions. There were no gender or condition differences in a control task in which a line had to be placed horizontally in tilted containers. Forced reliance on proprioceptive cues among both men and women under the totally haptic condition was contrasted with the critical role played in visual conditions by visual references; those used by men were correct, whereas the ones used by women were incorrect.
In the water-level task, it has been repeatedly shown that, compared with men, women more often fail to represent the surface of a liquid as horizontal regardless of the tilt of the container. An attempt was made to reduce this robust gender gap through the manipulation of relevant upright references conveyed both by the position of the stimuli and the posture of the subject. It was reasoned that bringing the women to focus on such gravitational references through postural adjustment might help their performance equal that of men, thus shedding some light on the nature of the difficulty they experience in the standard setting. A lesser effect was anticipated among men. However, the results showed that, even after controlling for proficiency in the correlated visuospatial situation of the rod-and-frame test, the performance of men always surpassed that of women. Irrespective of gender, water-level representation on vertical sheets was unaffected by the subject's posture, whereas it improved when horizontal sheets were coupled with the most unstable posture. Whereas the persistence of the yet-unaccounted-for gender difference was underscored, the contributions of visual and postural cues issued at arm and full-body levels were discussed.
Human seminal plasma contains a protein factor that has the capacity to inhibit the movement of demembranated and intact spermatozoa. This factor 'seminal plasma motility inhibitor' (SPMI) has been shown to originate exclusively from the seminal vesicles. The present results demonstrate that the biological activity of SPMI in semen decreases rapidly from 1000 U/ml, immediately after ejaculation, to 220 U/ml 2 h later. Immunoblots of seminal plasma proteins probed with an antibody against human SPMI, revealed the rapid processing of a predominant 52 kDa SPMI antigen, present in the seminal vesicle secretions. This precursor was degraded initially into intermediate molecular mass fragments of 25-40 kDa, and subsequently into smaller fragments of 17-21 kDa. When seminal vesicle fluid was mixed with prostatic secretions (3:1 v/v), proteases present in prostatic secretions were shown to be responsible for processing of the SPMI precursor. Addition of protease inhibitors such as phenylmethylsulphonyl fluoride (PMSF, 5 mM), benzamidine (100 mM) or ethylenediaminetetraacetic acid (EDTA, 5 mM) to the mixture of seminal vesicle and prostate secretions partially prevented the loss of activity of SPMI by 54%, 27% and 9%, respectively. However, the simultaneous addition of PMSF and benzamidine conferred almost total stability to the SPMI precursor activity. These results demonstrate that SPMI exists as a predominant 52 kDa precursor form in the seminal vesicles and is processed rapidly after ejaculation into less active, lower molecular mass forms by one or more serine proteases and/or metalloproteases of prostatic origin which are present in liquefied semen.
OBJECTIVE: To produce an index of lithogenic risk which identifies patients at risk of stone recurrence and facilitates the monitoring of prophylactic treatments. PATIENTS AND METHODS: The EQUIL2 program provides an evaluation of the state of urinary saturation, particularly of calcium oxalate, based on the pH and total concentrations (mmol/l) of sodium, potassium, calcium, magnesium, uric acid, chloride, ammonium, citrate, phosphate, sulphate, oxalate, pyrophosphate and carbon dioxide. The morning urinary calcium oxalate saturation coefficient was thus calculated for 30 stone-formers (Group 1) and 30 normal control subjects (Group 2). RESULTS: Urine from the majority of individuals was saturated, with no significant difference between the two groups. There appeared to be a correlation between the state of saturation and the urinary calcium oxalate molar product in both stone-formers (r = 0.931) and controls (r = 0.914). CONCLUSION: In future studies on urinary calcium oxalate saturation, it should be possible to supplement the sophisticated coefficient determined by the EQUIL2 program with the molar product, except in cases where monitoring therapies have little or no effect on urinary oxalate or urinary calcium levels.
OBJECTIVE: To evaluate the circadian fluctuations in the risk of urinary calcium oxalate stone formation with regard to critical periods of crystallization. PATIENTS AND METHODS: Over a given time period, the Tiselius index depends on urine volume and urinary excretion of oxalate, calcium, citrate and magnesium. This crystallization potential was evaluated during three successive periods spread over 24 h for 25 recurrent stone-formers aged 16-76 years (mean 50) and 25 control subjects aged 27-71 years (mean 44). RESULTS: There was no significant difference in the value of the Tiselius index for all equivalent time periods in both groups of patients. The minimum value was recorded in the afternoon and the circadian pattern of the index illustrated the predominant importance of urinary output in its determination. Morning urinary concentrations and excretions of citrate, and nocturnal levels of magnesium were significantly higher in the stone-formers when compared with the control subjects. CONCLUSION: The lithogenic risk for calcium oxalate stones was maximal at the end of the night or during the early morning, when urinary output was minimal. This circadian study revealed abnormalities that are not apparent from non-fractionated 24 h urine samples, and which were potentially relevant to therapy.
The passive extension of relaxed hip adductor muscles was measured in 20 normal children and 10 children (aged nine to 13 years) with cerebral palsy (CP) by a method that could distinguish between shortening of the muscle body and tendon. No muscle-body contracture occurred in the children with CP during treatment (physiotherapy plus moderate stretching on an apparatus for six hours a day); only the tendons were short. However, four children showed signs of muscle-body contracture after interrupting treatment for six to eight weeks. It is possible that muscle-body contracture can be prevented by non-surgical methods, although tendon shortening can, at present, only be treated surgically.
A prospective study was undertaken to evaluate the efficacy of (sodium) cromoglycate in the treatment of persistent wheezing in 31 children between 4 and 12 months of age. The subjects were randomised to receive either 40 mg of cromoglycate (n = 16) or physiological saline as placebo (n = 15) three times a day by wet nebulisation in a double blind fashion for a period of six weeks. The patients were evaluated with daily symptom scores and respiratory function testing measuring maximal expiratory flow at functional residual capacity (VmaxFRC) before initiating treatment and upon completion. At baseline, mean (SD) symptom scores between the two groups were comparable (cromoglycate 99.5 (29.8), placebo 104.5 (29.7)) as were VmaxFRC expressed as per cent of predicted normals (cromoglycate 48 (28), placebo 46 (20)). Upon completion of the treatment protocol, no significant difference could be found between the two groups for either symptom score (cromoglycate 67.6 (40.2), placebo 58.6 (41.4)), or VmaxFRC (cromoglycate 52 (24), placebo 60 (32)). It is concluded, therefore, that 40 mg of cromoglycate three times a day administered via facemask and wet nebulisation was no more effective than placebo in the treatment of our sample of persistently wheezing infants under 1 year of age.
From May 1992 to October 1993, 150 ureteral stones, impervious to piezoelectric extracorporeal shock wave lithotripsy (ESWL) with ultrasound localization (EDAP LT.01), were treated with the Lithoclast. The maximum dimensions varied from 5 to 25 mm with a mean of 11 mm. 46 calculi were situated in the pelvic ureter, 82 in the abdominal ureter, and 22 were stuck in the ureteropelvic junction. There was no complete failure of fragmentation, but 39 abdominal calculi (48%) required additional treatment by ESWL due to migration of the fragments into the calyces. Apart from a few needle-sized perforations, ureteral tissue was not damaged by the Lithoclast. The use of this endoscopic lithotripter, which is highly efficient and painless, is, however, limited by the significant effect of retrograde propulsion of very mobile stones or fragments in the urinary tract.
INTRODUCTION: Melanoma is rare in children. We report a new case. CASE REPORT: A black tumor on the medial aspect of the right thigh was removed at the age of 5 years. Histologic diagnosis was melanoma. One year later, a metastasic inguinal lymph node appeared in the right inguinal fold. Exeresis with curetage was performed followed with chemotherapy. Outcome has been favourable to date. DISCUSSION: The diagnosis of melanoma is difficult in children and is usually mistaken. In this case, the histologic diagnosis appears to have been exact and chemotherapy was performed. The rationale and modalities have been discussed.
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INTRODUCTION: Restricted passive hip abduction in children with cerebral palsy (CP) may be caused by uninhibited resting contractions and/or retractions, i.e., shortened muscle body or tendons. Pathological short tendons require surgical intervention, but lack of muscle body elasticity responds to physiotherapy or a postural splinting. Clinical examination can distinguish between short tendons and short muscle body. The thigh is slowly and passively extended while palpating the tendon. Tension is detected in the tendon when the leg is at angle Ao. The elastic tension of the muscle body then increases until no further movement is possible, at angle Amax. The difference Amax-Ao is an index of the structural length of the muscle body. If this difference is reduced during passive straightening there is shortening of the muscle body; if it is displaced it indicates shortening of the tendon. The value Ao indicates the muscular or tendon origin of the retraction for a given passive limitation (Amax). This study defines the physiological values of Ao and the relative precisions of chemical and instrumental measurements. MATERIALS AND METHODS: A total of 30 children aged 9-11 years, 10 CP patients (7 girls and 3 boys, mean age 10.3 years) and 20 controls (11 girls and 9 boys, mean age 10.5 years) were studied. All the CP children had lower limb spasticity and adopted an adduction posture. None had undergone hip muscle surgery. Ao and Amax were measured clinically with a goniometer and EMG to monitor muscle silence, and experimentally using a deformable parallelogram and force transducers. RESULTS: The minimum physiological value of Ao was 8 degrees with the knee flexed and 0 degree with the knee extended. Smaller values of this angle indicated tendon retraction. The difference between Ao and Amax in the controls and CP children was < or = 10 degrees; the reproducibilities of the clinical measurement of Ao and Amax were very similar. DISCUSSION: Clinical examination provides an acceptably accurate method of distinguishing between tendon and muscle body retraction of adductor muscles in CP children. The conditions required for successful measurement are: careful examination with strict positional reference and sufficiently relaxed pelvic muscles. A hip extension angle Ao of less than 8 degrees with the knee flexed or 0 degree with the knee straight indicates tendon retraction requiring tendon surgery, otherwise, the retraction involves only the muscle body. This reduced elasticity can be overcome by prolonged extension (at least 6 hours/24). Effective muscle extension may be hindered by non-suppressed adductor contractions. This must be overcome prior to physiotherapy by surgery of the ramus ant. n. obturatorii. CONCLUSION: Clinical measurement of Ao of adductor muscles is a reliable way of distinguishing between tendon retractions requiring surgery and muscle body retractions resulting from staying too long in a position with the muscle shortened. This muscle body shortening can be due to lack of physiotherapy or a stretching apparatus treatment, pathological contractions, or compensation for disorders of the controlateral limb.
Endo-urological techniques and extracorporeal shock waves lithotripsy (ESWL) have dramatically improved the management of urolithiasis in children. ESWL has been shown to be safe and effective, achieving a stone clearance rate up to 85% with minimal short-term morbidity, and this non-invasive method has become the first-line treatment for most upper urinary tract calculi in children. However, it long-term effects on kidney function and growth remain unknown, and its repeated use should therefore be restricted. Endo-urological techniques, mainly percutaneous procedures and ureteroscopy, and surgical procedures, are only indicated for large multiple stones, or secondary stones needing simultaneous treatment of an underlying uropathy.