SMARCA4-deficient rhabdoid tumours show intermediate molecular features between SMARCB1-deficient rhabdoid tumours and small cell carcinomas of the ovary, hypercalcaemic type

Extracranial rhabdoid tumours (ECRTs) are an aggressive malignancy of infancy and early childhood. The vast majority of cases demonstrate inactivation of SMARCB1 (ECRT_SMARCB1 ) on a background of a remarkably stable genome, a low mutational burden, and no other recurrent mutations. Rarely, ECRTs can harbour the alternative inactivation of SMARCA4 (ECRT_SMARCA4 ) instead of SMARCB1. However, very few ECRT_SMARCA4 cases have been published to date, and a systematic characterization of ECRT_SMARCA4 is missing from the literature. In this study, we report the clinical, pathological, and genomic features of additional cases of ECRT_SMARCA4 and show that they are comparable to those of ECRT_SMARCB1. We also assess whether ECRT_SMARCB1 , ECRT_SMARCA4 , and small cell carcinomas of the ovary, hypercalcaemic type (SCCOHT) represent distinct or overlapping entities at a molecular level. Using DNA methylation and transcriptomics-based tumour classification approaches, we demonstrate that ECRT_SMARCA4 display molecular features intermediate between SCCOHT and ECRT_SMARCB1 ; however, ECRT_SMARCA4 appear to be more closely related to SCCOHT by DNA methylation. Conversely, both transcriptomics and DNA methylation show a larger gap between SCCOHT and ECRT_SMARCB1 , potentially supporting their continuous separate classification. Lastly, we show that ECRT_SMARCA4 display concomitant lack of SMARCA4 (BRG1) and SMARCA2 (BRM) expression at the protein level, similar to what is seen in SCCOHT. Overall, these results expand our knowledge on this rare tumour type and explore the similarities and differences among entities from the 'rhabdoid tumour' spectrum. © 2021 The Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

Nationwide incidence of sarcomas and connective tissue tumors of intermediate malignancy over four years using an expert pathology review network

BACKGROUND

Since 2010, nationwide networks of reference centers for sarcomas (RREPS/NETSARC/RESOS) collected and prospectively reviewed all cases of sarcomas and connective tumors of intermediate malignancy (TIM) in France.

METHODS

The nationwide incidence of sarcoma or TIM (2013-2016) was measured using the 2013 WHO classification and confirmed by a second independent review by expert pathologists. Simple clinical characteristics, yearly variations and correlation of incidence with published clinical trials are presented and analyzed.

RESULTS

Over 150 different histological subtypes are reported from the 25172 patients with sarcomas (n = 18712, 74,3%) or TIM (n = 6460, 25.7%), with n = 5838, n = 6153, n = 6654, and n = 6527 yearly cases from 2013 to 2016. Over these 4 years, the yearly incidence of sarcomas and TIM was therefore 70.7 and 24.4 respectively, with a combined incidence of 95.1/106/year, higher than previously reported. GIST, liposarcoma, leiomyosarcomas, undifferentiated sarcomas represented 13%, 13%, 11% and 11% of tumors. Only GIST, as a single entity had a yearly incidence above 10/106/year. There were respectively 30, 64 and 66 different histological subtypes of sarcomas or TIM with an incidence ranging from 10 to 1/106, 1-0.1/106, or < 0.1/106/year respectively. The 2 latter incidence groups represented 21% of the patients with 130 histotypes. Published phase III and phase II clinical trials (p<10-6) are significantly higher with sarcomas subtypes with an incidence above 1/106 per.

CONCLUSIONS

This nationwide registry of sarcoma patients, with exhaustive histology review by sarcoma experts, shows that the incidence of sarcoma and TIM is higher than reported, and that tumors with a very low incidence (1<106/year) are less likely to be included in clinical trials.

Tibial post fracture pain is reduced in kinin receptors deficient mice and blunted by kinin receptor antagonists

BACKGROUND

Tibial fracture is associated with inflammatory reaction leading to severe pain syndrome. Bradykinin receptor activation is involved in inflammatory reactions, but has never been investigated in fracture pain.

METHODS

This study aims at defining the role of B1 and B2-kinin receptors (B1R and B2R) in a closed tibial fracture pain model by using knockout mice for B1R (B1KO) or B2R (B2KO) and wild-type (WT) mice treated with antagonists for B1R (SSR 240612 and R954) and B2R (HOE140) or vehicle. A cyclooxygenase (COX) inhibitor (ketoprofen) and an antagonist (SB366791) of Transient Receptor Potential Vaniloid1 (TRPV1) were also investigated since these pathways are associated with BK-induced pain in other models. The impact on mechanical and thermal hyperalgesia and locomotion was assessed by behavior tests. Gene expression of B1R and B2R and spinal cord expression of c-Fos were measured by RT-PCR and immunohistochemistry, respectively.

RESULTS

B1KO and B2KO mice demonstrated a reduction in post-fracture pain sensitivity compared to WT mice that was associated with decreased c-Fos expression in the ipsilateral spinal dorsal horn in B2KO. B1R and B2R mRNA and protein levels were markedly enhanced at the fracture site. B1R and B2R antagonists and inhibition of COX and TRPV1 pathways reduced pain in WT. However, the analgesic effect of the COX-1/COX-2 inhibitor disappeared in B1KO and B2KO. In contrast, the analgesic effect of the TRPV1 antagonist persisted after gene deletion of either receptor.

CONCLUSIONS

It is suggested that B1R and B2R activation contributes significantly to tibial fracture pain through COX. Hence, B1R and B2R antagonists appear potential therapeutic agents to manage post fracture pain.

A three-gene signature to predict survival in pediatric osteosarcoma (OS) to follow patients toward liquid biopsy: A collaborative work in OS2006 protocol

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Background: The survival of pediatric OS is stable worldwide since two decades. The management of OS is lacking new approaches to classify closely the patients and adapt thereafter the treatments. The objectives of our molecular study, using allelotyping, quantitative PCR (qPCR) and droplet digital PCR (ddPCR), were to determine the survival impact of tumor molecular profiling in the initial tumor biopsy, in the tumor resection after neoadjuvant chemotherapy and on circulating DNA at different treatment steps. The gene panel based on biomarkers of bone dedifferentiation was already identified in the large tumor cohort of the French national protocol OS94 and demonstrated a significant prognostic impact of 3 genes MET, TWIST and APC. To go further and understand its significance throughout protocols, the same study was performed in OS2006 tumors. Methods: We applied retrospectively in the cohort of OS2006 protocol (135 patients) the same molecular assessment comprising the targeting of those 3 genes with 3 techniques evaluating their rearrangement by allelotyping, their copy number variations by qPCR and ddPCR. A preliminary cohort of 20 patients with liquid biopsies at diagnosis, before tumor surgery and at the end of chemotherapy was screened by ddPCR. Results: We were able to determine frequent rearrangements in the regions containing these 3 genes and a statistically significant correlation was made between the presence of a gene rearrangement and a worst outcome. The 3-gene signature was significantly predicting the outcome of more than 85% of patients diagnosed for an OS. Furthermore, the persistence of those genes’ rearrangements in the primitive tumor after neoadjuvant chemotherapy comparatively to the initial biopsy was correlated to a higher risk of relapse. This 3-gene signature was also used for assessment of residual disease (RD) in liquid biopsies and was able to determine before tumor surgery the level of RD. Conclusions: This molecular signature seems to be clearly associated with patient outcome and was able to provide evidence that this approach is a powerful tool to be used in pediatric OS follow up to determine early relapse or progression.

[Histological diagnosis of bone tumors: Guidelines of the French committee of bone pathologists reference network on bone tumors (RESOS)]

The management of patients having a bone lesion requires in many cases the realization of a histological sample in order to obtain a diagnosis. However, with the technological evolution, CT-guided biopsies are performed more frequently, often in outpatient clinics. Interpretation of these biopsies constitutes new challenges for the pathologists within the wide spectrum of bone entities. The purpose of the document is to propose guidelines based on the experience of the French committee of bone pathologists of the reference network on bone tumors (RESOS) regarding the indications and limitations of the diagnosis on restricted material.

The AF-1-deficient estrogen receptor ERα46 isoform is frequently expressed in human breast tumors

BACKGROUND

To date, all studies conducted on breast cancer diagnosis have focused on the expression of the full-length 66-kDa estrogen receptor alpha (ERα66). However, much less attention has been paid to a shorter 46-kDa isoform (ERα46), devoid of the N-terminal region containing the transactivation function AF-1. Here, we investigated the expression levels of ERα46 in breast tumors in relation to tumor grade and size, and examined the mechanism of its generation and its specificities of coregulatory binding and its functional activities.

METHODS

Using approaches combining immunohistochemistry, Western blotting, and proteomics, antibodies allowing ERα46 detection were identified and the expression levels of ERα46 were quantified in 116 ERα-positive human breast tumors. ERα46 expression upon cellular stress was studied, and coregulator bindings, transcriptional, and proliferative response were determined to both ERα isoforms.

RESULTS

ERα46 was expressed in over 70% of breast tumors at variable levels which sometimes were more abundant than ERα66, especially in differentiated, lower-grade, and smaller-sized tumors. We also found that ERα46 can be generated via internal ribosome entry site-mediated translation in the context of endoplasmic reticulum stress. The binding affinities of both unliganded and fully-activated receptors towards co-regulator peptides revealed that the respective potencies of ERα46 and ERα66 differ significantly, contributing to the differential transcriptional activity of target genes to 17β estradiol (E2). Finally, increasing amounts of ERα46 decrease the proliferation rate of MCF7 tumor cells in response to E2.

CONCLUSIONS

We found that, besides the full-length ERα66, the overlooked ERα46 isoform is also expressed in a majority of breast tumors. This finding highlights the importance of the choice of antibodies used for the diagnosis of breast cancer, which are able or not to detect the ERα46 isoform. In addition, since the function of both ERα isoforms differs, this work underlines the need to develop new technologies in order to discriminate ERα66 and ERα46 expression in breast cancer diagnosis which could have potential clinical relevance.

Study of the expression of integrin pathway's proteins as predictive markers of response to neoadjuvant chemotherapy in pretreatment biopsies of patients with high-grade osteosarcoma

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Background: Up to now, chemosensitivity to neoadjuvant chemotherapy performed for patients with osteosarcoma is evaluated on the surgical resection by the evaluation of the percentage of necrotic cells. No predictive profile of chemotherapy has been described yet. Because we have previously shown that integrin pathway controls genotoxic-induced cell death and hypoxia via ILK, FAK and RhoB, we hypothesized that the expression of the proteins involved in this pathway in pre-treatment biopsies could be associated with sensitivity to chemotherapy in osteosarcoma. Methods: We studied by immunohistochemistry β1, β3, β5, integrins, ILK, FAK, GSK-3β, RhoB and Ang-2 expression in 36 osteosarcomas biopsies of patients obtained before treatment. All the patients were treated by the SFOP OS94 chemotherapy protocol and underwent wide conservative surgery. Response to preoperative chemotherapy was assessed on the surgical resection by the Rosen’s protocol. An immunoreactive score (IRS) was assessed, combining the percentage of positive tumour cells and staining intensity. We evaluated the correlation of the selected markers expression with response to preoperative chemotherapy and clinical outcome. Results: FAK expression was statistically linked with ILK expression (rho=0.43; p=0.020), β1integrin expression with FAK expression (rho=0.51); p=0.003), RhoB with ILK expression (rho=0.55; p=0.002), and β1 with β3integrin expression (rho=0.70; p<.001), suggesting that a regulation of the integrin pathway that we studied might exist in high grade osteosarcoma. Moreover, the combination of β5 integrin, FAK and GSK-3β discriminated good and poor responder to chemotherapy (89.9%; 95% CI= [77.4;1.00], yielding a sensitivity of 94.1%, a specificity of 85.7% and a diagnostic accuracy of 90.3%. Conclusions: We report for the first time a protein expression profile on pre-treatment biopsies associating β5 integrin FAK and GSK-3β related with a poor response to neoadjuvant chemotherapy. This profile could help to select patients for clinical trials using inhibitors of this pathway in association with chemotherapy.

Osteosarcomas of the mandible: are they different from other tumor sites?

BACKGROUND

Osteosarcomas of the mandible (MOS) affect 1/10 million persons/year, mostly the young adult. Due to lack of specific data, the treatment of MOS is extrapolated from that of extragnathic OS but varies widely between institutions.

MATERIALS AND METHODS

We aimed at providing a focused description of MOS histologies and grades through the English literature, at determining the evidence-based role of chemotherapy, of adjuvant radiation therapy and the potential of reconstructive surgery tailored through modern pre-operative multi-modal imaging.

RESULTS

The estimated proportion of high grade MOS was 58%. However, low-grade MOS may be underestimated as they are mostly reported as case reports. The intermediate grade was hardly found in the literature. Estimated weighted-mean proportions of chondroblastic and osteoblastic MOS were 37% and 46%, respectively. Multimodal imaging modalities including MRI has a great potential for accurate pre-operative assessment of tumor extensions into bone and soft tissues. Surgery is the mainstay of treatment and margins the most important factor. The role of neoadjuvant chemotherapy in treating occult systemic metastases and in increasing the probability of clear margins is controversial, as well as the histology-dependent response to chemotherapy. The role of adjuvant radiotherapy (mostly proposed for positive margins) and/or adjuvant chemotherapy is still controversial. Crude survival is around 77% and local control around 67%. Local failure is the main cause of death in MOS compared to extragnathic sites.

Osteoid osteoma invading the posterior labyrinth of the petrous bone

We report a painless osteoid osteoma of the inner ear in an elderly woman presenting with hearing loss, tinnitus, and vertigo. CT showed a heterogeneous mass containing calcifications involving the posterior labyrinth, which heterogeneously enhanced on postcontrast MR images. Osteoid osteoma should be included in the differential diagnosis of an osteolytic petrous bone lesion with central calcification and enhancement.

Molecular characterization of the response to chemotherapy in conventional osteosarcomas: predictive value of HSD17B10 and IFITM2

The therapy regimen of high-grade osteosarcoma includes chemotherapy followed by surgical resection and postoperative chemotherapy. The degree of necrosis following definitive surgery remains the only reliable prognostic factor and is used to guide the choice of postoperative chemotherapy. The aim of this study was to find molecular markers able to classify patients with an osteosarcoma as good or poor responders to chemotherapy before beginning treatment. Gene expression screening of 20 nonmetastatic high-grade osteosarcoma patients was performed using cDNA microarray. Expression of selected relevant genes was validated using QRT-PCR. Immunohistochemistry on tissue microarrays sections of 73 biopsies was performed to investigate protein expression. Fluorescent in situ hybridization was performed for RPL8 gene. We have found that HSD17B10 gene expression was up-regulated in poor responders and that immunohistochemistry expression of HSD17B10 on biopsy before treatment was correlated to response to chemotherapy. Other results include correlation of IFITM2, IFITM3, and RPL8 gene expression to chemotherapy response. A statistical correlation was found between polysomy 8 or gain of RPL8 and good response to chemotherapy. These data suggest that HSD17B10, RPL8, IFITM2, and IFITM3 genes are involved in the response to the chemotherapy and that HSD17B10 may be a therapeutic target. RPL8 and IFITM2 may be useful in the assessment at diagnosis and for stratifying patients taking part in randomized trials.

Clinical and densitometric efficacy of the association of interferon alpha and pamidronate in the treatment of osteoporosis in patients with systemic mastocytosis

Osteoporosis accompanying severe mastocytosis leads to numerous compressed vertebrae. We treated four patients (mean age 52 years) with severe osteoporosis and mastocytosis proven by bone marrow biopsy (more than 40 mast cells/mm3), according to the following protocol: interferon alpha (IFN) 3 million units (MU) three times a week, reduced to 1.5 MU three times a week in the event of intolerance, and pamidronate (Pam) 90 mg/month in infusion. This treatment was given for 2 years. It was followed by Pam alone at a dose of 90 mg/month. After 3 or 4 years of treatment, no patient presented new vertebral or extravertebral fractures. The mean increase in bone mineral density (BMD) with IFN and Pam was 16.05+/-6.12% at the spine, 5+/-2.24% at the femoral neck, and 4.12+/-3.03% for the whole body; the increase or loss of BMD with Pam alone was +0.2+/-2.13% at the spine, -2.25+/-2.78% at the femoral neck, and -0.1+/-3.35% for the whole body. In one patient, the IFN dose was halved because of a flu-like syndrome, and in another IFN was discontinued at one year for the same reason. The association of IFN and Pam led to a major increase in bone marrow density in osteoporosis with concomitant mastocytosis and this gain was then maintained by monthly infusions of Pam.

[Metastasis on previous hip arthroplasty: three cases]

Three cases of metastasis on a previous total hip arthroplasty are reported. The hips had been operated a few years earlier for osteoarthritis. The patients then developed a carcinoma (kidney, prostate, breast) which disseminated producing bony metastases around the prosthesis which caused loosening. All three patients underwent a revision procedure for prosthesis replacement with a metaphysodyaphyseal implant. Carcinological resection was performed in one patient because the metastasis appeared to be unique. At last follow-up two years later, this patient was doing well.

Fourier Transform Infrared Imaging of focal lesions in human osteoarthritic cartilage

Fourier Transform Infrared Imaging (FTIRI) is a new method for quantitatively assessing the spatial-chemical composition of complex materials. This technique has been applied to examine the feasibility of measuring changes in the composition and distribution of collagen and proteoglycan macromolecules in human osteoarthritic cartilage. Human cartilage was acquired post-operatively from total joint replacement patients. Samples were taken at the site of a focal lesion, adjacent to the lesion, and from relatively healthy cartilage away from the lesion. Sections were prepared for FTIRI and histochemical grading. FTIRI spectral images were acquired for the superficial, intermediate, and deep layers for each sample. Euclidean distance mapping and quantitative partial least squares analysis (PLS) were performed using reference spectra for type-II collagen and chondroitin 6-sulphate (CS6). FTIRI results were correlated to the histology-based Mankin scoring system. PLS analysis found relatively low relative concentrations of collagen (38 +/- 10%) and proteoglycan (22 +/- 9%) in osteoarthritic cartilage. Focal lesions were generally found to contain less CS6 compared to cartilage tissue adjacent to the lesion. Loss of proteoglycan content was well correlated to histological Mankin scores (r=0.69, p<0.0008). The evaluation of biological tissues with FTIRI can provide unique quantitative information on how disease can affect biochemical distribution and composition. This study has demonstrated that FTIRI is useful in quantitatively assessing pathology-related changes in the composition and distribution of primary macromolecular components of human osteoarthritic cartilage.

Role of FAN in tumor necrosis factor-alpha and lipopolysaccharide-induced interleukin-6 secretion and lethality in D-galactosamine-sensitized mice

Tumor necrosis factor (TNF) alpha-induced neutral sphingomyelinase-mediated generation of ceramide, a bioactive lipid molecule, is transduced by the adaptor protein FAN, which binds to the intracellular region of the CD120a TNFalpha receptor. FAN-deficient mice do not exhibit any gross abnormality. To further explore the functions of FAN in vivo and because CD120a-deficient mice are resistant to endotoxin-induced liver failure and lethality, we investigated the susceptibility of FAN-deficient animals to lipopolysaccharide (LPS). We show that after d-galactosamine sensitization, FAN-deficient mice were partially resistant to LPS- and TNFalpha-induced lethality. Although LPS challenge resulted in a hepatic ceramide content lower in mutant mice than in control animals, it triggered similar histological alterations, caspase activation, and DNA fragmentation in the liver. Interestingly, LPS-induced elevation of IL-6 (but not TNFalpha) serum concentrations was attenuated in FAN-deficient mice. A less pronounced secretion of IL-6 was also observed after LPS or TNFalpha treatment of cultured peritoneal macrophages and embryonic fibroblasts isolated from FAN-deficient mice, as well as in human fibroblasts expressing a mutated FAN. Finally, we show that d-galactosamine-sensitized IL-6-deficient mice were partially resistant to endotoxin-induced liver apoptosis and lethality. These findings highlight the role of FAN and IL-6 in the inflammatory response initiated by endotoxin, implicating TNFalpha.

Does the meniscus exist in the elbow joint in children?

The authors report a case of meniscus at the elbow joint in a 15-month-old infant causing a limitation of elbow extension. Histological examination demonstrated that this tissue was not a synovial fold or a chondroid metaplasia of the synovial fold. As a meniscus does not appear at any stage of the embryological evolution of the elbow joint, it has been concluded that the presence of the meniscus can be considered as an abnormal condition.

[Metabolic problems and nutrition in burns]

Metabolic changes with burns patients are enormous. The loss of skin substance and the necessity of its reconstruction are at the origin of this exceptional situation. In this context of major aggression with important metabolic alteration the nutritional needs are considerable. To assure a tissue reconstruction, nutrition is as important as the fight against infection. The authors make the point on the quantity needs and the quality needs. They raise up the perspectives concerning immunonutriments and note the importance of enteral administration. As a conclusion, they insist on the fundamental role of the clinical aspect, in the survey of nutritional state.

Does vascular endothelial growth factor in the rheumatoid synovium predict joint destruction? A clinical, radiological, and pathological study in 12 patients monitored for 10 years

OBJECTIVE

Synovial angiogenesis is at the epicenter of rheumatoid pannus development and is largely dependent on vascular endothelial growth factor (VEGF). We sought to determine whether the VEGF level in rheumatoid synovial tissue is a marker for disease severity.

PATIENTS AND METHODS

Twelve patients with rheumatoid arthritis (RA) underwent a clinical and radiological evaluation at the time of a synovial biopsy done during joint surgery required by RA progression (T1) and, on average, 10 years later (T2). Immunohistochemistry was used to detect and quantitate VEGF in the synovial biopsy taken at T1.

RESULTS

VEGF labeling was seen on endothelial cells and macrophages in all 12 synovial biopsies. The amount of endothelial-cell VEGF labeling (assessed semi-quantitatively) was significantly correlated with Larsen score progression during the 10-year follow-up. The amounts of endothelial cell or macrophage VEGF labeling was not correlated with the joint count, radiological stage of the biopsied joint or progression of this stage, Larsen scores at T1 or T2, presence of rheumatoid factor, or presence of extra-articular manifestations.

CONCLUSION

Our results suggest that the amount of VEGF in the rheumatoid synovium may be a marker for joint destruction in patients with RA.

[Recurrent aggressive chondroblastoma: two cases and a review of the literature]

Chondroblastoma is a rare benign bone tumor. Treatment currently consists of curettage and bone graft. Prognosis depends basically on a relatively high rate of recurrence, between 5 and 38%, sometimes with local seeding of soft tissues and joint space. Such recurrences require wide resection with arthrodesis or even amputation. A 13-year-old girl with a humeral head chondroblastoma as treated by curettage and iliac bone graft. Six months later, a recurrence occurred with extension into the rotator cuff and the metaphysis. Remission was achieved by extensive surgical resection and hemiarthroplasty. The second case was a 14-year-old boy with a chondroblastoma of the right talus. He was treated by curettage and packing with bone substitute. After 2 recurrences with soft tissue and intra-articular extension, we performed a wide resection with reconstruction using a vascularized fibular graft. Many other cases in the literature illustrate such complications. We tried to find factors predictive of recurrence. Recurrence is observed when curettage was incomplete or when tumor cells were disseminated during surgery. Chondroblastoma is a benign bone tumor, but prognosis depends on the rapidity and severity of recurrence. Curettage should be as complete as possible and care should be taken to avoid contaminating the operative field.

Stress-induced apoptosis is not mediated by endolysosomal ceramide

A major lipid-signaling pathway in mammalian cells implicates the generation of ceramide from the ubiquitous sphingolipid sphingomyelin (SM). Hydrolysis of SM by a sphingomyelinase present in acidic compartments has been reported to mediate, via the production of ceramide, the apoptotic cell death triggered by stress-inducing agents. In the present study, we investigated whether the ceramide formed within or accumulated in lysosomes indeed triggers apoptosis. A series of observations strongly suggests that ceramide involved in stress-induced apoptosis is not endolysosomal: 1) Although short-chain ceramides induced apoptosis, loading cells with natural ceramide through receptor-mediated endocytosis did not result in cell death. 2) Neither TNF-alpha nor anti-CD95 induced the degradation to ceramide of a natural SM that had been first introduced selectively into acidic compartments. 3) Stimulation of SV40-transformed fibroblasts by TNF-alpha or CD40 ligand resulted in apoptosis equally well in cells derived from control individuals and from patients affected with Farber disease, having a genetic defect of acid ceramidase activity leading to lysosomal accumulation of ceramide. Also, induction of apoptosis using anti-CD95 (Fas) or anti-CD40 antibodies, TNF-alpha, daunorubicin, and ionizing radiation was similar in control and Farber disease lymphoid cells. In all cases, apoptosis was preceded by a comparable increase of intracellular ceramide levels. 4) Retroviral-mediated gene transfer and overexpression of acid ceramidase in Farber fibroblasts, which led to complete metabolic correction of the ceramide catabolic defect, did not affect the cell response to TNF-alpha and CD40 ligand.

[Continuous administration of vancomycin in patients with severe burns]

OBJECTIVES

In the severely burned patient, a marked, rapid fall in serum concentrations is often observed after intermittent infusion of vancomycin at the usual dose of 30 mg/kg. This specific "jagged" pharmokinetic course with inadequate residual concentrations raises the problem of the efficacy of this time-dependent antibiotic. Studies in patients in general resuscitation units have shown the interest of vancomycin administration in continuous infusion.

METHODS

We analyzed variations in serum concentrations of vancomycin during continuous infusion in 18 patients with burns involving a mean of 40% total body surface and reported the doses necessary to maintain serum vancomycin at therapeutic levels; the possible correlations between serum vancomycin concentrations, burn parameters, age and renal function; and clinical and biological tolerance.

RESULTS

Higher initial doses were required in burn patients (40 mg/kg in patients aged under 60) than in other patients. Impairment of renal function is a contra-indication of continuous infusion.

CONCLUSION

This mode of administration has the advantage of ensuring greater efficacy by preventing fluctuations in serum concentrations.

[Anaphylactic shock caused by pancuronium and vecuronium]

A case is reported of anaphylactic shock due to vecuronium occurring in a patient who had already had such a shock, due then to pancuronium, during a previous general anaesthesia. The need for a full immuno-allergological investigation, the occasional efficiency of the anti-histamine premedication, and crossed allergies between muscle relaxants are stressed. It is noted that an anaphylactic shock can be seen on first using a new molecule, as the patient can have been sensitized to it by other muscle relaxants. This case was the first to be described of an anaphylactic shock due to vecuronium bromide.