A Retrospective Self-Controlled Study Evaluating the Prophylactic Effects of CACIPLIQ20 on Postsurgical Scars.

Background: CACIPLIQ20 (OTR3, Paris, France) is a medical device used for the treatment of chronic skin ulcers. It contains a heparan sulfate mimetic that accelerates tissue healing by stabilizing matrix proteins and protecting heparin-binding growth factors. In humans, an open self-controlled study suggested that the topical application of CACIPLIQ20 optimizes skin healing following surgery. Objectives: To expand previous findings using a different CACIPLIQ20 administration regimen. Methods: Twenty-four females were referred for breast-reduction surgery. Each patient had their own control with 1 CACIPLIQ20-treated and 1 saline-treated control breast. The treated side (right or left) was randomly assigned by the operating surgeon. Scar appearance was assessed by 6 independent raters using a global visual scar comparison scale based on scar photographs. All raters were blinded toward the CACIPLIQ20-treated side. Results: The follow-up period following surgery ranged from 1 to 12 months with a median follow-up of 6 months. Overall, there was a mean improvement of 15.2% (SD = 26.7) in favor of CACIPLIQ20 (P = .016). On the CACIPLIQ20-treated side, the mean score per patient was above 20% in 11 patients and above 30% improvement in 8 cases. In contrast, only 3 patients were considered improved by at least 20% on the control side and only 1 above 30%. A comparison of different application regimens suggested that the best trend was obtained with a single administration of CACIPLIQ20 at Day 0. Conclusions: In conclusion, CACIPLIQ20 could represent an interesting scar prophylactic therapy, based on a single administration at the time of surgery, and without any known adverse effects.

Cerebral folate deficiency in adults: A heterogeneous potentially treatable condition.

OBJECTIVE: To describe the phenotype and the response to folinic acid supplementation of cerebral folate deficiency (CFD) in adults, a disorder diagnosed on low 5-methyltetrahydro-folate (5MTHF) in cerebrospinal fluid (CSF), which can correspond to a inherited disorder of folate metabolism (IDFM) or to a metabolic consequence of various neurological diseases. METHODS: We conducted a retrospective study on 224 adult patients with neurological symptoms who had a 5MTHF CSF dosage, collecting their neurologic and neuroimaging data. RESULTS: 69 patients had CFD (CSF 5MTHF level < 41 nmol/L), 25 of them had severe CFD (sCFD; ≤25 nmol/L) with adult onset neurological symptoms in 41%. 56% of sCFD patients had an underlying identified neurologic disorder, mainly mitochondrial diseases, hepatic encephalopathy and primary brain calcifications (no identified IDFM), the others were classified as undiagnosed. sCFD patients presented most frequently pyramidal syndrome (75%), movement disorders (56%), cerebellar syndrome (50%) and intellectual disability (46%). MRI findings mostly showed white matter abnormalities (WMA; 32%) and calcifications (12%), and were normal in 23%. The clinico-radiological phenotype of sCFD patients was not clearly different from non CFD patients in terms of manifestations frequency. However, their neurological picture was more complex with a higher number of combined neurological symptoms (4.7±1.6 vs 3.4±1.7, p = .01). In Magnetic Resonance Spectroscopy (MRS), Choline/Creatine (Cho/Cr) ratio was lower in sCFD patients (n = 7) compared to non-CFD patients (n = 73) (p = .005), with good sensitivity (71%) and excellent specificity (92%). Among twenty-one CFD patients treated with folinic acid, nine had a sustained improvement, all with sCFD but one (50% of sCFD patients improved). In two undiagnosed patients with extremely low 5MTHF CSF values, MRI WMA and low Cho/Cr ratios, folinic acid treatment leaded to a dramatic clinical and radiological improvement. CONCLUSION: CSF 5MTHF dosage should be considered in patients with mitochondrial diseases, primary brain calcifications and unexplained complex neurological disorders especially if associated with WMA, since folinic acid supplementation in patients with sCFD is frequently efficient.

Natural history of cerebrotendinous xanthomatosis: a paediatric disease diagnosed in adulthood.

Cerebrotendinous xanthomatosis (CTX) is among the few inherited neurometabolic disorders amenable to specific treatment. It is easily diagnosed using plasma cholestanol. We wished to delineate the natural history of the most common neurological and non-neurological symptoms in thirteen patients with CTX. Diarrhea almost always developed within the first year of life. Cataract and school difficulties usually occurred between 5 and 15 years of age preceding by years the onset of motor or psychiatric symptoms. The median age at diagnosis was 24.5 years old. It appears critical to raise awareness about CTX among paediatricians in order to initiate treatment before irreversible damage occurs.

Cirrhosis and liver failure: expanding phenotype of Acid sphingomyelinase-deficient niemann-pick disease in adulthood.

Acid sphingomyelinase-deficient Niemann-Pick disease (ASMD) includes the severe neuronopathic type A, the non-neuronopathic type B, and rare intermediate cases. Here we report on such an atypical type B patient who died at 31 years of age from liver failure. This male subject was first seen in a paediatric department at the age of 3 years because of significant hepatosplenomegaly. Foam cells in bone marrow, interstitial pneumonitis, a slight facial dysmorphy and normal psychomotor development were additional findings. Acid sphingomyelinase studies in lymphocytes (and later SMPD1 gene studies [c.151_154delGACT; c.1341-21_1341-18delAATG]) established the diagnosis of ASMD. Between the ages 6-27, he developed growth retardation, peripheral neuropathy, kyphoscoliosis, alopecia, and aortic valve insufficiency requiring valve replacement. Surgery for bilateral inguinal hernias was performed twice, when the patient was 10 and 21 years of age, respectively. At the age of 28, he was noted to have hepatosplenomegaly and follow-up investigations revealed ascites and gastric varices. Liver biopsy showed cirrhosis without areas of necrosis (A6 in Child-Pugh classification). He developed haematemesis and worsening encephalopathy leading to his death at age 31. In conclusion, cirrhosis should be considered as a possible complication of ASMD in adult patients, even if hepatic tests are normal.

Psychiatric manifestations of treatable hereditary metabolic disorders in adults.

Detecting psychiatric disorders of secondary origin is a crucial concern for the psychiatrist. But how can this reliably be done among a large number of conditions, most of which have a very low prevalence? Metabolic screening undertaken in a population of subjects with psychosis demonstrated the presence of treatable metabolic disorders in a significant number of cases. The nature of the symptoms that should alert the clinician is also a fundamental issue and is not limited to psychosis. Hereditary metabolic disorders (HMD) are a rare but important cause of psychiatric disorders in adolescents and adults, the signs of which may remain isolated for years before other more specific organic signs appear. HMDs that present purely with psychiatric symptoms are very difficult to diagnose due to low awareness of these rare diseases among psychiatrists. However, it is important to identify HMDs in order to refer patients to specialist centres for appropriate management, disease-specific treatment and possible prevention of irreversible physical and neurological complications. Genetic counselling can also be provided. This review focuses on three HMD categories: acute, treatable HMDs (urea cycle abnormalities, remethylation disorders, acute intermittent porphyria); chronic, treatable HMDs (Wilson's disease, Niemann-Pick disease type C, homocystinuria due to cystathionine beta-synthase deficiency, cerebrotendinous xanthomatosis); and chronic HMDs that are difficult to treat (lysosomal storage diseases, X-linked adrenoleukodystrophy, creatine deficiency syndrome). We also propose an algorithm for the diagnosis of HMDs in patients with psychiatric symptoms.

Diagnostic and treatment implications of psychosis secondary to treatable metabolic disorders in adults: a systematic review.

OBJECTIVE: It is important for psychiatrists to be aware of certain inborn errors of metabolism (IEMs) as these rare disorders can present as psychosis, and because definitive treatments may be available for treating the underlying metabolic cause. A systematic review was conducted to examine IEMs that often present with schizophrenia-like symptoms. DATA SOURCES: Published literature on MEDLINE was assessed regarding diseases of homocysteine metabolism (DHM; cystathionine beta-synthase deficiency [CbS-D] and homocysteinemia due to methyltetrahydrofolate reductase deficiency [MTHFR-D]), urea cycle disorders (UCD), acute porphyria (POR), Wilson disease (WD), cerebrotendinous-xanthomatosis (CTX) and Niemann-Pick disease type C (NP-C). STUDY SELECTION: Case reports, case series or reviews with original data regarding psychiatric manifestations and cognitive impairment published between January 1967 and June 2012 were included based on a standardized four-step selection process. DATA EXTRACTION: All selected articles were evaluated for descriptions of psychiatric signs (type, severity, natural history and treatment) in addition to key disease features. RESULTS: A total of 611 records were identified. Information from CbS-D (n = 2), MTHFR-D (n = 3), UCD (n = 8), POR (n = 12), WD (n = 11), CTX (n = 14) and NP-C publications (n = 9) were evaluated. Six non-systematic literature review publications were also included. In general, published reports did not provide explicit descriptions of psychiatric symptoms. The literature search findings are presented with a didactic perspective, showing key features for each disease and psychiatric signs that should trigger psychiatrists to suspect that psychotic symptoms may be secondary to an IEM. CONCLUSION: IEMs with a psychiatric presentation and a lack of, or sub-clinical, neurological signs are rare, but should be considered in patients with atypical psychiatric symptoms.

POLG mutations associated with remitting/relapsing neurological events.

Recent experimental data underline the relationship between mitochondria and immune function. Clinical reports of patients presenting with mitochondrial dysfunction associated with dysimmune responses in the central nervous system reinforce this new concept. We describe the first case of a woman presenting with symptoms related to a novel compound heterozygous mutation of the mitochondrial polymerase γ (POLG) gene, associated with neurological events suggestive of a demyelinating process. Clinical examination revealed bilateral ptosis, progressive external ophthalmoplegia and axonal sensitive polyneuropathy suggestive of a mitochondrial disease. In line with this, muscle biopsy showed ragged red fibers, and sequencing of POLG revealed two heterozygous mutations. In addition, the patient exhibited relapsing neurological symptoms, and cerebral and spinal MRI mimicking multiple sclerosis. This patient stresses the relationship between mitochondrial dysfunction and inflammation. Recent studies suggest that targeting mitochondrial dysfunction could provide benefits in treating some inflammatory diseases.

Niemann-Pick type C Suspicion Index tool: analyses by age and association of manifestations.

OBJECTIVE: The Suspicion Index (SI) screening tool was developed to identify patients suspected of having Niemann-Pick disease type C (NP-C). The SI provides a risk prediction score (RPS) based on NP-C manifestations within and across domains (visceral, neurological, and psychiatric). The aim of these subanalyses was to further examine the discriminatory power of the SI by age and manifestation-associations by NP-C suspicion-level and leading manifestations. METHODS: The original retrospectively collected data were split into three patient age groups, where NP-C-positive cases were >16 years (n = 30), 4-16 years (n = 18), and <4 years (n = 23), and patients' RPS were analyzed by logistic regression. Co-occurrence of manifestations within groups of suspicion level (low, medium, high) and leading manifestations (presence/absence of ataxia, cognitive decline, psychosis, and splenomegaly) were analyzed descriptively. RESULTS: NP-C-positive cases versus controls showed strong discriminatory power of RPS. Area under the receiver operating characteristic curve was 0.964 (>16 years) and 0.981 (4-16 years) but weaker 0.562 for infants (<4 years). Patients with RPS <70 were characterized by a lack of psychiatric manifestations and low levels of neurological involvement, suggestive of a preneurological phase of the disease. In patients >4 years, prominent leading manifestation-associations were ataxia with dystonia, dysarthria/dysphagia, and cognitive decline. Psychosis was associated with dysarthria/dysphagia but also with cognitive decline and treatment-resistant psychiatric symptoms. CONCLUSIONS: The SI tool maintains strong discriminatory power in patients >4 years but is not as useful for infants <4 years. The SI is also informative regarding the association and co-occurrence of manifestations in patients with NP-C.

Genetic analysis of inherited leukodystrophies: genotype-phenotype correlations in the CSF1R gene.

IMPORTANCE: The leukodystrophies comprise a clinically and genetically heterogeneous group of progressive hereditary neurological disorders mainly affecting the myelin in the central nervous system. Their onset is variable from childhood to adulthood and presentation can be with a variety of clinical features that include mainly for adult-onset cases cognitive decline, seizures, parkinsonism, muscle weakness, neuropathy, spastic paraplegia, personality/behavioral problems, and dystonia. Recently, Rademakers and colleagues identified mutations in the CSF1R gene as the cause of hereditary diffuse leukoencephalopathy with spheroids (HDLS), offering the possibility for an in-life diagnosis. The detection of mutations in this gene in cases diagnosed with different clinical entities further demonstrated the difficulties in the clinical diagnosis of HDLS. OBJECTIVE: To better understand the genetic role of mutations in this gene, we sequenced a large cohort of adult-onset leukodystrophy cases. DESIGN: Whole-exome sequencing and follow up-screening by Sanger sequencing. SETTING: Collaborative study between the Institute of Neurology, University College London and the Inserm, Paris, France. PARTICIPANTS: A total of 114 probands, mostly European patients, with a diagnosis of adult-onset leukodystrophy or atypical cases that could fit within a picture of leukodystrophy. These included 3 extended families within the spectrum of leukodystrophy phenotype. INTERVENTIONS: Whole-exome sequencing in a family and Sanger sequencing of CSF1R. MAIN OUTCOMES AND MEASURES: Mutations in CSF1R. RESULTS: We identified 12 probands with mutations in CSF1R. The clinical diagnoses given to these patients included dementia with spastic paraplegia, corticobasal degeneration syndrome, and stroke disorders. Our study shows that CSF1R mutations are responsible for a significant proportion of clinically and pathologically proven HDLS. CONCLUSIONS AND RELEVANCE: These results give an indication of the frequency of CSF1R mutations in a European leukodystrophy series and expand the phenotypic spectrum of disorders that should be screened for this gene.

Acute but transient neurological deterioration revealing adult polyglucosan body disease.

Adult polyglucosan body disease (APBD) is a metabolic disorder usually caused by glycogen branching enzyme (GBE) deficiency. APBD associates progressive walking difficulties, bladder dysfunction and, in about 50% of the cases, cognitive decline. APBD is characterized by a recognizable leukodystrophy on brain MRI. We report here a novel presentation of this disease in a 35-year old woman who presented with an acute deterioration followed by an unexpected recovery. Enzymatic analysis displayed decreased GBE activity in leukocytes. Molecular analyses revealed that only one mutated allele was expressed, bearing a p.Arg515His mutation. This is the first observation reporting acute and reversible neurological symptoms in APBD. These findings emphasize the importance of searching GBE deficiency in patients presenting with a leukodystrophy and acute neurological symptoms mimicking a stroke, in the absence of cardiovascular risk factors.

Myoclonus and dystonia in cerebrotendinous xanthomatosis.

BACKGROUND: Cerebrotendinous xanthomatosis (CTX) is an inherited neurometabolic disorder. The main neurological manifestations of the disease are pyramidal syndrome, ataxia, peripheral neuropathy, cognitive impairment, epilepsy, and psychiatric disturbances. Myoclonic dystonia has been reported on in the setting of various neurometabolic diseases. Anecdotal reports describe movement disorders associated with CTX, but no dystonia with myoclonic events. METHODS: We collected clinical, biochemical, electrophysiological, neuroradiological, and genetic data of 6 patients with myoclonus and mild dystonia associated with CTX. From a systematic literature review, we analyzed 31 patients with movement disorders secondary to CTX. RESULTS: Our 6 patients presented distal myoclonus with mild dystonia of the upper limbs. Myoclonus was of subcortical origin, based on neurophysiological recordings, and differed from oromandibular myoclonus previously described in CTX patients. CONCLUSIONS: These results expand the phenotype of CTX and suggest that myoclonus and/or dystonia are underdiagnosed. In keeping with our findings, tremors previously observed in CTX patients might actually correspond to myoclonic events. We hypothesize that a dysfunction of the dentate nuclei-basal ganglia pathway may be involved.

The French Gaucher's disease registry: clinical characteristics, complications and treatment of 562 patients.

BACKGROUND: Clinical features, complications and treatments of Gaucher's disease (GD), a rare autosomal-recessive disorder due to a confirmed lysosomal enzyme (glucocerebrosidase) deficiency, are described. METHODS: All patients with known GD, living in France, with ≥ 1 consultations (1980-2010), were included in the French GD registry, yielding the following 4 groups: the entire cohort, with clinical description; and its subgroups: patients with ≥ 1 follow-up visits, to investigate complications; recently followed (2009-2010) patients; and patients treated during 2009-2010, to examine complications before and during treatment. Data are expressed as medians (range) for continuous variables and numbers (%) for categorical variables. RESULTS: Among the 562 registry patients, 265 (49.6%) were females; 454 (85.0%) had type 1, 22 (4.1%) type 2, 37 (6.9%) perinatal-lethal type and 21 (3.9%) type 3. Median ages at first GD symptoms and diagnosis, respectively, were 15 (0-77) and 22 (0-84) years for all types. The first symptom diagnosing GD was splenomegaly and/or thrombocytopenia (37.6% and 26.3%, respectively). Bone-marrow aspiration and/or biopsy yielded the diagnosis for 54.7% of the patients, with enzyme deficiency confirming GD for all patients. Birth incidence rate was estimated at 1/50,000 and prevalence at 1/136,000. For the 378 followed patients, median follow-up was 16.2 (0.1-67.6) years. Major clinical complications were bone events (BE; avascular necrosis, bone infarct or pathological fracture) for 109 patients, splenectomy for 104, and Parkinson's disease for 14; 38 patients died (neurological complications for 15 type-2 and 3 type-3 patients, GD complications for 11 type-1 and another disease for 9 type-1 patients). Forty-six had monoclonal gammopathy. Among 283 recently followed patients, 36 were untreated and 247 had been treated during 2009-2010; 216 patients received treatment in December 2010 (126 with imiglucerase, 45 velaglucerase, 24 taliglucerase, 21 miglustat). BE occurred before (130 in 67 patients) and under treatment (60 in 41 patients) with respective estimated frequencies (95% CI) of first BE at 10 years of 20.3% (14.1%-26.5%) and 19.8% (13.5%-26.1%). CONCLUSION: This registry enabled the epidemiological description of GD in France and showed that BE occur even during treatment.

Medical and developmental risk factors of catatonia in children and adolescents: a prospective case-control study.

CONTEXT: Rare diseases have been associated with more and more genetic and non genetic causes and risk factors. But this has not been systematically assessed in catatonia, one of the psychiatric syndromes, that is most frequently associated with medical condition. OBJECTIVE: We sought to assess the medical and developmental risk factors of catatonia in children and adolescents. METHODS: From 1993 to 2009, 58 youths aged 10 to 18 years were prospectively admitted for catatonia and were followed up after discharge. A multidisciplinary approach assessed patients' medical condition and developmental history. A causality assessment scored medical risk (maximum score=10; κ=0.91). We compared the prevalence of catatonia in these patients to that of 80 inpatients with bipolar I disorder admitted from 1993 to 2003 who were also followed up. RESULTS: We found that 13 (22.4%) patients had medical conditions and 18 (31%) had a history of developmental disorder in the catatonia group, whereas 1 (1.3%) and 17 (22.6%) patients had the same conditions in the bipolar group (p<0.001; p=0.17, respectively). Medical conditions associated with catatonia included auto-immune encephalitis (systemic lupus erythematosus [N=3] and anti-NMDA-receptor encephalitis [N=1]), seizures (N=1), ciclosporin encephalitis (N=1), post hypoglycaemic coma encephalitis (N=1), and genetic or metabolic conditions (chorea [N=2], 5HT cerebrospinal fluid deficit [N=1], storage disease [N=1], fatal familial insomnia [FFI; N=1], and PRODH mutations [N=1]). Six patients responded to a specific treatment approach related to their medical condition (e.g., plasma exchange in the case of auto-immune encephalitis). CONCLUSION: Catatonia in children and adolescents is associated with a high prevalence of medical conditions. This needs to be acknowledged as it may greatly delay the treatment of catatonia and the diagnosis of medically related catatonia. Tragically, this may deny patients treatment opportunities.

A long nuclear-retained non-coding RNA regulates synaptogenesis by modulating gene expression.

A growing number of long nuclear-retained non-coding RNAs (ncRNAs) have recently been described. However, few functions have been elucidated for these ncRNAs. Here, we have characterized the function of one such ncRNA, identified as metastasis-associated lung adenocarcinoma transcript 1 (Malat1). Malat1 RNA is expressed in numerous tissues and is highly abundant in neurons. It is enriched in nuclear speckles only when RNA polymerase II-dependent transcription is active. Knock-down studies revealed that Malat1 modulates the recruitment of SR family pre-mRNA-splicing factors to the transcription site of a transgene array. DNA microarray analysis in Malat1-depleted neuroblastoma cells indicates that Malat1 controls the expression of genes involved not only in nuclear processes, but also in synapse function. In cultured hippocampal neurons, knock-down of Malat1 decreases synaptic density, whereas its over-expression results in a cell-autonomous increase in synaptic density. Our results suggest that Malat1 regulates synapse formation by modulating the expression of genes involved in synapse formation and/or maintenance.

Cerebrotendinous xanthomatosis presenting with severe externalized disorder: improvement after one year of treatment with chenodeoxycholic Acid.

Cerebrotendinous xanthomatosis (CTX) is a rare inborn disorder of sterol storage with autosomal recessive inheritance and a variable clinical presentation. We describe two siblings with an early psychiatric presentation of CTX-associated attention-deficit/hyperactivity disorder and oppositional defiant disorder, also associated with a mild intellectual disability and major behavioral impairments. In both cases, treatment with chenodeoxycholic acid improved externalized symptoms and a partial recovery of cognitive impairments was observed. This suggests that CTX is potentially reversible, demonstrating the need for early diagnosis and treatment of this disorder before irreversible neurological lesions can occur.

Recommendations on the diagnosis and management of Niemann-Pick disease type C.

Niemann-Pick disease type C (NP-C) is a lysosomal storage disease in which impaired intracellular lipid trafficking leads to excess storage of cholesterol and glycosphingolipids in the brain and other tissues. It is characterized clinically by a variety of progressive, disabling neurological symptoms including clumsiness, limb and gait ataxia, dysarthria, dysphagia and cognitive deterioration (dementia). Until recently, there has been no disease-modifying therapy available for NP-C, with treatment limited to supportive measures. In most countries, NP-C is managed through specialist centers, with non-specialist support provided locally. However, effective patient support is hampered by the absence of national or international clinical management guidelines. In this paper, we seek to address this important gap in the current literature. An expert panel was convened in Paris, France in January 2009 to discuss best care practices for NP-C. This commentary reviews current literature on key aspects of the clinical management of NP-C in children, juveniles and adults, and provides recommendations based on consensus between the experts at the meeting.

Multidisciplinary approach of organic catatonia in children and adolescents may improve treatment decision making.

Catatonia is an infrequent but severe condition in young people. Organic diseases may be associated and need to be investigated though no specific recommendations and guidelines are available. We extensively reviewed the literature of all the cases of organic catatonia in children and adolescents from January 1969 to June 2007. We screened socio-demographic characteristics, organic diagnosis, clinical characteristics and treatment. We found 38 cases of children and adolescents with catatonia due to an organic condition. The catatonic syndrome occurred in 21 (57%) females and 16 (43%) males. The mean age of patients was 14.5 years (+/-3.39) [range=7-18 years], and three died from their condition. The organic conditions included infectious diseases (N=10), neurological conditions (N=10), toxic induced states (N=12) and genetic conditions including inborn errors of metabolism (N=6). The onset was dominantly acute, and the clinical presentation most frequently stuporous. Although benzodiazepines were recommended as primary symptomatic treatment, they were rarely prescribed. In several cases, therapeutic approach was related to organic cause (e.g., plasma exchange in lupus erythematosus; copper chelators in Wilson's disease). Based on this review and on our own experience of catatonia in youth, we proposed a consensual and multidisciplinary diagnostic strategy to help practitioners to identify underlying organic diseases.

Macrophage-derived tumor necrosis factor alpha, an early developmental signal for motoneuron death.

Mechanisms inducing neuronal death at defined times during embryogenesis remain enigmatic. We show in explants that a developmental switch occurs between embryonic day 12 (E12) and E13 in rats that is 72-48 hr before programmed cell death. Half the motoneurons isolated from peripheral tissues at E12 escape programmed cell death, whereas 90% of motoneurons isolated at E13 enter a death program. The surrounding somite commits E12 motoneurons to death. This effect requires macrophage cells, is mimicked by tumor necrosis factor alpha (TNFalpha), and is inhibited by anti-TNFalpha antibodies. In vivo, TNFalpha is detected within somite macrophages, and TNF receptor 1 (TNFR1) is detected within motoneurons precisely between E12 and E13. Although motoneuron cell death occurs normally in TNFalpha-/- mice, this process is significantly reduced in explants from TNFalpha-/- and TNFR1-/- mice. Thus, embryonic motoneurons acquire the competence to die, before the onset of programmed cell death, from extrinsic signals such as macrophage-derived TNFalpha