Mutant NDUFS3 subunit of mitochondrial complex I causes Leigh syndrome

Respiratory chain complex I deficiency represents a genetically heterogeneous group of diseases resulting from mutations in mitochondrial or nuclear genes. Mutations have been reported in 13 of the 14 subunits encoding the core of complex I (seven mitochondrial and six nuclear genes) and these result in Leigh or Leigh-like syndromes or cardiomyopathy. In this study, a combination of denaturing high performance liquid chromatography and sequence analysis was used to study the NDUFS3 gene in a series of complex I deficient patients. Mutations found in this gene (NADH dehydrogenase iron-sulphur protein 3), coding for the seventh and last subunit of complex I core, were shown to cause late onset Leigh syndrome, optic atrophy, and complex I deficiency. A biochemical diagnosis of complex I deficiency on cultured amniocytes from a later pregnancy was confirmed through the identification of disease causing NDUFS3 mutations in these cells. While mutations in the NDUFS3 gene thus result in Leigh syndrome, a dissimilar clinical phenotype is observed in mutations in the NDUFV2 and NDUFS2 genes, resulting in encephalomyopathy and cardiomyopathy. The reasons for these differences are uncertain.

[Bladder fibrosis caused by eosinophilic cystitis]

A 70-years-old man with no history of allergy or genitourinary problems had bilateral hydronephrosis, a marked decrease in bladder capacity and severe eosinophilic infiltration with fibrosis of the bladder wall. A total cystoprostatectomy with ileal bladder replacement was performed. We reviewed the literature of eosinophilic cystitis for clinical presentation, diagnosis and therapeutic options.

Impaired mitochondrial pyruvate importation in a patient and a fetus at risk

The patient was the first child of healthy consanguineous parents. She presented at birth with hypotonia, mild facial dysmorphism, periventricular cysts, marked metabolic acidosis, hyperlactacidemia with normal lactate/pyruvate molar ratios, normoglycemia, and normal ammonia. Hyperlactacidemia was severe (5-14 mmol/l) and not corrected with bicarbonate, thiamine (10 mg/d), 2-chloropropionate (100 mg/kg/d) and a ketogenic diet. Pyruvate dehydrogenase (PDHC) activity was normal in lymphocytes and fibroblasts. Functional assays were performed in digitonin-permeabilized fibroblasts to measure oxidation rates from radiolabeled pyruvate and malate. The production of [14C]acetylcarnitine or [14C]citric cycle intermediates derived from [2-14C]pyruvate as well as the release of 14CO(2) from [1-14C]pyruvate was severely impaired, whereas decarboxylation of [U-14C]malate was normal. With increasing concentrations of [1-14C]pyruvate, the patient's fibroblasts behave like control fibroblasts incubated in the presence of alpha-cyano-4-hydroxycinnamate, a specific inhibitor of mitochondrial pyruvate uptake: a progressive increase in 14CO(2) production was observed, likely due to passive diffusion of [1-14C]pyruvate through the mitochondrial membranes. Our results are consistent with a defect of mitochondrial pyruvate transport in the patient. Mutational analysis was precluded as the cDNA sequence of the pyruvate carrier has not been identified as yet in any organism. An affected fetus was recognized in a subsequent dichorionic twin pregnancy using the coupled assay measuring [2-14C]pyruvate oxidation rates on digitonin-permeabilized trophoblasts. After selective feticide, the pregnancy was uncomplicated with delivery at 37w of a healthy female, who is currently 2-month old.

Mutational spectrum and DNA-based prenatal diagnosis in carnitine-acylcarnitine translocase deficiency

Carnitine-acylcarnitine translocase (CAC) deficiency is a rare autosomal recessive disorder of long-chain fatty acid oxidation with a severe outcome. We report mutation analysis in a cohort of 12 patients. Twelve mutations were identified of which 9 have not been reported so far (G28C, D32N, R178Q, P230R, D231H, 179delG, 802delG, 69-70insTGTGC, and 609-1g>a). Altogether, including our results, 22 mutations of the CAC gene have been published to date in 23 patients demonstrating the allelic heterogeneity of CAC deficiency. DNA-based prenatal diagnosis was performed for the first time in pregnancies at risk for CAC deficiency. Two fetuses were affected and one pregnancy was terminated by family decision. Two other fetuses had normal genotype and five others were heterozygotes. All the offspring of these seven pregnancies are alive and apparently healthy.

[Anesthesia for cesarean section in a Marfan patient with complicated aortic dissection]

We report the anaesthetic management of a 32-year-old pregnant women with aortic dissection and Marfan syndrome for caesarean section. The patient has presented at 31 weeks gestation of a first pregnancy an aortic dissection that required an emergency aortic replacement. Three years later, she presented at 31 weeks gestation with aortic dissection, mitral valve dysfunction and acute pulmonary oedema. She was treated in intensive care unit with deslanoside, diuretic and twice a day echographic examination. Delivery was planned by caesarean section after haemodynamic stabilisation on the sixth day. Combined spinal and epidural anaesthesia was performed after monitoring. The initial intrathecal injection of bupivacaine, morphine and fentanyl provided rapid onset of analgesia. Epidural anaesthesia was used with diluted lidocaine and fentanyl boluses. With appropriate preoperative care and monitoring, uneventful combined spinal and epidural anaesthesia for Caesarean section was achieved in a patient with Marfan syndrome in the presence of aortic dissection complicated by mitral valve dysfunction and acute pulmonary oedema.

[Maternal emergencies requiring controlled ventilation: epidemiology and prognosis]

OBJECTIVE

Evaluation of severe maternal morbidity in peripartum period leading to controlled ventilation in the obstetrical intensive care unit.

STUDY DESIGN

A retrospective study was carried out during a period of three years, from March 1998 to March 2001, in the obstetrical intensive care unit (ICU) of Farhat Hached hospital, Sousse (Tunisia).

PATIENTS AND METHODS

Twenty obstetric patients requiring controlled ventilation were admitted in the ICU. Obstetric data included maternal age, gestational age, parity, diagnosis of the disease requiring controlled ventilation and maternal outcome.

RESULTS

A total of 24812 deliveries occurred during the study period at Farhat Hached maternal center. Twenty patients (0.08 percent) required controlled ventilation for a mean duration of 38 hours (range: five hours- 21 days). The mean age was 30 +3 years. Eight patients were primigravida. The mean gestational age was 33 +2 weeks. Seventeen patients (85 percent) underwent cesarean section. The mean duration in the ICU was six days (range: 5 hours - 34 days). There were six maternal deaths (30 percent). Maternal mortality was attributed to neurologic 40 percent, hemodynamic 30 percent or respiratory 30 percent failure which complicated eclampsia, hemorrhagic shock, pulmonary edema or sepsis.

CONCLUSION

There were 0.08 percent of obstetric patients requiring controlled ventilation. The serious maternal morbidity and the high mortality require better care of obstetric patients.

[Mandibular odontogenic carcinosarcoma: a case report]

The last W.H.O classification of odontogenic tumors (1992) individualized a new entity called odontogenic carcinosarcoma. We report a case in which we encountered some difficulties to establish the diagnosis. The patient J.Z., a 26 year-old woman was operated on for a left mandibular tumor corresponding, histologically, to an ameloblastic fibrosarcoma. One year later, we noted a submandibular swelling considered as a local recurrence. After resection, the pathologic examination diagnosed a lymph node metastasis from the same tumor. We decided to observe the patient. Three years post operatively, metastatic lymph nodes appeared, involving a double-component tumor: ameloblastic fibrosarcoma and malignant ameloblastoma. These features allowed the diagnosis of odontogenic carcinosarcoma. We insist on difficulties of the diagnosis and the necessity of radical resection of the tumor with neck dissection.

[Influence of general practitioners' personal knowledge on migraine in medical attitudes towards their patients suffering from migraine]

The subjective aspects of the doctor-patient relationship may impact disease management methods applied to migraine patients. This prospective study compared the medical attitudes of doctors towards migraine headache in relationship to their personal sensitivity to this disease. The study concerned data on the health care management of migraine headache by 711 general practitioners, 325 of whom suffer from migraine headache themselves, 227 who do not suffer from migraines, but who have a close family member that does, and 159 who neither suffer from migraine headache, nor have anyone close who does. Each doctor filled out a medical practice questionnaire concerning this pathology and included one migraine patient in the survey. Each patient answered a specific quality of life questionnaire. It was shown that doctors suffering from migraine headache themselves declared having more migraine patients in their practices than the other doctors. Nonetheless, the doctor's sensitivity to migraine headache does not seem to have an impact on the diagnosis and therapeutic care of patients; diagnosis criteria are the same within the three groups and correspond to international headache society criteria. Furthermore, the therapeutic means applied, whether acute first or second intention treatment, or long-term treatment, do not differ amongst the three groups. Quality of life and patients' feelings about medical support were significantly related to the doctor's level of sensitivity towards the disease: they were highest amongst patients treated by doctors suffering from migraines themselves, and lowest amongst patients treated by doctors with no close family members suffering from migraines. Although therapeutical attitudes do not vary, the quality of life perceived by patients is better when the doctors themselves are concerned by the disease.

Decrease in calbindin content significantly alters LTP but not NMDA receptor and calcium channel properties

The contribution of the cytosolic calcium binding protein calbindin D(28K) (CaBP) to the synaptic plasticity was investigated in hippocampal CA1 area of wild-type and antisense transgenic CaBP-deficient mice. We showed that long-term potentiation (LTP) induced by tetanic stimulation in CaBP-deficient mice was impaired. The fundamental biophysical properties of NMDA receptors and their number were not modified in CaBP-deficient mice. We also demonstrated that the physiological properties of calcium channels were identical between genotypes. An insufficient Ca(2+) entry through NMDA receptors or calcium channels, or a decrease in NMDA receptor density are unlikely to explain this impairment of LTP. Interestingly, we showed that the loss of LTP was not prevented by glycine but was restored in the presence of a low concentration of the NMDA receptor antagonist D-APV (5 microM) and of the calcium chelator BAPTA-AM (5 microM). Moreover, we observed a loss of LTP in the wild-type mice when the postsynaptic tetanic-induced [Ca(2+)](i) rise is excessively increased. Conversely, a weaker tetanus stimulation allowed LTP induction and maintenance in CaBP-deficient mice. These results suggest that a higher cytosol [Ca(2+)](i), due to the decrease of CaBP expression may impair LTP induction and maintenance mechanisms without affecting the mechanisms of calcium entry. Thus, CaBP plays a critical role in long term synaptic plasticity by limiting the elevation of calcium rise in the cytosol to some appropriate spatio-temporal pattern.

[CagA status and virulence of Helicobacter pylori strains. Results of a French multicentric prospective study]

Previous experimental and epidemiological studies with few patients suggested that the presence of the cagA gene was a virulence factor for Helicobacter pylori (H. pylori).

AIM

To establish in this large epidemiological cohort study the relationship between the histological virulence of H. pylori infection and the cagA status of the bacteria.

METHODS

This prospective cohort study (6 month follow-up) was conducted on adult patients undergoing endoscopy for upper gastrointestinal symptoms. The cagA status of H. pylori-positive patients was established using the polymerase chain reaction (PCR) method on an antral biopsy. A score of histological virulence (inflammation, activity) was recorded on the basis of the Sydney system (on antral, angular and fundic biopsies). Eradication treatment given was not imposed and a clinical follow-up was performed at 3 and 6 months. H. pylori eradication was verified by a 13C urea breath test at 3 months.

RESULTS

Four hundred and twenty two centers recruited 652 patients (mean age: 51 +/- 15 years, 55% female). Upper GI endoscopy was abnormal in 80% of the patients of whom 68% had a gastritis aspect; 38% were infected by H. pylori, and among them 51% were cagA-positive. The histological virulence scores associated with the cagA-positive strains were significantly higher than those associated with the cagA-negative strains, globally (P = 0.0035), in the antrum (P = 0.0063), and in the angulus (P = 0.046), but not in the fundus (P = 0.05). The cagA status was correlated neither with the symptom severity at inclusion and at 6 months (P > 0.05), nor with the H. pylori eradication rate at 3 months (75% in cagA-positive and 70% in cagA-negative strains, P = 0.52).

CONCLUSION

This study on a large cohort of patients confirms the greater histological virulence of H. pylori cagA-positive strains. However, this virulence was not associated with more severe symptoms nor with an increase in resistance to H. pylori eradication treatment.

Clinicoanatomic studies in dysarthria: review, critique, and directions for research

More than 30 years ago, Darley, Aronson, and Brown (1969) proposed clinicoanatomic correlations for seven perceptual types of dysarthria. These correlations have not been systematically re-examined even though imaging technologies developed in recent years provide the means to do so. This review considers data from published imaging studies as well as data from selected medical interventions to evaluate the current state of knowledge that relates lesion site to the nature of a speech disturbance. Although the extant data are not sufficient to allow a complete evaluation of the seven types of dysarthria described by Darley et al., relevant information has been reported on lesions of the pyramidal pathway, extrapyramidal pathway, and cerebellum. In general, the results are best explained by an equivalence mode of brain-behavior relationship in which a type of dysarthria is associated with a lesion in one of two or more brain structures. Criteria also are proposed for future studies of clinicoanatomic relationships in neurogenic communication disorders.

Mitochondrial respiratory chain deficiency revealed by hypothermia

We observed a 17-month-old girl with profound and initially isolated episodes of hypothermia. Thereafter, she developed growth delay, repetitive corneal and bone lesions. Persistent hyperlactataemia in plasma and in CSF prompted us to investigate respiratory chain enzymes. A deficit in respiratory chain complexes III and IV was demonstrated in isolated skeletal muscle mitochondria, circulating lymphocytes and fibroblasts by spectrophotometric and polarographic studies. Moreover, UCP3 mRNA expression in muscle was decreased.

[Paratesticular rhabdomyosarcoma]

The authors report a case of embryonal paratesticular rhabdomyosarcoma in a 9-year-old child and discuss the treatment modalities in the light of data from the literature.

[Maternal and perinatal morbidity and mortality associated with hellp syndrome]

OBJECTIVES

Our purpose was to describe the effects of serious obstetric complications on maternal and perinatal outcome in pregnancies complicated by Hellp syndrome.

STUDY DESIGN

Retrospective study.

PATIENTS

Sixteen patients managed from January 1994 through December 1998 in whom pregnancy was complicated by Hellp Syndrome.

RESULTS

The incidence of Hellp syndrome among women with severe preeclampsia and/or eclampsia (164 cases) was 9.7%. Fourteen cases occurred before and two after delivery. In nine cases, Hellp occurred before 32 weeks of gestation and later in two other cases. Mean gestational age at delivery was 32.4 weeks. Serious maternal morbidity included acute renal failure (five cases), disseminated intravascular coagulation (two cases), pulmonary oedema (one case), severe ascites (five cases), pleural effusion (three cases), adult respiratory distress syndrome (one case). Abruptio placenta, acute renal failure and disseminated intravascular coagulation were always associated. Ten patients required transfusions with blood products. Caesarean delivery was performed in 15 cases. General anaesthesia was used in all patients. There was one maternal death from multiple organ failure. Perinatal outcome was poor. Six perinatal deaths were related to abruptio placenta, intrauterine asphyxia and extreme prematurity.

CONCLUSION

The high maternal and perinatal mortality and morbidity reported with the presence of Hellp syndrome requires maternal-fetal follow-up in a tertiary centre where intensive maternal and neonatal care are available.

[Bladder leiomyosarcoma: report of a case]

Leiomyosarcoma of the urinary bladder is an extremely rare disease. In this study, which also includes a review of the literature, a new case of urinary bladder leiomyosarcoma has been reported in a 65-year old male, which was detected during an investigation of total hematuria accompanied by burning upon micturition. The clinical examination was normal, but ultrasonography followed by bladder endoscopy showed the presence of a large bladder tumor. The definitive diagnosis of this type of tumor can only be made after histological and immunohistochemical investigation, and to avoid unnecessary surgery it is essential to first differentiate it from an inflammatory pseudosarcoma. Although in the present study the outcome following total cystoprostatectomy was favorable at 3 months follow-up, in general the prognosis is uncertain due to the potentially invasive character of this type of tumor. Given the limited number of studies on the subject treatment still remains controversial, but is essentially based on surgical excision, possibly with adjuvant chemotherapy.

[Epidemiology of gastro-esophageal-reflux in general practice. . Predictive factors for health care utilization in the course of a year]

AIM

To assess the epidemiology and course of GORD, treatment demand, and factors predictive of GORD course in a 1-year study in patients with heartburn consulting general practitioners.

METHODS

A total of 984 patients with pyrosis were included by general practitioners. After the initial visit, they had follow up at 3, 6 and 12 months by phone contact.

RESULTS

Most patients (87%) had been suffering from heartburn for 4+/-1.5 years; upper GI endoscopy had been performed in 63% of patients. Patients evaluated the symptoms of the current episode as mild (6%), moderate (60%), or severe/incapacitating (34%). During the year of follow up, 12% of the patients were free of heartburn; the mean number of consultations with general practitioners and gastroenterologists was 5.1 and 0.5 respectively. At day 90, discomfort due to heartburn was absent in 4% of patients, slight in 51%, moderate in 32%, and severe in 6%. At day 360, predictive factors for discomfort were: discomfort related to heartburn on D90, the length of time the patients had been suffering from GORD, and the main reason for consultation on D1; patients for whom heartburn was not the main reason for consultation on D1 experienced a higher level of discomfort. The predictive factors for the extent of treatment demand over 12 months were: age, discomfort related to heartburn on D90, severity on D1, the frequency of episodes prior to the episode on D1 and the levels of stress and anxiety measured on D1.

CONCLUSIONS

Epidemiologic characteristics of patients with heartburn consulting a general practitioner were different from these of the general population. Treatment demand depends both on severity of heartburn and level of stress and anxiety.

Persistent mitochondrial dysfunction and perinatal exposure to antiretroviral nucleoside analogues

BACKGROUND

Zidovudine is commonly administered during pregnancy to prevent mother-to-child HIV-1 transmission. We investigated mitochondrial toxic effects in children exposed to zidovudine in utero and after birth.

METHODS

We analysed observations of a trial of tolerance of combined zidovudine and lamivudine and preliminary results of a continuing retrospective analysis of clinical and biological symptoms of mitochondrial dysfunction in children born to HIV-1-infected women in France. Mitochondrial dysfunction was studied by spectrophotometry and polarography of respiratory-chain complexes in various tissues.

FINDINGS

Eight children had mitochondrial dysfunction. Five, of whom two died, presented with delayed neurological symptoms and three were symptom-free but had severe biological or neurological abnormalities. Four of these children had been exposed to combined zidovudine and lamivudine, and four to zidovudine alone. No child was infected with HIV-1. All children had abnormally low absolute or relative activities of respiratory-chain complexes I, IV, or both months or years after the end of antiretroviral treatment. No mutation currently associated with constitutional disease was detected in any patient.

INTERPRETATION

Our findings support the hypothesis of a link between mitochondrial dysfunction and the perinatal administration of prophylactic nucleoside analogues. Current recommendations for zidovudine monotherapy should however be maintained. Further assessment of the toxic effects of these drugs is required.

[Peripartum cardiomyopathy. Clinical case series]

We report a retrospective analysis of four cases of peripartum cardiomyopathy admitted, within a 10-year period, to the maternity hospital of Sousse. The age of the patients was over 30 years, two had gemellary pregnancies and two suffered toxaemia. Congestive cardiac failure, mainly of the left ventricle, with acute pulmonary oedema, was the main symptom. Chest X-ray showed a cardiothoracic index above 0.58 and echocardiography a left ventricular telediastolic diameter above 5.7 cm and a shortening ratio of 25% or less. Endomyocardial biopsy for ascertaining the diagnosis was not available. Treatment included bed rest, water and salt restriction, digitalis, a diuretic and an anticoagulant in case antepartum cardiomyopathy, a converting enzyme inhibitor and a diuretic in case of postpartum cardiomyopathy. Three patients recovered totally and in one echocardiography showed a persisting impaired left ventricular function. Five neonates had a favourable outcome and one foetus died in utero. Main problems raised by peripartum cardiomyopathy are discussed.

Recognition and management of fatty acid oxidation defects: a series of 107 patients

In a personal series of 107 patients, we describe clinical presentations, methods of recognition and therapeutic management of inherited fatty acid oxidation (FAO) defects. As a whole, FAO disorders appear very severe: among the 107 patients, only 57 are still living. Including 47 siblings who died early in infancy, in total 97 patients died, of whom 30% died within the first week of life and 69% before 1 year. Twenty-eight patients presented in the neonatal period with sudden death, heart beat disorders, or neurological distress with various metabolic disturbances. Hepatic presentations were observed in 73% of patients (steatosis, hypoketotic hypoglycaemia, hepatomegaly, Reye syndrome). True hepatic failure was rare (10%); cholestasis was observed in one patient with LCHAD deficiency. Cardiac presentations were observed in 51% of patients: 67% patients presented with cardiomyopathy, mostly hypertrophic, and 47% of patients had heart beat disorders with various conduction abnormalities and arrhythmias responsible for collapse, near-miss and sudden unexpected death. All enzymatic blocks affecting FAO except CPT I and MCAD were found associated with cardiac signs. Muscular signs were observed in 51% of patients (of whom 64% had myalgias or paroxysmal myoglobinuria, and 29% had progressive proximal myopathy). Chronic neurologic presentation was rare, except in LCHAD deficiency (retinitis pigmentosa and peripheral neuropathy). Renal presentation (tubulopathy) and transient renal failure were observed in 27% of patients. The diagnosis of FAO disorders is generally based on the plasma acylcarnitine profile determined by FAB-MS/MS from simple blood spots collected on a Guthrie card. Urinary organic acid profile and total and free plasma carnitine can also be very helpful, mostly in acute attacks. If there is no significant disturbance between attacks, the diagnosis is based upon a long-chain fatty acid loading test, fasting test, and in vitro studies of fatty acid oxidation on fresh lymphocytes or cultured fibroblasts. Treatment includes avoiding fasting or catabolism, suppressing lipolysis, and carnitine supplementation. The long-term dietary therapy aims to prevent periods of fasting and restrict long-chain fatty acid intake with supplementation of medium-chain triglycerides. Despite these therapeutic measures, the long-term prognosis remains uncertain.

Defects in activation and transport of fatty acids

The oxidation of long-chain fatty acids in mitochondria plays an important role in energy production, especially in skeletal muscle, heart and liver. Long-chain fatty acids, activated to their CoA esters in the cytosol, are shuttled across the barrier of the inner mitochondrial membrane by the carnitine cycle. This pathway includes four steps, mediated by a plasma membrane carnitine transporter, two carnitine palmitoyltransferases (CPT I and CPT II) and a carnitine-acylcarnitine translocase. Defects in activation and uptake of fatty acids affect these four steps: CPT II deficiency leads to either exercise-induced rhabdomyolysis in adults or hepatocardiomuscular symptoms in neonates and children. The three other disorders of the carnitine cycle have an early onset. Hepatic CPT I deficiency is characterized by recurrent episodes of Reye-like syndrome, whereas severe muscular and cardiac signs are associated with episodes of fasting hypoglycaemia in defects of carnitine transport and translocase. Convenient metabolic investigations for reaching the diagnosis of carnitine cycle disorders are determination of plasma free and total carnitine concentrations, determination of plasma acylcarnitine profile by tandem mass spectrometry and in vitro fatty acid oxidation studies, particularly in fresh lymphocytes. Application of the tools of molecular biology has greatly aided the understanding of the carnitine palmitoyltransferase enzyme system and confirmed the existence of different related genetic diseases. Mutation analysis of CPT II defects has given some clues for correlation of genotype and phenotype. The first molecular analyses of hepatic CPT I and translocase deficiencies were recently reported.