[Cytochrome c oxydase-deficient Leigh syndrome with homozygous mutation in SURF1 gene]. / Syndrome de Leigh avec déficit en cytochrome c oxydase lié à une mutation homozygote du gène SURF1.

Leigh syndrome is a heterogeneous disorder, usually due to a defect in oxidative metabolism. Mutations in SURF1 gene have been identified in patients with cytochrome c oxidase deficiency. We report a homozygous splice site deletion [516-2_516-1delAG] in a young girl presenting with cytochrome c oxidase-deficient Leigh syndrome. Identification of molecular defect is indispensable for genetic counselling and prenatal diagnosis.

Phenotypic expression of diabetes secondary to a T14709C mutation of mitochondrial DNA. Comparison with MIDD syndrome (A3243G mutation): a case report.

OBJECTIVE: To analyze the clinical and biochemical features of a recently described point mutation of mitochondrial DNA associated with diabetes. This mutation, characterized by a T14709C transition of a highly conserved nucleotide in the region coding for the glutamic acid tRNA, is heteroplasmic. RESEARCH DESIGN AND METHODS: The phenotypic expression in the insulin-requiring diabetic proband from the pedigree was compared to that of diabetic probands from three families with the classic A3243G mtDNA mutation (maternally inherited diabetes and deafness [MIDD] syndrome). The same investigations to evaluate pancreatic neurosensorial and muscle involvement were performed in all four patients. RESULTS: The natural courses of the diabetes and the hearing defects were not different between the two mutations. The patient with the 14,709 mutation, however, exhibited a milder alteration of pigmentary epithelium of retina and a much more severe muscle involvement, as attested by the clinical expression and the concurrent anomalies of muscle energy production evidenced by 31P magnetic resonance spectroscopy, confirming the profound impairment of oxidative processes. CONCLUSIONS: This novel mutation has to be added to the other known mtDNA anomalies in order to ascribe some diabetes suspected to arise from mitochondrial defects to this nosological framework.

Mutation and haplotype analyses in 26 Spanish Sanfilippo syndrome type A patients: possible single origin for 1091delC mutation.

Mucopolysaccharidosis IIIA, also known as Sanfilippo syndrome type A, is an autosomal recessive storage disorder caused by deficiency of sulfamidase. The disease results in severe central nervous system degeneration often with mild somatic features that may delay the clinical diagnosis. Molecular analyses would allow early and unequivocal heterozygote detection, providing a useful tool for genetic counselling. About 40 mutations have been reported in the sulfamidase gene, with a very uneven distribution in different patient populations. We have previously described the high prevalence of mutation 1091delC in a small number of Spanish Sanfilippo A patients. The aim of the present work is to extend the mutational study to a total of 26 unrelated patients and perform haplotype analysis in order to study the origin of some mutations. The whole coding region of the gene was scanned by SSCP analysis and sequencing. This allowed the identification of 14 different mutations, corresponding to 90% of the mutant alleles. Seven of these mutations were only found in this Spanish group of patients, three of which, R150W, R433Q and R433W, are described here for the first time. We have also analyzed four internal polymorphisms and constructed the corresponding haplotypes. Chromosomes bearing mutation 1091delC show a conserved haplotype suggesting a common origin for this mutation. Moreover, all other mutations found twice or more also have conserved haplotypes for those polymorphic markers.

Stüve-Wiedemann syndrome and defects of the mitochondrial respiratory chain.

The Stüve-Wiedemann syndrome (SWS) comprises short stature, congenital bowing of the long bones, respiratory distress, and recurrent episodes of unexplained hyperthermia. The skeletal radiographic changes include short and broad long bones, large metaphyses, internal cortical thickening, and angulation primarily of tibiae and femora, but also of humeri and forearm bones. We report 3 cases of SWS from 2 different unrelated consanguineous gypsy families. All 3 cases fulfilled the clinical and radiological criteria of SWS. Two patients died shortly after birth, whereas the third one was alive at the age of one year. Besides hyperthermic episodes, one patient had hyperaminoaciduria, hepatic failure, and megaloblastic anemia which prompted us to investigate mitochondrial respiratory chain in 2 cases. Abnormal results consisting of decreased activities of complex I and IV were found in both. The simultaneous occurrence of both SWS phenotype and abnormal mitochondrial metabolism in two unrelated cases strongly supports the hypothesis of a pathogenetic relationship between the two events. These cases may also be related to recent reports on the effects of the mitochondrial respiratory chain defects on embryogenesis.

Assessment of resorbable bioactive material for grafting of critical-size cancellous defects.

Bioactive glasses form a surface apatite layer in vivo that enhances the formation and attachment of bone. Sol-gel Bioglass graft material provides greater nanoscale porosity than bioactive glass (on the order of 50-200 A), greater particle surface area, and improved resorbability, while maintaining bioactivity. This study histologically and biomechanically evaluated, in a rabbit model, bone formed within critical-sized distal femoral cancellous bone defects filled with 45S5 Bioglass particulates, 77S sol-gel Bioglass, or 58S sol-gel Bioglass and compared the bone in these defects with normal, intact, untreated cancellous bone and with unfilled defects at 4, 8, and 12 weeks. All grafted defects had more bone within the area than did unfilled controls (p < 0.05). The percentage of bone within the defect was significantly greater for the 45S5 material than for the 58S or 77S material at 4 and 8 weeks (p < 0.05), yet by 12 weeks equivalent amounts of bone were observed for all materials. By 12 weeks, all grafted defects were equivalent to the normal untreated bone. The resorption of 77S and 58S particles was significantly greater than that of 45S5 particles (p < 0.05). Mechanically, the grafted defects had compressive stiffness equivalent to that of normal bone at 4 and 8 weeks. At 12 weeks, 45S5-grafted defects had significantly greater stiffness (p < 0.05). At 8 and 12 weeks, all grafted defects had significantly greater stiffness than unfilled control defects (p < 0.05). In general, the 45S5-filled defects exhibited greater early bone ingrowth than did those filled with 58S or 77S. However, by 12 weeks, the bone ingrowth in each defect was equivalent to each other and to normal bone. The 58S and 77S materials resorbed faster than the 45S5 materials. Mechanically, the compressive characteristics of all grafted defects were equivalent or greater than those of normal bone at all time points.

Development and characterization of type 2 pneumocyte-related cell lines from normal adult mouse lung.

Cell lines which exhibit epithelial morphology with surface microvilli and inclusion bodies characteristic of type 2 pneumocytes have been derived from normal adult mouse lung by a simple procedure involving enzymatic dispersal and mechanical elimination of other cell types. One of these cell lines designated NAL 1A, examined in detail, shows features consistent with its being related to type 2 pneumocytes of mouse lung. These features include desmosomes, dense lamellar bodies as well as phospholipid profiles related to immature surface active material, the inhibition of cell growth rate by dexamethasone, and the close similarity of the cytoskeletal protein patterns of this cell line to those of a metastatic type 2 pneumocyte-related cell line of mouse lung. The cell line from normal lung demonstrated near diploid chromosome number at low passage number with some evidence of karyotype instability at high passage number.

Dietary fiber consumption in an adult Dutch population.

The intake of dietary fiber in an adult Dutch population aged 25 to 65 years was found to be 24.0 +/- 6.9 gm. per day (mean +/- SD), or 10.5 +/- 2.6 gm. per 1,000 kcal. Important sources of dietary fiber were bread and other cereals (32 percent of dialy intake), potatoes (17 percent), other vegetables (24 percent), and fruit (15 percent). For estimating group means of daily dietary fiber intake, equal precision can obtained by using a seven-day record method or by collecting one-day records from twice as many subjects.

Mechanical strength of fracture callus in osteopenic bone at different phases of healing.

OBJECTIVES: To quantify and compare peak bending force and stiffness of fractured femurs during healing of ovariectomized (OVX) and sham-operated (SHAM) rats. DESIGN: Temporal biomechanical animal study. SETTING: Rat femurs were fractured and surgically fixed by a qualified surgeon. The inherent instability of the fixation system employed produced delayed union of the fracture. All biomechanical assessments were performed with servohydraulic test machines (Instron Inc., Canton, MA, U.S.A.; and MTS Corp., Eden Prairie, MN, U.S.A.). INTERVENTION: OVX was performed sixteen weeks before femur fracture, and the effect of OVX on healing fractures was determined. MAIN OUTCOMES: Peak bending force and stiffness of the healing femurs at four, six, and eight weeks after fracture. RESULTS: Peak bending loads of the healing fractured femurs in the OVX and SHAM animals were not significantly different. Peak bending loads for the OVX animals at four and six weeks were significantly lower than the peak load at eight weeks (p < 0.05), whereas no difference was found in the peak load with respect to time for the SHAM animals. Both SHAM and OVX animals had greater bending stiffness of the healing fractured femur after eight weeks of healing than at four weeks (p < 0.05). CONCLUSIONS: OVX is known to reduce cancellous bone mass and strength, but the effect of OVX on healing of fractures in cortical bone is controversial. This study, using a delayed-union model, found no significant differences between OVX and SHAM animals in the breaking strength of healing fractures.

Differential healing response of bone adjacent to porous implants coated with hydroxyapatite and 45S5 bioactive glass.

This study tested the hypothesis that the rate and the extent of bone formation adjacent to porous, coated Ti-6Al-4V implants are differentially affected by the type of bioactive ceramic coating. Forty-eight rabbits received cylindrical Ti-6Al-4V intramedullary distal femoral implants bilaterally. Implants for the right limbs were coated with 45S5 Bioglass (45S5). Implants used for the left limbs either were coated with tricalcium phosphate/hydroxyapatite (HA) or were left uncoated as controls (CTL). The 45S5-coated implants histologically and biomechanically were compared to HA-coated and CTL implants at 4, 8, 12, and 16 weeks. After 12 and 16 weeks of healing, more bone and thicker trabeculae were measured histomorphometrically within the implant pores for the 45S5-coated implants compared to the HA-coated and CTL implants (p < 0.05). With time the HA-coated and CTL groups exhibited a significant decline in percent of bone and of trabecular thickness (p < 0.05) while the 45S5-coated implants did not. Biomechanical analyses indicated similar shear strengths for all treatment groups. In summary, 45S5-coated implants exhibited greater bone ingrowth compared to HA-coated and CTL implants, and they maintained their mechanical integrity over time.

Genetic fine localization of the beta-glucocerebrosidase (GBA) and prosaposin (PSAP) genes: implications for Gaucher disease.

Mutations in the glucocerebrosidase (GBA) and prosaposin (PSAP) genes are responsible for Gaucher disease, the most prevalent sphingolipidosis. Somatic cell hybrid analysis and in situ hybridization experiments have localized the GBA gene to 1q21 and the PSAP gene to 10q21-q22. We performed pairwise and multi-point linkage analyses between the two genes and several highly polymorphic markers from the Généthon human linkage map. Our results show that six markers cosegregate with the GBA gene (Zmax = 8.73 at theta = 0.00 for marker D1S2714) and define a 3.2-cM interval between D1S305 and D1S2624 as the most probable location for the gene. Three of these markers (D1S2777, D1S303, and D1S2140), as well as the gene encoding pyruvate kinase (PKLR), are contained in a single YAC clone together with the GBA gene. A new polymorphism was identified within the PSAP gene (C16045T) and used for linkage studies. The multi-point analysis places the gene in a 9.8-cM interval between D10S1688 and D10S607. The fine localization of these genes provides a useful tool for cosegregation analysis, indirect molecular diagnosis, and population genetic studies.

Establishment of epithelial cell strains from normal adult mouse lung resembling a urethane-induced lung adenoma cell strain and a metastasizing mouse lung carcinoma cell line.

Epithelial cell strains, designated NAL, have been established from normal lungs of adult female Balb/c mice. The ultrastructural characteristics, effect of dexamethasone on cellular morphology and proliferation rate, and the cytoskeletal protein pattern of NAL suggests that these cell strains may be related to a urethane-induced mouse lung adenoma cell strain NUL and to a metastasizing mouse lung tumour cell line CMT. NAL exhibited no anchorage-independent growth under normal conditions, however extensive passaging in the presence of 5 X 10(-6)M dexamethasone resulted in a colony forming efficiency in soft agar of 8.4% at passage number 30.

Reliable co-segregation analysis for prenatal diagnosis and heterozygote detection in Gaucher disease.

Mutations in the gene encoding beta-glucocerebrosidase are the main cause of Gaucher disease. The identification of some of these mutations in prenatal tests is a good complement to enzymatic assay and allows diagnosis and, in some cases, prognosis of the disease to be made. DNA analysis is particularly useful for carrier detection since the results of biochemical analyses are often ambiguous. The main drawback of mutation analysis for prenatal diagnosis and carrier detection in Gaucher disease is that rare mutations account for more than 30 per cent of the mutant alleles in most populations. The individual detection of these mutations is too expensive and time-consuming for routine use. Here we present a diagnostic protocol based on co-segregation analysis, using highly polymorphic markers, to be applied when at least one disease allele does not correspond to the most common mutations. Because of the frequency of the N370S mutation and its relevance for prognosis, an improved PCR detection method is included.

Differences in individual responsiveness of serum cholesterol to fat-modified diets in man.

In the period 1963-1974, 82 monks and 48 nuns from five Dutch and Belgian Trappist monasteries each participated in two or more out of nine different trials designed to test the effect of 58 different fat-modified diets on serum cholesterol. We analysed these data to quantify the extent to which healthy, normolipaemic subjects differ in the responsiveness of their serum cholesterol to a change in dietary fatty acid composition. Statistically significant between-person variance components (SD2p) were found in the serum cholesterol responses for the whole group (SD2p = [0.20 mmol l-1]2), for the men (SD2p = [0.24 mmol l-1]2) and for those women who participated in three or more trials (SD2p = [0.14 mmol l-1]2). The between-person variation (expressed as SD) was on average only half as large as the within-person variation in response when the same subject was challenged repeatedly. It is concluded that medically significant differences in responsiveness to fat-modified diets exist in both men and women. However, few subjects fail entirely to respond to a change in dietary fatty acid composition. In addition, the large within-subject variability makes it difficult to identify hypo- and hyperresponders.

Clinical features and neuroradiological findings of mitochondrial pathology in six neonates.

OBJECTS: We hoped to itemize the clinical and neuroradiological features of six neonates with mitochondrial disorders. METHODS: We examined a case series of six neonates. The diagnosis of mitochondrial cytopathy was made on the basis of spectrophotometric measurements of respiratory chain enzyme activities in skeletal muscle biopsy specimens. Magnetic resonance (MR) imaging was performed in all cases. CONCLUSIONS: The antenatal onset in five cases and the lack of any symptom-free interval are suggestive of fetal expression of the disease. No specific symptoms were found: arthrogryposis congenita multiplex in one, progressive hepatocellular dysfunction in three, encephalomyelopathy and cardiomyopathy in four. Complex I deficiency was found in three patients, while one patients had a defect of complex IV and the last a combined defect of complexes I and IV. Neuroradiological findings were either cerebral atrophy or white matter abnormalities of the brain stem in all cases but one and gave additional information, because clinical symptoms are not quite specific. The combination of clinical and MRI findings in neonatal cases can rule out hypoxic ischemic encephalopathy, which suggests an additional screening method to look for mitochondrial disorder.

Mutation 1091delC is highly prevalent in Spanish Sanfilippo syndrome type A patients.

The gene resposible for Sanfilippo syndrome type A, a lysosomal disorder caused by deficiency of sulfamidase, was recently cloned and more than 40 mutations were identified. This paper presents the mutation analysis and clinical findings in 11 Spanish patients in whom 19 of the 22 mutant alleles have been identified. This is the first report on mutations in Spanish Sanfilippo A patients. Seven different mutations were found, four of which (Q85R, R206P, A354P, and L386R) were not previously described. Mutation 1091delC was the most prevalent, accounting for nearly one-half of the mutated alleles, while mutations R245H and R74C were not found. Haplotype analysis suggests a founder effect as the cause of the high frequency of 1091delC in this population.