Insight into the Pathology of a COL1A1 Signal Peptide Heterozygous Mutation Leading to Severe Osteogenesis Imperfecta.

Osteogenesis imperfecta or "brittle bone disease" is a congenital disorder of connective tissue causing the bone to break easily. Around 85-90% of cases are due to autosomal dominant mutations in the genes encoding type I collagen, the major organic component of bone. Genotype-phenotype correlations have shown that quantitative defects of collagen type I lead to mild OI, whereas structural defects show a wide clinical range from mild to perinatal lethal. This may partially be explained by the type of amino acid substitution and the relative location in the domain structure. To fully understand the variability of the clinical manifestation and the underlying pathomechanisms, further investigations are required. Here we provide the first biochemical characterization of a mutation at the signal peptide cleavage site of COL1A1, a domain not yet characterized. By steady-state analysis, we observed reduced production of collagen type I. Furthermore, by pulse-chase analysis we detected delayed secretion and partial intracellular retention of collagen I. In the cellular fraction, the electrophoretic migration was abnormal; however, secreted type I collagen showed a normal migration pattern. The intracellular retention of collagen I was confirmed by immunofluorescent staining. Moreover, transmission electron microscopy of cultured fibroblasts revealed enlargement of ER cisternae. These results further support the hypothesis that mechanisms interfering with ER integrity play an important role in the pathology of severe OI.

Influence of ethanol, malate and arginine on histamine production of Lactobacillus hilgardii isolated from an Italian red wine.

Wine, like other fermented foods, may contain biogenic amines produced by lactic acid bacteria via amino acids decarboxylation. The most relevant amines from the toxicological standpoint are histamine and tyramine. The complexity of fermented substrates makes it difficult to suggest a priori how variables can modulate amine production. Lactobacillus hilgardii ISE 5211 was isolated from an Italian red wine. Besides producing lactate from malate, this strain is also able to convert arginine to ornithine and histidine to histamine. In the present investigation we studied the influence of malate, arginine and ethanol on histamine accumulation by L. hilgardii ISE 5211. Ethanol concentrations above 13% inhibit both histamine accumulation and bacterial growth; concentrations below 9% affect neither growth nor histamine production. However, an ethanol concentration of 11% allows a low but continuous accumulation of histamine to occur. Arginine also delays histamine accumulation, while malate appears to have no effect on histidine-histamine conversion.

Suppression of tumorigenicity and anchorage-independent growth of BK virus-transformed mouse cells by human chromosome 11.

Viral transformation models may be useful for detecting and mapping human tumor suppressor genes. BK virus (BKV), a human papovavirus, readily transforms rodent cells but is unable to transform human cells, suggesting that oncosuppressive functions expressed in human cells control BKV oncogenic activity. We have transferred human chromosome 11 to BKV-transformed mouse cells. All of the cell clones were suppressed in the tumorigenic phenotype and anchorage-independent growth, except one clone which was nontumorigenic but maintained the ability to grow in soft agar. Cytogenetic analysis and DNA hybridization with chromosome 11-specific probes showed that all the reverted hybrids had an intact human chromosome 11, except the clone growing in semisolid medium which had lost the short arm. The results suggest that a gene located on 11p controls anchorage independence, whereas a gene on 11q controls the tumorigenicity of BKV-transformed cells. BKV T-antigen was expressed in all the hybrid clones at the same level as in the parental cell line, indicating that the putative human tumor suppressor gene(s) do not inhibit expression of the viral oncogene and must operate by another mechanism in inducing reversion of the oncogenic phenotype. Since BKV-transformed mouse cells are highly susceptible to retrovirus infection, this model can be used for searching and cloning tumor suppressor gene(s) by retrovirus-mediated "insertional mutagenesis".

Hepatic removal of 125I-DLT gelatin after burn injury: a model of soluble collagenous debris that interacts with plasma fibronectin.

The decline of plasma fibronectin after surgery, trauma, and burn, as well as during severe sepsis after injury, appears to limit hepatic Kupffer cell phagocytic activity. Intravenous infusion of gelatin-coated particles to simulate blood-borne particulate collagenous tissue debris in the circulation after injury also depletes plasma fibronectin. We used soluble gelatin conjugated with 125I-labeled dilactitol tyramine (DLT-gelatin) as a model of soluble collagenous tissue debris. We studied its blood clearance as well as organ localization in normal and postburn rats. Fibronectin-deficient plasma harvested early after burn exhibited limited ability to support in vitro phagocytic uptake of the gelatinized microparticles by Kupffer cells in liver tissue from normal rats. However, Kupffer cells in liver tissue from normal and postburn rats phagocytized the test particles at a normal rate when incubated in normal plasma. The DLT-gelatin ligand bound to fibronectin in a dose-dependent manner as verified by its capture with anti-fibronectin coated plastic wells when coincubated with purified fibronectin. By gel filtration chromatography, the binding of fibronectin with the DLT-gelatin ligand was readily detected, resulting in the formation of a high-molecular-weight complex. In normal animals the plasma clearance and liver localization of 125I-DLT-gelatin was competitively inhibited by infusion of excess nonradioactive gelatin. The blood clearance and liver localization of the soluble gelatin ligand were also impaired after burn injury during periods of fibronectin deficiency similarly to the pattern observed with gelatin-coated microparticles. By autoradiography, the cellular site for the uptake of the 125I-DLT-gelatin was primarily but not exclusively hepatic Kupffer cells; 125I-DLT-asialofetuin and 125I-DLT-ovalbumin were removed by hepatocytes and sinusoidal endothelial cells, respectively. Thus, gelatin conjugated with 125I-DLT can be used to simulate blood-borne soluble collagenous tissue debris after burn. It rapidly binds to plasma fibronectin before its hepatic Kupffer cell removal, and its blood clearance is markedly delayed after burn injury during periods of plasma fibronectin deficiency.

Characterization of 11 new mutations in COL3A1 of individuals with Ehlers-Danlos syndrome type IV: preliminary comparison of RNase cleavage, EMC and DHPLC assays.

We report on 12 patients with EDS IV in whom clinical diagnosis was confirmed by biochemical analysis of collagen type III, and further proven by mutation analysis of the COL3A1 gene. Four overlapping RT-PCR products covering the coding sequence for the triple-helical domain of type III collagen were analyzed by direct sequencing. So far, we have identified, 4 base changes at donor splice junctions, and 1 base change at an acceptor splice site, which all affect mRNA splicing; 1 genomic deletion, which removes exon 45; and 6 nucleotide changes, which cause substitutions of glycine residues within the triple helix. Eleven of the 12 identified mutations are newly recognized. Furthermore, we report a preliminary comparison of RNase cleavage, EMC and DHPLC assays in mutation detection in the COL3A1 gene.

Purification, biochemical properties and substrate specificity of a catechol 1,2-dioxygenase from a phenol degrading Acinetobacter radioresistens.

A catechol 1,2-dioxygenase (C1,2O) has been purified to homogeneity from Acinetobacter radioresistens grown on phenol as the sole carbon and energy source. The C1,2O appears to be a homodimer, with a molecular mass of 78,000 Da. At relatively high ionic strengths (0.5 M Na2SO4) subunit dissociation occurs and the monomeric unit (38,700 Da) is shown to be active. This phenomenon has never been observed before in dioxygenases. The purified C1,2O contains 0.96 iron(III) ions per unit and spectroscopic measurements suggest the presence of one high-spin iron(III) ion in an environment characteristic of intradiol cleaving enzymes. The NH2-terminal amino acid sequence has been determined and compared to the primary structures of intradiol rings cleaving dioxygenases from other Acinetobacter strains revealing 45% homology with the benzoate-grown A. calcoaceticus ADP-1 and an identity of only one of the 20 amino acids sequenced for the phenol-grown A. calcoaceticus NCIB 8250.

Compound heterozygosity for a disease-causing G1489E [corrected] and disease-modifying G530S substitution in COL5A1 of a patient with the classical type of Ehlers-Danlos syndrome: an explanation of intrafamilial variability?

The classical type of Ehlers-Danlos syndrome (EDS) is an autosomal dominant connective tissue disorder characterized by skin hyperelasticity, tissue fragility, and joint hypermobility. We investigated the molecular defect of EDS in a three-generation family. Cultured dermal fibroblasts from the propositus and his daughter produced abnormal alpha1(V) and alpha2(V) collagen molecules. Mutation analysis by means of RNase cleavage and direct sequencing of reverse transcription-polymerase chain reaction products showed in both the presence of a heterozygous G1489E [correction] mutation in the COL5A1 gene, which represents the first report of a glycine substitution in the main triple-helical region of alpha1(V) collagen. In the propositus, his unaffected daughter, and mother we identified a further newly recognized G530S substitution in the NH2-terminal domain, which did not cosegregate with the EDS phenotype and was found in only one of 51 unrelated control individuals. Because the NH2-terminal domain plays a crucial role in modulating fibril formation, the G530S substitution may alter the structure and function of this region and consequently the formation of collagen fibrils. Indeed, indirect evidence supports our hypothesis: (1) the EDS phenotype in the compound heterozygous propositus is more severe than that of his affected daughter with the G1489E [correction] mutation only; (2) his unaffected daughter and mother with the G530S substitution present with thin skin and delayed wound healing; (3) as does the only control individual with the same substitution. Thus, in the compound heterozygous propositus the EDS phenotype is caused by the G1489E [correction] mutation and possibly aggravated by the G530S substitution, which may explain intrafamilial variability.

Sibs affected with both Ehlers-Danlos syndrome type IV and cystic fibrosis.

We report on the unprecedented combination of two recessively inherited disorders, the kyphoscoliosis type of Ehlers-Danlos syndrome (EDS type VI) and cystic fibrosis (CF), in two sibs born to consanguineous Turkish parents. Because of failure to thrive and bronchitis CF was diagnosed in the index patient early whereas EDS VI was recognized only very late. Both patients had marked muscular hypotonia at birth, delayed gross motor development, progressive kyphoscoliosis, joint dislocations, Marfanoid habitus, hypertrophic and atrophic scars, and osteopenia. EDS VI was proven by collagen studies and the pathognomonic pattern of urinary pyridinolines. Because the genes coding for the two disorders are located on different chromosomes and a chromosomal rearrangement was excluded, we conclude that their combination is a chance association. The cardiopulmonary impairment common to both diseases makes the prognosis dismal.

Homozygous Gly530Ser substitution in COL5A1 causes mild classical Ehlers-Danlos syndrome.

Skin hyperelasticity, tissue fragility with atrophic scars, and joint hypermobility are characteristic for the classical type of Ehlers-Danlos syndrome (EDS). The disease is usually inherited as an autosomal dominant trait; however, recessive mode of inheritance has been documented in tenascin-X-deficient EDS patients. Mutations in the genes coding for collagen alpha1(V) chain (COL5A1), collagen alpha2(V) chain (COL5A2), tenascin-X (TNX), and collagen alpha1(I) chain (COL1A1) have been characterized in patients with classical EDS, thus confirming the suspected genetic heterogeneity. Recently, we described a patient with severe classical EDS due to a Gly1489Glu substitution in the alpha1(V) triple-helical domain who was, in addition, heterozygous for a disease-modifying Gly530Ser substitution in the alpha1(V) NH(2)-terminal domain [Giunta and Steinmann, 2000: Am. J. Med. Genet. 90:72-79; Steinmann and Giunta, 2000: Am. J. Med. Genet. 93:342]. Here, we report on a 4-year-old boy with mild classical EDS, born to healthy consanguineous Turkish parents; the mother presented a soft skin, while the father had a normal thick skin. Ultrastructural analysis of the dermis revealed in the patient the typical "cauliflower" collagen fibrils, while in both parents variable moderate aberrations were seen. Mutation revealed the presence of a homozygous Gly530Ser substitution in the alpha1(V) collagen chains in the patient, while both parents were heterozygous for the same substitution. An additional mutation in either the COL5A1 and COL5A2 genes was excluded. Furthermore, haplotype analysis with polymorphic microsatellite markers excluded linkage to the genes coding for alpha3(V) collagen (COL5A3), tenascin-X (TNX), thrombospondin-2 (THBS2), and decorin (DCN). These new findings support further our previous hypothesis that the heterozygous Gly530Ser substitution is disease modifying and now suggest that in the homozygous state it is disease causing.

Rapid diagnosis of germline p53 mutation using the enzyme mismatch cleavage method.

The p53 tumor suppressor gene is the most commonly altered gene in human cancers. Germline mutations in p53 are the genetic alteration underlying predisposition to multiple cancers in Li-Fraumeni syndrome and Li-Fraumeni-like syndrome. We describe a patient who presented with developed adrenocortical carcinoma at age 19 months and a cerebral primitive neuroectodermal tumor at age 5 years. The patient did not have a family history of cancer. We used the enzyme mismatch cleavage (EMC) method to screen for mutations in the p53 gene and found a germline mutation in exon 7 (codon 248). Loss of heterozygosity analysis in one tumor revealed loss of the wild-type p53 allele. In our report we demonstrate the EMC method to be a rapid and sensitive method for mutation detection.

Improved resistance to transition metals of a cobalt-substituted alcohol dehydrogenase 1 from Saccharomyces cerevisiae.

Cobalt-substituted alcohol dehydrogenase 1 was purified from a yeast culture of Saccharomyces cerevisiae. Its reactivity towards different transition metals was tested and compared with the native zinc enzyme. The cobalt enzyme displayed a catalytic efficiency 100-fold higher than that of the zinc enzyme. Copper, nickel and cadmium exerted a mixed-type inhibition, with a scale of inhibition efficiency: Cu(2+)>Ni(2+)>Cd(2+). In general, a higher resistance of the modified protein to the inhibitory action of transition metals was observed, with two orders of magnitude for copper I(50). The presence of nickel in the complexes enzyme-coenzyme-inhibitor-substrate resulted in a decrease of the ampholytic nature of the catalytic site. On the contrary, cadmium and copper exerted an enhancement of this parameter. Electrostatic or other types of interactions may be involved in conferring a good resistance in the basic pH range, making cobalt enzyme very suitable for biotechnological processes.

Risk factors for emotional/behavioral problems in young adolescents: a prospective analysis of adolescent and parental stress and symptoms.

Stressful events in the lives of 309 10- to 15-year-olds and stressful events and psychological symptoms reported by their parents were examined in a 9-month study. Ss' self-reported emotional/behavioral problems were predicted by their reports of stressful events and their fathers' reports of psychological symptoms in cross-sectional analyses. Analyses at follow-up after controlling for initial reports of emotional/behavioral problems and prospective analyses predicting from first assessment to follow-up yielded significant effects for Ss' self-reported stressful events. Mothers' reports of children's problems were predicted by mothers' psychological symptoms in cross-sectional analyses and at follow-up after controlling for initial emotional/behavioral problems. Only prior levels of maternal reports of emotional/behavioral problems predicted mothers' reports of their children's problems 9 months later.

Ehlers-Danlos syndrome type VII: clinical features and molecular defects.

We evaluated the clinical features, molecular defects, and problems associated with the management of two patients who had type-VII Ehlers-Danlos syndrome and reviewed the cases of eighteen patients with this condition who had been reported on previously. The typical clinical features associated with this syndrome include bilateral congenital dislocation of the hip; severe generalized hypermobility of the joints; multiple dislocations of joints other than the hip; muscular hypotonia; and hyperelasticity, fragility, and a doughy texture of the skin. Collagen and DNA analyses demonstrated that both of our patients had type-VIIB Ehlers-Danlos syndrome, which is caused by heterozygous new mutations of the COL1A2 gene that encodes the proalpha2(I) chain of type-I procollagen. The obligatory GT dinucleotide at the splice donor site of intron 6 was altered in both of our patients: one patient (Case 1) had an A substitution of the G nucleotide, and the other patient (Case 2) had a C substitution of the T nucleotide. Abnormal splicing resulted in the loss of the exon 6-encoded N-telopeptide, which includes the N-proteinase cleavage site. Despite multiple operative procedures, one of our patients, who was thirty-seven years old at the time of the most recent follow-up, continued to have persistent subluxation of the right hip and osteoarthritis of the left hip. Closed reduction of the dislocated hips, regardless of the type of immobilization used, was unsuccessful in all twenty patients. The results of open reduction were improved when capsulorrhaphy was combined with iliac or femoral osteotomy, or both.

Adult daughters of alcoholics: are they unique?

To test the assertion in the clinical literature that adult children of alcoholics (ACOAs) are uniquely impacted by their parents' alcohol abuse, 25-35 year old daughters (N = 184) of alcohol-abusing, psychiatrically distressed, comorbid and normal parents were compared on measures of fear of intimacy, generalized psychological distress, perceived love inconsistency from parents and perceived interparental conflict. Neither fear of intimacy nor daughters' psychological distress differed across groups. Daughters of psychiatrically distressed and comorbid mothers recalled greater love inconsistency from mother than from father. Daughters of psychiatrically distressed and comorbid fathers recalled greater interparental conflict and daughters of comorbid fathers recalled greater love inconsistency from fathers than did daughters of alcoholic fathers. The proposed unique features of ACOA daughters and of the alcoholic family environment were not identified. The findings are discussed in terms of the clinical literature on ACOAs.

Syntenic groups between human chromosome 9 and Indian muntjac chromosomes revealed by ZOO-FISH.

The recent techniques of chromosome painting allow the molecular comparison of chromosomes from distantly related mammals. Here we show a modified ZOO-FISH technique based on lower stringency which allows to identify syntenic regions between human and Indian muntjac chromosomes. While when probing with human chromosome 2, no consistent cluster of hybridization were observed, with human chromosome 9, a number of discrete fluorescent regions along the Indian muntjac chromosomes were found.

Heteromorphism of human chromosome 18 detected by fluorescent in situ hybridization.

The individual variations of pericentromeric heterochromatin in human chromosome 18 were analysed using the C-banding techniques and nonradioactive fluorescence in situ hybridization (FISH) with chromosome 18 alpha-satellite DNA probe. FISH analysis shows heteromorphisms almost undetectable by C-banding and which regularly segregate in a family.

Extraction, purification and characterization of ADH1 from the budding yeast Kluyveromyces marxianus.

The enzyme ADH1 has been extracted and purified from the budding yeast Kluyveromyces marxianus, and its enzymatic activity has been compared, with the ADH1 extracted and purified in the same way from the well known yeast Saccharomyces cerevisiae. K. marxianus ADH1 has an optimal temperature higher than the S. cerevisiae enzyme (45-50 degrees vs 35 degrees C), a better stability to pH variations in the oxidative reaction (pH optimum 7.5), a lower Michaelis constant for acetaldehyde, and a good catalytic activity both for fermentative and oxidative reactions. In fact, while in Saccharomyces the constants ratio (velocity constant fermentation/velocity constant oxidation) is about 20,000, in Kluyveromyces the same ratio is only 15. Even if these two Genera are quite related (they belong to the same subfamily) it seems that their ADH1s possess different catalytic properties.

Mare's colostrum globules stimulate fibroblast growth in vitro: a biochemical study.

The wound repair function of mare's milk and colostrum was investigated. Mare's colostrum improved wound healing in vivo; thus fibroblast growth activation by mare's milk and colostrum was examined. As expected, colostrum was more effective than milk. To establish the biochemical nature of the bioactive molecules involved, colostrum was fractionated into whey, casein, and fat globules, and the efficacy of these fractions on fibroblast proliferation was studied. The fat globule fraction provided the strongest stimulation; its composition was studied and compared with the less-active milk fat globule fraction. The lipid pattern highlighted several differences between mare's colostrum and milk; in particular, total lipid, linoleic acid, linolenic acid, ganglioside, and glycolipid contents were higher in colostrum. A proteomic investigation revealed some differences between the protein composition of colostrum and milk fat globules. Adipophylin and lactadherin were significantly overexpressed in colostrum fat globules. The role of specific lipids on skin wound repair and that of the epidermal growth factor-like domain, embedded within the lactadherin molecule and probably released in conditions stimulating proteolysis, are discussed.

Hallazgos bucales en niños con enfermedad renal / Buccal finding in children with renal disease

La frecuencia e incidencia de enfermedades renales en niños ha sido documentada, destacándose las disfunciones tubulares, acidosis tubular, insuficiencia renal crónica, litiasis renal, entre otras. El objetivo de la investigación fue caracterizar los hallazgos bucales en niños de 1 a 13 años con enfermedad renal. Se realizó una investigación de tipo descriptiva con diseño transversal durante enero-abril de 2010, en el Servicio de Nefrología Pediátrica de la Ciudad Hospitalaria "Dr. Enrique Tejera", en Valencia-Estado Carabobo, Venezuela, se evaluaron 50 pacientes con edad promedio 6.85 años, con diversas enfermedades renales, la mayoría con hipercalciuria (58%) y sin otro compromiso sistémico. Los hallazgos bucales encontrados fueron hipoplasias de esmalte 30%, caries dental 36%, retardo en la erupción 16%, maloclusiones 10% y lengua geográfica 6%; ningún paciente presentó cálculo dental. Un dato importante fue que 44% de los pacientes nunca habían asistido a consulta odontológica. Se concluye que los hallazgos bucales con mayor frecuencia encontrados en niños con enfermedad renal fueron hipoplasias del esmalte, caries dental y retardo en la erupción dentaria, destacándose el desinterés por parte de los pacientes a la consulta odontológica

The frequency and incidence of renal disease in children had been documented, highlighting tubular dysfunctions, tubular acidosis, renal insufficiency, renal lithiasis, among others. The aim of this investigation was to characterize the buccal findings in children of 1 to 13 years old with renal disease. The investigation was a descriptive type, in a transversal design during january-april of 2010, in the Pediatric Nephrologic Service of the Hospital City "Dr. Enrique Tejera", in Valencia, Carabobo State, Venezuela, there were 50 patients with a mean age 6.85 years old, with hypercalciuria in 56% with no other systemic disease. The buccal findings were enamel hypoplasia 30%, dental caries 36%, delay eruption 16%, maloclussion 10% and geographic tongue 6%; none of the patients presented dental calculus. An important data was that 44% of the patients never had assisted to a dental appointment. The conclusions of this study are that the buccal findings more seen in children with renal disease are enamel hypoplasias, dental caries and delay eruption, underlying the lack of interest of the patients to the dental consult