Dominant negative mutants of the Cdc2 kinase uncouple cell division from iterative plant development

Because plant cells do not move and are surrounded by a rigid cell wall, cell division rates and patterns are believed to be directly responsible for generating new structures throughout development. To study the relationship between cell division and morphogenesis, transgenic tobacco and Arabidopsis plants were constructed expressing dominant mutations in a key regulator of the Arabidopsis cell cycle, the Cdc2a kinase. Plants constitutively overproducing the wild-type Cdc2a or the mutant form predicted to accelerate the cell cycle did not exhibit a significantly altered development. In contrast, a mutation expected to arrest the cell cycle abolished cell division when expressed in Arabidopsis, whereas some tobacco plants constitutively producing this mutant protein were recovered. These plants had a reduced histone H1 kinase activity and contained considerably fewer cells. These cells were, however, much larger and underwent normal differentiation. Morphogenesis, histogenesis and developmental timing were unaffected. The results indicate that, in plants, the developmental controls defining shape can act independently from cell division rates.

Germline E-cadherin mutations in hereditary diffuse gastric cancer: assessment of 42 new families and review of genetic screening criteria

BACKGROUND

Mutations in the E-cadherin (CDH1) gene are a well documented cause of hereditary diffuse gastric cancer (HDGC). Development of evidence based guidelines for CDH1 screening for HDGC have been complicated by its rarity, variable penetrance, and lack of founder mutations.

METHODS

Forty three new gastric cancer (GC) families were ascertained from multiple sources. In 42 of these families at least one gastric cancer was pathologically confirmed to be a diffuse gastric cancer (DGC); the other family had intestinal type gastric cancers. Screening of the entire coding region of the CDH1 gene and all intron/exon boundaries was performed by bi-directional sequencing.

RESULTS

Novel mutations were found in 13 of the 42 DGC families (31% overall). Twelve of these mutations occur among the 25 families with multiple cases of gastric cancer and with pathologic confirmation of diffuse gastric cancer phenotype in at least one individual under the age of 50 years. The mutations found include small insertions and deletions, splice site mutations, and three non-conservative amino acid substitutions (A298T, W409R, and R732Q). All three missense mutations conferred loss of E-cadherin function in in vitro assays. Multiple cases of breast cancers including pathologically confirmed lobular breast cancers were observed both in mutation positive and negative families.

CONCLUSION

Germline truncating CDH1 mutations are found in 48% of families with multiple cases of gastric cancer and at least one documented case of DGC in an individual under 50 years of age. We recommend that these criteria be used for selecting families for CDH1 mutational analysis.

cdc2a expression in Arabidopsis is linked with competence for cell division

A key regulator of the cell cycle is a highly conserved protein kinase whose catalytic subunit, p34(cdc2), is encoded by the cdc2 gene. We studied the control of the expression of the Arabidopsis cdc2a gene in cell suspensions and during plant development. In cell cultures, arrest of the cell cycle did not significantly affect cdc2a mRNA levels, but nutrient conditions were important for cdc2a expression. During plant development, the pattern of cdc2a expression was strongly correlated with the cell proliferation potential. The effects of external signals on cdc2a expression were analyzed. Wounding induced expression in leaves. Lack of light altered temporal regulation of cdc2a in the apical but not root meristem of seedlings. Differential cdc2a responses were obtained after different hormone treatments. Signals present only in intact plants were necessary to mediate these responses. Although other control levels have yet to be analyzed, these results suggest that the regulation of cdc2a expression may contribute greatly to spatial and temporal regulation of cell division in plants. Our results also show that cdc2a expression is not always coupled with cell proliferation but always precedes it. We propose that cdc2a expression may reflect a state of competence to divide, and that the release of other controls is necessary for cell division to occur.

Patients' priorities with respect to general practice care: an international comparison. European Task Force on Patient Evaluations of General Practice (EUROPEP)

BACKGROUND AND OBJECTIVES

Improving the sensitivity of general practice to patients' needs demands a good understanding of patients' expectations and priorities in care provision. Insight into differences in expectations of patients in different cultures and health care systems may support decision-making on desirable models for care provision in general practice. An international study was conducted to determine priorities of patients in general practice care: which views do patients in different countries have in common and which views differ?

METHODS

Written surveys in general practices in the UK, Norway, Sweden, Denmark, The Netherlands, Germany, Portugal and Israel were performed. Samples of patients from at least 12 practices per country, stratified according to area and type of practice, were included. Patients rated the importance of 38 different aspects of general practice care, selected on the basis of literature analysis, qualitative studies and consensus discussions. Rankings between countries were compared.

RESULTS

A total number of 3540 patients (response rate on average 55%) completed the questionnaire. Patients in different countries had many opinions in common. Aspects that got the highest ranking were: getting enough time during the consultation; quick services in case of emergencies; confidentiality of information on patients; telling patients all they want to know about their illness; making patients feel free to talk about their problems; GPs going to courses regularly; and offering preventive services. However, differences between opinions of patients in different countries were also found for some of the selected aspects. A confounding effect of patients' characteristics may have played a role in these differences.

DISCUSSION

The study provides information on what patients expect of and value in general practice care. It shows that patients in different cultures and health care systems may have different views on some aspects of care, but most of all that they have many views in common, particularly as far as doctor-patient communication and accessibility of services are concerned.

Mutation of DNAJC19, a human homologue of yeast inner mitochondrial membrane co-chaperones, causes DCMA syndrome, a novel autosomal recessive Barth syndrome-like condition

BACKGROUND

A novel autosomal recessive condition, dilated cardiomyopathy with ataxia (DCMA) syndrome, has been identified in the Canadian Dariusleut Hutterite population, characterised by early onset dilated cardiomyopathy with conduction defects, non-progressive cerebellar ataxia, testicular dysgenesis, growth failure, and 3-methylglutaconic aciduria.

OBJECTIVE

To map DCMA syndrome and identify the mutation underlying this condition.

METHODS

A genome wide scan was undertaken on consanguineous Hutterite families using a homozygosity mapping approach in order to identify the DCMA associated chromosomal region. Mutation analysis was carried out on positional candidate genes in this region by sequencing. Reverse transcriptase polymerase chain reaction and bioinformatics analyses were then used to characterise the mutation and determine its effect on the protein product.

RESULTS

The association of DCMA syndrome with a 2.2 Mb region of chromosome 3q26.33 was found. A disease associated mutation was identified: IVS3-1 G-->C in the DNAJC19 gene, encoding a DNAJ domain containing protein of previously unknown function (Entrez Gene ID 131118).

CONCLUSIONS

The DNAJC19 protein was previously localised to the mitochondria in cardiac myocytes, and shares sequence and organisational similarity with proteins from several species including two yeast mitochondrial inner membrane proteins, Mdj2p and Tim14. Tim14 is a component of the yeast inner mitochondrial membrane presequence translocase, suggesting that the unique phenotype of DCMA may be the result of defective mitochondrial protein import. It is only the second human disorder caused by defects in this pathway that has been identified.

Glycogen storage disease in adults

OBJECTIVE

To identify complications amenable to prevention in adults with glycogen storage disease (GSD) types Ia, Ib, and III and to determine the effect of the disease on social factors.

DESIGN

Case series and clinical review.

SETTING

Referral medical centers in the United States and Canada.

PATIENTS

All patients with GSD-Ia (37 patients), GSD-Ib (5 patients), and GSD-III (9 patients) who were 18 years of age or older.

MEASUREMENTS

Ultrasound or radiographic studies identified liver adenomas, nephrocalcinosis, or kidney stones. Radiographic studies identified osteopenia. Reports of the clinical examination, serum chemistry results, and social data were obtained.

RESULTS

For patients with GSD-Ia, problems included short stature (90%), hepatomegaly (100%), hepatic adenomas (75%), anemia (81%), proteinuria or microalbuminuria (67%), kidney calcifications (65%), osteopenia or fractures or both (27%), increased alkaline phosphatase (61%) and gamma-glutamyltransferase (93%) activities, and increased serum cholesterol (76%) and triglyceride (100%) levels. Hyperuricemia was frequent (89%). Patients with GSD-Ib had severe recurrent bacterial infections and gingivitis. In patients with GSD-III, 67% (6 of 9) had increased creatinine kinase activity. Four of these patients had myopathy and cardiomyopathy.

CONCLUSIONS

For GSD-Ia, hyperuricemia and pyelonephritis should be treated to prevent nephrocalcinosis and additional renal damage. For GSD-Ib, granulocyte-colony-stimulating factor may prevent bacterial infections. For GSD-III, more data are required to determine whether the myopathy and cardiomyopathy can be prevented. Most of the patients with GSD-I and GSD-III had 12 or more years of education and were either currently in school or employed.

Association of ERBB2 gene status with histopathological parameters and disease-specific survival in gastric carcinoma patients

The clinical significance of ERBB2 amplification/overexpression in gastric cancer remains unclear. In this study, we evaluated the ERBB2 status in 463 gastric carcinomas using immunohistochemistry (IHC) and fluorescence in situ hybridisation (FISH), and compared the findings with histopathological characteristics and with disease-specific survival. ERBB2 overexpression (2+ and 3+) and amplification (ratio ERBB2/CEP17⩾2) were found in 43 (9.3%) and 38 (8.2%) gastric carcinomas, respectively. Perfect IHC/FISH correlation was found for the 19 cases scored as 0 (all negative by FISH), and also for the 25 cases scored as 3+ (all positive by FISH). One out of six carcinomas scored as 1+ and 12 out of 18 carcinomas scored as 2+ were positive by FISH. ERBB2 amplification was associated with gastric carcinomas of intestinal type (P=0.007) and with an expansive growth pattern (P=0.021). ERBB2 amplification was detected in both histological components of two mixed carcinomas, indicating a common clonal origin. A statistically significant association was found between ERBB2 amplification and worse survival in patients with expansive gastric carcinomas (P=0.011). We conclude that ERBB2 status may have clinical significance in subsets of gastric cancer patients, and that further studies are warranted to evaluate whether patients whose gastric carcinomas present ERBB2 amplification/overexpression may benefit from therapy targeting this surface receptor.

Genes regulating the plant cell cycle: isolation of a mitotic-like cyclin from Arabidopsis thaliana

A key element of cell cycle control in eukaryotes is the M-phase kinase, composed of p34cdc2 and cyclin. To dissect the plant cell cycle, we have previously isolated a cdc2 gene homolog from Arabidopsis thaliana. We have now cloned an Arabidopsis cDNA corresponding to cyclins. This gene (cyc1At) encodes a protein with a predicted molecular mass of 48.4 kDa and a domain homologous to the cyclin box of mitotic cyclins. However, by sequence comparison the cyc1At gene could not be assigned to the A- or B-type group. The mRNA accumulates preferentially in actively dividing cells and when these cells are blocked during the cell cycle, the amount of transcripts decreases dramatically. cyc1At mRNA is found mainly in G2-phase nuclei, suggesting that its expression is periodic in the cell cycle. Microinjection of synthetic cyc1At mRNA induced meiotic maturation in Xenopus oocytes. Cyc1At is encoded by a single gene, but the amplification by the polymerase chain reaction of other fragments homologous to cyclins indicates the presence of a family of cyclins in Arabidopsis.

Astrocyte reactivity influences amyloid-β effects on tau pathology in preclinical Alzheimer's disease

An unresolved question for the understanding of Alzheimer's disease (AD) pathophysiology is why a significant percentage of amyloid-β (Aβ)-positive cognitively unimpaired (CU) individuals do not develop detectable downstream tau pathology and, consequently, clinical deterioration. In vitro evidence suggests that reactive astrocytes unleash Aβ effects in pathological tau phosphorylation. Here, in a biomarker study across three cohorts (n = 1,016), we tested whether astrocyte reactivity modulates the association of Aβ with tau phosphorylation in CU individuals. We found that Aβ was associated with increased plasma phosphorylated tau only in individuals positive for astrocyte reactivity (Ast⁺). Cross-sectional and longitudinal tau-positron emission tomography analyses revealed an AD-like pattern of tau tangle accumulation as a function of Aβ only in CU Ast⁺ individuals. Our findings suggest astrocyte reactivity as an important upstream event linking Aβ with initial tau pathology, which may have implications for the biological definition of preclinical AD and for selecting CU individuals for clinical trials.

Identification of a genetic alteration in the code for bilirubin UDP-glucuronosyltransferase in the UGT1 gene complex of a Crigler-Najjar type I patient

Patients with Crigler-Najjar syndrome (CN) type I inherit an autosomal recessive trait for hyperbilirubinemia, which is characterized by the total absence of bilirubin UDP-glucuronosyltransferase (transferase) activity. The recent identification of two bilirubin transferase isoforms with identical carboxyl termini (Ritter, J. K., J. M. Crawford, and I. S. Owens. 1991. J. Biol. Chem. 266:1043-1047) led to the discovery of a unique locus, UGT1, which encodes a family of UDP-glucuronosyltransferase isozymes, including the two bilirubin forms (Ritter, J. K., F. Chen, Y. Y. Sheen, H. M. Tran, S. Kimura, M. T. Yeatman, and I. S. Owens. 1992. J. Biol. Chem. 267:3257-3261). The UGT1 locus features a complex of six overlapping transcriptional units encoding transferases, each of which shares the four most 3' exons (2, 3, 4, and 5) specifying the 3' half of the transferase coding regions (condons 289-533) and the entire 3' untranslated region of each mRNA. This gene model predicts that a single critical mutation in any of these four "common" exons may inactivate the entire family of encoded transferases. In agreement with this prediction, we show here that in the first CN type I individual analyzed (patient F.B.), a 13-bp deletion has occurred in exon 2. Analysis of product generated by the polymerase chain reaction and genomic DNA demonstrated that F.B. is homozygous for the defective allele (UGT1*FB), and that the consanguineous parents are both heterozygotic at this locus. The mutation is predicted to result in the synthesis of severely truncated bilirubin transferase isozymes that are lacking a highly conserved sequence in the carboxyl-terminus and the characteristic membrane (endoplasmic reticulum)-anchoring segment of the protein molecule.

Novel microporous europium and terbium silicates

The synthesis and structural characterization of the first examples of microporous europium(III) and terbium(III) silicates (Na(4)K(2)X(2)Si(16)O(38) x 10H(2)O, X = Eu, Tb) are reported. The structure of these solids was solved by powder X-ray diffraction ab initio (direct) methods and further characterized by chemical analysis (EDS), thermogravimetric analysis (TGA), scanning electron microscopy (SEM), (23)Na and (29)Si magic-angle spinning (MAS) NMR, and luminescence spectroscopy. Both materials display interesting photoluminescence properties and present potential for applications in optoelectronics. This work illustrates the possibility of combining in a given silicate microporosity and optical activity.

Cat eye syndrome chromosome breakpoint clustering: identification of two intervals also associated with 22q11 deletion syndrome breakpoints

The supernumerary cat eye syndrome (CES) chromosome is dicentric, containing two copies of 22pter-->q11.2. We have found that the duplication breakpoints are clustered in two intervals. The more proximal, most common interval is the 450-650 kb region between D22S427 and D22S36, which corresponds to the proximal deletion breakpoint interval found in the 22q11 deletion syndrome (DiGeorge/velocardiofacial syndrome). The more distal duplication breakpoint interval falls between CRKL and D22S112, which overlaps with the common distal deletion interval of the 22q11 deletion syndrome. We have therefore classified CES chromosomes into two types based on the location of the two breakpoints required to generate them. The smaller type I CES chromosomes are symmetrical, with both breakpoints located within the proximal interval. The larger type II CES chromosomes are either asymmetrical, with one breakpoint located in each of the two intervals, or symmetrical, with both breakpoints located in the distal interval. The co-localization of the breakpoints of these different syndromes, plus the presence of low-copy repeats adjacent to each interval, suggests the existence of several specific regions of chromosomal instability in 22q11.2 which are involved in the production of both deletions and duplications. Since the phenotype associated with the larger duplication does not appear to be more severe than that of the smaller duplication, determination of the type of CES chromosome does not currently have prognostic value.

Bidentate Lewis base adducts of methyltrioxorhenium(VII) and their application in catalytic epoxidation

Methyltrioxorhenium(VII) (MTO) forms octahedral adducts with bidentate Lewis bases. These complexes were isolated and fully characterized, including X-ray crystallography. The compounds display distorted octahedral geometry in the solid state with a tendency of disorder concerning the Re central atom. At elevated temperatures, they undergo rapid ligand-exchange reactions in solution. The ease of this ligand exchange depends mainly on the Lewis basicity of the ligand. The more Lewis basic the ligand is, the stronger the metal-ligand interaction is, as can be shown by NMR spectroscopy. All examined complexes are temperature stable but quite sensitive to light and moisture. In the presence of H(2)O(2), the complexes form very active and highly selective epoxidation catalysts. Peroxo complexes are generated, and at least one of the Re-N interactions is cleaved during this process. Total ligand dissociation only occurs in the case of very weakly coordinating bidentate ligands. The peroxo complexes of the MTO Lewis base adducts are, in general, more sensitive to water than MTO itself.

Modification of the biopolymer castor oil with free isocyanate groups to be applied as bioadhesive

Surgical adhesives have been used for several applications, including haemostasis, sealing air leakages and tissue adhesion. The aim of this work was to develop a biodegradable urethane-based bioadhesive containing free isocyanate groups. This material presents the advantage of being biodegradable, biocompatible and having the capacity of reacting with amino groups present in the biological molecules. A urethane based on castor oil (CO) was synthesized by reaction of the molecule with isophorone diisocyanate (IPD). The characterization of the material was accomplished by different techniques: ATR-FT-IR (attenuated transmittance reflection-Fourier transform infrared), swelling capacity determination, evaluation of the moisture curing kinetics, reaction with aminated substrates and determination of surface energy by contact angle measurement. The study of the urethane thermal properties was performed by DMTA (dynamical mechanical thermal analysis) and TGA (thermogravimetric analysis). The haemocompatibility of the urethane was also evaluated by thrombosis and haemolysis tests.

Synthesis and characterization of membranes obtained by graft copolymerization of 2-hydroxyethyl methacrylate and acrylic acid onto chitosan

Chitosan based membranes to be applied on wound healing as topical drug delivery systems were developed by graft copolymerization of acrylic acid (AA) and 2-hydroxyethyl methacrylate (HEMA) onto chitosan using cerium ammonium nitrate as chemical initiator. Evidence for graft copolymerization of the vinyl monomers onto chitosan was obtained by FTIR and DMTA. Swelling degree, cytotoxicity, thrombogenicity and haemolytic activity of these membranes were evaluated. Chitosan-graft-AA-graft-HEMA showed to be the best matrix for drug delivery systems than chitosan-graft-AA because it retains good swelling properties, but the content in HEMA has improved cytocompatibility, hemocompatibility and thrombogenic character.

Three discrete classes of Arabidopsis cyclins are expressed during different intervals of the cell cycle

We have isolated cDNAs encoding four additional mitotic-like cyclins from Arabidopsis: cyc2aAt, cyc2bAt, cyc3aAt, and cyc3bAt. Examination of amino acid sequences deduced from plant cyclin cDNAs isolated so far showed that they can be grouped into three distinct classes. The members of each plant cyclin family are more related to each other than to any animal or yeast cyclin. Reverse transcription-PCR analysis demonstrated that cyc2aAt was expressed in all plant organs, whereas cyc2bAt mRNAs were found only in roots; cyc3aAt was not expressed in leaves and was barely expressed in flowers. On the other hand, cyc3bAt transcripts were observed in all organs. Whole-mount in situ hybridizations on roots showed that the cyclin mRNAs were confined to parts of the roots with mitotic activity. Furthermore, results of whole-mount in situ hybridizations on roots treated with either oryzalin or hydroxyurea suggest that the different cyclin classes have distinct functions in the cell cycle.

Genetic polymorphisms and other risk factors associated with bisphosphonate induced osteonecrosis of the jaw

Bisphosphonate induced osteonecrosis of the jaw (BONJ) is a complication in patients taking bisphosphonate (BP) that affects their quality of life and compliance. In this cohort study, patients with multiple myeloma (MM) on intravenous BP therapy were enrolled over 1 year. Demographic and clinical data and genotyping of 10 single nucleotide polymorphisms (SNPs) from seven candidate genes associated with drug or bone metabolism were determined. Of the 78 patients enrolled, 12 had BONJ. The median time to developing BONJ was 28 months. Univariate and multivariate analysis revealed a significant association between BONJ and smoking (p=0.048) and type of BP treatment (p=0.03). A trend for higher odds for BONJ was found for SNPs in five genes: COL1A1 (rs1800012), RANK (rs12458117), MMP2 (rs243865), OPG (rs2073618) and OPN (rs11730582). Considering all five SNPs together, patients with genotype scores ≥ 5 had a BONJ event rate of 57%; those with scores < 5 had a rate of 10%. The adjusted odds ratio was 11.2 (95% confidence interval of 1.8-69.9; p value 0.0097). Smoking, type of BP and combined genotype score of COL1A1, RANK, MMP2, OPG and OPN were significantly associated with BONJ in MM patients undergoing BP therapy.

Whole-exome sequencing broadens the phenotypic spectrum of rare pediatric epilepsy: a retrospective study

Whole-exome sequencing (WES) has transformed our ability to detect mutations causing rare diseases. FORGE (Finding Of Rare disease GEnes) and Care4Rare Canada are nation-wide projects focused on identifying disease genes using WES and translating this technology to patient care. Rare forms of epilepsy are well-suited for WES and we retrospectively selected FORGE and Care4Rare families with clinical descriptions that included childhood-onset epilepsy or seizures not part of a recognizable syndrome or an early-onset encephalopathy where standard-of-care investigations were unrevealing. Nine families met these criteria and a diagnosis was made in seven, and potentially eight, of the families. In the eight families we identified mutations in genes associated with known neurological and epilepsy disorders: ASAH1, FOLR1, GRIN2A (two families), SCN8A, SYNGAP1 and SYNJ1. A novel and rare mutation was identified in KCNQ2 and was likely responsible for the benign seizures segregating in the family though additional evidence would be required to be definitive. In retrospect, the clinical presentation of four of the patients was considered atypical, thereby broadening the phenotypic spectrum of these conditions. Given the extensive clinical and genetic heterogeneity associated with epilepsy, our findings suggest that WES may be considered when a specific gene is not immediately suspected as causal.

Identification of seven novel germline mutations in the human E-cadherin (CDH1) gene

Hereditary diffuse gastric cancer (HDGC) is a cancer predisposition syndrome caused by germline mutation of the gene encoding the tumour-suppressor E-cadherin (CDH1). We describe the search for CDH1 mutations in 36 new diffuse gastric cancer families. All 16 CDH1 exons, neighbouring intronic sequence and an essential promoter region were screened by DNA sequencing. We detected nine different mutations, seven of which were novel. Of the seven novel mutations, five were identified in families who met the IGCLC clinical criteria for HDGC. Two mutations resulted in a premature stop codon and truncation of the protein. Three mutations affected splice sites; two of the splice-site mutations were shown by RT-PCR to disturb normal CDH1 splicing, while the third splice-site mutation was present in two unrelated HDGC families. The remaining two mutations resulted in amino acid substitutions and impaired the ability of E-cadherin protein to form cellular aggregates and suppress invasion in vitro. Together with the occurrence of extra-gastric tumours such as lobular breast and colorectal cancer, these findings further extend the types of CDH1 mutations and the spectrum of tumours associated with HDGC.

The effects of age, smoking, and alcohol on routine laboratory tests

The effects of age, smoking, and alcohol intake on the results of some routine hematology and clinical chemistry tests have been determined for a group of 1,826 healthy male workers. Increasing age was significantly associated with higher hemoglobin, hematocrit, SGOT, BUN, and creatinine levels and with lower total protein concentration, but there was no significant association with leukocyte count, total bilirubin, or alkaline phosphatase. Smoking was significantly associated with higher hemoglobin, hematocrit, leukocyte count, and alkaline phosphatase, and with lower total bilirubin, SGOT, total protein, and BUN, but there was no significant association with creatinine levels. Alcohol consumption was significantly associated with higher hematocrit, bilirubin, and SGOT and with lower BUN and creatinine, but there was no significant association with hemoglobin, leukocyte count, alkaline phosphatase, or total protein. The possible reasons for these effects, and their implications, are discussed.

Development of a new photocrosslinkable biodegradable bioadhesive

Adhesives provide a needle-free method of wound closure and do not require local anaesthetics. Polymeric adhesives have been used for about 3 decades for joining several tissues of the organism. Also, they can accomplish other tasks, such as haemostasis and the ability to seal air leakages and have the potential to serve as delivery systems. PCL was modified with 2-isocyanatoethylmethacrylate to form a macromer that was crosslinked via UV irradiation using Irgacure 2959 by CIBA as the photoinitiating agent. The characterization of the materials was accomplished by: attenuated total reflectance-Fourier transform infrared (ATR-FTIR), swelling capacity determination, evaluation of adhesive capacity (by reaction with aminated substrates) and determination of surface energy by contact angle measurement. Thermal characterization of the adhesive was performed by dynamical mechanical thermal analysis (DMTA) and thermogravimetric analysis (TGA). The morphology of PCL networks was observed using scanning electron microscopy (SEM) both after crosslinking process and following biodegradation in human plasma. The haemocompatibility of the membranes was also evaluated by thrombosis and haemolysis tests.

Induction of cdc2a and cyc1At expression in Arabidopsis thaliana during early phases of nematode-induced feeding cell formation

Root-knot and cyst nematodes are plant parasites that induce large multinucleated feeding cells in the roots of their hosts. Cytological observations have shown that root-knot nematodes induce giant cells by cycles of mitosis without cytokinesis whereas cyst nematodes provoke cell wall degradation leading to the formation of a large syncytium. This study was intended to characterize and compare the ability of both types of nematodes to induce progression through the cell cycle. For this purpose, the expression, upon nematode infection, of two cell cycle markers was followed: a marker for division competence, the cyclin-dependent kinase cdc2a and a marker for the G2 phase, the mitotic cyclin cyc1At. For both types of nematodes, transcriptional activation of these markers was correlated with early phases of feeding cell development. Using molecular markers, it was thus possible to confirm and extend the observations of repeated mitosis in root-knot nematode-induced giant cells. Surprisingly, promoter activation of both cdc2a and cyc1At markers was also found upon cyst nematode infection, in feeding cells in which mitosis has not been clearly reported. Incorporation of tritiated thymidine in these syncytia confirms that they progress through the S phase of the cell cycle. One possibility is that cyst nematodes induce cycles of DNA endoreduplication shunting the M phase. Despite obvious differences in ontogeny, common molecular mechanisms, involving cycles of DNA endoreduplication and cdc2a and cyc1At expression, might thus be involved in the formation of a giant cell or a syncytium.

Plasmapheresis as an effective treatment for opsoclonus-myoclonus syndrome

A 6-year-old female diagnosed with idiopathic opsoclonus-myoclonus syndrome at 22 months of age who failed to respond to treatment with adrenocorticotropic hormone (ACTH), IV gammaglobulin (IVIG), and azathioprine is presented. Because of marked and progressive deterioration in motor function and speech, this patient received a course of plasmapheresis with concomitant steroids and azathioprine. Within 1 week, marked improvements in motor function were noted. Eighteen months later, the patient ambulates, walks without support, and attends a regular school in the appropriate grade level.

Hydrops fetalis associated with erythrocyte pyruvate kinase deficiency

The authors report a case of hydrops fetalis due to severe pyruvate kinase deficiency, the most unusual clinical manifestation of this disease.

CONCLUSION

Pyruvate kinase deficiency, as other erythrocyte enzymopathies, must be considered in the differential diagnosis of non-immune hydrops fetalis. This has important implications for clinical investigations, therapy and genetic counselling.

Hyperphenylalaninemia with high levels of 7-biopterin is associated with mutations in the PCBD gene encoding the bifunctional protein pterin-4a-carbinolamine dehydratase and transcriptional coactivator (DCoH)

Pterin-4a-carbinolamine dehydratase (PCD) is required for efficient tetrahydrobiopterin regeneration after phenylalanine hydroxylase activity. This catalytic function was proposed to be specifically defective in newborns with a mild form of hyperphenylalaninemia (HPA) and persistent high urinary levels of primapterin (7-biopterin). A second regulatory task of the same protein is DCoH, a coactivation of transcription by hepatocyte nuclear factor 1alpha (HNF-1alpha), a function that is apparently not impaired in these HPA individuals. It has been shown elsewhere that the human PCD/DCoH bifunctional protein is encoded by a single 4-exon-containing gene, PCBD, located on chromosome 10q22. We have now examined the PCBD gene for mutations at the genomic level in six such HPA patients from four different families. By the use of new intron-specific primers, we detected, in all six patients, single, homozygous nucleotide alterations, in exon 4, that were inherited from their parents. These homozygous alterations predicted mutant PCD/DCoH with a single amino acid exchange, in two cases (alleles T78I), or premature stop codons, in the other four patients (alleles E86X and Q97X). Recombinant expression in Escherichia coli revealed that the mutant proteins-T78I, E86X, and Q97X-are almost entirely in the insoluble fraction, in contrast to wild type, which is expressed as a soluble protein. These data support the proposal that HPA in combination with urinary primapterin may be due to autosomal recessive inheritance of mutations in the PCBD gene specifically affecting the dehydratase activity.