Clinical Characteristics Suggestive of a Genetic Cause in Cerebral Palsy: A Systematic Review

BACKGROUND

Cerebral palsy (CP) is a clinical diagnosis and was long categorized as an acquired disorder, but more and more genetic etiologies are being identified. This review aims to identify the clinical characteristics that are associated with genetic CP to aid clinicians in selecting candidates for genetic testing.

METHODS

The PubMed database was systematically searched to identify genes associated with CP. The clinical characteristics accompanying these genetic forms of CP were compared with published data of large CP populations resulting in the identification of potential indicators of genetic CP.

RESULLTS

Of 1930 articles retrieved, 134 were included. In these, 55 CP genes (described in two or more cases, n = 272) and 79 candidate genes (described in only one case) were reported. The most frequently CP-associated genes were PLP1 (21 cases), ARG1 (17 cases), and CTNNB1 (13 cases). Dyskinesia and the absence of spasticity were identified as strong potential indicators of genetic CP. Presence of intellectual disability, no preterm birth, and no unilateral distribution of symptoms were classified as moderate genetic indicators.

CONCLUSIONS

Genetic causes of CP are increasingly identified. The clinical characteristics associated with genetic CP can aid clinicians regarding to which individual with CP to offer genetic testing. The identified potential genetic indicators need to be validated in large CP cohorts but can provide the first step toward a diagnostic algorithm for genetic CP.

Consensus guidelines for the monitoring and management of metachromatic leukodystrophy in the United States

Metachromatic leukodystrophy (MLD) is a fatal, progressive neurodegenerative disorder caused by biallelic pathogenic mutations in the ARSA (Arylsulfatase A) gene. With the advent of presymptomatic diagnosis and the availability of therapies with a narrow window for intervention, it is critical to define a standardized approach to diagnosis, presymptomatic monitoring, and clinical care. To meet the needs of the MLD community, a panel of MLD experts was established to develop disease-specific guidelines based on healthcare resources in the United States. This group developed a consensus opinion for best-practice recommendations, as follows: (i) Diagnosis should include both genetic and biochemical testing; (ii) Early diagnosis and treatment for MLD is associated with improved clinical outcomes; (iii) The panel supported the development of newborn screening to accelerate the time to diagnosis and treatment; (iv) Clinical management of MLD should include specialists familiar with the disease who are able to follow patients longitudinally; (v) In early onset MLD, including late infantile and early juvenile subtypes, ex vivo gene therapy should be considered for presymptomatic patients where available; (vi) In late-onset MLD, including late juvenile and adult subtypes, hematopoietic cell transplant (HCT) should be considered for patients with no or minimal disease involvement. This document summarizes current guidance on the presymptomatic monitoring of children affected by MLD as well as the clinical management of symptomatic patients. Future data-driven evidence and evolution of these recommendations will be important to stratify clinical treatment options and improve clinical care.

Newborn screening in metachromatic leukodystrophy - European consensus-based recommendations on clinical management

INTRODUCTION

Metachromatic leukodystrophy (MLD) is a rare autosomal recessive lysosomal storage disorder resulting from arylsulfatase A enzyme deficiency, leading to toxic sulfatide accumulation. As a result affected individuals exhibit progressive neurodegeneration. Treatments such as hematopoietic stem cell transplantation (HSCT) and gene therapy are effective when administered pre-symptomatically. Newborn screening (NBS) for MLD has recently been shown to be technically feasible and is indicated because of available treatment options. However, there is a lack of guidance on how to monitor and manage identified cases. This study aims to establish consensus among international experts in MLD and patient advocates on clinical management for NBS-identified MLD cases.

METHODS

A real-time Delphi procedure using eDELPHI software with 22 experts in MLD was performed. Questions, based on a literature review and workshops, were answered during a seven-week period. Three levels of consensus were defined: A) 100%, B) 75-99%, and C) 50-74% or >75% but >25% neutral votes. Recommendations were categorized by agreement level, from strongly recommended to suggested. Patient advocates participated in discussions and were involved in the final consensus.

RESULTS

The study presents 57 statements guiding clinical management of NBS-identified MLD patients. Key recommendations include timely communication by MLD experts with identified families, treating early-onset MLD with gene therapy and late-onset MLD with HSCT, as well as pre-treatment monitoring schemes. Specific knowledge gaps were identified, urging prioritized research for future evidence-based guidelines.

DISCUSSION

Consensus-based recommendations for NBS in MLD will enhance harmonized management and facilitate integration in national screening programs. Structured data collection and monitoring of screening programs are crucial for evidence generation and future guideline development. Involving patient representatives in the development of recommendations seems essential for NBS programs.

Ophthalmic manifestations in children with tuberous sclerosis complex

PURPOSE

To report on the ophthalmic findings in children with tuberous sclerosis complex (TSC) in southern Sweden, and to investigate the frequency of refractive errors, strabismus and cerebral visual impairment associated with this condition.

METHODS

This was a retrospective cohort study including all paediatric patients with TSC in southern Sweden born between 1983 and 2020. Medical records were reviewed regarding retinal findings, visual acuity, refractive error, strabismus, full-field electroretinography results and cerebral visual impairment.

RESULTS

Ophthalmological records were available for 50 of the 52 children in the region diagnosed with TSC. The mean age at the last visit was 12.4 (SD 7.2) years. Monocular visual acuity had been measured in 38 patients, and the median value did not deviate from that expected for their age in the better eye, but by -0.2 Snellen decimal acuity in the worse eye. Refractive errors were found in 62% of the patients, and strabismus in 16%. Retinal astrocytic hamartomas were found in 34% and achromatic patches in 34%. Ten of the patients on medication with vigabatrin were examined with full-field electroretinography and treatment had to be stopped or lowered in three (30%), due to a reduced response. Investigation of cerebral visual impairment had not been conducted in any of the children.

CONCLUSION

Refractive errors and strabismus were common among children with TSC. None of the patients in this cohort had undergone investigation for cerebral visual impairment. The general awareness of cerebral visual impairment among ophthalmologists is poor and constitutes an important area for improvement.

Abnormal glucose tolerance and lung function in children with cystic fibrosis. Comparing oral glucose tolerance test and continuous glucose monitoring

BACKGROUND

Cystic fibrosis (CF) related diabetes (CFRD) is a common complication of CF. CFRD is associated with declining lung function even before its onset. Regular screening for CFRD using oral glucose tolerance test (OGTT) is recommended. Additionally, continuous glucose monitoring (CGM) has surfaced as a possible surveillance method, but evidence for its use and concordance with OGTT has not been established.

METHODS

Children were prospectively recruited at CF center Lund to undergo both intermittent scan CGM (isCGM) and OGTT. Lung function was evaluated by spirometry and multiple breath washout. Demographic and clinical data were collected from the Swedish national CF registry.

RESULTS

32 patients participated in the study, yielding 28 pairs of isCGMs and OGTTs. The OGTTs showed that two patients met the criteria of CFRD, seven had impaired glucose tolerance (IGT) and indeterminate glycemia (INDET) was found in eleven cases. The isCGM percent of measurements >8mmol/L and the number of peaks per day >11 mmol/L have correlations with intermediate OGTT glucose time points, but not the 2hour glucose value. Patients with abnormal glucose tolerance (AGT) had lower lung function than those with normal glucose tolerance demonstrated by both FEV1% predicted and lung clearance index (LCI).

CONCLUSION

Correlations can be found between isCGM and OGTT in regards to the latter's intermediate time points. LCI demonstrates as well as FEV1% of predicted, worse lung function in children and adolescents with abnormal glucose tolerance in CF.

Liquid Chromatographic Determination of Ochratoxin A in Barley, Wheat Bran, and Rye by the AOAC/IUPAC/NMKL Method: NMKL Collaborative Study1

In an inter laboratory study of the AOAC/lnternational Union of Pure and Applied Chemistry (IUPAC)/ Nordic Committee on Food Analysis (NMKL) liquid chromatographic method for ochratoxin A (OTA), 3 spiked samples each of wheat bran and rye and 3 naturally contaminated barley samples with expected OTA contents between 2 and 9 μg/kg were analyzed by 12 European laboratories. Mean recoveries ranged from 64 to 72%. Within-laboratory standard deviations were 21,17, and 12% for wheat bran, rye, and barley, respectively. Corresponding between-laboratory standard deviations were 23-28,20-28, and 18-31%. Horwitz ratio values ranged from 0.50 to 0.77. The method was accepted as an official NMKL method for determining OTA at ≥2 μg/kg in cereals and cereal products.

Enzymatic Determination of Lactose and Galactose in Foods: NMKL Collaborative Methods Performance Study

Enzymes are widely used in food chemistry as analytical tools. An enzymatic method for determining lactose and galactose in foods was evaluated in an interlaboratory methods performance study by 12 laboratories in 4 countries. The method is based on enzymatic hydrolysis of lactose and enzymatic oxidation of the hydrolysis products. The exchange of the coenzyme in the second reaction is the basis of quantitation. The method may be used for various types of foods, such as liquid and solid milk products, meat products, cereal products, fats, dressings, sweets, chocolate, and foods for special dietary uses. It is also applicable to lactose-free foods but not to products in which lactose has been partially hydrolyzed enzymatically to glucose and galactose. Six commonly used foodstuffs with lactose concentrations ranging from 0.4 g/100 g to 40 g/100 g and galactose concentrations up to 0.7 g/100 g were analyzed: crisp rye bread, milk chocolate, sausage, cheese, margarine, and baby food containing milk powder. They were distributed to the 12 participants as 12 randomly numbered test samples, representing blind duplicates of the 6 materials. The relative standard deviations for reproducibility (RSDR) were between 2.3-11% for lactose and 6.8-50% for galactose.

IUPAC Collaborative Trial Study of a Method To Detect Genetically Modified Soy Beans and Maize in Dried Powder

This paper presents results of a collaborative trial study (IUPAC project No. 650/93/97) involving 29 laboratories in 13 countries applying a method for detecting genetically modified organisms (GMOs) in food. The method is based on using the polymerase chain reaction to determine the 35S promoter and the NOS terminator for detection of GMOs. Reference materials were produced that were derived from genetically modified soy beans and maize. Correct identification of samples containing 2% GMOs is achievable for both soy beans and maize. For samples containing 0.5% genetically modified soy beans, analysis of the 35S promoter resulted also in a 100% correct classification. However, 3 false-negative results (out of 105 samples analyzed) were reported for analysis of the NOS terminator, which is due to the lower sensitivity of this method. Because of the bigger genomic DNA of maize, the probability of encountering false-negative results for samples containing 0.5% GMOs is greater for maize than for soy beans. For blank samples (0% GMO), only 2 false-positive results for soy beans and one for maize were reported. These results appeared as very weak signals and were most probably due to contamination of laboratory equipment.

Immunoaffinity Column Cleanup with Liquid Chromatography Using Post-Column Bromination for Determination of Aflatoxin B1 in Cattle Feed: Collaborative Study

A collaborative study was conducted to evaluate the effectiveness of an immunoaffinity column cleanup liquid chromatography (LC) method for determination of aflatoxin B1 in cattle feed at a possible future European regulatory limit (1 ng/g). The test portion was extracted with acetone–water (85 + 15), filtered, diluted with water, and applied to an immunoaffinity column. The column was washed with water to remove interfering compounds, and the purified aflatoxin B1 was eluted with methanol. Aflatoxin B1 was separated and determined by reversed-phase liquid chromatography (RP–LC) and detected by fluorescence after post column derivatization (PCD) involving bromination. PCD was achieved with either pyridinium hydrobromide perbromide (PBPB), used by 14 laboratories, or an electrochemical cell and addition of bromide to the mobile phase, used by 7 laboratories. Both derivatization techniques were not significantly different when compared by the t-test; the method was statistically evaluated for all laboratories together (bromination and PBPB). The cattle feed samples, both spiked and naturally contaminatedwithaflatoxinB1, were sent to 21 laboratories in 14 different countries (United States, Japan, and Europe). Test portions were spiked at levels of 1.2 and 3.6 ng/g for aflatoxin B1. Recoveries ranged from 74 to 157%. Based on results for spiked samples (blind pairs at 2 levels) as well as naturally con-taminated samples (blind pairs at 3 levels), the relative standard deviation for repeatability (RSDr) ranged from 5.9 to 8.7%. The relative standard deviation for reproducibility (RSDR) ranged from 17.5 to 19.6%. The method showed acceptable within-and between-laboratory precision for this matrix, as evidenced by HORRAT values, at the target levels of determination for aflatoxin B1. No major differences in RSD were observed, showing that the composition of the feeds was not a factor for the samples tested and that the method was applicable for all materials used.

Determination of Ochratoxin A in Wine and Beer by Immunoaffinity Column Cleanup and Liquid Chromatographic Analysis with Fluorometric Detection: Collaborative Study

The accuracy, repeatability, and reproducibility characteristics of a liquid chromatographic method for the determination of ochratoxin A (OTA) in white wine, red wine, and beer were established in a collaborative study involving 18 laboratories in 10 countries. Blind duplicates of blank, spiked, and naturally contaminated materials at levels ranging from ≤0.01 to 3.00 ng/mL were analyzed. Wine and beer samples were diluted with a solution containing polyethylene glycol and sodium hydrogen carbonate, and the diluted samples were filtered and cleaned up on an immunoaffinity column. OTA was eluted with methanol and quantified by reversed-phase liquid chromatography with fluorometric detection. Average recoveries from white wine, red wine, and beer ranged from 88.2 to 105.4% (at spiking levels ranging from 0.1 to 2.0 ng/mL), from 84.3 to 93.1% (at spiking levels ranging from 0.2 to 3.0 ng/mL), and from 87.0 to 95.0% (at spiking levels ranging from 0.2 to 1.5 ng/mL), respectively. Relative standard deviations for within-laboratory repeatability (RSDr) ranged from 6.6 to 10.8% for white wine, from 6.5 to 10.8% for red wine, and from 4.7 to 16.5% for beer. Relative standard deviations for between-laboratories reproducibility (RSDR) ranged from 13.1 to 15.9% for white wine, from 11.9 to 13.6% for red wine, and from 15.2 to 26.1% for beer. HORRAT values were ≤0.4 for the 3 matrixes.

Combined Phenyl Silane and Immunoaffinity Column Cleanup with Liquid Chromatography for Determination of Ochratoxin A in Roasted Coffee: Collaborative Study

A collaborative study was conducted to evaluate a liquid chromatography (LC) method for ochratoxin A using sequential phenyl silane and immunoaffinity column cleanup. The method was tested at 3 different levels of ochratoxin A in roasted coffee, which spanned the range of possible future European regulatory limits. The test portion was extracted with methanol and sodium bicarbonate by shaking for 30 min. The extract was filtered, centrifuged, and then cleaned up on a phenyl silane column before being eluted from the washed column with methanol–water. The eluate was diluted with phosphate-buffered saline (PBS) and applied to an ochratoxin A immunoaffinity column, which was washed with water. The ochratoxin A was eluted with methanol, the solvent was evaporated, and the residue was redissolved in injection solvent. After injection of this solution onto a reversed-phase LC apparatus, ochratoxin A was measured by fluorescence detection. Eight laboratory samples of low-level naturally contaminated roasted coffee and 2 laboratory samples of blank coffee (< 0.2 ng/g ochratoxin A at the signal-to-noise ratio of 3:1), along with ampules of ochratoxin A calibrant and spiking solutions, were sent to 15 laboratories in 13 different European countries. Test portions of the laboratory samples were spiked at levels of 4 ng/g ochratoxin A, and recoveries ranged from 65 to 97%. Based on results for spiked blank material (blind duplicates) and naturally contaminated material (blind duplicates at 3 levels), the relative standard deviation for repeatability (RSDr) ranged from 2 to 22% and the relative standard deviation for reproducibility (RSDR) ranged from 14 to 26%. The method showed acceptable within- and between-laboratory precision, as evidenced by HORRAT values, at the low level of determination for ochratoxin A in roasted coffee.

Validation of an Immunoassay for Detection and Quantitation of a Genetically Modified Soybean in Food and Food Fractions Using Reference Materials: Interlaboratory Study

An immunoassay for detection of a specific genetically modified soybean (Roundup-Ready®) was validated on dried soybean powder in an interlaboratory study. Different percentages of genetically modified soybeans in nonmodified soybean matrix were evaluated in a blind study. Thirty-eight laboratories from 13 countries participated. The immunoassay was evaluated for 2 endpoints: (1) To give a semiquantitative result, i.e., determination of a given sample above or below a given threshold, or (2) to compute a quantitative result, i.e., percentage of genetically modified soybeans in the sample. Semiquantitative results showed that a given sample which contained <2% genetically modified soybeans was identified as below 2% with a 99% confidence level. Quantitative use of the assay resulted in a repeatability (r) and reproducibility (R) that were computed to be RSDr = 7% and RSDR = 10%, respectively, for a sample containing 2% genetically modified soybeans. Application of this method depends on availability of appropriate reference materials for a specific food matrix. Only matrix-matched reference materials can be used for analysis of food or food fractions.

Dermatan sulfate epimerase 1 deficient mice as a model for human abdominal wall defects

BACKGROUND

Dermatan sulfate (DS) is a highly sulfated polysaccharide with a variety of biological functions in extracellular matrix organization and processes such as tumorigenesis and wound healing. A distinct feature of DS is the presence of iduronic acid, produced by the two enzymes, DS-epimerase 1 and 2, which are encoded by Dse and Dsel, respectively.

METHODS

We have previously shown that Dse knockout (KO) mice in a mixed C57BL/6-129/SvJ background have an altered collagen matrix structure in skin. In the current work we studied Dse KO mice in a pure NFR genetic background.

RESULTS

Dse KO embryos and newborns had kinked tails and histological staining revealed significantly thicker epidermal layers in Dse KO mice when compared with heterozygote (Het) or wild-type (WT) littermates. Immunochemical analysis of the epidermal layers in newborn pups showed increased expression of keratin 5 in the basal layer and keratin 1 in the spinous layer. In addition, we observed an abdominal wall defect with herniated intestines in 16% of the Dse KO embryos. Other, less frequent, developmental defects were exencephaly and spina bifida.

CONCLUSION

We conclude that the combination of defective collagen structure in the dermis and imbalanced keratinocyte maturation could be responsible for the observed developmental defects in Dse KO mice. In addition, we propose that Dse KO mice could be used as a model in pathogenetic studies of human fetal abdominal wall defects.

The importance of fibroblasts in remodelling of the human uterine cervix during pregnancy and parturition

It is well established that fibroblasts play a crucial role in pathophysiological extracellular matrix remodelling. The aim of this project is to elucidate their role in normal physiological remodelling. Specifically, the remodelling of the human cervix during pregnancy, resulting in an enabled passage of the child, is used as the model system. Fibroblast cultures were established from cervices of non-pregnant women, women after 36 weeks of pregnancy and women directly after partus. The cells were immunostained and quantified by western blots for differentiation markers. The cultures were screened for cytokine and metalloproteinase production and characterized by global proteome analysis. The cell cultures established from partal donors differ significantly from those from non-pregnant donors, which is in accordance with in vivo findings. A decrease in alpha-smooth actin and prolyl-4-hydroxylase and an increase in interleukin (IL)-6, IL-8 and matrix metalloproteinases (MMP)-1 and MMP-3 were observed in cultures from partal donors. 2D-gel electrophoresis followed by mass spectrometry showed that the expression of 59 proteins was changed significantly in cultures of partal donors. The regulated proteins are involved in protein kinase C signalling, Ca2+ binding, cytoskeletal organization, angiogenesis and degradation. Our data suggest that remodelling of the human cervix is orchestrated by fibroblasts, which are activated or recruited by the inflammatory processes occurring during the ripening cascade.

Intracranial hemorrhage as the initial manifestation of a congenital disorder of glycosylation

Intracranial hemorrhage in a term neonate is a rare event in the absence of an identifiable precipitating factor such as severe thrombocytopenia, mechanical trauma, asphyxia, infections, or congenital vascular malformations. Congenital disorders of glycosylation are a genetically and clinically heterogeneous group of multisystem disorders characterized by the abnormal glycosylation of a number of glycoproteins. Although bleeding caused by abnormal glycosylation of various coagulation factors is a well-known clinical complication of several types of congenital disorders of glycosylation, intracranial hemorrhage has not been reported as an initial manifestation of this entity. Here we report the detailed history of a family with 2 consecutive male infants, both born at term with intracranial hemorrhage diagnosed within the first 24 hours of life. The diagnosis of a congenital disorder of glycosylation was established in the second infant by an abnormal glycosylation of serum transferrin detected by electrospray-ionization mass spectrometry. Both infants showed significant neurologic deterioration during the first month of life, and both died at 5 months of age. Intracranial hemorrhage in a term neonate without a potential precipitating factor represents yet another clinical feature that should raise the suspicion for a congenital disorder of glycosylation.

Regulation of the chondroitin/dermatan fine structure by transforming growth factor-beta1 through effects on polymer-modifying enzymes

The chondroitin/dermatan sulfate proteoglycans (CS/DSPGs), biglycan, decorin, and versican play several important roles in extracellular matrix influencing matrix organization, cell proliferation, and recruitment. Moreover, they bind and regulate growth factors in the extracellular matrix. We have previously shown that cultured human lung fibroblasts treated with transforming growth factor-beta (TGF-beta) alone or in combination with epidermal growth factor and platelet-derived growth factor, increase the production of these PGs. In this report, we describe that the structure of their galactosaminoglycan side chains is altered, albeit there is no alteration of polysaccharide length. The findings showed that iduronic acid content is reduced by 50% in decorin and biglycan, whereas 4-O-sulfation is increased 2-fold in versican. To unravel the mechanism behind these changes, the activities of chondroitin C-5 epimerase and of O-sulfotransferases in cellular fractions prepared from fibroblasts were quantitated, and transcript levels of the relevant sulfotransferases were measured by real time polymerase chain reaction (RT-PCR). The C-5 epimerase activity was reduced by 25% in TGF-beta1 treated cells and 50% in fibroblasts treated with the growth factor combination. No change in activity in dermatan 4-O sulfotransferase was observed, and only a minor decrease in dermatan 4-O-sulfotransferase-1 (D4ST-1) mRNA was observed. On the other hand, chondroitin 4-O sulfotransferase activity increased 2-fold upon TGF-beta1 treatment and 3-fold upon treatment with the growth factor combination. This is in agreement with a 2-fold up-regulation of chondroitin-4-O-sulfotransferase 1 (C4ST-1) mRNA, and no changes in chondroitin-4-O-sulfotransferase 2 (C4ST-2) mRNA. Thus, cellular activity and transcript level correlated well with the changes in the structure of the dermatan/chondroitin sulfate chains.

Carbohydrate deficient glycoprotein syndrome type Ia

Carbohydrate deficient glycoprotein syndromes (CDG) are inherited multisystem disorders characterized by the abnormal glycosylation of a number of serum glycoproteins. CDG-Ia results from deficiency of phosphomannomutase that catalyzes the conversion of mannose-6-phosphate to mannose-1-phosphate in the cytosol. We report a case of CDG-Ia in an 11-month-old girl with developmental delay, failure to thrive, inverted nipples and abnormal fat pads. The abnormal pattern of transferrin glycosylation and phosphomannomutase activity assay confirmed the diagnosis of CDG type Ia. Unfortunately, an efficient treatment is still not available for CDG type Ia patients. This is the first report of a Taiwanese patient with this syndrome.

The Human Antimicrobial Peptide LL-37 Transfers Extracellular DNA Plasmid to the Nuclear Compartment of Mammalian Cells via Lipid Rafts and Proteoglycan-dependent Endocytosis

Antimicrobial peptides, such as LL-37, are found both in nonvertebrates and vertebrates, where they represent important components of innate immunity. Bacterial infections at epithelial surfaces are associated with substantial induction of LL-37 expression, which allows efficient lysis of the invading microbes. Peptide-mediated lysis results in the release of bacterial nucleic acids with potential pathobiological activity in the host. Here, we demonstrate that LL-37 targets extracellular DNA plasmid to the nuclear compartment of mammalian cells, where it is expressed. DNA transfer occurred at physiological LL-37 concentrations that killed bacterial cells, whereas virtually no cytotoxic or growth-inhibitory effects were observed in mammalian cells. Furthermore, LL-37 protected DNA from serum nuclease degradation. LL-37.DNA complex uptake was a saturable time- and temperature-dependent process and was sensitive to cholesterol-depleting agents that are known to disrupt lipid rafts and caveolae, as shown by flow cytometry. Confocal fluorescence microscopy studies showed localization of internalized DNA to compartments stained by cholera toxin B, a marker of lipid rafts, but failed to demonstrate any co-localization of internalized DNA with caveolin-positive endocytotic vesicles. Moreover, LL-37-mediated plasmid uptake and reporter gene expression were strictly dependent on cell surface proteoglycans. We conclude that the human antimicrobial peptide LL-37 binds to, protects, and efficiently targets DNA plasmid to the nuclei of mammalian cells through caveolae-independent membrane raft endocytosis and cell surface proteoglycans.

Initiation of the decorin glycosaminoglycan chain in the endoplasmic reticulum-Golgi intermediate compartment

We have transiently expressed decorin with a C-terminal KDEL endoplasmic reticulum retention signal peptide in COS-7 cells to study initiation of galactosaminoglycan synthesis in the endoplasmic reticulum-Golgi intermediate compartment. All decorin-KDEL molecules were substituted with N-linked oligosaccharides sensitive to endoglycosidase H, indicating that the core protein was located proximal to the medial-Golgi. O-Linked glycosylation was only initiated in a minor fraction of the molecules. The O-linked saccharides were characterized by gel filtration after stepwise degradations using chondroitin ABC/AC-I lyases, beta1-3-glycuronidase, beta-galactosidase, and alkaline phosphatase. The major O-linked saccharide was the linkage region pentasaccharide GalNAcbeta1-4GlcUAbeta1-3Galbeta1-3Galbeta1-4Xyl-2-phosphate, demonstrating initiation of chondroitin synthesis in the endoplasmic reticulum-Golgi intermediate compartment. In the presence of brefeldin A, partial elongation of a chondroitin chain took place, indicating retrieval of polymerases but not of sulfotransferases.

Local release of eosinophil peroxidase following segmental allergen provocation in asthma

BACKGROUND

Eosinophil peroxidase (EPO) is an eosinophilic basic protein, which leads to increased permeability and damage of bronchial epithelial cells in asthma.

OBJECTIVE

As little is known about its local expression and release in humans the intracellular expression in lung and peripheral eosinophils and the concentrations of EPO in bronchoalveolar lavage (BAL) fluid and serum was investigated in patients with asthma.

METHODS

Twelve mild atopic asthmatic and nine control subjects underwent segmental sham and allergen challenge. EPO concentrations in BAL fluid and serum were determined by immunoassay and flow cytometry was used to determine the intracellular expression of EPO in BAL-derived and peripheral eosinophils.

RESULTS

In asthmatic patients a large increase in BAL eosinophils--total cells: median 9.5 x 10(6) (range: 0.5 to 455.0 x 10(6)); relative: 38% (1 to 91%)--was detectable 24 h following allergen challenge, but peripheral blood eosinophil counts did not change. Concentrations of EPO in BAL fluid increased from 1 microg/L (1.0 to 6.8 microg/L) to 42 microg/L (5.6 to 379.6 microg/L; P < 0.01) after allergen but not after saline challenge (1.5 microg/L; 1.0 to 21.9 microg/L), whereas in control subjects all measurements were below the detection limit. Serum concentrations of EPO increased slightly from 18.3 microg/L (3.0 to 56.8 microg/L) to 27 microg/L (3.8 to 133.9 microg/L; P < 0.05) 24 h after allergen challenge in asthmatic patients. Furthermore, the intracellular expression of EPO (measured as mean fluorescence intensity) was decreased in BAL eosinophils compared with blood eosinophils (mean fluorescence intensity 29 (7 to 71) vs. 48 (20 to 85); P < 0.01) after allergen challenge.

CONCLUSION

The finding of increased EPO concentrations in the BAL fluid and decreased intracellular EPO expression in pulmonary eosinophils of asthmatic patients reflects the allergen-triggered release of EPO into the bronchial space.

Proteoglycan production in disomic and trisomy 7-carrying human synovial cells

To gain further insight into the synthesis and structure of the synovial matrix of joints, we have established cell cultures from synovial specimens and elaborated their production of hyaluronan and proteoglycans. The cultures secreted mainly the small proteoglycan decorin, but also considerable amounts of the related biglycan and the large proteoglycan versican. Only minor amounts of heparan sulfate proteoglycans were found. All cultures also had a high production of hyaluronan, which highlights the important role for normal joint function of these cells. In joint diseases, a common feature is the presence of an extra chromosome 7 (trisomy 7) in the synovial cells. To study the possible consequences of trisomy 7 on the synovial cell function, we extended our study to cultures that had been sub-cloned to contain high amounts of trisomy 7-carrying cells. These cell cultures had approximately four times more versican than their disomic counterparts in the cell culture medium, indicating that versican may be a mediator in the processes of joint destructive disorders. To find an explanation for this increase in versican, we investigated the expression/secretion of PDGF-AA and IL-6, cytokines with their genes located to chromosome 7. Indeed, both these cytokines were increased in the cultures with high frequencies of trisomy 7. We then added the two cytokines to cell cultures of disomic synovial cells, but only cells treated with IL-6 displayed an increased amount of versican. Thus, we suggest that the increased amount of versican in cultures of trisomy 7-carrying cells relates to an autocrine loop involving an increased IL-6 production.

Expression of a Functional Proteinase Inhibitor Capable of Accepting Xylose: Bikunin

Bikunin is a Kunitz-type proteinase inhibitor, which is cross-linked to heavy chains via a chondroitin sulfate chain, forming inter-alpha-inhibitor and related molecules. Rat bikunin was produced by baculovirus-infected insect cells. The protein could be purified with a total yield of 20 mg/liter medium. Unlike naturally occuring bikunin the recombinant protein had no galactosaminoglycan chain. Endoglycosidase digestion also suggested that the recombinant form lacked N-linked oligosaccharides. Bikunin is translated as a part of a precursor, alpha1-microglobulin/bikunin, but the functional significance of the cotranslation is unknown. Our results indicate that the proteinase inhibitory function of bikunin is not regulated by the alpha1-microglobulin-part of the alpha1-microglobulin/bikunin precursor since recombinant bikunin had the same trypsin inhibitory activity as the recombinant precursor. Both free bikunin and the precursor were also functional as a substrate in an in vitro xylosylation system. This demonstrates that the alpha1-microglobulin-part is not necessary for the first step of galactosaminoglycan assembly.

Dermatan is a better substrate for 4-O-sulfation than chondroitin: implications in the generation of 4-O-sulfated, L-iduronate-rich galactosaminoglycans

The biosynthesis of dermatan sulfate is a complex process that involves, inter alia, formation of L-iduronic acid residues by C5-epimerization of D-glucuronic acid residues already incorporated into the growing polymer. It has been shown previously that this reaction is promoted by the presence of the sulfate donor 3'-phosphoadenosine-5'-phosphosulfate. In the present investigation, the role of sulfation in the biosynthesis of L-iduronic acid-rich galactosaminoglycans was examined more closely by a study of the substrate specificities and kinetic properties of the sulfotransferases involved in dermatan sulfate biosynthesis. Comparison of the acceptor reactivities of oligosaccharides from chondroitin and dermatan, in an in vitro system containing microsomes from cultured human skin fibroblasts and 3'-phosphoadenosine-5'-phosphosulfate, showed that Km values for the dermatan fragments were substantially lower than those for their chondroitin counterparts. Calculation of Vmax values likewise showed that dermatan was the better substrate. Whereas dermatan incorporated [35S]sulfate exclusively at the C4 position of N-acetylgalactosamine residues, approximately equal amounts of radioactivity were found at the C4 and C6 positions in the labelled chondroitin. Under standard assay conditions, the 4-O-sulfation of dermatan proceeded about six times faster than the 4-O-sulfation of chondroitin. On the basis of these results, we propose that L-iduronic acids, formed in the course of the biosynthesis of dermatan sulfates, enhance sulfation of their adjacent N-acetylgalactosamine residues, and will thereby be locked in the L-ido configuration.

Intracellular expression and serum levels of eosinophil peroxidase (EPO) and eosinophil cationic protein in asthmatic children

BACKGROUND

Eosinophils are involved in the chronic inflammatory response in asthma and their basic proteins are thought to play a major pathophysiological role in this process. While serum levels of basic proteins have been used to monitor the ongoing allergic disease, little is known about the intracellular expression of these proteins in clinical situations.

OBJECTIVE

The aim of the study was to determine the intracellular expression of eosinophil cationic protein (ECP) and eosinophil peroxidase (EPO) in asthmatic children and control subjects and relate it to serum levels of both proteins, lung function tests and immunoglobulin (Ig)E levels.

METHODS

Serum ECP and EPO concentrations were determined by immunoassays in 13 asthmatic children (mean age: 9 +/- 1 years, mean FEV1: 92 +/- 10% predicted, geometric mean PC20 histamine 0.5 mg/mL) and 10 age-matched, healthy control subjects. A flow cytometric single cell assay was employed to detect intracellular ECP and EPO in peripheral blood eosinophils.

RESULTS

While serum concentrations of both ECP (asthma: median 15.0 microg/L [range 3.6-57.7] vs control: 5.9 microg/L [2.7-9.1]; P = 0.02) and EPO (22.9 microg/L [5.2-82.5] vs 7. 2 microg/L [2.5-12.7]; P = 0.008) were significantly elevated in asthmatics, the intracellular expression of ECP and EPO (measured as mean fluorescence intensity) was decreased (EG1: 55.3 [17.7-120.8] vs 100.3 [46.5-264.4]; P = 0.01; EG2: 80.2 [24.1-135.3] vs 133.7 [32. 1-244.9]; P = 0.04 and EPO: 49.7 [23.1-155.8] vs 94.9 [28.8-115.2]; P = 0.03). In asthmatics there was a significant correlation of FEV1 with intracellular ECP and of bronchial hyperresponsiveness with serum EPO and ECP. Furthermore, total IgE levels were positively correlated with serum EPO only.

CONCLUSION

We conclude that in asthmatics the intracellular content of ECP and EPO in peripheral eosinophils is reduced possibly due to degranulation. Epitope masking in activated eosinophils or a shift to early bone marrow-derived progenitors with less granule proteins are further possible explanations.

IUPAC collaborative trial study of a method to detect genetically modified soy beans and maize in dried powder

This paper presents results of a collaborative trial study (IUPAC project No. 650/93/97) involving 29 laboratories in 13 countries applying a method for detecting genetically modified organisms (GMOs) in food. The method is based on using the polymerase chain reaction to determine the 35S promotor and the NOS terminator for detection of GMOs. reference materials were produced that were derived from genetically modified soy beans and maize. Correct identification of samples containing 2% GMOs is achievable for both soy beans and maize. For samples containing 0.5% genetically modified soy beans, analysis of the 35S promotor resulted also in a 100% correct classification. However, 3 false-negative results (out of 105 samples analyzed) were reported for analysis of the NOS terminator, which is due to the lower sensitivity of this method. Because of the bigger genomic DNA of maize, the probability of encountering false-negative results for samples containing 0.5% GMOs is greater for maize than for soy beans. For blank samples (0% GMO), only 2 false-positive results for soy beans and one for maize were reported. These results appeared as very weak signals and were most probably due to contamination of laboratory equipment.

Determination of free concentration of sameridine in blood plasma by ultrafiltration and coupled-column liquid chromatography

Sameridine is a new candidate drug with both local anaesthetic and analgesic properties. The free concentration of sameridine in blood plasma was determined by coupled-column liquid chromatography. Following adjustment of the pH and the temperature of the plasma samples, the free fraction was prepared by ultrafiltration. The coupled-column liquid chromatographic system consisted of a reversed-phase column, a cation-exchange extraction column and a cation-exchange analytical column. Sameridine was detected by UV determination at 205 nm and the system showed high selectivity. The limit of quantification was 1 nM and the within-day precision was 4.6% (R.S.D., n = 10).

Biosynthesis of the proteoglycan decorin -- identification of intermediates in galactosaminoglycan assembly

Biosynthesis of decorin was investigated by incubating a rat fibroblast cell line with various radiolabelled protein and galactosaminoglycan precursors. The following cell-associated and distinct intermediates were isolated and identified: a pool of non-glycosylated core protein, two pools of decorin with incomplete chains, one with three sulphated disaccharide repeats and another with five or more sulphated disaccharide repeats, as well as decorin with mature chains. Results of pulse/chase experiments indicated that these pools represented discrete stages in chain growth. Treatment with brefeldin A, which blocks transport from the endoplasmic reticulum to the Golgi, resulted in accumulation of decorin with an incomplete chain containing six or seven largely unsulphated disaccharide repeats. During recovery from drug treatment, 4-sulfation reappeared earlier than 6-sulfation. The results suggest that the galactosaminoglycan assembly-line consists of separate multienzyme complexes that build only a limited section of the chain. Furthermore, brefeldin A causes segregation of compartments involved in separate stages of the assembly line. In an earlier report [Moses, J., Oldberg. A., Cheng, F. & Fransson, L.-A. (1997) Eur. J. Biochem. 248, 521-526] we took advantage of such segregation to identify and characterize a transient 2-phosphorylation of xylose in the linkage region.

The differential release of eosinophil granule proteins. Studies on patients with acute bacterial and viral infections

BACKGROUND

Earlier in vitro studies have suggested that the eosinophil may release its granule proteins selectively depending on the stimulus to which the cell is exposed.

OBJECTIVE

The object of the present study was to study the question of selective release in vivo by means of serum measurements of the two eosinophil granule proteins eosinophil cationic protein (ECP) and eosinophil peroxidase (EPO) in acute infections.

METHODS

Fourty-six subjects with acute infections were studied before treatment, 20 with bacterial infections and 26 with viral infections. Serum ECP, EPO and MPO were measured by specific RIA.

RESULTS

In acute bacterial infections ECP, but not EPO, was significantly raised in serum (P < 0.0001) compared with non-infected healthy subjects. In acute bacterial infections ECP was significantly correlated to the levels of the neutrophil marker myeloperoxidase (MPO) (rs = 0.96, P < 0.0001) but not to EPO. In acute viral infections neither ECP nor EPO were on average raised. However, almost 20% the patients had elevated levels of bot proteins. In the viral infections the serum-levels of ECP and EPO were correlated (rs = 0.63, P < 0.001), but no correlation was found with MPO.

CONCLUSION

It is concluded that eosinophils are activated during acute bacterial infections and that this activation results in the preferential mobilisation of ECP. The simultaneous assay of the two eosinophil proteins, ECP and EPO, may give new insight into the role of the eosinophil in disease.

Determination of free concentration of ropivacaine and bupivacaine in blood plasma by ultrafiltration and coupled-column liquid chromatography

A coupled-column liquid chromatographic method for determining the free concentration of ropivacaine and bupivacaine in blood plasma was developed. Following adjustment of the temperature and pH, the plasma samples were ultrafiltrated. Ropivacaine or bupivacaine in the ultrafiltrate was determined by direct injection into a coupled-column liquid chromatographic system, consisting of one reversed-phase and one ion-exchange column. The system was highly selective. Ropivacaine and bupivacaine were detected by UV at 210 nm. The limit of determination was 10 nM and the inter-assay precision at a concentration level of about 100 nM was 6% (R.S.D., n = 30) for ropivacaine and 7% (R.S.D., n = 30) for bupivacaine.

Phase II trial of high-dose cisplatin plus etoposide plus vinblastine in non-small-cell lung cancer. A Hoosier Oncology Group study

Fifty-one patients with advanced non-small-cell lung cancer were treated on a Hoosier Oncology Group protocol with an aggressive, high-dose cisplatin combination chemotherapy regimen. All patients had a Karnofsky performance status of 80% or higher and had no prior chemotherapy. The drug regimen consisted of cisplatin 30 mg/m2 days one through five, etoposide 40 mg/m2 days one through five, and vinblastine 5 mg/m2 day one. Therapy was given every three weeks for a total of three courses. Forty-five patients were evaluable for response and an objective response was seen in 15 patients (33%) with only one complete responder. The median duration of response was 16.5 weeks. The median survival for the entire group was 29.0 weeks. Toxicity was moderately severe with two treatment-related deaths (4%). Despite an aggressive chemotherapy regimen in a favorable patient population, there was no obvious evidence of a major therapeutic value.

A new radioimmunoassay for human mast cell tryptase using monoclonal antibodies

A solid phase immunoradiometric assay was developed for the quantitation of tryptase released from activated human mast cells. Tryptase exhibits a linear dose-response curve over the standard range of 2-50 micrograms/l in buffer, serum, and plasma. The dose-response curve approached a plateau at a tryptase concentration of 100 micrograms/l and exhibited partial inhibition at concentrations above 10,000 micrograms/l. The sensitivity of the assay was 0.2-0.4 micrograms/l, and the intra-assay and interassay coefficients of variation were below 4% at 2 micrograms/l or higher tryptase concentrations. The recovery of known amounts of purified tryptase added to serum ranged from 91 to 115%. Detection of tryptase was evaluated with several body fluids and was accurate in sera, plasma, bronchoalveolar lavage fluid, nasal lavage fluid, and saliva. The concentration of tryptase was examined in serum samples from 100 healthy controls; in each case the level was less than 2 micrograms/l. The immunoassay also was utilized to examine serum levels of tryptase after the onset of a hypotensive reaction in one patient receiving general anesthesia. A maximally elevated level of tryptase (25 micrograms/l) was detected at the first time point, 0.5 h, and elevated levels persisted to 6 h before a return to normal levels was documented at 24 h. Thus, the involvement of mast cell activation in hypotensive subjects can be ascertained by this new tryptase radioimmunoassay.