Investigation of the concentration ratios of anthropogenic metal elements in fresh snow at mountain area as a tracer for the discrimination between short- and long-range transport contributions

Atmospheric deposition of anthropogenic aerosols, which is concerned about several targets of SDGs, was investigated in Japan. Concentrations of trace metal elements (V, Ni, Cd, and Pb), which are index of source for fossil fuel combustion, in winter wet deposition (fresh snow) in mountain area were determined. Average concentrations of snow samples were 0.338 ± 0.289 μg L^-1 for V, 0.409 ± 0.724 μg L^-1 for Ni, 0.109 ± 0.110 μg L^-1 for Cd, and 1.77 ± 1.81 μg L^-1 for Pb μg L^-1. No significant correlations between V and Ni were found for snow samples at remote mountains. A significant correlation between Cd and Pb was observed when the back trajectories of air mass deriving snowfall passed through Northeast China and Huabei. Significant correlations between V and Pb were found in mountains when the air mass passed through Northeast China and Huabei. Changes in normalized concentrations of trace metal elements in snow at the same snowfall event indicated contributions from short-range transportation in suburb area. The metal element concentration ratios were shown to be useful tracers for discrimination between short- and long-range contributions of anthropogenic elements in snow.

Controlling joint instability after anterior cruciate ligament transection inhibits transforming growth factor-beta-mediated osteophyte formation

OBJECTIVE

Abnormal joint instability contributes to cartilage damage and osteophyte formation. We investigated whether controlling joint instability inhibited chronic synovial membrane inflammation and delayed osteophyte formation and examined the role of transforming growth factor-beta (TGF-β) signaling in the associated mechanism.

DESIGN

Rats (n = 94) underwent anterior cruciate ligament (ACL) transection. Anterior tibial instability was either controlled (CAM group) or allowed to continue (SHAM group). At 2, 4, and 8 weeks after surgery, radiologic, histopathologic, immunohistochemical, immunofluorescent, and enzyme-linked immunosorbent assay examinations were performed to evaluate osteophyte formation and TGF-β signaling.

RESULTS

Joint instability increased cartilage degeneration score and osteophyte formation, and cell hyperplasia and proliferation and synovial thickening were observed in the synovial membrane. Major findings were increased TGF-β expression and Smad2/3 following TGF-β phosphorylation in synovial membarene, articular cartilage, and the posterior tibial growth plate (TGF-β expression using ELISA: 4 weeks; P = 0.009, 95% CI [260.1-1340.0]) (p-Smad2/3 expression density: 4 weeks; P = 0.024, 95% CI [1.67-18.27], 8 weeks; P = 0.034, 95% CI [1.25-25.34]). However, bone morphogenetic protein (BMP)-2 and Smad1/5/8 levels were not difference between the SHAM model and the CAM model.

CONCLUSIONS

This study showed that the difference between anterior tibial instability caused a change in the expression level of TGF in the posterior tibia and synovial membrane, and the reaction might be consequently involved in osteophyte formation.

Sulfur Chemical State and Chemical Composition of Insoluble Substance in Soft Rime, Hard Rime, and Snow Collected in Remote and Rural Areas in Japan Using Wavelength-dispersive X-ray Fluorescence

Using a commercially available wavelength-dispersive X-ray fluorescence (WDXRF) spectrometer, the chemical composition and S-Kα spectrum of rime and snow samples collected in remote and rural areas of Japan were measured with a membrane filter sample technique to investigate the long-range transport of aerosol from the East Asian continent. Insoluble substances are derived into three categories: 1) conventional mineral origin (crustal substance), 2) urban dust origin (Fe-Zn-Ca) and 3) coal origin (S-As). Assuming that (i) S(VI) was found as a plaster-like substance in hard rime, depending on [Ca], and that (ii) S(-II) was found as non-crustal sulfur compounds, fractions of S(VI) and S(-II) in rime could be calculated as 35 ± 6 and 66 ± 7% by [Ca], which is in agreement with 32 ± 8 and 68 ± 8%, respectively, by the chemical shift of the S-Kα line. During a one-day meteorological event that included the accumulation of both rime and snow, differences to the snow-like content corresponded to characteristics typical of rime since the chemical compositions of rime also includes the composition of the snow. The fractions of 22 ± 12% of S(VI) and 76 ± 12% of S(-II), respectively, were found in rime. The fraction of S(-II) decreased from the Chugoku district towards the Shikoku district. Along the coast of the Japan Sea, the fraction of S(-II) decreased from Chugoku district toward the Northeast Japan. It can be proposed that other analytical techniques of S, Al, and Ca in that are favorable to this fractionation.

Equilibrium studies on lithium(I) transfer into ionic liquid with a water-soluble octabromoporphyrin (H2(OBTMPyP)4+) from aqueous phase

A water-soluble octabromoporphyrin 2,3,7,8,12,13,17,18-octabromo-5,10,15,20-tetrakis(1-methylpyridinium-4-yl)porphyrin (H2(OBTMPyP)4+), H2P4+) and its lithium complex, Li(OBTMPyP)3+ , (LiP3+) , transferred quantitatively to an ionic liquid (IL), 1-butyl-3-methylimidazolium hexafluorophosphate (BMIM+PF6-) with no addition of other counter ions. The acid-dissociation constants of H2(OBTMPyP)4+ between aqueous and BMIM+PF6- phases were determined spectrophotometrically and found to be 10-7.67 and 10-11.33 at I = 0.1 for K a1,IL = [H+]aq[HP3+]IL/[H2P4+]IL and K a2,IL = [H+]aq[P2+]IL/[HP3+]IL , respectively. Since the acid-dissociation constants involve the partition of H2(OBTMPyP)4+ between aqueous and IL phases, the determined values are ten times as low as those observed in aqueous solution. The transfer equilibrium constants of LiP3+ and NaP3+ to IL defined by K MP,IL = [MP3+]IL/[M+]aq[P2+]IL (M = Li+ or Na+) were found to be 104.83 and 101.31 for K LiP,IL and KNaP,IL , respectively. LiP3+ transferred selectively in the presence of Na+ (K LiP,IL /K NaP,IL = 103.52) to IL phase through an ion-exchange mechanism between BMIM+PF6- and Li(OBTMPyP)3+ .

Capture probability of released males of two Bactrocera species (Diptera: Tephritidae) in detection traps in California

The genus Bactrocera (Diptera: Tephritidae) includes approximately 70 polyphagous species that are major pests of fruit and vegetable crops. Most Bactrocera species have limited geographic distributions, but several species are invasive, and many countries operate continuous trapping programs to detect infestations. In the United States, California maintains approximately 25,000 traps (baited with male lures) specifically for Bactrocera detection distributed over an area of approximately 6,400 km2 (2,500 miles2) in the Los Angeles area. Although prior studies have used male lures to describe movement of Bactrocera males, they do not explicitly relate capture probability with fly distance from lure-baited traps; consequently, they do not address the relative effectiveness of male lures in detecting incipient populations of Bactrocera species. The objective of this study was to measure the distance-dependent capture probability of marked, released males of Bactrocera dorsalis (Hendel) and Bactrocera cucurbitae (Coquillett) (methyl eugenol- and cue lure-responding species, respectively) within the detection trapping grid operating in southern California. These data were then used to compute simple probability estimates for detecting populations of different sizes of the two species. Methyl eugenol was the more powerful attractant, and based on the mark-recapture data, we estimated that B. dorsalis populations with as few as approximately 50 males would always (>99.9%) be detected using the current trap density of five methyl eugenol-baited traps per 2.6 km2 (1 mile2). By contrast, we estimated that certain detection of B. cucurbitae populations would not occur until these contained approximately 350 males. The implications of the results for the California trapping system are discussed, and the findings are compared with mark-release-recapture data obtained for the same two species in Hawaii.

Extraction of chromium(VI) by salting-out with a homogeneous, mixed solvent of water and 2-propanol: a laboratory study

BACKGROUND, AIMS AND SCOPE

Chromium enters into the aquatic environment as a result of effluent discharge from steel works, electroplating, leather tanning industries and chemical industries. As the Cr(VI) is very harmful to living organisms, it should be quickly removed from the environment when it happens to be contaminated. Therefore, the aim of this laboratory research was to develop a rapid, simple and adaptable solvent extraction system to quantitatively remove Cr(VI) from polluted waters.

METHODS

Aqueous salt-solutions containing Cr(VI) as CrO4(2-) at ppm level (4-6 ppm) were prepared. Equal volumes (5 ml) of aqueous and organic (2-PrOH) phases were mixed in a 10 ml centrifuge tube for 15 min, centrifuged and separated. Concentrations of Cr(VI), in both the aqueous and organic phases, were determined by atomic absorption spectrometry. The effects of salt and acid concentrations, and phase-contact time on the extraction of Cr(VI) were investigated. In addition, the extraction of Cr(VI) was assessed in the presence of tetramethylammonium chloride (TMAC) in 2-PrOH phase. Effects of some other metals, (Cd(II), Co(II), Cu(II), Ni(II) and Zn(II)), on the extraction of Cr(VI) were also investigated.

RESULTS AND DISCUSSION

The Cr(VI) at ppm level was extracted quantitatively by salting-out the homogeneous system of water and 2-propanol(2-PrOH) using chloride salts, namely CaCl2 or NaCl, under acidic chloride media. The extracted chemical species of Cr(VI) was confirmed to be the CrO3Cl-. The ion-pair complex extracted into the organic phase was rationalized as the solvated ion-pair complex of [2-PrOH2+, CrO3Cl-]. The complex was no longer stable. It implied the reaction between extracted species. Studies revealed that salts and acid directly participated in the formation of the above complex. Use of extracting agents (TMAC) didn't show any significant effect on the extraction of Cr(VI) under high salting-out conditions. There is no significant interference effect on the extraction of Cr(VI) by the presence of other metals. The Cr(VI) in the organic phase was back-extracted using an aqueous ammonia solution (1.6 mol dm(-3)) containing 3 mol dm(-3) NaCl. The extraction mechanism of Cr(VI) is also discussed.

CONCLUSIONS

Salting-out of homogeneous mixed solvent of 2-propanol can be employed to extract Cr(VI) quantitatively, as an ion-pair of [2-PrOH2+ * CrO3Cl-] solvated by 2-PrOH molecules. Then, the complex becomes 'solvent-like' and is readily separated into the organic phase. The increase of Cl- ion concentration in the aqueous phase favors the extraction. The 2-PrOH, salts and acid play important roles in the extraction process. There is no need to use an extracting agent at a high salting-out condition.

RECOMMENDATIONS AND PERSPECTIVES

Chromium(VI) must be quickly removed before it enters into the natural cycle. As the 2-PrOH is water-miscible in any proportion, ion-pairing between 2-PrOH2+ and CrO3Cl- becomes very fast. As a result, Cr(VI) can easily be extracted. Therefore, the method is recommended as a simple, rapid and adaptable method to quickly separate Cr(VI) from aqueous samples.

Toluene/ter-Butanol Mixed Solvent for the Selective Extraction of Cr(VI) from Divalent Heavy Metals

A solvent-extraction system comprising toluene/ter-butanol (ter-BuOH) mixed solvent as the organic phase was developed to selectively extract Cr(VI) from acidic chloride media in the presence of divalent metals, namely Cd(II), Co(II), Cu(II), Ni(II) and Zn(II) under 5 M CaCl2 salting-out conditions. Chromium(VI) was selectively extracted as a solvated ion-pair of [ter-BuOH2+ x CrO3Cl-] at ter-BuOH mole fractions of between 0.1 and 0.6 (9.0-57.2% in volume). Divalent metals were extracted at ter-BuOH mole fraction over 0.6 with extraction percents of Co (< 20%), Cu (< 15%), Ni (< 10%) and Zn (< 20%). The concentrations of Ca2+, water and ter-BuOH in the organic phase and ter-BuOH in the aqueous phase were determined to find out the effects on the extraction of Cr(VI). The chemical species of Cr(VI) in acidic chloride media containing 5 M CaCl2 and 0.1 M HCl was confirmed to be the CrO3Cl- species. The effects of the acid, salt concentrations in the aqueous phase and the solvent composition of a mixed organic solvent on the extraction of Cr(VI) were evaluated. Based on the above studies, the extraction mechanism was elucidated and the optimum extraction conditions were determined.

Molecular form and subcellular distribution of acid beta-galactosidase in fibroblasts from patients with GM1 gangliosidosis, Morquio B disease and galactosialidosis

The molecular form and subcellular distribution of acid beta-galactosidase in cultured fibroblasts from patients with beta-galactosidase deficiency (GM1-gangliosidosis, Morquio B disease and galactosialidosis) were studied, using antibodies against three different forms of the human enzyme: a high-molecular-weight multienzymic complex, a recombinant 84-kDa precursor, and a 64-kDa tryptic product of the precursor. The mature enzyme from normal fibroblasts was immunoprecipitated by the anti-complex and anti-64-kDa protein antibodies, but not by the anti-84-kDa precursor one. immunofluorescence staining of normal fibroblasts revealed the granular (lysosomal) distribution with anti-64-kDa protein antibody and the perinuclear reticular distribution with anti-84-kDa precursor antibody, probably representing the Golgi apparatus. Both patterns were demonstrated in Morquio B disease, but the residual enzyme activity was exclusively due to the mature enzyme. In Type 1 galactosialidosis, most of the expressed enzyme was detected as the precursor form with a perinuclear reticular distribution. In type 2 galactosialidosis, more than half of the enzyme activity was due to the mature form with a lysosomal distribution. Fibroblasts from a patient with GM1 gangliosidosis, expressing no beta-galactosidase mRNA, did not react against either anti-64-kDa protein antibody or anti-84-kDa precursor antibody. The combined use of immunoprecipitation and immunostaining was useful for analysing the pathophysiology of the intracellular processing and transport of the mutant beta-galactosidase.

Molecular cloning and expression of cDNA for murine galactocerebrosidase and mutation analysis of the twitcher mouse, a model of Krabbe's disease

The cDNA for a murine galactocerebrosidase was isolated from a murine testis cDNA library on the basis of its homology with the cDNA for human galactocerebrosidase and a PCR method was used to clone the 5' end. It has a 2,278-nucleotide sequence including a 2,004-nucleotide open reading frame, which encodes 668 amino acid residues. The identity between the human and murine amino acid sequences was very high, being calculated to be 84%. Sequencing of cDNA from liver of the twitcher mouse revealed a nonsense mutation at codon 339 (TGG-->TGA). The most abundant mRNA of the murine galactocerebrosidase gave a 3.6-kb band, which was not detected in twitcher mice. This suggests that the cDNA (2,278 bp) we characterized represents a minor species generated by an alternate poly(A) signal and that most of the mRNA has a much longer 3'-untranslated region. Genome analysis revealed that this mutation was homozygous in the twitcher and heterozygous in the carrier but was not present in normal mice. The normal mouse cDNA but not the mutant cDNA of the galactocerebrosidase transfected into COS1 cells gave rise to an increase in enzymatic activity. We concluded that this mutation results in the deficiency of galactocerebrosidase in the twitcher mouse.

Molecular defects in Krabbe disease

Krabbe disease (globoid cell leukodystrophy) is an autosomal recessive neurodegenerative disorder that affects both the central and peripheral nervous systems due to an enzymatic defect of the galactocerebrosidase. In this study, molecular defects in Krabbe disease were investigated in 11 patients (seven Japanese and four non-Japanese) using cultured skin fibroblasts. A Japanese late infantile patient had a missense mutation of Pro at codon 302 to Ala and a non-Japanese patient had a missense mutation of Val at codon 550 to Gly. The reduced enzymatic activities expressed from the cDNAs with these missense mutations and from the previously reported nonsense mutation (E369X, Glu at codon 369 to stop codon) were confirmed. Genomic DNA analyses revealed that the P302A and E369X mutations were heterozygous and the V550G mutation was homozygous in these patients. A 12 base deletion with a 3 base insertion was found in three unrelated Japanese infantile patients, but not in 30 controls. The mutation was homozygous in two patients and heterozygous in one patient. We could not find any confirmed mutation in the coding region in the other six patients. These findings suggest that mutations in infantile and late infantile patients are relatively heterogeneous.

Krabbe disease: isolation and characterization of a full-length cDNA for human galactocerebrosidase

Human galactocerebrosidase, the enzyme deficient in Krabbe disease, was purified, through several hydrophobic column steps and gel filtration, 22,650-fold from human lymphocytes. Using information on its N-terminal and internal amino acid sequences, and the polymerase chain reaction method, we cloned a full-length cDNA for the enzyme. The deduced amino acid sequence matched all amino acid sequences determined. The 3780 nucleotide sequence included 2007 nucleotides which encoded a single chain peptide of 669 amino acid residues with a 26 amino acid N-terminal signal peptide and six potential asparagine-linked glycosylation sites. The galactocerebrosidase cDNA detected an about 4 kb mRNA band material in human cultured skin fibroblasts. A nonsense mutation was found at codon 369 (GAA-->TAA) in the coding sequence of cDNA amplified from cultured skin fibroblast mRNA from a patient with typical Krabbe disease.

Effects of double amino-acid substitution polymorphism in acid beta-galactosidase gene in two inbred strains of mice

We observed earlier that there are 5 nucleotide polymorphisms in the protein coding sequence of the acid beta-galactosidase gene between the C57BL/6J and DBA/2J strains of mice. Two of them result in amino acid substitutions. Consequences of the difference in the primary amino acid sequence were studied by introducing the two DBA polymorphisms into the C57BL cDNA, individually and in combination, by oligonucleotide-directed mutagenesis and expressing the resultant cDNAs in the COS-1 cell expression system. Introduction of one polymorphism, Asn517-->Asp into the C57BL cDNA, did not alter the acid beta-galactosidase activity in the transfected COS-1 cells, while introduction of Gly539-->Arg completely abolished the catalytic activity. When both polymorphisms were introduced together, as in the DBA mice, however, the acid beta-galactosidase activity was restored to that of the C57BL level. Thus, Asn517-->Asp appears to counteract the activity-abolishing effect of Gly539-->Arg, although it does not by itself raise the catalytic activity. All four types of cDNA generated similarly large amounts of stable mRNA in COS-1 cells. These results do not explain the significantly low acid beta-galactosidase activity in tissues of DBA mice, described earlier and also confirmed in this study.

A case of Hallervorden-Spatz disease: progressive and intractable dystonia controlled by bilateral thalamotomy

We present a 10-year-old girl with Hallervorden-Spatz disease diagnosed clinically from the neurological manifestations and the characteristic MRI findings. Her main symptom, dystonia, was progressive and resistant to medication, but this dystonia was controlled by bilateral thalamotomy. No clinical progression of the symptoms was recognized at 21 months from the last operation.

A case of pigmentary type of orthochromatic leukodystrophy with early onset and globoid cells

We report herein a sporadic case of the pigmentary type of orthochromatic leukodystrophy with early onset and very rapid clinical course. The patient's development was normal until 2 years old, when he experienced visual disturbance. Rapid deterioration resulted in death 1.5 years after the onset. Metachromatic leukodystrophy, globoid cell leukodystrophy and adrenoleukodystrophy were excluded by biochemical assays. Autopsy findings were compatible with the diagnosis of the pigmentary type of orthochromatic leukodystrophy. However, there were unique findings of severe neuronal loss and the collection of globoid-like cells in the interface of the gray matter and the white matter. Immunohistochemical staining of myelin basic protein, proteolipid protein and galactocerebroside demonstrated that these myelin constituents were equally preserved in the posterior column, while absent in the lateral and anterior columns of the spinal cord.

GM1-gangliosidosis (genetic beta-galactosidase deficiency): identification of four mutations in different clinical phenotypes among Japanese patients

GM1-gangliosidosis is a genetic neurological disorder caused by mutations in the lysosomal acid beta-galactosidase gene. While its phenotypic expression is complex, it is usually classified as being of infantile, juvenile, or adult form, on the basis of age at onset, the rate of symptomatic progression, and severity of central nervous system involvement. We have analyzed the acid beta-galactosidase gene in 12 Japanese patients from nine families. The aim was to identify mutations in individual patients and then to examine possible correlation between the mutations and the clinical phenotypes. Northern blotting studies with a full-length human beta-galactosidase cDNA showed that the mRNA ranged from undetectable to substantially decreased in the infantile patients but was normal in quantity and size in all juvenile and adult patients. Four distinct missense mutations have been identified, each limited to the respective clinical forms within our small-size samples. In the infantile patient with decreased but detectable mRNA, a point mutation was found resulting in Arg49----Cys. In the infantile patient with nearly undetectable mRNA, mutation Arg457----Ter was identified. The mutation Arg201----Cys was found in all four of the juvenile patients, while all six adult patients were homozygous for the point mutation Ile51----Thr. The mutations found in the juvenile and adult patients alter restriction sites in the normal gene and thus are amendable to quick screening. The prediction that these mutations are responsible for the clinical disease was confirmed by no expression of the catalytic activity of the mutant proteins in the COS-I cell expression system.(ABSTRACT TRUNCATED AT 250 WORDS)

Expression of the beta-hexosaminidase alpha subunit gene with the four-base insertion of infantile Jewish Tay-Sachs disease

One of the two mutations responsible for the classical infantile Jewish form of Tay-Sachs disease is a four-base insertion in exon 11 of the beta-hexosaminidase alpha subunit gene. The gene is known to be transcribed normally, but the mRNA is essentially undetectable. It is not clear why such a relatively minor abnormality results in complete failure to generate stable mRNA. The four-base insertion was introduced into the normal beta-hexosaminidase cDNA by site-directed mutagenesis. When COS-1 cells were transfected with the resultant mutant cDNA, it generated stable mRNA and a truncated, relatively stable but catalytically inactive enzyme protein. The mutant enzyme protein was not processed nor released into the culture medium. The mutant cDNA also generated the truncated enzyme protein in an in vitro translation system with rabbit reticulocyte lysate. COS-1 cells transfected with a 3' end of the gene segment, from intron 8 through the 3' terminus, generated processed RNA of approximately 2 kilobases, the size expected from normal splicing, irrespective of presence or absence of the four-base insertion in exon 11. These results indicate that the four-base insertion does not destabilize properly spliced mRNA, nor does it interfere with normal splicing of the transcript, at least in the expression system utilized. If the four-base insertion is responsible for the undetectable mRNA in the mutant cells, it must interfere with some other steps in the processing/splicing/transport of the primary transcript yet to be examined. On the other hand, the possibility cannot be excluded definitively that another still unidentified abnormality in the same allele might be responsible for the nearly complete absence of mRNA.

Genetic cause of a juvenile form of Tay-Sachs disease in a Lebanese child

Abnormality in the beta-hexosaminidase alpha gene underlying the clinical phenotype of a Lebanese patient with a juvenile form of Tay-Sachs disease has been studied. Clinical features were progressive spasticity, ataxia, and cognitive decline. The protein coding sequence of several beta-hexosaminidase alpha-chain complementary DNAs isolated by polymerase chain reaction was completely normal except for a G-to-A transition at nucleotide position 1511 within exon 13, which resulted in substitution of the normal arginine 504 (CGC) with histidine (CAC). Although the patient was from a first-cousin marriage, she was heterozygous for this mutation. The abnormality in the other allele, which is carried by the father, was not identified, except that it is neither of the two mutations responsible for the infantile Jewish Tay-Sachs disease. Biosynthetic and immunoprecipitation studies in cultured fibroblasts showed synthesis of the alpha-chain precursor, but the mature form of the alpha-subunit was not detected.

Study of pathogenesis in twitcher mouse, an enzymatically authentic model of Krabbe's disease

The twitcher mouse was investigated by examining in vivo synthesis of galactosylceramide (Galcer) and galactosylsphingosine (Galsph) in a sciatic nerve culture, and in vitro enzymic activities for synthesis of Galcer and Galsph in the spinal cord from normal and affected mice. For the in vivo study, the sciatic nerve was incubated for 24 h in medium containing [3H]galactose, or [3H]-sphingosine-labeled Galcer or Galsph. With [3H]galactose, reduced synthesis of Galcer was found as early as 1 week of age and synthesis decreased to about 15% of normal value at 4 weeks. Increased Galsph was detected after 7 days of feeding with galactose. In a study of [3H]sphingosine-labeled Galcer and Galsph feeding, Galcer did not induce Galsph synthesis in either normal or affected mice, and synthesis of Galcer from Galsph was found only in normal mice, suggesting that Galcer was synthesized from sphingosine after hydrolysis of Galsph. In vitro, the activities of UDP-galactose: ceramide galactosyltransferase and UDP-galactose: sphingosine galactosyltransferase were reduced to less than 50% of control after 2 weeks of age in affected mice. We conclude that (1) decreased Galcer was due to impaired synthesis of Galcer, (2) Galsph was synthesized from galactose and not from deacylation of Galcer, and (3) Galsph accumulation was due not to increased synthesis but to decreased hydrolysis.

Impaired cholesterol esterification in cultured skin fibroblasts from patients with I-cell disease and pseudo-Hurler polydystrophy

Cholesterol esterification was examined in cultured skin fibroblasts from patients with I-cell disease and pseudo-Hurler polydystrophy by incubating cells pretreated without fetal calf serum for 48h, with (14C) cholesterol for 24h. Impaired cholesterol esterification was found in these cells and free cholesterol was accumulated in plasma membrane and Golgi fractions. This impairment was also induced in control cells by adding leupeptin (20 micrograms/ml) or monensin (2 micrograms/ml). These findings suggest the importance of the role of lysosomes for esterification of cholesterol and give a hint as to the basic defect in type C Niemann-Pick disease.

Biochemical studies on lymphoblastoid cells with inherited N-acetyl-glucosamine 1-phosphotransferase deficiency (I-cell disease)

Lymphoblastoid cells transformed by Epstein-Barr virus from peripheral lymphocytes of normal individuals and I-cell disease (ICD) patients were used for the enzymic study of lysosomal hydrolases and N-acetylglucosamine 1-phosphotransferase. ICD lymphoblastoid cells secreted a larger amount of hydrolases into medium than normal cells, although the intracellular hydrolases were not deficient in ICD cells. The stimulating effect of 10 mM ammonium chloride on secretion of hydrolases was found only with normal cells, and not with ICD cells, indicating that the hydrolase molecule bearing mannose 6-phosphate was secreted. The ICD lymphoblastoid cells retained the enzymologic characteristics of both lysosomal hydrolases and N-acetylglucosamine 1-phosphotransferase seen in ICD fibroblasts, which allows us to study the pathophysiology of ICD in cells other than fibroblasts.

A family with pseudodeficiency of acid alpha-glucosidase

A unique family is presented which consists of a patient with the juvenile muscular dystrophy form of glycogenosis type II and four healthy individuals, both parents and sisters, with low acid alpha-glucosidase activity. It was almost impossible to distinguish the homozygote from the heterozygous members by lymphocyte assay alone. In cultured skin fibroblasts, acid alpha-glucosidase activity measured with a synthetic substrate was less than 1% of the normal mean value in the patient and about 15% in the parents. The activity toward glycogen was not detectable in the patient and was about 30% of the normal mean value in the parents. These values are also lower than expected in heterozygotes. To explain these results properly, a new mutant allele of acid alpha-glucosidase is proposed. Both parents could be compound heterozygotes for the pseudodeficiency allele and the juvenile form of glycogenosis type II allele.

Biochemical heterogeneity in I-cell disease. Sucrose-loading test classifies two distinct subtypes

Since we observed the normalization of intracellular hydrolases in some cell lines of I-cell disease (ICD) by 88 mmol/l sucrose, we have hypothesized that the degree of responses of the hydrolases might be due to biochemical heterogeneity among ICD. In this study the changes of intracellular lysosomal enzymes as well as Golgi enzymes including N-acetylglucosaminyl phosphotransferase (GlcNAcPTase) and extracellular hexosaminidase (HEX) were investigated using normal and ICD fibroblasts. Sucrose loading induced the activities of intracellular HEX and GlcNAcPTase simultaneously only in responding-type ICD cells, and not in nonresponding-type ICD cells, indicating that two biochemical heterogeneous groups exist in ICD.