Occupational asthma and IgE sensitization to grain dust

To evaluate type I hypersensitivity to grain dust (GD), its prevalence and relationship to respiratory dysfunction, we studied clinical and immunologic features, including skin prick tests (SPT), serum specific IgE, and bronchoprovocation tests of 43 employees working in the animal feed industry. To further characterize IgE-mediated reaction, SDS-PAGE and electroblot studies were performed. Our survey revealed that 15 (34.9%) subjects had work-related skin response (> or =2+ of A/H ratio) to GD, thirteen (30.2%) had high specific IgE antibody against GD. The specific IgE antibody was detected more frequently in symptomatic workers (40%) than in asymptomatic workers (11%). Significant association was found between specific IgE antibody and atopy or smoking (p<0.05). The ELISA inhibition test of GD revealed significant inhibitions by GD extract and minimal inhibitions by the house dust mite, storage mite and corn dust. Immunoblot analysis showed 8 IgE binding components within GD ranging from 13.5 to 142.5 kDa. Two bands (13.5, 33 kDa) were bound to the IgE from more than 50% of the 14 sera tested. In conclusion, these findings suggest that GD inhalation could induce IgE-mediated bronchoconstriction in exposed workers.

Identification of a candidate human spectrin Src homology 3 domain-binding protein suggests a general mechanism of association of tyrosine kinases with the spectrin-based membrane skeleton

Spectrin is a widely expressed protein with specific isoforms found in erythroid and nonerythroid cells. Spectrin contains an Src homology 3 (SH3) domain of unknown function. A cDNA encoding a candidate spectrin SH3 domain-binding protein was identified by interaction screening of a human brain expression library using the human erythroid spectrin (alphaI) SH3 domain as a bait. Five isoforms of the alphaI SH3 domain-binding protein mRNA were identified in human brain. Mapping of SH3 binding regions revealed the presence of two alphaI SH3 domain binding regions and one Abl-SH3 domain binding region. The gene encoding the candidate spectrin SH3 domain-binding protein has been located to human chromosome 10p11.2 --> p12. The gene belongs to a recently identified family of tyrosine kinase-binding proteins, and one of its isoforms is identical to e3B1, an eps8-binding protein (Biesova, Z., Piccoli, C., and Wong, W. T. (1997)Oncogene 14, 233-241). Overexpression of the green fluorescent protein fusion of the SH3 domain-binding protein in NIH3T3 cells resulted in cytoplasmic punctate fluorescence characteristic of the reticulovesicular system. This fluorescence pattern was similar to that obtained with the anti-human erythroid spectrin alphaI SigmaI/betaI SigmaI antibody in untransfected NIH3T3 cells; in addition, the anti-alphaI SigmaI/betaI SigmaI antibody also stained Golgi apparatus. Immunofluorescence obtained using antibodies against alphaI SigmaI/++betaI SigmaI spectrin and Abl tyrosine kinase but not against alphaII/betaII spectrin colocalized with the overexpressed green fluorescent protein-SH3-binding protein. Based on the conservation of the spectrin SH3 binding site within members of this protein family and published interactions, a general mechanism of interactions of tyrosine kinases with the spectrin-based membrane skeleton is proposed.

A multifunctional repeated motif is present in human bifunctional tRNA synthetase

Tandem repeats located in the human bifunctional glutamyl-prolyl-tRNA synthetase (EPRS) have been found in many different eukaryotic tRNA synthetases and were previously shown to interact with another distinct repeated motifs in human isoleucyl-tRNA synthetase. Nuclear magnetic resonance and differential scanning calorimetry analyses of an isolated EPRS repeat showed that it consists of a helix-turn-helix with a melting temperature of 59 degrees C. Specific interaction of the EPRS repeats with those of isoleucyl-tRNA synthetase was confirmed by in vitro binding assays and shown to have a dissociation constant of approximately 2.9 microM. The EPRS repeats also showed the binding activity to the N-terminal motif of arginyl-tRNA synthetase as well as to various nucleic acids, including tRNA. Results of the present work suggest that the region comprising the repeated motifs of EPRS provides potential sites for interactions with various biological molecules and thus plays diverse roles in the cell.

Protection from reoxygenation injury by inhibition of rac1

We demonstrate that adenoviral-mediated gene transfer of a dominant negative rac1 gene product (N17rac1) inhibits the intracellular burst of reactive oxygen species (ROS) that occurs after reoxygenation of vascular smooth muscle cells. In contrast, expression of a dominant negative ras gene (N17ras) had no effect. Challenge of control cells and cells expressing N17rac1 with a direct oxidant stress produced an equivalent increase in intracellular ROS levels and subsequent cell death. This suggests that N17rac1 expression appears to block production of harmful oxygen radicals and does not act directly or indirectly to scavenge ROS generated during reoxygenation. Expression of N17rac1 results in protection from hypoxia/reoxygenation-induced cell death in a variety of cell types including vascular smooth muscle cells, fibroblasts, endothelial cells, and ventricular myocytes. These results suggest that reoxygenation injury requires the activation of rac proteins, and that inhibition of rac-dependent pathways may be a useful strategy for the prevention of reperfusion injury in ischemic tissues.

arfI and arfII, two genes encoding alpha-L-arabinofuranosidases in Cytophaga xylanolytica

arfI encoded the 57.7-kDa subunit of Cytophaga xylanolytica arabinofuranosidase I (ArfI). arfII encoded a 59.2-kDa subunit of ArfII. Products of both cloned genes liberated arabinose from arabinan and arabinoxylan. The deduced amino acid sequences of ArfI and ArfII revealed numerous regions that were identical to each other and to regions of homologous proteins from Bacteroides ovatus, Bacillus subtilis, and Clostridium stercorarium.

Specific inhibition of immunoglobulin E-mediated allergic reaction using antisense Fc epsilon RI alpha oligodeoxynucleotides

We have investigated the ability of an antisense immunoglobulin E (IgE) receptor alpha-subunit oligodeoxynucleotide (Fc epsilon RI alpha ODN) specifically to inhibit IgE-mediated allergic reactions in the mouse. Synthetic antisense Fc epsilon RI alpha ODN dose-dependently inhibited passive cutaneous anaphylaxis and histamine release from the mouse peritoneal mast cells (MPMC) activated by anti-dinitrophenyl (DNP) IgE. Northern blot analysis showed that the mast cells treated with antisense Fc epsilon RI alpha ODN exhibited no detectable levels of L-histidine decarboxylase mRNA after anti-DNP IgE stimulation, whereas the cells treated with sense Fc epsilon RI alpha ODN possessed significant amounts of this mRNA. Examination of the elevation of cAMP levels in MPMC following the activation with anti-DNP IgE demonstrated a significant rise in activated cells, but not in the antisense Fc epsilon RI alpha ODN-treated cells. Moreover, antisense Fc epsilon RI alpha ODN had a significant inhibitory effect on anti-DNP IgE-induced tumour necrosis factor-alpha production. Our results demonstrated that antisense Fc epsilon RI alpha ODN inhibited the IgE-mediated allergic reaction in vivo and in vitro.

The Leu-3 residue of Serratia marcescens metalloprotease inhibitor is important in inhibitory activity and binding with Serratia marcescens metalloprotease

Serratia marcescens metalloprotease inhibitor (SmaPI) is a proteinase inhibitor toward Serratia marcescens metalloprotease (SMP). In sequential deletion analysis of the N-terminal region of the SmaPI, SmaPIs starting at Ser-2 and Leu-3 residues, respectively, had nearly a full inhibitory activity toward SMP. However, SmaPI starting at Ala-4 residue showed severely decreased inhibitory activity. Furthermore, kinetic analysis demonstrated that SmaPI starting at the Ala-4 residue had an inhibition constant for SMP approximately fourfold higher than that of wild-type SmaPI. The interactions of Leu-3 with SMP contribute 0.73 kcal mol-1 to the overall stability of the SMP-SmaPI complex (8.44 kcal mol-1). To elucidate the detailed role of the Leu-3 residue in inhibitory activity of SmaPI, several site-directed mutations were introduced. The inhibitory activities of Leu-3 mutants in which the Leu-3 has been converted to Ala, Asp, Gly, Ile, Lys, Phe, or Pro were correlated with the hydrophobicities of substituted amino acids. About 0.3 kcal mol-1 is attributable to the side chain of the Leu-3 residue in the binding with SMP. From these results, it is suggested that (i) in contrast with the Erwinia chrysanthemi inhibitor, Gly-1 and Ser-2 of SmaPI are not critical and (ii) the hydrophobicity of Leu-3 may be important in its inhibitory activity and binding with SMP.

Lymphoepithelial cysts of the pancreas: CT and sonographic findings

Two cases of rare lymphoepithelial cyst (LEC) of the pancreas are presented. Although the histogenesis of this lesion is not known, it can be histologically differentiated from other pancreatic and retropancreatic cysts. The importance of its recognition is in the distinction from cystic neoplasm of the pancreas.

The effect of botulinum toxin type A injection for intrinsic rhinitis

Botulinum toxin type A (BTA) is known to inhibit the release of acetylcholine from cholinergic nerve endings. Owing to the characteristics of BTA, we thought that it could be used for the treatment of intrinsic rhinitis acting as an anticholinergic drug. In a double-blind placebo-controlled study four units of BTA were injected into the middle turbinate (two units) and inferior turbinate (two units) in each nasal cavity. Rhinorrhoea, nasal obstruction, and sneezing were recorded in a symptom diary on the basis of a scale of 5 and the number of paper tissues used per day was also recorded for 24 weeks. Rhinorrhoea was significantly diminished in severity (24.1-41.5 per cent reduction) and paper tissue use (54.3 per cent reduction) in the BTA group compared with the placebo group. This effect could be maintained for four weeks. Sneezing and nasal stuffiness were not affected by BTA. These results suggest that BTA can be used to treat rhinorrhoea in intrinsic rhinitis patients, however, the effective period is short.

Neuromuscular interactions between mivacurium and esmolol in rabbits

We compared the dose-response relationship and the neuromuscular blocking effects of mivacurium during infusions of esmolol in 40 anaesthetised rabbits. Train-of-four stimuli were applied every 10 s to the common peroneal nerve and the force of contraction of the tibialis anterior muscle was measured. Plasma cholinesterase activity decreased by 13% after esmolol infusion. The ED95 of mivacurium increased significantly from 29 (4.8) micrograms.kg-1 with placebo to 61 (9.8) micrograms.kg-1 during esmolol 100 micrograms.kg-1.min-1, 49 (8.2) micrograms.kg-1 during esmolol 300 micrograms.kg-1.min-1 and 54 (7.3) micrograms.kg-1 during esmolol 500 micrograms.kg-1.min-1, respectively (p < 0.001). The duration of neuromuscular block with mivacurium 0.16 mg.kg-1 was prolonged by 30% with esmolol due to diminished plasma cholinesterase activity (p < 0.05). Heart rate and mean arterial blood pressure decreased by 15% with esmolol (p < 0.05). The results of this study show that, in rabbits, esmolol decreased plasma cholinesterase activity, antagonised the neuromuscular blocking potency of mivacurium and prolonged its neuromuscular blocking effect.

Sialoglycoproteins and penultimate sugar expression pattern in developing murine olfactory and respiratory mucosa

Sialic acid residues are constant constituents of the glycoproteins of the airways in all species. Sialoglycoproteins are the main acidic glycoprotein and their functions are to mediate cell adherence, to control the viscoelasticity of mucus and to serve as receptor sites for the binding of exogenous macromolecules. The purpose of this study was to investigate the differences in the distribution of sialoglycoproteins as a terminal sugar and in the composition of the penultimate sugar according to aging in the murine nasal respiratory and olfactory mucosa. Nasal cavities of mice (BALB/c) were fixed by intracardiac perfusion with 2.0% glutaraldehyde and embedded in Epon 812. First, the serial sections were stained with Maackia amurensis agglutinin (MAA) and Sambucus nigra agglutinin (SNA). Then, the adjacent sections were stained with DBA and PNA before and after neuraminidase digestion in all experimental groups. Apical cell surfaces of olfactory mucosa and cilia on a few ciliated cells in the mucosa of the septum and nasal floor were labelled with MAA, but cell surfaces of respiratory mucosa, Bowman's glands and goblet cells were not labelled with MAA, irrespective of aging. Apical cell surfaces of both olfactory and respiratory mucosa and Bowman's glands were stained with SNA, however, goblet cells were not labelled with SNA. After neuraminidase digestion to remove terminal sialic acid residues of sialoglycoproteins, only cell surfaces of respiratory mucosa were labelled with PNA, but goblet cells, cell surfaces of olfactory mucosa and Bowman's glands were not labelled with PNA. Cell surfaces and Bowman's glands of olfactory mucosa were labelled with DBA after neuraminidase digestion, but cell surfaces of respiratory mucosa and goblet cells were not labelled with DBA. Our results indicate that there were different carbohydrate structures of sialoglycoconjugates in olfactory and respiratory mucosa, and it was not influenced by aging.

Neuronal differentiation of human neuroblastoma SH-SY5Y cells by gangliosides

Exogenous administration of gangliosides induced neuronal differentiation with prominent neuritogenesis in human neuroblastoma SH-SY5Y cells in vitro. Neuritogenesis was characterized by ruffling of the cell membrane, the development of lamellipodia and filopodia, and the subsequent elongation and branching of the neurites ultrastructurally. Both axons and neurites were identified. Increased numbers of cell organelles in the neurites and cell bodies were noted. Nonsynaptic contacts and gap junctions formed between neurites or between each neurite and cell body. These findings could be implicated in histopathologic changes from neuroblastoma to ganglioneuroblastoma.

Increased plasma amyloid beta protein 1-42 levels in Down syndrome

Amyloid beta protein 1-40 (A beta40) and A beta42 levels were quantitated in plasma from 43 persons with Down syndrome (DS; 26-68 years of age), 43 age-matched normal controls, and 19 non-DS mentally retarded (MR) persons (26-91 years of age) by using a sandwich enzyme linked immunosorbent assay. A beta40 levels were higher in DS and MR than controls, but were similar between DS and MR groups. A beta42 levels were higher in DS than controls or MR persons. The ratios of A beta42/A beta40 were higher in DS than controls or MR persons. The findings are consistent with those seen in DS brains.

Cloning and nucleotide sequence of the DNA gyrase gyrA gene from Serratia marcescens and characterization of mutations in gyrA of quinolone-resistant clinical isolates

The sequence of the DNA gyrase gyrA gene of Serratia marcescens ATCC 14756 was determined. An open reading frame of 2,640 nucleotides coding for a polypeptide with a calculated molecular mass of 97,460 was found, and its sequence complemented the sequence of an Escherichia coli gyrA temperature-sensitive mutation. Analysis of the PCR products of the quinolone resistance-determining regions of gyrA genes from six quinolone-resistant clinical isolates revealed a single amino acid substitution, Ser-83 to Arg or Asp-87 to Tyr, in all six mutants, suggesting that a mutational alteration in gyrA is a common mechanism of quinolone resistance in S. marcescens.

MR imaging of intersexuality

Intersexuality involves an intermingling of the characteristics of each sex in varying degrees as a result of some flaw in embryonic development. Accurate demonstration of genital anatomy is essential for proper gender assignment and for treatment of intersexual disorders. Genital anatomy is well demonstrated with MR imaging, which offers unsurpassed soft-tissue contrast, multiplanar capability, and no radiation exposure. Intersexual disorders can be categorized into female pseudohermaphroditism, male pseudohermaphroditism, gonadal dysgenesis or agenesis, and true hermaphroditism. In female pseudohermaphroditism, MR images show normal internal female genitalia with masculinized external genitalia. In male pseudohermaphroditism, MR images show normal or mildly defective testes with incompletely masculinized external genitalia. In gonadal dysgenesis, combinations of normal, dysgenetic, and streak gonads are seen on MR images; in gonadal agenesis, no gonads are evident. In true hermaphroditism, both testicular and ovarian tissue is seen on MR images. MR imaging is essential for management of intersexual disorders.

Octopine-type Ti plasmids code for a mannopine-inducible dominant-negative allele of traR, the quorum-sensing activator that regulates Ti plasmid conjugal transfer

Conjugal transfer of Agrobacterium tumefaciens Ti plasmids is regulated by two hierarchical signalling systems. Transfer is dependent on a subset of opines produced by the plant tumours induced by the bacterium. Induction also requires an acyl-homoserine lactone signal, called AAI, that is produced by the bacteria themselves. AAI is the co-inducer for TraR, the transcriptional activator required for expression of the tra regulon. Octopine induces conjugation of the octopine-mannityl opine-type Ti plasmids by regulating the expression of traR via OccR, the octopine-dependent activator of the opine regulon. We have discovered a second traR-like gene, trlR, on the octopine-mannityl opine-type Ti plasmids pTi15955 and pTiR10. This gene is located in an operon coding for a mannopine transport system and is expressed as part of the mannityl opine regulon. Sequence analysis indicated that trlR is a frameshift allele of traR, and the resulting protein lacks the carboxy-terminal domain thought to constitute the DNA-binding region of TraR. Expression of trlR inhibited octopine-induced conjugation of pTi15955 and pTiR10 by suppressing the TraR-mediated transcription of the tra and trb operons. Although TrlR had no effect on the expression of traR, TraR activated the expression of trlR. Southern hybridizations indicated that several other Ti and opine-catabolic plasmids contain more than one copy of genes homologous to traR. We propose that trlR is a dominant negative allele of traR and that TrlR inhibits conjugation by forming inactive heteromultimers with TraR.

Cloning and sequence analysis of another Shiga-like toxin IIe variant gene (slt-IIera) from an Escherichia coli R107 strain isolated from rabbit

An Escherichia coli R107 strain (O26 serotype) producing a Shiga-like toxin IIe variant (SLT-IIera) was isolated from the mesenteric lymph node of a freshly dead rabbit carcass. The entire structural gene for this SLT-IIera was cloned from chromosomal DNA by PCR using primers based on previously published slt-IIe sequences. Nucleotide sequence analysis indicated that the slt-IIera gene was very similar to slt-IIe (formerly called slt-IIv) from E. coli strains S1191 and 412; five and one nucleotide changes were detected in A and B subunits, respectively, which resulted in changes in amino acid sequences of the corresponding subunits by three and one residues. Recombinant SLT-IIera and SLT-IIe produced using an E. coli host-vector system showed similar cytotoxicity, suggesting that the variations in the structural gene of SLT-IIera have no significant effect on cytotoxic level.

Invasion of brain microvascular endothelial cells by group B streptococci

Group B streptococci (GBS) are the leading cause of meningitis in newborns. Although meningitis develops following bacteremia, the precise mechanism or mechanisms whereby GBS leave the bloodstream and gain access to the central nervous system (CNS) are not known. We hypothesized that GBS produce meningitis because of a unique capacity to invade human brain microvascular endothelial cells (BMEC), the single-cell layer which constitutes the blood-brain barrier. In order to test this hypothesis, we developed an in vitro model with BMEC isolated from a human, immortalized by simian virus 40 transformation, and propagated in tissue culture monolayers. GBS invasion of BMEC monolayers was demonstrated by electron microscopy. Intracellular GBS were found within membrane-bound vacuoles, suggesting the organism induced its own endocytic uptake. GBS invasion of BMEC was quantified with a gentamicin protection assay. Serotype III strains, which account for the majority of CNS isolates, invaded BMEC more efficiently than strains from other common GBS serotypes. GBS survived within BMEC for up to 20 h without significant intracellular replication. GBS invasion of BMEC required active bacterial DNA, RNA, and protein synthesis, as well as microfilament and microtubule elements of the eukaryotic cytoskeleton. The polysaccharide capsule of GBS attenuated the invasive ability of the organism. At high bacterial densities, GBS invasion of BMEC was accompanied by evidence of cellular injury; this cytotoxicity was correlated to beta-hemolysin production by the bacterium. Finally, GBS demonstrated transcytosis across intact, polar BMEC monolayers grown on Transwell membranes. GBS invasion of BMEC may be a primary step in the pathogenesis of meningitis, allowing bacteria access to the CNS by transcytosis or by injury and disruption of the endothelial blood-brain barrier.

Biallelic expression of the H19 and IGF2 genes in hepatocellular carcinoma

The imprinted genes, H19 and insulin-like growth factor II (IGF2), have been demonstrated to be necessary for embryonal development in humans. Both genes are reciprocally imprinted, with expression of the maternal H19 and paternal IGF2 alleles, and are normally characterized by monoallelic expression. Recently, loss of imprinting of these genes producing biallelic expression has been observed in childhood tumors including Wilms' tumors (WT), embryonal rhabdomyosarcoma, and adulthood tumors such as lung cancer. To test the existence of loss of imprinting in hepatocellular carcinoma (HCC), we analyzed the status of imprinting of H19 and IGF2 genes in three independent tumors, three HCC and one hepatoblastoma cell lines using AluI and ApaI polymorphisms of these genes, respectively. In contrast to the previous report, all the cases except one tumor and one HCC cell line showed biallelic expression of both H19 and IGF2 genes. Unlike WT, loss of imprinting (LOI) of IGF2 in HCC was not linked to down-regulation of H19 expression, but rather associated with coexpression for H19 and IGF2. Thus, Hl9 and IGF2 expression can be uncoupled in tumors with LOI. The frequent biallelic expression of H19 and IGF2 in hepatocellular carcinoma might play a causal role in the epigenetic mechanism involved in tumor development and/or process.

A report on 387 cases of microsurgical tubal reversals

OBJECTIVE

To survey what factors influence the pregnancy outcome in an effort to improve the pregnancy rate (PR) after microsurgical reversal of tubal sterilization.

DESIGN

Retrospective clinical study.

PATIENT(S)

Three hundred eighty-seven patients who had microsurgical tubal reversal between March 1982 and January 1994.

INTERVENTION(S)

Postoperative pregnancy outcomes were determined by telephone, letters, and direct interviews.

RESULT(S)

Pregnancy outcomes were identified in 94.1% of the total patients. The overall PR was 91.6%, of which 3.9% spontaneously aborted and 1.7% were ectopic. The probability that pregnancy occurred within the first 12 months was 0.80. The median interval from the tubal reversal to pregnancy was 5.34 months. The pregnancy success rate after reversal of Falope ring sterilization was statistically significantly higher than in the other groups. Patients with reversed tubal length > or = 7 cm had a statistically significantly higher PR than those with < 7 cm.

CONCLUSION(S)

The overall probability of pregnancy was 0.89. The tubal length reconstructed after tubal reversal and the type of sterilization performed previously were the important factors affecting the PR.

Loss of heterozygosity of the retinoblastoma and p53 genes in primary cervical carcinomas with human papillomavirus infection

OBJECTIVE

Paired DNA samples from 55 primary uterine cervical carcinomas and normal bloods were studied for chromosomal allelic loss (loss of heterozygosity; LOH) of the retinoblastoma (Rb) and p53 gene loci by polymerase chain reaction (PCR) or PCR-restriction fragment length polymorphism analysis. All the study samples contained at least one of the oncogenic human papillomavirus (HPV) type 16 and/or 18 sequences. And the relationships between allelic losses of these genes and conventional clinicopathological parameters were evaluated.

METHODS

In order to detect LOH of the Rb gene in cervical cancers, we analyzed four polymorphic intronic sites (intron 1, 17, 20, and 25) of the Rb gene and one additional microsatellite near the Rb locus (D13S118). For detection of the LOH in p53, three intragenic polymorphisms (exon 1, exon 4, intron 6) and one microsatellite distal to the p53 gene (D17S5) were examined.

RESULTS

By analyzing this system, we could increase the heterozygosity of the Rb and p53 loci up to 0.91 and 1, respectively. The observed allelic loss rates of the Rb and p53 loci in informative cases were 14% (7/50) and 5.5% (3/55), respectively. The patients with LOH at the D13S118 locus also had the allelic loss of the Rb gene, whereas only one of the four patients with LOH at the D17S5 locus showed a concomittant allelic loss of the p53 gene. The frequency of cervical cancer with one LOH at the Rb or p53 loci was 20% (11/55). No shifted bands were observed in the PCR-single-strand conformation polymorphism analysis of the p53 gene. The LOH of the Rb or p53 gene was not significantly associated with other parameters including clinical stage, histological type, degree of differentiation, status of HPV infection, and p53 gene mutation.

CONCLUSION

Concerning the results above, we conclude that the allelic imbalance of the Rb or p53 gene itself is not implicated as a major contributing factor in the malignant transformation or the tumor progression in HPV-positive uterine cervical cancers.