[Parapharyngeal space neoplasms]

OBJECTIVE

To study parapharyngeal space (PPS) neoplasms which are rarely seen clinically.

METHODS

A retrospective review was made of 59 patients with PPS neoplasm operated on from 1986 to July, 1997 in our institution.

RESULTS

Neurogenic tumors were the most common neoplasms, which constituted about 60 percent in the primary parapharyngeal space neoplasms. High-resolution computed tomography or magnetic resonance imaging was essential for diagnosis and presurgical planning. The transcervical approach was the preferred procedure for 75% benign parapharyngeal tumors. Middle mandibulotomy was used in 3 cases, including 2 small tumors confined to the superior aspect of the PPS and 1 carotid body tumor which extended to the skull base. Lateral skull base approach was utilized for 1 schwannoma originating in the jugular foramen with extension into the PPS.

CONCLUSIONS

We believe that transoral approach can be used for small tumors and transparotid approach may be especially indicated for removal of deep lobe parotid tumors with extension to the PPS. Middle mandibulotomy is a safe and efficacious approach for the removal of special PPS neoplasms.

(+/-)-trans-2-[3-methoxy-4-(4-chlorophenylthioethoxy)-5-(N-methyl-N- hydroxyureidyl)methylphenyl]-5-(3,4, 5-trimethoxyphenyl)tetrahydrofuran (CMI-392), a potent dual 5-lipoxygenase inhibitor and platelet-activating factor receptor antagonist

By incorporating an N-hydroxyurea functionality onto diaryltetrahydrofurans, a novel series of compounds was investigated as dual 5-lipoxygenese (5-LO) inhibitor and platelet-activating factor (PAF) receptor antagonist. These dual functional compounds were evaluated in vitro for 5-LO inhibition in RBL cell extracts and human whole blood, and PAF receptor antagonism in a receptor binding assay. PAF-induced hemoconcentration and arachidonic acid- and TPA-induced ear edema in mice were used to determine in vivo activities. The structure-activity relationship analysis to define a preclinical lead is presented. (+/-)-trans-2-[3-methoxy-4-(4-chlorophenylthioethoxy)-5-(N-methyl- N-h ydroxyureidyl)methylphenyl]-5-(3,4, 5-trimethoxyphenyl)tetrahydrofuran (40, CMI-392) was selected for further study. In the arachidonic acid-induced mouse ear edema model, 40 was more potent than either zileuton (a 5-LO inhibitor) or BN 50739 (a PAF receptor antagonist), and it demonstrated the same inhibitory effect as a physical combination of the latter two agents. These results suggest that a single compound which both inhibits leukotriene synthesis and blocks PAF receptor binding may provide therapeutic advantages over single-acting agents. The clinical development of compound 40 is in progress.

[Leiomyosarcoma of larynx and hypopharynx]

The laryngeal and hypopharyngeal smooth muscle tumors are very rare. One case of hypopharyngeal leiomyosarcoma and two cases of laryngeal smooth muscle tumors were reported: one angioleiomyoma, one leiomyosarcoma and one carcinoleiomyosarcoma. The patients usually present no characteristic symptoms in early stage and the clinical symptoms are similar to squamous cell carcinoma. It is difficult to make a correct diagnosis before operation. Treatment of first choice consists of primary radical resection including a large part of normal tissue. Early lymph node metastasis is rare. Precautary neck dissection is not indicated for subclinic cervical nodal disease. Radiotherapy may be taken as adjuvant or palliative measures.

Molecular cytogenetic characterization of Thinopyrum and wheat-Thinopyrum translocated chromosomes in a wheat-Thinopyrum amphiploid

The wheat-Thinopyrum amphiploid 'Agrotriticum # 3425' (AT 3425), which is highly resistant to Cephalosporium stripe, was identified to carry seven pairs of Thinopyrum chromosomes, three pairs of wheat-Thinopyrum translocated chromosomes and 18 pairs of wheat chromosomes. Fluorescence genomic in situ hybridization (FGISH), C-banding, sequential C-banding and FGISH, and denaturing polyacrylamide gel electrophoresis (SDS-PAGE) were used to characterize and identify the chromosomes. The Thinopyrum chromosomes in AT 3425 were designated as T1 through T7 based on their C-banding patterns. The FGISH and C-banding patterns of mitotic chromosomes in AT 3425 and meiotic chromosomes in the hybrid between AT 3425 and wheat cultivar 'Chinese Spring' (CS) revealed that wheat chromosomes 1D, 2B and 3D were involved in the three wheat-Thinopyrum chromosome translocations designated as (W-T)1, (W-T)2, and (W-T)3 respectively. The analysis of high-molecular-weight glutenin subunits in single seeds of AT 3425 confirmed the involvement of wheat chromosome 1D in the translocation (W-T)1. The designations 1DSx1DL-1TL, 2BSx2BL-2TL and 3DSx3DL-3TL were suggested for the wheat-Thinopyrum translocated chromosomes (W-T)1, (W-T)2 and (W-T)3 in AT 3425 respectively.

[Nonepithelial malignant neoplasms of the larynx and hypopharynx]

OBJECTIVES

Nonepithelial Malignant Neoplasms of the larynx and hypopharynx are rare. Their clinical features, diagnosis and treatment were discussed.

METHODS

From 1985 to 1996, 23 cases of nonepithelial malignant neoplasms of the larynx and 3 cases of hypopharynx were diagnosed. There were 21 males and 5 females. Age of the patients ranged from 16 to 65 years. Laryngeal tumours included 11 cases of sarcomas, 1 extramedullary plasmocytoma, 9 lymphomas and 2 malignant melanomas. Hypopharyngeal tumours included 1 leiomyosarcoma and 2 malignant melanomas. Extensive resection was the first treatment for 21 patients. Then, according to their histopathologic features, irradiation or/and chemotherapy were chosen.

RESULTS

Follow-up period was from 6 months to 10 years. There were 12 patients survived for 4 to 10 years, including 6 cases of laryngeal sarcomas, 2 supraglottic lymphomas, 2 malignant melanomas of the larynx, 1 malignant melanoma and 1 leiomyosarcoma of the hypopharynx.

CONCLUSIONS

Characteristics for these tumours were: 1. usually covered by intact mucosa; 2. laryngeal tumours rarely metastasize to the cervical lymph nodes; 3. difficulties in histopathological diagnosis, and immunohistochemistry is helpful to differentiation and determination.

[Neurilemmoma of the larynx with three case reports]

Neurilemmoma of the larynx is rare. We report three cases who were treated in our hospital in recent decade. The tumours mainly involves the aryepiglottic folds, the ventricular folds or extending to the pyriform fossa, uncommon being subglottic. It is believed that the most likely nerve of origin is the superior laryngeal nerve. Surgical approach was median laryngotomy for 2 cases and lateral pharyngotomy for 1 case.

Position 120-123, a potential active site of trichosanthin

Trichosanthin (TCS) is a type-I ribosome-inactivating protein (RIP) with wide spectrum of biological and pharmacological activities. In the present study, a potential site on the TCS molecule (position 120-123) is identified which may be important for the biological activities of TCS. By using site-directed mutagenesis, position 120-123 of TCS was either deleted or changed from Lys-Ile-Arg-Glu (hydrophilic) to Ser-Ala-Gly-Gly (hydrophobic). Deletion of these residues rendered a TCS molecule completely deprived of ribosome inactivating activity, while hydrophobic replacement caused 4000-fold decrease in ribosome inactivating activity. The abortifacient activity of these two mutants was retained with decreased potency. This implies that position 120-123 of the native TCS molecule plays a critical role in maintaining its biological activity.

PCR-SSCP of rDNA for the identification of Trichinella isolates from mainland china

A polymerase chain reaction (PCR)-based single strand conformation polymorphism (SSCP) analysis of the expansion segment 5 (domain IV) of the large subunit of ribosomal DNA was employed to characterize seven isolates of Trichinella from China (A-G), including six of pig origin from regions in Dengxian (A), Tianjin (B), Harbin (D), Baoshan (E), Xinye (F) and Xian (G), and one of canine origin from Changchun (C). Isolates A, D, E, F and G were classified as Trichinella spiralis based on SSCP patterns, while the patterns for isolates B and C were consistent with those of Trichinella nativa or Trichinella T6. The results were supported by random amplified polymorphic DNA (RAPD) analysis using five decamer primers and were in accordance with ecological information for the isolates. Single strand conformation polymorphism results also allowed the direct display of mutational sequence variation in the expansion segment among the five isolates of T. spiralis from China, indicating its usefulness for studying population variation within that species.

Expression of neuron-specific beta-III tubulin during olfactory neurogenesis in the embryonic and adult rat

The olfactory neuroepithelium retains the unique capacity to produce a new set of mature neurons every three to four weeks from a precursor population situated at the base of the epithelium. It is not known however, whether developing olfactory neurons in the adult rat follow the same program that is initiated embryonically. By tracking the expression of beta-III tubulin (by immunoreactivity to TuJ-1, an isoform-specific antibody) throughout embryogenesis, we have demonstrated a commitment to the olfactory neuron lineage in a subset of cells in the embryonic olfactory placode and followed their development into adulthood. We have also shown that this developmental pattern of beta-III tubulin expression is recapitulated in neurons undergoing a synchronized neurogenic response to either physical or chemical lesion in the adult neuroepithelium. The embryonic expression pattern reported here is similar to, but earlier than that reported for other markers of developing neurons, such as growth-associated protein-43 and neural cell adhesion molecule. The results of these studies suggest the retention of a conserved neurogenic program from embryonic to adult life in the olfactory neuron and, in addition, support the use of a readily accessible system such as the regenerating olfactory neuroepithelium as an alternative means of studying genes which may be crucial to normal neuronal development.

Mismatch-sensitive hybridization detection by peptide nucleic acids immobilized on a quartz crystal microbalance

A quartz crystal microbalance DNA hybridization biosensor, based on thiol-derivatized peptide nucleic acid (PNA) probes, offers unusual in situ differentiation of single-base mismatches. A large excess of a single-base mismatch oligonucleotide has no effect on the frequency response of the target. Such remarkable distinction between perfect matches and mismatches is illustrated by the detection of a common mutation in the p53 gene. The greater specificity of the new mass-sensitive indicatorless hybridization device over those of analogous PNA-based carbon electrodes is attributed to the formation of a PNA monolayer and the use of a hydrophilic ethylene glycol linker. The improved specificity is coupled to very fast (3-5 min) hybridization in a low-ionic-strength medium.

Expression cloning of a mammalian amino acid transporter or modifier by complementation of a yeast transport mutant

A cDNA clone named L21 was isolated from L6 rat muscle cells by complementation of a yeast proline transport mutant. L21 cDNA has 2,268 bp and codes for a peptide of 228 amino acids with four potential transmembrane domains. The amino acid sequence of L21 shows no homology to any known proteins. Expression of L21 cDNA enables the mutant yeast to grow in proline as the sole nitrogen source and to transport proline, alpha-aminoisobutyric acid (AIB) and leucine. The Km for proline is about 1.0 mM. The substrate specificity of L21 expressed in yeast shows no striking similarity to known mammalian amino acid transporters.

Genes regulated by androgen in the rat ventral prostate

Genes that are regulated by androgen in the prostate were studied in the rat. Four of the less than 10 genes that are down-regulated by androgen in the ventral prostate of a 7-day castrated rat were identified; their mRNAs decayed with identical kinetics. Twenty-five of the estimated 56 genes that are up-regulated by androgen in the castrated prostate have been isolated. The up-regulated genes fall into two kinetic types. Early genes are significantly up-regulated by 6.5 hr whereas the delayed genes respond mainly after 24 hr from the time of androgen replacement. These androgen-response genes are also regulated in the prostate by castration, indicating that these genes could play important roles in androgen-induced regrowth and/or castration-induced regression of the prostate during hormonal manipulation. A survey of the tissue specificity showed that the androgen-response gene expression program in the prostate is mainly prostate-specific. Total RNA Northern blot analysis detects the expression of about 16 up-regulated genes and 3 down-regulated genes in the prostate only. Four up-regulated genes and one down-regulated gene are regulated by androgen in both the prostate and seminal vesicles but not in other organs. The expression of the remaining androgen-response genes is not limited to the prostate but is only responsive to androgen in the prostate. This survey of the androgen-response gene expression program provides insights into the molecular and cellular mechanisms of androgen action in the prostate.

Nucleic-acid immobilization, recognition and detection at chronopotentiometric DNA chips

Wide-scale DNA testing requires the development of fast, small, easy-to-use biosensing devices. Various synthetic oligonucleotides and DNA have thus been immobilized onto microfabricated thick-film carbon transducers for performing several new nucleic-acid assay protocols. These include hybridization detection of nucleic acid sequences, determination of small molecules (drugs, pollutants) based on their collection into the dsDNA layer or via monitoring their effect upon the intrinsic DNA oxidation signal, and direct adsorptive stripping measurements of ultratrace levels of nucleic acids. Transduction of these DNA recognition processes is accomplished by a new highly-sensitive constant-current stripping chronopotentiometric operation. Comparison to traditional electrodes indicates that the biosensing performance is not compromised by the use of mass-producible disposable transducers. Such thick-film DNA biosensors have been coupled to a compact, user-friendly, hand-held analyzer. Applicability for the detection of sequences from M. tuberculosis and HIV-1 DNAs is illustrated. Such activity in the author's laboratory, aimed at developing DNA-coated screen-printed electrodes, is reviewed.

Characterization of colorectal-cancer-related cDNA clones obtained by subtractive hybridization screening

In an attempt to seek out new factors that are related to colorectal carcinogenesis at the molecular level, subtractive hybridization between cDNA of normal mucosal tissues and mRNA of colorectal carcinoma tissues was performed. Subsequent screenings of the cDNA libraries, constructed from normal mucosal tissues, using the "subtractive probes" generated a total of 46 clones that were expressed in normal mucosa but were either expressed at a significantly reduced level or not expressed at all in cancer tissues. Partial nucleotide sequences of all of these cDNA clones were determined, and sequence homology analyses were performed with the Genbank database. Of the 46 cDNA samples, 44 contained substantial sequence homologies with 32 immunoglobulin gene fragments, a helix-loop-helix basic phosphoprotein gene, an acidic ribosomal phosphoprotein P2 gene, a BLR1 gene for Burkitt's lymphoma receptor 1 gene, D5S419 DNA segment containing (C-A) repeats, a glucokinase (GCK) gene, a Na+, K+-ATPase alpha-subunit gene, a histocompatibility system HLA-DR heavy-chain gene, a dystrophic gene, a mucin (MUC2) gene, a mu-glutathione S-transferase gene, a Menkes disease protein gene, and a 40-kDa keratin intermediate filament precursor gene. The remaining two cDNA clones (now registered under GenBank accession numbers U17714 and U20428) showed few (less than 60%) sequence homologies with any known sequences in the GenBank database and, therefore, may represent novel genes whose expression was down-regulated in human colorectal carcinomas. The possible clinical significance of these findings and the involvement of these two genes in the carcinogenesis of colorectal as well as other cancers are being investigated.

Correlation between retinal fluorescein angiography and blood viscosity and other factors in patients with primary open angle glaucoma

OBJECTIVE

To investigate the correlation among retinal fluorescein angiography, blood viscosity, and other factors in patients with open angle glaucoma (POAG).

METHODS

Multiple step regression analysis was made to investigate the correlation between each of the following blood vessel filling times: the arm-choroid (A-CT), arm-retinal artery (A-AT), and retinal artery-venous (A-VT) of the fundus fluorescein angiography (FFA) in 122 eyes with POAG and each of the following related factors in hemorrheology: whole blood apparent viscosity at low, medium and high shear rates, plasma viscosity and hematocrit. Also, the same analysis was applied to investigate the correlation between each of the A-AT, A-VT of the FFA in 70 eyes with POAG and the following factors: systolic blood pressure, diastolic blood pressure, age and whole blood apparent viscosity at low shear rate.

RESULTS

The whole blood apparent viscosity at low shear rate was closely related to A-CT and A-AT, while hematocrit was closely related to A-VT of the FFA. The whole blood apparent viscosity at low shear rate and age, especially the whole blood apparent viscosity, was closely related to A-AT, A-VT of the FFA.

CONCLUSION

Blood viscosity can affect the filling times of the FFA in POAG.

[Determination of minor flavor components in Chinese spirits by direct-injection technique with capillary columns]

Chinese spirits are among the best-known distilled alcoholic beverages in the world. Because of the longer multiple-strain fermentation, Chinese spirits are richer than yeast fermented western liquors in fragrance and mellow. The complex nature of Chinese spirits often makes it difficult to separate, identify and quantify major and minor flavor components. Among the several analytical methods for flavor components in Chinese spirits developed in recent years, the direct-injection technique using capillary columns is by far the best. In this study of direct injection with crosslinked PEG 20M, HP-INNOWax and bonded SGE BP21 columns, up to 68 flavor components including alcohols, organic acids, esters, acetals, carbonyl and heterocyclic compounds were identified with fine-tuning separation and followed by GC/MS to identify. The gas chromatographic separation of flavour components of Maotai Liquor by the method on PEG 20M, SGE BP21 and HP-INNOWax are shown. The compounds of the numbered peaks in the chromatograms are listed. Three compounds of, ie., amyl acetate, t-pentanol and 2-ethyl butyric acid, were used as internal standards to minimize discrimination in quantitative determination. The operation procedures for these tests were provided. The application identities of three capillary columns for the analysis of minor flavor components with direct injection were summarized respectively.

Comparison of fusion phage libraries displaying VH or single-chain Fv antibody fragments derived from the antibody repertoire of a vaccinated melanoma patient as a source of melanoma-specific targeting molecules

A single-chain Fv (scFv) fusion phage library derived from random combinations of VH and VL (variable heavy and light chains) domains in the antibody repertoire of a vaccinated melanoma patient was previously used to isolate clones that bind specifically to melanoma cells. An unexpected finding was that one of the clones encoded a truncated scFv molecule with most of the VL domain deleted, indicating that a VH domain alone can exhibit tumor-specific binding. In this report a VH fusion phage library containing VH domains unassociated with VL domains was compared with a scFv fusion phage library as a source of melanoma-specific clones; both libraries contained the same VH domains from the vaccinated melanoma patient. The results demonstrate that the clones can be isolated from both libraries, and that both libraries should be used to optimize the chance of isolating clones binding to different epitopes. Although this strategy has been tested only for melanoma, it is also applicable to other cancers. Because of their small size, human origin and specificity for cell surface tumor antigens, the VH and scFv molecules have significant advantages as tumor-targeting molecules for diagnostic and therapeutic procedures and can also serve as probes for identifying the cognate tumor antigens.

APOE is linked to Alzheimer's disease in a large pedigree

Although previous association studies have demonstrated that the APOE4 allele is a risk factor for Alzheimer's disease (AD), its value for the prediction of AD in individuals is <100%. The limited predictive value of epsilon4 is also seen in multiply affected families where the epsilon4 allele is not tightly linked to AD. We analyzed a large pedigree multiply affected with AD by lod score linkage analysis at the known loci associated with AD. In this pedigree, the APOE/APOCI gene area was linked to the development of AD, while no linkage was detected to any of the other loci known to be associated with the disease. In this family, then, the inheritance of an epsilon4 allele is highly associated with the early development of the disease (mean age of onset, 62 years), and is a good predictor of disease. However, given the wealth of evidence for association, but not linkage, of APOE4 to AD, we believe this finding suggests that another factor (or factors) interact(s) with APOE to precipitate early disease, and produce positive linkage results. The nature of this factor presently remains unknown.

Screening and identification of down-regulated genes in colorectal carcinoma by subtractive hybridization: a method to identify putative tumor suppressor genes

OBJECTIVE

To search for new putative tumor suppressor genes in colorectal carcinoma.

METHODS

Subtractive hybridization technologies were applied to screen and select genes, the expression of which was down-regulated in colorectal carcinoma. mRNAs uniquely expressed in normal cells but not in colorectal carcinoma were recovered as cDNA (sub-cDNA) after two rounds of subtractive hybridization with mRNA prepared from colorectal carcinoma. The sub-cDNAs were then used as probes to screen a normal human colon cDNA library constructed in lambda-Zap II phage. The DNAs of positive clones were in vivo excised, and partial DNA sequences were analyzed and compared with DNA sequence database Genbank.

RESULTS

A total of 46 different clones with an average of about 1 kilobases in transcript size was recovered. Among these 46 down-regulated genes in colorectal carcinoma were genes encoding immunoglobulin (n = 32), 40-kDa keratin intermediate filamentous protein or IFP (n = 1), major histocompatibility complex-related protein (n = 1), unrelated structural proteins (n = 10) and gene products yet to be identified (n = 2). RNA dotblot hybridizations confirmed that all 46 clones contained genes that were down-regulated and have not been reported before in colorectal carcinoma.

CONCLUSION

The results of this study suggested that the 46 clones were down-regulated in colorectal carcinoma, they should be further studied as new putative tumor suppressor genes and could be used as new tumor markers of colorectal carcinoma.

Interactions of the amino-terminal noncollagenous (NC1) domain of type VII collagen with extracellular matrix components. A potential role in epidermal-dermal adherence in human skin

Type VII collagen, the major component of anchoring fibrils, consists of a central collagenous triple-helical domain flanked by two noncollagenous domains, NC1 and NC2. The NC1 domain contains multiple submodules with homology to known adhesive molecules including fibronectin type III-like repeats and the A domain of von Willebrand factor. In this study, we produced the entire NC1 domain of human type VII collagen in the stably transfected human kidney 293 cell clones and purified large quantities of the recombinant NC1 protein from serum-free culture media. The recombinant NC1 formed interchain disulfide-bonded dimers and trimers and was N-linked glycosylated. Tunicamycin inhibited the cellular secretion of NC1, suggesting that N-linked glycosylation may play a role in NC1 secretion. The recombinant NC1 was indistinguishable from the authentic NC1 obtained from human amnions or WISH cells with respect to N-linked sugar content, electrophoretic mobility, rotary shadow imaging, and binding affinity to type IV collagen. Purified recombinant NC1, like authentic NC1, also bound specifically to fibronectin, collagen type I, and a laminin 5/6 complex. Both monomeric and trimeric forms of NC1 exhibited equal affinity for these extracellular matrix components, suggesting that the individual arms of NC1 can function independently. The multiple interactions of NC1 with other extracellular matrix components may support epidermal-dermal adhesion.

Characterization of a soluble IL-6 receptor alpha mutant C277D/H280I expressed in E.coli

The pleiotropic cytokine interleukin-6(IL-6) triggers the formation of a high affinity receptor complex constituted by the ligand-binding subunit IL-6 receptor alpha (IL-6R alpha) and the signal transducer gp130. To construct the antagonist of IL-6, a DNA segment encoding the soluble human IL-6R alpha (shIL-6R alpha) mutant with two substitutions C277D/H280I was generated by overlap extension polymerase chain reaction. The DNA segment was then subcloned into vector pET-3b and expressed in E.coli at a high level. The refolded and purified recombinant protein, which was designated as DM650, exhibited an increased IL-6-binding capability by 8-fold. DM650 antagonized IL-6 perfectly, resulting in the growth-inhibition of human myeloma AF-10 cells. DNA fragmentation assay proved that the growth of AF-10 cells was inhibited through the induction of apoptosis suppressed by IL-6.

Use of arsenic trioxide (As2O3) in the treatment of acute promyelocytic leukemia (APL): I. As2O3 exerts dose-dependent dual effects on APL cells

Recent clinical studies in China showed that As2O3 is an effective and relatively safe drug in the treatment of acute promyelocytic leukemia (APL). We found previously that As2O3 can trigger apoptosis of APL cell line NB4 cells, which is associated with downregulation of bcl-2 gene expression and modulation of PML-RAR alpha chimeric protein. To further understand the mechanisms of this alternative therapy for APL, we investigated in this report the effects of a wide range of concentrations of As2O2 on cultured primary APL cells, all-trans retinoic acid (ATRA)-susceptible (NB4 cells) and ATRA-resistant (MR2 subclone) APL cell lines. The results indicated that As2O3 had dose-dependent dual effects on APL cells: inducing preferentially apoptosis at relatively high concentrations (0.5 to 2 micromol/L) and inducing partial differentiation at low concentrations (0.1 to 0.5 micromol/L). The rapid modulation and degradation of PML-RAR alpha proteins, which was induced by As2O3 at 0.1 to 2 micromol/L, could contribute to these two effects. Bone marrow and peripheral blood examination showed that myelocyte-like cells, probably as a result of partial in vivo differentiation, and degenerative cells increased after 2 to 3 weeks of continuous in vivo As2O3 treatment when leukemic promyelocytes decreased. In conclusion, combination of induction of apoptosis and partial differention could be the main cellular mechanisms of As2O3 in the treatment of APL, and PML-RAR alpha could play an important role in determining the specific effects of As2O3 on APL cells.

[Assignment of a novel colorectal cancer-associated gene HSU17714 gene to human chromosome band 22q13 by in situ hybridization]

OBJECTIVE

To identify the chromosomal localization of novel colorectal cancer-related gene HSU17714.

METHODS

Enhanced fluorescence in situ hybridization technique was applied with tyramine as the enhancer.

RESULTS

80%(128/160) interphase and 60% (104/174) metaphase cells showed obvious hybridization signals of HSU17714. 85%(40/47) metaphase cells showed hybridization signals at 22q13 in the fluorescence R-banding assay.

CONCLUSION

HSU17714 is assigned to human chromosome 22q13.

No association between the intronic presenilin-1 polymorphism and Alzheimer's disease in clinic and population-based samples

Mutations in the Presenilin 1 (PS1) gene on chromosome 14 cause most early-onset familial Alzheimer's disease (AD). An intronic polymorphism in the PS1 gene was recently identified and reported to be associated with late-onset AD [Wragg et al., Lancet 347: 509-512, 1996]. The authors found an excess of homozygotes for the more common allele (allele 1) in AD cases, associated with an approximate doubling of risk. In the present study, we report the PS1 polymorphism distributions in clinic and population-based samples. We were not able to replicate the findings of Wragg et al. [1996]. Our results are consistent with those of other researchers and do not support the conclusion that the PS1 polymorphism is associated with late-onset AD.

Modulation of type VII collagen (anchoring fibril) expression by retinoids in human skin cells

We examined the effects of retinoids on the expression of type VII collagen, a major component of anchoring fibrils, in human keratinocytes and amnion cells (WISH). All-trans retinoic acid (RA) (5 X l0(-6) M) decreased the steady-state levels of type VII collagen mRNA by at least 80% after 18 h. The inhibition was evident within 6 h after the addition of RA, maximal at 18 h, and was dose-dependent. Reduction of type VII mRNA expression also occurred when cell cultures were incubated with retinol, retinal, and 13-cis RA. Retinoid-mediated inhibition of type VII collagen mRNA expression was observed in keratinocytes growing in either serum-free keratinocyte growth medium (KGM) or KGM supplemented with 1.4 mM Ca2+. Cycloheximide blocked RA-mediated inhibition of type VII collagen mRNA, demonstrating the need for de novo protein synthesis. The mRNA levels for fibronectin and glyceraldehyde phosphate dehydrogenase were not affected by the retinoids, suggesting selective inhibition on type VII collagen expression. In addition, the decrease in type VII collagen mRNA was accompanied by a parallel decrease in secretion of the 290 kDa, type VII collagen alpha chains.

[Application of subtractive hybridization in screening for colorectal cancer negatively related genes]

OBJECTIVE

To search previously uncertained factors that corelated with the occurence and development of human colorectal cancer.

METHOD

Subtractive hybridization technique was employed to screen down-regulated genes of colorectal cancer.

RESULTS

We obtained 46 clones which highly were expressed in normal intestinal mucosa but much lower or none in colorectal cancer. Two of the 46 clones, SCN6 and SCN19, were accepted by the Genbank Database as novel genes with the accession numbers U17714 and U20248. Full length cDNA (2932bp) of SNC6 was sequenced, and supposed to encode a protein comprised 271 amino acids, MW30kd, which shared less than 30% homology with the protein database. The gene was localized to human chromosome 22q13. RNA dot blot analysis showed that the expression level of SNC6 was lower in colorectal cancer than in normal intestinal mucosa, and similar results were found in breast cancer. Northern blot showed higher expression levels of SNC6 in liver, lung, prostate, testis, ovary and K562 cell line than in other tissues.

CONCLUSION

SNC6 can be further investigated as a novel colorectal cancer negatively related gene.

Polyomavirus major capsid protein VP1 is capable of packaging cellular DNA when expressed in the baculovirus system

Using the p2Bac dual multiple cloning site transfer vector, the polyomavirus major capsid protein gene VP1 was cloned for expression in the baculovirus-insect cell expression system. The 5-day-infected cellular lysate from this recombinant preparation was purified by cesium chloride density gradient centrifugation. Capsid-like particles were observed in the resulting preparation. The purified particle preparation was analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and was shown to have accurately expressed the polyomavirus VP1 protein as cloned. It was found that the preparation revealed the presence of host histones in the stained gels, which is indicative of DNA packaging. To determine if cellular DNA was being packaged in the particles, Sf9 insect cells were prelabeled with [3H] thymidine. The label was removed, and the cells were subsequently infected with a recombinant Autographa californica multiple nuclear polyhedrosis virus (AcMNPV) carrying the polyomavirus VP1 gene. Upon purification through three cesium chloride gradients and DNase I treatment, capsid-like particles, containing [3H]thymidine-labeled DNA, were isolated which were found to coincide with hemagglutination activity. Studies have indicated that the AcMNPV appears to have the ability to fragment Sf9 cellular DNA. When infected with the recombinant AcMNPV carrying the VP1 gene of polyomavirus, these host DNA fragments are being packaged by the VPI major capsid protein; further, these DNA fragments have been shown to be approximately 5 kb in size, which corresponds to the size of the native polyomavirus genome. These studies demonstrate that the recombinant polyomavirus VP1 protein has the ability to package DNA in the absence of the minor structural proteins VP2 and VP3 and independently of the polyomavirus T antigens.

[Inhibition effect of p53 antisense RNA on malignant phenotype of colorectal cancer cells]

OBJECTIVE

Inhibition effect of p53 antisense RNA on malignant phenotype of colorectal cancer cells was studied.

METHODS

For the purpose of inhibiting tumorigenecity of mutant p53 gene in colorectal cancer cells, a 2.1 kb human p53 full length cDNA was inserted into a mammalian expression vector pREP9 to make a p53 antisense RNA expression vector pREP9-p53 (AS). pREP9-p53 (AS) was then introduced into human colorectal cancer cell line SW1116 (with mutated endogenous p53). MTT method and FCM analysis were performed to measure the effect of p53 antisense RNA expressed by pREP9-p53 (AS) on SW1116 cell cycle progression.

RESULTS AND CONCLUSION

It was shown that the growth rate of SW1116 cells with pREP9-p53 (AS) was significantly suppressed by the expression of p53 antisense RNA as compared to the control SW1116 cells and SW1116 cells with pREP9 vector alone. FCM analysis showed that SW1116 cells with pREP9-p53 (AS) were arrested at G0/1 phase, whereas no significant influence can be observed on control SW1116 cells with pREP9.

Analysis of the solubilization of steroids by bile salt micelles

Bile salt mixed micelles play an important role in the emulsification, solubilization, and absorption of cholesterol, fats, and lipid-soluble vitamins. Studies have also revealed the importance of wetting and solubilization of drugs by the bile salts; however, the capacity and specificity of bile salt simple and mixed micelles for solubilization are still undefined. Thus, in this study the aqueous solubility and the extent of solubilization in bile salt micellar solutions of a series of steroids were determined. The melting point and enthalpy of fusion were measured to determine the ideal mole fraction solubility of each steroid. From the ideal mole fraction solubility and the observed solubility of each steroid, the activity coefficient of each steroid in solution was calculated with respect to the supercooled pure liquid as the standard state. In aqueous solution, the activity coefficients decreased with increasing number of hydroxyl groups on the steroids. This trend also occurred in the bile salt solutions, although the values of the activity coefficients were smaller by about three orders of magnitude. The stereochemical position of the hydroxyl groups influenced the rank order of the activity coefficients in the aqueous and micellar solutions. Incorporation of a fluoro or methyl group resulted in an increase in the activity coefficient, whereas aromatization of the A ring of the steroid frame markedly decreased the activity coefficient. The results for the aqueous solubility are consistent with the expected interaction of the functional groups with the polar environment. The relatively small activity coefficients observed with the micellar solutions result from the nonpolar environment of the aggregates. However, the similarity of the relationship between the activity coefficient and the number of hydroxyl groups in the aqueous and micellar solutions indicates the importance of polar interactions for solubilization. These results may provide new insight into the solubilization of steroids by bile salt micellar solutions and may provide a basis for predicting solubilization of other compounds by bile salt aggregates.

Development of an ELISA for rapid detection of anti-type VII collagen autoantibodies in epidermolysis bullosa acquisita

Epidermolysis bullosa acquisita (EBA) is an acquired blistering skin disease characterized by the presence of IgG autoantibodies to type VII collagen. EBA autoantibodies recognize four major immunodominant epitopes localized within the amino-terminal, noncollagenous (NC1) domain. In this study, we developed a rapid, quantitative enzyme-linked immunosorbent assay (ELISA) to detect autoantibody activity against the complete NC1 domain of type VII collagen with the use of an eukaryotic-expressed, recombinant human NC1 antigen. With the ELISA, we tested serum from patients with EBA (n = 24), bullous systemic lupus erythematosus (BSLE) (n = 3), bullous pemphigoid (n = 16), pemphigus (n = 11), and normal controls (n = 12). All EBA and BSLE serum, including four sera that were negative by indirect immunofluorescence, demonstrated reactivity with immobilized NC1 in the ELISA. In contrast, none of the sera from healthy control subjects or patients with unrelated blistering skin diseases reacted with NC1. The EBA sera also reacted with recombinant NC1 by immunoblot analysis but with less sensitivity. Thus, the newly developed ELISA using recombinant NC1 is a sensitive, specific assay and a useful tool for rapidly screening EBA and BSLE serum.

Dopamine DRD2/Cys311 is not associated with chronic schizophrenia

A mutation in the DRD2 receptor gene has been reported in association with schizophrenia in Japanese and Caucasian populations. The variation, Ser to Cys at codon 311, occurs in the third intracellular loop of the receptor and is therefore putatively functional. We report the results of screening US Caucasian schizophrenic and nonschizophrenic populations. We detected the occurrence of the DRD2 Cys311 variant in both schizophrenics and controls. Our data demonstrates no significant difference between the frequency of Cys311 in Caucasian schizophrenic and non-schizophrenic populations, indicating no association with schizophrenia.

[Cloning and identification of fliCi gene of Salmonella typhimurium]

Purified Salmonella typhimurium 8705 chromosomal DNA was digested with EcoRI. DNA fragments above 400 bp were obtained by Sepharcyl S-400 chromatography and cloned into vector pGEM-3Zf(-), then transformed into host cell LC2a (hag- is recA-). One out of 6013 transformants was found to be motile and this clone was named pGI4015. Miniprep proved that pGI4015 contained an inserted fragment about 15.3 kb. Motility/inhibition tests as well as Southern blot hybridization showed that pGI4015 bear the H-1i gene of S. typhimurium. With the aid of BamHI and SalI site, sequences unrelated to flagellin in the cloned DNA fragment was removed, and a 3.8kb fragment containing fliC gene was subcloned.

DNA electrochemical biosensor for the detection of short DNA sequences related to the human immunodeficiency virus

An electrochemical biosensor for the detection of short DNA sequences related to the human immunodeficiency virus type 1 (HIV-1) is described. The sensor relies on the immobilization and hybridization of the 21- or 42-mer single-stranded oligonucleotide from the HIV-1 U5 long terminal repeat (LTR) sequence at carbon paste or strip electrodes. The extent of hybridization between the complementary sequences is determined by the enhancement of the chronopotentiometric peak of the Co(phen)3(3+) indicator. Numerous factors affecting the probe immobilization, target hybridization, and indicator binding reactions are optimized to maximize the sensitivity and speed the assay time. A detection limit of 4 x 10(-9) M HIV-1 U5 LTR segment is reported following a 30 min hybridization. The hybridization biosensor format obviates the use of radioisotopes common in radioactive methods for the detection of HIV-1 DNA. We also report on the direct adsorptive chronopotentiometric stripping measurements of trace levels of various HIV-1 DNAs.

A melanoma-specific VH antibody cloned from a fusion phage library of a vaccinated melanoma patient

The human antimelanoma antibody V86 was cloned from a single-chain Fv molecule (scFv) fusion phage library displaying the heavy chain variable domain (VH) and light chain variable domain (VL.) repertoire of a melanoma patient immunized with genetically-modified autologous tumor cells. Previous ELISA tests for binding of the V86 fusion phage to a panel of human metastatic melanoma and carcinoma cell lines and primary cultures of normal melanocytes, endothelial, and fibroblast cells showed that measurable binding occurred only to the melanoma cells. In this communication, the strict specificity of V86 for melanoma cells was confirmed by immunohistochemical staining tests with cultured cells and frozen tissue sections. The V86 fusion phage stained melanoma cell lines but did not stain carcinoma cell lines or cultured normal cells; V86 also stained specifically the melanoma cells in sections of metastatic tissue but did not stain any of the cells in sections from normal skin, lung, and kidney or from metastatic colon and ovarian carcinomas and a benign nevus. An unexpected finding is that V86 contains a complete VH domain but only a short segment of a VL, domain, which terminates before the CDR1 region. This VL deletion resulted from the occurrence in the VL cDNA of a restriction site, which was cleaved during construction of the scFv library. Thus V86 is essentially a VH antibody. The effect of adding a VI. domain to V86 was examined by constructing scFv fusion phage libraries in which V86 was coupled to Vlambda or Vkappa domains from the original scFv library of the melanoma patient and then panning the libraries against melanoma cells to enrich for the highest affinity antibody clones. None of the V86-Vlambda clones showed significant binding to melanoma cells in ELISA tests; although binding occurred with most of the V86-Vkappa clones, it was generally weaker than the binding of V86. These results indicate that most of the VL domains in the original scFv library reduce or eliminate the affinity of V86 for melanoma cells. Accordingly, VH libraries could provide access to anti-tumor antibodies that might not be detected in scFv or Fab libraries because of the incompatibility of most randomly paired VH and VL, domains.

Abnormal coronary flow reserve in patients with angina pectoris and hypertensive left ventricular hypertrophy

OBJECTIVE

To assess coronary flow reserve using a computer-assisted method with intracoronary papaverine in patients with angina pectoris.

PATIENTS AND METHODS

Coronary arterial diameter, cross-sectional area and blood flow velocity were measured during coronary arteriography before and after intracoronary papaverine in 26 control subjects, 45 patients with significant coronary artery disease (> 50% luminal narrowing), 16 patients with syndrome X and 14 patients with hypertension and left ventricular hypertrophy (LVH).

RESULTS

After intracoronary administration of papaverine, proximal diameter, cross-sectional area, blood velocity, flow volume and reserve capacity of both left anterior descending and right coronary arteries were lower in patients with significant coronary stenosis than in the controls. Despite similar changes in diameter and cross-sectional area, the blood velocity, flow volume and reserve capacity of the two vessels were also lower in patients with syndrome X than in the controls. In 14 patients with hypertension and LVH, although the blood velocity and flow volume were augmented for the two arteries and did not differ from those in the controls, the flow reserve was reduced because of higher baseline blood velocity and flow volume.

CONCLUSIONS

Coronary flow reserve is reduced in patients with coronary artery disease, syndrome X or hypertensive LVH, which may be related to abnormal changes at different levels of the coronary vasculature or resting flow states.

Inhalation challenge effects of perfume scent strips in patients with asthma

BACKGROUND

Perfume- and cologne-scented advertisement strips are widely used. There are, however, very few data on the adverse effects of perfume inhalation in asthmatic subjects.

OBJECTIVES

This study was undertaken to determine whether perfume inhalation from magazine scent strips could exacerbate asthma.

METHODS

Twenty-nine asthmatic adults and 13 normal subjects were included in the study. Histories were obtained and physical examinations performed. Asthma severity was determined by clinical criteria of the National Heart, Lung, and Blood Institute (NHLBI). Skin prick tests with common inhalant allergens and with the perfume under investigation were also performed. Four bronchial inhalation challenges were performed on each subject using commercial perfume scented strips, filter paper impregnated with perfume identical to that of the commercial strips, 70% isopropyl alcohol, and normal saline, respectively. Symptoms and signs were recorded before and after challenges. Pulmonary function studies were performed before and at 10, 20, and 30 minutes after challenges.

RESULTS

Inhalational challenges using perfume produced significant declines in FEV1 in asthmatic patients when compared with control subjects. No significant change in FEV1 was noted after saline (placebo) challenge in asthmatic patients. The percent decline in FEV1 was significantly greater after challenge in severely asthmatic patients as compared with those with mild asthma. Chest tightness and wheezing occurred in 20.7% of asthmatic patients after perfume challenges. Asthmatic exacerbations after perfume challenge occurred in 36%, 17%, and 8% of patients with severe, moderate, and mild asthma, respectively. Patients with atopic asthma had greater decreases in FEV1 after perfume challenge when compared with patients with nonallergic asthma.

CONCLUSIONS

Perfume-scented strips in magazines can cause exacerbations of symptoms and airway obstruction in asthmatic patients. Severe and atopic asthma increases risk of adverse respiratory reactions to perfumes.

Anti-melanoma antibodies from melanoma patients immunized with genetically modified autologous tumor cells: selection of specific antibodies from single-chain Fv fusion phage libraries

Fusion phage libraries expressing single-chain Fv antibodies were constructed from the peripheral blood lymphocytes of two melanoma patients who had been immunized with autologous melanoma cells transduced the gamma-interferon gene to enhance immunogenicity, in a trial conducted at another institution. Anti-melanoma antibodies were selected from each library by panning the phage against live cultures of the autologous tumor. After two or three rounds of panning, clones of the phage were tested by ELISA for binding to the autologous tumor cells; > 90% of the clones tested showed a strong ELISA reaction, demonstrating the effectiveness of the panning procedure for selecting antimelanoma antibodies. The panned phage population was extensively absorbed against normal melanocytes to enrich for antibodies that react with melanoma cells but not with melanocytes. The unabsorbed phage were cloned, and the specificities of the expressed antibodies were individually tested by ELISA with a panel of cultured human cells. The first tests were done with normal endothelial and fibroblast cells to identify antibodies that do not react, or react weakly, with two normal cell types, indicating some degree of specificity for melanoma cells. The proportion of phage clones expressing such antibodies was approximately 1%. Those phage were further tested by ELISA with melanocytes, several melanoma lines, and eight other tumor lines, including a glioma line derived from glial cells that share a common lineage with melanocytes. The ELISA tests identified three classes of anti-melanoma antibodies, as follows: (i) a melanoma-specific class that reacts almost exclusively with the melanoma lines; (ii) a tumor-specific class that reacts with melanoma and other tumor lines but does not react with the normal melanocyte, endothelial and fibroblast cells; and (iii) a lineage-specific class that reacts with the melanoma lines, melanocytes, and the glioma line but does not react with the other lines. These are rare classes from the immunized patients' repertoires of anti-melanoma antibodies, most of which are relatively nonspecific anti-self antibodies. The melanoma-specific class was isolated from one patient, and the lineage-specific class was isolated from the other patient, indicating that different patients can have markedly different responses to the same immunization protocol. The procedures described here can be used to screen the antibody repertoire of any person with cancer, providing access to an enormous untapped pool of human monoclonal anti-tumor antibodies with clinical and research potential.

Reduction of FK-506 requirements by combination with polyethylene glycol superoxide dismutase in orthotopic rat liver transplantation

Reperfusion after ischemia results in endothelial cell injury and Kupffer cell activation. Inflammatory cytokines thus released can induce major histocompatibility complex antigens and increase the immunogenecity of the graft. An orthotopic rat liver allotransplant model was used to test the hypothesis that prevention of reperfusion injury by infusion of polyethylene glycol superoxide dismutase (PEG-SOD) would result in long-term allograft survival in the presence of subthreshold immunosuppressive dosages. ACI rats were used as donors, and Lewis strain rats as recipients. Orthotopic liver transplantation was initially performed to identify a subthreshold dose of the immunosuppressant FK-506, which would be unable to extend survival longer than control untreated rats with this strain combination. After testing three intramuscular FK-506 doses of 0.04, 0.08, and 0.16 mg/kg, it was observed that an FK-506 dose of 0.04 mg/kg/day for 14 days was unable to extend survival longer than in untreated recipients. This dose of FK-506 was used in combination with PEG-SOD at doses of 1000, 3000, 10,000, or 30,000 units. Recipient animals were treated intravenously with PEG-SOD as a loading dose to facilitate tissue penetration on day 1, and beginning on the day of transplantation, every 2 days for the duration of the study. Results of histologic studies and mean survival time were compared in untreated recipients and in rats treated with PEG-SOD plus 0.04 mg/kg/day FK-506.(ABSTRACT TRUNCATED AT 250 WORDS)

[The study of correlation between hemorrheology and fluorescein angiography in open-angle glaucoma]

PURPOSE

To observe the correlation between hemorrheology and arm-retinal filling time of fluorescein angiogaphy in patients with primary open-angle glaucoma.

METHODS

The whole blood apparent viscosity in high (125 S-1), moderate (23 S-1) and low (1.2435 S-1) shear rates, plasma viscosity and hematocrit were measured in 50 cases (50 eyes) with primary open-angle glaucoma whose intraocular pressures were controlled. They also underwent fluorescein angiography. The duration from arm to retina arteria filling was named arm-retinal arteria filling time.

RESULTS

There were positive correlation between the whole blood apparent viscosity in high and moderate shear rates, hematocrit and arm-retinal arteria filling time (P < 0.05-0.005). The higher blood viscosity, the longer arm-retinal arteria filling time.

CONCLUSION

The blood viscosity in patients with primary open-angle glaucoma can affect the arm-retinal arteria filling time of fluorescein angiography. So, the increasing blood viscosity in patients with primary open-angle glaucoma can reduce the blood supply to the optic disc.

Characterization and structural organization of the cardiac beta-myosin heavy chain gene from Syrian hamster

In order to perform comparative studies of the cardiac myosin heavy chain (MyHC) genes, we determined the sequence of the Syrian hamster beta-MyHC gene and its 5' flanking region. This 33,960 basepair (bp) sequence contains 12,196 bp of the 5' flanking region as well as 21,731 bp of the complete beta-MyHC gene, with its 3' end overlapping with the alpha-MyHC gene. All the exon/intron boundaries were determined and relative to the human beta-MyHC gene, an extra 5' untranslated exon was identified. The isolation and sequencing of the Syrian hamster beta-MyHC gene may further the understanding about the regulation and the evolution of the cardiac MyHC genes.

Social aspects of malaria in Heping, Hainan

This paper presents findings from a study conducted in Heping Town, Qiongzhong County, Hainan Province, China. The study, conducted in 1992, used qualitative as well as quantitative methods to gather social, cultural and behavioural data associated with the acquisition, transmission and prevention of malaria, and the diagnosis and treatment of disease. These methods included focus groups, key informant and other in-depth interviews, and observations, a household survey and tests of school children of knowledge of malaria. The study is among the first to our knowledge that has utilized this broad mix of methods for tropical disease research in China.

[The role of intestinal permeability in the pathogenesis of ankylosing spondylitis]

By use of low molecular weight polyethlene glycol (PEG400) as tracer, a revised Chedwick method with capillary gas chromatography was used to examine the intestinal permeability in 49 subjects including patients with ankylosing spondylitis (AS) and rheumatoid arthritis (RA) and healthy controls. Recovery percentage, maximal recovery percentage [Rmax(%)] and Rmax(w) were used to find the effect of bowel permeability in the pathogenesis and disease flare up of AS, as well as the role of HLA-B27 for the bowel permeability. The results showed that in AS group, the recovery of first component (242D) was higher and the Rmax(%) was lower than those in the controls. No statistical difference was found with other indexes. The results indicated that bowel permeability is not elevated in AS. The passage of enteral bacteria antigen into the host may not result from the process of nonspecific penetration. We postulate that there may somehow be a process of "active transportation" in the pathogenesis of AS. More studies of the process are necessary to clarify its importance in the early stage of AS.