Regulation of the B cell response to T-dependent antigens by classical pathway complement

Mice deficient in complement components C3 (C3 -/-) and C4 (C4 -/-) were found to have a profound defect in their Ab response to a T-dependent Ag (bacteriophage (phi X174). Characterization of the deficient mice demonstrated a diminished level of peanut agglutinin+ germinal centers and a failure in isotype switching despite normal B cell signaling in vitro. The nature of the defect was found to lie at the B cell level, as the T cells were primed in C3- and C4-deficient mice as well as those in wild-type mice. These results, and the finding that the defect could be partly reversed by a 10-fold increase in Ag dose, support the hypothesis that covalent attachment of complement ligands, i.e., C3b and C3d to the Ag-Ab complex, increases its immunogenicity.

Regulation of the B cell response to T-dependent antigens by classical pathway complement

Mice deficient in complement components C3 (C3 -/-) and C4 (C4 -/-) were found to have a profound defect in their Ab response to a T-dependent Ag (bacteriophage (phi X174). Characterization of the deficient mice demonstrated a diminished level of peanut agglutinin+ germinal centers and a failure in isotype switching despite normal B cell signaling in vitro. The nature of the defect was found to lie at the B cell level, as the T cells were primed in C3- and C4-deficient mice as well as those in wild-type mice. These results, and the finding that the defect could be partly reversed by a 10-fold increase in Ag dose, support the hypothesis that covalent attachment of complement ligands, i.e., C3b and C3d to the Ag-Ab complex, increases its immunogenicity.

Ratiometric measurement of endothelial depolarization in arterioles with a potential-sensitive dye

A fluorescence ratio technique based on the voltage-sensitive dye 1-(3-sulfonatopropyl)-8-[beta-[2-di-n-butylamino)-6-naphythyl++ +]vinyl] pyridinium betaine (di-8-ANEPPS)has been developed for recording membrane potential changes during vascular responses of arterioles. Perfusion of hamster cheek pouch arterioles with the dye labeled the endothelial cell layer. voltage responses from the endothelium of intact arterioles were determined by analysis of voltage-induced shifts in fluorescence emission wavelengths from dye spectra imaged from the vessel wall. Membrane depolarization caused the dye spectrum to shift toward blue wavelengths, with maximal fluorescence changes near 560 and 620 nm. In isolated nonperfused arterioles, comparison of continuous dual-wavelength recordings with simultaneous microelectrode recordings showed that the ratio of fluorescence intensities (fluorescence at 620 nm to fluorescence at 560 nm) accurately followed changes in membrane potential (6-21 mV) during vasoconstriction. The dye response was linear with respect to potential changes from -56 to -6 mV, with a voltage sensitivity of 9.7% change in the ratio per 100 mV. Membrane potential responses from in vitro and in vivo arterioles after potassium stimulation consisted of rapid ( < 0.5 -s) depolarization followed by slow repolarization over several seconds. Potassium-induced depolarizations were conducted along arterioles, and the values of the electrical length constant for conducted depolarization determined by optical and microelectrode methods were in agreement. We conclude that ratio analysis of di-8-ANEPPS fluorescence emission can be used to accurately record membrane potential changes on the time scale of seconds during vasomotor activity from arterioles.

[Quantitative study of velopharyngeal function post-palatoplasty]

The computer of nasopharyngeal fiberscope(NPF) for quantitative analysis was carried out to assess the palate articulation of 43 subjects,and normal articulation of 60 subjects.The rest,/a/,/s/and /m/ articulation of NPF pictures were calculated for veloparyngreal function via computer.

[Diagnosis and surgical management of pancreatic pseudocysts]

Fifty-two patients with pancreatic pseudocysts were treated surgically between 1968 and 1994. Clinical symptoms were non-specific. Ten patients with acute pancreatitis were managed conservatively and resolution occurred in 3 patients. 42 patients underwent operation. Internal drainage was performed in 28 patients, external drainage in 8, others in 6. Pancreatic fistulas occurred in the external drainage group, 2 patients died and 1 patient had the of recurred pseudocyst. There were no complications in the internal drainage group. It was quite different in the external drainage group. The management should differ in that acute and chronic pancreatic pseudocysts. Patients with pseudocysts of chronic pancreatitis could undergo emergent surgery of internal drainage because waiting 6 weeks for maturation of the pseudocysts after diagnosis was unnecessary and even hazardous. However, if pseudocyst developed after acute pancreatitis, it should be watched for up to 6-8 weeks. During this period the pseudocyst perhap disappeared spontanously or matured for surgery.

Polymers with Very Low Polydispersities from Atom Transfer Radical Polymerization

A radical polymerization process that yields well-defined polymers normally obtained only through anionic polymerizations is reported. Atom transfer radical polymerizations of styrene were conducted with several solubilizing ligands for the copper(I) halides: 4,4'-di-tert-butyl, 4,4'-di-n-heptyl, and 4,4'-di-(5-nonyl)-2,2'-dipyridyl. The resulting polymerizations have all of the characteristics of a living polymerization and displayed linear semilogarithmic kinetic plots, a linear correlation between the number-average molecular weight and the monomer conversion, and low polydispersities (ratio of the weight-average to number-average molecular weights of 1.04 to 1.05). Similar results were obtained for the polymerization of acrylates.

Disruption of the Cr2 locus results in a reduction in B-1a cells and in an impaired B cell response to T-dependent antigen

Covalent attachment of activated products of the third component of complement to antigen enhances its immunogenicity, but the mechanism is not clear. This effect is mediated by specific receptors, mCR1 (CD35) and mCR2 (CD21), expressed primarily on B cells and follicular dendritic cells in mice. To dissect the role of mCR1 and mCR2 in the humoral response, we have disrupted the Cr2 locus to generate mice deficient in both receptors. The deficient mice (Cr2-/-) were found to have a reduction in the CD5+ population of peritoneal B-1 cells, although their serum IgM levels were within the range of normal mice. Moreover, Cr2-/- mice had a severe defect in their humoral response to T-dependent antigens that was characterized by a reduction in serum antibody titers and in the number and size of germinal centers within splenic follicles. Reconstitution of the deficient mice with bone marrow from MHC-matched Cr2+/+ donors corrected the defect, demonstrating that the defect was due to B cells themselves. These results indicate an obligatory role of B cell complement receptors in responses of the B cells to protein antigens.

Carbon monoxide dehydrogenase from Clostridium thermoaceticum: quaternary structure, stoichiometry of its SDS-induced dissociation, and characterization of the faster-migrating form

The molecular mass (M(r)) of the nickel- and iron-sulfur-containing enzyme CO dehydrogenase from Clostridium thermoaceticum was determined by sedimentation equilibrium ultracentrifugation to be 300,000 +/- 30,000 Da. Since the enzyme is known to contain equal numbers of two types of subunits (M(r) = 82,000 Da for alpha and 73,000 Da for beta), this indicates an alpha 2 beta 2 quaternary structure. The enzyme was previously thought to have an alpha 3 beta 3 structure because it migrates through calibrated size-exclusion chromatographic columns with an apparent M(r) of about 420,000 Da. The disproportionately fast migration rate suggests that the enzyme is nonspherical. SDS induces the dissociation of an alpha subunit, yielding a stable species called FM-CODH. FM-CODH had a molecular mass of 210,000 +/- 30,000 Da, indicating an alpha 1 beta 2 structure. It contained 2.1 +/- 0.3 Ni and 16 +/- 3 Fe per alpha 1 beta 2, exhibited S-->Fe charge-transfer transitions typical of Fe-S proteins, and afforded the gav = 1.82, 1.86, and 1.94 EPR signals. Quantitation of the 1.82 and (1.94 +/- 1.86) signals afforded 0.35 and 1.9 spin/alpha 1 beta 2, respectively. FM-CODH samples exhibited CO oxidation activity, but little CO/acetyl-CoA exchange activity. Some FM-CODH samples exhibited CO oxidation activities as high as native enzyme. These results, along with the quantified spin intensities of the EPR signals, indicate that FM-CODH contains the B- and C-clusters and suggest that these clusters are located in the beta subunit. The alpha subunit that dissociated during formation of FM-CODH is not required for CO oxidation activity. FM-CODH is either devoid of A-clusters, or if such clusters are present, they have lost their ability to exhibit substantial NiFeC signals and CO/acetyl-CoA exchange activity. Incubating FM-CODH and alpha yielded a species that migrated through polyacrylamide gels at the same rate as native enzyme, and had a molecular mass indicating an alpha 2 beta 2 structure. Thus, the SDS-induced dissociation of the enzyme appears to be reversible.

Drug delivery systems: water soluble taxol 2'-poly(ethylene glycol) ester prodrugs-design and in vivo effectiveness

Water soluble 2'-taxol poly(ethylene glycol) (PEG) esters have been synthesized and shown to function in vitro as prodrugs. However, in vivo experiments clearly establish that in order for these prodrugs to behave in a predictable fashion, the molecular weight of PEG must be of such magnitude so as to maintain a t1/2(circulation) > t1/2(hydrolysis). When PEG derivatives of molecular weight approximately 40 kDa were employed with paclitaxel, ca. 4% by weight of paclitaxel was carried by the water soluble prodrug form, and equivalent in vivo toxicity and increased life expectancy in the P388-treated mouse was observed. An effective method for prescreening prodrugs was found to be the acute murine lethality, which reflects the equivalency of the solubilized transport form and the native drug.

[Investigation on VNTR in intron 40 of vWF gene in Chinese Han population]

The VNTR in the intron 40 of vWF gene was investigated with a method of combination of Amp-FLP and RFLP. Two amplified fragments from a heterozygous person were separated by a non-hydratable polyacrylamide electrolyte gradient electrophoresis. After elution from gel, the preliminary products were amplified again, the amplified fragments were digested with AluI, then the genotype could be directly determined through electrophoresis. For the first time SSCP was used to detect the subtypes of microsatellite DNA. 136 alleles were found from 156 unrelated Hans in Changsha area. There were 153 genotypes in this sample and all of them were heterozygous. The calculated heterozygosity was 0.9884. The distribution of genotypes was in according with the Hardy-Weinberg equilibrium. The polymorphic information content (PIC) was 0.9883. The polymorphism of this VNTR was the highest one in the Amp-FLPs that had been found before. Our data did not show any recombination even in 2 generations of 66 families and 3 generations of 5 families. Aco-dominant segregation was demonstrated.

Fumonisin toxicity and sphingolipid biosynthesis

Fumonisins are inhibitors of sphinganine (sphingosine) N-acyltransferase (ceramide synthase) in vitro, and exhibit competitive-type inhibition with respect to both substrates of this enzyme (sphinganine and fatty acyl-CoA). Removal of the tricarballylic acids from fumonisin B1 reduces the potency by at least 10 fold; and fumonisin A1 (which is acetylated on the amino group) is essentially inactive. Studies with diverse types of cells (hepatocytes, neurons, kidney cells, fibroblasts, macrophages, and plant cells) have established that fumonisin B1 not only blocks the biosynthesis of complex sphingolipids; but also, causes sphinganine to accumulate. Some of the sphinganine is metabolized to the 1-phosphate and degraded to hexadecanal and ethanolamine phosphate, which is incorporated into phosphatidylethanolamine. Sphinganine is also released from cells and, because it appears in blood and urine, can be used as a biomarker for exposure. The accumulation of these bioactive compounds, as well as the depletion of complex sphingolipids, may account for the toxicity, and perhaps the carcinogenicity, of fumonisins.

Electromechanical coupling and the conducted vasomotor response

Conducted vasomotor responses are viewed as one mechanism that functionally integrates the microvasculature. It is hypothesized that the conducted vasomotor response is the result of an electrical current and its passive electrotonic spread along the length of a microvessel. We tested this hypothesis in isolated, unpressurized arterioles from the hamster cheek pouch using conventional intracellular membrane potential recording techniques. The mean resting membrane potential (RMP) was -67 mV. KCl and phenylephrine (PE) pulse-stimulation applied through micropipettes could both induce transient depolarizations and vasoconstrictions at the site of stimulation (local) and at conducted (560 microns) sites. It was noted, however, that the conducted vasomotor response could not be induced until the conducted electrical response exceeded a threshold of -45 mV for a minimum amount of time. The relationship between the amplitude of constriction and the amplitude-time area of depolarization above -45 mV was the same for local and conducted KCl and for conducted PE but was significantly different from that for local PE. Nifedipine greatly reduced the local and conducted mechanical but not electrical responses. Our results indicate that the conducted vasomotor responses are the result of the generation and subsequent conduction of electrical signals along the vessel but that the corresponding mechanical response occurs only when the electrical response exceeds a threshold level.

Cellular pathways of the conducted electrical response in arterioles of hamster cheek pouch in vitro

We have previously shown that conducted vasomotor responses follow patterns that are consistent with a passive spread of electrical current along the length of the arterioles [(Xia and Duling, Am. J. Physiol. 269 (Heart Circ. Physiol. 38): H2022-H2030, 1995]. In this study, we define the cells through which the current flows. Isolated arterioles of hamster cheek pouch were used. The mean resting membrane potential (RMP) for randomly sampled arteriolar cells was -67 mV. When cell types were identified by dye injection, the RMPs were -68 and -67 mV for smooth muscle (SM) and endothelium (EC), respectively. Pulses of KCl induced transient, monophasic depolarizations at the site of stimulation (local), which were conducted decrementally along the length of the arteriole over several millimeters. During electrical conduction, three patterns of responses could be observed, but identical patterns of the conducted electrical responses were always observed in SM and EC. Phenylephrine stimulation also caused transient local and conducted depolarizations in both SM and EC. As with KCl stimuli, shapes of conducted electrical responses were identical in records made in both cell types. The results suggest that SM and EC are electrically coupled both homocellularly and heterocellularly.

[Study on the retrofascial space of the dorsum nasi and its clinical significance]

Fifty-seven adult and two children cadavers were dissected to study the position, size and structure of the retrofascial space of the dorsum nasi. The space lay between the periosteum, perichondrium and the fascia dorsum nasi. The shape of the space is like a pyramid. The space averaged 3.09 +/- 0.66 cm in length. The anatomical characteristics, individual variation and clinical significance of this space were discussed.

DNA content and morphological parameters in synovial sarcoma and synovioma

By using image analysis technique with 6 normal synovial tissue specimens as controls, nuclear DNA content and morphological parameters in specimens from 51 synovial sarcomas and 15 synovioma were examined quantitatively. The DNA content in synovial sarcoma and synovioma was significantly different (P < 0.01), and that of synovioma and normal synovial tissue was also different (P < 0.05). Morphological parameters including nuclear areas and perimeters differed significantly among the above three groups (P < 0.01). There was no correlation between the DNA content of synovial sarcoma and its histologic type (P > 0.05), but the DNA content greatly differed between its higher and lower differentiated grade in each type (P < 0.01). The DNA content in synovial sarcoma IIA stage, according to Enneking's staging system was lower than that in IIB, IIIA and IIIB (P < 0.05). The 5-year survival rate of synovial sarcoma with diploid/nearly diploid (D/ND) pattern was higher than that of aneuploid (AN) pattern (P = 0.028). The study suggests that analysis of the DNA content and morphological parameters of tumor cells is helpful in the diagnosis and pathologic grading of synovial sarcoma. It also provides a guide to clinical operation and estimation of the prognosis. Although synovioma is usually a well-differentiated and benign lesion, this investigation also suggested that increased DNA content may be an indication of poor prognosis for this neoplasm.

Poly(ethylene glycol) fluorescent linkers

The first examples of PEG linkers containing the highly fluorescent dansyl group have been synthesized. Quantum yields of these PEG fluorescent linkers (PFL) were determined and utilized in calculating the PEG number of various protein conjugates. The method was also shown to be applicable to lower molecular weight drugs as exemplified by taxol.

[Processing of pyritum from different sources]

Studies on the processing of Pyritum from different source were conducted by means of indentical technological procedure using total sulphur, S,FeS2 and Fe7S8 as indexes. The results showed considerable differences in compositions of the processed products.

Excessive insulin receptor serine phosphorylation in cultured fibroblasts and in skeletal muscle. A potential mechanism for insulin resistance in the polycystic ovary syndrome

We investigated the cellular mechanisms of the unique disorder of insulin action found in the polycystic ovary syndrome (PCOS). Approximately 50% of PCOS women (PCOS-Ser) had a significant increase in insulin-independent beta-subunit [32P]phosphate incorporation (3.7-fold, P < 0.05 vs other groups) in skin fibroblast insulin receptors that was present in serine residues while insulin-induced tyrosine phosphorylation was decreased (both P < 0.05 vs other groups). PCOS skeletal muscle insulin receptors had the same abnormal phosphorylation pattern. The remaining PCOS women (PCOS-n1) had basal and insulin-stimulated receptor autophosphorylation similar to control. Phosphorylation of the artificial substrate poly GLU4:TYR1 by the PCOS-Ser insulin receptors was significantly decreased (P < 0.05) compared to control and PCOS-n1 receptors. The factor responsible for excessive serine phosphorylation appeared to be extrinsic to the receptor since no insulin receptor gene mutations were identified, immunoprecipitation before autophosphorylation corrected the phosphorylation defect and control insulin receptors mixed with lectin eluates from affected PCOS fibroblasts displayed increased serine phosphorylation. Our findings suggest that increased insulin receptor serine phosphorylation decreases its protein tyrosine kinase activity and is one mechanism for the post-binding defect in insulin action characteristic of PCOS.

Decomposition of carbon monoxide dehydrogenase into alpha metallosubunits and a catalytically-active form consisting primarily of beta metallosubunits

Carbon monoxide dehydrogenase from Clostridium thermoaceticum, with an alpha 3 beta 3 quaternary structure, was incubated with dithiothreitol and 740-78,000 equiv/alpha 3 beta 3 of sodium dodecyl sulfate (SDS), followed by electrophoresis under anaerobic native conditions. Three catalytically-active bands and four inactive bands were obtained, in proportions dependent on the amount of SDS added. The catalytically-active bands, called SM-CODH, NM-CODH, and FM-CODH, migrated slower than, similar to, and faster than native enzyme, respectively. Two-dimensional electrophoresis revealed that SM-CODH and NM-CODH contained approximately equal proportions of the alpha and beta subunits, while the beta/alpha ratio for FM-CODH was about 2.7. The four inactive bands were identified as the beta subunit, two forms of the alpha subunit (called alpha and alpha'), and a form that migrated similarly to native enzyme. Overloaded gels revealed that alpha and each active band had brown color, indicating intact Fe-S clusters in these species. Higher concentrations of SDS (> 1600 equiv/alpha 3 beta 3) and/or incubation at temperatures > 15 degrees C yielded more alpha and beta subunits at the expense of the catalytically-active bands. When incubated at 70 degrees C in 78,000 equiv/alpha 3 beta 3 of SDS, alpha quantitatively converted to alpha', suggesting that alpha' is a denatured form. FM-CODH appears to be an intermediate in the decomposition of CODH by SDS and to have either an alpha 1 beta 3 or alpha 1 beta 2 quaternary structure.(ABSTRACT TRUNCATED AT 250 WORDS)

[Cytogenetic analysis of four cases of hermaphroditism]

On the basis of cytogenetics karyotype analysis, southern blot hybridization using sex-determining region of the Y chromosome (SRY) probe and amplified cation of the genomic DNA between the SRY code region by specific primers through polymerase chain reaction (PCR) have been performed in four cases of hermaphroditism. The results showed that, in 1 46, XY female and 1 45, XO/46, XY female, the SRY specific hybridization band and PCR amplified band could not be detected; in 1 46, XX male, the specific hybridization and PCR band showed SRY gene as in normal male; in another true hermaphrodite, the karyotype is 46, XX/47,XXY, PCR band is detectable but not hybridization band. The mechanism of the abnormal sex differentiation of the cases was analyzed and the two detection methods were compared.

Dye tracers define differential endothelial and smooth muscle coupling patterns within the arteriolar wall

Dye tracers were chosen, based on net charge, chemical structure, and reactive groups, to test for the existence of and to provide novel insight into channel selectivities of junctional pathways connecting smooth muscle and endothelial cells of the arteriolar wall. Dyes were injected into individual smooth muscle or endothelial cells of hamster cheek pouch arterioles using microiontophoresis. Coupling, independent of tracer net charge, was seen both within and between cell layers. Endothelial cells were well coupled by all of the tested dyes. Smooth muscle junctions appeared less effective in dye transfer than endothelial junctions. Lucifer yellow was confirmed to be a poor tracer of smooth muscle gap junctions, and remarkably this dye and other related sulfate-containing molecules interfered with dye movement through smooth muscle but not endothelial junctions. Myoendothelial junctions showed a striking polarity of dye movement, with dye transfer from endothelial to smooth muscle cells but little or no transfer in the reverse direction. Because the dyes have size and charge characteristics similar to those of known cellular second messengers, these findings have important implications for cell-cell signaling in the vessel wall.

Structural characterization of an Ascaris myoglobin

Globin was purified from the body wall of adults of the parasitic nematode Ascaris suum. Internal peptide fragments were sequenced and cDNAs encoding a polypeptide of 154 amino acids isolated by polymerase chain reaction. The polypeptide lacks a signal sequence, identifying it as a cytosolic myoglobin-like species. The native protein is a dimer. The predicted amino acid sequence shares several unusual substitutions with other nematode globins. Like the abundant pseudocoelomic A. suum hemoglobin it has a Tyr at B10 and a Gln at E7, substitutions thought to be determinants of high affinity. However, the 10-fold lower oxygen affinity of body wall globin suggests that in this molecule Tyr(B10) does not form an additional hydrogen bond with the heme bound oxygen. Evolutionary analysis of the nematode globins suggests that the monodomain myoglobin-like molecules and the two-domain hemoglobin-like molecules diverged about 500 million years ago, well before the divergence of the ascarid genera Ascaris and Pseudoterranova. The absence of introns in the A. suum myoglobin, in contrast to other nematode globin genes, is consistent with the hypothesis that during evolution intron elimination was the predominant event.

Absence of insulin receptor gene mutations in three insulin-resistant women with the polycystic ovary syndrome

Women with polycystic ovary syndrome (PCOS) are markedly insulin-resistant, but the molecular mechanisms of these changes and their relationship to the hyperandrogenic state remain to be clarified. Mutations have recently been identified in the insulin receptor gene of patients with extreme forms of insulin resistance associated with hyperandrogenism (eg, type A insulin resistance), and these mutations account for the insulin resistance in such patients. We performed this study to determine whether mutations in the coding portion of the insulin receptor gene were responsible for insulin resistance in PCOS. Insulin binding studies using cultured skin fibroblasts of three obese (body mass index > 27 kg/m2) women with PCOS (ie, mild hyperandrogenemia and chronic anovulation of unknown etiology) and documented insulin resistance showed no apparent abnormalities in either the number or affinity of insulin binding sites. Direct sequencing of all 22 exons of the insulin receptor gene from two of the women with PCOS did not reveal any mutations. Furthermore, both alleles of the gene were expressed at equal levels. In a third insulin-resistant PCOS woman, there was no evidence for a mutation in the coding portion of the insulin receptor gene as determined by denaturing gradient gel electrophoresis (DGGE). We conclude that the insulin resistance in these PCOS women was caused by a defect extrinsic to the insulin receptor.

[One-stage surgical procedure of adult cleft palate with dentofacial deformity]

2 cases with primary adult cleft palate combining severe dentofacial deformities were undergone one-stage procedure of modified Le Fort I segmental osteotomy and Furlow's double reserving Z plasty,and with with satisfactory clinical effectiveness.Follow-up results show that the one-stage procedure is not only reducing treatment time and period,but also correcting velopharyngeal function.

Extracellular human T-cell lymphotropic virus type I Tax protein induces cytokine production in adult human microglial cells

Tropical spastic paraparesis (HAM/TSP) is caused by human T-cell lymphotropic virus type I (HTLV-I) infection. Although the virus infects T cells in vivo and is capable of infecting microglia in vitro, the inflammatory demyelination has not been linked to virus in central nervous system tissue. Thus, indirect mechanisms (e.g., cytokines) could be involved in demyelination and inflammation. The ability of HTLV-I Tax protein to induce tumor necrosis factor-alpha (TNF-alpha), interleukin-1 beta (IL-1 beta), and IL-6 in primary adult human microglia and peripheral blood macrophages (PBMs) was examined by enzyme-linked immunosorbent assay and reverse transcription-polymerase chain reaction (RT-PCR). Tax (20 ng/ml) induced TNF-alpha in microglia (from undetectable or low basal levels to 215-1,075 pg/ml, mean 576 +/- 375 pg/ml, n = 4) and in PBMs (70-1,900, mean 646 +/- 844 pg/ml, n = 4). This induction was dose dependent, Tax specific, and maximal at 8 hours after stimulation. IL-6 levels in microglia increased from a basal level of 368 +/- 194 to 664 +/- 270 pg/ml 24 hours after Tax stimulation. In contrast, IL-1 beta levels were modestly induced (< or = 26 pg/ml). An increase in mRNA levels of the three cytokines was observed by semiquantitative RT-PCR (TNF-alpha = 28-fold; IL-6 = 5.6-fold; IL-1 beta = 3.6-fold). Thus, in HAM/TSP, extracellular Tax released from infiltrating T cells could induce cytokine release by microglia and contribute to demyelination and inflammation in the absence of detectable virus.

[Orthognathic surgery of dentofacial deformities post surgerical repairing of cleft palate and lip.]

10 cases with maxillary development limited post surgical repairing of cleft palate and lip were undergone modified Le Fort I segmental osteotomy,that is,put the maxilla forward without velopharyngeal function change and oro-nasal fistula.By Computer Aided Simulation System for orthognathic surgery(CASSOS),analysis of dental pulp,evaluation of velopharyngeal function,compacting profile pre-to-post operation, authors described that surgical procedure has the satisfactory effectiveness.

Cephalometric studies on the upper airway space in normal Chinese

A detailed cephalometric analysis of the soft and hard tissues of the upper airway was conducted with lateral cephalographs from 116 normal Chinese, aged between 18 and 25 years. Normal values and deviation range were preliminarily established for the size of the tongue, soft palate, nasopharynx, oropharynx, and hypopharynx, and for the relative position of the hyoid bone and vallecula in both sexes. Statistical findings showed that there were significant differences between the sexes. Significant relationships (P < 0.001) were observed 1) between the hypopharyngeal depth and the position of the hyoid bone and the vallecula, in which the horizontal position of vallecula appears to be the best predictor of the hypopharyngeal depth, as confirmed by the multiple regression equation; 2) between the upper airway depths at four different levels; and 3) between the naso-oropharyngeal area and tongue, soft palate, and oral area. The present data can be used to investigate further the upper airway in abnormal states.

[A study of computer aided simulation system for orthognathic surgery]

How easily to stimulate the orthognathic surgery with high accuracy and good reliability and visually explain the prediction of surgery to the patient with maxillomandibular deformities remains a key focus in oral and maxillofacial surgery. A Computer Aided Simulation System for Orthognathic Surgery (CASSOS) was developed by means of the technique of digital image processing, with which a detailed analysis could automatically be performed, including 71 measurements of distance, degree and ratio for frontal cephalograms and 68 measurements for lateral one with a computer aided diagnosis. A quantitatively surgical simulation for prediction of operation could satisfactorily be done for the clinical use. All data and images were printed by laserjet and color video printer. All procedures were finished in 20 minutes.

[Evaluation of velopharyngeal function after later surgical repair of cleft palate. ]

This study detected 60 cases of patients of later surgical cleft palate repairing with different operative procedures,based on nasopharyngeal fiberscope and image processing detective system of nasopharyngeal function.They were divided into two groups,30 cases with Furlow's double reversing Z plasty,and others with traditional palatoplasty.The results were as follows:the type of velopharyngeal closure with later palatoplasty mainly were circus,semi-circus,and the rate of operative success only was 46.6%,which was lower than other reports.Author described that compensation of lateral and posterior pharyngeal wall made the type of velopharyngeal closure.The elder the age,the more the compensation is.For the late cleft palate repair,although the variable surgical procedure made a condition for speech improvement, patients with later cleft palate repair still can't improve their phonation.

[The study of assessing methods for velopharyngeal function in patients with operated cleft palate]

This paper describes the study and quantitative analysis of velopharyngeal function in 103 patients with operated cleft palate using NPF,vedio-camera system and computer.The percentange of semi-circluar and circular closure patterns after surgery was distinct higher in VPI group than in VPC group,but coronary closure pattern was significant lower in VPI group than in VPC group(P<0.05).We compared the results of different operative age by VPI after surgery.The results showed that postoperative RVPI was in direct proportion to operated age.VPI in the group less than 3 years of age.VPI in the group less than 3 years of age was 28.57%,but in the group of over 7 years of age was 96.43%.Both showed significant difference(P<0.01).

Disruption of sphingolipid metabolism and stimulation of DNA synthesis by fumonisin B1. A molecular mechanism for carcinogenesis associated with Fusarium moniliforme

Consumption of grains contaminated with Fusarium moniliforme (Sheldon) causes liver cancer in rats and has been correlated with esophageal cancer in humans. The causative agents are believed to be a family of compounds known as fumonisins, which bear remarkable structural resemblances to sphingosine and sphinganine, the long-chain (sphingoid) base backbones of sphingolipids. Recently, fumonisin B1 has been shown to block de novo synthesis of sphingolipids by inhibiting sphingosine (sphinganine) N-acyltransferase, which leads to accumulation of sphingoid bases. Because the exogenous addition of sphingosine and sphingosine 1-phosphate to Swiss 3T3 cells has been shown to stimulate DNA synthesis (Zhang, H., Buckley, N.E., Gibson, K., and Spiegel, S. (1990) J. Biol. Chem. 265, 76-81; Zhang, H., Desai, N.N., Olivera, A., Seki, T., Brooker, G., and Spiegel, S. (1991) J. Cell Biol. 114, 155-167), we hypothesized that fumonisins might stimulate DNA synthesis by disrupting sphingolipid metabolism. Fumonisin B1 caused accumulation of sphinganine and sphingosine in Swiss 3T3 fibroblasts and, as occurred when these sphingoid bases were added exogenously, stimulated thymidine incorporation into DNA and augmented the mitogenic effect of insulin in a concentration-dependent manner. The mechanism underlying the mitogenic effect of fumonisin B1 was further investigated by using beta-fluoroalanine to block the initial step of sphingolipid biosynthesis catalyzed by serine palmitoyltransferase. beta-Fluoroalanine reduced sphingoid base accumulation in fumonisin B1-treated fibroblasts and inhibited fumonisin B1-stimulated DNA synthesis, but had no effect on mitogenesis when added alone. Fumonisin B1 did not cause accumulation of sphinganine 1-phosphate; therefore, it appears that sphingoid bases per se can stimulate DNA synthesis. To prove that the 1-phosphate is not obligatory, a 1-deoxysphinganine was synthesized, and it was as potent as sphinganine in stimulating DNA synthesis. These results establish that fumonisin B1 is mitogenic via accumulation of sphingoid bases rather than inhibition of complex sphingolipid biosynthesis per se. Because mitogens can often affect cell transformation, this provides a plausible molecular mechanism to explain the carcinogenicity of fumonisins.

[A comparative study of velopharyngeal function after palatoplasty with different age group]

That the most suitable age of palatoplasty is still an argumentative question.The final purpose of palatoplasty is to obtain the satisfactory effectiveness is to obtain the satisfactory effectiveness of phonetic distinctness.So,early palatoplasty is suported by more more experts and patient's parents.This study detected 60 cases velopharyngeal function after traditional palatoplasty with two flaps,adopting nasopharyngeal fiberscope and detective system of image processing and quantitative analysis of velopharyngeal function,for long term evaluation of traditional palatoplasty with different operative success iin early palatoplasty group (less than 3 years old) was 80.0% while that in later palatoplasty group (more than 6 years old) was 53.3%.From other aspects of types of velopharyngeal competence,mobility of soft palate and rate of velopharyngeal coronary contraction,the author described advantages of early palatoplasty.

Serum platelet-reactive IgG of autoimmune thrombocytopenic purpura patients is not F(ab')2 mediated and a function of storage

Serum platelet-reactive and glycoprotein (GP) IIb-GPIIIa-reactive IgG and F(ab')2 was examined in 39 patients with classic autoimmune thrombocytopenic purpura (ATP), two patients with anti-PLA1 antibody and 25 control subjects in an enzyme-linked immunosorbent assay. IgG was purified by diethyl aminoethyl chromatography and centrifuged at 100,000g before testing of the supernatant. Significant IgG binding (threefold to fourfold control IgG binding) was noted with 8 of 17 ATP patients' IgG, 2 anti-PLA1 IgGs, and 2 ATP patients with multiple platelet transfusions. However, F(ab')2 fragments of nine of nine positive ATP IgGs were nonreactive; F(ab')2 from the two anti-PLA1 and two multiply transfused ATP IgGs were as reactive as their intact IgG. Antiplatelet or anti-GPIIb-GPIIIa reactivity of ATP IgG could be adsorbed to fixed platelets or solid-phase GPIIb-GPIIIa and eluted with 0.1 mol/L glycine, pH 2.5. However, binding of IgG to GPIIb-GPIIIa could not be inhibited with F(ab')2 of ATP IgG or Fc fragments of control subjects. When platelet- or GPIIb-GPIIIa-reactive ATP IgG was applied to a Sephacryl 300 gel filtration column, no reactivity was noted in the 7S region, whereas anti-PLA1 localized to this region. Antiplatelet or anti-GPIIb-GPIIIa reactivity was noted in the void volume and accompanied by a high molecular weight protein region. An immunoblot of the void volume fraction with goat antihuman IgG (gamma chain) antibody showed high molecular weight bands greater than 250 Kd, which after reduction converted to a 55-Kd heavy-chain band. Fresh samples of ATP and control IgG processed within 1 to 2 days of blood withdrawal had no reactivity for GPIIb-GPIIIa. After storage at -20 degrees C for greater than 3 months, 5 of 19 ATP IgG became reactive, whereas 16 of 16 controls were nonreactive. Thus, platelet-reactive IgG of ATP sera appears to be caused by the development of IgG aggregates held together by disulfide bonds that develop on storage, and is not F(ab')2 mediated.

Effects of neuropeptide Y and agonists selective for neuropeptide Y receptor sub-types on arterioles of the guinea-pig small intestine and the rat brain

1. The actions of neuropeptide Y (NPY) and agonists selective for NPY receptor subtypes were examined on arterioles from the guinea-pig small intestine and the rat pia in order to characterize the receptors mediating the vasoconstrictor and potentiating effects of NPY. 2. A method was developed for measuring the potentiating effects of NPY in situations where it was not possible to obtain a full concentration-response relationship for the vasoconstrictor. NPY, 50 nM, had a greater potentiating effect on the guinea-pig intestinal arterioles than those from the rat pia. 3. NPY and the Y1-selective agonist, NPY[Leu31,Pro34], potentiated the constrictor responses to U46619 in both arterioles and responses to noradrenaline in the guinea-pig arterioles. There was marked desensitization of the potentiating effect, and cross-desensitization between NPY and NPY[Leu31,Pro34]. Both NPY and NPY[Leu31,Pro34] caused constriction of the rat pial arterioles but not of those from the guinea-pig intestine. 4. The Y2-selective agonist PYY(13-36) caused no potentiation or vasoconstriction and did not affect the potentiation by NPY or NPY[Leu31,Pro34]. 5. The potentiating and vasoconstrictor effects of NPY on these arterioles were mediated by Y1 receptors.

[RFLPs study of parental origin and mechanism of 3 cases with X chromosome structural abnormality]

In this study, we analysed the parental origin and mechanism of X chromosome abnormalities in 3 cases by using RFLPs on short or long arm of X chromosome as genetic markers. Their karyotypes were 46,X,dup(X)(p21); 46,X,del(X)(p11); 46,X,i(Xq). The results demonstrated that the dup(X)(p21) and the del(X)(p11) were of paternal origin and i(Xq) was of maternal origin. The dup(X)(p21) arose from an unequal sister chromatid exchange. The del(X) (p11) occurred through X chromosome breakage and deletion mechanism. The i(Xq) resulted from X chromosome centromere misdivision in oocyte.

Use of shed snake skin as a model membrane for in vitro percutaneous penetration studies: comparison with human skin

The potential usefulness of shed snake skin as a model membrane for transdermal research was examined. There are similarities between shed snake skin and human stratum corneum in terms of structure, composition, lipid content, water permeability, etc. The permeability of various compounds and the contribution of several functional groups to the permeability were also found to be similar between shed snake skin and human skin. Moreover, the permeability of compounds through shed snake skin was increased by Azone, one of the most extensively studied transdermal penetration enhancers. Considering the similarities between shed snake skin and human skin, ease of storage and handling, and low cost, shed snake skin may offer a good model membrane for transdermal research.

Clinical report on 62 cases of acute dimethyl sulfate intoxication

Sixty-two cases of accidental acute intoxication from the inhalation of dimethyl sulfate (DMS) are reported. To facilitate clinical evaluation and treatment, as well as identification of capacity for physical labor, a grading system was established according to the history of exposure to DMS, symptoms and signs of respiratory mucosal irritation, findings on chest radiographs, and abnormalities of leukocyte count. Emergency treatment included prophylactic use of glucocorticoids, supplemental oxygen, sedatives, and antibiotics for prevention and treatment of laryngeal and pulmonary edema, pulmonary infections, and other complications. Follow-up studies for 2-12 years have found only mild to moderate impairment in ventilatory capacity in eight cases, with no abnormal findings in ECG, chest films, and routine blood tests. Nearly all patients have resumed their usual work.