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.