PBT／PC共混体系流变性能与形态结构研究

采用毛细管流交仪测定了ＰＢＴ／ＰＣ共混物的表观粘度、剪切应力，观察了不同共混物组成和不同温度下共混物的流变行为，并借助扫描电镜对共混物和微观形态结构进行分析。结果表明：ＰＢＴ／ＰＣ熔体共混物的流变行为接近假塑性流体．温度对共混物的流变行为影响很大，共混物的熔体粘度在ＰＢＴ／ＰＣ为９０／１０和６０／４０时呈双极值．共混物为两相结构，ＰＣ含量为４－５０％时呈两互锁结构。     

Intrinsic resistance to anticancer agents in the murine pancreatic adenocarcinoma PANC02

Summary PANC02 is a ductal adenocarcinoma of the pancreas that is resistant to every known class of clinically active antitumor agent. To study the mechanism(s) underlying the intrinsic drug resistance of this tumor, a mammary adenocarcinoma (CA-755) that also grows in C57/BL mice and is known to be drugsensitive was used for comparison. PANC02 resistance and CA-755 sensitivity to several antitumor agents and to X-ray therapy was confirmed in mice, and PANC02 also demonstrated relative resistance in tissue culture. Relative to Chinese hamster ovary (CHO) and CA-755 cells, PANC02 did not appear to show a higher rate of mutation to drug resistance in culture as based on the 6-thioguanine resistance marker. Although P-glycoprotein characteristic of the multidrug resistance (MDR) phenomenon could be demonstrated at the mRNA level using a sensitive RNAse protection assay, the level of expression found was several orders of magnitude lower than that observed in phenotypic MDR cell lines. Furthermore, quinidine failed to increase the sensitivity of PANC02 cells to Adriamycin under conditions that clearly potentiated the toxicity of the drug to a CHO cell line exhibiting classic MDR traits. The heterogeneity in the distribution of drugs was inferred as being significantly greater in PANC02 versus CA-755 cells in vivo as based on measurements of within-animal, within-tumor variance in the distribution of the marker compounds inulin and antipyrine. Although it may not be the only mechanism involved, this greater intratumor heterogeneity in drug distribution could theoretically play a major role in the intrinsic drug resistance of PANC02 in vivo.Supported by grant CH-458 from the American Cancer Society, by grant CA-28034 from the National Cancer Institute, and in part by Cancer Center Core Support grant, NIH-NCI-CA-16672. Animals were maintained in facilities approved by the American Association for Accreditation of Laboratory Animal Care and in accordance with current United States Department of Agriculture, Department of Health and Human Services, and National Institutes of Health regulations and standards     

Paraneoplastic cerebellar degeneration. III. Cerebellar degeneration, cancer, and the Lambert-Eaton myasthenic syndrome.

We studied nine patients with a subacute onset of a pancerebellar syndrome. Six had known cancer (three small-cell carcinoma of the lung [SCLC], one metastatic small-cell carcinoma, one small-cell carcinoma of the prostate, and one non-Hodgkin's lymphoma). Six of eight who had neurophysiologic testing, including the three patients without detectable cancer, had coexistent Lambert-Eaton myasthenic syndrome (LEMS). In two of the patients, LEMS was discovered only by neurophysiologic testing. We looked for anti-Purkinje cell autoantibodies in all patient's sera and in four patients' CSF. We also looked for autoantibodies to voltage-gated calcium channels (VGCCs) in seven patients' sera and two patients' CSF, using the 125I-omega-conotoxin radioimmunoassay. We were unable to detect anti-Purkinje cell autoantibodies in any patients' serum or CSF. However, there were raised titers of anti-VGCC autoantibodies in five of seven patients' serum, including one patient with SCLC who did not have LEMS, and in the CSF of one of two patients. We conclude that the frequency of presentation of a pancerebellar syndrome with LEMS is higher than expected by chance and is usually associated with cancer. In some of these patients, LEMS may be clinically occult. The presence of LEMS and raised titers of anti-VGCC autoantibodies in some patients with subacute cerebellar degeneration is suggestive of an autoimmune etiology even though anti-Purkinje cell antibodies could not be detected. Anti-VGCC autoantibodies are not confined to LEMS. They may be found at high titer in CSF as well as serum.     

Autoantibodies to Serum Proteins in Women with Recurrent Spontaneous Abortion: Subsequent Pregnancy Outcome

Sera from 130 first trimester pregnant women were tested for their serum antibody level against a naturally occurring serum antigen purified from non-pregnancy sera. IgG and IgM antibody level was measured using enzyme linked immunosorbant assay. Results indicate that patients with multiple abortion (n=26) have significantly (p=0.0029) lower level of IgG antibody and significantly (p=0.0001) higher level of IgM antibodies; against the serum antigen as compared to the patients with successful pregnancies with no history of miscarriage (n=63). Western blot analysis identified the scrum antigen recognized by the IgM antibody as a 24 kDa molecular mass component. These IgG and IgM antibodies may play an important role in the outcome of pregnancy.     

Chirurgie bei immunsupprimierten Patienten unter Notfall- und Elektivbedingungen

Zusammenfassung. Die Auswirkungen einer Immunsuppression auf perioperative pathophysiologische Vorg?nge stellen besondere Anforderungen sowohl in bezug auf die Indikationsstellung zu einem operativen Eingriff als auch an das perioperative Management. Eine immunsuppressive Therapie kann ein ver?ndertes oder v?llig fehlendes Abwehrverhalten bei entzündlichen Prozessen bewirken, so da? die hierfür typischen klinischen Anzeichen nur schwach oder gar nicht ausgepr?gt werden. Dies kann zu einer gef?hrlichen Latenz in der Diagnostik akut lebensbedrohlicher Erkrankungen bei immunsupprimierten Patienten führen. Darüber hinaus tragen die ver?nderte Reaktivit?t des Patienten auf Stre?, eine verz?gerte und verminderte Wundheilung sowie insbesondere die erh?hte Infektanf?lligkeit zu einem gesteigerten Operationsrisiko bei. Perioperativ sind daher eine konsequente klinische überwachung des Patienten und ein lückenloses Monitoring der Immunsuppression unverzichtbar. Für den klinischen Umgang mit immunsupprimierten Patienten ergeben sich hieraus 2 unterschiedliche Pr?missen hinsichtlich der Indikationsstellung bei Elektiv- und Notfalleingriffen. W?hrend unter Elektivbedingungen eine sorgf?ltige Operationsplanung unter besonderer Berücksichtigung der m?glichen Risiken für Patient und Transplantat unabdingbar ist, so lassen die oftmals gro?en diagnostischen Unsicherheiten bei entzündlichen Vorg?ngen sowie die erheblichen Risiken eines verz?gerten Therapiebeginns eine eher etwas gro?zügigere Indikationsstellung zur operativen Intervention in Zweifelsf?llen berechtigt erscheinen. Operativ technisch ist generell auf ein gewebeschonendes und atraumatisches Vorgehen zu achten, weiterhin sollte eine besondere Sorgfalt bei Anastomosenn?hten und Wundverschlu? bestehen. Darüber hinaus sind von Seiten des Chirurgen die Einflu?m?glichkeiten auf den postoperativen Verlauf begrenzt.      

甲状腺病变患者血清Leptin的浓度变化

目的探讨甲状腺病变患者血清瘦素(leptin)浓度的变化及意义.方法本文用放射免疫分析(RIA)方法测定了114例甲状腺病变患者血清Leptin和总睾酮(TT)的浓度.结果统计学处理结果显示各病变组男性与正常对照组男性间,Leptin和TT的浓度差异均有显著性意义.结论血清Leptin的浓度变化可作为了解甲状腺病变患者营养状况的辅助指标.     

Upper Airway Obstruction With Hypoxaemia And Sleep Disruption In Down Syndrome

Six of 12 children with Down syndrome (DS) tested by means of long-term tape-recordings of oxygen saturation, breathing movements and expired CO2 were found to have previously undetected and severe upper airway obstruction during sleep. In five cases the obstruction occurred in the pharynx and in the sixth it was due to bilateral choanal stenosis. When compared with age-matched controls, overnight tape-recordings showed episodes of abnormal arterial hypoxaemia and an abnormally elevated end-tidal CO2. Episodes of obstruction were most marked during sleep associated with a non-regular breathing pattern. Abnormal episodes of hypoxaemia were associated with continued breathing movements. Sometimes there was no airflow (complete obstruction); at other times airflow continued normally or was reduced in amplitude (partial obstruction). During episodes of partial or complete airway obstruction the inspiratory waveform showed a characteristic shape. These results show sleep-related upper airway obstruction to be an often undetected complication of DS and all necessary measures should be taken to overcome the obstruction when it reaches the stage of producing abnormal hypoxaemia. Choanal dilatation and tracheostomy were successful in treating two of the children. Tonsillectomy and adenoidectomy were successful for one child, but only of marginal benefit for two others.     

Sexually transmitted diseases in abused children and adolescents

The prevalence of abnormal physical signs (e.g., bleeding, scars, or bruises) and genital infections, notably Chlamydia Trachomatis, Neisseria Gonorrhea, and Herpes Simplex Genitalis was studied in 219 female children with validated sexual abuse. They were compared to 113 nonabused female children. The average abused child was 8.3 years old, with 69% having been abused on multiple occasions. Most offenders were family members (65%) or a close family friend (22%). Stranger-perpetrated sexual assault, in the sample, was low (9.1%). Few children had severe vaginal tears, though 56% showed signs of subtle anatomical injury to their genitalia. No similar anatomical abnormalities were present in nonabused children. Among the sexually abused children and adolescents, 35% were colonized with a pathogen or a potential pathogen, compared to a prevalence rate of 18.5% in non-abused children. The proportion of abused children colonized with Ureaplasma Urealyticum and Mycoplasma Hominis was not significantly different from that found in nonabused children. At present, Neisseria gonorrhea and Chlamydia Trachomatis remain the only conclusive markers for sexual abuse. It is recommended that routine cultures of the pharyngeal, rectal, and vaginal areas be taken in all cases of suspected child sexual abuse, regardless of clinical findings.     

母血中胎儿有核红细胞的荧光原位杂交法在产前诊断中的可行性探讨

探讨荧光原位杂交法（FISH）对母血中胎儿有核红细胞（NRBC）进行无创性产前诊断的可行性。20例孕龄15-20周的孕妇外周血经不连续密度梯度离心、制片、显微镜下识别并共计数NRBC及定位，然后行Y染色体的FISH检测。结果发现10例孕男性胎儿的孕妇外周血细胞涂片中每例均有阳性杂交信号出现；阳性率为60％（24/40）。10例孕女性胎儿的孕妇外周血细胞涂片中1例出现阳性杂交信号；阴性率为95％（38/40），假阳性率仅为5％（2/40）。结果提示FISH法对于用母血中分离到的胎儿细胞进行染色体异常的无创性产前遗传学检查具有重要意义。