硫酸多糖对体外人脐静脉内皮细胞损伤的保护作用

研究表明,硫酸多糖体外对多聚阳离子和氧自由基损伤的人脐静脉内皮细胞有保护作用。肝素、硫酸软骨素A抗多聚阳离子损伤作用比同浓度低分子肝素和甘糖酯强。肝素、硫酸软骨素A、甘糖酯抗氧自由基损伤作用优于同浓度低分子肝素。结果显示硫酸多糖有保护血管内皮的作用,其作用可能与所带阴离子基团有关。     

Intra-abdominal surgery in patients with advanced cirrhosis

Between 1971 and 1984, intra-abdominal surgical procedures were required in 51 patients with cirrhosis who had advanced liver dysfunction and/or ascites. These included the following types of surgery: gastric, 17 patients; small bowel, two patients; colon, five patients; hepatic, nine patients; and pancreas, nine patients. Twelve patients also underwent exploratory celiotomy for an acute condition of the abdomen (six patients) and jaundice (six patients). Patients fell into two groups: (1) those with prothrombin time (PT) greater than 2.5 s over control (24 patients), and (2) those with PT within 2.5 s of control (27 patients). The 30-day mortality rate was 34 (67%) of 51 patients. Nineteen (83%) of 23 patients who had ascites died. Twenty-two (91%) of 24 patients with elevated PT greater than 2.5 s of control died. Twenty-five (86%) of 29 patients who underwent surgery under emergency conditions died. Intraabdominal surgery in decompensated patients with cirrhosis must be undertaken with great caution.     

Radiologic diagnosis of an intra-abdominal abscess. Do multiple tests help?

A review was made of the charts of 94 patients who underwent ultrasonography (US), computed tomography (CT), and gallium citrate Ga 67 (Gall) scan to rule out intra-abdominal abscesses. Of all the clinical and laboratory data, only the presence of pain and tenderness differentiated patients with and without abscesses. A review of radiologic data showed that CT was superior to US, and that US was superior to Gall scan with regard to sensitivity, specificity, accuracy, and positive and negative predictive values. When multiple radiologic tests were performed, results agreed in 72% of cases; therefore, the additional tests were essentially redundant. When radiologic test results disagreed, accuracy rates were CT, 0.86; US, 0.00; and Gall scan, 0.44. These findings suggest that, except to rule out pelvic abscesses in the presence of pelvic inflammatory disease, CT is usually the only special radiologic test that should be performed to localize a suspected intra-abdominal abscess.     

Surgical margins after needle-localization breast biopsy

: The use of needle-localization breast biopsy (NLBB) for the early diagnosis of breast cancer is common. The therapeutic adequacy of tumor-free margins following NLBB is unknown. We hypothesized that the presence of residual tumor after reexcision (mastectomy, tylectomy, or quadrantectomy) does not depend on the margin status following NLBB. : Retrospective cohort analysis was performed on 890 consecutive NLBBs executed between January 1990 and June 1994. Patients with invasive breast neoplasia were divided into two groups based on the tumor margins after NLBB. Group 1 were the women with positive margins, and group 2 had negative margins. Breast specimens after reexcision were reviewed for evidence of residual invasive carcinoma. : Invasive neoplasia was present in 107 patients (12%). Surgical margins and definitive records of care were avaliable for 96 of them (90%). All 45 patients in group 1 and 38 (75%) of 51 patients in group 2 underwent reexcision of the initial biopsy site (P = 0.36). Residual invasive carcinoma was present in 10 patients (22%) in group 1 and 3 (8%) in group 2 (P = 0.13). : Invasive breast neoplasia diagnosed by NLBB requires reexcision regardless of tumor margins to achieve complete local surgical eradication of tumor.     

Treatment of dural sinus thrombosis using selective catheterization and urokinase

Thrombosis of the cerebral dural venous sinuses, cortical draining veins, and deep cerebral veins is a rare clinical finding. Because of its low incidence and multiple etiologies, the optimum therapy for this condition will only be elucidated by a multicenter, randomized prospective study. At our institution, we favor early and aggressive management of cerebral venous sinus thrombosis with transfemoral, venous intradural infusions of the fibrinolytic agent urokinase. To date, treatment of only 13 patients using this technique has been reported in the English literature. This report adds 12 more such treated patients. Despite the presence of preinfusion infarcts in 5 patients, four of which were hemorrhagic, we incurred no major therapeutic morbidity. Functional sinus patency was achieved in 11 of 12 patients, with our only true failure occurring in an individual with symptoms of at least 2 months' duration. Good to excellent clinical outcome was achieved in 10 of 11 patients (one newborn had inadequate follow-up).     

Human ovarian granulosa cells and follicular fluid indices: the relationship to oocyte maturity and fertilization in vitro

The study investigates the correlation between oocyte maturity and fertilization and a variety of hormonal parameters in follicular fluid and ovarian granulosa cells. A methodology for purification of granulosa cells from contaminating blood cells is also established. A total of 63 follicular aspirates were collected at oocyte retrieval from 30 women superovulated using the long luteinizing hormone- releasing hormone (LHRH analogue)/human menopausal gonadotrophin regimen. Oestradiol, progesterone, testosterone and human chorionic gonadotrophin (HCG) were quantified in follicular fluid and granulosa cells were immunostained for human chorionic gonadotrophin. Immunopurification of granulosa cells from contaminating blood cells was performed. HCG in follicular fluid was significantly high in follicles yielding immature (grade 3) oocytes (P=0.002); there was no correlation with fertilization. Aspirates from follicles containing mature (grade 1) oocytes and oocytes that subsequently fertilized had significantly more granulosa cells immunobound to HCG (P < 0.001, P=0.02). Moreover, the immunomagnetic purification technique provided >98% pure population of granulosa cells. The data demonstrate that HCG in follicular fluid and on granulosa cells may help to predict oocyte maturity and fertilization. Furthermore, immunomagnetic beads provide a reliable procedure for the purification of ovarian granulosa cells.      

Attenuation of lung inflammation and fibrosis in interferon-gamma-deficient mice after intratracheal bleomycin

Because mouse strains susceptible to bleomycin, such as C57BL/ 6J, tend to produce T helper type 1 (Th1) cytokines in response to immune activation, we hypothesized that the inflammatory response to bleomycin is mediated, in part, by local production of the Th1 cytokine interferon-gamma (IFN-gamma). Consistent with this hypothesis, fibrosis-prone C57BL/6J and A/J mice demonstrated significantly elevated expression of IFN-gamma protein (by enzyme-linked immunosorbent assay) in bronchoalveolar lavage fluid at 24 h, and subsequently increased lung inflammation, weight loss, and mortality 10 d after intratracheal bleomycin administration compared with fibrosis-resistant BALB/c mice or saline control mice. To directly determine a role for IFN-gamma in bleomycin toxicity, we exposed C57BL/6J mice with a homozygous null mutation of the IFN-gamma gene (IFN-gamma[-/-]) and wild-type C57BL/6J mice to intratracheal bleomycin. IFN-gamma(-/-) mice demonstrated significantly lower parenchymal inflammation, weight loss, and mortality 10 d after 5 U/kg intratracheal bleomycin administration compared with control mice. At 3 wk after 1.5 U/kg bleomycin exposure, single lung collagen determined by hydroxyproline assay was significantly lower in IFN-gamma(-/-) mice compared with wild-type C57BL/6J mice. Together, these results suggest that IFN-gamma mediates, in part, bleomycin-induced pulmonary inflammation and fibrosis.     

Autosomal glycogenosis of liver and muscle due to phosphorylase kinase deficiency is caused by mutations in the phosphorylase kinase beta subunit (PHKB)

Glycogen storage disease due to phosphorylase kinase deficiency occurs in several variants that differ in mode of inheritance and tissue- specificity. This heterogeneity is suspected to be largely due to mutations affecting different subunits and isoforms of phosphorylase kinase. The gene of the ubiquitously expressed beta subunit, PHKB, was a candidate for involvement in autosomally transmitted phosphorylase kinase deficiency of liver and muscle. To identify such mutations, the complete PHKB coding sequence was amplified by RT-PCR of RNA isolated from blood samples of patients and analyzed by direct sequencing of PCR products. The characterization of mutations was complemented by PCR of genomic DNA. In one female and four male patients, we identified five independent nonsense mutations (Y418ter; R428ter; Y974H+E975ter; Q656ter in two cases), one single-base insertion in codon N421, one splice-site mutation affecting exon 31, and a large deletion involving the loss of exon 8. Although these severe translation-disrupting mutations occur in constitutively expressed sequences of the only known beta subunit gene of phosphorylase kinase, PHKB, they are associated with a surprisingly mild clinical phenotype, affecting virtually only the liver, and relatively high residual enzyme activity of approximately 10%.      

Delivery of a hammerhead ribozyme specifically down-regulates the production of fibrillin-1 by cultured dermal fibroblasts

The hammerhead ribozyme is a small catalytic RNA molecule. Potential hammerhead ribozymes that possess a catalytic domain and flanking sequence complementary to a target mRNA can cleave in trans at a putative cleavage site within the target molecule. We have investigated the potential of hammerhead ribozymes to down-regulate the product of the fibrillin-1 gene (FBN1). Fibrillin is a 347 kDa glycoprotein that is a major constituent of the elastin-associated microfibrils. Mutations in the FBN1 gene are responsible for Marfan syndrome (MFS), a common systemic disorder of the connective tissue. Many FBN1 mutations responsible for MFS appear to act in a dominant-negative fashion, raising the possibility that reduction of the amount of product from the mutant FBN1 allele might be a valid therapeutic approach for MFS. A trans-acting hammerhead ribozyme (FBN1-RZ1) targeted to the 5' end of the human FBN1 mRNA has been designed and synthesized, and shown to cleave its target efficiently in vitro. FBN1-RZ1 cleavage is magnesium dependent and efficient at both 37 and 50 degrees C. Delivery of the FBN1-RZ1 ribozyme into cultured dermal fibroblasts, by receptor- mediated endocytosis of a ribozyme-transferrin-polylysine complex, specifically reduces both cellular FBN1 mRNA and the deposition of fibrillin in the extracellular matrix. These results suggest that the use of hammerhead ribozymes is a valid approach to the study of fibrillin gene expression and possibly to the development of a therapeutic approach to MFS.