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。     

Kawasaki disease manifesting with acute cholangitis. A case report.

A 3-year-old boy, who developed the signs and symptoms characteristic of Kawasaki disease, is described. The child also had an 8 cm tender hepatomegaly. Hydrops of the gallbladder could not be shown. Liver biopsy showed marked infiltration of inflammatory cells, including neutrophil and eosinophil leucocytes in the portal tracts involving the periphery of the portal arteries and veins, and acute inflammation of the bile ducts with neutrophil and eosinophil infiltration of the walls. Overt cholangitis has been described only once before in Kawasaki disease, when a viral agent was suggested as being important in the pathogenesis. Although the clinical and laboratory findings in cases of Kawasaki disease clearly suggest an acute infection--as they did in this case--no aetiological agent has yet been incriminated. The possibility of a drug-induced auto-allergic or hypersensitivity state is considered. Evidence for such a state includes a history of drug administration, pathological findings similar to peri-arteritis nodosa--a condition often associated with a hypersensitivity state--the presence of eosinophils in the lesions and a response to treatment with aspirin, a drug known to ameliorate hypersensitivity states.     

Immunological disorders--the evolution of an hypothesis.

In honouring the memory of Dr Alwyn Zoutendyk, a respected member of the staff of the South African Institute for Medical Research, attention is called to the studies of the immunological disorders. While investigating serum hepatitis affecting soldiers of the US army following the administration of yellow fever vaccine, an antigen similar to that later called the Australia antigen, now hepatitis B surface antigen, was found in the acute phase serum and the corresponding antibody was found in convalescence. This finding and subsequent studies suggested there was a group of disease, which we called the hyperreactive auto-allergic disorders, of which examples were to be found in every system. The obverse of these we called the hyporeactive immunologically deficient disorders resulting from defects of the cell or serum components of the immunological reactions, of which many examples have also been found.     

AIDS and South Africa--towards a comprehensive strategy. Part II. Screening and control

In this, the second of a three-part series of articles in which we propose steps towards a comprehensive strategy for the control of HIV infection, we consider controversies relating to screening for HIV, the indications for and desirability of mandatory testing of certain groups at risk, and the place of voluntary testing in the control of HIV transmission and infection. Key recommendations are that mandatory testing of donors of blood and other vital tissues, patients on haemodialysis and haemodialysis unit staff is justified, and that children put up for adoption may require testing. We make further recommendations regarding HIV testing as a prerequisite for life insurance and recommend that voluntary testing be offered, supported by adequate pre- and post-test counselling. We consider that all health care workers should accept as their moral obligation the care and management of HIV-infected individuals, and that they should be adequately educated and skilled in such work. These recommendations were reached largely by consensus, although there were occasions when individual authors condoned recommendations with which they did not personally agree.     

Self-dilatation of oesophageal strictures.

A new technique for the management of upper and mid-oesophageal benign strictures is reported. A deflated oesophageal balloon catheter coated with steroid paste is passed by the patient through the stricture, the balloon is inflated and then withdrawn. This technique can be used for both strictures caused by tablet or corrosive damage that recur rapidly and where stricturing is the result of a chronic disease not amenable to medical or surgical treatments. Three patients in who this technique has been used with satisfactory patient tolerance and compliance and good relief of symptoms are reported.     

Inhibition of VEGFR2 prevents DMBA-induced mammary tumor formation

Preinvasive mammary pathologies in humans and rat chemical carcinogenesis model systems have an increased microvascular density relative to normal tissue. This suggests the possibility of preventing invasive breast cancer by inhibiting angiogenesis. Vascular endothelial cell growth factor (VEGF) is a potent angiogenic growth factor, commonly involved in tumor-induced angiogenesis. Here, we show that both VEGF and VEGFR2 expression increase with histological progression to invasive disease in the rat 7,12-dimethylbenz[a]anthracene (DMBA) model. Other VEGF receptors, VEGFR1, neuropilin 1 and neuropilin 2, are constitutively expressed throughout progression. To examine whether VEGF signaling is functionally relevant to tumor-induced endothelial tubule formation in vitro and for tumor formation in vivo, we utilized the VEGFR2 inhibitor, ZD6474. In vitro endothelial cell tubulogenesis induced by isolated mammary organoids or carcinoma in situ from DMBA-treated rats is inhibited by ZD6474, in a dose-dependent fashion. The administration of ZD6474 to DMBA-treated rats inhibits the formation of atypical ductal hyperplasia and carcinoma in situ by greater than 95% (P < 0.05), when administered 1 week or 6 weeks post-DMBA initiation. Invasive disease was absent in all ZD6474 cohorts. These data support the hypothesis that progression of DMBA-induced preinvasive mammary pathologies to palpable disease requires angiogenesis via a VEGF-dependent mechanism.     

Protective cytotoxic T lymphocyte responses against paramyxoviruses induced by epitope-based DNA vaccines: involvement of IFN-gamma

Plasmid DNA vectors have been constructed with minigenes encoding a single cytotoxic T lymphocyte (CTL) epitope from either the M2 protein of respiratory syncytial virus (RSV) or from the nucleoprotein of measles virus (MV) with or without a signal sequence (also called secretory or leader sequence). Following intradermal immunization, plasmids in which the CTL epitopes were expressed in-frame with the signal sequence were more effective at inducing peptide- and virus- specific CTL responses than plasmids expressing CTL epitopes without the signal sequence. This immunization resulted in protection against MV-induced encephalitis and a significant reduction in viral load following RSV challenge. The reduction of viral load following RSV challenge was abrogated by prior injection with anti-IFN-gamma antibodies. These results highlight the ability of epitope-based DNA immunization to induce protective immune responses to well-defined epitopes and indicate the potential of this approach for the development of vaccines against infectious diseases.      

Bioelectrochemical enzyme immunoassay of human choriogonadotropin with magnetic electrodes

We describe an amperometric technique for quantification of an enzyme immunoassay in which we use a magnetic working electrode, both to separate bound and free analyte and to monitor the electrochemical response. We used a "two-site" immunometric assay with monoclonal antibodies for human choriogonadotropin (hCG) as a model system in which magnetic particles were used as the solid phase. Separation of bound and free label is readily achieved by localizing the particles at the electrode. Activity of the bound enzyme in the environment of the electrode is determined electrochemically, permitting rapid quantification of the analyte without the need for a separate incubation step to measure enzyme activity. The sensitivity of the system is 150 int. units of hCG per litre (1st Int. Ref. Preparation). Correlation between the amperometric measurement of urinary hCG and data for an immunoradiometric assay was r = 0.9. The assay is rapid, requiring a total assay time for each sample of 20 min, which includes 15 min for antibody/antigen binding.     

Response from lieberman and colleagues

Respond on comments on Lieberman's article: Cyclosiloxanes Produce Fatal Liver and Lung Damage in Mice. Environ Health Perspect 107:161-165     

Biomechanical performance of a braided absorbable suture

Lactomer and Polyglactin 910 sutures are both made of copolymers of lactide and glycolide. Biomechanical performance tests demonstrated superior handling characteristics of the Lactomer sutures. Using sutures comparable in size and knot construction, the Lactomer sutures exhibited knot holding force superior to the Polyglactin 910. Moreover, the low knot rundown forces encountered by the Lactomer sutures facilitated construction of secure knots that failed by breakage rather than by slippage.