Gemini表面活性剂在气/液界面上的微区形貌随表面压的变化

测定了Gemini表面活性剂在pH值为10．86，NaBr浓度为1．0mol／L的溶液气／液界面上的表面压一分子面积的等温线。用自制的Brewster角显微镜(BAM)观察了由Gemini表面活性剂在界面上所形成单分子膜的微区形貌随表面压的变化。结果表明：当pH值为10．86时，Gemini表面活性剂在1．0mol／L NaBr溶液的气／液界面上生成了凝聚态的单分子膜；当表面压较低时，观察到在界面上形成了同心圆结构；随着表面压的增加，这些同心圆可发生聚并而形成多中心结构。     

Sertoli-Leydig cell tumour in an infertile patient after stimulated ovulation

A 36 year-old infertile female developed a stage IV (FIGO) ovarian carcinoma consisting of a poorly differentiated Sertoli-Leydig cell tumour after receiving one course of ovulation induction with follicle stimulating hormone (FSH), human menopausal gonadotrophin (HMG) and human chorionic gonadotrophin (HCG) followed by gonadotrophin-releasing hormone analogue (GnRHa). The patient died of liver metastasis and hepatic failure 4 1/2 months after first diagnosis, despite aggressive treatment consisting of debulking surgery and aggressive adjuvant chemotherapy.      

Signal transduction and the regulation of actin conformation during myeloid maturation: studies in HL60 cells

Maturation of human myeloid cells is associated with quantitative and qualitative changes in protein kinase C (PKC) and increases in N-formyl- L-methionyl-L-leucyl-L-phenylalanine (FMLP) receptors, actin, and actin regulatory proteins. We have studied the actin responses and cell shape changes caused by FMLP and its second messenger pathways in HL60 cells undergoing neutrophilic maturation. In uninduced cells, the PKC activators 12-O-tetradecanoyl phorbol-13-acetate (TPA), bryostatin, and 1-oleyl-2-acetylglycerol (OAG) resulted in 15% to 30% decreases in F- actin, whereas FMLP had no effect. Ionomycin had no effect on actin but did cause a 10-fold increase in intracellular calcium. Cells grown for 24 hours in 1% dimethyl sulfoxide (DMSO) acquired the ability to polymerize actin in response to FMLP and ionomycin. TPA continued to cause a decrease in F-actin at 24 hours, but caused an increase in F- actin at 48 to 72 hours of maturation. The PKC inhibitor 1-5- isoquinolinesulfonyl 2-methylpiperazine (H7) partially blocked the F- actin increase caused by TPA in induced cells, but had no effect on the decrease in F-actin caused by TPA in uninduced cells or the increase in F-actin seen in FMLP-treated neutrophils. F-actin rich pseudopods developed following TPA or FMLP stimulation of induced HL60 cells; in uninduced cells neither agent caused pseudopod formation but TPA caused a dramatic loss of surface ruffles. The ability of FMLP and ionomycin to elicit a neutrophil-like actin response in HL60 cells within 24 hours after DMSO treatment shows that the actin regulatory mechanism is mature by that time. The inability of ionomycin to increase F-actin in uninduced cells supports the view that calcium increases alone are insufficient for actin polymerization. The longer maturation time required for HL60 cells to develop an actin polymerization response to TPA compared with FMLP, coupled with the inability of H7 to block the FMLP-mediated F-actin increase in neutrophils, suggests that the F- actin increase caused by FMLP is not mediated solely by PKC. Lastly, the TPA-induced F-actin decrease and shape changes in uninduced HL60 cells, and the longer time required for a "mature" response to TPA, may reflect immaturity in the PKC isoenzyme pattern rather than immaturity of the actin regulatory mechanism.     

Studies of circulating hemopoietic progenitor cells in human fetal blood

High levels of committed erythroid and granulocytic/monocytic progenitor cells have been demonstrated in fresh blood obtained at fetoscopy. The fetal progenitor cells were more sensitive to appropriate stimuli (erythropoietin and colony-stimulating factor) than adult progenitor cells grown under the same conditions, and this was shown to be due to intrinsic differences in the progenitor cells at the different developmental stages.     

Asbestos — A hazard to the community

During a recent study of pulmonary fibrosis in one clinic area in Glasgow 21 proven cases of lung pathology associated with exposure to asbestos have come to light.

Difficulties in diagnosis may be due to “patient error” in that the patient may not remember that he had been in contact with asbestos, or know that he is exposed to asbestos in his current occupation — a joiner, for example, sawing up asbestos boards.

Examples are given of asbestosis or pleural tumours occurring many years after a short period of exposure to the dust.

Persons in innocent-looking occupations, such as joinery, may be in great danger from working near persons like laggers, who use asbestos. Especially in confined spaces on shipboard.

The importance is stressed of taking a very full occupational history, from the time the patient left school, where there is obscure pulmonary fibrosis.

The value of open lung biopsy is shown in diagnosing doubtful cases of early asbestosis.

The impression is gained that the incidence of asbestosis is increasing, and that it may come to assume great public health importance owing to the increased importation and more widespread use of asbestos.

The proposal to mix asbestos with tarmacadam for road use is viewed with concern.     

Multidrug-resistant organisms in patients from Ukraine in the Netherlands,March to August 2022

Since March 2022, there has been an emergence of multidrug-resistant organisms (MDRO) in the Netherlands in patients originating from Ukraine (58 patients, 75 isolates). For about half of these patients, recent hospitalisation in Ukraine was reported. Genomic surveillance revealed that the majority of the MDRO represent globally spread epidemic lineages and that 60% contain New Delhi metallo-β-lactamase (NDM) genes. Professionals should be aware of an increase in such MDRO associated with migration and medical evacuation of people from Ukraine.