颅神经嵴细胞向成骨细胞表型分化的诱导实验

目的：观察颅神经嵴细胞（CNCC）在体外是否可以向成骨细胞表型进行诱导分化。方法：用标准的无血清培养液和含10^-8mol/L地塞米松、50mg/L左旋抗坏血酸和10mmol/L β－磷酸甘油钠的矿化诱导培养液对CNCC进行培养。15d后取两组细胞用于实验，观察两组间细胞形态，群体倍增时间、活力细胞数、碱性磷酸酶的活性和OC的含量等方面的变化。结果：诱导后的CNCC形态由成纤维样转变为多角形，细胞群体倍增时间延长，细胞活力数减少，碱性磷酸酶的活性和OC的含量升高。结论：CNCC在特定的矿化诱导培养液中，可以向成骨细胞表型分化。     

Sexually transmitted organisms in sexually abused children

OBJECTIVE: To establish the prevalence of sexually transmitted organisms and other genital organisms in potentially sexually abused children. DESIGN: Prospective study of children attending an inner London department of community paediatrics for evaluation of possible sexual abuse. SUBJECTS: Children under 16 referred for evaluation of possible sexual abuse. OUTCOME MEASURES: Prevalence of sexually transmitted organisms in relation to age, symptoms, and type of abuse. RESULTS: Swabs were taken from 159 of 242 girls evaluated. The overall prevalence of sexually transmitted organisms was 3.7%: three girls were infected with gonorrhoea, four with Trichomonas vaginalis, and two with Chlamydia trachomatis. One girl had all three infections plus mycoplasmas. Mycoplasmas were identified in 22% of girls swabbed. Of 30 boys swabbed, none yielded a sexually transmitted organism. CONCLUSIONS: There is a low prevalence of definitely sexually transmitted organisms in children who might have been abused. Other organisms possibly associated with sexual activity can be identified in this population. Screening for infection should be mandatory in presumed sexually abused girls with vaginal discharge and ideally should be undertaken in all children attending for evaluation of sexual abuse.     

DERMAL NEUROVASCULAR DYSFUNCTION IN TYPE 2 DIABETES

The present article summarizes recent observations obtained in our laboratory which clearly indicate that sex steroids exert relevant effects on the peripheral nervous system. In particular, the following important points have emerged: (1) Steroids exert stimulatory actions on the synthesis of the proteins proper of the peripheral myelin (e.g., glycoprotein Po and peripheral myelin protein 22) in vivo and on the Schwann cells in culture; (2) in many cases the actions of hormonal steroids are not due to their native molecular forms but rather to their metabolites (e.g., dihydroprogesterone and tetrahydroprogesterone in the case of progesterone; dihydrotestosterone and 5 alpha-androstane-3 alpha,17 beta -diol in the case of testosterone); (3) the mechanism of action of the various steroidal molecules may involve both classical (progesterone and androgen receptors) and nonclassical steroid receptors (GABA, receptor); and finally, (4) the stimulatory action of steroid hormones on the proteins of the peripheral myelin might have clinical significance in cases in which the rebuilding of myelin is needed (e.g., aging, peripheral injury, demyelinating diseases, and diabetic neuropathy).