Phenotypically distinct subsets of CD4+ T cells induce or protect from chronic intestinal inflammation in C. B-17 scid mice

CD4⁺ T cells in the mouse can be subdivided into two fractionsbased on the level of expression of the CD45RB determinant.Previous studies have shown that these subsets are functionallydistinct. We have further characterized the properties of thesesubpopulations in vivo by injecting them into C. B-17 scid mice.The animals restored with the CD45RB^highCD4⁺ T cell populationdeveloped a lethal wasting disease with severe mononuclear cellinfiltrates into the colon and elevated levels of IFN- mRNA.In contrast, animals restored with the reciprocal CD45RB^lowsubset or with unfractionated CD4⁺ T cells did not develop thewasting or colitis. Importantly, the co-transfer of the CD45RB^lowpopulation with the CD45RB^high population prevented the wastingdisease and colitis. These data indicate that important regulatoryinteractions occur between the CD45RB^high and CD45RB^lowCD4⁺T cell subsets and that disruption of this mechanism has fatalconsequences.     

“Dark” (compacted) neurons may not die through the necrotic pathway

Dark neurons were produced in the cortex of the rat brain by hypoglycemic convulsions. In the somatodendritic domain of each affected neuron, the ultrastructural elements, except for disturbed mitochondria, were remarkably preserved during the acute stage, but the distances between them were reduced dramatically (ultrastructural compaction). Following a 1-min convulsion period, only a few neurons were involved and their environment appeared undamaged. In contrast, 1-h convulsions affected many neurons and caused swelling of astrocytic processes and neuronal dendrites (excitotoxic neuropil). A proportion of dark neurons recovered the normal structure in 2 days. The non-recovering dark neurons were removed from the brain cortex through two entirely different pathways. In the case of 1-h convulsions, their organelles swelled, then disintegrated and finally dispersed into the neuropil through large gaps in the plasma membrane (necrotic-like removal). Following a 1-min convulsion period, the non-recovering dark neurons fell apart into membrane-bound fragments that retained the compacted interior even after being engulfed by astrocytes or microglial cells (apoptotic-like removal). Consequently, in contrast to what is generally accepted, the dark neurons produced by 1-min hypoglycemic convulsions do not die as a consequence of necrosis. As regards the case of 1-h convulsions, it is assumed that a necrotic-like removal process is imposed, by an excitotoxic environment, on dark neurons that previously died through a non-necrotic pathway. Apoptotic neurons were produced in the hippocampal dentate gyrus by intraventricularly administered colchicine. After the biochemical processes had been completed and the chromatin condensation in the nucleus had reached an advanced phase, the ultrastructural elements in the somatodendritic cytoplasm of the affected cells became compacted. If present in an apparently undamaged environment such apoptotic neurons were removed from the dentate gyrus through the apoptotic sequence of morphological changes, whereas those present in an impaired environment were removed through a necrotic-like sequence of morphological changes. This suggests that the removal pathway may depend on the environment and not on the death pathway, as also assumed in the case of the dark neurons produced by hypoglycemic convulsions.     

Effect of benactyzine and arecoline on the45Ca uptake by rat brain nerve endings

The effect of the central cholinolytic benactyzine and the cholinomimetic arecoline on the uptake of⁴⁵Ca by rat brain synaptosomes was studied in vitro. Benactyzine was shown to cause biphasic changes (a decrease followed by an increase) in the intensity of uptake of the isotope, whereas arecoline led to a rapid initial increase in⁴⁵Ca uptake. Benactyzine was shown to depress the effect of arecoline and depolarization on uptake of the isotope. It is concluded that the increase in⁴⁵Ca uptake through the action of arecoline is connected with activation of Nachannels. Benactyzine, on the other hand, reduces the permeability of the these channels for⁴⁵Ca and activates the Ca-channels proper.(Presented by Academician of the Academy of Medical Sciences of the USSR S. S. Golikov.) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 86, No. 9, pp. 301–304, September, 1978.     

Recent advances in understanding the pathogenesis of the hemolytic uremic syndromes

One of the requirements for an agent to cause hemolytic uremic syndrome (HUS) is its ability to injure endothelial cells. Shiga-like toxin (SLT) can do this. SLT is produced byEscherichia coli andShigella dysenteriae serotype 1; both have been implicated as causes of typical HUS. Endothelial cells have receptors (GB₃) for SLT and the toxin can inhibit eukaryotic protein synthesis, thereby causing cell death. Glomerular endothelial cell injury or death results in a decreased glomerular filtration rate and many of the perturbations seen in HUS. It is no longer certain that hemolysis is the result of a microangiopathy. Cell injury results in release of von Willebrand multimers; if these are ultra-large, thrombosis may ensue. There is also increasing evidence that neutrophils have a role in the pathogenesis of typical HUS.Streptococcus pneumoniae can also cause HUS and care must be taken to avoid giving plasma to patients withS. pneumoniae-associated HUS. There is compelling evidence that types of HUS are inherited by autosomal recessive and autosomal dominant modes. Patients with autosomal recessive HUS may have recurrent episodes. Mortality and morbidity rates are high for the inherited forms.     

Use of radiolabeled antibodies in the treatment of childhood acute leukemia

Abstract: Despite advances in therapy for acute leukemia, relapse continues to be the major cause of treatment failure. Hematopoietic stem cell transplant can rescue some patients after relapse, but the ability to escalate the intensity of preparative regimens is limited by toxicity to normal organs. Radiolabeled monoclonal antibodies against hematopoietic antigens have emerged as an alternative to deliver targeted supplemental radiation to sites of leukemic involvement while relatively sparing normal organs. This paper will review the rationale for using this approach, our current experience with radiolabeled anti-CD45 antibody, and the potential challenges encountered in treating children with radiolabeled antibodies.     

CD44分子对胃癌细胞腹膜种植影响的体外实验研究

目的体外研究CD44分子对胃癌细胞(MKN45)腹膜种植转移的影响.方法在体外预先将抗CD44S抗体与MKN45细胞在细胞培养箱中作用45 min,然后在24孔培养板或Boyden小室中与生长良好的间皮细胞共同培养不同时间,在显微镜下直接计数与间皮细胞粘附的MKN45细胞,而用MTT法评估胃癌细胞在间皮细胞间的迁移和侵袭情况.结果在体外,抗CD44S抗体对MKN45细胞与间皮细胞间的粘附有明显的抑制作用(P＜0.01),在高浓度时对迁移和侵袭也有一定的抑制作用.结论CD44分子参与了胃癌细胞腹膜种植转移过程,抗CD44S抗体对胃癌细胞腹膜种植转移有一定的抑制作用.     

肝血管平滑肌脂肪瘤5例临床病理观察

目的:研究肝血管平滑肌脂肪瘤(hepatic angiomyolipoma,HAML)的形态学特点,探讨其诊断和鉴别诊断要点. 方法采用HE切片、光镜观察和免疫组织化学SP法染色对5例HAML进行分析. 结果5例HAML镜下见由厚壁的畸形血管、肌样细胞和脂肪组织混合组成,免疫组化瘤细胞表达HMB 45 、S-100和Desmin. 结论HAML 3种成分分布、比例及病理形态变化多样,HMB45阳性是诊断HAML 的重要指标之一.     

PCR ANALYSIS OF Y-CHROMOSOME SEQUENCES IN A 45,X MALE PATIENT AND A REVIEW OF THE LITERATURE

The 45,X karyotype is usually associated with Turner syndrome, while male phenotype is exceptional. The authors report a 45,X male patient with normal external genitalia and sex behavior, but who was azoospermic. He had a normally developed musculature and pilose distribution, testicular volume of 15 mL and no gynecomastia but clinical stigmata of Turner syndrome (short stature, short neck and 4th metacarpal bones) and azoospermia. Hormonal plasma levels of testosterone, estradiol, prolactin, and gonadotrophins were within the normal range as was the response of luteinizing hormone (LH) and follicle-stimulating hormone (FSH) (30 and 60 min) after 100 mug iv of LH-RH administration. Testicular biopsy could not be performed. Karyotype was 45,X without evidence of mosaicism. Polymerase chain reaction of genomic DNA studied with 12 different sequences of Y chromosome revealed only the presence of SRY gene (testis determining factor). It is possible that SRY/autosomal translocation had occurred in this patient. The study of 45,X male should be of great value in elucidating the complex mechanisms involved in normal male sex differentiation.     

超声引导后下45°角进针心包穿剌术的研究

目的：降低心包穿剌术的危险性,提高成功率。材料和方法：超声引导采用针梗与前上胸壁呈４５°左右夹角,从上向后下进针行心包穿刺。结果：对５１例行６３次心包穿剌均成功,未见并发症。结论：该方法安全、可靠、易掌握。