Retinal specificity in eye fragments: investigations on the retinotectal projections of different quarter-eyes in Xenopus laevis

According to Sperry's chemoaffinity hypothesis, the projection of a small eye fragment with a reduced amount of optic fibres should be restricted to that position in the optic tectum corresponding to its own specificity. However, previous investigations on different types of quarter-eyes in Xenopus laevis have revealed that their retinal projection was always restricted to the rostral part of the tectum, no matter what the origin of the remaining retinal quadrant. To get an indication of the state of specificity in such eye fragments, we investigated by electrophysiological and histological methods several features of the retinal projections of temporoventral (TV), naso-ventral (NV) and ventral (V) quarter-eyes which referred to their positional identity. Irrespective of their different origins, the projections were always located in the rostral part of the tectum, the size of the innervated tectal area depending for all fragment types on the size of the quarter-eyes, i.e. number of optic fibres. However, quantitative analyses revealed that with increasing eye size the various fragments expand their projections preferentially into those tectal areas that match their original specificity: TV projection is more concentrated in the rostral tectum, NV eyes expand their projections mainly to the caudal tectum, and V eyes enlarge their projections equally into the medial and caudal tectum. In addition, fibre-tracing experiments with cobaltic lysine showed that, according to the different origins of the quarter-eyes, retinal fibres follow the appropriate branch of the optic tract selectively: fibres of NV and V eyes pass mainly through the medial tract, and most fibres of TV eyes innervate the rostral tectum directly from a central position between the two side branches. All these findings suggest that the different types of quarter-eyes retain their original positional identity. Thus, their rostrally located retinotectal projections are not in register with their retinal specificity. We conclude that in X. laevis local positional markers in the tectum, if present at all, do not influence the development of the retinotectal projection. Instead we suggest a concept of self-sorting of the optic fibres, which can account for the partial innervation of the rostral tectum in different types of quarter-eyes.     

新型重组人源抗狂犬病毒糖蛋白单链抗体的制备及活性分析

目的：利用大肠杆菌表达新型人源抗狂犬病毒糖蛋白单链抗体ScFv,并验证其活性。方法：采用基因融合获得ScFv基因,构建重组表达质粒pET-22b（＋）-ScFv,转化大肠杆菌BL21（DE3）,经IPTG诱导获得高效表达。结果：Western印迹显示目的蛋白表达正确,表达产物以包涵体形式存在,经Ni-NTA柱纯化和体外复性,获得纯度达90%的ScFv蛋白。ELISA结果显示在PBS及人血清中ScFv的结合稳定性有所提高,流式细胞术证明目的蛋白能靶向结合狂犬病毒,通过中和效价测定实验测得ScFv的中和效价为40 U/mg。结论：成功利用原核表达系统实现了对人源抗GPRV ScFv的表达,并且具有一定的中和活性。     

Calcium transport and ATPase activity in mitochondria and fragments of sarcoplasmic reticulum of the heart and muscles of rabbits with hypercholesteremia

Keeping rabbits on a high-cholesterol diet (1 g/kg) for 3–7 months led to an increase in cholesterol concentration in the mitochondrial membranes and fragments of the sarcoplasmic reticulum (SPR) of the myocardium and skeletal muscles. Saturation of the membranes with cholesterol led to a decrease in efficiency of the Ca-pump of the SPR, as reflected in lowering of the Ca/ATP ratio and an increase in the outflow of Ca⁺⁺ from the SPR. Under these conditions the rate of accumulation of Ca⁺⁺ was higher in SPR than in the mitochondria. Activity of mitochondrial Mg⁺⁺-activated 2,4-DNP-ATPase was reduced in hypercholesteremia.Laboratory of Molecular Pathology and Biochemistry, Institute of General Pathology and Pathological Physiology, Academy of Medical Sciences of the USSR, Moscow. (Presented by Academician of the Academy of Medical Sciences of the USSR A. M. Chernukh.) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 89, No. 3, pp. 292–294, March, 1980.     

Matrix metalloproteinase expression in basal cell carcinoma: relationship between enzyme profile and collagen fragmentation pattern

Matrix metalloproteinases (MMPs) with collagenolytic and gelatinolytic activities are up-regulated in basal cell carcinoma. In the present study we demonstrate that the major collagenolytic enzyme detected is MMP-1 (interstitial collagenase) while gelatinolytic enzymes include both MMP-2 (72-kDa gelatinase A) and MMP-9 (92-kDa gelatinase B). Significant fractions of all three enzymes are present as active forms. In spite of the fact that high levels of gelatinolytic enzymes are present, the major fragmentation products resulting from digestion of intact type I collagen are the 1/4 and 3/4 fragments (products of MMP-1-mediated digestion). Thus, it appears that the gelatinolytic enzymes are not capable of degrading the collagen fragments as rapidly as they are produced. Since previous studies have demonstrated that interaction of interstitial fibroblasts with high molecular weight fragments of type I collagen leads to increased MMP production, the present results suggest a mechanism underlying altered function of stromal elements in the connective tissue adjacent to the growing neoplasm.     

Renal metabolism of corticosteroid hormones

Summary IK and STF from male and female rats have been used to study in vitro the renal metabolism of B. in male rat tissue four lipid soluble metabolites (I–IV) have been found, I+II being more polar and III+IV being less polar than B. I and II have been identified as 11-dehydro-20-hydroxy-B and 20-hydroxy-B. The structure of III and IV remains to be determined. Renal tissue from female rats produced predominantly III indicating sexual variations of steroid metabolism in kidneys. — The literature has been reviewed which documents that the kidneys in addition to B metabolize A, cortisol, progesterone and other corticosteroids.

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Abbreviations A Aldosterone - B Corticosterone - Alb Albumin - CS Corticosteroids - MCS/GCS Mineralo-/gluco-CS - IK Isolated (perfused) kidney - STF Suspended tubular fragments Supported by Deutsche Forschungsgemeinschaft Hi 97/16     

涎腺腺样囊性癌高、低转移细胞系基因表达谱及基质金属蛋白酶表达差异

目的筛选与涎腺腺样囊性癌转移相关的候选基因，并对其中的候选基因进行初步的验证。方法用限制片段差异显示PCR技术（restriction fragments differential display PCR, RFDD-PCR）建立涎腺腺样囊性癌高、低转移细胞株（ACC-M、ACC-2）的表达谱。对两个表达谱的片段进行比较，通过生物信息学的分析，初步筛选出候选基因。用半定量逆转录PCR技术对筛选出的基因进行初步验证。结果RFDD-PCR方法共获得5420个基因片段，其中包含12个基质金属蛋白酶（matrix metalloproteinase，MMP）基因。半定量逆转录PCR方法发现MMP2、MMP7、MMP9、MMP14、MMP15、MMP24在ACC-M和ACC-2中的表达存在明显差异。结论构建了ACC-M和ACC-2细胞株的表达谱，为寻找目的基因奠定了基础。发现MMP2、MMP7、MMP9和MMP15与涎腺腺样囊性癌的发生、发展、转移有关，不同肿瘤细胞的转移能力可能与不同的MMPs家族基因相关。     

Biophysical studies and anti‐growth activities of a peptide,a certain analog and a fragment peptide derived from α‐fetoprotein

Abstract: A chemically synthesized 34‐amino acid peptide, an analog, and a fragment of the peptide have been purified and studied. Biophysical studies were carried out to determine some of the metal ion binding properties of the original peptide and an analog of this parent peptide, in which the two histidine residues were replaced by alanines. As shown by visible absorption spectroscopy, Co (II) forms a complex with the parent peptide, but not with the analog peptide, and one or two histidines in the parent peptide are ligands for Co (II) ion binding. The effects on disulfide bond formation in the peptide by Zn (II) and Co (II) ions were also examined for this analog. Anti‐growth assays were performed using the original cysteine‐containing peptide with Zn (II) ion complexed to the peptide through the two cysteine residues. These rat uterine growth assays showed that the complexing of Zn (II) ion to the peptide maintained the anti‐growth activity of the peptide, while gel‐filtration experiments showed the zinc ions maintained the peptide in its anti‐growth form indefinitely in solution. A saliently important part of this research was the discovery that a fragment of the peptide consisting of a middle sequence of 14 amino acids was found to have significant anti‐growth activity in the rat uterine assay. Its activity suggested that this fragment might be considered a viable candidate for testing in anti‐cancer protocols.     

食管癌中特异表达的人类omega蛋白(Igll3)基因的序列分析及意义

目的筛选食管癌中差异表达的基因,进一步了解食管癌发生的分子机制。方法利用荧光差异显示技术(DD-PCR)从食管癌组织相对癌旁组织中获得差异表达片段,对这些片段进行克隆和序列分析。通过在GenBank中同源性检索,查找差异片段相对应的同源基因。利用定量PCR检测验证该基因表达的差异性。设计引物获得该基因全长。结果通过DD-PCR得到3个差异片段,分别为人类10号常染色体上的开放阅读框99;人类信号转导和激活转录因子2及人类omega蛋白(Igll3)。定量PCR验证的结果表明,Igll3在食管癌组织中的表达量高于癌旁组织。设计引物得到该基因全长,测序表明该基因长为711bp,编码236aa。结论 Igll3在食管癌组织中异常表达,可能在食管癌发生过程中起着重要的作用。     

Plant thorn synovitis of elbow in children

Four rare cases of plant thorn synovitis of left elbow were admitted at our institution, which were initially misdiagnosed as partially treated septic arthritis of elbow or Juvenile inflammatory arthritis. All of them were of paediatric age group. Symptoms included pain, swelling, and decreased range of motion of affected joint. On examination synovitis was present in all patients.Roentgenograms & Ultrasonography were inconclusive in all patients, Definitive diagnosis was made only after arthrotomy, Thorn fragments (Acacia arabica) were recovered from the hypertrophied synovium & subtotal synovectomy was done and sent for histopathological examination. All patients improved after surgery with mean residual flexion deformity of 12.5 ± 2.86°. Plant thorn induced synovitis of elbow is rare, it must be included in the differential diagnosis of monoarthritis of elbow and a high index of suspicion is needed for retained thorn fragments in elbow joint causing synovitis. Its optimal treatment is arthrotomy, foreign body removal and total/subtotal synovectomy.     

Matricryptins and matrikines: biologically active fragments of the extracellular matrix

Numerous extracellular proteins and glycosaminoglycans (GAGs) undergo limited enzymatic cleavage resulting in the release of fragments exerting biological activities, which are usually different from those of the full‐length molecules. In this review, we define matrikines and matricryptins, which are bioactive fragments released from the extracellular matrix proteins, proteoglycans and GAGs and report their major biological activities. These fragments regulate a number of physiopathological processes including angiogenesis, cancer, fibrosis, inflammation, neurodegenerative diseases and wound healing. The challenges to translate these fragments from molecules biologically active in vitro and in experimental models to potential drugs are discussed in the last part of the review.