Localization of antigens on the inner-acrosomal membrane of the rabbit sperm by immunofluorescence

The acrosome-reacted spermatozoa interact with the zona pellucida through their limiting inner acrosomal membrane (IAM). The antigenic properties of IAM were determined using the antibody to IAM raised in a male guinea pig. The antisera was incubated with the acetone powder of rabbit lung, liver, kidney, heart, muscle, and blood cells. The unabsorbed antibodies specifically interacted with antigens on the IAM as determined by the immunofluorescence technique.     

Schistosoma mansoni: Characterization of two circulating polysaccharide antigens and the immunological response to these antigens in mouse,hamster, and human infections

In this study the nature and occurrence of two circulating polysaccharide antigens of Schistosoma mansoni, circulating anodic antigen (CAA) and circulating cathodic antigen (CCA), and the immunological response to these antigens in mouse, hamster, and human infections were investigated. Both CAA and CCA showed a large molecular weight range, less than 50,000 to over 300,000 for CAA and 50,000 to over 300,000 for CCA, possibly representing monomers and polymers. CAA and CCA could be purified from the trichloroacetic acid-soluble fraction of adult worm antigen (AWA-TCA) by means of DEAE ion exchange chromatography. The presence of at least two other components in AWA-TCA was shown. Both CAA and CCA were found to be gut associated, and could be demonstrated in the vomitus and in the excretory and secretory antigens of adult worms. Both antigens were present in the kidney eluates of infected hamsters, while CCA could normally be detected in the urine of these hamsters and CAA only occasionally. CAA was demonstrated in the Kupffer cells of the livers of infected mice and hamsters. Antibodies against CAA and CCA were shown in mouse, hamster, and human infections. In human infections specific IgM titers against these antigens were especially elevated in children and in recent infections of adults.     

Temporal changes in lectin binding of peri-implantation mouse blastocysts

Mouse blastocysts were exposed to a series of ferritin-conjugated lectins during Day 5 (preadhesive) and Day 6 (adhesive; collected Day 5, 24 hr in vitro) of embryogenesis to determine whether there were any changes in lectin binding characteristics that coincided with the acquisition of adhesiveness. After exposure to lectin, the blastocysts were processed for electron microscopy and lectin binding sites were determined by visualization of ferritin particles with the electron microscope. No binding sites were observed for either Dolichos biflorus agglutinin or soybean agglutinin on blastocysts from either stage examined. Binding sites for Ulex europaeus agglutinin, Con A, and wheat germ agglutinin were seen on blastocysts from both stages without apparent increase or reduction in binding sites from either stage. Ricinus communis agglutinin-I (RCA-I) bound heavily to the surface of Day 5 blastocysts and did not bind at all to $\text{3}\text{12}$ Day 6 blastocysts and did bind, though with apparent diminution, to $\text{9}\text{12}$ Day 6 blastocysts, as compared with the binding observed on Day 5 blastocysts. Peanut agglutinin (PNA) did not bind at all to Day 5 blastocysts but did bind heavily to the surface of Day 6 blastocysts. Both RCA-I and PNA bound to the surface of embryos during Day 5 of delayed implantation, thus indicating that neither the appearance of PNA binding sites on Day 6 blastocysts nor the apparent reduction of RCA-I binding sites on Day 6 blastocysts could be solely implicated in the acquisition of adhesiveness. PNA binding sites were abolished from the surface of Day 6 blastocysts by treatment with Pronase, indicating that the PNA binding molecule was associated with a glycoprotein rather than a glycolipid.     

Characterization of 2'':3''-Cyclic Nucleotide 3''-Phosphodiesterase: Limited Proteolytic Digestion, Plant Lectin Affinity Chromatography, and Immunological Identification

Purified bovine brain 2':3'-cyclic nucleotide 3'-phosphodiesterase (CNPase) migrates as a protein double band in SDS-polyacrylamide gel electrophoresis. The positions of the two protein bands correspond to approximate molecular weights (MW) of 56,000 and 53,000. Limited protease treatment of isolated CNPase leads to subsequent degradation of the enzyme into smaller polypeptides having MWs of approximately 40,000, 30,000, and 20,000. During proteolytic digestion CNPase remains enzymatically active. Binding studies with several immobilized plant lectins as well as periodic acid-Schiff reagent (PAS) staining of SDS gels indicate that CNPase is a glycoprotein. An antiserum against purified CNPase, prepared in rabbits, was used to confirm the immunological identity of various CNPase preparations obtained in our laboratory.     

Common antigenic determinants of pneumococcal penicillin-binding protein (PBP) 1a and Streptococcus pyogenes PBP 2

Abstract Antisera raised against penicillin-binding protein (PBP) 1a of Streptococcus pneumoniae reacted with PBP 2 in certain strains of Streptococcus pyogenes . Cross-reactivity could be demonstrated on immunoblots as well as by immunoprecipitation of native solubilised proteins, indicating a similar structural arrangement also in the native form of the two PBPs.     

家兔伏核注射吗啡引起的镇痛可被中脑导水管周围灰质注射纳洛酮或甲啡肽抗体所阻断

本实验室以往的资料表明,在家兔中脑导水管周围灰质(PAG)到伏核之间存在一条与镇痛有夫的神经通路,该通路以5-羟色胺(5-HT)和甲啡肽(ME)为其递质。本工作进一步探讨从伏核到PAG的下行镇痛通路。 以辐射热照射家兔嘴侧部皮肤,测量其躲避反应的潜伏期(ERL)作为痛反应阈,简称痛阈。通过预先埋植的慢性套管向伏核内微量注射吗啡,20min后向PAG内双侧注射纳洛酮(NX)或脑啡肽抗血清,观察ERL的变化。(1)伏核内注射吗啡20μg/1μl,引起ERL升高80％以上,作用持续50min以上。(2)PAG内注射NX(每侧0.5、1.0或2.0μg)可不同程度地阻断伏核内注射吗啡的镇痛效应,且呈明显的剂效关系。(3)PAG内注入甲啡肽抗血清(每侧1μl)可部分阻断伏核内注射吗啡的镇痛效应,而注入亮啡肽抗血清或正常兔血清则无效。 实验结果提示,从伏核到PAG存在一条下行镇痛通路,在PAG内可能以ME为其递质。该通路与PAG到伏核的上行镇痛通路构成一个环形的“中脑边缘镇痛回路”,并在针刺镇痛和吗啡镇痛中发挥重要作用。     

家兔隔核中去甲肾上腺素对皮肤与内脏痛阈的影响

本工作以电刺激内脏大神经或耳尖部皮肤测定清醒家兔内脏痛阈或皮肤痛阈,以探讨隔核去甲肾上腺素在内脏镇痛和皮肤镇痛中的作用以及与中脑导水管周围灰质(PAG)中内阿片肽系统的关系。实验观察到,双侧隔核内微量注射α受体激动剂可乐宁(10μg/2μl)或α受体阻断剂酚妥拉明(10μg/2μl)对内脏痛阈无明显影响。注入β受体激动剂异丙肾上腺素(1μg/2μl)使内脏痛阐明显升高;而注入β受体阻断剂心得安(1Cμg/2μl)则内脏痛阈明显降低。隔核内注入酚妥拉明(10μg/2μl)或心得安(10μg/2μl)均可使皮肤痛阈明显提高。提示,隔核内NA通过β受体调制内脏痛;通过α受体和β受体调制皮肤痛。隔核内注入异丙肾上腺素(1μg/2μl)明显地镇内脏痛,此作用可被PAG内注射纳洛酮(1μg/2μl)或注射抗亮啡肽抗血清(1:20,000)所减弱;但可使PAG内亮啡肽样物质释放量增加。这提示,隔核内NA的镇内脏痛作用与PAG的内阿片肽系统有关;其中亮非肽在这一过程中具有重要作用。     

Effect of sulfolipid antibodies on the macromolecular synthesis of Mycobacterium smegmatis ATCC607

Abstract The biosynthesis of DNA, RNA, proteins and lipids in the presence of antiserum to sulfolipids was investigated by studying the incorporation of radiolabelled precursors like ³H-thymidine ¹⁴C-uracil, ¹⁴C-leucine and ¹⁴C-Acetate into their respective macromolecules. Antiserum to sulfolipids had a inhibitory effect on the biosynthesis of all these components. Antiserum also exhibited a growth inhibitory effects as compared to normal serum.     

Differentiation of typical and atypical enteropathogenic Escherichia coli using colony immunoblot for detection of bundle‐forming pilus expression

Aims: The aim of study was to develop a colony immunoblot assay to differentiate typical from atypical enteropathogenic Escherichia coli (EPEC) by detection of bundle‐forming pilus (BFP) expression. Methods and Results: Anti‐BFP antiserum was raised in rabbits and its reactivity was confirmed by immunoelectron microscopy and by immunoblotting recognizing bundlin, the major pilus repeating subunit. The bacterial isolates tested in the colony immunoblot assay were grown in different media. Proteins from bacterial isolates were transferred to nitrocellulose membrane after treatment with phosphate buffer containing Triton X‐100, EDTA and sodium chloride salts. When 24 typical EPEC and 96 isolates including, 72 atypical EPEC, 13 Gram‐negative type IV‐expressing strains and 11 enterobacteriaceae were cultivated in Dulbecco’s Modified Eagle’s Medium agar containing fetal bovine serum or in blood agar in the presence of CaCl₂, they showed a positivity of 92 and 83%, and specificity of 96 and 97%, respectively. Conclusion: The assay enables reliable identification of BFP‐expressing isolates and contributes to the differentiation of typical and atypical EPEC. Significance and Impact of the Study: The colony immunoblot for BFP detection developed in this study combines the simplicity of an immunoserological assay with the high efficiency of testing a large number of EPEC colonies.     

Mesodermal and neural crest derived ovine tibial and mandibular osteoblasts display distinct molecular differences

Mandibular osteoblasts originate from the neural crest and deposit bone intramembranously, mesoderm derived tibial osteoblasts by endochondral mechanisms. Bone synthesized by both cell types is identical in structure, yet functional differences between the two cell types may exist. Thus, both matched juvenile and adult mandibular and tibial osteoblasts were studied regarding their proliferative capacity, their osteogenic potential and the expression of osteogenic and origin related marker genes. Juvenile tibial cells proliferated at the highest rate while juvenile mandibular cells exhibited higher ALP activity depositing more mineralized matrix. Expression of Hoxa4 in tibial cells verified their mesodermal origin, whereas very low levels in mandibular cells confirmed their ectodermal descent. Distinct differences in the expression pattern of bone development related genes (collagen type I, osteonectin, osteocalcin, Runx2, MSX1/2, TGF-β₁, BAMBI, TWIST1, β-catenin) were found between the different cell types. The distinct dissimilarities in proliferation, alkaline phosphatase activity, the expression of characteristic genes, and mineralization may aid to explain the differences in bone healing time observed in mandibular bone when compared to long bones of the extremities.