Differentiation of adenovirus hexon epitopes with monoclonal antibodies by gel diffusion assays

Nine monoclonal antibodies (MAbs) directed against crystallized human adenovirus type 1 (Ad h 1) hexon were tested with purified homologous and heterologous hexon preparations by gel diffusion. Six MAbs formed a single line with the homologous hexon in a 2-well pattern, and 3 MAbs formed lines only in biclonal combinations with an appropriate MAb. All of the 6 precipitating MAbs formed a continuous line of complete identity when tested simultaneously against homologous and different heterologous hexons. With Ad h 1 hexon a line of double partial identity (double spur) was formed when some pair combinations of 2 MAbs were placed in 2 juxtaposed wells. Other MAbs in the adjacent wells formed a line of identity. The MAbs could be divided into 2 antibody groups (groups A and B) based on this phenomenon. Members of antibody groups A and B apparently identified 2 sterically distinct epitopes: one of them is presumably the genus-specific epitope of the hexons (group A) and the other(s) should be intertype-specific epitope(s). Thus, the gel diffusion method can be used for selecting pairs of MAbs for their specificity to sterically independent epitopes. Mixtures of 2 MAbs belonging to the different antibody groups formed double lines with Ad h 1 hexons. Members of group A showed some helper effect to the members of group B for their precipitin line formation.     

C225单用及与DDP联用对HeLa细胞的抑制作用与机制研究

探讨C225单用及与DDP联用对人子宫颈癌HeLa细胞的体外抑制作用及其机制。分别用C225(100、300μg/ml)与DDP(0.1、0.5、1μg/ml)以单用和联用处理HeLa细胞72 h后,MTT法检测对HeLa细胞生长的抑制作用及协同效应;FCM技术检测C225(300μg/ml)与不同工作浓度DDP单用及联用72 h后对细胞周期及凋亡的影响;并用HOE-CHEST33258染色技术进行细胞凋亡的形态学检测。结果C225能明显抑制HeLa细胞增殖,与DDP联合具有协同作用或相加作用;C225能使细胞周期阻滞于G1期,并诱导细胞凋亡;与DDP联用后凋亡率更高,使细胞周期进一步阻滞于G2期,同时降低S期细胞比例。荧光显微镜下可见实验对照组所发荧光较弱,无凋亡小体出现,而各药物干预组均出现一定数量的凋亡细胞,并随药物浓度的增加而增多,其中尤以联合用药组最为明显。两药单用及联用均对HeLa细胞的体外生长具有显著抑制作用,C225可通过将细胞周期阻滞于G0-G1期及诱导细胞凋亡发挥其抑瘤效应;两药间存在协同作用,机制可能与C225增加HeLa细胞对DDP的敏感性有关。     

Microfluorometric evaluation of the specificity of fluorescent antisera against mouse immunoglobulins with the defined antigen substrate spheres (DASS) system

Highly purified MOPC-21 IgG₁, MOPC-173 IgG_2a, MOPC-195 IgG_2b, MOPC-104 E IgM, and MOPC-315 IgA paraproteins, heterogeneous mouse IgG, Fab and Fc fragments of heterogeneous IgG were prepared and coupled to Sepharose beads. These beads were then used as artificial substrates to test the specificity of fluorescent antisera against mouse immunoglobulins by microfluorometry. By comparing the visual evaluation of stained plasma cells and measurements on beads, the highest permissible percentage impurity in a conjugate was determined. It was 14% for a fluorescein iso thiocyanate (FITC) and 6% for a tetramethyl rhodamine iso thiocyanate (TRITC) conjugate. By application of these criteria, 1 out of 7 tested commercial antisera and 6 out of 8 conjugates prepared in this laboratory proved to be satisfactory. The most common impurities were anti-light chain antibodies, as revealed by their reaction with Fab. With the bead system, a good impression of the specificity of an antiserum can be obtained. It gives, however, only approximate information on whether the conjugate will cause a high background staining in the biological specimen.     

Genetic diversity of HLA system in two populations from Yucatán,Mexico: Mérida and rural Yucatán

We studied HLA class I (HLA-A, -B) and class II (HLA-DRB1, -DQB1) alleles by PCR-SSP based typing in 324 Mexicans from the state of Yucatán living in the city of Mérida (N = 192) and rural communities (N = 132), to obtain information regarding allelic and haplotypic frequencies. We found that the most frequent haplotypes in the state of Yucatán include 16 Native American and one European haplotype. Admixture estimates revealed that the main genetic components in Yucatán are Native American (81.54 ± 4.99% by ML; 62.92% of Native American haplotypes) and European (11.50 ± 15.43% by ML; 23.26% of European haplotypes), and a less prominent African genetic component (6.96 ± 10.47% by ML; 5.93% of African haplotypes).     

Genetic diversity of HLA system in two populations from Michoacán,Mexico: Morelia and rural Michoacán

We studied HLA class I (HLA-A, -B) and class II (HLA-DRB1, -DQB1) alleles by PCR-SSP based typing in 498 Mexicans from the state of Michoacán living in the city of Morelia (N = 150) and rural communities (N = 348), to obtain information regarding allelic and haplotypic frequencies. We find that the ten most frequent haplotypes found in the state of Michoacán include 12 Native American and two European haplotypes. Admixture estimates revealed that the main genetic components in the state of Michoacán are Native American (48.79 ± 1.44%) and European (43.10 ± 0.86%), while African genetic component is less apparent (8.11 ± 0.85%). Our findings add to the growing knowledge on the population genetics of Western Mexico and provide new HLA data on populations from Michoacán.     

Aprendizaje y prácticas clínicas

This collaboration briefly reviews the characteristics of professional learning. It pays special attention to the learning that takes place during clinical practices and to the fundamental role of reflection in the construction of knowledge and in the better understanding of the situation of the other (patients, family members, professionals) and oneself. It emphasizes the learning of values and attitudes, which are manifested in behaviors. Finally, it describes the characteristics of learning by role modeling and the influence of hidden curriculum on the development of professional competences.     

Targeting colorectal cancer cells with single-walled carbon nanotubes conjugated to anticancer agent SN-38 and EGFR antibody

In this study, single-walled carbon nanotubes (SWNTs) conjugated with antibody C225 were used to achieve targeted therapy against EGFR over-expressed colorectal cancer cells. In addition, the control release of the chemotherapeutic drug, 7-Ethyl-10-hydroxy-camptothecin (SN38), was studied. We used three different colorectal cancer cell lines, HCT116, HT29, and SW620, listed in the order of decreasing expression levels of EGFR. Our results showed that SWNT could use C225 to specifically bind to EGFR-expressed cells. The cellular uptakes of SWNT of EGFR over-expressed cells (HCT116 and HT29) were much higher than that of the negative control (SW620). We, next, demonstrated that receptor-mediated endocytosis was the primary cell entry route for SWNT. As a consequence, abundant amount of SN38 was released and EGFR over-expressed cells were killed. The drug control release process was studied by utilizing human carboxylesterase enzyme (hCE) that would break the bond linking SN38 and SWNT-carrier in cytoplasm. The intracellular SN38 release observed by confocal microscopy showed that SN38 actually dissociated from the SWNT-carrier first. SN38's entry to nucleus was then followed while the SWNT-carrier still remained in the cytoplasm. Overall, all these data suggested that SWNT could be a good carrier for targeting controlled release therapy.     

Sacral co-ossification in dinosaurs: The oldest record of fused sacral vertebrae in Dinosauria and the diversity of sacral co-ossification patterns in the group

The fusion of the sacrum occurs in the major dinosaur lineages, i.e. ornithischians, theropods, and sauropodomorphs, but it is unclear if this trait is a common ancestral condition, or if it evolved independently in each lineage, or even how or if it is related to ontogeny. In addition, the order in which the different structures of the sacrum are fused, as well as the causes that lead to this co-ossification, are poorly understood. Herein, we described the oldest record of fused sacral vertebrae within dinosaurs, based on two primordial sacral vertebrae from the Late Triassic of Candelária Sequence, southern Brazil. We used computed microtomography (micro-CT) to analyze the extent of vertebral fusion, which revealed that it occurred only between the centra. We also assessed the occurrence of sacral fusion in Dinosauria and close relatives. The degree of fusion observed in representatives of the major dinosaur lineages suggested that there may be a sequential pattern of fusion of the elements of the sacrum, more clearly observed in Sauropodomorpha. Our analyses suggest that primordial sacral vertebrae fuse earlier in the lineage (as seen in Norian sauropodomorphs). Intervertebral fusion is observed to encompass progressively more vertebral units as sauropodomorphs evolve, reaching up to five or more fully fused sacrals in Neosauropoda. Furthermore, the new specimen described here indicates that the fusion of sacral elements occurred early in the evolution of dinosaurs. Factors such as ontogeny and the increase in body size, combined with the incorporation of vertebrae to the sacrum may have a significant role in the process and in the variation of sacral fusion observed.     

Association Between PTPN22 Polymorphisms and IgE Responses to Staphylococcal Superantigens in Chronic Urticaria

Protein tyrosine phosphatase-22 (PTPN22) gene encodes lymphoid-specific tyrosine phosphatase (Lyp), an inhibitor of T cell activation. A polymorphism of the PTPN22 gene has been found to be associated with chronic urticaria (CU). We investigated the associations between PTPN22 gene polymorphisms and CU characteristics, including serum specific IgE antibodies response to toxic shock syndrome toxin-1 (TSST-1) and staphylococcal enterotoxin A (SEA). CU patients (n=409) and normal healthy controls (n=388) were enrolled in the present study. Serum specific IgE to TSST-1 and SEA were measured by ImmunoCAP®. Five PTPN22 single nucleotide polymorphisms, -1123G>C, 1858C>T, 13145A>G, 14943C>T, and 20628A>G, were genotyped. There were no significant differences in genotype or haplotype frequencies of these polymorphisms between the 2 groups. CU patients carrying the GG genotype at 20628A>G (P=0.035) or haplotype 3 [GGG] (P=0.047) had a significantly higher prevalence of serum specific IgE to TSST-1 compared to non-carriers. Similarly, CT/TT genotype at 14943C>T had a significantly higher prevalence of serum specific IgE to SEA (P=0.045). The findings suggest that the PTPN22 gene polymorphisms at 20628A>G and 14943C>T may enhance serum specific IgE responses to TSST-1 and SEA, which may contribute to CU pathogenesis.     

The value of 'mesothelium-associated' antibodies in distinguishing between metastatic renal cell carcinomas and mesotheliomas

AIMS: Despite increasing usage of mesothelium-associated antibodies in diagnosis, a meta-analysis of studies analysing these antibodies in relation to distinguishing mesothelioma from renal cell carcinoma shows a paucity of published data. Given the clinical importance of elucidating this differential diagnosis, we compared the phenotypes of these two tumours using a panel of antibodies comprising recently described 'mesothelium-associated' antibodies and the more established 'epithelium-associated' antibodies. METHODS AND RESULTS: We applied an antibody panel comprising calretinin, cytokeratin (CK)5/6, thrombomodulin, carcinoembryonic antigen (CEA), BerEP4 and BCA225 to 37 cases of pleural mesotheliomas and 40 cases of renal cell carcinoma (27 primary tumours and 13 metastatic to the pleura). All mesotheliomas were either purely epithelioid or of mixed type. Cases of renal cell carcinoma were graded and classified as to cell type and architecture. For mesotheliomas, 0% stained for CEA, 16% for BerEP4, 83% for BCA225, 78% for CK5/6, 86% for thrombomodulin and 97% showed nuclear staining for calretinin. For renal cell carcinomas, 0% stained for CEA, 50% for BerEP4, 88% for BCA225, 5% for CK5/6, 32% for thrombomodulin and 10% showed nuclear staining for calretinin. CONCLUSION: Calretinin, CK5/6 and BerEP4 appear the most useful antibodies in helping to distinguish between renal cell carcinomas and mesotheliomas, although BerEP4 was not particularly sensitive for renal cell carcinomas. Thrombomodulin was not as specific as the other 'mesothelium-associated' antibodies in this study, reflecting how staining for mesothelium-associated antibodies varies in carcinomas from different primary sites, and such variations should be taken into account when assessing the differential diagnosis of mesothelioma. In cases where doubt remains over distinguishing metastatic renal cell carcinoma from mesothelioma, data from such a panel should be viewed with caution and assessed in association with clinical, imaging and morphological features.     

Simultaneous detection of SCE and Q-bands on human chromosomes by a double-staining technique

Human lymphocytes were cultured for two cell cycles in the presence of bromodeoxyuridine (BrdU), and the resulting metaphase chromosomes were first stained with quinacrine mustard (QM) and then, immediately afterwards, with Hoechst 33258, without any intermediate destaining. Both Q-banding patterns and sister chromatid differential staining were photographed subsequently on the same metaphase using two different filter blocks of the fluorescence microscope.     

Asymmetric oculomotor apraxia,optic ataxia,and simultanagnosia with right hemispatial neglect from a predominantly left-sided lesion of the parieto-occipital area

Introduction: Bálint’s syndrome involves bilateral damage to the parieto-occipital area. The extent of the effect of unilateral damage on the Bálint’s triad (oculomotor apraxia, optic ataxia, and simultanagnosia) remains unknown.

Methods: We examined a 63-year-old, right-handed woman who developed right hemianopia, oculomotor apraxia, optic ataxia, simultanagnosia, and hemispatial neglect (HSN) for the right after a cerebral infarction, with detailed neuropsychological tests, magnetic resonance imaging, and single photon emission computed tomography (SPECT).

Results: Neuropsychological examination showed that oculomotor apraxia, optic ataxia, and simultanagnosia were more pronounced in the right hemi-space, probably due to the limited eye movement in the right visual field, whereas HSN was restricted to the right hemi-space. Diffusion-weighted MR images revealed hyperintensity in the left parieto-temporo-occipital region, and several spotty areas of the bilateral frontal and parietal subcortical regions. SPECT revealed hypoperfusion in the left parieto-occipital region and frontal operculum and small areas of the right superior parietal lobule.

Conclusions: The case suggests that asymmetric (more pronounced in the right hemi-space) oculomotor apraxia, optic ataxia, and simultanagnosia occur in an extensive lesion of the left parieto-occipital cortices. Although HSN is not a prerequisite for simultanagnosia, the coexistence of HSN aggravates simultanagnosia in the hemi-space opposite the lesion.     

Pain medication contracts for problem patients.

Pain manifested by hospital patients is a source of concern for both patients and staff. The staff's attempts to provide reasonable freedom from pain are not always satisfactory to the patient, however. Demands for increasing medication often become struggles between patient and staff for control, and such struggles may seriously interfere with treatment. Pain medication contracts can aid communication and decrease power struggles.     

HLA and T-lymphocyte function in old age

The role of the major histocompatibility complex in the genetic control of reactivity of peripheral blood mononuclear cells (T lymphocytes) to lectins and allogeneic cells as a function of age was investigated. In randomly selected aged subjects the frequencies of HLA-A, B, and some C locus alleles did not differ significantly from those in the control group. However, some tendencies of haplotype frequency differences between young and aged subjects were found. Significant associations of impaired or preserved T-lymphocyte function could be detected in connection with some HLA-A (A3, A11) antigens only. The tendency of some phenotypic HLA-A and B or C and B antigen associations to be in correlation with impaired or preserved T-lymphocyte reactivity in old age seemed to be independent of their age-related frequency differences. In family studies of a partially inbred Hungarian population, differences were found in the rate of diminution of allogeneic reactivity in groups sharing different HLA haplotypes. Based on statistical analysis of these data, a genetic factor segregating with the MHC and taking part in the regulation of the age-dependent decline of T-lymphocyte reactivity can be postulated.