4种支架构建复合式口腔黏膜的组织学特点

目的利用4种不同支架材料构建复合式口腔黏膜,并比较其组织结构特点。方法体外培养人口腔黏膜的成纤维细胞和角质形成细胞,在4种支架材料中加入成纤维细胞,培养7d后,在支架表面加入角质形成细胞,培养4d后,移至气-液界面继续培养7d。苏木精-伊红染色镜下观察构建的复合式口腔黏膜的组织形态学特点。结果 4种支架均可构建形成复层上皮。其中,上皮层与脱细胞真皮基质材料(de-epidermised dermis,DED)结合紧密,形成的人工黏膜有明显的上皮钉突。不同于以往报道,上皮层与Alloderm结合并不十分紧密。以胶原凝胶为基质形成的人工口腔黏膜最厚,有明显分层。以胶原海绵-胶原凝胶为基质形成的复层上皮在部分区域长入至胶原海绵的空隙中。结论以DED和胶原凝胶为支架构建的口腔黏膜更接近于天然结构,而后者脆性较大,限制了其临床应用的可能。     

Prospective evaluation of posttransfusion hepatitis

The incidence of posttransfusion hepatitis (PTH) was determined prospectively at our institution. An active surveillance program of transfused surgical patients was set up; alanine aminotransferase (ALT) levels were determined before transfusion and at monthly intervals for 6 months after transfusion. Patients with confirmed ALT values greater than 2.5 times the upper reference values were referred to the out-patient clinics for diagnosis. Of 4051 surgical patients who underwent transfusion between January 1986 and December 1989, 2459 (60.7%) were enrolled in the surveillance program, and 1018 (25.1%) completed the follow-up; 238 patients received autologous blood only and were used as controls. No PTH was observed in the control patients, and the incidence of the disease in patients receiving homologous blood was 10.97 percent in 1986, 6.58 percent in 1987, 5.55 percent in 1988, and 4.29 percent in 1989; the decreasing trend is significant (p = 0.018).     

Cloning and Characterization of the Acidic Ribosomal Protein P2 of Cryptosporidium parvum,a New 17-Kilodalton Antigen

Cryptosporidium infection is commonly observed among children and immunocompromised individuals in developing countries, but large-scale outbreaks of disease among adults have not been reported. In contrast, outbreaks of cryptosporidiosis in the United States and Canada are increasingly common among patients of all ages. Thus, it seems likely that residents of regions where Cryptosporidium is highly endemic acquire some level of immunity, while residents of the developed world do not. A new immunodominant Cryptosporidium parvum antigen in the 15- to 17-kDa size range was identified as the Cryptosporidium parvum 60S acidic ribosomal protein P2 (CpP2). We developed a recombinant protein-based enzyme-linked immunosorbent assay for serologic population surveillance for antibodies that was 89% sensitive and 92% specific relative to the results of the large-format Western blot assay. The human IgG response is directed almost exclusively toward the highly conserved, carboxy-terminal 15 amino acids of the protein. Although IgG antibody cross-reactivity was documented with sera from patients with acute babesiosis, the development of an anti-CpP2 antibody response in our Peru study population correlated better with Cryptosporidium infection than with infection by any other parasitic protozoan. In Haiti, the prevalence of antibodies to CpP2 plateaus at 11 to 20 years of age. Because anti-CpP2 IgG antibodies were found only among residents of countries in the developing world where Cryptosporidium infection occurs early and often, we propose that this response may be a proxy for the intensity of infection and for acquired immunity.Cryptosporidium parvum and C. hominis are enteric protozoan parasites that commonly cause outbreaks of diarrheal disease in the developed world (for reviews, see references 24 and 26). All age groups are affected, and the disease is usually self-limiting in immunocompetent individuals (5, 13). Outbreaks have been linked to public water system treatment failures, recreational exposure to contaminated water, contamination of unpasteurized fresh-squeezed juices, and contamination of food products by infected food handlers (14, 28, 35, 37, 39, 58). In the developing world, where potential sources of food and water contamination are widespread, acute cryptosporidiosis is usually limited to young children and to immunocompromised populations (4, 5, 48, 50, 59). In a longitudinal serologic study of enteric parasites in Peru, we reported that repeated infection was common among young children and that Cryptosporidium-specific IgG antibody levels increased with age and with experience of infection (54). Large-scale outbreaks of overt illness among immunocompetent adults in these regions where cryptosporidiosis is highly endemic have not been reported. These observations suggest that some level of immunity to disease (although not necessarily to infection) may eventually develop upon repeated exposure to the parasite (20).In previous work (68), we noted that sera from individuals who live in Haiti often contain IgG antibodies to several C. parvum antigens, in addition to the immunodominant 27- and 17-kDa antigens. In the current work, we demonstrate that one of these novel antigens, located in the 17-kDa-molecular-mass range but distinct from the C. parvum 17-kDa antigen family (56), is the C. parvum acidic ribosomal protein P2 (CpP2). Several acidic ribosomal proteins (P0, P1, P2, or variants) have been described as prominent antigens in leishmaniasis (69, 70), Chagas'' disease (32, 65, 67), malaria (10), Brucella abortus infection (6), Babesia bovis infection (12), and systemic lupus erythematosus (SLE) (16, 17, 62). In particular, ribosomal proteins P0 and P2 from Leishmania spp., Plasmodium falciparum, and Trypanosoma cruzi have been reported to be immunostimulatory, as sera from infected animals and humans recognize these antigens (10, 65, 66, 67,69, 70). Although the acidic ribosomal proteins are classically associated with the cytoplasmic ribosomes, they have also been localized to the cell surface of some parasites. Chatterjee et al. (9) used antibody fluorescence to demonstrate the presence of the P0 protein on the surface of P. falciparum merozoites, and Sehgal et al. (63) used transiently transfected Toxoplasma gondii cells to demonstrate the translocation of tagged P0 to the parasite surface.Because of their surface localization and immunogenicity, it has been suggested that P proteins may be possible vaccine candidates. In recent reports, immunization with the P-domain peptide of ribosomal protein P0 provided protection against P. falciparum challenge (60), immunization with Babesia gibsoni P0 protein was cross-protective for infection with Babesia microti (73), and antibodies against Neospora caninum P0 inhibited infection with T. gondii in vitro (79). Furthermore, a Leishmania infantum ribosomal protein DNA vaccine conferred protective immunity against Leishmania major infection in mice (22). The strong anti-CpP2 antibody responses observed for most of the Haitians who were also antibody positive for the 27-kDa antigen suggest that the CpP2 antigen may play a role in the generation of immune responses against C. parvum in areas where it is highly endemic and, therefore, might be a potential vaccine target.     

A founder mutation in BBS2 is responsible for Bardet‐Biedl syndrome in the Hutterite population: utility of SNP arrays in genetically heterogeneous disorders

Innes AM, Boycott KM, Puffenberger EG, Redl D, MacDonald IM, Chudley AE, Beaulieu C, Perrier R, Gillan T, Wade A, Parboosingh JS. A founder mutation in BBS2 is responsible for Bardet‐Biedl syndrome in the Hutterite population: utility of SNP arrays in genetically heterogeneous disorders. Bardet‐Biedl syndrome (BBS) is a multisystem genetically heterogeneous disorder, the clinical features of which are largely the consequence of ciliary dysfunction. BBS is typically inherited in an autosomal recessive fashion, and mutations in at least 14 genes have been identified. Here, we report the identification of a founder mutation in the BBS2 gene as the cause for the increased incidence of this developmental disorder in the Hutterite population. To ascertain the Hutterite BBS locus, we performed a genome‐wide single nucleotide polymorphism (SNP) analysis on a single patient and his three unaffected siblings from a Hutterite family. The analysis identified two large SNP blocks that were homozygous in the patient but not in his unaffected siblings, one of these regions contained the BBS2 gene. Sequence analysis and subsequent RNA studies identified and confirmed a novel splice site mutation, c.472‐2A>G, in BBS2. This mutation was also found in homozygous form in three subsequently studied Hutterite BBS patients from two different leuts, confirming that this is a founder mutation in the Hutterite population. Further studies are required to determine the frequency of this mutation and its role, if any, in the expression of other ciliopathies in this population.     

Barriers to effective self-management in cardiac patients: The patient's experience

Objective

This paper identifies common obstacles impeding effective self-management among patients with heart disease and explores how for disadvantaged patients access barriers interfere with typical management challenges to undermine patients’ efforts to care for their illnesses.

Methods

We convened 33 focus group discussions with heart patients in 10 U.S. communities. Using content analysis, we identified and grouped the most common barriers that emerged in focus group discussions.

Results

We identified nine major themes reflecting issues related to patients’ ability to care for and manage their heart conditions. We grouped the themes into three domains of interest: (1) barriers that interfere with getting necessary services, (2) barriers that impede the monitoring and management of a heart condition on a daily basis, and (3) supports that enable self-management and improve care.

Conclusion

For disadvantaged populations, typical problems associated with self-management of a heart condition are aggravated by substantial obstacles to accessing care.

Practice implications

Ensuring disadvantaged patients with chronic heart conditions are linked to formal systems of care, such as cardiac rehabilitation programs, could better develop patients’ self-management skills, reduce barriers to receiving care and improve the overall health outcomes of these patients.     

DFNB74, a novel autosomal recessive nonsyndromic hearing impairment locus on chromosome 12q14.2-q15

Autosomal recessive nonsyndromic hearing impairment (ARNSHI) segregating in three unrelated, large consanguineous Pakistani families (PKDF528, PKDF859 and PKDF326) is linked to markers on chromosome 12q14.2-q15. This novel locus is designated DFNB74 . Maximum two-point limit of detection (LOD) scores of 5.6, 5.7 and 2.6 were estimated for markers D 12 S 313, D 12 S 83 and D 12 S 75 at θ = 0 for recessive deafness segregating in these three families. Haplotype analyses identified a critical linkage interval of 5.35 cM (5.36 Mb) defined by D 12 S 329 at 74.58 cM and D 12 S 313 at 79.93 cM. DFNB74 is the second ARNSHI locus mapped to chromosome 12, but the physical intervals do not overlap with one another. A locus contributing to the early onset, rapidly progressing hearing loss of A/J mice ( ahl4 , age-related hearing loss 4) was reported to map to chromosome 10 in a region of conserved synteny to DFNB74 , suggesting that ahl4 and DFNB74 may be due to mutations of the same gene in these two species.