Platelet-rich fibrin (PRF): a second-generation platelet concentrate. Part I: technological concepts and evolution.

Platelet-rich fibrin (PRF) belongs to a new generation of platelet concentrates geared to simplified preparation without biochemical blood handling. In this initial article, we describe the conceptual and technical evolution from fibrin glues to platelet concentrates. This retrospective analysis is necessary for the understanding of fibrin technologies and the evaluation of the biochemical properties of 3 generations of surgical additives, respectively fibrin adhesives, concentrated platelet-rich plasma (cPRP) and PRF. Indeed, the 3-dimensional fibrin architecture is deeply dependent on artificial clinical polymerization processes, such as massive bovine thrombin addition. Currently, the slow polymerization during PRF preparation seems to generate a fibrin network very similar to the natural one. Such a network leads to a more efficient cell migration and proliferation and thus cicatrization.     

An XPS and SEM evaluation of six chemical and physical techniques for cleaning of contaminated titanium implants

The purpose of the present study was to analyse clinically failed and retrieved implants prior to and after cleaning by means of scanning electron microscopy (SEM) and X-ray induced photoelectron spectroscopy (XPS) as compared to unused controls. Six different chemical and physical techniques for cleaning of contaminated titanium implants were evaluated: 1) rinsing in absolute ethanol for 10 min, 2) cleaning in ultrasonic baths containing trichloroethylene (TRI) and absolute ethanol, 10 min in each solution, 3) abrasive cleaning for 30 s, 4) cleaning in supersaturated citric acid for 30 s, 5) cleaning with continuous CO2-laser in dry conditions at 5 W for 10 s, 6) cleaning with continuous CO2-laser in wet conditions (saline) at 5 W for 10 s. SEM of failed implants showed the presence of contaminants of varying sizes and XPS showed almost no titanium but high carbon signals. XPS of unused titanium implants showed lower levels of titanium as previously reported, probably due to contamination of carbon which increased with time in room air. Cleaning of used implants in citric acid followed by rinsing with deionized water for 5 min followed by cleaning in ultrasonic baths with TRI and absolute ethanol gave the best results with regard to macroscopical appearance and surface composition. However, as compared to the unused implants the results from an element composition point of view were still unsatisfactory. It is concluded that further development and testing of techniques for cleaning of organically contaminated titanium is needed.     

Overexpression/amplification of HER-2/neu is uncommon in hepatocellular carcinoma

BACKGROUND： Hepatocellular carcinoma （HCC） is one of the most prevalent fatal cancers in the world. Despite advances in early diagnosis and improvements in surgical techniques, the survival of patients with HCC even after resection is poor because of the high incidence of recurrences. Therefore, the identification of prognostic factors may be helpful in the development of new treatment protocols. AIMS： To investigate HER-2/neu status in HCC by immunohistochemistry （IHC） and fluorescence in situ hybridisation （FISH）, and to explore the possibility of using trastuzumab in the treatment of HCC. METH ODS： Eight hundred and sixty eight surgical samples from patients with primary HCC were examined for their HER-2/neu status. IHC for HER-2/neu was performed with the HercepTest kit; FISH analysis was performed with the PathVysion HER-2 DNA probe kit. The correlations between HER-2/neu overexpression and clinicopathological characteristics were analysed statistically. RESULTS： HER-2/neu overexpression was detected in 21 （2.42%） of the 868 primary HCCs. Only one specimen showed HER-2/neu gene amplification by FISH. No significant associations were found between HER-2/neu overexpression and the clinicopathological parameters. CONCLUSIONS： There is a low frequency of HER-2/neu overexpression/amplification in HCC. There appears to be no role for HER-2/neu as a prognostic marker and no benefit of anti-HER-2/neu trastuzumab treatment in patients with HCC.     

The use of enzyme-linked immunosorbent assay for the quantitation of Calloselasma rhodostoma (Malayan pit viper) venom and venom antibodies

The specificity and sensitivity of an indirect and two (an ‘ordinary’ and a ‘rapid’) double sandwich enzyme-linked immunosorbent assay (ELISA) procedures for the quantitation of Calloselasma rhodostoma (Malayan pit viper) venom were examined. The three assays were equally sensitive and the accuracy of the assays was not substantially affected by individual variation in the venom composition. The specificity of the assays was examined against 26 venoms from snakes of the families Viperidae and Elapidae. While the double sandwich ELISA procedures were sufficiently specific to be used in the clinical immunodiagnosis of C. rhodostoma bite in Malaysia, the indirect ELISA procedure exhibited extensive cross-reactivity with other Malaysian pit viper venoms. Attempts were made to improve the specificity of the indirect ELISA procedure for the quantitation of C. rhodostoma venom. A ‘low ELISA cross-reactivity’ venom fraction (termed VF52) was isolated from C. rhodostoma venom by repeated Sephadex G-100 gel filtration chromatography. The indirect ELISA procedure using antibodies to VF52 as immunoreagent showed an improvement in specificity. The use of the indirect ELISA procedure for the detection of C. rhodostoma antibodies was also examined and the results show that the assay was sufficiently specific to be used for retrospective diagnosis of C. rhodostoma bite in Malaysia, in particular when VF52 was used as the coating antigen.     

中西医结合医院单病种的质量管理及其作用

针对中西医结合医院单病种质量评定没有现成的、规范的标准的现状,就中西医结合单病种的质量管理方法及其在中西医结合医院建设中的作用进行了论述。     

Human ovarian granulosa cells and follicular fluid indices: the relationship to oocyte maturity and fertilization in vitro

The study investigates the correlation between oocyte maturity and fertilization and a variety of hormonal parameters in follicular fluid and ovarian granulosa cells. A methodology for purification of granulosa cells from contaminating blood cells is also established. A total of 63 follicular aspirates were collected at oocyte retrieval from 30 women superovulated using the long luteinizing hormone- releasing hormone (LHRH analogue)/human menopausal gonadotrophin regimen. Oestradiol, progesterone, testosterone and human chorionic gonadotrophin (HCG) were quantified in follicular fluid and granulosa cells were immunostained for human chorionic gonadotrophin. Immunopurification of granulosa cells from contaminating blood cells was performed. HCG in follicular fluid was significantly high in follicles yielding immature (grade 3) oocytes (P=0.002); there was no correlation with fertilization. Aspirates from follicles containing mature (grade 1) oocytes and oocytes that subsequently fertilized had significantly more granulosa cells immunobound to HCG (P < 0.001, P=0.02). Moreover, the immunomagnetic purification technique provided >98% pure population of granulosa cells. The data demonstrate that HCG in follicular fluid and on granulosa cells may help to predict oocyte maturity and fertilization. Furthermore, immunomagnetic beads provide a reliable procedure for the purification of ovarian granulosa cells.      

Recombinant VP9-based enzyme-linked immunosorbent assay for detection of immunoglobulin G antibodies to Banna virus (genus Seadornavirus)

Banna virus (BAV, genus Seadornavirus, family Reoviridae) is an arbovirus suspected to be responsible for encephalitis in humans. Two genotypes of this virus are distinguishable: A (Chinese isolate, BAV-Ch) and B (Indonesian isolate, BAV-In6969) which exhibit only 41% amino-acid identity in the sequence of their VP9.The VP7 to VP12 of BAV-Ch and VP9 of BAV-In6969 were expressed in bacteria using pGEX-4T-2 vector. VP9 was chosen to establish an ELISA for BAV, based mainly on two observations: (i). VP9 is a major protein in virus-infected cells and is a capsid protein (ii). among all the proteins expressed, VP9 was obtained in high amount and showed the highest immuno-reactivity to anti-BAV ascitic fluid.The VP9s ELISA was evaluated in three populations: French blood donors and two populations (blood donors and patients with a neurological syndrome) from Malaysia, representing the region where the virus was isolated in the past.The specificity of this ELISA was >98%. In mice injected with live BAV, the assay detected IgG-antibody to BAV infection 21 days post-injection, which was confirmed by Western blot using BAV-infected cells.The VP9 ELISA permits to determine the sero-status of a population without special safety precautions and without any requirements to propagate the BAV. This test should be a useful tool for epidemiological survey of BAV.     

Molecular characterisation of extended-spectrum β-lactamase-producing Escherichia coli and Klebsiella spp. isolates at a tertiary-care centre in Lebanon

The prevalence of bla _CTX-M, bla _TEM and bla _SHV genes among extended-spectrum β-lactamase (ESBL)-producing clinical isolates of Escherichia coli ( n  = 50) and Klebsiella spp. ( n  = 50) from Lebanon was 96%, 57% and 67%, and 40%, 82% and 84%, respectively. Genotyping revealed that the clonal diversity was unrelated to the presence of bla genes. Sequence analysis of 16 selected isolates identified the bla _CTX-M-15, bla _TEM-1, bla _OXA-1 and six bla _SHV genes, as well as the gene encoding the quinolone-modifying enzyme AAC(6')-Ib-cr. The genes encoding CTX-M-15 and AAC(6')-Ib-cr were carried on a 90-kb plasmid of the pC15-1a or pCTX-15 type, which transferred both ESBL production and quinolone resistance from donors to transconjugants.