Reepithelialization of experimental scalds effected by topically applied superoxide dismutase: controlled animal studies

Highly reactive metabolites, such as oxygen free radicals, initiate a cascade of inflammatory processes in thermally damaged skin, leading to enhanced tissue loss and delayed wound healing. The extent of tissue necrosis in the zone of stasis is of prognostic significance in the wound healing process. In this study, the effect of oxygen free radical removal by recombinant human-Cu/Zn-superoxide dismutase, given in three different formulations during the inflammatory postburn phase and wound repair, was examined. Recombinant human superoxide dismutase was either injected directly into the lesions, spread as enzyme-containing gel onto the burned tissue, or encapsulated into liposomes consisting of 1,2 dipalmitoy-sn-glycero-3-phosphocholine, cholesterol and stearylamine, suspended into a hydrophilic gel and administered to burned animals immediately after trauma. Controls were treated with plain gel or kept untreated. Edema formation, size of lesions, deepening of necrosis, and reepithelialization were examined. Results indicate that superoxide dismutase treatment resulted in reduced and faster recruitment of edema formation, smaller wound sizes, and minor tissue necrosis compared to the controls, thus resulting in significantly faster reepithelialization after 3 weeks. These animal studies on the efficacy of liposomal oxygen free radical scavenger showed accelerated wound healing in all parameters tested.     

Fast-phase instabilities in normally sighted relatives of congenital nystagmus patients—autosomal dominant and x-chromosome recessive modes of inheritance

Verification of inheritance in congenital nystagmus (CN) is only possible through the identification of more than one affected member in a family, since in a single case there are no accurate clinical differentiations between spontaneous and inherited CN. We performed electronystagmographic examinations (ENG) to search for abnormal involuntary eye movements as a sign of heredity in seemingly unaffected members of CN families.ENG registrations were performed under three test conditions: (1) with the subject fixating a target, (2) with the room lights off and (3) with closed eyes.Fifty normally sighted individuals (group (a) underwent the test procedure to provide a baseline of normality. Five CN families (three dominant, two sex-linked recessive) were tested as group (b). The eye movement recordings were analysed in terms of nystagmus intensity (amplitude x frequency of the involuntary saccade). In every one of the five families, abnormalities in seemingly non-affected members could be demonstrated: in four families, fastphase instabilities, in the fifth family a true (CN) (slowphase instability).All certain gene carriers were diagnosed correctly by the ENG.These findings indicate a method for detecting slightly affected members in dominant pedigrees and female gene carriers in sex-linked mode of transmission.     

Measured attenuation correction methods

Accurate attenuation correction is a prerequisite for the determination of exact local radioactivity concentrations in positron emission tomography. Attenuation correction factors range from 4–5 in brain studies to 50–100 in whole body measurements. This report gives an overview of the different methods of determining the attenuation correction factors by transmission measurements using an external positron emitting source. The long-lived generator nuclide⁶⁸Ge/⁶⁸Ga is commonly used for this purpose. The additional patient dose from the transmission source is usually a small fraction of the dose due to the subsequent emission measurement. Ring-shaped transmission sources as well as rotating point or line sources are employed in modern positron tomographs. By masking a rotating line or point source, random and scattered events in the transmission scans can be effectively suppressed. The problems of measured attenuation correction are discussed: transmission/emission mismatch, random and scattered event contamination, counting statistics, transmission/emission scatter compensation, transmission scan after administration of activity to the patient. By using a double masking technique simultaneous emission and transmission scans become feasible.This article was presented at the 1st EEC workshop on accuracy determination in PET, January 19–20th. 1989 Pisa, Italy (COMAC-BME Concerted Project Characterization and Standardization of PET Instrumentation)     

Decrease of elastic tissue fibres in stem villus blood vessels of the human placenta during IUGR and IUGR with concomitant pre-eclampsia

In a recent study we described an increase of elastic tissue fibres in blood vessel walls of placental stem villi during pre-eclampsia when compared to uncomplicated pregnancies. Furthermore, the thickness of these blood vessel walls was enhanced in pre-eclampsia. Since it is known that elastic tissue fibres increase in systemic hypertension, it may be assumed that the enhancement of elastic tissue fibres in placental stem villi during pre-eclampsia may be induced by the hypertension. To get further insight into this assumption, we examined the amount of elastic tissue fibres in stem villus blood vessels of placentae of pregnancies complicated by intrauterine growth retardation (isolated IUGR, fourteen cases), a disease without hypertension of the mother and such with pre-eclampsia and concomitant IUGR (IUGR+PE, nine cases). Each study group was compared with uncomplicated pregnancies (twenty-six cases). Unfixed cryostat serial sections were processed for conventional orcein staining and for the demonstration of alpha-actin-immunoreactivity. The intensity of orcein staining of stem villus blood vessel walls was evaluated by a semiquantitative score method. Significant lower intensities of orcein staining were calculated for blood vessel walls of placentae of isolated IUGR (P=0.0007) and IUGR+PE (P=0.0039) when compared to uncomplicated pregnancies each. Additionally, the blood vessel wall thickness of stem villi of isolated IUGR (P=0.0081) and IUGR+PE (P=0.0007) was significantly reduced. In comparison to the above mentioned investigation, our results show that, in contrast to isolated pre-eclampsia, elastic tissue fibres are decreased during pregnancies complicated by IUGR, independently of the occurrence of concomitant pre-eclampsia when compared to uncomplicated pregnancies. From our studies it may be considered that the increase of elastic tissue fibres in placentae of patients with isolated pre-eclampsia may be induced by systemic hypertension. Furthermore, our study underline arguments that IUGR may be an independent disease of the fetus.     

Investigations on the biology,epidemiology, pathology and control of<Emphasis Type="Italic"> Tunga penetrans</Emphasis> in Brazil: I. Natural history of tungiasis in man

Tungiasis is an important health problem in poor communities in Brazil and is associated with severe morbidity, particularly in children. The causative agent, the female flea Tunga penetrans, burrows into the skin of its host, where it develops, produces eggs and eventually dies. From the beginning of the penetration to the elimination of the carcass of the ectoparasite by skin repair mechanisms, the whole process takes 4-6 weeks. The present study is based on specimens from 86 patients, for some of whom the exact time of penetration was known. Lesions were photographed, described in detail and biopsied. Biopsies were examined histologically and by means of scanning electron microscopy (SEM). Based on clinical, SEM and histological findings, the "Fortaleza classification" was elaborated. This allows the natural history of tungiasis to be divided into five stages: (1) the penetration phase, (2) the phase of beginning hypertrophy, (3) the white halo phase, (4) the involution phase and (5) residues in the host's skin. Based on morphological and functional criteria, stages 3 and 4 are divided into further substages. The proposed Fortaleza classification can be used for clinical and epidemiological purposes. It allows a more precise diagnosis, enables the assessment of chemotherapeutic approaches and helps to evaluate control measures at the community level.     

Antigen-independent cross-talk between macrophages and CD8+ T cells facilitates their cooperation during target destruction

Inflammatory sites associated with tissue destruction often contain a complex mixture of cells including macrophages as well as CD8+ and CD4+ T cells. Here, we have investigated, using islets of Langerhans as targets, if CD8+ T cells and macrophages can cooperate in tissue destruction. CD8+ T cells obtained from the islet inflammatory lesion of non-obese diabetic mice or cloned islet-specific CD8+ T cells were ineffective in destroying islets on their own. Including increasing numbers of macrophages in co-cultures of islets and islet-derived or cloned CD8+ T cells progressively increased and accelerated islet destruction. Macrophages alone were ineffective. Macrophage-depleted islets were not destroyed by islet-derived CD8+ T cells. For cooperative islet destruction to occur, beta cells, but not macrophages, needed to be able to present antigens to CD8+ T cells. CD8+ T cells triggered NO production by macrophages, while macrophages triggered IFN-gamma production by CD8+ T cells. Each of these factors was partially effective, but not sufficient, for maximal islet destruction. Antibodies specific for ICAM-1 and LFA-1 inhibited both cooperative islet destruction and cross-stimulation of CD8+ T cells and macrophages. The data suggest that if CD8+ T cells become only weakly activated by target cells, they are not able to destroy target tissue on their own. However, such CD8+ T cells and local macrophages may still cross-stimulate each other, which then facilitates target destruction. For this to occur, target cells, but not macrophages, need to present antigen to CD8+ T cells.     

Identification of the Yersinia enterocolitica urease beta subunit as a target antigen for human synovial T lymphocytes in reactive arthritis.

The local T-cell response to bacterial antigens is involved in the pathogenesis of reactive arthritis (ReA). Here, we have identified a 19-kDa antigen of Yersinia enterocolitica O:9 recognized by Yersinia-specific synovial fluid CD4+ T cells in two patients with Yersinia-induced ReA. N-terminal amino acid sequencing of this protein revealed that it was identical to the 19-kDa urease beta subunit of Y. enterocolitica O:9. This protein has previously been shown to be arthritogenic in preimmunized rats after intra-articular injection. Analysis of the T-cell response to this protein showed that it contains several T-cell epitopes, one of which cross-reacts with other enterobacteria not able to induce ReA. This indicates that the arthritogenicity of the 19-kDa antigen is not a property of the 19-kDa protein alone but is dependent on its expression in bacteria able to induce ReA.     

Predominance of Th1-type T cells in synovial fluid of patients with Yersinia-induced reactive arthritis.

The pathogenetic mechanisms underlying the development of reactive arthritis and the functional capacities of synovial T cells specific for Yersinia enterocolitica are still unclear. In this study we have determined the cytokine secretion patterns of 24 CD4+ synovial fluid (SF)-derived T cell clones from 2 patients with Yersinia-induced reactive arthritis, 16 clones specific for different Yersinia antigens and 8 clones as controls. The clones specific for Yersinia antigens predominantly belong to the T helper cell 1 (Th1) subset with production of interferon (IFN)-gamma and interleukin (IL)-2, but no IL-4, whereas SF T cells not reactive with Yersinia antigens produce IL-2, IL-4 and IFN-gamma and thus belonged to the Th0 subset. Moreover, short-term T cell lines established from SF and peripheral blood showed the same pattern. To further analyze the functional relevance of these data we investigated the influence of IFN-gamma and IL-4 on the intracellular killing of Yersinia in a human glioblastoma cell line. Our data show that the Th1 cytokine IFN-gamma promotes intracellular killing of Yersinia, whereas this effect is antagonized by the Th2 cytokine IL-4. Furthermore, the Th2 cytokine IL-10 inhibited the antigen-specific proliferative response and IFN-gamma and IL-2 production by the Th1 cells. These results provide insight into the antibacterial mechanisms at work in reactive arthritis after infection with Yersinia enterocolitica and, for the first time, reveal the cross-regulatory properties of cytokines derived from Th1 and Th2 cells in a human immune response to bacterial antigens.     

Automated extraction of genomic DNA from medically important yeast species and filamentous fungi by using the MagNA Pure LC system

A fully automated assay was established for the extraction of DNA from clinically important fungi by using the MagNA Pure LC instrument. The test was evaluated by DNA isolation from 23 species of yeast and filamentous fungi and by extractions (n = 28) of serially diluted Aspergillus fumigatus conidia (10(5) to 0 CFU/ml). Additionally, DNA from 67 clinical specimens was extracted and compared to the manual protocol. The detection limit of the MagNA Pure LC assay of 10 CFU corresponded to the sensitivity when DNA was extracted manually; in 9 of 28 runs, we could achieve a higher sensitivity of 1 CFU/ml blood, which was found to be significant (p 相似文献