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A Brand

Publications and source records attributed to A Brand.

At least 37 records · Page 2Linked to original sources
PubMed2002

Autoantibodies to human endogenous retrovirus-K are frequently detected in health and disease and react with multiple epitopes.

A number of studies have found increased levels of antibodies to human endogenous retroviruses (HERVs) in autoimmune rheumatic diseases. It is not clear whether this immune response is driven by the HERV itself or by cross-reactions with an exogenous virus or an autoantigen. To address this question, we examined the antibody response to the Env protein of two closely related members of the HERV-K family, HERV-K10 and IDDMK1,222. By immunoblotting of recombinant proteins, antibodies were found in 32-47% of 84 sera from patients with autoimmune rheumatic disease, and 29% of 35 normal controls. Epitope mapping with overlapping 15mers identified multiple reactive peptides on both antigens, with one (GKTCPKEIPKGSKNT) containing immunodominant epitope(s). By ELISA, the median titre of antibody to this peptide was significantly increased in 39 patients with SLE compared to 39 healthy controls and 86 patients with other rheumatic diseases (P < 0.003). We have shown that there is a high frequency of IgG antibodies to HERV-K env sequences in human sera, both in health and autoimmune rheumatic disease, and that the response is to multiple epitopes. This supports the hypothesis that the autoimmune response to HERV-K is antigen-driven and may be an early stage in the chain of events that leads to tolerance breakdown to other autoantigens.

Amino Acid Sequence↗
PubMed2002

Microbial contamination of cord blood stem cells.

BACKGROUND AND OBJECTIVES: After storage, low levels of contaminating bacteria in standard blood components can reach bacteraemic levels, causing severe transfusion-associated sepsis. For cord blood (CB), the significance of low levels of contaminating bacteria and the optimal detection method is unknown and not supported by available guidelines. MATERIALS AND METHODS: Spiking experiments and testing of various subfractions of CB units were used to determine the behaviour of bacteria during centrifugation, freezing and thawing. For routine testing of CB, different volumes were compared for the detection of potential pathogens and micro-organisms of low pathogenicity. RESULTS: Centrifugation, as applied to CB fractionation, does not show concentration of bacteria in any particular fraction and supports the possibility of culture of waste fractions. Dimethylsulphoxide (DMSO) and freezing does not affect the viability of bacteria under the conditions used in this study. Owing to the low contamination level, a large sample volume of 20 ml was more sensitive than a 10-ml sample volume. Eighty five per cent of the isolated strains can be considered to be of low pathogenicity. CONCLUSION: When an optimal waste fraction sample volume of 20 ml was cultured, the contamination rate of CB was found to be approximately 13%, with low levels of < 1 colony-forming unit (CFU)/ml. Such levels of bacteria of low pathogenicity are expected to be of clinical importance only when CB is expanded in vitro for a prolonged period of time.

Bacteria↗
PubMed2002

The band III ligand dipyridamole protects human RBCs during photodynamic treatment while extracellular virus inactivation is not affected.

BACKGROUND: Recently, the potential usefulness of dipyridamole (DIP) in protecting RBCs against the harmful side effects of photodynamic sterilization was demonstrated. In the present study, the use of DIP for selective protection of RBCs was investigated under conditions more relevant for blood bank practice. STUDY DESIGN AND METHODS: WBC-reduced RBC suspensions (30% Hct) were treated with 1,9-dimethylmethylene blue and red light, and the influence of the inclusion of DIP on photohemolysis was assessed as a function of sensitizer concentration, light dose, and storage time. Furthermore, the possible interference of DIP with inactivation of extracellular virus by use of a panel of different viruses (HIV-1, pseudorabies virus [PRV], bovine viral diarrhea virus [BVDV], VSV, encephalomyocarditis, and canine parvovirus) was investigated. RESULTS: In WBC-reduced RBC suspensions (30% Hct), DIP exerted a clear protective effect against photohemolysis. Part of this protection was achieved with concentrations near the dissociation constant for band III binding. Importantly, efficiency of inactivation of extracellular HIV-1, PRV, BVDV, and VSV was not significantly impaired by the inclusion of DIP. Phototreatment conditions, resulting in a 4 to 5 log inactivation of extracellular HIV-1 and PRV, resulted in a high level of hemolysis after 28 days of storage. This long-term hemolysis could be decreased, but not completely prevented, by the inclusion of DIP. CONCLUSION: Photohemolysis in RBC concentrates can be reduced substantially by the application of DIP, while the efficacy of inactivation of HIV-1 and other viruses remains unchanged.

Anion Exchange Protein 1, Erythrocyte↗
PubMed2002

[Predictive genetic testing - change in paradigms for prevention and health care?].

The post-genomic era promises to offer new insights into the nature of disease, its prevention, and treatment. But now that there is a draft code of the human genome, what does this knowledge mean and how might it be applied? How to use genetic information to promote health and prevent disease - the fundamental mission of public health - will be one of the most challenging tasks in future. Assessing the benefits and risks of predictive genetic testing and the efficacy of early interventions as well as exploring complex issues that have emerged (e. g., rapid commercialization of genetic tests, availability of and access to interventions, and potencial discrimination) call for public health leadership.

Forecasting↗
PubMed2001

Investigation of serum response to PMP22, connexin 32 and P(0) in inflammatory neuropathies.

We investigated serological immune responses against three major peripheral nerve myelin constituents in patients with immune-mediated neuropathies. Connexin 32 (Cx32), myelin protein zero (MPZ, P(0)) and peripheral myelin protein 22 (PMP22) were produced in Chinese hamster ovary (CHO)-K1 cells. From a panel of 25 Guillain-Barré syndrome (GBS) and 24 chronic inflammatory demyelinating polyneuropathy (CIDP) patients, only two patients showed reactivity towards Cx32 and P(0).

Animals↗
PubMed2001

Morbidity and mortality in adults with idiopathic thrombocytopenic purpura.

To study outcomes of adults with idiopathic thrombocytopenic purpura (ITP), we performed a follow-up study in a cohort of 152 consecutive patients who were treated according to a well-defined algorithm. Long-term outcomes were determined relative to the response 2 years after diagnosis, because most (93%) patients who ultimately attained platelet counts above 30.0 x 10(9)/L (30 000/microL) did so within this time frame. Complete follow-up for mortality could be studied in 99% of patients and for morbidity in 95% of patients, with a mean of 10.5 years. Within 2 years after diagnosis, 4 patients died, 2 were lost to follow-up, and 12 were reclassified as having secondary immune thrombocytopenia. Of the remaining 134 patients, 114 (85%) had obtained platelet counts above 30.0 x 10(9)/L while all therapies had been discontinued. These patients had a long-term mortality risk equal to the general population. Twelve of 134 patients (9%), all with severe thrombocytopenia, had refractory disease and suffered a mortality risk of 4.2 (95% confidence interval, 1.7-10.0). Bleeding and infection equally contributed to the death of these patients. Another 8 patients (6%) had platelet counts above 30.0 x 10(9)/L while on maintenance therapy. Similar to patients with refractory disease, these latter patients had considerably increased ITP-related hospital admissions, but mortality was only slightly higher than in the general population. In conclusion, most adults with ITP have a good outcome with infrequent hospital admissions and no excess mortality. The absence of gross morbidity and mortality in patients with moderate thrombocytopenia supports clinical practice refraining from further treatment.

Adolescent↗
PubMed2001

Malignant rhabdoid tumor of the vulva: case report and review of the literature with emphasis on clinical management and outcome.

BACKGROUND: Malignant extrarenal rhabdoid tumors (ERTs) of the vulva are rare but aggressive neoplasms. We describe the eighth reported case and the first to have long-term survival despite initial rapid recurrence. CASE: A 40-year-old woman presented with a painless lump on the mons pubis. It was excised and revealed an ERT. One month later, the tumor had regrown. A wide local excision and superficial right groin node dissection was performed. Local recurrence was noted 11 months after the initial excision and was treated by wide excision and radiotherapy. She is without evidence of disease 61 months after initial presentation. CONCLUSION: A review of previously reported cases of ERT reveals that the median survival is 9 months. Local recurrences are common and the appearance of distant metastases is almost invariably rapidly fatal. Chemotherapy and radiotherapy do not appear to be effective in controlling disease. Initial surgical extirpation may offer the best chance of cure.

Adult↗
PubMed2001

Adenosine A(1) and A(3) receptors mediate inhibition of synaptic transmission in rat cortical neurons.

Intracellular recordings were made in rat brain slice preparations containing pyramidal cells of the associative frontal cortex in order to characterize the action of selective adenosine A(1) and A(3) receptor ligands on synaptic neurotransmission. The selective A(1) receptor agonist N(6)-cyclopentyladenosine (CPA) inhibited concentration-dependently the excitatory postsynaptic potentials (PSPs) which were evoked by focal electrical stimulation. The CPA-mediated inhibition was blocked by 1, 3-dipropyl-8-cyclopentylxanthine (DPCPX), a highly A(1) receptor-selective antagonist. The A(3) receptor agonist N(6)-(3-iodobenzyl)-adenosine-5'-N-methylcarboxamide (IB-MECA) inhibited concentration-dependently the evoked PSPs while the A(1) receptors were blocked continuously by DPCPX. Under these conditions, the A(3) receptor antagonist 9-chloro-2-(2-furanyl)-5-[(phenylacetyl)amino]-1,2,4-triazolo[1, 5-c]quinazoline (MRS 1220) did not influence the PSPs but inhibited completely the effect of IB-MECA. The inhibitory effect of IB-MECA was unaffected by DPCPX. CPA additionally inhibited the PSPs when applied after IB-MECA. Pharmacological dissociation of the N-methyl-D-aspartate (NMDA) and non-NMDA receptor components of the PSPs showed that CPA as well as IB-MECA reduced both. We conclude that adenosine A(1) and A(3) receptors are present on cortical pyramidal cells and involved in the inhibition of excitatory neurotransmission. Our results indicate no interplay between the two receptor subtypes. The separate inhibition may become particularly evident in situations where there are high levels of endogenously released adenosine, as seen in hypoxia.

Adenosine↗
PubMed2001

Effect of an adenosine A(1) receptor agonist and a novel pyrimidoindole on membrane properties and neurotransmitter release in rat cortical and hippocampal neurons.

Activation of adenosine A(1) receptors by endogenous adenosine plays a neuroprotective role under various pathophysiological conditions including hypoxia. Intracellular recordings were made in rat pyramidal cells of the somatosensory cortex. Hypoxia (5 min) induced a membrane depolarization and a decrease of input resistance. The A(1) receptor agonist N(6)-cyclopentyladenosine (CPA, 100 microM) reversibly inhibited the hypoxic depolarization. The inhibition was also present after blockade of the A(2A), A(2B) and A(3) receptor subtypes by selective antagonists. CPA had no effect on the hypoxic decrease of input resistance. 1,3-Dipropyl-8-cyclopentylxanthine (DPCPX), a selective A(1) receptor antagonist, which did not alter hypoxic depolarization when given alone abolished the inhibitory effect of CPA. Neither CPA nor DPCPX influenced membrane potential or apparent input resistance under normoxic conditions. The novel pyrimidoindole (R)-9-(1-methylbenzyl)-2-(4'-pyridyl)-9H-pyrimido[4,5-b]indole-4-amine (APPPI, 1 and 10 microM) reversibly diminished hypoxic depolarization but had no significant effect on input resistance. The effect of APPPI at a concentration of 1 microM, but not at 10 microM, was blocked by DPCPX (0.1 microM). CPA (100 microM) inhibited [(3)H]-noradrenaline ([(3)H]-NA) release from rat hippocampal brain slices significantly only in the presence of rauwolscine (0.1 microM), an alpha(2)-adrenoceptor antagonist. APPPI (1 and 10 microM) exhibited an inhibitory effect similar to that observed with CPA. The effects of both CPA and APPPI were antagonized by DPCPX (0.1 microM). The present data suggest that mainly presynaptic mechanisms prevent neurons from hypoxic changes by an inhibition of transmitter release. However, in contrast to CPA, APPPI exhibited additional effects, which require further investigation.

Adenosine↗
PubMed2001

Modulation of the alloimmune response by blood transfusions.

Blood transfusions can induce both immune activation and immunosuppression. The former is expressed by the induction of HLA alloantibodies and T cell activation, while the latter is accompanied by enhanced graft survival in transfused versus non-transfused recipients. The immunological mechanism leading to downregulation of the alloimmune response has not yet been elucidated. Possible explanations include the induction of a Th2 response by non-professional antigen presentation by the transfused blood cells and blockage of alloreactive T cell reactivity by soluble HLA and soluble FasL in the supernatant of blood components. These mechanisms, however, do not explain the observations which have shown that the degree of HLA compatibility between the transfusion donor and patient is a determining factor. Transfusions in which the donor blood shares at least one HLA-DR antigen with the recipient induce tolerance, while fully HLA-DR mismatched transfusions lead to immunization. The importance of HLA-DR sharing suggests a central role for CD4+ regulatory T cells. In this case, indirect recognition of an allopeptide in the context of self-HLA-DR on the transfusion donor by CD4+ T cells of the recipient might be the clue to the induction of tolerance. Recent data from our laboratory in fact show that CD4+ T cells specific for an allopeptide in the context of self HLA-DR are able to downregulate the alloimmune response of autologous T cells. As these regulatory T cells produce IL-10, they may also be involved in the extension of tolerance via their modulatory effect on dendritic cells. It remains to be established whether these regulatory T cells are indeed responsible for the 'blood transfusion effect' in organ transplantation.

Blood Transfusion↗
PubMed2001

Evaluation of preventive technologies in Germany: case studies of mammography, prostate cancer screening, and fetal ultrasound.

OBJECTIVE: In this article, three preventive strategies-mammography screening for breast cancer, PSA screening for prostate cancer, and routine ultrasound in normal pregnancy-are discussed in the context of German health care. METHODS: Epidemiologic data and German studies evaluating different aspects of these preventive measures were identified and analyzed. RESULTS: Only a few studies could be identified that investigate these preventive measures. Despite sufficient evidence, in part derived from a German study, there is not yet a mammography screening program. In contrast, ultrasound in pregnancy is offered routinely, although there are controversies regarding the benefit of this practice. PSA screening is not offered as part of the screening program for prostate cancer. However, PSA tests as well as mammographies are done in large numbers in German ambulatory care-a practice that could be considered wild or opportunistic screening. CONCLUSIONS: These case studies show that preventive programs and practices in Germany are not sufficiently based on sound evidence. The paucity of evaluation activities related to prevention in Germany is probably due to the low threshold to introduce new preventive programs into the German healthcare system in the past.

Adult↗
PubMed2001

Perioperative blood transfusions, with or without allogeneic leucocytes, relate to survival, not to cancer recurrence.

BACKGROUND: Perioperative blood transfusions are reported to be related to cancer recurrence and reduced survival. Different underlying mechanisms have been proposed, and allogeneic leucocytes in transfused blood have been suggested to contribute to this phenomenon. METHODS: Packed red cells without buffy coat (PC group) were compared with filtered, leucoreduced, red cells (LD group) in a randomized trial of 697 patients with colorectal carcinoma. Five-year survival and cancer recurrence rates were determined, with special emphasis on the location of recurrence. RESULTS: The intention-to-treat analysis showed a survival rate of 63.6 per cent in the PC group and 65.3 per cent in the LD group (P = 0.69), with recurrence rates of 27.8 and 27.9 per cent respectively. The observational analysis showed a significant difference in survival between transfused and non-transfused patients (59.6 versus 72.9 per cent; P < 0.001). The difference in cancer recurrence rate between transfused and non-transfused patients was not statistically significant (29.8 versus 24.3 per cent; P = 0.13). Local recurrences were more frequent in transfused than non-transfused patients (11.9 versus 7.6 per cent; P = 0.09). CONCLUSION: Leucocyte depletion of perioperative transfused blood has no effect on long-term survival and/or cancer recurrence. Perioperative blood transfusions are associated with impaired survival, but not with cancer recurrence. The slight increase in local recurrence rate in transfused patients appears to be related to complicated, in particular rectal, surgery.

Blood Transfusion↗