Risk prediction of very early recurrence, death and progression after acute ischaemic stroke.

BACKGROUND AND PURPOSE: Early recurrent strokes lead to extended hospitalization and high number of complications. We investigated three stroke scores, the Essen Stroke Risk Score (ESRS), the ABCD(2) and the Recurrence Risk Estimator at 90 days (RRE-90) for their prognostic value to predict early recurrent stroke, death and progressive stroke. METHODS: Clinical and radiological data from 1727 consecutive patients with ischaemic stroke, being admitted to the stroke unit, were evaluated retrospectively. Predictive value of stroke scores was tested for early recurrence within 7 days, death and progressive stroke expressed as observational risk and area under the receiver operator curve (AUROC). RESULTS: Early recurrent stroke occurred in 56 patients (3.2%), 40 patients (2.3%) died within the first 7 days and 125 patients (7.2%) had a progressive stroke. ESRS was not predictive for early recurrence, death or progressive stroke. ABCD(2) score was predictive for death (P<0.01; χ(2); AUROC, 0.65; 0.58-0.72), and progressive stroke (P<0.001; χ(2); AUROC, 0.70; 0.66-0.74). RRE-90 predicted early recurrent stroke (P<0.001; χ(2); AUROC, 0.65; 0.58-0.73), early death (P<0.001; χ(2); AUROC, 0.72; 0.66-0.78) and progressive stroke (P<0.001; χ(2); AUROC, 0.66; 0.61-0.71). CONCLUSIONS: RRE-90 bears high potential to not only predict early recurrence but also death and progression after ischaemic stroke. ABCD(2) appears to be useful to predict risk of death and progression. These findings have relevant clinical implications for early triage of patients being admitted to stroke units.

Inhibition of HIV-1-specific T-cells and increase of viral load during immunosuppressive treatment in an HIV-1 infected patient with Chlamydia trachomatis induced arthritis.

BACKGROUND: Studies in HIV-1 infected long-term non-progressors could demonstrate a strong HIV-1-specific CTL response, but it is difficult to prove that this strong CTL response actually is the cause of the efficient control of HIV-1 and not the consequence of low HIV-1 replication in these patients. OBJECTIVE: Studies of HIV-1-specific immunity and viral replication in patients undergoing immunosuppressive therapy provide important opportunities to understand the role of HIV-1-specific T-cells. RESULTS: In this report we describe an HLA B27 positive patient with normal CD4 counts and a low viral load of 200 copies/ml without antiretroviral therapy who exhibited a very strong HIV-1-specific CTL response. He had to be treated with steroids, NSAIDS and hydroxchloroquine because of a severe inflammatory reactive arthritis triggered by an acute Chlamydia trachomatis infection. Analysis of HIV-1 specific T-cells by gamma-IFN-ELISPOT revealed a high frequency of HIV-1 gag-specific CTL both in blood and synovial fluid, whereas gag-specific CD4-cells could be detected only in the peripheral blood. Further analysis revealed that the gag-specific T-cells were predominantly targeting the HLA B27-restricted CTL epitope KRWIILGLNK (KK10). Immunosuppressive therapy by prednisone was associated with a moderate increase of HIV-1 viremia and a decrease both in the number and in the gamma-IFN production of KK10-specific CTL indicating that inhibition of CTL function contributed to the increase of viral load. CONCLUSIONS: This study is suggesting that HIV-1 specific CTL play an important role in the control of HIV-1, at least in this patient. Inhibition of CTL function by immunosuppressive therapy with prednisone may enhance viral replication. In addition, we could demonstrate for the first time the migration of HIV-1 specific T-cells into the synovial fluid.

European experience with a novel noninvasive sensor for intra-amniotic or extra-amniotic evaluation of fetal oxygen saturation.

OBJECTIVE: We evaluated the feasibility of a new instrument for continuous fetal pulse oximetry during labor. The measuring sensor can be placed on the fetal back before or after rupture of membranes. METHODS: One hundred adult women who had completed 32 weeks of gestation and had an anticipated duration of labor greater than 30 minutes were included in the study. Patients with premature rupture of membranes for 24 hours or more, low placental localization, placenta previa or abruption, vaginal bleeding, acute infection, polyhydramnios, oligohydramnios, or uterine or congenital abnormalities were excluded. RESULTS: All sensors were placed successfully. The mean continuous recording time was 276 minutes. Peripheral oxygen saturation as measured by pulse oximeter values were obtained during a median of 64.05% of the recording time. No chorioamnionitis or endometritis was noted. CONCLUSION: The new sensor instrumentation was safe for mother and fetus and was well accepted by parents and physicians.

Isotype-switched immunoglobulin genes with a high load of somatic hypermutation and lack of ongoing mutational activity are prevalent in mediastinal B-cell lymphoma.

Primary mediastinal B-cell lymphoma (PMBL) is a subentity of diffuse large B-cell lymphoma with characteristic clinical, histomorphologic, immunophenotypical, and genetic features. Unlike other B-cell lymphomas, PMBL has not yet been the subject of comprehensive molecular studies on the rearranged immunoglobulin (Ig) gene. Such investigations have proved essential to obtaining information about the differentiation stage of the lymphomagenic B cell. In the present study, the clonally rearranged immunoglobulin heavy-chain gene of 13 PMBL cases is analyzed by polymerase chain reaction (PCR) in conjunction with cloning and DNA sequencing. Twelve of 13 rearrangements were potentially functional. All clonally rearranged immunoglobulin genes bore a high load of somatic mutations (average, 13.0%), which appeared to be selected for a functional antibody in the majority of cases. The comparison of cloned PCR products revealed no evidence of ongoing mutation of the immunoglobulin variable gene. By means of reverse-transcriptase PCR, lymphoma-specific immunoglobulin transcripts were detected in 8 of 13 cases, all of which were of the postswitched type, whereas immunoglobulin protein expression was undetectable except for 1 case. A PMBL cell line, MedB-1, generated from an IgG(-) parental tumor, constitutively expressed IgG protein in a subset of cells, which was moderately suppressed by interleukin-4 and up-regulated in the presence of dexamethasone. PMBL is thus characterized by a heavily mutated, class-switched immunoglobulin gene without evidence of ongoing mutational activity. Moreover, our data indirectly suggest that regulation by extrinsic signals contributes to the immunoglobulin-negative phenotype of PMBL.

Core histones and linker histones are imported into the nucleus by different pathways.

Histones are the major structural proteins in eukaryotic chromosomes. This group of small very basic proteins consists of the H1 linker histones and the core histones H2A, H2B, H3 and H4. Despite their small size, the nuclear import of histones occurs by an active transport mechanism and not simply by diffusion. Histones contain several nuclear localisation signals (NLS) that can be subdivided into two different types of signal structures. We have previously shown that H1 histones are transported by a heterodimeric import receptor complex consisting of importin beta and importin 7, and we now describe the receptors required for the import of the core histones. Competition experiments using the in vitro transport assay indicate that the import pathway of the core histones differs from that of the linker histones and of nuclear proteins with classical NLS. In vitro binding assays show that each of the import receptors importin beta, importin 5, importin 7 and transportin, has the capacity to bind to any of the four core histones. Reconstitution experiments with recombinant factors indicate that each of these factors can independently serve as an import receptor for each of the core histones.

Specific recognition of lamivudine-resistant HIV-1 by cytotoxic T lymphocytes.

OBJECTIVE: The reverse transcriptase (RT) M184V mutation within the HLA-A2-restricted HIV-1 cytotoxic T lymphocyte (CTL) epitope VL9 (VIYQYMDDL; RT 179-187) not only induces drug escape against lamivudine but also abolished recognition by a CTL clone derived from a long-term non-progressor. To test whether the variant VL9 epitope containing the M184V mutation represents a new CTL epitope, we studied recognition of this epitope in a cohort of HLA-A2-positive HIV-1-infected patients. METHODS: Peripheral blood mononuclear cells isolated from 28 HIV-1-infected patients were stimulated with the peptide VIYQYVDDL, containing the M1 84V mutation. Outgrowing cell lines were tested for specific recognition in a standard chromium-release assay. RESULTS: In one subject, a CTL line could be isolated recognizing the peptide VIYQYVDDL in conjunction with HLA-A2. The CTL clone also recognized the M1841 mutation, but it failed to recognize the wild-type epitope VIYQYMDDL. CONCLUSION: CTL can specifically recognize lamivudine-resistant HIV-1 variants. Therefore, the cellular immune response could have an important influence on the control of drug-resistant virus. Furthermore, this demonstrates that the immune system can generate new CTL specificities even in patients with advanced disease, as the M184V HIV variants emerges only after drug treatment. Specific immunotherapy against this epitope might be helpful in delaying or preventing lamivudine resistance.

Mitochondrial Hsp70 cannot replace BiP in driving protein translocation into the yeast endoplasmic reticulum.

To determine whether mitochondrial hsp70 (mHsp70) could substitute for the endoplasmic retuculum (ER) Hsp70 (BiP) during protein translocation, we assembled ER-derived reconstituted proteoliposomes supplemented with either protein. We found that only BiP restored translocation in kar2 mutant vesicles and stimulated translocation approximately 3-fold in wild type proteoliposomes. mHsp70 associated poorly with both a BiP binding (DnaJ) domain of Sec63p and an ER precursor, and its ATPase activity was poorly enhanced upon incubation with the DnaJ domain. In contrast, BiP bound to the Sec63p-DnaJ domain in an ATP-dependent manner and its ATPase activity was stimulated significantly by this polypeptide. We conclude that mHsp70 is unable to support protein translocation into the ER because it fails to associate productively with Sec63p and a precursor.