Hepatitis G and C Viruses Respond to Interferon-α with Different Virologic Kinetics

The aim of this work was to specify the timecourse of response to interferon (IFN) of hepatitis Gvirus (HGV) and hepatitis C virus (HCV) in coinfectedindividuals. A group of 33 patients, undergoing 12 months of IFN therapy for chronic hepatitis C,was screened for the presence of both HGV and HCV RNAsto select seven coinfected patients. Spontaneousrecovery from HGV infection was excluded through the detection of antibodies to the envelope-2protein of HGV and HCV isolates were genotyped. Withinthree months of treatment, we found that HGV RNA wastransiently cleared in 6/7 patients, but the rate of long-term favorable response was very low(1/7). In addition, considering the same individualsseparately, it was shown that HGV and HCV responded toIFN with different kinetics in 5/7 patients. Takentogether, these results underscore the importance of thevirological basis of the resistance to IFNtreatment.     

Gemcitabine combined with oxaliplatin is safe and effective in patients with previously untreated advanced pancreatic adenocarcinoma

AIM: The aim of this study was to determine the safety and the efficacy of a gemcitabine/oxaliplatin combination (GEMOX) as first line therapy in patients with metastatic or unresectable locally-advanced pancreatic cancer. PATIENTS AND METHODS: Patients received gemcitabine 1000 mg/m2 as a 10-mg/m2/min infusion on day 1 followed on day 2 by oxaliplatin 100 mg/m2 as a 2-hour infusion, each cycle being given every 2 weeks. All patients had measurable disease and histological diagnosis before inclusion. Patients were treated until progression or for 12 cycles in the absence of progression. Tumor lesions were assessed by computed tomography scan every 4 cycles. RESULTS: Between January 2001 and January 2003, 32 patients were eligible for the study. The objective response rate (OR) was 28.1% with a 12.5% complete response rate (CR). Median progression-free survival and median overall survival were 7 and 9 months, respectively. Median overall survival for patients with metastatic disease and locally-advanced disease were 7 and 25 months, respectively (P < 0.0007). Eleven patients were alive at 1 year (34.4%), six at 2 years (18.8%) and two at 3 years (6%). Fourteen (43.8%) of 32 patients experienced a clinical benefit response. CONCLUSION: These results support the safety, the antitumor activity and the possibility of durable responses of the GEMOX regimen in patients with locally-advanced disease.     

Ursodeoxycholic acid modulates cyclosporin A oral absorption in liver transplant recipients

The aim was to study the ursodeoxycholic acid (UDC) effect on the cyclosporin A (CsA) pharmacokinetics after oral administration of the microemulsion formulation Neoral (CsA-ME) in liver transplant recipients, and test the potential protective effect of this bile acid on liver and renal CsA-ME-induced toxicity. At entry into the study, 12 patients who underwent orthotopic liver transplantation received CsA-ME, for at least 6 months. They then received a cotreatment CsA-ME plus UDC (13.8 mg x kg(-1) x day(-1)) for three months. Blood concentrations of CsA were measured using a monoclonal antibody specific for the parent compound. The kinetic data were analysed by a mathematical model incorporating a time dependent rate coefficient for CsA intestinal absorption, before and after UDC treatment. Changes in serum markers of hepatic and renal injury were assessed. Individual serum bile acids were determined by chromatography. Serum levels of UDC increased from 3 to about 45% of total serum bile acids after UDC treatment. The estimated model parameters indicate that UDC administration modulates CsA intestinal absorption. In the nine non-cholestatic patients, UDC reduced the absorption rate and the bioavailability of CsA without modifying the elimination rate constant of CsA and the CsA pre-drug levels. In contrast, in the three cholestatic patients, the bioavailability tended to be higher and the absorption rate faster when CsA was combined with UDC. UDC significantly decreased elevated gamma-glutamyl transferase and creatinine serum levels and induced some clinical improvements such as disappearance of headaches in four patients. In conclusion, a 3-month UDC treatment modifies CsA intestinal absorption without affecting CsA elimination rate constant. On the other hand, UDC supplementation appears to improve CsA tolerability.     

Results of a prospective phase 2 study combining imatinib mesylate and cytarabine for the treatment of Philadelphia-positive patients with chronic myelogenous leukemia in chronic phase

In chronic myelogenous leukemia (CML) imatinib mesylate has been shown to selectively inhibit the tyrosine kinase domain of the oncogenic bcr-abl fusion protein. Using this agent alone high rates of cytogenetic responses were recorded. However, several mechanisms of resistance have been described. In vitro studies examining the effects of imatinib mesylate plus cytarabine have shown synergistic antiproliferative effects of this combination. Thus, the CML French Group decided to perform a phase 2 trial testing a combination of imatinib mesylate and low-dose cytarabine in 30 previously untreated patients in chronic phase. Treatment was administered on 28-day cycles. Patients were treated continuously with imatinib mesylate orally at a dose of 400 mg daily. Cytarabine was given on days 15 to 28 of each cycle at an initial dose of 20 mg/m2/d via subcutaneous injection. Adverse events were frequently observed with grade 3 or 4 hematologic toxicities and nonhematologic toxicities in 53% (n = 16) and 23% (n = 7) of patients, respectively. The cumulative incidence of complete cytogenetic response (CCR) at 12 months was 83% and at 6 months 100% of the patients achieved complete hematologic response (CHR). We concluded that the combination was safe and promising given the rates of response.     

Inter-laboratory study on standardized MPS libraries: evaluation of performance,concordance, and sensitivity using mixtures and degraded DNA

International Journal of Legal Medicine - We present results from an inter-laboratory massively parallel sequencing (MPS) study in the framework of the SeqForSTRs project to evaluate forensically...     

XerD-mediated FtsK-independent integration of TLC? into the Vibrio cholerae genome

As in most bacteria, topological problems arising from the circularity of the two Vibrio cholerae chromosomes, chrI and chrII, are resolved by the addition of a crossover at a specific site of each chromosome, dif, by two tyrosine recombinases, XerC and XerD. The reaction is under the control of a cell division protein, FtsK, which activates the formation of a Holliday Junction (HJ) intermediate by XerD catalysis that is resolved into product by XerC catalysis. Many plasmids and phages exploit Xer recombination for dimer resolution and for integration, respectively. In all cases so far described, they rely on an alternative recombination pathway in which XerC catalyzes the formation of a HJ independently of FtsK. This is notably the case for CTXϕ, the cholera toxin phage. Here, we show that in contrast, integration of TLCϕ, a toxin-linked cryptic satellite phage that is almost always found integrated at the chrI dif site before CTXϕ, depends on the formation of a HJ by XerD catalysis, which is then resolved by XerC catalysis. The reaction nevertheless escapes the normal cellular control exerted by FtsK on XerD. In addition, we show that the same reaction promotes the excision of TLCϕ, along with any CTXϕ copy present between dif and its left attachment site, providing a plausible mechanism for how chrI CTXϕ copies can be eliminated, as occurred in the second wave of the current cholera pandemic.The causative agent of the epidemic severe diarrheal disease cholera is the Vibrio cholerae bacterium. A major determinant of its pathogenicity, the cholera enterotoxin, is encoded in the genome of the filamentous cholera toxin phage, CTXϕ (1). Like many other V. cholerae filamentous phages, CTXϕ uses a host chromosomally encoded, site-specific recombination (Xer) machinery for lysogenic conversion (2–4). The Xer machinery normally serves to resolve chromosome dimers, which result from homologous recombination events between the two chromatids of circular chromosomes during or after replication. In V. cholerae, as in most bacteria, the Xer machinery consists of two tyrosine recombinases, XerC and XerD. They act at a unique specific chromosomal site, dif, on each of the two circular chromosomes, chrI and chrII, of the bacterium (5). Integrative mobile elements exploiting Xer (IMEXs) carry a dif-like site on their circular genome, attP (3, 4) (Fig. 1A). XerC and XerD promote their integration by catalyzing a recombination event between this site and a cognate chromosomal dif site (3, 4) (Fig. 1A). Based on the structure of their attP site, IMEXs can be grouped into at least three families (3, 4) (Fig. 1B). In all cases, however, a new functional dif site is restored after integration, which permits multiple successive integration events (Fig. 1A). Indeed, most clinical and environmental V. cholerae isolates harbor large IMEX arrays (6, 7).Open in a separate windowFig. 1.Systems that use Xer. (A) Scheme depicting the sequential integration of IMEXs. Triangles represent attP and dif sites, pointing from the XerD binding site to the XerC binding site. Chromosomal DNA (black), TLCϕ DNA (blue), and CTXϕ DNA (magenta) are indicated. Dotted triangles represent nonfunctional CTXϕ sites. (B) Sequence alignment of dif1, attP^CTX, attP^VGJ, attP^TLC, difA, and dif2. Bases differing from dif1 are indicated in color. Bases that do not fit the XerD binding site consensus are indicated in lowercase. XerC (●) and XerD (○) cleavage points are indicated. (C) Xer recombination pathways. XerC (light gray circles), XerD (dark gray circles), dif sites (red and black lines), and attP^CTX and attP^VGJ (magenta and green lines) are indicated. XerC and XerD catalysis-suitable conformations are depicted as horizontal and vertical synapses, respectively. Cleavage points are indicated as in B.IMEX array formation participates in the continuous and rapid dissemination of new cholera toxin variants in at least three ways. First, CTXϕ integration is intrinsically irreversible because the active form of its attP site consists of the stem of a hairpin of its ssDNA genome, which is masked in the host dsDNA genome (8, 9) (Fig. 1 A and B). However, free CTXϕ genome copies can be produced by a process analogous to rolling circle replication after the integration of a second IMEX harboring the same integration/replication machinery, such as the RS1 satellite phage, which permits the production of new CTXϕ viral particles (10). Second, the V. cholerae Gillermo Javier filamentous phage (VGJϕ) belongs to a second category of IMEXs whose attP site permits cycles of integration and excision by Xer recombination (11). VGJϕ excision allows for the formation of hybrid molecules harboring the concatenated genomes of CTXϕ and VGJϕ, provided that VGJϕ integrated before CTXϕ (11). The hybrid molecules can be packaged into VGJϕ particles. VGJϕ particles have a different receptor than CTXϕ, which permits transduction of the cholera toxin genes to cells that do not express the receptor of CTXϕ (11–13). Finally, integration of the toxin-linked cryptic phage (TLCϕ), a satellite phage that defines a third category of IMEXs, seems to be a prerequisite to the toxigenic conversion of many V. cholerae strains (14, 15). IMEXs from this family are found integrated in the genome of many bacteria outside of the Vibrios, including human, animal, and plant pathogens, which sparked considerable interest in the understanding of how they exploit the Xer machinery at the molecular level (3, 4).Xer recombination sites consist of 11-bp XerC and XerD binding arms, separated by an overlap region at the border of which recombination occurs (Fig. 1B). XerC and XerD each promote the exchange of a specific pair of strands (Fig. 1B). Recombination between dif sites is under the control of a cell division protein, FtsK, which restricts it temporally to the time of constriction and spatially to a specific zone within the terminus region of chromosomes (16–19). FtsK triggers the formation of a Holliday junction (HJ) by XerD catalysis, which is converted into product by XerC catalysis after isomerization (20, 21) (Fig. 1C). The intermediate HJ is stable enough to be converted into product by replication when XerC catalysis is impeded (5, 17) (Fig. 1C). The integration of IMEXs of the CTXϕ and VGJϕ families escapes FtsK control. The lack of homology in the overlap regions of their attP sites and the dif sites they target prevents any potential XerD-mediated strand exchange (Fig. 1B). CTXϕ and VGJϕ rely on the exchange of a single pair of strands by XerC catalysis for integration, with the resulting HJ being converted into product by replication (8, 9, 11) (Fig. 1C). In the case of CTXϕ, integration is facilitated by an additional host factor, EndoIII, which impedes futile cycles of XerC catalysis once the pseudo-HJ is formed (22) (Fig. 1C). In contrast, the overlap region of TLCϕ attP, attP^TLC, is fully homologous to the overlaps of dif1 and difA, the two sites in which it was found to be integrated (Fig. 1B). Four integration pathways could thus be considered, depending on whether recombination is initiated by XerC or XerD catalysis, and whether it ends with a second pair of strand exchange or not. In addition, attP^TLC lacks a consensus XerD binding site, which could affect the whole recombination process (Fig. 1B).Here, we show that attP^TLC is a poor XerD binding substrate. Nevertheless, we show that TLCϕ integration is initiated by XerD catalysis and that the resulting HJ is converted into product by XerC catalysis. We further show that TLCϕ integration is independent of FtsK. Finally, we demonstrate that the same reaction can lead to the excision of TLCϕ–CTXϕ arrays, providing a plausible mechanism for how all of the CTXϕ copies integrated on V. cholerae chrI can be eliminated in a single step, as occurred in ancestors of strains from the second wave of the current cholera pandemic (23–25).     

Imatinib induces durable hematologic and cytogenetic responses in patients with accelerated phase chronic myeloid leukemia: results of a phase 2 study

Chronic myelogenous leukemia (CML) is caused by expression of the BCR-ABL tyrosine kinase oncogene, the product of the t(9;22) Philadelphia translocation. Patients with CML in accelerated phase have rapidly progressive disease and are characteristically unresponsive to existing therapies. Imatinib (formerly STI571) is a rationally developed, orally administered inhibitor of the Bcr-Abl kinase. A total of 235 CML patients were enrolled in this study, of whom 181 had a confirmed diagnosis of accelerated phase. Patients were treated with imatinib at 400 or 600 mg/d and were evaluated for hematologic and cytogenetic response, time to progression, survival, and toxicity. Imatinib induced hematologic response in 82% of patients and sustained hematologic responses lasting at least 4 weeks in 69% (complete in 34%). The rate of major cytogenetic response was 24% (complete in 17%). Estimated 12-month progression-free and overall survival rates were 59% and 74%, respectively. Nonhematologic toxicity was usually mild or moderate, and hematologic toxicity was manageable. In comparison to 400 mg, imatinib doses of 600 mg/d led to more cytogenetic responses (28% compared to 16%), longer duration of response (79% compared to 57% at 12 months), time to disease progression (67% compared to 44% at 12 months), and overall survival (78% compared to 65% at 12 months), with no clinically relevant increase in toxicity. Orally administered imatinib is an effective and well-tolerated treatment for patients with CML in accelerated phase. A daily dose of 600 mg is more effective than 400 mg, with similar toxicity.     

Familial Hemiplegic Migraine: A New Case

SYNOPSIS
The definition of familial hemiplegic migraine is still unsettled. We report the case of a young man who has had hemiplegic migraine attacks for ten years. CT of the brain was abnormal with a low density in the temporal lobe, suggesting infarction and probably having no relation to the attacks. There was a clear family history of hemiplegic migraine, possibly with the same type of attack. Ergotamine tartrate seemed to be effective in preventing headache. This case challenges the current clinical definition of familial hemiplegic migraine, in that while the attack pattern was hereditary, the hemiplegia occurred as an aura rather than accompanying and outlasting the headache.