Ex vivo intraoperative angiography for rectus abdominis musculocutaneous free flaps

In this study, the vascular architecture of rectus abdominis free flaps nourished by deep inferior epigastric vessels was investigated using an ex vivo intraoperative angiogram. Oblique rectus abdominis free flaps were elevated and isolated from the donor site. In 11 patients, the vascular architecture of these flaps was analyzed before the flap was thinned. Radiographic study identified an average of 2.1 large deep inferior epigastric arterial perforators in each flap. In nine of the 11 flaps, the axial artery was visible. In four flaps, the axial artery originated from the perforator of the lateral branch of the deep inferior epigastric artery; in five others, it originated from the medial branch. In each flap, the angle of the axial perforator from its anterior rectus sheath in the vertical plane was measured; its mean was 50.6 degrees. All flaps survived, although three showed partial necrosis in the distal portions. In two of these three flaps, the axial artery was not visible in the angiograms, and the third revealed a one-sided distribution of axial flap arteries. Using ex vivo intraoperative angiography, the architecture of the individual flap, its axial perforator, and its connecting axial flap vessel could be investigated. This information can help the surgeon safely thin and separate the flap.     

Three new secoiridoid glucosides from Eustoma russellianum

Three new secoiridoid glucosides, eustomoside, eustoside and eustomorusside, have been isolated along with three known glucosides, sweroside, swertiamarin and gentiopicroside, as well as one unknown glycoside from Eustoma russellianum.     

Metronomic chemotherapy with low-dose cyclophosphamide plus gemcitabine can induce anti-tumor T cell immunity in vivo

Several chemotherapeutic drugs have immune-modulating effects. For example, cyclophosphamide (CP) and gemcitabine (GEM) diminish immunosuppression by regulatory T cells (Tregs) and myeloid-derived suppressor cells (MDSCs), respectively. Here, we show that intermittent (metronomic) chemotherapy with low-dose CP plus GEM can induce anti-tumor T cell immunity in CT26 colon carcinoma-bearing mice. Although no significant growth suppression was observed by injections of CP (100 mg/kg) at 8-day intervals or those of CP (50 mg/kg) at 4-day intervals, CP injection (100 mg/kg) increased the frequency of tumor peptide-specific T lymphocytes in draining lymph nodes, which was abolished by two injections of CP (50 mg/kg) at a 4-day interval. Alternatively, injection of GEM (50 mg/kg) was superior to that of GEM (100 mg/kg) in suppressing tumor growth in vivo, despite the smaller dose. When CT26-bearing mice were treated with low-dose (50 mg/kg) CP plus (50 mg/kg) GEM at 8-day intervals, tumor growth was suppressed without impairing T cell function; the effect was mainly T cell dependent. The metronomic combination chemotherapy cured one-third of CT26-bearing mice that acquired tumor-specific T cell immunity. The combination therapy decreased Foxp3 and arginase-1 mRNA levels but increased IFN-γ mRNA expression in tumor tissues. The percentages of tumor-infiltrating CD45⁺ cells, especially Gr-1^high CD11b⁺ MDSCs, were decreased. These results indicate that metronomic chemotherapy with low-dose CP plus GEM is a promising protocol to mitigate totally Treg- and MDSC-mediated immunosuppression and elicit anti-tumor T cell immunity in vivo.     

Preparation of 8-Chloropurine Nucleosides Through the Reaction Between their C-8 Lithiated Species and p-Toluenesulfonyl Chloride

Abstract

Chlorination of purine nucleosides protected with tert-butyldimethylsilyl (TBDMS) group was examined by the reaction of the C-8 lithiated species, generated by LDA, with p-toluenesulfonyl chloride as an electrophile. This provides a new method for the preparation of 8-chloropurine nucleosides.     

Mutation underlying resistance of Plasmodium berghei to atovaquone in the quinone binding domain 2 (Qo(2)) of the cytochrome b gene

The anti-malarial agent atovaquone specifically targets the cytochrome bc₁ complex and inhibits the parasite respiration. Resistance to this drug, a coenzyme Q analogue, is associated with mutations in the mitochondrial cytochrome b gene. We previously reported atovaquone resistant mutations in Plasmodium berghei, in the first quinone binding domain (Qo₁) of the cytochrome b gene (M133I and L144S) with V284F in the sixth transmembrane domain. However, in P. falciparum the most common mutations are found in the Qo₂ region. To obtain a better model for biochemical and genetic studies, we have now extended our study to isolate a wider range of P. berghei resistant strains, in particular those in the Qo₂. Here we report four new mutations (Y268N, Y268C, L271V and K272R), all in the Qo₂ domain. Two of these mutations are convergent to codon 268 (nt802–804) drug-induced mutation in P. falciparum.     

Intravesical treatment of bladder cancer with recombinant human interferon-β

Summary In order to examine its clinical efficacy, recombinant human interferon- (rIFN-) was instilled intravesically into 51 patients with superficial bladder cancer. Ten patients, who received intermittent intravesical instillation at a dose of (3–36) × 10⁶ U rIFN- on days 1–3 every week, showed no response. Thirty-two patients received intravesical instillation at a dose of (3–36) × 10⁶ U every day for 10–20 days. Eight patients showed partial response, indicating an efficacy rate of 25%. Nine patients received divided doses of 18 × 10⁶ U twice a day every day for 10–20 days. Six patients showed partial response, indicating an efficacy rate of 67%. This value was significantly higher than that obtained by administering divided doses. The response to intravesical instillation therapy with rIFN- varies with treatment protocol. Frequent and longer exposure to rIFN- may induce better regression of superficial bladder cancer. Six incidences of side-effects were found in five cases (9.8%): pollakiuria in one, pain on micturition in two, fever in two, and eruption in one case. All of these side-effects were slight and reversible after drug withdrawal. Laboratory tests showed only a few changes with low severity. Thus, rIFN- is potentially a new drug for instillation therapy of superficial bladder cancer, in view of the absence of adverse effects.     

Identification and characterization of ispA, a Shigella flexneri chromosomal gene essential for normal in vivo cell division and intercellular spreading

The virulent phenotype of Shigella requires loci on the chromosome as well as on the large virulence plasmid, and is regulated via a complex web of interactions amongst various chromosomal and large plasmid genes. To further investigate the role of chromosomal loci in virulence, we performed random Tn 10 mutagenesis in Shigella flexneri YSH6000T, and isolated an avirulent mutant (V3404) incapable of spreading throughout an epithelial cell monolayer. Although V3404 initially spread intercellularly at the same rate as the wild-type, it gradually slowed down and ceased spreading as a result of increasing defects in cell division, leading to the formation of long filamentous bacteria lacking septa, trapped within cells. In addition, the mutation affected the ability of V3404 to polymerize actin, a prerequisite for intra- and inter-cellular spreading ability. Sequencing of Tn 10 -flanking DNA revealed that the mutated gene, designated ispA (intracellular septation), was equivalent to a previously sequenced but uncharacterised gene of Escherichia coli located between trp and tonB . Using E. coli sequence data, we cloned the ispA gene from the YSH6000T chromosome and found that it complemented the V3404 mutation. Nucleotide sequencing and in vitro expression experiments revealed that ispA coded for a small (21 kDa), very hydrophobic protein. These results thus show that ispA is an essential virulence gene affecting several functions of the virulence process.