Motor blockade associated with continuous epidural infusion after abdominal hysterectomy: a randomized controlled trial comparing 0.1% ropivacaine-plus-fentanyl versus 0.2% ropivacaine-alone

We compared rates of motor blockade, analgesia, adverse effects and patient satisfaction of 0.1% ropivacaine+fentanyl versus 0.2% ropivacaine-alone in a randomized, controlled trial. Fifty-four women who had undergone abdominal hysterectomy were randomly allocated into two groups to receive an epidural block at L_1–2 or L_2–3: group R received 0.2% ropivacaine-alone and group RF received 0.1% ropivacaine plus 2 μg fentanyl/ml, both at 8 ml/h. Rescue analgesia was provided via a morphine-loaded PCA device. Motor blockade (using a modified Bromage scale), pain intensity (visual analogue scale (VAS)), morphine consumption, level of sensory blockade and adverse effects, were measured at 4, 8 and 21 h after infusion. Patient satisfaction with pain management was assessed at the end of the study. The rates of motor blockade were not different at 8 h after infusion but at 21 h, group RF had significantly less motor blockade than group R. There were no differences in VAS, level of sensory blockade, adverse effects and patient satisfaction. Morphine consumption at each measurement was comparable but the total amount used by group RF was less than group R (12 mg versus 20 mg, P=0.049). Therefore, 0.1% ropivacaine with fentanyl 2 μg/ml appears to offer advantages over 0.2% ropivacaine-alone.     

Genetic diversity and molecular identification of mosquito species in the Anopheles maculatus group using the ITS2 region of rDNA.

The species diversity and genetic structure of mosquitoes belonging to the Anopheles maculatus group in Southeast Asia were investigated using the internal transcribed spacer 2 (ITS2) of ribosomal DNA (rDNA). A molecular phylogeny indicates the presence of at least one hitherto unrecognised species. Mosquitoes of chromosomal form K from eastern Thailand have a unique ITS2 sequence that is 3.7% divergent from the next most closely related taxon (An. sawadwongporni) in the group. In the context of negligible intraspecific variation at ITS2, this suggests that chromosomal form K is most probably a distinct species. Although An. maculatus sensu stricto from northern Thailand and southern Thailand/peninsular Malaysia differ from each other in chromosomal banding pattern and vectorial capacity, no intraspecific variation was observed in the ITS2 sequences of this species over this entire geographic area despite an extensive survey. A PCR-based identification method was developed to distinguish five species of the group (An. maculatus, An. dravidicus, An. pseudowillmori, An. sawadwongporni and chromosomal form K) to assist field-based studies in northwestern Thailand. Sequences from 187 mosquitoes (mostly An. maculatus and An. sawadwongporni) revealed no intraspecific variation in specimens from Thailand, Cambodia, mainland China, Malaysia, Taiwan and Vietnam, suggesting that this identification method will be widely applicable in Southeast Asia. The lack of detectable genetic structure also suggests that populations of these species are either connected by gene flow and/or share a recent common history.     

Significant differences between plasma HIV-1 RNA assays in HIV-1 subtype E infected patients treated with antiretroviral therapy

A total of 72 HIV-1 infected Thai patients treated with didanosine (ddI) or stavudine (d4T) plus ddI at the time of interim analysis were analyzed. Sixty patients (83%) carried subtype E documented by HIV-1 V3 serotyping. HIV-1 RNA levels were measured using three commercial viral load assays. At baseline (n = 57), Quantiplex 2.0 and NucliSens 2.0 showed mean log10 HIV-1 RNA of 0.7 log10 or 5 fold lower than Amplicor 1.5 (mean 4.29 versus 5.0 log10, respectively, p < 0.001). At week 20 of treatment (n = 29), HIV-1 RNA levels were detected in 55.2%, 31%, and 33.5% of subjects tested by Amplicor 1.5, Quantiplex 2.0, and NucliSens 2.0, respectively. In conclusion: plasma HIV-1 RNA analyses showed comparable values with Quantiplex 2.0 and NucliSens 2.0 assays. In contrast, Amplicor 1.5 resulted in approximately 5 folds higher HIV-1 RNA levels and a 25% higher rate of detection of plasma HIV-1 RNA as compared to the other two assays. As the current goal of therapy is to suppress plasma viral load below the detection limit of the assays, the significant differences between the assays may influence antiretroviral efficacy evaluation and management.     

Comparison of hematin-targeting properties of pynacrine,an acridine analog of the benzonaphthyridine antimalarial pyronaridine

The hematin-targeting properties of pynacrine, an acridine analog of the schizontocidal antimalarial drug, pyronaridine, were evaluated to probe the role of the latter's benzonaphthyridine moiety. Pynacrine was as active as pyronaridine in inhibiting glutathione-induced hematin degradation and in enhancing hematin-mediated membrane lysis. It formed a 1:2 complex with hematin but was 50-fold less effective in inhibiting β-hematin formation. However, pynacrine was as potent as pyronaridine in inhibiting intra-erythrocytic Plasmodium falciparum growth in culture, suggesting that it has other off-target(s) effects.     

Cost savings by reagent reduction in flow cytometry-based CD4+ T cell counts: an approach to improve accessibility for HIV management

In Thailand, the cost of antiretrovirals has recently been reduced more than 10 fold. Likewise strategies for a cost reduction in laboratory monitoring are warranted. This study was designed to explore if the most expensive reagent in flow cytometry based CD4+ cell monitoring, the CD4+/CD8+ monoclonal antibodies, can be reduced without a loss of accuracy. Blood samples from 55 HIV seronegative (HIV-) and 76 HIV+ subjects were analyzed for %CD4+ and %CD8+ T cells using a two color monoclonal antibody panel (BD Biosciences, CA, USA) with 3 different amounts of the recommended reagents for staining: 1) standard, 2) half, and 3) one-fourth. A significant Spearman correlation of 0.987 was shown for the % CD4+ T cell test results for one half as well as one-fourth of the recommended amount compared to the standard staining according to the manufacturer's instruction (p < 0.0001). For the % CD8+ T cell test results, the correlation between the standard and the half or one-fourth reduced staining was 0.972 (p < 0.0001). Bland-Altman analysis showed no significant bias between the results from one half or one-fourth of the recommended amount versus the standard. The sensitivity and specificity of the two methods at the CD4+ T cell count cut-off of 200 cells/microl were 93% and 100%; and 96% and 99%, respectively. Our study indicates that a reduction of the reagents to half or one-fourth of the amount recommended by the manufacturer was still able to generate reliable results for CD4+ and CD8+ T cell counts. Such an approach will significantly reduce the cost of CD4+ monitoring for resource limited settings where a flow cytometer is available.     

Dissecting the Akt/mammalian target of rapamycin signaling network: emerging results from the head and neck cancer tissue array initiative.

PURPOSE: As an approach to evaluate the expression pattern and status of activation of signaling pathways in clinical specimens from head and neck squamous cell carcinoma (HNSCC) patients, we established the Head and Neck Cancer Tissue Array Initiative, an international consortium aimed at developing a high-density HNSCC tissue microarray, with a high representation of oral squamous cell carcinoma. EXPERIMENTAL DESIGN: These tissue arrays were constructed by acquiring cylindrical biopsies from multiple individual tumor tissues and transferring them into tissue microarray blocks. From a total of 1,300 cases, 547 cores, including controls, were selected and used to build the array. RESULTS: Emerging information by the use of phosphospecific antibodies detecting the activated state of signaling molecules indicates that the Akt-mammalian target of rapamycin (mTOR) pathway is frequently activated in HNSCC, but independently from the activation of epidermal growth factor receptor or the detection of mutant p53. Indeed, we identified a large group of tissue samples displaying active Akt and mTOR in the absence of epidermal growth factor receptor activation. Furthermore, we have also identified a small subgroup of patients in which the mTOR pathway is activated but not Akt, suggesting the existence of an Akt-independent signaling route stimulating mTOR. CONCLUSIONS: These findings provide important information about the nature of the dysregulated signaling networks in HNSCC and may also provide the rationale for the future development of novel mechanism-based therapies for HNSCC patients.     

Intraspecific hybridization of Anopheles minimus (Diptera: Culicidae) species A and C in Thailand

Hybridization tests of laboratory-raised, isolines of Anopheles minimus, species A and C were conducted by induced copulation. The three isolines were established based on three morphological variants of wild-caught, fully engorged females and two distinct types of metaphase chromosomes. They were An. minimus species A: V form (X1,Y1), M form (X2,Y1); species C: P form (X3,Y2). The results of reciprocal and back crosses indicated that the two morphologically variant forms of species A were genetically compatible, providing viable progeny and completely synaptic salivary gland polytene chromosomes, whereas they were genetically incompatible with species C and/or the P form. Hybrid progeny was only obtained from both forms of species A females x species C males, but asynaptic salivary gland polytene chromosomes on 3L and partial development of ovarian follicles in females were seen. Back crosses of F1 hybrid males with parental species A females provided viable progeny, while back crosses of F1 hybrid females with parental species C males provided progeny of low viability and adult males with abnormal spermatozoa, suggesting the partial reproductive isolation of An. minimus species A and C.