Two new species of the genus Sectonema Thorne, 1930 (Nematoda, Dorylaimida, Aporcelaimidae) from Iran, with new insights into its evolutionary relationships.

Two new species of the genus Sectonema found in northern Iran are characterized, including morphological descriptions and molecular (18S-, 28S-rDNA) analyses. Sectonema tehranense sp. nov. is distinguished by its 7.22 - 8.53 mm long body, lip region offset by constriction and 24 - 31 µm wide with perioral lobes and abundant setae- or cilia-like projections covering the oral field, mural tooth 15.5 - 17 µm long at its ventral side, neck 1091 - 1478 µm long, pharyngeal expansion occupying 61 - 71% of the total neck length, female genital system diovarian, uterus simple and 3.9 - 4.2 times the corresponding body diameter long, transverse vulva (V = 49 - 59), tail short and rounded (44 - 65 µm, c = 99 - 162, c' = 0.6 - 0.8), spicules 111 - 127 µm long, and 7 - 10 spaced ventromedian supplements with hiatus. Sectonema noshahrense sp. nov. displays a 4.07 - 4.73 mm long body, lip region offset by constriction and 23 - 25 µm wide with perioral lobes and abundant setae- or cilia-like projections covering the oral field, odontostyle 14 - 14.5 µm long, neck 722 - 822 µm long, pharyngeal expansion occupying 66 - 68% of the total neck length, female genital system diovarian, uterus simple and 2.4 - 2.7 times the corresponding body diameter long, transverse vulva (V = 54 - 55), tail convex conoid (39 - 47 µm, c = 91 - 111, c' = 0.8 - 0.9), spicules 82 µm long, and seven spaced ventromedian supplements with hiatus. Molecular analyses confirm a maximally supported (Epacrolaimus + Metaporcelaimus + Sectonema) clade and a tentative biogeographical pattern, with sequences of Indolamayan taxa forming a clade separated from those of Palearctic ones. Parallel or convergent evolution processes might be involved in the phylogeny of the species currently classified under Sectonema. This genus is certainly more heterogeneous than previously assumed.

Effect of lidocaine, fentanyl, or dexmedetomidine on minimum infusion rate and cardiorespiratory variables in dogs undergoing ketofol total intravenous anesthesia.

Background: It has been proposed that dose reduction via co-administration of other agents might ameliorate respiratory depression associated with ketofol. Aims: The present study was designed to evaluate the effects of adding lidocaine, fentanyl, or dexmedetomidine on the required dose and cardiorespiratory variables in dogs undergoing total intravenous anesthesia (TIVA) with ketofol. Methods: In phase I, twelve dogs (six per each treatment) were induced and maintained with two out of four anesthetic regimens of (1) ketofol (4 mg/kg and 0.3 mg/kg/min, respectively; KET), (2) ketofol and lidocaine (1.5 mg/kg and 0.25 mg/kg/min, respectively; KLD), (3) ketofol and fentanyl (5 µg/kg and 0.1 µg/kg/min, respectively; KFN), and (4) ketofol and dexmedetomidine (2 µg/kg and 2 mg/kg/h, respectively; KDX) with at least one-week interval. The minimum infusion rate (MIR) of ketofol was determined. In phase II, the other twelve dogs were given the same anesthetic regimens for 60 min with the determined infusion rate of ketofol, and cardiorespiratory variables were recorded. Results: Mean MIR of ketofol for KET, KLD, KFN, and KDX were 0.35, 0.23, 0.15, and 0.08 mg/kg/min, respectively. In phase II, the times of recovery events were shorter in KFN and KDX than KET and KLD. The heart rate was significantly higher than baseline in KET and KLD, which was also significantly lower than KFN and KDX at several time points. In all treatments, respiratory depression was detected. Conclusion: Despite the decrease in the dose of ketofol, none of the added drugs attenuated respiratory depression caused by this agent.