RESUMO
BACKGROUND AND OBJECTIVES: The purposes of this study were to evaluate the onset, quality and duration of sensory and motor blockade between hyperbaric bupivacaine and clonidine combination with bupivacaine alone when administered intrathecally for unilateral spinal anesthesia in below-knee orthopedic surgery, efficacy of clonidine for post-operative analgesia and side-effects of clonidine, if any. METHODS: Sixty ASA I and ASA II patients scheduled for elective surgery with time duration up to 90 min were studied. Patients were randomised in two equal groups by the lottery method. Group A (control group) was given Inj. bupivacaine (hyperbaric) 0.5% - 12.5 mg (2.5 ml) + 0.5 ml of normal saline intrathecally. Group B (clonidine group) was given Inj. bupivacaine (hyperbaric) 0.5% - 12.5 mg (2.5 ml) + 50 mcg clonidine in 0.5 ml volume intrathecally. RESULTS: The mean peak sensory block was earlier in Group B (4.7±1.23 min) as compared with Group A (6.27±1.51 min). The mean peak motor block was earlier in Group B (6.17±1.20 min) as compared with Group A (8.63±1.71 min). The two-segment regression of sensory block was longer in Group B (106.23±9.17 min) as compared with Group A (104.43±17.75 min), which is clinically significant. Requirement of rescue analgesia was considerably prolonged in Group B (450.33±95.10 min) as compared with Group A (220±36.36 min), which was also clinically highly significant. CONCLUSION: Intrathecal clonidine potentiates bupivacaine induced spinal sensory block and, motor block and reduces the analgesic requirement in the early post-operative period in unilateral spinal anesthesia for lower limb below knee surgery.
RESUMO
Characterization of the human antibody (Ab) repertoire in mouse models of the human immune system is essential to establish their relevance in translational studies. Single human B cells were sorted from bone marrow and periphery of humanized NOD/SCID γc(null) (hNSG) mice at 8-10 months post engraftment with human cord blood-derived CD34(+) stem cells. Human IG variable heavy (V(H)) and kappa (V(κ)) genes were amplified, cognate V(H)-V(κ) gene-pairs assembled as single-chain variable fragment-Fc Abs (scFvFcs) and functional studies were performed. Although overall distribution of V(H) genes approximated the normal human Ab repertoire, analysis of the V(H)-third complementarity-determining regions in the mature B-cell subset demonstrated an increase in length and positive charges, suggesting autoimmune characteristics. Additionally, >70% of V(κ) sequences utilized V(κ)4-1, a germline gene associated with autoimmunity. The mature B-cell subset-derived scFvFcs displayed the highest frequency of autoreactivity and polyspecificity, suggesting defects in checkpoint control mechanisms. Furthermore, these scFvFcs demonstrated binding to recombinant HIV envelope corroborating previous observations of poly/autoreactivity in anti-HIVgp140 Abs. These data lend support to the hypothesis that anti-HIV broadly neutralizing antibodies may be derived from auto/polyspecific Abs that escaped immune elimination and that the hNSG mouse could provide a new experimental platform for studying the origin of anti-HIV-neutralizing Ab responses.
