Transient Neurologic Symptoms after Spinal Anesthesia: A Lower Incidence with Prilocaine and Bupivacaine than with Lidocaine

Background: Recent evidence suggests that transient neurologic symptoms (TNSs) frequently follow lidocaine spinal anesthesia but are infrequent with bupivacaine. However, identification of a short-acting local anesthetic to substitute for lidocaine for brief surgical procedures remains an important goal. Prilocaine is an amide local anesthetic with a duration of action similar to that of lidocaine. Accordingly, the present, prospective double-blind study compares prilocaine with lidocaine and bupivacaine with respect to duration of action and relative risk of TNSs.

Methods: Ninety patients classified as American Society of Anesthesiologists physical status I or II who were scheduled for short gynecologic procedures under spinal anesthesia were randomly allocated to receive 2.5 ml 2% lidocaine in 7.5% glucose, 2% prilocaine in 7.5% glucose, or 0.5% bupivacaine in 7.5% glucose. All solutions were provided in blinded vials by the hospital pharmacy. Details of spinal puncture, extension and regression of spinal block, and the times to reach discharge criteria were noted. In the evening of postoperative day 1, patients were evaluated for TNSs by a physician unaware of the drug administered and the details of the anesthetic procedure.

Results: Nine of 30 patients receiving lidocaine experienced TNSs, 1 of 30 patients receiving prilocaine (P = 0.03) had them, and none of 30 patients receiving bupivacaine had TNSs. Times to ambulate and to void were similar after lidocaine and prilocaine (150 vs. 165 min and 238 vs. 253 min, respectively) but prolonged after bupivacaine (200 and 299 min, respectively; P < 0.05).     

Active catabolism of glucocorticoids by 11 beta-hydroxysteroid dehydrogenase in vivo is a necessary requirement for natural resistance to infection with Listeria monocytogenes

The results from the present study demonstrate that the innate defense mechanisms which control the progressive growth of Listeria monocytogenes in normal animals in vivo are dependent upon the active catabolism of endogenous glucocorticoids by the enzyme 11 beta- hydroxysteroid dehydrogenase (11 beta-HSD). When 11 beta-HSD activity was pharmacologically inhibited in vivo, host susceptibility to progressive bacterial disease was markedly increased. Depressed natural resistance following 11 beta-HSD inhibition correlated with changes in the patterns of inducible cytokines by macrophages and T cells. Similar changes were observed when normal adult animals were treated with low doses of dexamethasone prior to experimental infection with Listeria.      

Dorsal cortical regions subserving visually guided saccades in humans: an fMRI study

Neurophysiological studies in non-human primates have identified saccade-related neuronal activity in cortical regions including frontal (FEF), supplementary (SEF) and parietal eye fields. Lesion and neuroimaging studies suggest a generally homologous mapping of the oculomotor system in humans; however, a detailed mapping of the precise anatomical location of these functional regions has not yet been achieved. We investigated dorsal frontal and parietal cortex during a saccade task vs. central fixation in 10 adult subjects using functional magnetic resonance imaging (fMRI). The FEF were restricted to the precentral sulcus, and did not extend anteriorly into Brodmann area 8, which has traditionally been viewed as their location in humans. The SEF were located in cortex along the interhemispheric fissure and extended minimally onto the dorsal cortical surface. Parietal activation was seen in precuneus and along the intraparietal sulcus, extending into both superior and inferior parietal lobules. These findings localize areas in frontal and parietal cortex involved in saccade generation in humans, and indicate significant differences from the macaque monkey in both frontal and parietal cortex. These differences may have functional implications for the roles these areas play in visuomotor processes.      

Reactive perforating collagenosis associated with scabies in a diabetic

Reactive perforating collagenosis (RPC) in adults commonly manifests in patients with diabetes mellitus. Pruritus and consequent induced scratching have been identified as the bases for the evolution of this skin disease. We present the unusual case of a 55-year-old female diabetic with characteristic umbilicated skin lesions and a long history of scabies. Histology from a crusty nodule revealed transepidermal elimination of collagen. Following antiscabietic treatment, two courses of oral doxycycline demonstrated beneficial effects in controlling the perforating skin disorder.     

Induction of LFA-1 on pluripotent CD34+ bone marrow cells does not affect lineage commitment

Leukocyte function associated antigen 1 (LFA-1) is an adhesion molecule indispensable in immune and inflammatory reactions, but its role in hematopoiesis remains obscure. Since LFA-1 is predominantly expressed by leukocytes, it is considered as a marker of late stage stem cell maturation when expressed on CD34+ bone marrow cells, and represents more mature hematopoietic progenitor cells. We observed that freshly isolated CD34+ bone marrow cells express LFA-1, and that the level of expression is highly variable. Interestingly, the expression of LFA-1 specific activation epitope L16 on these cells is low, even after culture. This demonstrates the LFA-1 is not activated, as was confirmed by low adhesion to ICAM-1. Culturing sorted CD34+ LFA-1+ cells in single cell per well assays in medium supplemented with SCF, Epo, IL-3, Il-6, GM-CSF, and G-CSF revealed that they gave rise to dispersed macrophage-like colonies, supporting the notion that CD34+LFA-1+ cells indeed consist of a mature committed cell population. In contrast, sorted CD34+LFA-1- cells had high proliferative potential and developed into large multilineage colonies within 14 days of culture. Unanticipated, in time course experiments we observed that these CD34+LFA-1- cells expressed LFA-1 within 24 hours upon culture. This induction was neither caused by the monoclonal antibody used to tag CD34 cells, nor dependent on growth factors present in the medium. These findings demonstrate that two populations of CD34+LFA-1+ cells can be discriminated: leukocyte lineage committed CD34+ cells in freshly isolated bone marrow cells, and multipotent CD34+ cells that acquired LFA-1 upon in vitro culture. These in vitro findings support the hypothesis that once contacts with bone marrow stroma are lost, LFA- 1 is upregulated by default, due to the lack of negative regulating signals from stromal cells. This might also explain the widely variable expression of LFA-1 as a result of crowding of cells in the bone marrow with subsequent loss of contact with stroma and upregulation of LFA-1, providing those cells with adhesion receptors enabling migration in the periphery.     

Immunohistological and ultrastructural differences between recurrent type I membranoproliferative glomerulonephritis and chronic transplant glomerulopathy

In renal transplant recipients with type I membranoproliferative glomerulonephritis (MPGN), the posttransplantation course can be complicated by a recurrence of the original disease. However, it is well known that a recurrence of type I MPGN and chronic transplant glomerulopathy (CTG) cannot easily be distinguished. It has been suggested that the two entities can be differentiated by using electron microscopy (EM) and immunofluorescence (IF) techniques. However, studies are lacking that compare biopsy specimens from patients with either a recurrence of type I MPGN or CTG. We have studied renal biopsy specimens from 10 patients with CTG and compared the ultrastructural and IF findings with biopsy specimens from 12 patients with a possible recurrence of type I MPGN. All the patients with CTG showed an electron-lucent zone of finely flocculent material in the subendothelial space, whereas all patients with a recurrence of type I MPGN showed subendothelial electron-dense deposits on EM. On IF, all patients with CTG showed Immunoglobulin M (IgM) with greater intensity than C3. For the patients with recurrent type I MPGN, the opposite was true. Eleven specimens showed C3 deposits with greater intensity than IgM, and in one patient, C3 and IgM were found in equal intensity. In conclusion, when IF and EM studies are available, CTG and recurrence of type I MPGN can reliably be distinguished.     

Effects of transforming growth factor beta on the production of prostaglandin E and caseinase activity of unstimulated and interleukin 1-stimulated human articular chondrocytes in culture

Transforming growth factor beta (TGF beta) has previously been shown to have actions on chondrocytes and cartilage both in vitro and in vivo which suggest a role in connective tissue repair. In particular, some of its actions have been shown to be antagonistic to those of interleukin 1 (IL-1). In this study, the effects of TGF beta on prostaglandin E (PGE) production and caseinase activity, in the presence and absence of IL-1, in human articular chondrocytes were investigated. TGF beta 1 and TGF beta 2 were shown to modulate IL-1 beta-stimulated PGE production and caseinase activity. Both TGF beta 1 and beta 2 inhibited IL-1 beta-stimulated PGE production in the absence of serum and augmented it in the presence of serum. TGF beta 1 and TGF beta 2 inhibited IL-1-stimulated caseinase activity with and without serum. In general, the TGF beta s had little or no effect on basal PGE or caseinase levels. TGF beta s may be important modulators of chondrocyte metabolism, their effects on PGE production may depend on cytokine interactions; furthermore, their effects on caseinase activity may help prevent cartilage breakdown.      

Peripheral nerve block at the elbow and wrist

Wrist and elbow blocks are used to provide anaesthesia and analgesiafor hand and forearm surgery. They may be used to supplementa brachial plexus block or to provide perioperative analgesiaafter a regional or a general anaesthetic. Wrist or elbow blocksalone may be used to provide anaesthesia for minor hand procedures;thus, sparing the patient the complications of general anaesthesiaand providing excellent postoperative analgesia with a reducedrequirement for opioid analgesics.¹ Proximal brachial plexusblock is associated with more motor block, but will providepartial or complete tourniquet anaesthesia. Therefore, solereliance on peripheral arm blocks can only be advocated in proceduresthat do not require a tourniquet or last approximately <20min.²