Biomedical subjects
Publications and source records attributed to S Sia.
The case of a 49-year-old woman with an intermediate-sized choroidal melanoma who was treated with stereotactic radiosurgery with good tumour resolution is presented. Sight and globe preservation were achieved. The treatment technique is discussed.
PURPOSE: To assess the efficacy of iodine-125 (I-125) episcleral plaque therapy in the management of uveal melanoma with regard to local control, survival, globe preservation and visual outcome. METHODS: Between January 1985 and January 1997, 50 patients with the diagnosis of uveal melanoma were treated with I-125 episcleral plaques. The mean initial tumour height was 5.5 mm (range, 2.0-9.5 mm) and basal diameter 9.5 mm (range, 4.0-14.5 mm). I-125 seeds with a mean activity of 1259.1 MBq were used. The mean apical dose was 80.5 Gy (range, 68.0-95.0 Gy). Scleral dose ranged from 225.0 to 940.0 Gy. Pretreatment visual acuity was 6/60 or better in 43 patients. RESULTS: One patient was lost to follow up and excluded from analysis. The remaining 49 patients had a mean follow up of 39.5 months. There were seven local failures, with a mean duration to tumour progression of 16.7 months. All seven patients were successfully managed with enucleation. Five other enucleations were performed for treatment-related complications. At the time of analysis, 10 patients have died, five of metastatic melanoma. Of the patients with preserved globes, corrected visual acuity was 6/60 or better in 31 patients. CONCLUSIONS: Good local tumour control and survival can be achieved with episcleral plaque therapy. Globe preservation with useful vision was possible in the majority of cases. Our findings are in keeping with other reported series.
UNLABELLED: We conducted this prospective study to compare the onset time and the success rate of a multiple-injection axillary brachial plexus block performed by using two methods of nerve localization: paresthesia elicitation or nerve stimulation. Each of the major nerves of the plexus was located by elicitation of a paresthesia (Group PAR; n = 50) or by nerve stimulation (Group PNS; n = 50) and injected with 10 mL of local anesthetic solution. Time to perform the block, onset time of the primary block, time to achieve readiness for surgery, and total anesthetic time were significantly shorter in Group PNS than in Group PAR. The incidence of complete block was larger in Group PNS than in Group PAR (91% vs 76%; P: < 0. 05), and this was related to a larger success rate for anesthetizing the radial and the musculocutaneous nerves (P: < 0.05). The frequency of venous puncture was larger in Group PAR (P: < 0.05). For multiple-injection axillary brachial plexus block, we conclude that nerve stimulation resulted in a greater success rate and a faster onset than paresthesia elicitation, and it should be considered when the radial and musculocutaneous nerve distributions are involved in the surgical area. IMPLICATIONS: Two methods of nerve localization were compared when performing an axillary brachial plexus block by the multiple-injection technique. Nerve stimulation provided a faster onset and a greater incidence of complete block, related to a better success rate for anesthetizing the radial and the musculocutaneous nerves, than paresthesia elicitation.
UNLABELLED: Used as the sole analgesic, clonidine produces analgesia after epidural, intrathecal, and intraarticular administration. We conducted this double-blinded study to determine whether clonidine has analgesic effects when administered into the brachial plexus sheath. At the conclusion of hand or forearm surgery, performed under axillary brachial plexus block, 45 patients were randomly divided into three groups of 15 each to receive, through an axillary catheter, 15 mL of saline (Group Saline), clonidine 150 microg in 15 mL of saline (Group Clonidine), or bupivacaine 15 mL (Group Bupivacaine). The analgesic effects of the three solutions were evaluated for 6 h. Times to onset of pain and to first analgesic request were longer, and the total dose of pain medication was smaller in Group Bupivacaine compared with the other groups. Visual analog scores were significantly lower in Group Bupivacaine. There was no significant difference in time to onset of pain, time to first analgesic request, total dose of pain medication, and visual analog scores between Group Saline and Group Clonidine at any time. We conclude that the administration of clonidine 150 microg into the brachial plexus sheath does not prolong the onset of postoperative pain. IMPLICATIONS: Used as the sole analgesic, clonidine produces analgesia after epidural, intrathecal, and intraarticular administration. It also prolongs the analgesic effect of brachial plexus block when mixed with local anesthetics. In this study, the administration of clonidine 150 microg alone into the brachial plexus sheath did not produce postoperative analgesia.
We have studied the efficacy of i.v. clonidine to prevent shivering in 100 healthy patients who received extradural block for knee arthroscopy. Patients were randomly allocated to two groups. Just before extradural anaesthesia (0 min = baseline), group I (n = 50) received i.v. clonidine 1 microgram kg-1, group II (n = 50) received a saline bolus. Systolic arterial pressure (SAP), heart rate (HR), oxygen saturation (SpO2), cutaneous temperature and level of sedation, were all recorded at baseline and after 10, 20, 30, 45, 60 min. Shivering was evaluated by a blinded investigator for a period of 90 min and was graded as moderate or severe. Three patients in group I shivered compared with 19 in group II (P < 0.001). Patients with severe shivering were seen only in group II. There were no significant differences between the groups during the study period in SAP, HR, SpO2, cutaneous temperature or level of sedation. We conclude that preventive use of i.v. clonidine 1 microgram kg-1 provides a significant reduction in the incidence of post-extradural shivering without clinically relevant adverse side effects.
Several cases have been reported in which symptoms suggestive of transient radicular irritation occurred after the use of lidocaine (lignocaine) for spinal anaesthesia. We report three patients in whom we observed similar symptoms after uneventful spinal anaesthesia using isobaric 2% mepivacaine.
The X-ray crystallographic structure of the recombinant poliovirus 3C gene product (Mahoney strain) has been determined by single isomorphous replacement and non-crystallographic symmetry averaging and refined at 2.1 A resolution. Poliovirus 3C is comprised of two six-stranded antiparallel beta-barrel domains and is structurally similar to the chymotrypsin-like serine proteinases. The shallow active site cleft is located at the junction of the two beta-barrel domains and contains a His40, Glu71, Cys147 catalytic triad. The polypeptide loop preceding Cys147 is flexible and likely undergoes a conformational change upon substrate binding. The specificity pockets for poliovirus 3C are well-defined and modeling studies account for the known substrate specificity of this proteinase. Poliovirus 3C also participates in the formation of the viral replicative initiation complex where it specifically recognizes and binds the RNA stem-loop structure in the 5' non-translated region of its own genome. The RNA recognition site of 3C is located on the opposite side of the molecule in relation to its proteolytic active site and is centered about the conserved KFRDIR sequence of the domain linker. The recognition site is well-defined and also includes residues from the amino and carboxy-terminal helices. The two molecules in the asymmetric unit are related by an approximate 2-fold, non-crystallographic symmetry and form an intermolecular antiparallel beta-sheet at their interface.
The fluorescent labeling of peptides at concentrations as low as 10(-8) M can be achieved by using a solid-phase reactor. Using oxidized insulin chain B as a test peptide, we demonstrate the use of an Immobilon CD membrane to capture and preconcentrate peptides. Insulin chain B can then be labeled with a fluorogenic reagent, 3-(2-furoyl)quinoline-2-carboxaldehyde, while it is still attached to the membrane. Unwanted fluorescent products (attributed to secondary reactions) can be washed away with methanol without significant removal of the labeled insulin chain B, which then can be extracted with a low pH buffer. The analysis by micellar electrokinetic capillary chromatography with post-column laser-induced fluorescence detection (mass limit of detection of 2.4 x 10(-21) moles insulin chain B) results in electropherograms that show great improvement in terms of unwanted peaks and high number of theoretical plates (up to 20 million). The use of the solid-phase reactor allows easy handling of as little as 5 picomoles of insulin chain B.
OBJECTIVE: To determine the incidence of hypoxaemia and the efficacy of oxygen therapy in the early postoperative period. DESIGN: Prospective, randomized study. SETTING: Regional hospital. PATIENTS: 89 patients undergoing general anaesthesia divided into two groups, I (n = 45) and II (n = 44). INTERVENTIONS: Patients of group I breathed room air while patients of group II received supplementary oxygen. MEASUREMENTS AND MAIN RESULTS: Oxygenation was monitored continuously for 60 minutes with a pulse oximeter after the end of surgery; hypoxaemia was graded into four values of SpO2: mild (86-90%), moderate (81-85%), severe (76-80%), extreme (< or = 76%). One or more episodes of mild hypoxaemia were recorded in 68% of patients in group I and in 36% of patients in group II (p < 0.005); moderate hypoxaemia were recorded in 51% of patients in group I compared with 13% of patients in group II (p < 0.001). Episodes of severe or extreme hypoxaemia were recorded in 22% and in 6% of patients in group I; no patients in group II exhibited such small values of saturation. The smallest recorded SpO2 values were 81 +/- 5.94% in group I and 89 +/- 8.63% in group II (p < 0.001). CONCLUSIONS: There is a high incidence of clinically unsuspected hypoxaemia in the early postoperative period, the use of supplemental oxygen reduces but does not prevent hypoxaemic episodes, every patient should be monitored continuously with a pulse oximeter in the recovery room.
BACKGROUND AND OBJECTIVES: The multiple-injection technique for axillary block, in which the 4 distal nerves of the plexus are located by a nerve stimulator and separately injected, has been shown to produce a rapid onset and a high success rate. However, this technique may be more difficult and time consuming than other axillary block methods. A simplified multiple-nerve stimulation technique, in which the ulnar nerve was not located, was compared in the present double-blind study to the 4-injection approach. METHODS: Eighty-four patients were randomly allocated to 2 groups. In group IV, all 4 distal nerves of the plexus were located by a nerve stimulator and injections made. In group III, all the nerves but the ulnar were located and injections made. The block was defined as complete when analgesia was present in all the sensory areas distal to the elbow. RESULTS: The time to perform the block was shorter in group III (5 +/- 2 v 8 +/- 3 minutes; P <.001). Block performance pain was lower in group III patients (8 +/- 2 v 13 +/- 2 mm; P <.001). The onset time (15 +/- 6 v 16 +/- 7 minutes) and the frequency (90% v 92%) of complete block were not different between the groups. CONCLUSIONS: A triple-injection method of axillary block in which the ulnar nerve was not purposely located provides a spread and a latency of sensory block equal to that obtained with a 4-injection technique. A shorter performance time is an advantage of this approach.
BACKGROUND AND OBJECTIVES: The multiple-injection technique for axillary block, in which the main 4 nerves of the plexus are located by a nerve stimulator and separately injected, has been shown to produce a high success rate. However, this technique may prove to be more difficult and time-consuming than other methods. Therefore, a simplified technique, with a reduced number of injections, might be desirable. A comparison between 2- and 3-injection techniques was made in the present double-blind study. METHODS: One hundred patients were randomly allocated to 2 groups. In group 3N, the radial, median, and musculocutaneous nerves were located by a nerve stimulator and injections made. In group 2N, the radial and median nerves were located and injections made. Forty milliliters of local anesthetic was used. RESULTS: A greater success rate for anesthetizing the musculocutaneous nerve was found in group 3N (98% v 80%; P <.005). No differences between the groups were found in the success rate for blocking the radial, median, and ulnar nerves. The rate of complete block (all the sensory areas distal to the elbow) was 90% in group 3N and 76% in group 2N. The time to perform the block was shorter in group 2N (5 +/- 1 v 6 +/- 1 minutes; P <.001). CONCLUSIONS: The 2-injection technique offers a success rate in blocking the 3 nerves innervating the hand similar to that obtained with the 3-injection technique. The latter approach should be considered when the musculocutaneous nerve distribution is involved in the surgical area.
AIM: In this double-blinded, randomized controlled trial, we compared the clinical advantages and disadvantages of patient-controlled-analgesia (PCA) with continuous infusion (CI) with tramadol alone versus a combination of tramadol plus ketorolac in the management of postoperative pain after major abdominal surgery. METHODS: Sixty adult patients were randomly assigned to 2 groups. Group T, was given 10 mg/mL tramadol and Group TK was given 1.50 mg/mL ketorolac plus 5 mg/mL tramadol. After an i.v. loading dose of 0.07 mL/kg, the demand bolus injection was set at 0.2 mL, with a lockout interval of 30 min, and a continuous background i.v. infusion was set at 1.5 mL/h. Data of PCA demand, dose delivered and total analgesic consumption were retrieved from the computer memory bank of PCA device. Visual analogue scale at rest, sedation score and the occurrence of adverse effects were assessed every 3 h for 18 h. RESULTS: No significant differences were found with regard to pain scores and side effects. Patients in Group TK were significantly more alert. CONCLUSIONS: We concluded that the combination of ketorolac plus tramadol in the same PCA device was an effective and safe treatment for postoperative analgesia in abdominal surgery.