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Biomedical subjects

A Ng

Publications and source records attributed to A Ng.

At least 37 records · Page 2Linked to original sources
PubMed2003

Analgesic effects of parecoxib following total abdominal hysterectomy.

BACKGROUND: Forty-eight ASA I-II patients undergoing total abdominal hysterectomy (TAH) were studied in a double blind, randomized placebo controlled trial of parecoxib for postoperative analgesia. METHODS: All patients were given propofol 2-4 mg kg(-1) i.v., a non-depolarizing muscle relaxant, morphine 10 mg i.v. and prochlorperazine 12.5 mg i.m. intraoperatively. Their lungs were ventilated with nitrous oxide and isoflurane 1-1.5% in oxygen. Morphine was self-administered for postoperative analgesia via a patient controlled analgesia (PCA) device. Patients were allocated randomly to receive either parecoxib 40 mg i.v. or normal saline on induction of anaesthesia. RESULTS: Twelve patients did not complete the study. Of the remaining 36 patients, there was no significant difference between the treatment groups in age, weight, ASA status, duration of surgery, or intraoperative dose of morphine. However, mean (95% CI) 24 h morphine consumption of 54 (42-65) mg in the parecoxib group was significantly (P=0.04) lower than that of 72 (58-86) mg in the placebo group. Pain intensity scores on sitting up were significantly lower (P=0.02) in the parecoxib group compared with placebo. There was no significant difference between the treatment groups in pain intensity scores at rest and on deep inspiration, or in nausea, total number of vomiting episodes, median number of rescue antiemetic doses, and sedation scores. CONCLUSIONS: Parecoxib 40 mg i.v. may be recommended in patients having TAH as it provides morphine-sparing analgesia.

Adult↗
PubMed2003

Upper gastrointestinal endoscopy performed by nurses: scope for the future?

BACKGROUND: Previous researchers have shown that non-medical endoscopists can perform lower gastrointestinal endoscopy as safely and effectively as medical staff. However, it is not known if upper gastrointestinal endoscopy performed by medical and non-medical endoscopists in clinical practice yields similar results in terms of performance, patient discomfort, and satisfaction. AIM: To determine differences in the yield of diagnosis for significant disease during upper gastrointestinal endoscopy performed by nurse and medical endoscopists and to measure patient discomfort, satisfaction, and attitudes towards future endoscopy. PATIENTS: This two part study included 3009 patients in a retrospective analysis and 480 in a prospective study. METHODS: The first part of the study assessed indications for endoscopy, diagnoses, and procedures performed by medical and nurse endoscopists. In a second prospective study, 480 patients were included to determine the association between endoscopist type and sedation, patient anxiety, discomfort, satisfaction, and attitudes towards future sedation. RESULTS: No patient refused endoscopy by either a nurse or medical endoscopist and there were no complications in either group. Nurses performed 1487 procedures and reported fewer endoscopies as "normal" than medical staff (p=0.006). Multivariate analysis showed that male sex, older age, inpatient status, dysphagia, and gastrointestinal bleeding, but not endoscopist type, were all associated with significant disease. In relation to discomfort and satisfaction, a similar proportion of patients received sedation in both groups (p=0.81). There were no differences in pre-procedure anxiety (p=0.61), discomfort during intubation (p=0.97), discomfort during examination (p=0.90), or post-procedure examination rating (p=0.79) in patients examined by medical or nurse endoscopists. CONCLUSION: Experienced nurses perform routine diagnostic gastroscopy safely in everyday clinical practice and with as little discomfort and as much patient satisfaction as medical staff.

Age Factors↗
PubMed2003

Gastric reflux and pulmonary aspiration in anaesthesia.

Although aspiration is a relatively rare event during anaesthesia, it represent an important cause of anaesthesia related mortality and also of ventilator associated pneumonia in intensive care unit. The incidence of aspiration is markedly increased after trauma owing to the risk of recent ingestion of food, depression of consciousness and airways reflexes, and gastric stasis induced by raised sympathoadrenal tone. The factors which contribute to the likelihood of aspiration include the urgency of surgery, airways problems, inadequate depth of anaesthetic, use of the lithotomy position, gastrointestinal problems, depressed consciousness, increased severity of illness and obesity. Factors that predispose to aspiration pneumonia are: a gastric content with a pH less than 2.5 and a gastric volume of 0.4 ml kg-1; a reduction in lower oesophageal sphincter tone; a reduction of upper oesophageal sphincter tone and a not coordination between the pharyngeal muscle and the upper oesophageal sphincter tone during swallowing; and a depression of protective airway reflexes. Methods to minimize regurgitation and aspiration involve control of gastric contents (preoperative starvation is the method universal accepted), application of cricoid pressure and control of the airways.

Anesthesia↗
PubMed2003

Cloning and expression of pinB gene from Triticum monococum seeds.

Puroindolines (PIN) are low molecular weight, cysteine-rich, endosperm-specific, basic proteins with a unique tryptophan-rich domain found in wheat (Triticum aestivum L.) and barley (Hordeum vulgare L.) as well as other members of Triticaceae. PINs appear to be involved in both flour softness as well as resistance against fungal diseases. These proteins are known to be the major components of 'friabilin' associated with the surface of water washed starch grains and possess lipid binding properties. Structural characterization of puroindolines from Triticum monococum was initiated by amplifying and subsequently cloning the corresponding pin gene into an expression vector, known as pET-32a(+). The protein contains five tryptophanin domains and ten cysteine residues. The pinB gene was fused with the 109aa Trx.Tag thioredoxin for a high-level expression. The cloning sites used for producing fusion proteins also contained cleavable His.Tag and S.tag sequences for detection and purification. After transformation of competent Origami cells, fusion protein expression was detected by growing a transformant in LB medium in the presence of 0.1 mM IPTG at room temperature for 6 hrs on a shaker. Both soluble and insoluble fusion proteins were extracted from Origami cells after sonication. Ni-NTA column (Qiagen) was used to extract and purify these fractions. Following an overnight digestion of the recombinant protein with enterokinase at room temperature, the corresponding fractions were electrophoresed in polyacrylamide gel, electroblotted onto a nitrocellulose membrane and cross-reacted with the anti-friabilin monoclonal antibody. We found that the recombinant PINB protein had a molecular weight of 16 kDa whereas TrxB was 21 kDa. Fusion protein ran at 34 kDa. PINB protein from wheat was shown to be immunologically related to a homologue, tryptophanin, in oat seed. Further study is currently underway to characterize these proteins structurally using NMR.

Cloning, Molecular↗
PubMed2002

The impact of lower leg compartment syndrome on health related quality of life.

Although the aetiology, pathophysiology and treatment of acute compartment syndrome have been well described in the literature, there is limited information on the long-term impact of compartment syndrome on quality of life. We reviewed the medical records and radiographs of all the patients treated with surgical decompression of compartment syndrome. Between 1993 and 1998, 42 cases were identified. There were 30 cases of tibial compartment syndrome and 12 cases involving other limbs. These 30 patients were recalled for a follow-up assessment during which they were asked to complete an EQ-5D (EuroQol), a standardised measure of health related quality of life based on five dimensions (self-care, pain/discomfort, mobility, usual activities and anxiety/depression). Patients were compared with EQ-5D age/sex norms derived from a randomly selected group of patients that had sustained isolated closed tibial shaft fractures. The minimum follow-up time was 12 months. Patients who stated that the appearance of the surgical site was a problem, reported significantly poorer health related quality of life than did patients who had no problem with the appearance. Patients with skin graft reported more problems with pain and discomfort than patients without skin graft. Patients with faster closure times of the wound showed significantly better self-rated health status than patients in whom the wound closure time was longer. Although the patients in this study reported significantly more problems on the dimensions of EQ-5D than were reported in the control group, their overall self-rated health was not statistically different. This study has demonstrated that compartment syndrome may be associated with long-term impact on health related quality of life.

Adult↗
PubMed2002

Randomized controlled trial investigating the effect of transcervical papaverine and bupivacaine on postoperative analgesia following laparoscopic sterilization.

BACKGROUND AND OBJECTIVE: A critical factor that delays patient discharge following day-surgery is severe postoperative pain and the requirement for strong analgesics. Laparoscopic sterilization is a day case procedure and is associated with additional postoperative pain compared with diagnostic laparoscopy. This pain, associated with application of Filshie clips, may be ischaemic or spasmodic in aetiology. Papaverine relaxes smooth muscle, and the aim of the study was to investigate if papaverine would be effective in improving postoperative pain if administered directly to the Fallopian tubes. Bupivacaine is used commonly in day-surgery and so we compared the effect of this local anaesthetic with saline placebo. METHODS: Sixty-six ASA I-II females undergoing laparoscopic sterilization were entered into the prospective, randomized, double-blind, placebo-controlled clinical trial. They received intrauterine papaverine (30 mg) or bupivacaine (0.375% 30 mL) or normal saline (30 mL) via the transcervical route before application of Filshie clips. RESULTS: There were no significant differences in the postoperative period between the three groups in the number of patients needing analgesia in the first 60 min postoperatively, the time to first analgesia, the rescue analgesic or antiemetic consumption, the incidence of postoperative nausea and vomiting, and the sedation and visual analogue pain scores. CONCLUSIONS: From the data presented, we would not recommend routine transcervical administration of papaverine or bupivacaine for pain following laparoscopic sterilization.

Administration, Topical↗
PubMed2002

Does the opioid-sparing effect of rectal diclofenac following total abdominal hysterectomy benefit the patient?

BACKGROUND: The aim of this prospective, double-blind, randomized, placebo-controlled clinical trial was to investigate the opioid-sparing effects of rectal diclofenac following total abdominal hysterectomy. METHODS: Forty ASA I-II patients, aged 20-60 yr, were randomized to receive identical-looking suppositories of either diclofenac 75 mg or placebo, twice daily. All patients were given a standardized anaesthetic, with intravenous morphine via a patient-controlled analgesia device and either diclofenac or placebo for postoperative analgesia. RESULTS: The median 24 h morphine consumption (interquartile range) was significantly higher (P=0.02) in the placebo group [59 (45-85) mg] than in the diclofenac group [31 (14-65) mg]. In comparison with the placebo group, there were significant reductions in total pain score in the diclofenac group at rest (P=0.04) and on movement (P<0.01). Total (SD) sedation score was significantly lower (P=0.04) in the diclofenac group [90 (73) mm] than in the placebo group [148 (89) mm]. Total (interquartile range) nausea score was significantly lower (P<0.01) in the diclofenac group [14 (0-53) mm] than in the placebo group [64 (30-109) mm]. There was no significant difference between the two groups of patients in episodes of vomiting or number of rescue antiemetics. CONCLUSIONS: Rectal diclofenac reduces morphine consumption, improves postoperative analgesia, and reduces the incidence of adverse effects such as sedation and nausea.

Administration, Rectal↗
PubMed2002

The analgesic effects of intraperitoneal and incisional bupivacaine with epinephrine after total abdominal hysterectomy.

UNLABELLED: The objective of our study was to see if incisional and intraperitoneal bupivacaine with epinephrine produces analgesia after total abdominal hysterectomy. Forty-six ASA physical status I and II patients received a standardized anesthetic, patient-controlled analgesia (PCA) morphine, and rectal paracetamol 1 g every 6 h. Patients were randomized to receive 50 mL of bupivacaine 0.25% with epinephrine 5 microg/mL or 50 mL of normal saline. Thirty milliliters and 20 mL of treatment solution were administered into the peritoneum and incision, respectively, before wound closure. Seventeen and 16 patients in the Placebo and Bupivacaine groups, respectively, completed the study. The reasons for withdrawal were PCA malfunction, PCA discontinued too early, nausea, chest infection, intraabdominal drain insertion, and protocol violation. There were no significant differences between the Bupivacaine and Placebo groups in age, height, weight, or duration of surgery. Pain on movement was significantly more intense in the Placebo group than in the Bupivacaine group on awakening. Morphine consumption (interquartile range) over 24 h was 62 mg (53-85 mg) in the Placebo group compared with 44 mg (33-56 mg) in the Bupivacaine group (P < 0.01). This significant difference was attributable to the larger morphine consumption in the Placebo group in the first 4 postoperative h. We conclude that a combination of intraperitoneal and incisional bupivacaine with epinephrine provides significant morphine-sparing analgesia for 4 h after total abdominal hysterectomy. IMPLICATIONS: A combination of intraperitoneal and incisional bupivacaine with epinephrine may be recommended because it provides significant morphine-sparing analgesia for 4 h after total abdominal hysterectomy.

Adult↗
PubMed2001

Temperature measurements of shock compressed liquid deuterium up to 230 GPa.

Pyrometric measurements of single-shock-compressed liquid deuterium reveal that shock front temperatures T increase from 0.47 to 4.4 eV as the pressure P increases from 31 to 230 GPa. Where deuterium becomes both conducting and highly compressible, 30< or =P< or =50 GPa, T is lower than most models predict and T< 50 Gpa, where the optical reflectivity is saturated, there is an increase in the rate that T increases with P.

Journal Article↗
PubMed2001

Molecular interactions of the Gbeta binding domain of the Ste20p/PAK family of protein kinases. An isolated but fully functional Gbeta binding domain from Ste20p is only partially folded as shown by heteronuclear NMR spectroscopy.

The transmission of the mating signal of the budding yeast Saccharomyces cerevisiae requires Ste20p, a member of the serine/threonine protein kinases of the Ste20p/PAK family, to link the Gbeta subunit of the heterotrimeric G protein to the mitogen-activated protein kinase cascades. The binding site of Ste20p to the Gbeta subunit was mapped to a consensus sequence of SSLphiPLI/VXphiphibeta (X for any residue; phi for A, I, L, S or T; beta for basic residues), which was shown to be a novel Gbeta binding (GBB) motif present only in the noncatalytic C-terminal domains of the Ste20p/PAK family of protein kinases (Leeuw, T., Wu, C., Schrag, J. D., Whiteway, M., Thomas, D. Y., and Leberer, E. (1998) Nature 391, 191-195; Leberer, E., Dignard, D., Thomas, D. Y., and Leeuw, T. (2000) Biol. Chem. 381, 427-431). Here, we report the results of an NMR study on two GBB motif peptides and the entire C-terminal domain derived from Ste20p. The NMR data show that the two peptide fragments are not uniquely structured in aqueous solution, but in the presence of 40% trifluoroethanol, the longer 37-residue peptide exhibited two well defined, but flexibly linked helical structure elements. Heteronuclear NMR data indicate that the fully functional 86-residue C-terminal domain of Ste20p is again unfolded in aqueous solution but has helical secondary structure preferences similar to those of the two peptide fragments. The NMR results on the two GBB peptides and the entire GBB domain all indicate that the two important binding residues, Ser(879) and Ser(880), are located at the junction between two helical segments. These experimental observations with the prototype GBB domain of a novel family of Gbeta-controlled effectors may have important implications in understanding the molecular mechanisms of the signal transduction from the heterotrimeric G protein to the mitogen-activated protein kinase cascade.

Electrophoresis, Polyacrylamide Gel↗
PubMed2001

Identification of vaccine candidate antigens from a genomic analysis of Porphyromonas gingivalis.

Porphyromonas gingivalis is a key periodontal pathogen which has been implicated in the etiology of chronic adult periodontitis. Our aim was to develop a protein based vaccine for the prevention and or treatment of this disease. We used a whole genome sequencing approach to identify potential vaccine candidates. From a genomic sequence, we selected 120 genes using a series of bioinformatics methods. The selected genes were cloned for expression in Escherichia coli and screened with P. gingivalis antisera before purification and testing in an animal model. Two of these recombinant proteins (PG32 and PG33) demonstrated significant protection in the animal model, while a number were reactive with various antisera. This process allows the rapid identification of vaccine candidates from genomic data.

Amino Acid Sequence↗
PubMed2001

Gastroesophageal reflux and aspiration of gastric contents in anesthetic practice.

General anesthesia may predispose patients to aspiration of gastroesophageal contents because of depression of protective reflexes during loss of consciousness. In addition, some patients may be at increased risk of pulmonary aspiration because of retention of gastric contents caused by pain, inadequate starvation, or gastrointestinal pathology resulting in reduced gastric emptying and gastroesophageal reflux. Despite increasing knowledge of the problems associated with aspiration, the relatively small incidence and associated mortality rates in the perioperative period do not appear to have changed markedly over the last few decades. In this review article, the physiological factors associated with an increased risk of gastroesophageal reflux and aspiration are considered together with some of the methods that are used to prevent aspiration. In particular, preoperative starvation, the use of drugs designed to increase gastric pH, recent developments in airway devices, and appropriate application of cricoid pressure are critically appraised.

Anesthesia↗
PubMed2001

Does choosing the "worse" ear for cochlear implantation affect outcome?

OBJECTIVE: To determine whether choosing the "better" ear or the "worse" ear for cochlear implantation impacts performance outcome. DESIGN: Retrospective cohort study. SETTING: University teaching hospital-cochlear implant program. METHODS: Two groups of cochlear implantees were selected and matched based on clinical parameters, including duration of deafness/age at implantation, implant types, and processing strategies. Nineteen patients received an implant in his or her "better" ear of the two that had been amplified. An equal number of patients received an implant in the "worse" ear--an ear that was not amplified or was chosen to avoid causing oscillopsia; or if the patient was not willing to relinquish his or her hearing aid in the "better" ear based on subjective or objective criteria. Standard speech perception testing was performed. RESULTS: The average open-set speech perception responses at 1 year after implantation were as follows: word recognition score 40.4% and sentence recognition score 81% in the aided subjects (better ears); word recognition score 41.5% and sentence recognition score 84.5% in the unaided group (worse ears). CONCLUSION: No differences were found between the two groups of implantees. Choosing the "worse" ear for implantation did not appear to have a negative impact on performance outcome in this match-paired study.

Adolescent↗
PubMed2001

Atypical presentation of plantar fasciitis secondary to soft-tissue mass infiltration.

This article describes a patient with plantar fascial pain who presented to the office of one of the authors. Physical examination and the patient's description of the history of symptoms revealed classic signs and symptoms of plantar fasciitis. The patient was treated with numerous conservative modalities, including ultrasound, nonsteroidal anti-inflammatory medications, trigger-point injections, over-the-counter orthoses, and stretching exercises. When the pain was not relieved by these conservative measures, magnetic resonance imaging of the area was performed. Visualization of the insertional area of the plantar fascia revealed a mass inferior to, as well as infiltrated into, the plantar fascia. Surgical excision of the lesion resulted in complete elimination of the patient's pain.

Aged↗
PubMed2001

Posttraumatic ankle arthrosis.

Until there is a total ankle implant developed that stands the test of time, ankle arthrodesis will continue to be the gold standard in the operative treatment of the arthritic ankle joint. Ankle arthrodesis techniques include minimally invasive methods that can be performed via arthroscopy or with miniarthrotomy. Extensile techniques include extra-articular fusions, the transfibular approach, removal of both malleoli, and the Blair fusion. An ankle arthrodesis can be fixated utilizing either internal or external fixation. The form of fixation chosen depends on availability and surgeon preference and/or experience, and most importantly, which is the optimal method for the patient. Although ankle arthrodesis is the mainstay treatment for posttraumatic arthrosis, innovations and technical improvements have resulted in reconstructive alternatives for ankle arthritis, including distraction ankle arthroplasty, supramalleolar osteotomy, and total ankle replacement. Advances in biomaterials and instrumentation have allowed for the evolution of arthrodesis techniques as evidenced by the myriad of techniques reported in the literature.

Ankle Injuries↗
PubMed2000

Identification of a thrombin-binding region in the sixth epidermal growth factor-like repeat of human thrombomodulin.

The interaction of thrombin with a 28-residue peptide corresponding to the N-terminal subdomain of the sixth EGF-like repeat of human thrombomodulin plus the junction between the fifth and the sixth EGF-like domains was characterized in solution by use of NMR spectroscopy, particularly differential resonance perturbations and transferred nuclear Overhauser effects (transferred NOEs). The EGF-like thrombomodulin fragment, or hTM422-449, is conformationally flexible in the absence of thrombin. Upon addition of thrombin, differential resonance perturbations and transferred NOEs are observed for the thrombomodulin peptide, suggesting specific and rapidly reversible binding and structuring of hTM422-449 in complex with thrombin. Residue-specific analysis of the differential line broadening, resonance shifts, and transferred NOEs identified regions of hTM422-449 responding to thrombin binding as the N-terminal residues Thr422-Ile424 and residues His438-Ile447 corresponding to the central beta-hairpin, or B-loop, of the consensus EGF-like repeat. The formation of the beta-hairpin is supported by the pattern of transferred NOEs bringing the two beta-strands together and characterizing a type I beta-turn. Docking of the thrombomodulin peptide to the anion-binding exosite I of thrombin revealed structural details capturing binding contacts identified so far as essential for the thrombin-thrombomodulin interaction. Definition of specific interactions between thrombin and a minimal fragment of the sixth EGF-like domain of human TM may lead to the discovery of new peptidomimetic molecules as modulators of blood coagulation.

Amino Acid Sequence↗