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Biomedical subjects

T Engelhardt

Publications and source records attributed to T Engelhardt.

At least 19 recordsLinked to original sources

Inhibition of neuronal nitric oxide synthase reduces isoflurane MAC and motor activity even in nNOS knockout mice.

BACKGROUND: The glutamate-nitric oxide-cyclic GMP pathway has been identified as a potential target for volatile anaesthetic agents as acute inhibition of nitric oxide synthase (NOS) reduces the minimum alveolar concentration (MAC) in most animal studies. However, mice deficient in the type I NOS isoform (nNOS) are reported to have a similar MAC for isoflurane and are not affected by non-isoform specific inhibitors. METHODS: We determined whether the nNOS specific inhibitor, 7-nitroindazole (7-NI), had an effect on isoflurane MAC and righting reflex (RRF) and investigated spontaneous motor activity in an open-field study in wild-type (WT) and knockout (KO) mice. RESULTS: 7-NI reduced isoflurane MAC and RRF in both WT and KO animals (all P<0.04). 7-NI profoundly reduced spontaneous motor activity in both the WT and KO animals in the open-field study as indicated by a reduction in the number of line crossings and rearings in both WT and KO mice (both P<0.001). CONCLUSION: We conclude that isoform specific inhibition of nNOS reduces MAC and spontaneous motor activity even in nNOS KO animals. Our results indicate that the NMDA receptor-nitric oxide-cyclic GMP pathway remains a credible target in modulating the effects of isoflurane.

Anesthetics, Inhalation↗

Inhibition of neuronal nitric oxide synthase reduces the propofol requirements in wild-type and nNOS knockout mice.

BACKGROUND AND OBJECTIVE: The glutamate-nitric oxide-cyclic guanosine monophosphate pathway has been identified as a potential target for anaesthetic agents. However, mice deficient in neuronal nitric oxide synthase have a similar susceptibility to volatile anaesthetic agents to wild-type mice and are not affected by non-isoform selective inhibitors. We hypothesized that the neuronal nitric oxide synthase selective inhibitor, 7-nitroindazole, would also reduce the propofol requirements in wild-type mice but would have no effect in neuronal nitric oxide synthase knockout mice. METHODS: We determined the time to loss of righting reflex, time to painful stimulus and time to regaining the righting reflex in neuronal nitric oxide synthase knockout and wild-type mice following the intraperitoneal injection of propofol in untreated, 7-nitroindazole and vehicle only treated animals (n = 6 per group). Propofol (200 mg kg(-1)) resulted in loss of righting reflex in the untreated and vehicle only groups but was lethal in 7-nitroindazole pre-treated mice, requiring a reduced dose of propofol (100 mg kg(-1)). RESULTS: 7-nitroindazole pre-treatment significantly reduced the loss of righting reflex (P < 0.001) in both wild-type and knockout mice when compared to untreated and vehicle only pre-treated animals, but had no effect on time to painful stimulus or regaining of the righting reflex. 7-nitroindazole reduced the propofol requirements in knockout mice to the same extent as in wild-type animals. CONCLUSIONS: Propofol exerts its anaesthetic effects at least partially via the glutamate-nitric oxide-cyclic guanosine monophosphate pathway. The neuronal nitric oxide synthase knockout mice are sensitive to neuronal nitric oxide synthase selective inhibition suggesting that compensatory pathways in neuronal nitric oxide synthase knockout mice exist.

Anesthetics, Intravenous↗

[Xanthoma disseminatum: a rare case involving the upper extremity].

We describe a dramatic case of class II non-Langerhans cell histiocytosis, xanthoma disseminatum, in a 30-year-old male patient with progressive involvement of the skin, vocal cords, eyes, bones and nerves in spite of chemotherapy with Vespesid and immunotherapy with interferon-gamma. At the age of 43 years, the patient required surgical clearance of airways, eyelids and peripheral nerves, but at present exhibits stable disease on a combination of lipid-lowering drugs including thiazolidinedione.

Adult↗

[Long-term cosmetic results following thyroid resection].

BACKGROUND: The long-term cosmetic results following thyroid resection may soon become more relevant because minimally invasive techniques are also being promoted. PATIENTS AND METHODS: Two hundred forty-four patients were prospectively enrolled for a questionnaire regarding long-term results following thyroid resection. Ninety of these patients were clinically examined. RESULTS: The cosmetic results were judged by more than 90% of the patients as excellent or good. Women were slightly more critical about their results (P=0.06). Some kind of wound infection was reported in 4.1%, hypertrophic scar in 4.1%, and mild dysphagia in 7%. The results were not associated with the kind or extent of resection. The length of the scars was 4 cm (range 3-7) and the width 2 mm (range 1-4). The surgeons also judged the scars as good or excellent in most cases but were more critical than the patients. CONCLUSION: Since the long-term results of conventional surgery are, in most cases, so good, it seems difficult to improve the results by new minimally invasive techniques.

Adult↗

Selenium supplementation for critically ill adults.

BACKGROUND: Selenium is a trace mineral essential to human health, which has an important role in the immune response, defence against tissue damage and thyroid function. Improving selenium status could help protect against overwhelming tissue damage and infection in critically ill adults. OBJECTIVES: This review assessed the effects of selenium supplementation including the selenium-containing compound, ebselen, on adults recovering from critical illness. SEARCH STRATEGY: We searched CENTRAL (The Cochrane Library, Issue 2, 2003), MEDLINE, (1966 to July 2003), EMBASE (1980 to Week 30 2003),CAB NAR (1973 to March 2003), BIOSIS (1985 to July 2003), CINAHL (1982 to July 2003), HEALTHSTAR (1975 to September 2002), Current Controlled Trials, and reference lists. We contacted investigators, and handsearched four journals. Date of the most recent search: December 2003. SELECTION CRITERIA: Randomized trials of selenium or ebselen supplementation by any route, in adults with critical illness (including burns, head injury, brain haemorrhage, cerebrovascular accident and surgery). DATA COLLECTION AND ANALYSIS: Two reviewers independently extracted data and assessed trial quality. We sought additional information as required from trialists. We also undertook pooling of data for outcomes and selected exploratory analyses were undertaken. MAIN RESULTS: Seven randomized trials involving813participants were included. The quality of trials, as reported, was poor, particularly for allocation concealment. The availability of outcome data was limited and trials involving selenium supplementation, were small. Thus the results must be interpreted with caution. Because of heterogeneity, results are presented for the random effects models. Four selenium trials showed no statistically significant difference in mortality (relative risk (RR) 0.52, 95% confidence interval (CI) 0.20 to 1.34). Three trials of ebselen also showed no statistically significant difference in mortality (RR 0.83, 95% CI 0.51 to 1.35). One trial of selenium found no statistically significant difference between groups for participants developing infection (RR 1.33, 95% CI 0.55 to 3.24). Three trials of ebselen provided data for participants developing infections (pyrexia, respiratory infections or meningitis), which was not statistically significant (RR 0.60, 95% CI 0.36 to 1.02). No clear evidence emerged for the benefits of selenium or ebselen supplementation for the outcomes of days on a ventilator, length of intensive care unit stay, length of hospital stay or quality of life. REVIEWERS' CONCLUSIONS: There is insufficient evidence to recommend supplementation of critically ill patients with selenium or ebselen. Trials are required which overcome the defects of the reviewed studies, particularly inadequate size and methodology. This review will be updated when four ongoing trials are completed.

Adult↗

[Indication for laparoscopic resection of colorectal cancer].

Whether a laparoscopic resection for colorectal cancer is indicated depends on the technical feasibility as well as on the potential advantages of the laparoscopic approach compared to conventional surgery. Short-term results from 11 randomized studies are available showing potential advantages. Long term results from 2 randomized trials do not suggest disadvantages but more likely some survival benefits.

Colorectal Neoplasms↗

Saliva cyclic GMP increases during anaesthesia.

BACKGROUND: Cyclic GMP (cGMP) has been implicated in modulating the effects of general anaesthesia. Changes in cGMP in humans undergoing anaesthesia have not been reported previously. METHODS: In this pilot study we measured cGMP in the saliva of six healthy volunteers and eight patients undergoing general anaesthesia for minor gynaecological procedures. Samples were obtained using a commercially available sampling device and cGMP was determined with an enzyme immunoassay and results expressed as a cGMP per mg protein. RESULTS: There was no statistically significant variation in salivary cGMP either day-to-day or between time points in healthy volunteers. Analysis of variance of salivary cGMP of patients undergoing general anaesthesia showed that cGMP increased significantly intraoperatively and returned to preoperative levels after surgery (P=0.03). CONCLUSIONS: This is the first time that real time in vivo changes in salivary cGMP levels during general anaesthesia in humans have been demonstrated and may allow an alternative technique for measuring depth of anaesthesia in the future.

Adult↗

Sublingual morphine may be a suitable alternative for pain control in children in the postoperative period.

The purpose of this pilot study was to compare the effects of sublingual morphine with intravenous morphine in the treatment of postoperative pain following adenotonsillectomy in children. Twenty-nine children scheduled for adenotonsillectomy were randomly assigned to group 1 (n=14) receiving 0.1 mg x kg(-1) sublingual morphine and group 2 (n=15) 0.1 mg x kg(-1) intravenous morphine followed by 1 mg x kg(-1) diclofenac rectally in both groups after induction of anaesthesia. Postoperatively, time to first eye opening, sedation score, pain score, time for further analgesia requests and incidence of nausea and vomiting were recorded. There was no statistical significant difference in any of these parameters between the two groups. The results suggest that sublingual morphine may be a suitable alternative to various other routes of opioid administration in children, but further investigations of the sublingual route of administration of opioids in children are required.

Adenoidectomy↗

Aspiration and regurgitation prophylaxis in paediatric anaesthesia.

BACKGROUND: Surveys of aspiration prophylaxis in paediatric anaesthesia do not exist. METHODS: A postal survey was sent out to all UK members of the Association of Paediatric Anaesthetists (APA) to assess current practice. We asked about minimum fasting times for liquids and solids/milk, their routine acid aspiration prophylaxis and perceived risk factors for emergency and elective surgery in children those less than 1 year old and those aged 1-14 years. We also asked if the APA member had more than 10 years experience in paediatric anaesthesia. RESULTS: One hundred and two (55.1%) APA members replied out of a total of 185 questionnaires sent. Eighty-eight (88/102) were considered valid. Fasting in emergencies is approximately 4 h for solids/milk and 2 h for clear liquids. Fasting for elective surgery is between 5 and 6 h for solids/milk and 2 h for clear liquids. Pharmacological methods to reduce the risk of aspiration are not used. Mechanical methods vary from 40-50% for cricoid pressure and 20-30% for nasogastric aspiration if a tube is present. The presence of a hiatus hernia is perceived by over 80% as a risk factor, previous aspiration by over 60%, difficult intubation, cerebral palsy and sepsis by 20-30%. CONCLUSION: Perceived risk factors vary with "experience": hiatus hernia, difficult intubation and cerebral palsy are less important whereas previous aspiration and renal failure appear to be more important for paediatric anaesthetists with less than 10 years in paediatric anaesthetic practice.

Adolescent↗

Fluid management in pre-eclampsia.

We review the evidence base for fluid management in pre-eclampsia. Current understanding of the relevant pathophysiology and the possible impact of styles of fluid management on maternal and fetal outcome are presented. There is little evidence upon which to base the management of fluid balance in pre-eclampsia. Reports are conflicting and no large prospective outcome studies of fluid management have been performed. Volume expansion does not appear to reduce the incidence of fetal distress. Pulmonary oedema and oliguria receive particular attention. There is no evidence of long-term renal damage in pre-eclampsia, but there are strong suggestions that pulmonary oedema is linked to fluid administration. Monitoring is discussed and some principles of management are suggested

Journal Article↗