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Biomedical subjects

S Lee

Publications and source records attributed to S Lee.

At least 127 records · Page 7Linked to original sources
PubMed2003

Effects of adrenaline and potassium on QTc interval and QT dispersion in man.

BACKGROUND: Hypoglycaemia alters cardiac repolarization acutely, with increases in rate-corrected QT (QTc) interval and QT dispersion (QTd) on the electrocardiogram (ECG); such changes are related to the counterregulatory sympatho-adrenal response. Adrenaline produces both QTc lengthening and a fall in plasma potassium (K+) when infused into healthy volunteers. Hypokalaemia prolongs cardiac repolarization independently however, and therefore our aim was to determine whether adrenaline-induced repolarization changes are mediated directly or through lowered plasma K+. MATERIALS AND METHODS: Ten healthy males were studied on two occasions. At both visits they received similar l-adrenaline infusions but on one occasion potassium was also administered; infusion rates were adjusted to maintain circulating K+ at baseline. The QTc interval, QTd, peripheral physiological responses and plasma adrenaline and potassium concentrations were measured during both visits. RESULTS: The QTc interval and QTd increased both with and without potassium clamping. Without K+ replacement, mean (SE) QTc lengthened from 378 (5) ms to a final maximum value of 433 (10) ms, and QTd increased from 36 (5) ms to 69 (8) ms (both P < 0.001). During K+ replacement, QTc duration at baseline and study end was 385 (7) ms and 423 (11) ms, respectively (P < 0.001), and QTd 38 was (4) ms and 63 (5) ms (P = 0.001). CONCLUSIONS: These data suggest that disturbed cardiac repolarization as a result of increases in circulating adrenaline occurs independently of extracellular potassium. A direct effect of adrenaline upon the myocardium appears the most likely mechanism.

Adult↗
PubMed2003

Working with sex offenders with intellectual disability: evaluation of an introductory workshop for direct care staff.

BACKGROUND: Sexual aggression by men with intellectual disability (ID) is a serious problem requiring attention from the relevant agencies. Training for staff working with this problem is often not given sufficient attention and is rarely evaluated. In the present study, an introductory workshop for direct care staff that aimed to increase knowledge and improve attitudes towards work with this client group was evaluated. METHOD: Sixty-six staff working in inpatient and community settings completed a 2.5-day workshop. Before training began, the participants completed a survey questionnaire concerning their experiences of work with this client group. An assessment of their knowledge and attitudes was carried out prior to and at the end of training in order to evaluate any changes. The participants also rated the effectiveness of the workshop and their level of satisfaction with the training at the end of the workshop. RESULTS: The participants' knowledge and attitudes improved significantly following the workshop. Staff with greater experience over time and those who had worked with fewer sex offender clients responded to different aspects of the training. The participants' ratings indicated that they were highly satisfied with the training and found it to be effective. CONCLUSIONS: Brief workshop training is acceptable to and can be effective in improving the knowledge, attitudes and confidence of direct care staff working with sex offenders with ID. However, because the results are based on participant self-report, caution should be exercised concerning their external validity.

Attitude of Health Personnel↗
PubMed2003

Inducible nitric oxide synthase is responsible for nitric oxide release from murine pituicytes.

This study investigated whether pituicytes were able to produce and release nitric oxide (NO), and which type of nitric oxide synthase (NOS) would be responsible for this phenomenon. Lipopolysaccharide (LPS) 1 micro g/ml was used as inflammatory mediator. Because pituicytes are known to secrete interleukin (IL)-6 upon stimulation with LPS, this parameter was also investigated. Cultured pituicytes, from 4-week-old male mice, were stimulated with LPS for 6 h or 24 h. At 24 h, there was a significant increase in accumulated nitrite indicating NO formation. In contrast, IL-6 release was already significantly higher 6 h after stimulation and further increased at 24 h. The correlation between accumulated nitrite and secreted IL-6 was 0.84 after 24 h of incubation with LPS. The expression of inducible NOS (iNOS) mRNA in the pituicytes was significantly higher than the control level after 6 h and 24 h of exposure to LPS, with levels at 6 h being significantly higher than those at 24 h. There was no detected expression of endothelial NOS or neuronal NOS mRNA. Cultured pituicytes were also subjected to immunocytochemistry for iNOS protein at 6, 12, and 24 h after stimulation with LPS. Most cells were positive for iNOS, but there were no observable differences with the time points that we used. Collectively, these results show that pituicytes are able to produce NO, and that the inducible form of NOS is responsible for this production. Furthermore, there is a weak correlation between NO and IL-6 released from pituicytes after 24 h of stimulation with LPS.

Animals↗
PubMed2003

Role of specific adrenergic receptors in mediating the adrenocorticotropic hormone response to increased nitric oxide levels.

We investigated the role played by catecholamine-dependent pathways in modulating the ability of the nitric oxide (NO) donor 3-morpholino-sydnonimine (SIN-1) to release adrenocorticotropic hormone (ACTH) following its intracerebroventricular (i.c.v.) or intravenous (i.v.) injection. We first showed that the nonspecific adrenergic agonist noradrenaline, the alpha- or beta-adrenergic agonists phenylephrine or dobutamine, or the noradrenergic uptake inhibitor desipramine, all significantly stimulated ACTH secretion by freely moving, nonanaesthetized rats. We then observed that destruction of noradrenergic nerve endings with the neurotoxin 6-hydroxydopamine, respectively abolished and significantly decreased the ACTH response to the i.c.v. or i.v. administration of SIN-1. Finally, we sought to identify the type of adrenergic receptor(s) mediating the influence of catecholamines. beta-Adrenergic receptors did not appear to be involved in the stimulatory effect of SIN-1 regardless of its route of injection. By contrast, alpha 2-adrenergic receptors played an important role in the ACTH response to i.v. or i.c.v. administered SIN-1. Collectively, these results indicate that while hypothalamic alpha 1- and beta-adrenergic receptors are important for hypothalamic-pituitary-adrenal (HPA) axis activity, only alpha 2-adrenergic receptors are involved in modulating the ability of NO to release ACTH. Our laboratory and others have previously reported that NO increased hypothalamic noradrenaline levels, while conversely noradrenaline up-regulated levels of NO synthase, the enzyme responsible for NO formation; and that injection of corticotropin-releasing factor into the brain ventricles releases catecholamines and stimulates NO formation. Taken together with these observations, our results point to complex functional relationships between NO, catecholamines and the HPA axis.

Adrenal Glands↗
PubMed2003

Views of nursing staff on the use of physical restraint.

A postal questionnaire survey was employed in regional secure and psychiatric intensive care units in England and Wales, in respect of mental health nurses' training in the use of physical restraint. The nurses' views were sought relating to their last experience of implementing the procedure. Whilst most nurses (n = 259, 96.3%) reported positive outcomes in so far that the incident was brought under control, the views of the aftereffects of the procedure were of concern and ambivalence. The literature suggests that service users did not necessarily hold the same positive views. A range of alternatives, which were consistent with the literature, was made by staff to improve intervention in the management of violence. Negative aspects relating to the use of physical restraint were also highlighted. They included procedural, injury, clinical and management issues. Some respondents also expressed concerns about the negative attitudes of their colleagues. The findings of this aspect of the survey highlights that the therapeutic value of physical restraint can only be achieved with appropriate monitoring and with emphasis on psychological intervention in the prevention and management of violence.

Attitude of Health Personnel↗
PubMed2003

Aspirin and salicylate inhibit colon cancer medium- and VEGF-induced endothelial tube formation: correlation with suppression of cyclooxygenase-2 expression.

To determine whether aspirin and salicylate suppress colon cancer cell-mediated angiogenesis, we evaluated the effects of aspirin and sodium salicylate on endothelial tube formation on Matrigel. Aspirin and sodium salicylate concentration-dependently inhibited human endothelial cell (EC) tube formation induced by conditioned medium collected from DLD-1, HT-29 or HCT-116 colon cancer cells. Aspirin and sodium salicylate at pharmacological concentrations were equally effective in blocking tube formation. Neutralizing antivascular endothelial growth factor (VEGF) antibodies blocked colon cancer medium-induced tube formation. VEGF receptor 2 but not receptor 1 antibodies inhibited tube formation to a similar extent as anti-VEGF antibodies. These results indicate that VEGF interaction with VEGF receptor 2 is the primary mechanism underlying colon cancer-induced angiogenesis. Aspirin or sodium salicylate inhibited VEGF-induced tube formation in a concentration-dependent manner comparable to that of inhibition of colon cancer medium-induced endothelial tube formation. It has been shown that cyclooxygenase-2 (COX-2) is pivotal in cancer angiogenesis. We found that colon cancer medium-induced COX-2 protein expression in EC and aspirin or sodium salicylate suppressed the cancer-induced COX-2 protein levels at concentrations correlated with those that suppressed endothelial tube formation. Furthermore, aspirin and sodium salicylate inhibited COX-2 expression stimulated by VEGF. These findings indicate that aspirin and other salicylate drugs at pharmacological concentrations inhibit colon cancer-induced angiogenesis which is correlated with COX-2 suppression.

Anti-Inflammatory Agents, Non-Steroidal↗
PubMed2003

Factors affecting the quality of life in patients with epilepsy in Seoul, South Korea.

OBJECTIVES: The level of, and factors affecting the quality of life (QOL) in patients with epilepsy may be different in Korea where social prejudice toward them is still pronounced. However, these issues have not yet been addressed properly. METHODS: We consecutively identified 154 epilepsy patients who visited the outpatient clinic at the Seoul National University Hospital. An interview was performed by two research nurses with the use of a standardized questionnaire, which included data pertaining to seizure characteristics, symptoms of depression/anxiety, social support, family life/social life satisfaction, and the activities of daily living (ADLs). The QOL was assessed with the use of QOL in Epilepsy Inventory (QOLIE-31). RESULTS: Factors affecting the QOL were: age (P<0.01), education in years (P<0.01), employment status (P<0.05), employment type (P<0.05), current economic status (P<0.05), seizure frequency (P<0.01), the number of antiepileptic drugs (P<0.01), family life/social life dissatisfaction (P<0.01, respectively), social support (P<0.01), the symptoms of anxiety and depression (P<0.01, respectively) and ADL dysfunction (P<0.01). In multiple regression analysis, the symptom of anxiety was the most important factor in explaining lower QOL in patients with epilepsy, while depression (P<0.01), social life dissatisfaction (P<0.01), ADL dysfunction (P<0.05) and seizure frequency (P<0.05) were also significant factors. CONCLUSION: Psycho-social factors outweighed the physical factors in determining QOL in Korean epilepsy patients. Recognition of these factors will lead health professionals to develop different strategies to improve the QOL of these patients.

Adult↗
PubMed2003

A survey of filamentous organisms at the Deer Island treatment plant.

The Deer Island Treatment Plant (DITP) treating both domestic and industrial wastewater, has a peak flow capacity of up to 1270 million gallons per day (MGD) (3342 m3 min(-1). The DITP contains a Pilot Plant, which consists of two identical pure oxygen activated sludge treatment trains, each with a maximum capacity of 1 MGD (2.63 m3 min(-1)) to simulate the maximum flow of the full size facility. This study documents the community of filamentous organisms living in the activatedsludge under various operational conditions in the Pilot Plant. Sixteen types of filamentous organisms were identified. The major filamentous organisms present in the Pilot Plant were Type 1701, Type 0041, Sphaerotilus natans, Microthrix parvicella, and Nocardia sp. Nocardia sp. was quite dominant in the early stages of the experimental period during high ambient temperatures (summer), indicating that temperature is one determining factor in the distribution of Nocardia sp. Thiothrix sp. was very sensitive to the dissolved oxygen (DO) level, with low DO values favoring the growth of the organisms. Microbiological observations made during the start-up and stable operation of the full-scale secondary treatment plant (maximum capacity 780 MGD) are also reported. No dominant filamentous species existed during the start-up period. Type 0803 and Type 1701, indicators of low oxygen level for the applied food to microorganism ratio, confirmed the low DO conditions of activated sludge tanks.

Data Collection↗
PubMed2003

Clinical experience of e-PTFE membrane implant surgery for refractory glaucoma.

AIMS: To evaluate the clinical efficacy of membrane tube implant made of expanded polytetrafluoroethylene (e-PTFE, Gore-Tex) membrane and silicone tube in treating refractory glaucoma. METHODS: A retrospective chart review was performed on 43 eyes of 40 patients who underwent glaucoma tube shunt implant surgery using double layered e-PTFE membrane and silicone tube to treat refractory glaucoma. The surgeries were performed from May 1991 to September 1995, and the subjects were patients with terminal glaucoma without useful vision on the study eye. RESULTS: The mean follow up period was 32.9 months. The Kaplan-Meier survival for intraocular pressure (IOP) control (IOP between 6 and 21mm Hg without significant complication) was 80.9% at 1 year, 73.9% at 2 years, and 62.2% at 3 years after surgery. After excluding three eyes of three patients who were dropped within 3 months after surgery and did not have any serious complication or problem in IOP control, the average preoperative IOP was 42.5 (SD 14.6) mm Hg and IOP on the last visit was 17.3 (10.2) mm Hg (p = 0.000, n = 40). The number of antiglaucoma medications before surgery (2.2 (0.6)) was reduced to 0.5 (0.8) on the last visit (p = 0.000). The IOP was controlled within the range of 6-21 mm Hg in 26 eyes (65.0%). In the remaining 14 eyes (35%), we could not control the IOP or additional surgery was needed to control the IOP or to treat severe complications. Two cases of endophthalmitis and three of phthisis were found as serious complications. The other complications were similar to those of other commercially available glaucoma implants. CONCLUSION: A comparable clinical result was obtained with this new implant as with the other commercially available implants. This implant with a thin and non-rigid reservoir has a potential to reduce some complications associated with the large volume and rigid consistency of the other implants, although it is not yet proved. This membrane tube implant may be considered as another substitute in the surgery of refractory glaucoma.

Adult↗
PubMed2003

Short term outcome and risk factors for adverse clinical outcomes in adults with severe acute respiratory syndrome (SARS).

BACKGROUND: Severe acute respiratory syndrome (SARS) was diagnosed in Hong Kong in over 1700 patients between March and early June 2003. METHODS: 115 patients diagnosed with SARS were admitted to Queen Elizabeth Hospital, a large regional hospital in Hong Kong, from March 2003, of whom 100 were either discharged or were dead at 31 May. The patients were prospectively studied after admission to assess their short term outcomes and the risk factors associated with adverse outcomes, defined as death or the need for mechanical ventilation RESULTS: At the time of writing 18 patients had died, with a crude mortality rate of 15.7% and a 21 day mortality of 10% (standard error 3%). Thirty nine patients (34%) were admitted to the intensive care unit, 30 of whom (26%) required mechanical ventilation. Multivariate analysis showed that age above 60 (hazards ratio (HR) 3.5, 95% CI 1.2 to 10.2; p=0.02), presence of diabetes mellitus or heart disease (HR 9.1, 95% CI 2.8 to 29.1; p<0.001), and the presence of other comorbid conditions (HR 5.2, 95% CI 1.4 to 19.7; p=0.01) were independently associated with mortality. However, only the presence of diabetes mellitus and/or cardiac disease (HR 7.3, 95% CI 3.1 to 17.4; p<0.001) was associated with adverse outcomes as a whole. CONCLUSION: SARS is a new disease entity that carries significant morbidity and mortality. Specific clinical and laboratory parameters predicting unfavourable outcomes have been identified.

Adult↗
PubMed2003

A consensus report of the role of serum thyroglobulin as a monitoring method for low-risk patients with papillary thyroid carcinoma.

Recent studies have provided new information regarding the optimal surveillance protocols for low-risk patients with differentiated thyroid cancer (DTC). This article summarizes the main issues brought out in a consensus conference of thyroid cancer specialists who analyzed and discussed this new data. There is growing recognition of the value of serum thyroglobulin (Tg) as part of routine surveillance. An undetectable serum Tg measured during thyroid hormone suppression of TSH (THST) is often misleading. Eight studies show that 21% of 784 patients who had no clinical evidence of tumor with baseline serum Tg levels usually below 1 micro g/liter during THST had, in response to recombinant human TSH (rhTSH), a rise in serum Tg to more than 2 micro g/liter. When this happened, 36% of the patients were found to have metastases (36% at distant sites) that were identified in 91% by an rhTSH-stimulated Tg above 2 micro g/liter. Diagnostic whole body scanning, after either rhTSH or thyroid hormone withdrawal, identified only 19% of the cases of metastases. Ten studies comprising 1599 patients demonstrate that a TSH-stimulated Tg test using a Tg cutoff of 2 micro g/liter (either after thyroid hormone withdrawal or 72 h after rhTSH) is sufficiently sensitive to be used as the principal test in the follow-up management of low-risk patients with DTC and that the routine use of diagnostic whole body scanning in follow-up should be discouraged. On the basis of the foregoing, we propose a surveillance guideline using TSH-stimulated Tg levels for patients who have undergone total or near-total thyroidectomy and (131)I ablation for DTC and have no clinical evidence of residual tumor with a serum Tg below 1 micro g/liter during THST.

Carcinoma, Papillary↗
PubMed2003

Leukotriene synthesis by epithelial cells.

Leukotrienes (LTs) are intercellular signaling molecules that evoke a variety of responses. They are best known as potent promoters of inflammation. Normally, LTs are produced primarily by leukocytes. As a result, current models regarding the production of LTs in the context of disease focus on the leukocytes as the site of production. Structural cells, including epithelial cells, are typically relegated to supportive roles. It is recognized that epithelial cells normally contain all the components necessary for LT synthesis except the enzyme 5-lipoxygenase (5-LO). There is accumulating evidence that some populations of epithelial cells normally express low levels of 5-LO and can synthesize LTs autonomously. Moreover, certain factors, including bacterial and viral infection, can promote the expression of 5-LO in airway, gastrointestinal and skin epithelial cells. The appearance of active 5-LO enzyme in epithelial cells at these sites may contribute to diseases like cancer, colitis and psoriasis. This paper reviews the state of our knowledge regarding the expression of 5-LO in epithelial cells, the factors that modify that expression, and the implications regarding pathogenesis.

Animals↗
PubMed2002

Specific heat of single crystal MgB2: a two-band superconductor with two different anisotropies.

Heat-capacity measurements of a 39 microg MgB2 single crystal in fields up to 14 T and below 3 K allow the determination of the low-temperature linear term of the specific heat, its field dependence, and its anisotropy. Our results are compatible with two-band superconductivity, the band carrying the smaller gap being isotropic, that carrying the larger gap having an anisotropy of approximately 5. Three different upper critical fields are thus needed to describe the superconducting state of MgB2.

Journal Article↗
PubMed2002

Learning curve of video-assisted thoracoscopic esophagectomy and extensive lymphadenectomy for squamous cell cancer of the thoracic esophagus and results.

BACKGROUND: The efficacy of thoracoscopic radical esophagectomy for cancer of the thoracic esophagus and the learning curve required have yet to be clearly established. METHODS: Eighty treatment-naive patients with esophageal cancer without contiguous spread underwent esophageal mobilization and extensive mediastinal lymphadenectomy through a 5-cm minithoracotomy and four trocar ports. The outcomes in the first 34 patients (group 1) and the last 46 patients (group 2) were compared. RESULTS: There were no differences in background or clinicopathologic factors between the two groups. The duration of the thoracoscopic procedure and blood loss were less (p <0.0001), the incidence of postoperative pulmonary infection was less (p = 0.0127), and the number of mediastinal nodes retrieved was greater (p = 0.0076) in group 2. Multivariate analysis demonstrated that surgical experience (number of cases performed) predicted the risk of pulmonary infection (p = 0.0331). CONCLUSION: Video-assisted thoracoscopic radical esophagectomy can be performed with safety and efficacy comparable to those of open esophagectomy. Morbidity decreases with the surgeon's experience.

Adult↗
PubMed2002

Involvement of the protein kinase C pathway in thyrotropin-induced STAT3 activation in FRTL-5 thyroid cells.

The binding of thyrotropin (TSH) to the TSH receptor (TSHR) activates two signaling pathways: the cAMP-protein kinase A (PKA) and the protein kinase C (PKC) systems. We have recently demonstrated that TSH activates the Janus kinases (JAK)/signal transducer and activator of transcription (STAT) pathway via TSHR. This study aimed to investigate whether the cAMP/PKA or the PKC system is involved in STAT3 activation in response to TSH. Treatment with TSH activated STAT3 phosphorylation in FRTL-5 thyrocytes and human TSHR-expressing Chinese hamster ovary cells. TSH-induced STAT3 activation was inhibited by a blocking antibody directed against TSHR that was isolated from patients with primary myxoedema. Increased intracellular cAMP activated STAT3 but inhibition of PKA did not affect STAT3 activation. On the other hand, the PKC stimulant PMA induced STAT3 phosphorylation and the PKC inhibitors inhibited it. Moreover, inhibition of PKC blocked STAT3 activation induced by a stimulator of cAMP. Our data suggest that TSH activates STAT3 via TSHR and cAMP- and PKC-dependent pathways, and provide evidence that PKC may be involved in the pathway downstream from cAMP.

Animals↗