Associations between attitudes towards and reported intakes of sugars, low/no-calorie sweeteners, and sweet-tasting foods in a UK sample

Public health initiatives are currently aiming to lower free sugar intakes for health benefits, but attitudes towards sugars, their alternatives such as low/no-calorie sweeteners (LNCS), and towards sweet-tasting foods may be hampering efforts. This work investigated associations between attitudes towards and the reported intakes of sugars, LNCS and sweet-tasting foods, and identified latent attitude profiles in subpopulations of adults in the United Kingdom. A total of 581 adults completed a questionnaire assessing their usual intake of sugars, LNCS and sweet-tasting foods, attitudes towards these foods and various demographic characteristics. Six principal components explained 39.1% of the variance in the attitude responses, named: 'Personal Impact', 'Personal Management', 'Apathy', 'Negativity', 'Perceived Understanding' and 'Perceived Nonautonomy'. Personal Impact was negatively associated with reported consumption of sugar-food and sweet-tasting food groups more frequently (smallest β = -0.24, p < .01). Personal Management was positively associated with reporting adding sugar and consuming sugar-food and sweet-tasting food groups more frequently (smallest β = 0.14, p < .01). Three latent classes of participants with distinct patterns of attitudes were identified, labelled: 'Feeling Ill-equipped' (n = 52), 'Actively Engaged' (n = 162) or 'Unopinionated' (n = 367). Individuals who were classed as Actively Engaged reported adding LNCS more frequently than those classed as Feeling Ill-equipped (t(212) = -2.14, p<.01), who reported consuming sweet-tasting food groups more frequently than those classed as Unopinionated (t(417) = 2.65, p < .01). These findings suggest the need for personalised approaches within public health initiatives, to reduce free sugar intakes.

Study protocol of the sweet tooth study, randomized controlled trial with partial food provision on the effect of low, regular and high dietary sweetness exposure on sweetness preferences in Dutch adults

BACKGROUND

Several health organizations recommend lowering the consumption of sweet-tasting foods. The rationale behind this recommendation is that a lower exposure to sweet foods may reduce preferences for sweet tasting foods, thus lowering sugar and energy intake, and in turn aiding in obesity prevention. However, empirical data supporting this narrative are lacking. In fact, relatively little is known about the contribution of long-term sweet taste exposure on one's sweetness preferences.

METHODS

The primary objective of this randomized controlled trial is to assess the effect of low, regular and high dietary sweetness exposure on preference for sweet foods and beverages, and to compare these effects between intervention groups. One hundred and eighty adults aged 18-65 years with a BMI of 18.5-30.0 kg/m² will be recruited and randomly allocated to either: low dietary sweetness exposure (LSE) (10-15% daily energy from sweet tasting foods), regular dietary sweetness exposure (RSE) (25-30% daily energy from sweet tasting foods), or high dietary sweetness exposure (HSE) (40-45% daily energy from sweet tasting foods), for 6 months, followed by a 4-month follow up. Intervention foods are provided ad libitum, covering approximately 50% of the daily number of food items, to include sugar-sweetened, low-calorie-sweetener-sweetened and non-sweet foods. The primary outcome measure is the difference in change in sweetness preference from baseline to 6 months between intervention groups. Secondary outcomes include: change in sweet taste preferences at different time-points; taste intensity perception; behavioral outcomes: food choice and intake, sweet-liker type, food cravings, dietary taste preferences and dietary taste patterns; anthropometric outcomes: body composition, waist-hip circumference, body weight; and biochemical outcomes: glucose variability and biomarkers related to CVD and diabetes.

DISCUSSION

This study will generate important data on the effect of dietary sweetness exposure on sweetness preferences in terms of effect size and change, duration of change and its impact on food intake, body weight status and associated health outcomes.

TRIAL REGISTRATION

The study protocol has been registered on ClinicalTrials.gov (ID no. NCT04497974, Registered 4 August 2020, https://clinicaltrials.gov/ct2/show/NCT04497974 ) and approved by Wageningen's Medical Ethical Committee (ABR no. NL72134).

[Hemodynamic changes in standing-up test of children and adolescents with postural tachycardia syndrome]

OBJECTIVE

To explore the hemodynamic changes in standing-up test of children and adolescents with postural tachycardia syndrome (POTS) and to compare hemodynamic parameters of POTS patients with decreased cardiac index (CI) and those with not-decreased CI.

METHODS

A retrospective study was conducted to show the trends of CI, total peripheral vascular resistance index (TPVRI), heart rate and blood pressure in standing-up test of 26 POTS patients and 12 healthy controls, and to compare them between the two groups. The POTS patients were divided into two groups based on CI decreasing or not in standing-up test, namely decreased CI group (14 cases) and not-decreased CI group (12 cases). The trends of the above mentioned hemodynamic parameters in standing-up test were observed and compared between decreased CI group and not-decreased CI group.

RESULTS

In standing-up test for all the POTS patients, CI (F=6.936, P=0.001) and systolic blood pressure (F=6.049, P<0.001) both decreased significantly, and heart rate increased obviously (F=113.926, P<0.001). However, TPVRI (F=2.031, P=0.138) and diastolic blood pressure (F=2.018, P=0.113) had no significant changes. For healthy controls, CI (F=3.646, P=0.016), heart rate (F=43.970, P<0.001), systolic blood pressure (F=4.043, P=0.020) and diastolic blood pressure (F=8.627, P<0.001) all increased significantly in standing-up test. TPVRI (F=1.688, P=0.190) did not change obviously. The changing trends of CI (F=6.221, P=0.001), heart rate (F=6.203, P<0.001) and systolic blood pressure (F=7.946, P<0.001) over time were significantly different between the patients and healthy controls, however, no difference was found in TPVRI and diastolic blood pressure (P > 0.05). Among the POTS patients, CI was significantly different between decreased CI group and not-decreased CI group (F=14.723, P<0.001). Systolic blood pressure of the former decreased obviously (F=8.010, P<0.001), but it did not change obviously in the latter (F=0.612, P=0.639). Furthermore, none of the changes of TPVRI, heart rate and diastolic blood pressure in standing-up test were significantly different between the two groups (P > 0.05). Age was an independent factor for decreased CI patients (P=0.013, OR=2.233; 95% CI, 1.183 to 4.216).

CONCLUSION

POTS patients experience vital hemodynamic changes in standing-up test, part of them suffering from decreased CI, but others from not-decreased CI. Age is an independent factor for patients suffering from decreased CI.

[Progress in diagnosis and management of syncope in children]

Syncope is a common emergency of children and adolescents, which has serious influence on the quality of life. Neurally-mediated syncope, including postural tachycardia syndrome, vasovagal syncope, orthostatic hypotension and orthostatic hypertension, is the main cause of syncope in children and adolescents. The main manifestations of neurally-mediated syncope are diverse, such as dizziness, headache, chest tightness, chest pain, pale complexion, fatigue, pre-syncope and syncope. Although the clinical manifestations are similar, each subtype of syncope has its hemodynamic feature and optimal treatment option. The diagnosis rate of syncope in children has been greatly improved on account of the development of the diagnostic procedures and methods. In recent years, with the promotion of head-up tilt test and drug-provocated head-up tilt test, the hemodynamic classification of neurally-mediated syncope gets continually refined. In recent years, with the effort of clinicians, an appropriate diagnostic protocol for children with syncope has been established. The initial evaluation consists of history taking, physical examination, standing test and standard electrocardiography. After the initial evaluation, some patients could be diagnosed definitely, such as postural tachycardia syndrome, orthostatic hypotension, and situational syncope. Those with a specific entity causing syncope need selective clinical and laboratory investigations. Patients for whom the cause of syncope remained undetermined should undergo head-up tilt test. The precise pathogenesis of neurally-mediated syncope is not entirely clear. In recent years, studies have shown that neurally-mediated syncope may be related to several factors, including hypovolemia, high catecholamine status, abnormal local vascular tension, decreased skeletal muscle pump activity and abnormal neurohumoral factors. Currently based on the possible pathogenesis, the individualized treatment of neurally-mediated syncope has also been studied in-depth. Generally, the management of neurally-mediated syncope includes non-pharmacological and pharmacological interventions. Patient education is the fundamental part above all. In addition to exercise training, the first-line treatments mainly include oral rehydration salts, beta adrenoreceptor blockers, and alpha adrenoreceptor agonists. By analyzing the patient's physiological indexes and biomarkers before treatment, the efficacy of medication could be well predicted. The individualized treatment will become the main direction in the future researches.

Serum tumour necrosis factor-alpha is associated with poor health-related quality of life and depressive symptoms in patients with systemic lupus erythematosus

OBJECTIVES

While patients with systemic lupus erythematosus (SLE) have poorer health-related quality of life (HRQoL) and are more depressed than healthy people, the impact of proinflammatory cytokines, particularly tumour necrosis factor-alpha (TNFα), on these unfavourable psychosocial parameters is unclear. We aim to explore potential relationships between lupus-related proinflammatory cytokines, HRQoL and depressive symptoms in patients with SLE.

METHODS

Patients with SLE and age-matched healthy subjects were assessed for HRQoL and depressive and anxiety symptoms by the Short Form Health Survey-36 (SF-36) and Hospital Anxiety and Depression Scale (HADS) respectively. Using multiplex immunoassay, a panel of serum proinflammatory cytokines including TNFα, interleukin (IL)-1β, IL-6, IL-17, IL-23 and IL-33 were determined and compared between both groups. Independent associations between SF-36, serum proinflammatory cytokine levels and HADS scores were studied by regression models.

RESULTS

In total, 54 patients and 54 healthy controls were studied. Lupus patients had significantly poorer HRQoL (p < 0.001) and were significantly more depressed (p = 0.006) and anxious (p = 0.022) than their healthy counterparts. Amongst the proinflammatory cytokines studied, serum TNFα was significantly higher in lupus patients (p < 0.001). After multivariate adjustment, higher serum TNFα (β = -0.224, p = 0.047) remained significantly associated with lower SF-36, along with smoking (β = -0.253, p = 0.014) and more severe depressive symptoms (β = -0.433, p = 0.002). In healthy subjects, serum TNFα was associated with depressive symptoms but not with SF-36.

CONCLUSIONS

Higher serum TNFα level is independently associated with poorer HRQoL and more severe depressive symptoms in SLE patients. These associations suggest a potential impact of inflammatory response on depressive symptoms and the quality of life in patients with SLE.

Fine mapping of the 9q31 Hirschsprung's disease locus

Hirschsprung’s disease (HSCR) is a congenital disorder characterised by the absence of ganglia along variable lengths of the intestine. The RET gene is the major HSCR gene. Reduced penetrance of RET mutations and phenotypic variability suggest the involvement of additional modifying genes in the disease. A RET-dependent modifier locus was mapped to 9q31 in families bearing no coding sequence (CDS) RET mutations. Yet, the 9q31 causative locus is to be identified. To fine-map the 9q31 region, we genotyped 301 tag-SNPs spanning 7 Mb on 137 HSCR Dutch trios. This revealed two HSCR-associated regions that were further investigated in 173 Chinese HSCR patients and 436 controls using the genotype data obtained from a genome-wide association study recently conducted. Within one of the two identified regions SVEP1 SNPs were found associated with Dutch HSCR patients in the absence of RET mutations. This ratifies the reported linkage to the 9q31 region in HSCR families with no RET CDS mutations. However, this finding could not be replicated. In Chinese, HSCR was found associated with IKBKAP. In contrast, this association was stronger in patients carrying RET CDS mutations with p = 5.10 × 10⁻⁶ [OR = 3.32 (1.99, 5.59)] after replication. The HSCR-association found for IKBKAP in Chinese suggests population specificity and implies that RET mutation carriers may have an additional risk. Our finding is supported by the role of IKBKAP in the development of the nervous system.

Dynamic, Electronically Switchable Surfaces for Membrane Protein Microarrays

Microarray technology is a powerful tool that provides a high throughput of bioanalytical information within a single experiment. These miniaturized and parallelized binding assays are highly sensitive and have found widespread popularity especially during the genomic era. However, as drug diagnostics studies are often targeted at membrane proteins, the current arraying technologies are ill-equipped to handle the fragile nature of the protein molecules. In addition, to understand the complex structure and functions of proteins, different strategies to immobilize the probe molecules selectively onto a platform for protein microarray are required. We propose a novel approach to create a (membrane) protein microarray by using an indium tin oxide (ITO) microelectrode array with an electronic multiplexing capability. A polycationic, protein- and vesicle-resistant copolymer, poly(l-lysine)-grafted-poly(ethylene glycol) (PLL-g-PEG), is exposed to and adsorbed uniformly onto the microelectrode array, as a passivating adlayer. An electronic stimulation is then applied onto the individual ITO microelectrodes resulting in the localized release of the polymer thus revealing a bare ITO surface. Different polymer and biological moieties are specifically immobilized onto the activated ITO microelectrodes while the other regions remain protein-resistant as they are unaffected by the induced electrical potential. The desorption process of the PLL-g-PEG is observed to be highly selective, rapid, and reversible without compromising on the integrity and performance of the conductive ITO microelectrodes. As such, we have successfully created a stable and heterogeneous microarray of biomolecules by using selective electronic addressing on ITO microelectrodes. Both pharmaceutical diagnostics and biomedical technology are expected to benefit directly from this unique method.

Strain-induced coupling of spin current to nanomechanical oscillations

We propose a setup which allows us to couple the electron spin degree of freedom to the mechanical motions of a nanomechanical system not involving any of the ferromagnetic components. The proposed method employs the strain-induced spin-orbit interaction of electrons in narrow gap semiconductors. We have shown how this method can be used for detection and manipulation of the spin flow through a suspended rod in a nanomechanical device.

Locally Addressable Electrochemical Patterning Technique (LAEPT) applied to poly(L-lysine)-graft-poly(ethylene glycol) adlayers on titanium and silicon oxide surfaces

The protein-resistant polycationic graft polymer, poly(L-lysine)-g-poly(ethylene glycol) (PLL-g-PEG), was uniformly adsorbed onto a homogenous titanium surface and subsequently subjected to a direct current (dc) voltage. Under the influence of an ascending cathodic and anodic potential, there was a steady and gradual loss of PLL-g-PEG from the conductive titanium surface while no desorption was observed on the insulating silicon oxide substrates. We have implemented this difference in the electrochemical response of PLL-g-PEG on conductive titanium and insulating silicon oxide regions as a biosensing platform for the controlled surface functionalization of the titanium areas while maintaining a protein-resistant background on the silicon oxide regions. A silicon-based substrate was micropatterned into alternating stripes of conductive titanium and insulating silicon oxide with subsequent PLL-g-PEG adsorption onto its surfaces. The surface modified substrate was then subjected to +1800 mV (referenced to the silver electrode). It was observed that the potentiostatic action removed the PLL-g-PEG from the titanium stripes without inducing any polyelectrolyte loss from the silicon oxide regions. Time-of-flight secondary ions mass spectroscopy and fluorescence microscopy qualitatively confirmed the PLL-g-PEG retention on the silicon oxide stripes and its absence on the titanium region. This method, known as "Locally Addressable Electrochemical Patterning Technique" (LAEPT), offers great prospects for biomedical and biosensing applications. In an attempt to elucidate the desorption mechanism of PLL-g-PEG in the presence of an electric field on titanium surface, we have conducted electrochemical impedance spectroscopy experiments on bare titanium substrates. The results showed that electrochemical transformations occurred within the titanium oxide layer; its impedance and polarization resistance were found to decrease steadily upon both cathodic and anodic polarization resulting in the polyelectrolyte desorption from the titanium surface.

Expression of the grapevine stilbene synthase gene VST1 in papaya provides increased resistance against diseases caused by Phytophthora palmivora

The phytoalexin resveratrol (trans-3,5,4'-trihydroxy-stilbene), a natural component of resistance to fungal diseases in many plants, is synthesized by the enzyme trihydroxystilbene synthase (stilbene synthase, EC 2.3.1.95), which appears to be deficient or lacking in susceptible plants. Earlier workers isolated a stilbene synthase gene (Vst1) from grapevine (Vitis vinifera L.), which has subsequently been introduced as a transgene into a range of species to increase resistance of hosts to pathogens to which they were originally susceptible. Papaya (Carica papaya L.) is susceptible to a variety of fungal diseases, including root, stem, and fruit rot caused by the pathogen Phytophthora palmivora. Since resveratrol at 1.0 mM inhibited mycelium growth of P. palmivora in vitro, we hypothesized that papaya resistance to this pathogen might be increased by transformation with the grapevine stilbene synthase construct pVst1, containing the Vst1 gene and its pathogen-inducible promoter. Multiple transformed lines were produced, clonally propagated, and evaluated with a leaf disk bioassay and whole plant response to inoculation with P. palmivora. RNA transcripts of stilbene synthase and resveratrol glycoside were induced in plant lines transformed with the grapevine pVst1 construct shortly after pathogen inoculation, and the transformed papaya lines exhibited increased resistance to P. palmivora. The immature transformed plants appear normal and will be advanced to field trials to evaluate their utility.

The role of adrenomedullin and its receptor system in cardiovascular calcification of rat induced by Vitamin D(3) plus nicotine

Adrenomedullin (ADM) is a potent vasodilatory peptide which regulates blood pressure, cell growth and bone formation. Our work was aimed to explore the production of ADM, changes and pathophysiological significance of ADM mRNA and ADM receptor components--calcitonin receptor like receptor (CRLR) and receptor activity modifying proteins (RAMPs) mRNA in calcified myocardium and aorta of rats induced by Vitamin D3 plus nicotine. Contents of ADM in plasma, myocardium and aorta were measured by radioimmunoassay (RIA). The amount of ADM, CRLR and RAMPs mRNA was determined by semi-quantitative RT-PCR. The calcium content and alkaline phosphatase activity in myocardium and aorta of rats were measured. The results showed that the contents of calcium in calcified myocardium and aorta were increased by 3.5- and 6-fold (all P < 0.01), respectively, and alkaline phosphatases activity in calcified myocardium and aorta were increased by 66.5 and 82.7% (all P < 0.01 ), respectively, compared with control. Contents of ADM in plasma, myocardium and aorta were increased by 58% (P < 0.01), 14.3% (P < 0.01) and 27.8% P < 0.05). Furthermore, it was found that the amount of ADM, CRLR and RAMP2 mRNA in calcified myocardium was elevated by 90.6, 157.5 and 119.6% (all P < 0.01), RAMP3 mRNA was decreased by 14.1% (P < 0.01), respectively, compared with control. The amount of ADM, CRLR, RAMP2 and RAMP3 mRNA in calcified aorta was elevated by 37.7% (P < 0.01), 41.4% (P < 0.01), 60.1% (P < 0.05) and 13% P < 0.01), respectively, compared with control. The elevated level of CRLR and RAMP2 mRNA were in positive correlation with that of ADM mRNA (r = 0.992 and 0.882, respectively, P < 0.01) in calcified myocardium. The elevated level of CRLR and RAMP3 mRNA were also in positive correlation with that of ADM mRNA (r = 0.727, P < 0.05 and 0.816, P < 0.01, respectively) in calcified aorta. These results demonstrated that calcified myocardium and aorta generated an increased amount of ADM, up-regulated gene expressions of ADM, CRLR and RAMP2 mRNA. While the alteration of RAMP3 mRNA in calcified myocardium and aorta was different. These suggested that ADM and its receptor system might involve in the regulation of calcification in heart and aorta.

Correct positioning of the venous port-a-cath catheter: comparison of intravascular electrocardiography signal from guidewire and sodium bicarbonate flushed catheter

A prospective study comparing the efficacy of wire-conducted intravascular ECG (IVECG) signal and signal from the port with a sodium bicarbonate (NaHCO3) flushed catheter to correctly place a catheter tip was carried out in 100 patients. The correct position of the catheter tip was confirmed as follows: with technique G, the IVECG signal was conducted from a guide wire to identify the tip position. With technique P, the IVECG signal was conducted from the port with a NaHCO3 (0.8 mmol/ml) flushed catheter to ascertain the tip position. Each patient received both technique G and technique P in a randomized sequence. The quality of IV-ECG signals, which included baseline drift, P wave pattern and QRS wave pattern, were assessed for ten seconds. Satisfactory quality of these IVECG signals was observed in all of the patients with technique P and 90 of the 100 patients with technique G, and this difference was significant (P=0.001). There was no obvious difference between the techniques in catheter tip placement time or the measured optimal catheter length. The incidence of atrial premature contractions was higher with technique G than with technique P (13% vs 2%; P=0.003). Therefore, technique P is a practical alternative for correctly placing the catheter tip of a Port-A-Cath.

Impact of job characteristics on psychological health of Chinese single working women

This study aims at investigating the impact of individual and contextual job characteristics of control, psychological and physical demand, and security on psychological distress of 193 Chinese single working women in Hong Kong. The mediating role of job satisfaction in the job characteristics-distress relation is also assessed. Multiple regression analysis results show that job satisfaction mediates the effects of job control and security in predicting psychological distress; whereas psychological job demand has an independent effect on mental distress after considering the effect of job satisfaction. This main effect model indicates that psychological distress is best predicted by small company size, high psychological job demand, and low job satisfaction. Results from a separate regression analysis fails to support the overall combined effect of job demand-control on psychological distress. However, a significant physical job demand-control interaction effect on mental distress is noted, which reduces slightly after controlling the effect of job satisfaction.

[Influence of interleukin-10 on nitric oxide /nitric oxide synthase system of the aorta]

To study the influence of the inflammatory factor---interleukin-10 on nitric oxide (NO) and nitric oxide synthase system of rat aorta, Griess assay, production of (3)H-citrulline and Western blot were used to determine the release of NO, and the activity and expression of nitric oxide synthase, respectively. The results showed that lipopolysaccharide (LPS) stimulated the activity of inducible nitric oxide synthase (iNOS) and the release of NO. 10(-10) 10(-8) g/ml of IL-10 induced the activity and expression of endothelial nitric oxide synthase (eNOS), but not of iNOS. 10(-9) 10(-8) g/ml of IL-10 also downloaded the release of NO, and the activity and expression of iNOS induced by LPS, while 10(-7) g/ml of IL-10 significantly stimulated the activity and expression of iNOS but not eNOS. In summary, IL-10 presents a duple role in NO/NOS system. On the one hand, IL-10 inhibits the activity and expression of iNOS induced by inflammatory factor; on the other hand, IL-10 stimulates the release of endothelial NO.

Low-dose dexamethasone effectively prevents postoperative nausea and vomiting after ambulatory laparoscopic surgery

PURPOSE

To evaluate the prophylactic effect of low-dose dexamethasone (5 mg) on postoperative nausea and vomiting (PONV) in women undergoing ambulatory laparoscopic surgery. Metoclopramide and saline served as controls.

METHODS

One hundred twenty women (n=40 in each of the three groups) undergoing ambulatory laparoscopic tubal ligation under general anesthesia were enrolled in this randomized, double-blinded, placebo-controlled study. After tracheal intubation, group I received i.v. dexamethasone 5 mg, whereas groups II and III received i.v. metoclopramide 10 mg and saline, respectively.

RESULTS

Patients in group I reported a lower incidence of PONV and requested less rescue antiemetics than those in group III during the first four postoperative hours (P <0.01). Patients in group I reported a lower incidence of PONV than those in groups II (P <0.05) and III (P <0.01) during the 24-hr postoperative period. Groups II and III did not differ from each other in the incidence of PONV and the proportion of patients who requested rescue antiemetics.

CONCLUSION

Prophylactic iv dexamethasone 5 mg significantly reduces the incidence of PONV in women undergoing ambulatory laparoscopic tubal ligation. At this dose, dexamethasone is more effective than metoclopramide 10 mg or placebo.

Desensitization of adrenomedullin and calcitonin gene-related peptide receptors in vascular smooth muscle cells--effects of receptor activity-modifying protein

Recent researches suggest that adrenomedullin (ADM) and calcitonin gene-related peptide (CGRP) bind to the same calcitonin receptor-like receptors (CRLR), with receptor specificity being determined by a receptor activity-modifying protein (RAMP). Our objective was to explore the significance of CRLR/RAMP hypothesis in cardiovascular tissues through experiments on the phenomenon of desensitization of both ADM and CGRP receptors using cultured rat aortic vascular smooth muscle cells (VSMCs). VSMCs were incubated for 20 min either in serum-free medium (SFM) alone or in the SFM containing vasoactive agonist [10(-8) mol/L ADM, CGRP and proadrenomedullin (PAMP)]. Cells were washed twice and incubated for another 20 min in SFM containing a repetitive agonist ADM or CGRP and 0.5 mmol/L isobutyryl methylxant (an inhibitor of phosphodiesterase). VSMCs were harvested and assayed for cAMP. Exposure of VSMCs to ADM, CGRP, or PAMP alone increased intracellular cAMP generation by 191% (P < 0.01), 385% (P < 0.01) and 67% (P < 0.05), respectively, compared with SFM group. Pre-treatment of VSMCs to ADM or CGRP decreased cAMP generation in response to subsequent stimulation with CGRP by 44% (P < 0.05) and 48% (P < 0.01), respectively. Pre-treatment of VSMCs with 100 nmol/L H-89, a protein kinase A (PKA) inhibitor, abolished the desensitization of CGRP-acting receptor, implying that this desensitization was mediated through PKA. In contrast, there was no attenuation in cAMP response to stimulation with ADM by pre-exposure to ADM or CGRP. Identical results were seen with or without PKA inhibition by H-89. Pre-exposure of VSMCs to PAMP resulted in no change in cAMP generation in response to subsequent stimulation with ADM or CGRP. These results indicate that ADM receptors do not desensitize in VSMCs in contrast to CGRP-receptors, which are desensitized by pre-exposure to ADM or CGRP. These data also suggest that the desensitization phenomenon of ADM is different from that of CGRP.

[Ameliorative effects of adrenomedullin on rat cardiac sarcoplasmic reticulum injured by isoproterenol]

Five indices were used to assess the degree of the ameliorative effects of adrenomedullin (Adm) in isoproterenol (ISO) induced injury of cardiac sarcoplasmic reticulum (SR) of rats: +/- LV dp/dtmax, SR Ca2+ uptake, Ca2+ release (in nmol/mg SR protein) and Ca(2+)-ATPase activity. Adm (5 x 10(-5) mol/L) was perfused into rat heart before cardiac function +/- LV dp/dtmax was determined. Cardiac SR was purified and SR Ca2+ uptake, Ca2+ release, Ca(2+)-ATPase activity, and 3H-ryanodine maximal binding (Bmax) were measured. After perfusion of Adm (5 x 10(-5) mol/L), the +LV dp/dtmax and -LV dp/dtmax in ISO injured heart were increased by 16.9% (2,135 +/- 281 vs 1980 +/- 302, P < 0.05) and 29.2% (1375 +/- 267 vs 1064 +/- 355, P < 0.05), respectively. Cardiac SR Ca2+ uptake and Ca2+ release were increased by 23.0% (15.0 +/- 1.4 vs 12.2 +/- 1.2, P < 0.01) and 43.5% (6.6 +/- 1.0 vs 4.6 +/- 0.6, P < 0.01), respectively. Ca(2+)-ATPase activity and 3H-ryanodine binding were increased by 23.0% (P < 0.01) and 42.2% (P < 0.05), respectively. It seems that Adm exerted a protective effect on cardiac function in injured rat heart by enhancing SR Ca2+ uptake and release, suggesting that Adm may play a therapeutic role in myocardial injury.

[The biochemical properties of L-arginine/nitric oxide pathway in rat brain mitochondria]

Biochemical property of L-arginine (L-Arg)/nitric oxide synthase (NOS)/nitric oxide (NO) system was observed in rat brain mitochondria. The results showed that there existed L-Arg transporters of high-affinity, low-transport and saturability in mitochondria membrane of normal rat brain. The maximum transport velocity (V(max)) and Michaelis constant (Km) were 5.87+/ -0.46 nmol/mg pro x min(-1) and 7.8+/- 0.56 micromol/L respectively. In normal condition, endothelium-type NOS was expressed in the mitochondria of rat brain, with its V(max) and Km being 2.7+/-0.3 nmol/mg pro x min(- 1) and 20.85+/-3.27 micromol/L, respectively. NO production was increased in a time-dependent manner and reached a maximum value at 60 min. These results suggest that the L-Arg transporters in MT membrane of normal rat brain were similar with Y(+) type amino acid transporters in cellullar membrane. Furthermore the NOS of mitochondria belongs to eNOS, whereas the L-Arg/NOS/NO system may be a source of NO.

[Regulation of the transcription of oxidized low-density-lipoprotein receptor by angiotensin II]

AIM

To observe the effects of different concentrations Angiotensin II on the transcription of LOX1 in culture human umbilical vein endothelial cells and to explore its mechanism.

METHODS

Reverse transcription-polymerase chain reaction (RT-PCR).

RESULTS

(1) Angiotensin II cause a concentration-dependent increase of the level of LOX1 mRNA. (2) Losartan, the inhibitor of AT1 receptor subtypes, inhibited this effects.

CONCLUSION

Angiotensin II stimulated the gene expression of LOX1 by activating AT1 receptor subtype in culture human endothelial cells.

Gender-related psychosocial and cultural factors associated with condom use among Chinese married women

The present study explored the interplay of psychosocial, gender, and cultural factors on Chinese married women's condom use. A total of 433 Chinese married women residing in Hong Kong participated in the study. Correlation results showed that participants' conservative gender attitudes toward sexuality and sexual decision making were related to less accurate HIV/AIDS knowledge and less concern about contacting the disease from their husbands. About 34.4% of the sexually active participants never used condoms in the past 6 months, and current condom use was associated with egalitarian gender attitudes, positive feelings about condom use, and concerns about contacting HIV/AIDS from their husbands. Among all participants, 32.5% reported that they would not use condoms in their future sexual encounters. Future condom use was related to shorter duration of marriage, accurate HIV/AIDS knowledge, egalitarian gender attitudes, current condom use, and positive feelings about condom use. Results from the logistic regression analyses showed that egalitarian gender attitudes toward sexuality and positive feelings about condom use were the most salient predictors for current and future condom use.

[Influence of myocardial ischemia/reperfusion in vitro on nuclear envelope NTPase activity and mRNA export in the cardiomyocyte of rabbits]

AIM

To study the alteration of nuclear envelope associated NTPase activity and mRNA nucleocytoplasmic transport in rabbit cardiomyocyte following in vitro ischemia and reperfusion.

METHODS

The model of myocardial perfusion in rabbit was used to produce myocardial I/R injury and cardiomyocyte nuclear envelope vesicles were prepared by density gradient centrifugation for the assay of mRNA transport rate and NTPase activity.

RESULTS

NTPase activity was reduced and mRNA transport rate was significantly decreased in I/R (P < 0.01) but not in ischemia group( P > 0.05).

CONCLUSION

The nuclear envelope vesicles had been injured following ischemia and reperfusion and resulted in NTPase activity reduced and egress of mRNA interrupted, and therefore may lead to decreasing of protein synthesis.

Involvement of pressure-related mechanism in activation of inducible nitric oxide synthase

The goal of this study was to clarify the relationship between blood pressure and inducible nitric oxide synthase (iNOS) activity. Different levels of blood pressure were obtained by long-term (six days) intravenous infusion of different concentrations (0.3%-8%) of NaCl solution to normal SD rats. iNOS activity assay and measurement of urinary nitrate/nitrite (UNOx), an index of NO production of the whole body, were carried out by isotope-labeled L-arginine conversion rate measurement and Greiss Reaction respectively. Groups of normotensive and hypertensive rats including normal Wistar rats, normal Sprague-Dawley (SD) rats, high NaCl-induced hypertensive rats (NaHR) and spontaneously hypertensive rats (SHR) were used to detect the changes in iNOS protein under normotension and hypertension by Western blotting. iNOS activity of aorta and kidney tissues and UNOx increased more significantly in hypertensive animals than in the normotensive control ones. Accordingly, iNOS protein in the aortas of NaHR and SHR increased by 149% and 261% respectively. It is suggested that in addition to cytokine and bacterial products etc, blood pressure is also an effective regulatory factor involved in iNOS activation and expression.

Smoking status and body size increase carbon monoxide concentrations in the breathing circuit during low-flow anesthesia

The major sources for intraoperative carbon monoxide (CO) in the breathing circuit are related to patient's hemoglobin catabolism, smoking and the degradation between absorbent and anesthetics. We performed this study to evaluate their combined effects on CO production during low-flow anesthesia. We used a direct-measurement instrument to measure real-time CO concentrations in the breathing circuit during different anesthetic conditions for patients who received desflurane or isoflurane. By applying multiple linear regression models, we determined the significant factors related to CO concentrations in the circuit. We identified patients' smoking status, preoperative smoking and body weight as well as gas flow rates as important factors for affecting peak and time-weighted CO levels. These four factors predicted approximately 44.1% and 42.7% of peak and mean inspiratory CO concentrations respectively. We found that chronic and preoperative smokers and patients with larger body weights are associated with increased CO concentrations, whereas increase in gas flow rates could decrease CO concentrations. After controlling these four important factors, we found that inspiratory CO concentrations were not significantly associated with the choice of anesthetic and its concentration during low-flow anesthesia.

Transcriptional mRNA of bone morphogenetic proteins 2, 3, 4, and 5 in trigeminal nerve, benign and malignant peripheral nerve sheath tumors

Bone morphogenetic proteins (BMPs) have been shown to play an important role in cell growth and differentiation. BMPs, a rapidly expanding family closely related to transforming growth factor-beta (TGF-beta) superfamily, have been proven recently to possess a regulatory role and neurotrophic capacity in neurogenesis. The aim of the present study is to reveal the relationship among BMPs, peripheral nerve and neoplastic lesions of nerve sheath tumors. The mRNA transcriptions of BMP 2, 3, 4 and 5 in 12 cases of schwannoma, four cases of malignant schwannoma and three cases of trigeminal neuralgia were detected using an in situ hybridization technique. Our results demonstrated that the myelin sheaths of schwann cell from the peripheral neuroectomy of trigeminal neuralgia were positively expressing mRNA of BMP-2, 3, 4 and 5. However, the nerve fibers of trigeminal nerve showed only BMP-2 positive staining. All of the neoplastic lesions of nerve sheath showed a consistent but variant expression of BMP-2, 3, 4, and 5. Except for the BMP-4 mRNA, the expression signals of BMP-2, 3 and 5 mRNA in malignant schwannoma were relatively lower than in benign lesions. On the basis of the findings, we concluded that selected members of BMPs existed in the peripheral nerves and might contribute to the health maintenance, proliferation, regeneration and neoplastic transformation of the peripheral nerve system. Moreover, the effects of BMP-2, 3, 4 and 5 on peripheral nerve system and its neoplastic transformation might be widespread, diverse and antagonistic.

Intraoperative stroke under epidural anesthesia for bipolar hemiarthroplasty in a patient with multiple myeloma: a case report

A 56-yr-old, 58-kg woman with right femoral neck fracture underwent right bipolar hemiarthroplasty. Her medical problems included diabetes mellitus and multiple myeloma. Epidural anesthesia was performed uneventfully. No other drug except for local anesthetic (2% lidocaine) was administered during the procedure. Unfortunately, we "witnessed" the dramatically hemodynamic change of an intraoperative stroke, which was preceded by a hypotensive episode and followed by sustained hypertension. The stroke was presented with decreased level of consciousness initially and confirmed by the brain CT, which revealed acute infarction at the right middle cerebral artery territory, four days after the procedure. Multiple mechanisms such as intraoperative hypotensive episode and vascular atherosclerotic change due to poor controlled diabetes mellitus might be involved in the event. In the meanwhile, hyperviscosity (3.7 centipoise units of the patient v.s. 1.4-1.8 centipoise units of normal range) caused by multiple myeloma might also have contributed to the intraoperative stroke. Clinical presentation of this case will be discussed.

Dexamethasone for prophylaxis of nausea and vomiting after epidural morphine for post-Caesarean section analgesia: comparison of droperidol and saline

We have evaluated the prophylactic effect of i.v. dexamethasone 8 mg in preventing nausea and vomiting during epidural morphine for post-Caesarean section analgesia. Droperidol 1.25 mg and saline served as the control. We studied 120 parturients (n=40 in each group) receiving epidural morphine for post-Caesarean section analgesia, in a randomized, double-blind, placebo-controlled study. All parturients received epidural morphine 3 mg. Both dexamethasone and droperidol significantly decreased the total incidence of nausea and vomiting compared with saline, with incidences of 18, 21 and 51% for the three treatments respectively (P<0.01 and P<0.05 respectively). Parturients who received droperidol reported a more frequent incidence of restlessness (16%) than those who received dexamethasone (P<0.05).

[Content and activity of the focal adhesion kinase in cultured vascular smooth muscle cells enhanced by urotensin II]

Urotensin II (U II) is the most potent vasoconstrictor identified in vivo, which plays an important role in the smooth muscle cell proliferation in atherosclerosis. All available information suggests that focal adhesion kinase (FAK) is at the crossroads of multiple signaling pathways and is essential for cell proliferation. But the effect of U II on the FAK mediated signal transduction pathway is unclear. In this study, FAK content and tyrosine phosphorylation were assessed by Western blot and immunoprecipitation in cultured rat vascular smooth muscle cells. Increased protein tyrosine phosphorylation was observed within 5 min of U II 10(-7) (mol/L) addition and was maximal by 30 min, while FAK protein content showed no change during the first 30 min but it increased at 2 h reaching a plateau by 4 h, and decreased after 6 h. In addition, the elevated phosphorylation of FAK was detected upon U II stimulation at 10(-8) mol/L, being maximal at 10(-7) mol/L, but decreased at 10(-6) mol/L. Treatment of the cells with cytochalasin B (50 micromol/L), which disrupted the organization of cytoskeleton, had no influence on the increased FAK tyrosine phosphorylation in response to U sti II mulation. In order to study the relationship between FAK and mitogen-activated protein kinase, calmodulin and protein kinase C, selective inhibitors PD98059 (50 micromol/L), W7 (50 micromol/L) and H7 (50 micromol/L) were added following U II treatment. Neither PD98059 nor W7 influenced the increased FAK tyrosine phosphorylation, but H7 further increased it. These findings indicate that FAK activation is independent of the integrity of cytoskeleton and closely related to protein kinase C, but had no relation with mitogen activated protein kinase and calmodulin.

Efficacy of mycophenolate mofetil in patients with diffuse proliferative lupus nephritis. Hong Kong-Guangzhou Nephrology Study Group

BACKGROUND

The combination of cyclophosphamide and prednisolone is effective for the treatment of severe lupus nephritis but has serious adverse effects. Whether mycophenolate mofetil can be substituted for cyclophosphamide is not known.

METHODS

In 42 patients with diffuse proliferative lupus nephritis we compared the efficacy and side effects of a regimen of prednisolone and mycophenolate mofetil given for 12 months with those of a regimen of prednisolone and cyclophosphamide given for 6 months, followed by prednisolone and azathioprine for 6 months. Complete remission was defined as a value for urinary protein excretion that was less than 0.3 g per 24 hours, with normal urinary sediment, a normal serum albumin concentration, and values for serum creatinine and creatinine clearance that were no more than 15 percent above the base-line values. Partial remission was defined as a value for urinary protein excretion that was between 0.3 and 2.9 g per 24 hours, with a serum albumin concentration of at least 30 g per liter.

RESULTS

Eighty-one percent of the 21 patients treated with mycophenolate mofetil and prednisolone (group 1) had a complete remission, and 14 percent had a partial remission, as compared with 76 percent and 14 percent, respectively, of the 21 patients treated with cyclophosphamide and prednisolone followed by azathioprine and prednisolone (group 2). The improvements in the degree of proteinuria and the serum albumin and creatinine concentrations were similar in the two groups. One patient in each group discontinued treatment because of side effects. Infections were noted in 19 percent of the patients in group 1 and in 33 percent of those in group 2 (P = 0.29). Other adverse effects occurred only in group 2; they included amenorrhea (in 23 percent of the patients), hair loss (19 percent), leukopenia (10 percent), and death (10 percent). The rates of relapse were 15 percent and 11 percent, respectively.

CONCLUSIONS

For the treatment of diffuse proliferative lupus nephritis, the combination of mycophenolate mofetil and prednisolone is as effective as a regimen of cyclophosphamide and prednisolone followed by azathioprine and prednisolone but is less toxic.

Dexamethasone alone does not prevent postoperative nausea and vomiting in women undergoing dilatation and curettage: a comparison with droperidol and saline

BACKGROUND

The aim of this study was to evaluate the prophylactic effect of dexamethasone on postoperative nausea and vomiting (PONV) in women undergoing dilatation and curettage. Droperidol and saline were served as control.

METHODS

One hundred and sixty women (n = 40 in each group) undergoing dilatation and curettage under intravenous anesthesia were enrolled in this randomized, double-blinded, placebo-controlled study. Immediately before the induction of anesthesia, group 1 patients received i.v. dexamethasone 8 mg; group 2 patients received i.v. droperidol 1.25 mg; group 3 patients received i.v. droperidol 1.25 mg and dexamethasone 8 mg, and group 4 received i.v. saline.

RESULTS

We found that dexamethasone alone did not reduce the incidence of PONV in a 24 h postoperative period. Droperidol was effective for this purpose with incidence of PONV of 25% (P < 0.05). A combination of droperidol and dexamethasone was also effective and was the most effective regimen during the postoperative period of 2-24 h.

CONCLUSIONS

We conclude that dexamethasone (8 mg) alone does not prevent PONV in women undergoing dilatation and curettage. Droperidol is effective. Dexamethasone enhances the antiemetic effect of droperidol.

[The changes in the heart and erythrocyte L-arginine transport of spontaneously hypertensive rats]

Changes of L-arginine/nitric oxide pathway in heart and of L arginine transport in erythrocytes and their relationship were investigated in spontaneously hypertensive rats (SHR). 12 and 16 weeks old SHR, 16 weeks old SHR with captopril treatment for 4 weeks and 16 weeks old Wistar-Kyoto (WKY) rats were used. L arginine transport of myocardial ventricular tissue and erythrocytes, total nitric oxide synthase (tNOS) activity, nitrite and nitrate (NO(2) + NO(3)) and cyclic GMP (cGMP) content in myocardium were measured. The result showed that in myocardial ventricular tissue of SHR L-arginine transport decreased significantly with V(max) of the high-affinity transport being decreased by 24.3% (P<0.05, 12W group), 36.4% (P<0.01, 16W group) as compared with WKY group. Michaelis constant (K(m)) of low affinity transport was significantly lower than that of WKY group. NO(2) + NO(3) and cGMP content were respectively decreased by 24.6%, 19.8% (P>0.05, P<0.05, 12W group), 52.5%, 60.4% (P<0.05, P<0.01, 16W group) and 14.8%, 23% (P>0.05, P<0.05, SHR+C group) as compared with WKY group. But the K(m) of L-arginine high-affinity transport and the V(max) of low affinity transport and tNOS activity were not significantly changed. In erythrocytes, the changes of L-arginine transport coincided with those of myocardial tissue. The V(max) had significant positive correlation with the V(max) of high-affinity transport in myocardial tissue, r=0.5606, P=0.01 and had negative correlation with left ventricular weight to body weight radio, r=0.6231,P<0.01. These results indicate that the activity of L-arginine/nitric oxide pathway inhibited in myocardial tissue of SHR. The correlation between the inhibitory degree of L-arginine/nitric oxide pathway and the degree of ventricular hypertrophy is negative. The changes of L-arginine transport in erythrocytes coincide with those in myocardium.

[Inhibition of ERK1/2 activity and c-fos mRNA after coronary artery balloon injury by intracoronary radiation in swine]

The effect of intracoronary radiation on extracellular signal regulated kinase 1/2 (ERK1/2) activity and c-fos mRNA after coronary artery balloon injury was investigated in swine. Twenty three swines were randomly divided into a radiation group and a control group after coronary balloon over stretch. The dilated segments in the radiation group were exposed to a dose of 20 Gy by a catheter based radiation system. The animals were sacrificed at 3 (6 swines from each group) and 30 days (6 swines from radiation group and 5 from control group) after the operation. The injured segments were processed to examine c-fos gene expression by reverse transcription polymerase chain reaction (RT PCR) and to measure the activity of ERK1/2 biochemically. Intracoronary radiation decreased significantly the ERK1/2 activity and gene expression of c-fos in the radiation treated animals 3 days after coronary balloon injury (20.5%,P<0.01; 47.7%,P<0.05), but neither ERK1/2 activity nor c-fos gene expression was significantly affected by endovascular radiation in animals 30 days after balloon injury. Therefore, both ERK1/2 and c-fos may be involved in inhibiting restenosis.

[Role of calcineurin in cardiac fibroblast proliferation stimulated by angiotensin II]

The present study was undertaken to observe the role of calcineurin (CaN) in the angiotensin II (Ang II) stimulated cardiac fibroblast proliferation. In cultured cardiac fibroblasts of neonatal rats, Ang II was used to stimulate proliferation while CaN was inhibited by CaN CsA inhibitor cyclosporin A (CsA). (3)H-TdR incorporation, activity of CaN and intracellular calcium concentration were measured. (3)H-TdR incorporation of Ang II stimulated fibroblasts was 72% higher than control (P<0.01), which was inhibited by CsA (0.1 10 micromol/L) in a dose dependent manner. Intracellular Ca(2+) level and CaN activity of Ang II stimulated fibroblasts were respectively 112% (P<0.01) and 17%(P<0.05) higher than control. It is concluded that CaN may play an important role in signal transduction of the Ang II induced cardiac fibroblast proliferation.

The effect of timing of dexamethasone administration on its efficacy as a prophylactic antiemetic for postoperative nausea and vomiting

We evaluated the timing effect of a 10-mg IV administration of dexamethasone on its efficacy as a prophylactic antiemetic on postoperative nausea and vomiting (PONV). One hundred twenty women (n = 40 in each of three groups) undergoing abdominal total hysterectomy under general anesthesia were enrolled in this randomized, double-blinded, placebo-controlled study. Group 1 received dexamethasone before the induction of anesthesia, Group 2 received dexamethasone at the end of anesthesia, and Group 3 received placebo (saline). The incidence of PONV was evaluated. During the postoperative period of 0-2 h, patients in Group 1 reported a less frequent incidence of PONV (15%) than those in Groups 2 and 3 (45% and 53%, respectively). Patients in Group 1 also requested less rescue antiemetic (8%) than those in Groups 2 and 3 (30% and 35%, respectively). During the postoperative period of 2-24 h, patients in both Groups 1 and 2 reported less frequent incidences of PONV (25% and 28%) and requested fewer rescue antiemetics (13% and 15%) than those in Group 3 (55% and 38%, respectively). In conclusion, the prophylactic IV administration of dexamethasone immediately before the induction, rather than at the end of anesthesia, was more effective in preventing PONV.

IMPLICATIONS

We evaluated the effect of timing of dexamethasone administration on its efficacy as a prophylactic antiemetic on postoperative nausea and vomiting. We found that dexamethasone, when given immediately before the induction of anesthesia, was more effective than when given at the end of anesthesia.

Comparison of two bioassay methods for determining deltamethrin resistance in German cockroaches (Blattodea: Blattellidae)

Susceptibility to deltamethrin of 10 strains of the German cockroach, Blattella germanica (L.), trapped in hotel kitchens in Singapore was determined. Two resistance detection bioassay methods (topical application and World Health Organization glass jar method) were compared. Resistance ratios based on 50% knockdown, obtained by comparison with the S strain, ranged from 17.7 to 4,235 for topical application and from 2.2 to 22 for the glass jar method. A field strain, with consistently low resistance ratios (topical method = 17.7, glass jar method = 2.2), was identified as a potential field strain to be used as a baseline for comparison with other field strains. Resistance ratios for the other field strains obtained by comparison with the R5 strain ranged from 24.5 to 239 for topical application and from 1.2 to 9.8 for the glass jar method. The results of our study demonstrate that deltamethrin-resistant German cockroaches are numerous in Singapore. Comparison between the two bioassay methods showed that there was significant correlation between KD50 and KT50 values. The glass jar method is similar to field situations but topical application is sensitive enough to define the magnitude of resistance. Differences between the two detection bioassays and the factors governing the choice of bioassay in monitoring resistance in German cockroaches are discussed.

Basic fibroblast growth factor increases nitric oxide and endothelin production in rat aorta

The study was undertaken to investigate the effect of basic fibroblast growth factor (bFGF) on aortic production of nitric oxide (NO) and endothelin of aorta in spontaneously hypertensive rats (SHR) and WKY rats. Rat aortas were cut into vessel slices and incubated with 10 or 100 ng/ml bFGF for 6 hours. Nitric oxide synthase (NOS) activity in aortic slices and contents of NO(-)(2) and endothelin in the medium were determined. The results showed that NOS activity in aortic slices of SHR was 17.6% lower than that of WKY (P<0.01). NO(-)(2) and endothelin contents in the medium of SHR aortic slices were 59.7% lower and 37.4% higher than those of WKY aortic slices. Upon the exposure of low and high doses of bFGF, NOS activity in the aorta of SHR was increased by 29.7% and 59.6% (both P<0.01),respectively, while the NO(-)(2) contents in the medium were increased respectively by 28.2% (P<0.05) and 70.5% (P<0.01). Aortic endothelin production was increased by 24.1% and 44.5% (both P<0.01) respectively while the NOS activity in the aorta of WKY was increased by 24.4% and 53.7% (both P<0.01). NO(-)(2) contents in the medium were augmented by 18.8% (P<0.05)and 25.9% (P<0.01), respectively. Aortic endothelin production was increased by 84.1% and 93.1% (both P<0.01). It is concluded that bFGF may modulate the production of NO and endothelin in both SHR and WKY rats.

[Plasmid pcDNA3 enhances Ca(2+) transport of sarcoplasmic reticulum in ischemic skeletal muscle of rats]

The effects of plasmid pcDNA3 on Ca(2+) transport of sarcoplasmic reticulum (SR) in ischemic skeletal muscle was investigated. The results show that Ca(2+) transport (including Ca(2+) uptake and Ca(2+) release) rate of SR in ischemic skeletal muscle was markedly increased compared with that in non-ischemic muscle (P<0.01 or P<0.05). After plasmid pcDNA3 bound to the DNA binding proteins of SR, Ca(2+) transport of SR was further increased. The results suggest that the effect of plasmid DNA on the ability of Ca(2+) transport in SR of ischemic skeletal muscle is the same as is observed in normal skeletal muscle. The pathophysiological significance of the present finding deserves further exploration.

A novel approach of intravenous electrocardiograph technique in correct position the long-term central venous catheter

Intravenous electrocardiograph (IVECG) can correctly positioning the catheter tip by enlarging p wave as it is moved toward right atrium, and it is a safe, reliable and accurate technique. To evaluate the efficacy of wire-conducted IVECG signal and IVECG signal from the port with sodium bicarbonate (NaHCO3) flushed catheter and to compare those with conventional anatomy landmark method was the propose of this study. This prospective study was carried out in 216 patients who suffered from malignant diseases. The correct position of the catheter tip among these groups was confirmed as follows. In group 1 (n = 80), the anatomy landmark method and portable chest radiograph recognized the correct position. In group 2 (n = 72), IVECG signal was conducted from guide wire to identify the tip position. In group 3 (n = 64), IVECG signal was conducted from the port with NaHCO3 (0.8 mEq/mL) flushed catheter to ascertain the tip position. The patient characteristics did not differ significantly among the groups. The duration of operation was significantly (P < 0.001) longer in group 1 than in group 2 and group 3 (45.4 +/- 9.3 minutes vs 35.7 +/- 8.0 minutes and 35.2 +/- 9.7 minutes, respectively). Catheter tip placement times were shorter in group 2 and group 3 than in group 1 (5.3 +/- 2.9 minutes and 6.4 +/- 3.0 minutes vs 16.7 +/- 5.7 minutes, respectively); there was a statistically significant difference between the group 1 and group 2 and group 3 (p < 0.001). Nonetheless, the duration of operation and catheter tip placement time was similar in group 2 and group 3. Early and late complications within the subsequent 3 months showed no significant difference among groups. We concluded that IVECG signal conducted from guide wire obtained a similar efficiency to that signal from the port with NaHCO3 flushed catheter on positioning the catheter tip of the venous Port-A-Cath system. It is recommended to use these methods to facilitate implanting long-term central venous devices.

Influences of tramadol on emergence characteristics from sevoflurane anesthesia in pediatric ambulatory surgery

Sevoflurane is used for pediatric ambulatory surgery due to its low blood solubility, rapid emergence, non-pungency and low airway irritability. Nevertheless, its tendency to induce agitation during emergence may offset its benefits. The following study was designed to evaluate the effects of intravenous (i.v.) tramadol (1 mg/kg) on the emergence from sevoflurane anesthesia. Forty ASA I children, ranging from 1 to 8 years old, scheduled for inguinal surgery, were randomized into two groups (Group S--control group, Group ST--i.v. tramadol, 20 in each group). The patients were first premedicated with oral atropine (0.01 mg/kg), then anesthesia was induced with i.v. application of thiamylal (3-4 mg/kg) and maintained with mask anesthesia with sevoflurane. Topical infiltration with 2-3 ml of 1% lidocaine was applied over skin incision area. I.v. tramadol (1 mg/kg) was given before the end of operation in Group ST. The emergence agitation was recorded on a visual analog scale (VAS, 0-10) by a blinded anesthesiologist in the PACU (postoperative anesthesia care unit), as well as the length of other recovery stages and complications after anesthesia. The age, weight, gender, and duration of surgery and anesthesia were similar in the two groups. The emergence agitation score (6.3 +/- 3.5 vs. 3.2 +/- 2.8, P < 0.05), incidences of agitation (VAS > 5, 55% vs 20%, P < 0.05), and postoperative pain (65% vs 30%, P < 0.05) were higher for the control group. I.v. Tramadol (1 mg/kg) before the end of operation reduced postoperative pain and the incidence and degree of emergence agitation from sevoflurane anesthesia in pediatric ambulatory surgery.

Effect of metallothionein on tolerance of nitroglycerin in rats

AIM

To assess whether metallothionein (Met) could improve the nitroglycerin tolerance in vivo.

METHODS

Nitrate tolerance was induced by 2-d treatment of nitroglycerin (Nit) patch (0.05 mg.h-1). Endogenous Met production was induced by pretreatment of ZnCl2 and coadministration of intravenous Met (15 mg.kg-1.d-1) 2 d with Nit in tolerant rats. The induction of Met production was confirmed by the assay of liver and plasma Met levels.

RESULTS

ZnCl2 induced large amount of endogenous Met production in liver and plasma in Nit + ZnCl2 group than that in control group, (89 +/- 4) micrograms/g tissue vs (11.0 +/- 2.4) micrograms/g tissue in liver, P < 0.01, and in plasma (85 +/- 6) micrograms.L-1 vs (71 +/- 6) micrograms.L-1, P < 0.01. There was no significant difference in plasma Met levels in Nit and control groups [(75 +/- 6) micrograms.L-1 vs (71 +/- 6) micrograms.L-1, P > 0.05]. The endogenous Met production enhanced the hypotensive response in Nit + ZnCl2 group [(15.7 +/- 0.8) kPa vs (11.5 +/- 0.6) kPa, n = 6, P < 0.05]. The maximal vessel relaxation induced by sodium nitroprusside (SNP) was the same in 4 different groups but the highest EC50 (concentration which produces 50% of the maximal response to SNP) was found in tolerant group [(42 +/- 9) nmol.L-1, P < 0.01].

CONCLUSION

Exogenous Met or induction of endogenous Met production antagonize the development of Nit tolerance.

[Signal transduction pathways in cardiac myocyte hypertrophy]

Cardiac hypertrophy is the consequence of hypertrophic stimulus-induced changes in gene expression, which is linked by intracellular signal transduction. It is likely, however, that there are "molecular phenotypic" differences underlying cardiac hypertrophy triggered by different stimuli, which is caused by the different signal pathways that they initiated. Studying on the signal pathways in cardiac myocyte hypertrophy contributed to elucidate the cellular and molecular mechanisms of cardiac hypertrophy and might find some new strategies for the prevention of cardiac hypertrophy.

Effect of batroxobin against dog heart ischemia/reperfusion injury

AIM

To study the effect of batroxobin(Bat) on dog heart ischemia/reperfusion (I/R) injury.

METHODS

Dog heart I/R injury was induced by occluding the left anterior descending coronary artery for 30 min and restoring blood perfusion for 90 min. Bat was intravenously injected before heart ischemia and 15 min before reperfusion. Plasma creatine kinase (CK), lactate dehydrogenase (LDH), and myocardial malondiaedehyde (MDA) concentrations were measured. The pathologic changes of I/R myocardium were observed.

RESULTS

Bat reduced the mortality rate of I/R dog (I/R group 65.0% vs Bat-I group 30.0% and Bat-II group 28.6%, P < 0.05). Myocytes of I/R heart showed intracellular edema, damaged mitochondria, and concentrated nucleus. Bat decreased these changes. In Bat-I and Bat-II group, plasma CK and LDH level were reduced, the +dp/dtmax and -dp/dtmax at 30 min after ischemia and 90 min after reperfusion were elevated, and left ventricular end dilation pressure (LVEDP) was lowered. The myocardial MDA contents were decreased by 42.3% and 38.1% (P < 0.01) in Bat-I and Bat-II group, respectively.

CONCLUSION

Bat may exert an apparent role against dog heart ischemia/reperfusion injury and improve myocardial function.

Correlation of arterial and end-tidal carbon dioxide in spontaneously breathing patients during ambulatory gynecologic laparoscopy

Laparoscopy can be performed while patients are under total intravenous anesthesia (TIVA), or sedated and breathing spontaneously through the normal airway. Respiratory monitoring is difficult when patients are sedated or anesthetized, however. The purposes of this study were to evaluate the reliability of end-tidal carbon dioxide (ETCO2) measurement for monitoring arterial carbon dioxide pressure (PaCO2), and to assess the PaCO2/ETCO2 gradient among patients receiving TIVA while breathing spontaneously through the normal airway. Sixty patients were divided into two groups: group 1 patients (n = 30) received general anesthesia with controlled ventilation, while group 2 patients (n = 30) received TIVA with spontaneous breathing through the normal airway; ETCO2 was sampled through a 10-French suction catheter inserted into the nasopharynx via the nasal airway. Arterial blood gas and ETCO2 were recorded at the time of preinduction, induction, CO2 insufflation, and change to Trendelenburg tilt position (20 degrees-30 degrees), and at 10-minute intervals thereafter. The results showed that ETCO2 was highly correlated with PaCO2 in group 1 (correlation coefficient r = 0.85), but not in group 2 (r = 0.55). In group 2, the PaCO2/ETCO2 gradient increased as time elapsed, with significant differences (p < 0.05) between the values at induction and those at 30 minutes after the change to the Trendelenburg position and thereafter. These results indicate that the ETCO2 and PaCO2 values correlate well during the first 20 minutes after the change to the Trendelenburg position in laparoscopy patients receiving TIVA with spontaneous breathing, but that PaCO2 monitoring is still necessary.