bluuebunny/crossref_metadata_2025_split huggingface dataset:
Responses To Microinjections Of Endomorphin And Nociceptin Into The Medullary Cardiovascular Areas
Authors: Sapru HN , Chitravanshi VC 
Published: March 2003

SUMMARY1. Cardiovascular effects of microinjections of nociceptin and endomorphin‐2 into the following medullary areas were studied in urethane‐anaesthetized rats: chemoreceptor projection site (CPS), intermediate portion of the nucleus tractus solitarius (I‐NTS), caudal ventrolateral medullary depressor area (CVLM) and rostral ventrolateral medullary pressor area (RVLM).2. Microinjections of nociceptin or endomorphin‐2 (0.6 mmol/L each) into the CPS and RVLM elicited depressor and bradycardic responses, whereas similar injections into the I‐NTS and CVLM elicited pressor and tachycardic responses.3. The mechanism of cardiovascular responses to microinjections of these opioid peptides into different medullary areas involved in cardiovascular function can be postulated as follows: the direct effect of nociceptin and endomorphin‐2 on neurons is usually inhibitory. Because the activation of CPS and RVLM by microinjections of L‐glutamate results in pressor and tachycardic responses, inhibition
of these areas by nociceptin and endomorphin‐2 elicits depressor and bradycardic
responses. Similarly, activation of neurons in the I‐NTS and CVLM by microinjections
of L‐glutamate elicits depressor and bradycardic responses. Therefore, inhibition of these areas by microinjections of these opioid peptides elicits an increase in blood pressure and heart rate.
Effects Of Combined Pioglitazone And Metformin On Diabetes And Obesity In Wistar Fatty Rats
Authors: Suzuki Masami , Odaka Hiroyuki , Suzuki Noriko , Sugiyama Yasuo , Ikeda Hitoshi 
Published: March 2003

SUMMARY1. The effects of combined treatment with pioglitazone·HCl and metformin on diabetes and obesity were investigated in Wistar fatty rats, which are hyperglycaemic and hypertriglyceridaemic and have higher plasma levels of total ketone bodies than lean rats.2. Plasma glucose was significantly decreased when pioglitazone·HCl or metformin was administered alone and combined treatment accentuated this decrease. The administration of pioglitazone·HCl, but not metformin, also decreased plasma levels of triglyceride and total ketone bodies.3. The glycogen content of skeletal muscle was not increased by pioglitazone·HCl or metformin alone, but was increased by combined treatment (P = 0.003, ANOVA).4. Pioglitazone·HCl produced increased food intake and bodyweight in hyperphagic Wistar fatty rats; however, concurrent administration of metformin significantly ameliorated these pioglitazone·HCl‐induced increases.5. These results indicate that combined treatment with pioglitazone·HCl and metformin induces a marked hypoglycaemic effect accompanied by a reduction in plasma levels of total ketone bodies and prevention of excessive bodyweight gain in Wistar fatty rats. These favourable effects suggest that the combination would be beneficial in treating patients with type 2 diabetes.
Altered Expression Of Vascular Natriuretic Peptide Receptors In Experimental Hypertensive Rats
Authors: Lee JongUn , Kim Sunmi , Jung Mehye , Oh YoonWha , Kim Soo Wan 
Published: March 2003

SUMMARY1. The aim of the present study was to determine whether the regulation of vascular natriuretic peptide receptors (NPR) is related to the local renin–angiotensin system (RAS).2. Male Sprague‐Dawley rats were made two‐kidney, one‐clip (2K1C) and deoxycorticosterone acetate (DOCA)‐salt hypertensive to activate and inhibit the RAS, respectively. Another model of hypertension was induced by treatment with an inhibitor of nitric oxide synthesis, namely NG‐nitro‐L‐arginine methyl ester
(L‐NAME).3. The mRNA expression of NPR‐A, NPR‐C, angiotensin‐ converting enzyme (ACE) and angiotensin AT1 receptors was determined in the thoracic aorta by semiquantitative reverse transcription–polymerase chain reaction. The particulate guanylyl cyclase activity stimulated by atrial natriuretic peptide (ANP) was also determined in the membrane fraction of the thoracic aorta.4. The plasma concentrations of ANP were increased significantly in the three models of hypertension. Plasma renin activity was increased in 2K1C hypertension, decreased in DOCA‐salt hypertension and not significantly altered in L‐NAME hypertension.5. The mRNA expression of NPR‐A and NPR‐C was decreased, whereas that of ACE and AT1 receptors was increased in 2K1C and L‐NAME hypertension.
The mRNA expression of NPR‐A and NPR‐C was increased, whereas that of ACE and AT1 receptors was decreased in DOCA‐salt hypertension.6. The particulate guanylyl cyclase activity was decreased in 2K1C and L‐NAME hypertension and increased in DOCA‐salt hypertension.7. The vascular expression of NPR may be reciprocally regulated by local RAS activity.
Decrease In Catechol‐O‐Methyltransferase Activity In The Liver Of Streptozotocin‐Induced Diabetic Rats
Authors: Wang JP , Liu IM , Tzeng TF , Cheng JT 
Published: March 2003

SUMMARY1. The present study compared the activity of catechol‐ O‐methyltransferase (COMT) in the liver and plasma of streptozotocin (STZ)‐induced diabetic rats with that in normal rats. The activity of COMT was estimated by the metabolism of noradrenaline to metanephrine (MN), both measured by high‐performance liquid chromatography with electrochemical detection.2. Formation of MN was decreased in the liver of STZ‐ diabetic rats compared with normal rats. The amount of MN was also decreased in plasma obtained from STZ‐diabetic rats. A Michaelis–Menten plot showed a reduction in the maximum velocity and an increase in the Km for COMT in liver samples from STZ‐diabetic rats.3. The role of hyperglycaemia in the lowering of COMT activity was then investigated using phlorizin or insulin at doses sufficient to normalize plasma glucose from STZ‐diabetic rats. Both insulin and phlorizin treatment of STZ‐diabetic rats for 4 days restored the activity of COMT to that seen in normal rats. Thus, correction of hyperglycaemia in STZ‐diabetic rats can reverse the decrease in COMT activity. The activity of COMT is lower in STZ‐diabetic rats than in normal rats mainly due to the higher plasma glucose.
Effects Of A 1 Day Fast On Biohumoral Variables Associated With Human Circadian Rhythmicity
Authors: Uezono Keiko , Kawasaki Terukazu , Itoh Kazue , Cugini Pietro 
Published: March 2003

SUMMARY1. The aim of the present study was to investigate the effects of a short (1 day) fast by testing biohumoral variables associated with the human circadian rhythm.2. Fifteen clinically healthy male volunteers (32 ± 8 years old) participated in the study. Subjects were fed a control diet for 7 days. The last day was a control day and the following 8th day was the fasting day. Each subject was asked to collect urine seven times over a 24 h period. Chemical and hormonal variables were measured in each fractionated urine specimen. The time‐ qualified urinary excretion rates were biometrically analysed using conventional and chronobiological methods.3. During fasting, significant incremental changes were detected in the urinary excretion rates of potassium, aldosterone, 17‐hydroxycorticosteroids and adrenaline and significant decremental changes were detected in the excretion rates of sodium, chloride, creatinine, urea nitrogen, uric acid, 17‐ketosteroids, noradrenaline and dopamine. The circadian rhythmicity of the variables was well preserved and remained almost stable throughout the fasting phase.4. Fasting affected the mean oscillatory levels and oscillatory amplitudes of variables, suggesting that nutrients may have played roles as tonic and phasic modulators on the mechanisms that physiologically regulate ircadian rhythmicity.
Effects Of Blockade Of α‐ and β‐Adrenoceptors And Neuropeptide Y1 Receptors, As Well As Brachial Plexus Blockade, On Endothelium‐Dependent Vasodilation In The Human Forearm
Authors: Johansson Kristina , Eriksson Mats , Wahlqvist Inger , Mühlen Bengt von zur , Lind Lars 
Published: March 2003

SUMMARY1. The aim of the present study was to investigate the effects of α‐adrenoceptor
blockade (phentolamine), β‐adrenoceptor blockade (propranolol), neuropeptide
Y1 receptor blockade and neurogenic blockade (brachial plexus) on endothelium‐dependent vasodilation (EDV) in the human forearm.2. Forty‐four young healthy volunteers underwent forearm blood flow (FBF) measurements, using venous occlusion plethysmography, during local intra‐arterial infusions of methacholine (MCh; inducing EDV) and sodium nitroprusside (SNP; inducing endothelium‐independent vasodilation (EIDV)). These measurements were undertaken at baseline and were repeated with either concomitant local intra‐arterial infusion of phentolamine (n = 8),
propranolol (n = 7) or saline (n = 6) in the forearm, neuropeptide
Y1 receptor blockade (n = 12) given i.v. or during axillary plexus
blockade (n = 11).3. Both α‐adrenoceptor blockade and neurogenic blockade induced an
upward shift in the dose–response curve for both EDV and EIDV. β‐Adrenoceptor
blockade did not change resting FBF or EIDV, but induced a significant decrease in
EDV (P = 0.015). Neuropeptide Y1 receptor blocker induced no significant changes in resting FBF, EDV and EIDV and neither did saline. No changes in blood pressure or heart rate were induced by any of the blockades.4. Whereas β‐adrenoceptor blockade impaired EDV, α‐adrenoceptor blockade and neurogenic blockade caused a general vasodilation that was not endothelium dependent. Neuropeptide Y does not seem to influence blood flow in the resting forearm.
Functional Analysis Of Histamine Receptor Subtypes Involved In Endothelium‐Mediated Relaxation Of The Human Uterine Artery
Authors: Spitaler Michaela M , Hammer Astrid , Malli Roland , Graier Wolfgang F 
Published: March 2003

SUMMARY1. This work was designed to introduce human uterine arteries as a new model for cardiovascular research. Advantages of this model include considerable availability of tissue because of the appearance of uterus myomatosus in post‐menopausal women who undergo surgery and the chance to work on dysfunctional and healthy vessels.2. Histamine evoked relaxation of the uterine artery that was prevented by removal of the endothelium or by the presence of NG‐nitro‐L‐arginine.3. Receptor antagonists for histamine H1 (mepyramine) and H2 (ranitidine) receptors increased the EC50 of histamine by 112‐ and 67‐fold, respectively.4. Remarkably, isolated uterine arteries could be stored in incubators for 5 days without any change in contractility to phenylephrine and endothelium‐dependent relaxation to acetylcholine and histamine.5. Endothelial cells could be isolated and cultured in high purity, as demonstrated by histochemical staining of factor VIII, low CD45‐RO for macrophages and no smooth muscle α‐actin. In addition, cultured human uterine artery endothelial cells could be used for single cell Ca2+ measurements.6. In agreement with our findings in the intact vessel, histamine‐initiated elevation of the intracellular free Ca2+ concentration was reduced in the presence of mepyramine and ranitidine by 59 and 55%, respectively.7. These data indicate that, in the human uterine artery, H1 and H2 receptors are involved in histamine‐induced endothelium‐dependent relaxation that is mediated by nitric oxide.8. In addition, this vessel can be stored for possible virus‐mediated gene expression for 5 days without any loss of reagibility.9. Finally, endothelial cells can be isolated and cultured from the human uterine artery and maintain their reactivity to histamine in culture.
Problems In The Use Of Herbal And Natural Substances, With A Specific Example Concerning The Cardiovascular System
Authors: Pang Peter KT , Benishin Christina , Lewanczuk Richard , Shan Jacqueline 
Published: March 2003

SUMMARY1. There has been increasing awareness and use of natural preparations for health purposes by consumers.2. However, recent studies have repeatedly shown that many natural products marketed as nutraceuticals or health food do not deliver the health benefit as claimed and are inconsistent from batch to batch.3. The present paper describes the scientific rationale of such inconsistency and uses an antihypertensive preparation as an example to demonstrate the significant value of natural products if developed scientifically and properly.
Intratracheal Administration Of Glucocorticoids Using Surfactant As A Vehicle
Authors: Nimmo Alan J , Carstairs Jill R , Patole Sanjay K , Whitehall John , Davidson Kate , Vink Robert 
Published: March 2003

SUMMARY1. Glucocorticoids are an effective treatment in the amelioration of chronic lung disease in neonates. However, systemic administration of glucocorticoids to neonates is associated with significant side‐effects that preclude them as an early intervention to prevent onset of the condition. Conversely, local intratracheal administration of glucocorticoids may prevent inflammatory insult to the lungs without the development of systemic side‐effects. We therefore investigated whether local intratracheal delivery of corticosteroids could be facilitated using surfactant as a vehicle.2. Addition of dexamethasone to either diluted or commercial artificial surfactant, Survanta (Abbott Industries, Sydney, NSW, Australia), did not alter the surface properties of the surfactant.3. After intratracheal instillation to rats, radiolabelled dexamethasone in Survanta was well distributed throughout all four lobes of the lungs. A concentration gradient of the steroid was observed between the root and the peripheral sections of all lobes.4. Our results suggest that surfactant is an effective vehicle for intratracheal delivery of glucocorticoids. Moreover, we propose that prophylactic intratracheal administration of glucocorticoids administered shortly after birth may prevent inflammatory insult to the lungs and thereby reduce the likelihood of chronic lung disease developing.
Clinical trials and tribulations
Authors: McInnes Gordon T 
Published: March 2003

Summary1. Pharmacologists should be involved in all stages of drug development. Often neglected is the final step, the clinical trials and other studies that determine clinical utility. The present article illustrates how pharmacoepidemiology can facilitate evaluation of the clinical potential of different drugs used to treat hypertension.2. The evidence base for the drug treatment of hypertension is very strong. Large‐scale outcome trials, largely based on diuretics, indicate that stroke events are prevented to the extent expected from blood pressure reduction, but there appears to be a shortfall in the prevention of coronary heart disease events.3. On theoretical grounds, newer agents may be expected to have benefits in coronary heart disease prevention beyond blood pressure reduction. Recent trials with angiotensin‐converting enzyme inhibitors and calcium channel blockers suggest no advantage over conventional drugs, but shortcomings in these studies mean that each is uninformative.4. Observational studies based on pharmacoepidemiological principles offer an alternative approach to evaluating outcomes in treated hypertensives.5. Evidence from the Glasgow Blood Pressure Clinic database suggest that there are outcome differences between antihypertensive agents. Angiotensin‐converting enzyme inhibitor treatment is associated with a mortality advantage, whereas calcium channel blocker therapy is associated with a poorer prognosis. Preliminary findings from a primary care database support these observations.6. Long‐term follow up of a well‐documented high‐risk clinical population may allow detection of outcome differences not apparent in relatively short‐term clinical trials.7. Appropriate interpretation of observational data necessitates an understanding of the strengths and limitations of observational data. Clinical pharmacologists have a critical role in design and evaluation of pharmacoepidemiology studies.
Effects of glutathione S‐transferase inhibitors on nitroglycerin action in pig isolated coronary arteries
Authors: Matsuzaki Toshihiro , Sakanashi Mayuko , Nakasone Junko , Noguchi Katsuhiko , Miyagi Kanako , Sakanashi Makiko , Kukita Ichiro , Aniya Yoko , Sakanashi Matao 
Published: March 2003

Summary1. The present study was designed to clarify the role of glutathione S‐transferase (GST) in the vasorelaxation response and development of tolerance to nitroglycerin (GTN) using GST inhibitors.2. In pig isolated coronary arteries, GST activity was significantly changed to 77 and 82, or 69% of the control level (100%) following treatment with bromosulphophthalein (BSP; 10−3 and 10−4 mol/L) or ethacrynic acid (ETA; 10−4 mol/L), both GST inhibitors, respectively, but not following treatment with 10−3 and 10−4 mol/L GTN (GST activity 97 and 98% of control, respectively).3. In KCl‐contracted coronary artery strips pre‐incubated with 10−5 and 10−4 mol/L GTN, 10−4 and 10−3 mol/L BSP or 10−4 mol/L ETA, concentration‐dependent relaxations produced by GTN were significantly decreased compared with control.4. 8‐Bromo cGMP (8‐Br‐cGMP), a membrane‐permeable cGMP analogue, produced concentration‐dependent relaxations in GTN‐pretreated arterial strips that were identical to control responses. However, there was weak but significant decrease in concentration‐dependent relaxations in response to 8‐Br‐cGMP in BSP‐ and ETA‐pretreated arteries.5. The cGMP content in coronary arteries was significantly increased with GTN, GTN + BSP or GTN + ETA to similar high levels compared with control.6. The results of the present study show that BSP and ETA decrease GTN‐ and 8‐Br‐cGMP‐induced vasorelaxation, but have no effect on the GTN‐induced increase in cGMP content in coronary arteries, suggesting a possibility that the GST inhibitors may have depressant actions on GTN‐ and 8‐Br‐cGMP‐induced vasorelaxation through direct inhibition of the vasorelaxation of vascular smooth muscle themselves, in addition to having inhibitory effects GST activity.
Responses to endothelium‐derived factors and their interaction in mesenteric arteries from Wistar‐Kyoto and stroke‐prone spontaneously hypertensive rats
Authors: Sekiguchi Fumiko , Nakahira Tomohiro , Kawata Kyoko , Sunano Satoru 
Published: March 2003

Summary1. Responses to endothelium‐derived nitric oxide (EDNO), indomethacin‐sensitive endothelium‐derived contracting factor (EDCF) and hyperpolarization by endothelium‐derived hyperpolarizing factor (EDHF) and the interaction among these factors in mesenteric arteries from 16‐week‐old Wistar Kyoto (WKY) rats and age‐matched stroke‐prone spontaneously hypertensive rats (SHRSP) were studied, observing the time‐course of the response to 10−5 mol/L acetylcholine (ACh).2. The effects of EDNO, EDCF and EDHF were blocked by Nω‐nitro‐l‐arginine (10−4 mol/L), indomethacin (10−5 mol/L) and a combination of apamin (5 × 10−6 mol/L) and charybdotoxin (10−7 mol/L), respectively.3. The response to EDNO observed in the absence of EDCF and EDHF was not different between preparations from WKY rats and SHRSP. The response to EDCF observed in the absence of EDNO and EDHF was slightly greater in preparations from SHRSP. The response to EDHF in the absence of EDNO and EDCF was much greater in preparations from WKY rats.4. Endothelium‐derived contracting factor attenuated the relaxation in response to EDNO, the attenuation being greater in preparations from SHRSP. Relaxation in response to EDNO was blocked by EDHF in preparations from WKY rats, but not in preparations from SHRSP.5. The response to EDCF was augmented by both EDNO and EDHF. The augmentation was greater in preparations from SHRSP.6. The response to EDHF was attenuated by EDNO in preparations from WKY rats, but not in preparations from SHRSP. The response to EDHF was attenuated by EDCF in preparations from both WKY rats and SHRSP, the attenuation being greater in preparations from SHRSP.7. These results suggest that there are interactions among these factors in terms of their release or the response to ACh in mesenteric arteries that differ between preparations from WKY rats and SHRSP. In addition, involvement of factors other than these three factors, which also differs between preparations from WKY rats and SHRSP, is suggested.
Parasitism of mosquitoes (Diptera: Culicidae) by larval mites (Acari: Parasitengona) in Adelaide, South Australia
Authors: Williams Craig R , Proctor Heather C 
Published: March 2003

AbstractLarval mites (Acari) from the cohort Parasitengona were collected from adult female mosquitoes captured in Adelaide, South Australia, from 1997 to 2000. Larvae from three families were identified: Arrenuridae, Hydryphantidae and Erythraeidae. Arrenurid larvae were associated with mosquitoes that use ground pools for larval habitat, while hydryphantids were associated with tree‐hole and container‐breeding species. Only a single erythraeid record was made. The overall prevalence of parasitism was very low (0.27% of 19 280 mosquitoes) and ranged from 0 to 5.6% for the 16 mosquito species collected. New mite–host records are presented.
Reduction in cricket (Orthoptera: Ensifera) populations along a gradient of sulphur dioxide from mining emissions in northern Australia
Authors: Hoffmann Benjamin D , Lowe Lyn M , Griffiths Anthony D 
Published: March 2003

AbstractThe impact of SO2 dry deposition from mining emissions on cricket abundance,

diversity and composition was investigated at Mount Isa in the semiarid tropics of

northern Australia. Seventy‐one sites were sampled, stratified at two levels: sulphur

deposition zones (high, medium, low, and background zones) and habitat (rocky ridge,

rocky plain and alluvial plain). The three habitats did not support distinctly different

cricket assemblages. Crickets responded to SO2 emissions, but impacts

were largely restricted to the high‐sulphur zone. Generalised linear modelling showed

significant reductions in the probability of presence in the high‐sulphur zone for

the three genera Eurepella, Salmanites and Endacusta, and the subfamily

Eneopterinae. In ordination space, the three high‐sulphur zone by habitat combinations

were clearly separated from all other combinations, and vector fitting of environmental

variables showed soil SO4 to be a primary correlative factor of this separation.

Crickets are sensitive to SO2 emissions and they appear to be a good indicator group in this context.
The clinical effects of spider bites in southern Tasmania
Authors: Woo Kathy Ml , Smart David R 
Published: March 2003

Objectives: To analyse the clinical features and outcomes of patients with spider bites who presented to the Department of Emergency Medicine, Royal Hobart Hospital, Tasmania, Australia. Methods: A retrospective study of all patients with an emergency department discharge diagnosis of confirmed spider bite during a 5 year period was performed. Results: Twenty‐two cases were identified, 15 of which involved unidentified spiders. Most victims were in the 15–34 years age group and were bitten in the home. Identified spiders included: redback (Latrodectus hasselti), white‐tailed house (Lampona cylindrata), black house (Badumna insignis) and huntsman (Delena cancerides). Pain, swelling and erythema were the main presenting symptoms; main presenting signs were erythema, swelling, bite marks, local tenderness, lymphadenopathy and blistering. In 23% of cases, no clinical signs were detectable. Treatment consisted of antihistamines (36%) and antibiotics (32%). Four patients had signs consistent with necrotizing arachnidism; two of the four healed with hyperbaric oxygen after antibiotic treatment failed. Redback antivenom was administered to four patients. Three patients required in‐patient treatment for local complications. Conclusions: Most spider bites presenting to Royal Hobart Hospital were uncomplicated; redback bites were uncommon. Treatment strategies were ill‐defined and microbiological specimens were taken infrequently. Patients’ tetanus immunization status was poorly documented. There is a need for a national register of spider bites in Australia.