bluuebunny/crossref_metadata_2025 huggingface dataset:
Effects of Alcohol Intake on Organ Injuries in Normotensive and Hypertensive Human Subjects
Authors: Ishimitsu Toshihiko , Yoshida Kaori , Nakamura Miki , Tsukada Kohju , Yagi Shigeru , Ohrui Masami , Hisauchi Tohru , Matsuoka Hiroaki
Published: August 2015

1. This cross-sectional study examined the influence of alcohol intake on organ injuries in normotensive and hypertensive subjects.

2. A total of 514 normotensive subjects and 302 never-treated hypertensive subjects were screened from 4557 men who entered the health check programme of our institute during the period 1990 to 1994. According to the daily alcohol consumption data reported by a self-administered questionnaire, the normotensive and hypertensive subjects were both classified into four categories; very light and non- (0–10 ml of ethanol), light (11–29 ml), moderate (30–58 ml) and heavy (≥59 ml) drinker groups. In these four pairs of groups, organ injuries in the heart, kidney and optic fundus were evaluated and serum lipids were measured.

3. Although the blood pressure levels were similar among the four groups of hypertensive subjects, the electrocardiographic findings of left ventricular hypertrophy were significantly more common among the moderate and heavy drinkers but not in the light drinkers compared with the very light and non-drinkers (very light and non-drinkers 25%, light drinkers 23%, moderate drinkers 38%, heavy drinkers 40%; P = 0.026). The alcohol intake increased the serum level of high-density lipoprotein cholesterol in a dose-dependent manner without changing the total cholesterol level; however, the serum γ-glutamyl transpeptidase and triacylglycerol levels were increased in the moderate and heavy drinkers. Urinary albumin excretion and fundoscopic lesions were not associated with the drinking habit in either the normotensive or hypertensive subjects.

4. These data suggest that habitual alcohol consumption exceeding 29 ml per day facilitates the development of left ventricular hypertrophy in hypertensive patients. Among the hypertensive subjects, light drinkers consuming 11 to 29 ml of ethanol daily showed preferable profiles in terms of organ injuries and risks of cardiovascular diseases.
Elevated Renal Endothelin-1 Clearance and mRNA Levels Associated with Albuminuria and Nephropathy in Non-Insulin-Dependent Diabetes Mellitus: Studies in Obese fa/fa Zucker Rats
Authors: Turner N. C. , Morgan P. J. , Haynes A. C. , Vidgeon-Hart M. , Toseland N. , Clapham J. C.
Published: August 2015

1. The obese fa/fa Zucker rat is a genetic model of obesity and insulin resistance which develops a number of metabolic and endocrine features of non-insulin-dependent diabetes, including hypertension, proteinuria and glomerular sclerosis.

2. We have investigated the urinary excretion of the metabolites of thromboxane (thromboxane B2) and prostacyclin (6-keto prostaglandin F1α), and of endothelin and cyclic GMP as markers for changes in the balance of renal haemodynamic factors in the obese Zucker rat.

3. Obese fa/fa Zucker rats were hypertensive compared with their lean counterparts (161 ± 3 and 138 ± 3 mmHg respectively, P < 0.01); obese animals were also markedly proteinuric (16.7 ± 6.7 versus 1.1 ± 0.1 mg/ml) and albuminuric (8.3 ± 2.9 versus 0.4 ± 0.25 mg/ml) and excreted less creatinine than lean animals (all P < 0.01). Urinary excretion of endothelin was greater in obese rats (123 ± 24 versus 62 ± 10 pg/15 h, P < 0.05) as was the level of pre-proendothelin mRNA, but excretion of cyclic GMP was depressed (12.5 ± 1.6 versus 27.2 ± 3.1 nmol/ 15 h, P < 0.01). Histological examination of kidneys from obese animals showed evidence of focal glomerulosclerosis and cortical tubular damage.

4. These results show that increased urinary endothelin is associated with proteinuria and early stage nephropathy in this animal model of non-insulin-dependent diabetes mellitus. This finding, coupled with a decreased excretion of cyclic GMP, suggests that these increased renal vasoconstrictor/vasodilator forces might contribute to the renal functional changes in non-insulin-dependent diabetes mellitus.
Long- and Short-Term Blood Pressure and Rr-Interval Variability and Psychosomatic Distress in Chronic Fatigue Syndrome
Authors: Duprez Daniel A. , De Buyzere Marc L. , Drieghe Benny , Vanhaverbeke Friedl , Taes Youri , Michielsen Walter , Clement Denis L
Published: August 2015

1. Chronic low blood pressure has been associated with fatigue and low mood. However, in the chronic fatigue syndrome (CFS) the blood pressure (BP) and heart rate profile and their variabilities have not been characterized as yet.

2. We performed office and 24 h ambulatory BP recordings in 38 subjects (age, 34.8 ± 8.0 years) who fulfilled the Holmes criteria for CFS and in 38 healthy control subjects (age 35.6 ± 10.5 years), as well as short-term beat-to-beat BP and RR-interval recordings for 10 min in supine and standing position, and calculated spectral indices.

3. In CFS office (123 ± 19/70 ± 12 mmHg) as well as 24-h, day- and night-time blood pressure values (116 ± 11.1/71 ± 11.1, 121 ± 9.2/77 ± 8.0 and 110 ± 10.5/65 ± 9.2 mmHg respectively) were within reference limits.

4. Heart rate was consistently higher (P < 0.01) in CFS patients, based on both office (77 ± 12 compared with 68 ± 12 beats min−-1) and 24 h ambulatory recordings (77 ± 12 compared with 67 ± 15 beats min−-1).

5. In supine position, spectral indices of BP variability (total, low-frequency and high-frequency variances) were all significantly (P < 0.01) lower in CFS. In standing position the differences disappeared. Analysis of RR-interval variability could not detect major alterations in autonomic function in CFS.
Applicability of New Techniques in the Assessment of Arterial Baroreflex Sensitivity in the Elderly: A Comparison with Established Pharmacological Methods
Authors: James Martin A. , Panerai Ronney B. , Potter John F.
Published: August 2015

1. There has been considerable interest in techniques recently developed for the study of arterial baroreceptor—cardiac reflex sensitivity based on analysis of spontaneous baroreflex sequences and on spectral analysis. This study examined how these newer techniques agreed with the established pharmacological methods in elderly subjects.

2. In 20 elderly subjects [10 hypertensive (clinic blood pressure 180 ± 4/88 ± 2 mmHg) and 10 normotensive (clinic blood pressure 136 ± 3/73 ± 2 mmHg)], we assessed baroreflex sensitivity from spontaneous sequences of increasing and decreasing blood pressure and pulse interval and their mean, and from spectral analysis to derive α, the index of overall baroreflex gain. Pharmacological baroreflex sensitivity was derived from the blood pressure and pulse interval responses to depressor (sodium nitroprusside) and pressor (phenylephrine) stimuli, and their mean.

3. Baroreflex sensitivity was significantly lower in the hypertensive group by the pharmacological, sequence and spectral methods (all P < 0.05).

4. There was acceptable agreement between pharmacological baroreflex sensitivity and sequences of the same direction, but with some systematic bias. There was also reasonable agreement between pharmacological and spectral baroreflex sensitivity and close agreement without bias between sequence and spectral methods.

5. The newer and established techniques demonstrate acceptable agreement in the elderly, albeit with some systematic bias. Pharmacological methods have enjoyed historical precedence but newer techniques give equivalent results, and are preferable in some circumstances. The newer techniques may be more descriptive of the spontaneous behaviour of the arterial baroreflex at rest rather than under artificially stimulated conditions.
Dynamics of Circulatory Adjustments to Head-Up Tilt and Tilt-Back in Healthy and Sympathetically Denervated Subjects
Authors: Wieling W. , Van Lieshout J. J. , Ten Harkel A. D. J.
Published: August 2015

1. The initial circulatory adjustments induced by head-up tilt and tilt-back were investigated in six healthy subjects (aged 30–58 years) and six patients with orthostatic hypotension due to pure autonomic failure (aged 33–65 years).

2. Continuous responses of finger arterial pressure and heart rate were recorded by Finapres. A pulse contour algorithm applied to the arterial pressure waveform was used to compute stroke volume responses.

3. In the healthy subjects, head-up tilt induced gradual circulatory adjustments. After 1 min upright stroke volume and cardiac output had decreased by 39 ± 9% and 26 ± 10% respectively. Little change in mean blood pressure at heart level (+1 ± 7 mmHg) indicated that systemic vascular resistance had increased by 39 ± 24%. The gradual responses to head-up tilt contrasted with the pronounced and rapid circulatory responses upon tilt-back. After 2–3 s a rapid increase in stroke volume (from 62 ± 8% to 106 ± 10%) and cardiac output (from 81 ± 11% to 118 ± 20%) was observed with an overshoot of mean arterial pressure above supine control values of 16 ± 3 mmHg at 7 s. In the patients a progressive fall in blood pressure on head-up tilt was observed. After 1 min upright mean blood pressure had decreased by 59 ± 8 mmHg. No change in systemic vascular resistance and a larger decrease in stroke volume (60 ± 7%) and cardiac output (53 ± 8%) were found. On tilt-back a gradual recovery of blood pressure was observed.

4. In healthy humans upon head-up tilt neural compensatory mechanisms are very effective in maintaining arterial pressure at heart level. The gradual circulatory adjustments to head-up tilt in healthy subjects contrast with the pronounced and abrupt circulatory changes on tilt-back. In patients with a lack of neural circulatory reflex adjustments, gradual blood pressure decreases to head-up tilt and gradual increases to tilt-back are observed.
Fibroblasts from Post-Burn Hypertrophic Scar Tissue Synthesize Less Decorin than Normal Dermal Fibroblasts
Authors: Scott P. G. , Dodd C. M. , Ghahary A. , Shen Y.J. , Tredget E. E.
Published: August 2015

1. Fibroblast cultures were established from biopsies of hypertrophic scar and normal dermis taken from nine patients recovering from second- and third-degree burns. The capacity of these fibroblasts to synthesize the small proteoglycan decorin was assessed by quantitative Western blot analysis of conditioned medium collected from confluent cultures. Levels of mRNA for decorin were assessed by quantitative Northern analysis. Since transforming growth factor-β1 is implicated in various fibrotic conditions, including post-burn hypertrophic scar, its effect on decorin synthesis by these paired fibroblast cell strains was assessed.

2. Production of decorin was lower in all cell strains of hypertrophic scar fibroblasts tested, compared with normal dermal fibroblasts cultured from the same patients (mean 49 ± 23%; P < 0.001, n = 9). Levels of mRNA for decorin were also lower (mean 59 ± 28%; P < 0.02, n = 7) but those for biglycan and versican were not significantly different. Four pairs of cell strains were examined at more than one passage and the differences in decorin protein were found to be phenotypically persistent. Treatment of confluent cultures with transforming growth factor-β1 for 3 days caused a reduction in both decorin protein and mRNA in all six strains of hypertrophic scar fibroblasts tested and in five of six strains of normal dermal fibroblasts. An increase in the length of the dermatan sulphate chain on decorin, a previously reported characteristic of this glycosaminoglycan in hypertrophic scar, was seen in all but two of the strains treated with transforming growth factor-β1. The depression of decorin synthesis by transforming growth factor-β1 was reversed on removal of the agent and passaging the fibroblasts.

3. The reduced capacity of fibroblasts in hypertrophic scar tissue to synthesize decorin may have implications for the development of the condition since this small proteoglycan is involved in tissue organization and may also play a role in modulating the activity in vivo of fibrogenic cytokines such as transforming growth factor-β1.
Increased Oxidative Stress in Rat Liver and Pancreas during Progression of Streptozotocin-Induced Diabetes
Authors: Kakkar Rakesh , Mantha Subrahmanyam V. , Radhi Jasim , Prasad Kailash , Kalra Jawahar
Published: August 2015

1. Oxygen free radicals have been suggested to be a contributory factor in complications of diabetes mellitus. There are many reports indicating the changes in parameters of oxidative stress in diabetes mellitus. In this study we aimed to identify whether oxidative stress occurs in the liver and pancreas in the initial stages of development of diabetes.

2. We therefore investigated the lipid peroxide level (thiobarbituric acid-reactive substances, TBARS) and activities of antioxidant enzymes [superoxide dismutase (SOD), catalase and glutathione peroxidase] in liver and pancreas of control and streptozotocin-induced diabetic rats at various stages of development of diabetes.

3. Male Sprague—Dawley rats were divided into two groups: group I, control (n = 42) and group II, diabetic (n = 42). Each group was further subdivided into seven groups consisting of six rats each. Rats in these subgroups were studied at weekly intervals (0 to 6 weeks). Plasma glucose levels, TBARS levels and activities of antioxidant enzymes were measured in liver and pancreas at various time intervals.

4. There was a significant (P < 0.05) and progressive increase in TBARS levels of liver and pancreas in the diabetic group. Total SOD and Cu—Zn-SOD activity increased (P < 0.05) with progression of diabetes while Mn-SOD activity showed no significant change in either tissue. Catalase and glutathione peroxidase activities increased significantly (P < 0.05) in liver and pancreas.

5. Immunohistochemical study of pancreatic islet revealed a decrease in the expression of insulin with progression of diabetes. However, glucagon and somatostatin showed an increase in immunoreactivity and a difference in their distribution pattern.

6. The findings of the present study suggest that oxidative stress starts at early onset of diabetes mellitus and increases progressively. In conclusion, the structural damage to these tissues or complications of diabetes mellitus may be due to oxidative stress.
Effect of Long-Term Octreotide and Isosorbide Dinitrate on Haemodynamics in Rats with Portal Vein Stenosis
Authors: Lin Han-Chieh , Huang Yi-Tsau , Cheng Yuh-Ren , Hou Ming-Chih , Lee Fa-Yauh , Chang Full-Young , Tsai Yang-Te , Lee Shou-Dong
Published: August 2015

1. Both octreotide and isosorbide dinitrate have been shown to have portal hypotensive effects in animals with portal hypertension. Moreover, in both animals and humans with portal hypertension, the reduction of portal pressure was enhanced when nitrovasodilators were combined with propranolol or vasopressin. The present study was undertaken to evaluate the effect of long-term administration of octreotide and isosorbide dinitrate on haemodynamics in rats with portal vein stenosis.

2. Portal hypertension was induced by portal vein stenosis. Portal hypertensive rats were allocated into one of four groups (eight rats in each group): vehicle group, octreotide group (100 μg/kg via subcutaneous injection every 12 h), isosorbide dinitrate group (5 mg/kg via gastric gavage every 12 h) and combined treatment group. Drug was given for eight consecutive days, starting 1 day before surgery. Haemodynamic values were measured using a radioactive microsphere technique.

3. Long-term octreotide treatment decreased portal pressure and improved the hyperdynamic circulation. In contrast, long-term administration of isosorbide dinitrate reduced portal pressure but did not ameliorate vasodilatation. A combination of octreotide and isosorbide dinitrate improved the hyperdynamic circulation with a reduction of portal pressure. In addition, the mean value of portal pressure after combination treatment was significantly lower than in rats receiving octreotide alone.

4. These results showed that, in rats with portal hypertension, long-term combined administration of octreotide and isosorbide dinitrate improved the hyperdynamic circulation together with a more profound reduction of portal pressure than rats receiving octreotide alone.
Concentration-Dependent Stimulation of Intestinal Phase III of Migrating Motor Complex by Circulating Serotonin in Humans
Authors: Lördal Mikael , Wallén Håkan , Hjemdahl Paul , Beck Olof , Hellström Per M.
Published: August 2015

1. The influence of circulating 5-hydroxytryptamine (serotonin) on small intestinal motility was investigated in healthy volunteers.

2. Small intestinal motility was studied by means of a constantly perfused multi-channel manometry tube, connected to a computer system.

3. Intravenous infusions of either 5-hydroxytryptamine at increasing doses or saline were given over a period of 4 h.

4. 5-Hydroxytryptamine infusion dose-dependently increased plasma 5-hydroxytryptamine from approximately 2 to 10 and 25 nmol/l respectively, as well as urinary excretions of 5-hydroxytryptamine and 5-hydroxyindole acetic acid, a major 5-hydroxytryptamine metabolite.

5. The number of phase III of the migrating motor complex originating in the small intestine was dose-dependently increased by 5-hydroxytryptamine, and found to correlate to the plasma concentration of 5-hydroxytryptamine. The fraction of phase III also increased at the expense of phase II activity. In addition, 5-hydroxytryptamine increased the motility index, propagation velocity of phase III activity and the amplitude of contractions during phase III.

6. Whereas the low dose of 5-hydroxytryptamine (15 nmol · min−1 · kg−1) had no haemodynamic effects, an increase in heart rate by approximately 20 beats/min, without change in blood pressure, was observed at the higher dose (60 nmol · min−1 · kg−1). Respiratory parameters did not change during infusion of 5-hydroxytryptamine at either dose.

7. In conclusion, elevation of circulating 5-hydroxytryptamine by intravenous infusion results in more frequent and faster propagating migrating motor complexes in the human small intestine during the interdigestive period.
Regional Differences in Protein Carboxymethylation in Post-Mortem Human Brain
Authors: Goggins Michael , Scott John M. , Weir Donald G.
Published: August 2015

1. The aim of this study was to determine the pattern of protein carboxymethylation in different regions of the human brain.

2. The availability of protein methylation sites was determined by measurement of the incorporation of methyl-3H groups into proteins isolated from postmortem brain tissue. The stability of protein carboxymethylation in post-mortem brain was determined by sampling post-mortem pig and human brain tissue at intervals during the first 24 h after death. This method has previously been used to demonstrate that decreased protein carboxymethylation occurred in post-mortem pig brain when methionine synthase was inhibited.

3. There were no significant differences in the protein carboxymethyltransferase activity in samples of pig brain obtained at the time of death compared with that obtained when the same tissue was maintained at room temperature for up to 24 h after death. Similarly, there were no significant differences in the protein carboxymethyltransferase activity in samples isolated from human brain 12 h after death compared with that obtained from the same human brain tissue maintained at room temperature for up to 24 h after death. These results suggest that the level of carboxymethylation of proteins from human post-mortem brain obtained within 24 h of death is not significantly different to the level present at the time of death. To characterize the distribution of protein carboxymethylation in human brain, nine regions of post-mortem brain were sampled from 16 human subjects. Protein carboxymethyltransferase activity was lowest in the cerebellum (P < 0.05) and highest in cortical white matter compared with other regions of the brain (P < 0.05). No significant differences in protein carboxymethyltransferase activity were noted between other regions of the cortex or the subcortical regions.

4. In human cortical white matter there are more available sites for protein carboxymethylation than other brain regions. This may explain the greater sensitivity of white matter to the adverse consequences of hypomethylation associated with vitamin B12 deficiency. Post-mortem brain tissue can serve as a tool for the study of physiological or pathological factors which influence human brain protein methylation in vivo.
Clinical and therapeutic significance of the Na+,K+ pump*
Authors: CLAUSEN Torben
Published: August 2015

1.The Na+,K+-ATPase or Na+,K+-pump, mediating the active transport of Na+ and K+, which was first identified 40 years ago, is a central target for acute and long-term regulation, as well as for therapeutic intervention. Acute stimulation of the Na+,K+-pump in skeletal muscle by insulin, catecholamines, β2-agonists or theophylline increases the intracellular uptake of K+ and accounts for the hypokalaemia elicited by these agents. Conversely, digitalis intoxication elicits hyperkalaemia via acute inhibition of the Na+,K+-pump.

2.Simple and accurate methods have been developed for the quantification of the total concentration of Na+,K+-pumps in small (0.5–5 mg) fresh or frozen biopsies of human skeletal muscle, myocardium or other tissues. This has allowed the identification of several long-term regulatory changes in the concentration of this transport system in human tissues. In skeletal muscle, upregulation is induced by training, thyroid hormones or glucocorticoids. Downregulation is seen in hypothyroidism, cardiac insufficiency, myotonic dystrophy, McArdle disease, K+ deficiency and after muscle inactivity.

3.Since the skeletal muscles contain one of the major pools of Na+,K+-pumps, these changes are important for the ability to counterregulate the hyperkalaemia elicited by exercise or the ingestion of K+. Moreover, downregulation or inhibition of the Na+,K+-pumps in skeletal muscle interferes with contractile performance. Since digitalis glycosides bind to the Na+,K+-pump, the muscles constitute a large distribution volume for these agents and are therefore an important determinant for their plasma level.

4.In cardiac insufficiency, the decrease in the concentration of Na+,K+-pumps in the myocardium is over a wide range correlated to the concomitant reduction in ejection fraction. The regulatory and pathophysiological changes in the activity and concentration of Na+,K+-pumps are important for the contractile function of skeletal muscle and heart as well as for K+ homoeostasis and the response to digitalization.
Renal haemodynamics, sodium and water reabsorption during continuous intravenous infusion of recombinant interleukin-2
Authors: GEERTSEN Poul F. , MAASE Hans VON DER , OLSEN Niels Vidiendal , FOGH-ANDERSEN Niels , NIELSEN Steen Levin , LEYSSAC Paul P.
Published: August 2015

1.Renal haemodynamics, lithium and sodium clearance were measured in 14 patients treated with recombinant interleukin-2 for metastatic renal cell carcinoma.

2.Patients were studied before and after 72 h of continuous intravenous infusion of recombinant interleukin-2 (18×106 i.u.·24 h-1·m-2) and 48 h post therapy. Cardiac output was measured by impedance cardiography. Effective renal plasma flow and glomerular filtration rate were determined by the renal clearances of 131I-hippuran and 99mTc-diethylenetriaminepenta-acetic acid (DTPA) respectively. Renal clearance of lithium (CLi) was used as an index of proximal tubular outflow.

3.Treatment caused a transient decrease in mean arterial blood pressure and systemic vascular resistance, but cardiac output remained unchanged. Renal blood flow decreased and renal vascular resistance increased during and after treatment. Sodium clearance decreased from 1.10 (0.63/1.19) ml/min to 0.17 (0.18/0.32) ml/min (P = 0.003). Glomerular filtration rate remained unchanged, whereas the median CLi decreased from 26 (17/32) ml/min to 17 (10/21) ml/min (P = 0.008). Calculated absolute proximal reabsorption rate of water increased from 63 (40/69) ml/min to 71 (47/82) ml/min (P = 0.04). The urinary excretion rate of thromboxane B2 and the ratio between excretion rates of thromboxane B2 and 6-keto-prostaglandin-F1α increased by 98% (P = 0.022) and 175% (P = 0.022) respectively.

4.The study suggests a specific recombinant interleukin-2-induced renal vasoconstrictor effect. Changes in renal prostaglandin synthesis may contribute to the decrease in renal blood flow. The lithium clearance data suggest that an increased proximal tubular reabsorption rate may contribute to the decreased sodium clearance during recombinant interleukin-2 treatment.
Possible interaction between exposure to environmental tobacco smoke and therapy in children with asthma
Authors: DUBUS Jean-Christophe , ODDOZE Christiane , BADIER Monique , GUILLOT Chantal , BRUGUEROLLE Bernard
Published: August 2015

1.The aim of the study was to determine the carbachol and albuterol responsiveness in treated and untreated asthmatic and allergic children exposed to environmental tobacco smoke assessed by urinary cotinine measurements.

2.Forty-six asthmatic and allergic children with normal spirometric values were recruited. The doubling dose, concentration of carbachol producing a 2-fold increase in specific airway resistance (SRaw) was determined and 200 ;μg of albuterol were administered via a Volumatic® spacer. The percentage of bronchodilatation was defined as the difference between the largest obtained SRaw and the post-β2 SRaw divided by the largest SRaw. Data were compared by a Mann–Whitney U-test.

3.The 23 children with a high urinary cotinine, compared with the 23 children without urinary cotinine, had a decreased doubling dose (108.2±14.7 ;μg versus 160.9±19.5 ;μg; P = 0.04) and an increased percentage of bronchodilatation (74.8±1.4% versus 68.8±1.8%; P = 0.03). A prophylactic anti-inflammatory treatment induced a weaker bronchial reactivity to carbachol and a slightly greater bronchodilatation in children exposed to environmental tobacco smoke.

4.Environmental tobacco smoke increases bronchial reactivity in asthmatic and allergic children. This effect might be reduced by anti-inflammatory therapy. The bronchodilator response may be enhanced in exposed children and may be caused by one or several direct interactions between tobacco smoke compounds and albuterol.
A method for examining differential mRNA expression along the crypt–villus axis of the human small intestine
Authors: CHUA Eddy , WANG Qiong , O'TOOLE Paul , LOMBARD Martin
Published: August 2015

1.The aim of this study was to devise a method of segregating crypt and villus cell subpopulations from endoscopic human small intestinal biopsies which might be used to examine changes associated with functional differentiation at the molecular level.

2.Routine endoscopic biopsies from the human small intestine were subjected to a modified protocol of mechanical disruption and chelation to yield subpopulations of different cell types. The purity and character of the cell populations isolated was assessed by measuring enzyme activity and thymidine incorporation and by histology. A guanidinium isothiocyanate method was adapted for small samples to extract RNA from the isolated subpopulations, and probes for RNA with a known predilection for crypt and villus cells were used to further investigate the application and usefulness of the technique.

3.Sequential histological examination during the segregation protocol demonstrated that different cell types were removed serially from the biopsy samples. Cell-type enrichment of the segregated subpopulations was demonstrated by differential alkaline phosphatase activity and by differences in thymidine incorporation in the samples isolated. Sufficient quantities of RNA could be extracted from the segregated subpopulations for Northern blot analysis and the differential expression of mRNA for sucrase-isomaltase and transferrin receptor was demonstrated in the villus and crypt subpopulations respectively.

4.Messenger RNA can be successfully extracted from different cell types segregated from routine human endoscopic small intestinal biopsies. This technique should prove useful for investigating the mechanisms regulating the functional differentiation of epithelial cells in the small intestine and the regulatory mechanisms governing absorption of macromolecules.
Rat hepatic stellate cell expression of α2-macroglobulin is a feature of cellular activation: implications for matrix remodelling in hepatic fibrosis
Authors: KAWSER C. A. , IREDALE J. P. , WINWOOD P. J. , ARTHUR M. J. P.
Published: August 2015

1.Hepatic stellate cells are key mediators of hepatic fibrosis. We have studied hepatic stellate cell expression of the collagenase and general protease inhibitor α2-macroglobulin after activation in tissue culture and in response to certain cytokines.

2.Hepatic stellate cells isolated by Pronase–collagenase digestion were activated by culture on uncoated plastic. By Northern analysis hepatic stellate cells undergoing activation (5 days) expressed α2-macroglobulin mRNA and α2-macroglobulin could be immunolocalized to hepatic stellate cells from 5 to 15 days of culture.

3.By ELISA of cell culture supernatants hepatic stellate cell secretion of α2-macroglobulin was found to increase from 2.78±1.13 ;ng·ml-1·μg-1 DNA per 24 ;h at 5 days of culture (n = 8) to 13.55±4.64 ;ng·ml-1·μg-1 DNA per 24 ;h at 15 days of culture (n = 7). Stimulation of hepatic stellate cells with interleukin-6 at 5 days caused a significant increase in α2-macroglobulin expression as did exposure to Kupffer-cell conditioned medium. However, exposure of hepatic stellate cells to interleukin-1, transforming growth factor-β1 and tumour necrosis factor-α had no significant effect.

4.During profibrotic liver injury plasma α2-macroglobulin levels were found to increase to between 850% and 250% of the control value (100%) after bile duct ligation (72 ;h to 13 days respectively), and to 1166% and 1106% of the control value during progressive CCl4-induced fibrosis (24 ;h to 4 weeks respectively).

5.These data suggest that hepatic stellate cells are a potential source of the potent protease inhibitor α2-macroglobulin, expression of which may inhibit matrix remodelling during progressive fibrosis.
Proteasome blockers inhibit protein breakdown in skeletal muscle after burn injury in rats
Authors: FANG Cheng-Hui , WANG Jing Jing , HOBLER Scott , LI Bing Guo , FISCHER Josef E. , HASSELGREN Per-Olof
Published: August 2015

1.Burn injury stimulates ubiquitin-dependent protein breakdown in skeletal muscle. The 20S proteasome is the proteolytic core of the 26S proteasome that degrades ubiquitin conjugates. We examined the effects of the proteasome inhibitors N-acetyl-l-leucinyl-L-leucinal-l-norleucinal (LLnL), lactacystin and β-lactone on protein breakdown in muscles from burned rats.

2.A full-thickness burn of 30% total body surface area was inflicted on the back of rats. Control rats underwent a sham procedure. After 24 ;h, extensor digitorum longus muscles were incubated in the absence or presence of 20S proteasome blocker and protein turnover rates and ubiquitin mRNA levels were determined.

3.LLnL resulted in a dose- and time-dependent inhibition of total protein breakdown in incubated muscles from burned rats. Lactacystin and β-lactone blocked both total and myofibrillar muscle protein breakdown. In addition to inhibiting protein breakdown, LLnL increased ubiquitin mRNA levels, possibly reflecting inhibited proteasome-associated RNase activity.

4.Inhibited muscle protein breakdown caused by LLnL, lactacystin and β-lactone supports the concept that the ubiquitin–proteasome pathway plays a central role in burn-induced muscle proteolysis. Because the proteasome has multiple important functions in the cell, in addition to regulating general protein breakdown, further studies are needed to test the role of proteasome blockers in the treatment or prevention of muscle catabolism.
A central γ-aminobutyric acid mechanism in cardiac vagal control in man revealed by studies with intravenous midazolam
Authors: FARMER Matthew R. , VAILE Julian C. , OSMAN Faisal , ROSS Hamish F. , TOWNEND Jonathan N. , COOTE John H.
Published: August 2015

1.Animal studies show that cardiac vagal tone can be modified by γ-aminobutyric acid neurons acting at several sites in the central nervous system. The present study has attempted to determine whether similar control exists in humans by using midazolam, a benzodiazepine. Benzodiazepines exert their main actions on the central nervous system by interacting co-operatively at the γ-aminobutyric acid receptor.

2.Twenty patients took part in the study before undergoing cardiac catheterization. After resting for 20 ;min in a semi-supine position on a couch, ECG, blood pressure and respiration were recorded for 5-min periods with either controlled (fixed) or free respiration. During this time a baroreceptor sensitivity test was conducted.

3.Doses of 1 ;mg and 5 ;mg of midazolam were administered intravenously.

4.Five-minute segments of data, before and after midazolam, were subjected to power spectral and time-domain analysis.

5.Midazolam caused a decrease in the high-frequency and an increase in the low-frequency components of the power spectral density plot, and in addition reduced the mean R–R interval and R–R variability expressed as the interquartile difference, and pNN50. There were no significant changes in the sensitivity of the baroreflex or in the systolic, diastolic and average blood pressures.

6.This decrease in variability of heart period, particularly at a controlled respiratory frequency, strongly suggests that cardiac vagal tone in man can be regulated by γ-aminobutyric acid neurons.
Influences of carvedilol treatment on the effects of acetylcholine on regional haemodynamics in the spontaneously hypertensive rat
Authors: GRANSTAM Sven-Olof , FELLSTRÖM Bengt , LIND Lars
Published: August 2015

1.Investigations that assess cardiac autonomic function include non-linear techniques such as fractal dimension and approximate entropy in addition to the common time and frequency domain measures of both heart period and heart rate. This article evaluates the differences in using heart rate versus heart period to estimate fractal dimensions and approximate entropies of these time series.

2.Twenty-four-hour ECG was recorded in 23 normal subjects using Holter records. Time series of heart rate and heart period were analysed using fractal dimensions, approximate entropies and spectral analysis for the quantification of absolute and relative heart period variability in bands of ultra low (< 0.0033 ;Hz), very low (0.0033–0.04 ;Hz), low (0.04–0.15 ;Hz) and high (0.15–0.5 ;Hz) frequency.

3.Linear detrending of the time series did not significantly change the fractal dimension or approximate entropy values. We found significant differences in the analyses using heart rate versus heart period between waking up and sleep conditions for fractal dimensions, approximate entropies and absolute spectral powers, especially for the power in the band of 0.0033–0.5 ;Hz. Log transformation of the data revealed identical fractal dimension values for both heart rate and heart period. Mean heart period correlated significantly better with fractal dimensions and approximate entropies of heart period than did corresponding heart rate measures.

4.Studies using heart period measures should take the effect of mean heart period into account even for the analyses of fractal dimension and approximate entropy. As the sleep–awake differences in fractal dimensions and approximate entropies are different between heart rate and heart period, the results should be interpreted accordingly.
Methylenetetrahydrofolate reductase polymorphism (C-677T) and coronary artery disease
Authors: MALIK N. M. , SYRRIS P. , SCHWARTZMAN R. , KASKI J. C. , CROSSMAN D. C. , FRANCIS S. E. , CARTER N. D. , JEFFERY S.
Published: August 2015

1.Many studies have shown that hyperhomocysteinaemia is a risk factor for atherosclerotic vascular disease. A mutation (C-677T) in the gene coding for the methylenetetrahydrofolate reductase (MTHFR) enzyme has been shown to produce a thermolabile form of the enzyme. Homozygosity for this mutation has been correlated with an elevated plasma homocysteine concentration. The present study aimed to determine whether this mutation was a risk factor for coronary artery disease (CAD). This was achieved by comparing the frequency of the C-677T mutation in patients with angiographically proven CAD against angiographically normal patients in two separate U.K. samples. The analysis was repeated with CAD patients split into those with ⩾ 99% stenosis of arteries and those without, to establish whether the C-677T mutation could be correlated with severity of CAD.

2.Two patient groups were selected from London and Sheffield. The London group comprised 174 cases and 148 controls. The Sheffield group comprised 93 cases and 85 controls. The DNA samples of the patients were genotyped by polymerase chain reaction and restriction enzyme digestion.

3.For London the homozygous C-677T frequencies were: 0.07 (controls), 0.09 (CAD without ⩾ 99% stenosis) and 0.10 (CAD with ⩾ 99% stenosis). For Sheffield the homozygous C-677T frequencies were: 0.08 (controls), 0.10 (CAD without ⩾ 99% stenosis) and 0.11 (CAD with ⩾ 99% stenosis). No association was found between the C-677T mutation and CAD in our sample geographical groups. Statistical comparison by genotype distribution for 0 ;VD (no vessel disease, i.e. 0% diameter reduction in all epicardial arteries) versus CAD without ⩾ 99% stenosis: London, P = 0.19; Sheffield, P = 0.53; 0 ;VD versus CAD with ⩾ 99% stenosis: London, P = 0.23; Sheffield, P = 0.55.
Diminished insulin clearance during late pregnancy in patients with Type I diabetes mellitus
Authors: BJÖRKLUND Anders O. , ADAMSON Ulf K. C. , LINS Per-Eric S. , WESTGREN L. Magnus R.
Published: August 2015

1.Intensive insulin treatment of patients with Type I diabetes mellitus during pregnancy is associated with a high frequency of serious hypoglycaemic events. A potential change in insulin metabolism during pregnancy may affect both the frequency and the severity of insulin-induced hypoglycaemia.

2.In 10 patients with Type I diabetes, during the third trimester of pregnancy and 5 to 13 months after delivery, hypoglycaemia was induced by the hyperinsulinaemic hypoglycaemic clamp technique. A constant high-dose intravenous insulin infusion was administered for 150 ;min and arterial blood glucose was clamped at 2.2 ;mmol/l by counterregulation with intravenous glucose. During the experiment venous samples were collected for later analysis of free plasma insulin, whereby the metabolic clearance rate of insulin could be calculated.

3.The desired blood glucose level was approached after approximately 60 ;min of insulin infusion. After just 30 ;min the insulin levels were significantly higher during pregnancy compared with after delivery. In addition, the steady-state insulin level from 90 to 150 ;min was significantly higher during pregnancy.

4.From the steady-state insulin levels at 90 to 150 ;min, the metabolic clearance rate of insulin was calculated, being 24% higher after delivery.

5.We conclude that there is a decreased metabolic clearance rate of insulin during pregnancy. This might be due to altered blood-flow distribution, decreased hepatic insulin extraction and relative increase in body fat during pregnancy. A decreased clearance of insulin will contribute to the risk for serious hypoglycaemic events in patients with Type I diabetes during pregnancy.
Stimulation of apoptosis by sulindac and piroxicam
Authors: WADDELL William R.
Published: August 2015

1.Sulindac, cis-5-fluoro-2-methyl-1-(p-methylsulphinylbenzylidene)indene-3-acetic acid, inhibits growth of colon polyps and cancers. This effect has been attributed to inhibition of prostaglandin synthesis but more recent observations indicate that, in vitro, cells that do not have cyclo-oxygenase nor RNA for synthesis of such enzymes are affected by sulindac. Therefore the presumptive effect is probably not correct.

2.It has also been found that sulindac stimulates apoptosis. It is herein postulated that in tumour cells such effects may be due to interaction of the anionic form of the drug with protons in the intermembrane space of mitochondria to disrupt the potential across the inner mitochondrial membrane and thereby initiate apoptosis. Normal cells are not affected.
Renal arginine metabolism in fasted rats with subacute short bowel syndrome
Authors: DEJONG Cornelis H. C. , WELTERS Carlo F. M. , DEUTZ Nicolaas E. P. , HEINEMAN Erik , SOETERS Peter B.
Published: August 2015

1.Arginine can be produced in the kidney from citrulline. An important source of circulating citrulline is the intestinal breakdown of glutamine. Consequently, partial enterectomy leads to decreased plasma citrulline levels. The aim of the present study was to investigate the effect of diminished arterial citrulline levels on renal arginine production and total-body free arginine pools.

2.Renal amino acid metabolism was studied 24 ;h after 75% small bowel resection in rats fasted overnight (16 ;h) (n = 12; total fast 40 ;h). Sham-operated (n = 9) and non-operated 16-h and 40-h fasted controls were studied in parallel (n = 8/n = 7). During anaesthesia, l-(2,3-3H)-arginine and para-aminohippuric acid were infused until steady state. Subsequently, arterial and renal venous blood samples were taken. Concentrations of para-aminohippurate and amino acids and specific activity of arginine and citrulline were measured to calculate renal plasma flow, net renal uptake or release, and unidirectional influx or efflux of arginine and citrulline, as well as whole-body arginine turnover.

3.Arterial citrulline was decreased in enterectomized rats compared with sham-operated rats (23±3 versus 44±6 ;μM). Net renal citrulline uptake and arginine release were almost stoichiometric (-36±7 and 38±6 ;nmol·min-1·100 ;g-1 body weight respectively in sham-operated rats) and were both diminished by 50% in enterectomized versus sham-operated rats. In all groups, net renal arginine production accounted for less than 10% of whole-body rate of arginine appearance (488 ;nmol·min-1·100 ;g-1 body weight in the sham group). Despite decreased net renal citrulline consumption and renal arginine production in enterectomized rats, whole-body rate of arginine appearance and arterial arginine did not change significantly.

4.In conclusion, net renal arginine production is reduced 24 ;h after 75% enterectomy in fasted rats. However, this does not have important effects on whole-body arginine production.
A comparison of the development of renal hypertension in male and female rats
Authors: OKUNIEWSKI Rachel , DAVIS Elizabeth A. , JARROTT Bevyn , WIDDOP Robert E.
Published: August 2015

1.The objective of this study was to determine the influence of gender on the development of renal hypertension in Sprague–Dawley rats using the Goldblatt two-kidney, one-clip (2K1C) model. In addition, this study examined the effect of ovariectomy upon the development of hypertension in female rats.

2.At 10 weeks of age, male, intact female and ovariectomized female rats underwent clipping of the right renal artery or sham operation. Tail-cuff plethysmography was used to monitor the systolic blood pressure of all animals for 7 weeks post-clipping or sham operation. Rats were sub-grouped according to whether or not they developed hypertension (systolic blood pressure ⩾ 150 ;mmHg).

3.Within 2 to 3 weeks of clipping, hypertension was induced in only 53% (n = 120) of the intact female 2K1C rats, but in 83% (n = 18) of the male and 78% (n = 18) of the ovariectomized female rats.

4.Seven weeks after right renal artery clipping, plasma renin activity was determined in a subset of each group and was found to be 5–6 fold higher in male (17.29±4.04 ;ng angiotensin I·h-1·ml-1) and ovariectomized female (9.71±1.25 ;ng angiotensin I·h-1·ml-1) hypertensive rats compared with their respective normotensive or sham-operated counterparts (3.39±0.58 ;ng angiotensin I·h-1·ml-1 and 1.60±0.41 ;ng angiotensin I·h-1·ml-1 respectively) (P< 0.05, analysis of variance). In contrast, the plasma renin activity measured in intact female hypertensive rats was not significantly different from that measured in the corresponding 2K1C normotensive or sham-operated groups.

5.These results indicate that the success rate of inducing renal hypertension in Sprague–Dawley rats is higher in males than in intact females. Furthermore, these results suggest that the induction of 2K1C hypertension may be influenced by ovarian hormones.
Arrhythmogenic effect of ventriculography in patients with left ventricular dilation and/or hypertrophy
Authors: SERAFI Abdulhalim S. , EVANS Stephen J. , JONES John V.
Published: August 2015

1.This study examined the effect of an acute injection of contrast medium on generation of arrhythmias in diseased hearts in man.

2.Subjects were 100 patients in sinus rhythm undergoing cardiac catheterization in whom good quality echocardiograms could be obtained. The subjects comprised 78 males and 22 females aged 37–83 years.

3.Arrhythmia induced by left ventricular angiography ranged from nil to brief bursts of ventricular tachycardia. There was a strongly positive relationship between left ventricular internal dimension in diastole (LVIDd) and induced arrhythmia. Out of 26 patients, 25 developed arrhythmia when LVIDd ⩾ 5 ;cm (96%), but only 24 out of 74 patients developed arrhythmia when LVIDd < 5 ;cm (32%) (P< 0.001). In non-dilated hearts where K+ < 4.0 ;mmol/l, arrhythmia developed in 100% (10 out of 10) of those with left ventricular hypertrophy (LVH), but in only 40% (8 out of 20) without LVH (P< 0.005). Where K+ ⩾ 4.0 ;mmol/l, no arrhythmia occurred in patients with LVH but was present in 52% (31 out of 60) of patients without LVH (P< 0.005). There were no relationships with age, end-diastolic pressure, blood pressure, ischaemic heart disease or sex of patient.

4.These data support the view that acute injection of contrast medium in humans induces arrhythmias dependent upon the underlying state of the heart, with potentially complex interplay between left ventricular dimension, hypertrophy and potassium status, supporting similar observations in experimental animals.
Porcine hepatic response to sepsis and its amplification by an adrenergic receptor α1 agonist and a β2 antagonist
Authors: TIGHE D. , MOSS R. , BENNETT D.
Published: August 2015

1.We investigated the effect of adrenergic receptor stimulation or inhibition on the hepatic ultrastructural changes in a porcine faecal peritonitis model of multi-organ failure. We infused either the α1 adrenergic receptor agonist methoxamine or the β2 adrenergic receptor antagonist ICI 118551 during 8 ;h of the study.

2.Anaesthetized pigs (25–30 ;kg) were divided into four non-septic groups (control, non-septic, non-septic methoxamine and non-septic ICI 118551) and three septic groups (septic, septic methoxamine and septic ICI 118551).

3.Changes in hepatic ultrastructure were measured by morphometric analysis. The septic group was significantly worse than all the non-septic groups. Septic methoxamine and septic ICI 118551 were significantly worse than the septic group.

4.Septic methoxamine and septic ICI 118551 had a significantly increased perisinusoidal space; septic methoxamine had significant hepatocyte vacuolation.

5.Hepatic ultrastructural changes were independent of hepatic blood flow.

6.Septic methoxamine had significant myocardial depression.

7.The α1 adrenergic receptor agonist methoxamine or the β2 antagonist ICI 118551 both amplified the hepatic injury normally found during sepsis in our porcine model.

8.These findings suggest that during sepsis a protective endogenous β2 adrenergic receptor-mediated anti-inflammatory response is activated via cell membrane transduction to stimulate the trimeric G-protein complex Gs and activate the second cell messenger cAMP.

9.In addition, it is likely that α1 adrenergic receptor agonists amplify the inflammatory response by stimulating the cell-surface receptor-linked trimeric G-protein complex to activate Gq and the second cell messenger phospholipase C.