1 Guanosine 5′‐triphosphate (GTP) and guanosine can relax both endothelium‐intact and ‐denuded ar... more 1 Guanosine 5′‐triphosphate (GTP) and guanosine can relax both endothelium‐intact and ‐denuded arterial preparations. In the present work the P1 and P2Y purinoceptor antagonists, 8‐phenyltheophylline and reactive blue 2, respectively, were used to study the mechanisms of relaxation responses induced by GTP, guanosine, adenosine 5′‐triphosphate (ATP) and adenosine in noradrenaline‐precontracted rat mesenteric artery rings. 2 GTP (10 μm – 1 mm) dose‐dependently relaxed endothelium‐intact mesenteric artery rings and also induced moderate relaxation responses in endothelium‐denuded preparations. Pretreatment of the rings with 8‐phenyltheophylline (10 μm) or reactive blue 2 (10 μm) did not attenuate the relaxant effect of GTP. 3 Guanosine (10 μm – 1 mm) relaxed both endothelium‐intact and ‐denuded artery rings in a dose‐dependent manner. The presence of 8‐phenyltheophylline or reactive blue 2 had no effects on guanosine‐induced relaxations. 4 ATP‐induced (0.1 μm – 0.1 mm) relaxation of e...
A large healthcare-associated epidemic mainly caused by one methicillin-resistant Staphylococcus ... more A large healthcare-associated epidemic mainly caused by one methicillin-resistant Staphylococcus aureus (MRSA) strain broke out in Pirkanmaa County, Finland, in 2001. This study describes the impact of infection control and screening practices on the epidemic. The number of hospital-acquired (HA)-MRSA findings obtained from clinical and screening samples during the epidemic was calculated. Strains were typed by pulsed-field electrophoresis (PFGE) or spa typing. Strain type distribution was studied in relation to sample type, year of the epidemic and site of transmission. Several infection control interventions were launched stepwise and screening protocols were expanded. A total of 4118 cases were identified during 2001-2014, of which 3527 were classified as HA. One strain (spa t067) dominated in the epidemic. HA-MRSA cases decreased constantly from the year 2011. The number of new HA-MRSA cases was 57% less in the year 2014 (n = 171) as compared with the year 2011 (n = 399). The proportion of the epidemic strain declined significantly over the years. Screening samples comprised 71% (2439/3527) and clinical samples 29% (1034/3527) of HA-MRSA findings. The number of HA-MRSA cases found from clinical samples started to decrease when screening was expanded. An increase in hand-rub consumption was associated with a decrease in transmissions in Tampere University Hospital (TAUH). Implementation of universal screening together with several other interventions is effective in containing an MRSA epidemic. The proportion of other than Pirkanmaa epidemic (PE)-MRSA strain findings increased throughout the period, indicating the changing epidemiology of MRSA.
The effects of calcium and deoxycorticosterone (DOC) were studied in four groups of spontaneously... more The effects of calcium and deoxycorticosterone (DOC) were studied in four groups of spontaneously hypertensive rats (SHR): control, calcium, DOC and DOC + calcium. Calcium was administered in drinking fluid as 1.5% calcium chloride, and DOC was injected weekly (25 mg/kg subcutaneously). During the 9-week study the increase in systolic blood pressure was enhanced in the DOC and attenuated in the calcium group, but did not differ from control values in the DOC + calcium group. DOC augmented in vitro contractions of aortic and mesenteric arterial rings induced by noradrenaline and impaired relaxations in response to nitroprusside and acetylcholine. Calcium alone enhanced the relaxation in response to nitroprusside in the mesenteric artery. In the DOC + calcium group vascular contractions did not differ from control values, but the relaxations caused by nitroprusside and acetylcholine were augmented in the mesenteric artery. The activity of erythrocyte Ca2(+)-ATPase increased in both calcium groups. The Na+:K+ ratio of tail artery tissue was reduced in the calcium group. In conclusion, calcium supplementation attenuates the development of hypertension, and prevents DOC-induced blood pressure increases in SHR by altering vascular reactivity. Changes in smooth muscle electrolyte ratios and Ca2(+)-ATPase activity may account for these alterations.
The effects of calcium and deoxycorticosterone (DOC) on blood pressure, plasma renin activity (PR... more The effects of calcium and deoxycorticosterone (DOC) on blood pressure, plasma renin activity (PRA), urinary sodium excretion and aortic responses were studied in spontaneously hypertensive rats (SHR). The animals (age 9 weeks) were divided into four treatment groups: control, calcium, DOC and DOC+calcium (n = 12 and the mean systolic blood pressure 174-177 mmHg in each). Calcium was given as 1.5% CaCl2 in drinking fluid, and DOC trimethylacetate by weekly injections (25 mg/kg s.c.). During the 4-week study systolic blood pressure rose in all groups, but the increase was attenuated by calcium (final levels: control 201 +/- 3, calcium 186 +/- 3, DOC 206 +/- 2, DOC + calcium 203 +/- 2 mmHg, mean +/- SE). PRA was reduced in both groups receiving DOC, but it was not affected by calcium. Calcium supplementation increased urinary excretion of sodium in DOC-treated animals. DOC enhanced the in vitro contractility of helically cut aortic strips to noradrenaline, and decreased the relaxation of the strips to nitroprusside and nifedipine. The results indicate that calcium supplementation attenuates the development of hypertension in SHR, and that this attenuation is not mediated by the renin-angiotensin system. DOC abolished this lowering effect of calcium on blood pressure possibly by its action on vascular smooth muscle, resulting in increased vascular contractility and impaired relaxation.
... 1990). Mika Kähönen · Xiumin Wu · Valérie B. Schini-Kerth · Outi Ylikotila · Pertti Arvola · ... more ... 1990). Mika Kähönen · Xiumin Wu · Valérie B. Schini-Kerth · Outi Ylikotila · Pertti Arvola · Jari-Petteri Tolvanen · Eeva Moilanen · Ilkka Pörsti Interleukin-1β-induced nitric oxide synthesis in aortic rings from normal and hyperinsulinaemic rats: effect of physical exercise ...
A large healthcare-associated epidemic mainly caused by one methicillin-resistant Staphylococcus ... more A large healthcare-associated epidemic mainly caused by one methicillin-resistant Staphylococcus aureus (MRSA) strain broke out in Pirkanmaa County, Finland, in 2001. This study describes the impact of infection control and screening practices on the epidemic. The number of hospital-acquired (HA)-MRSA findings obtained from clinical and screening samples during the epidemic was calculated. Strains were typed by pulsed-field electrophoresis (PFGE) or spa typing. Strain type distribution was studied in relation to sample type, year of the epidemic and site of transmission. Several infection control interventions were launched stepwise and screening protocols were expanded. A total of 4118 cases were identified during 2001-2014, of which 3527 were classified as HA. One strain (spa t067) dominated in the epidemic. HA-MRSA cases decreased constantly from the year 2011. The number of new HA-MRSA cases was 57% less in the year 2014 (n = 171) as compared with the year 2011 (n = 399). The proportion of the epidemic strain declined significantly over the years. Screening samples comprised 71% (2439/3527) and clinical samples 29% (1034/3527) of HA-MRSA findings. The number of HA-MRSA cases found from clinical samples started to decrease when screening was expanded. An increase in hand-rub consumption was associated with a decrease in transmissions in Tampere University Hospital (TAUH). Implementation of universal screening together with several other interventions is effective in containing an MRSA epidemic. The proportion of other than Pirkanmaa epidemic (PE)-MRSA strain findings increased throughout the period, indicating the changing epidemiology of MRSA.
Sphincter of Oddi (SO) motility has an important role in the regulation of bile flow. SO function... more Sphincter of Oddi (SO) motility has an important role in the regulation of bile flow. SO function disturbances (stenosis or dyskinesia) may prevent normal bile flow and thus enhance the probability of common bile duct (CBD) stone formation. Previously we have shown that there is an increased prevalence of diagnosed hypothyroidism in CBD stone patients, compared with gallbladder stone patients or age-, sex-, and hospital-admission-adjusted controls. The present study was done to test the hypothesis that thyroxine directly effects the SO. The specificity of the effects of thyroxine were studied by comparing with triiodothyronine (T3), progesterone, cortisone, estrogen, and testosterone. For ex vivo studies three or four successive 1 to 1.5-mm SO rings were prepared from each pig and placed between two hooks in oxygenated physiologic salt solution at 37 degrees C. SO contraction was measured with isometric force displacement transducers and registered on a polygraph. Each SO ring was s...
1. Alterations in the function of the endothelium and arterial smooth muscle may be important in ... more 1. Alterations in the function of the endothelium and arterial smooth muscle may be important in the establishment of hypertension. Thus, the possible favorable influences of blood pressure-lowering agents on vascular responsiveness may be important in the chronic antihypertensive actions of these compounds. 2. A number of reports have suggested that ACE inhibitors can improve arterial function in hypertension, whereas the knowledge about the vascular effects of other antihypertensive drugs, like beta-blockers, calcium channel blockers, and diuretics remains rather limited. 3. In this article, the effects of antihypertensive therapy on arterial function in human and experimental hypertension are reviewed.
American Journal of Hypertension - AMER J HYPERTENS, 1996
The effects of long-term high calcium diet and physical exercise and their combined effects on th... more The effects of long-term high calcium diet and physical exercise and their combined effects on the development of hypertension, plasma and tissue atrial natriuretic peptide, and arterial function were studied in spontaneously hypertensive rats with Wistar-Kyoto rats serving as normotensive controls. Hypertensive rats were made to exercise by running on a treadmill up to 900 m/day. Calcium supplementation was instituted by increasing the calcium content of the chow from 1.1% to 2.5%. During the 23-week study, calcium supplementation attenuated the rise in blood pressure in both trained and nontrained hypertensive animals, whereas exerise training had no significant effect on blood pressure. The high calcium diet alone was associated with reduced plasma and ventricular tissue contents of atrial natriuretic peptide, both of which were increased by exercise. Responses of mesenteric arterial rings in vitro were examined at the end of the study. Neither increased dietary calcium nor endur...
A patient with severe capillary leakage syndrome caused by a Puumala hantavirus infection was tre... more A patient with severe capillary leakage syndrome caused by a Puumala hantavirus infection was treated with a single dose of icatibant, a bradykinin receptor antagonist, with a dramatic positive response. We suggest that this drug should be tested in a larger number of patients with severe hantavirus infection.
Nifedipine has been used in the treatment of sphincter of Oddi dyskinesia, a biliary disease char... more Nifedipine has been used in the treatment of sphincter of Oddi dyskinesia, a biliary disease characterized by upper abdominal pains and increased pressure in the sphincter. The effects of other calcium channel antagonists on sphincter of Oddi have not been elucidated. We compared the effects of three calcium blockers with differing smooth muscle selectivity (verapamil, nifedipine and felodipine) on human sphincter of Oddi contractions. Transverse sections of the sphincter obtained from five patients undergoing Whipple resection were studied in an organ bath chamber in vitro. All three calcium blockers significantly (>50%) inhibited the acetylcholine-induced and KCl-induced sphincter contractions in a dose-dependent manner. Both nifedipine and felodipine were more potent than verapamil in inhibiting the acetylcholine-induced contractions, whereas only nifedipine, but not felodipine, reduced the KCl-elicited contractions more than verapamil. The smooth muscle selective calcium channel antagonists are potent inhibitors of human sphincter of Oddi contractions. Although nifedipine is, to date, the only agent studied in clinical settings, other dihydropyridines are also likely to be useful in sphincter of Oddi dyskinesia.
Naunyn-Schmiedeberg's Archives of Pharmacology, 1999
... 1990). Mika Kähönen · Xiumin Wu · Valérie B. Schini-Kerth · Outi Ylikotila · Pertti Arvola · ... more ... 1990). Mika Kähönen · Xiumin Wu · Valérie B. Schini-Kerth · Outi Ylikotila · Pertti Arvola · Jari-Petteri Tolvanen · Eeva Moilanen · Ilkka Pörsti Interleukin-1β-induced nitric oxide synthesis in aortic rings from normal and hyperinsulinaemic rats: effect of physical exercise ...
1 Guanosine 5′‐triphosphate (GTP) and guanosine can relax both endothelium‐intact and ‐denuded ar... more 1 Guanosine 5′‐triphosphate (GTP) and guanosine can relax both endothelium‐intact and ‐denuded arterial preparations. In the present work the P1 and P2Y purinoceptor antagonists, 8‐phenyltheophylline and reactive blue 2, respectively, were used to study the mechanisms of relaxation responses induced by GTP, guanosine, adenosine 5′‐triphosphate (ATP) and adenosine in noradrenaline‐precontracted rat mesenteric artery rings. 2 GTP (10 μm – 1 mm) dose‐dependently relaxed endothelium‐intact mesenteric artery rings and also induced moderate relaxation responses in endothelium‐denuded preparations. Pretreatment of the rings with 8‐phenyltheophylline (10 μm) or reactive blue 2 (10 μm) did not attenuate the relaxant effect of GTP. 3 Guanosine (10 μm – 1 mm) relaxed both endothelium‐intact and ‐denuded artery rings in a dose‐dependent manner. The presence of 8‐phenyltheophylline or reactive blue 2 had no effects on guanosine‐induced relaxations. 4 ATP‐induced (0.1 μm – 0.1 mm) relaxation of e...
A large healthcare-associated epidemic mainly caused by one methicillin-resistant Staphylococcus ... more A large healthcare-associated epidemic mainly caused by one methicillin-resistant Staphylococcus aureus (MRSA) strain broke out in Pirkanmaa County, Finland, in 2001. This study describes the impact of infection control and screening practices on the epidemic. The number of hospital-acquired (HA)-MRSA findings obtained from clinical and screening samples during the epidemic was calculated. Strains were typed by pulsed-field electrophoresis (PFGE) or spa typing. Strain type distribution was studied in relation to sample type, year of the epidemic and site of transmission. Several infection control interventions were launched stepwise and screening protocols were expanded. A total of 4118 cases were identified during 2001-2014, of which 3527 were classified as HA. One strain (spa t067) dominated in the epidemic. HA-MRSA cases decreased constantly from the year 2011. The number of new HA-MRSA cases was 57% less in the year 2014 (n = 171) as compared with the year 2011 (n = 399). The proportion of the epidemic strain declined significantly over the years. Screening samples comprised 71% (2439/3527) and clinical samples 29% (1034/3527) of HA-MRSA findings. The number of HA-MRSA cases found from clinical samples started to decrease when screening was expanded. An increase in hand-rub consumption was associated with a decrease in transmissions in Tampere University Hospital (TAUH). Implementation of universal screening together with several other interventions is effective in containing an MRSA epidemic. The proportion of other than Pirkanmaa epidemic (PE)-MRSA strain findings increased throughout the period, indicating the changing epidemiology of MRSA.
The effects of calcium and deoxycorticosterone (DOC) were studied in four groups of spontaneously... more The effects of calcium and deoxycorticosterone (DOC) were studied in four groups of spontaneously hypertensive rats (SHR): control, calcium, DOC and DOC + calcium. Calcium was administered in drinking fluid as 1.5% calcium chloride, and DOC was injected weekly (25 mg/kg subcutaneously). During the 9-week study the increase in systolic blood pressure was enhanced in the DOC and attenuated in the calcium group, but did not differ from control values in the DOC + calcium group. DOC augmented in vitro contractions of aortic and mesenteric arterial rings induced by noradrenaline and impaired relaxations in response to nitroprusside and acetylcholine. Calcium alone enhanced the relaxation in response to nitroprusside in the mesenteric artery. In the DOC + calcium group vascular contractions did not differ from control values, but the relaxations caused by nitroprusside and acetylcholine were augmented in the mesenteric artery. The activity of erythrocyte Ca2(+)-ATPase increased in both calcium groups. The Na+:K+ ratio of tail artery tissue was reduced in the calcium group. In conclusion, calcium supplementation attenuates the development of hypertension, and prevents DOC-induced blood pressure increases in SHR by altering vascular reactivity. Changes in smooth muscle electrolyte ratios and Ca2(+)-ATPase activity may account for these alterations.
The effects of calcium and deoxycorticosterone (DOC) on blood pressure, plasma renin activity (PR... more The effects of calcium and deoxycorticosterone (DOC) on blood pressure, plasma renin activity (PRA), urinary sodium excretion and aortic responses were studied in spontaneously hypertensive rats (SHR). The animals (age 9 weeks) were divided into four treatment groups: control, calcium, DOC and DOC+calcium (n = 12 and the mean systolic blood pressure 174-177 mmHg in each). Calcium was given as 1.5% CaCl2 in drinking fluid, and DOC trimethylacetate by weekly injections (25 mg/kg s.c.). During the 4-week study systolic blood pressure rose in all groups, but the increase was attenuated by calcium (final levels: control 201 +/- 3, calcium 186 +/- 3, DOC 206 +/- 2, DOC + calcium 203 +/- 2 mmHg, mean +/- SE). PRA was reduced in both groups receiving DOC, but it was not affected by calcium. Calcium supplementation increased urinary excretion of sodium in DOC-treated animals. DOC enhanced the in vitro contractility of helically cut aortic strips to noradrenaline, and decreased the relaxation of the strips to nitroprusside and nifedipine. The results indicate that calcium supplementation attenuates the development of hypertension in SHR, and that this attenuation is not mediated by the renin-angiotensin system. DOC abolished this lowering effect of calcium on blood pressure possibly by its action on vascular smooth muscle, resulting in increased vascular contractility and impaired relaxation.
... 1990). Mika Kähönen · Xiumin Wu · Valérie B. Schini-Kerth · Outi Ylikotila · Pertti Arvola · ... more ... 1990). Mika Kähönen · Xiumin Wu · Valérie B. Schini-Kerth · Outi Ylikotila · Pertti Arvola · Jari-Petteri Tolvanen · Eeva Moilanen · Ilkka Pörsti Interleukin-1β-induced nitric oxide synthesis in aortic rings from normal and hyperinsulinaemic rats: effect of physical exercise ...
A large healthcare-associated epidemic mainly caused by one methicillin-resistant Staphylococcus ... more A large healthcare-associated epidemic mainly caused by one methicillin-resistant Staphylococcus aureus (MRSA) strain broke out in Pirkanmaa County, Finland, in 2001. This study describes the impact of infection control and screening practices on the epidemic. The number of hospital-acquired (HA)-MRSA findings obtained from clinical and screening samples during the epidemic was calculated. Strains were typed by pulsed-field electrophoresis (PFGE) or spa typing. Strain type distribution was studied in relation to sample type, year of the epidemic and site of transmission. Several infection control interventions were launched stepwise and screening protocols were expanded. A total of 4118 cases were identified during 2001-2014, of which 3527 were classified as HA. One strain (spa t067) dominated in the epidemic. HA-MRSA cases decreased constantly from the year 2011. The number of new HA-MRSA cases was 57% less in the year 2014 (n = 171) as compared with the year 2011 (n = 399). The proportion of the epidemic strain declined significantly over the years. Screening samples comprised 71% (2439/3527) and clinical samples 29% (1034/3527) of HA-MRSA findings. The number of HA-MRSA cases found from clinical samples started to decrease when screening was expanded. An increase in hand-rub consumption was associated with a decrease in transmissions in Tampere University Hospital (TAUH). Implementation of universal screening together with several other interventions is effective in containing an MRSA epidemic. The proportion of other than Pirkanmaa epidemic (PE)-MRSA strain findings increased throughout the period, indicating the changing epidemiology of MRSA.
Sphincter of Oddi (SO) motility has an important role in the regulation of bile flow. SO function... more Sphincter of Oddi (SO) motility has an important role in the regulation of bile flow. SO function disturbances (stenosis or dyskinesia) may prevent normal bile flow and thus enhance the probability of common bile duct (CBD) stone formation. Previously we have shown that there is an increased prevalence of diagnosed hypothyroidism in CBD stone patients, compared with gallbladder stone patients or age-, sex-, and hospital-admission-adjusted controls. The present study was done to test the hypothesis that thyroxine directly effects the SO. The specificity of the effects of thyroxine were studied by comparing with triiodothyronine (T3), progesterone, cortisone, estrogen, and testosterone. For ex vivo studies three or four successive 1 to 1.5-mm SO rings were prepared from each pig and placed between two hooks in oxygenated physiologic salt solution at 37 degrees C. SO contraction was measured with isometric force displacement transducers and registered on a polygraph. Each SO ring was s...
1. Alterations in the function of the endothelium and arterial smooth muscle may be important in ... more 1. Alterations in the function of the endothelium and arterial smooth muscle may be important in the establishment of hypertension. Thus, the possible favorable influences of blood pressure-lowering agents on vascular responsiveness may be important in the chronic antihypertensive actions of these compounds. 2. A number of reports have suggested that ACE inhibitors can improve arterial function in hypertension, whereas the knowledge about the vascular effects of other antihypertensive drugs, like beta-blockers, calcium channel blockers, and diuretics remains rather limited. 3. In this article, the effects of antihypertensive therapy on arterial function in human and experimental hypertension are reviewed.
American Journal of Hypertension - AMER J HYPERTENS, 1996
The effects of long-term high calcium diet and physical exercise and their combined effects on th... more The effects of long-term high calcium diet and physical exercise and their combined effects on the development of hypertension, plasma and tissue atrial natriuretic peptide, and arterial function were studied in spontaneously hypertensive rats with Wistar-Kyoto rats serving as normotensive controls. Hypertensive rats were made to exercise by running on a treadmill up to 900 m/day. Calcium supplementation was instituted by increasing the calcium content of the chow from 1.1% to 2.5%. During the 23-week study, calcium supplementation attenuated the rise in blood pressure in both trained and nontrained hypertensive animals, whereas exerise training had no significant effect on blood pressure. The high calcium diet alone was associated with reduced plasma and ventricular tissue contents of atrial natriuretic peptide, both of which were increased by exercise. Responses of mesenteric arterial rings in vitro were examined at the end of the study. Neither increased dietary calcium nor endur...
A patient with severe capillary leakage syndrome caused by a Puumala hantavirus infection was tre... more A patient with severe capillary leakage syndrome caused by a Puumala hantavirus infection was treated with a single dose of icatibant, a bradykinin receptor antagonist, with a dramatic positive response. We suggest that this drug should be tested in a larger number of patients with severe hantavirus infection.
Nifedipine has been used in the treatment of sphincter of Oddi dyskinesia, a biliary disease char... more Nifedipine has been used in the treatment of sphincter of Oddi dyskinesia, a biliary disease characterized by upper abdominal pains and increased pressure in the sphincter. The effects of other calcium channel antagonists on sphincter of Oddi have not been elucidated. We compared the effects of three calcium blockers with differing smooth muscle selectivity (verapamil, nifedipine and felodipine) on human sphincter of Oddi contractions. Transverse sections of the sphincter obtained from five patients undergoing Whipple resection were studied in an organ bath chamber in vitro. All three calcium blockers significantly (>50%) inhibited the acetylcholine-induced and KCl-induced sphincter contractions in a dose-dependent manner. Both nifedipine and felodipine were more potent than verapamil in inhibiting the acetylcholine-induced contractions, whereas only nifedipine, but not felodipine, reduced the KCl-elicited contractions more than verapamil. The smooth muscle selective calcium channel antagonists are potent inhibitors of human sphincter of Oddi contractions. Although nifedipine is, to date, the only agent studied in clinical settings, other dihydropyridines are also likely to be useful in sphincter of Oddi dyskinesia.
Naunyn-Schmiedeberg's Archives of Pharmacology, 1999
... 1990). Mika Kähönen · Xiumin Wu · Valérie B. Schini-Kerth · Outi Ylikotila · Pertti Arvola · ... more ... 1990). Mika Kähönen · Xiumin Wu · Valérie B. Schini-Kerth · Outi Ylikotila · Pertti Arvola · Jari-Petteri Tolvanen · Eeva Moilanen · Ilkka Pörsti Interleukin-1β-induced nitric oxide synthesis in aortic rings from normal and hyperinsulinaemic rats: effect of physical exercise ...
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