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Biomedical subjects

V Saano

Publications and source records attributed to V Saano.

At least 37 records · Page 2Linked to original sources
PubMed1994

Controlled ocular timolol delivery: systemic absorption and intraocular pressure effects in humans.

Timolol eyedrops may cause systemic side-effects in glaucoma patients due to absorption of the drug into systemic circulation. In a previous study, timolol concentrations in plasma were reduced if timolol was administered in ocular inserts instead of eyedrops. We compared the intraocular pressure lowering effect and systemic absorption of timolol inserts to those of 0.5% timolol eyedrops in humans. Inserts of silicone tubing released 90.3 +/- 13.9 micrograms of timolol in 24 hours in vivo. Timolol inserts afforded similar decreases in intraocular pressure in open-angle glaucoma patients as did b.i.d. eyedrops, but produced lower peak timolol concentrations in plasma, 0.70 +/- 0.10 ng/ml and 0.24 +/- 0.05 ng/ml, respectively. After eyedrops, peak concentrations were achieved at 15.0 +/- 2.2 min, while application of an insert resulted in a delayed peak (tmax = 623 +/- 195 min). The insert resulted in a higher systemically absorbed fraction of the timolol dose than the eyedrop, but the peak timolol concentration and daily absorbed amount of timolol were decreased. The release rate of timolol from the inserts in vivo was only slightly less than that in vitro. Silicone devices are useful for clinical testing of controlled delivery properties of ocular drugs.

Absorption↗
PubMed1994

Ciliary beat frequency at six levels of the respiratory tract in cow, dog, guinea-pig, pig, rabbit and rat.

1. The ciliary beat frequency (CBF) of six animal species from six regions of the respiratory tract were measured: inferior turbinate, nasopharynx, the upper part of trachea from first to second cartilage, the lower part of trachea, main bronchus and subsegmental bronchi. Cow, pig, dog, rabbit, guinea-pig and rat were studied. 2. There were no significant differences in the CBF values between cow, pig and dog, and the ciliary activity was essentially the same (11.3-16.9 Hz) in all parts of the respiratory tract. 3. In the rat, the CBF was slower, especially in subsegmental bronchi (6.8 Hz). 4. In general, CBF was higher in upper than lower airways, with the exception of guinea-pig. 5. Signal quality was the highest in guinea-pig tissue, whereas rat tissue produced the signal with the widest variation in CBF and the highest proportion of distorted waveforms. 6. Therefore, for studying drug effects on ciliary activity, guinea-pig seems to be a more suitable animal than the more commonly used rabbit or rat. In drug comparisons, the same part of the respiratory tract and the same animal species should be used.

Analysis of Variance↗
PubMed1993

Ciliary beating frequency in chronic sinusitis.

Ciliary beating frequency, one component of mucociliary function, was measured outside of the sinus in vitro with a photoelectric method in 150 patients with chronic sinusitis and in 26 control subjects. In the mucosal samples of 35 patients (23%), no ciliary activity was seen. Ciliary beating frequency in maxillary sinus mucosa of the rest of the 115 patients (77%) was, as an average, 16.6 +/- 3.0 Hz (range, 10.9 to 23.3 Hz) and it was 15.9 +/- 2.6 Hz (range, 13.2 to 22.8 Hz) for the control patients. No differences in ciliary beating frequency were found according to quality of sinus secretion, prevalent respiratory allergy, or mucosal thickness. However, in sinuses with purulent secretion, ciliary beating frequency was slightly better (P < .05) than in "empty" sinuses. The study suggests that in many cases of chronic sinusitis, the sinus mucosa still has a capacity to recure.

Adolescent↗
PubMed1993

Influence of chinoin-170, a novel antitussive, on the mucociliary activity in respiratory airways of rats, rabbits, guinea-pigs and man.

Chinoin-170 (Ch-170; 3,7-dihydro-1,3-dimethyl-7-[(5-methyl-1,2,4- oxadiazol-3-yl)methyl]1H-purine-2,6-dione) is a new antitussive with bronchodilating activity. Its effects on the ciliary beating frequency (CBF) and mucociliary clearance were studied. In tracheal explants of rats, Ch-170 dose-dependently at concentrations 2 and 5 mg mL-1 depressed CBF by 24 and 33%, respectively. In human mucosal explants, however, no effects were seen at concentrations up to 5 mg mL-1. In anaesthetized guinea-pigs, an intravenous 50 mg kg-1 dose of Ch-170 caused no changes, and 100 mg kg-1 increased the CBF by 15%. Intravenous Ch-170 dose-dependently increased by 93 (50 mg kg-1), 179 (70 mg kg-1) and 253% (100 mg kg-1) the tracheobronchial mucociliary clearance in rabbits. The effect, studied using 99mTc-labelled red blood cells as a marker, was of similar quantity to that brought about by administering 16, 25 and 40 mg kg-1 doses of bromhexine. It is concluded that unlike many older antitussives, Ch-170 in-vitro only slightly decreases the CBF in rats and has no adverse effects on the CBF in human mucosal explants at concentrations up to 5 mg mL-1. In-vivo, Ch-170 does not significantly alter the CBF in guinea-pigs, but dose-dependently increases the mucociliary clearance in rabbits. The increase is most probably a result of changes in the production and the properties of respiratory mucus.

Animals↗
PubMed1993

Medications and chronic diseases as risk factors for falling injuries in the elderly.

Diseases and medications associated with the occurrence of falls leading to medical treatment in elderly Finns (65 yrs or older) during a one-year period are presented. The design was that of a case-control study involving 380 fallers seeking medical treatment and 342 unmatched controls selected randomly from the population register. The occurrence of a fall was shown by logistic regression analysis to be related to advanced age, presence of benzodiazepine in the serum, hypertrophy of the prostate, poor mental capacity, presence of chronic lung disease and asthma, use of analgesics and use of digitalis in the men, and to advanced age, poor mental capacity, presence of benzodiazepine in the serum, use of analgesics and non-occurrence of lower limb arthrosis in the women. The corresponding log-linear models showed advanced age and the presence of benzodiazepine in the serum to be independent risk factors for falling both in the men and women. Furthermore, the use of analgesics was related to falling in the women with normal mental capacities. No disease was independently associated with falls. The results suggest caution in the use of benzodiazepines among the elderly.

Accidental Falls↗
PubMed1992

Binding of strychnocarpine and related beta-carbolines to brain receptors in vitro.

The affinity of strychnocarpine and related beta-carbolines for serotonin, benzodiazepine, tryptamine, opiate and GABA receptors in rat brain was studied. Strychnocarpine showed a low to very low affinity for all the receptors tested. The weak binding to tryptamine receptors might explain part of the tremorigenic effects found earlier in the in vivo studies.

Animals↗
PubMed1992

The effect of chronic treatment with peripheral benzodiazepine receptor ligands on behavior and GABAA/benzodiazepine receptors in rat.

Rats were twice daily (2 x 10 mg/kg, i.p.) treated for three weeks with the peripheral benzodiazepine (BZ) receptor ligands Ro 5-4864 (4'-chlorodiazepam) and PK 11,195 (1-(2-chlorophenyl)-N-methyl-N-(1-methylpropyl)-3-isoquinoline-carbox ami de). After the first injection there were no differences between the drug-treated and control animals in behavioral tests. After 10 days treatment, the number of sniffings was increased in Ro 5-4864-treated rats. After the last injection, sniffings and ambulations were decreased in PK 11,195-treated animals. The number of rearings and groomings remained unchanged throughout the treatment, and there were no changes in the results in the elevated plus-maze test. Apparently these compounds are devoid of anxiolytic and anxiogenic effects at moderate doses. The effect of 72 a h withdrawal from the above mentioned chronic treatment on peripheral and central BZ receptors as well as on GABAA receptors was studied with receptor binding techniques using 3H-Ro 5-4864, 3H-flumazenil and 3H-muscimol, respectively, as ligands. The number of GABAA and central BZ receptors was lower after Ro 5-4864 treatment, as was the effect of progesterone-induced stimulation of 3H-muscimol binding. The number of peripheral BZ receptors was decreased after Ro 5-4864 and PK 11,195 treatments in the olfactory bulb but not in the cerebral cortex. The chronic treatment with peripheral BZ receptor ligands Ro 5-4864 and PK 11,195 produced only little behavioral effects. Ro 5-4864, often presented as an agonist of peripheral BZ receptors, was behaviorally inactive.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1992

Influence of azelastine and some selected drugs on mucociliary clearance.

The effect of azelastine and some selected compounds on ciliary beating frequency (CBF) was investigated in vitro using human mucosal samples and in vivo using anesthetized guinea pigs. Further influence of azelastine on mucus secretion was evaluated in mice and on mucociliary clearance in anesthetized rabbits. Azelastine influenced the ciliary beating frequency neither in vitro nor in vivo. Azelastine, similarly to salbutamol, ambroxol, and bromhexine, increased mucus secretion measured by the tracheal output of phenol red. Azelastine dose-dependently enhanced mucociliary clearance measured by elimination of 99mTc-labeled erythrocytes in rabbits. The activity of azelastine proved to be about 10 times stronger than that of bromhexine. Since the ciliary activity remained unchanged under the influence of azelastine, it is likely that azelastine increases the mucociliary clearance by enhancing bronchial secretion. It is possible that the observed increase in mucociliary clearance may contribute to the beneficial effect of azelastine in the treatment of respiratory diseases.

Animals↗
PubMed1992

Colonic absorption of human calcitonin in man.

1. Human calcitonin was administered into the distal colon and by intravenous infusion in eight healthy subjects in an open, fixed sequence, cross-over bioavailability study. 2. Intravenously infused human calcitonin elicited a standard pharmacokinetic profile in eight healthy subjects with a biphasic elimination with half-lives of 10.2 +/- 0.7 min and 37.8 +/- 2.5 min. 3. Colonoscopically administered human calcitonin was absorbed across the distal colonic mucosa in low amounts with a bioavailability of 0.00-0.22%. 4. Absorption from the distal colon was impeded by the presence of faecal material in three of the eight subjects. 5. We conclude that human calcitonin crosses the gastrointestinal epithelium of man. This may demonstrate the feasibility of an oral form for clinical use.

Adult↗
PubMed1992

Interactions and comparative effects of zopiclone, diazepam and lorazepam on psychomotor performance and on elimination pharmacokinetics in healthy volunteers.

A randomised, placebo-controlled, double blind single-dose cross-over study was arranged to investigate possible interactions between zopiclone (7.5 mg) and two widely used benzodiazepine (BZD) anxiolytics diazepam (5 mg) and lorazepam (1 mg) during the elimination phase of drugs. Psychomotor performance was tested before and 1, 6, 8, 12 and 24 hr after the drug administration. Simultaneously, blood samples were drawn for determination of plasma drug concentrations. The elimination of each compound was not altered by coadministration of other drugs. As expected, one hour after drug ingestion, psychomotor performance was impaired. The coadministration of drugs increased the effect. During the elimination phase, 6 and 8 hr after the drug intake, only zopiclone and lorazepam in combination slightly impaired performance as compared with the pretreatment levels, but there was no difference as compared with placebo. Adverse events after active treatments were not significantly different from those after placebo. At the recommended dose of 7.5 mg, zopiclone does not alter the elimination pharmacokinetics of the BZD anxiolytics diazepam (5mg) and lorazepam (1 mg), and neither is the elimination of zopiclone affected by these BZDs. Due to the rapid elimination of zopiclone, the increase in sedation seen after concurrent administration with BZDs is of short duration.

Administration, Oral↗
PubMed1992

ATP induces respiratory ciliostimulation in rat and guinea pig in vitro and in vivo.

Adenosine triphosphate (ATP) has been shown to revitalize the disturbed nasal mucociliary function in man. We investigated the effects of ATP on the ciliary beat frequency (CBF) in animals by immersing tracheal explants from rats in various concentrations of ATP, and by infusing ATP intravenously to guinea pigs. CBF was measured with a photodetector technique from the surface of the explants or from the incised trachea. ATP (from 0.01 to 1 mg/ml) in vitro increased CBF in rat tracheal explants up to 10.5% (p less than 0.05). In vivo ATP (1 mg/kg) increased the CBF by 29% (p less than 0.01) in the guinea pig trachea. As the CBF was increased by ATP, both in vitro and in vivo, it can be suggested that the improvement in mucociliary transport by exogenous ATP as shown in previous studies is caused by the ciliostimulatory effect of ATP.

Adenosine Triphosphate↗
PubMed1991

The effect of medetomidine on GABA and benzodiazepine receptors in vivo: lack of anxiolytic but some evidence of possible stress-protective activity.

Medetomidine, a new selective alpha 2-adrenoceptor agonist, potentiated bicuculline seizures in mice. In vivo pretreatment with medetomidine in mouse cerebral cortex reduced dose-dependently (2.5-100 micrograms/kg) GABA-potentiated 3H-flunitrazepam binding. The affinity of 3H-muscimol was also reduced by medetomidine. This effect of medetomidine on GABA-potentiated benzodiazepine binding was reversed by pretreatment with atipamezole (1 mg/kg), a specific alpha 2-antagonist. In an elevated plus-maze model of anxiety medetomidine (0.5-10 micrograms/kg) was inactive both in rats and mice and did not antagonize the behavioural effects of an anxiogenic beta-carboline, DMCM. However, at lower doses medetomidine (10 but not 50 micrograms/kg) antagonized the swimming stress caused increase of central benzodiazepine binding sites (labeled with 3H-Ro 15-1788) in mouse cerebral cortex. The increase of peripheral benzodiazepine binding sites on brain and heart cryostat cut slices caused by stress was also antagonized by pretreatment with medetomidine. The behavioural and biochemical data obtained in this study are evidence that medetomidine does not have anxiolytic effect but may have, in lower doses, stress-protective activity.

Animals↗
PubMed1991

Relative pharmacokinetics of three oral 400 mg ibuprofen dosage forms in healthy volunteers.

The pharmacokinetic properties of two solid form, 400 mg ibuprofen (IP) preparations, a soft gelatin capsule and a film-coated tablet, were compared to those obtained after the administration of liquid prepared from effervescent IP tablets. IP was absorbed rapidly (tmax 0.6-1.9 h). The fastest absorption was observed after the ingestion of the soft gelatin capsule; liquid and film-coated tablet produced 12.2-7.8 times longer absorption half-lives, 50-39% lower peak concentrations of IP in serum and 3.5-3.2 times higher tmax values. Bioavailabilities were close to similar after all products. All products were tolerated without side effects in this single-dose, crossover study on 14 healthy volunteers. The results of this study support the earlier findings that after oral administration, IP is absorbed equally well from solid formulations as from liquid form. Liquid formulations of IP often deliver slower absorption than expected probably due to incomplete dissolution of the active principle. This may have therapeutic significance, and it should be taken into account when studies on the relative bioavailability of IP from pharmaceutical drug products are planned.

Absorption↗
PubMed1991

Effect of codeine on rat and guinea pig tracheal ciliary beat frequency.

Codeine, the basic antitussive drug, has generally been thought to impair mucociliary function. Using the photodetection method the effect of codeine on mucociliary function was studied in rat after local and systemic administration and in guinea pig after systemic administration. In vitro rat tracheal ciliary beat frequency (CBF) was measured up to 40 min. There was 24.6 +/- 2.5% and 26.6 +/- 1.6% decrease in CBF after 1 mg/ml and after 10 mg/ml codeine solutions, respectively. In vivo codeine was administered in single i.v. doses of 10 and 15 mg/kg. No statistically significant differences were found in CBF responses, although there was a CBF decreasing tendency after the 15 mg/kg dose. The total follow-up time was 120 min. In guinea pig, 10 days s.c. codeine administration in daily doses of 3, 10 and 30 mg/kg had no effect on CBF. Although codeine was used in much higher concentrations than tissues concentrations after therapeutic doses of codeine, the effects on CBF were minimal. So it can be concluded that the generally accepted ciliostatic effect of codeine is overestimated.

Animals↗
PubMed1991

The effect of ATP on the ciliary activity of normal and pathological human respiratory mucosa in vitro.

The effect of adenosine triphosphate (ATP) on the airway ciliary beating frequency (CBF) of mucosal explants excised from human maxillary sinuses was studied by measuring CBF photoelectrically before and after immersion of the explants in a solution containing ATP. In samples from 64 patients with chronic sinusitis the CBF was not significantly different from the CBF in mucosal specimens from healthy tissue of 22 patients without infection. During 15 min immersion, ATP (1 mg/ml) slightly (by 5%, p less than 0.05 in healthy tissue; by 2.7%, p less than 0.01, in tissue from sinusitis patients) increased the CBF. The effect of 10 mg/ml concentration was more pronounced (19.6%). It is concluded that the impairment in ciliary function caused by chronic sinusitis is reversible when the mucosal endothelium is cleansed of the infected mucus, and that the ciliostimulatory action of ATP seen in animals is also present in human respiratory mucosa.

Adenosine Triphosphate↗
PubMed1990

Effects of intravenous ATP on tracheal ciliary activity, airway resistance and haemodynamics in rats.

The effect of the intravenous administration of ATP on the airway ciliary beating frequency (CBF) of anaesthetized rat was studied by measuring CBF photoelectrically from the inner surface of incised trachea. ATP (1 or 10 mg/kg) caused no changes in the CBF, but the decrease in CBF, which was seen after 70 min. in control rats, was abolished by ATP (10 mg/kg). ATP acutely decreased blood pressure; at 10 mg/kg, the decrease was 70 mmHg in systolic, and 60 mmHg in diastolic blood pressure. ATP also tended to increase rectal temperature and airway resistance, but these effects were not significant. ECG remained normal. Intravenous administration of ATP helps to maintain the function of tracheal cilia in anaesthetized rats at doses that, although lower blood pressure, do not cause fatal untoward effects.

Adenosine Triphosphate↗