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Biomedical subjects

K Nieminen

Publications and source records attributed to K Nieminen.

12 recordsLinked to original sources
PubMed1999

The effect of toremifene on bone and uterine histology and on bone resorption in ovariectomised rats.

The effect of the selective oestrogen receptor modulator, toremifene, to inhibit ovariectomy-induced bone loss was studied in rats. The oral doses were 0.3, 3.0 or 30 mg/kg/day for 2 months. 17beta-oestradiol (5 microg/kg/day, subcutaneously) was used as positive control. One group was also treated with a combination of 17beta-oestradiol (5 microg/kg) and toremifene (3.0 mg/kg). Biochemical markers were urinary hydroxyproline and calcium (adjusted with urinary creatinine levels) and the serum level of pyridinoline cross-linked carboxy terminal telopeptide, a bone specific collagen breakdown product. The femoral and sternal trabecular bone thickness served as histological parameters. Ovarectomy increased the levels of hydroxyproline and pyrodinoline and decreased the trabecular bone thickness compared to the sham-operated control group. This was inhibited by both test compounds but 17beta-oestradiol was more efficient. Toremifene did not reverse the ovariectomy-induced reduction of urinary calcium but inhibited the 17beta-oestradiol-related increase. When administered together with oestradiol, toremifene did not reverse the positive effect of 17beta-oestradiol on bone, however toremifene reversed the oestradiol-related uterothrophic effects. These findings indicate that the antagonistic features of toremifene dominate in the rat uterus the agonistic properties do in the bone.

Amino Acids↗
PubMed1997

Effective obstetric paracervical block with reduced dose of bupivacaine. A prospective randomized double-blind study comparing 25 mg (0.25%) and 12.5 mg (0.125%) of bupivacaine.

BACKGROUND: To study whether paracervical block (PCB) with 12.5 mg (0.125%) of bupivacaine is as effective as with 25 mg (0.25%) and if there are differences in fetal heart rate (FHR) patterns between the doses. METHODS: A prospective, randomized double-blind study. Fifty-two patients received PCB with 25 mg and 45 patients with 12.5 mg of bupivacaine. Pain intensity was assessed by the patients on a horizontal visual analog scale (VAS). Fetal heart rates of the fetuses were analyzed visually concerning basal rate, variability, accelerations, bradycardia, silent pattern and decelerations. RESULTS: The pain relief was statistically significant in both groups up to 120 min after PCB. The VAS-values were similar in both groups both before and after PCB. Fetal heart rate changes appeared in both groups more frequently after than prior to PCB. In patients receiving 25 mg of bupivacaine there appeared to be more FHR changes than in those receiving 12.5 mg. CONCLUSIONS: Paracervical block with 12.5 mg of bupivacaine is an effective method to relieve pain during labor. Fetal heart rate changes seemed to appear less frequently with this reduced dose. It seems that by lowering the dose of bupivacaine it is possible to reduce fetal side-effects without losing analgesic effect.

Adolescent↗
PubMed1989

Serum levels and urinary excretion of mequitazine after a single oral dose.

Pharmacokinetics of mequitazine, a recently introduced peripheral H1-histamine receptor antagonist of phenothiazine type, was followed up to 72 h after the single oral dose of 5 mg of the drug to eight fasted healthy volunteers. Each subject was treated thrice with a dosing interval of 15 days or more. Thus all the results were triplicated. Serum mequitazine was measured by mass fragmentography using a gas-liquid chromatograph/mass spectrometer set in the electron impact mode. Urine phenothiazines were determined fluorometrically before and after cleaving phenothiazines from their glucuronide conjugates. Peak concentration of mequitazine in serum was 3.19 +/- 1.70 (s.d.) ng.ml-1, time to peak concentration 5.67 +/- 1.68 h, elimination half-life 45 +/- 26 h, and elimination rate constant 0.018 +/- 0.007 h-1. Only 10.9 +/- 3.3% of the dose appeared in urine in unconjugated plus the glucuronidated form during the first 72 h. About 46% of the urinary phenothiazines were glucuronide conjugates. The results suggested that after the oral administration only low mequitazine concentrations appeared in serum, most of the drug seemed to be deactivated by the extrarenal route, and the kinetic properties of the drug resembled those of several phenothiazines used for psychiatric therapy.

Administration, Oral↗
PubMed1988

Electrical properties of cultured dorsal root ganglion neurons from normal and trisomy 21 human fetal tissue.

Dorsal root ganglion (DRG) neurons, in 22 degrees C tissue culture containing nerve growth factor, taken from normal and trisomy 21 human fetal tissues, were subjected to current and voltage clamp measurements using a tight-seal whole-cell recording technique. Measurements were made between 1 and 2 weeks in culture, when the electrical properties of both neuron groups were shown to be constant and when mean values for passive electrical parameters did not differ significantly between groups. The duration of the action potential was significantly less in trisomic than in control neurons, and both depolarization and repolarization were accelerated. Tetraethylammonium (5 mM), which partially blocked outward currents, prolonged the rate of repolarization of the action potential in both neuron groups, and abolished the difference in the rate between the groups. Furthermore, the activation rate constants of two model-defined outward potassium currents were significantly higher in trisomic than in control neurons, suggesting that acceleration of repolarization of the action potential in trisomic neurons was due to shorter activation time-constants of outward potassium currents.

Action Potentials↗