Search PubMed⌕ Search

Biomedical subjects

L Kangas

Publications and source records attributed to L Kangas.

At least 145 records · Page 8Linked to original sources
PubMed1977

Nitrazepam premedication for minor surgery.

Sixty-one patients received nitrazepam 5 mg by mouth on the night before operation, followed by 2.5 mg given on the morning of operation and were compared with 60 patients who received no premedication. All were undergoing either therapeutic abortion, by dilatation and curettage, or explorative curettage. The plasma concentrations of nitrazepam were determined by gas chromatography and compared with the clinical effects of the drug. The premedicated patients slept better on the night before operation, and were more sedated and less apprehensive. Headache was more frequent following nitrazepam. There was no significant difference between the groups in respect of dizziness and nausea. The unpremedicated patients had a faster average heart rate. There was no obvious relationship between the plasma concentration of nitrazepam and the quality of sleep, degree of sedation, apprehension, excitement or headache.

Administration, Oral↗
PubMed1977

Unchanged protein binding and the increase of serum diazepam levels after food intake.

Seven subjects received diazepam 0.3 mg/kg intravenously twice with a 2-week interval between the doses. The subjects ingested a fatty or carbohydrate meal in a cross-over fashion 4 hours after the injection on both experimental days. Venous blood samples were drawn 2, 3, 4, 5 and 6 hours after the injection of diazepam for measurement of the serum levels of total and free (unbound) diazepam, N-desmethyldiazepam, and free fatty acids. Serum levels of diazepam decreased progressively with time until the food intake, after which a significant (P less than 0.01) postprandial increase (average 23%) occurred with both diets as compared to the preprandial levels at 4 hours (average 240 ng/ml). Serum levels of free fatty acids decreased significantly both after a fatty (P less than 0.01) and a carbohydrate (P less than 0.05) meal. Diazepam was extensively (96 to 98%) bound to proteins and no changes in its protein binding was found. It is concluded that the late impairment of psychomotor skills that occurs with an increase in the diazepam serum level after its intravenous administration is due rather to its re-mobilization from a storage site than to variations in its protein binding.

Adult↗
PubMed1977

Plasma nitrazepam concentrations after an acute intake and their correlation to sedation and serum growth hormone levels.

Concentrations of nitrazepam in plasma were determined by gas chromatography in healthy volunteers after an acute peroral administration of nitrazepam (5 and 10 mg). Placebo tablets were also used, and an assessement of subjective drug effects was made during each medication. In addition serum growth hormone levels were determined. The peak plasma nitrazepam concentration was achieved at 120 minutes (46.9 +/- 3.2 ng/ml, mean +/- S.E.M.) after 5 mg of nitrazepam and at 180 minutes (82.8 +/- 10.5 ng/ml) after the dose of 10 mg. The half-life of nitrazepam in plasma ranged from 16.5 to 48.3 (mean 28.8) hours. A significant positive correlation was seen between the subjective sedative effects and the magnitude of the peak nitrazepam concentrations in plasma. This drug effect was highly significant when the plasma levels of nitrazepam were rising. The subjective sedative effects were more prominent after 10 mg than after 5 mg dose of nitrazepam. The plasma nitrazepam concentration was not significantly correlated with the subjective sedative effect the next morning, 12 hours after the drug intake. Serum growth hormone levels rose significantly during the study both after 5 mg and 10 mg nitrazepam doses (peak levels 16.3 +/- 4.0 and 12.7 +/- 3.1 ng/ml) and were significantly higher than after placebo administration (3.7 +/- 0.7 ng/ml).

Administration, Oral↗
PubMed1977

Cerebrospinal-fluid concentrations of nitrazepam in man.

The concentrations of nitrazepam in the plasma and cerebrospinal-fluid (CSF) of 38 neurological patients were determined by gas chromatography 2-36 hours after a single 5 mg oral dose. The percentage ratio between the mean CSF and the plasma concentrations increased from 8.0% at 2 hours to 15.6% at 36 hours. This percentage rise was significant (P less than 0.001). The maximum concentration of nitrazepam in the plasma was 36.7 +/- 5.7 ng/ml (at 2 hours) and CSF 3.0 +/- 0.3 ng/ml (at 4 hours). During the beta-phase the half-life of nitrazepam in plasma was about 27 hours and in the CSF markedly longer about 68 hours, indicating a very slow elimination of nitrazepam from the CSF.

Administration, Oral↗
PubMed1976

Feto-maternal concentrations of diazepam and W-demethyldiazepam after intra-amniotic diazepam injection.

Ten milligrams of diazepam were injected intraamniotically in 8 mothers prior to therapeutic abortion between 12 and 19 weeks. The diazepam concentrations in the maternal plasma were comparable to those found after the same intramuscular diazepam dose to the mother. The concentration of diazepam in the amniotic fluid 12 to 18 hours after the injection was no longer significantly higher than in the maternal plasma. The concentrations of diazepam in the fetal plasma, liver and brain were comparable to the concentrations resulting from a 10 mg intramuscular diazepam dose to the mother about 2 hours before legal abortion. The feto-maternal ratio of diazepam was of same magnitude as after the intramuscular application to the mother. The results indicate that the disappearance of diazepam from the amniotic fluid in this stage of pregnancy occurs extraplacentally, through the mambranes into the uterine circulation. In the treatment of a fetus with drugs having properties similar to diazepam, intra-amniotic administration is no better than intramuscular administration to the mother.

Adolescent↗
PubMed1976

Halothane anaesthesia in caesarean section.

The safety and efficacy of halothane anaesthesia were investigated in 97 caesarean sections using 0.4-0.6% halothane added to a mixture of 61 N2O/3-4 1 O2. The administration of halothane was initiated before intubation and terminated immediately prior to delivery. Only one patient reported memories from the operation. The mean Apgar score 1 min after delivery (8.5) was significantly better than that (8.2) in 100 caesarean sections in which a mixture of 71 N2O/3 1 O2 was used. In 17 caesarean sections, the halothane concentrations were examined after 0.9% halothane had been given for exactly 1 min after intubation. It was found that halothane reached and passed the placenta after only 1 min. The levels in the maternal artery and umbilical vein were comparable. The levels in the maternal artery, maternal vein and umbilical vein were markedly higher than in the umbilical artery, which indicated an accumulation of halothane in the foetal tissues. However, due to the vigour of the newborn, halothane concentrations 10 min after birth were very low. The half-life of halothane in the maternal circulation was approximately 1 min with the described method of administration. Blood gas determinations, which were made in seven newborns, proved satisfactory.

Anesthesia, Inhalation↗
PubMed1976

The protein binding of diazepam and N-demethyldiazepam in patients with poor renal function.

The plasma protein binding of diazepam and of its main metabolite, N-demethyldiazepam, was measured in patients with renal disease and in healthy volunteers by ultracentrifugation. The total and non-protein bound concentrations of diazepam and N-demethyldiazepam, and the concentration of unconjugated oxazepam in the plasma were determined by gas chromatography after an oral 10 mg dose of diazepam. In the volunteers 98% of diazepam and N-demethyldiazepam were bound to the plasma proteins. In patients with renal disease the corresponding values were 92% and 95%, respectively. In the patients with renal disease no correlation could be found between the percent protein binding of diazepam or N-demethyldiazepam in the plasma and the serum creatinine concentration. Considerable variations in diazepam concentrations at 1 and 24 hours and in N-demethyldiazepam concentrations at 24 hours were found in the patients with renal disease. In contrast to the volunteers, 5 patients out of 28 with renal disease had measurable amounts of unconjugated oxazepam in the plasma. The deficient ability of the plasma proteins of patients with renal disease to bind diazepam may increase its clinical effect.

Adolescent↗
PubMedDate not supplied

The proliferation in uterine compartments of intact rats of two different strains exposed to high doses of tamoxifen or toremifene.

Uterine Cell proliferation was studied in intact Sprague-Dawley (SD) and Fischer 344 (F344) rats exposed to the antiestrogens tamoxifen (TAM; 5, 10, 20, or 40 mg/kg) and toremifene (TOR: 21.2 or 42.4 mg/kg). The antiestrogens were administered to animals via gavage daily for 2 or 12 wk. Uterine proliferation was assessed using markers for the proliferating cell nuclear antigen (PCNA) and by the bromodeoxyuridine (BrdU) method. Diethylstilbestrol (DES) was used as an estrogenic reference compound. The antiestrogens either reduced or prevented changes of myometrial and stromal proliferation indices (PI). TAM and TOR caused a time-dependent reduction of endometrial glands without an associated decrease in cell proliferation. In the luminal columnar epithelium, the antiestrogens depressed PCNA PI but enhanced BrdU PI, indicating a low continuous DNA synthesis in otherwise quiescent cells. The antiestrogens induced focal hyperplastic multilayered epithelia with PCNA-positive basal cells along segments of the luminal uterine epithelium. We suggest that this hyperplastic epithelium represents remnants from the glandular epithelium. DES was less efficient in inducing these changes but induced squamous metaplasias in the F344 rats. Uterine effects of the 2 antiestrogens were comparable with the exception of I TAM-exposed (40 mg/kg) SD rat that showed squamous metaplasia. F344 rats were more sensitive to the estrogenic action of DES than were the SD rats.

Animals↗
PubMedDate not supplied

Immunotherapy of the SL2-5 murine lymphoma with natural killer cells and tamoxifen or toremifene.

It is well established that tamoxifen (TX) has a therapeutic effect on estrogen receptor positive tumors by inhibiting the binding of estradiol to its receptor. However, repeated clinical observations indicate that tamoxifen may also have beneficial effects on estrogen receptor negative tumors. In vitro cytotoxicity experiments were performed with the SL2-5 murine lymphoma using interleukin (IL)-2 activated syngeneic NK cells as effectors with or without TX or TO treatment. The effect of TX or TO (10 mg/kg/day/animal in feed) on the immunotherapy of SL2-5 lymphoma with syngeneic IL-2 activated NK cells was also investigated in syngeneic DBA/2 mice. Assays of SL2-5 cells for estrogen and progesterone receptors were also performed. Both TX and TO enhanced significantly the susceptibility of the SL2-5 lymphoma to lysis by IL-2 activated NK cells in vitro. When TX or TO treatment was combined with NK cell immunotherapy of this tumor, both drugs potentiated significantly tumor regression and cure rate when compared to groups receiving NK therapy alone. This tumor does not express classical receptors for estrogens or progesterone. These results indicate that combination treatment with the antiestrogens, TX and TO, acts synergistically with the immunotherapeutic effect of IL-2 activated NK cells in a syngeneic tumor host system.

Adoptive Transfer↗
PubMedDate not supplied

Anti-estrogens potentiate the immunotherapy of the P815 murine mastocytoma by cytotoxic T lymphocytes.

Many animal and human tumors are infiltrated with killer cells. Recent studies have shown that the stimulation of such killer cells with interleukin-2 improves their tumor rejecting capacity. In this paper we demonstrate that the anti-estrogens, tamoxifen (TX) and toremifene (TO), enhance host resistance by sensitizing the tumor target to killer cell mediated lysis. The P815 mastocytoma syngeneic to DBA/21 mice was used. Cytotoxic T lymphocytes (CTL) were detected in the spleens of mice 12-14 days after tumor inoculation. In vitro target, effector, or both cell types were treated with either TX (1 microM) or TO (5 microM) for 4 hours prior to cytotoxicity testing by 51Cr release. Mice bearing P815 mastocytomas, 5 mm in diameter, were treated orally with TX or TO and were given CTL isolated from the spleens of tumor bearing donors i.p. Tumor growth, mortality, and immunological memory in cured animals were monitored. Both TX and TO treatment sensitized P815 target cells to lysis by CTL isolated from tumor bearing animals. The transfer of killer cells from the spleens of tumor bearing mice produced tumor suppression in the recipients, which could be enhanced by additional oral treatment by TX or TO. Complete cure was achieved in a significant number of animals, showing partial or complete resistance to a subsequent lethal dose of P815 cells. These experiments indicate that killer cells isolated from mice bearing progressive tumors can have an immunotherapeutic effect in syngeneic tumor bearing recipients and that the antiestrogens, TX and TO, may be used to potentiate the immunotherapy of this tumor.

Adoptive Transfer↗
PubMedDate not supplied

Combination therapy of the H2712 murine mammary carcinoma with cytotoxic T lymphocytes and anti-estrogens.

BACKGROUND: The triphenylethylene antiestrogenic agents, tamoxifen (TX) and toremifene (TO), are currently being used for the therapy of estrogen dependent breast carcinomas and for some other estrogen receptor positive tumors. Some observations indicate that these drugs may have a beneficial effect on estrogen receptor negative tumors as well. MATERIALS AND METHODS: The H2712 mammary carcinoma of C3H/HeJ mice was studied in combination immunotherapy experiments using cytotoxic T lymphocytes (CTL) and TX or TO. The effect of TX and TO on the in vitro lysis of H2712 cells by CTL was also investigated. Finally, the H2712 cells were examined for the presence of estrogen receptors. RESULTS: Both TX and TO potentiated the lysis of H2712 cells by CTL in vitro, and exerted a growth inhibitory and therapeutic effect on H2712 mammary carcinomas in vivo. The therapeutic effect of CTL isolated from tumor bearing mice was improved on H2712 carcinomas when the animals were also treated orally by TX or TO. Using the dextran-coated charcoal assay, H2712 cells were found to be negative for classical estrogen receptors. CONCLUSIONS: These results indicate that the anti-estrogens, TX and TO, have the ability to suppress the growth of the estrogen receptor negative mammary carcinoma and to amplify target cell lysis by tumor-reactive CTL. By this mechanism these drugs enhance host immunity to an estrogen receptor negative tumor.

Animals↗