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At least 433 records · Page 24Linked to original sources
PubMed1981

[Complex radionuclide evaluation of the hemodynamic state in varicose veins of the lower extremities].

The main parameters of central hemodynamics and regional blood volumes were determined in 106 patients with lower limb varicosity by computer radiocardiography and radiometry of the lower limbs in horizontal and vertical positions of the body. It was found that the clinical stages of compensation and decompensation are paralleled by definite combinations of changes in the circulation volume, minute and stroke values of the cardiac output and regional blood volumes in the lower limbs. Comprehensive appraisal of circulation enabled the authors to distinguish a "transient" stage of the disease according to the character of changes in the main hemodynamic values. It is very difficult to determine this stage from the clinical signs. The study showed that the transition from the stage of compensation to that of decompensation in varicose disease is due to the time factor which is within the limits of up to ten years from the onset of the disease in most cases.

Adult↗
PubMedDate not supplied

[Age dependence of the early reaction in glycosaminoglycan metabolism of the rat liver on damage following a single dose of thioacetamide].

Wistar rats aged 7 or 22 months resp. were treated with 50 mg/kg of thioacetamide (TAA) i.p. The TAA-treated animals as well as control groups of the same ages and containing the same number of animals were injected i.p. with 3H-glucosamine (0.2 microCi/g body weight) 2 hours before sacrifice. Previously to sacrifice, the livers had been perfused in narcosis with NaCl (0.9%). Following degradation of the tissue by pronase, specimen of the substances precipitable by ethanol were digested with chondroitinases, streptomyces-hyaluronidase, keratanase, and nitrite. The quantities of substances were estimated photometrically using Alcian blue; radiometry was performed following precipitation with cetylpyridiniumchloride. In aging animals the amount of dermatan-sulphate (DS) and of the total acidic glycosaminoglycans (a.GAG) is increased as compared to the younger animals, although there ist no age related difference in the incorporation of glucosamine. The incorporation per microgram a.GAG (spec. act.) is decreased. Following TAA the amount of DS is increased in both age groups, whereas the total amount of GAG is increased only in the younger animals. The incorporation per mg dry weight is also increased in all GAG types of both age groups which is also the case with the spec. act. (with the exception of HS in the younger animals). The increase of the incorporation per mg dry weight in DS is significantly lower in the older TAA-animals as compared to the younger ones. HS shows the same tendency, but there is no significance. The age related increase of hydroxyproline parallels that of DS.(ABSTRACT TRUNCATED AT 250 WORDS)

Acetamides↗
PubMed1984

[Disposition and metabolism of 14C-dehydrocorydaline in mice and rats].

Dehydrocorydaline, an alkaloid from Corydalis bulbosa possessing anti-ulceric activity, was labeled by methyl-14C at position 13, and its disposition and metabolism were studied in mice and rats after oral (50 mg/kg) or intravenous (6.8 mg/kg) administration. Blood levels were as low as 0.5 (mice) and 0.06 (rats) microgram eq./ml at maximum, conceivably due to its poor absorption from digestive tracts. Radiometric and autoradiographic studies after oral administration of 14C-dehydrocorydaline revealed that appreciable radioactivity was distributed in rather restricted organs, namely, digestive tracts, liver and kidney. Comparison of distribution with that after intravenous administration suggested that the compound is subject to the significant first pass effect by the liver. The distribution pattern of radioactivity in the liver was heterogeneous regardless to administration routes. Radiometry and autoradiography also revealed that the disposition did not differ significantly from each other in normal rats and those with experimentally induced gastric ulcer. Excretion of radioactivity occurred largely in feces. Excretion via urine and bile was quite minor. Metabolite analysis suggested that dehydrocorydaline was metabolized by O-demethylation and subsequent conjugation with glucuronic acid. However, metabolites were minor relative to the unchanged compound.

Alkaloids↗
PubMed1983

[Effect of heparin on the thyroid gland].

Effect of heparin on the white rat thyroid gland has been studied in vivo and in vitro by means of light microscopy, electron microscopy and radiometry methods. Heparin is injected subcutaneously (1,000 units per 100 g of the body mass) once in 24 h. In the in vitro experiments heparin contents in medium is 10 units/ml and 10 units/ml. Heparin produces a decrease in thyrocyte height (control--12.6 +/- 0,5, experiment--10.4 +/- 0.6 mcm), a decrease in the number of folds on the basal surface of thyrocytes, changes in Golgi complex and an increase in electron density of the mitochondrial matrix. In endotheliocytes of the perifollicular blood capillaries the number of fenestrae decreases. Iodine accumulation in the thyroid is lowered under the effect of heparin. The thyroid gland blood stream (estimated by accumulation of 86Rb) decreases by 35%. The data obtained support the previous suggestion of the authors on a system-forming role of the tissue basophils in the thyroid micro-region.

Animals↗
PubMedDate not supplied

Prostaglandin E1 infusion for small vessel arterial ischaemia.

The effects on severe arterial ischaemia of infusions of Prostaglandin E1 (PGE1) a vasodilator and inhibitor of platelet aggregation, were studied in 49 patients (aged 17-80). Criteria for patient selection included rest pain and/or digital ulceration and gangrene secondary to predominantly small vessel disease. PGE1 was infused at a low (6 ng/kg/min), intermediate (10 ng/kg/min) or high (14 ng/kg/min) dose rate via a central venous cannula on 52 occasions without serious side effects. Doppler studies, pulse volume recordings and infra red radiometry were used to quantify the clinical effects. Improvements in digital perfusion were demonstrated by increased pulse volume amplitude (7.1 +/- 1.1 to 21.6 +/- 2.7 mm mean +/- SEM) which remained significantly raised at 6 weeks (14.2 +/- 2.9 mm; P = less than 0.001 paired t test). Infra red digital temperatures were also significantly raised 6 weeks post infusion (27.2 +/- 0.6 degrees C to 29.5 +/- 0.6 degrees C; P less than 0.001). The majority of patients reported improvement in pain, and two thirds of 12 superficial ulcers healed in 6 weeks. These results show that PGE1, improves digital perfusion for several weeks in patients with severe arterial ischaemia.

Adolescent↗
PubMed1978

[Formation of DNA--protein crosslinks and their possible elimination in cultures of normal human fibroblasts after exposure to embichin].

New methods of radiometry and fractionation of cell lysates on hydroxyapatite were applied to determine the crosslinkage between DNA and protein induced by embiquin in cell culture of normal human skin fibroblasts. Such crosslinks were found to be formed; they were eliminated in long-term cultivation of the cells after mutagen treatment.

Cells, Cultured↗
PubMed1981

Fourth interlaboratory study of methods for determining total migration of plastic materials in liquids simulating fatty foodstuffs.

Results are reported for the fourth interlaboratory study organized by the Commission of the European Communities for the adoption of an official method for determining the total migration of plastic materials in liquids simulating fatty foodstuffs. In each method, a sample of plastic material was weighed before and after it was placed in contact with fatty simulants. The fat absorbed by the sample, extracted or dissolved by suitable solvents, was determined by gas chromatography or radiometry. The results obtained confirm the conclusions given previously. Each method was moderately satisfactory, but less so between laboratories.

Chromatography, Gas↗
PubMed1981

[Myelinotoxic activity of sera from animals with experimental allergic encephalomyelitis in organotypic cultures of the rat cerebellum at different stages of differentiation].

Radiometry was used to assay myelinization and demyelinization in organotypic long-surviving cultures of the cerebellum from newborn rats. It was shown that serum from guinea-pigs with allergic encephalomyelitis suppresses by 45% the incorporation of labeled cholesterol into nerve tissue cells in the early periods of cultivation (within 10 days), i.e. before myelinization commencement. It also suppresses thymidine and cholesterol incorporation in the later periods of cultivation, i.e. in the last stages of differentiation, this suppression being increased twofold in the myelinized cultures of the nerve tissue. The effect of humoral factors of the sera from sick animals on the neuroglial cells in the course of nerve tissue differentiation in vitro is discussed.

Animals↗
PubMed1981

Cancer detection studies using a 4.7 Gigahertz radiometer.

Our laboratory has begun to evaluate the cancer detection capabilities of a microwave thermographic unit that employs a 4.7 GHz radiometer. The technique is passive and noninvasive. The temperature sensitivity of the unit is less than 0.1 degrees C. Malignant tumors are often about 1 degree C warmer than normal tissues. Microwave radiometry can provide information related to subsurface temperatures, whereas infrared thermography is limited to surface temperatures. Positive results were obtained in four of six biopsy-proved primary carcinomas of the breast, in four of four patients with lymphoma, and in nine of ten women with recurrent breast cancer. Negative results were obtained in patients with deeply seated tumors such as in lung, liver, esophagus, femur, and humerus. Microwave thermography is a promising new method of noninvasive cancer detection, and the choice of a 4.7 GHz frequency may represent an improvement over units operated at other frequencies.

Adult↗
PubMed1980

[Characteristics of the steroid hormone binding system in hepatocyte plasma membranes].

Parameters of cortisone and estradiol binding to plasmatic membranes of rat hepatocytes were studied by liquid scintillation radiometry. Two systems of binding these hormones were revealed in the membranes. One of the systems is specific (saturated) and binds the hormones in physiological concentrations. The capacity and affinity of this system for cortisone is significantly higher as compared to estradiol. The parameters of binding over the temperature range of 4-37 degrees C are as follows for cortisone and estradiol, respectively: dissociation constant 2.1-3 and 2.7-4.5 nM; the number of binding sites 2.0-2.4 and 0.14-0.18 nM per one g protein. Experiments with parachlormercuribenzoate indicate participation of proteins in this system functioning. The other (unsaturated) system is nonspecific, its funtioning being determined by the lipid component of the membranes. Corticosteroid affinity for hepatocytes seems likely to be due to the functioning of the specific (saturated) system of the plasmatic membranes of these cells.

Animals↗
PubMed1980

[Autoradiographic study of the distribution of 99mTc-pertechnetate in rat testes].

It has been shown by direct radiometry that 99m Tc-pertechnetate is excreted from the rat testes according to the exponential dependence, the maximum accumulation being observed 10 minutes after the injection (0.5% per 1 g tissue of the injected activity). Autoradiography has revealed that most of the radionuclide is located in the vascular system of the testes, whilst the minor part in the seminiferous tubules, the maximum accumulation being reached one hour after injection. It is concluded that 99mTc-pertechnetate behaviour pattern in the testes is first of all determined by its content in the vascular system of the organ.

Animals↗
PubMed1995

Disposition of gabapentin (neurontin) in mice, rats, dogs, and monkeys.

Gabapentin, an analog of gamma-aminobutyric acid, exhibits anticonvulsant properties in both animal models and humans. Gabapentin pharmacokinetics was studied in laboratory animals using HPLC and radiometry. Oral bioavailability was 40% in monkeys administered 25 mg/kg, 79% in mice and rats receiving 50 mg/kg, and 80% in dogs administered 50 mg/kg. Binding to plasma proteins was < 3%. Maximum blood or plasma concentrations generally occurred within 2 hr of an oral dose. In rats and monkeys, increases in maximum plasma concentrations and/or areas under the curve were less than dose-proportional following oral administration, most likely because of saturable absorption. However, intravenous pharmacokinetics in rats were linear over the dosage range of 4-500 mg/kg. Mean intravenous elimination half-life was 1.7 hr in rats, 2.9 hr (14C only) in dogs, and 3.0 hr in monkeys. In rats and dogs, repeated administration did not alter gabapentin or 14C pharmacokinetics. Additionally, gabapentin did not induce hepatic cytochrome P450 monooxygenases in rats. There were no age- (rats only) or gender-associated changes in pharmacokinetic parameters. [14C]Gabapentin was extensively distributed to tissues. In the dog, gabapentin was metabolized to N-methylgabapentin (approximately 34% of dose); whereas metabolism in mouse, rat, and monkey was minimal (< 5%). The principal route of excretion was via urine. In summary, as an antiepileptic drug, gabapentin exhibited desirable pharmacokinetic properties, such as linear elimination kinetics, not highly bound to plasma proteins, not extensively metabolized, and not an inducer of hepatic cytochrome P450.

Acetates↗
PubMed1993

[Studies in oocyte maturation and embryonic development].

A clearer understanding of biochemical properties of oocytes and embryos and their changes in oocyte maturation and embryonic development may have significant clinical implications, especially for in vitro fertilization techniques. Microtechniques and highly sensitive methods such as enzymatic cycling, micro-Western analysis, reverse transcription polymerase chain reaction and so on were employed to study these processes. Low hexokinase activity and high activities of enzymes in the phosphate pathway were characteristic of immature oocytes. During maturation, the activities of hexokinase and phosphofructokinase increased significantly. These changes were used to analyze involvement of epidermal growth factor (EGF) and prostaglandins (PG) in oocyte maturation. EGF is shown to stimulate maturation by increasing PG production in granulosa cells. Electrophysiologically, the sensitivity of oocyte to inositol triphosphate increased and Ca2+ release system developed during maturation. Progesterone production of oocyte and embryos are shown by enzymatic cycling and other methods using radiometry. This hormone produced by embryos themselves may play a role in embryonic development in intracrine fasion. There is 100-fold increase in glucose uptake from oocyte to blastocyst in mice. A switch in substrate preference of the embryo from pyruvate to glucose during preimplantation development may be explained by increases in the activity of hexokinase and expression of glucose transporter, GLUT1. Hexokinase activities determined by NADP cycling increased 20-fold while expression of GLUT1 assessed by micro-Western method 10-fold. GLUT1 expression was also analyzed by RT-PCR, which indicated that the expression is regulated at transcription level. There is a delay in the developmental changes in glucose uptake, hexokinase activity and GLUT1 expression when the embryos are developed in vitro.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMedDate not supplied

[Regularities of drug desorption from soft contact lenses. 2. In vitro study].

Radiometry of distribution of drugs introduced with soft contact lenses (with 40 and 70% humor content and thickness of 0.2 and 0.7 mm) in the ocular cavity was carried out to compare this mode of drug administration with the traditional methods. The maximal concentrations of the drugs in the anterior chamber humor and in the vitreous body were attained by using saturated highly hydrophilic 0.7 mm thick contact lenses. The drug content in the anterior chamber of the eye upon such a mode of administration was higher than after injection and much higher than after instillation.

Animals↗
PubMed1995

[Accumulation sites of kanamycin in cochlear basal membrane cells].

The dissection technique of cochlear basal membrane, the fractional technique of tissular homogenization, and the radiometry technique were used to study the toxicity of kanamycin on the hair cells. It was found that after the cochlea was perfused with a 0.25% perilymph solution of kanamycin, there were 3.14 fg KM in a nucleus, 7.61 fg KM in a mitochondria and 21.16 fg KM in a lysosome. It showed that after entering the cell, KM mainly accumulated with in the mitochondria. Simultaneously the lysosome also phagocytized a lot of kanamycin. The germicidal mechanism of kanamycin is to inhibit the synthesis of protein in bacteria and the mitochondria has the same way of protein synthesis, the mitochondria can combine with kanamycin specifically; the drug in lysosome may be related to its phagocytic function.

Animals↗
PubMed1996

[Elucidation of the mechanism of fertilization and clinical application of assisted reproductive technology].

Fertilization is the process including many events such as maturation of egg and sperm, attachment, binding, acrosomal reaction, penetration, fusion, cortical reaction, zona reaction and nuclear fusion of both gamete, whereby individual gametes from the female and male unite to create offspring. Although the reason for mechanism of fertilization is still not clearly understood, this process may accelerate the rate adaptation in evolution. In this special lecture, I would like to present our experimental and clinical results especially concerning with morphological, physiological, biochemical and molecular approach on the mechanism of fertilization. 1. Development and maturation of follicles and oocytes. It is well known that pituitary FSH, LH control the ovarian function. Follicular development and ovum maturation are also controlled by both pituitary gonadotropins and local factors such as autocrine and paracrine agents. When hMG is injected during 1-6 day of menstrual cycle, several dominant follicles are developed. If hMG is injected after selection of dominant follicles, only one dominant follicle develop in the ovary. When PMS-treated immature rats were injected with immature or mature follicle fluids, rats injected with mature follicular fluid showed strongly suppress in the ovarian weights and numbers of ovulated follicles. Also mature follicle suppress aromatization from and androstenedione to estradiol. These findings mean that mature follicular fluid contains inhibitory factors. Apoptosis of granulosa cells and follicular steroids are related to fertilization. 2. Intracellular calcium of oocyte. Intracellular calcium concentration is known to start to increase in a periodic manner after fertilization in oocytes of mammalians. In 65% of tested mouse oocytes, fertilization occurred during 4 hours observation after sperm insemination in vitro. An initial long lasting intracellular calcium concentration was observed and followed by periodic manner. This calcium oscillation is inhibited by calcium blockers such as verpamil and nifedipine, but increased by high concentration of extracellular calcium concentration in the medium. Role of increase of intracellular calcium are understood to prevent polysperm and activate metabolism of oocytes. 3. Glucose metabolism of oocytes. Mouse embryo utilizes pyruvate as an essential nutrient until the 8-cell stage, and glucose thereafter. We have devised non-radiometrie and enzymatic microassay method to measure glucose, deoxyglucose, deoxyglucose 6-phosphate incorporated into individual mouse oocytes and preimplantation embryo. In parallel, the activities of several enzymes of glycolytic pathway were also determined. In this study, glucose metabolism is necessary to develop in fertilized ova with changing activity of enzymes. 4. Molecular bases of ovarian fluid. The zona pellucida ZP is involved in a number of events in fertilization, all these fertilization events occur in the oviduct. Oviductal glycoprotein 200-240 KD has been identified from oviductal zona pellucida. Monoclonal antibody of oviductal glycoprotein reacted with ZP of oviductal egg but not with the ovarian egg. Anti-ZPO antibody inhibit to bind sperm to ZP. Sequences in mouse and hamster oviduct specific glycoprotein are estimated, this glycoprotein mRNA was observed in only oviduct by northern blotting method. These molecular gene expression was observed by in situ hybridization in the oviduct of estrous cycle of hamster. 5. Microinsemination of sperm. Microinsemination of sperm into oocyte is widely used in clinical medicine. Sperm penetration assay (hamster test) is useful method to estimate fertilization capacity of sperm. But immotile sperm cannot estimate it. So modified micro sperm penetration assay was established to estimate fertilization capacity of sperm by using micro-manipulator. Subzonal sperm injection (SUZI) and intracytoplasmic sperm injection (ICSI) promotes fertilization and cleavage rate in immotile

Animals↗
PubMedDate not supplied

[Clinical characteristics of primary hypothyroidism in Dakar. Apropos of 37 cases].

Primary hypothyroidism, other than cases of endemic goiter, has rarely been described in Africa. We conducted a retrospective study of the patients admitted to our hospital unit between 1985 and 1996. The inclusion criteria were clinical signs of hypothyroidism and low levels of thyroid-stimulating hormone. We investigated socio-demographic, clinical (hypometabolic syndrome, cutaneomucal syndrome, muscular syndrome) and etiological (spontaneous thyroid atrophy, thyroidectomy, multinodular goiter) factors. Overall, our study population contained 37 cases, 8 men and 29 women. The mean age of the men was 40.8 +/- 19.2 years and that of the women was 41.5 +/- 14.5 years. Eighteen patients (about 50%) lived in the suburbs, 25% of patients were from urban areas and 25% from rural areas. The associated clinical signs were: 1) hypometabolism: constipation (51% of cases), bradycardia (45%), physical asthenia (40%), sleeping during the day (32%), frilosity (35%); 2) cutaneomucal syndrome: hoarseness (48%), alopecia (32%), facial puffiness (27%), macroglossia (24%), hypoacousia (21%), weight gain (18%), dry skin (16%), pallor (2%); 3) muscular syndrome was rare: myalgia (4 cases), muscle weakness (2 cases). Mean total cholesterol concentration was 2.54 +/- 0.75 g/l; mean total T3 was 1.027 +/- 0.84 nmol/l; mean total T4 was 16.70 +/- 16.89 nmol/l; mean TSH concentration, measured by radiometry, was 63.74 +/- 51.01 mIU/l. The etiology was goiter in 13 cases, thyroidectomy (11 cases) and spontaneous thyroid atrophy (13 cases). Thus, primary hypothyroidism does occur in African hospitals, particularly in Senegal. This disease, which has traditionally been reported in public health studies of endemic goiter, also occurs in cosmopolitan African environments.

Adolescent↗
PubMedDate not supplied

[The late neurological radiation sequelae in participants in the cleanup of the accident at the Chernobyl Atomic Electric Power Station].

As many as 119 subjects who took part in the elimination of the aftermath of the Chernobyl Nuclear Power Plant breakdown were studied for their neurological status 7-8 years following the accident. Changes were revealed at all levels of the brain, such as cortex, subcortex, truncus cerebri. Parameters characterizing blood were studied in the examinees together with results of radiometry of brain tissue of deceased liquidators, that suggested cause-and-effect relationship between cerebral symptomatology and radiation.

Brain Diseases↗