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PubMed1989

Quantitation of gastrointestinal protein loss.

Plasma proteins leak into the gastrointestinal tract under physiological conditions. This may assume enormous proportions in certain pathological conditions associated with the stomach, intestines, intestinal lymphatics and capillaries, resulting in severe hypoproteinemia. Quantitation of this leakage has been achieved by using plasma proteins or non-protein foreign colloids and macromolecules labelled with radioactive isotopes. The requirements of an ideal label have been listed and the advantages/disadvantages of different tracer labels have been reviewed. No label presently available fulfils all the requirements of an ideal tracer. In spite of this, a wealth of information has been acquired by gastroenterologists to unravel the mystery of hypoproteinemia of unknown cause.

Digestive System↗
PubMedDate not supplied

[Antifibrillatory effect of the calcium antagonist foridon in acute myocardial ischemia in conscious rabbits].

The effect of ryodipine on disorders of rhythm induced by occlusion of the left descending coronary artery was studied in experiments on 40 conscious immobilized rabbits. Ryodipine was injected intravenously (50 mcg/kg 5 minutes prior to and 25 mcg/kg after occlusion). Ventricular fibrillation developed in 19 (66%) rabbits of the control group and in 3 (27%) animals in the experimental group (p less than 0.03). The parameters of systemic and regional hemodynamics were studied in 7 rabbits of the control group and in 5 animals of the experimental group before and 30 minutes after occlusion; microspheres (15 mcm) labelled with various radioactive isotopes were used in the study. The blood flow in the intact myocardium of rabbits given ryodipine was higher than the initial level by 14% (p less than 0.05). The coronary fraction of the cardiac output increased by 21%. It is concluded that the antifibrillation effect of ryodipine is due to its favourable action on the myocardial blood flow.

Animals↗
PubMedDate not supplied

[Entry of cyclic nucleotides into frog muscles in vivo and in vitro].

The radioactive isotopes of cyclic nucleotides were used to study the possibility of their income to the isolated frog muscle from the environment as well as their distribution between blood plasma and muscle after injection to an animal. It is shown that the intracellular levels of nucleotides may be considerably higher after soaking the isolated muscle in 10(-6) M cGMP or 10(-4) cAMP solutions. After the cAMP injection into the lymphatic sac its content in blood and especially in muscles is high for a long time. In this case the label loss in muscles proceeds slower than in blood. A conclusion is drawn that conduction of studies on the artificial increase of the intracellular level of cyclic nucleotides by means of their injection to an animal is appropriate.

Animals↗
PubMedDate not supplied

[Functional activity of cells suppressing the humoral immune response in internal irradiation].

In the adoptive transfer system of (CBA X C57BL/6)F1 mice, the estimation was made of the function of splenic cells, suppressors of the humoral immune response to sheep erythrocytes 1 and 6 months following the injection of 125I and 131I. Low absorbed doses of the radioactive isotopes were shown to stimulate the activity of the suppressors generated in mouse spleen.

Animals↗
PubMedDate not supplied

Cerebral hemodynamics in arteriovenous malformations: evaluation by single-photon emission CT.

Cerebral hemodynamics in six patients with supratentorial arteriovenous malformations (AVMs) were studied by using single-photon emission CT with three types of radioactive isotopes: N-isopropyl-p-[123I] iodoamphetamine, 81mKr, and 99mTc-RBC in order to determine the local cerebral blood flow and blood volume associated with these malformations. The AVMs were shown to have high flow while other areas of the brain, including the contralateral hemisphere, had variable areas of diminished perfusion. There was increased blood volume in the regions of AVMs, and poor but evenly distributed blood volume in the other regions. CO2 reactivity during hypocapnia was preserved throughout the brain except for the region of the AVMs. In large AVMs, the ischemic state surrounding the nidus was considered to be caused mainly by the cerebral steal phenomenon.

Adult↗
PubMedDate not supplied

[Effect of space flight factors on the blood circulation function in primates].

Using radioactive isotopes, central, peripheral and organ blood circulation was investigated in two rhesus-monkeys before the 7-day space flight, 1.5 hours after touchdown, and 4 months after recovery. Blood distribution and shifts were measured in different body segments, viz. head, chest, abdomen, legs. Postflight measurements revealed a decrease of plasma and blood volume. They also demonstrated changes in cardiac output and stroke volume, decrease of total peripheral resistance, reduction of mean arterial pressure and a slight increase of heart rate. Pulmonary blood flow velocity and time varied insignificantly and in a different manner. Blood was pooled in the legs. Blood flow velocity in the skin of the upper and lower body decreased while in muscles it increased above the baseline values. Postflight, muscles acted as a hemodynamic blood pool. The tolerance of both monkeys to the tilt test was satisfactory. It can be concluded that the monkeys tolerated the 7-day space flight well enough.

Animals↗
PubMed1988

Sternal blood flow after median sternotomy and mobilization of the internal mammary arteries.

Although the internal mammary artery (IMA) is superior to the saphenous vein graft for bypassing certain coronary arterial obstructive lesions, such operations may predispose the patient to sternal infection or dehiscence--presumably as a result of sternal ischemia. This study was designed to measure sternal blood flow before and after median sternotomy and IMA mobilization in order to quantify the hemodynamic effects of these procedures. Rhesus primates were randomized into control, unilateral IMA-harvested, and bilateral IMA-harvested groups. After selective angiography enabled confirmation of IMA patency, 15 micron microscopheres, labeled with specific-spectra radioactive isotopes, were injected at baseline, after sternotomy, and after IMA harvesting. The sternal halves were subjected to gamma counting, and sternal circulation was accurately quantified. Our results showed that blood flow to the sternal halves in which the IMA was harvested decreased precipitously (from 4.5 to 0.8 ml/gm/min; p less than or equal to 0.001), although it remained unchanged in response to median sternotomy. This represented a 90% decrease in the mean rate of flow within the IMA-harvested sterna versus a stable flow rate for the unharvested sides. We conclude that mobilization of the internal mammary artery, as in coronary bypass procedures, significantly devascularizes the sternal half from which it was harvested.

Animals↗
PubMed1988

Retinal projections in the red belly squirrel (Callosciurus erythraeus Roberti): an autoradiographic study.

Tritiated labeled materials, [3H]proline and [3H]fucose, were used as tracers of the visual pathway by injection into the right eve of the red belly squirrel, After a designated survival period, the animals were sacrificed, and the brains were removed and processed using standard autoradiographic procedures. Sections were then examined under a microscope and some subcortical nuclei including the suprachiasmatic nucleus (SCN), dorsal and ventral lateral geniculate nuclei(dLGN and vLGN), three optic accessory nuclei (i.e., the medial, lateral and dorsal terminal nuclei - MTN, LTN and DTN), the nuclei of the pretectal area(PTN) and the superior colliculus(SC) in the subcortical regions were marked by labeled isotopes. Radioactive materials were found in the pulvinar nucleus(Pul), parabigeminal nucleus(PB) and dorsal lateral pontine gray(DLP). Some nuclei among the targets of retinal projection in the red belly squirrel received their projection bilaterally while others only did contralaterally. In addition, layered structures of the SC and LGN were clearly demonstrated in the brain of the red belly squirrel. Some differences in the optic system between the red belly squirrel and its near relative, the grey squirrel of North American, and other mammals are discussed.

Animals↗
PubMed1987

A population-based case-control study of thyroid cancer.

A population-based case-control interview study of thyroid cancer (159 cases and 285 controls) was conducted in Connecticut. Prior radiotherapy to the head or neck was reported by 12% of the cases and 4% of the controls [odds ratio (OR) = 2.8; 95% confidence interval = 1.2-6.9]. Risk was inversely related to age at irradiation and was highest among children exposed under age 10. Few persons born after 1945 received prior radiotherapy, consistent with the declining use of radiation to treat benign conditions in the 1950's. Among females the radiogenic risk appeared to be potentiated by the number of subsequent live-births. Other significant risk factors included a history of benign thyroid nodules (OR = 33) or goiter (OR = 5.6). Miscarriage and multiparity increased risk but only among women who developed thyroid cancer before age 35 years. Consumption of shellfish (a rich source of iodine) seemed to increase the risk of follicular thyroid cancer, whereas consumption of goitrogen-containing vegetables appeared to reduce risk of total thyroid cancer, possibly because of their cruciferous nature. A significantly low risk was observed among persons of English descent, whereas Italian ancestry appeared to increase risk. No significant associations were found with a number of suspected risk factors: diagnostic x-rays, radioactive isotope scans, occupational radiation exposure, tonsillectomy, Jewish ethnicity, alcohol intake, cigarette smoking, oral contraceptives, lactation suppressants, menopausal estrogens, most other common medications, and water source. New associations were suggested for obesity among females (OR = 1.5), surgically treated benign breast disease (OR = 1.6), use of spironolactone (OR = 4.3) or vitamin D supplements (OR = 1.8), and a family history of thyroid cancer (OR = 5.2). About 9% of the incident thyroid cancers could be attributed to prior head and neck irradiation, 4% to goiter, and 17% to thyroid nodular disease, leaving the etiology of most thyroid cancers yet to be explained.

Adult↗
PubMed1986

Monoclonal antibody technology.

The development, production, limitations, and uses of monoclonal antibody (MoAb) technology are presented. The first MoAbs were developed in 1975 using a process whereby the antibody-producing spleen cells of mice that had been immunized against sheep red blood cells were fused with the cells of a mouse myeloma cell line, producing hybridomas. These hybridoma cells are used to produce MoAbs, which are antibodies that will bind to only one specific target site on an antigen. Large quantities of MoAbs are grown, either in cell cultures or in the peritoneum of mice, and harvested. Although large quantities of MoAbs can be produced, these techniques are limited because of the potential for contamination by mouse viruses and the inability of the hybridomas to yield sufficient quantities of MoAbs. MoAbs are currently used in diagnostic techniques, including pregnancy tests and drug assays, as well as in tests for detecting viral and bacterial infections and cancer. MoAbs, coupled with dyes or radioactive isotopes, can be used in imaging techniques. Other possible applications of MoAbs include tissue typing, purification, therapy of cancer and autoimmune diseases, and treatment of drug toxicities. As the use of MoAbs in health care increases, pharmacists will need to have a good understanding of the functions and applications of these agents.

Antibodies, Monoclonal↗
PubMed1979

[Data to substantiate the early immunological diagnosis of dysentery].

The interaction of the whole blood from patients with dysentery and gastrointestinal diseases of non-dysenteric etiology, with the causative agents of dysentery, Sh. sonnei and Sh. flexneri, and saprophytic, staphylococci labeled with radioactive isotopes was studied in vitro. In dysentery an increase in the capacity of the blood for Shigella fixation was observed from the beginning of the disease. During the 1st week of the disease this reaction was strictly specific and accompanied by a decrease in the fixation of staphylococci, but later the reaction became relatively specific. An increase in Shigella fixation occurred considerably earlier than immune antibody formation, as revealed by the indirect hemagglutination test. This research substantiates the possibility of an earlier immunological diagnosis of dysentery as compared with the serological methods.

Acute Disease↗
PubMed1985

Distribution of 64copper in the blood and different tissues of mice bearing induced fibrosarcoma.

To understand the nature of copper distribution during malignancy, 27 strains A/RB mice with fibrosarcoma were used. Tracer methodology with radioactive isotope of copper (64Cu) was applied. In the study made at different time intervals after isotope administration whole blood plasma and different tissues like liver, heart, spleen kidney and brain were investigated. Liver nuclear fractions were also examined. Distribution of 64Cu in different tissues reflected interesting results. While the incorporation pattern in the liver showed gradual fall from 8 h of isotope administration, the tumor tissue exhibited gradual elevation, compared to the controls. The effect of this finding is discussed.

Absorption↗
PubMed1979

[So-called coronary angiographic paradoxes].

The results of examination of 25 patients (18 with ischemic heart disease and 7 with cardialgia of other etiology) are discussed. The arteriolo-capillary bed of the coronary arteries was studied by intraarterial injection of albumin aggregates labelled with radioactive isotopes. A correlation was revealed between the degree of microcirculatory disorders and the results of electrocardiography. With increase in the degree of microcirculatory disorders, cicatricial changes in the left ventricular myocardium were found more frequently and a history of myocardial infarction (in 11 persons) and the development of left ventricular aneurysm (in 2 patients) were noted. Certain indices of integral function (EF, VcF, MNSER) and regional contractility (% delta r, L) of the left ventricle were determined in 14 patients. Among these parameters characterizing left ventricular function (EF, VCF, MNSER, % delta r, L), VCF, MNSER, and % delta r, L are most sensitive. No correlation was revealed between the state of the myocardial microcirculation bed and EF, VCF, and MNSER, but a definite correlation was found between it and % delta r, L (in the form of regional hypo- and hyperkinesia and paradoxical pulsation). Normal coronary arteriograms do not exclude the presence of ischemic heart disease and other primary diseases of the myocardium. Patients of this category should be examined more scrupulously to detect disorders of blood supply to the myocardium and function of the left ventricle.

Coronary Angiography↗
PubMed1984

Immunochemical and biological properties of monoclonal antibodies (MCAs) against human chorionic gonadotrophin (hCG).

The paper reviews properties and applications of MCAs against hCG in comparison with classical antisera against this hormone. The first part begins with a brief survey of immunochemical tests and assays based on classical antisera to set the stage for the use of MCAs in various test systems. Monoclonal antibodies (MCAs) against hCG are often subdivided in three groups depending on where the epitope on the antigen is situated: on the alpha or beta-subunit, or solely on the complete hCG molecule. MCAs belonging to these three groups were investigated both immunochemically and biologically. Competitive immunoassays using anti-alpha MCAs do not discriminate against the other glycoprotein hormones (LH, FSH, TSH). Application of anti-beta MCAs can but need not lead to assays specific for hCG. The same was found for those MCAs which react with the complete hCG but not with its subunits (anti-alpha beta). These competitive assay systems are usually of mode-rate sensitivity since MCAs with high affinities (K greater than 10(10)) are quite rare. In contrast, application of selected combinations of two MCAs in sandwich assays (with either an enzyme or a radioactive isotope as label) or in agglutination tests (using erythrocytes, latex or gold sol particles) lead to much more specific and sensitive assay systems. In the second part, biological biological activities of classical antibodies but particularly of MCAs are discussed. Most MCAs against hCG studied by us were unable to affect the biological activity of the hormone. The few which did, either potentiated or inhibited the biological activity.(ABSTRACT TRUNCATED AT 250 WORDS)

Antibodies, Monoclonal↗
PubMed1980

Microiontophoresis of biogenic amines on cortical neurons: amounts of NA, DA and 5-HT ejected, compared with tissue content.

The present series of studies were carried out to quantify the amounts of dopamine (DA), noradrenaline (NA) and serotonin (5-HT) ejected from iontophoresis micropipettes and that produce inhibitory and modulatory effects on cortical neurons, in the frontoparietal cortex of the rat and in the occipital cortex of the cat. Using radioactive isotopes of the biogenic amines the effective transport number (n) was found to be 0.08 for DA; 0.13 for NA, and 0.22 for 5-HT. In addition, similar determinations were made, for comparison purposes, of the transport numbers of the neurotransmitters acetylcholine (ACh; n = 0.44), gamma-amino-n-butyrate (GABA, n = 13), and glutamate (GLU; n = 0.27). The quantities ejected under in vivo conditions were then estimated using Faraday's formula and fell in the pmol range (10(-12) mol). The effects of DA, NA and 5-HT on cortical units were studied; the amounts ejected were compared with the endogenous tissue content of these amines, determined by means of specific and sensitive radioenzymatic assays in the regions where the microiontophoretic experiments were performed. These results are discussed in the light of the anatomical, biochemical and electrophysiological data suggesting a modulatory role for the biogenic amines in the cerebral neocortex.

Acetylcholine↗
PubMed1984

Immunological studies of aging. IX. Impaired proliferation of T lymphocytes detected in elderly humans by flow cytometry.

Lymphocytes from humans over the age of 65 incorporate approximately 50% less tritiated thymidine than do lymphocytes from young donors when cultured with phytohemagglutinin. Because lymphocytes from elderly humans are more sensitive to cell cycle arrest induced by tritiated thymidine, it was impossible to determine to what extent impaired thymidine incorporation reflected a defect in proliferation or the increased sensitivity to the radioactive isotope. Flow cytometry was used to measure the proliferative response of T cells from young and old donors in culture with PHA. It was found that 25 percent fewer lymphocytes from old as compared to young humans enter the G1 or complete the S phase of the cell cycle. However, the rate of progression through the cell cycle by activated cells from young and old humans is comparable. Thus, flow cytometry suggested that the difference in thymidine incorporation by lymphocytes from old and young donors is attributable equally to a proliferative defect and to cell cycle arrest induced by tritiated thymidine. This conclusion was supported by the fact that the relative impairment of thymidine incorporation by lymphocytes from old donors was only one-half as great when a 20-min instead of a 24-hr pulse of tritiated thymidine was used.

Adult↗
PubMed1978

Detection and pathogenesis of visceral calcification in dialysis patients and patients with malignant disease.

Scintiscanning to detect the uptake of bone-seeking radioactive isotopes by soft tissue is a promising technique for the in vivo study of visceral calcification. Visceral uptake of such radioisotopes was studied in 40 patients: 22 undergoing long-term dialysis, 9 with malignant disease and hypercalcemia and 9 with primary hyperparathyroidism and hypercalcemia.Fifteen patients, 11 undergoing dialysis and 4 with malignant disease, had radioisotope uptake in the lungs, and 5, 3 undergoing dialysis and 2 with malignant disease, had uptake in the stomach. None of the patients with primary hyperparathyroidism had visceral uptake, nor did the patients with uptake have radiologic evidence of pulmonary or gastric calcification. The dialysis patients with visceral uptake had a mean calcium x phosphate product of 84.3 +/- 23.7 (standard deviation), which was significantly greater (P < 0.001) than that of patients without such uptake (59.2 +/- 14.0). Similarly, in patients with malignant disease and visceral uptake the Ca x P product was 72.2 +/- 6.4 - significantly greater (P < 0.005) than that of patients without such uptake (49.3 +/- 6.7).These findings indicate that scintiscanning for the visceral uptake of a bone-seeking radioisotope is a simple and effective technique for the in vivo study of visceral calcification. An elevation in the Ca x P product seems to be the single most important factor in the production of visceral calcification.

Adult↗
PubMed1984

Comparison of intramuscular and epidural morphine for postoperative analgesia in the grossly obese: influence on postoperative ambulation and pulmonary function.

In a randomized double-blind study of thirty grossly obese patients undergoing gastroplasty for weight reduction, the effects of intramuscular and epidural morphine were compared as regards analgesia, ambulation, gastrointestinal motility, early and late pulmonary function, duration of hospitalization, and occurrence of deep vein thrombosis in the postoperative period. The patients were operated on under thoracic epidural block combined with light endotracheal anesthesia. A six-grade scale was devised to quantify postoperative mobilization. A radioactive isotope method using 99mTc -plasmin was employed to detect postoperative deep vein thrombosis. For 14 hr after the first analgesic injection, respiratory frequency was noted every 15 min and arterial blood gases were measured hourly. Peak expiratory flow was recorded daily until the patient was discharged from hospital. Spirometry was performed the day before and the day after surgery. Plasma concentrations of morphine were measured after both intramuscular and epidural administration. Both intramuscular and epidural morphine gave effective analgesia, but the average dose of intramuscular morphine was up to seven times greater than that required by the epidural route. A larger number of patients receiving epidural morphine postoperatively were able to sit, stand, or walk unassisted within 6, 12, and 24 hr, respectively. Being alert and more mobile as a result of superior postoperative analgesia from epidural morphine, patients in this group benefited more from vigorous physiotherapy routine, which resulted in fewer pulmonary complications. Furthermore, earlier postoperative recovery of peak expiratory flow and bowel function presumably contributed to a significantly shorter hospitalization in patients receiving epidural morphine. There was no evidence of prolonged respiratory depression in this high-risk category of patients. The 99mTc -plasmin tests revealed no significant difference between the two groups.

Adult↗

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