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Biomedical subjects

G Ronquist

Publications and source records attributed to G Ronquist.

At least 199 records · Page 11Linked to original sources
PubMed1983

Urinary adenylate kinase isoenzyme pattern in patients with myocardial infarction.

Adenylate kinase was purified in pooled urinary samples from patients with uncomplicated myocardial infarction. The purification procedure included ammonium sulfate precipitation and column chromatographic steps. It was necessary to stabilize the enzyme during purification with 2-mercaptoethanol and AMP. Polyacrylamidgelelectrophoresis in sodium dodecanyl sulfate revealed the release of 4 different isoenzymes of AK into urine from patients with myocardial infarction. The molecular weights of these isoenzymes were estimated to be 21,000; 24,000; 33,000 and 36,000, respectively.

Adenylate Kinase↗
PubMed1983

Ultrastructural localization of the prostasome - an organelle in human seminal plasma.

Secretory granules and vesicles were demonstrated within human prostatic cells and in the acinar lumen. In size and ultrastructure the granules and vesicles were the same as those previously isolated from human prostatic fluid and seminal plasma. "Prostasomes" is suggested as the designation for these secretory granules and vesicles. As a rule they were found in storage vesicles within the secretory cells. Two mechanisms for translocation of the prostasomes from the cell interior to the acinar lumen are described. One mechanism involves exocytosis with binding of storage vesicles to, and fusion with the plasma membrane, resulting in release of prostasomes directly into the acinar lumen. The other mechanism implies displacement of storage vesicles in toto from the cell interior to the acinar lumen. This process differs from exocytosis and is here designated "diacytosis". Both phenomena appear to be of roughly equal frequency.

Cell Membrane↗
PubMed1983

Perspectives on serum acid phosphatase in prostatic disease. An evaluation of two methods.

Acid phosphatase in serum was measured in 116 patients with prostatic disease, benign in 59 and malignant in 57 cases. Comparisons were made between radioimmunoassay (RIA) and an enzymatic method. The correlation coefficient between the respective values was 0.96 in patients with untreated prostatic cancer, indicating that no significant difference between results with the two methods was to be expected. The correlation coefficient between RIA values and cancer stage was 0.48, and between catalytic activity and cancer stage it was 0.50. The validity of the two methods consequently was equal. RIA, however, was the more sensitive method, giving elevated values in 10 of 11 patients with untreated stage III or stage IV prostatic cancer, as compared with only 4 of the same 11 in the enzymatic assay. This seeming paradox most probably was attributable to differing intrinsic properties of the methods when the upper limits of normal range were established. Neither RIA nor enzymatic analysis discriminated early prostatic cancer (stages I and II) from benign lesions.

Acid Phosphatase↗
PubMed1983

Multicentre investigation of myocardial protection with cold cardioplegia.

In order to analyze factors of importance for the efficiency of myocardial protection during open-heart surgery, a study was made of 144 patients undergoing isolated aortic valve replacement with various cardioplegic techniques. The cardioplegia was of Bretschneider type in 54 cases, St Thomas in 31 and Ringer-potassium type in 11 cases. Single or multi-dose blood cardioplegia was used in 11 cases and continuous blood cardioplegia in 30 cases. Local cardiac hypothermia was additionally employed in all patients. The efficiency of myocardial protection was assessed mainly from the incidence of postoperative conduction disturbances, myocardial enzyme release and need for inotropic support. All patients survived the operation. In 20% surgery was followed by transient or persistent disturbance of conduction, in 9% by abnormally increased CK-MB release and in 5% by requirement for inotropic support. Preoperative risk factors such as high age or severe left ventricular (LV) hypertrophy or dysfunction had little influence on the results. Patients in whom aortic stenosis (AS) was dominant in the complex with aortic insufficiency (AS + AI) showed 20-hour postoperative CK-MB enzyme activity twice as high as those with pure aortic insufficiency. The most important factors in myocardial protection were the duration of aortic occlusion and the myocardial temperature during cardioplegia. When the aortic occlusion lasted more than 80 min there was a 32% incidence of conduction disturbances and 20-hour CK-MB activity thrice as high as after shorter occlusion. Patients with mean myocardial temperature below 18 degrees C during cardioplegia invariably had low enzyme activities, which indicated good myocardial protection. The best overall results were obtained in patients operated on during hypothermia at 25-27 degrees C, with single or multi-dose blood cardioplegia and with efficient local cooling of the heart.

Adult↗
PubMed1983

High fucosyl transferase activity in human seminal plasma.

High fucosyl transferase activity was recorded in human seminal plasma whether spermatozoa were present or not. This activity exceeded that of sialyl transferase by a factor of 111. The corresponding factor for blood serum incubated under identical conditions was 0.60-0.90.

Adult↗
PubMed1983

Increased activity of serum fucosyl transferase in diabetic patients.

Serum fucosyl- (but not sialyl-) transferase activity was significantly (p less than 0.001), increased in 57 patients with diabetes mellitus. A correlation also existed in diabetics between fucosyl- (but not sialyl-) transferase activity and glycosylated serum protein (r = 0.52, p less than 0.001). Sialyl (but not fucosyl) transferase activity on the other hand correlated with hemoglobin A1 (r = 0.28, p less than 0.05). The data suggest a relationship between fucosyl/sialyl- transferase activities and long-term glucose control. Changes in these enzyme activities may affect cell membrane glycoprotein turnover which may be of importance both for insulin receptor function and later development of diabetic microangiopathy.

Adolescent↗
PubMed1982

Release of adenylate kinase into cerebrospinal fluid during open-heart surgery and its relation to postoperative intellectual function.

In 33 of 36 patients having open-heart surgery, the levels of adenylate kinase in cerebrospinal fluid (CSF-AK) were raised. No such increase was seen in 8 patients who had had lung operations without cardiopulmonary bypass. A significant increase in CSF-AK was recorded in 18 patients whose CSF was examined both preoperatively and postoperatively, and this increase was correlated with change in an index of intellectual function. Since there was no evidence of damage to the blood-brain barrier, these findings point to a causal relation between brain-cell injury during cardiopulmonary bypass and release of AK into CSF. Measurement of CSF-AK may therefore prove useful in research to improve the quality of open-heart surgery.

Adenylate Kinase↗
PubMed1982

Promotive effect on human sperm progressive motility by prostasomes.

Seminal plasma constituents were separated on Sephadex G200 gel columns. The column eluate was analysed with regard to protein content, ATPase activity and promotive activity on sperm progressive motility. Two different chromatographic fractions were also subjected to electron microscopy after sedimentation by preparative ultracentrifugation. A maximum promotive value on sperm progressive motility coincided with a maximum ATPase activity value in a single peak from seminal plasma eluted first on the column and containing less protein than the other peaks appearing later in the chromatogram. This first peak was the only one containing ATPase activity and membrane-surrounded organelles named prostasomes. Other peaks, rich in protein but lacking ATPase and prostasomes, displayed a moderate and rather irregular pattern in reference to promotive activity on sperm progressive motility. Evidence is given that the positive effect by prostasomes is specific on sperm progressive motility. Hence, procedures aiming at a change of membrane integrity of the prostasomes resulted in diminished effects on sperm progressive motility. This could be explained by a probable dissipation of the electrochemical gradient of calcium ions.

Adenosine Triphosphatases↗
PubMed1982

Cerebrospinal fluid markers of disturbed brain cell metabolism.

Reversibly and irreversibly disturbed brain cell metabolism may be monitored in an indirect way by the analyses of enzymes in the CSF according to the hypothesis of cell swelling induced by energy shortage. Adenylate kinase fulfils the criteria for an ideal CSF marker with the exception that it is not organspecific, which necessitates precautions to avoid influence of AK in erythrocytes and serum. When taking such limitating factors into account, AK determinations may be diagnostically useful in combination with radiological and clinical observations. Besides, it is possible that a combination of AK analyses and clinical signs are useful in the prognostication in individual patients suffering from global cerebral ischemia and cerebral infarction.

Adenylate Kinase↗
PubMed1982

Distribution of some non-physiological amino acids (AIB, DAB, MeAIB) in mice.

The distribution of labelled 2-aminoisobutyric acid (AIB), 2,4-diaminobutyric acid (DAB) and 2-(methylamino)-isobutyric acid (MeAIB) was studied by whole body autoradiography in mice. All the amino acids were rapidly cleared from the blood and were taken up in most of the organs in the body. The results suggest the presence of operating transport systems for these amino acids into the majority of different cell types in mice. In the central nervous system, small amounts could be registered and in the pancreas there was a marked difference between DAB, which was not taken up, and the other two amino acids which were heavily accumulated. In an early embryo only MeAIB was observed in a high concentration.

Aminobutyrates↗
PubMed1982

Effect of cardiac glycosides on the release of adenylate kinase into cerebrospinal fluid of patients with cerebral arteriosclerosis.

48 patients with cerebral arteriosclerosis were found to have a manifest release of adenylate kinase (AK) into cerebrospinal fluid (CSF). This release was most probably due to an increased leak in the brain cells subsequent to a lowered adenylate charge potential followed by a diminished electrochemical potential in these cells suffering from disturbed oxygen supply. A further increase of AK release into CSF was noted for the 22 patients receiving cardiac glycosides compared to the 26 patients not treated with these drugs. The mean AK value of the former group was 0.119 +/- 0.028 U/l compared to that of the latter group, being 0.089 +/- 0.025 U/l, and this difference was significant (p less than 0.001). The effect of cardiac glycosides is most probably explained by an additional lowering of the membrane electrochemical potential in brain cells of these patients due to the direct action of cardiac glycosides on the Na+- and K+-dependent ATPase system in these cells, resulting in an increased leak in the plasma membrane.

Adenylate Kinase↗
PubMed1982

Stimulation of sperm progressive motility by organelles in human seminal plasma.

A simple method for objective determination of sperm progressive motility is described. Comparisons were made between results with this method and subjective grading of motility. Although congruence between the two methods was demonstrated, the subjective evaluation had obvious disadvantages. In suspensions of NaCl-washed spermatozoa, seminal plasma was required for progressive motility. Various isotonic salt solutions without seminal plasma were ineffective in this respect. Washed spermatozoa, however, were always motile in a medium consisting of pellet II, obtained from ultracentrifugation of human seminal plasma, thoroughly mixed with isotonic NaCl solution. The progressive sperm motility was two to three times as great in that medium as in seminal plasma mainly devoid of organelles. Magnesium, calcium and zinc ions, in the presence of seminal plasma, could exert stimulatory and inhibitory effects on sperm progressive motility, depending on the concentration of each divalent cation. Magnesium gave the greatest stimulatory and zinc the greatest inhibitory effect.

Adult↗
PubMed1982

Distribution of cyclic AMP in human seminal plasma and its relation to sperm progressive motility.

Organelles and amorphous substance (pellet II) isolated from human seminal plasma contained 3'5' AMP (cyclic AMP, cAMP) in manifold smaller amounts than did the particle-free seminal plasma. The amount of cAMP associated with pellet II did not differ significantly between normospermic and oligozoospermic or teratozoospermic ejaculates. In analyses of split ejaculate fractions, the distribution of cAMP coincided with that of fructose and protein (but not with the Mg2+- and Ca2+-dependent ATPase activity or with zinc), indicating secretion of cAMP by the seminal vesicles. The distribution profiles of cAMP in the various ejaculate fractions were similar for particle-free seminal plasma and for pellet II material. The cAMP contents of the fractions were compared with sperm motility in the same fractions. An inverse relationship was found, with the first three fractions displaying higher sperm motility and the last three fractions higher cAMP content.

Adult↗
PubMed1982

Calcium, magnesium, and zinc contents in organelles of prostatic origin in human seminal plasma.

Human seminal plasma contains organelles (granules and vesicles) of prostatic origin. A Mg2+- and Ca2+-dependent ATPase activity, associated with the membranes of the organelles, was determined and related to the contents of calcium, magnesium and zinc in the granules. The samples were obtained from total ejaculates of 42 men. Fourteen had normal spermiograms. Sperm-free, post-vasectomy ejaculates were obtained in 12 cases. In 16 other men, 9 had sperm concentrations less than 40 X 10(6)/ml and 7 had asthenospermia and/or teratazoospermia. No statistically significant intergroup differences were found when the organelle contents of the metals were determined with flameless atomic absorption spectroscopy. In fractionated ejaculate specimens, the distribution of the metals was correlated to the organelles rather than to the amorphous substance also present in ejaculate. In comparison with the surrounding seminal plasma, an unambiguous enrichment of metals was obtained in the organelles. It is suggested that the organelles exert a regulatory function on spermatozoa by modulating in their microenvironment the concentration of divalent cations necessary for the spermatozoan motility.

Adenosine Triphosphatases↗
PubMed1982

A paracorporeal rat heart model for ischemic and reperfusion studies.

Paracorporeal rat hearts were supplied with blood derived from the abdominal aorta of a supporting rat. The circulatory stability and working capacity of the supporting animal was analyzed in the experimental situation in terms of PO2, SO2, PCO2, HCO3, pH and electrolytes, all of which were within the normal range before and during a 60 min period of paracorporeal perfusion. For evaluation of ischemic damage in this model studies were made on three groups of excised hearts. They were subjected to 10, 15 or 20 min of complete global ischemia at 37 degrees C (ambient temperature) and reperfused for 30 min, including ECG, observations of contractility and an analysis of creatine kinase efflux in the coronary effluent. The results showed good reproducibility and the data were in accordance with reports from similar studies on Langendorff preparations. The model, which is easily set up, inexpensive and based upon pulsatile blood perfusion, should be more physiologic than the conventional Langendorff preparation.

Animals↗