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J Smits

Publications and source records attributed to J Smits.

At least 37 records · Page 2Linked to original sources
PubMed1988

Glycolytic enzyme activities in breast cancer metastases.

The activities of hexokinase, phosphofructokinase, aldolase, enolase and pyruvate kinase were studied in breast cancer metastases occurring at various sites and compared with the enzyme activities in a series of primary breast cancers. The activities of all enzymes studied were significantly higher in the metastases compared to the primary tumors (p less than or equal to 0.05). However, no changes in the isoenzyme patterns of enolase and pyruvate kinase were observed when the metastases were compared with primary breast cancers. Differences in location of the metastases did not lead to differences in enzyme activities. Our data suggest an association of an increasing rate of glycolysis with tumor progression.

Aged↗
PubMed1988

Interference of ketanserin with baroreflex control of the circulation in the conscious spontaneously hypertensive rat.

Ketanserin suppresses baroreflex-mediated tachycardia following the administration of hypotensive doses of sodium nitroprusside in conscious spontaneously hypertensive rats (SHR). The purpose of this study was to compare the baroreflex effects of ketanserin with those of the more selective S2-serotonergic receptor antagonist ritanserin and the alpha 1-blocker prazosin. In conscious SHR, both ketanserin (3 mg/kg) and prazosin (0.01 and 0.1 mg/kg) caused a significant reduction in blood pressure. Ritanserin (3 mg/kg) and the combination of a low dose of prazosin (0.01 mg/kg) and ritanserin (3 mg/kg) did not lower blood pressure significantly. Baroreflex responses were determined by measuring the maximal changes in heart period (HP = 60,000/HR) after administration of 20 to 100 micrograms/kg sodium nitroprusside. Whereas saline and prazosin lacked an effect on changes in HPmax, ketanserin reversed the decrease in delta HPmax into a significant increase. Ritanserin alone caused a slight but insignificant inhibition, whereas the combination of ritanserin and prazosin blocked the sodium nitroprusside-induced reflex tachycardia. Ritanserin, in contrast to prazosin or ketanserin, lowered resting heart rate values. We conclude that the interference of ketanserin with the baroreflex in SHR is a unique property of this agent, related to its simultaneous effects on serotonin (5-HT) S2-receptors and alpha 1-adrenoceptors.

Animals↗
PubMed1987

Glycolytic enzymes in breast cancer, benign breast disease and normal breast tissue.

The activities of hexokinase, phosphofructokinase, aldolase, enolase and pyruvate kinase were studied in breast cancer tissues, in comparison to benign breast disease and normal breast tissues. The enzyme activities in breast cancer were significantly increased compared to normal and benign breast tissues (p less than 0.001). Also the increase in activity in benign disease compared to normal was statistically significant (p less than 0.001). Within the group of benign diseases, fibroadenomas could be distinguished from fibrocystic disease, the former generally showing higher activities compared to the latter (p less than or equal to 0.05). Carcinoma subgroups, classified according to their histology, could not be recognized enzymologically. In addition, isozyme composition of pyruvate kinase and enolase was studied. We did not find a significant shift towards K type pyruvate kinase expression in benign disease compared to normal breast tissues. Also fibroadenomas did not differ from fibrocystic disease. However, the amount of K type pyruvate kinase in carcinomas proved to be significantly higher in comparison to benign disease and normal breast tissues (p less than 0.001). Expression of alpha gamma-enolase in normal breast tissue was virtually absent. In benign disease only a minority of specimens did show the hybrid alpha gamma-enolase. Nearly all carcinomas had alpha gamma-enolase expression and in 20% of the carcinomas gamma gamma-enolase could be detected (so-called neuron-specific enolase). By discriminant analysis, the function giving the best discrimination compared to the histological data was based on natural logarithm aldolase and the total of gamma-enolase subunits. Contrary to expectation, the regulator enzymes of glycolysis; i.e., hexokinase, phosphofructokinase and pyruvate kinase were not included in this discriminant function. The best fit produced a 90% correct classification in both benign and malignant disease. If these findings are confirmed to a larger series, the discrimination is sufficiently strong to form the basis of a clinically useful tool.

Biomarkers, Tumor↗
PubMed1985

Percutaneous transluminal angioplasty in fibromuscular dysplasia of the internal carotid artery: one year clinical and morphological follow-up.

A case of fibromuscular dysplasia (FMD) of the internal carotid artery was treated by percutaneous transluminal angioplasty (PTA) using a Grüntzig balloon. A control angiographic study performed with intravenous digital subtraction angiography (IV DSA) showed a completely patent dilated vessel. This result, together with the total relief of clinical signs and symptoms, is evidence of the value of PTA in the treatment of FMD of the internal carotid artery.

Angiography↗
PubMed1983

Digital intraarterial subtraction technique of the extracerebral vascular system.

We report the results from intraarterial digital subtraction angiography (IA DSA) of the extracerebral vessels with aortic arch injection of contrast medium via femoro-arterial puncture, instead of the more widely used intravenous digital subtraction angiography (IV DSA). Intraarterial DSA is performed using a lower contrast dose and rate, making this study less invasive and costly than the conventional arteriographic study of the aortic arch. Intraarterial DSA provides better resolution than IV DSA. The diagnostic accuracy is almost equivalent to conventional angiography and is largely superior to photographic subtraction angiography with intravenous injection of contrast media.

Angiography↗
PubMed1983

Digital intravenous and intraarterial subtraction angiography. Applications to the intracranial vascular system.

Digital intravenous subtraction angiography (DIVSA) appears a promising and not highly invasive technique in the study of intracranial tumors and vascular lesions. In combination with computed tomography it should be sufficient in future for determining a preoperative tumourovascular balance. Already now it can be a valuable method in the screening for vascular malformation, in the postoperative evaluation of vascular intracranial lesions or after embolization of those lesions. In the study of the dural venous sinuses, DIVSA appears largely superior to conventional angiography. Advantages of the intravenous approach are the outpatient base, the low risk and low cost.--Low contrast dose and low pressure intraarterial subtraction technique is equivalent to conventional angiography with less risk and discomfort to the patient and resulting in considerable saving in cost.

Adenoma↗
PubMed1983

Biparietal thinning: correlation with CT findings.

A typical case of thinning of the parietal bones in an elderly female patient is reported. Frontal CT sections adequately demonstrate the disappearance of the diploë and the flattening of the outer table.

Aged↗
PubMed1981

Method for measuring cardiac dimensions and intramural deformations.

Information about the geometry and intramural deformations of the left ventricle of the heart throughout the cardiac cycle is necessary for the analysis of contractile function of the intact heart. In this study a method is developed to measure dimensions and intramural deformations of the left ventricle of a dog heart during the cardiac cycle. Radiopaque markers (platinum spheres of 1mm diameter) were implanted in the wall of the left ventricle. The spatial positions of these markers were determined from pairs of perpendicular X-ray projections, obtained with the aid of rotational X-ray equipment. Preliminary results of ventricular deformations are in agreement with measurements by other techniques.

Animals↗
PubMed1977

Strategy in drug research. Synthesis and study of the progestational and ovulation inhibitory activity of a series of 11beta-substituted-17alpha-ethynyl-4-estren-17beta-ols.

Using the strategy based on the Hansch method which analyses effects of substituents on biological activity in terms of their hydrophobic, electronic and steric effects we selectively synthesised a series of 11beta-substituted-17alpha-ethynyl-4-estren-17beta-ols that combine ease of synthesis with good discrimination between these factors aiming at finding the compounds with optimum biological activity in that series. The compounds were tested quantitatively in the Clauberg test (rabbit) and the ovulation inhibition test (rat). The differences in biological activity could reasonably be correlated with two steric effects introduced by the 11beta-substituent. These were a change in the overall shape of the 11beta-substituent and the angular methyl group, and direct steric hindrance of the steroid-receptor protein binding. Some exceptions were found possibly due to metabolic conversion of these compounds to the corresponding 11beta-substituted-17alpha-ethynyl-1,3,5(10)-estra-triene-3,17beta-diols.

Animals↗
PubMedDate not supplied

Midgut volvulus in an adult patient.

The authors report on a case of midgut volvulus in a 27-year-old man who presented with bilious vomiting and acute abdominal pain. US demonstrated a reversal of the normal relationship between the superior mesenteric artery (SMA) and superior mesenteric vein (SMV). A clockwise whirlpool sign, diagnostic for midgut volvulus, was not visualised. In a further assessment, upper gastrointestinal series demonstrated obstruction in the second part of the duodenum highly suspicious of Ladd's bands. Malpositioning of bowel structures, as already suggested by the reversal of the SMA and SMV on ultrasound, and a distinctive whirl pattern due to the bowel wrapping around the SMA was demonstrated on CT. Furthermore angiography revealed focal twisting of the SMA. US is the first imaging modality to perform in suspicion of midgut volvulus. When inconclusive, CT is in our opinion the next stage in the diagnostic work-up.

Abdomen, Acute↗
PubMedDate not supplied

Proximal pulmonary artery aneurysm.

The authors report on a case of proximal pulmonary artery aneurysm detected on a routine chest X-ray. The scintigraphic and angiographic features of the condition are described and the importance of including the entity in the differential diagnosis of lung masses is stressed.

Adult↗