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Biomedical subjects

J Láng

Publications and source records attributed to J Láng.

At least 19 recordsLinked to original sources

Oncological scintigraphy in dogs with 99mTechnetium MIBI and DMSA(V)--two case reports.

Oncological scintigraphy is described in two dogs with malignant lymphoma and malignant schwannoma, respectively. The distribution of the radiopharmaceuticals could be visualized for the purpose of detection of neoplasia and eventual metastases, and to evaluate the effectivity of therapy. It is concluded that 99mTechnetium MIBI and 99mTc DMSA (V) scintigraphy is useful for the detection of soft tissue malignancy in dogs.

Animals↗

[Clinical experience with rhenium-188 HEDP therapy for metastatic bone pain].

Rhenium-188 hydroxyethylidene diphosphonate (Re-188 HEDP) is a new radiopharmaceutical for treatment of metastatic bone pain. Re-188 is a generator-produced radionuclide emitting high energy beta and gamma rays and having a relative short physical half-life makes it of especially interesting for therapeutic purpose. Seven patients (pts) with multiple painful bone metastases were treated with Re-188 HEDP. Five pts with prostate cancer and 2 pts with breast cancer received a fixed activity of 3000 MBq of Re-188 HEDP intravenously in two steps. Complete blood counts were determined, blood chemistry examinations and urine-analysis were performed before and 1, 2, 3, 4, 6, 8, 12 weeks following the treatment. A visual analogue score, a verbal rating scale, the Spitzer index and the Karnofsky score were used to assess pain and performance status. Three hours after Re-188 HEDP administration at 1 m from the anterior mid-trunk of the pts gamma and at the patient body surface beta-radiation dose measurements were made, together with urine radioactivity measurements. Three pts become pain-free, 2 pts exhibited partial pain improvement and 1 patient gave no response to the Re-188 HEDP therapy. In 1 patient due to central nervous system metastasis the modification of the pain intensity could not be evaluated. Three pts displayed a flare reaction within 1 week after the treatment. Transient decreases in platelet and white blood cell counts were observed. There were no significant changes in the liver and renal functions. Radiation dose rate values of 6.3 +/- 1.0 microSv/h for gamma, and of 183 +/- 40 s-1 for beta-radiation were found. 25-32% of the administered dose was eliminated via the urinary tract in the first three hours. The preliminary data suggests that Re-188 HEDP is an effective radiopharmaceutical in treatment for metastatic bone pain. An administered activity of 3000 MBq can bring about a pain reduction without causing any clinically significant bone marrow toxicity.

Alkaline Phosphatase↗

[Leukocyte scintigraphy in the diagnosis of acute pancreatitis].

The authors investigate the place and clinical usability of the 99mTc-HM-PAO leukocyte scintigraphy (LS) in patients with acute pancreatitis. Another purpose was to establish the diagnostic value of LS to differenciate between infected and noninfected pseudocysts following acute pancreatitis. Seventy-five patients with acute pancreatitis were examined and divided into two groups. In group 1, LS was performed in 46 consecutive patients in the early phase (mean 3 days following the beginning of the symptoms, range 1-6 days) of acute pancreatitis. In group 2, LS was performed in 29 patients with pancreatic pseudocysts following acute pancreatitis. The diagnosis of acute pancreatitis was based on the typical clinical symptoms, laboratory parameters, Ranson criteria, US and CT findings. In group 1, most of the cases with a severe clinical outcome (Ranson classification) gave positive LS results (13/15). Leukocyte accumulation was also detected in patients with mild acute pancreatitis (5/26), but at a lower frequency. The scintigraphic activity correlated with the leukocyte count, fever, and duration of hospitalization. In group 2, there were seven LS positive cases. A pancreatic abscess or infected pseudocyst was found in all of them during surgery. In 9 LS negative cases surgery and bacterial culturing revealed sterile pseudocyst. In conclusion, a positive LS indicated a severe course of acute pancreatitis. The method also seems useful for differentiation between infected and noninfected pancreatic pseudocysts.

Acute Disease↗

Tc-99m HMPAO leukocyte and Tc-99m nanocolloid scintigraphy in posttraumatic bone infection.

Posttraumatic osteomyelitis was investigated in 23 patients using nuclear medicine techniques. Tc-99m hexamethylpropilene amine oxime (HMPAO)-labeled leukocyte scintigraphy was performed in 11 patients, and Tc-99m nanocolloid scanning was performed in the other 12 patients. The scintigraphic findings were compared with clinical, laboratory, radiologic, and bacteriologic results. The findings on leukocyte imaging were consistent with the clinical symptoms in 7 of 11 patients, with the laboratory pattern in 7 of 10 patients, with the radiologic findings in 7 of 11 patients, and with the results of bacteriology in 6 of 7 patients. The findings on nanocolloid scintigraphy corresponded with the clinical symptoms in 9 of 12 patients, with the laboratory pattern in 8 of 10 patients, with the radiologic findings in 8 of 12 patients, and with the bacteriology in 4 of 5 patients. The results suggest that both methods were of similar value for the detection of chronic posttraumatic osteomyelitis regardless of whether the process was active. Conversely, on the basis of semiquantitative analysis of the images, leukocyte scintigraphy seemed to characterize the grade of inflammation better than did nanocolloid scintigraphy.

Adult↗

Prognostic role of 99mTc-HM-PAO-leukocyte scintigraphy in acute pancreatitis and in patients with pancreatic pseudocysts.

Fifty-five leukocyte scintigraphies were performed. Thirty-five patients (group 1) with acute pancreatitis in the early phase and 20 patients (group 2) with pancreatic chronic pseudocysts following acute pancreatitis were tested. The clinical features, laboratory parameters, and Ranson classifications were registered during hospitalization. In group 1, most of the cases with a severe clinical outcome gave positive leukocyte scintigraphic results (10/12). Leukocyte accumulation was also detected in patients with mild acute pancreatitis (4/23), but at a lower frequency. In the acute phase, significant differences in laboratory parameters (sedimentation rate and leukocyte count) were found in the leukocyte scintigraphy-positive versus-negative cases. The scintigraphic activity correlated with the sedimentation rate, leukocyte count, fever, and duration of hospitalization. In group 2 there were five cases with a positive leukocyte scan. A pancreatic abscess was found in four of them during surgery. In seven patients with a normal scintigram, surgery revealed a noninfected pancreatic pseudocyst. Leukocyte infiltration of the pancreas can be demonstrated by leukocyte scintigraphy. A positive leukocyte scan indicated a severe course of acute pancreatitis. The method also seems useful for differentiation between infected and noninfected chronic pancreatic pseudocysts.

Acute Disease↗

HM-PAO-labeled leukocyte scintigraphy in pediatric patients with inflammatory bowel disease.

Leukocyte scintigraphy (LS) was performed in 20 pediatric patients with inflammatory bowel disease (IBD: 10 with ulcerative colitis, 2 with indeterminate colitis, and 8 with Crohn disease) in different stages of clinical activity. Leukocytes were separated from 15 to 60 ml venous blood and were labeled in vitro with [99mTc]HM-PAO. The segmental extent (small intestine; ascending, transverse, and descending colon; and recto-sigmoideum) of the process was determined by LS. The uptake of each bowel segment was scored in relation to the bone marrow uptake. The scintigraphic activity, calculated by summing the segment scores, was compared with laboratory parameters. The mean labeling efficacy was 76% (60-86%). The segmental extent of the process determined by LS was compared with the results of barium enema or colonoscopy with regard to 32 bowel segments. The sensitivity, specificity, and accuracy of LS were 93, 88, and 91%, respectively. Two extraintestinal manifestations (abdominal abscess and joint involvement) were also detected by LS. These lesions were verified by computed tomography (CT) (abscess) and on the basis of the clinical outcome (arthritis). The scintigraphic activity correlated with the C-reactive protein (CRP) level (r = 0.82, p < 0.001), the alpha 2-globulin level (r = 0.63, p < 0.02), the sedimentation rate (r = 0.51, p < 0.05), and the fS iron level (r = -0.66, p < 0.005). LS is applicable in pediatric patients. The method is an excellent technique for assessment of the extent of IBD in children. Extraintestinal manifestations of IBD can also be investigated by LS. The scintigraphic activity is a useful parameter for determination of the activity of IBD in children.

Adolescent↗

Experimental study on the kinetics of mucociliary activity in rabbit airways.

Noninvasive radioaerosol technique was applied to investigate the mucociliary activity of bronchial mucosa using 99mTc-labelled homologous erythrocytes for inhalation. Radioactivity was continuously measured for 60 min with a gamma camera connected online to the computer. Time-activity kinetic parameters were calculated by a monoexponential model. Test substance azelastine and bromhexine were used to demonstrate the validity of experimental method discussed.

Administration, Inhalation↗

Technetium-99m hexamethylpropylene amine oxime labelled leucocyte scintigraphy in ulcerative colitis and Crohn's disease.

Technetium-99m hexamethylpropylene amine oxime labelled leucocyte scintigraphy (LS) was performed on 45 occasions in 30 patients with ulcerative colitis and on 53 occasions in 34 patients with Crohn's disease. Serial images were taken following re-injection of the labelled leucocytes. The segmental extent of the inflammation and the grade of the leucocyte uptake were calculated, and compared with the laboratory results and colonoscopy findings. The sensitivity and specificity of LS proved higher in ulcerative colitis (87% and 93%) than in Crohn's disease (53% and 89% in cases with large intestine involvement, and 82% and 100% in cases with small intestine involvement). The activity of the process determined by LS correlates with the alpha 2-globulin level (r = 0.47), fibrinogen level (r = 0.50), fS iron level (r = -0.57), sedimentation (r = 0.44), leucocyte count (r = 0.38), platelet count (r = 0.34) and Best index (r = 0.31) in ulcerative colitis, but not in Crohn's disease.

Adolescent↗

The role of vasopressin in the pathogenesis of ethanol-induced gastric hemorrhagic erosions in rats. Is vasopressin an endogenous aggressor toward the gastric mucosa?

The role of vasopressin in the development of gastric hemorrhagic erosions induced by the oral administration of 1 mL of 75% ethanol in rats was studied. The area of the lesions in homozygous Brattleboro rats, having a defective vasopressin synthesis, was only 20% of that found in Wistar and heterozygous Brattleboro rats, which have normal vasopressin production. It is well known that vasopressin acts via the V1 (pressor) and V2 (antidiuretic) receptors. Administration of V1 and V2 vasopressin-receptor agonists and antagonists in this model showed that pressor-receptor activity is needed for the generation of all lesions in Wistar and heterozygous Brattleboro rats. Ethanol damage to the gastric mucosa was diminished by the V1 antagonist with similar efficacy as in the case of a vasopressin deficiency. Administration of the V1 antagonist and the absence of endogenous vasopressin were shown to protect the deeper layer of the gastric mucosa (assessed by histology) and to reduce significantly the ethanol-induced vascular injury and increase in vascular permeability (assessed by the monastral blue technique). Thus, endogenous vasopressin is clearly of great importance in the pathogenesis of gastric hemorrhagic lesions induced by ethanol. These results strongly suggest that vasopressin is an endogenous aggressor toward the gastric mucosa.

Animals↗

[Cardiolite (99m-Tc-isonitrile) SPECT studies in patients prior to coronary bypass surgery].

The authors studied with 99m-Tc Cardiolite (methoxy-isobutyl-isonitrile) SPECT examination the effect of coronary bypass operation on the myocardial perfusion. One week before and 3 weeks after the operation examinations were performed first with dipyridamol loading and 24 hours later in rest. The regional perfusion of the myocardium was studied on the basis of transversal section-pictures of corrected axis position. In the examinations preceding the operation the global sensitivity of the method was found to be 100%. In the demonstration of the structures of the ramus descendens 95%, of the ramus circumflexus and of the right coronary artery 100% sensitivity was reached. In postoperative examinations following the bridging of the ramus descendens anterior the improvement of the perfusion of the corresponding ventricular segment was found in 15/20 during the loading and in 7/8 cases following the bridging of the ramus circumflexus and right coronary artery. Improving perfusion was demonstrated in 17/20 and in 6/8 cases in rest. On the basis of the results the authors consider their method suitable for the study of the regional blood perfusion and for the examination of the changes taking place upon coronary bypass operations.

Aged↗

[Regional cerebral blood flow studied by single photon emission computed tomography (SPECT)].

Clinical experience based on regional cerebral blood flow investigations with 99mTc HMPAO SPECT in 164 patients is reported. The pharmacokinetics of the 99mTc HMPAO are summarised, and the important indications of the investigations are interpreted in case reports (stroke, surgical solution of intracavernous aneurysm, Alzheimer and multiinfarct types of dementias). The literature data suggest that the diagnostic possibilities with this method are good in other diseases too, this area is surveyed briefly.

Alzheimer Disease↗

Comparison of some haemodynamic parameters determined by invasive methods as well as by the noninvasive radionuclide estimation of the left ventricular ejection fraction in conscious and anaesthetized dogs.

An attempt was made to elaborate an optimal method for noninvasive radionuclide determination of left ventricular ejection fraction in conscious and lightly anaesthetized dogs, as well as to assess the value of this procedure in estimating cardiac functional state. Repeated determinations in the same animals have shown that the 45 degree left anterior oblique position (LAO-45) for imaging is optimal, giving the most uniform values of the calculated left ventricular ejection fraction. Neither the latter, nor the haemodynamic parameters (LVSP, LVEDP and dP/dt) determined by invasive methods were changed by light pentobarbital anaesthesia (20 mg/kg i. v.). Results confirm the validity of noninvasive radionuclide determination of left ventricular ejection fraction for estimation of the functional state and of the pharmacological actions on the latter in both conscious and anaesthetized animals.

Angiocardiography↗

Mucosal blood flow changes in the human stomach measured by the 99mTc-4-methylaminophenazone clearance technique.

The effect of gastric secretory inhibitors, vasoactive agents and gastrointestinal peptide hormones were investigated on gastric mucosal blood flow (MBF) and HCl secretion in 197 subjects. Changes in MBF were estimated by a new clearance substance, 99mTc-4-methyl-aminophenazone originally described by the authors. The procedure seemed to be suitable for characterizing changes in MBF without any toxic side effect or considerable radioactive loading of the patient or its surroundings. The studies were performed after a secretory steady state had been achieved by continuous pentagastrin infusion. Some experiments were done in the fasting stomach instilled with 0.160 N HCl. Secretory inhibition following atropine, pirenzepine, ranitidine and somatostatin was a primary effect of these substances, the observed MBF decrease being a secondary one. In contrast, vasopressin caused a fall in mucosal blood supply through vasoconstriction, the concomitant secretory inhibition being a secondary phenomenon. Certain doses of dopamine and terbutaline increased MBF without influencing HCl secretion. Glucagon in the dose used did not influence either mucosal blood flow or acid secretion. Synthetic secretin in the fasting stomach increased MBF without affecting HCl production; during pentagastrin stimulation it inhibited acid production while MBF remained unchanged. Cholecystokinin-octapeptide proved to be a direct vasodilating agent with a slight acid output increasing effect. Divergent effects of some drugs on mucosal blood flow and HCl production may be important in the pathology of hypoxic ulcerative damage and in the reparative processes of gastric ulceration. The 99mTc-4-methyl-aminophenazone clearance technique proved to be a reliable method for screening of drugs possessing vasoactive or secretion influencing properties.

Aminopyrine↗

Changes in gastric mucosal blood flow in patients with duodenal ulcer following proximal selective vagotomy (PSV).

Pentagastrin-stimulated mucosal blood flow and acid secretion were studied in duodenal ulcer patients by means of the 99mTc-4-methylaminophenazone clearance method in the active and inactive phases of the disease, and before and after proximal selective vagotomy. The results suggest that the mucosal blood flow--acid secretion ratio in the patients differs from that found in normosecretory subjects. In duodenal ulcer patients in the inactive phase, the secretory capacity of the gastric mucosa was found to be significantly elevated as compared with the mucosal blood flow. In the active phase of the disease the mucosal blood flow increased in parallel with acid secretion. Following proximal selective vagotomy the normal blood flow-secretion ratio was restored. Comparison of the pre- and postoperative gastric mucosal blood flow and secretion values via the 99mTc-methylaminophenazone clearance technique proved useful for the evaluation of the effectiveness of vagotomy.

Adult↗

Kidney scintigraphy in the diagnostics of urological renal diseases.

The authors report on their experiences in the diagnostics of urological renal diseases gained by 256 kidney scintigraphies of a total of 227 patients. The more important trends of progress made in the recent years in nuclear medicine are outlined. The sensitivity (93%) and specificity (86%) of the examination based on the surgical and histological findings are determined. The technical importance of the study made from several directions using up-to-date radiopharmaca is emphasized in obtaining the results being favourable even in international comparison. The importance of the coordination between the urologists and experts well-versed in nuclear medicine is pointed out in selecting the examination best suited for the purpose (dynamic, static examination). Based on the literature and on their own experiences, the diagnostic results of the examination in detecting and controlling renal diseases are summarized.

Adolescent↗