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Biomedical subjects

M T Ercan

Publications and source records attributed to M T Ercan.

At least 55 records · Page 3Linked to original sources
PubMed1991

Phagocytosis by macrophages in zinc-deficient rats.

Phagocytosis by polymorphonuclear cells has been found to be significantly reduced in zinc-deficient patients and this finding was confirmed in animal experiments. In order to find out whether phagocytosis by macrophages is similarly altered, experiments were conducted in three groups of 18 rats. Control, zinc-deficient and pair-fed rats were given 99mTc nanocolloid intravenously. In ten other experiments (5 experimental and 5 control rats) 99mTc-sulfur colloid was injected intravenously. The biodistribution was determined by a well-type gamma counter and the results were evaluated statistically. The greatest amount of radioactivity was taken up by the liver, followed by the spleen, lung and kidney. In both series of experiments however the zinc-deficient animals appeared to take up a greater amount of the radiotracer (P less than 0.05).

Animals↗
PubMed1991

Evaluation of 99mTc labelled monodisperse polystyrene/polyacrylate latex particles for the study of colon transit and morphology.

A new radiopharmaceutical for the study of colon transit time and morphology is proposed. Polymeric latexes, as monodisperse polymeric spheres (1-10 microns in diameter), were prepared by a coaxial dispersion polymerization of styrene and dimethylaminoethyl-methacrylate (DMAEA). They were labelled with 99mTc by the tin reduction method with high efficiency (greater than 99%). The label was stable up to 48 h at pH values of 1-8 at room temperature. Scintigrams obtained in rabbits after oral administration of 37 MBq of 99mTc-latex particles showed that greater than 90% of the dose remained in the gastrointestinal tract. The cumulative faecal excretion was 8.6 +/- 6.7 in 24 h and 21.3 +/- 13.8% in 48 h. In human studies the colon was well visualized at 4 h. The thyroid and the urinary bladder were not detected on scintigrams, indicating the stability of the label in vivo. Our results demonstrated that the radiopharmaceutical developed in the present study was ideal for the intended purpose.

Adult↗
PubMed1991

Functional assessment of human gastrointestinal tract using 99Tcm-latex particles.

99Tcm-latex particles (LP) is a newly developed radiopharmaceutical for the evaluation of the gastrointestinal (GI) tract. Following oral ingestion, it passes through the entire GI tract undissolved. The purpose of the present investigation was to introduce the clinical application of 99Tcm-LP. A group of 11 healthy volunteers was studied. Following a 12 h fast, the subjects were given 150 ml of water containing 37 MBq of 99Tcm-LP orally. Dynamic images up to 2 h were recorded to document temporal progression of radioactivity. Static images of the abdomen and whole body were taken at intervals. In normal subjects the tracer arrival times at the caecum and sigmoid colon were 3.2 +/- 0.9 and 11.2 +/- 3.2 h, respectively. The average t1/2 value for gastric emptying, 50% colonic filling and small bowel transit time were found to be 21.6 +/- 5.6, 233 +/- 72 and 211 +/- 66.4 min, respectively. In conclusion, 99Tcm-LP has the potential of providing functional information of the GI tract.

Adult↗
PubMed1991

Visualization of bone pathologies and lung cancer with 99mTc-glucose phosphate: a comparative study.

Glucose phosphate (GP) labelled with 99mTc was used to obtain scintigraphic images of bone lesions in one group of patients (n = 28) and of lung tumors in another (n = 35). All bone lesions detected by 99mTc-MDP were also demonstrated by 99mTc-GP; all lung tumors except 4 were detected by 99mTc-GP, the failure rate being about the same as that for 67Ga. The use of 99mTc-GP is preferable to that of 99mTc-MDP because the former does not accumulate in normal bone; the advantage of 99mTc-GP over 67Ga lies in its better physical characteristics and in the fact that the result of the study is available within a few hours rather than three days.

Adolescent↗
PubMed1991

The in vivo distribution of the 99mTc-labelled albumin and gelatin microspheres of a tuberculostatic agent, rifampicin.

The preparation of albumin and gelatin microspheres with a tuberculostatic agent, rifampicin, was studied, and its in vivo distribution was investigated by providing its accumulation in the target organ lungs. The purpose of the study is to improve the effectiveness by injecting the microspheres intravenously with much smaller doses than normally required with generalized systemic administration, whilst reducing the systemic side effects. The emulsion polymerization method is applied in microsphere preparation, and glutaraldehyde is employed for albumin and formaldehyde for gelatin microspheres as the cross-linking agents. Biodistribution was determined by intravenous administration of particles of 25 to 27 microns 99mTc-labelled microspheres to Swiss albino mice. The radioactivity of the lungs was compared with the radioactivity of the liver, spleen, kidney, stomach and heart at 10, 30 and 60 min, and 6 and 24 h post-injection. The percentage accumulated was higher in the lungs than in the other organs for both albumin and gelatin microspheres, whereas free rifampicin accumulated mainly in the liver. To support the data of the in vivo distribution studies, the microspheres were histopathologically investigated after the intravenous injection to Swiss albino mice. After the microscopic determination of the lungs and liver, the spherical microspheres were observed after 10,30 and 60 min, and 6 and 24 h post-injection.

Animals↗
PubMed1991

Evaluation of 99mTc-labelled vitamin K4 as an agent for testicular imaging.

Vitamin K4 was labelled with 99mTc with an efficiency higher than 97%. The compound was stable up to 24 h at room temperature, and its biodistribution in NMRI mice indicated its in vivo stability. Blood radioactivity levels were high over a wide range. 10% of the injected activity remained in blood after 24 h. Excretion was mostly via kidneys. Only the liver and kidneys concentrated appreciable amounts of radioactivity. Testis/soft tissue ratios were 1.4 and 1.57 at 6 and 24 h, respectively. Testis/blood ratios were lower than 1. In vitro studies with mouse blood indicated that 33.9 +/- 9.6% of the radioactivity was associated with RBCs; it was washed out almost completely with saline. Protein binding was 28.7 +/- 6.3% as determined by TCA precipitation. Blood clearance of 99mTc-K4 in normal subjects showed a slow decrease of radioactivity, reaching a plateau after 16 h at 20% of the injected activity. In scintigraphic images in men the testes could be well visualized. The right/left testis ratio was 1.08 +/- 0.13. Testis/soft tissue and testis/blood activity ratios were highest at 3 h. These ratios were higher than those obtained with pertechnetate at 20 min post injection. 99mTc-K4 appears to be a promising radiopharmaceutical for the scintigraphic visualization of testes.

Animals↗
PubMed1990

Iliopelvic lymphoscintigraphy with 99mTc-dextran in malignant lymphoma.

99mTc-Dextran (99mTc-D) was evaluated as an iliopelvic lymphoscintigraphic agent in 49 patients with malignant lymphoma and the results were compared with ultrasound (US), lymphangiography (LA) and CT where available. Scintigrams were obtained by a gamma camera at 2 h postinjection and evaluated by comparing opposite sides. In 29 of 49 patients, normal lymphoscintigrams of excellent quality, deliniating the iliopelvic and paraaortic lymph nodes bilaterally were obtained. In 20 patients lymphoscintigraphy (LS) was positive. US was performed in 46 patients, 20 had positive and 26 negative findings. There was one false positive and one false negative in LS compared to US. Ten patients had LA and 3 had CT. These results were in complete agreement with LS. There was also a positive correlation between the clinical stages and the results of LS. This study showed that 99mTc-D is an excellent radiopharmaceutical for the visualization of the lymph system with high correlation with other imaging modalities.

Adolescent↗
PubMed1990

A simple and efficient method of labelling RBCs with 99mTc for spleen imaging.

A new method of labelling human RBCs with 99mTc by the use of Sn-alpha-D-glucose 1-phosphate (GP) is presented. It was tested for spleen imaging in 16 normal volunteers. The labelling was carried out during the heating (30 min at 49.5 degrees C) to damage the cells and cooling (10 min at R.T.) steps. The labelling efficiency was 95.5 +/- 1.5% with Sn-GP and was better than Sn-PYP (61.5 +/- 25.0%). The radioactivity retention of RBCs was greater than 96% after 6 washings. The spleen was delineated very well in all the subjects. The spleen activity reached a plateau at 20 min post-injection. Spleen-to-liver and spleen-to-cardiac blood pool concentration ratios were high (10.4 +/- 2.2 and 10.1 +/- 3.2, respectively) calculated at 30 min. The method is simple, rapid and efficient.

Erythrocytes↗
PubMed1990

Internal mammarial lymphoscintigraphy with SPECT after ultrasound-guided injection of 99mTc-dextran.

Twenty-two women with stage II or III breast cancer were evaluated by SPECT to determine the number, size, three-dimensional localization and depth from skin surface of the internal mammary lymph nodes for accurate radiotherapy portal planning. The results were also compared with those of planar imaging (PI). Two-step injections of 99mTc-dextran were made under ultrasound guidance into the anterior sheath of the M. rectus abdominis first at the ablation side. 1.5 h thereafter an anterior planar view was obtained to evaluate cross drainage (13.6% was observed). Then, the second injection was done at the opposite side in the same manner. Planar and tomographic images were obtained 1.5 h after the second injection. Similar values were obtained for the depth from skin surface, distance from the midline and diameter of the lymph nodes with both PI and SPECT. The total number of nodes in 22 patients detected by SPECT was higher (138) than that from PI (129), the difference being statistically significant (0.005 greater than p greater than 0.0005).

Adult↗
PubMed1989

99mTc-MDP adsorption of some dental alloys with varying surface roughness: effect of oral environment.

The purpose of this study was to measure the surface characteristics of some dental alloys by 99mTc-MDP adsorption and to investigate the effect of oral environment on 99mTc-MDP adsorption. Sample discs of five different dental alloys were prepared. The surfaces were sandblasted, ground with sandpaper, polished and electrolysed in succession. The surface roughness of each disc was measured by the use of a profilometre. Contact angles (theta) of the surfaces were also measured. 99mTc-MDP adsorption of the discs was determined both prior to and after 2 h of exposure to the oral environment. Our results indicated that the discs sandblasted and electrolysed had the maximum surface roughness and those polished the minimum surface roughness. The 99mTc-MDP adsorption showed variation according to the type of alloy used and its surface roughness prior to exposure to the oral environment. After exposure 99mTc-MDP adsorption was essentially the same for all the alloys.

Adsorption↗
PubMed1988

An improved method for the in vivo labelling of red blood cells with 99mTc in gated cardiac imaging.

Red blood cells of 10 patients were labelled with 99mTc by the in vivo method, 5 of the patients were orally administered with 400 mg potassium perchlorate at the time of stannous pyrophosphate injection and 5 ml blood was withdrawn at 10 min postinjection of pertechnetate to determine the labelling efficiency of RBC's. The RBC and plasma volumes were also determined in all patients by the 51Cr method. Our results indicated higher incorporation of injected radioactivity into RBC's in the perchlorate administered group (83.8% +/- 9.2%) compared to the other (58.5% +/- 22.0%) (P less than 0.01). The thyroid and stomach were visualized in the control group, but not in the perchlorate administered group. In routine application, 50 MUGA studies have been done with perchlorate administration with excellent results. In 60 patients without perchlorate administration previous to the present study the EF could not be determined in 6 patients (10%). Our results indicated that potassium perchlorate may be used routinely for in vivo labelling of RBC's to improve the labelling efficiency and the quality of gated cardiac imaging.

Erythrocytes↗
PubMed1988

Parasternal lymphoscintigraphy using 99Tcm-dextran.

99Tcm-dextran was evaluated as a lymphoscintigraphic agent in 10 normal volunteers and 24 patients with breast cancer. 99Tcm-dextran (0.5-1 mCi) in a volume of 0.1-0.2 ml was injected into the posterior rectus sheath in the subcostal site on one side. Scintigrams were obtained at 2-2.5 h after injection and the injection was repeated on the other side. The final image was taken at 4.5-5 h after the first injection. The normal distribution of lymph nodes and anatomical variations in scintigraphic images were first determined in normal subjects. In the patient group, eight scintigrams were evaluated as pathological and the rest as normal. In the 25 women whose lymphoscintigrams were normal the mean number of parasternal nodes visualized was six (range: 3-11). Bilateral symmetrical or asymmetrical chain was observed in 20 subjects (80%) and unilateral chain in five subjects (20%). There was cross-drainage in five subjects (20%). Supraclavicular lymph nodes were visualized in 11 subjects (44%). Varying abnormal images were obtained in eight patients. Our results are in good agreement with those reported in the literature, using radiocolloids. It is concluded that 99Tcm-dextran is a promising agent and may well replace radiocolloids because of the simplicity of the labelling procedure, stability of the label, easy availability and low cost.

Adult↗
PubMed1987

Blood flow to palatal mucosal grafts in mandibular labial vestibuloplasty measured by 133Xe clearance technique.

In 11 subjects, the blood flow to alveolar and palatal mucosa was measured by intra-mucosal injection of 133Xe. Later, mandibular labial vestibuloplasty was performed with mucosal grafts in all of them. The use of a stent was omitted. The subjects were followed by clinical observation and by blood flow measurements up to 6 weeks postoperatively. At certain intervals (3 and 10 days, 4 and 6 weeks), 133Xe clearance in the graft was determined. Under normal conditions, the mean blood flows to the alveolar and to palatal mucosa were 53.2 +/- 12.9 and 58.3 +/- 3.5 ml/100 g/min, respectively. The difference between them was statistically insignificant (P greater than 0.05). The graft blood flow was 13.4 +/- 3.2 and 21.7 +/- 15.0 ml/100 g/min on the 3rd and 10th days after operation. The decrease in both compared to normal values was statistically significant (P less than 0.001). The blood flow reached almost normal levels (46.2 +/- 16.9 ml/100 g/min) and above (63.9 +/- 9.7 ml/100 g/min; P less than 0.05) at 4 and 6 weeks after operation, respectively. These results were in agreement with the clinical observations. The palatal donor area healed in 3-5 weeks. The graft showed complete adaptation with the surrounding tissue and healing in 4-6 weeks. Our results also indicated that injections in the graft do not retard graft healing.

Aged↗
PubMed1985

Evaluation of 99mTc-dextran as a lymphoscintigraphic agent in rabbits.

Dextran (clinical grade, average mol. wt. 82,200) was labelled with 99mTc and the labelling efficiency was checked by paper and thin-layer chromatography and electrophoresis. The amount of free 99mTcO-4 was always less than 1%. The radiopharmaceutical was injected ID into the web space in hind legs of ten rabbits (200-600 microCi/0.05 ml). Scintigrams were taken at 10-min intervals up to 3 h in three rabbits. The injection site and the hind legs were massaged after injection in the other seven rabbits and scintigrams were taken at 10-min intervals up to 2 h. Blood samples were obtained at 5, 15, 30, 90 and 120 min in both groups. In addition a 180-min sample was also taken in the first group. At the end of the study the rabbits were killed and the popliteal lymph nodes and the organs were removed to be weighed and counted. Our results indicated a high concentration of radioactivity in the popliteal lymph nodes and massage at the injection site increased the average uptake of the popliteal lymph node from 1.12% +/- 0.77% to 4.28% +/- 1.57% at 3 and 2 h, respectively (P less than 0.001). In scintigrams the lymph channels and the nodes were very well visualised. The blood radioactivity levels were too low to present a background problem. With massage 30% of the injected dose was removed from the injection site in 2 h. We have shown that 99mTc-dextran is a good radiopharmaceutical for the visualisation of the lymph system and deserves further experimental and clinical studies.

Animals↗
PubMed1985

Measurement of tonsillar blood flow in normal and pathological conditions by the use of the 133Xe clearance technique.

By using the 133Xe clearance technique, we measured the blood flow to the human palatine tonsil in 10 normal volunteers, 11 patients with chronic tonsillitis, and 11 with hypertrophic tonsils. We found that the mean blood flow was 30.08 +/- 5.39 ml/ 100 g per min in normal tonsils, 17.06 +/- 3.72 in chronic tonsillitis and 49.50 +/- 9.30 in hypertrophic tonsils. Our results show a statistically significant decrease in blood flow in chronic tonsillitis (P less than 0.01) and a significant increase in hypertrophic tonsils (P less than 0.01) when compared to the normal controls. The difference between the blood flow in chronic tonsillitis and hypertrophic tonsils was also statistically significant (P less than 0.01). In all three groups studied, no statistically significant difference was observed in the blood flow to the right and left tonsils (P greater than 0.05).

Adolescent↗
PubMed1984

Testicular blood flow in experimental torsion and epididymo-orchitis measured by 133Xe clearance technique in rabbits.

Testicular blood flow was measured by intratesticular injection of 133Xe both under control conditions and in experimental 720 degree intravaginal torsion (10 rabbits) and in epididymo-orchitis (5 rabbits). The results were statistically compared with each other. The blood flow was 35.8 +/- 13.7 ml/100 g/min to the right testis and 35.4 +/- 12.7 ml/100 g/min to the left testis under control conditions. The blood flow decreased to 16% and 8% of the control values 1 h and 8 h after torsion respectively. In epididymo-orchitis testicular blood flow stayed within normal limits. There was a significant difference in blood flow between the torsion and epididymo-orchitis groups (p less than 0.001). Further investigation in man will demonstrate whether the 133Xe clearance method can be used in the differential diagnosis of these two pathologies.

Animals↗