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Biomedical subjects

M T Ercan

Publications and source records attributed to M T Ercan.

At least 37 records · Page 2Linked to original sources
PubMed1996

In utero defecation by the normal fetus: a radionuclide study in the rabbit.

An experimental study was performed to investigate the excretion function of the liver, gastrointestinal motility, and in utero defecation by radionuclide techniques in 24 New Zealand white rabbit fetuses at 25 days' gestation (fullterm, 31 to 32 days). 0.1 mL of technetium 99m (99mTc)-HIDA (a derivative of iminodiacetic acid) containing 1 mCi of radioactivity was injected into the gluteus muscle of each fetus which had been exposed through the uterus. After replacing the fetus and uterus into the abdomen, and beginning 1 hour after injection, a live fetus was killed each hour for 24 hours Tissue samples from the lung heart, stomach, kidney, bladder, liver, meconium in the proximal, mid and distal bowel, and amniotic fluid were taken. The radioactivity of each sample was determined by a gamma counter and the percentage uptake per gram of tissue was calculated. The very low radioactivity levels detected in the stomach, kidneys, and bladder indicated the in vivo stability of 99mTc-HIDA 99mTc-HIDA is predominantly trapped by the liver via systemic circulation and is excreted into the gastrointestinal tract through which it passes into the amniotic fluid. Demonstrated passage of excreted 99mTc-HIDA through the fetal liver and into the gastrointestinal tract and amniotic fluid strongly suggests that fetal defecation is a physiological event.

Amniotic Fluid↗
PubMed1995

Experimental induction of osteosarcoma by subperiosteal radioactive phosphorus injections in rats.

In search of a predictable experimental model for the study of therapeutic modalities for osteosarcoma, a group of rats had injections of phosphorus-32 (P-32) colloid subperiostally and were followed for the occurrence of malignant bone tumors until death or for 18 months. Of 50 rats, 26 died of unrelated causes and only 24 were included in the study. Two cases of osteosarcomas, one occurring in month 16 and the other at month 18 were induced; one case demonstrated multiple lung metastases. Clear evidence of the sarcoma inducing effect of P-32 has been obtained in this study. However, a high yield experimental osteosarcoma model was not produced.

Animals↗
PubMed1995

The value of Tc-99m citrate scintigraphy in chronic osteomyelitis. An indicator of the involved bone.

The authors present a prospective analysis of Tc-99m MDP and Tc-99m citrate scintigraphy in 29 patients who were clinically suspected of having chronic osteomyelitis. All of the patients showed increased Tc-99m MDP uptake on bone scintigraphy involving the area of concern. However, Tc-99m citrate scintigraphy clearly identified the patients with osteomyelitis (N = 18) confirmed either by biopsy or clinical follow-up. Eleven patients who were free of osteomyelitis showed only minimal radiotracer uptake on Tc-99m citrate scintigraphy. These patients had other benign musculoskeletal diseases that were diagnosed by other imaging modalities. In addition to visually interpreting the scintigraphic images, a semi-quantitative analysis was performed by drawing regions of interest over the areas involved and the normal contralateral side, and patients with osteomyelitis were found to have lesion to nonlesion ratios of greater than 1.70. Because Tc-99m MDP is a nonspecific radiopharmaceutical for the evaluation of bone infection, other imaging agents have been investigated. Tc-99m citrate is a small molecule that makes it suitable to penetrate injured capillaries to the edema fluid known to be present in areas of infection. The authors conclude that Tc-99m citrate is a promising agent for localizing and showing the extent of bone infection that will help the surgeon to determine areas of debridement before surgery.

Adult↗
PubMed1995

The visualization of pulmonary tuberculosis with Tc-99m (V) DMSA and Tc-99m citrate in comparison to Ga-67 citrate.

Two patients with active tuberculosis confirmed by chest radiography and positive sputum smears were included in this study to determine whether a Tc-99m labeled agent, such as DMSA or citrate could localize such lesions in comparison to Ga-67 citrate. Both patients had Tc-99m (V) DMSA, Tc-99m citrate, and Ga-67 citrate scanning at 1-day to 5-day intervals. Both patients had positive scan findings with all three radiopharmaceuticals. However, the quality of Tc-99m (V) DMSA scans was superior to Tc-99m citrate, which showed faint uptake. Tc-99m (V) DMSA may be a better alternative to Ga-67 citrate in the assessment of the activity and extent of tuberculosis.

Adult↗
PubMed1995

Clinical evaluation of metastases of malignant melanoma imaging with 99Tcm-glutathione and 99Tcm-anti-melanoma antibody: a comparative study.

The aim of this investigation was to test for the scintigraphic detection of metastases of malignant melanoma with a new radiopharmaceutical, 99Tcm-glutathione (99Tcm-GSH), in comparison with 99Tcm-anti-melanoma antibody (99Tcm-AMAb). Glutathione was labelled with 99Tcm by a Sn2+ reduction method with an efficiency of > 99% as determined by instant thin layer chromatography (ITLC). Anti-melanoma antibody was obtained as a kit from SORIN (Italy) and labelled with 99TcmO-4. Forty-three patients with a total of 55 biopsy-proven metastatic melanoma foci, 1 ocular melanoma and 20 benign pathologic foci, also confirmed by ultrasound, computed tomography and magnetic resonance imaging, were included in the study after giving their informed consent. Following the intravenous (i.v.) injection of 500 MBq 99Tcm-AMAb, scintigraphic images of the involved areas were obtained 6 h post-injection. Three days later, the same patients were given 500 MBq 99Tcm-GSH i.v. and images were obtained 6 and 24 h post-injection. The images were classified as positive (focal abnormal accumulation) or negative. Quantitative evaluation was also applied. Regions of interest were drawn over the involved areas and nearby soft tissues and the target-to-nontarget (T/NT) ratios obtained with 99Tcm-AMAb (T/NT: 1.92 +/- 0.2) and 99Tcm-GSH (T/NT: 1.84 +/- 0.2) were compared (0.1 < P < or = 0.3). The sensitivity (and specificity) of 99Tcm-AMAb and 99Tcm-GSH in the detection of malignant melanoma metastases were 91% (95%) and 84% (90%), respectively. Compared with 99Tcm-AMAb, the advantages of 99Tcm-GSH are lower levels of blood radioactivity, lower costs and easy in-house preparation. In conclusion, our results show that 99Tcm-GSH is a potentially useful radiopharmaceutical for the detection of metastases of malignant melanoma.

Antibodies, Neoplasm↗
PubMed1995

The release of isoconazole nitrate from different suppository bases: in-vivo release of drug labelled with 99mTc in rabbits.

The influence of the suppository bases on the in-vivo release of 99mTc-labelled isoconazole nitrate was investigated. The single-dose vaginal suppository formulations for local treatment of vaginitis were prepared by a fusion method using polyethylene glycols, Witepsol H15, Novata BD and Cremao. Prepared vaginal suppositories containing solid-labelled substance were applied to the vagina of rabbits and at 0, 2 and 24 h after administration, the amounts of radioactivity in the vagina were detected by the SPECT Gamma Camera and the release rates of the drug were calculated. The percent released was found to be in the following order; polyethylene glycol (PEG) 6000 > PEG 4000 > Witepsol > PEG 1500 > Novata BD > Cremao. The results obtained in both in-vitro and in-vivo studies indicated that the vaginal suppository of isoconazole nitrate prepared with polyethylene glycols could confidently be used in therapy.

Animals↗
PubMed1995

Persistence of 99mTc-labelled microorganisms on surfaces of impression materials.

Impression materials or prostheses can be contaminated with oral microflora and provide a significant source for cross-contamination. A study of such contamination was carried out using an approach different from that of infection control, which has often been investigated in previous studies. The study focused on microorganisms known to cause local and systemic diseases and which are normally found in the oral flora. The persistence of Streptococcus mutans (S. mutans), Escherichia coli (E. coli), Staphylococcus aureus and Candida albicans (C. albicans) on zinc-oxide eugenol, silicone rubber, irreversible hydrocolloid and polyether-rubber was investigated using 99mTc-labelled microorganisms. Ten specimens from each of the four impression materials were prepared as discs of 3 mm in height and 10 mm in diameter. After the specimens had been placed into a suspension of 99mTc-labelled microorganisms, remaining radioactivity was counted in a gamma counter. According to own findings, S. mutans was the most, and E. coli the least persistent on the specimen surfaces. The number of microorganisms removed after washing was less than the amount remaining on the surfaces. C. albicans was removed most easily from all impression surfaces that bore persistent microorganisms after washing. Other microorganisms showed various degrees of persistence according to the impression material.

Alginates↗
PubMed1994

Accumulation of some small molecular weight complexes of 99mTc in experimental abscesses.

The purpose of the present investigation was to evaluate the feasibility of imaging inflammatory lesions with some small molecular weight complexes of 99mTc with renal excretion in comparison to 99mTc-dextran (D), 99mTc-HIG and 67Ga-citrate. The biodistributions of pertechnetate (P), 99mTc-citrate (Cit), -gluconate (G), -glucoheptonate (GH), -DTPA, -glucose phosphate (GP), -D, -HIG and 67Ga-Cit were determined in mice with turpentine-induced abscesses at 1, 3, 6 and 24 h after i.v. injection of 15 MBq. % uptake/g tissues and abscess/muscle (A/M), blood (A/B), liver (A/L), intestine (A/J) and kidney (A/K) concentration ratios were calculated. The scintigraphic images of all mice were obtained by a 7-camera. The abscesses were well visualized with all the radiopharmaceuticals (RPs). The excretion was mainly via the kidneys except for 99mTc-D, 99mTc-HIG and 67Ga-Cit. They showed variable amounts of liver and kidney uptake. Similar A/M ratios were obtained with all the RPs, reaching max. at 3 h with pertechnetate, 99mTc-Cit and 99mTc-GP, at 6 h with 99mTc-DTPA and at 24 h with 99mTc-G, 99mTc-GH, 99mTc-D and 99mTc-HIG. The max. A/M ratios were 3.61 +/- 1.63, 4.61 +/- 3.92, 5.21 +/- 1.24, 3.60 +/- 0.52, 3.43 +/- 0.92, 5.37 +/- 0.67, 5.98 +/- 1.17 and 4.76 +/- 2.03 for 99mTc-P, -Cit, -G, -GH, -DTPA, -D, -HIG and 67Ga-Cit, respectively. Our results indicated that small molecular weight complexes of 99mTc can be used in imaging inflammation as well as high molecular weight complexes such as 99mTc-D, 99mTc-HIG and 67Ga-Cit. However, the first group is preferred, because of rapid blood clearance and excretion predominantly via the kidneys, which is an advantage for the identification of abdominal abscesses. The main mechanism of accumulation of all the RPs might be a simple diffusion process through the injured capillaries. An additional mechanism of binding to proteins was considered in view of the increasing concentration ratios with 99mTc-G, -GH, -D and -HIG as time progressed.

Abscess↗
PubMed1994

99Tcm-glutathione for imaging inflammatory lesions.

The purpose of this study was to demonstrate the accumulation of 99Tcm-glutathione (GSH) in experimental abscesses. The biodistribution of 99Tcm-GSH was determined in mice with turpentine-induced abscesses in comparison with 99Tcm-human immunoglobulin (HIG) at 1, 3, 6 and 24 h. Arthritis was induced by intra-articular injection of ovalbumin in the right front knees of 16 rabbits. Each radiopharmaceutical (RP) was administered intravenously to eight rabbits. Scintigrams were obtained and regions of interest (ROIs) over the involved and contralateral knees were compared. Blood clearance of both RPs was studied in 10 normal rabbits. Biodistribution studies indicated accumulation of 99Tcm-GSH in abscesses. Abscess to liver, muscle, intestine and blood ratios were higher at all time points compared to 99Tcm-HIG. The maximum abscess:muscle ratios were 7.57 +/- 0.73 and 5.98 +/- 1.17 at 24 h for 99Tcm-GSH and 99Tcm-HIG, respectively. Scintigraphic images demonstrated both the abscesses and arthritic joints very well. 99Tcm-GSH is superior to 99Tcm-HIG due to clearance predominantly via kidneys, no significant accumulation in any other organs, high target-to-nontarget ratios attained a few hours after administration, low cost and in-house preparation by a simple procedure.

Abscess↗
PubMed1994

Accumulation of 99mTc-glutathione in head and neck tumors.

Glutathione labelled with 99mTc was used to study blood clearance and normal distribution in 3 healthy volunteers and in 10 patients with biopsy-proven tumors in the head and neck region. Static scintigrams were obtained at 1, 3, 6, and 24 h. ROIs over tumors and normal soft tissues were compared to obtain T/N ratios. In normal subjects blood clearance reached a plateau at 6 h; no radio-activity accumulation in the head and neck region was observed. Only the cardiac blood pool, the liver, the kidneys and the urinary bladder were evident. Excretion was via the kidneys. Malignant tumors and metastases were well visualized in 7 patients (true-positive), starting at 1 h. The mean T/N ratio was 2.69 +/- 0.77. The best images were obtained at 3-6 h. 1 false-positive (granulamatous reaction), 1 false-negative (malignant epithelial tumor in the radix of tongue) and 1 true-negative (angiofibroma) results were obtained. 99mTc-GSH is a potential radiopharmaceutical for the scintigraphic visualization of head and neck tumors. Further clinical studies are warranted to show its sensitivity and accuracy.

Adult↗
PubMed1993

99mTc-citrate versus 67Ga-citrate for the scintigraphic visualization of inflammatory lesions.

Citric acid was labeled with 99mTc with an efficiency of > 99%. The biodistribution of 99mTc-citrate was studied in mice with turpentine-induced abscesses in comparison to 67Ga-citrate. The max. abscess/muscle concentration ratios were 4.61 +/- 1.92 (3 h) for 99mTc-citrate and 4.76 +/- 2.04 (4 h) for 67Ga-citrate. Arthritis was induced in 10 rabbits by intra-articular injection of ovalbumin Scintigrams obtained 4 days later and at 3 h post-injection of 99mTc-citrate showed increased activity involving the synovium. The max. arthritic/contralateral knee ratio was 3.19 +/- 1.29 (3 h) and 6.47 +/- 3.71 (24 h) for 99mTc- and 67Ga-citrate, respectively. The blood clearance curve of 99mTc-citrate in rabbits was biexponential with a fast (T1/2 = 36 min) and a slow (T1/2 = 18 h) component, compared to mono-exponential clearance of 67Ga-citrate (T1/2 = 23 h). In 10 patients with rheumatoid arthritis whole-body scintigrams and spot images of involved joints indicated localization of the tracer in inflamed tissues. The mean target-to-soft tissue ratios were 3.04 +/- 0.81 and 4.95 +/- 2.56 for 99mTc-citrate and 99mTc-MDP, respectively. Renal clearance of radioactivity was evident from the scintigrams. Our results demonstrated that 99mTc-citrate is effective as a radiopharmaceutical for the visualization of inflammatory lesions and may be preferred to 67Ga-citrate due to the ideal physical characteristics of the radionuclide, easy preparation, low cost, early accumulation and the preference for the renal route of excretion.

Abscess↗
PubMed1993

Scintigraphic visualization of acute pancreatitis in cats with 99Tcm-citrate.

The accumulation of 99Tcm-citrate in abscesses and arthritic joints has previously been demonstrated. In the present study its usefulness was evaluated in 10 mongrel cats with acute pancreatitis induced by metronidazole infusion. Five cats, used as normal controls, were given physiological saline. All 15 cats were injected intravenously with 185 MBq 99Tcm-citrate. Scintigrams were obtained at 30 min intervals up to 2 h after injection by a gamma camera. The cats were then sacrificed. Tissue samples were obtained, weighed and counted against a 1/1000 dilution of the injected dose. In normal cats the kidneys and the urinary bladder were the only organs that could be visualized. In acute pancreatitis the pancreas and its exudate in the abdomen were also evident on the images. The pancreas to other neighbouring organ ratios increased 2.3-9.7 fold in acute pancreatitis compared to normal controls. Gross autoradiograms showed localization of radioactivity in the lobules of pancreas. Histologic examination of sections of pancreas demonstrated oedema, haemorrhage and some fat necrosis in pancreatic parenchyma, confirming acute pancreatitis. In conclusion, it has been demonstrated that acute pancreatitis in cats can be visualized scintigraphically with 99Tcm-citrate.

Acute Disease↗
PubMed1993

Evaluation of 99Tcm-labelled alpha-D-glucose 1-phosphate aerosols for SPECT ventilation lung imaging.

The purpose of the present investigation was to evaluate 99Tcm-labelled alpha-D-glucose 1-phosphate (GP) aerosols for single photon emission computed tomographic (SPECT) ventilation lung imaging in comparison to 99Tcm-diethylenetriaminepentaacetate (DTPA) aerosols. Ten normal nonsmoking male volunteers (aged 20-30 years) were included in this study after obtaining their informed consent. 99Tcm-GP, 30 mCi, in 2 ml was placed in the nebulizer (Venticis II) and inhalation continued for 5 min of normal breathing with oxygen flowing through. In 10 subjects dynamic images were obtained from the posterior position for 90 min with 45 frames on a 64 x 64 matrix by the use of a gamma camera. At the end of the dynamic study planar images of the lung (anterior, posterior and laterals) were recorded. Decay corrected clearance curves and kep values were obtained by the pulmonary epithelial programme and T1/2 values were calculated. The same procedure was followed by the use of 99Tcm-DTPA in the same subjects 2 weeks later. SPECT studies of the lung were performed in five subjects after inhalation of 99Tcm-GP aerosols. Clearance curves were monoexponential. The difference in T1/2 values between the right and left lungs was statistically insignificant (P > 0.10). The mean T1/2 values were 316.5 +/- 44.7 and 80.8 +/- 13.4 min for 99Tcm-GP and 99Tcm-DTPA, respectively. The difference was significant (P < 0.0005). On scintigraphic images 99Tcm-GP showed high alveolar deposition and low adhesion to major airways like 99Tcm-DTPA. However, it is preferred to 99Tcm-DTPA for SPECT studies because of its prolonged pulmonary clearance.

Adult↗
PubMed1992

Evaluation of 99mTc-erythromycin and 99mTc-streptomycin sulphate for the visualization of inflammatory lesions.

99mTc-erythromycin (E) and 99mTc-streptomycin sulphate (SS) were prepared with greater than 98% labelling efficiency. The labels were stable up to 24 h of testing, using ITLC-SG strips and acetone and saline as solvents. The biodistributions of both radiopharmaceuticals versus 67Ga-citrate were studied in mice with turpentine-induced abscesses at 6 days post-induction. The mice were sacrificed at 1, 3 and 6 h post-injection of 15 MBq of 99mTc-E or 99mTc-SS. Mice injected with 67Ga-citrate were sacrificed at 4 and 24 h. The maximum abscess-to-muscle ratios obtained by biodistribution studies were 2.36 +/- 1.04 (6 h), 2.38 +/- 0.38 (6 h) and 4.76 +/- 2.04 (4 h) with 99mTc-E, 99mTc-SS and 67Ga-citrate, respectively. The maximum abscess-to-contralateral tissue ratios by ROIs over respective areas on scintigrams were 2.38 +/- 0.16 (6 h), 3.21 +/- 0.14 (3 h) and 3.24 +/- 0.92 (24 h) for 99mTc-E, 99mTc-SS and 67Ga-citrate, respectively. The uptake mechanism might be infiltration into interstitial space due to increased capillary permeability.

Abscess↗
PubMed1992

Autoradiography of lymph nodes with 99mTc-dextran in rabbits.

99mTc-dextran (D) was further evaluated in the present study as a lymphoscintigraphic agent compared to radiocolloids. It was injected intra-dermally into the web space between the second and third toes in both hind feet of two rabbits. 99mTc-nanocolloid (NC) was injected subcutaneously in both hind feet of two other rabbits. Popliteal lymph nodes were taken out and frozen in liquid nitrogen after the animals were sacrificed at 2 h post-injection. Three frozen sections in 10 microns thickness were prepared from each node for autoradiographic studies. The lymph node slices were exposed for 18 h using Ilford G 5 emulsion. The obtained autoradiographs showed that the distribution of 99mTc-D radioactivity within lymph nodes was more uniform indicating better tissue penetration compared to 99mTc-NC which remained mostly in the lymph canaliculi.

Animals↗
PubMed1992

Blood flow to human gingiva measured by the 133Xe clearance technique.

Blood flow to the maxillary and mandibular gingivae was determined in 9 subjects under both normal conditions and in inflammation using the 133Xe clearance technique. A total of 36 sites (18 healthy and 18 inflamed) were selected for 133Xe injection. The clearance of radioactivity was monitored by a gamma camera. The calculated mean blood flows were 51.1 +/- 11.4 and 48.7 +/- 6.7 ml/100 g/min to the normal maxillary and mandibular gingivae, respectively. In inflamed gingiva, the corresponding mean blood flows were 55.0 +/- 13.0 and 54.7 +/- 11.7 ml/100 g/min, respectively. A statistical comparison of the healthy and diseased sites was done according to the paired t and Student's t tests. The difference between the sites was not significant (p > 0.05) in the maxilla, but significant (p < 0.05) in the mandible. There was no significant difference (p > 0.05) when the total healthy and diseased sites were compared.

Adolescent↗
PubMed1991

Effect of wearing complete dentures on human palatal mucosal blood flow measured by 133Xe clearance.

In eight edentulous subjects, who had not previously worn dentures, blood flow was measured by 133Xe clearance after intramucosal injection. Upper and lower complete dentures were then constructed for these subjects, and 133Xe clearance was measured after the dentures had been worn for 7 and 40 days. Before the insertion of dentures the mean blood flow to palatal mucosa was 18.9 +/- 7.1 ml/100 g/min. Seven and 40 days after wearing dentures the mean flows to the palatal mucosa were 10.6 +/- 4.5 and 12.6 +/- 5.3 ml/100 g/min, respectively. The difference before and after wearing dentures was statistically significant (p less than 0.05). The subjects were asked not to wear the dentures for 24 h after the third visit on the 40th day whereupon the blood flow reached almost normal levels (16.2 +/- 5.45 ml/100 g/min). The findings show that wearing dentures hinders the blood supply to the palatal mucosa, and that after resting the oral tissues, blood flow may return to normal levels.

Blood Flow Velocity↗