Evaluation of Tc-99m(V) DMSA for imaging inflammatory lesions: An experimental study

The present study evaluated^99mTc(V) DMSA as an agent for the visualization of inflammatory lesions in comparison to^99mTc(HI) DMSA and^99mTc-HIG. All three radiopharmaceuticals were prepared with commercial kits.^99mTc(V) DMSA was prepared at neutral pH by the addition of first bicarbonate and then pertechnetate to the kit contents. The labeling efficiency was 99% as determined by ITLC. Abscesses were induced by i.m. injection of 50 μl turpentine into the right thighs of 36 Swiss albino mice. Six days later 3.7 MBq of each radiopharmaceutical was i.v. administered to 12 mice. The mice were sacrificed at 1,3,6 and 24 h later. Scintigrams were obtained with a gamma camera. The abscesses were better visualized on scintigrams with^99mTc(V) DMSA compared to^99mTc(III) DMSA, starting at 1 h. The animals were dissected and the organs were removed, weighed and the radioactivity determined with a gamma counter. The abscess to other tissue ratios were higher with^99mTc(V) DMSA than the other radiopharmaceuticals. The max. abscess/muscle ratios were 9.46 ± 3.20 (24 h), 4.19 ± 1.39 (6 h) and 5.98 ± 1.17 (24 h) and max. abscess/blood ratios were 6.22 ± 1.41, 4.09 ± 0.84 and 0.914 ± 0.351 all at 24 h for^99mTc(V) DMSA,^99mTc(III) DMSA and^99mTc-HIG, respectively. Experimental arthritis was produced in 6 New Zealand white rabbits by intra-articular injection of ovalbumin. Four days later 37 MBq of^99mTc(V) DMSA and^99mTc-HIG were each i.v. administered to 3 rabbits. Scintigrams obtained at 1, 3, 6, and 24 h clearly demonstrated arthritic joints. ROFs over arthritic joints were compared to contralateral normal joints (A/C). The max. A/C ratios were 2.10 ± 0.31 (3 h) and 2.92 ± 0.99 (24 h) for^99mTc(V) DMSA and^99mTc-HIG, respectively. Our results indicated the feasibility of imaging inflammatory lesions with^99mTc(V) DMSA.     

Radiation dose reduction during hysterosalpingography: an application of scanning-beam digital radiography

Hysterosalpingography was performed in 31 patients by means of a low-dose scanning-beam digital radiographic system. The technique permits adequate evaluation of gynecologic abnormalities while allowing significant reduction in radiation: 2.4-mR (6.1 X 10(-7) C/kg) exposure to the skin and 0.7-mrad (7 X 10(-6) Gy) mean dose to the ovaries per image obtained. Sixteen patients demonstrated readily recognizable and documented abnormalities, corroborated by laparoscopy, laparotomy, or other supportive evidence.     

Rapidly advancing invasive endomyocardial aspergillosis.

The exposure to Aspergillus organisms/spores is likely common, but disease caused by tissue invasion with these fungi is uncommon and occurs primarily in the setting of immunosuppression. We report a case of rapidly advancing invasive endomyocardial aspergillosis secondary to prolonged usage of multiple broad-spectrum antibiotics in a nonimmunocompromised host. A 36-year-old cotton textile worker presented to our institution with a 3-month history of weight loss and fatigue. He reported receiving prolonged use of multiple broad-spectrum antibiotic treatment. The echocardiogram demonstrated multiple endomyocardial vegetations and a mass in the left atrium. Myocardial biopsy specimen revealed an invasive endomyocardial aspergillosis. The patient was investigated for immune deficiency including HIV, and this workup was negative. Treatment was started with amphotericin B and heparin for presumed left atrial thrombus. The patient died because of a rupture of mycotic aneurysm that resulted in cerebral hemorrhage. This case illustrates the risk of an invasive fungal infection in a nonimmunocompromised host who is a prolonged user of antibiotics in the setting of environmental exposure of opportunistic invasive fungal infections.     

Presurgical ultrasound-assisted neuro-examination in the surgical repair of peripheral nerve injury.

In spite of electrodiagnostic examinations, the determination of the precise localization of the injured site along the involved peripheral nerve may remain obscure or uncertain. Before starting the operation, a surgeon should have knowledge about the type of injury, the position of the proximal and distal nerve stumps, and the presence or absence of a neuroma and excessive perilesional scar tissue formation for orientation and planning of the surgical intervention. We hypothesized that real-time ultrasound could be helpful in the determination of the type of injury, the localisation of proximal and distal nerve stumps, as well as for diagnosing a neuroma. Fourteen patients with traumatic peripheral nerve injuries that were verified by neurological examinations and electrodiagnostic tests underwent surgical repair, and were examined by ultrasound before and during the surgical intervention. Visualisation of the injured site, the type of the injury, the position of the nerve stumps and the diagnosis of the neuroma were reliably feasible in all the patients by using ultrasonography. Axonal swelling of a nerve was diagnosed in 4 (29 %) patients, a stump neuroma was diagnosed in 3 (21 %) patients, a total nerve interruption (neurotmesis in the Seddon classification) was diagnosed in 9 (64 %) patients, and surrounding scar tissue was diagnosed in 5 (35 %) patients. Presurgical and intraoperative ultrasound-assisted neuroexamination is a useful diagnostic method in the determination of the precise localisation of the injured site, the type of injury, the position of stumps, and the diagnosis of a neuroma. The use of preoperative and intraoperative ultrasound can enhance the orientation of the surgeon to the surgical field. The application of our method to our patients shows that presurgical ultrasonographic neuroexamination can be used in the surgical repair of peripheral nerve injury.     

Evaluation of neointimal hyperplasia on tranilast-coated synthetic vascular grafts: an experimental study.

Tranilast is an antiallergic drug that interferes with proliferation and migration of vascular smooth muscle cell induced by platelet-derived growth factor (PDGF) and transforming growth factor-beta1 (TGF-beta1). We investigated the local effect of tranilast on neointimal hyperplasia using tranilast-coated prosthetic grafts. The inner sides of the thin-walled polytetrafluoroethylene (PTFE) grafts were coated with chitosan and tranilast containing chitosan solution. Wistar albino rats (32) were used in the study. Patches (1 x 2 mm) for vascular grafts were prepared. Three groups were tested: group 1 (n = 12; tranilast coated), group 2 (n = 10; adhesive-only film-layer-coated), and group 3 (n = 10; normal ePTFE patch grafts sutured to the carotid arteries of the rats). Recipient sites of the carotid arteries were excised 4 weeks after surgery. All sections were examined histologically for graft patency, thrombus formation, and neointimal thickness. Expression of PDGF, fibroblast growth factor, and TGF-beta1 on cross-sections of the neointima were evaluated by immunohistochemistry. No significant differences were found regarding mean neointimal thicknesses. PDGF and TGF-beta-1 expressions were significantly lower in group 1. Although a decrease in local effect of tranilast was observed for growth factor expressions at a drug concentration of 0.05 mg/cm(2), a significant reduction in neointimal hyperplasia was not achieved. The coating concentration of 0.05 mg/cm(2) may have been too low to produce an antiproliferative effect. Given our promising results, further studies are recommended and planned using different drug concentrations and time intervals.