Thyroid uptake error in four different gamma camera systems

The thyroid uptake of (123)I and (131)I is generally measured by a gamma camera system. We evaluated the error in determining thyroid uptake caused by different methods of calculation among four gamma camera systems with various collimators. We first designed an original thyroid phantom that consisted of the thyroid and a body containing various levels of radioiodine activity. The applications for thyroid uptake equipped in two gamma camera systems performed calculations by the automatic method with background counts not subtracted from the capsule counts. When the size of the rectangular region of interest (ROI) for the capsule was set at 10x8 cm (a typical ROI size for the thyroid), percentages of thyroid uptake as calculated by the manual method with background counts subtracted from the capsule counts and thyroid counts were 52% to 57% when the value was set at 55% for (123)I; and 54.2% and 58.7%, respectively, when the value was set at 60% for (131)I. On the other hand, the percentages of thyroid uptake calculated by the automatic method with the application using two gamma camera systems with non-subtraction of background counts from the capsule counts were 46% and 50.5% when the value was set at 55%; and 49.6% when the value was set at 60%. The values calculated by the automatic method were underestimated as a result of background counts that were not subtracted from the capsule counts. When ROI size for the capsule was set at 4x4 cm, which is slightly larger than the capsule size, even thyroid uptake as determined by the automatic method using the application showed a difference of less 2% from the set values. There was no difference in thyroid uptake among the various kinds of collimators, high-resolution collimators, all-purpose collimators, and a suitable collimator for gamma-ray energy of (123)I.     

Evaluation of myocardial viability following acute myocardial infarctic using201Tl SPECT after thallium-glucose-insulin infusion —Comparison with18F-FDG positron emission tomography—

OBJECTIVE AND METHODS: The aim of this study was to evaluate myocardial viability in patients after acute myocardial infarction (AMI). We compared 201Tl SPECT after 201Tl with GIK (10% glucose 250 ml, insulin 5 U and KCl 10 mEq) infusion (GIK-201Tl) with resting 201Tl and 99mTc-pyrophosphate (PYP) dual SPECT, positron emission computed tomography (PET) using 18F-fluorodeoxyglucose (18F-FDG) in 21 patients with their first AMI, who all underwent successful reperfusion. GIK-201Tl SPECT, 201Tl and 99mTc-PYP dual SPECT were done within 10 days after admission and 18F-FDG-PET was performed at 3 weeks. GIK-201Tl SPECT was obtained after 30 min of GIK-201Tl infusion. 18F-FDG (370 MBq) was injected intravenously after oral glucose (1 g/ kg) loading, and then PET was obtained. PET and SPECT images were divided into 20 segments. Regional tracer uptake was scored using a 4-point scoring system (3 = normal to 0 = defect), and summed to a regional uptake score (RUS). Regional area means the infarcted area in which 99mTc-PYP accumulated. The number of decreased uptake segments (ES) was then determined. The infarcted area was defined as the area of 99mTc-PYP uptake. RESULTS: The ESs for the GIK-201Tl and 18F-FDG-PET images were significantly lower than the number of 99mTc-PYP uptake segments. The RUS for GIK-201Tl was higher than that for resting-201Tl imaging and similar to those for 18F-FDG-PET. CONCLUSIONS: In the detection of myocardial viability following AMI, GIK-201Tl imaging is useful with findings similar to those of 18F-FDG-PET.     

Incarceration of the Inferior Oblique Muscle Branch of the Oculomotor Nerve in Two Cases of Orbital Floor Trapdoor Fracture

Background Incarceration of the inferior oblique muscle (IO) branch of the oculomotor nerve may occur in cases of orbital floor trapdoor fracture.Cases Two orbital floor trapdoor fracture cases, with lesions located just outside of the inferior rectus muscle but without its incarceration, were examined pre- and postoperatively for visual acuity, intraocular details, the nine diagnostic ocular positions of gaze, binocular single vision field with the Hess chart, and by computed tomography (CT). One case was also examined by magnetic resonance imaging (MRI; T1-weighted images). A forced duction test was conducted intraoperatively.Observations Each case presented good visual acuity and neither globe showed any injury. Motility disturbance of the IO was shown in each case by binocular single vision field testing and the Hess chart. The possibility of the incarceration of the IO branch of the oculomotor nerve, which runs from the incarcerated lesion to the superior belly of the IO, in an orbital floor trapdoor fracture was shown on CT and MRI. Intraoperative forced duction testing revealed a restriction due to the incarceration of the connective tissue septa.Conclusions As inferred from the CT and MRI analyses conducted in this study, IO palsy may be one of the causes of ocular motility disturbance of the IO in an orbital floor trapdoor fracture, in addition to the ocular motility disturbance due to the connective tissue septa. Jpn J Ophthalmol 2005;49:246–252 © Japanese Ophthalmological Society 2005     

Surgical results for hepatocellular carcinoma with bile duct invasion: a clinicopathologic comparison between macroscopic and microscopic tumor thrombus

BACKGROUND: The aim of this study was to evaluate the prognostic factors and long-term results after surgery in patients with hepatocellular carcinoma (HCC) with bile duct invasion. METHODS: The records of 38 HCC patients with microscopic (tumor thrombus was found in more than the second order branch of the biliary tree; n = 19) and macroscopic (tumor thrombus was found in no more than the second order branch of the biliary tree; n = 19) bile duct invasion were reviewed in this study. Survival rates were calculated with regard to 18 clinicopathological factors. A log-rank analysis was performed to identify which factors predict the prognosis. The relationships between the degree of bile duct invasion and 17 clinicopathologic factors were also compared. RESULTS: The overall 1-, 3-, and 5-year survival rates were 79%, 45%, and 33%, respectively. The indicators of a favorable prognosis included no intrahepatic metastases, curative surgical resection, and macroscopic bile duct invasion. CONCLUSION: We found a favorable long-term postoperative result for HCC patients with macroscopic bile duct invasion. Even if HCC tumor thrombus is recognized in the major branches of bile duct, extensive and curative surgical treatment should be recommended when hepatic functional reserve is satisfactory without intrahepatic metastases.     

Possible endocrine control by follistatin 315 during liver regeneration based on changes in the activin receptor after a partial hepatectomy in rats

BACKGROUND/AIMS: Activin A is an autocrine inhibitor of cell growth in the liver. The biological activity of activin A is mediated by a heteromeric receptor complex. Follistatin (FS) binds to activin and inhibits its biological effects, and acts as a negative regulator of muscle cells. The role of activin receptors during liver regeneration following a hepatectomy has not been fully assessed. This study investigates the mechanism underlying how activin receptors regulate hepatocyte growth, and the effects of intravenous administration of FS during liver regeneration. METHODOLOGY: The expression of both activins and activin receptors in the liver after a 70% partial hepatectomy (HT) was assessed by RT-PCR and immunohistochemistry. FS 315 or 288 was infused for different periods of time based on changes in hepatocyte activin receptor expression after HT. RESULTS: Activin receptor expression peaked between 48 and 72 hours after HT. 72 hours after HT, an injection of FS 315 resulted in a more potent stimulation of DNA synthesis and produced a greater increase in body weight compared with the control rats. CONCLUSIONS: The expression of activin receptors after peak DNA synthesis might be a key component in the downregulation of DNA synthesis. Intravenous administration of FS 315 might promote liver regeneration and have anabolic actions.     

Neuronal migration in cortical development

Cortical formation in the developing brain is a highly complicated process involving neuronal production (through symmetric or asymmetric cell division) interaction of radial glia with neuronal migration, and multiple modes of neuronal migration. It has been convincingly demonstrated by numerous studies that radial glial cells are neural stem cells. However, the processes by which neurons arise from radial glia and migrate to their final destinations in vivo are not yet fully understood. Recent studies using time-lapse imaging of neuronal migration are giving investigators an increasingly more detailed understanding of the mitotic behavior of radial glia and the migrating behavior of their daughter cells. In this review, we describe recent progress in elucidating neuronal migration in brain formation and how neuronal migration is disturbed by mutations in genes that control this process.     

Neuroprotective effect of donepezil, a nicotinic acetylcholine-receptor activator, on cerebral infarction in rats

This study evaluated the potential effect of donepezil, which is known as an acetylcholinesterase inhibitor used for treatment of Alzheimer's disease, against cerebral infarction induced by permanent left middle cerebral artery (MCA) occlusion. Donepezil was given orally in various regimens, prior to MCA occlusion in rats. Pretreatment with a single oral dose of donepezil (12 mg/kg), 2 h before ischemia, significantly attenuated cerebral infarction volume (165.5 +/- 105.3 vs. 377.1 +/- 48.5 mm(3); P < 0.05). These neuroprotective effects were prevented by coinjection with mecamylamine, a nicotinic acetylcholine-receptor (nAChR) antagonist, indicating that protection was mediated by nAChR activation.