Reliability of MIBG myocardial scintigraphy in the diagnosis of Parkinson's disease

AIM: To evaluate the reliability of [(123)I]meta-iodobenzylguanidine (MIBG) myocardial scintigraphy for diagnosing Parkinson's disease (PD). PATIENTS/METHODS: A series of 391 outpatients showing one or more parkinsonian-like symptoms was longitudinally followed up for accurate clinical diagnosis. MIBG scintigraphy was performed in the patients and 10 normal controls of similar age. The heart to mediastinum uptake ratio was calculated in each person, and the values were considered abnormal if they were greater than two standard deviations below the control mean. RESULTS: MIBG uptake was decreased in most patients with PD (87.7%), and was seen in all advanced cases with Hohen-Yahr stage III or more; the sensitivity and specificity of scintigraphy for detecting PD were 87.7% and 37.4%, respectively. Surprisingly, over half of the patients without PD (66.5%) also exhibited low uptake, resulting in considerable overlap in the ratios between PD and the other disorders. CONCLUSION: MIBG scintigraphy is a sensitive, but not specific, test for PD. Low MIBG uptake does not necessarily indicate PD, but is essential for diagnosing advanced PD.     

Possible synergic effect of angiotensin-I converting enzyme gene insertion/deletion polymorphism and angiotensin-II type-1 receptor 1166A/C gene polymorphism on ischemic heart disease in patients with Kawasaki disease

ACE I/D and AT1R 1166A/C polymorphisms are considered to comprise individual risk factors for the development of coronary disease. We sought to demonstrate that the ACE I/D and AT1R 1166A/C polymorphisms affect coronary artery stenosis in patients with Kawasaki disease (KD). We examined 147 healthy controls and 281 Japanese children with KD. The patients were further divided into group N (n = 246, no ischemia) and group I (n = 35, severe coronary artery stenosis with myocardial ischemia), and we studied the genotype of ACE I/D and AT1R 1166A/C polymorphisms. We also examined ACE activity in patients with acute KD. We did not detect any prevalent genotypes of the ACE and AT1R polymorphisms between controls and KD patients. However, the prevalence of the D allele in the ACE polymorphism and of the C allele in the AT1R polymorphism tended to be higher in group I than in group N (odds ratios, 2.00 and 2.32, respectively). In addition, the presence of the D and/or C alleles significantly increased the relative risk of developing myocardial ischemia (odds ratio, 2.71; p = 0.038). During the convalescent phase of KD, ACE activity was increased despite significant attenuation during the acute phase. These results suggested that the renin-angiotensin system is associated with the formation of severe coronary artery stenosis and myocardial ischemia.     

Early graft failure due to a veno-occlusive disease after a pediatric living donor liver transplantation

A 10-month-old boy with biliary atresia after Kasai procedure underwent a living donor liver transplantation (LDLT). Five days after the LDLT, high fever and increased ascites followed by poor bile drainage was accompanied by elevation of serum liver enzymes. Liver biopsy showed occlusion of the central veins by fibro-edematous endothelium and submassive necrosis of the parenchyma. Veno-occlusive disease (VOD) was suspected, and re-LDLT was urgently performed because of deterioration of hepatic failure. There are few cases of VOD after liver transplantation and this is the first one in an infant after LDLT.     

The effect of ascorbic acid on the pharmacokinetics of levodopa in elderly patients with Parkinson disease

Levodopa (LD) is one of the most effective drugs for clinical symptoms in patients with Parkinson disease (PD). Most PD patients are advanced in age and may have trouble with LD absorption because aging influences drug absorption processes. Previous reports have indicated that ascorbic acid (AsA) can reduce LD dosage without losing its effectiveness. The current study sought to determine whether AsA affects LD absorption in elderly PD patients. Sixty-seven elderly PD patients took a tablet orally containing 100 mg LD and 10 mg carbidopa following an overnight fast. Plasma LD concentrations were determined at 6 points up to 3 hours, using high-performance liquid chromatography with electrochemical detection. The area under the curve (AUC), peak drug concentration (Cmax), and time to peak drug concentration (Tmax) were calculated. The pharmacokinetic evaluation was repeatedly performed 1 week later in the same way except for adding 200 mg AsA to the tablet. The changes in AUC, Cmax, and Tmax between the tests were evaluated. Significant changes in these parameters were not observed when analyzed using data from all patients. However, significant increases in AUC and Cmax, and a significant reduction in Tmax by adding AsA were observed in 25 patients with baseline AUC < or =2500 ng.hour/mL. In conclusion, AsA can improve LD absorption in elderly PD patients with poor LD bioavailability. LD therapy in combination with AsA may be one of the strategies for PD treatment.     

Drainage of subcutaneous lymphatic fluid for the management of respiratory distress in a case of generalized lymphangiectasia in an infant

A 10-month-old girl was referred to our hospital because of congenital and persistent bilateral chylothorax and generalized lymphedema as well as long-standing respiratory disturbance. Radiological studies showed a diffuse network of superficial lymphatic vessels without major trunks throughout her entire body as well as the lung. She was diagnosed with systemic lymphangiomatosis complicated with pulmonary lymphangiectasia. Percutaneous puncture in the lower leg was performed to discharge the lymphatic fluid and proved to be effective for the respiratory disturbance. This procedure is safe and easy and effectively improves the quality of life of the patient and the family in case of such a persistent disease.     

Characterization of cutaneous primary afferent fibers excited by acetic acid in a model of nociception in frogs

Acetic acid applied to the hind limb of a frog evokes nocifensive behaviors, including a vigorous wiping of the exposed skin, referred to as the wiping response. The aim of this study was to examine the responses of cutaneous primary afferent fibers in frogs to acetic acid (pH 2.84-1.42) applied topically to the skin. Conventional electrophysiological methods were used to record neuronal activity from single identified primary afferent fibers with cutaneous receptive fields on the hind limb. Fibers were classified according to their conduction velocities and responses evoked by mechanical and thermal (heat and cold) stimuli. One hundred and twenty-two mechanosensitive afferent fibers were studied (44 Abeta, 60 Adelta, and 18 C fibers). Thirty-nine percent of all fibers were excited by acetic acid, but a greater percentage of Adelta (52%) and C fibers (44%) were excited than Abeta fibers (20%). Evoked responses of fibers increased with increasingly more acidic pH until the greatest responses were evoked by acetic acid at pH 2.59-2.41. Application of acetic acid at pHs <2.41 evoked less excitation, suggesting that fibers became desensitized. Similar percentages of nociceptors and low-threshold mechanoreceptors were excited by acetic acid. Thus primary afferent fibers were excited by acetic acid at pHs that have been shown to evoke the wiping response in our previous study. The results of the present study suggest that the model of acetic acid-induced nociception in frogs may be useful for studying the mechanisms by which tissue acidosis produces pain.     

Activation of the prefrontal cortex to trauma-related stimuli measured by near-infrared spectroscopy in posttraumatic stress disorder due to terrorism

To develop a noninvasive method for psychophysiological assessment of posttraumatic stress disorder (PTSD), 34 victims of the Tokyo Subway Sarin Attack in 1995 including 8 diagnosed as PTSD and 12 controls were examined by a multichannel near-infrared spectroscopy (NIRS) system. Hemodynamic response in the prefrontal cortex was monitored during the presentation of trauma-related and control stimuli by video images. Skin conductance response (SCR) was also examined. Oxygenated hemoglobin significantly increased during the trauma-related image in the victims with or without PTSD. Deoxygenated hemoglobin significantly decreased only in victims with PTSD. No significant alteration was found in controls. Significantly enhanced SCR was also observed in the victims with PTSD during trauma-related stimuli. The findings suggest that measurement of cerebral hemodynamic response by NIRS is useful for psychophysiological assessment of PTSD.