Electrical preconditioning attenuates progressive necrosis and cavitation following spinal cord injury

This study evaluates the influence of preconditioning and subsequent electrical stimulation on the formation of primary and secondary lesions following spinal cord injury in rats. The dorsal surface of the spinal cord at the T7 level was stimulated 24 h before right-side hemisection (500 Hz, 10 pulses/train, at an inter-train interval of 10 sec for 2 h). Stimulation was again administered immediately after injury and then every 24 h for 7 days. Preconditioning electrical stimulation of the spinal cord activated reactive astrocytes, then significantly attenuated edema, progressive necrosis, and cavitation, especially in the secondary cavity lesions (24 h, 1 week, and 3 weeks post-injury). Upregulation of glial fibrillary acidic protein (GFAP) and vimentin immunoreactivity, a measure of reactive astrocytic response, were increased at 1 week after injury in the rats treated with electrical stimulation. These results suggest that preconditioning with electrical stimulation prevents the formation of secondary lesions after spinal cord injury. This beneficial effect may be related to the ability of electrical stimulation to attenuate trauma-induced cellular cascades.     

Clear cell carcinoma of the pancreas: an adenocarcinoma with unusual phenotype of duct cell origin

Although clear cell carcinoma has been found in various organs, only six cases have been reported in the pancreas. Moreover, the histogenesis of clear cell carcinoma of the pancreas remains controversial. We report a case of clear cell carcinoma of the pancreas in a 61-year-old woman, with an unusual pheno- or genotype detected by histochemical, immunohistochemical, and K-ras oncogene analyses. Histologically, the pancreatic tumor was predominantly composed of clear cell nests with scanty fibrous stroma and scattered duct-like structures. Neither clear cell nor duct-like components of the tumor showed mucin production. Immunohistochemical analysis of neoplastic cells showed a positive reaction to antibodies against cytokeratins 8 and 19, carbohydrate antigen 19-9, and -1-antitrypsin, and showed no reaction to antibodies against carcinoembryonic antigen, neuroendocrine markers, trypsin, amylase, and HMB45. K-ras analysis revealed no mutation at codon 12 in either clear cell or duct-like components. The patient has had no recurrence as yet. The pancreatic carcinoma in our patient may be of duct cell origin, but the results of histochemical, immunohistochemical, and gene analyses and patients outcome were unusual compared with those of previous cases.     

Neonatal ovarian cysts: management with reference to magnetic resonance imaging

OBJECTIVE: Ultrasound (US) has been used as a tool to determine the indication for surgery for neonatal ovarian cysts. The purpose of this study was to investigate whether magnetic resonance imaging (MRI) contributes to optimal management. METHODS: Between 1993 and 2001, US and MRI studies were simultaneously performed on 13 consecutive infants younger than 2 months of age with ovarian cysts. The US Patterns were classified as complex or simple. Signal intensity (SI) of the cysts on MRI was compared with that of the liver on T1-weighted images (T1WI) and with urine on T2-weighted images (T2WI). We assumed that high SI on T1WI and iso or low SI on T2WI indicated complications. RESULTS: There were 10 complex and three simple cysts on US. Of the 10 complex cysts, two had no complications at surgery or resolved spontaneously. These two cysts showed low SI on T1WI. Eight complex cysts showed high SI on T1WI and all were haemorrhagic. The US diagnosis corresponded to the MRI findings in three simple cysts. The sensitivity of US for haemorrhage was 80%, and that of MRI was 100%. CONCLUSIONS: We found that MRI was a more reliable diagnostic modality than US for diagnosing neonatal ovarian cysts.     

A female patient with malarial nephropathy

Malaria remains one of the worlds major health problems, particularly in developing tropical countries. Imported malaria is reportedly increasing in Western countries. Acute renal failure (ARF) is the most common cause of death in severe malaria. We report the case of a 63-year-old female patient with a history of travel to a rural area in South Africa who was in coma and had a high fever on admission. Thirty percent of her erythrocytes were infected with Plasmodium falciparum. She had cerebral malaria, malarial nephropathy, anemia, hepatic dysfunction, and disseminated intravenous coagulation (DIC). Quinine and artesunate treatment decreased the number of parasites in the blood. To manage renal failure, hemodialysis was performed for 11 days. A relationship between ARF and hepatic dysfunction was suggested. This relationship is an indication of the clinical course of the disease. In this article, we discuss the mechanism underlying the development of malarial nephropathy and its management, particularly the usefulness of hemodialysis.     

Solitary neurocysticercosis case caused by Asian genotype of Taenia solium confirmed by mitochondrial DNA analysis

A Japanese woman presenting with neurologic symptoms was presumptively diagnosed with neurocysticercosis based on imaging findings. Hooklets in the scolex of the resected lesion were not confirmed through histopathological observation. However, the illness was confirmed by mitochondrial DNA analysis to be a solitary neurocysticercosis case caused by the Asian genotype of Taenia solium.     

Monitoring and switching of cortico-basal ganglia loop functions by the thalamo-striatal system

Recent physiological and tract tracing studies revealed tight coupling of the centre médian and parafascicular nuclei (the CM-Pf complex), which are posterior intralaminar nuclei (ILN) of the thalamus, with basal ganglia circuits. These nuclei have previously been classified as part of the ascending reticulo-thalamo-cortical activating system, with studies of single neuron activity and of interruption of neuronal activity suggested that they participate in the processes of sensory event-driven attention and arousal, particularly in the context of unpredicted events or events contrary to predictions. In this article, we propose a hypothetical model that envisions that the CM-Pf complex functions in two different modes depending on the predictability of external events, i.e., one for monitoring 'top-down' biased control through the cortico-basal ganglia loop system for selecting signals for action and cognition and the other for switching from biased control to 'bottom-up' control based on the signals of salient external events. This model provides a new insight into the function of the CM-Pf complex and should lead to a better understanding of this important brain system.     

Degradation of pre-beta-high density lipoproteins and their binding activity to human blood monocytes

We have previously reported that high density lipoprotein3 (HDL3), apolipoprotein A-I (apoA-I) rich lipoprotein, binds specifically to the surface of human blood monocytes. Pre-beta-HDL with a pre-beta mobility on agarose gels is an apoA-I (MW 28 kDa)-rich and a lipid-poor lipoprotein. In the present study, we found that pre-beta-HDL purified by ion-exchange chromatography was susceptible to degradation if isolated in the absence of anti-proteases, resulting in the smaller lyso-pre-beta-HDL. The mass of lyso-pre-beta-HDL was confirmed using a delayed extraction matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (DE-MALDI-TOF MS), which showed a fragment of approximately 22,378.9 Da. We further investigated limited proteolysis of apo A-I purified from human plasma HDL with various proteases, and cleavage appeared to be limited to the C-terminal end of apo A-I (amino acids 188-223). The ability of pre-beta-HDL and lyso-pre-beta-HDL to compete for HDL binding to monocytes was determined using a flow cytometry-based assay. Pre-beta-HDL competed efficiently for binding whereas lyso-pre-beta-HDL was significantly less effective. The data may indicate that the binding sites on monocytes specifically recognize apoA-I. We suggest that limited proteolysis around amino acids 188-223 of apo A-I may affect lipid binding, which may in turn affect HDL structure and function.     

Region-dependent G-protein activation by kappa-opioid receptor agonists in the mouse brain

The G-protein activations induced by kappa-opioid receptor agonists, (-)U50,488H, U69,593 and TRK-820 in the mouse lower midbrain, striatum and limbic forebrain were determined by monitoring guanosine-5'-o-(3-[35S]thio)triphosphate ([35S]GTP gamma S) binding. All kappa-opioid receptor agonists produced approximately 40, 20 and 10% increases of [35S]GTP gamma S binding over baseline in the lower midbrain, striatum and limbic forebrain, respectively. The increases of [35S]GTP gamma S binding induced by kappa-opioid receptor agonists were completely reversed by the selective kappa-opioid receptor antagonist, norbinaltorphimine (norBNI), in all brain regions. The intrinsic activities of kappa-opioid receptor agonists for G-protein activation in brain regions observed in the present study are not correlated with densities of kappa-opioid receptor binding sites from previous reports. The present results suggest that the catalytic efficiency of kappa-opioid receptor-G-protein coupling may be variable in different brain regions.     

Metastasis of renal cell carcinoma to the thyroid gland 19 years after nephrectomy: a case report

Although metastases to the thyroid are never uncommon at autopsy in patients who died of malignancy, metastatic thyroid carcinomas are rarely detected in clinical practice in most cases and cases of secondary thyroid cancer which require thyroid surgery clinically are few. A clinical case of thyroid metastasis from renal cell carcinoma with thyroidectomy is described herein. An 87-year-old Japanese woman was referred to us for a slow-growing palpable neck tumor with dysphagia. She had undergone a nephrectomy for renal clear cell carcinoma 19 years earlier at another hospital. Preoperative imaging examinations suspected an adenomatous goiter and a fine needle aspiration (FNA) cytology was suggestive of an atypical follicular tumor. Hemithyroidectomy was performed as a follicular tumor of thyroid for restriction of subjective symptom. A pathological examination of the thyroid tumor revealed clear cell carcinoma, postoperatively. The negative result of immunohistochemical staining for thyroglobulin also suggested metastatic renal cell carcinoma to the thyroid. Clinically significant metastases to the thyroid gland are relatively infrequent. However, if patient who bears a thyroid tumor has a history of malignancy, the possibility of metastatic disease should be taken under consideration.