An experimental study of radiation-induced cognitive dysfunction in an adult rat model

The objectives of this study were to establish an adult rat model for the late onset of radiation-induced cognitive dysfunction and to compare behavioural dysfunction with histopathological changes. While under anaesthesia, 30 rats (experimental group) were irradiated with a total dose of 40 Gy, given as eight fractions in 24 days. Another 30 rats (control group) underwent sham irradiation. The cognitive functions of all rats were evaluated at 6, 9 and 12 months after irradiation using the Morris water maze and passive avoidance tasks. Histopathological examination of these rats was carried out after the evaluation of cognitive functions was complete. At 6 and 9 months after irradiation there were no significant differences between the control and irradiated groups in passive avoidance and water maze tests. At 12 months after irradiation, the passive avoidance task revealed a deterioration of cognitive function in the experimental group. Histopathological observations revealed no abnormal findings in the irradiated brains at the light microscope level. Late onset cognitive dysfunction following cranial irradiation was observed in an adult rat model. Pathological investigations showed no abnormalities in the irradiated brains. These findings indicate that radiation-induced cognitive dysfunction can precede morphological changes in the brain or that they arise without them. The present model seems useful for elucidating the pathogenesis of radiation-induced cognitive dysfunction and for developing methods for therapy and prophylaxis.     

Propofol decreases diaphragmatic contractility in dogs

Volatile anesthetics depress diaphragmatic muscle function; however, no data are available regarding the effect of propofol on diaphragmatic contractility. We therefore studied this effect in dogs. Pentobarbital-anesthetized animals were divided into three groups of 10 each. Group I received only maintenance fluid; Group II was infused with a subhypnotic dose of propofol (0.1-mg/kg initial dose plus 1.5-mg x kg(-1) x h(-1) maintenance dose); Group III was infused with an anesthetic dose of propofol (0.1-mg/kg initial dose plus 6.0-mg x kg(-1) x h(-1) maintenance dose). We assessed diaphragmatic contractility by transdiaphragmatic pressure (Pdi). With an infusion of propofol in Groups II and III, Pdi at low-frequency (20-Hz) stimulation decreased from the baseline values (P < 0.05), whereas Pdi at high-frequency (100-Hz) stimulation did not change. Compared with Group I, Pdi at 20-Hz stimulation decreased during propofol administration in Groups II and III (P < 0.05). The decrease in Pdi was more in Group III than in Group II (P < 0.05). We conclude that propofol is associated with a dose-related inhibitory effect on diaphragmatic contractility in dogs. IMPLICATIONS: Propofol is an effective IV anesthetic for the induction and maintenance of anesthesia. Subhypnotic and anesthetic doses of propofol decrease diaphragmatic contractility in dogs.     

Two cases of bladder tumor producing granulocyte colony stimulating factor

Two cases of bladder tumor producing granulocyte colony-stimulating factor (G-CSF) are reported. The first case was in a 79-year-old female patient. A large bladder tumor was diagnosed as right-sided hydronephrosis. The tumor consisted mostly of squamous cell carcinoma with a few transitional cells. Total cystectomy could not be performed because of direct invasion by the tumor into the pelvis. The patient died without aggressive treatment about 7 months after admission. Her leukocyte count consistently increased up to 76,200/mm3. The serum G-CSF levels were not analyzed. However, immunohistochemical examination revealed a high concentration of G-CSF in the tumor specimen. The other case was in an 80-year-old male patient. The patient, who had refused total cystectomy for bladder tumor (transitional cell carcinoma, grade 2, T2N0M0) 2 years earlier, underwent ureterocutaneostomy for obstructive renal insufficiency. Total cystectomy was not performed at this admission because of tumor invasion into the rectum and his advanced age. Radiotherapy was administered. However, he developed ileus caused by direct tumor invasion into the ileum. He died about 10 months after the urinary diversion. Leukocytosis, which improved transiently following radiotherapy, became more severe. The maximum leukocyte count was 49,500/mm3 just before death. The serum G-CSF levels during and after radiotherapy were 54 pg/ml and < 30 pg/ml, respectively. Immunohistochemical examination revealed the presence of G-CSF in the tumor. These findings suggest the production of G-CSF by the bladder tumor.     

A case of crossed fused kidney with simple ureterocele

A 32-year-old man consulted Osaka National hospital with chief complaints of dysuria and macrohematuria. DIP and CT revealed that the right kidney deviated to the lower pole of the left kidney and they fused together. The right ureter crossed over the supine. The calcified shadow existed in the lower end of the left ureter with cobra head image. He had no external anomalies. Under diagnosing crossed fused kidney (inverted L shaped) complicated the left ureterocele with a stone, transurethral incision of ureterocele (TUI) was performed. We made transverse incision and extracted stone, 7 mm in size (calcium oxalate 96% and calcium phosphate 4%). Three months later after the operation, IVP, CG and VCG revealed the down-sized ureterocele and no VUR. Crossed renal ectopia complicated many anomalies about 50%. Among them anomalies of the urinary tract was most frequent about 30%. But crossed renal ectopia with ureterocele wasn't reported so far in Japanese literature.     

Highly sensitive analysis for N-myc amplification in neuroblastoma based on fluorescence in situ hybridization

BACKGROUND/PURPOSE: The N-myc amplification status in neuroblastoma has been evaluated previously for the whole tumor by the Southern blot method. The aim of this study is to evaluate the effectiveness of the fluorescence in situ hybridization (FISH) method to analyze N-myc amplification in neuroblastoma and compare the findings with those using the Southern blot method. METHODS: In 26 neuroblastoma primary tumors and metastatic lesions, the N-myc amplification status was evaluated by both the Southern blot method and FISH method. RESULTS: Of the 22 samples with no N-myc amplification using Southern blot, no cells with N-myc amplification using FISH were present in 21 of the samples. However, one metastatic liver lesion showed 16% of the nuclei to display more than 10 copies of N-myc based on FISH analysis. In the 4 remaining samples with N-myc amplification using the Southern blot method (17 copies, 15 copies, 6 copies, and 3 copies), the rates of cells with more than 10 copies of N-myc based on a FISH analysis were 79%, 68%, 94%, and 9%, respectively. CONCLUSIONS: The FISH method can detect more accurately N-myc amplification than the Southern blot method either when the rate of cells with N-myc amplification is low or intratumor heterogeneity is present.     

Clinical application of three-dimensional anisotropy contrast magnetic resonance axonography. Technical note

The utility of three-dimensional anisotropy contrast (3DAC) magnetic resonance (MR) axonography, a method sensitive to neuronal fibers and their directionality, was investigated in the clinical setting using a 3-tesla MR imaging system based on a General Electric Signa platform. The study focused on healthy volunteers and patients with common structural central nervous system disorders, namely chronic infarction, brainstem cavernous hemangioma, supratentorial meningioma, and astrocytoma. Three orthogonal anisotropic diffusion-weighted images were first obtained. Three primary colors were each assigned to a diffusion-weighted image, respectively, and the images were subsequently combined into a single-color image in full-color spectrum (3DAC MR axonography image). Fiber-tract definition in the cerebral peduncle of the midbrain of healthy volunteers showed intersubject variation, with two general patterns recognized: dispersed (60% of cases) and compact (40% of cases). Pathological alterations in the fiber tracts were readily identified in cases involving wallerian degeneration of the pyramidal tract, as illustrated in the cases of chronic infarction. Displacement of major tracts, such as the medial lemniscus or corticospinal tract, as well as fiber directionality, was also easily recognized in cases of mass lesions. As an imaging method uniquely capable of providing information regarding axonal connectivity, 3DAC MR axonography appears to have promising potential for routine clinical application.     

An angiographically occult arteriovenous malformation in the medial parietal lobe presenting as seizures of medial temporal lobe origin

We present an unusual case of a patient who was diagnosed with temporal lobe epilepsy and whose seizures were reduced markedly after excision of an angiographically occult arteriovenous malformation (AVM) located in the left medial parietal lobe. A 38-year-old man had complex partial seizures characterized by motionless staring with oroalimentary and behavioral automatisms since the age of 15 years. Magnetic resonance imaging (MRI) demonstrated a small lesion extending from the left posterior cingulate gyrus to the precuneus. There was no MRI evidence of mesial temporal sclerosis. Intracranial EEG recordings showed ictal onset from the left medial parietal lobe propagating to the medial temporal lobes. Clinical signs appeared when these discharges reached the temporal lobes. After excision of the lesion (which was histologically confirmed as an AVM), together with the marginal cortex, seizures were reduced significantly. Careful diagnostic evaluation of lesions such as the this one may reveal an epileptogenic lesion (zone) far from the region where scalp ictal discharges seem to arise. In our case, we hypothesize that false localization was due to propagation of ictal discharges from the parietal focus through the limbic system.     

Vasogenic edema on MELAS: a serial study with diffusion-weighted MR imaging

The authors performed a serial study of a patient with mitochondrial myopathy, encephalopathy, lactic acidosis, and stroke-like syndrome (MELAS) who presented with diffusion-weighted MRI (DWI). DWI demonstrated a higher apparent diffusion coefficient in the lesion than in the control region during the acute stage of stroke. Vasogenic edema is present in stroke-like episodes in MELAS.