Cavernous hemangioma in the anterior mediastinum; report of a case

A rare case of mediastinal hemangioma was reported in this article. A 63 years old male was pointed out an abnormal shadow in the chest CT scan though he had no symptoms. It showed a well-defined round mass with low density in the anterior mediastinum. MRI (T2 weight) showed the lesion as a high intensity tumor. We diagnosed it thymoma and planned the surgical treatment. The tumor was resected completely through median partial sternotomy. The tumor was 2 cm in diameter. Histological examination revealed it cavernous hemangioma, and neither coagulations nor phleboliths were identified in vessels of the tumor.     

Loss of heterozygosity and the smoking index increase with decrease in differentiation of lung adenocarcinomas: etiologic implications

To better understand causative relations of smoking to lung adenocarcinomas, the frequency of loss of heterozygosity (LOH) of all autosomal chromosomes was compared among the three grades of histological differentiation with 119 pulmonary adenocarcinomas (AC) and 41 squamous cell carcinomas (SCC), using Southern blotting. The fractional allelic loss (FAL) values, defined as (number of chromosome arms with LOH)/(number of informative arms), and smoking index (a product of number of cigarettes per day and duration in years) for all ACs were 0.19 and 520 whereas those for SCCs were 0.34 and 1,160, respectively. Those for well- (n=33), moderately (n=63) and poorly (n=23) differentiated ACs were 0.100, 0.197, 0.295 and 310, 480, 1,010, respectively. These results showed that less differentiated ACs are more similar to SCC in terms of LOH frequency and smoking.     

Incidence of p53 and ras gene mutations in DMBA-induced rat leukemias

Leukemia, a form of haematological malignancy, is a multi-stage disease and a wide range of diverse genes has been speculated to correlate with its initiation and development. Ras has been speculated to be an initiating gene for haematological malignancy, but more investigation will be needed to determine the genes associated with the progression of the disease. 7,12-dimethylbenz(a)anthracene (DMBA)-induced rat leukemia provides a good tool for research into various stages of the disease. The entire coding regions of p53 and ras genes were examined for mutations in the present study. In this experiment, we used fluorescence-labeled polymerase chain reaction single-stranded conformation polymorphism analysis (PCR-SSCP) and direct sequencing to detect mutations of both genes on rat erythroleukemia. Fifteen out of 18 (83.3%) rat leukemias were found to have N-ras codon 61 mutation, consistent with previous results. The result of direct sequencing showed a single base substitution (CAA to CTA), resulting in an amino-acid change from Gln to Leu. No mutations were found in H-ras, K-ras or codon 12 of N-ras. The incidence of p53 gene mutation was 16.6% (3/18) in rat leukemia at late-stage. In the present study, mutation of the p53 gene was detected in three DMBA-induced leukemias as follows: a single-base substitution (CAT to CGT) at codon 177 (exon 5), resulting in an amino-acid change from Arg to Leu, a CGG to CTG/CGG changed at codon 211 (exon 6) resulting in an amino-acid change from His to Arg/His, and a GGG to TGG at codon 242 (exon 6) resulting in an amino-acid change from Gly to Trp, respectively. Thus, mutations of p53 gene do not seem to respond to the carcinogenesis of the DMBA-induced leukemia, in contrast to mutation of the N-ras oncogene, and may possibly be involved in the progress of multi-stage leukemogenesis.     

A case of cerebellar ataxia showing severe dystonia masquerading as myoclonic jerky movements on arm extension]

A 43-year-old man was admitted to our hospital due to unstable walking, head tilting to the left and difficulty in extending his arm. He was quite healthy until the age of 20 years, when these symptoms appeared and progressed slowly afterward. Due to his unstable walking, he started to use a wheelchair when he was 39 years old. He had no family history of similar disease. On admission, neurological examination revealed spasmodic torticollis, ataxic speech and marked limb and truncal ataxia. Myoclonic jerky flexion of the forearm was induced when he raised and extended his forearm. He also showed mild hyperreflexia in the lower limbs without pathological reflexes. He had weakness and atrophy of the left supraspinatus, infraspinatus, deltoid and biceps brachii muscles and mild superficial sensory impairment in the left axillary nerve territory due to cervical spondylotic radiculopathy of the left C5 root. MRI of the brain demonstrated severe bilateral atrophy of the cerebellar hemispheres and vermis but minimal atrophy of the cerebrum and brainstem. Because surface electromyography revealed continuous discharge with phasic components in the biceps and wrist flexor muscles on extending the upper limbs, the jerky flexion movement of the forearm was considered to be primarily dystonia. Although no giant SEP was observed, a C-response was detected in the long-loop reflex in response to right median nerve stimulation. Nuclear examinations showed diffuse hypoperfusion and decreased glucose metabolism in the cerebellum. Based on these findings, we hypothesized that cerebellar dysfunction may have induced severe dystonic movement resembling myoclonus. We would like to name this complicated involuntary movement an "arm thrust". This is the first case to be reported of sporadic, chronic, progressive cerebellar ataxia accompanied by severe dystonic movement, especially on stretching the forearms, that mimics myoclonic movement.     

A GDP/GTP exchange protein for the Rab3 small G protein family up-regulates a postdocking step of synaptic exocytosis in central synapses

The Rab3 GDP/GTP exchange protein (Rab3 GEP) activates the Rab3 small GTP-binding protein (G protein) family, including Rab3A that is an important member controlling synaptic vesicle trafficking. Here, we examined the role of Rab3 GEP in regulating neurotransmitter release in autapses of mouse hippocampal neurons in culture. The release probability was markedly reduced in Rab3 GEP-/- neurons, whereas the readily releasable pool size was not different between WT and Rab3 GEP-/- neurons, indicating that Rab3 GEP up-regulates a postdocking step of synaptic exocytosis. Because Rab3A reportedly down-regulates Ca(2+)-triggered fusion of synaptic vesicles, these results provide evidence for a role of Rab3 GEP in the postdocking process distinct from Rab3A activation.     

Longitudinal Observation of a Patient with Leri-Weill Dyschondrosteosis and SHOX Haploinsufficiency

Haploinsufficiency of the short stature homeobox-containing (SHOX) gene causes Turner skeletal features, a certain proportion of idiopathic short stature and Leri-Weill dyschondrosteosis (LWD). Here we report a Japanese female with LWD. Her physical growth, skeletal deformity, and endocrine status were recorded longitudinally. She exhibited a constant growth rate (average + 6.2 cm/yr) from 6 to 9 yr old, followed by a downward shift at 10 yr old. Her final height was 135 cm (–4.4 SD for an adult female) and weight was 50.5 kg (–0.3 SD) at 12 yr and 10 mo old. Mesomelia and cubitus valgus were noticed from 2 yr old, and metaphyseal lucency and epiphyseal hypoplasia of the medial side of the distal radius were detected at 6 yr old. Madelung deformity was obvious at 10 yr old, when menarche occurred. Fluorescence in situ hybridization (FISH) analysis demonstrated a single copy of the SHOX gene. The short stature of the patient was thought to be exaggerated by the combination of SHOX haploinsufficiency and relatively early puberty.     

Lithium chloride inhibits thrombin-induced intracellular calcium mobilization in C6 rat glioma cells

In this study, the authors have demonstrated the effect of lithium, a typical mood stabilizer, on thrombin-evoked Ca2+ mobilization in C6 cells to elucidate the action mechanisms of the drug. Thrombin-induced Ca2 mobilization was reduced 24 hr after 1 or 10 mM lithium chloride (LiCl) pretreatment. The Ca2+ rise was reduced in a time-dependent manner, and the significant inhibition was observed 9 hr pretreatment with 10 mM LiCl. On the other hand, pretreatment of the cells with 10 mM LiCl for 24 hr did not alter the amount of Galphaq/11 significantly. Pretreatment with 10 mM LiCl for 24 hr failed to reduce the 5-HT-induced Ca2+ mobilization or to affect the desensitization of the 5-HT signal. Finally, thrombin-elicited Ca2+ rise was markedly inhibited in the presence of 0.05 U/ml plasmin, however, the Ca2+ rise was not further attenuated in the presence of plasmin in C6 cells pretreated with LiCl for 24 hr. These results indicate that pretreatment with LiCl attenuated thrombin-evoked intracellular Ca2+ mobilization in plasmin sensitive manner in C6 rat glioma cells. Thus, it is important to investigate the effect of lithium on thrombin-induced cellular responses to clarify the action mechanism of lithium in relation to some abnormality in thrombin-evoked Ca2+ rise observed in bipolar disorders.