Memory impairment caused by cerebral hematoma in the left medial temporal lobe due to ruptured posterior cerebral artery aneurysm

BACKGROUND: Cognitive disorders, such as memory disturbances, are often observed following a subarachnoid hemorrhage. We present a very rare case where rupture of a posterior cerebral artery aneurysm caused restricted damage to the hippocampus unilaterally, and caused memory disturbances. CASE PRESENTATION: A 56-year-old, right-handed man, with a formal education history of 16 years and company employees was admitted to our hospital because of a consciousness disturbance. He was diagnosed as having a subarachnoid hemorrhage due to a left posterior cerebral artery dissecting aneurysm, and coil embolization was performed. Subsequently, he had neither motor paresis nor sensory disturbances, but he showed disorientation, and both retrograde and anterograde amnesia. Although immediate recall and remote memory were almost intact, his recent memory was moderately impaired. Both verbal and non-verbal memories were impaired. Brain computed tomography (CT) and magnetic resonance imaging (MRI) revealed a cerebral hematoma in the left temporal lobe involving the hippocampus and parahippocampal gyrus, and single-photon emission computed tomography (SPECT) demonstrated low perfusion areas in the left medial temporal lobe. CONCLUSIONS: We suggest that the memory impairment was caused by local tissue destruction of Papez’s circuit in the dominant hemisphere due to the cerebral hematoma

Agraphia Caused by Left Thalamic Hemorrhage

A 71-year-old right-handed man was admitted to our hospital with right hemiparesis and sensory impairment associated with mild aphasia. Although aphasia gradually resolved within 2 weeks after stroke onset, his writing ability remained disturbed. A computed tomography (CT) scan at stroke onset revealed a hematoma in the left thalamus, but no cortical lesions were observed. Further, a single-photon emission CT (SPECT) scan showed decreased blood flow in the left thalamus, in the cortical region extending from the left superior temporal gyrus to the parietal lobe, and in the frontal lobe. It is possible that agraphia may have directly resulted from the thalamic lesion, but SPECT findings strongly suggested that a general decrease in left cortical function concomitant with a disruption of the thalamocortical and cortico-thalamocortical projection fibers produced these cognitive deficits

A Case of Curable Dementia Treated by Effective Endovascular Embolization for Dural Arteriovenous Fistula

Background: We report a case in which an effective endovascular treatment cured the worsening of dementia due to a dural arteriovenous fistula (dAVF). Case Report: A 73-year-old woman suffered for 1.5 years from gait disturbance and disorientation that were suspicious of dementia. A brain MRI revealed that her symptoms were likely due to dAVF. An angiography provided a definitive diagnosis of dural transverse-sigmoid sinus fistula. Transvenous embolization completely occluded the fistula and led to a significant improvement of her cognitive function in tandem with a restoration of the cerebral blood flow. Conclusion: Endovascular treatment for dAVF is sometimes effective in treating worsening dementia, which might be due to the drastic change in cerebral blood flow in the area relevant to the cognitive function

Existence of phenol oxidase in the argasid tick Ornithodoros moubata

Phenol oxidase (PO, EC 1.10.3.1) activity was detected in the hemolymph of the fourth instar nymphs of the argasid tick, Ornithodoros moubata, with peak levels corresponding to the days before the majority of the nymphs had molted, suggestive of a protective role of PO during the ecdysial phase. Higher PO activity was detected in plasma relative to the hemolymph and was negligible in hemocytes. The concentration of the hemolymph and plasma assayed clearly influenced the level of PO activity, and was significantly reduced (P\u3c0.005) after treatment with 1-phenyl-2 thiourea, a specific PO inhibitor. This is the first report of the existence of PO in the hemolymph and plasma of a soft tick species. The regulation of PO activity and its precise role in soft tick immunity, particularly during the ecdysial phase, are interesting and need to be examined further

Analyses of cDNAs from growth and slug stages of Dictyostelium discoideum

Dictyostelium is a favored model for studying problems in cell and developmental biology. To comprehend the genetic potential and networks that direct growth and multicellular development, we are performing a large-scale analysis of Dictyostelium cDNAs. Here, we newly determine 7720 nucleotide sequences of cDNAs from the multicellular, slug stage (S) and 10 439 from the unicellular, vegetative stage (V). The combined 26 954 redundant ESTs were computer assembled using the PHRAP program to yield 5381 independent sequences. These 5381 predicted genes represent about half of the estimated coding potential of the organism. One-third of them were classified into 12 functional categories. Although the overall classification patterns of the V and S libraries were very similar, stage-specific genes exist in every category. The majority of V-specific genes function in some aspect of protein translation, while such genes are in a minority in the S-specific and common populations. Instead, genes for signal transduction and multicellular organization are enriched in the population of S-specific genes. Genes encoding the enzymes of basic metabolism are mainly found in the common gene population. These results therefore suggest major differences between growing and developing Dictyostelium cells in the nature of the genes transcribed