No abstract

The formation of arachidonic acid metabolites [prostaglandin (PG)D2, PGE2, PGF2 alpha, 6oxo-PGF1 alpha and thromboxane (TX)B2] has been examined in the frontal, temporal, and parieto-occipital regions of the cortex in the postmortem brains from five patients with a pathologically verified Alzheimer-type dementia (ATD) and in eight, age-matched controls. The study disclosed that the amount of PGD2 and TXB2 found in the ATD brains was greater than in controls, and that the formation of PGD2 was significantly increased in the frontal cortex of the ATD brains. Other PG metabolites, however, showed no significant changes in the ATD group. Since it is known that PGD2 is synthesized mainly in neurons, our results seem to suggest that the preserved cortical neurons in the ATD brain have an accelerated PGD2 production.

The relationship between blood vessels and amyloid beta (A beta)-protein deposits in the cortex of the Alzheimer's disease (AD) brain is still controversial. It is difficult to distinguish whether the A beta deposits are associated with blood vessels or neurons because of their widespread and complicated distribution. In this study, we investigated the distribution of A beta deposits in the cerebral white matter of the AD brain as a means of removing the bias of neuronal distribution. An immunohistochemical study of 100 serial sections, after pretreatment with formic acid for 24 h, revealed the presence of A beta deposits in the cerebral white matter of the AD brain. There are various morphological types of plaques containing A beta deposits in the white matter, the same as in the gray matter. While the majority of A beta deposits was of a circumscribed type such as "classic" and "primitive" plaques, "compact" and "diffuse" plaques were also observed in the white matter. The location of the A beta deposits was, for the most part, immediately beneath the gray matter. The distribution of A beta deposits in the white matter was found to correspond to the orientation of the blood vessels. Serial sections also revealed that these A beta deposits were distributed along a single blood vessel. These findings suggest that the deposition of A beta in the cerebral white matter is primarily related to the blood vessels.

No abstract

Although a number of radiological studies have suggested that brains of patients suffering from schizoprenia have morphological abnormalities, the results are inconsistent. In the present study, in order to examine the brain, morphological features of homogeneous schizophrenics' brain magnetic resonance imagings (MRI) were taken, before neuroleptic treatment, from subjects suffering from disorganized-type schizophrenia, (DOS) during their first episodes. Results showed that DOS had significantly smaller indices for bilateral frontal gray matter (GM), left hippocampal formation (HF), left parahippocampal gray matter (PHGM) and left cingulate gyrus gray matter (CGM) than normal controls. These findings support the previous computed tomography (CT) and MRI studies on schizophrenic brains, although the subjects were not defined as disorganized-type, and may suggest the involvement of a neurocircuit between the bilateral frontal lobe and the left side of limbic system in the first-episode DOS group.