To investigate changes in caliber of vessels in leukoencephalopathy with cerebral amyloid angiopathy (CAA) we performed a histological and morphometric study of cerebral arteries in this disease. We histologically examined changes in cortico-leptomeningeal arteries in five cases of leukoencephalopathy with CAA and compared their morphometrically determined wall-to-lumen ratio [(external diameter-internal diameter) x 0.5/internal diameter] with those of amyloid-negative arteries to estimate stenotic changes. Additionally, we compared wall-to-lumen ratios of medullary arteries in brains with CAA and white matter lesions (WML) (CAA(+)/WML(+), n = 5), subcortical arteriosclerotic encephalopathy without CAA (CAA(-)/WML(+), n = 7), and neither CAA nor white matter lesions (CAA(-)/WML(-), n = 5). Amyloid-positive arteries had thinned walls and dilated lumens. The external diameter and the wall-to-lumen ratio for amyloid-positive arteries was smaller than for amyloid-negative arteries in CAA(+)/WML(+) brains. There was no significant difference in the external diameters among the three groups. The wall-to-lumen ratio for medullary arteries in CAA(-)/WML(+) brains was significantly greater than for CAA(+)/WML(+) and CAA(-)/WML(-), but there was no significant difference between CAA(+)/WML(+) and CAA(-)/WML(-). Amyloid deposition causes degeneration of the tunica media, resulting in thinning of the wall and dilation of the lumen. The tunica media of small arteries is important in regulation of cerebral blood flow with degeneration causing impairment of cerebrovascular autoregulation in response to blood pressure. This impairment may lead to white matter lesions.

A case of malignant cystosarcoma phyllodes of the prostate is reported in a 45‐year‐old male. This tumor was composed of benign columnar or squamous cystic folds and sarcomatous stroma including rhabdomyomatous elements. The prostatic origin of the tumor was clearly proved by the unlabeled immunoperoxidase method. ACTA PATHOL. JPN. 34: 663–668, 1984.

No abstract

To investigate the relationship between cerebral amyloid angiopathy (CAA) and cystatin C, we studied five CAA patients on whose cerebral blood vessels colocalization of cystatin C and beta-protein was recognized immunohistochemically. One patient was suspected as familial CAA and the other patients were sporadic cases. Two patients had low concentration of cystatin C in their cerebrospinal fluid (CSF) as we have previously reported in CAA patients. Enzyme-linked immunosorbent assay (ELISA) revealed that cystatin C and beta-protein have been included at the ratio of about 1:100 in the crude amyloid fibrils of one patient. Using a monoclonal antibody (MAb) against cystatin C, we performed affinity chromatography and immunoblotting on her amyloid fibril fraction. Eluate showed a band with a mol wt of 14,000 and the N-terminal 14 amino acid residues of 14-kDa protein were identical with that of cystatin C. This molecular weight is not identical to that of the truncated form of cystatin C deposited in hereditary cerebral hemorrhage with amyloidosis in Iceland (HCHWA-I), but that of normal cystatin C. DNA sequence analysis of five patients showed no point mutations in the cystatin C gene. Cystatin C and beta-protein colocalization, which was recognized in amyloid lesions of CAA, suggests that cystatin C deposition may be related to beta-protein deposition. We hypothesize that cystatin C deposition in sporadic cerebral amyloid angiopathy with cystatin C deposition (SCCAA) involves a different mechanism from that in HCHWA-I, which may be related to low CSF concentration of cystatin C without amino acid substitutions.

The potassium permanganate method and the unlabeled immunoperoxidme (PAP) method were applied for distinguishing -rent types of amyloid Abril proteins in conventionally fixed, paramn-embedded tissue sections obtained from --one autopsied cases of systemic amyloidosis and three control cases of well-analysed fibril proteins. All of the eimteen cases %ensitive" to permanganate treatment, whose amyloid deposits lost completely their a-ty to Congo red and birefringence under polarized light, were shown to have AA antigenic determinants by the PAP method. Meanwhile, all of the remaining thirty-three 44resistant" cases, where Congo red afilnity and birefringence were retained at various degree even only in minimal areas, were negative for AA antigenicity. This indicated the feasibility of potassium permanganate method for the identification of AA protein based on this criterion of "sensitivity". 'benty-eight cases were classifled a8 M, AX, AK or AA+[Aw] the remaining twenty-three cases were unclassified, and there were some discrepancies between the preliminary cljnicopathological classification and the protein nature of the amyloid. It is important to Merentiate the types of amyloid fibril protein of individual patients because the expedience of selective therapeutic approaches had been suggested. The two methods applied herein are handy and useful for this purpose. ACTA PATHOL. JPN. 32: 771-782, 1982. IdroactionSystemic amyloidosis is a disease condition caused by extracellular deposition of fibrillar protein, amyloid, in various organs throughout the body.Although the etiology and pathogenesis of systemic amyloidosis have been unclear, recent advances in biochemical and immunological analyses of amyloid fibril proteins have disclosed the presence of at least three major different types of amyloid fibril proteins; (I) Protein AL, of immunoglobulin hght chain origin, includmg lamda type (AX) and kappa type (AK), found in immunoglobulin amyloidOsis.@ (11) Protein AA, of