Malignant melanoma of the gallbladder

A rare case of primary malignant melanoma of the gallbladder was studied with the electron microscope. Two interesting patterns were observed: numerous melanophages were present in the tumor tissue and wrapped compound melanosomes were found in nonneoplastic mucosal epithelium. The infiltration of melanophages was considered to be a reaction to degenerated tumor cells. Concerning the mechanism of melanosome transport into the epithelial cells, a cooperative action between epithelial and melanoma cells seemed to be the most important factor.

Induction of sister chromatid exchanges by transformation with simian virus 40

The frequency of sister chromatid exchange (SCE) has been followed sequentially after the addition of SV40 to human diploid fibroblast cultures. The SCE frequency was nearly the same in uninfected controls and in infected cultures before they became tumor antigen positive. When cells exhibited tumor antigen, the SCE frequency increased over a wide range, and changes in chromosome number and structure were observed simultaneously. Cells with induced chromosome abnormalities without increased SCE's and the reverse present the possibility that the two phenomena have different viral mechanisms. This increase in SCE can be added to the previously demonstrated change in chromosome number and increase in chromosome breakage and rearrangement as indicators of genetic damage associated with viral transformation.

Screening for autosomal aberrations

A method of screening for autosomal aberrations is important as an indication for chromosome analysis such as that used in sex-chromatin examination for sex chromosome aberrations. In our clinic, malformed patients with mental retardation and abnormal dermatoglyphic patterns are strong suspects for autosomal aberrations. Abnormal dermatoglyphic patterns are separated into two categories: (1) Absolutely abnormal--radial loop of 1st finger, radial loop of 4th finger, radial loop of 5th finger, arch over 6 fingers, arch tibial, loop tibial, and arch fibular; (2) Borderline abnormalities--high axial triradius (t' and t"), simian crease, interdigital loop, and single crease of 5th finger. Of 416 cases showing malformation, retardation, and abnormal dermatoglyphics, 308 had autosomal aberrations, while 108 had normal karyotypes. In the group with autosomal aberrations, 279 patients (90.6%) had absolutely abnormal dermatoglyphics. In the group with normal karyotypes only 8 patients (7.4%) had absolutely normal dermatoglyphics, while most had abnormal dermatoglyphics in the borderline category. These clinical manifestations: absolutely abnormal dermatoglyphics, mental retardation, and malformations are therefore very useful in screening for autosomal aberrations.

Congenital muscular dystrophy as a disease of the central nervous system

Profound abnormalities of the brain were noted in a 6-year-old Japanese boy with congenital muscular dystrophy (CMD). Pathological alterations included diffuse cerebral and cerebellar micropolygyria, with bilateral temporal agyria, and abnormal fusion of gray matter in the basal portions of both frontal hemispheres. Microscopically, the architecture of both cerebral and cerebellar cortices was severely distorted, with irregular arrangement of neurons and increased vascularization. Skeletal muscles showed dystrophic changes rather than neurogenic atrophy. Eight autopsy cases of CMD with similar pathologic findings have been reported in Japan, although the lesions in the brain are quantitatively different from case to case. The findings indicate that CMD is a dysplastic disease of the central nervous system, with dystrophic involvement of skeletal muscles.

Muscle pathology in cytochrome c oxidase deficiency

Muscle biopsies from 16 patients with cytochrome c oxidase (CCO) deficiency were examined morphologically. Two siblings had the fatal infantile form. The muscle of the older sister at the age of 5 months had numerous ragged-red fibers (RRF) and increased numbers of lipid droplets; at 28 days the brother had no RRF suggesting that the RRF formed later than 28 days. The muscle pathology in two patients with the benign infantile form improved as they grew older; numbers of RRF, lipid droplets and glycogen particles decreased and CCO activity increased in the second biopsy. In the encephalomyopathic form, RRF were seen in 5 of 12 muscles mostly in patients more than 6 years of age. Muscle spindles and blood vessel walls in the biopsies from three patients with rapid clinical aggravation had no CCO activity, suggesting that enzyme activity differed from tissue to tissue (tissue specificity).