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Biomedical subjects

K Lapis

Publications and source records attributed to K Lapis.

At least 289 records · Page 16Linked to original sources
PubMed1975

Fine structural alterations of muscle fibers in diseases accompanied by myotonia.

The authors have reported the results of examination by electron microscopy of two muscle biopsy specimens from cases of myotonia congenita and three cases of myotonia dystrophica. They have stated that "peripheral annular formation" was a frequently observed alteration in the myotonia congenita cases. In the myotonia dystrophica cases there were additionally disorganized myofibrils in the subsarcolemmal region and inclusion body vacuoles morphologically connected with the sarcolemma. The term "peripheral annular formation" refers to the situation in which the peripheral myofibrils of the muscle fiber fracture and the fragments retract and form a helical sheath around the central myofibrils of the same muscle fiber.

Adolescent↗
PubMed1975

[Scanning electron microscopic study of human bronchial mucosa under normal and pathological conditions].

Scanning electronmicroscopic picture of the normal human bronchial mucosa and alterations of it in chronic bronchitis are described. According to the author's findings in chronic bronchitis the regular arrangement of cilia disappears, the number of them decreases and they become shortened with a club-like formation on the end. Focal destruction of the cilia can also be seen. In the epithelium of the mucosa number of the cells without cilia increases. This is a consequence of the destruction of the cilia on one hand, and increase of the number of mucus secreting goblet cells on the other. Alterations of the bronchial mucosa in chronic bronchitis revealed by scanning electron microscopy may play an important part in the pathogenesis and persistence of chronic bronchitis of different origine.

Aged↗
PubMed1975

Transplantation of hepatomas induced in the avian liver by MC29 leukosis virus.

A hepatomatous growth derived from primary liver tumors induced in chickens by i.v. inoculation with MC29 leukosis virus has been established and maintained in the avian host. Hepatoma tissue transplanted into the abdominal cavity in a total of 278 chicks in 35 experiments yielded tumors in 222 animals (80%). The i.m. implantation in 69 birds in 7 experiments resulted in growth in 67 chicks (97%). Tumor tissue introduced inadvertently into the s.c. tissue likewise grew very rapidly. Histological and cytological features of the transplants in all sites showed preservation of the morphological characteristics of the original primary liver tumors through repeated passages. The properties of this first transplantable hepatoma derived from virus-induced primary liver tumors are compared with those of other transplantable hepatomas.

Abdomen↗
PubMed1975

[Electron microscopic study of cytoplasmic crystals in liver damages caused by alcoholism].

Liver biopsy of 50 patients with liver disease of alcoholic etiology was examined electronmicroscopically. In every stage of the disease presence of intramitochondrial paracrystalloids was revealed. Hyalin of alcoholic origin of fibrillar structure was seen in cases of alcoholic hepatitis. By the electronmicroscopic examination of three cases of alcoholic fatty liver a special form of cytoplasmatic paracristalloid inclusion could be seen. This inclusion consists of membranless parallely lying fibrills. Changing the plain of the preparats containing inclusions by the aid of a goniometer the structure of the inclusions appeared in a form of "honey-comb". Inclusion in the question can not be regarded identical neither with intramitochondrial inclusions nor with the fibrills of the so called alcoholic hyalin. Formation and function of these inclusions are as yet unknown.

Adult↗
PubMed1975

Neoplastic response of the avian liver to host infection with strain Mc29 leukosis verus.

Studies were made on the oncogenic response of 3086 young chicks to i.v. inoculation of MC29 avian leukosis virus from blood plasma of previous-passage birds or the supernatant fluid of cultures of chick embryo cells infected with strain MC29. Among the large variety of neoplasms of other tissues previously described, there occurred a high incidence of primary growths of the liver. Pathomorphology of the growths frequently differed greatly in both different hosts and the same bird, but some uniformity of the types of neoplasms was evident in many animals. Despite much variation in histopathology, the large proportion of growths could be grouped in several distinctive categories. Examinations by light and electron microscopy provided evidence of derivation of the tumors by alteration of hepatocytes originating principally in the portal regions as indicated by forms transitional from the parenchymal cells to the cells of the different types of growths. Neoplastic aspects of the growths were evident by infiltration and invasion of adjacent tissues, penetration of blood vessels, transplantability to other avian hosts (described in another report), and metastasis to distant organs including the lung, kidney, and spleen. There was no evidence of tumors arising from the biliary system, and growths of cells resembling the biliary type could be traced to altered hepatocytes. None of the findings suggested conversion of biliary-type cells to hepatocytes. Continued growth resulted in anaplastic and metaplastic changes in cell morphology and structural organization and in the formation of cartilage, osteoid, and sarcoma-like spindle-cell tumors of probable epithelial origin. Development of the growths wasnot associated with cirrhosis, and necrosis was limited to infrequent disseminated, essentially unicellular changes or necrobiosis of small groups of cells. The marked variations in the type of virus-induced growths demonstrated the remarkable capacity of cells morphologically inidistinguishable from the hepatocytes for the most diverse alterations in cell structure and tissue organization. This neoplastic response of hepatocytes to the MC29 strain constitutes the only demonstration thus far of the specific hepatocarcinogenic activity of an avian tumor virus.

Adenocarcinoma↗
PubMed1975

Electron spin resonance spectra of chicken hepatoma and liver tissue.

When studied by electron spin resonance (ESR) (Swartz et al., 1972), tumorous tissues differ from their normal equivalents in the following aspects: 1. In tumourous tissues the signal measured in the vicinity of the g=2 region of the spectrum is of a smaller amplitude or completely absent (Commoner et al., 1954; Commoner, Ternberg, 1961; Mallard, Kent, 1964; Dodd, 1973). 2. Signals attributed to certain paramagnetic metal ions are also decreased (Nebert and Mason, 1963; Swartz et al., 1973). New lines may exceptionally appear, too (Mallard, Kent, 1966). So far mostly human and mammalian tumours (hepatoma and liver tissue) induced by carcinogens have been studied. The aim of the present work was to extend these observations to a fowl tumour of viral origin.

Animals↗