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Biomedical subjects

G Musil

Publications and source records attributed to G Musil.

14 recordsLinked to original sources
PubMed1985

Surface ultrastructure of the gill arch of the killifish, Fundulus heteroclitus, from seawater and freshwater, with special reference to the morphology of apical crypts of chloride cells.

The surface ultrastructure of the gill arches of the killifish, Fundulus heteroclitus, adapted to seawater or freshwater, was found to be similar to that reported for other euryhaline teleosts. Two rows of gill filaments (about 42 filaments per row) extended posterolaterally, and two rows of gill rakers (about 10 rakers per row) extended anteromedially from each arch. Leaf-like respiratory lamellae protruded along both sides of each filament, from its base to its apex. The distributions, sizes, and numbers of various surface cells and structures were also determined. All surfaces were covered by a mosaic of pavement cells, which measured about 7 X 4 microns and exhibited concentrically arranged surface ridges. Taste buds were especially prominent on the rakers and the pharyngeal surfaces of the first and second gill arches, but were often replaced by horny spines on the third and fourth gill arches. Apical crypts of chloride cells occurred mostly on the surfaces of the gill filaments adjacent to the afferent artery of the filament. In seawater adapted killifish, crypts resembled narrow, deep holes along the borders of adjacent pavement cells, had openings of about 2 microns2, and occurred at a frequency of about 1 per 70 microns2 of surface area. In freshwater fish, the crypts usually had larger openings (about 10 microns2), occurred less frequently (1 per 123 microns2), and exhibited many cellular projections in their interiors. Changes in crypt morphology may be related to the ion transport function of chloride cells.

Adaptation, Physiological↗
PubMed1984

Metastasis of bronchogenic carcinoma to the skin involved by melanoma.

In a 52-year-old man, a cutaneous malignant melanoma developed concurrently with an adenocarcinoma of the right lung. The latter disseminated widely, and autopsy disclosed that it had also metastasized to the dermal tissue involved with the melanoma. Because it was not a metastasis into the substance of the melanoma, it was classified as an unusual type of "collision tumor" rather than a "cancer-to-cancer" metastasis.

Carcinoma, Bronchogenic↗
PubMed1984

Knee arthropathy in ochronosis: diagnosis by arthroscopy with ultrastructural features.

Knee arthroscopy in a patient with undiagnosed chronic monoarticular arthritis revealed dark pigmentation of the snyovium; synovial biopsy revealed histologic and ultrastructural features characteristic of ochronosis. Synovial fluid (SF) was non-inflammatory, without pigmented shards of cartilage; calcium pyrophosphate dihydrate crystals were absent in both the SF and biopsy specimen. Homogentisic acid was detectable in the urine by thin layer chromatography, and asymptomatic spondylosis with intervertebral disc calcification was found. The negative family history, lack of mucocutaneous pigmentation and failure of the urine to spontaneously darken obscured the diagnosis, which was easily made by arthroscopy.

Arthritis↗
PubMed1983

Staphylococcal septic arthritis presenting as acute flare of pseudogout: clinical, pathological and arthroscopic findings with a review of the literature.

A patient with primary hyperparathyroidism and known pseudogout presented with an acute flare of the right knee. Gram stain was negative, and many intracellular calcium pyrophosphate dihydrate (CPPD) crystals were seen by both compensated polarized light and transmission electron microscopy. Cultures grew Staphylococcus aureus; the joint was probably seeded by an antecedent skin infection, with enzymatic "strip mining" precipitating acute pseudogout. The patient was refractory to therapy with oxacillin, naproxen, intravenous colchicine, and closed drainage. Arthroscopic debridement with insertion of drainage tubes led to rapid improvement, and offers an alternative to arthrotomy in septic knee arthritis unresponsive to closed drainage.

Aged↗
PubMed1970

Action of penicillin G on endosymbiote lambda particles of Paramecium aurelia.

The kinetics of loss from the cytoplasm and changes in ultrastructure of symbiont lambda particles after treatment of axenically cultivated lambda-bearing Paramecium aurelia with penicillin G was investigated. Low concentrations (1 to 2 unit/ml) of the antibiotic caused many particles within the cell to become filamentous; high concentrations (2,000 unit/ml) caused lysis of the particles without noticeably affecting the protozoan. The ED(50) value (2 to 3 unit/ml) was within the range of values found to cause lysis of many gram-negative bacteria. Rapidly dividing lambda were more vulnerable to the action of the antibiotic than slowly dividing particles. Nondividing particles were not affected by exposure to the antibiotic. Ultrastructural changes observed in lambda during lysis by penicillin G were consistent with the view that penicillin interferes with the synthesis of a vital component of the cell envelope of the particle, possibly a peptidoglycan similar to that found in the cell walls of bacteria. The deoxyribonucleic acid of lambda was dispersed throughout the particle as electron dense fibers enclosed within electron transparent areas. The cell envelope appeared to consist of at least two morphologically distinguishable layers, an inner layer homologous to the plasma membrane of bacteria and an outer layer homologous to the bacterial cell wall. Lambda may be regarded as a randomly distributed population of bacteria growing and dividing synchronously within the collective cytoplasm of its protozoan host.

Animals↗