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Biomedical subjects

F B Johnson

Publications and source records attributed to F B Johnson.

At least 91 records · Page 5Linked to original sources
PubMed1981

Pulmonary blue bodies.

Pulmonary blue bodies are intra-alveolar laminated basophilic concretions of uncertain etiology. Blue bodies were studied in lung biopsy specimens from 10 patients. The patients ranged in age from 47 to 69 years and were predominantly men. Three had a history of overt exposure to environmental dusts such as sawdust and asbestos, and two showed occasional ferruginous bodies in the lung, raising the possibility of pneumoconiosis. In eight cases there was interstitial pneumonitis, which resembled desquamative interstitial pneumonia by light microscopy but which was often seen to be patchy and asymmetrically distributed in the lung by chest x-ray examination. Of two other patients, one had xanthogranulomatous inflammation and the other, necrotizing granulomatous inflammation. Light and electron microscopic, histochemical, microchemical, and x-ray diffraction studies of blue bodies were also performed. Calcium carbonate is a major component of blue bodies and is responsible for their birefringence in unstained sections and ready solubility in acid solutions. Blue bodies also contain a mucopolysaccharide matrix and iron. We offer the hypothesis that blue bodies (calcium carbonate) are a product of histiocytic catabolism.

Aged↗
PubMed1981

Calcium oxalate crystal growth in human urinary stones.

Calcium oxalate stones are very common and increasing. Crystal growth is no less important than the crystal nucleation in the pathogenesis of stone formation. The crystal growth was studied in human calcium oxalate stones by a combined electron microscopy and x-ray diffraction. The main mode of weddellite growth was interpenetration twinning of tetrahedral bipyramids. Bipyramids may form as initial crystal seeds, develop from anhedral crystals (crystals which lack flat symmetric faces) of spherular or mulberry shape, develop on the surface of preformed bipyramids by spiral dislocation mechanisms, or develop on whewellite crystal by heterogeneous nucleation and epitaxy. Heterogeneous nucleations of whewellite on weddellite, and calcium apatite on whewellite were also observed. Whewellite grew mainly by parallel twinning. Interpenetration twinning was exceptional. Transformation of anhedral to euhedral (completely bounded by flat faces that are set ar fixed angles to one another) whewellite occurred by parallel fissurations followed by brick wall like stacking of the crystals, while euhedral transformation of weddellite occurred by protrusion of bipyramids frm anhedral crystal surface. Occasionally, an evidence of crystal dissolution was noted. Although an aggregation of crystals is believed to play a pivotal role in stone nidus formation, growth in size of the formed crystals, and twinning and epitactic crystal intergrowth apparently play a significant role in the obstructive urinary stone formation.

Calcium Oxalate↗
PubMed1980

Identification of graphite in tissue sections.

Graphite can be identified in tissue sections by its birefringence, in spite of its black color, and by its resistance to conventional incineration, but it is removed by exposure to radiofrequency-excited oxygen plasma. Amorphous carbon is removed by conventional or radiofrequency incineration.

Birefringence↗
PubMed1980

Long-term effects of diazepam on plasma lipids and atheroma in roosters fed in atherogenic diet.

Long-term effects of diazepam on plasma lipids and atheroma in roosters fed an atherogenic diet have been studied. Our data indicate that long-term administration (8 months) of diazepam (Valium) 0.2 mg/kg orally lowered the plasma cholesterol level when compared to the atherogenic group, but this was not statistically significant (P greater than 0.05). However, at the dose of 0.4 mg/kg of Valium the plasma cholesterol was significantly lowered when compared to the controls on an atherogenic diet (P less than 0.05). Both doses of Valium significantly decreased the incidence and severity of lesions on the endothelial surface of the aorta and coronary artery in roosters fed an atherogenic diet. No changes in plasma triglyceride values were noted. Administration of 0.4 mg/kg of Valium to birds receiving the atherogenic diet produced a small but significant increase of mean, systolic and diastolic blood pressures as compared to the birds receiving an atherogenic diet but no Valium. A similar increase in blood pressure was also noted in the control group on plain mash diet receiving 0.2 mg/kg of Valium. Microscopic examination of the coronary arteries showed that birds on an atherogenic regimen receiving Valium had less atherosclerosis than those not receiving Valium.

Animals↗
PubMed1979

Adenovirus-associated virus structural protein sequence homology.

Adenovirus-associated virus (AAV) structural proteins (VP1, VP2, and VP3) have been examined to determine if areas of sequence homology exist between these three virion proteins. Tryptic and chymotryptic maps have been produced which demonstrate extensive areas of sequence homology common to all three proteins. The amino acid compositions of the proteins were also determined and were found to be very similar. These data are consistent with the hypothesis that all three virion proteins arise either from a common precursor of similar transcripts.

Amino Acid Sequence↗
PubMed1978

Remission of relapsed leukaemia during a graft-versus-host reaction. A "graft-versus-leukaemia reaction" in man?

Acute lymphoblastic leukaemic in two boys relapsed after engraftment of marrow from siblings identical at HLA A, B, and D loci but went into remission during subsequent graft-versus-host reactions without specific anti-leukaemia therapy. Later leukaemic relapse was primarily in extramedullary sites, with little or no involvement of bone-marrow, liver, or spleen. Cytogenetic studies in both cases showed that the relapsed leukaemic blasts were those of the recipients while marrow cells and blood lymphocytes detected during marrow remission originated from the female donors. Blood lymphocytes from one of the recepients kiled. 51Cr-labelled autologous lymphoblast. The prolonged bone-marrow remission in the face of active and even massive extramedullary leukaemia suggests a graft-versus-leukaemia reaction in these two patients.

Adolescent↗
PubMed1978

Silica reaction simulating fibrous histiocytoma.

An unusual foreign body reaction to silica (quartz), resembling fibrous histiocytoma, is described in 7 patients (age range 22 to 71 years). These lesions occurred in the inguinal region (4 cases) or the abdominal wall (3 cases), and in 5 instances were associated with a history of injection at the same site 10 to 41 years previously. Most commonly the injection consisted of the administration of a sclerosing agent for the repair of a hernia. Microscopically these lesions contained broad sheets of histiocytes separated by bands or concentrically lamellated nodules of collagen. Intra- and extra-cellular birefringent crystals, identified by x-ray diffraction as silica (quartz), were present in all cases and served to distinguish this process from a true neoplasm. Although the injection therapy for hernia is now obsolete, it was formerly practiced in the United States with a variety of sclerosing agents including silica (quartz). Since these lesions are often confused with a benign or malignant fibrous histiocytoma it is recommended that fibro-histiocytic lesions associated with a previous hernia or injection at the same site be examined for the presence of silica.

Adult↗
PubMed1977

Sclerosing lipogranuloma of male genitalia. Review of 23 cases.

In 1950 the term "sclerosing lipogranuloma" was introduced to designate a praticular subcutaneous granulomatous reaction that was believed to be a "local reactive process following injury to adipose tissue." Subsequent reports have shown that exogenous lipid injections probably are responsible for this lesion. We have studied 23 cases involving penis, scrotum, spermatic cord, and perineum, nine of which had been previously reported. We have been able to identify paraffin hydrocarbons by means of infrared-absorption spectrophotometry in 21 of these cases. We belive this entity should be redefined as a "local reactive process following injection of exogenous lipids into the subcutaneous tissues." In conventional microscopical sections, the lesion must be differentiated from adenomatoid tumor, sclerosing liposarcoma, and lymphangioma.

Adult↗
PubMed1976

Angiomatosis retinae. An ultrastructural study and lipid analysis.

A nonfamilial case of agiomatosis retinae (retinal hemangioblastoma) was studied by electron microscopy. In addition to the three major types of cells previously identified within the tumor (endothelial cells, pericytes, heavily lipidized stromal cells), fibrous astrocytes in different stages of lipidization were also found. The endothelial cells were fenestrated, providing the basis for the extravasated exudate that is characteristic of the tumor. The pericytes were completely surrounded by casement membranes and displayed no significant lipidization; in a cellular plaque of vasular tissue at the base of the lesion, however, some of the multilaminar pericytes showed evidence of early smooth muscle differentiation. The stromal cells contained abundant lipid vacuoles and a few organelles, and exhibited granular degeneration of cytoplasmic filaments between the lipid vacuoles. There was spotty basement membrane formation where the stromal cells abutted on the vascular elements. No interconversion could be demonstrated among the endothelial cells, pericytes, and stromal cells. A source for the stromal cells was discovered in the early lipisization of fibrous astrocytes. Analysis of the extracted lipid from the tumor by means of infrared spectroscopy, lipid chromatography, and x-ray diffraction disclosed that the lipid was mostly cholestrol stearate, a plasma lipid. It is suggested that in the retinal lesions the leaky (fenestrated) capillaries of the tumor allowed the passive imbibition of plasma lipid by the fibrous astrocytes, leading to their gradual transformation into the fully lipidized stromal cells.

Adult↗
PubMed1976

Multiplication of bovine parvovirus in two cell strains.

Bovine parvovirus has been found to infect two cell strains: buffalo lung fibroblasts and embryonic bovine tracheal cells. Infectivity titers were best determined by plaque assays. Immunofluorescence studies revealed intranuclear staining, whereas complement fixation tests confirmed bovine parvovirus antigen production. These cell strains represent economical and convenient cell types which can be used in studies on bovine parvovirus.

Animals↗