Differentiation among strains of goat mycoplasma by incident light immunofluorescence

Antigenic differentiation between strains of goat mycoplasma was studied by direct fluorescent antibody reactions employing incident (vertical) ultraviolet light. Agar colonies of the mycoplasma grown in petri dishes were fixed by alcohol in situ, and stained with conjugated globulin before examination with ultraviolet light. The fluorescent antibody (FA) conjugate against Vom strain of Mycoplasma mycoides var. capri was Vom strain-specific, no cross reaction with Mexico, Connecticut, or Maryland strains. Similarly, the Mexico strain conjugate was specific for colonies of Mexico, and did not cross with the Vom, strain. Additionally, the conjugate of the PG-2 strain of Mycoplasma agalactiae, which was specific for the colonies of PG-2 was refractory for the strain #99 of M. agalactiae. It was therefore possible to utilize an immunofluorescent technique (incident ultraviolet light) to demonstrate differences among strains of M. mycoides var. capri and M. agalactiae.

A satisfactory medium and technique for the mass cultivation of Sphaerophorus necrophorus

A modified casitone (MC) medium was used successfully in the cultivation of the pathogenic non-sporing anaerobe, Sphaerophorus necrophorus. The medium is suitable for various physiological, biochemical, and immunological assays of the test organism and obviates the need for frequent passage to susceptible animal hosts. When cultured under a 5% CO2–95% N2 atmosphere at 37 °C, the logarithmic phase of growth occurred at 18–24 h postinoculation. A detailed description of an inexpensive apparatus and the technique for the large-scale production of S. necrophorus is included.

The localization of catecholamine fluorescence to dog hypothalamic neuromelanin-bearing neurons

By use of histochemical methods, a survey has been made of the localization of catecholamine to neuronal perikarya and processes in relation to neuromelanin accumulation in neuronal perikarya in the hypothalamus of dogs of various ages. Catecholamine was visualized in sections as a green fluorescence by means of the formaldehyde gasinduced fluorescence method of Falck and Hillarp. Neuromelanin, if also present in these sections, was identified on the basis of its characteristic optical properties as visualized through bright field, dark field and fluorescence microscopy. The study demonstrated a sequential replacement of temporally diminishing catecholamine fluorescence by accumulating neuromelanin within the same neuronal perikaryon wherein they were found to overlap during part of the 1st year of life. Catecholamine in processes in the perifornical region of the hypothalamus, where the neuromelanin-accumulating neurons were situated, was also diminished with age. If neuromelanin was extensively exposed to ultraviolet light, as required for viewing and for photography, the initially nonfluorescent pigment was converted to one which appeared fluorescent yellow. The larger and older accumulations of neuromelanin were more resistant to this induced alteration than the smaller and younger accumulations. These results support the concept that catecholamine contributes to the formation of neuromelanin although they do not exclude the possibility that the presence of both these substances in the same perikaryon is entirely coincidental.

Improved staining of extracellular polymer for electron microscopy: examination of Azotobacter, Zoogloea, Leuconostoc, and Bacillus

Phase contrast, ultraviolet microscopy, and freeze-etching were used to determine the amount of exocellular polymer surrounding unfixed cells of four genera of bacteria: Azotobacter vinelandii, Zoogloea ramigera, Leuconostoc mesenteroides, and an acid-tolerant, floc-forming Bacillus species. Thin-sectional electron microscopy was employed to measure the effectiveness of a modified ruthenium red staining method. The results obtained with this modification of ruthenium red staining technique were compared to results obtained when previously proposed ruthenium red methods of fixation were employed. The results of these relations were then compared to the amounts of exocellular material as determined with phase-contrast microscopy, ultraviolet microscopy, and freeze-etching. The data obtained indicate that improved fixation of exocellular polymer is achieved when cells are pretreated with ruthenium red as described herein. In addition, the modified methods also reveal cytological detail not apparent when other methods of ruthenium fixation are employed.

A study of the ultraviolet microscopy of renal vascular diseases

Newer methods of microscopy promise to provide a better insight into the physicochemical aspects of tissue structure than has been attained by conventional technics. An exploratory investigation is reported of the ultraviolet absorptive behavior of renal arterioles and arteries, employing the Polaroid color-translating ultraviolet microscope. In the arteriolar necrosis accompanying malignant hypertension and renal periarteritis nodosa changes of particular interest were observed.

Ultraviolet microscopy of glomerular diseases

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