Isolation and Characterization of Desulfovibrio dechloracetivorans sp. nov., a Marine Dechlorinating Bacterium Growing by Coupling the Oxidation of Acetate to the Reductive Dechlorination of 2-Chlorophenol

Strain SF3, a gram-negative, anaerobic, motile, short curved rod that grows by coupling the reductive dechlorination of 2-chlorophenol (2-CP) to the oxidation of acetate, was isolated from San Francisco Bay sediment. Strain SF3 grew at concentrations of NaCl ranging from 0.16 to 2.5%, but concentrations of KCl above 0.32% inhibited growth. The isolate used acetate, fumarate, lactate, propionate, pyruvate, alanine, and ethanol as electron donors for growth coupled to reductive dechlorination. Among the halogenated aromatic compounds tested, only the ortho position of chlorophenols was reductively dechlorinated, and additional chlorines at other positions blocked ortho dechlorination. Sulfate, sulfite, thiosulfate, and nitrate were also used as electron acceptors for growth. The optimal temperature for growth was 30°C, and no growth or dechlorination activity was observed at 37°C. Growth by reductive dechlorination was revealed by a growth yield of about 1 g of protein per mol of 2-CP dechlorinated, and about 2.7 g of protein per mole of 2,6-dichlorophenol dechlorinated. The physiological features and 16S ribosomal DNA sequence suggest that the organism is a novel species of the genus Desulfovibrio and which we have designated Desulfovibrio dechloracetivorans. The unusual physiological feature of this strain is that it uses acetate as an electron donor and carbon source for growth with 2-CP but not with sulfate.     

Semi-automated imaging system to quantitate Her-2/neu membrane receptor immunoreactivity in human breast cancer.

BACKGROUND: Immunocytochemical methods for quantitating Her-2/neu immunoreactivity rest on subjective semi-quantitative interpretations with resulting interobserver, intraobserver, and fatigue variability. METHODS: To standardize and quantitate measurements of Her-2/neu immunoreactivity, we created epithelial-recognition and specific membrane-recognition algorithms, which could image breast cancer cells against a background of stroma, compartmentalize the cancer cell into nucleus, cytoplasm and membrane, and quantitate the degree of Her-2/neu membrane immunoreactivity based on both gray scale intensity and RGB colorimetric determinations. Image acquisition utilized either scanner or microscope with attached camera with a resolution of 20 pixels/10 microm. Areas of 150 whole slides were screened and the regions of interest manually selected for image processing. Three hundred TMA cores were directly processed. Images were acquired by jpg conversion of svs virtual slides or direct jpg photomicrograph capture. Images were then assessed for quality and processed. RESULTS: The digital algorithms successfully created a semi-automated imaging system whose algorithm-based ordinal values for Her-2/neu both strongly correlated with the subjective measurements (intraclass correlation: 0.84; 95% confidence interval: 0.79-0.89) yet exhibited no run variability. In addition, the algorithms generated immunocytochemical measurements of Her-2/neu on an expanded continuous scale, which more reliably distinguished true Her-2/neu positivity from true Her-2/neu negativity (determined by FISH) than subjective or algorithmic ordinal scale measurements. Furthermore, the continuous scale measurements could better resolve different levels of Her-2/neu overexpression than either subjective or algorithmic ordinal interpretation. Other semi-automated analysis systems have been used to measure Her-2/neu and other cellular immunoreactivities, but these either have required proprietary hardware or have been based on luminosity differences alone. In contrast, our algorithms are independent of proprietary hardware and are based on not just luminosity but also many other imaging properties including epithelial recognition and membrane morphology. CONCLUSION: These features provide a more accurate, versatile, and robust imaging analysis platform.     

THE FINE STRUCTURE OF NEURONS

1. Thin sections of representative neurons from intramural, sympathetic and dorsal root ganglia, medulla oblongata, and cerebellar cortex were studied with the aid of the electron microscope. 2. The Nissl substance of these neurons consists of masses of endoplasmic reticulum showing various degrees of orientation; upon and between the cisternae, tubules, and vesicles of the reticulum lie clusters of punctate granules, 10 to 30 mµ in diameter. 3. A second system of membranes can be distinguished from the endoplasmic reticulum of the Nissl bodies by shallower and more tightly packed cisternae and by absence of granules. Intermediate forms between the two membranous systems have been found. 4. The cytoplasm between Nissl bodies contains numerous mitochondria, rounded lipid inclusions, and fine filaments.     

SYNAPSES IN THE CENTRAL NERVOUS SYSTEM

A number of different synapses have been described in the medulla, cerebellar cortex, and cerebral cortex of the rat. All of these possess the same fundamental fine structure as follows: 1. Close apposition of the limiting membranes of presynaptic and postsynaptic cells without any protoplasmic continuity across the synapse. The two apposed membranes are separated by a cleft about 200 A wide, and display localized regions of thickening and increased density. 2. The presynaptic expansion of the axon, the end-foot or bouton terminal, contains a collection of mitochondria and clusters of small vesicles about 200 to 650 A in diameter. Although the significance of these structures in the physiology of the synapse is still unknown, two suggestions are made: that the mitochondria, by means of the relation between their enzymatic activity and ion transport, participate in the electrical phenomena about the synapse; and that the small synaptic vesicles provide the morphological representation of the prejunctional, subcellular units of neurohumoral discharge at the synapse demanded by physiological evidence.     

EVALUATION OF EXPOSURE TREATMENT OF BURNS

For purposes of comparison with the occlusive dressing method of treating burns, the exposure method was used in 30 cases—16 of first and second degree and 14 of third degree. Attempt was made to simulate the conditions which might be expected to prevail in mass treatment of burned patients—inadequate personnel and materials. Elaborate measures to immobilize burned areas were not employed.Healing of first and second degree burns was natural and the results satisfactory without further treatment. In third degree burns, skin grafting was necessary after the eschar was removed. Cracking of the eschar several days before time to remove it in some cases of third degree burns necessitated use of occlusive dressings in the last few days before skin grafting was done.The exposure method is considered valuable in circumstances in which saving of time, material and personnel is indicated. Generally it is not suitable for treatment of encircling burns of the trunk or extremities, since maintaining the integrity of the eschar is extremely difficult in such situations.