Variations of matrix electrondensity in brain mitochondria.

The configuration of brain mitochondria was compared in situ, after aldehyde perfusion and/or osmium immersion fixation and in isolated fractions of different functional performance. After combined aldehyde perfusion osmium immersion fixation in situ, mitochondria were condensed having a dark matrix. Fractions capable of controlled respiration also consisted of condensed mitochondria. On the contrary, expanded mitochondria with light matrix were brought about by immersion fixation. Fractions consisting predominantly of light mitochondria displayed no controlled respiration. Light matrix and expanded form are therefore regarded as a functionally impaired state of brain mitochondria. The condensed form is thought to be a landmark of good fixation.     

Effect of a single dose of inducers and inhibitors on the rate of synthesis of cytochromes and reductases in liver organelles

Summary Measurement of the effect of drugs on the in vivo rates of synthesis of rabbit liver organelle bound proteins were measured following individual treatments with the inducers phenobarbital, 3-methylcholanthrene and PCB (a mixture of polychlorinated biphenyls) and the inhibitors, cycloheximide, aflatoxin 13, chloramphenicol and actinomycin D. Following their isolation from a homogenate containing the combined livers of ¹⁴C-leucine injected experimental animals and 3H-leucine injected control animals, purified fractions of the following proteins were prepared: microsomal cytochrome b₅, cytochrome P-450, NADH-cytochrome b₅ reductase, NADPH-cytochrome P-450 reductase and proteolipids, outer mitochrondrial membrane cytochrome b5, NADH-cytochrome b₅ reductase and proteolipids, inner mitochrondrial membrane cytochrome c, NADH dehydrogenase and proteolipids, intermitochrondrial membrane cytochrome b₅ and circulating serum albumin.This research was supported by grants from the PSC-BHE Research Award Program of The City University of New York, US Public Health Service Grant SO 7 PRO7132-07 and the Alma Toorock Fund for Cancer Research.     

Ultrastructure of the muscles of the dorsal diaphragm in Locusta migratoria

Summary The alary muscles of Locusta migratoria adults make up the major tissue of the dorsal diaphragm which separates pericardial and perivisceral sinuses in the abdomen. The alary muscles are striated with a sarcomere at rest measuring about 9 m. The Z-line has a staggered-beaded arrangement with A-bands and I-bands readily discernable. Thick myofilaments are surrounded by 10 or more thin filaments. The sarcoplasm has few mitochondria near the area of the Z-line, dyads are present and sarcoplasmic reticulum is poorly developed. Axons which innervate the alary muscle are either contained within invaginated folds of the sarcolemma of the muscle cells or the muscle cells send finger-like projections to envelop the axons. The synaptic terminals contain synaptic vesicles between 40 and 45 nm in diameter and a few electron-dense granules near or less than 170 nm in diameter. Away from synaptic terminals the axon profiles show few or no granules. The axons are accompanied everywhere by well-developed glial cells. This then is not typical neurosecretomotor innervation, however, the presence of electron-dense granules suggests the possibility of peptidergic neurotransmission.     

Preparation and testing of a polyvalent conjugate for direct fluorescent-antibody detection ofLegionella pneumophila

A polyvalent conjugate forLegionella pneumophila, the Legionnaires’ disease bacterium, was prepared by combining monospecific antibodies for the four recognized serogroups ofL. pneumophila. Pure cultures ofL. pneumophila and other bacteria representing 18 genera and 50 species of heterologous organisms were used in evaluating the reagent. A total of 358 specimens from patients suspected of having Legionnaires’ disease also were tested. The results show the practicality and advantages of using a polyvalentL. pneumophila conjugate for screening clinical specimens.