Riboflavin and mouse hepatic cell structure and function. II. Division of mitochondria during recovery from simple deficiency

Mice which had been on a riboflavin-free diet for 6-8 wk were given daily intraperitoneal injections of riboflavin. The hepatic mitochondria, which in the deficient animals were greatly enlarged, were restored to normal dimensions within 3 days. Normalization of the mitochondrial population was brought about by division of the giant organelles. Dividing mitochondria were characterized by a membranous partition separating the inner compartment into two distinct chambers. Such organelles showed varying degrees of pinching at the level of the partition. The most common site of partition formation was at the base of a small mitochondrial bud. During the 1st day of recovery, dividing mitochondria were so common that they could be easily found in mitochondrial pellets. Injection of riboflavin into normally nourished mice also produced an apparent increase in the frequency of dividing mitochondria in the liver cells.

Induction of brain D(--)-beta-hydroxybytrate dehydrogenase activity by fasting

D(m)-beta-hydroxybutyrate dehydrogenase activity is very low in normal adult rat brain; but during fasting it increases severalfold in parallel with the ketosis. The increase may represent part of a mechanism by which the brain adapts to changing patterns of substrate supply during starvation.

Optimizing the operating parameters of infrared spectrometers

In order to achieve best results with modern ir spectrometers, users must take considerable care to optimize the setting of the slit program, response time, gain, and scan time. In this paper, explicit recommendations are given for carrying out such adjustments in a logical and self-consistent manner. First, a set of conditions is derived for the recording of general purpose spectra. From this starting point, settings may be modified to record spectra under the following special conditions: low noise level, limited optical energy, high resolution, and rapid scanning. Proper use of the scan speed suppression control is discussed.

A Series of Ten Cases of Complete Rupture of the Uterus

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