Early averaged electroencephalic responses to clicks in neonates

The early (approximately 8–50 msec latency) averaged electroencephalic responses (AER) to 55 dB HL clicks were elicited from ten normal newborns 36 to 72 hours after birth. Early components were observed in all ten babies with 512 clicks presented at 4.5/sec and 9.0/sec. Mean peak latencies in msec were: Po — 11, Na — 17, Pa — 28, Nb — 35, and Pb — 51. The neonates' early component waveforms closely resemble those of adults. The latency and waveform stability of the early components in neonates and adults support the belief in the primary auditory (lemniscal) system as the mediator of these responses. Furthermore, the repeatability of the early components of the AER makes them more reliable response indices than the late components (approximately 50–400 msec) for audiometry with neonates.

Microsomal lipid peroxidation: morphological characterization

Lipid peroxidation of liver and kidney microsomes induces a highly characteristic sequence of morphological changes typified by detachment of ribosomes and formation of large aggregates of vesicles bound together by dense amorphous material and myelin figure-like debris. The trilaminar structure of the membrane is, however, retained even after complete peroxidation, though its spacing may be increased. The aggregates resemble lysosomal lipofuscin pigment as well as the membranous aggregates of endoplasmic reticulum seen in the liver after carbon tetrachloride poisoning.

Serum transaminases during salicylate therapy

In 8 out of 32 juvenile patients suffering from chronic polyarthritis and in one patient with dermatomyositis, raised transaminase levels were found; the salicylate level was above 35 mg/100 ml in all except one. Reduction in the salicylate level led to a prompt fall in the serum transaminases. Despite a rise in alkaline phosphatase in three cases there was no other evidence of liver dysfunction in the children. Only one of the adults showed a rise in transaminase levels, and she had mild cirrhosis.

Oestrogen and progesterone content of ovarian vein blood of the ewe during the oestrous cycle

Ovarian vein blood was collected by cannulating the ovarian vein of 37 ewes at various times during the oestrous cycle. Plasma progesterone and oestrogen concentrations, determined by chemical methods, showed marked cyclic variations during the cycle. Progesterone was detected at all stages of the cycle. Plasma concentrations were rising rapidly by the 4th day after the onset of oestrus and were maintained at levels greater than 100 μg./100 ml. plasma from the 8th to the 14th day of the cycle. They started to fall about 48 hr. before the onset of oestrus. Very low levels, of the order of 1 μg./100 ml. plasma, were maintained from 24 hr. before to 8–16 hr. after the onset of oestrus.

Oestradiol-17β made up almost all of the oestrogens measured. Oestrone accounted for less than one-eighth of the total oestrogens. Oestradiol first appeared on the 14th day of the cycle and its concentration rose rapidly during the immediate pre-oestrous period to reach peak levels of over 100 ng./100 ml. plasma 20–30 hr. before the onset of oestrus. They then rapidly declined and by 24 hr. after the onset had reached almost non-detectable levels.

The ovarian secretion rate of progesterone was calculated to be 3·5 mg./day at mid-cycle and the total secretion of oestradiol during the follicular phase was 4·9 μg. Blood flow through the cannula was not affected by either the stage of cycle at which blood was collected or by the structure (corpus luteum or Graafian follicle) in the ovary bled.

Further observations on the Kober colour and Ittrich fluorescence reactions in the measurement of oestriol, oestrone and oestradiol

Higher temperatures allow lower sulphuric acid concentrations and shorter heating times to be used in the Kober colour reaction for oestrogens. A one-stage reaction which is completed in 5 min. at 120° is described for oestrone and oestradiol, and a two-stage reaction which requires two periods of heating for 5 min. at 120° is described for oestriol. The conditions were applied to the Ittrich fluorescence procedure. A spectrophotofluorimetric correction was developed in which fluorescence was measured at wavelengths for excitation and emitted light near the optima for the oestrogens and at another combination at which the oestrogens produced virtually no fluorescence whereas that of impurities was not diminished. Extraction, centrifugation and fluorimetry were performed in specially designed cells. The sensitivity is 0·05–0·1 ng./sample with a linear response up to 300 ng. and a precision better than 4% in the range 1·0–100 ng.