Pseudocyst of the pancreas due to trauma: spontaneous intraperitoneal rupture

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The Imaging Photopolarimeter Experiment on Pioneer 10

A 2.5-centimeter telescope aboard Pioneer 10 is capable of making two-dimensional spin-scan maps of intensity and polarization in red and blue light at high spatial resolution. During the recent flyby of Jupiter, a large quantity of imaging and polarimetric data was obtained on Jupiter and the Galilean satellites over a wide range of phase angles.

Femoro-femoral cross-over grafts. A report of 7 cases

Seven patients who had femoro-femoral by-pass grafts are reported and the results are noted.

The value of the operation in poor-risk patients with unilateral disease and ischaemic rest pain is confirmed. It is suggested that the indications for doing this procedure could be extended.

Closed trauma to the popliteal vessels

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Sector mastectomy in selected cases of breast cancer

Seventy-seven patients with stage I or II carcinoma of the breast, usually less than 5 cm. in diameter and more than 2·5 cm. from the nipple, were treated by sector mastectomy and postoperative radiotherapy. Fourteen subsequently required simple mastectomy for local recurrence. The 5-year survival rate was 71 per cent; the 10-year rate 50 per cent. The cosmetic result was good in the majority of cases.

Electrotonic coupling between neurones in the rat mesencephalic nucleus

Electrical stimulation of the trigeminal nerve evokes a ;short latency depolarization' (SLD) in the first order sensory neurones of the mesencephalic nucleus (MSN) of the Vth nerve in the rat. A series of experiments suggesting ;electrotonic coupling' as the mechanism for this SLD is provided.1. Electrical activity of MSN neurones was recorded intracellularly as action potentials were conducted from the periphery (somatopetally) to the masticatory nucleus. Typical sequential invasion of the initial segment and somatic region (IS-S) of the neurones was seen. The somatopetal activation of MSN neurones was characterized by the brevity, short refractoriness, high safety factor (IS-S), and short after-hyperpolarization of the spike potential.2. In twenty-three (10.5%) of the penetrated neurones, stimulation at levels subthreshold for somatopetal activation uncovered a SLD with a mean latency of 180 musec.3. The SLDs were found to be all-or-none in nature, and to have constant amplitude and latency for a given cell, plus a short half decay time.4. Hyperpolarization of a MSN neurone through the recording electrode produced a blockage of the IS-S spike and revealed M-spikes and SLDs which could be clearly separated, in every instance, as distinct all-or-none components. The amplitude of the SLD was found to be insensitive to the level of membrane potential within the ranges tested.5. In fifteen neurones the SLD generated action potentials which were conducted somatofugally as shown by their collision with somatopetally conducted action potentials in the same cell. The lack of collision between the SLD and somatopetal spikes demonstrated the independent origin of these two potentials.6. The independence of the SLD from the somatopetal invasion of the cell was also demonstrated by collision of a somatofugal action potential following direct stimulation through the recording micro-electrode and a somatopetal spike following trigeminal stimulation.7. Two possible mechanisms are considered for the genesis of the SLD: chemical synaptic transmission and electrotonic coupling between neighbouring cells. The conclusion is drawn that SLDs must be generated by the latter mechanism.