Na is essential for activation of the inseminated sea urchin egg

The presence of at least 2.5 mM Na during the first several min after insemination is required for the activation of sea urchin eggs. Of those chemical species examined that exist entirely as cations, and which did not activate the unfertilized egg, only Li substitutes for Na. Ammonium and other amines, with pKa values between 9 and 10.8, in the complete absence of Na (a) can induce nuclear activation of unfertilized eggs, and (b) permit the development of the early fertilized egg through the stage that normally requires Na.     

Barium enema, proctosigmoidoscopy and upper gastrointestinal series in the preoperative evaluation of the cancer patient

Charts of 566 patients admitted to the Surgery Branch, National Cancer Institute over a five year period were reviewed. Routine upper gastrointestinal series was performed in 453 patients; barium enemas in 490; and proctosigmoidoscopies in 342. Upper gastrointestinal series detected no metastases or second primary malignancies but delineated the extent of large intra-abdominal tumors. Barium enema and proctosigmoidoscopy together revealed three unsuspected primary colonic tumors (1.2% in patients over 50 years of age). Sigmoidoscopy and examination of the stool for occult blood would have detected the same patients. Barium enema may be limited to surgical cancer patients in whom the extent of local tumor invasion is to be defined and to older patients in whom colonic tumors are suspected. Neither UGIS nor barium enema appear to be of value as a routine preoperative screening test in surgical cancer patients.     

Comments on CSUN program

The somitic mesoderm of the wing level was replaced in a two-day chick embryo by quail somitic mesoderm obtained from the level of the wing, the leg or the neck. The musculature of the host's wing on the operated side was exclusively or almost exclusively constituted by quail cells, whereas the skeleton, the dermis, the tendons and the muscular envelopes were formed by chick cells. This result demonstrates that, under the present experimental conditions, the wing musculature is originated from the somitic mesoderm of any level of the cephalocaudal axis.     

Cerebral Ischemia during carotid endarterectomy with severe but reversible changes

Electroencephalographic monitoring of a patient during carotid endarterectomy demonstrated severe ipsilateral voltage suppression with preservation of rhythms when the common carotid artery was clamped. Because the atheromatous plaque extended almost to the base of the skull, it was impossible to insert a shunt. Occlusion time was 19 minutes. After carotid flow was re-established, there was a rapid recovery of voltage. The patient awoke with a profound hemiparesis, but this cleared almost completely within a week. The EEG changes indicated severe ischemia, but, though function was transiently impaired, there was no apparent cerebral necrosis. This case represents the most severe yet reversible episode of ischemia during carotid clamping reported to date. Preservation of EEG rhythms, even in the face of voltage suppression, may have been a favorable sign.     

Fixation of canine tendons to metal

For the purpose of developing a method to attach tendons directly to the prosthesis, canine supraspinatus tendons were attached in vitro to a metallic surface, using 3 different fixation devices: a spiked polyacetal washer (Synthes), a spiked soft tissue fixation plate (Synthes), and a newly designed Enhanced Tendon Anchor (ETA), which straddled the tendon with interlocking spikes oriented at a 20-degree angle. 2 methods were used: 1) the tendon was fixed directly to the metallic surface, or 2) a bone block containing the tendon insertion was fixed to the metallic surface. The specimens were tested for initial fixation strength in tension to failure; intact bone-muscle-tendon-bone units were used as controls. Bone block fixations were stronger than direct tendon fixations when the spiked washer or the ETA was used; this was not true of the fixation plate. The ETA was stronger than the other techniques in ultimate strength in both direct tendon fixation and bone block fixation. The soft tissue fixation plate was found to be weaker than the other techniques in bone block fixation.