Definitive evidence for the existence of tight junctions in invertebrates.

Extensive and unequivocal tight junctions are here reported between the lateral borders of the cellular layer that circumscribes the arachnid (spider) central nervous system. This account details the features of these structures, which form a beltlike reticulum that is more complex than the simple linear tight junctions hitherto found in invertebrate tissues and which bear many of the characteristics of vertebrate zonulae occludentes. We also provide evidence that these junctions form the basis of a permeability barrier to exogenous compounds.

Acute renal failure after total hip replacement.

Eight of forty-one patients undergoing total hip replacement experienced acute but not fatal renal failure postoperatively. All forty-one patients received transfusions of frozen blood and albumin and their wounds were irrigated with a bacitracin-neomycin-polymyxin solution. All subsequently had some relative hypotension.

Gliding edge dislocations in proteins as a mechanism for active ion transport.

A mechanism for the translocation of ions across biological membranes is proposed in which transconformational changes occur in the membrane-bound ion pump. In particular, it is suggested that such conformational changes are effected by means of the propagation of crystal defects in the form of edge-dislocation glide.

Metal-filled resin composites. II.

Various particulate materials were combined with a BIS-GMA resin, and the resulting composites were evaluated. The fillers prevented, altered, had no apparent effect, or accelerated polymerization. Coupling agents also influenced polymerization.

Gliding edge dislocations and flipping in the conformational change of helical proteins.

The general problem of transconformation of one helical form of protein to another is considered from a topological point of view. A notation is presented which reflects the topology of the bonding. Any helix belongs to one of two geometrical classes, the positive and negative classes.

Uptake of bone imaging agents by diffuse pulmonary metastatic calcification.

Three cases of diffuse lung uptake of the bone scanning agent 99mTc diphosphonate, which appears to reflect metastatic pulmonary calcification, are described. Each patient had hypercalcemia and renal failure. Clinical features common to patients with this scan pattern were ascertained from a review of the literature.

An evaluation of techniques for finishing margins of gold inlays.

The following conclusions on finishing margins of gold inlays were reached: 1. Instruments should be rotated perpendicular to the margin from gold to enamel. 2.

Some observations on the quality control testing of Clostridium chauvoei vaccines.

Agglutination tests are not suitable for the estimation of the protective antibody level in the sera of vaccinated animals and should not be used for the quality control testing of blackleg vaccines. Some highly virulent strains of Cl. chauvoei are only effectively protected against by vaccines containing cells with a heat labile protective antigen in addition to the heat stable antigen common to all cells of Cl.

Porcelain occlusal posterior fixed partial dentures.

A method for using the functionally generated-path technique to fabricate full occlusal porcelain-fused-to-metal fixed partial dentures and crowns has been described. Proper use of this technique in carefully selected patients should eliminate occlusal adjustments and the concomitant polishing and glazing that are often necessary before the restoration can be permanently cemented.

Teaching of formal courses by medical librarians.

Medical education should include formal course work on the use of the medical library. The formal teaching effort of medical librarians at the University of Tennessee Center for the Health Sciences is described. Three courses on the use of the library are offered to graduate students in basic medical sciences, dentistry, and pharmacy and to undergraduate students in medical records administration.