Circulatory Assistance with a Cardiac Allograft after Exclusion of the Canine Left Ventricle

Cardiogenic shock after myocardial infarction still carries a high mortality despite use of intraaortic counterpulsation and early surgical revascularization. An experimental canine model of left ventricular exclusion and circulation support was developed by closing the mitral valve and by interposing “in series” a cardiac allograft between pulmonary and systemic circulations. This preparation was able to support the recipient circulation after cardiopulmonary bypass in 25 animals. In 16 dogs the graft sustained life for from 1 to 32 days.It is hypothesized that such left ventricular assistance could be used to maintain the life of patients in cardiogenic shock after myocardial infarction. By providing maximal left ventricular decompression and improvement of the native coronary perfusion, this method may reverse the metabolic imbalance responsible for extension of the infarction, thereby salvaging muscle that is in jeopardy but still viable.     

Neuropathic joint disease (Charcot joints) in Waldenström's macroglobulinemia with amyloidosis

A 51 year old man with a monoclonal elevation of serum macroglobulin, generalized osteoporosis and infiltration of the marrow with lymphocytoid plasma cells is described. He also had nephrotic syndrome due to para-amyloid deposition and severe peripheral neuropathy. A dramatic sequela of the neuropathy, and not previously reported in plasma cell dyscrasias, was severe neuropathic joint destruction (Charcot joints).     

The oxygen free radical system: potential mediator of myocardial injury

The sequential univalent reduction of oxygen gives rise to very reactive intermediate products including superoxide anion radical, hydrogen peroxide and free hydroxyl radicals. Normally, the tissue concentration of these intermediate products of oxygen is severely limited; however, if oxygen free radicals are produced in excess of the capacity of the tissues to eliminate them, they may cause serious damage. The biochemistry and possible sources of free radical generation in animal models of ischemic/reperfusion injury are reviewed. The ability of scavengers of oxygen free radicals to improve mechanical, mitochondrial and sarcoplasmic reticulum function in animal models of ischemic/reperfusion injury suggests that oxygen free radicals are partly responsible for myocardial injury in these models. Future research should be directed at establishing the relevance of oxygen radical-mediated myocardial injury in the experimental setting to analogous clinical situations.     

Measurement of red cell velocity with a two-slit technique and cross-correlation: Use of reflected light,and either regulated dc or unregulated ac power supplies

The data illustrate red cell velocity values obtained from microvessels of brain and muscle by utilizing a two-slit technique and cross-correlator in settings employing reflected light. Similarities are shown between these data and data obtained or reported from transilluminated vessels. These similarities include relative independence of apparent centerline velocities on the plane of focus, and relatively low ratios of velocities at the center to velocities near the wall. It is shown, in addition, that accurate velocity measurements can be made utilizing a nonregulated ac power supply, although it cannot be stated that such measurements could be obtained in circumstances other than those described.     

Enigmatic,ultrasmall, uncultivated Archaea

Metagenomics has provided access to genomes of as yet uncultivated microorganisms in natural environments, yet there are gaps in our knowledge—particularly for Archaea—that occur at relatively low abundance and in extreme environments. Ultrasmall cells (<500 nm in diameter) from lineages without cultivated representatives that branch near the crenarchaeal/euryarchaeal divide have been detected in a variety of acidic ecosystems. We reconstructed composite, near-complete ~1-Mb genomes for three lineages, referred to as ARMAN (archaeal Richmond Mine acidophilic nanoorganisms), from environmental samples and a biofilm filtrate. Genes of two lineages are among the smallest yet described, enabling a 10% higher coding density than found genomes of the same size, and there are noncontiguous genes. No biological function could be inferred for up to 45% of genes and no more than 63% of the predicted proteins could be assigned to a revised set of archaeal clusters of orthologous groups. Some core metabolic genes are more common in Crenarchaeota than Euryarchaeota, up to 21% of genes have the highest sequence identity to bacterial genes, and 12 belong to clusters of orthologous groups that were previously exclusive to bacteria. A small subset of 3D cryo-electron tomographic reconstructions clearly show penetration of the ARMAN cell wall and cytoplasmic membranes by protuberances extended from cells of the archaeal order Thermoplasmatales. Interspecies interactions, the presence of a unique internal tubular organelle [Comolli, et al. (2009) ISME J 3:159–167], and many genes previously only affiliated with Crenarchaea or Bacteria indicate extensive unique physiology in organisms that branched close to the time that Cren- and Euryarchaeotal lineages diverged.     

High-molecular weight dextran in human infertility surgery

The use of intraperitoneal 32% high-molecular weight dextran 70 (Hyskon, Pharmacia Inc.) has been reported to reduce the incidence of surgical adhesions in several species. The present study was undertaken to determine the effect of 32% dextran 70 in human females who underwent major abdominal infertility operations. Adhesions were quantitated by means of standardized objective criteria in 44 women in a prospective, randomized, double-blind study, and reevaluated at second-look laparoscopy approximately 6 weeks later. The mean change in the adhesion score for all patients in the 32% dextran 70 group (n = 23) was -2.57 units (i.e., clinically "improved") versus +2.41 units (i.e., clinically "worsened") in the control group (n = 21), p = 0.016. For the subgroup of patients who underwent lysis of adhesions, the 32% dextran 70 group (n = 17) improved significantly, whereas the control group (n = 12) tended not to improve with careful technique alone (-4.2 units versus +0.3 unit, p less than 0.05). These data indicate that 32% dextran 70 not only significantly reduces the formation of adhesions overall in human infertility operations, but also is highly effective in reducing the reformation of adhesions after lysis.