Biologically derived epicardial patch induces macrophage mediated pathophysiologic repair in chronically infarcted swine hearts

There are nearly 65 million people with chronic heart failure (CHF) globally, with no treatment directed at the pathologic cause of the disease, the loss of functioning cardiomyocytes. We have an allogeneic cardiac patch comprised of cardiomyocytes and human fibroblasts on a bioresorbable matrix. This patch increases blood flow to the damaged heart and improves left ventricular (LV) function in an immune competent rat model of ischemic CHF. After 6 months of treatment in an immune competent Yucatan mini swine ischemic CHF model, this patch restores LV contractility without constrictive physiology, partially reversing maladaptive LV and right ventricular remodeling, increases exercise tolerance, without inducing any cardiac arrhythmias or a change in myocardial oxygen consumption. Digital spatial profiling in mice with patch placement 3 weeks after a myocardial infarction shows that the patch induces a CD45pos immune cell response that results in an infiltration of dendritic cells and macrophages with high expression of macrophages polarization to the anti-inflammatory reparative M2 phenotype. Leveraging the host native immune system allows for the potential use of immunomodulatory therapies for treatment of chronic inflammatory diseases not limited to ischemic CHF.

Critical care voices: including sexual counseling in clinical practice

We asked four practicing critical care nurses for tips on how they include sexual counseling in their practice with MI patients and families. Each one has developed a different, but effective, approach.

DNA sequence analysis of spontaneous mutations in the SUP4-o gene of Saccharomyces cerevisiae

A collection of 196 spontaneous mutations in the SUP4-o gene of the yeast Saccharomyces cerevisiae was analyzed by DNA sequencing. The classes of mutation identified included all possible types of base-pair substitution, deletions of various lengths, complex alterations involving multiple changes, and insertions of transposable elements. Our findings demonstrate that at least several different mechanisms are responsible for spontaneous mutagenesis in S. cerevisiae.

DNA sequence analysis of the mutational specificity of u.v. light in the SUP4-o gene of yeast

We have characterized mutations induced in the SUP4-o gene of Saccharomyces cerevisiae by u.v. irradiation. Mutants were selected following treatment with 60 J/m2 u.v. light which reduced cell survival to 10% and increased the SUP4-o mutation frequency 100-fold above background. DNA sequence analysis of 120 mutants revealed that u.v. induced all types of base substitutions, although transitions, in particular G:C----A:T events predominated. In addition, a small number of single base pair deletions and double mutations, occurring in tandem or separated by a few base pairs, were recovered. The base pair substitutions were not distributed randomly in the SUP4-o gene and, with one exception, were all located at sites of adjacent pyrimidines, suggesting that they were targeted by u.v. photolesions. A substantial fraction of the mutations were detected at hotspots for u.v. mutagenesis. The majority of changes occurred at the 3' base of dipyrimidine sequences where both cyclobutane dimers and [6-4]-photoproducts could form. Approximately one-third of the induced base substitutions were found at potential pyrimidine dimer sites where [6-4]-photoproducts would be expected to occur rarely. The possible origins of the induced mutations and the role of cyclobutane dimers as premutational u.v. lesions in yeast are considered.

Development of a yeast system to assay mutational specificity

We have developed a system wherein DNA alterations occurring in a target gene in the yeast Saccharomyces cerevisiae can be determined by DNA sequencing. The target gene, SUP4-o, an ochre suppressor allele of a yeast tyrosine tRNA gene, has been inserted into a shuttle vector (YCpMP2) which is maintained in yeast at a copy number of one per cell Mutations in SUP4-o are selected by virtue of their inactivation of suppressor activity. Rapid DNA preparations from these mutants are used to transform an appropriate bacterial strain. Since YCpMP2 also carries the M13 phage replication origin, superinfection of bacterial cells containing the plasmid with wild-type M13 phage yields single stranded YCpMP2 DNA suitable for dideoxynucleotide chain termination sequencing. We have used this system to examine mutations arising spontaneously in the SUP4-o gene. The spontaneous mutants occurred at a frequency of 3.2 X 10(-6)/viable cell, corresponding to a rate of 2.7 X 10(-7) events/cell division. Following bacterial transformation, 16% of the recovered plasmids tested displayed altered gel mobility consistent with loss of significant portions of the plasmid. Hybridization analysis of total yeast DNA and use of purified YCpMP2 revealed that these very large deletions were not generated in yeast but were associated with bacterial transformation. Among the SUP4-o mutants analyzed by DNA sequencing, we identified each type of single base pair substitution (transitions and transversions), small deletions of varying length (1-32 base pairs) and more extensive deletions of undetermined size. These results demonstrate that the SUP4-o system can be used to detect various types of mutation at numerous sites in a single eukaryotic gene and to characterize the DNA sequence changes responsible for the mutations selected.

Surgical management of strictures of the cervical esophagus

Strictures of the esophagus are difficult and challenging problems. Whether a result of caustic ingestion, trauma, or surgery, or a congenital abnormality, the patient suffers a disruption of the fundamental act of swallowing. The seven cases of stricture of the cervical esophagus presented here were not alleviated by the usual methods of antegrade and retrograde dilation. Each patient underwent a two-stage reconstruction of the esophagus. The strictures in four patients were secondary to a caustic agent, two were congenital, and one was of unknown etiology. All patients no longer require dilation and are essentially cured. This procedure will add to the armamentarium of the surgeon who deals with "hopeless" strictures of the cervical esophagus and, in properly selected cases, should be successful.

Cervical esophageal strictures - a surgical approach

Seven patients have successfully undergone surgical correction of their cervical esophageal strictures. The strictures are secondary to caustic ingestion or follow the repair for Zenker's diverticulum. In the first stage the stricture is exteriorized with an extended cervical esophagostomy. The second stage follows in four or six weeks, at which time the adjacent skin to the stoma is trap-doored over the defect and provides a significant amount of skin to augment the esophageal lumen. All of these patients are eating normally.

Carcinoma of the external auditory canal

Successful management of carcinoma of the external auditory canal depends upon four factors: 1. early diagnosis is imperative if a high cure rate is to be expected; 2. correct evaluation of the extent of the malignancy; 3. adequate surgery based upon correct evaluation; and 4. postoperative radiation in certain selected cases. In this review of 35 cases, two factors were used to determine whether the disease was localized or extensive. When extension occurs inot the mastoid as deep as the middle ear cleft or into the facial nerve, it should be designated as extensive tumor. Tumors which do no go as deep as the facial nerve or involve the mucosa of the middle ear should be designated as localized tumors. In localized tumors, it is possible to perform a wide en bloc resection of the bony and cartilaginous external auditory canal including the tympanic membrane and malleus, and if necessary, including the superficial lobe of the parotid. Postoperative radiation is indicated when the pathological specimen shows unclear margins in the surgical dissection. With localized tumors, en bloc resection of the external auditory canal offers a high cure rate. In extensive lesions, an en bloc dissection removing the bulk of the tumor mass, followed by irradiation, seems to offer at least as good a prognosis as more radical surgery.