Polyneuropathy and myopathy in the elderly.

Critical illness polyneuropathy and myopathy is associated with intensive care unit therapies; it is an independent predictor of mortality and will be increasingly affecting the practice of critical care. Most patients with this illness are over 50 years of age, and as our population demographics shift in favor of an aging population, physicians must be aware that this malady will have a rising incidence in the perioperative period. Intensivists, anesthesiologists, surgeons, and geriatricians/internists must remain vigilant. Here we present a concise overview of critical illness polyneuropathy and myopathy, its diagnosis, associations, and possible interventions.

Concordance of Porphyromonas gingivalis colonization in families.

Periodontitis is a widespread disease that appears to be due to a specific bacterial infection. Several species of bacteria have been investigated as potential pathogens, and particularly strong evidence links the presence of Porphyromonas gingivalis with indicators of periodontitis. Information concerning the transmission of P. gingivalis between human contacts may be important in determining risk factors for disease and developing preventive strategies. A few small studies have provided some evidence of transmission between related individuals, but no large-scale study of families that would reflect the typical transmission of this pathogen in the population has been reported. The purpose of this study was to investigate the transmission of P. gingivalis within randomly selected, extended families. The colonization status of 564 members of multigeneration families was determined, and the degree of concordance observed among members of these families was then compared to that expected to occur based on the prevalence of colonization in the population studied. A PCR assay was used for detection of P. gingivalis. Concordance in colonization was more frequently observed within entire families (P = 0.0000) and for spouses (P < 0.001), children and their mothers (P < 0.001), children and their fathers (P < 0.01), adults and their mothers (P < 0.005), and siblings (P < 0.05) than would be expected if P. gingivalis were randomly distributed in the population studied. Results showed that contact with an infected family member substantially increased the relative risk of colonization in these intrafamilial pairs. This indicates that P. gingivalis is commonly transmitted by contact with an infected family member.

Bilateral peritonsillar abscesses and quinsy tonsillectomy.

Two patients presented with history, symptoms, and clinical findings suggesting unilateral peritonsillar abscesses. At the time of quinsy tonsillectomy, the patients were found to have pus present in the contralateral peritonsillar spaces. These findings prompted a review of the literature to determine the actual frequency of bilateral peritonsillar abscesses and to reassess the approach to treatment of patients presenting with peritonsillar abscesses.Peritonsillar abscess frequently develops following the onset of acute tonsillitis, and it is possible that this process occurs bilaterally with the developmental stages of the abscesses being different on each side. Intensive antibiotic treatment, incision and drainage of the obvious abscess probably suppresses the development of and masks the presence of the abscess on the opposite side.Quinsy tonsillectomy has been indicated previously for patients not responding to intravenous antibiotic treatment and incision and drainage of their peritonsillar abscess. The possibility of a subclinical contralateral peritonsillar abscess being present is an additional indication for proceeding with a quinsy tonsillectomy, especially in patients who remain febrile after apparent satisfactory drainage of the clinically evident abscess.

In vitro translation of the major capsid polypeptide from Ustilago maydis virus stain P1.

Double-stranded RNA (dsRNA) from Ustilago maydis virus strain P1 was translated in vitro using a nuclease-treated rabbit reticulocyte lysate system. Following heat denaturation of the H2 double-stranded RNA segment in 90% dimethyl sulfoxide and incubation in the cell free extract, a primary translation product was observed which showed the same molecular weight and co-migrated with viral coat protein on 10% SDS-polyacrylamide gels. The in vitro product of the H2 dsRNA segment could also be immunoprecipitated with antibodies prepared against viral coat protein. Limited proteolysis of the in vitro product and authentic viral coat protein using Staphylococcus aureus V8 protease produced similar peptide patterns on SDS gels. In vitro translation products from other dsRNA segments that make up the P1 viral genome could not be precipitated by antibody to viral coat protein. These results complement the genetic data that indicated that information for coat formation and maintenance was contained within the H segments of dsRNA.

The molecular weight and packaging of dsRNAs in the mycovirus from Ustilago maydis killer strains.

The mycoviruses of Ustilago maydis killer strains are isometric, 43 nm in diameter, and contain several dsRNA segments designated heavy (H), medium (M), and light (L) according to their relative size. To determine the number of dsRNA segments per virion, major sedimenting and density components were isolated, their molecular weights determined from hydrodynamic properties, and their dsRNA contents determined by electron microscopy and/or polyacrylamide gel electrophoresis. The H dsRNA segments of 2.9, 3.1, and 4.2 x 10(6) daltons are separately encapsidated in isometric capsids that band in CsCI at 1.383, 1.394, and 1.418 g/cm8, respectively. The P1 strain contains the 3.1 and 4.2 x 10(6)-dalton segments, and the 3103 strain contains the 2.9 and 4.2 x 106-dalton segments. The T-4 strain contains the 3.1 x 106-dalton H segment and two M segments of 0.67 and 0.60 x 10(6) daltons. The H segments are separately encapsidated in virions which banded at 1.394 g/cm8, whereas the M segments are encapsidated in sets of one, two, or three in virions which banded at 1.314, 1.341, and 1.370 g/cm8. Molecular weights of 9.8 and 13.0 x 106 daltons were calculated for empty capsids (pCsCl = 1.278 g/cm8) and capsids containing the 3.1 x 10(6)-dalton dsRNA segments (pCsCl = 1.394 g/cm8). Analysis of components that banded at other densities in CsCl were consistent with the hypothesis that the banding pattern is the result of the encapsidation of a finite number of dsRNA segments in a capsid of 9.8 x 106 daltons. Although one to three M dsRNA segments were encapsidated in a single virion, no particles were detected with more than one H dsRNA segment per virion.

Pharmacodynamic distinctions between ouabain, digoxin and digitoxin.

Current pharmacologic texts recognize no significant pharmacodynamic differences between the various cardiac glycosides. To reconsider this concept, a special recording device was constructed so that electrocardiograms and phonocardiograms could be obtained in small mammals without anesthesia or premedication, and a spectrum of cardiac glycosides was studied. Utilizing guinea-pigs, cardiac rate reduction of 20% was sought and achieved with 0.07 mg/kg ouabain, 0.34 mg/kg digoxin and 1.12 mg/kg digitoxin. With comparable rate reduction, digitoxin produced significantly greater shortening of electro-mechanical systole than did ouabain or digoxin (P less than 0.05). Other authors have shown that cardiac glycosides produce slowing of cardiac rate prior to onset of positive inotropic effect. Therefore it is probable that for a given amount of vagal effect (sinoatrial slowing) digitoxin possesses greater positive inotropic effect (abbreviation of electromechanical systole) in guinea-pigs than do ouabain or digoxin. A review of the literature suggests that the same holds true for humans.