An Ultrasensitive Radioligand Assay for IgC Using the Protein A on Staphylococcus aureau Bacteria

The purpose of this study was to develop a simple and sensitive assay to measure IgG. Human IgG was radiolabelled with ¹²⁵Iodine and 7.5 ng was incubated with heat-killed Staphylococcus aureus bacteria (Cowan 1 strain). To replicate sets of tubes, increasing amounts of a standard IgG preparation were added. The samples were incubated at room temperature for two hours and separated by centrifugation. Using this assay it was found that the IgG concentration could readily be determined in one nanoliter or less of human serum. There was no significant cross-reactivity with IgA, IgE and IgM or the F(ab')₂ fragment of IgG. Serial dilutions of normal human or SLE sera, rabbit or guinea pig sera, the Fc fragment of human IgG and a mouse monoclonal anti-human DNA antibody parallelled the dose response curve obtained with standard human IgG. The method correlated well (r=0.89) with a routinely used nephelometric method. The mean (±SD) IgG concentration in 20 normal subjects measured by this assay was 10 ± 3.6 g/L.     

Anatomic guide and sonography for surgical repair of leg muscle lacerations

Background

There were over 110,000 leg laceration cases reported in the United States in 2011. Currently, muscle laceration is repaired by suturing epimysium to epimysium. Tendon-to-tendon repair is stronger, restores the muscle's resting length, and leads to a better functional recovery. Tendons retract into the muscle belly following laceration and surgeons have a difficult time finding them. Many surgeons are unfamiliar with leg muscle anatomy and the fact that the leg muscles have long intramuscular tendons that are not visible in situ. A surgical anatomic guide exists to help surgeons locate forearm tendons; no such guide exists for tendons in the leg.

Materials and methods

The leg tendon ends of 11 cadavers were dissected, measured, and recorded as percentages of leg length. High-frequency ultrasound was used to locate tendon ends in three additional cadavers. These locations were compared with the actual tendon ends located via dissection.

Results

There was little variation in tendon end position within the cadaver group, between men and women or right and left legs. The data are presented as an anatomic guide to inform surgeons of the tendon ends' likely locations in the leg.

Conclusion

The location of leg intramuscular tendon ends is predictable and the anatomic guide will help surgeons locate tendon ends and perform tendon-to-tendon repairs. Ultrasound is a potentially effective tool for detection of accurate location of repairable tendon ends in leg muscle lacerations.     

Essentials of cell physiology

Cell physiology and molecular genetics now provide the basis for the fundamental understanding of the mechanisms involved in normal and pathological physiology, modes of drug action, and risks involved in surgical procedures. Some explanations, often involving a single mutation in a protein are straightforward (e.g. cystic fibrosis transmembrane conductance regulator (CFTR) in cystic fibrosis). Others may involve a constellation of effects (e.g. obesity) and surprisingly there still remain important areas lacking comprehensive explanation (e.g. the mode of action of general anaesthetics) or close to resolution but still lacking detail (aldosterone controlling both K and Na regulation in the kidney). The present article presents a concise summary of regulation of cell function, concentrating on the cell membrane and important organelles. Signalling and second messengers, together with the role of membrane channels and transporters constitute an important aspect of this, mediated via kinases and phosphatases. Cell volume regulation, reflecting swelling and oedema, are an important aspect of organ transplantation and brain function.     

Review: quantifying mitochondrial dysfunction in complex diseases of aging

There is accumulating evidence that mitochondrial respiratory malfunction is associated with aging-associated complex diseases. However, progress in our understanding of these diseases has been hampered by the sensitivity and throughput of systems employed to quantify dysfunction and inherent limitations of the biological systems studied. In this review, we describe and contrast two methodologies that have been developed for measuring mitochondrial function to address the need for improved sensitivity and increased throughput. We then consider the utility of each methodology in studying three biological systems: isolated mitochondria, cultured cells, and cell fibers and tissues. Finally, we discuss the application of each methodology in the study of mitochondrial dysfunction in Alzheimer's disease, type 2 diabetes mellitus, and aging-associated autophagy impairment and mitochondrial malfunction. We conclude that the methodologies are complementary, and researchers may need to examine multiple biological systems to unravel complex diseases of aging.     

Polyvalent mechanical bacterial lysate for the prevention of recurrent respiratory infections: a meta-analysis

BackgroundRespiratory tract infections are common and remain a major source of morbidity, mortality and economic cost worldwide, despite advances in modern medicine. One treatment approach is to non-specifically increase the immune response or augment innate defense mechanisms through the use of bacterial lysates. Polyvalent Mechanical Bacterial Lysate (PMBL) is a bacterial lysate made from a wide range of pathogenic bacteria, including all of the most commonly occurring pathogens of the upper and lower respiratory tract obtained by mechanical lysis.AimTo test the available evidence that PMBL is able to prevent respiratory tract infections.MethodsA number of studies investigating randomized comparisons of PMBL (active) with placebo or no treatment (control) were selected for analysis. The primary outcome measure was the prevention of exacerbations or acute respiratory tract infection. The results were expressed as relative risk (RR) and the number of patients needed to treat for one to benefit (NNTB).ResultsData from 2557 patients from 15 randomized clinical trials (RCTs) was investigated. PMBL induced a significant reduction of infections vs placebo (RR ?0.513; 95% CI; ?0.722 – ?0.303; p = 0.00). The NNTB was 1.15. The RR was always in favor of PMBL (in recurrent respiratory infections other than COPD, chronic bronchitis and tuberculosis, RR ?0.502; 95% CI ?0.824 – ?0.181; in children RR ?2.204; 95% CI ?3.260 – ?1.147; in COPD or chronic bronchitis, RR ?0.404; 95% CI ?0.864–0.057; in tuberculosis, RR ?0.502; 95% CI ?0.890 – ?0.114).ConclusionsThe results of the present meta-analysis suggest that PBML is effective in both in children and in adults in preventing respiratory tract infections. Our current meta-analysis shows that there is a trend with PBML toward clinically significant results in patients with COPD but it did not quite achieve statistical significance due to the small number of COPD studies.