Use of negative-pressure dressings to manage a difficult surgical neck wound

We used negative-pressure dressings to treat a poorly healing cervical rotation flap following radical neck dissection in an elderly man. The wound had failed to heal properly after 2 weeks of conservative management. Following application of the negative-pressure dressings, the wound granulated quickly and healed well by secondary intention.     

Molecular mimicry in mercury toxicology

Molecular mimicry occurs when one molecular entity is "mistaken" for another by cellular or other biological processes, and is thought to arise from structural similarities between the two molecules in question. It has been postulated by others to be important in the mechanism of uptake of toxic metal species into living tissues. A widely accepted example is the transport of methylmercury-cysteine species, which are thought to mimic the amino acid methionine. We have used mass spectrometry and mercury L(III)-edge X-ray absorption spectroscopy to understand the solution structure of complexes between methylmercury and cysteine. With a view to understanding the basis of the suggested molecular mimicry mechanisms, we have used computational chemistry to compare the structure of methionine with that of the dominant solution species L-cysteinato(methyl)mercury(II), and the structure of cystine with that of mercury(II) bis-L-cysteineate. We conclude that the structural similarities between metal compounds and natural products are insufficient to support a mechanism based on molecular mimicry, but instead, mechanisms involving a less-specific mimicry based on similarity with the L(alpha) region of the amino acid part of the molecule.     

Taking sociology seriously: a new approach to the bioethical problems of infectious disease

After a history of neglect, bioethicists have recently turned their attention to the topic of infectious disease. In this paper we link bioethicists' earlier neglect of infectious disease to their under-appreciation of the extent to which the problem of infectious disease is related to social factors and thus to questions of justice. We argue that a social causation of illness model - well-known to sociologists of medicine, but incompletely understood by bioethicists - will improve future bioethical analysis of issues related to infectious disease. By emphasising the relationships between social and economic structures of inequality and health, the social causation model provides a richer approach to ethical issues associated with infectious disease than the more commonly used biomedical model.     

Quality assessment and correlation of microsatellite instability and immunohistochemical markers among population- and clinic-based colorectal tumors results from the Colon Cancer Family Registry

The detection of defective mismatch repair (MMR), as assessed by the presence of tumor microsatellite instability (MSI) and/or loss of MMR protein expression by IHC, has been useful for risk assessment, prognosis, and prediction of treatment in patients with colorectal cancer. We analyzed tumors for the presence of defective MMR from 5927 Colorectal Cancer Family Registry patients recruited at six international consortium sites. We evaluated the appropriate percentage instability cutoff used to distinguish the three MSI phenotypes [ie, stable (MSS), low instability (MSI-L), and high instability (MSI-H)]; the sensitivity, specificity, and performance characteristics of individual markers; and the concordance between MSI and IHC phenotypes. Guided by the results of the IHC testing, our findings indicate that the distinction between an MSI-H phenotype from a low-instability or MSS phenotype can best be accomplished by using a cutoff of 30% or greater of the markers showing instability. The sensitivity and specificity of the mononucleotide markers were higher than those of the dinucleotide markers. Specifically, BAT26 and BAT25 had the highest sensitivity (94%) and specificity (98%), and the use of mononucleotide markers alone identified 97% of the MSI-H cases correctly. As expected, the presence of MSI-H correlated with an older age of diagnosis, the presence of tumor in the proximal colon, and female sex.     

Safety of transesophageal echocardiography in patients who are obese.

Patients with obesity tend to have a higher incidence of hypertension, coronary artery disease, and sleep apnea, conditions that could potentially predispose to complications during transesophageal echocardiography (TEE). In addition, patients who are obese are more likely to have oxygen desaturation during upper gastrointestinal endoscopy. However, the safety of TEE in a large cohort of patients with obesity has not been reported. Thus, the safety of TEE in 341 patients who were obese (body mass index >/= 27.5 kg/m(2), mean 41.0 +/- 10.3) and in 323 control patients who were not obese was compared. Minor complications (ie, complications of a transient duration and requiring no or only simple intervention) occurred with equal frequency in the control and obese groups (16.5% vs 16.7%, P = not significant). Transient oxygen desaturation did not differ between the control versus obese group (2.5% vs 3.8%, P = not significant), but was more common (6.7%) in a subgroup (n = 150) of patients who were morbidly obese as compared with control patients (P <.05). Transient hypotension was observed in 3.5% of the obese group compared with 7.4% in the control group (P <.05). However, transient hypertension was noted in 10.6% of the patients who were obese compared with 6.5% in the control group (P =.072). A major complication occurred in 2 patients with obesity, one who required vasopressor medication for persistent hypotension and another needing pharmacologic rate control of atrial fibrillation. One patient in the control group had provoked supraventricular tachycardia and angina. No deaths occurred in either group. Subjective tolerance for the procedure was similar (P = not significant) in both groups with 84% of patients with obesity having good to excellent tolerance compared with 88% in that of the control group. Thus, TEE can be safely performed in patients who are obese.     

Incidentally detected bilaterally symmetrical seminal and vas calcification in young infertile male: a case report, literature review and algorithm for diagnosis

Bilateral seminal and vas calcification is not common, especially in young age. Association with many disease conditions has been described, with diabetes mellitus being the most common association. A 34-year-old man presented with primary infertility and right upper ureteric calculus. His evaluation revealed extensive, bilateral seminal and vas calcification with normal semen analysis and first-time detected diabetes mellitus. His female partner was evaluated and found to have bilateral fallopian tubes blockage. We reviewed the literature and present here the algorithm for diagnosis of such patients, along with details of this particular patient.     

Skeletal muscle gene expression profiles in 20-29 year old and 65-71 year old women

Gene expression profiling may provide leads for investigations of the molecular basis of functional declines associated with aging. In this study, high-density oligonucleotide arrays were used to probe the patterns of gene expression in skeletal muscle of seven young women (20-29 years old) and eight healthy older women (65-71 years old). The older subjects had reduced muscle mass, strength, and peak oxygen consumption relative to young women. There were approximately 1000 probe sets that suggested differential gene expression in younger and older muscle according to statistical criteria. The most highly overexpressed genes (>3-fold) in older muscle were p21 (cyclin-dependent kinase inhibitor 1A), which might reflect increased DNA damage, perinatal myosin heavy chain, which might reflect increased muscle fiber regeneration, and tomoregulin, which does not have a defined function in muscle. More than 40 genes encoding proteins that bind to pre-mRNAs or mRNAs were expressed at higher levels in older muscle. More than 100 genes involved in energy metabolism were expressed at lower levels in older muscle. In general, these results support previous observations on the differences in gene expression profiles between younger and older men.