Non-clostridial gas gangrene of the neck and mediastinum

Herein we report a case of gas gangrene of the neck and mediastinum in a poorly managed Type II diabetic with concomitant chronic renal failure and a recent history of mucormycosis. Despite the burden of co-morbidities and the gravity of the illness, the patient was successfully treated and remained free of complications in the long term.     

Screening the human prepro-orexin gene in a single-centre narcolepsy cohort

BACKGROUND AND PURPOSE: Although the orexin system has an established role in narcolepsy, the mechanism of orexin deficiency in human cases is unknown. The strong association with human leukocyte antigen (HLA) DQB1*0602 suggests an autoimmune basis, but supporting evidence is lacking. Although data indicate that HLA status is not the sole genetic factor, only a single case of a functional orexin system mutation has been discovered, in a study with a selection bias designed to increase yield. In this study, we examined the prepro-orexin gene for mutations in a cohort of unrelated patients with narcolepsy from a national UK referral centre. PATIENTS AND METHODS: Subjects with a diagnosis of narcolepsy were recruited from a patient database. DNA samples were obtained using buccal smear kits. The prepro-orexin gene was amplified using polymerase chain reactions and screened for polymorphisms and mutations. RESULTS: Eighty-one patients were recruited, of whom 69 provided DNA samples. A previously described intronic single nucleotide polymorphism, of unlikely significance, was identified in one subject who had typical clinical and electrophysiological features of narcolepsy. It was located 16 base pairs downstream from exon 1. No other mutations were found. CONCLUSION: This result supports existing evidence which indicates that mutations of the prepro-orexin gene are rare and that the genetic contribution to the aetiology of human narcolepsy is likely to be complex.     

Significant Caval Penetration by the Celect Inferior Vena Cava Filter: Attributable to Filter Design?

This report describes transmural penetration of the inferior vena cava (IVC) by a newly introduced IVC filter within 9 days of its placement. A computed tomographic study demonstrated filter penetration with one of the primary struts lodging in the uncinate process of the pancreas. Because of the close resemblance of this new filter to another filter that has not been associated with penetration injuries, the key differences between the two designs were examined and the determination was made that the new filter, unlike the older one, has unprotected primary struts. Only filters with an unprotected primary strut design have been associated with penetration injuries such as the one described in this case.     

A developmental framework for endodermal differentiation and polarity

The endodermis is a root cell layer common to higher plants and of fundamental importance for root function and nutrient uptake. The endodermis separates outer (peripheral) from inner (central) cell layers by virtue of its Casparian strips, precisely aligned bands of specialized wall material. Here we reveal that the membrane at the Casparian strip is a diffusional barrier between the central and peripheral regions of the plasma membrane and that it mediates attachment to the extracellular matrix. This membrane region thus functions like a tight junction in animal epithelia, although plants lack the molecular modules that establish tight junction in animals. We have also identified a pair of influx and efflux transporters that mark both central and peripheral domains of the plasma membrane. These transporters show opposite polar distributions already in meristems, but their localization becomes refined and restricted upon differentiation. This “central–peripheral” polarity coexists with the apical–basal polarity defined by PIN proteins within the same cells, but utilizes different polarity determinants. Central–peripheral polarity can be already observed in early embryogenesis, where it reveals a cellular polarity within the quiescent center precursor cell. A strict diffusion block between polar domains is common in animals, but had never been described in plants. Yet, its relevance to endodermal function is evident, as central and peripheral membranes of the endodermis face fundamentally different root compartments. Further analysis of endodermal transporter polarity and manipulation of its barrier function will greatly promote our understanding of plant nutrition and stress tolerance in roots.     

Occlusal Plane Location in Edentulous Patients: A Review

Occlusal plane orientation is an important factor in the construction of a complete denture. Occlusal plane could be oriented using landmarks in the mandibular arch as well as in the maxillary arch. In the mandibular arch there are few landmarks which could be used to orient the occlusal plane like the retromolar pad, corner of the lips (lower lip length) whereas the maxillary arch has a number of landmarks, of which the ala-tragal line is the most commonly used and the same being the most controversial. In the following article different landmarks and its accuracy for orientating the occlusal plane in an edentulous subject as studied by various authors has been discussed.