12 minute consultation: a patient with nasal crusting

BACKGROUND

Nasal crusting is frequently encountered by the otorhinolaryngologist and often requires no specific treatment. It is, however, important to carry out a full history and examination, followed by appropriate investigations, in order to detect the small number of cases in which crusting is caused by systemic or malignant disease.

METHODS

This review was based on a literature search last performed on 30th July 2009. The MEDLINE, EMBASE and Cochrane databases were searched using the subject headings (nasal crusting OR crusts) and in combination with diagnosis, therapy and surgery. Similar searches were performed for relevant diseases, e.g. Wegener's granulomatosis, sarcoidosis. Results were limited to English language articles including clinical trials, meta-analyses, systematic reviews and review articles. Relevant references from selected articles were reviewed.

RESULTS

Knowledge of the causes of nasal crusting will help to target the history, examination and investigation of patients with this condition. Screening tests for systemic conditions can be useful but most have limited sensitivity and must be interpreted cautiously. Nasal septal biopsy is indicated when there is a suspicion of malignancy, or to support a suspected diagnosis of vasculitis. The treatment offered depends upon the cause of crusting and the severity of symptoms.

CONCLUSION

A careful and thorough history and examination, and targeted investigation, of the patient with nasal crusting will ensure correct diagnosis and treatment of patients with this common condition.

Endovascular management of the carotid blowout syndrome

Bleeding from the carotid artery or its branches (‘carotid blowout’) is a well recognized complication following treatment or recurrence of head and neck cancer. The traditional surgical treatment for carotid blowout is often technically difficult and is associated with an unacceptably high morbidity and mortality. The majority of such patients are currently treated conservatively with end of life supportive measures.

We report the case of a young patient with recurrent supraglottic carcinoma complicated by carotid blowout on two separate occasions over a five month period, which was successfully treated endovascularly under local anaesthetic, without neurological sequelae. With the continuing development of interventional radiology, endovascular techniques are now emerging as a viable, low morbidity treatment option in selected patients.

Circulating factors and insulin resistance. I. A novel myoinositol 1,2-cyclic phosphate phosphoglycan insulin antagonist from human plasma is elevated in noninsulin-dependent diabetes mellitus

A novel low mol wt inositol phosphoglycan inhibitor (M tau 1200-1500) of insulin action in rat adipocytes has been partially purified from normal human plasma. This inhibitor, termed fraction V after the first purification step and fraction V3 after the second, is different from other reported serum insulin antagonists. It contains myoinositol, galactosamine, and mannose in approximate molar ratios of 1:1:3.3. The myoinositol has a 1,2-cyclic phosphate substituent, which is essential for the inhibitory activity. Its inhibitory activity is significantly elevated (161%, P < 0.05 for fraction V; 278%, P < 0.05 for fraction V3) in plasma of humans with noninsulin-dependent diabetes mellitus as compared with plasma of nondiabetic controls. These findings represent the first report of a naturally occurring mammalian inositol 1,2-cyclic phosphate containing phosphoglycan related to insulin action.

Characterization of an antibody to the cross-reacting determinant of the glycosyl-phosphatidylinositol anchor of human membrane dipeptidase

A polyclonal antiserum raised to the phospholipase C-solubilized form of membrane dipeptidase (EC 3.4.13.11) purified from human kidney was found to cross-react with unrelated trypanosomal and porcine glycosyl-phosphatidylinositol anchored proteins. Those antibodies recognising the cross-reacting determinant (CRD) were isolated by chromatography on a column of immobilized phospholipase C-solubilized porcine aminopeptidase P (EC 3.4.11.9), and the epitopes involved in the recognition were then characterized by immunoelectrophoretic blot analysis and by a competitive ELISA. The phospholipase C-solubilized forms of human and porcine membrane dipeptidase, porcine aminopeptidase P and trypanosome variant surface glycoprotein were recognised by the anti-CRD antiserum, and this recognition was abolished by prior treatment of the proteins with either mild acid or nitrous acid. In contrast, the detergent-solubilized, membrane-forms of human and porcine membrane dipeptidase were not recognised. Of a range of components of the glycosyl-phosphatidylinositol anchor, only inositol 1,2-cyclic monophosphate and the insulin-mimetic disaccharide, glucosaminyl-1,6-inositol 1,2-cyclic monophosphate, inhibited in the micromolar range the binding of the anti-CRD antiserum to immobilized porcine aminopeptidase P. These results indicate that the major epitope recognised by this anti-CRD antiserum is the inositol 1,2-cyclic monophosphate formed on phospholipase C cleavage of the glycosyl-phosphatidylinositol anchor.

Characterization of antibodies to the glycosyl-phosphatidylinositol membrane anchors of mammalian proteins

Two polyclonal antisera were raised in rabbits to the phospholipase C-solubilized forms of pig renal dipeptidase (EC 3.4.13.11) and pig aminopeptidase P (EC 3.4.11.9). These antisera were purified and shown to cross-react with other glycosyl-phosphatidylinositol (G-PI)-anchored proteins isolated from pig, human and trypanosomes. The epitopes involved in this cross-reactivity were characterized by Western-blot analysis after mild acid or nitrous acid treatment of the G-PI-anchored proteins and by a competitive e.l.i.s.a. with other G-PI-anchored proteins and individual components of the anchor structure. These studies revealed that the primary epitope for both antisera is the inositol 1.2-(cyclic)monophosphate that is formed on phospholipase C cleavage of the intact G-PI anchor. Other minor epitopes, such as phosphoethanolamine, probably involve side-chain modifications to the core anchor structure that may be species-specific.