Characterisation of anti-neutrophil cytoplasmic antibody target antigens using electrophoresis and western blotting techniques.

Anti-neutrophil cytoplasmic antibodies (ANCA) are a family of autoantibodies which react with components of phagocytic cells, and are associated with vasculitis and other idiopathic inflammatory disorders. However, the antigenic targets of many of these autoantibodies have not been defined yet. In this study, sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE) and isoelectric focusing (IEF) were evaluated for characterising the antigenic specificity of unidentified ANCA. The uncharacterised sera included those from patients with ulcerative colitis (n = 21), Crohn's disease (n = 5), cystic fibrosis (n = 16) and sarcoidosis (n = 2). In addition, sera from patients with antibodies to the phagocytic enzymes proteinase 3 (PR3) (n = 11) and myeloperoxidase (MPO) (n = 5) were also included. The sub-cellular localisation of antigens was determined by testing sera against crude neutrophil extract and sub-cellular fractions consisting of azurophilic granules, specific granules and cytosolic, fractions using enzyme-linked immunosorbent assays (ELISAs). All sera reacted with the crude and azurophilic granule extracts. The native system of IEF followed by capillary immunoblotting successfully detected anti-PR3 and anti-MPO in azurophilic granule extracts. In contrast, SDS-PAGE Western blotting failed to detect any reactivity, either to PR3 or MPO, in the crude extract or azurophilic granule extract. However, the antibody specificity of patient sera with uncharacterised autoantibodies could not be detected by IEF/capillary immunoblotting or SDS-PAGE. This study showed that the sub-cellular azurophilic granules are the antigenic target of a variety of uncharacterised ANCA. It also showed that IEF characterised both anti-PR3 and anti-MPO but failed to detect other forms of ANCA. In contrast, the majority of common ANCA were not detected by SDS-PAGE.     

Endoscopic alternatives in the management of colonic strictures

A 10-year review of our experience with all patients with symptoms of colonic narrowing (n = 61) revealed 14 patients who were treated endoscopically. The site of narrowing was the sigmoid colon in 12 patients and the rectum in two patients. The strictures occurred after anastomosis in seven patients, with carcinoma in four patients, and with inflammatory disease, external compression, and idiopathy in one patient each. Although combinations of endoscopic techniques were occasionally used, the predominant method responsible for successful management of the narrowing was bouginage in four patients, endoscopy with a prototype dilating endoscope in four patients, balloon dilatation in three patients, and electrocautery and laser surgery in one patient each. There were no perforations or bleeding complications. Repeated treatments were usually needed. As less invasive methods evolve to treat colonic narrowing, appropriate matching of available techniques with the underlying disease becomes easier. We have found that dilation with a bougie, balloon, or a prototype dilating endoscope can provide especially beneficial results when used on patients with strictures resulting from inflammatory disease or external compression. Cutting and ablating tools such as the electrocautery and laser tools are more suited for management of strictures that result from carcinoma and anastomotic webs. Appropriate matching of endoscopic technique to underlying colonic pathology will allow increasingly successful and safer management of colonic narrowing without operation.     

Visual processing in patients with Frégoli syndrome

We investigated four paranoid schizophrenic patients diagnosed with Frégoli delusion, and four matched psychotic controls. Neuropsychological testing included visual and verbal recognition memory, in addition to a comparison of left and right hemispheric processing of two different classes of stimuli, animate and inanimate objects. Performance on the recognition memory test failed to discriminate between the two psychotic groups on the basis of facial recognition, however, the patients with Frégoli delusion failed to show the right hemisphere processing advantage for the animate class of stimuli found for the set of norms and also present in the psychotic control group. These results are discussed in the context of both current theories of the delusional misidentification syndromes in general, and models of facial recognition in particular.     

Primary melanocytic schwannoma of the stomach. Evidence of dual melanocytic and schwannian differentiation in an extra-axial site in a patient without neurofibromatosis

Pigmented neoplasms of the peripheral nervous system are uncommon. Such lesions, while well documented in the para-axial region, are infrequently encountered in more peripheral extra-axial sites. The authors present a case of a melanocytic schwannoma arising in the gastric antrum of a 51-year-old woman. Ultrastructural features attesting to the nerve sheath origin of the neoplasm included the presence of a well-developed basal lamina, complex infoldings of the plasma membrane, and intercellular bundles of long spaced collagen ("Luse bodies"). Premelanosomes and melanosomes in all stages of development were identified within the cytoplasm of many of the neoplastic cells, providing morphologic support for a close relationship between Schwann cells and melanocytes. Immunoperoxidase studies with S-100 protein disclosed intense cytoplasmic staining throughout the tumor. The S-100 protein antigen has been documented in both nerve sheath elements and melanocytes; this shared antigenicity lends further support to the close relationship between melanocytic and schwannian elements suggested by ultrastructural observations. Additional immunoperoxidase studies employing antibody to glial fibrillary acidic protein revealed focal cytoplasmic staining, an uncommon phenomenon in peripheral nerve sheath neoplasms. A review of the literature failed to provide any previous well documented cases of melanocytic schwannoma of the stomach. The patient was treated with en bloc resection of the tumor and gastric antrum, and was free of evidence of recurrent or metastatic disease 22 months postoperatively. Theories regarding the histogenesis of pigmented nerve sheath neoplasms and prognostic implications are discussed, based on experience with this and previously reported pigmented nerve sheath tumors.