Production of a monoclonal antibody,DF-5, that identifies cells at the epithelial-mesenchymal interface in normal human skin. APN/CD13 is an epithelial-mesenchymal marker in skin

Epithelial-mesenchymal interactions play a critical role in skin development and differentiation, and similar interactions may also regulate the day-to-day proliferation and differentiation events of the epidermis that occur in normal adult skin. This study was directed at identifying molecules that are selectively located at the dermal-epidermal junction in normal adult skin as they may be involved in regulating these homeostatic events. To this end, monoclonal antibodies were raised against the crude cell membrane fraction of cultured human dermal fibroblasts. Screening of antibodies that recognized cell surface antigen on cultured human dermal fibroblasts was followed by determining which of these antibodies selectively localized cells at sites of epithelial-mesenchymal interactions. Antibody DF-5 fit these criteria and was further characterized. This antibody was found to recognize the cell surface ectopeptidase aminopeptidase N (APN), a molecule homologous to the cluster differentiation antigen CD13. Antibody DF-5 and anti-CD13 antibodies both identified cells at sites of epithelial-mesenchymal interactions in fetal, neonatal, and adult human skin, and the APN/CD13 enzyme activity was also identified at these sites. A second ectopeptidase, dipeptidyl peptidase IV (DPPIV) or CD26, presented a significantly different immunohistochemical and histochemical pattern in skin samples, confirming the specificity of the APN/CD13 studies. The function of APN/CD13 in skin has yet to be determined. Its invariant localization at sites of epithelial-mesenchymal interactions argues for a role particular to this region. It may play a role in regulating the activity of neuropeptides or other signaling peptides that are released in this region of skin or it may have an as yet undefined role in mediating communication between dermal and epidermal cells.     

Extensive cerebral venous thrombosis associated with moderate hyperhomocyst(e)inemia and successfully treated with thrombolysis

Cerebral venous thrombosis (CVT) is a relatively rare condition caused by multiple etiologies, usually secondary to hypercoagulable states. The optimal treatment is controversial, especially in the presence of hemorrhagic infarcts. We describe an unusual patient with extensive CVT associated with moderate hyperhomocyst(e)inemia who was aggressively treated with chemical and mechanical thrombolysis with an excellent outcome.     

Spontaneous intracranial internal carotid artery dissection: report of 10 patients

BACKGROUND: Spontaneous intracranial internal carotid artery (ICA) dissection is an uncommon cause of cerebral infarction, particularly when compared with the dissection of the ICA's cervical portion. Most reports describe extensive strokes with very high mortality rates. OBJECTIVE: To report the clinical and radiological findings of 10 patients with spontaneous intracranial ICA dissection. METHODS: Ten patients (5 women) were included with ages ranging from 15 to 59 years (mean age, 28 years). RESULTS: Nine patients had a stroke (1 had an associated subarachnoid hemorrhage), whereas 1 patient had only transient ischemic attacks. Severe retro-orbital or temporal headache followed by contralateral hemiparesis was the most common initial clinical symptom. No patient had vascular risk factors or a history of neck or head trauma. Stenosis of the supraclinoid portion of the ICA occurred in 8 patients, with extension to the middle cerebral artery or anterior cerebral artery in 2 patients each. Aneurysm formation in the ipsilateral anterior cerebral artery was seen in 1 patient. Two patients had a total occlusion of the supraclinoid portion of the ICA. All patients did well, with no (n = 3), mild (n = 4), or moderate (n = 3) disability on the Modified Rankin Scale during a 3-month follow-up period. CONCLUSIONS: Spontaneous intracranial ICA dissection can cause ischemic stroke with or without subarachnoid hemorrhage and should be considered in the differential diagnosis of intracranial ICA stenosis or occlusion, especially in young patients. Some patients survive with few or moderate deficits.     

Nurses' perceived barriers to the implementation of a Fall Prevention Clinical Practice Guideline in Singapore hospitals

Background  

Theories of behavior change indicate that an analysis of barriers to change is helpful when trying to influence professional practice. The aim of this study was to assess the perceived barriers to practice change by eliciting nurses' opinions with regard to barriers to, and facilitators of, implementation of a Fall Prevention clinical practice guideline in five acute care hospitals in Singapore.     

Necrotizing Enterocolitis: A Review of Pathogenetic Mechanisms and Implications for Prevention

Necrotizing enterocolitis (NEC) is a devastating gastrointestinal disease of premature neonates that accounts for 3000 to 4000 deaths each year in the United States. The pathogenesis is not well understood, however theories suggest that prematurity, enteral feeding, bacterial colonization, and intestinal ischemia contribute to the intestinal injury. Furthermore, recent studies have shown that platelet activating factor and perhaps other inflammatory mediators mediate bowel necrosis in animals and possibly in humans. Although no specific intervention for NEC treatment exists, preventive therapy using either enteral IgA supplementation, breast milk feeding, antibiotic prophylaxis, or exogenous steroid administration have reduced the incidence of this overwhelming disease in small randomized trials. These modalities and perhaps PAF antagonists or other inflammatory mediator inhibitors may reduce the incidence or severity of NEC in the next several years.