Computed tomography perfusion imaging in acute stroke

The development of thrombolytic and neuroprotective agents for the treatment of acute stroke has created an imperative for improved imaging techniques in the assessment of acute stroke. Five cases are presented to illustrate the value of perfusion CT in the evaluation of suspected acute stroke. To obtain the perfusion data, a rapid series of images was acquired without table movement following a bolus of contrast medium. Cerebral blood flow, cerebral blood volume and mean transit time were determined by mathematically modelling the temporal changes in contrast enhancement in the brain and vascular system. Pixel‐by‐pixel analysis allowed generation of perfusion maps. In two cases, CT‐perfusion imaging usefully excluded acute stroke, including one patient in whom a low‐density area on conventional CT was subsequently proven to be tumour. Cerebral ischaemia was confirmed in three cases, one with an old and a new infarction, one with a large conventional CT abnormality but only a small perfusion defect, and one demonstrating infarct and penumbra. Perfusion CT offers the ability to positively identify patients with non‐haemorrhagic stroke in the presence of a normal conventional CT, to select those cases where thrombolysis is appropriate, and to provide an indication for prognosis.     

Cell interaction with three-dimensional sharp-tip nanotopography

Cells in their native microenvironment interact with three-dimensional (3D) nanofeatures. Despite many reports on the effects of substrate nanotopography on cells, the independent effect of 3D parameters has not been investigated. Recent advances in nanofabrication for precise control of nanostructure pattern, periodicity, shape, and height enabled this systematic study of cell interactions with 3D nanotopographies. Two distinct nanopatterns (posts and grates) with varying three-dimensionalities (50-600 nm in nanostructure height) were created, while maintaining the pattern periodicity (230 nm in pitch) and tip shape (needle- or blade-like sharp tips). Human foreskin fibroblasts exhibited significantly smaller cell size and lower proliferation on needle-like nanoposts, and enhanced elongation with alignment on blade-like nanogrates. These phenomena became more pronounced as the nanotopographical three-dimensionality (structural height) increased. The nanopost and nanograte architectures provided the distinct contact guidance for both filopodia extension and the formation of adhesion molecules complex, which was believed to lead to the unique cell behaviors observed.     

The clinical spectrum of postpartum thyroid disease

The clinical and biochemical features of postpartum thyroid disease were analysed in 152 antithyroid peroxidase antibody-positive (anti TPO+ve) women and compared with 239 anti-TPO-ve age-matched control postpartum women. All were assessed monthly for up to 12 months postpartum. Seventy three anti-TPO+ve women developed post-partum thyroiditis (PPT): 19.2% hyperthyroid alone, 49.3% hypothyroid alone, and 31.5% characterized by hyper- followed by hypothyroidism. None of the antibody-negative women developed any thyroid dysfunction. A significant increase in many of eleven symptoms of hypothyroidism and some of eight symptoms of hyperthyroidism compared to control women was observed in all anti-TPO+ve women, independent of thyroid status. This was particularly seen in women who later developed PPT when they were euthyroid, but was also observed in euthyroid anti-TPO+ve women who showed no decline of thyroid function during the postpartum period. Although PPT is usually transient, this condition, and the euthyroid antibody-positive state, may be associated with significant symptomatology, including an increased incidence of minor to moderate depression. Early recognition of this syndrome by antenatal screening of thyroid antibodies may contribute to improved management of women during the postpartum period.      

Defective T suppressor-inducer cell function in human immune deficiency virus-seropositive hemophilia patients

In human immune deficiency virus (HIV)-seropositive hemophilia patients, a low number of CD4 + lymphocytes is found, as well as a low CD4+/CD8+ ratio. In previous studies, it has been shown that antigen- specific T-helper cell (CD4+) function was present and no excessive antigen-specific T-suppressor cell (CD8+) function could be demonstrated. In this report, we studied another activity of CD4+ cells, namely the capacity to induce T-suppressor cell activity. The results clearly show a selective dysfunction of CD4+ suppressor-inducer (Tsi) cell function. Since these HIV-seropositive hemophilia patients showed the presence of activated B cells in the peripheral circulation refractory to antigen-specific T-helper cell signals and secreting specific antibodies spontaneously, we raised the hypothesis that the activated B cells in the patients activate the Tsi cells in vivo. This constant activation leads to a functional exhaustion of the Tsi cell pool.     

Malabsorption and mucosal abnormalities of the small intestine in the acquired immunodeficiency syndrome

Diarrhea and weight loss may accompany the acquired immunodeficiency syndrome. We studied 30 patients with the syndrome, 20 of whom had diarrhea and weight loss and 10 of whom did not. Patients with identifiable enteric infections or small intestinal Kaposi's sarcoma were excluded. Malabsorption was common in the patients with diarrhea and weight loss, as shown by abnormal D-xylose and 14C-glycerol-tripalmitin absorption tests. In these patients, duodenal biopsy specimens showed a histiocytic infiltrate containing numerous acid-fast organisms in 5 and a mild-moderate chronic inflammation in 13. In asymptomatic patients, duodenal biopsy specimens were normal in 6 and showed chronic inflammation in 4. These results suggest that malabsorption is common in patients with the acquired immunodeficiency syndrome with chronic diarrhea and may contribute to their weight loss.     

Review article: Identifying occupational violence patient risk factors and risk assessment tools in the emergency department: A scoping review

Occupational violence (OV) is a daily risk for ED staff. It contributes to staff stress, sick leave, turn‐over and burn‐out, and limits the capacity of staff to provide unimpeded quality care to patients and their families. Many factors contribute to incidents of OV; however, early detection of such risk factors could pre‐empt incidences of OV during ED episodes of care. A five‐stage methodological framework for scoping reviews was used to identify, summarise and synthesise OV risk factors from five key databases. A validated tool was used to appraise the quality of included studies. Independent evaluation by the reviewers was used throughout. Patient factors were extracted and described from 24 methodologically and geographically diverse papers. Methodological quality for these studies varied from moderate to high. A total of 34 OV risk factors were identified. Although there was variation in, and differences between, staff‐perceived and objective (documented) OV risk factors, patient risk factors can be categorised into three main groups: clinical presentation, behaviours and past history. Five existing ED OV risk assessment tools were identified, with limited supporting evidence for each. The results support the development of a reliable and validated OV risk assessment tool to be initiated at triage.     

Solitary fibrous tumour of the cheek: An unusual presentation of a rare soft tissue tumour

This case report discusses the unusual presentation and ultrasound features of a solitary fibrous tumour of the face. Solitary fibrous tumour is an uncommon form of soft tissue tumour which, although seen predominantly within the lung pleura, can occur throughout the body in sites such as the peritoneum, mediastinum and head and neck. Ultrasound is an excellent imaging modality in the assessment of soft tissue masses in the head and neck. The ultrasound features demonstrated by this example of solitary fibrous tumour are reviewed. This report also highlights that ultrasound alone is ultimately limited in reaching a definitive diagnosis. The roles of other investigations such as ultrasound-guided biopsy and cross-sectional imaging are discussed.     

Cell markers in hairy cell leukemia studied in cells from 51 patients

To determine the maturation arrest of the neoplastic cells of hairy- cell leukemia (HCL) and the spectrum of the surface markers on these cells, a series of 51 patients with this disease was studied. The cells of all but two of the patients showed monoclonal surface Ig with respect to light chains. In about one-third of the cases, only gamma heavy chain determinants were present on the cells; the majority carried multiple heavy chain determinants as documented by the application of different fluorochromes. Two patients each showed two different clones of cells, both of the same light chain type. In one of these two patients, two paraproteins were present in the serum. Intracytoplasmic Ig was found in only 4 of 39 cases, in all instances being IgM. All cases studied concerned cells with FclgG receptors; however, the density of this receptor varied. FcIgM receptors also showed a spectrum of density, with some cases showing very few FcIgM- positive cells. Receptors C3 were not observed on the hairy cells. Serum immunoglobulin levels were normal or increased. Paraproteins were found in the sera of 4 of 38 patients. These data suggest that HCL is a neoplasm of B lymphocytes. The neoplastic cells are probably arrested at a more mature stage than the cells of chronic lymphocytic leukemia. The multiple isotypes on the cells indicate a block at the "switch" phase from the small micro-carrying lymphocyte to the larger Ig- producing lymphocyte or plasma cell.     

Drug-induced thrombocytopenia is associated with increased binding of IgG to platelets both in vivo and in vitro

Thrombocytopenia is a common serious adverse effect of drug treatment. A variety of in vitro diagnostic techniques to confirm the diagnosis are available, but the majority lack sufficient sensitivity to detect all cases of drug-induced thrombocytopenia. We studied 19 patients with suspected drug-induced thrombocytopenia and demonstrated that platelet- associated IgG (PAIgG) was elevated in all at the time of thrombocytopenia, and PAIgG returned to normal levels as the thrombocytopenia resolved. In the majority of patients, the platelet count rapidly returned to normal after the drug was discontinued; however, in six patients, the thrombocytopenia persisted well beyond the period of time that the offending drug would be expected to be cleared from the blood. In 13 patients, serum obtained after recovery was used to identify the drug responsible for the thrombocytopenia in an in vitro assay. In all cases, the addition of the drug historically associated with the thrombocytopenic episode was associated with an increased binding of IgG to control platelets. For uncertain reasons, the concentration of drug required to increase the in vitro binding of IgG to test platelets was often more than the concentration usually achieved in vivo. Wider application of these techniques may provide better understanding of the clinical characteristics and mechanisms responsible for drug-induce thrombocytopenia.