What constitutes a true hyperdense middle cerebral artery sign?

OBJECTIVES: The 'hyperdense MCA sign' refers to an appearance of increased attenuation of the proximal middle cerebral artery (MCA) that is often associated with thrombosis of the M1 MCA segment and may be the only diagnostic feature on computed tomography early after ischaemic stroke. False positives are recognized, and correct recognition of this sign has, therefore, assumed greater importance with the advent of thrombolytic therapy for stroke. We sought to define objective criteria for hyperdensity of the MCA. METHODS: Brain computed tomographs obtained by a standard protocol in a neuroradiology department were analyzed by a single observer. All consecutive scans reported as exhibiting a hyperdense MCA were compared to controls reported as having normal scans. Ovoid regions of interest were placed over the vessels and cerebral cortices, and the attenuation in Hounsfield units (HU) measured. Absolute attenuation and ratios of one side to the other were compared. RESULTS: MCA attenuation was unrelated to age in cases (n = 18) and controls (n = 80). The mean MCA attenuation was greater in the affected MCA of cases as compared with controls [54.0 HU (99% confidence interval CI 46.7-61.2) vs. 41.3 HU (99% CI 39.7-43.0); p < 0.00001]. Cases were subdivided into true and false positives by the ratio of denser:less dense MCA (within or without the 95% prediction interval for controls). In all true positives, the MCA ratio was > 1.2. 9 of 10 true positives had acute ischaemic stroke; 1 patient had herpes simplex encephalitis, but had MCA attenuation within the 95% CI for controls. False positives had mature cerebral infarction or non-ischaemic pathologies. The ratio of MCA attenuation to adjacent cerebral cortex was significantly higher in both true and false positives than in controls. CONCLUSIONS: Hyperdense MCAs associated with acute ischaemic stroke can be distinguished from normal vessels and false positives by measurement of absolute attenuation of affected and normal vessels: an absolute density of >43 HU and a MCA ratio of >1.2 defined hyperdensity and excluded all other pathologies. Confirmation in other centres is required.     

Pharmacological effects of green tea on the gastrointestinal system

Green tea is rich in polyphenolic compounds, with catechins as its major component. Studies have shown that catechins possess diverse pharmacological properties that include anti-oxidative, anti-inflammatory, anti-carcinogenic, anti-arteriosclerotic and anti-bacterial effects. In the gastrointestinal tract, green tea was found to activate intracellular antioxidants, inhibit procarcinogen formation, suppress angiogenesis and cancer cell proliferation. Studies on the preventive effect of green tea in esophageal cancer have produced inconsistent results; however, inverse relationships of tea consumption with cancers of the stomach and colon have been widely reported. Green tea is effective to prevent dental caries and reduce cholesterols and lipids absorption in the gastrointestinal tract, thus benefits subjects with cardiovascular disorders. As tea catechins are well absorbed in the gastrointestinal tract and they interact synergistically in their disease-modifying actions, thus drinking unfractionated green tea is the most simple and beneficial way to prevent gastrointestinal disorders.     

Fabrication of Large-Area Mullite–Cordierite Composite Substrates for Semiconductor Probe Cards and Enhancement of Their Reliability

This work aims to fabricate a large-area ceramic substrate for the application of probe cards. Mullite (M) and cordierite (C), which both have a low thermal expansion coefficient, excellent resistance to thermal shock, and high durability, were selected as starting powders. The mullite–cordierite composites were produced through different composition ratios of starting powders (M:C = 100:0, M:C = 90:10, M:C = 70:30, M:C = 50:50, M:C = 30:70, and M:C = 0:100). The effects of composition ratio and sintering temperature on the density, porosity, thermal expansion coefficient, and flexural strength of the mullite–cordierite composite pellets were investigated. The results showed that the mullite–cordierite composite pellet containing 70 wt% mullite and 30 wt% cordierite sintered at 1350 °C performed exceptionally well. Based on these findings, a large-area mullite–cordierite composite substrate with a diameter of 320 mm for use in semiconductor probe cards was successfully fabricated. Additionally, the changes in sheet resistance and flexural strength were measured to determine the effect of the environmental tests on the large-area substrate such as damp heat and thermal shock. The results indicated that the mullite–cordierite composite substrate was extremely reliable and durable.     

Intralymphatic Histiocytosis Associated with Osteoarthritis: A Case Report

Intralymphatic histiocytosis (ILH) is a rare cutaneous condition with uncertain pathogenesis. It is characterized by dilated lymphatic vessels that contain histiocytes within their lumina. Although the etiology of ILH remains unknown, it has been associated with various inflammatory and neoplastic diseases, such as rheumatoid arthritis (RA), reaction to metal joint implants and Merkel cell carcinoma, breast cancer and colon cancer. An 83-year-old female presented with an erythematous patch on the left forearm that had appeared six months previous. She had suffered from osteoarthritis (OA) and the cutaneous lesion was located in the vicinity of the affected joint. Skin biopsy from the lesion showed dilated dermal vessels and some ectatic vessels that contained many mononuclear histiocytes. Based on the clinical and histopathological findings, we diagnosed her with ILH with OA. Two sessions of intralesional triamcinolone acetonide injection (5 mg/ml) were administered to treat the skin lesion, which gradually improved over a period of a few months. We here report a rare case of ILH associated with degenerative OA.     

Metabolic Dysfunction-Associated Fatty Liver Disease Predicts Long-term Mortality and Cardiovascular Disease

Background/AimsWe investigated the effect of metabolic dysfunction-associated fatty liver disease (MAFLD) on future mortality and cardiovascular disease (CVD) using a prospective community-based cohort study.MethodsIndividuals from two community-based cohorts who were 40 to 70 years old were prospectively followed for 16 years. MAFLD was defined as a high fatty liver index (FLI ≥60) plus one of the following conditions overweight/obesity (body mass index ≥23 kg/m²), type 2 diabetes mellitus, or ≥2 metabolic risk abnormalities. Nonalcoholic fatty liver disease (NAFLD) was defined as FLI ≥60 without any secondary cause of hepatic steatosis.ResultsAmong 8,919 subjects (age 52.2±8.9 years, 47.7% of males), 1,509 (16.9%) had MAFLD. During the median follow-up of 15.7 years, MAFLD independently predicted overall mortality after adjustment for confounders (hazard ratio [HR], 1.33; 95% confidence interval [CI], 1.05 to 1.69) but NAFLD did not (HR, 1.20; 95% CI, 0.94 to 1.53). MAFLD also predicted CVD after adjustment for age, sex, and body mass index (HR, 1.35; 95% CI, 1.13 to 1.62), which lost its statistical significance by further adjustments. Stratified analysis indicated that metabolic dysfunction contributed to mortality (HR, 1.51; 95% CI, 1.21 to 1.89) and CVD (HR, 1.27; 95% CI, 1.02 to 1.59). Among metabolic dysfunctions used for defining MAFLD, type 2 diabetes mellitus in MAFLD increased the risk of both mortality (HR, 2.07; 95% CI, 1.52 to 2.81) and CVD (HR, 1.42; 95% CI, 1.09 to 1.85).ConclusionsMAFLD independently increased overall mortality. Heterogeneity in mortality and CVD risk of subjects with MAFLD may be determined by the accompanying metabolic dysfunctions.