Caffeine restores regional brain activation in acute hypoglycaemia in healthy volunteers.

AIMS: Caffeine enhances counterregulatory responses to acute hypoglycaemia. Our aim was to explore its effects on cortical function, which are not known at present. METHODS: Regional brain activation during performance of the four-choice reaction time (4CRT) at different levels of complexity was measured using functional magnetic resonance imaging (fMRI) at euglycaemia (5 mmol/l) and hypoglycaemia (2.6 mmol/l) in the presence and absence of caffeine in six healthy right-handed men. RESULTS: During hypoglycaemia, caffeine enhanced adrenaline responses to hypoglycaemia (2.5 +/- 0.7 nmol/l to 4.0 +/- 1.0 nmol/l, P = 0.01) and restored the brain activation response to the non-cued 4CRT, the linear increases in regional brain activation associated with increased task complexity and the ability to respond to a cue that were lost in hypoglycaemia alone. CONCLUSIONS: Caffeine can sustain regional brain activation patterns lost in acute hypoglycaemia, with some restoration of cortical function and enhanced adrenaline responsiveness. A methodology has been established that may help in the development of therapies to protect against severe hypoglycaemia in insulin therapy for patients with diabetes and problematic hypoglycaemia.     

Impact of clinical history on fracture detection with radiography

The effect of knowledge of localizing symptoms and signs in the detection of fractures was studied. Forty radiographs of the extremities were examined twice by seven radiologists; the sessions were separated by 4 months. In 26 cases, a subtle fracture was present; 14 cases were normal. In half of the cases at each session, the precise location of pain, tenderness, or swelling was provided. The observer was asked to determine if the case was normal or abnormal (provide the exact location of the fracture) and to indicate the degree of confidence in the diagnosis. Responses were converted to a numeric scale for analysis. Analysis of receiver operator characteristic parameters indicates that clues regarding location of trauma facilitate detection of fractures. The improvement is based largely on an increased true-positive rate without an increased false-positive rate, regardless of the decision criteria of the radiologist (overall willingness to "overread" or "underread"). This has direct clinical applicability and reinforces the plea of radiologists for precise clinical information.     

Lymph node infarction – a rare complication associated with disseminated intra vascular coagulation in a case of dengue fever

Background  

Lymph node infarction is known to occur in association with many non-neoplastic and neoplastic conditions however its occurrence in association with DIC is not reported hitherto in the literature.     

Heterotopic heart transplants in Biomphalaria glabrata (mollusca: pulmonata). Fate of congeneric xenografts

Hearts were implanted heterotopically into the hemocoel of NIH albino Biomphalaria glabrata from three xenogeneic donor snails, including two New World (B. obstructa, B. tenagophila) and one Old World (B. alexandrina) species, as well as from wild type allogeneic donors. Recipients were examined histologically at 1, 3, 7, 10, 15, 30, 60, 120, and 180 days postimplantation (PI). Grafts from all four donor species were temporarily infiltrated by recipient hemocytes at early intervals PI and in most instances also became encapsulated. Furthermore, the grafts subsequently showed histopathological alterations and abnormal heartbeat relative to preimplantation controls. However, hemocytic reactions eventually subsided, the implants remained structurally intact, and implant myocardial cells both maintained high levels of intracellular glycogen and continued to contract rhythmically for 6 months. No major differences occurred in fates among different xenografts, or between xenografts and allografts. Our observations of prolonged xenograft survival differ from those of previous investigators, most of whom have reported rapid destruction of implanted xenogeneic tissues in molluscs.     

Clinical and genetic features of variegate porphyria in a Chinese patient

Acute porphyria is rare in orientals. We describe a Chinese woman with recurrent generalised tonic-clonic seizures and abdominal pain. Genomic DNA studies identified a heterozygous base substitution from guanine to adenine at nucleotide position 503, resulting in substitution of arginine by histidine at position 168 of the protein (R168H). This genetic abnormality is similar to the mutation reported in Caucasians with variegate porphyria. To the best of our knowledge, this is the first report in the English literature a Chinese patient with variegate porphyria with an identifiable mutation. A brief review of porphyria is presented.     

Acute coronary syndromes

The first 150 words of the full text of this article appear below. Key points Coronary artery disease accounts for >30% ofdeaths in Western society. The diagnosis of myocardial infarctionshould be qualified by size, causation and time from occurrence. Mortalityis reduced by immediate or ‘primary’ percutaneouscoronary intervention or thrombolysis within the first 24 hof onset of ST-segment elevation myocardial infarction. Strategiesto reduce platelet activation (glycoprotein IIb/IIIa receptorantagonists, or clopidogrel) are now recommended in the treatmentof high-risk non-ST-segment myocardial infarction/unstable angina. Elevatedserum troponins may be the result of non-ischaemic myocardialdamage, especially in critical illness.