Serum brain‐derived neurotrophic factor and platelet activation evaluated by soluble P‐selectin and soluble CD‐40‐ligand in patients with acute myocardial infarction

Little is known about the role of neurotrophins (NT) under adult vascular homeostasis in normal and pathological conditions. The NT family, including nerve growth factor and brain‐derived neurotrophic factor (BDNF) are expressed in atherosclerotic vessels. Previous studies demonstrated that plasma BDNF levels were increased in the coronary circulation in patients with unstable angina. However, the role of BDNF during the onset and evolution of unstable angina remains to be elucidated. The objective of this study was to evaluate the relationship between BDNF, functional parameters and biological markers associated with inflammatory processes and platelet activation. BDNF serum levels were assessed in patients with acute myocardial infarction (MI) (n = 20) or stable angina pectoris (SAP) (n = 20) who underwent coronary angiography. Serum levels of IL‐6, MCP1, sVCAM, soluble CD‐40‐ligand (sCD40L) and soluble P‐selectin (sP‐selectin) were measured simultaneously by flux cytometry. Median BDNF levels were higher in the MI than in the SAP group (1730 vs. 877 pg/mL, respectively; P = 0.025). In MI patients, we observed a significant correlation between BDNF and sP‐selectin (r = 0.58, P = 0.023), although we found a non‐significant trend between BDNF and sCD40L (r = +0.35, P = 0.144). By contrast, no such correlation was observed in SAP patients (r = ?0.22, P = 0.425). No difference was observed between the two groups regarding baseline demographics, risk factors, biological data and angiographic findings. The study suggests that BDNF serum levels in MI patients could be related to platelet activation and the inflammatory response. Further studies are needed to investigate the role of NT in the setting of acute MI.     

Infections by viruses of the families Bunyaviridae and Filoviridae

Rift Valley fever is the most important bunyaviral disease of animals in Africa. The virus, transmitted by mosquitoes, causes abortions and mortality in young animals in addition to haemorrhagic fevers in humans. Although vaccines against this virus are available, the uses of these vaccines are limited because of deleterious effects or incomplete protection, justifying further studies to improve the existing vaccines or to develop others. Nairobi sheep disease is transmitted by ticks. The disease is endemic in East Africa and sporadic cases are reported in India and Sri Lanka. Other viruses transmitted by mosquitoes or midges are teratogenic in cattle or sheep, these include Akabane and related viruses in Asia, Australia and the Middle East, and Cache Valley in North America. The Marburg and Ebola viruses of the genus Filovirus are associated with epidemics in Central Africa with high fatality rates in humans; some outbreaks were related to contact with monkeys. Another subtype of Ebola virus was first described in a quarantine facility in the United States of America among cynomolgus monkeys (Macaca fascicularis) from the Philippines. The reservoir of these viruses remains unknown.     

Effects of dexamethasone on the hypothalamic-pituitary-adrenal axis in preterm infants

The effects of dexamethasone therapy on the hypothalamic-pituitary-adrenal axis were tested in 10 premature infants with bronchopulmonary dysplasia by means of the corticotropin-releasing hormone stimulation test before therapy and on the seventh day of therapy. Adrenocorticotropic hormone and cortisol levels were determined by radioimmunoassay. There was significant suppression of the hypothalamic-pituitary-adrenal axis after 7 days of a currently used dexamethasone treatment regimen. A site of suppression was located at the level of the pituitary gland.     

Isolated congenital tuberculosis otitis in a preterm infant

We report an unusual case of localized congenital tuberculosis otitis in a preterm infant. Unlike disseminated congenital cases, the manifestations of localized otitis are associated with a triad of signs: (i) regional lymphadenopathy in the absence of typical systemic features of tuberculosis; (ii) delayed onset of presentation; and (iii) refractory otitis unresponsive to conventional antimicrobial agents. The need for greater diligence in looking for neonatal tuberculosis is emphasized, especially in an ethnic or socioeconomic environment where the disease is prevalent. Congenital tuberculosis, otitis, preterm
PC Ng, Department of Paediatrics, Level 6, Clinical Sciences Building, Prince of Wales Hospital, Shatin, NT, Hong Kong     

Inhibition of O6-alkylguanine-DNA alkyltransferase in animal and human ovarian tumor cell lines by O6-benzylguanine and sensitization to BCNU

O⁶-Alkylguanine-DNA alkyltransferase (O⁶-AGT) activity in rat ovarian tumor lines O-342 and O-342/DDP was 103.4±18.4 and 240.9±40.2 fmol/mg protein, respectively; thus, cisplatin (DDP) resistance was paralleled by an increase in O⁶-AGT activity by a factor of approximately 2.3. The DDP-resistant line expressed a collateral resistance to BCNU. Both lines could be sensitized to BCNU by O⁶-BG, with sensitization factors of 6.0 and 2.1, respectively. In neither line did depletion of O⁶-AGT have any sensitizing effect towards DDP. In the human ovarian cancer lines SK-OV-3 and OAW 42, O⁶-AGT activity was 337.6±18.2 and 180.0±39.9 fmol/mg protein, respectively; in these lines depletion of O⁶-AGT activity by O⁶-BG treatment resulted in sensitization factors of 3.0 and 4.1, respectively. The increase in sensitivity of ovarian tumor cell lines against a chloroethylating agent by O⁶-AGT depletion and possible pharmacological advantages of regional (i.p.) administration of this combination might be beneficial in advanced ovarian cancer.Abbreviations BCNU (1,3-bis(2-chloroethyl)-1-nitrosourea) - CENU 2-chloroethylnitrosourea - DDP cisplatin ED₅₀, the effective dose required to inhibit colony formation or cell proliferation by 50% - O⁶-AGT O⁶-alkylguanine-DNA alkyltransferase - O⁶-BG O⁶-benzylguanine SF sensitization factor     

Three pyrone glucosidic derivatives from Conyza albida

Three new pyrone glucosidic derivatives, together with the known pyromeconic acid glucoside, three acytelenes and two eudesmanes, were obtained from the aerial parts of Conyza albida. The structures were elucidated by high field NMR spectroscopy.