The aging lung

Structural changes occur in the respiratory system with advancing age. Lung elasticity decreases, stiffness of the chest wall increases, and respiratory muscle strength declines. These alterations contribute to gradual, but progressive, reductions in forced vital capacity, expiratory flow rates, diffusing capacity, gas exchange, ventilatory drive, and respiratory sensation. Cigarette smoking accelerates the age-related decline in flow rates. Understanding the effects of aging on the lung is important in order to distinguish pathologic changes from changes that are part of the normal aging process.     

The National Stem Cell Therapy Patient Registry of Malaysia—Measuring Clinical Outcomes of Stem Cell Therapy

Very few registries worldwide focus on clinical outcomes of stem cell therapy (SCT) as the large number of applications and rapid development of the field complicates registry design considerably. The National Stem Cell Therapy Patient Registry of Malaysia aims to accommodate this by using a main protocol which covers the overall design and administration of the registry, and condition-specific sub-protocols which deal with outcome measures. The registry will start with a few sub-protocols covering existing modes of SCT in Malaysia, with new sub-protocols released periodically as the need arises.     

Characterization of oligonucleotide transport into living cells.

Addition of antisense oligonucleotides to cell cultures has been used to specifically inhibit gene expression. We have investigated the mechanism by which oligonucleotides enter living cells. These compounds are taken up by cells in a saturable, size-dependent manner compatible with receptor-mediated endocytosis. Polynucleotides of any length are competitive inhibitors of oligomer transport, providing they possess a 5'-phosphate moiety. Using oligo(dT)-cellulose for affinity purification, we have identified an 80-kDa surface protein that may mediate transport. Knowledge of the oligonucleotide transport mechanism should facilitate the design of more effective synthetic antisense oligomers as potential clinical agents.     

Paradoxical release of nitric oxide by an L-type calcium channel antagonist, the R+ enantiomer of amlodipine.

Amlodipine is a mixture of two enantiomers, one having L-type channel blocking activity (S-) and the other about 1,000-fold weaker activity and of little known other activity (R+). To determine whether the R+ enantiomer releases nitric oxide, the ability of amlodipine, its enantiomers, and nitrendipine to release nitric oxide in isolated coronary microvessels and to regulate cardiac tissue oxygen consumption via nitric oxide release was studied in vitro. Amlodipine and the R+ enantiomer released nitric oxide in a concentration-dependent fashion, increasing nitrite release from coronary microvessels by 57 +/- 12 and 45 +/- 5 pmol/mg/20 min at 10(-6) M (p < 0.05 from control). Nitrite release was entirely blocked by N(omega)-nitro-L-arginine methyl ester (L-NAME), a nitric oxide synthase inhibitor, and HOE-140, a B2-kinin receptor antagonist. The S- enantiomer had no effect on nitrite release at any concentration. Amlodipine and the R+ enantiomer also reduced oxygen consumption in canine cardiac tissue in vitro and this was in an L-NAME-blockable manner. The S- enantiomer of amlodipine had no effect. This study shows that the R+ enantiomer of amlodipine is responsible for the release of nitric oxide and not the S- enantiomer (the L-type calcium channel blocking portion of amlodipine). Interestingly, nitric oxide release is dependent on the production of kinins because it is blocked by HOE-140. This study defines a potentially important property by which calcium channel blockers may release nitric oxide and may contribute to their use in the treatment of cardiovascular disease.     

钩藤碱对血小板聚集和血栓形成的影响

钩藤碱(Rhy)明显抑制AA,胶原及ADP诱导的大鼠血小板聚集。Rhy不影响血小利用外源性AA合成TXA_2,但抑制胶原诱导的TXA_2生成;在抗血小板聚集有效剂量时,对PGI_2的生成无影响。Rhy有显著降低血栓形成诱导剂ADP及胶原加肾上腺素静脉注射所致小鼠死亡率。     

Management of low-grade lymphomas in Hong Kong Chinese

During a 14-year period, 122 of 840 (14.5) Hong Kong patients with non-Hodgkin's lymphomas were diagnosed to have low-grade lymphomas according to the Working Formulation. Only 28 (23%) of them had stage I and II disease and local radiotherapy appeared to be curative in some of them. Although remissions were achieved with chemotherapy in a majority of the stage III and IV patients, a pattern of continuous relapses was noted in their disease-free survival curve. Multivariate analysis revealed that clinical stage and presence of B symptoms were significant independent prognostic factors.     

Aspirin or paracetamol – what’s good for you?

Paracetamol is widely used as an over the counter analgesic because it is perceived to be safer than aspirin. In carefully selected trial populations, aspirin therapy carries a relatively low (but statistically significant) absolute risk increase in gastrointestinal adverse events. The risk from aspirin may potentially be higher in individuals who have risk factors for peptic ulcer or gastrointestinal haemorrhage. As such, paracetamol may well be the preferred choice in many instances.     

Pharmacokinetic and pharmacodynamic interactions between caffeine and diazepam

The pharmacokinetic and dynamic interactions of caffeine and diazepam after single doses were investigated in six young healthy adults. Subjects received 6 mg/kg of caffeine, 0.3 mg/kg of diazepam, and their combination at 2-week intervals according to a Latin square design and a double-blind procedure. Subjects had blood samples withdrawn at 0, 5, 10, 20, 30, 45, 60 minutes and every 30 minutes thereafter until 210 minutes after treatment. A battery of behavioral tests were administered before treatment and after each blood sampling, starting with the 20-minute period. The coadministration of caffeine with diazepam resulted in a 22% reduction in diazepam plasma levels. Caffeine produced hand tremors and diazepam produced sedation and impaired memory and cognition. The two drugs did not antagonize the effects of each other except in the symbol cancellation task. There were significant correlations between the caffeine and diazepam plasma levels and performance on several tasks and evidence for the development of acute tolerance to both drugs.     

Dietary habits of patients with coronary atherosclerosis: case-control study

AIM: The aim of this study was to identify the dietary-related risk factors for coronary atherosclerosis among Hong Kong Chinese people. BACKGROUND: Prevalence and mortality figures for coronary atherosclerosis are increasing in Chinese communities, including those in Hong Kong. Changes in dietary patterns might explain the increased risk of coronary artery disease among the Hong Kong Chinese. METHOD: A total of 145 consecutive patients scheduled to have coronary angiogram in a regional hospital in Hong Kong completed a self-reported questionnaire on their dietary intake for 1 week. A case-control design was used, and the data were collected from December 2000 to February 2001. RESULTS: Consumption of more than 1120 g of fish [28 tael (Chinese weight unit, 1 tael equals approximately 42 g)] per week (OR = 0.07) and soybean (OR = 0.17) had a beneficial effect in preventing coronary atherosclerosis. In addition, an increased waist-hip ratio (OR = 4.81) and consumption of more than 28 teaspoons of fat per week (OR = 42.36) were identified by logistic regression as independent risk factors for coronary atherosclerosis. Moreover, people who smoked (OR = 1.72), had a lower educational level (OR = 0.51) or higher family income (OR = 1.92) were more vulnerable to coronary atherosclerosis. Patients confirmed as having coronary atherosclerosis were more likely than those with normal coronary vessels to rank deep fry, stir fry, and pan fry as their preferred cooking methods over steaming or boiling. CONCLUSION: The results provide nurses with information on which to develop appropriate health education programmes for patients and the general public in Hong Kong to promote cardiovascular health. Efforts should be directed particularly to promoting boiling and steaming as major cooking methods, rather than frying or deep frying, as protective actions against coronary atherosclerosis.