Protein-bound cobalamin absorption declines in the elderly.

A modified protein-bound cobalamin absorption test was used to study dietary cobalamin absorption in healthy adults of different age groups and patients with isolated low serum concentrations of cobalamin. Dietary cobalamin absorption was significantly reduced in healthy adults aged 55-75 years compared with young adults, with a further reduction in those older than 75 years. No difference was detected between dietary cobalamin absorption in patients with isolated low serum cobalamin and controls of a similar age group. Cobalamin malabsorption was associated with elevated serum gastrin. The diagnostic value of this protein-bound cobalamin absorption test in the elderly was limited by the frequent finding of reduced absorption in healthy elderly people with normal serum cobalamin concentrations. The performance of such tests should be evaluated in different age groups before application in diagnosis.     

Cromolyn sodium in seasonal allergic conjunctivitis

A formulation of 2% cromolyn sodium (CS) ophthalmic solution without the preservative, 2-phenylethanol, was compared with placebo in 58 patients with seasonal allergic conjunctivitis. Selection was based on history and positive skin tests. Neither immunotherapy nor use of antihistamines was allowed. This study was double-blinded and stratified by RAST scores to assure comparable groups. Either CS or placebo was used six times daily. Patients were observed weekly for 5 weeks during the peak of the fall weed-pollen exposure. Nasal symptoms were treated as required with beclomethasone nasal spray, and uncontrolled ocular symptoms were treated with boric acid and ephedrine solution. Nasal and ocular symptoms were recorded. There was a significant suppression of eye symptoms in the group receiving CS ophthalmic solution (p less than 0.02) during weeks 2, 4, and 5. There was a trend for nasal symptoms and the requirement for nasal beclomethasone to be less in patients receiving CS.     

Basal glucose turnover inPsammomys obesus

The aim of this study was to examine wholebody glucose turnover and glucose uptake into individual tissues inPsammomys obesus. The animals were classi-fied according to the level of circulating glucose and insulin in the fed state: group A was normoglycaemic and normoinsulinaemic (glucose <8.0 mmol/l, insulin <150 mU/l), group B was normoglycaemic and hyperinsulinaemic (glucose <8.0 mmol/l, insulin 150 mU/l), and group C was hyperglycaemic and hyperinsulinaemic (glucose 8.0 mmol/l, insulin 150 mU/l). The animals were deprived of food for 6 h, after which they were anaesthetized and cannulated, using the jugular vein for infusions and the carotid artery for blood sampling. Whole-body glucose turnover was measured using a primed-continuous infusion of 6-[³H]-glucose and saline to quantitatively assess hepatic glucose production (HGP), glucose disposal (Rd), and the metabolic clearance rate of glucose (MCR). Following the 2-h infusion period, the glucose metabolic index (Rg) of individual tissues was measured using a fixed-dose bolus of 2-deoxy-[¹⁴C]glucose. Under the steady-state conditions of the experiment, HGP was assumed to be equal to Rd, and both variables were found to be significantly correlated to the fasting glucose concentration (r=0.534,P<0.05,n=19). On the other hand, MCR was found to be inversely correlated to the fasting plasma glucose concentration (r=0.670,P<0.01,n=19). When the animals were divided into three groups as described above, HGP in group C animals was significantly elevated compared with group A (20.8±2.6 vs 12.7±0.6 mg · kg^–1 · min^–1;P<0.05), and MCR showed a tendency to be lower in group C than group A, although the difference was not statistically significant. HGP and MCR were not significantly different between groups A and B. Measurement of the glucose metabolic index in individual tissues showed that group C animals had significantly higher Rg values in muscles and adipse tissues compared with those in group A (P<0.05). In addition, Rg in group B white gastrocnemius and soleus were significantly higher than in group A despite similar rates of HGP and levels of glycaemia. These findings suggest that an early increase in skeletal muscle glucose uptake and hyperinsulinaemia can be demonstrated in group BPsammomysobesus before significant hyperglycaemia.     

回春液补肾助阳药效学的实验研究

回春液由人参、鹿茸、貂鞭等名贵中药组成。有补肾助阳,填精益气等功效。药效学研究证实,该药有促进幼鼠发育及增加去势大鼠前列腺——精液囊的重量,亦显著增加小鼠血红蛋白的含量,表明回春液有雄性激素样作用。