Similar dose responsiveness of hepatic glycogenolysis and gluconeogenesis to glucagon in vivo

This study was undertaken to determine whether the dose-dependent effect of glucagon on gluconeogenesis parallels its effect on hepatic glycogenolysis in conscious overnight-fasted dogs. Endogenous insulin and glucagon secretion were inhibited by somatostatin (0.8 micrograms X kg-1 X min-1), and intraportal replacement infusions of insulin (213 +/- 28 microU X kg-1 X min-1) and glucagon (0.65 ng X kg-1 X min-1) were given to maintain basal hormone concentrations for 2 h (12 +/- 2 microU/ml and 108 +/- 23 pg/ml, respectively). The glucagon infusion was then increased 2-, 4-, 8-, or 12-fold for 3 h, whereas the rate of insulin infusion was left unchanged. Glucose production (GP) was determined with 3-[3H]glucose, and gluconeogenesis (GNG) was assessed with tracer (U-[14C]alanine conversion to [14C]glucose) and arteriovenous difference (hepatic fractional extraction of alanine, FEA) techniques. Increases in plasma glucagon of 53 +/- 8, 199 +/- 48, 402 +/- 28, and 697 +/- 149 pg/ml resulted in initial (15-30 min) increases in GP of 1.1 +/- 0.4 (N = 4), 4.9 +/- 0.5 (N = 4), 6.5 +/- 0.6 (N = 6), and 7.7 +/- 1.4 (N = 4) mg X kg-1 X min-1, respectively; increases in GNG (approximately 3 h) of 48 +/- 19, 151 +/- 50, 161 +/- 25, and 157 +/- 7%, respectively; and increases in FEA (3 h) of 0.14 +/- 0.07, 0.37 +/- 0.05, 0.42 +/- 0.04, and 0.40 +/- 0.17, respectively. In conclusion, GNG and glycogenolysis were similarly sensitive to stimulation by glucagon in vivo, and the dose-response curves were markedly parallel.     

全科医生札记--布朗医生日记

汽车机械学 Bobby是我的汽车修理师，他有一种我喜欢效仿的工作风格。首先他是一位伟大的诊断专家；如果你告诉他汽车出现了什么问题，他会帮你做出鉴别诊断。“运货车是否发动不着了？发动机是否转动？你是否听到了滴滴答答的声音？”问了几个问题后，他便会做出判断。比如我的发动机供不上汽油了，排除了几种可能性后他认为是由燃油泵造成的。     

A methodological review of non-therapeutic intervention trials employing cluster randomization, 1979-1989

A methodological review is presented of 16 non-therapeutic intervention trials published over the last decade which have randomized intact clusters rather than individuals in treatment groups. Each of the trials was surveyed as to the information supplied on six methodological criteria. Although there is increasing recognition of the methodological issues associated with cluster randomization, many investigators are still not aware of the impact of this design on sample size requirements and analysis considerations. Investigators are urged to publish the cluster-specific event rates observed in their trials as a guide for the planning of future studies.     

Impact of a Pharmacist-Based Consult Service on Nutritional Rehabilitation of Nonambulatory Patients with Severe Developmental Disabilities

A pharmacist consult service was developed to evaluate the appropriateness of enteral feeding through a permanent ostomy in 24 nonambulatory patients with severe developmental disabilities. Several problems with enteral nutrition were identified. Policies to improve them were instituted, and several educational presentations were made. Pharmacists' actions were implemented, including assessment of energy needs by indirect calorimetry and rearrangement of enteral feeding schedules to achieve optimal nutrition support and pharmacotherapy administration. By the fourth month of the consult service, body weight in these patients increased from 101 ± 6% of baseline to 109 ± 7% (p<0.05). Weight continued to increase through the seventh month of the consult service to 116 ± 12% of baseline (p<0.0001). Measured resting energy expenditure for the group was 889 ± 170 kcal/day compared with the predicted 1055 ± 163 kcal/day.     

Binucleated and multinucleated forms of plasma cells in synovia from patients with rheumatoid arthritis

A morphological examination of synovial tissue from 25 patients with rheumatoid arthritis revealed that binucleated or multinucleated plasma cells were present in all samples and absent in synovia obtained from 16 control patients. Plasma cells containing two, three of four nuclei constitutet a mean 3% of the total plasma cell population. They were aways found amongst plasma cell infiltrates and in close association with small blood vessels. Ultrastructural analysis found no evidence of cellular membranes separating the individual nuclei in binucleated or multinucleated plasma cells, suggesting that the cells did not arise from fusion. Some of these plasma cells had a diameter approaching 100 μm, and many were in intimate contact with macrophages. The demonstration of a few cells with mitotic figures within the infiltrates suggests that the maintenance of plasma cell numbers in rheumatoid synovium may depend, in part, upon their local proliferation. Received: 25 August 1997 / Accepted: 2 October 1997     

Spinal cord stimulation in the treatment of failed back surgery syndrome

A significant number of patients undergoing lumbar spine surgery do not obtain pain relief. Such patients with chronic low back or lower extremity pain may be difficult to treat. A frequent component of therapy is the use of spinal cord stimulation to help control pain. With careful patient selection, many patients can achieve reasonable levels of pain relief. We review recent clinical reports, including prospective and randomized studies, that demonstrate up to three quarters of patients implanted with a spinal cord stimulator for the treatment of failed back surgery syndrome may benefit from its use. This technology must not be indiscriminately applied. Careful patient selection and a period of trial stimulation are vital to the successful use of spinal cord stimulation as treatment for chronic pain.