早产儿维生素D需求

美国儿科学会建议新生儿、儿童、青少年尽早开始补充维生素D,推荐补充量为400IU/d,同时建议早产儿也应补充维生素D,但未指出早产儿维生素D的具体需要量.早产儿需要综合考虑胎儿及新生儿的健康需求,因此,调研维生素D的需要量,明确体内维生素D的状态,评价补充剂量的安全性及有效性对保证早产儿的健康有决定性意义.     

The effects of background white noise on memory performance in inattentive school children

Background  

Noise is typically conceived of as being detrimental for cognitive performance; however, a recent computational model based on the concepts of stochastic resonance and dopamine related internal noise postulates that a moderate amount of auditive noise benefit individuals in hypodopaminergic states. On the basis of this model we predicted that inattentive children would be enhanced by adding background white noise while attentive children's performance would deteriorate.     

Concomitant administration of granulocyte transfusions and amphotericin B in neutropenic patients: absence of significant pulmonary toxicity

One hundred and ninety-five series of granulocyte transfusions in 144 patients were evaluated with respect to possible severe pulmonary toxicity from concomitant administration of granulocytes and amphotericin B. Dyspnea as a side effect of granulocyte transfusion was equally common among patients receiving amphotericin B and those in a matched control group not receiving amphotericin B. Granulocyte transfusions and amphotericin B were given simultaneously in 35 transfusion series, involving 32 patients. Respiratory deterioration, defined as the appearance of new pulmonary infiltrates on chest x-ray, occurred in 11 of these 35 episodes. Patients developing respiratory deterioration were similar to those not developing respiratory deterioration in age, diagnosis, disease status, duration of concomitant therapy, and outcome, but more often had positive fungal cultures as an indication for treatment (91% versus 58%; p = 0.1). In 8 patients, the episodes of respiratory deterioration were readily explained by congestive heart failure, by simultaneous bacteremia or fungemia, or by fungal pneumonia discovered at autopsy. One patient had a leukoagglutinin reaction (responsive to steroids) and the other 2 had unexplained, but reversible respiratory deterioration. We concluded that concomitant administration of granulocyte transfusions and amphotericin B is not associated with unexpected or rapidly fatal pulmonary toxicity and when appropriate, can be safely accomplished.     

Metabolism of ara-C by blast cells from patients with ANLL

The dose-response relationship between extracellular concentration of cytosine arabinoside (ara-C) and intracellular formation of the putative active metabolites of ara-C [ara-C incorporation into DNA and intracellular pools of ara-C in triphosphate form (ara-CTP)] was investigated in blast cells obtained from patients with acute nonlymphocytic leukemia (ANLL) by exposing these cells in vitro to 10, 100, or 1,000 nmol/L of ara-C. We studied 23 untreated patients who subsequently achieved complete remission (CR) with a regimen using daunorubicin and conventional doses of ara-C (ara-C-sensitive group), and 30 patients judged to be ara-C-resistant either by failing initial induction therapy (16 patients) or by having relapsed on an ara-C- containing maintenance regimen (14 patients). In both patient groups, ara-C incorporation into DNA and intracellular ara-CTP both displayed statistically significant increases in response to increasing extracellular concentrations of ara-C (P = .0001 in both cases), with the rate of increase of ara-CTP greater than that of ara-C incorporation. Moreover, blast cells from all patients, even those who were most clinically resistant to ara-C, were able to form ara-CTP and to incorporate ara-C into DNA. Each tenfold increment in extracellular ara-C concentration caused an 8.5-fold increase in ara-CTP, but only a 3.6-fold increase in ara-C incorporation into DNA. Thus, the efficiency of incorporation of ara-C into DNA (defined as the ratio of ara-C incorporation to ara-CTP pools) decreased by 58% with each tenfold increment in the extracellular concentration of ara-C (P less than .0001), presumably as a result of the inhibitory effect of ara-CTP on DNA polymerase. Using an analysis of covariance, modest differences were found in the levels of the ara-C metabolite variables in the ara-C- sensitive group as compared with the resistant group. However, because there was considerable overlap in ara-C metabolite formation among the patient groups, it was not possible to predict clinical outcome by these in vitro assessments of ara-C metabolism.     

Differential north to south gastric cancer-duodenal ulcer gradient in China

There are suggestions that duodenal ulcer protects individuals from gastric cancer and that rice is ulcerogenic while wheat is gastro-protective. We aimed to examine the relationship of gastric cancer, duodenal and gastric ulcers in different geographical regions in China and identified dietary risk factors for duodenal ulcer and gastric cancer. The prevalence of peptic ulcer and gastric cancer among symptomatic patients in eight major cities, four each from the north and the south representing all the six defined regions of China were studied. Endoscopy and case records over a 10 year period were reviewed and cases of confirmed duodenal and gastric ulcer and gastric cancer, together with the total number of endoscopies performed per year, were recorded. Rates were expressed as cases/1000 endoscopies. Results were compared to another epidemiological study on diet and mortality in the same regions in China conducted at the same time. Duodenal ulcer rates were 2.4-fold higher in southern China than northern China, whereas gastric cancer rates were 1.6-fold higher in the north than in the south. Correlation studies showed for the first time an inverse linear relationship between the gastric cancer rates and the duodenal ulcer rates (r=-0.8076, P=0.015), as well as the duodenal ulcer: gastric ulcer ratios (r=-0.9133, P=0.002). Gastric ulcer rates were higher in southern China but did not correlate with the gastric cancer rates (r=0.1455, P=0.731). Duodenal ulcer rates were found to be related to daily rice intake (r=0.8554, P=0.029) and inversely related to daily wheat flour intake (r=-0.8472, P=0.033). Gastric cancer rates were not related to any dietary risk factors tested. We concluded there was an inverse relationship between gastric cancer rates and duodenal ulcer rates. Although duodenal ulceration and gastric cancer are both linked to Helicobacter pylori infection, the findings of this study indicate independent additional aetiological factors for the pathogenesis of these conditions. Dietary factors such as rice or wheat intake may play a role.