The evolving ribosome: from non-coded peptide bond formation to sophisticated translation machinery

Structural analysis supported by biochemical, mutagenesis and computational evidence, revealed that the contemporary ribosome's active site is a universal symmetrical pocket made of ribosomal RNA. This pocket seems to be the remnant of the proto-ribosome, a dimeric RNA assembly evolved by gene duplication, capable of autonomously catalyzing peptide bond formation and non-coded amino acid polymerization.     

Distorting the visual size of the hand affects hand pre-shaping during grasping

Vision of the body is known to affect somatosensory perception (e.g. proprioception or tactile discrimination). However, it is unknown whether visual information about one’s own body size can influence bodily action. We tested this by measuring the maximum grip aperture (MGA) parameter of grasping while eight subjects viewed a real size, enlarged or shrunken image of their hand reaching to grasp a cylinder. In the enlarged view condition, the MGA decreased relative to real size view, as if the grasping movement was actually executed with a physically larger hand, thus requiring a smaller grip aperture to grasp the cylinder. Interestingly, MGA remained smaller even after visual feedback was removed. In contrast, no effect was found for the reduced view condition. This asymmetry may reflect the fact that enlargement of body parts is experienced more frequently than shrinkage, notably during normal growth. In conclusion, vision of the body can significantly and persistently affect the internal model of the body used for motor programming.     

Enzymatic activity of glycogen metabolism in chorionic villi

Glycogen content and six major enzymatic activities involved in glycogen metabolism were analysed in chorionic villi (CV). Glycogen levels were found to be lower than those known to exist in liver and muscle. Activities of alpha-glucosidase, amylo-1,6-glucosidase, phosphorylase b and phosphorylase kinase were detectable by standard methods. The enzymatic activities of glucose-6-phosphatase and phosphorylase a were undetectable. These findings suggest that CV biopsies can be useful for first-trimester diagnosis of glycogen storage disease types II, III and VI, but not for type I (glucose-6-phosphatase deficiency).     

The effect of the duration of the second stage of labour on the acid-base state of the fetus

A prospective study was made in 153 patients with a second stage of labour lasting 1 to 120 min. Maternal venous, umbilical artery and vein blood were analysed for acid-base variables and lactate levels. Blood was obtained immediately at delivery. Fetal heart rate monitoring data and blood test results were related to the duration of the second stage of labour and clinical outcome. In primiparae and multiparae there was a steady rise in umbilical artery lactate levels, with duration of second stage of labour, P less than 0.025 and P = 0.023, respectively. The median umbilical artery pH decreased significantly from 7.31 in patients with a second stage of labour that lasted less than or equal to 15 min to a pH of 7.25 in patients with a second stage of labour that lasted more than 30 min. Changes in PO2 and PCO2 were not statistically significant.     

An algorithmic approach to diagnosis of hypoglycemia

An algorithm has been devised to facilitate the diagnostic approach to the causes of hypoglycemia. This systematic approach enables the physician to reach the final diagnosis in a logical way without subjecting the child to unnecessary and possibly hazardous investigations. The algorithm is based on the following measurements as required by each patient: concentrations of blood glucose, lactate, ketone bodies, and glucose-regulating hormones. These measurements are performed with the patient in the fasting state and after loading tests (glycerol and galactose) as needed. If indicated, an enzymatic test is performed to establish the final diagnosis. Eighteen children aged 1 month to 7 years who had persistent or recurrent hypoglycemia have been examined according to this algorithm. The correct diagnosis was arrived at in 17 patients. The diagnosis was not reached in one neonate who had glucose-6-phosphatase deficiency and initially did not have lactic acidosis; once lactic acidosis developed, his illness fitted perfectly into the algorithm.     

Nursing of tracheostomy

In this abstract we have analyzed the different techniques of tracheostomy, considering new semplified methods of this procedure and therefore the common use of it in weaning from mechanical ventilation the critical care patients. We've tried to summarize guide lines of the preoperative, operative and postoperative procedures of tracheostomy, comparing our nursing clinical experience in ICU and the latest literature. We've primarily analyzed the nursing aspects of this issue, trying to focus on the priority of the treatment of the tracheostomezed patient.     

Melatonin production in infants

This study investigated the relationships of the excretion of the melatonin metabolite, 6-sulfatoxymelatonin, to prenatal, natal, and postnatal variables and its possible relation to psychomotor development. nocturnal urinary excretion of 6-sulfatoxymelatonin was studied over a 13-hour period in 355 term infants at 8 weeks of age (n = 320) and 16 weeks of age (n = 96). data on a variety of perinatal factors including pregnancy course, delivery, early postnatal course, birth weight, medical problems, growth (length, weight, and head circumference), and psychomotor development were collected at 1, 3, 6, 9, 12, and 18 months. the relationship between nocturnal 6-sulfatoxymelatonin excretion at 8 and 16 weeks of age and these factors was investigated and analyzed. 6-sulfatoxymelatonin levels at 16 weeks of age were significantly lower in infants with abnormal vs normal development at 3 months of age (7.27 + 1.44 vs 7.97 + 1.06, p = 0.05) as well as at 6 months of age (7.15 + 1.29 vs 7.95 + 1.10, p = 0.04). no other significant relation was evident among growth, perinatal complications, medical problems, and 6-sulfatoxymelatonin excretion at 8 weeks of age and at 16 weeks of age. low melatonin excretion in the first weeks of life correlates with delayed psychomotor achievements at 3 and 6 months of age. this association suggests a causal or predictive link between melatonin and neurodevelopment in infants.     

Predictive factors associated with long-term survival in patients with neuroendocrine tumors of the pancreas

Background Neuroendocrine tumors of the pancreas are rare tumors. We identified predictive factors that are associated with long-term survival (≥5 years). Methods Fifty patients with a diagnosis of neuroendocrine tumors of the pancreas were retrospectively evaluated. The following factors were evaluated for disease-specific mortality: age, sex, primary tumor location, functional status, type of primary tumor treatment, presence or absence of liver metastases, timing of liver metastases occurrence, and type of liver metastases treatment. Aggressive treatment of the liver metastases included surgery, chemoembolization, or intrahepatic arterial infusion chemotherapy. Results Twenty-three patients (47%) had tumor located in the head of the pancreas, and 29 patients (58%) had nonfunctioning tumor. Thirty-nine patients (78%) had liver metastases. The median follow-up for the entire group was 35 months (range, 76–206 months). The median survival for the entire group was 40 months, and the overall 1-, 2-, and 5-year survival rates were 84%, 69%, and 36%, respectively. Factors that had a significant favorable effect on survival included curative resection of the primary tumor, metachronous liver metastases, absence of liver metastases, and aggressive treatment of the liver metastases. Conclusions Definitive surgical resection of the primary tumor, absence of liver metastases, metachronous liver metastases, and aggressive treatment of the liver metastases were predictors of long-term survival in patients with neuroendocrine tumors of the pancreas. Presented as a poster presentation at the Society of Surgical Oncology 55th Annual Cancer Symposium, Denver, Colorado, March 14–17, 2002.