Retinoid-binding proteins in the cerebellum and choroid plexus and their relationship to regionalized retinoic acid synthesis and degradation

The expression of cellular retinoic-acid-binding protein (CRABP) and cellular retinol-binding protein (CRBP), as well as their relationship to retinoic acid (RA) synthesis and degradation were examined in the developing mouse cerebellum and choroid plexus of the fourth ventricle. The choroid plexus, which expresses the RA-synthesizing retinaldehyde dehydrogenase RALDH-2, is likely to represent a diffusion source of RA for the closely apposed cerebellum, regulating its development. We found CRBP to be expressed in the choroid plexus and, in an in-vitro assay, addition of recombinant CRBP to RALDH-2 increased RA synthesis from retinaldehyde, with the amount of increase depending on the CRBP/retinaldehyde ratio. A technique that characterizes RA-binding proteins according to their isoelectric point showed both CRABP I and CRABP II to be present in the cerebellum and P19 cells, and only CRABP II to be present in the choroid plexus. With this technique, CRABP I could also be detected in the HL60 cell line. In addition to the two known acidic RA-binding proteins CRABP I and II, the cerebellum expressed a third RA-binding protein distinguishable by its neutral isoelectric point; the same binding protein was also detected in the olfactory bulb, kidney and testes. We used the RA-binding technique to follow the rate of elimination of bound RA from the cerebellum. A systemic injection of 0.3 micromols RA into postnatal day-1 mice was almost completely removed after 8 hours. These results suggest mechanisms by which the retinoid-binding protein may regulate the equilibrium of RA synthesis and catabolism in the cerebellum and choroid plexus.     

Characterization of rifamycin oxidase immobilized on alginate gel

Rifamycin oxidase of Curvularia lunata was immobilized on alginate gel. The pH and temperature optima of the immobilized enzyme preparation were 6.5 and 50 degrees C, respectively. Transformation reaction was carried out with the immobilized enzyme preparation. It took 8 h for the complete transformation of rifamycin B (10 g/L) to rifamycin S. The immobilized enzyme preparation was found to be mechanically weak even in the presence of CaCl2 in the reaction mixture. Reusability studies showed that the catalyst can not be repeatedly used very effectively.     

Follow-up of renal function and urinary protein excretion in childhood IgA nephropathy

Homocystinuria is a rare inherited metabolic disease. Arterial and venous thromboembolic events represent frequent and life-threatening complications in homocystinuric patients. It has been suggested that mild homocysteinemia could be a risk factor for vascular disease. We have therefore measured total plasma homocysteine (HCy) concentrations by radioisotopic assay in 50 subjects with venous or arterial thrombosis and studied the relationship between HCy, coagulation and fibrinolytic parameters. Values were considered abnormal if they were higher than 2.7 standard deviations (SD) above the mean, i.e., 14.1 mmol/l. Thus, eighteen of the 50 patients with thrombosis were classified in the hyperhomocysteinemia group. Nine of these subjects had only this isolated risk factor. No correlations were found between HCy and antithrombin III, protein C, protein S and plasminogen levels, or plasma plasminogen activator inhibitor activity. Nevertheless, the correlation between tissue-plasminogen activator antigen and total plasma HCy was significant (r = 0.61, p < 0.001). Increased homocysteinemia seems to be a risk factor for thrombotic events especially knowing that HCy presents a direct cytotoxic effect. Vitamin therapy, already used in homozygote homocystinuric patients, might be beneficial in the prevention of thromboembolic disease in heterozygous patients.     

Planning and execution of action in children with and without developmental coordination disorder

Ninety-five children from six English primary schools were identified on the basis of the Movement Assessment Battery for Children (Movement ABC) as having developmental coordination disorder (DCD) and, together with age- and ability-matched controls, were given three tasks that involved proprioception in the control and discrimination of limb position, and two tasks that involved planning for end state comfort after a bar was grasped and turned. The children in the DCD group performed less well on the majority of the proprioceptive tasks, but did not differ from controls in planning of grip selection. There was an improvement in grip planning with age. The results are contrasted with research indicating that people with autism do have a difficulty with planning grip selection.     

Urinary tract infections in children due to Pseudomonas aeruginosa in Enugu, Nigeria

Ileal duplication cysts within a giant omphalocele are very rare. Only a few cases have been reported in the English literature (4). We report one case of giant omphalocele, which included a huge ileal duplication cyst, detected by prenatal US, and diagnosed at surgery after birth. This case illustrates the diagnostic and therapeutic problems occurring during pregnancy and the neonatal period.     

Determination of critical level of zinc in non-calcareous soils for predicting response of wheat to applied zinc

Studies were conducted in ten non-calcareous arid brown soils (India) to determine the critical level of soil Zn for predicting response of wheat to zinc fertilization. The per cent mean response at 5 mg kg^–1 added Zn varied from 1.3 to 51.4 with a mean value of 17.5 per cent over control in terms of grain yield (g pot^–1). Further, Zn application resulted in significant increase in Zn concentration in various plant parts in all the soils irrespective of the initial Zn status. The critical level of Zn in soil and plant below which response to applied Zn may be expected was found to be 1.75 mg kg^–1 for 0.1 N HC1 extractable soil Zn and 1.7 mg kg^–1 for plant tissue Zn.     

High-density screen of human tumor cell lines for homozygous deletions of loci on chromosome arm 8p

The purpose of this article is to describe a study that implemented concept maps as a methodology to teach and evaluate critical thinking. Students in six senior clinical groups were taught to use concept maps. Students created three concept maps over the course of the semester. Data analysis demonstrated a group mean score of 40.38 on the first concept map and 135.55 on the final concept map, for a difference of 98.16. The paired t value comparing the first concept map to the final concept map was -5.69. The data indicated a statistically significant difference between the first and final maps. This difference is indicative of the students' increase in conceptual and critical thinking.     

Endosonographic evaluation of the rectum in children with extrahepatic portal venous obstruction

OBJECTIVE: To determine the mechanism of the adverse relationship between perioperative blood transfusion and lung cancer recurrence, by focusing on endothelial cell adhesion molecules (CAMs), which are thought to play a role in distant tumor cell implantation. DESIGN AND OUTCOME MEASURES: Murine endothelial cells were cocultured with allogeneic leukocytes, syngeneic leukocytes, and syngeneic lung carcinoma cells for 60 hours. The percentage of endothelial cells expressing vascular CAMs (VCAMs) and intercellular CAMs (ICAMs) was quantified during this time using indirect immunofluorescence and flow cytometry. Tumor cell adhesion to the endothelium was quantified for 6 hours using cells labeled with sulfur 35 and a scintillation counter. SETTING: Laboratory. MATERIALS: C57/BL and Balb/C mice. RESULTS: Vascular CAM was not expressed on the endothelium, but ICAM was preferentially expressed without stimulation. Tumor-cell adhesion and endothelial ICAM expression were inversely related. After 15 hours of coculture, tumor cell adhesion was four-fold greater in the experimental group than in the control, and coincident endothelial ICAM expression was fourfold lower. CONCLUSION: Endothelial cell ICAM expression is negatively correlated with metastatic potential.