Extrahepatic portal venous obstruction in childhood: Etiology,clinical and laboratory findings and prognosis of 34 patients

Extrahepatic obstruction of the portal vein is a well known cause of portal hypertension in childhood, that causes severe morbidity. We evaluated 34 children (24 boys, 10 girls, age 4.5 months to 12 years, mean 5.5 ± 3.8 years) with this diagnosis, to define the clinical picture, laboratory changes, diagnostic tools and therapeutic modalities. Gastrointestinal bleeding was the commonest mode of presentation (64.7%), with the second being splenomegaly. The cause of the obstruction could be determined in 38.2% (13/34) of the subjects. At the beginning of the study the main diagnostic procedure was splenoportography although in more recent years pulsed duplex Doppler ultrasonography has been used. The follow up period was a median of 5 years (range 1–11 years). The mean number of bleeding episodes was 4.7 ± 5.9 (range 1–26), while nine patients never bled. There was no mortality. Ten patients underwent surgery, while sclerotherapy was performed on 10. Twenty-one patients received beta-blocker drugs. No difference was found among these therapeutic modalities. It is well established that the major risk for children with extrahepatic portal vein obstruction is gastrointestinal bleeding which is tolerated quite well. Surgery should be indicated only in children where bleeding cannot be controlled by medical means including sclerotherapy.     

Digital chest radiography: effect on diagnostic accuracy of hard copy, conventional video, and reversed gray scale video display formats

Observer performance tests were conducted to compare the effects on diagnostic accuracy of hard copy (film) versus video display and to determine the diagnostic merits of conventional negative ("white bone") versus positive ("black bone") video displays. Subjective preferences were elicited from each observer for each display modality, and diagnostic accuracy was determined with receiver operating characteristic analysis. Digitized chest radiographs were used, including normal and abnormal cases with a variety of subtle abnormalities. The hard copy was printed with a 1,024 X 1,024-matrix by a high-quality drum scanner in conventional white bone format only. The video images were displayed on a 1,023-line monitor (30 Hz, interlaced) in both white bone and black bone formats with fixed window and brightness settings. Most observers preferred hard copy to video, but preferences were sharply divided between white bone and black bone video. Diagnostic accuracy was significantly greater with hard copy than with video display, and the conventional white bone format was significantly superior in accuracy to the black bone display.     

Nutritional practices in type II diabetic patients in primary care. Mexican Social Security Institute

Nutritional practices of diabetics reflect both human behavior and the health culture of such patients. They also represent how the diabetic deals with the health/illness issue. The purpose of this survey was to identify and relate nutritional practices with metabolic control, age, sex, years of schooling, and time since diagnosis of illness. The sample was taken from 114 cases selected through systematic random sampling in five family practice units in Guadalajara. Using thirteen structured, coded, and quantified questions of the Likert type, the study evaluated nutritional practice with a range of 0-65. Results showed that 21% of the diabetics had appropriate nutritional practices (>31 points), and when related with years of schooling and time since diagnosis of illness, they showed statistically significant differences (p=0.05). Simple regression showed that 9% of metabolic control can be explained by nutritional practices.     

Changes in platelet aggregation during cardiopulmonary bypass: comparison of poly-2-methoxyethylacrylate and heparin as a circuit coating material

At present, there are various biomaterials that have high biocompatibility. In particular, there are many types of coated circuits in cardiopulmonary bypass (CPB) systems. However, only a few clinical studies have investigated platelet aggregation caused by these coated circuits. In this study, a CPB system coated with poly-2-methoxyethylacrylate (X coating) was used to ascertain whether platelet aggregation could be suppressed during CPB, and a comparison was made between X coating and ordinary (covalently bonded) heparin coating. The subjects were 19 adult patients who were scheduled to undergo valve replacement or valvuloplasty. They were divided into two groups: group X (X coating) and group H (heparin coating). The platelet aggregation threshold index (PATI, grading curve) and β-thromboglobulin and plalelet factor IV levels were assessed preoperatively (control), 5 min after heparin administration, 10 and 60 min after the start of CPB, and 0 and 2 h after the end of CPB. The results indicated that platelet aggregation was reduced during CPB and that platelets were activated. The changes in platelet aggregation associated with the X coating were shown to be similar to those associated with heparin coating.     

Little people, big discovery

Mutations in the pericentrin (PCNT) gene cause primordial dwarfism
Anita Rauch et al. (2008)
Science 319: 816–819     

Human methionine synthase: cDNA cloning and identification of mutations in patients of the cblG complementation group of folate/cobalamin disorders

Methionine synthase catalyzes the remethylation of homocysteine to methionine in a methylcobalamin-dependent reaction. We used specific regions of homology within the methionine synthase sequences of several lower organisms to clone a human methionine synthase cDNA by a combination of RT-PCR and inverse PCR. The enzyme is 1265 amino acids in length and contains the seven residue structure-based sequence fingerprint identified for cobalamin-containing enzymes. The gene was localized to chromosome 1q43 by the FISH technique. We have identified one missense mutation and a 3 bp deletion in patients of the cblG complementation group of inherited homocysteine/folate disorders by SSCP and sequence analysis, as well as an amino acid substitution present in high frequency in the general population. We discuss the possibility that a mild deficiency of methionine synthase activity could be associated with mild hyperhomocysteinemia, a risk factor for cardiovascular disease and possibly neural tube defects.      

Human leukemia cell line K562 responds to erythroid-potentiating activity

We report that erythroid-potentiating activity (EPA), known to stimulate the proliferation of normal human erythroid precursors in vitro, has a growth-promoting effect on human K562 erythroleukemia cells and Friend mouse erythroleukemia cells. Detailed studies were carried out using an EPA produced by a human T-lymphoblast line (Mo). Although EPA has not been purified to homogeneity, several observations indicate that the factor elaborated by Mo cells that stimulates erythroleukemia cell growth is the EPA molecule. The erythroleukemia growth factor cofractionates with EPA using gel exclusion chromatography, isoelectric focusing, and ion exchange chromatography. In addition, the activities exhibit similar kinetics of heat inactivation. A granulocyte-macrophage colony-stimulating factor also elaborated by Mo cells had no effect on the growth of the erythroleukemia cells. Other sources of EPA, such as peripheral blood leukocyte-conditioned medium, preparations from urine of anemic patients, and medium conditioned by a human monocyte-like cell line, stimulated erythroleukemia cell growth. Mouse sources of EPA (termed "burst-promoting activity") stimulated mouse but not human erythroleukemia cells. The availability of cell lines apparently responsive to EPA should prove useful for examining the mode of action of this regulator of erythropoiesis.     

Molecular genetic and phenotypic analysis reveals differences between TSC1 and TSC2 associated familial and sporadic tuberous sclerosis

Tuberous sclerosis (TSC) is an autosomal dominant disorder characterised by the development of hamartomatous growths in many organs. Sixty to seventy percent of cases are sporadic and appear to represent new mutations. TSC exhibits locus heterogeneity: the TSC2 gene is located at 16p13.3 whilst the TSC1 gene, predicted to encode a novel protein termed hamartin, has recently been cloned from 9q34. With the exception of a contiguous gene deletion syndrome involving TSC2 and PKD1 , TSC1 and TSC2 phenotypes have been considered identical. We have now comprehensively defined the TSC1 mutational spectrum in 171 sequentially ascertained, unrelated TSC patients by single strand conformation polymorphism and heteroduplex analysis of all 21 coding exons, and by assaying a restriction fragment spanning the whole locus. Mutations were identified in 9/24 familial cases, but in only 13/147 sporadic cases. In contrast, a limited screen revealed TSC2 mutations in two of the familial cases and in 45 of the sporadic cases. Thus TSC1 mutations were significantly under-represented among sporadic cases (Fisher's exact p -value = 3.12 x 10(-4)). Both large deletions and missense mutations were common at the TSC2 locus whereas most TSC1 mutations were small truncating lesions. Mental retardation was significantly less frequent among carriers of TSC1 than TSC2 mutations (odds ratio 5.54 for sporadic cases only, 6.78 +/- 1.54 when a single randomly selected patient per multigeneration family was also included). No correlation between mental retardation and the type of mutation was found. We conclude that there is a reduced risk of mental retardation in TSC1 as opposed to TSC2 disease and that consequent ascertainment bias, at least in part, explains the relative paucity of TSC1 mutations in sporadic TSC.      

Cognitive decline tracks motor progression and not disease duration in Parkinson patients

We performed an analysis of prospectively-acquired cross sectional data on 106 Parkinson disease (PD) patients who underwent comprehensive neuropsychological testing and the Unified Parkinson Disease Rating Scale (UPDRS) motor scale. A significant correlation between the UPDRS motor and neuropsychological tests in all cognitive domains except for general intelligence and visuo-spatial function was seen. In this study, cognitive decline within this PD cohort correlated with motor impairment but not disease duration. Our findings suggest that overall cognitive impairment (except visuospatial dysfunction) may track motor progression in PD more than duration of disease. Longitudinal studies are needed to confirm our results.