Human myeloid alpha 3-fucosyltransferase is involved in the expression of the sialyl-Lewis(x) determinant, a ligand for E- and P-selectin

The sialyl-Lex determinant (NeuAc alpha 2-->3Gal beta 1-->4[Fuc alpha- 1-->3]GlcNAc) has been identified as a major ligand in the selectin- mediated adhesion of neutrophils and monocytes to activated endothelium or platelets. This carbohydrate epitope is formed by the sequential action of alpha 3-sialyltransferase and alpha 3-fucosyltransferase on N- acetyllactosamine (Gal beta 1-->4GlcNAc) disaccharide termini of glycoconjugates. We have addressed the role of the human myeloid alpha 3-fucosyltransferase in the expression of this epitope at the leucocyte surface by determining its activity in human-mouse leukemic cell hybrids (WEGLI), normal human granulocytes and chronic myeloid leukemia (CML) cells using sialylated and desialylated glycoproteins and oligosaccharides as acceptor substrates. In contrast to what has been reported for the myeloid-type enzyme, we found that the alpha 3- fucosyltransferase of the cells studied can use sialylated acceptors be it that the activity is several times lower than with asialo- substrates. Characterization of the product obtained with a sialylated oligosaccharide indicated that the enzyme can catalyze the formation of the sialyl-Le(x) structure. Flow cytometry of the WEGLI cells using a sialyl-Le(x)-specific monoclonal antibody (MoAb) showed that these cells indeed express sialyl-Lex at their surface, provided that they contain human chromosome 11. Earlier the presence of this chromosome had been correlated with the expression of alpha 3-fucosyltransferase activity. In addition to sialyl-Le(x), WEGLI cells containing chromosome 11 showed high-expression levels of related structures recognized by antibodies VIM-2 and VIM-8, suggesting that fucose addition can occur at both distal and proximal GlcNAc residues in poly- N-acetyl-lactosaminoglycan sequences. Based on the human chromosome contents it could be ruled out that the alpha 3-fucosyltransferase of WEGLI cells is a Lewis-type alpha 3/4- or plasma-type alpha 3- fucosyltransferase, the genes of which have been mapped to chromosome 19. It is concluded that the enzyme studied is of the myeloid-type and indeed is involved in the synthesis of sialyl-Le(x) (and also VIM-2 and VIM-8 structures) in leukocytes provided that its expression is at a sufficiently high level.     

Do programmes of medicine self-administration enhance patient knowledge,compliance and satisfaction?

Self-administration of medicine (SAM) programmes for hospital in-patients have become increasingly popular Such programmes are considered to facilitate education and learning A quasi-experimental, longitudinal study was carried out to examine and compare knowledge acquisition, drug compliance, and satisfaction between patients who self-administered their medications and those who did not Improvements in knowledge and compliance with medication regimes could not be linked directly with a SAM programme All patients had a high level of knowledge of their medications and appeared to be compliant with prescribed drug regimes Study findings support the hypothesis that knowledge improves with time, regardless of how medications are administered, but do not support the hypothesis that patients who self-administrate are more knowledgeable about their medications than those who do not Therefore, SAM programmes may improve patient knowledge but opportunities to obtain knowledge may not be unique to such programmes The ward or unit philosophy may be such that other patients, who are less willing or able to participate directly in their own care, also have the opportunity to improve their knowledge     

Acute abdomen caused by placenta percreta in the second trimester

A woman with a history of "in utero" diethylstilbestrol exposure but no prior uterine surgery presented with an acute abdomen at 21 weeks' gestation. She had hemoperitoneum associated with placenta percreta.     

Imaging the dynamics of the auditory steady-state evoked response

This study used magnetoencephalography (MEG) to examine the dynamic patterns of neural activity underlying the auditory steady-state response. We examined the continuous time-series of responses to a 32-Hz amplitude modulation. Fluctuations in the amplitude of the evoked response were found to be mediated by non-linear interactions with oscillatory processes both at the same source, in the alpha and beta frequency bands, and in the opposite hemisphere.     

Colon perforation following percutaneous nephrostomy and renal calculus removal

Two patients had colonic perforation as a result of percutaneous nephrostomy placement followed by track dilatation and renal calculus removal. We present the technical aspects of nephrostomy placement and stone removal, as well as the clinical diagnosis and management of these cases. Both patients recovered well with conservative therapy and required no surgical intervention. This report reviews the anatomic considerations for percutaneous nephrostomy in patients undergoing renal stone removal.     

Role of paraoxonase (PON1) status in pesticide sensitivity: genetic and temporal determinants

Individual differences in detoxication capacities for specific organophosphorous (OP) compounds are due largely to differences in catalytic efficiency or abundance of the HDL-associated enzyme, paraoxonase (PON1). First, we provide evidence that children less than 2 years of age represent a particularly susceptible population for OP exposure due to low abundance of PON1 and variable onset of plasma PON1 activity. Second, we describe studies examining the neurotoxic effects of chronic, low-level OP pesticide exposure in mice. PON1 knockout (PON1(-/-)) and wild-type mice were exposed chronically (PN4 to PN21) to low levels of chlorpyrifos oxon (CPO). Endpoints included cholinesterase activity, histopathology, gene expression, and behavior. Even at PN4, when PON1 levels were low in wild-type mice, PON1(-/-) mice were more sensitive to inhibition of brain cholinesterase by CPO. At PN22, and persisting as long as 4 months, chronic developmental exposure to 0.18 mg/kg/d or 0.25 mg/kg/d CPO resulted in perinuclear vacuolization of cells in a discrete area of the neocortex and irregular distribution of neurons in the cortical plate, with an increase in the number of affected cells at 0.25mg/kg/d. Third, we describe a transgenic mouse model in which human transgenes encoding either hPON1Q192 or hPON1R192 were expressed at equal levels in place of mouse PON1. The developmental onset of expression followed the mouse time course and was identical for the two transgenes, allowing these mice to be used to assess the importance of the Q192R polymorphism during development. Adult mice expressing hPON1R192 were significantly more resistant than hPON1Q192 mice to CPO toxicity. Our studies indicate that children less than 2 years old, especially those homozygous for PON1Q192, would be predicted to be particularly susceptible to CPO toxicity.     

Villonodular synovitis (PVNS) of the spine

Objective To describe the imaging features of spinal pigmented villonodular synovitis (PVNS).Design and patients We retrospectively reviewed 15 cases of pathologically proven spinal PVNS. Patient demographics and clinical presentation were reviewed. Radiologic studies were evaluated by consensus of two musculoskeletal radiologists for spinal location, spinal segments affected, lesion center, detection of facet origin and intrinsic characteristics on radiography (n =11), myelography (n =7), CT (n =6) and MR imaging (n =6).Results Women (64%) were more commonly affected than men (36%) with an average age of 28 years. Clinical symptoms were pain (45%), neurologic (9%) or both (36%). Lesions most frequently affected the cervical spine (53%) followed by the thoracic (27%) and lumbar regions (20%). The majority of lesions (93%) were centered in the posterior elements with frequent involvement of the pedicle (67%), neural foramina (73%), lamina (67%) and facets (93%). No lesions showed calcification. Determination of a facet origin by imaging was dependent on imaging modality and lesion size. A facet origin could be determined in 45% of cases by radiography vs 67% of patients by CT (n=6) and MR (n=6). Large lesions (greater than 3 cm in at least one dimension) obscured the facet origin in all cases with CT and/or MR imaging (44%,n=4). Small lesions (less than 3 cm in any dimension) demonstrated an obvious facet origin in all cases by CT and/or MR imaging (56%,n=5). Low-to-intermediate signal intensity was seen in all cases on T2-weighted MR images resulting from hemosiderin deposition with blooming effect in one case with gradient echo MR images.Conclusions PVNS of the spine is rare. Large lesions obscure the facet origin and simulate an aggressive intraosseous neoplasm. Patient age, a solitary noncystic lesion centered in the posterior elements, lack of mineralization and low-to-intermediate signal intensity on all MR pulse sequences may suggest the diagnosis in these cases. Small lesions demonstrate a facet origin on CT or MR imaging. This limits differential considerations to synovial-based lesions and additional features of a solitary focus, lack of underlying disease or systemic arthropathy, no calcification as well as low-to-intermediate signal intensity on all MR images should allow spinal PVNS to be suggested as the likely diagnosis.The opinions and assertions contained herein are the private views of the authors and are not to be construed as official or as reflecting the views of the Departments of the Air Force, Army, Navy or Defense.     

Challenges to the measurement of health-related quality of life in children receiving cancer therapy

Measures of health-related quality of life (HRQL) assess those areas of a patient's functioning that are affected by their cancer and its therapy. Although HRQL measures are integrated frequently into studies of survivors of childhood cancer, their use in the assessment of children receiving therapy has been limited by several methodological challenges. These arise from issues specific to measuring HRQL in young children, who comprise a large proportion of the pediatric oncology population, and from issues associated with assessing HRQL during therapy, when the patient's health status is in constant flux. This study summarizes the commonly used HRQL measures, and examines factors that impact their broad application. These include the influence of developmental changes on the content and format of HRQL measures, the role of proxy assessors, the important characteristics of measurement tools used to assess patients receiving active therapy, and the issues related to the ideal timing of serial HRQL assessments in prospective trials.     

Economic evaluation of treatments for cancer in childhood

Treatment of cancer in childhood is an expensive undertaking for the health-care system and for the affected families. As there is a substantial burden of treatment-related morbidity, it is important to determine whether the effects of treatment are worth these monetary costs, especially from a societal perspective. Economic evaluation affords a comparison of the costs and consequences (effects) of relevant therapeutic alternatives. Preference-based measures of health-related quality of life are particularly useful for assessing the effects of treatment, for these tools integrate mortality and morbidity. These measures provide utility scores that can be used as weights on survival data to compute quality-adjusted life years (QALYs). Costs are incurred both within and outside of the health-care system. The former should include those in front-line patient care departments (e.g. nursing); the pro-rated share of the expenses of service departments (e.g. materials management) to those in the front line; and the fully allocated costs for capital invested in lands, building and equipment. The latter are costs borne by families that are both out-of-pocket (e.g. for over-the-counter drugs) as well as related to time spent in providing care, which may involve foregone income. Costs and consequences should be subject to discounting; a process for converting those items incurred in the future into contemporary equivalents. Economic evaluation provides estimates of incremental discounted costs per discounted QALY gained. By almost any interpretative standard this appears attractive with respect to cancer in childhood. Examples are provided with the encouragement that economic evaluation be undertaken in more clinical trials in paediatric oncology.