Effect of the use of an iPad on the attention span of a child with Smith Magenis Syndrome: A single case study

AIMS

To assess the effectiveness of iPad use on the attention span of a child with Smith Magenis Syndrome (n = 1), compared to attention span while working on the same tasks manually.

METHODS

An AB design with a baseline and an intervention phase was used. Three manual tasks were chosen for the baseline, which matched the participant's intellectual age by the Early Intervention Method: a jigsaw puzzle (six pieces), a shape sorter, and matching pictures. These same tasks were performed on an iPad during the intervention phase. Six baseline and nine intervention phase films were included in the analysis. The 15 films were independently scored twice by two observers: once to observe the types of distractions that occurred (such as standing up from the chair, calling the teacher, or turning around on the chair), and a second time to measure the effective working time.

RESULTS

iPad use led to a 45% decrease in the number of total distractions. The effective working time improved by 8% and showed a more consistent range compared to working on tasksbmanually. While task enjoyment was not directly measured, the observers and teachers agreed that working on the iPad appeared to be more enjoyable.

CONCLUSIONS

In this single case study the participant showed that in his case iPad use can be effective in decreasing his distractions and therefore can improve his attention span. Enjoyment was higher while working with the iPad than performing tasks manually. This technology could therefore create more learning engagement for the participant, which could positively impact his behavior. Further research into iPad implementation for children with intellectual disabilities, poor fine motor skills, and/or attention deficits is needed.

Silver Nitrate Grade and Its Effect on Physical Developer Performance-A Validation Study

Silver nitrate is a critical component of the physical developer (PD) reagent. Significant increases in the cost of silver nitrate in recent years have caused the United States Secret Service's Forensic Laboratory to look for a more economical way to produce physical developer. One possible solution to this dilemma is to use a lower grade of silver nitrate, which typically has a lower cost. This study compared the quality of fingerprints produced on various paper substrates by three physical developer working solutions, each prepared using either the American Chemical Society (ACS), U.S. Pharmacopeia (USP), or technical grade of silver nitrate. It was determined that the less pure grades of silver nitrate produced approximately the same quality of fingerprints as the ACS grade, which is currently used in the authors' laboratory for making PD working solutions. In the experiments comparing PD prepared using the ACS and USP grades of silver nitrate, the ACS grade was superior only 5% of the time, whereas the USP grade was chosen 27% of the time. In the experiments comparing PD prepared using the ACS and technical grades of silver nitrate, the ACS grade was superior only 10% of the time, whereas the technical grade was selected 17% of the time. For the majority of the sample comparisons, no difference in fingerprint quality was observed. The overall conclusion was that either USP or technical grade silver nitrate can be used in place of the current, and more expensive, ACS grade of silver nitrate.

Histologic Lesions Induced by Murine Norovirus Infection in Laboratory Mice

Murine noroviruses (MNVs) are highly prevalent in laboratory mice, can cause persistent infections, and have been shown to infect macrophages, dendritic cells, and B cells. To address the potential impact of MNV infection on research outcomes, numerous studies have been conducted with various mouse models of human disease and have generated mixed results, ranging from no impact to significant disease. Many of these studies included histologic evaluations after MNV infection, and these results have similarly been variable in terms of whether MNV induces lesions, despite the fact that localization of MNV by viral culture and molecular techniques have demonstrated systemic distribution regardless of mouse immune status. The aim of this review is to summarize the histologic findings that have been reported with MNV infection in several mouse models. The studies demonstrate that experimental infection of MNV in wild-type mice results in minimal to no histologic changes. In contrast, immunodeficient mice consistently have detectable MNV-induced lesions that are typically inflammatory and, in the most severe cases, accompanied by necrosis. In these, the liver is commonly affected, with more variable lesions reported in the lung, gastrointestinal tract, mesenteric lymph nodes, brain, and spleen. In specific disease models including atherosclerosis, MNV infection had a variable impact that was dependent on the mouse model, viral strain, timing of infection, or other experimental variables. It is important to recognize the reported MNV lesions to help discern the possible influence of MNV infection on data generated in mouse models.

Caregiver financial distress, depressive symptoms and limited social capital as barriers to children's dental care in a mid-western county in the United States

OBJECTIVE

To identify barriers to children's access to dental care.

BASIC RESEARCH DESIGN

A cross-sectional health survey.

SETTING

All residential census tracts in Genesee County, Michigan, USA.

PARTICIPANTS

498 adults who reported having children in their households, extracted from 2,932 randomly selected adult participants in the 2009 and 2011 surveys.

MAIN MEASURES

Stepwise logistic regression was used to predict two dependent variables: children's lack of any visits to dentists' offices and unmet dental care needs (defined as needing dental care but not receiving it due to cost) in the previous year as reported by the adults. Independent variables included gender, age, education, race/ethnicity, financial planning, financial distress, fear of crime, stress, depressive symptoms, experiences of discrimination, and neighbourhood social capital.

RESULTS

Of the 498 adults, 29.9% reported that they had children who had not visited a dentist in the past 12 months and 13% reported that they had household children with unmet dental care needs in the past year. Adults who reported higher depressive symptoms, lower neighbourhood social capital, greater financial distress, and who were younger were more likely to have household children who did not visit a dentist in the past year. Financial distress was the only significant predictor when controlling for other variables to predict unmet dental care needs.

CONCLUSIONS

Factors beyond financial distress affect children's dental care; these include parental depressive symptoms and lower neighbourhood social capital. Interventions promoting parental mental health and social integration may increase dental care among children.

Elastin content is high in the canine cruciate ligament and is associated with degeneration

Cruciate ligaments (CLs) are primary stabilisers of the knee joint and canine cranial cruciate ligament disease (CCLD) and rupture is a common injury. Elastin fibres, composed of an elastin core and fibrillin containing microfibrils, are traditionally considered minor components of the ligament extracellular matrix (ECM). However, their content and distribution in CLs is unknown. The purposes of this study were to determine the elastin content of canine CLs and to ascertain its relationship to other biochemical components and histological architecture. Macroscopically normal CLs were harvested from Greyhounds (n=11), a breed with a low risk of CCLD. Elastin, collagen and sulfated glycosaminoglycan content were measured and histological scoring systems were developed to quantify ECM changes using a modified Vasseur score (mVS) and oxytalan fibre (bundles of microfibrils) staining. Elastin contents were 9.86 ± 3.97% dry weight in the cranial CL and 10.79 ± 4.37% in the caudal CL, respectively, and did not alter with advancing histological degeneration. All CLs demonstrated mild degenerative changes, with an average mVS score of 11.9 ± 3.3 (maximum 24). Increasing degeneration of the ligament ECM showed a positive correlation (r=0.690, P<0.001) with increased oxytalan fibre staining within the ECM. Elastin is an abundant protein in CLs forming a greater proportion of the ligament ECM than previously reported. The appearance of oxytalan fibres in degenerative CL ECM may reflect an adaptive or reparative response to normal or increased loads. This finding is important for future therapeutic or ligament replacement strategies associated with cranial CL injury.

Neoadjuvant cetuximab, twice-weekly gemcitabine, and intensity-modulated radiotherapy (IMRT) in patients with pancreatic adenocarcinoma

BACKGROUND

Neoadjuvant therapy has been investigated for localized and locally advanced pancreatic ductal adenocarcinoma (PDAC) but no standard of care exists. Combination cetuximab/gemcitabine/radiotherapy demonstrates encouraging preclinical activity in PDAC. We investigated cetuximab with twice-weekly gemcitabine and intensity-modulated radiotherapy (IMRT) as neoadjuvant therapy in patients with localized or locally advanced PDAC.

EXPERIMENTAL DESIGN

Treatment consisted of cetuximab load at 400 mg/m(2) followed by cetuximab 250 mg/m(2) weekly and gemcitabine 50 mg/m(2) twice-weekly given concurrently with IMRT to 54 Gy. Following therapy, patients were considered for resection.

RESULTS

Thirty-seven patients were enrolled with 33 assessable for response. Ten patients (30%) manifested partial response and 20 (61%) manifested stable disease by RECIST. Twenty-five patients (76%) underwent resection, including 18/23 previously borderline and 3/6 previously unresectable tumors. Twenty-three (92%) of these had negative surgical margins. Pathology revealed that 24% of resected tumors had grade III/IV tumor kill, including two pathological complete responses (8%). Median survival was 24.3 months in resected patients. Outcome did not vary by epidermal growth factor receptor status.

CONCLUSIONS

Neoadjuvant therapy with cetuximab/gemcitabine/IMRT is tolerable and active in PDAC. Margin-negative resection rates are high and some locally advanced tumors can be downstaged to allow for complete resection with encouraging survival. Pathological complete responses can occur. This combination warrants further investigation.

Variations in cell morphology in the canine cruciate ligament complex

Cell morphology may reflect the mechanical environment of tissues and influence tissue physiology and response to injury. Normal cruciate ligaments (CLs) from disease-free stifle joints were harvested from dog breeds with a high (Labrador retriever) and low (Greyhound) risk of cranial cruciate ligament (CCL) rupture. Antibodies against the cytoskeletal components vimentin and alpha tubulin were used to analyse cell morphology; nuclei were stained with 4',6-diamidino-2-phenylindole, and images were collected using conventional and confocal microscopy. Both cranial and caudal CLs contained cells of heterogenous morphologies. Cells were arranged between collagen bundles and frequently had cytoplasmic processes. Some of these processes were long (type A cells), others were shorter, thicker and more branched (type B cells), and some had no processes (type C cells). Processes were frequently shown to contact other cells, extending longitudinally and transversely through the CLs. Cells with longer processes had fusiform nuclei, and those with no processes had rounded nuclei and were more frequent in the mid-substance of both CLs. Cells with long processes were more commonly noted in the CLs of the Greyhound. As contact between cells may facilitate direct communication, variances in cell morphology between breeds at a differing risk of CCL rupture may reflect differences in CL physiology.

Experimental study and model validation of selective spinal cord and brain hypothermia induced by a simple torso-cooling pad

In vivo experiments have been performed to test the effectiveness of a torso-cooling pad to reduce the temperature in the spinal cord and brain in rats. Coolant was circulated through the cooling pad to provide either mild or moderate cooling. Temperatures in the brain tissue, on the head surface, and on the spine and back surfaces were measured. During mild cooling, the temperature on the back surface was 22.82 +/- 2.43 degrees C compared to 29.34 +/- 1.94 degrees C on the spine surface. The temperature on the back surface during moderate cooling was 13.66 +/- 1.28 degrees C compared to 24.12 +/- 5.7 degrees C on the spine surface. Although the temperature in the brain tissue did not drastically deviate from its baseline value during cooling, there was a difference between the rectal and brain temperatures during cooling, which suggests mild hypothermia in the brain tissue. Using experimental data, theoretical models of the rat head and torso were developed to predict the regional temperatures and to validate the rat models. There was good agreement between the theoretical and experimental temperatures in the torso region. Differences between the predicted and measured temperatures in the brain are likely to be the result of imperfect mixing between the cold spinal fluid and the warm cerebrospinal fluid that surrounds the brain.

The influence of changing climate on the ecology and management of selected Laurentian Great Lakes fisheries

The Laurentian Great Lakes Basin provides an ecological system to evaluate the potential effect of climate change on dynamics of fish populations and the management of their fisheries. This review describes the physical and biological mechanisms by which fish populations will be affected by changes in timing and duration of ice cover, precipitation events and temperature regimes associated with projected climate change in the Great Lakes Basin with a principal focus on the fish communities in shallower regions of the basin. Lake whitefish Coregonus clupeaformis, walleye Sander vitreus and smallmouth bass Micropterus dolomieu were examined to assess the potential effects of climate change on guilds of Great Lakes cold, cool and warm-water fishes, respectively. Overall, the projections for these fishes are for the increased thermally suitable habitat within the lakes, though in different regions than they currently inhabit. Colder-water fishes will seek refuge further north and deeper in the water column and warmer-water fishes will fill the vacated habitat space in the warmer regions of the lakes. While these projections can be modified by a number of other habitat elements (e.g. anoxia, ice cover, dispersal ability and trophic productivity), it is clear that climate-change drivers will challenge the nature, flexibility and public perception of current fisheries management programmes. Fisheries agencies should develop decision support tools to provide a systematic method for incorporating ecological responses to climate change and moderating public interests to ensure a sustainable future for Great Lakes fishes and fisheries.

Tubular basement membrane immune deposits in association with BK polyomavirus nephropathy

Tubular basement membrane immune deposits (TBMID) are rare in renal allografts and usually have been found in association with immune complex mediated glomerular injury. We report an association between TBMID and BK polyomavirus nephropathy (BKN). We reviewed clinical data and results of allograft biopsies of 30 patients with BKN (16 with and 14 without TBMID). TBMID were detected by immunofluorescence or electron microscopy. Initial and follow-up biopsies were assessed for degree of interstitial inflammation and fibrosis and severity of viral infection, and were correlated with patients' clinical data. Biopsies initially diagnostic for BKN with TBMID, compared to BKN biopsies without deposits, demonstrated more severe interstitial inflammation and fibrosis, and greater numbers of virally infected cells. Similar findings were present in follow-up biopsies. Utilizing three different antibodies directed against viral epitopes, viral antigens could not be detected within TBMID. Thirty percent of patients with TBMID and 70% without deposits had follow-up biopsies, in which virus could not be detected immunohistochemically. Treatment for all included decreasing immunosuppression, cidofovir and/or leflunomide. Clinical data correlated well with histological findings. We conclude that a significant proportion of patients with BKN show TBMID on kidney biopsy. The prognostic significance of this finding remains to be elucidated.

A clinicopathologic study of thrombotic microangiopathy in the setting of IgA nephropathy

BACKGROUND

IgA nephropathy is the most common glomerulonephritis in the world. Thrombotic microangiopathy occurs in a number of clinical settings, including but not limited to thrombotic thrombocytopenic purpura/hemolytic uremic syndrome, malignant hypertension, anti-phospholipid antibody syndrome and radiation nephropathy. Renovascular complications, such as thrombotic microangiopathy, in the setting of IgA nephropathy may be overlooked and their significance as a concomitant histologic finding is unclear.

METHODS

We conducted a clinicopathologic study to understand the possible relationship between IgA nephropathy and a concurrent thrombotic microangiopathy injury process. We identified 10 patients with an established diagnosis of IgA nephropathy and concurrent findings of thrombotic microangiopathy based on their renal biopsies.

RESULTS

Six patients presented with malignant hypertension, while three others had severe hypertension (> or = 100 mmHg, diastolic). Five patients had nephrotic-range proteinuria. Seven patients had occasional arteriolar thrombi identified by light microscopy and prominent glomerular subendothelial space widening by electron microscopy, while three patients demonstrated only ultrastructural features of thrombotic microangiopathy. Other possible etiologic causes of thrombotic microangiopathy were not identified with the available clinical information.

CONCLUSION

Our study suggests that a thrombotic microangiopathy injury, when present, is usually found in advanced stages of IgA nephropathy and can be associated with severe proteinuria. Although other possible causes of thrombotic microangiopathy, such as anti-phospholipid antibody syndrome, were excluded in only two patients, the thrombotic microangiopathy injury process may be a cause or a consequence of the severe hypertension encountered in most of the patients which, in turn, may be a consequence of the disease progression of IgA nephropathy.

Ionizing radiation: a genetic switch for cancer therapy

Gene therapy of cancer represents a promising but challenging area of therapeutic research. The discovery of radiation-inducible genes led to the concept and development of radiation-targeted gene therapy. In this approach, promoters of radiation-inducible genes are used to drive transcription of transgenes in the response to radiation. Constructs in which the radiation-inducible promoter elements activate a transgene encoding a cytotoxic protein are delivered to tumors by adenoviral vectors. The tumoricidal effects are then localized temporally and spatially by X-rays. We review the conceptual development of TNFerade, an adenoviral vector containing radiation-inducible elements of the early growth response-1 promoter upstream of a cDNA encoding human tumor necrosis factor-alpha. We also summarize the preclinical work and clinical trials utilizing this vector as a treatment for diverse solid tumors.

Utilization of commercial laboratory results in management of hyperandrogenism in women

OBJECTIVE

To compare results from testosterone radioimmunoassay kits commonly used by commercial laboratories as well as their reference ranges and to analyze the scientific literature for ranges of serum testosterone levels in normal women and those with hyperandrogenism.

METHODS

We reviewed quality assurance reports of various testosterone ligand challenges from four groups of laboratories and summarized testosterone data from 17 published reports about normal women and 14 studies of hyperandrogenic women.

RESULTS

A significant variability was demonstrated between the radioimmunoassay kits at all concentrations (for example, a sample with a mean testosterone level of 96.1 ng/dL was reported by some laboratories as containing 71.8 ng/dL and by others as 123.4 ng/dL). All laboratories provide essentially the same "reference range" (approximately 10 to 90 ng/dL) but do not report how the range was established. The scientific literature clearly shows a significant separation in serum testosterone levels between normal (that is, not hyperandrogenic) and hyperandrogenic women. Most hyperandrogenic women had testosterone levels >50 ng/dL, whereas most normal control subjects had levels <40 ng/dL. Thus, most of these women with hyperandrogenism would have been considered to have normal testosterone levels if the reference ranges of commercial laboratories were used.

CONCLUSION

These data illustrate the difficulty that physicians face when they are required to use different commercial laboratories to measure serum testosterone levels. We propose that (1) reference ranges be established on a clinically defined population for each hormone and method used, (2) laboratory reports include information about method and reference range population, and (3) physicians be allowed to choose which laboratories are used for their patients' hormone determinations, for consistency of results.

Statistical analysis of MPSS measurements: application to the study of LPS-activated macrophage gene expression

Massively Parallel Signature Sequencing (MPSS), a recently developed high-throughput transcription profiling technology, has the ability to profile almost every transcript in a sample without requiring prior knowledge of the sequence of the transcribed genes. As is the case with DNA microarrays, effective data analysis depends crucially on understanding how noise affects measurements. We analyze the sources of noise in MPSS and present a quantitative model describing the variability between replicate MPSS assays. We use this model to construct statistical hypotheses that test whether an observed change in gene expression in a pair-wise comparison is significant. This analysis is then extended to the determination of the significance of changes in expression levels measured over the course of a time series of measurements. We apply these analytic techniques to the study of a time series of MPSS gene expression measurements on LPS-stimulated macrophages. To evaluate our statistical significance metrics, we compare our results with published data on macrophage activation measured by using Affymetrix GeneChips.

Is there a cloud in the silver lining for imatinib?

Imatinib mesylate (Gleevec) or Glivec), a small molecule tyrosine kinase inhibitor for the treatment of chronic myeloid leukaemia, has been said to herald the dawn of a new era of rationally designed, molecularly targeted oncotherapy. Lurking on the same new horizon, however, is the age-old spectre of drug resistance. This review sets the intoxicating clinical perspective against the more sobering laboratory evidence of such divergent mechanisms of imatinib resistance as gene amplification and stem cell quiescence. Polychemotherapy has already been considered to combat resistance, but a more innovative, as yet unformulated, approach may be advocated.

Toll-like receptor-5 and the innate immune response to bacterial flagellin

The innate immune system identifies the presence of infection by detecting structures that are unique to microbes and that are not expressed in the host. The bacterial flagellum (Latin, a whip) confers motility, on a wide range of bacterial species. Vertebrates, plants, and invertebrates all have evolved flagellar recognition systems that are activated by flagellin, the major component of the bacterial flagellar filament. In mammals, flagellin is recognized by Toll-like receptor-5 and activates defense responses both systemically and at epithelial surfaces. Here, we review the role for Toll-like receptor-5 in mediating the mammalian innate immune response to flagellin, and how this provides for defense against infections caused by many different species of flagellated bacteria.

Role of ALDP (ABCD1) and mitochondria in X-linked adrenoleukodystrophy

Peroxisomal disorders have been associated with malfunction of peroxisomal metabolic pathways, but the pathogenesis of these disorders is largely unknown. X-linked adrenoleukodystrophy (X-ALD) is associated with elevated levels of very-long-chain fatty acids (VLCFA; C(>22:0)) that have been attributed to reduced peroxisomal VLCFA beta-oxidation activity. Previously, our laboratory and others have reported elevated VLCFA levels and reduced peroxisomal VLCFA beta-oxidation in human and mouse X-ALD fibroblasts. In this study, we found normal levels of peroxisomal VLCFA beta-oxidation in tissues from ALD mice with elevated VLCFA levels. Treatment of ALD mice with pharmacological agents resulted in decreased VLCFA levels without a change in VLCFA beta-oxidation activity. These data indicate that ALDP does not determine the rate of VLCFA beta-oxidation and that VLCFA levels are not determined by the rate of VLCFA beta-oxidation. The rate of peroxisomal VLCFA beta-oxidation in human and mouse fibroblasts in vitro is affected by the rate of mitochondrial long-chain fatty acid beta-oxidation. We hypothesize that ALDP facilitates the interaction between peroxisomes and mitochondria, resulting, when ALDP is deficient in X-ALD, in increased VLCFA accumulation despite normal peroxisomal VLCFA beta-oxidation in ALD mouse tissues. In support of this hypothesis, mitochondrial structural abnormalities were observed in adrenal cortical cells of ALD mice.

Co-operative induction of pro-inflammatory signaling by Toll-like receptors

Toll-like receptors (TLRs) mediate detection of a broad range of pathogens and pathogen-derived products including LPS, peptidoglycan, bacterial lipopeptides, and lipoteichoic acid. Recent evidence indicates that the broad specificity of TLRs may be a consequence of the interactions between different TLRs. In this report, we demonstrate that while a constitutively active TLR4 homodimer can induce the production of pro-inflammatory cytokines, homodimers of TLR2 and TLR6 cannot. However, when co-expressed in the same cell, constitutively active TLR2 and TLR6 strongly induce cytokine production, indicating that these TLRs require partners to productively signal. Since TLR4 signals as a homodimer, while TLR2 and TLR6 do not, it is clear that, despite the conservation of their cytoplasmic signaling domains, the mechanisms by which they initiate signaling are different. We have localized the region of TLR4 that mediates its ability to signal as a homodimer to the membrane-proximal half of the cytoplasmic tail of the receptor.

Potential environmental and host participants in the early white matter lesion of adreno-leukodystrophy: morphologic evidence for CD8 cytotoxic T cells, cytolysis of oligodendrocytes, and CD1-mediated lipid antigen presentation

The 2 most common forms of X-linked adreno-leukodystrophy (ALD) are the juvenile or childhood cerebral form with inflammatory demyelination and the adult adrenomyeloneuropathy (AMN) involving spinal cord tracts without significant inflammation. Modifier genes or environmental factors may contribute to the phenotypic variability. We performed immunohistochemical, an in situ polymerase chain reaction, and TUNEL analyses to identify several viruses, lymphocyte subpopulations, apoptotic cells, and effector molecules, focusing on morphologically normal white matter, dysmyelinative and acute demyelinative lesions. No distinguishing viral antigens were detected. Most lymphocytes were CD8 cytotoxic T cells (CTLs) with the alpha/beta TCR, and they infiltrated morphologically unaffected white matter. Only a few oligodendrocytes were immunoreactive for caspase-3. MHC class II- and TGF-beta-positive microglia were present. CD44, which can mediate MHC-unrestricted target cell death, was seen on many lymphocytes and white matter elements. CD1 molecules, which play major roles in MHC-unrestricted lipid antigen presentation, were noted. Our data indicate that unconventional CD8 CTLs are operative in the early stages of dysmyelination/demyelination and that cytolysis of oligodendrocytes, rather than apoptosis, appears to be the major mode of oligodendrocytic death. The presentation of lipid antigens may be a key pathogenetic element in ALD and AMN-ALD.

The role of heterocellular hereditary persistence of fetal haemoglobin in beta(0)-thalassaemia intermedia

Beta(0)-thalassaemia intermedia (beta(0)-TI) describes patients who lack beta-globin synthesis yet manifest a non-transfusion-dependent form of beta-thalassaemia. Co-inheritance of alpha-thalassaemia, certain variants of the beta-like globin gene cluster and elevated fetal haemoglobin (HbF) production are all associated with beta(0)-TI. However, the mild phenotypes of many beta(0)-TI patients are unexplained. Genetically determined HbF levels in beta-thalassaemia are difficult to assess because erythrocytes containing HbF (F cells) preferentially survive over erythrocytes without HbF. To evaluate the importance of genetically elevated HbF in beta-thalassaemia, F-cell levels of 19 TI patients' relatives were compared with relatives of transfusion-dependent beta-thalassaemia major patients and those of beta-globin genotype-matched controls. The beta-globin and alpha-globin genotypes, as well as their Ggamma promoter were also examined. Using this approach, in all but one patient the mild phenotype was attributable to either alpha-globin genotype, gamma-globin promoter polymorphism or inherited elevated F-cell levels. The findings of this study establish the F-cell levels required to modify the degree of disease severity significantly and demonstrate that F-cell level is a crucial parameter in the understanding of phenotypic variation in beta-thalassaemia.

Evaluation of pharmacological induction of fatty acid beta-oxidation in X-linked adrenoleukodystrophy

X-linked adrenoleukodystrophy (X-ALD) is an inherited neurometabolic disorder associated with elevated levels of saturated unbranched very-long-chain fatty acids (VLCFA; C > 22:0) in plasma and tissues, and reduced VLCFA beta-oxidation in fibroblasts, white blood cells, and amniocytes from X-ALD patients. The X-ALD gene (ABCD1) at Xq28 encodes the adrenoleukodystrophy protein (ALDP) that is related to the peroxisomal ATP-binding cassette (ABCD) transmembrane half-transporter proteins. The function of ALDP is unknown and its role in VLCFA accumulation unresolved. Previously, our laboratory has shown that sodium 4-phenylbutyrate (4PBA) treatment of X-ALD fibroblasts results in increased peroxisomal VLCFA beta-oxidation activity and increased expression of the X-ALD-related protein, ALDRP, encoded by the ABCD2 gene. In this study, the effect of various pharmacological agents on VLCFA beta-oxidation in ALD mouse fibroblasts is tested. 4PBA, styrylacetate and benzyloxyacetate (structurally related to 4PBA), and trichostatin A (functionally related to 4PBA) increase both VLCFA (peroxisomal) and long-chain fatty acid [LCFA (peroxisomal and mitochondrial)] beta-oxidation. Isobutyrate, zaprinast, hydroxyurea, and 5-azacytidine had no effect on VLCFA or LCFA beta-oxidation. Lovastatin had no effect on fatty acid beta-oxidation under normal tissue culture conditions but did result in an increase in both VLCFA and LCFA beta-oxidation when ALD mouse fibroblasts were cultured in the absence of cholesterol. The effect of trichostatin A on peroxisomal VLCFA beta-oxidation is shown to be independent of an increase in ALDRP expression, suggesting that correction of the biochemical abnormality in X-ALD is not dependent on pharmacological induction of a redundant gene (ABCD2). These studies contribute to a better understanding of the role of ALDP in VLCFA accumulation and may lead to the development of more effective pharmacological therapies.

Disruption of a yeast very-long-chain acyl-CoA synthetase gene simulates the cellular phenotype of X-linked adrenoleukodystrophy

X-linked adrenoleukodystrophy (X-ALD) is characterized biochemically by elevated levels of saturated very long-chain fatty acids (VLCFAs) in plasma and tissues. In X-ALD, peroxisomal very-long-chain acyl-CoA synthetase (VLCS) fails to activate VLCFAs, preventing their degradation via beta-oxidation. However, the product of the defective XALD gene (ALDP) is not a VLCS, but rather a peroxisomal membrane protein (PMP). Disruption of either or both of two yeast PMP genes related to the XALD gene did not produce a biochemical phenotype resembling that found in X-ALD fibroblasts. The authors identified a candidate yeast VLCS gene (the FAT1 locus) by its homology to rat liver VLCS. Disruption of this gene decreased VLCS activity, but had no effect on long-chain acyl-CoA synthetase activity. In FAT1-disruption strains, VLCS activity was reduced to 30-40% of wild-type in both a microsome-rich 27,000 g supernatant fraction and a peroxisome- and mitochondria-rich pellet fraction of yeast spheroplast homogenates. Separation of the latter organelles by density gradient centrifugation revealed that VLCS activity was peroxisomal and not mitochondrial. VLCS gene-disruption strains had increased cellular VLCFA levels, compared to wild-type yeast. The extent of both the decrease in peroxisomal VLCS activity and the VLCFA accumulation in this yeast model resembles that observed in cells from X-ALD patients. Characterization of the gene(s) responsible for the residual peroxisomal VLCS activity may suggest new therapeutic approaches in X-ALD.

The innate immune response to bacterial flagellin is mediated by Toll-like receptor 5

The innate immune system recognizes pathogen-associated molecular patterns (PAMPs) that are expressed on infectious agents, but not on the host. Toll-like receptors (TLRs) recognize PAMPs and mediate the production of cytokines necessary for the development of effective immunity. Flagellin, a principal component of bacterial flagella, is a virulence factor that is recognized by the innate immune system in organisms as diverse as flies, plants and mammals. Here we report that mammalian TLR5 recognizes bacterial flagellin from both Gram-positive and Gram-negative bacteria, and that activation of the receptor mobilizes the nuclear factor NF-kappaB and stimulates tumour necrosis factor-alpha production. TLR5-stimulating activity was purified from Listeria monocytogenes culture supernatants and identified as flagellin by tandem mass spectrometry. Expression of L. monocytogenes flagellin in non-flagellated Escherichia coli conferred on the bacterium the ability to activate TLR5, whereas deletion of the flagellin genes from Salmonella typhimurium abrogated TLR5-stimulating activity. All known TLRs signal through the adaptor protein MyD88. Mice challenged with bacterial flagellin rapidly produced systemic interleukin-6, whereas MyD88-null mice did not respond to flagellin. Our data suggest that TLR5, a member of the evolutionarily conserved Toll-like receptor family, has evolved to permit mammals specifically to detect flagellated bacterial pathogens.

Adrenoleukodystrophy: incidence, new mutation rate, and results of extended family screening

Utilizing the plasma very long chain fatty acid assay, supplemented by mutation analysis and immunofluorescence assay, we determined the number of X-linked adrenoleukodystrophy (X-ALD) hemizygotes from the United States identified each year in the two laboratories that perform most of the assays in this country: the Kennedy Krieger Institute between 1981 and 1998 and the Mayo Clinic Rochester from 1996 to 1998. The minimum frequency of hemizygotes identified in the United States is estimated to be 1:42,000 and that of hemizygotes plus heterozygotes 1:16,800. Our studies involved 616 pedigrees with a total of 12,787 identified at-risk members. Diagnostic assays were performed in 4,169 at-risk persons (33%) and included members of the extended family. Only 5% of male probands and 1.7% of X-ALD hemizygotes were found to have new mutations. The extended family testing led to the identification of 594 hemizygotes and 1,270 heterozygotes. Two hundred fifty of the newly identified hemizygotes were asymptomatic and represent the group in which therapy has the greatest chance of success. Identification of heterozygotes provides the opportunity for disease prevention through genetic counseling. Diagnostic tests should be offered to all at-risk relatives of X-ALD patients and should include members of the extended family.

The repertoire for pattern recognition of pathogens by the innate immune system is defined by cooperation between toll-like receptors

Toll-like receptors (TLRs) have been shown to participate in the recognition of pathogens by the innate immune system, but it is not clear how a restricted family of receptors has the capacity to recognize the wide spectrum of TLR stimuli known to exist. We report here that two members of the TLR family, TLR2 and TLR6, together coordinate macrophage activation by Gram-positive bacteria and the yeast cell-wall particle, zymosan. TLR6 and TLR2 both are recruited to the macrophage phagosome, where they recognize peptidoglycan, a Gram-positive pathogen component. By contrast, TLR2 recognizes another component, bacterial lipopeptide, without TLR6. The requirement for TLR cooperation is supported by the finding that TLR2 needs a partner to activate tumor necrosis factor-alpha production in macrophages. Dimerization of the cytoplasmic domain of TLR2 does not induce tumor necrosis factor-alpha production in macrophages, whereas similar dimerization of the TLR4 cytoplasmic domain does. We show that the cytoplasmic domain of TLR2 can form functional pairs with TLR6 or TLR1, and this interaction leads to cytokine induction. Thus, the cytoplasmic tails of TLRs are not functionally equivalent, with certain TLRs requiring assembly into heteromeric complexes, whereas others are active as homomeric complexes. Finally, we show that TLR6, TLR2, and TLR1 are recruited to macrophage phagosomes that contain IgG-coated erythrocytes that do not display microbial components. The data suggest that TLRs sample the contents of the phagosome independent of the nature of the contents, and can establish a combinatorial repertoire to discriminate among the large number of pathogen-associated molecular patterns found in nature.

Very long-chain acyl-CoA synthetases. Human "bubblegum" represents a new family of proteins capable of activating very long-chain fatty acids

Activation by thioesterification to coenzyme A is a prerequisite for most reactions involving fatty acids. Enzymes catalyzing activation, acyl-CoA synthetases, have been classified by their chain length specificities. The most recently identified family is the very long-chain acyl-CoA synthetases (VLCS). Although several members of this group are capable of activating very long-chain fatty acids (VLCFA), one is a bile acid-CoA synthetase, and others have been characterized as fatty acid transport proteins. It was reported that the Drosophila melanogaster mutant bubblegum (BGM) had elevated VLCFA and that the product of the defective gene had sequence homology to acyl-CoA synthetases. Therefore, we cloned full-length cDNA for a human homolog of BGM, and we investigated the properties of its protein product, hsBG, to determine whether it had VLCS activity. Northern blot analysis showed that hsBG is expressed primarily in brain. Compared with vector-transfected cells, COS-1 cells expressing hsBG had increased acyl-CoA synthetase activity with either long-chain fatty acid (2.4-fold) or VLCFA (2.6-fold) substrates. Despite this increased VLCFA activation, hsBG-expressing cells did not have increased rates of VLCFA degradation. Confocal microscopy showed that hsBG had a cytoplasmic localization in some COS-1 cells expressing the protein, whereas it appeared to associate with plasma membrane in others. Fractionation of these cells revealed that most of the hsBG-dependent acyl-CoA synthetase activity was soluble and not membrane-bound. Immunoaffinity-purified hsBG from transfected COS-1 cells was enzymatically active. hsBG and hsVLCS are only 15% identical, and comparison with sequences of two conserved motifs from all known families of acyl-CoA synthetases revealed that hsBG along with the D. melanogaster and murine homologs comprise a new family of acyl-CoA synthetases. Thus, two protein families are now known that contain enzymes capable of activating VLCFA. Because hsBG is expressed in brain but previously described VLCSs were not highly expressed in this organ, hsBG may play a central role in brain VLCFA metabolism and myelinogenesis.

A comparison of calibrated and non-calibrated 5.07 nylon monofilaments

The study compares the mechanical performance of two types of nylon monofilaments used in testing for the presence of protective sensation in diabetics with peripheral neuropathy. Comparisons of the application force between a group of calibrated and a group of non-calibrated 5.07 nylon monofilaments were conducted to determine the properties of each type of filament. The analysis demonstrated that there was no significant difference in the application force generated between calibrated and non-calibrated nylon monofilaments.

Mobile software agents for Web-based medical image retrieval

Mobile software agents are a new tool which may assist rural and remote physicians to obtain medical data from digital medical libraries on the Internet. Mobile agents are autonomous software objects that can move from digital library to digital library, analysing data to determine their usefulness to the user. A proof-of-concept system applied to mammography is proposed and a simplified prototype for this system is reported. Enhancement and development plans for the complete proof-of-concept system are suggested.

Therapeutic developments in peroxisome biogenesis disorders

Clinically, peroxisome biogenesis disorders (PBDs) are a group of lethal diseases with a continuum of severity of clinical symptoms ranging from the most severe form, Zellweger syndrome, to the milder forms, infantile Refsum disease and rhizomelic chondrodysplasia punctata. PBDs are characterised by a number of biochemical abnormalities including impaired degradation of peroxide, very long chain fatty acids, pipecolic acid, phytanic acid and xenobiotics and impaired synthesis of plasmalogens, bile acids, cholesterol and docosahexaenoic acid. Treatment of PBD patients as a group is problematic since a number of patients, especially those with Zellweger syndrome, have significant neocortical alterations in the brain at birth so that full recovery would be impossible even with postnatal therapy. To date, treatment of PBD patients has generally involved only supportive care and symptomatic therapy. However, the fact that some of the milder PBD patients live into the second decade has prompted research into possible treatments for these patients. A number of experimental therapies have been evaluated to determine whether or not correction of biochemical abnormalities through dietary supplementation and/or modification is of clinical benefit to PBD patients. Another approach has been pharmacological induction of peroxisomes in PBD patients to improve overall peroxisomal biochemical function. Well known rodent peroxisomal proliferators were found not to induce human peroxisomes. Recently, our laboratory demonstrated that sodium 4-phenylbutyrate induces peroxisome proliferation and improves biochemical function (very long chain fatty acid beta-oxidation rates and very long chain fatty acid and plasmalogens levels) in fibroblast cell lines from patients with milder PBD phenotypes. Dietary supplementation and/or modification and pharmacological induction of peroxisomes as treatment strategies for PBD patients will be the subject of this review.

Determination of 30 X-linked adrenoleukodystrophy mutations, including 15 not previously described

X-linked Adrenoleukodystrophy (X-ALD) is the most frequent peroxisomal disease. It mainly involves the nervous system white matter, adrenal cortex and testes. Several distinct clinical phenotypes are known. The principal biochemical abnormality is the accumulation of saturated very-long-chain fatty acids (VLCFAs : > C22:0, mainly C26:0), which is due to impaired capacity for beta-oxidation in peroxisomes. Diagnosis is usually based on the VLCFA levels in plasma or cultured skin fibroblasts in both patients and carriers. In 0.1% of affected males, however, the plasma C26:0 level is borderline normal, and 15% of obligate female carriers have normal results. Effective mutation detection in these families is therefore fundamental to unambiguously determine the genetic status of each individual at risk. Of particular concern are female members of kindreds segregating X-ALD mutations, because normal VLCFA levels do not guarantee lack of carrier status. We describe a fast method for detection of X-ALD mutations. The method is based on SSCP analysis of nested PCR fragments followed by sequence-determination reactions. Using this methodology we have found X-ALD mutations in 30 kindreds, including 15 not previously reported.

Vertical transtalar Steinmann pin fixation for unstable ankle fractures

Ankle fractures are common injuries and can usually be managed by either cast immobilisation or open reduction and internal fixation. Occasionally, both of these methods are contra-indicated. In such cases, one solution is the use of a vertical transtalar Steinmann pin to stabilise the fracture. Over the last 7 years, we have managed 8 patients with severe ankle fractures using vertical transtalar Steinmann pin fixation. The median age of these patients was 76 years (range, 35-94 years). This method was used in two patients with open contaminated wounds, in 5 with atrophic and blistered skin, and in one following failure of internal fixation in a patient with atrophic skin. In all patients, a satisfactory reduction was achieved and maintained after removal of the pin. Although all patients began to develop osteo-arthritic changes secondary to their original fractures, no complications were directly attributable to the use of the pin. In unstable ankle fractures where damage and contamination of soft tissues would preclude internal fixation, we recommend the use of vertical transtalar Steinmann pin fixation.

Pharmacological induction of peroxisomes in peroxisome biogenesis disorders

Inherited aberrant peroxisome assembly results in a group of neurological diseases termed peroxisome biogenesis disorders (PBDs). PBDs include three major clinical phenotypes that represent a continuum of clinical features from the most severe form, Zellweger syndrome (ZS), through neonatal adrenoleukodystrophy (NALD) to the least severe form, infantile Refsum's disease (IRD). Somatic cell complementation studies have identified 13 PBD complementation groups, each representing a defect in a peroxisomal protein (peroxin) involved in peroxisome biogenesis. Most complementation groups include a range of clinical phenotypes. In this study, peroxisome numbers were determined in fibroblasts from 29 PBD (ZS, NALD, and IRD) patients, with various phenotypes from nine complementation groups, using antibodies against either a peroxisomal membrane protein (anti-Pex14p) or peroxisomal matrix proteins (anti-SKL). A correlation between the number of peroxisomes, determined with either antibody, and PBD phenotype was found, suggesting that induction of peroxisome number might have a favorable effect on PBD. After treatment of PBD fibroblasts with sodium 4-phenylbutyrate, a human peroxisome proliferator, there was an approximate twofold increase in peroxisome number. After 4-phenylbutyrate treatment, an increase in transcription of the adrenoleukodystrophy-related gene and the peroxin gene, PEX11alpha, was found in PBD fibroblasts. In NALD and IRD, but not ZS, fibroblasts there was an increase in very-long-chain fatty acid beta-oxidation and plasmalogen concentrations, and a decrease in very-long-chain fatty acid concentrations. These data suggest that pharmacological agents that induce peroxisome proliferation, such as 4-phenylbutyrate, may have therapeutic potential in the treatment of PBD patients with milder phenotypes (NALD and IRD).

The durability of the Semmes-Weinstein 5.07 monofilament

Peripheral neuropathy is a risk factor that predisposes diabetic patients to plantar foot ulcerations and lower extremity amputations. Clinicians have searched for a reliable, cost-effective, and simple method in the identification of diabetic patients who are at increased risk of developing plantar foot ulcers. Currently, many diabetic foot clinics utilize the Semmes-Weinstein 5.07/10 g monofilament in this identification process. Ten 5.07 monofilaments were placed in an Instron Dynamic Testing Instrument and their respective filament forces were measured utilizing a Mettler scale after being subjected to repetitive applications. After 500 cycles were performed, there was an average filament force reduction of 1.2 g. After 1,500 cycles, there was still an average reduction of 1.2 g. F-testing and the Duncan test identified a significant difference between filament forces at 0, 500, 1,000, and 1,500 cycles. These data lead to a conclusion that continual utilization of the nylon filaments may lead to a reduced ability to accurately detect peripheral neuropathy and identify those who are at risk for the development of plantar foot ulcerations.

Cerebral inflammation in X-linked adrenoleukodystrophy

X-linked adrenoleukodystrophy (X-ALD) is an inherited neurodegenerative disease that affects approximately 1 in 25 000 males. It is characterized by elevated levels of saturated very long chain fatty acids (VLCFA), i.e., >C22:0, particularly in ganglioside and cholesterol ester fractions of brain white matter and adrenal cortex. Failure of peroxisomal very long chain fatty acyl-CoA synthetase (VLCS) to activate these VLCFA prevents their degradation by peroxisomal beta-oxidation. X-ALD maps to Xq28 and the gene encodes a peroxisomal membrane protein and not the gene for VLCS. The two most common forms of X-ALD are the cerebral (CER) form, with an inflammatory demyelinating reaction that resembles multiple sclerosis (MS), and adrenomyeloneuropathy (AMN), which involves the spinal cord and in which the inflammatory reaction is mild or absent. Investigations into the nature of the cerebral inflammatory demyelinating reaction in X-ALD will be the subject of this review.

Toll-like receptor-2 mediates mycobacteria-induced proinflammatory signaling in macrophages

The recognition of mycobacterial cell wall components causes macrophages to secrete tumor necrosis factor alpha (TNF-alpha) and other cytokines that are essential for the development of a protective inflammatory response. We show that toll-like receptors are required for the induction of TNF-alpha in macrophages by Mycobacterium tuberculosis. Expression of a dominant negative form of MyD88 (a signaling component required for toll-like receptor signaling) in a mouse macrophage cell line blocks TNF-alpha production induced by M. tuberculosis. We identify toll-like receptor-2 (TLR2) as the specific toll-like receptor required for this induction by showing that expression of an inhibitory TLR2 (TLR2-P681H) blocks TNF-alpha production induced by whole M. tuberculosis. Further, we show that TLR2-dependent signaling mediates responses to mycobacterial cell wall fractions enriched for lipoarrabinomannan, mycolylarabinogalactan-peptidoglycan complex, or M. tuberculosis total lipids. Thus, although many mycobacterial cell wall fractions are identified to be inflammatory, all require TLR2 for induction of TNF-alpha in macrophages. These data suggest that TLR2 is essential for the induction of a protective immune response to mycobacteria.

Serum Testosterone Levels And Reference Ranges In Reproductive-Age Women

OBJECTIVE

To determine the levels of serum testosterone and dehydroepiandrosterone sulfate (DHEAS) in women with no clinical signs of hyperandrogenism and no history of glucocorticoid or oral contraceptive use and to compare these levels with the reference ranges provided by commercial laboratories.

METHODS

We undertook a cross-sectional retrospective study of 271 reproductive-age women encountered at an endocrinology clinic for complaints of potential thyroid problems. Serum testosterone and DHEAS levels were determined, and statistical analyses were performed.

RESULTS

The serum testosterone level in women with no acne, hirsutism, or menstrual dysfunction was 14.1 +/- 0.9 ng/dL (mean +/- standard error of the mean) (95% confidence interval [CI] = 12.4 to 15.8). This group was considered our study reference population. In women with menstrual dysfunction but no acne or hirsutism, the mean testosterone level was significantly higher (17.9 +/- 1.1 ng/dL; 95% CI = 15.7 to 20.0; P<0.002); with mild hirsutism, it further increased (38.4 +/- 5.1 ng/dL; 95% CI = 27.4 to 49.4; P<0.005); and with moderate to severe hirsutism, it was still higher (49.0 +/- 2.3 ng/dL; 95% CI = 44.4 to 53.6; P<0.003). Serum DHEAS levels showed similar patterns. The upper limit (mean + 2 standard deviations) of testosterone in our study reference population was 28 ng/dL, a level that provided a sensitivity of 84% for detecting hyperandrogenemia. The detection of hyperandrogenemia is essentially impossible when the upper limit of the reference range for testosterone from commercial laboratories (95 ng/dL) is used.

CONCLUSION

The testosterone levels reported herein and in the literature for hyperandrogenic women both are within the reference (normal) ranges provided by commercial laboratories. These observations demonstrate why diagnosis of hyperandrogenemia in hyperandrogenic women is difficult when commercial laboratories are used and why this condition is not detected in most affected women. Commercial laboratories should reevaluate the methods used for establishing their reference ranges for serum testosterone.

The relationship of serum androgens and ovulatory status to blood pressure in reproductive-age women

The objective of this cross-sectional study was to determine the relationship between hyperandrogenemia and blood pressure in women with menstrual irregularities seen at an endocrinology clinic. Women with serum testosterone levels (T) > or = 30 ng/dL were more likely to have general obesity (odds ratio [OR] = 6.8, 95% confidence intervals [CI] = 2.2-27.2) and central obesity (OR = 14.5, 95% CI = 6.1-38.7) than euandrogenemic women. Hyperandrogenemic women (HA) had an OR of 2.4 (95% CI = 1.0-6.2) for elevated SBP and an OR of 2.7 (95% CI = 0.8-8.8) for elevated DBP, independent of age and ovulatory status. Obese HA had an OR of 4.7 (95% CI = 2.3-10.4) for elevated SBP and an OR of 2.9 (95% CI = 1.9-9.9) for elevated DBP. In conclusion, T is associated with an increased risk for obesity and central adiposity. T predicts BP elevation independent of age and ovulatory status. There was a synergistic relationship between obesity and androgens in their affect on BP.

X-linked adrenoleukodystrophy: genes, mutations, and phenotypes

X-linked adrenoleukodystrophy (X-ALD) is a complex and perplexing neurodegenerative disorder. The metabolic abnormality, elevated levels of very long-chain fatty acids in tissues and plasma, and the biochemical defect, reduced peroxisomal very long-chain acyl-CoA synthetase (VLCS) activity, are ubiquitous features of the disease. However, clinical manifestations are highly variable with regard to time of onset, site of initial pathology and rate of progression. In addition, the abnormal gene in X-ALD is not the gene for VLCS. Rather, it encodes a peroxisomal membrane protein with homology to the ATP-binding cassette (ABC) transmembrane transporter superfamily of proteins. The X-ALD protein (ALDP) is closely related to three other peroxisomal membrane ABC proteins. In this report we summarize all known X-ALD mutations and establish the lack of an X-ALD genotype/phenotype correlation. We compare the evolutionary relationships among peroxisomal ABC proteins, demonstrate that ALDP forms homodimers with itself and heterodimers with other peroxisomal ABC proteins and present cDNA complementation studies suggesting that the peroxisomal ABC proteins have overlapping functions. We also establish that there are at least two peroxisomal VLCS activities, one that is ALDP dependent and one that is ALDP independent. Finally, we discuss variable expression of the peroxisomal ABC proteins and ALDP independent VLCS in relation to the variable clinical presentations of X-ALD.

Peroxisomal very long chain fatty acid beta-oxidation activity is determined by the level of adrenodeukodystrophy protein (ALDP) expression

Impaired peroxisomal beta-oxidation of saturated very long chain fatty acids (VLCFA, >/=C22:0) results in increased VLCFA levels in the tissues and body fluids of patients with disorders of peroxisomal biogenesis (i.e., Zellweger syndrome and neonatal adrenoleukodystrophy) and single peroxisomal protein defects (i.e., X-linked adrenoleukodystrophy (X-ALD) and acyl-CoA oxidase deficiency). We show that SV40T transformation also results in impaired peroxisomal beta-oxidation and VLCFA accumulation despite the presence of abundant peroxisomes. To explore the mechanism responsible for this observation, we have examined expression of key components of peroxisomal VLCFA beta-oxidation. We found that expression of both acyl-CoA oxidase, the rate limiting enzyme of peroxisomal VLCFA beta-oxidation and the adrenoleukodystrophy protein (ALDP), the defective gene product in X-ALD, are reduced after SV40T transformation. Surprisingly, ALDP overexpression by itself restores peroxisomal VLCFA beta-oxidation in SV40T-transformed control and X-ALD cells. These results demonstrate that ALDP is a fundamental component in VLCFA peroxisomal beta-oxidation and may serve as a "gatekeeper" for VLCFA homeostasis.

An Asian-Native American paternal lineage identified by RPS4Y resequencing and by microsatellite haplotyping

Human paternal population history was studied in 9 populations [three Native American, three Asian, two Caucasian and one African-derived sample(s)] using sequence and short tandem repeat haplotype diversity within the non-pseudoautosegmal region of the Y chromosome. Complete coding and additional flanking sequences (949 base pairs) of the RPS4Y locus were determined in 59 individuals from three of the populations, revealing a nucleotide diversity of 0.0147%, consistent with previous estimates from Y chromosome resequencing studies. One RPS4Y sequence variant, 711C > T, was polymorphic in Asian and Native American populations, but not in African and Caucasian population samples. The RPS4Y 711C > T variant, a second unique sequence variant at DYS287 and nine Y chromosome short tandem repeat (YSTR) loci were used to analyze the evolution of Y chromosome lineages. Three unambiguous lineages were defined in Asian, Native American and Jamaican populations using sequence variants at RPS4Y and DYS287. These lineages were independently supported by the haplotypes defined solely by YSTR alleles, demonstrating the haplotypes constructed from YSTRs can evaluate population diversity, admixture and phylogeny.

Modulation of sialyl Lewis X dependent binding to E-selectin by glycoforms of alpha-1-acid glycoprotein expressed in rheumatoid arthritis

Alpha-1-acid glycoprotein (AGP) is an extensively glycosylated acute phase protein of imprecisely defined physiological function. Nonetheless it is known that the oligosaccharide component comprising 42% of the 41 kDa molecular weight is critical to the previously described multifarious immunomodulatory functions of AGP in vitro. Complex oligosaccharides were enzymically released from AGP purified from the blood of rheumatoid arthritis sufferers by our oligosaccharide protective method. Oligosaccharide profiling was by means of high pH anion-exchange chromatography with pulsed amperometric detection (HPAEC-PAD). Monosaccharide composition analysis revealed increased fucosylation of inflammatory AGP oligosaccharide chains, suggesting the potential for expression of the tetrasaccharide antigen and E-Selectin ligand, sialyl Lewis X (sLeX). The hypothesis that AGP may function to inhibit blood cell binding to activated endothelium at E-Selectin was tested in a microtitre cell-protein binding assay. In this system we have shown that the oligosaccharide moiety of AGP, as expressed in inflammatory disease, can inhibit the sLeX/E-Selectin interaction. Thus we have identified a correlation between the abnormal glycosylation of AGP in rheumatoid arthritis and suppression of sLeX dependent cell adhesion through inhibition of E-selectin binding which could be the basis of a novel, site specific, anti-inflammatory agent.