The synaptic vesicle protein Mover/TPRG1L is associated with lipid droplets in astrocytes

Crucial brain functions such as neurotransmission, myelination, and signaling pose a high demand for lipids. Lipid dysregulation is associated with neuroinflammation and neurodegeneration. Astrocytes protect neurons from lipid induced damage by accumulating and metabolizing toxic lipids in organelles called lipid droplets (LDs). LDs have long been considered as lipid storage compartments in adipocytes, but less is known about their biogenesis and composition in the brain. In particular, proteins covering the LD surface are not yet fully identified. Here, we report that the presynaptic protein Mover/TPRG1L, which regulates the probability of neurotransmitter release in neurons, is a component of the LD coat in astrocytes. Using conventional and super-resolution microscopy, we demonstrate that Mover surrounds naive and oleic acid induced astrocytic LDs. We confirm the identity of astrocytic LDs using the neutral lipid stains Bodipy and LipidTox, as well as immunofluorescence for perilipin-2, a known component of the LD coat. In astrocytes, recombinant Mover was sufficient to induce an accumulation of LDs. Furthermore, we identified point mutations that abolish targeting to LDs and show similarities in the required binding sequences for association to the presynapse and LDs. Our results show that Mover is not only a presynaptic protein but also a candidate for LD regulation. This highlights the dual role of Mover in synaptic transmission and regulation of astrocytic LDs, which may be particularly important in the context of lipid-related neurological disorders.

Intakes of retinol and carotenoids and its determining factors in the Red River Delta population of northern Vietnam

OBJECTIVE

To describe the household intakes of retinol and carotenoids and social economic factors determining their intakes.

SUBJECTS

Data on a total of 1001 households (771 in rural areas and 230 in urban areas) were used in the analyses. Interviewed person was household food preparer.

RESULTS

Mean (s.d.) intake of carotenoids was 4178 (3154) microg/capita/day in rural and 4208 (3408) microg/capita/day in urban areas and intake of retinol was 101 (275) microg/capita/day in rural and 201 (470) microg/capita/day in urban areas. Multivariate analyses show that the subjects in households with four or more members consume about 700 microg carotenoids less compared to households with less than three members. Households with a higher expenditure (fourth quartile) consumed about 100 microg retinol/day more than those with a lower expenditure (first quartile).

CONCLUSION

Carotenoids from plant food sources is the main source of vitamin A intake of the population and its main determinants are household expenditure and size of household. Food fortification and dietary diversification with special emphasis on promotion of consumption of animal foods should be key strategies for overcoming vitamin A deficiency in Vietnam.

Evaluation of Diagnostic Tests for Trypanosoma evansi in Experimentally Infected Pigs and Subsequent Use in Field Surveys in North Vietnam and Thailand

This study is concerned with the evaluation of established diagnostic tests for diagnosis of Trypanosoma evansi in pigs. The immune trypanolysis test (TL), card agglutination test (CATT), latex agglutination test (LATEX), enzyme-linked immunosorbent assay (ELISA), microhaematocrit centrifugation technique (MHCT) and mouse inoculation (MI) tests were initially evaluated in experimentally infected fattening pigs. All infected pigs were confirmed parasitologically positive with both MHCT and MI. Results of the serological assays indicated that the TL could be a reference test for the presence of RoTat 1.2 antibodies in pigs. The results of the CATT and LATEX were inconsistent with the TL while the ELISA results correlated with the TL results. The four serological assays were subsequently used in two field surveys in Vietnam and Thailand. Results of the two agglutination assays (CATT and LATEX) were not consistent and did not correlate with TL results. The ELISA at percentage positivity of 22 appeared to have good ability to discriminate between seropositive and seronegative animals. Of the 437 samples collected at smallholder pig premises in northern Vietnam, no positive pigs were detected with the TL test. In Thailand, 77 samples were collected from five farrowing farms with a history of surra. Two parasitologically positive sows were found and on each farm seropositive sows were detected.

Receiver operating characteristic analysis of body mass index to detect increased risk of functional morbidity in Vietnamese rural adults

OBJECTIVE

To assess the performance of low BMI, and define optimal BMI cut-off values in order to detect fever-associated adult morbidity.

DESIGN

A cohort study of adults between 18 and 60 y in rural Vietnam, whose BMI and health status were assessed at baseline, and who were then monitored for illness events for 4 months. Nonparametric receiver operating characteristic (ROC) analysis was used to evaluate the performance of low BMI to detect the average number of restricted-days due to illness and to determine optimal cut-off values.

SETTING

A rural commune in the Red River Delta, northern Vietnam.

SUBJECTS

The study included 693 men and 739 women aged 18-60-y.

RESULTS

At baseline, 21% of the study participants had a BMI<18.5 kg/m(2). As BMI progressively decreased, the percentage of participants experiencing morbidity with fever increased. The areas under the ROC curves for BMI were significantly greater than 0.5 for all levels of monthly average restricted-days of illness (MARDI) with fever, with best performance for >5 days/month. Excluding participants with acute or chronic disease at baseline improved the performance of BMI to detect MARDI with fever of >5 days (area under ROC curve 0.95; 95% CI 0.92, 0.99). With increasing levels of MARDI with fever, BMI cut-offs fell to 17.9 kg/m(2) when MARDI with fever was >5 days.

CONCLUSIONS

The ROC analysis demonstrates that low BMI performs well as a risk indicator of MARDI with fever of >5 days with an optimal BMI cut-off value of 17.9 kg/m(2).

The effect of Trypanosoma evansi infection on pig performance and vaccination against classical swine fever

Although Trypanosoma evansi is not considered as an important pathogen in pigs, it may interfere with other pathogens or vaccinations by its immunosuppressive nature. In order to determine whether T. evansi alters pig performance and induces immunosuppression in pigs, induction of immune responses by vaccination against classical swine fever (CSF) and by immunization with a control antigen, human serum albumin (HSA), was assessed in T. evansi-infected and non-infected animals. Although T. evansi infection did not have a significant influence on growth performance, feed conversion or PCV, antibody responses against both the test antigen HSA and the CSF vaccine were significantly reduced in T. evansi-infected animals as compared to uninfected animals. Moreover, the reduced response against the CSF vaccine appears to be accompanied by a less well-developed protection against CSF with higher fever responses and leukopenia. This immunosuppression might explain the accounts of poor protection of CSF-vaccinated pigs reported in T. evansi-endemic areas of Vietnam, and suggests that prior treatments with trypanocidal drugs to improve the efficacy of CSF vaccination, may be justified.

PriA mutations that affect PriA-PriC function during replication restart

In Escherichia coli, repair and restart of collapsed replication forks is thought to be essential for cell growth. The replication restart proteins, PriA, PriB, PriC, DnaB, DnaC, DnaG, DnaT and Rep, form redundant pathways that recognize repaired replication forks and restart them. Recognition, modulation of specific DNA structures and loading of the replicative helicase by the replication restart proteins, is likely to be important for replication restart. It has been hypothesized that PriB and PriC function with PriA in genetically separate and redundant PriA-PriB and PriA-PriC pathways. In this study, the del(priB)302 or priC303:kan mutations were used to isolate the PriA-PriB and PriA-PriC pathways genetically so that the effects of three priA missense mutations, priA300 (K230R), priA301 (C479Y) and priA306 (L557P), on these pathways could be assessed. In a wild-type background, the three priA mutations had little, if any, effect on the phenotypes of UV resistance, basal levels of SOS expression and cell viability. In the priB mutant, priA300 and priA301 caused dramatic negative changes in the three phenotypes listed above (and others), whereas the third priA mutant allele, priA306, showed very little negative effect. In the priC mutant, all three priA mutations behaved similarly, producing little, if any, changes in phenotypes. We conclude that priA300 and priA301 mostly affect the PriA-PriC pathway and do so more than priA306. We suggest that PriA's helicase activity is important for the PriA-PriC pathway of replication restart.

Antimalarial compounds from Rhaphidophora decursiva

Bioassay-directed fractionation led to the isolation of 14 compounds, six of which possess antimalarial activity, from the dried leaves and stems of Rhaphidophora decursiva. Polysyphorin (1) and rhaphidecurperoxin (6) showed strong activities against Plasmodium falciparum. Rhaphidecursinol A (2), rhaphidecursinol B (3), grandisin (4), and epigrandisin (5) were less active against the same organism. Among the isolates, rhaphidecursinol A (2) and rhaphidecursinol B (3) were determined to be new neolignans, and rhaphidecurperoxin (6) is a new benzoperoxide. Known compounds isolated include polysyphorin (1), grandisin (4), epigrandisin (5), (+)-medioresinol, (-)-pinoresinol, (-)-syringaresinol, (+)-glaberide I, (+)-dehydrovomifoliol, (-)-liliolide, (-)-hydroxydihydrobovolide, and N-butylbenzamide, of which compound 1 appears worthy of further evaluation as an antimalarial agent. Structure elucidation and identification were accomplished by spectroscopic means including 1D and 2D NMR analyses.

Clinical and radiographic evaluation of bowlegs

Lower extremity bowing is a normal physiologic process that commonly occurs in walking children under the age of 2 years. After this age, any significant amount of residual bowing is abnormal and may be due to infections, traumatic physeal injuries, genetic predisposition, metabolic factors, or a combination of these. Of the pathologic conditions, infantile Blount's disease is the most common and is predominantly found in obese children with an early onset of walking. Because of its frequency in occurrence and general tendency for spontaneous resolution, physiologic genu varum must be clearly distinguished from other pathologic processes that result in bowleggedness. Treatment of the latter cases may consist of early bracing or surgery.

Food Intake and Lipid Status of Three Vietnamese Populations with Different Incomes

In order to have basic data for dietary preventive measures against some vascular diseases caused by disorder of lipid metabolism, food intake and lipid status were investigated in three Vietnamese populations with different per capita income levels. Totally, 299 people aged over 18 were involved in this study. Among them, 98 subjects were selected from one commune with low income, 100 and 101 subjects from two urban areas with medium and high income respectively. Food intake was assessed by 24-h recall method and lipid status was evaluated by measuring serum concentration of triglyceride, total cholesterol and its subfractions. The results showed that food consumption, dietary habits and lipid status varied with income levels. In general, diet was still unbalanced in all three groups, and low in fat and protein. In the rural, fat and protein intakes were lower than in the urban. The high prevalence of low serum cholesterol was observed in all three groups, the highest in the rural (45.3%) and the lowest in the urban (11.2%). On the contrary, the prevalence of high serum cholesterol was the lowest in the rural (2%) and the highest in the urban (16%). From these data, it is suggested that the majority of the Vietnamese might be vulnerable to some vascular diseases such as stroke if the situation of low fat intake and low serum cholesterol is not a problem of concern.

The epidemiology of nematode and fluke infections in cattle in the Red River Delta in Vietnam

Over a period of 13 months, faecal samples were collected monthly from approximately 45 cattle over 3 months of age. Additionally, 74 calves of 1-2 months were sampled to determine the presence of Toxocara vitulorum eggs. Individual egg counts and infective strongyle larvae from pooled faecal samples were examined. Post-mortem worm counts were carried out on six groups of tracer calves (n=12) that had been kept for 4 weeks on pasture in and around the village studied. The following helminths were identified: T. vitulorum, Cooperia punctata, C. pectinata, C. oncophora, Oesophagostomum radiatum, Trichostrongylus axei, T. colubriformis, Haemonchus spp., Fasciola spp. and Paramphistomum spp. In 8% of the samples collected from young calves, individual egg counts for T. vitulorum were found indicative for pathogenic worm burdens. Strongyle egg counts and worm counts indicated that transmission is low without a distinct seasonality. In animals of 3-9 months old, a strongyle egg count peak can be demonstrated which at a higher age steadily and significantly decreased. In faecal cultures Cooperia spp. were most prominent in all age groups throughout the year with the exception of the period September-November when Haemonchus spp. and Oesophagostomum spp. were most prevalent. Fasciola spp. eggs were found in 22% of the collected faecal samples and the egg counts were low indicating that the intensity of Fasciola spp. infection is mild. Based on the present data, regular anthelmintic treatments seem not to be justified, except for a single treatment at the age of 2 weeks against toxocariosis.

Serum fatty acids, lipoprotein(a) and apolipoprotein composition of rural, suburban and urban populations in North Vietnam

This study was conducted to investigate the concentrations of serum fatty acids, lipoprotein(a) and apolipoprotein of three populations in North Vietnam: rural area with low income (n = 101), suburban with average income (n = 97), and urban with high income (n = 95). The results showed the suburban and urban populations had higher fat intake than the rural. The fat intake in quality was different in these three populations. The suburban had the highest consumption of fatty foods rich in n-6 polyunsaturated fatty acid (PUFA). The rural consumed more fatty foods rich in monounsaturated fatty acid (MUFA), but less fatty foods rich in n-3 PUFA than the two other populations. The high index of thrombogenicity (IT) of the Vietnamese diet may result from their low intake of fish and vegetable oils. Risk factors for premature cardiovascular disease (CVD) assessed by serum lipoprotein(a) and apolipoprotein levels were not observed in all three populations. However, coronary heart disease (CHD) and stroke are problems that should be monitored because the increase of CVD morbidity has been reported in Vietnamese people. From a nutritional point of view, the increase of fish and vegetable oils consumption is necessary for the prevention of CVD and CHD in these Vietnamese populations.

Characterization of Na/K-ATPase in Macrobrachium rosenbergii and the effects of changing salinity on enzymatic activity

A ouabain-sensitive Na/K-ATPase kinetic assay system based on the hydrolysis of ATP and the oxidation of NADH was adapted in order to characterize enzymatic activity in gills and examine the effects of changing salinity in Macrobrachium rosenbergii. Maximum inhibition by ouabain occurred at a concentration of 1.4 mM, and the K(m) of the reaction was 0.2 mM. In a first experiment, animals were acclimated to freshwater, 1/3 seawater, 2/3 seawater and full seawater for up to 1 week. Na/K-ATPase activity in front gills was 1. 62+/-0.19 micromol ADP/mg protein per h in freshwater, and was seen to increase slightly in 1/3 seawater (1.88+/-0.19 micromol ADP/mg protein per h) and 2/3 seawater (2.09+/-0.24 micromol ADP/mg protein per h), decreasing slightly in full seawater (1.92+/-0.43 micromol ADP/mg protein per h); however, differences were not significant. Back gills showed slightly higher levels, and a similar pattern of Na/K-ATPase activity. In a second experiment, animals were acclimated to 1/3 seawater and 2/3 seawater, and then transferred to freshwater. However, no changes in activity were seen, indicating that exposure to dilute media did not effect enzymatic activity. Whereas Na/K-ATPase is important in osmoregulatory function in marine euryhaline crustaceans, it may not play a significant role in adaptation in freshwater crustaceans that inhabit a more narrow range of salinities.

Transient synovitis as a cause of painful limps in children

Transient synovitis of the hip is one of the most common causes of hip pain and limp in young children. Its cause is still largely unknown, but its natural history is that of a self-limiting disorder with no residual sequelae, although recurrences are possible. Because this benign condition is similar to more significant disorders, such as septic arthritis, the diagnosis should remain one of exclusion. Once transient synovitis is diagnosed, treatment consists of rest, anti-inflammatory agents, and a tincture of time.

Resection arthroplasty of the hip for patients with cerebral palsy: an outcome study

Thirteen patients (18 hips) with cerebral palsy and painful hip subluxation or dislocation underwent proximal femoral resection-interposition arthroplasty (PFRIA) as a salvage procedure for intractable pain or seating difficulty. Eleven patients (14 hips) had a prior failed soft-tissue or bony reconstruction. The average age at surgery was 26.6 years (range, 10.7-45.5 years), and average follow-up was 7.4 years (range, 2.2-20.8 years). All patients/caregivers noted significant improvement in subjective assessment of pain after the surgery. Upright sitting tolerance improved from an average preoperative value of 3.2-8.9 h postoperatively (p < 0.01). Four patients who were unable even to sit in a customized wheelchair before the operation could be easily seated in a custom chair after surgery. Hip range of motion including flexion, extension, and abduction was significantly improved postoperatively (p < 0.05). Single-dose radiation therapy was used postoperatively for five hips and resulted in a significantly lower grade of heterotopic ossification at final follow-up (p < 0.005). Skeletal traction in the postoperative period did not prevent proximal migration of the femur compared with skin traction. Maximal pain relief was achieved at an average of 5.6 months postoperatively (range, 0.03-14 months). Complications included transient postoperative decubitus ulceration (four patients), pneumonia (two patients), and symptomatic heterotopic bone (two patients). The significant improvements in pain management, sitting tolerance, and range of motion suggest that PFRIA is a reasonable salvage procedure for the painful, dislocated hip in cerebral palsy. Resolution of pain may not be immediate, as was noted in this series.

Sulfonamide-induced reactions in desensitized patients with AIDS--the role of covalent protein haptenation by sulfamethoxazole

BACKGROUND

Adverse reactions to sulfonamides cause significant morbidity in patients with AIDS. We have demonstrated previously a approximately 40 kd sulfamethoxazole (SMX)-substituted protein in the serum of some individuals treated with SMX.

OBJECTIVE

The purpose of this study was to examine patients with AIDS who had undergone SMX desensitization because of a prior history of SMX allergy for the presence of SMX-haptenated serum proteins and to determine whether these proteins, SMX-specific IgG antibodies, or both predict the development of subsequent clinical reactivity.

METHODS

Four patients with no history of allergy and in whom SMX prophylaxis was initiated and eight patients with AIDS who had undergone SMX desensitization because of prior allergy were evaluated. SMX-conjugated serum proteins were identified with an immunoblotting assay, and SMX-specific IgG antibodies were identified by ELISA inhibition.

RESULTS

One of the four patients receiving SMX prophylactic treatment demonstrated SMX-protein haptenation, none had detectable SMX-specific IgG antibodies, and none developed an SMX-associated reaction during the time in which they were followed. Of the eight patients who underwent SMX desensitization, six (75%) demonstrated SMX-protein haptenation, and three of these six (50%) subsequently developed SMX-induced cutaneous reactions. Only one of these six patients had detectable SMX-specific IgG antibodies. The two individuals who did not demonstrate SMX-protein haptenation have not developed a clinical reaction.

CONCLUSION

These preliminary data suggest that SMX haptenation, but not SMX-specific antibodies, may be important in the development of clinical sensitivity in patients with AIDS who have undergone SMX desensitization.

External fixation and limited internal fixation for complex fractures of the tibial plateau

Twenty-one complex fractures of the tibial plateau in twenty patients were treated with closed reduction, interfragmental screw fixation of the articular fragments, and application of a unilateral half-pin external fixator. The average duration of external fixation was twelve weeks (range, three to twenty weeks). The fixator was left in situ until the fracture had united in all but two patients. All of the fractures healed. The complications with this technique were attributable primarily to the proximal half-pins of the external fixator. Seven patients needed antibiotics for an infection at a pin site, and two had septic arthritis that necessitated arthrotomy and débridement. The average duration of follow-up was thirty-eight months. The range of motion of nineteen of the twenty-one knees was at least a 115-degree arc. Laxity was evident in seven knees, but no patient complained of instability of the knee. Radiographs showed malalignment of more than 6 degrees in three knees compared with the normal, contralateral knee and evidence of post-traumatic osteoarthrosis in five knees. The Iowa knee score, determined for nineteen patients, averaged 87 points (range, 55 to 100 points). The SF-36 general health survey demonstrated that most patients had function close to that of age-matched controls. We concluded that external fixation with limited internal fixation is a satisfactory technique for the treatment of selected complex fractures of the tibial plateau.

Effects of tissue geometry on initiation of a cardiac action potential

We used rabbit ventricular papillary muscles and isolated rabbit ventricular muscle cells to compare the effects of a decrease in cardiac excitability. For the papillary muscles, we defined tissue excitability as the inverse of the current required to initiate a propagated action potential from a local stimulus. For the isolated cells, we defined cellular excitability as the inverse of the current required to initiate a membrane action potential. For papillary muscles, lidocaine with elevated extracellular K+ concentration ([K+]o) decreased maximum rate of rise of membrane potential (Vmax), decreased conduction velocity, and strongly decreased tissue excitability. For the isolated cells, lidocaine with elevated [K+]o decreased Vmax but had little effect on cellular excitability. We interpret our results on the differences of effect on tissue excitability vs. cellular excitability as a consequence of the syncytial nature of the papillary muscle. The cell-to-cell electrical connections produce an electrical load on the locally stimulated region. This electrical load makes the tissue excitability dependent on the amount of inward current that the locally excited cells and the surrounding cells can generate. We simulated these phenomena with numerical solutions of action potential initiation in an isopotential cell compared with a two-dimensional disk of excitable tissue. The simulation results recreate the basic experimental observation that the sensitivity of the current threshold to agents that lower inward current is markedly larger for multidimensional current flow from a source compared with an isopotential system.

Localization of loci for hypoxanthine phosphoribosyltransferase and glucose-6-phosphate dehydrogenase and biochemical evidence of nonrandom X chromosome expression from studies of a human X-autosome translocation

We report a unique and complex karyotypic rearrangement involving chromosomes X, 3, 7, and 21. Blood cells and fibroblasts from the proband do not express the maternal allele for glucose-6-phosphate dehydrogenase (G6PD), providing biochemical evidence for nonrandom expression of X-linked genes in balanced X-autosome translocations. The break point on the X chromosome, at the junction of Xq27-Xq28, separates the loci for hypoxanthine phosphoribosyltransferase (HPRT) and G6PD. Studies of mouse-human hybrids derived from the proband's cells indicate that G6PD, at q28, is clearly distal to all other X loci now assigned. From these and previous studies, we can localize HPRT to that segment between Xq26 and Xq27. The studies also provide further evidence for the stability of the inactive X phenotype in hybrid cells.

Stability of the "two active X" phenotype in triploid somatic cells

We examined triploid cells of XXY karyotype heterozygous for glucose 6 phosphate dehydrogenase (G6PD) electrophoretic variants with regard to the stability of their X chromosome phenotype. Clonal populations of cells derived from these human fibroblasts maintained a precise 1:2:1 ratio of A:heteropolymer:B isozymes throughout their life span, indicating stability of the two active X chromosomes in these cells. To determine the influence of the autosomal complement on X chromosome expression, we attempted to perturb the relationship. Fusion of these triploid cells with human diploid fibroblasts carrying a novel G6PD variant (B') resulted in heterokaryons exprssing a novel heteropolymer, presumably indicating that all three parental X chromosomes were active. However, no derepression of the inactive X chromosome was observed. Analysis of interspecific hybrids derived from triploid cells and mouse fibroblasts confirmed that activity of parental X chromosomes is maintained. Some human mouse hybrid clones, however, expressed only a single human G6PD isozyme, probably attributable to segregation of the pertinent X chromosome, but elimination of a relevant autosome cannot be excluded. The triploid cells transformed by SV40 showed alterations in LDH pattern and an approximately 10-20% decrease in chromosome number, but maintained the precise G6PD phenotype of the untransformed cell. These studies provide evidence for the stability of the X chromosome phenotype in triploid cells.

In search of non-random X inactivation: studies of fetal membranes heterozygous for glucose-6-phosphate dehydrogenase

Extraembryonic membranes and fetal tissues were obtained from 55 specimens of 5--11 weeks conceptual age. The glucose-6-phosphate dehydrogenase (G6PD) electrophoretic phenotype was determined and correlated with that of maternal blood. Fifteen specimens were heterozygous for G6PD A, and for nine of these the maternal allele could be determined. In none of these specimens did the isozyme pattern of the membraneous chorion or chorionic villi differ significantly from that of fetal tissue. We have obtained no evidence of non-random inactivation in extraembryonic membranes of human fetal specimens at this stage of development.