Lifestyle strategies to promote proteostasis and reduce the risk of Alzheimer's disease and other proteinopathies

Unhealthy lifestyle choices, poor diet, and aging can have negative influences on cognition, gradually increasing the risk for mild cognitive impairment (MCI) and the continuum comprising early dementia. Aging is the greatest risk factor for age-related dementias such as Alzheimer's disease, and the aging process is known to be influenced by life events that can positively or negatively affect age-related diseases. Remarkably, life experiences that make the brain vulnerable to dementia, such as seizure episodes, neurotoxin exposures, metabolic disorders, and trauma-inducing events (e.g. traumatic injuries or mild neurotrauma from a fall or blast exposure), have been associated with negative effects on proteostasis and synaptic integrity. Functional compromise of the autophagy-lysosomal pathway, a major contributor to proteostasis, has been implicated in Alzheimer's disease, Parkinson's disease, obesity-related pathology, Huntington's disease, as well as in synaptic degeneration which is the best correlate of cognitive decline. Correspondingly, pharmacological and non-pharmacological strategies that positively modulate lysosomal proteases are recognized as synaptoprotective through degradative clearance of pathogenic proteins. Here, we discuss life-associated vulnerabilities that influence key hallmarks of brain aging and the increased burden of age-related dementias. Additionally, we discuss exercise and diet among the lifestyle strategies that regulate proteostasis as well as synaptic integrity, leading to evident prevention of cognitive deficits during brain aging in pre-clinical models.

Distinct and dementia-related synaptopathy in the hippocampus after military blast exposures

Explosive shockwaves, and other types of blast exposures, are linked to injuries commonly associated with military service and to an increased risk for the onset of dementia. Neurological complications following a blast injury, including depression, anxiety, and memory problems, often persist even when brain damage is undetectable. Here, hippocampal explants were exposed to the explosive 1,3,5-trinitro-1,3,5-triazinane (RDX) to identify indicators of blast-induced changes within important neuronal circuitries. Highly controlled detonations of small, 1.7-gram RDX spherical charges reduced synaptic markers known to be downregulated in cognitive disorders, but without causing overt neuronal loss or astroglial responses. In the absence of neuromorphological alterations, levels of synaptophysin, GluA1, and synapsin IIb were significantly diminished within 24 hr, and these synaptic components exhibited progressive reductions following blast exposure as compared to their stable maintenance in control explants. In contrast, labeling of the synapsin IIa isoform remained unaltered, while neuropilar staining of other markers decreased, including synapsin IIb and neural cell adhesion molecule (NCAM) isoforms, along with evidence of NCAM proteolytic breakdown. NCAM180 displayed a distinct decline after the RDX blasts, whereas NCAM140 and NCAM120 exhibited smaller or no deterioration, respectively. Interestingly, the extent of synaptic marker reduction correlated with AT8-positive tau levels, with tau pathology stochastically found in CA1 neurons and their dendrites. The decline in synaptic components was also reflected in the size of evoked postsynaptic currents recorded from CA1 pyramidals, which exhibited a severe and selective reduction. The identified indicators of blast-mediated synaptopathy point to the need for early biomarkers of explosives altering synaptic integrity with links to dementia risk, to advance strategies for both cognitive health and therapeutic monitoring.

microRNAs expression correlates with levels of APP, DYRK1A, hyperphosphorylated Tau and BDNF in the hippocampus of a mouse model for Down syndrome during ageing

Down syndrome (DS) patients are more susceptible to Alzheimer's disease (AD) due to the presence of three copies of genes on chromosome 21 such as DYRK1A, which encodes a broad acting kinase, and APP (amyloid precursor protein), leading to formation of amyloid beta (Aβ) peptide and hyperphosphorylation of Tau. In this study, we investigated the association among miRNAs miR-17, -20a, -101, -106b, -199b, -26a, 26b and some of their target mRNAs such as APP, DYRK1A and BDNF, as well as the levels of hyperphosphorylated Tau in the hippocampus of a 2 and 5 months old mice model of trisomy 21 (Ts65Dn). Results indicated that increased APP expression in the hippocampus of 5 months old DS mice might be correlated with decrease in miR-17, -20a, -101 and -106b. Whereas at 2 months of age normal levels of APP expression in the hippocampus was correlated with increased levels of miR-17, -101 and -106b in DS mice. DYRK1A mRNA also increased in the hippocampus of 5 months old DS mice and it is associated with decreased levels of miR-199b. Increased levels of DYRK1A in 5-month old mice are associated with increased phosphorylation of Tau at Thr212 residue but not at Ser199-202. Tau pathology is accompanied by decreased expression of BDNF and increased miR-26a/b in mice of 5 months of age. Taken together, data indicate that miR-17, -20a, -26a/b, -101, -106b and -199b might be interesting targets to mitigate Tau and Aβ pathology in DS.

Piperidine and piperazine inhibitors of fatty acid amide hydrolase targeting excitotoxic pathology

FAAH inhibitors offer safety advantages by augmenting the anandamide levels "on demand" to promote neuroprotective mechanisms without the adverse psychotropic effects usually seen with direct and chronic activation of the CB1 receptor. FAAH is an enzyme implicated in the hydrolysis of the endocannabinoid N-arachidonoylethanolamine (AEA), which is a partial agonist of the CB1 receptor. Herein, we report the discovery of a new series of highly potent and selective carbamate FAAH inhibitors and their evaluation for neuroprotection. The new inhibitors showed potent nanomolar inhibitory activity against human recombinant and purified rat FAAH, were selective (>1000-fold) against serine hydrolases MGL and ABHD6 and lacked any affinity for the cannabinoid receptors CB1 and CB2. Evaluation of FAAH inhibitors 9 and 31 using the in vitro competitive activity-based protein profiling (ABPP) assay confirmed that both inhibitors were highly selective for FAAH in the brain, since none of the other FP-reactive serine hydrolases in this tissue were inhibited by these agents. Our design strategy followed a traditional SAR approach and was supported by molecular modeling studies based on known FAAH cocrystal structures. To rationally design new molecules that are irreversibly bound to FAAH, we have constructed "precovalent" FAAH-ligand complexes to identify good binding geometries of the ligands within the binding pocket of FAAH and then calculated covalent docking poses to select compounds for synthesis. FAAH inhibitors 9 and 31 were evaluated for neuroprotection in rat hippocampal slice cultures. In the brain tissue, both inhibitors displayed protection against synaptic deterioration produced by kainic acid-induced excitotoxicity. Thus, the resultant compounds produced through rational design are providing early leads for developing therapeutics against seizure-related damage associated with a variety of disorders.

The Role of Lysosomes in a Broad Disease-Modifying Approach Evaluated across Transgenic Mouse Models of Alzheimer's Disease and Parkinson's Disease and Models of Mild Cognitive Impairment

Many neurodegenerative disorders have lysosomal impediments, and the list of proposed treatments targeting lysosomes is growing. We investigated the role of lysosomes in Alzheimer's disease (AD) and other age-related disorders, as well as in a strategy to compensate for lysosomal disturbances. Comprehensive immunostaining was used to analyze brains from wild-type mice vs. amyloid precursor protein/presenilin-1 (APP/PS1) mice that express mutant proteins linked to familial AD. Also, lysosomal modulation was evaluated for inducing synaptic and behavioral improvements in transgenic models of AD and Parkinson's disease, and in models of mild cognitive impairment (MCI). Amyloid plaques were surrounded by swollen organelles positive for the lysosome-associated membrane protein 1 (LAMP1) in the APP/PS1 cortex and hippocampus, regions with robust synaptic deterioration. Within neurons, lysosomes contain the amyloid β 42 (Aβ42) degradation product Aβ38, and this indicator of Aβ42 detoxification was augmented by Z-Phe-Ala-diazomethylketone (PADK; also known as ZFAD) as it enhanced the lysosomal hydrolase cathepsin B (CatB). PADK promoted Aβ42 colocalization with CatB in lysosomes that formed clusters in neurons, while reducing Aβ deposits as well. PADK also reduced amyloidogenic peptides and α-synuclein in correspondence with restored synaptic markers, and both synaptic and cognitive measures were improved in the APP/PS1 and MCI models. These findings indicate that lysosomal perturbation contributes to synaptic and cognitive decay, whereas safely enhancing protein clearance through modulated CatB ameliorates the compromised synapses and cognition, thus supporting early CatB upregulation as a disease-modifying therapy that may also slow the MCI to dementia continuum.

Engulfment and cell motility protein 1 potentiates diabetic cardiomyopathy via Rac-dependent and Rac-independent ROS production

Engulfment and cell motility protein 1 (ELMO1) is part of a guanine nucleotide exchange factor for Ras-related C3 botulinum toxin substrate (Rac), and ELMO1 polymorphisms were identified to be associated with diabetic nephropathy in genome-wide association studies. We generated a set of Akita Ins2C96Y diabetic mice having 5 graded cardiac mRNA levels of ELMO1 from 30% to 200% of normal and found that severe dilated cardiomyopathy develops in ELMO1-hypermorphic mice independent of renal function at age 16 weeks, whereas ELMO1-hypomorphic mice were completely protected. As ELMO1 expression increased, reactive oxygen species indicators, dissociation of the intercalated disc, mitochondrial fragmentation/dysfunction, cleaved caspase-3 levels, and actin polymerization increased in hearts from Akita mice. Cardiomyocyte-specific overexpression in otherwise ELMO1-hypomorphic Akita mice was sufficient to promote cardiomyopathy. Cardiac Rac1 activity was positively correlated with the ELMO1 levels, and oral administration of a pan-Rac inhibitor, EHT1864, partially mitigated cardiomyopathy of the ELMO1 hypermorphs. Disrupting Nox4, a Rac-independent NADPH oxidase, also partially mitigated it. In contrast, a pan-NADPH oxidase inhibitor, VAS3947, markedly prevented cardiomyopathy. Our data demonstrate that in diabetes mellitus ELMO1 is the "rate-limiting" factor of reactive oxygen species production via both Rac-dependent and Rac-independent NADPH oxidases, which in turn trigger cellular signaling cascades toward cardiomyopathy.

Early Synaptic Alterations and Selective Adhesion Signaling in Hippocampal Dendritic Zones Following Organophosphate Exposure

Organophosphates account for many of the world's deadliest poisons. They inhibit acetylcholinesterase causing cholinergic crises that lead to seizures and death, while survivors commonly experience long-term neurological problems. Here, we treated brain explants with the organophosphate compound paraoxon and uncovered a unique mechanism of neurotoxicity. Paraoxon-exposed hippocampal slice cultures exhibited progressive declines in synaptophysin, synapsin II, and PSD-95, whereas reduction in GluR1 was slower and NeuN and Nissl staining showed no indications of neuronal damage. The distinctive synaptotoxicity was observed in dendritic zones of CA1 and dentate gyrus. Interestingly, declines in synapsin II dendritic labeling correlated with increased staining for β1 integrin, a component of adhesion receptors that regulate synapse maintenance and plasticity. The paraoxon-induced β1 integrin response was targeted to synapses, and the two-fold increase in β1 integrin was selective as other synaptic adhesion molecules were unchanged. Additionally, β1 integrin-cofilin signaling was triggered by the exposure and correlations were found between the extent of synaptic decline and the level of β1 integrin responses. These findings identified organophosphate-mediated early and lasting synaptotoxicity which can explain delayed neurological dysfunction later in life. They also suggest that the interplay between synaptotoxic events and compensatory adhesion responses influences neuronal fate in exposed individuals.

Weaning practices in phenylketonuria vary between health professionals in Europe

Background

In phenylketonuria (PKU), weaning is considered more challenging when compared to feeding healthy infants. The primary aim of weaning is to gradually replace natural protein from breast milk or standard infant formula with solids containing equivalent phenylalanine (Phe). In addition, a Phe-free second stage L-amino acid supplement is usually recommended from around 6 months to replace Phe-free infant formula. Our aim was to assess different weaning approaches used by health professionals across Europe.

Methods

A cross sectional questionnaire (survey monkey®) composed of 31 multiple and single choice questions was sent to European colleagues caring for inherited metabolic disorders (IMD). Centres were grouped into geographical regions for analysis.

Results

Weaning started at 17–26 weeks in 85% (n = 81/95) of centres, >26 weeks in 12% (n = 11/95) and < 17 weeks in 3% (n = 3/95). Infant's showing an interest in solid foods, and their age, were important determinant factors influencing weaning commencement. 51% (n = 48/95) of centres introduced Phe containing foods at 17–26 weeks and 48% (n = 46/95) at >26 weeks. First solids were mainly low Phe vegetables (59%, n = 56/95) and fruit (34%, n = 32/95).

A Phe exchange system to allocate dietary Phe was used by 52% (n = 49/95) of centres predominantly from Northern and Southern Europe and 48% (n = 46/95) calculated most Phe containing food sources (all centres in Eastern Europe and the majority from Germany and Austria). Some centres used a combination of both methods.

A second stage Phe-free L-amino acid supplement containing a higher protein equivalent was introduced by 41% (n = 39/95) of centres at infant age 26–36 weeks (mainly from Germany, Austria, Northern and Eastern Europe) and 37% (n = 35/95) at infant age > 1y mainly from Southern Europe. 53% (n = 50/95) of centres recommended a second stage Phe-free L-amino acid supplement in a spoonable or semi-solid form.

Conclusions

Weaning strategies vary throughout European PKU centres. There is evidence to suggest that different infant weaning strategies may influence longer term adherence to the PKU diet or acceptance of Phe-free L-amino acid supplements; rendering prospective long-term studies important. It is essential to identify an effective weaning strategy that reduces caregiver burden but is associated with acceptable dietary adherence and optimal infant feeding development.

Mild Exercise Differently Affects Proteostasis and Oxidative Stress on Motor Areas During Neurodegeneration: A Comparative Study of Three Treadmill Running Protocols

Proteostasis and oxidative stress were evaluated in motor cortex and spinal cord of aged Lewis rats exposed to 1 mg/kg/day of rotenone during 4 or 8 weeks, prior or after practicing three protocols of mild treadmill running. Results demonstrated that exercise done after the beginning of neurodegeneration reverted the increased oxidative stress (measured by H₂O₂ levels and SOD activity), increased neuron strength, and improved proteostasis in motor cortex. Spinal cord was not affected. Treadmill running practiced before neurodegeneration protected cortical motor neurons of the rotenone-exposed rats; but in this case, oxidative stress was not altered, whereas proteasome activity was increased and autophagy decreased. Spinal cord was not protected when exercise was practiced before neurodegeneration. Prolonged treadmill running (10 weeks) increased oxidative stress, autophagy, and proteasome activity, whereas neuron viability was decreased in motor cortex. In spinal cord, this protocol decreased oxidative stress and increased proteasome activity. Major conclusions were that treadmill running practiced before or after the beginning of neurodegeneration may protect motor cortex neurons, whereas prolonged mild running seems to be beneficial for spinal cord.

Physical and thermal processing of Waste Printed Circuit Boards aiming for the recovery of gold and copper

The recovery of electronic waste to obtain secondary raw materials is a subject of high relevance in the context of circular economy. Accordingly, the present work relies on the evaluation of mining separation/concentration techniques (comminution, size screening, magnetic separation and gravity concentration) alone as well as combined with thermal pre-treatment to recover gold and copper from Waste Printed Circuit Boards. For that purpose, Waste Printed Circuit Boards were subjected to physical processing (comminution, size screening in 6 classes from <0.425 mm to > 6.70 mm, magnetic separation and gravity concentration) alone and combined with thermal treatment (200-500 °C), aiming the recovery of gold and copper. Mixed motherboards and graphic cards (Lot 1 and 3) and highly rich components (connectors separated from memory cards, Lot 2) were analyzed. Gold and copper concentrations were determined before and after treatment. Before treatment, concentrations from 0.01 to 0.6 % wt. and from 9 to 20 % wt. were found for gold and copper respectively. The highest concentrations were observed in the size fractions between 0.425 and 1.70 mm. The highest copper concentration was around 35 % wt. (class 0.425-0.85 mm) and when analyzing memory card connectors alone, gold concentrations reached almost 2% in the same class, reflecting the interest of separating such components. The physical treatment alone was more effective for Lot 1/3, compared to Lot 2, allowing recoveries of 67 % wt. and 87 % wt. for gold and copper respectively, mostly due to differences in particles size and shape. The thermal treatment showed unperceptive influence on gold concentration but significant effect for copper concentration, mostly attributed to the size of the copper particles. Concentrations increased in a factor of around 10 when the thermal treatment was performed at 300 °C for the larger particles (1.70-6.70 mm); the best results were obtained at 400 °C for the other sizes, when the highest rate of thermal decomposition of the material occurred.

Early feeding practices in infants with phenylketonuria across Europe

Background

In infants with phenylketonuria (PKU), dietary management is based on lowering and titrating phenylalanine (Phe) intake from breast milk or standard infant formula in combination with a Phe-free infant formula in order to maintain blood Phe levels within target range. Professionals use different methods to feed infants with PKU and our survey aimed to document practices across Europe.

Methods

We sent a cross sectional, survey monkey® questionnaire to European health professionals working in IMD. It contained 31 open and multiple-choice questions. The results were analysed according to different geographical regions.

Results

Ninety-five centres from 21 countries responded. Over 60% of centres commenced diet in infants by age 10 days, with 58% of centres implementing newborn screening by day 3 post birth. At diagnosis, infant hospital admission occurred in 61% of metabolic centres, mainly in Eastern, Western and Southern Europe. Breastfeeding fell sharply following diagnosis with only 30% of women still breast feeding at 6 months.

53% of centres gave pre-measured Phe-free infant formula before each breast feed and 23% alternated breast feeds with Phe-free infant formula. With standard infant formula feeds, measured amounts were followed by Phe-free infant formula to satiety in 37% of centres (n = 35/95), whereas 44% (n = 42/95) advised mixing both formulas together. Weaning commenced between 17 and 26 weeks in 85% centres, ≥26 weeks in 12% and < 17 weeks in 3%.

Discussion

This is the largest European survey completed on PKU infant feeding practices. It is evident that practices varied widely across Europe, and the practicalities of infant feeding in PKU received little focus in the PKU European Guidelines (2017). There are few reports comparing different feeding techniques with blood Phe control, Phe fluctuations and growth. Controlled prospective studies are necessary to assess how different infant feeding practices may influence longer term feeding development.

Effects of mild running on substantia nigra during early neurodegeneration

Moderate physical exercise acts at molecular and behavioural levels, such as interfering in neuroplasticity, cell death, neurogenesis, cognition and motor functions. Therefore, the aim of this study is to analyse the cellular effects of moderate treadmill running upon substantia nigra during early neurodegeneration. Aged male Lewis rats (9-month-old) were exposed to rotenone 1mg/kg/day (8 weeks) and 6 weeks of moderate treadmill running, beginning 4 weeks after rotenone exposure. Substantia nigra was extracted and submitted to proteasome and antioxidant enzymes activities, hydrogen peroxide levels and Western blot to evaluate tyrosine hydroxylase (TH), alpha-synuclein, Tom-20, PINK1, TrkB, SLP1, CRMP-2, Rab-27b, LC3II and Beclin-1 level. It was demonstrated that moderate treadmill running, practiced during early neurodegeneration, prevented the increase of alpha-synuclein and maintained the levels of TH unaltered in substantia nigra of aged rats. Physical exercise also stimulated autophagy and prevented impairment of mitophagy, but decreased proteasome activity in rotenone-exposed aged rats. Physical activity also prevented H₂O₂ increase during early neurodegeneration, although the involved mechanism remains to be elucidated. TrkB levels and its anterograde trafficking seem not to be influenced by moderate treadmill running. In conclusion, moderate physical training could prevent early neurodegeneration in substantia nigra through the improvement of autophagy and mitophagy.

Inhibitor of Endocannabinoid Deactivation Protects Against In Vitro and In Vivo Neurotoxic Effects of Paraoxon

The anticholinesterase paraoxon (Pxn) is related to military nerve agents that increase acetylcholine levels, trigger seizures, and cause excitotoxic damage in the brain. In rat hippocampal slice cultures, high-dose Pxn was applied resulting in a presynaptic vulnerability evidenced by a 64% reduction in synapsin IIb (syn IIb) levels, whereas the postsynaptic protein GluR1 was unchanged. Other signs of Pxn-induced cytotoxicity include the oxidative stress-related production of stable 4-hydroxynonenal (4-HNE)-protein adducts. Next, the Pxn toxicity was tested for protective effects by the fatty acid amide hydrolase (FAAH) inhibitor AM5206, a compound linked to enhanced repair signaling through the endocannabinoid pathway. The Pxn-mediated declines in syn IIb and synaptophysin were prevented by AM5206 in the slice cultures. To test if the protective results in the slice model translate to an in vivo model, AM5206 was injected i.p. into rats, followed immediately by subcutaneous Pxn administration. The toxin caused a pathogenic cascade initiated by seizure events, leading to presynaptic marker decline and oxidative changes in the hippocampus and frontal cortex. AM5206 exhibited protective effects including the reduction of seizure severity by 86%, and improving balance and coordination measured 24 h post-insult. As observed in hippocampal slices, the FAAH inhibitor also prevented the Pxn-induced loss of syn IIb in vivo. In addition, the AM5206 compound reduced the 4-HNE modifications of proteins and the β1 integrin activation events both in vitro and in vivo. These results indicate that Pxn exposure produces oxidative and synaptic toxicity that leads to the behavioral deficits manifested by the neurotoxin. In contrast, the presence of FAAH inhibitor AM5206 offsets the pathogenic cascade elicited by the Pxn anticholinesterase.

Aβ42-mediated proteasome inhibition and associated tau pathology in hippocampus are governed by a lysosomal response involving cathepsin B: Evidence for protective crosstalk between protein clearance pathways

Impaired protein clearance likely increases the risk of protein accumulation disorders including Alzheimer’s disease (AD). Protein degradation through the proteasome pathway decreases with age and in AD brains, and the Aβ₄₂ peptide has been shown to impair proteasome function in cultured cells and in a cell-free model. Here, Aβ₄₂ was studied in brain tissue to measure changes in protein clearance pathways and related secondary pathology. Oligomerized Aβ₄₂ (0.5–1.5 μM) reduced proteasome activity by 62% in hippocampal slice cultures over a 4-6-day period, corresponding with increased tau phosphorylation and reduced synaptophysin levels. Interestingly, the decrease in proteasome activity was associated with a delayed inverse effect, >2-fold increase, regarding lysosomal cathepsin B (CatB) activity. The CatB enhancement did not correspond with the Aβ₄₂-mediated phospho-tau alterations since the latter occurred prior to the CatB response. Hippocampal slices treated with the proteasome inhibitor lactacystin also exhibited an inverse effect on CatB activity with respect to diminished proteasome function. Lactacystin caused earlier CatB enhancement than Aβ₄₂, and no correspondence was evident between up-regulated CatB levels and the delayed synaptic pathology indicated by the loss of pre- and postsynaptic markers. Contrasting the inverse effects on the proteasomal and lysosomal pathways by Aβ₄₂ and lactacystin, such were not found when CatB activity was up-regulated two-fold with Z-Phe-Ala-diazomethylketone (PADK). Instead of an inverse decline, proteasome function was increased marginally in PADK-treated hippocampal slices. Unexpectedly, the proteasomal augmentation was significantly pronounced in Aβ₄₂-compromised slices, while absent in lactacystin-treated tissue, resulting in >2-fold improvement for nearly complete recovery of proteasome function by the CatB-enhancing compound. The PADK treatment also reduced Aβ₄₂-mediated tau phosphorylation and synaptic marker declines, corresponding with the positive modulation of both proteasome activity and the lysosomal CatB enzyme. These findings indicate that proteasomal stress contributes to AD-type pathogenesis and that governing such pathology occurs through crosstalk between the two protein clearance pathways.

Aged Lewis rats exposed to low and moderate doses of rotenone are a good model for studying the process of protein aggregation and its effects upon central nervous system cell physiology

Cell physiology is impaired before protein aggregation and this may be more relevant than inclusions themselves for neurodegeneration. The present study aimed to characterize an animal model to enable the analysis of the cell biology before and after protein aggregation. Ten-month-old Lewis rats were exposed either to 1 or 2 mg/kg/day of rotenone, delivered subcutaneously through mini-pumps, for one month. Hyperphosphorylated TAU, alpha-synuclein, amyloid-beta peptide and protein carbonylation (indicative of oxidative stress) were evaluated in the hippocampus, substantia nigra and locus coeruleus through immunohistochemistry or western blot. It was found that 2 mg/kg/day rotenone increased amyloid-beta peptide, hyperphosphorylation of TAU and alpha-synuclein. Rotenone at 1mg/kg/day did not alter protein levels. Protein carbonylation remained unchanged. This study demonstrated that aged Lewis rats exposed to a low dose of rotenone is a useful model to study cellular processes before protein aggregation, while the higher dose makes a good model to study the effects of protein inclusions.

Dietary practices in isovaleric acidemia: A European survey

Background

In Europe, dietary management of isovaleric acidemia (IVA) may vary widely. There is limited collective information about dietetic management.

Aim

To describe European practice regarding the dietary management of IVA, prior to the availability of the E-IMD IVA guidelines (E-IMD 2014).

Methods

A cross-sectional questionnaire was sent to all European dietitians who were either members of the Society for the Study of Inborn Errors of Metabolism Dietitians Group (SSIEM-DG) or whom had responded to previous questionnaires on dietetic practice (n = 53). The questionnaire comprised 27 questions about the dietary management of IVA.

Results

Information on 140 patients with IVA from 39 centres was reported. 133 patients (38 centres) were given a protein restricted diet. Leucine-free amino acid supplements (LFAA) were routinely used to supplement protein intake in 58% of centres. The median total protein intake prescribed achieved the WHO/FAO/UNU [2007] safe levels of protein intake in all age groups. Centres that prescribed LFAA had lower natural protein intakes in most age groups except 1 to 10 y. In contrast, when centres were not using LFAA, the median natural protein intake met WHO/FAO/UNU [2007] safe levels of protein intake in all age groups. Enteral tube feeding was rarely prescribed.

Conclusions

This survey demonstrates wide differences in dietary practice in the management of IVA across European centres. It provides unique dietary data collectively representing European practices in IVA which can be used as a foundation to compare dietary management changes as a consequence of the first E-IMD IVA guidelines availability.

Blast waves from detonated military explosive reduce GluR1 and synaptophysin levels in hippocampal slice cultures

Explosives create shockwaves that cause blast-induced neurotrauma, one of the most common types of traumatic brain injury (TBI) linked to military service. Blast-induced TBIs are often associated with reduced cognitive and behavioral functions due to a variety of factors. To study the direct effects of military explosive blasts on brain tissue, we removed systemic factors by utilizing rat hippocampal slice cultures. The long-term slice cultures were briefly sealed air-tight in serum-free medium, lowered into a 37°C water-filled tank, and small 1.7-gram assemblies of cyclotrimethylene trinitramine (RDX) were detonated 15cm outside the tank, creating a distinct shockwave recorded at the culture plate position. Compared to control mock-treated groups of slices that received equal submerge time, 1-3 blast impacts caused a dose-dependent reduction in the AMPA receptor subunit GluR1. While only a small reduction was found in hippocampal slices exposed to a single RDX blast and harvested 1-2days later, slices that received two consecutive RDX blasts 4min apart exhibited a 26-40% reduction in GluR1, and the receptor subunit was further reduced by 64-72% after three consecutive blasts. Such loss correlated with increased levels of HDAC2, a histone deacetylase implicated in stress-induced reduction of glutamatergic transmission. No evidence of synaptic marker recovery was found at 72h post-blast. The presynaptic marker synaptophysin was found to have similar susceptibility as GluR1 to the multiple explosive detonations. In contrast to the synaptic protein reductions, actin levels were unchanged, spectrin breakdown was not detected, and Fluoro-Jade B staining found no indication of degenerating neurons in slices exposed to three RDX blasts, suggesting that small, sub-lethal explosives are capable of producing selective alterations to synaptic integrity. Together, these results indicate that blast waves from military explosive cause signs of synaptic compromise without producing severe neurodegeneration, perhaps explaining the cognitive and behavioral changes in those blast-induced TBI sufferers that have no detectable neuropathology.

Presence of insoluble Tau following rotenone exposure ameliorates basic pathways associated with neurodegeneration

Protein aggregation is an important feature of neurodegenerative disorders. In Alzheimer's disease (AD) protein aggregates are composed of hyperphosphorylated Tau and amyloid beta peptide (Aβ). Despite the involvement and identification of the molecular composition of these aggregates, their role in AD pathophysiology is not fully understood. However, depositions of these insoluble aggregates are typically reported as pathogenic and toxic for cell homeostasis. New evidences suggest that the deposition of these aggregates is a protective mechanism that preserves cell from toxic insults associated with the early stages of neurodegenerative diseases. To better understand the biological role of the protein aggregation with regard its effects in cellular homeostasis, the present study investigated the role of insoluble Tau and Tau aggregates on crucial cellular parameters such as redox homeostasis, proteasome activity and autophagy in hippocampal cell cultures and hippocampus of aged Lewis rats using a rotenone-induced aggregation model. Neurons were exposed to rotenone in different concentrations and exposure times aiming to determine the interval required for Tau aggregation. Our experimental design allowed us to demonstrate that rotenone exposure induces Tau hyperphosphorylation and aggregation in a concentration and time-dependent manner. Oxidative stress triggered by rotenone exposure was observed with the absence of Tau aggregates and was reduced or absent when Tau aggregates were present. This reduction of oxidative stress along with the presence of insoluble Tau was independent of alterations in antioxidant enzymes activities or cell death. In addition, rotenone induced oxidative stress was mainly associated with decrease in proteasome activity and autophagy flux. Conversely, when insoluble Tau appeared, autophagy turns to be overactivated while proteasome activity remained low. Our studies significantly advance the understanding that Tau aggregation might exert protective cellular effects, at least briefly, when neurons are facing neurodegeneration stimulus. We believe that our data add more complexity for the understanding of protein aggregation role in AD etiology.

The challenges of managing coexistent disorders with phenylketonuria: 30 cases

INTRODUCTION

The few published case reports of co-existent disease with phenylketonuria (PKU) are mainly genetic and familial conditions from consanguineous marriages. The clinical and demographic features of 30 subjects with PKU and co-existent conditions were described in this multi-centre, retrospective cohort study.

METHODS

Diagnostic age of PKU and co-existent condition, treatment regimen, and impact of co-existent condition on blood phenylalanine (Phe) control and PKU management were reported.

RESULTS

30 patients (11 males and 19 females), with PKU and a co-existent condition, current median age of 14 years (range 0.4 to 40 years) from 13 treatment centres from Europe and Turkey were described. There were 21 co-existent conditions with PKU; 9 were autoimmune; 6 gastrointestinal, 3 chromosomal abnormalities, and 3 inherited conditions. There were only 5 cases of parental consanguinity. Some patients required conflicting diet therapy (n=5), nutritional support (n=7) and 5 children had feeding problems. There was delayed diagnosis of co-existent conditions (n=3); delayed treatment of PKU (n=1) and amenorrhea associated with Grave's disease that masked a PKU pregnancy for 12 weeks. Co-existent conditions adversely affected blood Phe control in 47% (n=14) of patients. Some co-existent conditions increased the complexity of disease management and increased management burden for patients and caregivers.

CONCLUSIONS

Occurrence of co-existent disease is not uncommon in patients with PKU and so investigation for co-existent disorders when the clinical history is not completely consistent with PKU is essential. Integrating care of a second condition with PKU management is challenging.

Practices in prescribing protein substitutes for PKU in Europe: No uniformity of approach

BACKGROUND

There appears little consensus concerning protein requirements in phenylketonuria (PKU).

METHODS

A questionnaire completed by 63 European and Turkish IMD centres from 18 countries collected data on prescribed total protein intake (natural/intact protein and phenylalanine-free protein substitute [PS]) by age, administration frequency and method, monitoring, and type of protein substitute. Data were analysed by European region using descriptive statistics.

RESULTS

The amount of total protein (from PS and natural/intact protein) varied according to the European region. Higher median amounts of total protein were prescribed in infants and children in Northern Europe (n=24 centres) (infants <1 year, >2-3g/kg/day; 1-3 years of age, >2-3 g/kg/day; 4-10 years of age, >1.5-2.5 g/kg/day) and Southern Europe (n=10 centres) (infants <1 year, 2.5 g/kg/day, 1-3 years of age, 2 g/kg/day; 4-10 years of age, 1.5-2 g/kg/day), than by Eastern Europe (n=4 centres) (infants <1 year, 2.5 g/kg/day, 1-3 years of age, >2-2.5 g/kg/day; 4-10 years of age, >1.5-2 g/kg/day) and with Western Europe (n=25 centres) giving the least (infants <1 year, >2-2.5 g/kg/day, 1-3 years of age, 1.5-2 g/kg/day; 4-10 years of age, 1-1.5 g/kg/day). Total protein prescription was similar in patients aged >10 years (1-1.5 g/kg/day) and maternal patients (1-1.5 g/kg/day).

CONCLUSIONS

The amounts of total protein prescribed varied between European countries and appeared to be influenced by geographical region. In PKU, all gave higher than the recommended 2007 WHO/FAO/UNU safe levels of protein intake for the general population.

Dietary management of urea cycle disorders: European practice

BACKGROUND

There is no published data comparing dietary management of urea cycle disorders (UCD) in different countries.

METHODS

Cross-sectional data from 41 European Inherited Metabolic Disorder (IMD) centres (17 UK, 6 France, 5 Germany, 4 Belgium, 4 Portugal, 2 Netherlands, 1 Denmark, 1 Italy, 1 Sweden) was collected by questionnaire describing management of patients with UCD on prescribed protein restricted diets.

RESULTS

Data for 464 patients: N-acetylglutamate synthase (NAGS) deficiency, n=10; carbamoyl phosphate synthetase (CPS1) deficiency, n=29; ornithine transcarbamoylase (OTC) deficiency, n=214; citrullinaemia, n=108; argininosuccinic aciduria (ASA), n=80; arginase deficiency, n=23 was reported. The majority of patients (70%; n=327) were aged 0-16y and 30% (n=137) >16y. Prescribed median protein intake/kg body weight decreased with age with little variation between disorders. The UK tended to give more total protein than other European countries particularly in infancy. Supplements of essential amino acids (EAA) were prescribed for 38% [n=174] of the patients overall, but were given more commonly in arginase deficiency (74%), CPS (48%) and citrullinaemia (46%). Patients in Germany (64%), Portugal (67%) and Sweden (100%) were the most frequent users of EAA. Only 18% [n=84] of patients were prescribed tube feeds, most commonly for CPS (41%); and 21% [n=97] were prescribed oral energy supplements.

CONCLUSIONS

Dietary treatment for UCD varies significantly between different conditions, and between and within European IMD centres. Further studies examining the outcome of treatment compared with the type of dietary therapy and nutritional support received are required.

Dietary practices in pyridoxine non-responsive homocystinuria: a European survey

BACKGROUND

Within Europe, the management of pyridoxine (B6) non-responsive homocystinuria (HCU) may vary but there is limited knowledge about treatment practice.

AIM

A comparison of dietetic management practices of patients with B6 non-responsive HCU in European centres.

METHODS

A cross-sectional audit by questionnaire was completed by 29 inherited metabolic disorder (IMD) centres: (14 UK, 5 Germany, 3 Netherlands, 2 Switzerland, 2 Portugal, 1 France, 1 Norway, 1 Belgium).

RESULTS

181 patients (73% >16 years of age) with HCU were identified. The majority (66%; n=119) were on dietary treatment (1-10 years, 90%; 11-16 years, 82%; and >16 years, 58%) with or without betaine and 34% (n=62) were on betaine alone. The median natural protein intake (g/day) on diet only was, by age: 1-10 years, 12 g; 11-16 years, 11 g; and >16 years, 45 g. With diet and betaine, median natural protein intake (g/day) by age was: 1-10 years, 13 g; 11-16 years, 20 g; and >16 years, 38 g. Fifty-two percent (n=15) of centres allocated natural protein by calculating methionine rather than a protein exchange system. A methionine-free l-amino acid supplement was prescribed for 86% of diet treated patients. Fifty-two percent of centres recommended cystine supplements for low plasma concentrations. Target treatment concentrations for homocystine/homocysteine (free/total) and frequency of biochemical monitoring varied.

CONCLUSION

In B6 non-responsive HCU the prescription of dietary restriction by IMD centres declined with age, potentially associated with poor adherence in older patients. Inconsistencies in biochemical monitoring and treatment indicate the need for international consensus guidelines.

Nutrition education tools used in phenylketonuria: clinician, parent and patient perspectives from three international surveys

BACKGROUND

Three international surveys were developed aiming to identify the current nutrition educational tools used in the management of phenylketonuria (PKU) and the perceived effectiveness of these tools by clinicians, parents and patients.

METHODS

The first two surveys were distributed through the Metabolic Dietitians ListServe (pno-metabl@listserv.cc.emory.edu), and the third survey was distributed by international clinics and the National PKU Alliance website (www.npkua.org). A total of 888 responses (S1, n = 88; S2, n = 81; S3, n = 719) were collected from all three surveys. The surveys represent participants from 17 countries, in Europe; North America (USA and Canada); Mexico; Argentina; Turkey; Australia; and Africa (Tunisia).

RESULTS

A consistent decline in 'parents as role models' as an educational tool was observed starting at age 10 years. Patients responded they feel their families are the most effective form of education, whereas handouts were selected as the least effective educational tool by patients. Parents responded they feel the most effective educational tool is one-on-one counselling. Patients and parents show a desirable trend in wanting to attend group clinic, even in centres where this type of educational tool is not offered.

CONCLUSIONS

There was a discrepancy between clinicians and patient views regarding the perceived effectiveness of the nutrition education tools. Future research is needed surrounding the impact nutrition education may have on improved dietary compliance in patients with PKU.

Vaccinating the vampire bat Desmodus rotundus against rabies

The objective of this study was to extend the previous work of indirect oral rabies immunization of vampire bats (Desmodus rotundus) maintained in captivity, which demonstrated the immunogenicity of the V-RG vaccine (Vaccinia-Rabies Glycoprotein) and indicated that although the results had been encouraging, a new method for concentrating the vaccine should be tested in order to avoid vaccine loss and increase the survival proportion of bats after rabies challenge. In this study, three groups of seven bats each were tested with vaccine concentrated by ultrafiltration through a cellulose membrane. The vaccine was homogenized in Vaseline paste and applied to the back of one vector bat, which was then reintroduced into its group. A dose of 10(5.0) MICLD(50) rabies virus was used by intramuscular route to challenge the bats postvaccination. The survival proportion in the three groups after the challenge was 71.4%, 71.4% and 100%.

Evaluation of cytokines concentration and percentage of survival of rabies virus-infected mice submitted to anti-rabies Vero-cell propagated vaccine and P. acnes

Previously, survival of rabies infection was shown to correlate with low IL-6 serum concentration in mice subjected to post-exposure treatment with the Fuenzalida Palacios rabies vaccine in conjunction with the immunomodulator Propionibacterium acnes, previously Corynebacterium parvum. Considering the substitution of the Fuenzalida Palacios rabies vaccine by the Vero cell raised anti-rabies vaccine in almost all countries, the objective of this work was to evaluate the survival and cytokine serum concentration of rabies virus-infected mice treated with P. acnes in conjunction with or the anti-rabies-VERO vaccine. For this, Swiss mice were experimentally infected with street rabies virus and subjected to vaccine and/or P. acnes following infection. Animals were killed at different times and serum was collected to evaluate cytokines. The greatest survival was observed in animals given one or two does of P. acnes in the absence of vaccination. Animals given anti-rabies VERO vaccine alone or with three doses of P. acnes had the second highest survival rate. The group that had the highest percentage of mortality also had the highest IL-6 concentration on the 10th day, a time correlating with clinical symptoms of the animals. The results reinforce the inefficacy of anti-rabies vaccine in only one dose as a post-exposure treatment irrespective of the type of vaccine used, the immunomodulation activity of P. acnes in rabies post-exposure treatment and suggest a role for IL-6 in rabies virus pathogenesis.

Experimental rabies infection in haematophagous bats Desmodus rotundus

In order to determine the susceptibility and serum neutralizing antibody response of Desmodus rotundus to rabies virus, bats were inoculated with a virus isolated from a naturally infected haematophagous bat. Bats were divided into four groups of 10 animals each. Dilutions of rabies virus containing 100, 1000, 10,000 and 100,000 MICLD50 (lethal dose 50% for mice inoculated by the intracerebral route) were administrated in the pectoral muscle. The presence of rabies virus was detected in brain and salivary glands by fluorescent antibody, mouse inoculation and RT-PCR. The observed mortality for each virus dose was 0, 20, 20 and 60% respectively. Serum neutralizing antibodies were tested for by the rapid fluorescent focus inhibition test, and antibody titres greater than 0.5 IU/ml were found in 53% of bats 30 days after virus inoculation. Resistance to infection was seen in bats that developed low or no detectable antibody response as well as in bats with high titres. Among the 10 bats that died of rabies, eight showed signs of paralytic rabies and two bats showed no clinical signs.

Increased interleukin-10 associated with low IL-6 concentration correlated with greater survival rates in mice infected by rabies virus vaccinated against it and immunomodulated with P. acnes

Macrophage activity, cytokines serum concentration, serum neutralizing antibodies and lethality by rabies were evaluated in swiss mice experimentally infected with street rabies virus and submitted or not to antirabies vaccination and immunomodulation with P. acnes. Animals were killed at different times and serum was collected in order to evaluate cytokines concentration; peritonial and splenic macrophages were collected for macrophage activity evaluation. Greater survival rates higher IL-10 and low IL-6 serum concentration were observed in vaccinated animals treated using P. acnes.

Direct determination of chlorophenols in landfill leachates by solid-phase micro-extraction-gas chromatography-mass spectrometry

Landfill leachates represent a serious environmental concern with regard to trace priority pollutants introduced into the aquatic environment. From the analytical point of view, they constitute complex matrices because of their high organic matter content and competition with the trace analytes in the extraction procedure. Although the use of SPME to extract chlorophenols in leachates has already been described in several publications, the limited number of chlorophenols restricts this analysis field of application. This paper presents a new analytical methodology to determine 13 chlorophenols and phenol by SPME-GC-MS in landfill leachates. The overall analysis was performed in 90 min and the detection limits range from 0.005 microg/l (pentachlorophenol) to 2.5 microg/l (phenol). Reproducibility, expressed by the coefficient of variation of repeated extractions at different concentration levels of the analytes, was on average inferior to 10%. Recovery, evaluated by standard addition to leachates, was 86.2% on average. Pentachlorophenol, 2,3,4,5-tetrachlorophenol and 2,3,4,6-tetrachlorophenol were the sole analytes detected at nanogram level in the landfill leachates analysed.

Expanded shoulder flap in burn sequela

The expanded shoulder flap is presented as an alternative for the treatment of cervical retraction secondary to burning. The flap has an axial pattern, mainly based on the transverse cervical artery. The anterior limit of the flap is a line that goes from ear lobule, towards the shoulder, to the deltoid muscle. The incision for inclusion of the tissue expander is made at the shoulder, and on that line, with extension and posterior, lateral and medial detachments broad enough to slightly exceed the expander dimensions, with the valve being placed in infraclavicular position. In the immediate postoperative period, a volume around 15% to 20% of the tissue expander's total capacity was infiltrated, which was followed by weekly infiltrations until the expanded area reached a circumference approximately 2 to 3 times larger than the supposed wound after creating the resection of the retraction. The expanded shoulder flap allows coverage of large extensions, by using a single donor shoulder, as it permits not only release of retraction, but also replacement of associated cervical scars by leaner skin, better adjusted to the region's anatomy. Twelve patients were treated with this method, with good results in all cases, and there being no flap delay. Closing of the donor area happened without any stress, which resulted in scars of good quality.

The GAbAergic and cholinergic systems in the retina are differentially affected by postnatal malnutrition during the suckling period

Malnutrition by severe protein deprivation induces deleterious consequences in the nervous system particularly in the initial period of development. These deficits can alter several important events during development, such as the expression of neurotransmitters. The induction of nutritional deficiency by using low protein diet, similar to that consumed by low income populations in Brazil, was applied in rats to investigate the effect of malnutrition on cells containing gamma-aminobutyric acid (GABA) and acetylcholine in the retina. GABA immunoreactivity was present in cells in the inner nuclear and ganglion cell layers and in processes in the inner and outer plexiform layers in retinas of control and malnourished animals. At postnatal day 8, there is a decrease (ca. 40%) of the GABAergic neurons in malnourished animals. At P13 and P21 the percentage of these neurons increased and was equivalent to control animals in the adult. Glutamic acid decarboxylase activity did not show significant changes between the two groups along development. Choline acetyltransferase immunoreactivity was localized in amacrine cells in the inner nuclear and ganglion cell layers and their processes in the inner plexiform layer. The percentage of cholinergic cells was always higher in malnourished animals than that observed in the control until postnatal day 30, when the same proportion of cholinergic neurons was found in the retinas of both groups. Choline acetyltransferase activity did not show significant changes between the two groups along development. In conclusion, our results show that despite the extreme somatic and behavioral changes observed the neurotransmitter systems studied were at a certain extent shielded from the insult.

Kinetics of chromium removal from spent tanning liquors using acetylene production sludge

The removal of Cr(III) present in spent leather tanning baths by precipitation with acetylene production sludge (APS) is studied. The hydroxide and carbonate contents in APS were 1.05 and 0.10 g of CaCO3/g of dry sludge, respectively, and the Cr concentration in the tanning bath was 2467 mg/L. The experimental work was carried out at 15, 20, 25, 30, and 35 degrees C using APS samples of different grain size (89, 178, and 356 microm). Percent removals after 180-min reaction time using 356-microm APS particles range from 99.0 to 99.9 as temperature increased from 15 to 35 degrees C. Similar or higher removal rates are obtained when using smaller APS particles. Chromium removal efficiencies using APS as precipitant are comparable with those obtained with NaOH, CaO, or MgO. The Cr conversion X increases with time t and is related to the particle radius and the absolute temperature T by the expression X/1 - X= r0(-0.22) exp(45.45-13401/T)t. The average activation energy for the reaction is 111.4 kJ mol(-1). Despite some deviations observed for the finer particles and the lower temperature (15 degrees C), the model describes adequately the results obtained for all APS particle sizes at 20 degrees C.

[Controversies in neonatal resuscitation]

OBJECTIVE: To describe the main controversies surrounding newborn resuscitation procedures. SOURCES: Systematic review of articles from MEDLINE, LILACS and Cochrane Library, and of abstracts published in Pediatric Research, using the keywords resuscitation, asphyxia neonatorum, and newborn infant. SUMMARY OF THE FINDINGS: The effectiveness of hypothermia and ambient air ventilation has been under study. The reduction of barotrauma and volutrauma in the ventilation of preterm infants is still a challenge. The indication of endotracheal intubation in preterm infants based only on their extremely low weight is not a general agreement, except if the use of exogenous surfactant is required. There is still some uncertainty about the ideal dosage of intravenous or endotracheal adrenaline and the need of sodium bicarbonate, mainly in preterm infants. The ethical dilemma includes the decision on whether or not resuscitation should be used in circumstances related to gestational age, birth weight and severe congenital anomalies. CONCLUSIONS: Only the results obtained through animal experiments and randomized controlled clinical trials, with a follow-up of the development of newborn infants submitted to certain resuscitation procedures, will allow changing currently used therapies.

Neutralizing antirabies antibodies in urban terrestrial wildlife in Brazil

The prevalence of rabies neutralizing antibodies (NA) in sera of wild animals from São Paulo City (Brazil) was investigated using the Rapid Fluorescent Focus Inhibition Test between 1994 and 1997. Sera from 547 specimens were examined. Marsupials represented 45% of the sample and primates 37%; carnivores, rodents, deer and edentates represented 6, 6, 3 and 2%, respectively. The overall prevalence of NA was 14%. The prevalence of NA was 18% in primates; whereas in marsupials, carnivores, edentates and rodents it was 13, 9, 8 and 6%, respectively. The stratification according to sex, age, and site of capture of the marsupials and primates showed a small predominance in males versus females and a large predominance of adults versus juveniles. The same relationship was seen in specimens captured near human habitations versus specimens captured in their own habitat. It is evident that there is circulation of rabies virus in wild animals, which are not recommended as pets since they represent a potential risk of exposure to rabies virus for both humans and domestic animals.

Rabies seroprevalence of street dogs from São Paulo City, Brazil

A sample of 602 street dogs captured by the São Paulo zoonosis-control municipal service was analyzed for the presence of serum antibodies against the rabies virus and compared to a control sample of 37 dogs from the kennel of the police of São Paulo. Data were stratified into 4 age intervals and the age from the street-dog sample was estimated by general aspects and dental observation according to standard techniques. We assumed that seropositivity was due to previous vaccination (no sub-clinical infection). From the prevalence data, we estimated the age-dependent incidence-density rate of vaccination by a simple mathematical model, which also allowed the estimation of the period of antibody protection given by the supposed vaccination. Crude seroprevalence in the street-dog sample was 16.5% and in the sample from the police-kennel dogs was 80%. The average age of first vaccination calculated for the street-dog sample was 5 years of age (if we assumed an average period of vaccine protection of 3 years) - but 5 months of age for the police-kennel sample.

Preoperative normovolemic hemodilution in aesthetic plastic surgery

Normovolemic autotransfusion was used with 11 healthy females who were about to undergo multiple aesthetic plastic surgeries. After collecting a unit of blood immediately prior to surgery, a quick infusion of isotonic saline solution is made, at a 4-to-1 ratio, until reaching a hematocrit equal to or lower than 30%, thus inducing olighemia. The intended consequence is that blood lost during surgery be poor in red cell mass, which means reduced blood loss, leading to improved tissue oxygenation and decreased risk of thromboembolism. The blood thus collected is reinstilled at the end of the intervention. Results indicate that the technique can be prescribed and bring benefits to any patient entering surgery for which the surgeon anticipates heavy blood loss. The method proposed herein is presented as an alternative to homologous and autologous programmed transfusions and as equivalent to these in terms of volume replenishment.

[Humoral immune response of dogs to the inactivated suckling mouse brain vaccine used in anti-rabies campaigns in Brazil]

INTRODUCTION

An anti-rabies campaign is undertaken annually in Brazil with of the Fuenzalida & Palacios vaccine. The humoral immune response of dogs vaccinated during the campaigns was researched with the objective of evaluating whether the dogs presented a protective titer (0.5 UI/ml) 12 months after vaccination and how many of these achieved this titer 30 days after a buttressing vaccination.

MATERIAL AND METHOD

Three hundred and forty-one specimens of serum of dogs domicilied, 259 in the S. Paulo and 82 in the Paulinia counties, were analyzed utilizing the Rapid Fluorescence Focus Inhibition Test. The immune response was evaluated taking into consideration the nutritional state of the animal and the number of previous vaccinations.

RESULTS

The larger number of the dogs had not achieved the 0.5 UI/ml titer after 12 months, independently of the nutritional state and the response to the buttressing vaccination was more apparent in dogs with two or more previous vaccinations.

DISCUSSION

The cut off of 0.5 UI/ml as protective titer in dogs and the influence of the nutritional state and health conditions of the animals as responsible for humoral immune response are discussed.

[Isolation of rabies virus from the insectivorous bat Myotis nigricans]

The following is a case study of the natural infection by the rabies virus of an insectiverous bat belonging to the species Myotis nigricans in the municipality of Ribeirão Pires, Greater S. Paulo. Diagnosis was made by means of immunofluorescence and intracerebral innoculation of mice with nervous and intrascapular muscular tissues.

[Laboratory diagnosis of rabies in chiroptera carried out in a metropolitan area of southeastern region Brazil]

Between January, 1988 and December, 1992 the S. Paulo Animal Disease Control Center subjected 289 bats to rabies examinations, utilizing the direct immunofluorescence and biological techniques. Two insectiverous bats belonging to the species Nyctinomops macrotis, representing 0.69% of the total sample, tested positive. Both animals had been captured alive in residential neighborhoods of the city, one in 1988 in the living room of a 7th floor apartment and the other in 1990 on top of a wall surrounding a private house. In the biological tests, the disease showed incubation periods of 13 and 11 days respectively. Although the existence of infected insectiverous bats in urban areas is cause for concern, indiscriminate predatory action against such species can in no way be justified-particularly bearing in mind their importance in preserving the ecological balance of the insect population so prevalent in cities.

[Positive serology for syphilis in neonatal period: prevalence in secondary level maternity. Association with maternal risk factors and with positive serology for HIV-1]

To study neonatal Syphilis seropositivity incidence, its association with HIV-1 seropositivity and the impact of Congenital Syphilis CDC case definition, cord blood VDRL and Indirect Hemagglutination (IHA) for Syphilis were performed in 3,664 newborns from Dec/91-July/92. A positive group was formed by those with positive VDRL and IHA or just positive IHA. The control group consisted of 200 VDRL and IHA negative neonates. Among the 3,664 neonates 5.6% were seropositive for Syphilis. A significant association was noted (p < or = 0.05) between neonatal seropositivity for Syphilis and mothers older than 20 years, single, with sexual promiscuity, drug use, no pre-natal care, multiparity and previous still-births. All positive neonates fitted in the Presumptive Congenital Syphilis CDC definition. In 50 seropositive for Syphilis neonates ELISA for HIV-1 was performed and 6/50 were positive. Congenital Syphilis is of concern, specially in neonates of mothers with risk factors for Syphilis acquisition. HIV-1 should be considered in seropositive for Syphilis neonates. Adoption of Congenital Syphilis new CDC case definition is advised, particularly in countries where prenatal care is deficient.