IL-4 shapes microglia-dependent pruning of the cerebellum during postnatal development

Interleukin-4 (IL-4) is a type 2 cytokine with pleiotropic functions in adaptive immunity, allergies, and cognitive processes. Here, we show that low levels of IL-4 in the early postnatal stage delineate a critical period in which microglia extensively prune cerebellar neurons. Elevating the levels of this cytokine via peripheral injection, or using a mouse model of allergic asthma, leads to defective pruning, permanent increase in cerebellar granule cells, and circuit alterations. These animals also show a hyperkinetic and impulsive-like phenotype, reminiscent of attention-deficit hyperactivity disorder (ADHD). These alterations are blocked in Il4rαfl/fl::Cx3cr1-CreER mice, which are deficient in IL-4 receptor signaling in microglia. These findings demonstrate a previously unknown role for IL-4 during a neuroimmune critical period of cerebellar maturation and provide a first putative mechanism for the comorbidity between allergic disease and ADHD observed in humans.

Microglial TNFα orchestrates protein phosphorylation in the cortex during the sleep period and controls homeostatic sleep

Sleep intensity is adjusted by the length of previous awake time, and under tight homeostatic control by protein phosphorylation. Here, we establish microglia as a new cellular component of the sleep homeostasis circuit. Using quantitative phosphoproteomics of the mouse frontal cortex, we demonstrate that microglia-specific deletion of TNFα perturbs thousands of phosphorylation sites during the sleep period. Substrates of microglial TNFα comprise sleep-related kinases such as MAPKs and MARKs, and numerous synaptic proteins, including a subset whose phosphorylation status encodes sleep need and determines sleep duration. As a result, microglial TNFα loss attenuates the build-up of sleep need, as measured by electroencephalogram slow-wave activity and prevents immediate compensation for loss of sleep. Our data suggest that microglia control sleep homeostasis by releasing TNFα which acts on neuronal circuitry through dynamic control of phosphorylation.

Machine Learning Approach for Fatigue Estimation in Sit-to-Stand Exercise

Physical exercise (PE) has become an essential tool for different rehabilitation programs. High-intensity exercises (HIEs) have been demonstrated to provide better results in general health conditions, compared with low and moderate-intensity exercises. In this context, monitoring of a patients' condition is essential to avoid extreme fatigue conditions, which may cause physical and physiological complications. Different methods have been proposed for fatigue estimation, such as: monitoring the subject's physiological parameters and subjective scales. However, there is still a need for practical procedures that provide an objective estimation, especially for HIEs. In this work, considering that the sit-to-stand (STS) exercise is one of the most implemented in physical rehabilitation, a computational model for estimating fatigue during this exercise is proposed. A study with 60 healthy volunteers was carried out to obtain a data set to develop and evaluate the proposed model. According to the literature, this model estimates three fatigue conditions (low, moderate, and high) by monitoring 32 STS kinematic features and the heart rate from a set of ambulatory sensors (Kinect and Zephyr sensors). Results show that a random forest model composed of 60 sub-classifiers presented an accuracy of 82.5% in the classification task. Moreover, results suggest that the movement of the upper body part is the most relevant feature for fatigue estimation. Movements of the lower body and the heart rate also contribute to essential information for identifying the fatigue condition. This work presents a promising tool for physical rehabilitation.

The Ubiquitinated Axon: Local Control of Axon Development and Function by Ubiquitin

Ubiquitin tagging sets protein fate. With a wide range of possible patterns and reversibility, ubiquitination can assume many shapes to meet specific demands of a particular cell across time and space. In neurons, unique cells with functionally distinct axons and dendrites harboring dynamic synapses, the ubiquitin code is exploited at the height of its power. Indeed, wide expression of ubiquitination and proteasome machinery at synapses, a diverse brain ubiquitome, and the existence of ubiquitin-related neurodevelopmental diseases support a fundamental role of ubiquitin signaling in the developing and mature brain. While special attention has been given to dendritic ubiquitin-dependent control, how axonal biology is governed by this small but versatile molecule has been considerably less discussed. Herein, we set out to explore the ubiquitin-mediated spatiotemporal control of an axon's lifetime: from its differentiation and growth through presynaptic formation, function, and pruning.

Botulinum toxin as a novel therapeutic approach for auriculotemporal neuralgia

OBJECTIVES/BACKGROUND

Auriculotemporal neuralgia is a rare headache disorder. Anesthetic nerve blockade seems to be effective in most cases; however, literature is scarce about the management of refractory cases.

METHODS

Case report.

RESULTS

We report a 44-year-old woman with migraine without aura presented with moderate-to-severe right temporoparietal headache. The pain was refractory to multiple pharmacological strategies, including intravenous analgesia. A more throughout examination lead to the diagnosis of auriculotemporal neuralgia and anesthetic nerve blocks were performed. Due to early pain recrudescence, botulinum toxin (BoNT) was tried with better and longstanding pain control.

CONCLUSION

BoNT may be a useful treatment option in refractory auriculotemporal neuralgia. The best approach is yet to be established; however, the "follow-the-pain" protocol may be a reasonable option.

Insulin treatment may not be associated with worse prognosis in acute heart failure diabetic patients

BACKGROUND

Diabetic patients with heart failure (HF) treated with insulin appear to have a worse prognosis compared to oral anti-diabetic (OAD) agents. Whether insulin is a risk factor or a marker of disease severity is unknown. We studied the prognostic impact of insulin treatment in an acute HF diabetic population.

METHODS

From a prospectively recruited population of hospital-admitted acute HF patients we retrospectively selected a convenience sample. Pair-matched analysis: each insulin-treated patient was matched with a diabetic patient with similar glycated hemoglobin (HbA1c±0.2%) under OAD. End-point: all-cause death.

FOLLOW-UP

5 years. Insulin-treated and OAD-treated patients were compared. Multivariate Cox-regression analysis was used to analyze the prognostic impact of insulin.

RESULTS

We studied 92 patients: 46 insulin-treated and 46 HbA1c-matched under OAD. Mean age: 74±9 years, 46.7% male and 63.5% had HF with reduced ejection fraction. HbA1c was 7.8±1.5% in both groups. In the subgroup under OAD: 87.0% metformin, 41.3% sulphonylurea, 28.3% dipeptidyl peptidase-4 inhibitors and 4.3% other agents. Insulin-treated patients had lower hemoglobin, higher creatinine and discharged B-type natriuretic peptide (BNP) levels (816.6 [289.2-1805.8] vs. 613.3 [205.6-1110.8]; P=0.02). Seventy three patients died. There were no differences in mortality up to 5 years. After multivariate adjustment accounting for hemoglobin, creatinine and discharge BNP, HR for 1-, 2-, 3-, and 5-year all-cause death in insulin-treated patients were 1.48 (0.62-3.54); P=0.38, 1.11 (0.55-2.25); P=0.77, 1.08 (0.56-2.08); P=0.28 and 1.24 (0.70-2.19); P=0.46, respectively.

CONCLUSIONS

Insulin-treated diabetic patients with HF and HbA1c-matched patients treated with OAD have similarly ominous prognosis. Our results favor insulin as a marker of poor health condition.

The proteasome controls presynaptic differentiation through modulation of an on-site pool of polyubiquitinated conjugates

The intra-axonal events governing formation of presynaptic terminals are still poorly understood. Pinto et al. reveal a mechanism by which a localized decrease in proteasome degradation and resultant accumulation of polyubiquitinated proteins at nascent sites signal assembly of presynaptic terminals.

Differentiation of the presynaptic terminal is a complex and rapid event that normally occurs in spatially specific axonal regions distant from the soma; thus, it is believed to be dependent on intra-axonal mechanisms. However, the full nature of the local events governing presynaptic assembly remains unknown. Herein, we investigated the involvement of the ubiquitin–proteasome system (UPS), the major degradative pathway, in the local modulation of presynaptic differentiation. We found that proteasome inhibition has a synaptogenic effect on isolated axons. In addition, formation of a stable cluster of synaptic vesicles onto a postsynaptic partner occurs in parallel to an on-site decrease in proteasome degradation. Accumulation of ubiquitinated proteins at nascent sites is a local trigger for presynaptic clustering. Finally, proteasome-related ubiquitin chains (K11 and K48) function as signals for the assembly of presynaptic terminals. Collectively, we propose a new axon-intrinsic mechanism for presynaptic assembly through local UPS inhibition. Subsequent on-site accumulation of proteins in their polyubiquitinated state triggers formation of presynapses.

Puzzling out presynaptic differentiation

Proper brain function in the nervous system relies on the accurate establishment of synaptic contacts during development. Countless synapses populate the adult brain in an orderly fashion. In each synapse, a presynaptic terminal loaded with neurotransmitters-containing synaptic vesicles is perfectly aligned to an array of receptors in the postsynaptic membrane. Presynaptic differentiation, which encompasses the events underlying assembly of new presynaptic units, has seen notable advances in recent years. It is now consensual that as a growing axon encounters the receptive dendrites of its partner, presynaptic assembly will be triggered and specified by multiple postsynaptically-derived factors including soluble molecules and cell adhesion complexes. Presynaptic material that reaches these distant sites by axonal transport in the form of pre-assembled packets will be retained and clustered, ultimately giving rise to a presynaptic bouton. This review focuses on the cellular and molecular aspects of presynaptic differentiation in the central nervous system, with a particular emphasis on the identity of the instructive factors and the intracellular processes used by neuronal cells to assemble functional presynaptic terminals. We provide a detailed description of the mechanisms leading to the formation of new presynaptic terminals. In brief, soma-derived packets of pre-assembled material are trafficked to distant axonal sites. Synaptogenic factors from dendritic or glial provenance activate downstream intra-axonal mediators to trigger clustering of passing material and their correct organization into a new presynaptic bouton. This article is part of a mini review series: "Synaptic Function and Dysfunction in Brain Diseases".

Visualizing K48 Ubiquitination during Presynaptic Formation By Ubiquitination-Induced Fluorescence Complementation (UiFC)

In recent years, signaling through ubiquitin has been shown to be of great importance for normal brain development. Indeed, fluctuations in ubiquitin levels and spontaneous mutations in (de)ubiquitination enzymes greatly perturb synapse formation and neuronal transmission. In the brain, expression of lysine (K) 48-linked ubiquitin chains is higher at a developmental stage coincident with synaptogenesis. Nevertheless, no studies have so far delved into the involvement of this type of polyubiquitin chains in synapse formation. We have recently proposed a role for polyubiquitinated conjugates as triggering signals for presynaptic assembly. Herein, we aimed at characterizing the axonal distribution of K48 polyubiquitin and its dynamics throughout the course of presynaptic formation. To accomplish so, we used an ubiquitination-induced fluorescence complementation (UiFC) strategy for the visualization of K48 polyubiquitin in live hippocampal neurons. We first validated its use in neurons by analyzing changing levels of polyubiquitin. UiFC signal is diffusely distributed with distinct aggregates in somas, dendrites and axons, which perfectly colocalize with staining for a K48-specific antibody. Axonal UiFC aggregates are relatively stable and new aggregates are formed as an axon grows. Approximately 65% of UiFC aggregates colocalize with synaptic vesicle clusters and they preferentially appear in the axonal domains of axo-somatodendritic synapses when compared to isolated axons. We then evaluated axonal accumulation of K48 ubiquitinated signals in bead-induced synapses. We observed rapid accumulation of UiFC signal and endogenous K48 ubiquitin at the sites of newly formed presynapses. Lastly, we show by means of a microfluidic platform, for the isolation of axons, that presynaptic clustering on beads is dependent on E1-mediated ubiquitination at the axonal level. Altogether, these results indicate that enrichment of K48 polyubiquitin at the site of nascent presynaptic terminals is an important axon-intrinsic event for presynaptic differentiation.

Diabetes induces changes in KIF1A, KIF5B and dynein distribution in the rat retina: implications for axonal transport

Diabetic retinopathy is a leading cause of vision loss and blindness. Disruption of axonal transport is associated with many neurodegenerative diseases and might also play a role in diabetes-associated disorders affecting nervous system. We investigated the impact of type 1 diabetes (2 and 8 weeks duration) on KIF1A, KIF5B and dynein motor proteins in the retina. Additionally, since hyperglycemia is considered the main trigger of diabetic complications, we investigated whether prolonged exposure to elevated glucose could affect the content and distribution of motor proteins in retinal cultures. The immunoreactivity of motor proteins was evaluated by immunohistochemistry in retinal sections and by immunoblotting in total retinal extracts from streptozotocin-induced diabetic and age-matched control animals. Primary retinal cultures were exposed to high glucose (30 mM) or mannitol (osmotic control; 24.5 mM plus 5.5 mM glucose), for seven days. Diabetes decreased the content of KIF1A at 8 weeks of diabetes as well as KIF1A immunoreactivity in the majority of retinal layers, except for the photoreceptor and outer nuclear layer. Changes in KIF5B immunoreactivity were also detected by immunohistochemistry in the retina at 8 weeks of diabetes, being increased at the photoreceptor and outer nuclear layer, and decreased in the ganglion cell layer. Regarding dynein immunoreactivity there was an increase in the ganglion cell layer after 8 weeks of diabetes. No changes were detected in retinal cultures. These alterations suggest that axonal transport may be impaired under diabetes, which might contribute to early signs of neural dysfunction in the retina of diabetic patients and animal models.

Diabetes alters KIF1A and KIF5B motor proteins in the hippocampus

Diabetes mellitus is the most common metabolic disorder in humans. Diabetic encephalopathy is characterized by cognitive and memory impairments, which have been associated with changes in the hippocampus, but the mechanisms underlying those impairments triggered by diabetes, are far from being elucidated. The disruption of axonal transport is associated with several neurodegenerative diseases and might also play a role in diabetes-associated disorders affecting nervous system. We investigated the effect of diabetes (2 and 8 weeks duration) on KIF1A, KIF5B and dynein motor proteins, which are important for axonal transport, in the hippocampus. The mRNA expression of motor proteins was assessed by qRT-PCR, and also their protein levels by immunohistochemistry in hippocampal slices and immunoblotting in total extracts of hippocampus from streptozotocin-induced diabetic and age-matched control animals. Diabetes increased the expression and immunoreactivity of KIF1A and KIF5B in the hippocampus, but no alterations in dynein were detected. Since hyperglycemia is considered a major player in diabetic complications, the effect of a prolonged exposure to high glucose on motor proteins, mitochondria and synaptic proteins in hippocampal neurons was also studied, giving particular attention to changes in axons. Hippocampal cell cultures were exposed to high glucose (50 mM) or mannitol (osmotic control; 25 mM plus 25 mM glucose) for 7 days. In hippocampal cultures incubated with high glucose no changes were detected in the fluorescence intensity or number of accumulations related with mitochondria in the axons of hippocampal neurons. Nevertheless, high glucose increased the number of fluorescent accumulations of KIF1A and synaptotagmin-1 and decreased KIF5B, SNAP-25 and synaptophysin immunoreactivity specifically in axons of hippocampal neurons. These changes suggest that anterograde axonal transport mediated by these kinesins may be impaired in hippocampal neurons, which may lead to changes in synaptic proteins, thus contributing to changes in hippocampal neurotransmission and to cognitive and memory impairments.

How does an Al-hyperaccumulator plant respond to a natural field gradient of soil phytoavailable Al?

The physiological ability of plants to cope with Al-toxicity has attracted considerable attention. In this study we used an endemic Al-hyperaccumulator plant, Plantago almogravensis, which is the only known representative of the Plantaginaceae with this trait growing under a field gradient of Al, to understand the root and shoot patterns of Al accumulation and tolerance in its natural environment. We analysed phytoavailable elements in the soil and their accumulation in the plant. For the first time under field conditions, the accumulation pattern of an Al-hyperaccumulator showed a saturation curve with a maximum accumulation capacity being reached (ca. 3.0 mg g(-1)). The Al toxicity was not associated with the expected reduction in the Ca and Mg uptake by the plant. Iron was accumulated in a more linear pattern. The magnitude and the proportion of the elements found in the apoplastic fraction of the root, compared to the soil and plant internal fractions, suggested that the control of uptake occurs at the rhizospheric level. Unlike the majority of the Al-hyperaccumulator plants that are found in tropical humid areas, this plant is described from a sub-arid Mediterranean climate, subject to drought conditions which give it a unique status that deserves to be studied further.

Usefulness of quantitative buffy coat blood parasite detection system in diagnosis of malaria

A rapid test for diagnosis of malaria based on acridine orange staining of centrifuged blood samples in a microhematocrit tube (QBC) was compared with thick and thin peripheral blood smears in 2274 samples. Malaria was diagnosed in 239 (10.5%) patients by Leishman's staining technique and QBC method. The QBC method allowed detection of an additional 89 (3.9%) cases. Thus the prevalence rate of malaria during the study was 14.4%. In 1946 patients who were negative by the QBC technique, the Leishman's stained smears did not provide any help in malaria diagnosis. Analysis of the relative quantity of parasites in the specimens, in the QBC method, revealed that 80 out of 89 QBC positive but smear negative cases, had a very low parasite number (less than 10 parasites per QBC field). Although QBC method was superior to the smear for malarial parasite detection, species identification was not possible in 26 (7.9%) cases by this technique. In 95.7% (n = 314) QBC positive cases, the buffy coat in the QBC tube appeared pigmented (gray to black). The colour of the buffy coat was therefore considered by us as a predictor of positivity and could be taken as an indicator for a careful and more prolonged search for the parasites. Thus, the QBC technique has its advantages in terms of speed, sensitivity and ease, especially in an endemic area as ours, where the level of parasitaemia is low and more than 70 to 80 smears need to be examined per day. However, the age old Romanowsky stains still appear superior for species identification.

Characterization of nonfermenters from clinical samples

OBJECTIVE

Nonfermenters are a group of aerobic non sporing gram-negative bacilli found primarily free in nature and as commensals, whose pathogenic potentials are well established. The current study was conducted to assess the role of these nonfermenters in various infections and to characterize these isolates.

METHODS

One hundred nonfermenters isolated from various clinical specimens were grouped according to Weaver-Hollis scheme based on growth on MacConkeys agar, oxidase activity and oxidation/fermentation of glucose. Species level identification was attempted based on a battery of biochemical tests. All isolates were then subjected to antimicrobial sensitivity.

RESULTS

Majority of the isolates were encountered from pus and urine (50%). These isolates belonged to six of the seven Weaver-Hollis groups. Fifty six per cent of the isolates belonged to genus Pseudomonas. Multidrug resistance with resistance to more than three antimicrobials was frequently seen. Amikacin and ciprofloxacin were found to be most effective.

CONCLUSION

Nonfermenting gram negative organisms are responsible for variety of infective conditions. Amongst them genus Pseudomonas and Acinetobacter calcoaceticus were more frequently encountered. Amikacin or ciprofloxacin (for nonfermenters other than Pseudomonas) appears to be the drug of choice for treatment of such infections.

Rapid diagnosis of falciparum malaria by detection of Plasmodium falciparum HRP-2 antigen

OBJECTIVE

Malaria is a resurging problem all over the country and rapid diagnosis is mandatory to decrease the morbidity and mortality and for control of malaria. In the current study the aim was to evaluate the usefulness of rapid Plasmodium falciparum antigen detection and to compare its utility over conventional peripheral thick and thin smear examination.

METHODS

Three hundred fifty seven randomly selected patients with pyrexia and or atypical presentations of malaria, found initially negative for malaria were subjected to thick and thin smear examination and Plasmodium falciparum antigen detection test by using commercially available Parasight F. kit.

RESULTS

54.6% of cases presented with pyrexia, while other presentations of falciparum malaria were less frequently encountered (162/357). Eighty five patients (23.8%) were diagnosed as having falciparum malaria based on smear/Parasight F. Test. Eighty- four of these patients were positive for Parasight F. test and only 34.51% of these cases were also positive on smear examination.

CONCLUSION

The antigen detection test for Plasmodium falciparum is useful for rapid diagnosis of Plasmodium falciparum malaria. It could detect 65.5% cases of falciparum malaria which were initially negative by peripheral smear examination. Hence, this technique is superior to peripheral smear staining and helps early diagnosis.

Evaluation of HBsAg carrier rate in acute viral hepatitis and high risk individuals using RPHA and ELISA

A total of 600 individuals including 500 cases of hepatitis and 100 individuals at high risk for developing hepatitis were screened for hepatitis B surface antigen (HBsAg) using reverse passive haemagglutination (RPHA) and enzyme linked immunosorbent assay (ELISA). HBsAg carrier rate in clinically diagnosed cases of hepatitis was 38% and 32.4% by RPHA and ELISA respectively. In high risk individuals, the carrier rate was 14% by RPHA and 11% by ELISA. Taking ELISA as gold standard, RPHA showed 5.33% false positivity and 0.33% false negativity. The over all correlation between RPHA and ELISA was to the tune of 82.66%.

Cholera epidemic in Goa

Two hundred and fifty stool samples were studied during an outbreak of cholera in Goa during the months of July to September, 1988. 80 strains of Vibrio were isolated with an isolation rate of 32%. 72.5% of those affected were adults. All strains of Vibrio cholerae isolated belonged to Eltor biotype, Fifty three (66.25%) of them being Ogawa serotype while 21 (26.25%) were Inaba. NAG Vibrios accounted for 6 (7.5%) strains. Antimicrobial sensitivity pattern showed high degree of sensitivity to chloramphenicol, gentamicin and naladixic acid.

Extralobar bronchopulmonary sequestration: a case report

Bronchopulmonary sequestration of the lung is a rare but well recognised congenital abnormality, which is clinically important because of the potential for medical and surgical complications. We report a case of extralobar bronchopulmonary sequestration on the left side in a newborn infant.

Bacterial pneumonias--evaluation of various sputum culture methods

With an objective of improving diagnostic value of sputum in bacterial pneumonias, 50 uncomplicated 'community' acquired cases were studied using Gram staining of sputum along with bedside inoculation with/without dilution of the specimen. Gram staining of sputum samples collected before treatment revealed pneumococcal infection in 46% cases. The results were however inconclusive on samples sent by routine procedure involving logistic delay. Cultural analysis of sputum processed by three different techniques showed that bedside inoculation of sputum after dilution to be the most efficient technique yielding Streptococcus pneumoniae in 34% cases, Gram positive cocci in lesser number (20%), Gram negative rods (GNR) in 18% cases. Sputum samples processed bedside without dilution yielded a lower number of pneumococci and other Gram positive cocci (24% & 16% cases respectively). Routine processing of sputum, involving logistic delay yielded a high number of Gram negative rods (62%), indicating their overgrowth. Thus bedside inoculation of sputum after dilution coupled with direct Gram staining serves as a simple and yet valuable laboratory aid in the diagnosis of uncomplicated 'community' acquired bacterial pneumonias.

Clinico-microbiological study of dermatophytoses

In the present series, 80 cases of dermatophytoses were subjected to mycological examination including microscopy and culture the mycological findings were correlated with clinical presentation of the patients. The isolation rate was 62.5 percent. Fungal culture was successful in 36.25 percent of cases, Trichophyton rubrum being the commonest etiological agent accounting for 55.18 percent of cases.