Hypersensitivity to Distractors in Fragile X Syndrome from Loss of Modulation of Cortical VIP Interneurons

Attention deficit is one of the most prominent and disabling symptoms in Fragile X syndrome (FXS). Hypersensitivity to sensory stimuli contributes to attention difficulties by overwhelming and/or distracting affected individuals, which disrupts activities of daily living at home and learning at school. We find that auditory or visual distractors selectively impair visual discrimination performance in humans and mice with FXS but not in typically developing controls. In both species, males and females were examined. Vasoactive intestinal polypeptide (VIP) neurons were significantly modulated by incorrect responses in the poststimulus period during early distractor trials in WT mice, consistent with their known role as error signals. Strikingly, however, VIP cells from Fmr1 -/- mice showed little modulation in error trials, and this correlated with their poor performance on the distractor task. Thus, VIP interneurons and their reduced modulatory influence on pyramidal cells could be a potential therapeutic target for attentional difficulties in FXS.SIGNIFICANCE STATEMENT Sensory hypersensitivity, impulsivity, and persistent inattention are among the most consistent clinical features of FXS, all of which impede daily functioning and create barriers to learning. However, the neural mechanisms underlying sensory over-reactivity remain elusive. To overcome a significant challenge in translational FXS research we demonstrate a compelling alignment of sensory over-reactivity in both humans with FXS and Fmr1 -/- mice (the principal animal model of FXS) using a novel analogous distractor task. Two-photon microscopy in mice revealed that lack of modulation by VIP cells contributes to susceptibility to distractors. Implementing research efforts we describe here can help identify dysfunctional neural mechanisms associated not only with sensory issues but broader impairments, including those in learning and cognition.

Hypersensitivity to distractors in Fragile X syndrome from loss of modulation of cortical VIP interneurons

Attention deficit is one of the most prominent and disabling symptoms in Fragile X Syndrome (FXS). Hypersensitivity to sensory stimuli contributes to attention difficulties by overwhelming and/or distracting affected individuals, which disrupts activities of daily living at home and learning at school. We find that auditory or visual distractors selectively impair visual discrimination performance in both humans and mice with FXS, but not their typically developing controls. Vasoactive intestinal polypeptide (VIP) neurons were significantly modulated by incorrect responses in the post-stimulus period during early distractor trials in WT mice, consistent with their known role as 'error' signals. Strikingly, however, VIP cells from Fmr1-/- mice showed little modulation in error trials, and this correlated with their poor performance on the distractor task. Thus, VIP interneurons and their reduced modulatory influence on pyramidal cells, could be a potential therapeutic target for attentional difficulties in FXS.

Toxin-antitoxin systems shows variability among Mycobacterium tuberculosis lineages

The toxin-antitoxin (TA) systems are operons involved in the formation of persistent cells and in stress situations in microorganism. TA systems are widely distributed in Mycobacterium tuberculosis (MTB). The objective of this study was to determine the distribution and variability of protein sequences of TA systems in seven MTB lineages. Protein prediction on 73 genomes of different lineage was made using Prodigal, and profile hidden Markov models (PHMMs) of 225 reference TA proteins were constructed with HMMER. An homology search was made comparing the predicted proteins to PHMMs. Consecutive proteins that matched PHMMs (forming an operon) were selected. Thereafter, clustering of orthologous genes was made for further mutation scanning through multiple alignments. All proteins found belong to TA types II and IV, and 45 proteins were found completely conserved. Six uncharacterized antitoxins homologous to VapB11, VapB5, VapB45, VapB13, ParD1 and RelB were found. Multiple alignments revealed differences among lineages with specific mutations suitable for genotyping. Significant changes in amino acid sequences caused by frameshift mutations were found in 46 TA proteins.

Assessment of mycobacteremia detection as a complementary method for the diagnosis of tuberculosis in HIV-infected patients

The purpose of this investigation was to assess the usefulness of mycobacteremia detection in human immunodeficiency virus (HIV) patients with suspected tuberculosis. The study included 47 patients with suspected tuberculosis and confirmed HIV infection. A first blood sample was incubated in a BACTEC 9050 MB system, while white blood cells isolation was performed on a second blood specimen before incubation in a BACTEC MGIT 960 system. The third specimen was taken from the affected organs of each patient according to their clinical profile. Twelve (25.5%) patients were positive for mycobacterial infection identified by any of the methods used. Ten (21.2%) were positive for Mycobacterium tuberculosis and 2 (4.3%) for M. avium. Six patients were diagnosed by the culture of specimen from affected organs only, whilst three other patients were positive exclusively for blood cultures. Three additional patients were diagnosed by both methods. Four patients with negative cultures were ultimately diagnosed with tuberculosis by measuring the adenosine deaminase levels. Mycobacteremia detection can be used to increase the sensitivity of the diagnosis of tuberculosis and other mycobacteria in patients with HIV. However, it cannot be used as the sole diagnostic method. Clinical specimen cultures do not provide 100% diagnostic accuracy and it is, therefore, critical to further improve the mycobacteria detection sensitivity.

Rapid detection of rifampicin and isoniazid resistance in Mycobacterium tuberculosis by the direct thin-layer agar method

We evaluated thin-layer agar (TLA) for the detection of resistance of Mycobacterium tuberculosis to rifampicin (RMP) and isoniazid (INH) as a direct method in patients at risk of multidrug-resistant tuberculosis (MDR-TB). Quadrant TLA plates contain 7H10 Middlebrook growth control, para-nitrobenzoic acid, INH and RMP. Detection of RMP and INH resistance by TLA was compared to that in indirect conventional drug susceptibility testing (DST) and conventional culture media. Median time for growth was respectively 22, 10 and 7.6 days for Löwenstein-Jensen, TLA and the Mycobacterial Growth Indicator Tube. TLA sensitivity, specificity and predictive values for RMP and INH resistance were 100%. Time to resistance detection was respectively 11 and 11.5 days for RMP and INH. TLA showed a rapid turnaround time and performance comparable to conventional DST methods.

High prevalence of infections in patients with systemic lupus erythematosus and pulmonary haemorrhage

The main objective of this study is to describe the presence of infections in patients with pulmonary haemorrhage and systemic lupus erythematosus. Patients with systemic lupus erythematosus and pulmonary haemorrhage were thoroughly evaluated in the first 48 hours with imaging plus bronchoscopy and bronchoalveolar fluid analysis. If needed, videoassisted thoracoscopy and lung biopsy were performed too. In all, search for bacterial, mycobacterial and fungal infections proceeded. Appropriate blood, bronchoalveolar fluid and tissue cultures were taken. Patients were treated with antibiotics and corticosteroids in case of infection. Otherwise, they received initial intravenous methylprednsiolone pulses for 3 days as standard therapy for pulmonary haemorrhage in systemic lupus erythematosus. Additional treatment with immunosuppressives was further decided by the treating physicians. Fourteen events in 13 patients were evaluated. In eight events (57%), an infection was demonstrated. Aetiological agents included Pseudomonas sp. and Aspergillus fumigatus. Four patients died, three of them because of the pulmonary infection and one because of cerebral haemorrhage secondary to severe systemic hypertension, 48 hours after methylprednisolone treatment. Patients with systemic lupus erythematosus and pulmonary haemorrhage have a high prevalence of infections. The influence of pulmonary haemorrhage in the setting of systemic lupus erythematosus needs further study to establish adequate treatment and to reduce the high mortality of this complication.

IGF-1 and insulin receptor expression in the minor salivary gland tissues of Sjögren's syndrome and mucoceles--immunohistochemical study

OBJECTIVE

To investigate the expression of IGF-1 receptors and insulin receptors on the minor salivary gland (MSG) tissues of patients diagnosed with Sjögren's syndrome (SS) and normal salivary gland tissue surrounding mucoceles.

SUBJECTS AND METHODS

Five MSG tissue sections from SS and seven from mucocele patients were stained immunohistochemically using antibody to IGF-1 receptor and insulin receptor in a horse radish peroxidase and DAB system.

RESULTS

The expression of the insulin receptor was increased in the SS sections compared with controls, while the insulin-like growth factor-1 receptor was more intensely expressed in the controls.

CONCLUSION

The presence of differential expression of receptors for IGF and insulin might suggest a possible role of these growth factors in the pathogenesis of SS.

[Analysis of 83 bronchospasm episodes seen at urgent care during one spring night]

BACKGROUND

The new treatments for the bronchial inflammation in asthma, have contributed to decrease the mortality rate. However, there is still a group of population with no diagnosis fo asthma, who requires urgent medical attention in situations such as air pollution or risen pollen levels. On 2nd June 2000, 83 subjects with an acute crisis of asthma, came to the Emergency Room in our Hospital in just 6 hours, coinciding with the highest annual pollen measurement and a strong storm.

METHODS AND RESULTS

Personal data from those 83 patients, medical behaviour at the Casualty and post-attention recommendations were considered for analysis. 21 % never had previous diagnosis of asthma and 93 % followed no regular medical control. 61.45 % did no treatment. A chest radiography was taken in 53.76 % of the patients. Salbutamol was administrated in most of them (92.18 %) and parentally administration of steroids in 23.47 %. 21 % were referred to an specialist.

CONCLUSIONS

A significant rate of asthmatics is under-diagnosed, under-controlled and under-treated. Public Health authorities should consider the creation of new Allergy Units, a fluid communication between general practitioners and specialists, and the monitorization of pollen recounts with special plans of emergency situations to contribute to solve this problem.

Evaluation of the polymerase chain reaction for the detection of Mycobacterium tuberculosis

The development of nucleic acid-based technologies has improved the sensitivity, specificity and speed of detection of Mycobacterium tuberculosis in clinical samples. Both commercially available and 'in-house' polymerase chain reaction (PCR) systems are in use, and a significant number of reports compare such systems with more traditional diagnostic tools for tuberculosis. Few studies, however, have focused on the reproducibility of the results when submitting a sample batch to PCR in different laboratories, especially in developing countries. Consequently, PCR results obtained from six laboratories in six different Latin American countries for samples reconstituted with defined amounts of M. tuberculosis cells were evaluated. Each laboratory used specific conditions of sample processing, nucleic acid amplification and amplicon detection. Analysis of results allowed large differences in sensitivity and specificity to be observed. We conclude that in its present setting, in-house PCR cannot be used as a single diagnostic tool for tuberculosis, and that special care needs to be taken upon interpretation of results by inclusion of a proper number of positive and negative controls.

Thermal conductivity of cement base materials

This study was designed to determine the most efficient dentin-cement-restorative material system to minimize temperature changes from either a hot (58 degrees C) or cold (4 degrees C) source. Extracted human molar teeth were used to conduct the experiment utilizing a standard Class I occlusal preparation 3.5 mm in diameter with a remaining dentin thickness of 0.5 or 1.0 mm and a control dentin thickness of 2.0 mm. A bi-electrode thermocouple was utilized with one thermocouple mounted on the roof of the pulp chamber and the other on the occlusal surface of the specimen. The cements investigated were zinc oxide and eugenol (ZOE), zinc phosphate (ZP), glass ionomer (GI), and zinc polycarboxylate (ZPC) with a thickness of either 0.5 mm or 1.5 mm. Statistical analysis consisted of a one-way analysis of variance followed by a multiple means comparison test. For heated specimens consisting of cement and dentin only, ZOE was the least effective in limiting temperature change. When cold was applied, ZOE was the most effective. Statistically for cold application, the other three cements, ZP, GI and ZPC, and 2.0 mm of dentin were the same for limiting temperature change. When amalgam was used to restore the tooth, ZOE and GI were most effective in limiting temperature change for cooled teeth. For heated teeth, all the cements were identical except for ZOE, which was the least effective. For composite restored teeth, all cements and dentin were identical in limiting temperature changes for either heating or cooling.

Single daily dose amikacin in paediatric patients with severe gram-negative infections

Twenty-five children with serious Gram-negative infections were treated in a prospective study with amikacin 20 mg/kg administered in a single daily dose as a 30 min iv infusion for 4 to 12 days. In nine cases the amikacin was combined with beta-lactam antibiotics. Escherichia coli were the most frequent bacteria isolated followed by K. pneumoniae, Providencia and Enterobacter spp. and Pseudomonas aeruginosa with MICs ranging from 1 to 16 mg/l. Mean (+/- S.D.) peak and trough concentrations of days 1 and 4 of therapy ranged from 49 +/- 13.5 to 53.6 +/- 13.4 mg/l and 6 + 1.4 to 7.7 +/- 4.1 mg/l respectively. All patients were clinically and bacteriologically cured. No significant adverse reactions were observed. The results suggest that administration of a single daily dose of 20 mg/kg amikacin should be considered practical and safe in children. Further studies are needed.

Effects of electromagnetic extracorporeal shock wave lithotripsy on the fine structure of the liver and gallbladder of the rabbit

The fine structure of the liver and gallbladder of rabbits submitted to lithotripsy was studied with transmission electron microscopy. Alterations found in both organs involved capilaries, venules and small veins as well as neighboring tissues. In the liver the most important alterations were seen in those areas located about central veins. These consisted in mitochondrial vacuolation, increase in the cytoplasmic electrondensity, and necrosis. In the gallbladder different stages of epithelial damage and regeneration (i.e. mitoses) were observed. Vascular damage was characterized by mitochondrial swollen and increase of nuclear and cytoplasmic electrondensities. The gallbladder's stroma displayed cell vacuolation, pyknosis, and edema. It is proposed that the damage produced by lithotripsy results from a direct colision of red blood cells upon blood vessels. Tissue damage was considered focal and in most cases reversible.

[Sodium benzoate in portal-systemic-encephalopathy-induced blood ammonia normalization and clinical improvement. Interim report of a double-blind multicenter trial]

To investigate the therapeutic efficacy of sodium benzoate (SB) in a cirrotic population with chronic portal systemic encepalopathy (PSE), we performed a double blind, randomised, multicentric, clinical trial, comparing SB versus a standard therapy of lactitol (LA). To perform the study blind, syrups containing the two drugs were prepared. To date 27 patients have been studied. Of these, 12 received SB (5.6 g/day) and 15 received LA (29 g/day). Standard PSE parameters were assessed and hippurate urinary excretion was measured before and after the trial. For the SB group, basal and final PSE index were 0.39 +/- 0.16 and 0.17 +/- 0.1 respectively (p < 0.001). The Group on LA had a PSE index of 0.40 + 0.1 and 0.23 +/- 0.18 (basal and final respectively) (p < 0.001). The final hippurate excretion for SB group was 2498.9 mg/24 h. The hippurate excretion for the LA group suffer no changes (traces). No serious side effects were observed with either therapy. We suggested that SB is a safe, efficacious and comfortable alternate treatment for PSE.

Itraconazole in the treatment of paracoccidioidomycosis: a preliminary report

The preliminary results of itraconazole therapy in 16 patients with active paracoccidioidomycosis were evaluated. The course of therapy--itraconazole administration for six months at a dose of 100 mg per day--was completed in 13 cases. This new triazole appeared as effective as ketoconazole in reducing the symptoms and arresting the progression of the mycosis. The scoring system employed to evaluate the effect of the drug showed that the condition of no patient worsened or remained the same during therapy. On the contrary, 11 (84.6%) of the 13 patients experienced major improvement and the other two (15.4%), minor improvement. No adverse reactions were reported by the patients, and there were no toxic effects on bone marrow or liver. Although experience with itraconazole is still limited, results to date indicate that this new drug is safe and effective for the treatment of paracoccidioidomycosis. Further trials with shorter periods of therapy seem warranted.

Itraconazole therapy in lymphangitic and cutaneous sporotrichosis

Itraconazole, a new orally absorbable azole derivative, was used for the treatment of 17 patients with cutaneous and lymphangitic sporotrichosis. The drug, administered at a dose of 100 mg/day, proved to be effective in all cases. Lesions disappeared and cultures became negative after 90 to 180 days of therapy. There were no major side effects. Posttherapy evaluations, done in 14 of 17 cases for an average of 115 days, revealed no relapses. Objective evaluation of the treatment by means of a scoring system indicated complete resolution of the pretherapy abnormalities at varying periods; thus, 35.3% (six of 17) of the patients had recovered by 90 days, 45.4% (five of 11) by 120 days, and 83.3% (five of six) by 150 days of therapy. Consequently, therapy with itraconazole is an adequate alternative to iodide treatment in sporotrichosis.