Motor cortex projections to red and pontine nuclei have distinct roles during movement in the mouse

Motor control largely depends on the deep layer 5 (L5) pyramidal neurons that project to subcortical structures. However, it is largely unknown if these neurons are functionally segregated with distinct roles in movement performance. Here, we analyzed mouse motor cortex L5 pyramidal neurons projecting to the red and pontine nuclei during movement preparation and execution. Using photometry to analyze the calcium activity of L5 pyramidal neurons projecting to the red nucleus and pons, we reveal that both types of neurons activate with different temporal dynamics. Optogenetic inhibition of either kind of projection differentially affects forelimb movement onset and execution in a lever press task, but only the activity of corticopontine neurons is significantly correlated with trial-by-trial variations in reaction time. The results indicate that cortical neurons projecting to the red and pontine nuclei contribute differently to sensorimotor integration, suggesting that L5 output neurons are functionally compartmentalized generating, in parallel, different downstream information.

POS1242 FACTORS ASSOCIATED WITH MORTALITY IN PATIENTS WITH RHEUMATIC DISEASES AND COVID-19 IN MEXICO

Background:

As of the 25th of January 2021, more than 150 thousand deaths as consequence of COVID-19 have been reported in Mexico [1]. Advanced age, male gender and comorbidities have been described as risk factors for severe disease and mortality in general population [2]. COVID-19 mortality in Mexican patients with rheumatic and musculoskeletal diseases (RMDs) is unknown.

Objectives:

To describe characteristics of Mexican patients with RMDs and COVID-19, and to analyse factors associated with mortality.

Methods:

The Global Rheumatology Alliance COVID-19 (GRA) physician reported registry, is an international effort to collect information on COVID19 in adult patients with RMDs. GRA is an observational registry. The first patient from Mexico was registered on April 17, 2020. All Mexican patients registered in GRA until October 30, 2020 were included in this analysis. The association of mortality with demographic and clinical variables was estimated using logistic regression analysis.

Results:

A total of 323 patients were registered, with a median age of 52 (IQR 41-61) years old, 166 (51.4%) patients lived in Mexico City. The most frequent RMDs were rheumatoid arthritis, 149 (46.1%) and systemic lupus erythematosus, 24 (19.8%). Over a third of patients with RMDs and COVID-19 (119 (36.8%)) were hospitalized, and 43 (13.3%) died. Table 1 shows clinical and demographic characteristics. In the univariable analysis, the absence of comorbidities was a protective factor, OR 0.3 (95% CI 0.1-0.6). Factors associated with mortality at COVID-19 diagnosis were age over 65 years old, having type 2 diabetes, chronic renal insufficiency, treatment at COVID-19 diagnosis with corticosteroids or with CD20 inhibitors. In the multivariable adjusted analysis, these factors remained independently associated with mortality. No associations with other treatments or comorbidities at COVID-19 diagnosis were found.

Conclusion:

Mexican patients with RMDs and COVID-19 in the GRA physician reported registry had a mortality of 13.3%. Factors associated with mortality were those described in the general population, such as older age and being on corticosteroids and CD20 inhibitors treatment at COVID-19 diagnosis.

References:

[1]WHO. Coronavirus disease (COVID-19) pandemic. https://www.who.int/emergencies/diseases/novel-coronavirus-2019. (accessed 26 January, 2021).

[2]Zhou F, et al. Lancet 2020;395(10229):1054-62.

Table 1.

Clinical and demographic characteristics of patients with rheumatic diseases and COVID-19 in Mexico and mortality.

Characteristics at COVID-19 diagnosisTotalN=323Death43 (13.3)Survivors280 (86.7)UnivariableOR (95% CI)MultivariableOR (95% CI)Women, n(%)268 (82.9)33 (76.7)235 (83.9)0.6 (0.3-1.4)0.5 (0.2-1.3)Age >65 years old, n(%)62 (19.2)18 (41.9)44 (15.7)3.9 (1.9-7.7)3.9 (1.9-8.3)RMDs* n(%)-Rheumatoid arthritis149 (46.1)23 (53.5)126 (45.0)1.6 (0.7-3.7)-Systemic Lupus Erythemathosus64 (19.8)10 (23.3)54 (19.3)1.6 (0.6-4.3)-Spondyloarthritis (axial and others)33 (10.2)2 (4.7)31 (11.1)0.1 (0.1-2.8)-Others77 (23.8)8 (18.6)69 (24.6)1-Moderate/High disease activity1, n(%)57 (18.6)7 (17.9)50 (18.7)1.0 (0.4-2.5)-None comorbidities, n(%)136 (42.1)8 (18.6)128 (45.7)0.3 (0.1-0.6)-Hypertension*, n(%)88 (27.2)12 (27.9)76 (27.1)1.0 (0.5-2.1)-Type 2 Diabetes*, n(%)49 (15.2)13 (30.2)36 (12.9)2.9 (1.4-6.1)2.4 (1.1-5.4)Obesity*, n(%)21 (6.5)3 (6.9)18 (6.4)1.1 (0.3-3.9)-Chronic obstructive pulmonary disease*, n(%)15 (4.6)1 (2.3)14 (5.0)0.5 (0.1-3.5)-Chronic renal insufficiency*, n(%)17 (5.2)6 (13.9)11 (3.9)3.9 (1.4-11.4)3.4 (1.1-10.4)Cardiovascular diseases*, n(%)14 (4.3)2 (4.7)12 (4.3)1.1 (0.2-5.0)-Corticosteroids*, n(%)171 (52.9)30 (69.7)141 (50.3)2.3 (1.1-4.5)3.0 (1.4-6.5)CsDMARD*, n(%)247 (76.5)33 (16.3)214 (76.4)1.0 (0.5- 2.2)-CD20 inhibitor*, n(%)21 (6.5)7 (16.3)14 (5.0)3.7 (1.4-9.9)4.9 (1.7-14.5)

*Overlapped, 1 307 patients.

Disclosure of Interests:

None declared

Lupus-associated endothelial dysfunction, disease activity and arteriosclerosis

OBJECTIVE

To analyze endothelial function in systemic lupus erythematosus (SLE), and its relationship with disease activity and subclinical arteriosclerosis.

METHODS

We studied a group of 26 patients with SLE and 21 age- and sex-matched controls. None of the patients or controls had had any ischemic event. Data were recorded on medical history, anthropometrics, prior treatment and the lupus activity index (LAI). Endothelial function was quantified by flow-mediated dilatation in the brachial artery. The presence of subclinical arteriosclerosis was assessed by the average intima-media thickness (IMT) on carotid ultrasound.

RESULTS

The patients and the controls had a similar degree of carotid IMT (0.58+/-0.08 mm vs. 0.57+/-0.07 mm, NS) and a similar prevalence of carotid plaque (27% vs. 24%, NS). However, the SLE patients had worse endothelial function than the controls (FMD 12.4+/-4.4% vs. 16.9+/-5.5%, p<0.05). This difference remained after adjusting for age, smoking, body mass index, waist circumference, total cholesterol, triglycerides, HDL cholesterol, apolipoproteins A-1 and B100 and postmenopausal status. A significant association was found in the SLE patients between FMD and LAI (Spearman Rho -0.462, p<0.05).

CONCLUSION

SLE-associated endothelial dysfunction is present in patients who have no prior ischemic events and with the same degree of subclinical arteriosclerosis as controls. The endothelial dysfunction is significantly associated with the degree of disease activity.

[Bipolar paediatric disorder early diagnosis]

The Bipolar Disorder in infants and youngsters is not very known and under-diagnosed in the concerned population. We hereby describe its clinical features, its comorbidity along with other frequent psychopathologies, such as ADHD, which enable us to describe the symptoms and the indicators of risk. According to how these indicators appear, we can establish various degrees of clinical risk. Irritability, impulsiveness, hyperactivity, intolerance to frustration and sleep disorders are the most frequent prodroms. If they present a clinic of suicidality, toxic abuse (cannabis, alcohol), or even psychotic symptoms, in the context of significant family history, the child psychiatrist should not doubt to diagnose Bipolar Disorder and start the corresponding treatment.

Ultrafast folding of WW domains without structured aromatic clusters in the denatured state

Ultrafast-folding proteins are important for combining experiment and simulation to give complete descriptions of folding pathways. The WW domain family comprises small proteins with a three-stranded antiparallel beta-sheet topology. Previous studies on the 57-residue YAP 65 WW domain indicate the presence of residual structure in the chemically denatured state. Here we analyze three minimal core WW domains of 38-44 residues. There was little spectroscopic or thermodynamic evidence for residual structure in either their chemically or thermally denatured states. Folding and unfolding kinetics, studied by using rapid temperature-jump and continuous-flow techniques, show that each domain folds and unfolds very rapidly in a two-state transition through a highly compact transition state. Folding half-times were as short as 17 micros at 25 degrees C, within an order of magnitude of the predicted maximal rate of loop formation. The small size and topological simplicity of these domains, in conjunction with their very rapid two-state folding, may allow us to reduce the difference in time scale between experiment and theoretical simulation.

Clinical and bacteriologic efficacy of amoxycillin b.d. (45 mg/kg/day) versus amoxycillin t.d.s (40 mg/kg/day) in children with group A beta-hemolytic streptococcal tonsillopharyngitis

This randomized, observer-blind, multicenter, parallel-group study compared the clinical and bacteriologic efficacy and safety of amoxycillin, 45 mg/kg/day b.d. and amoxycillin, 40 mg/kg/day t.d.s. after 7 days of treatment in 517 children with acute bacterial tonsillopharyngitis. At the end of treatment, a successful clinical response was recorded in more than 96% of patients in each of the treatment groups. A similar result was obtained at follow-up. Among those patients who were bacteriologically evaluable at the end of treatment, a successful bacteriologic response was achieved in more than 94% in each treatment group. Both treatments were well tolerated. Drug-related adverse events were recorded in just 12 patients (4.6%) in the b.d. group and six (2.4%) in the t.d.s. group. The study demonstrated that a twice-daily regimen of amoxycillin, 45 mg/kg/day, was as effective and as well tolerated as the standard three-times-daily regimen of amoxycillin, 40 mg/kg/day, in the treatment of acute bacterial tonsillopharyngitis in children.

Morphology of young and old cervical spine intervertebral disc tissues

The intervertebral disc of the cervical spine undergoes degenerative changes during the aging process. Although many studies have reported the qualitative changes in the disc, methodology to quantify these changes is lacking. The present study was designed to quantify the geometrical variations of the nucleus pulposus, annulus fibrosus and uncovertebral joints. The age groups of specimens were classified as juvenile, adult and aged. Fresh intervertebral discs with adjacent vertebral bodies of the lower cervical spine of primates were isolated. The specimens were sectioned sequentially in a coronal plane. Sections were stained with Hematoxylin and Eosin, Verhoeff's, Safranin O, and Trichrome methods to distinguish the nucleus, annulus and uncovertebral joints. Histological images were examined using light microscopy and processed using a computer imaging program to trace the boundaries of the disc components. Dorsal-to-ventral depth and medial-to-lateral width of the nucleus pulposus, and its relative location to the annulus pulposus were also obtained. In the juvenile and adult discs, the nucleus appeared as a light opaque region with scattered notochordal cells with a clear distinction from the annulus region. In contrast, in the aged discs, the nucleus appeared as a dense region of amorphous, irregular collagen materials with less distinction from the annulus region. With the progression of aging, the dorsal-to-ventral depth of the nucleus decreased considerably compared to medial-to-lateral width. The uncovertebral joints were clear in the adult discs. The joints were less distinct in the aged discs and their size decreased. Quantification of three-dimensional geometrical variations will assist in better defining the disc tissue in the mathematical models.

Locomotion induces changes in Trk B receptors in small diameter cells of the spinal cord

INTRODUCTION AND METHODS

Locomotor training leads to improvement of stepping ability in animals after spinal cord transection (1). Recent data point to neurotrophins as possible factors involved in this improvement. Motoneurones synthesising BDNF, NT-4 and NT-3 are a potent source of neurotrophins for the spinal network (2, 3). Physical exercise increases BDNF neurotrophin gene expression in the rat hippocampus (4). If exercise enhances BDNF expression also in the spinal cord, upregulation of its receptor Trk B may occur. To verify this hypothesis we tested whether exercise influences TrkB receptor system in the spinal cord. Six adult, male Wistar rats walked on the treadmill five days a week, 1,000 m daily with the speed of 20 to 25 cm/s. After 4 weeks of training animals were anaesthetised with pentobarbital sodium (80 mg/kg b.w.) and perfused with 0.01 M PBS followed by 2% paraformaldehyde and 0.2% parabenzoquinone in 0.1 M PB. Three non-trained animals were used as controls. Cryostat 40 microns sections were processed free-floating with TrkB polyclonal antibody (1:1,000, Santa Cruz) and ABC Vectastain detection system. Sections were examined under Nikon light microscope and analysed with Image-Pro Plus 4 software.

RESULTS AND DISCUSSION

TrkB immunoreactivity (IR) was detected in number of spinal cells at the lumbar level in non-trained animals (Fig. 1A). The strongest IR appeared in the perikarya and processes of small diameter cells rarely scattered in the grey and white matter. The average area of these cells was 50 micron 2 (+/- 10). Exercise increased by over 50% the number of TrkB immunostained small cells (Fig. 1B). An enhancement of perikaryonal immunostaining of these cells was also observed (Fig. 1B, inset). Testing the identity of Trk B IR small diameter cells did not prove their astroglial (GFAP IR) and gabaergic (GAD IR) phenotype in the grey matter. Some of TrkB IR cells in the white matter were astrocytes. Our data point to physical exercise as a potent method to make spinal cells more receptive to neurotrophic stimuli.

Children with both developmental and behavioral needs: profile of two clinic populations

Little has been written about evaluation and intervention services for children with a combination of behavioral and developmental needs. Two multidisciplinary clinic populations were compared, a traditional Developmental Disabilities (DD) clinic and a Behavioral-Developmental Problems (BDP) Clinic that had the additional services of a child psychiatrist. The BDP clinic children had lower IQ's and more severe overall behavioral problems than children in the traditional DD clinic, but differences were not statistically significant. Children with Attention Deficit Hyperactivity Disorder (ADHD) and other psychiatric diagnoses were referred to both clinics at comparable rates. The effort to involve qualified mental health professionals in all aspects of professional training and clinical service for the DD population should be accelerated.

A small region in phosducin inhibits G-protein betagamma-subunit function

G-protein betagamma-subunits (G(betagamma)) are active transmembrane signalling components. Their function recently has been observed to be regulated by the cytosolic protein phosducin. We show here that a small fragment (amino acids 215-232) contained in the C-terminus of phosducin is sufficient for high-affinity interactions with G(betagamma). Corresponding peptides not only disrupt G(betagamma)-G(alpha) interactions, as defined by G(betagamma)-stimulated GTPase activity of alpha(o), but also other G(betagamma)-mediated functions. The NMR structure of a peptide encompassing this region shows a loop exposing the side chains of Glu223 and Tyr224, and peptides with a substitution of either of these amino acids show a complete loss of activity towards G(o). Mutation of this Tyr224 to Ala in full-length phosducin reduced the functional activity of phosducin to that of phosducin's isolated N-terminus, indicating the importance of this residue within the short, structurally defined C-terminal segment. This small peptide derived from phosducin, may represent a model of a G(betagamma) inhibitor, and illustrates the potential of small compounds to affect G(betagamma) functions.

[Of glory and shame: a portrait of Oscar Wilde]

This study concerning the most controversial of British writers will surely evoke passionate reactions. Faced with the calibre and complexity of a figure such as Oscar Wilde, we concentrate our efforts on two lines of investigation event though we are aware that this will not satisfy all our readers. Firstly we look at the parallels between his principal work. The Picture of Dorian Gray, and his own tragic destiny. Many parallel themes can be found between the subject of the novel and the events of his own biography (particularly his relationship with an omnipresent mother in flagrant contrast to an absorbed and distant father). The second line of investigation looks at his problem of sexual identity. Oscar Wilde produced a work which described his own problems without any ambiguity. His homosexuality, his stage sense, his dandysm, as well as his taste for provocation and scandal are seen in the context of an unconditional relationship with a powerful mother which he attempted to find in his quest for substitutions love objects. It would seem that both, the relentless pursuit of his limits and the bearing of his secret fantasies, are not so much a reflection of a more or less verifiable reality but the product of as untiring elaboration of his fantasy-life.

Peritoneal dialysis efficiency in CAPD patients in treatment with rHuEPO

Possible modifications in peritoneal behaviour that can be caused by erythropoietin (EPO) treatment and/or correction of anemia in the ultrafiltration and peritoneal diffusion were studied in 24 CAPD patients. The evolution of the patients on the medium run was also studied. The dialysate to plasma ratio, the peritoneal clearance and the mass transfer coefficient of urea and creatinine and the ultrafiltration volume were studied, baseline, after reaching the hemoglobin target, and after eight months of treatment. The group of patients developed a decrease in the dialysate to plasma ratio and in the peritoneal clearance of creatinine. After evaluating the effects of the hemoglobin and the hematocrit, we found a decrease in the dialysate to plasma ratio of urea and creatinine, and in the peritoneal clearance of creatinine. A decrease was also found in the mass transfer coefficients of urea and creatinine. An increase in the ultrafiltration was also found in the patients with hemoglobin levels higher or equal to 11 g/dl. Those changes are reversible after turning the hemoglobin levels back to levels lower than 11 g/dl.

Comparison of Rous sarcoma virus RNA processing in chicken and mouse fibroblasts: evidence for double-spliced RNA in nonpermissive mouse cells

Rous sarcoma virus, an avian retrovirus, transforms but does not replicate in mammalian cells. To determine to what extent differences in RNA splicing might contribute to this lack of productive infection, cloned proviral DNA derived from the Prague A strain of Rous sarcoma virus was transfected into mouse NIH 3T3 cells, and the viral RNA was compared by RNase protection with viral RNA from transfected chicken embryo fibroblasts by using a tandem antisense riboprobe spanning the three major splice sites. The levels of viral RNA in NIH 3T3 cells compared with those in chicken embryo fibroblasts were lower, but the RNA was spliced at increased efficiency. The difference in the ratio of unspliced to spliced RNA levels was not due to the increased lability of unspliced RNA in NIH 3T3 cells. Although chicken embryo fibroblasts contained equal levels of src and env mRNAs, spliced viral mRNAs in NIH 3T3 cells were almost exclusively src. In NIH 3T3 cells the env mRNA was further processed by using a cryptic 5' splice site located within the env coding sequences and the normal src 3' splice site to form a double-spliced mRNA. This mRNA was identical to the src mRNA, except that a 159-nucleotide sequence from the 5' end of the env gene was inserted at the src splice junction. Smaller amounts of single-spliced RNA were also present in which only the region between the cryptic 5' and src 3' splice sites was spliced out. The aberrant processing of the viral env mRNA in NIH 3T3 cells may in part explain the nonpermissiveness of these cells to productive Rous sarcoma virus infection.

Effect of S-adenosylmethionine on experimental osteoarthritis in rabbits

Twenty-four rabbits with surgically induced osteoarthritis of the knee were allocated into three treatment groups (placebo, S-adenosylmethionine (SAMe) 30 mg/kg per day, and SAMe 60 mg/kg per day). Intramuscular administration of drug or placebo was begun immediately after surgery and continued for 12 consecutive weeks. At the end of the treatment period, animals were killed, and the articular surfaces of the knees were studied using histologic and histochemical techniques. Microscopic studies showed that the number of cells and the depth of the cartilage were significantly (p less than 0.001) increased in SAMe-treated rabbits in comparison with placebo-treated animals. No difference was found in comparing data in animals given SAMe at the two dosage levels. In conclusion, these results suggest a chondroprotective effect of SAMe in animals with experimental osteoarthritis.