Incomplete Recovery of Zebrafish Retina Following Cryoinjury.

Zebrafish show an extraordinary potential for regeneration in several organs from fins to central nervous system. Most impressively, the outcome of an injury results in a near perfect regeneration and a full functional recovery. Indeed, among the various injury paradigms previously tested in the field of zebrafish retina regeneration, a perfect layered structure is observed after one month of recovery in most of the reported cases. In this study, we applied cryoinjury to the zebrafish eye. We show that retina exposed to this treatment for one second undergoes an acute damage affecting all retinal cell types, followed by a phase of limited tissue remodeling and regrowth. Surprisingly, zebrafish developed a persistent retinal dysplasia observable through 300 days post-injury. There is no indication of fibrosis during the regeneration period, contrary to the regeneration process after cryoinjury to the zebrafish cardiac ventricle. RNA sequencing analysis of injured retinas at different time points has uncovered enriched processes and a number of potential candidate genes. By means of this simple, time and cost-effective technique, we propose a zebrafish injury model that displays a unique inability to completely recover following focal retinal damage; an outcome that is unreported to our knowledge. Furthermore, RNA sequencing proved to be useful in identifying pathways, which may play a crucial role not only in the regeneration of the retina, but in the first initial step of regeneration, degeneration. We propose that this model may prove useful in comparative and translational studies to examine critical pathways for successful regeneration.

Is cognition considered in post-stroke upper limb robot-assisted therapy trials? A brief systematic review.

The aim of this systematic review was, first, to determine whether or not individuals with cognitive deficits after stroke were enrolled in trials that investigated upper limb robot-assisted therapy effectiveness, and, second, whether these trials measured cognitive outcomes. We retrieved 6 relevant systematic reviews covering, altogether, 66 articles and 2214 participants. Among these 66 clinical trials, only 10 (15%) enrolled stroke participants with impaired cognition, whereas 50 (76%) excluded those with impaired cognition. The remaining six trials (9%) were classified as unclear as they either excluded individuals unable to understand simple instructions or did not specify if those with cognitive disorders were included. Furthermore, only 5 trials (8%) used cognitive measures as outcomes. This review highlights a lack of consideration for individuals with cognitive impairments in upper limb robotic trials after stroke. However, cognition is important for complex motor relearning processes and should not be ignored.

An intramembrane sensory circuit monitors sortase A-mediated processing of streptococcal adhesins.

Bacterial adhesins mediate adhesion to substrates and biofilm formation. Adhesins of the LPXTG family are posttranslationally processed by the cell membrane-localized peptidase sortase A, which cleaves the LPXTG motif. This generates a short C-terminal peptide (C-pep) that remains in the cell membrane, whereas the mature adhesin is incorporated into the cell wall. Genes encoding adhesins of the oral bacterium Streptococcus gordonii were differentially expressed depending on whether the bacteria were isolated from saliva or dental plaque and appeared to be coordinately regulated. Deletion of sspA and sspB (sspAB), both of which encode LPXTG-containing adhesins, unexpectedly enhanced adhesion and biofilm formation. C-peps produced from a model LPXTG-containing adhesin localized to the cell membrane and bound to and inhibited the intramembrane sensor histidine kinase SGO_1180, thus preventing activation of the cognate response regulator SGO_1181. The absence of SspAB C-peps induced the expression of the scaCBA operon encoding the lipoprotein adhesin ScaA, which was sufficient to preserve and even enhance biofilm formation. This C-pep-driven regulatory circuit also exists in pathogenic streptococci and is likely conserved among Gram-positive bacteria. This quality control mechanism ensures that the bacteria can form biofilms under diverse environmental conditions and may play a role in optimizing adhesion and biofilm formation.

Evaluation of manual ability in stroke patients in Benin: cultural adaptation and Rasch validation of the ABILHAND-Stroke questionnaire.

BACKGROUND: ABILHAND is a self-reported questionnaire assessing manual ability. It was validated and calibrated using the Rasch analysis for European stroke patients. After a stroke, performing upper limb activities of daily living is influenced by personal and environmental contextual factors. It is thus important to conduct a contextual validation to use this questionnaire outside of Europe. AIM: The aim of this study was to perform a cross cultural validation of the ABILHAND-Stroke questionnaire for post-stroke patients living in Benin, a West-African country. DESIGN: Observational cross-sectional study. SETTING: Outpatient rehabilitation centres. POPULATION: 223 Beninese chronic stroke patients. METHODS: The experimental questionnaire was made of 59 items evaluating manual activities. Patients had to estimate their difficulty of performing each activity according to four response categories: impossible, very difficult, difficult and easy. For construct validity analysis, patients were also evaluated with other assessment tools: Box and Block Test, the motor subscale of the Functional Independence Measure, the Stroke Impairment Assessment Set, and ACTIVLIM-Stroke. Data were analysed with the Rasch partial credit model. RESULTS: The response categories very difficult and difficult were merged and the number of response categories was reduced from 4 to 3 (impossible, difficult and easy). The Rasch analyses selected 16 bimanual activities that fit the Rasch model (chi square=42.35; P=0.10). The item location ranged from -1.10 to 2.24 logits. The standard error ranged from 0.15 to 0.22 logits. There is no differential item functioning between subgroups (age, sex, dexterity, affected side, time since stroke). The person separation index is 0.82. The questionnaire can measure 3 levels of manual ability, similarly to the occidental version. CONCLUSIONS: The ABILHAND-stroke is a Rasch validated, unidimensional and invariant questionnaire to assess manual ability among Beninese patients. The ordinal score can be transformed into linear score using a conversion table. CLINICAL REHABILITATION IMPACT: This assessment tool is clinically relevant in Benin, a developing country, since it requires no specific equipment or training. It should promote and standardize assessments for stroke patients in clinical practice and research in this African country.

The GalNAc-T Activation Pathway (GALA) is not a general mechanism for regulating mucin-type O-glycosylation.

Mucin-type O-glycosylation is initiated by the UDP-GalNAc polypeptide:N-acetylgalactosaminyltransferase (GalNAc-T) family of enzymes. Their activity results in the GalNAc α1-O-Thr/Ser structure, termed the Tn antigen, which is further decorated with additional sugars. In neoplastic cells, the Tn antigen is often overexpressed. Because O-glycosylation is controlled by the activity of GalNAc-Ts, their regulation is of great interest. Previous reports suggest that growth factors, EGF or PDGF, induce Golgi complex-to-endoplasmic reticulum (ER) relocation of both GalNAc-Ts and Tn antigen in HeLa cells, offering a mechanism for Tn antigen overexpression termed "GALA". However, we were unable to reproduce these findings. Upon treatment of HeLa cells with either EGF or PDGF we observed no change in the co-localization of endogenous GalNAc-T1, GalNAc-T2 or Tn antigen with the Golgi complex marker TGN46. There was also no enhancement of localization with the ER marker calnexin. We conclude that growth factors do not cause redistribution of GalNAc-Ts from the Golgi complex to the ER in HeLa cells.

Feasibility of a self-rehabilitation program for the upper limb for stroke patients in Benin.

INTRODUCTION: Stroke is a major cause of disability and represents a very high cost in developing countries. Self-rehabilitation programs represent a new and original treatment for stroke patients, likely to reduce upper limb impairments and improve activity and participation. The goal of this study is to evaluate the feasibility of a self-rehabilitation protocol in Benin. METHODS: Twelve chronic stroke patients carried out the upper limb self-rehabilitation program (3 hours/day, 5 days/week for 2 weeks). The performance of these patients was evaluated before and after the self-rehabilitation program, by measuring the number of exercises that patients were able to achieve during a three-hour session, and by assessing their gross manual dexterity. RESULTS: Twelve patients were effectively able to complete the entire program. The number of unimanual exercises and self-mobilizations performed during a three-hour session as well as the score of the Box and Block test were improved by the self-rehabilitation program (P<0.05). DISCUSSION AND CONCLUSION: Self-rehabilitation programs are feasible and inexpensive as they do not involve a therapist. It is then a promising approach in stroke rehabilitation, particularly in developing countries, where rehabilitation costs are usually supported by patients.

Box and block test in Beninese adults.

OBJECTIVE: To determine the Box and Block Test norm in a sub-Saharan population and to compare these data with published norms for North American adults. METHODS: A total of 692 healthy Beninese people, age range 20-85 years, were recruited. These subjects were asked to perform the Box and Block Test with both hands. RESULTS: Box and Block Test scores (mean and standard deviation (SD)) for women and men were, respectively, 81.3 (15.4) and 79 (16.6) for the dominant hand and 73.2 (13.7) and 72 (14.8) for the non-dominant hand. Mean Box and Block Test scores ranged from 89.1 (12.7) for people under the age of 25 years to 55.23 (10.5) for people over the age of 74 years. DISCUSSION: Manual dexterity was better for women than men, for dominant hand than non-dominant hand, and for younger subjects. In comparison with published results for US subjects, Beninese subjects had better dexterity below the age of 50 years in both sexes for the right hand and worse dexterity over 64 years of age in both sexes for the right hand. CONCLUSION: Developing and validating outcome scales in Africa will help to improve functional assessment of African populations in clinical practice and research.

[Thyroid metastasis of kidney cancer]. / Métastase intrathyroïdienne d'un cancer du rein.

Thyroid metastasis of solid tumors is rare and often asymptomatic. Differential diagnosis with malignant thyroid tumor is difficult. We report a 65-year-old man who presented with a solitary intrathoracic thyroid nodule of the left lobe, inaccessible to fine needle biopsy. His past medical history was remarkable for a nephrectomy for a kidney clear cell carcinoma one year before. The PET-scan did not show any abnormal fixation. A left lobo-isthmectomy was performed. Histologic examination revealed an intrathyroid metastasis of kidney carcinoma.

ABILOCO: a Rasch-built 13-item questionnaire to assess locomotion ability in stroke patients.

OBJECTIVE: To develop a questionnaire (ABILOCO), based on the Rasch measurement model, that can assess locomotion ability in adult stroke patients (International Classification of Functioning, Disability and Health activity domain). DESIGN: Prospective study and questionnaire development. SETTING: A faculty hospital. PARTICIPANTS: Adult stroke patients (N=100) (age, 64+/-15y). The time since stroke ranged from 1 to 260 weeks. INTERVENTION: A preliminary questionnaire included 43 items representing a large sample of locomotion activities. This questionnaire was tested on the 100 stroke patients, and their responses were analyzed using the Rasch model (RUMM 2020 software) to select items that had an ordered rating scale and fitted a unidimensional model. MAIN OUTCOME MEASURE: The ABILOCO questionnaire. RESULTS: The retained items resulted in a 13-item questionnaire, which includes a wide range of locomotion abilities well targeted to the sample population, leading to good reliability (R=.93). The item calibration was independent of age, sex, time since stroke, and affected side. The concurrent validity of ABILOCO was also investigated by comparing it with well-known, criterion standard scales (Functional Walking Category, Functional Ambulation Categories, item 12 of the FIM instrument evaluating walking ability) and the walking speed measured with the 10-meter walk test. CONCLUSIONS: The ABILOCO questionnaire presents good psychometric qualities to measure locomotion ability in adult stroke patients. Its range and measurement precision make it attractive for clinical use throughout the rehabilitation process and for clinical research.

Effect of botulinum toxin injection in the rectus femoris on stiff-knee gait in people with stroke: a prospective observational study.

OBJECTIVE: To study the effect of botulinum toxin type A (BTX-A) injection in the rectus femoris on the decreased knee flexion during the swing phase of gait (stiff-knee gait) in people with stroke. DESIGN: Intervention study (before-after trial) with an observational design. SETTING: Outpatient rehabilitation clinic and gait laboratory. PARTICIPANTS: Nineteen chronic hemiparetic adults presenting with stiff-knee gait. INTERVENTION: Injection of 200 U of BTX-A (Botox) into the rectus femoris. MAIN OUTCOME MEASURES: Before and 2 months after BTX-A rectus femoris injection: Stroke Impairment Assessment Set (SIAS), Duncan-Ely test, and an instrumented gait analysis. RESULTS: Median SIAS score improved from 53 (range, 36-65) to 57 (range, 42-70) (signed-rank test, P=.005) and the Duncan-Ely score from 3 (range, 1-3) to 1 (range, 0-3) (P<.001). In gait analysis, mean (+/- standard deviation) maximum knee flexion improved from 26 degrees +/-13 degrees to 31 degrees +/-14 degrees during the swing phase (paired t test, P<.001), knee flexion speed at toe-off improved from 82 degrees +/-63 degrees to 112 degrees +/-75 degrees/s (P=.009), and knee negative joint power (eccentric muscular contraction) improved from -.27+/-.23 to -.37+/-.26 W/kg (P<.001). The 4 patients who almost did not flex the knee (<10 degrees) before the BTX-A rectus femoris injection did not improve after the injection. The other 14 patients who flexed the knee more than 10 degrees before the BTX-A rectus femoris injection decreased the walking energy cost from 5.4+/-1.6 to 4.6+/-1.3 J x kg(-1) x m(-1) (P=.006). CONCLUSIONS: BTX-A rectus femoris injection may be beneficial in patients with a stiff-knee gait after stroke, particularly in patients with some knee flexion (>10 degrees).