Characterization of the structural modifications accompanying the loss of HBsAg particle immunogenicity

The aim of this work was to further understand the relationship between the immunogenicity and the structure of Hepatitis B surface antigen (HBsAg) particles used in Hepatitis B vaccines. To reach this aim, we compared by using a large range of techniques, the structure and properties of untreated particles with those of particles stored for 3 weeks at +60 °C, a treatment which resulted in a loss of HBsAg antigenicity (toward RF-1 mAb) and immunogenicity (in mice). While untreated particles imaged by electron microscopy and atomic force microscopy appeared as isolated nanoparticles of ∼ 20 nm, heated particles appeared as long chains of particle aggregates with a partial loss of their protein protrusions. Moreover, infrared spectroscopy and circular dichroism revealed that the secondary structure of the S proteins was significantly affected, with a loss of 10% of their α-helix content. Steady-state and time-resolved fluorescence data further revealed strong modifications of the most emitting Trp residues at the particle surface, confirming significant changes in the conformation of the S proteins. Moreover, modifications in the organization of both the lipid core and lipid membrane surface of the heated particles were evidenced by environment-sensitive 3-hydroxyflavone probes. Taken together, our data evidenced a clear relationship between the bona fide S protein structure and lipid organization notably at the particle surface and the particle immunogenicity.     

The specific features of the reproduction of the bovine coronavirus strain ARRIAH in the continuous RBT cell culture

Cultivation of the bovine coronavirus strain ARRHIAH in the continuous RBT versus MDBK and Taurus cell cultures made it possible to reduce the time taken to reproduce the virus and to increase its hemagglutination titer. The RBT cell line is suitable for determining the infectious activity of the coronavirus reproduced in the other cell cultures. Optimization of a manufacturing process for diagnostic agents and vaccines has been achieved while applying a roll tube method for both RBT cell cultivation and coronavirus reproduction.     

Kinematics of the contralateral and ipsilateral shoulder: a possible relationship with post-stroke shoulder pain.

OBJECTIVE: Post-stroke shoulder pain is a common phenomenon in hemiplegia and impedes rehabilitation. The aim of this study was to identify a possible relationship between post-stroke shoulder pain, scapula resting position and shoulder motion. METHODS: Shoulder kinematics of 27 patients after stroke (17 men) were compared with 10 healthy age-matched control subjects. Using an electromagnetic tracking device, the kinematics of both the contralateral and ipsilateral (i.e. paretic and non-paretic) arm during active and passive abduction and forward flexion were measured and expressed in Euler angles. RESULTS: Scapular lateral rotation relative to the thorax was increased in patients with post-stroke shoulder pain compared with both patients without post-stroke shoulder pain and control subjects at rest as well as during arm abduction and forward flexion. Additionally, glenohumeral elevation was decreased in patients with post-stroke shoulder pain during passive abduction. No differences were found regarding scapula position (displacement relative to the thorax). CONCLUSION: In patients with post-stroke shoulder pain a particular kinematical shoulder pattern was established, characterized by enhanced scapular lateral rotation and diminished glenohumeral mobility.     

Do Th1 or Th2 sequence motifs exist in proteins? Identification of amphipatic immunomodulatory domains in Helicobacter pylori catalase

The reasons why some proteins induce a particular type of T helper (Th) response are of fundamental importance but only partially understood. In the present study, amphipatic sequence motifs were identified in N- and C-terminal domains of Helicobacter pylori (Hp) catalase, which are linked to the induction of Th1 or Th2 immune responses, respectively. Alignment of these motifs with other proteins known to induce either Th1 or Th2 responses has lead to the identification of Th1 and Th2 consensus motifs, termed modulotopes. Their immunomodulatory potential was demonstrated by immunisation experiments using recombinant proteins comprising the C-terminal domain of catalase fused with one or several modulotopes and by co-immunisations of C- or N-terminal catalase domains with peptides containing these motifs. In addition to these in vivo data, in vitro assays using Limulus extracts suggested that modulotopes might interfere with responses triggered by danger signals such as LPS. Th1 and Th2 modulotopes are characterised by a specific hydrophobic/hydrophilic pattern, which might be the structural determinant for their activity. Our data suggest that Th1 and/or Th2 motifs may generally exist on proteins, thus offering the possibility of a rational modulation of the immune response.     

Kinematic alterations in the ipsilateral shoulder of patients with hemiplegia due to stroke

OBJECTIVE: To evaluate the assumption that shoulder kinematic patterns of the ipsilateral, nonparetic shoulder in hemiplegia are similar to kinematics recorded in a healthy population. DESIGN: Case control study of a convenience sample of ten patients with hemiplegia due to stroke in the subacute phase compared with a control group of similar age. Three-dimensional positions of the scapula and humerus were measured and expressed in Euler angles as a function of active arm elevation in the frontal and sagittal plane and during passive humeral internal/external rotation at an elevation angle of 90 degrees in the frontal and sagittal plane. RESULTS: Compared with controls, in the ipsilateral shoulder of patients, we found both a statistically significant diminished scapular protraction during elevation in the sagittal plane (35 +/- 5 vs. 51 +/- 8 degrees at 110 degrees of humeral elevation) and humeral external rotation during arm elevation in the frontal plane (51 +/- 7 vs. 69 +/- 14 degrees at 110 degrees of humeral elevation). Maximal passive humeral external rotation was found to be impaired in the frontal (64 +/- 13 vs. 98 +/- 14 degrees) and sagittal planes (65 +/- 11 vs. 94 +/- 12 degrees). In addition, there was significantly diminished anterior spinal tilt during humeral internal rotation (-5 +/- 10 vs. -20 +/- 9 degrees) and diminished posterior spinal tilt during external rotation in the frontal plane (-14 +/- 8 vs. -3 +/- 6 degrees). Maximal thoracohumeral elevation in patients was significantly impaired (126 +/- 12 vs. 138 +/- 8 degrees). CONCLUSION: Clear kinematic changes in the ipsilateral shoulder in patients with hemiplegia were found, indicating underlying alterations in muscle contraction patterns. The cause remains speculative. These results suggest that the ipsilateral shoulder should not be considered to function normally beforehand.     

Relationship Among Shoulder Proprioception, Kinematics, and Pain After Stroke

Niessen MH, Veeger DH, Meskers CG, Koppe PA, Konijnenbelt MH, Janssen TW. Relationship among shoulder proprioception, kinematics, and pain after stroke.

Objective

To identify a possible relationship among chronic poststroke shoulder pain (PSSP), scapular resting pose, and shoulder proprioception.

Design

Case-control study.

Setting

Rehabilitation center.

Participants

A total of 21 inpatients with stroke and 10 healthy control subjects.

Interventions

Not applicable.

Main Outcome Measures

Orientations of both the contralateral and ipsilateral (ie, paretic and nonparetic) shoulders during rest in degrees, angular displacement (degrees) for threshold to detection of passive motion (TDPM) tests, and absolute error (degrees) for passive reproduction of joint position (PRJP) tests.

Results

The contralateral shoulder of patients with PSSP showed more scapular lateral rotation and larger TDPM and PRJP scores than both patients without PSSP and control subjects. Additionally, the contralateral shoulder of patients with deteriorated proprioception showed more scapular lateral rotation than control subjects, whereas their ipsilateral shoulder showed more scapular lateral rotation than both control subjects and patients with good proprioception.

Conclusions

A clear relation among affected shoulder kinematics, affected proprioception, and PSSP was found. In determining the risk of developing PSSP, attention should be paid to a patients shoulder proprioception and kinematics. If both are altered after stroke, this could worsen the initial pathology or cause secondary pathologies and thus initiate a vicious circle of repetitive soft tissue damage leading to chronic PSSP. Additionally, more attention should be paid to the ipsilateral (ie, nonparetic) shoulder because it could be used in determining the risk of developing PSSP in the contralateral (ie, paretic) shoulder.     

Autologous Platelet-Rich Plasma for Clitoral Reconstruction: A Case Study

Clitoral reconstruction after female genital mutilation/cutting (FGM/C) is associated with significant post-operative pain and months-long recovery. Autologous platelet-rich plasma (A-PRP) reduces the time of healing and pain in orthopedic and burn patients and could also do so in clitoral reconstruction. In the present case, a 35-year-old Guinean woman who had undergone FGM/C Type IIb presented to our clinic for clitoral reconstruction. Her request was motivated by low sexual satisfaction and body image. We surgically reconstructed the clitoris using the Foldès method and applied plasma and glue of A-PRP. The patient was highly satisfied with the procedure. Two months post-operatively, her pain had ceased entirely and re-epithelialization was complete. We conclude that A-PRP may improve pain and healing after clitoral reconstruction. Extensive studies investigating long-term outcomes are needed.

     

Non-invasive diagnosis and assessment of tricuspid regurgitation and stenosis using one and two dimensional echo-pulsed Doppler.

Twenty normal subjects and 82 patients with valvular heart disease, whose lesions were independently assessed either by cardiac catheterisation and/or at operation, were studied using the pulsed Doppler technique combined with either one or two dimensional echocardiography. Of these, 41 patients had tricuspid lesions, including 40 with regurgitation and nine with stenosis. The tricuspid analogue flow velocity trace and the Doppler frequency spectrum (time interval histogram) were recorded. Characteristic differences were found between the records from subjects with and without tricuspid lesions. In subjects with tricuspid regurgitation there was a systolic negative wave on the analogue velocity display and broadening of the time interval histogram. In subjects with tricuspid stenosis there was an abnormal pattern, and significantly increased duration of the diastolic wave on the analogue velocity trace, again with broadening of the time interval histogram. Sensitivity and specificity ranged between 85 and 95%. The calculated ratio between the measured amplitudes of the systolic and diastolic waves correlated well with independently performed grading of the regurgitation on a three point scale in 85% of cases. Grading of the severity of tricuspid stenosis on a three point scale based on studies of the diastolic Doppler velocity anomalies was the same in 85% of cases as the grading based on established invasive techniques. The addition of two dimensional echocardiography to the pulsed Doppler technique increased the sensitivity for mild lesions.