Apabetalone, a BET inhibitor, attenuates inflammation induced by viral RNA mimetic and reduces SARS-CoV-2 spike protein binding regardless of variants

Background/Introduction

Hyperinflammatory responses to SARS-CoV-2 can cause myocarditis and cardiac dysfunction including congestive heart failure [1]. SARS-CoV-2 RNA induces type I interferon (IFN-I), activating IFN regulatory factors (IRFs) and downstream IFN stimulated genes (ISGs) to initiate inflammatory processes. SARS-CoV-2 variants may develop immune escape, undercutting benefits of vaccinations. These challenges highlight the need of variant-independent therapies to improve COVID-19 outcomes. Apabetalone is an epigenetic BD2-selective BET inhibitor in phase 3 trials for cardiovascular disease [2]. Apabetalone has the potential to treat COVID-19. It counters inflammatory signals caused by cytokine storm (CS), preventing cardiac dysfunction associated with severe COVID-19 symptoms in cardiac organoids [3]. It also downregulates angiotensin-converting enzyme 2 (ACE2) expression, the main host cell receptor for SARS-CoV-2 spike protein thus impeding propagation of wild-type SARS-CoV-2 [3,4].

Purpose

1) Evaluate apabetalone's effect on inflammatory processes induced by viral-RNA mimetic in human lung cells; 2) Assess apabetalone's ability to prevent binding of the highly contagious delta variant spike protein to human lung cells.

Methods

Inflammatory gene expression was examined by real-time PCR in apabetalone treated human bronchial epithelial cells (Calu-3) stimulated with poly I:C, a well-accepted viral RNA mimetic that elicits inflammatory signals similar to SARS-CoV-2 RNA [5]. Binding of SARS-CoV-2 delta or wild-type spike protein to apabetalone treated Calu-3 cells was determined by flow cytometry.

Results

In Calu-3 cells, apabetalone dose-dependently downregulated poly I:C induced transcription of key COVID-19 associated cytokines (IL6, CXCL10, CCL2) to a similar extent as baricitinib (up to 86%, p<0.0001), an anti-inflammatory agent in emergency use for COVID-19 treatment. Moreover, apabetalone but not baricitinib diminished IL1B mRNA levels (up to 66%, p<0.0001). Apabetalone and baricitinib opposed poly I:C induced expression of IFNB1 (an IFN-I), IRF1 and IRF9 (upstream regulators) as well as IFIT1 and IFIT2 (downstream ISGs that regulate CXCL10 expression; up to 90%, p<0.0001). Clinically relevant doses of apabetalone did not alter expression of anti-viral IFITM2, an ISG that blocks SARS-CoV-2, particularly omicron, endosomal entry [6]. Therefore, apabetalone counters the expression of inflammatory factors with roles in CS and IFN-I signaling in response to poly I:C. Additionally, apabetalone reduced delta and wild-type spike protein binding to unstimulated Calu-3 cells (up to 72%, p<0.0001).

Conclusions

Apabetalone's dual anti-viral and anti-inflammatory mechanism positions it as a variant-independent COVID-19 therapeutic. Together with an established safety profile from >2000 treatment-years with apabetalone, the data provide rationale for an ongoing clinical trial (NCT04894266) which includes analysis of cardiac damage.

Funding Acknowledgement

Type of funding sources: Private company. Main funding source(s): Resverlogix Corp

Essential role of CD8 palmitoylation in CD8 coreceptor function

To investigate the molecular basis that makes heterodimeric CD8alphabeta a more efficient coreceptor than homodimeric CD8alphaalpha, we used various CD8 transfectants of T1.4 T cell hybridomas, which are specific for H-2Kd, and a photoreactive derivative of the Plasmodium berghei circumsporozoite peptide PbCS 252-260 (SYIPSAEKI). We demonstrate that CD8 is palmitoylated at the cytoplasmic tail of CD8beta and that this allows partitioning of CD8alphabeta, but not of CD8alphaalpha, in lipid rafts. Localization of CD8 in rafts is crucial for its coreceptor function. First, association of CD8 with the src kinase p56lck takes place nearly exclusively in rafts, mainly due to increased concentration of both components in this compartment. Deletion of the cytoplasmic domain of CD8beta abrogated localization of CD8 in rafts and association with p56lck. Second, CD8-mediated cross-linking of p56lck by multimeric Kd-peptide complexes or by anti-CD8 Ab results in p56lck activation in rafts, from which the abundant phosphatase CD45 is excluded. Third, CD8-associated activated p56lck phosphorylates CD3zeta in rafts and hence induces TCR signaling and T cell activation. This study shows that palmitoylation of CD8beta is required for efficient CD8 coreceptor function, mainly because it dramatically increases CD8 association with p56lck and CD8-mediated activation of p56lck in lipid rafts.

[Transfer of the psoas tendon to the, at its origin detached, rectus femoris muscle in infantile cerebral palsy]

OBJECTIVES

Correction of flexion contracture of hip allowing an erect position while standing and walking. The gain in function helps to prevent a neurogenic dislocation of the coxofemoral joint.

INDICATIONS

In infants with cerebral palsy unable to straighten the body before they can stand or walk. In ambulatory spastic children and adolescents with bothersome hip flexion contracture.

CONTRAINDICATIONS

Severe retardation of motor development in patients with cerebral palsy in whom walking and standing cannot be anticipated. Marked spastic-dystonic muscle weakness.

SURGICAL TECHNIQUE

In general, soft tissue releases at hip and knee are performed at the same sitting. Anterior approach to the hip. Detachment of the sartorius from the anterior superior iliac spine and mobilization in a distal direction. Detachment of the rectus femoris from the anterior inferior iliac spine and retraction distally. Exposure of the femoral nerve in the lacuna musculorum. Exposure of the psoas and detachment from the lesser tuberosity. The tendon is mobilized in a proximal direction. Transfer of the rectus tendon on the divided psoas tendon. Reattachment of the sartorius or distal displacement into the fascia of the thigh.

RESULTS

A clinical and radiological follow-up of 71 bilaterally operated patients. A pertinent complete radiographic documentation was possible in all but 1 patient. 49.3% (n=35) of patients were able to walk preoperatively compared to 80.3% (n=57) at the time of follow-up. The average migration percentage according to Reimers amounted to 28.4% preoperatively; it had regressed to 18.2% at the time of follow-up. In none of the patients did a subluxation or dislocation occur.

Influence of different etching times on hybrid layer formation and tensile bond strength

PURPOSE

To correlate the thickness of the dentin/resin hybrid layer and the influence of different etching times to the composite resin tensile bond strength.

MATERIALS AND METHODS

775 human molars were prepared by removing the occlusal cusps to expose middle dentin using a microtome saw. Five commercially available dentin bonding agents were applied according to the manufacturers' instructions. Only the etching times were varied. For confocal laser scanning microscopy (CLSM) measurements, 325 teeth were used and the etching times were varied (not etched, 15, 30, 60 or 120 seconds). The primer components or self-priming adhesive, respectively, were fluorescence-labeled by rhodamine B isothiocyanate. In each case, the prepared surfaces were then covered by a layer of composite resin, sectioned and examined using a CLSM in fluorescent mode. The extension of hybrid layers was quantified by measuring the distances between the dentin-composite junction to a visible boundary. For the tensile bond strength measurements (Zwick testing machine), 450 molars were prepared, using different dentin etching times (not etched, 15, 30, 60, 120 and 180 seconds).

RESULTS

A hybrid layer was found in all etched teeth. The CLSM data gave evidence for an exponent-function relationship between the periods of etching and the thickness of the hybrid layer. The highest tensile bond strengths were achieved after 15 s of etching, followed by 30 s and 60 s. Under these etching conditions and irrespective of the bonding agent, bond strengths were significantly higher (P < or = 0.05) than without etching or after 120 and 180 s of etching. There was no linear correlation between the thickness of the hybrid layer and the bond strength.

Applications of confocal laser scanning microscopy to dental bonding

The introduction of confocal laser scanning microscopy (CLSM) has provided a valuable new technique for the visualization of bonding structures such as a hybrid layer in dentin (Watson, 1989, 1991). In the case of seven commercially-available dentin bonding systems, it could be demonstrated that the CLSM renders considerably more detailed information than the SEM because of its non-destructive nature and because of the possibility of a distinction between components of bonding agents. With most of the bonding systems, measurements of the thickness of the hybrid layer could be carried out when the primer component was labeled with rhodamine B. It was found that this thickness is significantly increased by increases in etching time and only slightly decreased by increases in the drying time of the dentin and of the primer. When rhodamine B was used for dye penetration tests on four different dentin bonding systems, a leakage within the demineralized zone in the dentin was found in each of the specimens. This structure appears similar to that which Sano et al. (1995) called "nanoleakage". The amount of nanoleakage could not be measured by this method. In the case of enamel or ceramic bonding, a penetration zone was found which corresponded to the etching patterns found in enamel and ceramics, respectively. We conclude that CLSM can offer a wealth of new information about bonding morphology and, therefore, should be used in addition to conventional methods so that the maximum information can be obtained.

Efficacy, cleaning ability and safety of different devices for gutta-percha removal in root canal retreatment

The purpose of this study was to evaluate the efficacy, cleaning ability and safety of five different devices and techniques to remove gutta-percha root canal fillings. One hundred and twenty extracted single-rooted anterior and premolar teeth were enlarged to ISO size 35 and obturated with laterally condensed gutta-percha using AH 26 as the sealer. Removal of gutta-percha was performed with the following devices and techniques: (a) Gates-Glidden and Hedstrom files, (b) only Hedstrom files, (c) Hedstrom files and chloroform, (d) the Endotec and Hedstrom files, and (e) the XGP drill and Hedstrom files. The following data were recorded: time taken to reach the desired working length, time required for the removal of the gutta-percha, and the amount of material extruded apically. The teeth were split longitudinally and photographed. Cleanliness of the root canal walls was scored using the projected slides with a total magnification of approximately 70x. The fastest technique to reach the working length was using the XGP drill (e), followed by the Gates-Glidden drills (a), Hedstrom files and chloroform (c), and the Endotec device (d). The use of Hedstrom files (b) without any additional support proved to be most time-consuming. Differences were statistically significant (U-test, P > 0.05) between the rotary devices and the manual techniques. Time for complete removal of gutta-percha was again shortest with the XGP drills (e), followed by the Gates-Glidden burs (a), the Endotec device (d), Hedstrom files with chloroform (c), and Hedstrom files alone (b). The XGP burs and the Gates-Glidden drills worked significantly faster than the other techniques. The amount of debris and filling material extruded apically in most cases did not exceed 0.1 mg. No significant differences could be detected between the groups (U-test, P > 0.05). Root canal cleanliness proved best following the use of Hedstrom files without additional support (b) and the Gates-Glidden drills (a), followed by Hedstrom files in combination with chloroform (c), the XGP-gutta-percha remover (e), and the Endotec device (d). When using the XGP two instrument fractures occurred in the apical parts of the root canals preventing further instrumentation to the apical foramen. When using the Gates-Glidden burs four instrument fractures occurred, but all fragments could be removed with forceps immediately. The results suggest that the XGP gutta-percha remover and the Gates-Glidden drills are efficient and time saving devices to remove gutta-percha but include a certain risk of instrument breakage and may leave some filling material inside the root canal. The best root canal cleanliness was achieved with Hedstrom files alone which, on the other hand, were shown to be the most time-consuming.

[Course and prognosis of congenital scoliosis]

75 patients (33 male, 42 female) with congenital scoliosis, diagnosed first time between birth and 40 years were examined. Type and site of the anomaly were classified and evaluated in accordance with a standardized scheme. The prognosis of congenital scoliosis depends strongly on the type of the anomaly. The differences of progression in the site of the abnormality are therefore minor. Unilateral unsegmented bars showed the most severe progression: the yearly rate of deterioration of the curve averages 7.6 degrees. Unilateral hemivertebrae showed 1.5 degrees (upper thoracic region) and 2.3 degrees (lower thoracic region). Two contralateral hemivertebraes and block vertebraes had a yearly rate of deterioration less than 1 degree. Operation is the treatment of choice in case of unilateral unsegmented bars. A conservative treatment is sufficient in most cases of other abnormalities.

A combined bony and soft-tissue tarsal stabilization procedure (Grice-Schede) for hindfoot valgus in children with cerebral palsy

This study deals with a combined bony and soft-tissue procedure (Grice-Schede) for the treatment of pes (equino) planovalgus in children suffering from cerebral palsy. Results of 43 treated feet in 28 children were assessed clinically and radiologically at a mean follow-up time of 6.7 years (range from 0.6 years to 13.8 years). In all, 58.1% excellent or good results, 14.0% satisfactory and 27.9% poor results were found. The procedure can be recommended for patients with hemiplegic and diplegic conditions. It is not suited for patients with total body involvement.

[Pathogenesis and prevention of spastic hip dislocation]

Based on retrospective analysis of 82 hips of 41 patients with cerebral palsy, a pathogenetic model of spastic paralytic dislocation of the hip is introduced including recent observations of the normal hip development. According to this model the reduced activity of the gluteus maximus, medius, minimus and quadriceps femoris muscles, which normally cause a decrease of valgus and anteversion, results in an increased subluxating coxa valga antetorta with a consecutive dislocation. In order to prevent a dislocation, these muscle groups have to undergo increased activation. Since walking has to be to undergo increased activation. Since walking has to be considered the strongest stimulus for the dislocation-preventing hip abductors, hip extensors, outward rotators and knee extensors, the erect gait should be encouraged with statomotorically favored children early as possible. This can be supported by muscle relaxing surgery of the antagonistically effective hip flexors, hip adductors and inward rotators as well as the knee flexors. These muscle release operations will counteract, although to a limited extent, a dislocation even with a severely handicapped child who is unable to walk.

[Surgical treatment concepts of deformities of the upper extremities in infantile cerebral palsy]

To correct the most frequent deformity of the spastic hand, muscle release and transfer operations, such as distal slide of hand and finger flexors (according to Scaglietti and Göb), release of the adductor pollicis and flexor pollicis brevis muscle (Matev), and transposition of the flexor carpi ulnaris muscle to the dorsal aspect of the hand, should be performed. These basic operations on the spastic hand can be supplemented by release or transposition of additional muscles of the fingers or hand. Bony procedures should be done to stabilize and augment the grip between thumb and second finger. In selected cases arthrodesis of the wrist can be performed to stabilize the hand in a functional position. The outcome of operations on the spastic hand depends on the application of correct indications as well as on postoperative physiotherapy. A slight functional gain, or even a purely cosmetic improvement, may mean a lot to the patient. In respect of professional rehabilitation of adolescents, operative correction of a deformed hand can help to improve manual skills and thereby increase job chances.

[Results of late synovectomy of the hip in juvenile chronic arthritis]

The aim of this study was to examine the indication for total synovectomy of the hip in juvenile chronic arthritis. For this purpose, five children with six treated hips were followed up. At the time of synovectomy all patients were suffering from therapy resistance and progressive destructive coxitis, as a result of juvenile chronic arthritis. The procedure carried out must, consequently, be regarded as late synovectomy. At the time of the follow-up examination--at least 2 years after the operation--all patients had lasting relief from pain. The range of hip movement could not be improved, despite being accompanied by tenotomies and consistent rehabilitation in the postoperative years. The functional capacity in everyday life also failed to improve. During the post-operative radiographic follow-up the deterioration of the hips proceeded more rapidly than expected for this spontaneous course of treatment. The results lead to the conclusion that the relief of pain due to a late synovectomy of the hip is achieved at the expense of a rapidly progressive destruction of the joints. For this reason, the late synovectomy of the hip in juvenile chronic arthritis should be regarded as the last possibility where resistance to conservative therapy exists.

[Concordant occurrence of grade I spondylolisthesis in childhood in a pair of monozygotic twins]

The case of two identical female twins is presented, who both showed concordantly spondylolisthesis L 5/S 1 grade I according to Meyerding at the age of ten. Further abnormalities in spinal development were detected in both girls. The course of 31 months is reported.

[Tarsal tunnel syndrome]

The natural history, diagnosis, and therapy of tarsal tunnel syndrome are given. Anatomical studies corresponding to the clinical picture and electrodiagnostic findings show two different narrow points in tarsal tunnel. Operative treatment should take into account the compression of the posterior tibial nerve by the flexor retinaculum and also of the plantar nerves under the abductor hallucis.

The proximal and distal tarsal tunnel syndromes. An anatomical study

Clinical and electromyographic studies in the tarsal tunnel syndrome may suggest compression of only one of the two terminal branches of the posterior tibial nerve. This anatomical study demonstrates the structures which may cause isolated damage to either the medial plantar or the lateral plantar nerves. A surgical approach to the tarsal tunnel is described.

Extraskeletal Osteosarcoma. Case report and differential diagnosis

In this case of an extraskeletal osteosarcoma initially there were typical difficulties in diagnosing a) a malignant mesenchymal tumor and b) a bone-producing tumor. Only focally the test-booking findings of an osteosarcoma were present. The differential diagnosis concerned mainly pseudosarcomatous lesions with bone formations, which histologically may appear suspicious, however, follow a benign course clinically.

["Adamantinoma" of the tibia and reactive bone changes (author's transl)]

A case of "adamantinoma" of the tibia is reported. 10 years ago a giant tumor with fibrous dysplasia had been diagnosed in a biopsy taken from the same site of cystic bone changes. These findings may occur as reaction in the periphery of "adamantinomas" of long bones. By this experience the importance was emphasized, to obtain tissue from the center portion of the tumor to include the typical epithelial islets pathognomonic for "adamantinomas", which in our case, were found only 10 years after the first operation. Our patient was treated by curetting and filling of the defect with bony splinters. At this time, 8 months after surgery, he is without complaints and in full use of his diseased leg.

[Orthopedics in infancy (author's transl)]

Early diagnosis and treatment is of decisive importance for the prognosis of many orthopedic diseases in infancy, especially of congenital skeletal lesions. Taking as examples deformities of the foot, hip dysplasia and luxation and infantile scoliosis, the principles of diagnosis and guide lines for therapy are indicated. Diseases of the locomotor apparatus can be considerably improved and late lesions to a great extent prevented by early recognition and treatment combined with good interdisciplinary cooperation.

[Malignant giant cell tumor of the femur with sarcomatous changes (author's transl)]

This is the report of a case with recurring giant cell tumor of the femur, which showed roentgenological evidence of pulmonary metastases. Only at the third biopsy sarcomatous changes as morphological signs of malignancy were found. Contrary to some elsewhere published giant cell tumors with sarcomatous components, there was no preceding irradiation in our case.

[Low back pain from the orthopedic point of view. Diagnosis and differential diagnostic. (author's transl)]

The diagnostic clarification of low back pain from the orthopedic point of view requires a specific exploration of the clinical history and an exact elicitation of findings not only of the vertebral column but also of the hip joints and the lower extremities. In the differential diagnosis of the disease processes which must be considered, congenital deformities, disturbances of statics and functional muscular states, inflammatory, degenerative, metabolic, tumorous and post-traumatic changes of the vertebral column must be demarcated from diseases of other etiology.