Kinetic properties of the alpha(2) homo-oligomeric glycine receptor impairs a proper synaptic functioning

Ionotropic glycine receptors (GlyRs) are present in the central nervous system well before the establishment of synaptic contacts. Immature nerve cells are known, at least in the spinal cord, to express alpha(2) homomeric GlyRs, the properties of which are relatively unknown compared to those of the adult synaptic form of the GlyR (mainly alpha(1)/beta heteromeres). Here, the kinetics properties of GlyRs at the single-channel level have been recorded in real-time by means of the patch-clamp technique in the outside-out configuration coupled with an ultra-fast flow application system (< 100 µs). Recordings were performed on chinese hamster ovary (CHO) cells stably transfected with the a, GlyR subunit. We show that the onset, the relaxation and the desensitisation of α(2) homomeric GlyR-mediated currents are slower by one or two orders of magnitude compared to synaptic mature GlyRs and to other ligand-gated ionotropic channels involved in fast synaptic transmission. First latency analysis performed on single GlyR channels revealed that their slow activation time course was due to delayed openings. When synaptic release of glycine was mimicked (1 mM glycine; 1 ms pulse duration), the opening probability of α(2) homomeric GlyRs was low (P-o ≈ 0.1) when compared to mature synaptic GlyRs (P-o = 0.9). This low P-o is likely to be a direct consequence of the relatively slow activation kinetics of α(2) homomeric GlyRs when compared to the activation kinetics of mature α(1)/β GlyRs. Such slow kinetics suggest that embryonic α(2) homomeric GlyRs cannot be activated by fast neurotransmitter release at mature synapses but rather could be suited for a non-synaptic paracrine-like release of agonist, which is known to occur in the embryo

A rare case of acantholytic squamous cell carcinoma presenting on non-sun exposed palpebral conjunctiva

Purpose: This report describes the clinical and histological characteristics and management of a keratinized lesion of the palpebral conjunctiva in a 59-year-old male. The lesion was identified as a rare acantholytic variant of squamous cell carcinoma that atypically arose from a non-sun exposed region of palpebral conjunctiva. Management was complete excision via Mohs surgery. Observations: A 59-year-old male presented with ocular irritation and chronic foreign body sensation in the right eye. Exam revealed a keratinized lesion in the right lower tarsal conjunctiva, and an initial shave biopsy was non-diagnostic. 12 months later, the patient presented with similar symptoms and a larger, more irregular lesion for which histopathology of a tarsal-involving excisional biopsy was consistent with acantholytic squamous cell carcinoma with involved margins. The patient subsequently underwent complete excision via Mohs surgery and a secondary reconstruction. Conclusions and importance: Acantholytic variants of squamous cell carcinoma are rare and are described as arising from areas with routine sun exposure. This case reports such a lesion arising from non-sun exposed tarsal conjunctiva, as identified by histopathology of a full-thickness excisional biopsy. The lesion was successfully managed with complete excision via Mohs surgery and secondary reconstruction. Given that this histologic variant may be more aggressive and have higher rates of recurrence than other forms of squamous cell carcinoma, this case highlights the importance of complete excisional biopsy and accurate histopathology of concerning periocular lesions and offers a template for management of similar lesions. The unique presenting location should bring awareness to consideration of this type of malignancy developing on palpebral conjunctiva

Beyond Regular Model Checking

In recent years, it has been established that regular model checking can be successfully applied to several parameterized verification problems. However, there are many parameterized verification problems that cannot be described by regular languages, and thus cannot be verified using regular model checking. In this study we try to practice symbolic model checking using classes of languages more expressive than the regular languages. We provide three methods for the uniform verification of non-regular parameterized systems

Outcomes of Patients With Thyroid Eye Disease Partially Treated With Teprotumumab

In response to the coronavirus (COVID-19) pandemic, teprotumumab production was temporarily halted with resources diverted toward vaccine production. Many patients who initiated treatment with teprotumumab for thyroid eye disease were forced to deviate from the standard protocol. This study investigates the response of teprotumumab when patients receive fewer than the standard 8-dose regimen. This observational cross-sectional cohort study included patients from 15 institutions with active or minimal to no clinical activity thyroid eye disease treated with the standard teprotumumab infusion protocol. Patients were included if they had completed at least 1 teprotumumab infusion and had not yet completed all 8 planned infusions. Data were collected before teprotumumab initiation, within 3 weeks of last dose before interruption, and at the visit before teprotumumab reinitiation. The primary outcome measure was reduction in proptosis more than 2 mm. Secondary outcome measures included change in clinical activity score (CAS), extraocular motility restriction, margin reflex distance-1 (MRD1), and reported adverse events. The study included 74 patients. Mean age was 57.8 years, and 77% were female. There were 62 active and 12 minimal to no clinical activity patients. Patients completed an average of 4.2 teprotumumab infusions before interruption. A significant mean reduction in proptosis (-2.9 mm in active and -2.8 mm in minimal to no clinical activity patients, P < 0.01) was noted and maintained during interruption. For active patients, a 3.4-point reduction in CAS ( P < 0.01) and reduction in ocular motility restriction ( P < 0.01) were maintained during interruption. Patients partially treated with teprotumumab achieve significant reduction in proptosis, CAS, and extraocular muscle restriction and maintain these improvements through the period of interruption