A systematic review on impact of SARS-CoV-2 infection

Innumerable pathogens including RNA viruses have catastrophic pandemic propensity, in turn, SARS-CoV-2 infection is highly contagious. Emergence of SARS-CoV-2 variants with high mutation rate additionally codifies infectious ability of virus and arisen clinical imputations to human health. Although, our knowledge of mechanism of virus infection and its impact on host system has been substantially demystified, uncertainties about the emergence of virus are still not fully understood. To date, there are no potentially curative drugs are identified against the viral infection. Even though, drugs are repurposed in the initial period of infection, many are significantly negative in clinical trials. Moreover, the infection is dependent on organ status, co-morbid conditions, variant of virus and geographic region. This review article aims to comprehensively describe the SARS-CoV-2 infection and the impacts in the host cellular system. This review also briefly provides an overview of genome, proteome and metabolome associated risk to infection and the advancement of therapeutics in SARS-CoV-2 infection management.

Is microbiological analysis of donor cornea transport culture media necessary?

PURPOSE

To investigate microbial contamination of the transport medium. Examination of corneoscleral rims is not included in this series.

METHODS

Transport media of 63 consecutive grafts done at Tennent Institute of Ophthalmology, Glasgow, were collected for microbial examination.

RESULTS

None of the culture plates showed any growth after prolonged culture, and microscopy was negative in 100% of cases.

CONCLUSIONS

Routine culture of transport media may not be necessary.

The use of a "cheese-wire" suture in trabeculectomy

AIM

To report a preliminary study on the safety and efficacy of the use of a cheese-wire suture in trabeculectomy.

PATIENTS AND METHODS

The case notes of 32 eyes of 25 patients with medically uncontrolled glaucoma who underwent trabeculectomy with cheese-wire suture at Stobhill Hospital, Glasgow, UK, between July 2001 and September 2002 were studied retrospectively. Diagnoses included primary open angle glaucoma (n = 24), normal tension glaucoma (n = 3), angle closure glaucoma (n = 2), ocular hypertension (n = 1), angle recession glaucoma (n = 1) and combined mechanism glaucoma (n = 1). The mean presenting intraocular pressure (IOP) was 29.5 mm Hg and mean intraocular pressure before operation was 23.5 mm Hg

OUTCOME MEASURES

Success was defined as lowering of IOP by at least 15% compared with IOP before removal.

RESULTS

A total of 20 eyes (62%) underwent removal of the cheese-wire suture. 17 eyes (85%) underwent removal for therapeutic reasons (failing/failed blebs) and three eyes (15%) underwent suture removal as the suture loops were exposed. The timing of removal was between 2 weeks and 12 months following surgery. A successful outcome was seen in 12/17 (70%) eyes in the eyes that had therapeutic suture removal. 15 eyes had undergone previous surgical interventions (trabeculectomy n = 12, extracapsular cataract extraction n = 1 and laser peripheral iridotomies n = 2). Mean IOP before removal was 23.66 mm Hg and mean IOP immediately following removal was 11.33 mm Hg. Of the 32 eyes that underwent trabeculectomy with cheese-wire suture, 24 eyes had intraoperative mitomycin C and one eye had 5-fluorouracil. The remaining seven eyes did not have any antimetabolites. Early complications related to the surgical procedure included conjunctival haematoma in one eye (3%), corneal abrasion in one eye (3%), wound leak in five eyes (15%), shallow anterior chamber in one eye (3%), hyphaema in six eyes (18%), choroidal effusion in six eyes (18%) and raised IOP in two eyes (6%). Late complications of suture exposure occurred in three eyes (9%). Complications related to removal of the cheese-wire suture included suture breakage in two eyes (10%), hypotony in one eye (5%) and transient hyphaema in one eye (5%).

CONCLUSION

The use of cheese-wire suture in trabeculectomy appears to be safe and may provide an alternative strategy in the management of bleb failure.

Pathogenesis, clinical features and management of recurrent corneal erosions

Recurrent corneal erosions (RCE) are common. They are characterised by repeated episodes of pain, difficulty in opening the eyes, watering, and photophobia resulting from poor epithelial adhesion. In the majority of patients with RCE, trauma is the initiating factor. Epithelial, stromal, and endothelial corneal dystrophies have all been described in association with RCE. Other causes that may lead to RCE include chemical and thermal injuries, previous herpetic keratitis, meibomian gland dysfunction, ocular rosacea, diabetes mellitus, Salzmann's nodular degeneration, band keratopathy, previous bacterial ulceration, kerato-conjunctivitis sicca, and epidermolysis bullosa. The conditions that are associated with RCE can be either primary or secondary depending on whether the basement membrane complex abnormality is intrinsic or acquired. Primary types tend to be bilateral, symmetrical and develop in multiple corneal locations. The pathogenetic mechanism of this disorder is related to poor adhesion of the corneal epithelium to the underlying stroma. Excessive matrix metalloproteinase (MMP) activity may play a role in the pathogenesis. Although the majority of patients will respond to simple measures such as padding and antibiotic ointment, RCE resistant to simple measures require approaches that are more elaborate. The common goal of these approaches is to encourage proper formation of adhesion complexes between the epithelium and the stroma. The use of long-term contact lenses, autologous serum eye drops, botulinum toxin, induced ptosis, oral MMP inhibitors, diamond burr polishing of Bowman's membrane have been reported with varying degree of success in treating RCE. Anterior stromal puncture with insulin needles or Neodymium : aluminium-yttrium-garnet may enhance the epithelial adhesion to the basement membrane by scar formation and success rates of up to 80% have been reported in the treatment of recalcitrant RCE. Excimer laser photo-therapeutic keratectomy (PTK) is now a well-established treatment modality for RCE and is being used both safely and effectively. Partial ablation of Bowman's layer with PTK gives a smooth surface for the newly generating epithelium to migrate and form adhesion complexes. The pathogenesis, clinical features, and management options of this common disorder are discussed in this review article.

Application of reversed-phase liquid chromatography and prepacked C18 cartridges for the analysis of oxytetracycline and related compounds

The reversed-phase (RP) chromatographic separation of oxytetracycline (OTC) 4-epioxytetracycline (4-epiOTC), alpha-apooxytetracycline (alpha-apoOTC), and beta-apooxytetracycline (beta-apoOTC) has been accomplished on an Inertsil C8 column at ambient temperature. Using the simplex method of solvent optimization, a 0.1 M ammonium acetate buffer (pH 3.0)-acetonitrile-tetrahydrofuran (72.5:12.5:15, v/v/v) mobile phase was found to give excellent separation of the compounds. OTC, 4-epiOTC, alpha-apoOTC and beta-apoOTC were resolved in 35 min with calculated detection limits of 40, 20, 50 and 140 ng/ml, respectively. Solid-phase extraction (using RP C18 cartridges) of OTC and OTC degradation compounds from distilled water and porcine muscle was tested at four concentration levels ranging from 200 to 2000 ng/ml (g); overall mean recovery of OTC from distilled water and porcine tissue was greater than 90% and 70%, respectively.