Metabolic and physiological adaptations of microalgal growth-promoting bacterium Azospirillum brasilense growing under biogas atmosphere: a microarray-based transcriptome analysis.

Using microalgal growth-promoting bacteria (MGPB) to improve the cultured microalga metabolism during biotechnological processes is one of the most promising strategies to enhance their benefits. Nonetheless, the culture condition effect used during the biotechnological process on MGPB growth and metabolism is key to ensure the expected positive bacterium growth and metabolism of microalgae. In this sense, the present research study investigated the effect of the synthetic biogas atmosphere (75% CH4-25% CO2) on metabolic and physiological adaptations of the MGPB Azospirillum brasilense by a microarray-based transcriptome approach. A total of 394 A. brasilense differentially expressed genes (DEGs) were found: 201 DEGs (34 upregulated and 167 downregulated) at 24 h and 193 DEGs (140 upregulated and 53 downregulated) under the same conditions at 72 h. The results showed a series of A. brasilense genes regulating processes that could be essential for its adaptation to the early stressful condition generated by biogas. Evidence of energy production is shown by nitrate/nitrite reduction and activation of the hypothetical first steps of hydrogenotrophic methanogenesis; signal molecule modulation is observed: indole-3-acetic acid (IAA), riboflavin, and vitamin B6, activation of Type VI secretion system responding to IAA exposure, as well as polyhydroxybutyrate (PHB) biosynthesis and accumulation. Moreover, an overexpression of ipdC, ribB, and phaC genes, encoding the key enzymes for the production of the signal molecule IAA, vitamin riboflavin, and PHB production of 2, 1.5 and 11 folds, respectively, was observed at the first 24 h of incubation under biogas atmosphere Overall, the ability of A. brasilense to metabolically adapt to a biogas atmosphere is demonstrated, which allows its implementation for generating biogas with high calorific values and the use of renewable energies through microalga biotechnologies.

Characterization of patients with ocular pain evaluated with ultrasound.

BACKGROUND: The cause of ocular pain in the quiet eye is challenging to diagnose. It is a common complaint in the ophthalmology clinic and there are no actual guidelines on the exams that should be ordered initially. We decided to characterize patients with eye pain and normal ophthalmological examination who underwent ocular ultrasound, their findings, and systemic work-up. METHODS: A retrospective chart review of patients who underwent ocular ultrasound due to ocular pain and no clinical findings on initial slit-lamp examination. We evaluated patient characteristics and analyzed systemic work-up results in contrast to ocular ultrasound findings. RESULTS: Two hundred and three patients with normal slit-lamp examination and ocular pain were evaluated using ocular ultrasound at Clinica Barraquer. Most of the patients were women (88.7%), and 55% were older than 50 years. Nearly all of the patients had echographic findings, 87.7% of patients showed evidence of scleral scars, from which 66.5% had signs of activity, and 42.9% had thickened extraocular muscles. In general, most patients with ocular pain had normal results on systemic work-up, but the patients who did have positive results tended to have echographic findings. CONCLUSION: Posterior inflammation is present in most patients with ocular pain in a quiet eye, and echography is an optimal tool to identify this. There is a tendency towards abnormal autoimmune test results and echographic findings. This should be considered in the initial work-up of these patients, given the importance of early diagnosis and the threat of vision loss with severe inflammation.

Confocal Microscopy Abnormalities Preceding Antibody Positivity and Manifestations of Sjogren's Syndrome.

An asymptomatic 26-year-old woman underwent confocal microscopy as part of a control population for a research study. Images revealed reduced sub-basal corneal nerve density and multiple activated dendritic cells. Three years later, she presented with a self-limited cutaneous vasculitis in her lower extremities which prompted an evaluation for autoimmune diseases. Laboratory testing revealed positive antinuclear antibodies (1:320, thick granular pattern), and anti-SSA/SSB (SSA, 53.6 U/mL, moderately positive; SSB, 142.7 U/mL, strongly positive). Two weeks later, she presented with ocular pain and an ophthalmologic examination revealed ocular surface staining. An ocular ultrasound was consistent with posterior scleritis. Based on this picture, a diagnosis of Sjögren syndrome (SS) was made. SS is a chronic autoimmune disease that can present with symptoms that diminish the patient's quality of life. Confocal microscopy might be a valuable tool for the early diagnosis of disease.

Epithelial downgrowth leading to graft rejection after penetrating keratoplasty.

PURPOSE: To report a case of epithelial downgrowth after penetrating keratoplasty. CASE DESCRIPTION: A 58-year-old man presented with graft rejection in his three-month-old, repeat penetrating keratoplasty. Examination revealed centripetal opacification of the posterior cornea due to deep epithelization. He had new retro-corneal membranes and anterior uveitis. Specular microscopy and anterior segment optical coherence tomography were performed, and a clinical diagnosis of epithelial downgrowth was made. The patient had intracameral injections with 5-fluorouracil (5FU) and achieved resolution of intraocular findings after treatment. CONCLUSIONS: Epithelial downgrowth is an uncommon complication of penetrating keratoplasty. It affects the patients' visual acuity and graft survival. Clinical observation is preferred in severe cases due to the high risk of intraocular damage; intracameral 5FU promises to be a good option in these cases.

Ophthalmological Approach for the Diagnosis of Dry Eye Disease in Patients with Sjögren's Syndrome.

Dry eye has two basic subdivisions: aqueous deficient dry eye (ADDE), with SS a major cause; and evaporative dry eye (EDE), due to either intrinsic or extrinsic factors. SS is a chronic inflammatory disorder defined by dysfunction of the exocrine glands leading to dry eye and dry mouth. The objective of this article was to carry out a systematic and critical review of several scientific publications on dry eye disease, with the aim of providing general recommendations to distinguish dry eye and its different variants in patients with SS, during the period 1979 to 2020, using search engines for articles indexed in Scopus, Latindex, Scielo, Clinical Trials, Medline, Embase, and Cochrane, allowing the analysis of 132 articles published in indexed journals on the subject of dry eye disease and SS, evidencing its conceptualization, prevalence, risk factors, etiopathogenesis, clinical manifestations, diagnosis, and treatment.

Limbal advancement technique in managing acute or impending peripheral corneal perforations.

Purpose: To describe the outcomes of a novel technique for the repair of peripheral corneal perforations using autologous limbal tissue. Methods: Two patients with peripheral corneal perforations with contraindications to other corneal procedures underwent limbal advancements. This technique involves creating a pedicle of the limbus, sclera and conjunctiva to cover the perforation. Results: The tissue had optimal integration in both patients; no aqueous leaks or flat anterior chambers were noted. None of the patients had recurrence of perforation or ocular discomfort. Conclusion: In conclusion, this technique is a cost-effective and straightforward alternative for the repair of impending acute peripheral perforations.

Brief incubation of corneal grafts in activated platelet rich plasma enhances corneal endothelial cell survival and regeneration.

Corneal transplantation is the most frequent organ transplantation worldwide. Unfortunately, corneal graft failure is common and endothelial decompensation is considered the major cause. Corneal endothelial cells (CECs) lack the capacity to reproduce, and perioperative and postoperative endothelial cell loss remains a significant challenge associated with corneal graft viability. Therefore, strategies to preserve CEC density are critical to extend graft survival. Activated platelet rich plasma (aPRP), a product extracted from autologous blood, has both antioxidant and regenerative properties. aPRP eye drops have shown effectiveness in the treatment of corneal pathologies such as ulcers, dry eye, and burns. Our purpose is to determine the protective and regenerative effect of aPRP on corneal grafts by evaluating aPRP's effect on the survival and proliferation of human CECs. Human corneal grafts were incubated in aPRP for 15 min to assess the activation of the CEC pAkt survival pathway as measured by ELISA. Evaluation of the protective effect of aPRP was made using an apoptotic model, which simulated oxidative stress conditions. Expression of apoptotic markers was measured using ELISA and endothelial cell viability was determined by optical microscopy. The CEC proliferation rate was measured in vitro with Ki-67 staining. Corneal graft gross structure was evaluated by Hematoxylin & Eosin and Masson trichrome staining. Our results indicate that a short incubation of human corneal grafts in aPRP protects CECs from apoptosis by upregulating the pAkt survival pathway and promoting CEC proliferation. Additionally, aPRP incubation does not induce histological changes in the grafts. A brief pre-treatment of human corneal grafts in aPRP may be beneficial for transplant longevity, as it protects CECs from apoptosis by upregulating intracellular survival pathways and promoting proliferation. In addition, this approach appears to be safe and has the potential to improve surgical outcomes following corneal transplantation.

An Atypical Case of Miller Fisher Syndrome with Multiple Autoimmunity.

Miller Fisher syndrome (MFS) is a rare variant of Guillain-Barré syndrome that is characterised by ataxia, ophthalmoplegia, and areflexia. Its relation with other autoimmune diseases is scarcely found in the literature, and in those few cases, treatment has been especially difficult. We report a case of a 28-year-old woman who presented with ophthalmoplegia and ptosis, later developing facial palsy and hyporeflexia. She had positive GD1a, GT1a, GQ1b antibodies confirming MFS. She also had positive antinuclear and lupus anticoagulant antibodies confirming antiphospholipid syndrome. She had a mild clinical course. MFS can present with multiple autoimmunity; it is unclear if there is cross-reactivity due to myelin damage.

Antibacterial effect of acetic acid during an outbreak of carbapenem-resistant Acinetobacter baumannii in an ICU (II).

INTRODUCTION: Acetic acid (AA) has been commonly used in medicine as an antiseptic agent for the past 6000 years. This study evaluated the antibacterial effect of AA during an outbreak in an intensive care unit (ICU) facility in Baja California Sur, México. METHODOLOGY: Thirty-five environmental samples were collected, subsequently, disinfection with AA (4%) was performed, and two days later the same areas were sampled inside the ICU facility. Carbapenem-resistant A. baumannii (CRAB) was detected with loop-mediated isothermal amplification assay (Garciglia-Mercado et al. companion paper), targeting blaOXA-23-like, blaOXA-24-like, blaOXA-51-like, blaOXA-58-like, blaIMP and blaVIM genes. CRAB isolates before and after disinfection were compared by PFGE. RESULTS: Eighteen (54.5%) and five (14.3%) of thirty-five environmental samples were identified as Acinetobacter baumannii before and after disinfection, respectively, showing a significant decrease of 85.7% (p < 0.05) both by Loop-mediated isothermal amplification (LAMP) and polymerase chain reaction (PCR). Furthermore, the presence of blaOXA-23-like and blaOXA-58-like genes significantly decreased (p < 0.05) both by LAMP and PCR methods. PFGE genotype showed high similarity among CRAB isolates before and after disinfection, suggesting wide clonal dissemination in the ICU facility. CONCLUSIONS: This study demonstrated the novel application of AA with the LAMP assays developed for detecting CRAB. AA promises to be a cheap and efficacious disinfectant alternative to both developed and especially developing countries, preventing the spread of this organism in the environment and to other susceptible patients in health care settings.

High resolution anterior segment optical coherence tomography of ocular surface lesions: A review and handbook.

Introduction: High resolution anterior segment optical coherence tomography (HR-OCT) has revolutionized the way by which clinicians can diagnose and differentiate ocular surface lesions. Careful interpretation of HR-OCT images can provide morphological information about the lesion of interest and help guide the diagnosis. Areas covered: This paper reviews the steps to interpreting HR-OCT images of ocular surface lesions and summarizes their characteristic findings. Expert opinion: Among the multiple modalities available to image the ocular surface and anterior segment, HR-OCT has emerged as an instrumental tool to obtain "optical biopsies" of various ocular surface lesions. A step-by-step approach to acquiring and interpreting HR-OCT images can allow for accurate in-office characterization and diagnosis of both benign and malignant ocular surface lesions.

Development of a LAMP method for detection of carbapenem-resistant Acinetobacter baumannii during a hospital outbreak.

INTRODUCTION: Carbapenem-resistant A. baumannii (CRAB) represents a public health threat increasing worldwide. We assess the suitability of a loop-mediated isothermal amplification (LAMP) method for on-site screening of CRAB in a hospital facility. METHODOLOGY: A set of six primers were designed for recognizing eight distinct sequences on six targets: blaOXA-23-like, blaOXA-24-like, blaOXA-51-like, blaOXA-58-like, blaIMP, and blaVIM. A LAMP method was developed, optimized and evaluated for the identification of CRAB in thirty-three environmental samples from an outbreak in an Intensive Care Unit (ICU) facility. RESULTS: The sensitivity of the LAMP assay for the detection of A. baumannii was ten-fold higher than the PCR assay (1.0 ng.µL-1). The LAMP assays showed a higher detection rate for CRAB samples and robust diagnosis performance in comparison to a conventional PCR, with clinical sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of 100% for blaOXA-23-like, blaOXA-51-like and blaVIM. CONCLUSIONS: The developed LAMP assays are powerful tools that can be useful in on-site screening of CRAB causing local outbreaks in clinics and hospitals facilities where costs and equipment restraints are imperative.

The use of high resolution anterior segment optical coherence tomography for the characterization of conjunctival lymphoma, conjunctival amyloidosis and benign reactive lymphoid hyperplasia.

BACKGROUND: Conjunctival lymphoma, conjunctival amyloidosis and benign reactive lymphoid hyperplasia (BRLH) are conditions that often have a similar appearance on the ocular surface. The use of high resolution anterior segment optical coherence tomography (HR-OCT) enables clinicians to evaluate distinctive differences in tissue morphology and cellular patterns in various ocular surface conditions. In this study, we characterize the morphological differences seen in conjunctival lymphoma, conjunctival amyloidosis and BRLH on HR-OCT imaging. METHODS: A retrospective chart review was performed of patients with biopsy proven conjunctival lymphoma, conjunctival amyloidosis and BRLH between 2012 and 2019 at the Bascom Palmer Eye Institute. Patients were excluded if HR-OCT imaging was not performed on initial presentation. RESULTS: Thirty-four total eyes of 27 patients were identified. Twenty eyes had conjunctival lymphoma (16 patients), 8 eyes had conjunctival amyloidosis (6 patients) and 6 eyes had BRLH (5 patients). All conditions appeared clinically as pink, red or yellow subepithelial lesions but had different features on HR-OCT. In lymphoma, HR-OCT images typically showed homogenous, dark subepithelial lesions with smooth borders, containing monomorphic dot-like infiltrates. HR-OCT images of amyloidosis typically showed heterogeneous, dark lesions with irregular borders, often containing hyperreflective linear infiltrates. HR-OCT images of BRLH showed variable infiltration of the subepithelial tissue, at times with homogenous lesions containing dot-like infiltrates like lymphoma and other times with more hyperreflective, subepithelial tissue. Flow cytometry and gene rearrangement was needed for final differentiation between BRLH and lymphoma lesions. CONCLUSIONS: Distinctive features on HR-OCT of conjunctival lymphoma, conjunctival amyloidosis and BRLH can help characterize these lesions beyond what is apparent with the clinical examination. Future studies can further validate this technology's use with more subtle and challenging lesions.

Use of High-Resolution Optical Coherence Tomography in the Surgical Management of Ocular Surface Squamous Neoplasia: A Pilot Study.

PURPOSE: To evaluate whether high-resolution optical coherence tomography (HR-OCT) can detect histologic tumor margins of ocular surface squamous neoplasia (OSSN). METHODS: Eight eyes of 8 patients with OSSN undergoing excision were studied prospectively. Immediately before surgery, the tumor was imaged using commercially available HR-OCT to identify the conjunctival margins of the neoplastic lesion. The tumor borders of the lesion determined by HR-OCT were mapped in relation to an anatomic reference point and transferred intraoperatively. The tumor was excised with 4-mm margins from the visible edge of the lesion with a "no-touch" technique. The specimens were sent for pathologic analysis and the histologic tumor margin was compared to the HR-OCT predicted tumor border. RESULTS: Mean age of the 8 patients was 67 ± 9.9 years. Seven were male, 7 were white, and, ethnically, 3 were Hispanic. All 8 tumors were bulbar and in the exposure zone. Seven tumors were limbal. Corneal extension was present in 5. Mean tumor area was 17.5 ± 11.1 mm2. Clinically, 2 of the tumors were leukoplakic, 1 papillomatous, and 3 gelatinous. A conjunctival tumor margin identified with the HR-OCT coincided with the pathologically confirmed margin mark in all eyes. CONCLUSIONS: HR-OCT has the potential to predict histologic tumor margins in OSSN. Optical identification of tumor margins could potentially decrease the incidence of residual positive margins and minimize healthy tissue removal. Advances in HR-OCT technology and integration into a microscope for "real-time" imaging are needed to further improve this technique. NOTE: Publication of this article is sponsored by the American Ophthalmological Society.

Surgical versus medical treatment for ocular surface squamous neoplasia: A quality of life comparison.

PURPOSE: To characterize vision-related and psychosocial quality of life (QoL) parameters in medically and surgically treated patients with OSSN. METHODS: Forty-one patients with OSSN treated with medical therapy consisting of interferon alpha 2b drops 1 MIU/ml (n = 22) or who underwent surgical excision (n = 19) were contacted. All subjects answered a quality of life assessment with an original questionnaire in which they were asked about a range of parameters. Overall satisfaction and motivating factors for treatment were also reviewed. RESULTS: The mean age at the time of the survey was 64.6 and 51% were male with similar demographics between groups. Based on the previous cohort, rates of tumor resolution and recurrences were comparable in the two groups. Reasons for choosing a particular treatment varied between the groups. Forty percent of individuals in the medical group reported a fear of surgery (p = 0.03) and often made the decision after personal research (p = 0.008). Thirty-two percent of patients in the surgical group chose surgery due to fear of decreased vision due to lesion growth, therefore wanting immediate resolution (p = 0.09). Drops precipitated more ocular symptoms such as tearing and itchiness, on the other hand, patients who had surgery reported having more pain. CONCLUSION: Quality of life considerations before, during, and after OSSN treatment is an important yet understudied topic. Our study is the first to look at QoL parameters in OSSN treatment and we found that patients in both medically and surgically treated groups had similar QoL metric but were driven to choose chemotherapy due to fear of surgery and/or prior literature review.

Challenging Treatment of Ocular Surface Squamous Neoplasia in Patients with Atopic Disease.

PURPOSE: Few studies have described ocular surface squamous neoplasia (OSSN) and its association with atopic diseases and there is no consensus on the course of OSSN in atopic patients. We thereby report three patients with atopy and OSSN. METHODS: Retrospective case series. RESULTS: Three male patients with mean age of 73 presented with OSSN and history of atopy treated with immunosuppressant therapy. Their histories included atopic dermatitis and keratoconjunctivitis. All patients had treatment complicated by multiple surgeries, recurrences, or advanced disease. The patients initially received medical treatment with topical interferon-alpha-2b (IFNα2b). However, all the patients had recurrences and required modification of treatment including topical 5-fluorouracil (5-FU). CONCLUSION: We report on three patients with a history of atopy whose OSSN presentation and course was challenging. Overall, our cases responded better to topical 5-fluorouracil compared to topical interferon-alpha-2b, but recurrences were common. These patients may benefit from more aggressive and long-term treatment.

Comparison of Topical 5-Fluorouracil and Interferon Alfa-2b as Primary Treatment Modalities for Ocular Surface Squamous Neoplasia.

PURPOSE: To compare the efficacy of topical 5-fluorouracil 1% (5FU) and interferon alfa-2b 1 MIU/mL (IFN) eye drops as primary treatment modalities for ocular surface squamous neoplasia (OSSN). DESIGN: Retrospective, comparative, interventional case series. METHODS: Fifty-four patients who received 5FU and 48 patients who received IFN as primary therapy for OSSN were included. Primary outcome measures were the frequency of clinical resolution and time to OSSN recurrence by treatment modality. Secondary outcome was the frequency of side effects with each therapy. RESULTS: The mean age of patients was 68 years. More Hispanics were treated with 5FU. In a univariable analysis, frequency of OSSN resolution was higher with 5FU (96.3%, n = 52) than with IFN (81.3%, n = 39), P = .01. In a multivariable analysis, treatment modality did not remain a significant predictor of resolution. In patients whose OSSN resolved, time to resolution was similar with both agents, (5FU mean 6.6 months, standard deviation (SD) 4.5 vs IFN mean 5.5 months, SD 2.9, P = .17). Of the 52 eyes whose OSSN resolved with 5FU, 11.5% of lesions (n = 6) recurred, whereas of the 39 eyes whose OSSN resolved with IFN, 5.1% of lesions (n = 2) recurred, P = .46. Kaplan-Meier survival curves of OSSN recurrence were similar between groups (log-rank = 0.16). One-year recurrence rates were 11.4% with 5FU and 4.5% with IFN. Eyelid edema (P = .04) and tearing (P = .02) were more significant with 5FU. CONCLUSIONS: This is the first direct comparison study between 5FU and IFN eye drops as primary treatment modalities for OSSN. Both modalities resulted in a high frequency of tumor resolution and low recurrence rates and are effective treatment options for OSSN.

Topical 5-Fluorouracil 1% as Primary Treatment for Ocular Surface Squamous Neoplasia.

PURPOSE: To determine the efficacy of topical 5-fluorouracil 1% (5-FU) as a primary treatment of ocular surface squamous neoplasia (OSSN). DESIGN: Retrospective study. PARTICIPANTS: Topical 5-FU was used as primary therapy in 44 patients with OSSN. METHODS: 5-Fluorouracil 1% administered topically 4 times daily for 1 week followed by a drug holiday of 3 weeks. Patients were identified through a pharmacy database. Patients were excluded if 5-FU was used as adjuvant therapy, if they did not complete therapy, or if they were still actively receiving treatment for OSSN at the time of last follow-up. MAIN OUTCOME MEASURES: The primary outcome measures were the frequency of complete resolution with topical 5-FU treatment and the rate of OSSN recurrence. RESULTS: Of the 44 patients identified, 32 were men and 12 were women. The mean age was 68 years. Complete resolution of OSSN was noted in 82% of patients (36/44); 18% (8/44) were considered treatment nonresponders. Patients were treated with a median of 4 cycles (range, 2-9 cycles). Nasal location was the only risk factor identified for nonresponse to therapy (P = 0.04). The median follow-up after resolution was 10 months (range, 2-77 months). In the 36 patients who showed complete resolution, 4 experienced tumor recurrence. Recurrence rates at 1 and 2 years were 6% and 15%, respectively, using Kaplan-Meier survival analysis. At least 1 side effect from the medication was reported by 61% of patients (21/44), but only 1 patient discontinued the medication because of intolerance. The most common side effect was pain (n = 17; 39%), followed by tearing (n = 10; 23%), photophobia (n = 6; 14%), itching (n = 4; 9%), swelling (n = 2; 5%), and infection (n = 1; 2%). No long-term complications were reported. CONCLUSIONS: 5-Fluorouracil is effective and well tolerated as a primary treatment for OSSN, with 82% of tumors responding completely to therapy.

Epidemiology of Meibomian Gland Dysfunction in an Elderly Population.

PURPOSE: To study the epidemiology of meibomian gland (MG) dysfunction in an elderly, predominantly male population. METHODS: Prospective study of 233 subjects seen in the Miami Veterans Affairs eye clinic. Patients underwent a complete ocular surface examination, including dry eye questionnaires and tear assessments (osmolarity, tear breakup time, corneal staining, Schirmer test). The main outcome measures were correlations between MG parameters and demographics, dry eye symptoms, and tear parameters. The studied MG parameters were eyelid vascularity and meibum quality; a score ≥2 for either parameter was considered abnormal. RESULTS: Mean age of the 233 subjects was 63 years (SD = 11); 91% were male and 59% had at least 1 abnormal MG parameter (abnormal quality 55%; vascularity 17%). Demographically, patients with abnormal MG parameters were significantly older than their counterparts without these findings. Whites were more likely to have abnormal eyelid vascularity compared with blacks [n = 36 (31%) vs. n = 1 (1%), P < 0.0005] but no differences were noted between races with respect to meibum quality. Abnormal meibum quality, but not abnormal vascularity, was significantly associated with more severe dry eye symptoms. Similarly, abnormal meibum quality, but not eyelid vascularity, was significantly associated with worse dry eye signs, including decreased tear breakup time and increased corneal staining (P < 0.05 for all). CONCLUSIONS: MG dysfunction is a frequent finding in an elderly, predominantly male population with racial differences noted in the frequency of abnormal eyelid vascularity but not in MG quality. Abnormal meibum quality was significantly associated with more severe dry eye symptoms and signs.