Internal limiting membrane peeling in macular hole surgery.

Since the era when macular hole was considered untreatable, macular hole surgery has come a long way to being one of the most successful surgeries. Internal limiting membrane (ILM) peeling has been an essential step of macular hole surgery since the establishment of the role of ILM in the aetiopathogenesis and progression of macular hole. However, the novel technique was not all virtuous. It had some vices which were not evident immediately. With the advent of spectral domain optical coherence tomography, short- and long-term effects of ILM peeling on macular structures were known; and with microperimetry, its effect on the function of macula could be evaluated. The technique has evolved with time from total peeling to inverted flap to just temporal peeling and temporal flap in an attempt to mitigate its adverse effects and to improve its surgical outcome. ILM abrasion technique and Ocriplasmin may eliminate the need of ILM peeling in selected cases, but they have their own limitations. We here discuss the role of ILM in the pathogenesis of macular hole, the benefits and adverse effects of ILM peeling, and the various modifications of the procedure, to then explore the alternatives.

Comparison of Hematological and Biochemical Parameters of SARS-CoV-2-Positive and -Negative Neonates of COVID-19 Mothers in a COVID-19 Hospital, Odisha State.

Introduction Data are scarce on the hematological and biochemical changes caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in neonates. This study aimed to compare hematological and biochemical parameters in SARS-CoV-2-positive neonates with healthy neonates born to mothers diagnosed with coronavirus disease 2019 (COVID-19) and assess disease severity in both groups. Methodology  This prospective observational study was conducted at a COVID-19 hospital at Kalinga Institute of Medical Sciences, Bhubaneswar, Odisha, India, from May 1 to November 30, 2020. Forty-eight babies, including 39 inborn and nine outborn, were enrolled in the study after their parents provided written informed consent. Neonates were diagnosed with COVID-19 via nasopharyngeal real-time reverse transcription-polymerase chain reaction testing. The hematological and biochemical parameters of these 48 neonates were recorded and analyzed. Results  SARS-CoV-2-infected neonates had lower hemoglobin, neutrophil to lymphocyte ratio, total white blood cell count, and absolute neutrophil count compared to noninfected babies (p<0.05). All SARS-CoV-2-infected neonates had serum transaminase levels and renal function tests within reference ranges. We saw no significant differences in hematological and biochemical parameters among asymptomatic SARS-CoV-2-infected and noninfected neonates.  Conclusions Hematological and biochemical parameters between asymptomatic SARS-CoV-2-infected and non-infected neonates were similar. The blood count abnormalities found in SARS-CoV-2-infected neonates could be due to other associated neonatal comorbidities. According to our results, asymptomatic SARS-CoV-2-infected newborns need close monitoring rather than a battery of investigation.

Prevalence of Allergic Sensitization in Childhood Asthma.

Introduction The allergic sensitization in childhood asthma is common and the prevalence varies in different geographical locations. The data on allergen sensitization to guide clinicians on allergy avoidance is limited. Method This prospective observational study was conducted between October 2019 and April 2020 on children aged two to 14 years attending an outpatient clinic. Those with recurrent wheezing or physician-diagnosed asthma were interviewed; eosinophil count, total serum immunoglobulin E (IgE) was measured; and skin prick test (SPT) was done using standardized reagents. Wheal size of ≥3mm was considered positive. Results A total of 80 children were enrolled. The mean age was 71.15 ± 33.52 months (M:F ratio =1.96:1). Allergic rhinitis, conjunctivitis, and dermatosis were seen in 76 (95.0%), 33 (41.3%), and 22 (27.5%) cases, respectively. The mean absolute eosinophil count was 576 ± 427per cmm. The mean total IgE was 800.9 ± 883.2IU/ml. Seasonal and diurnal variations were found in 34 (42.5%) and 79 (98.8%) cases. Out of 1753 skin pricks using 27 reagents, 355 (20.25%) were positive. Increasing age was significantly associated with increasing SPT positivity (P = 0.0001). The most common sensitive aeroallergens were Kentucky bluegrass (25%), Dermatophagoides pteronyssinus (22.5%), Dermatophagoides farinae (21.3%), Timothy grass, and Alternaria alternans (20% each). The most common sensitive food allergens were spinach (25%), banana (22.5%), carp (20%), shrimp and hen's egg (18.8% each), and cow's milk (17.5%). Conclusion Increasing age was associated with increasing SPT positivity in childhood asthma. The most common sensitive aeroallergens were Kentucky bluegrass and Dermatophagoides pteronyssinus; spinach and banana were the most common food allergen.

An exploration of the variability of physiological responses to soil drying in relation with C/N balance across three species of the under-utilized genus Vigna.

The genus Vigna (Fabaceae) is an agriculturally important taxon, which includes several crop species such as cowpea (Vigna unguiculata L.), mung bean (Vigna radiata) and azuki bean (Vigna angularis). Most studies have focused on cowpea (V. unguiculata (L.) as a drought-resistant crop, although insights on the mechanisms that confer this species the ability to grow in dry environment are still not fully resolved. The diversity of this rich genus has been overlooked in many physiological studies. This study explores the physiological mechanisms of response to soil drying (N2 fixation, transpiration rate and changes in C and N allocation) across three species of the Vigna genus: V. radiata, V. unguiculata, V. vexillata (tuber cowpea). A significant variability among the studied Vigna accessions was found for the threshold in decline of N2 fixation with soil drying. Less variability was observed in the transpiration threshold. Through the analysis of leaf traits variation under well-watered and water-deficit conditions, we were able to relate the variability in N2 fixation and transpiration response to C/N metabolism modifications resulting in different allocation of carbon and nitrogen to leaves under water deficit.

Microsphere stem blockage as a screen for nitrogen-fixation drought tolerance in soybean.

Symbiotic nitrogen-fixation of soybean (Glycine max [Merr.] L) commonly decreases in response to soil drying in advance of other plant processes. While a few soybean lines express nitrogen-fixation drought tolerance, breeding for genetic variation is hampered by laborious phenotyping procedures. The objective of this research was to explore the potential of an initial screen for nitrogen-fixation drought-tolerant genotypes based on a possible relationship with xylem-vessel diameter. The hypothesis was that nitrogen-fixation drought tolerance might result from fewer, large-diameter xylem vessels in the stem that are vulnerable to disrupted flow as water deficit develops. The disrupted flow could cause nitrogen products to accumulate in nodules resulting in negative feedback on nitrogen-fixation rate. The proposed screen involved exposing de-rooted shoots to a suspension containing microspheres (45-53 µm diameter) and recording the decrease in transpiration rate as a result of microsphere xylem-blockage. Two soybean populations were tested. One population was progeny derived from mating of two parents with high and low nitrogen-fixation drought sensitivity. A high correlation (R2  = 0.68; P < 0.001) was found in this population between decreasing transpiration rate resulting from the microsphere treatment and increasing sensitivity of nitrogen-fixation to soil drying. The second tested population consisted of 16 genotypes, most of which had been previously identified in germplasm screens as expressing nitrogen-fixation drought tolerance. Nearly half of the lines in this second population were identified in the screen as showing minimum blockage of transpiration when exposed to the microspheres. Overall, these results showed the potential of using the microsphere screen to identify candidate genotypes expressing nitrogen-fixation drought tolerance.

Inverted temporal internal limiting membrane flap technique for chronic large traumatic macular hole.

Various modifications of surgical techniques and surgical adjuncts are adopted with standard pars plana vitrectomy (PPV) to improve the outcome of traumatic macular hole (TMH) surgeries. We describe a successful closure of a chronic large TMH of three years duration with inverted temporal internal limiting membrane (ILM) flap technique. A 36-year-old male patient had an optical coherence tomography (OCT) documented chronic macular hole (MH) for three years following blunt trauma. Fundus examination also showed choroidal rupture scar temporal to fovea. The minimum MH diameter was 769 µ and the basal diameter 1431 µ in OCT. Standard PPV with inverted temporal ILM flap and gas tamponade was done. The postoperative period was uneventful. The best corrected visual acuity improved from 6/60 preoperatively to 6/18 six months postoperatively, and OCT showed a closed MH with anatomical type 1 closure. This case highlights that the inverted temporal ILM flap technique is a safe and effective technique for patients with even chronic and large TMH.

Variable presentation of diabetic papillopathy and treatment dilemma- A case series.

INTRODUCTION: Diabetic papillopathy (DP) is a diagnosis of exclusion in type 1 and type 2 diabetics with transient disc edema. It was initially described in young patients with type1 diabetes mellitus (DM) as a bilateral disease with minimal visual symptoms which resolved spontaneously. Lately, DP has been a focus of controversy because of its wide clinical spectrum. CASES: We describe three variable cases of DP. These are unilateral DP with Proliferative Diabetic Retinopathy (PDR) with macular edema (ME), unilateral DP with severe Non Proliferative Diabetic Retinopathy (NPDR) with ischemic maculopathy and a case of bilateral DP with Moderate NPDR with ME. We also discuss viable treatment for the variable presentation. DP has been reported in this case series in moderate NPDR, severe NPDR as well as PDR. Macular involvement in the form of macular edema as well as ischemia has been demonstrated to result in diminution of vision. It shows both unilateral and bilateral presentation. Remarkable visual loss seen, in these cases, call for intervention. CONCLUSIONS: DP has a wide spectrum of presentation and its knowledge is eminent to make a complete diagnosis. Individualisation of treatment has to be done for variable presentation and realistic outcomes should be explained to the patients.

Intraoperative Ocular Decompression Retinopathy During 23 Gauge Transconjunctival Vitrectomy: A Case Report.

PURPOSE: To report an uncommon case of intraoperative ocular decompression retinopathy (ODR). CASE REPORT: A 48-year-old man presented with decreased vision and pain in the left eye (LE) for 10 days following trauma with a bamboo stick. He had visual acuity of counting finger close to face in the same eye, along with corneal edema, dilated pupil and posteriorly dislocated lens. Intraocular pressure (IOP) was 42 mm of mercury (Hg). He underwent 23-gauge pars plana vitrectomy with removal of the dislocated lens. Towards the end of otherwise uneventful surgery, blot hemorrhages appeared over the posterior pole and equator. The following day, his vision was counting finger close to face and IOP was 16 mm of Hg. Fundus examination revealed large blotches of hemorrhages at different levels of the retina, later confirmed by optical coherence tomography. Disc hyperfluorescence and blocked fluorescence corresponding to blot hemorrhages were seen on fundus fluorescein angiography. Blood investigations to rule out blood dyscrasias were within normal limits. CONCLUSION: Ocular decompression retinopathy, though not common, has been reported to occur following various types of surgeries, especially if associated with preoperatively raised IOP. The event can also occur intraoperatively and the preoperative control of IOP is of paramount importance in the prevention of ODR.

An Encounter with a Worm in Anterior Chamber: A Case Report.

BACKGROUND: Several parasites are known to affect the eyes, some of them even causing blindness. Data on helminths infecting the eye are scant and mostly limited to case reports from different countries. CASE: A 53 years old female presented with complaint of redness, foreign body sensation and diminution of vision in right eye since one month. OBSERVATIONS: On examination a live motile worm was found wriggling in the anterior chamber which was surgically removed. The microscopic findings were in favour of Dirofilaria. However, detailed histopathological examination and determination of species couldn't be done. CONCLUSION: The occurrence of parasite in eye is an uncommon event. Most of these parasites are found in subconjunctival or subretinal regions. Those in anterior chamber is a very rare event. Recently Dirofilaria is being recognised as an emerging zoonosis.

Dynamic regulation of CD45 lateral mobility by the spectrin-ankyrin cytoskeleton of T cells.

The leukocyte common antigen, CD45, is a critical immune regulator whose activity is modulated by cytoskeletal interactions. Components of the spectrin-ankyrin cytoskeleton have been implicated in the trafficking and signaling of CD45. We have examined the lateral mobility of CD45 in resting and activated T lymphocytes using single-particle tracking and found that the receptor has decreased mobility caused by increased cytoskeletal contacts in activated cells. Experiments with cells that have disrupted betaI spectrin interactions show decreased cytoskeletal contacts in resting cells and attenuation of receptor immobilization in activated cells. Applying two types of population analyses to single-particle tracking trajectories, we find good agreement between the diffusion coefficients obtained using either a mean squared displacement analysis or a hidden Markov model analysis. Hidden Markov model analysis also reveals the rate of association and dissociation of CD45-cytoskeleton contacts, demonstrating the importance of this analysis for measuring cytoskeleton binding events in live cells. Our findings are consistent with a model in which multiple cytoskeletal contacts, including those with spectrin and ankyrin, participate in the regulation of CD45 lateral mobility. These interactions are a major factor in CD45 immobilization in activated cells. Furthermore, cellular activation leads to CD45 immobilization by reduction of the CD45-cytoskeleton dissociation rate. Short peptides that mimic spectrin repeat domains alter the association rate of CD45 to the cytoskeleton and cause an apparent decrease in dissociation rates. We propose a model for CD45-cytoskeleton interactions and conclude that the spectrin-ankyrin-actin network is an essential determinant of immunoreceptor mobility.

Sequential degradation of alphaII and betaII spectrin by calpain in glutamate or maitotoxin-stimulated cells.

Calpain-catalyzed proteolysis of II-spectrin is a regulated event associated with neuronal long-term potentiation, platelet and leukocyte activation, and other processes. Calpain proteolysis is also linked to apoptotic and nonapoptotic cell death following excessive glutamate exposure, hypoxia, HIV-gp120/160 exposure, or toxic injury. The molecular basis for these divergent consequences of calpain action, and their relationship to spectrin proteolysis, is unclear. Calpain preferentially cleaves II spectrin in vitro in repeat 11 between residues Y1176 and G1177. Unless stimulated by Ca++ and calmodulin (CaM), betaII spectrin proteolysis in vitro is much slower. We identify additional unrecognized sites in spectrin targeted by calpain in vitro and in vivo. Bound CaM induces a second II spectrin cleavage at G1230*S1231. BetaII spectrin is cleaved at four sites. One cleavage only occurs in the absence of CaM at high enzyme-to-substrate ratios near the betaII spectrin COOH-terminus. CaM promotes II spectrin cleavages at Q1440*S1441, S1447*Q1448, and L1482*A1483. These sites are also cleaved in the absence of CaM in recombinant II spectrin fusion peptides, indicating that they are probably shielded in the spectrin heterotetramer and become exposed only after CaM binds alphaII spectrin. Using epitope-specific antibodies prepared to the calpain cleavage sites in both alphaII and betaII spectrin, we find in cultured rat cortical neurons that brief glutamate exposure (a physiologic ligand) rapidly stimulates alphaII spectrin cleavage only at Y1176*G1177, while II spectrin remains intact. In cultured SH-SY5Y cells that lack an NMDA receptor, glutamate is without effect. Conversely, when stimulated by calcium influx (via maitotoxin), there is rapid and sequential cleavage of alphaII and then betaII spectrin, coinciding with the onset of nonapoptotic cell death. These results identify (i) novel calpain target sites in both alphaII and betaII spectrin; (ii) trans-regulation of proteolytic susceptibility between the spectrin subunits in vivo; and (iii) the preferential cleavage of alphaII spectrin vs betaII spectrin when responsive cells are stimulated by engagement of the NMDA receptor. We postulate that calpain proteolysis of spectrin can activate two physiologically distinct responses: one that enhances skeletal plasticity without destroying the spectrin-actin skeleton, characterized by preservation of betaII spectrin; or an alternative response closely correlated with nonapoptotic cell death and characterized by proteolysis of betaII spectrin and complete dissolution of the spectrin skeleton.

Antiviral peptides targeting the west nile virus envelope protein.

West Nile virus (WNV) can cause fatal murine and human encephalitis. The viral envelope protein interacts with host cells. A murine brain cDNA phage display library was therefore probed with WNV envelope protein, resulting in the identification of several adherent peptides. Of these, peptide 1 prevented WNV infection in vitro with a 50% inhibition concentration of 67 muM and also inhibited infection of a related flavivirus, dengue virus. Peptide 9, a derivative of peptide 1, was a particularly potent inhibitor of WNV in vitro, with a 50% inhibition concentration of 2.6 muM. Moreover, mice challenged with WNV that had been incubated with peptide 9 had reduced viremia and fatality compared with control animals. Peptide 9 penetrated the murine blood-brain barrier and was found in the brain parenchyma, implying that it may have antiviral activity in the central nervous system. These short peptides serve as the basis for developing new therapeutics for West Nile encephalitis and, potentially, other flaviviruses.

TROSPA, an Ixodes scapularis receptor for Borrelia burgdorferi.

The Lyme disease agent Borrelia burgdorferi naturally persists in a cycle that primarily involves ticks and mammals. We have now identified a tick receptor (TROSPA) that is required for spirochetal colonization of Ixodes scapularis. B. burgdorferi outer surface protein A, which is abundantly expressed on spirochetes within the arthropod and essential for pathogen adherence to the vector, specifically bound to TROSPA. TROSPA mRNA levels in ticks increased following spirochete infestation and decreased in response to engorgement, events that are temporally linked to B. burgdorferi entry into and egress from the vector. The blockade of TROSPA by TROSPA antisera or by the repression of TROSPA expression via RNA interference reduced B. burgdorferi adherence to the I. scapularis gut in vivo, thereby preventing efficient colonization of the vector and subsequently reducing pathogen transmission to the mammalian host. Identification of an I. scapularis receptor for B. burgdorferi is the first step toward elucidating arthropod ligands that are required for survival of spirochetes in nature.

Antibodies to betaISigma2 spectrin identify in-homogeneities in the erythrocyte membrane skeleton.

The cortical cytoskeleton of the mammalian red cell, composed of spectrin, actin, protein 4.1, adducin, and protein 4.9, is generally regarded as a homogeneous structure that maintains the integrity of the membrane and the lateral disposition of integral membrane proteins. The major component of this structure is a hetero-oligomer of alphaI and betaISigma1 spectrin. In other tissues, most notably muscle and brain, a transcript of the betaI spectrin gene is generated by alternative exon utilization, yielding a protein that has the COOH-terminal 19 residues of betaISigma1 spectrin replaced by 210 novel residues to generate betaISigma2 spectrin. This new transcript contains a pleckstrin homology (PH) domain and may even exist under some conditions in a homopolymeric form. Using antibodies specific for the COOH-terminal domains of either betaISigma1 or betaISigma2 spectrin, we find that contrary to previous understandings, mature human erythrocytes contain a subpopulation of spectrin that is immunoreactive with antibodies to the betaISigma2 isoform, and that this spectrin is distributed into distinct plasma membrane patches. These results suggest that the native mammalian erythrocyte membrane skeleton, rather than being homogeneous, contains discrete submicron-scale microdomains that differ in both their composition and dispersion across the cell surface. The precise nature and role of these putative microdomains is under active investigation.

Regulation of survivin function by Hsp90.

Pathways controlling cell proliferation and cell survival require flexible adaptation to environmental stresses. These mechanisms are frequently exploited in cancer, allowing tumor cells to thrive in unfavorable milieus. Here, we show that Hsp90, a molecular chaperone that is central to the cellular stress response, associates with survivin, an apoptosis inhibitor and essential regulator of mitosis. This interaction involves the ATPase domain of Hsp90 and the survivin baculovirus inhibitor of apoptosis repeat. Global suppression of the Hsp90 chaperone function or targeted Abmediated disruption of the survivin-Hsp90 complex results in proteasomal degradation of survivin, mitochondrial-dependent apoptosis, and cell cycle arrest with mitotic defects. These data link the cellular stress response to an antiapoptotic and mitotic checkpoint maintained by survivin. Targeting the survivin-Hsp90 complex may provide a rational approach for cancer therapy.