Studies using a viral challenge and CD8 T cell depletions on the roles of cellular and humoral immunity in the control of an SHIV-89.6P challenge in DNA/MVA-vaccinated macaques

Here, we study immune responses in four DNA/MVA-vaccinated macaques following an SHIV-89.6P challenge and a subsequent CD8 cell depletion. Both post-challenge and post-depletion peaks of viremia contracted with the expansion, or re-emergence, of CD8 T cells. Post-depletion, CD8 cells expanded in the presence of higher levels of neutralizing Ab and CD4 help than post-challenge and had superior maturational characteristics as measured by expression of the anti-apoptotic protein Bcl-2, the IL-7 receptor CD127 and co-production of IFN-gamma and IL-2. Pre-challenge and pre-depletion titers of neutralizing Ab correlated inversely with peaks of viremia and directly with peaks for anti-viral CD4 cells. Thus, our results reveal CD8 cells playing a central role, and neutralizing Ab, a supporting role in SHIV-89.6P control. They also suggest a dynamic relationship between neutralizing Ab, antigen load and anti-viral CD4 cells in the maturation of high-quality anti-viral CD8 T cells.     

Diffuse bipolar cells provide input to OFF parasol ganglion cells in the macaque retina

Parasol retinal ganglion cells are more sensitive to luminance contrast and respond more transiently at all levels of adaptation than midget ganglion cells. This may be due, in part, to differences between bipolar cells that provide their input, and the goal of these experiments was to study these differences. Midget bipolar cells are known to be presynaptic to midget ganglion cells. To identify the bipolar cells presynaptic to parasol cells, these ganglion cells were intracellularly injected with Neurobiotin, cone bipolar cells were immunolabeled, and the double-labeled material was analyzed. In the electron microscope, we found that DB3 diffuse bipolar cells labeled by using antiserum to calbindin D-28k were presynaptic to OFF parasol cells. In the confocal microscope, DB3 bipolars costratified with OFF parasol cell dendrites and made significantly more appositions with them than expected due to chance. Flat midget bipolar cells were labeled with antiserum to recoverin. Although they made a few appositions with parasol cells, the number was no greater than would be expected when two sets of processes have overlapping distributions in the inner plexiform layer. DB2 diffuse bipolar cells were labeled with antibodies to excitatory amino acid transporter 2, and they also made appositions with OFF parasol cells. These results suggest that DB2 bipolar cells are also presynaptic to OFF parasol ganglion cells, but midget bipolar cells are not. We estimate that midperipheral OFF parasol cells receive approximately 500 synapses from 50 DB3 bipolar cells that, in turn, receive input from 250 cones.     

Familial Monosomy 7 Syndrome Associated with Myelodysplasia

Indian Journal of Pediatrics -     

The role of Tenonplasty in the management of limbal and scleral ischemia due to acute ocular chemical burns

Of the various manifestations of ocular chemical burns (OCBs), ischemia of the limbus and the peri-limbal sclera indicates poor prognosis and in severe cases threaten the integrity of the globe. Tenonplasty is a surgical procedure which involves advancing the Tenon’s capsule over the ischemic areas to provide a vascular supply and to enable migration of the conjunctival epithelium. This review aims to provide an overview of the diagnosis of limbal ischemia and its management with Tenonplasty. A literature review was conducted using the keywords “Tenonplasty,” “Tenon’s capsule,” “ocular chemical injury,” “ocular thermal injury,” “Tenon advancement,” “scleral ischemia,” and “limbal ischemia,” and outcomes were studied from seven selected articles. In addition to clinical evaluation, in vivo imaging techniques such as anterior segment optical coherence tomography angiography can provide an objective method of measuring and monitoring the ischemia and re-perfusion of the peri-limbal vasculature. Tenonplasty can be performed in eyes with acute OCBs with scleral or limbal ischemia by dissecting the Tenon’s layer from the orbit and securing it to the limbus. The indications, mechanism of action, peri-operative considerations, surgical technique, and post-operative care of Tenonplasty are discussed in detail. The average time for post-operative re-epithelization ranges from 1 to 6 months with the formation of a symblepharon being the most common complication. In conclusion, Tenonplasty is a globe-salvaging procedure in cases with severe limbal and scleral ischemia because of OCBs and has good anatomical outcomes priming the globe for subsequent re-constructive and vision-restoring surgeries.     

A comparative analysis of surgical outcome in uveitic and non-uveitic steroid–induced glaucoma in children

Purpose:To compare outcomes of surgical management of uveitic glaucoma (UG) and steroid-induced glaucoma (SIG) in children in terms of intraocular pressure (IOP) control, visual acuity, and associations for failure.Methods:This was a retrospective case–control study of consecutive UG (cases) and non-uveitic SIG (controls) in children <18 years of age who underwent surgery between January 2005 and December 2017.Results:Primary trabeculectomy with mitomycin C (MMC) was performed in 12 cases (mean age: 9.2 ± 4.3 years) and 40 controls (mean age: 10.4 ± 3.7 years) (P = 0.33). Primary phaco-trabeculectomy with MMC was performed in 11 cases (mean age: 11.4 ± 4.7 years) and 16 controls (mean age: 10.4 ± 3.4 years) (P = 0.57). IOP control (P = 0.26), visual acuity (P = 0.97), number of glaucoma medications (P = 0.06), and survival rates (49% cases vs. 68% controls at 5 years; P = 0.22) were similar between the two groups following trabeculectomy. Survival rates in the phaco-trabeculectomy group at 5 years were 68% cases vs. 69% controls (P = 0.71). IOP was higher (P = 0.008) and visual acuity was worse (P = 0.02) in cases at the last visit. Associations for failure (univariate analysis) were younger age (OR: 6.29, 95% CL: 1.43, 27.67; P = 0.03) and male gender (OR: 4.79, 95% CL: 1.09, 20.97; P = 0.04). On multivariate analysis, younger age (OR: 11.985, 95% CL: 1.071, 134.153; P = 0.04) remained significant. Preoperative number of uveitic attacks was protective on univariate (OR: 0.75, 95% CL: 0.48, 1.15; P = 0.1) and multivariate analyses (OR: 0.49, 95% CL: 0.24, 0.09; P = 0.04).Conclusion:Outcomes of trabeculectomy between cases and controls were similar in our series. However, phaco-trabeculectomy in pediatric uveitic eye group fared worse than eyes with SIG.     

Comparison of breath-guards and face-masks on droplet spread in eye clinics

IntroductionCOVID-19 has impacted ophthalmic care delivery, with many units closed and several ophthalmologists catching COVID-19. Understanding droplet spread in clinical and training settings is paramount in maintaining productivity, while keeping patients and practitioners safe.ObjectivesWe aimed to assess the effectiveness of a breath-guard and a face mask in reducing droplet spread within an eye clinic.MethodsWe performed a randomised trial of droplet spread using a fluorescein-based cough model to assess the efficacy of a ‘breath-guard’ and ‘face-mask’ to prevent the spread of droplets. The ‘cough’ spray was collected on calibrated paper targets. The sheets were photographed under blue light, with an orange filter on the camera; the position and size of the spots was measured with software originally developed for astronomy.We performed 44 randomised coughs; 22 controls with no breath-guard or face-mask, 11 using breath-guard only and 11 with combined breath-guard and face-mask. We compared both the number of droplets detected and the area of drops on paper targets.ResultsThe average number of droplets in the controls was 19,430 (SE 2691), the breath-guard group 80 (SE 19) droplets (P < 0.001); in the combined In the group the count was 5 (SE 2), a significant drop from shield only (P = 0.008). The mean areas of each target covered by spots for each group were 5.7 ± 0.857% (95% CI), 0.004 ± 0.000104% (95% CI) and 0.001 ± 0.0000627% (95% CI) respectively.ConclusionThese results show that the breath-guard alone reduced the droplet count by 99.93%. Combining the breath-guard with a face-mask reduced the droplet count by over 99.98%. Breath-guards are widely used in clinics and this trial demonstrates that breath-guards with face-masks effectively block droplet spray.Subject terms: Risk factors, Microbiology     

Growth differences by school-age and adolescence according to in utero and peripartum antiretroviral therapy exposure among Ugandan children

In utero/peripartum antiretroviral (IPA) drug exposure in human immunodeficiency virus (HIV)-exposed children has established benefit for prevention of HIV mother-to-child-transmission but its association with height-for-age by adolescence is unknown. Hence we quantify IPA-associated growth differences at 6 to 18 years old among children with perinatally acquired HIV (CPHIV) infection and children HIV exposed but uninfected (CHEU) relative to children HIV unexposed and uninfected (CHUU). Cohort study. Kampala, Uganda. Two hundred thirty eight community controls and 490 children of women living with HIV born between 2000 and 2011 in a community were enrolled at 6 to 18 years of age and followed every 6 months for 1 year. Height-for-age determined at enrollment, 6 and 12 months after enrollment using the World Health Organization reference. IPA exposure was retrospectively determined from medical records and categorized as: no IPA, single-dose nevirapine with/without zidovudine (sdNVP ± AZT), sdNVP + AZT + lamivudine, or combination antiretroviral therapy (cART). Mean differences (β) with 95% confidence intervals (CIs) in height-for-age over 12 months were evaluated according to IPA exposure for CPHIV and CHEU and relative to CHUU using longitudinal linear mixed effects models adjusted for caregiver factors (sex, age, education, functioning in caregiving role, and lifetime adversity) in Statistical Analysis Software (v.9.4). Regardless of IPA type, CPHIV grew worse than CHUU by school-age/adolescence (β = −0.30, 95% CI: −0.48, −0.11). Relative to CHUU height-for-age was similar for CHEU exposed to sdNVP ± AZT (β = −0.16, 95% CI: −0.46, 0.14) and for CHEU exposed to sdNVP + AZT + lamivudine (β = 0.08, 95% CI: −0.20, 0.35). However, CHEU without any IPA exposure had lower height-for-age (β = −0.27, 95% CI: −0.52, −0.00) whereas CHEU with cART exposure had greater height-for-age (β = 0.41, 95% CI: 0.10, 0.71) in comparison with CHUU by 6 to 18 years old. Our findings suggest that CHEU may achieve height-for-age parity with CHUU by school-age and adolescent years- especially if provided benefit of effective cART in the peripartum period. However, CPHIV regardless of IPA exposure type and CHEU without IPA exposure remain at a disadvantage and will benefit from intervention to support their growth.