Differences in Physical and Biochemical Properties of Thermus scotoductus SA-01 Cultured with Dielectric or Convection Heating.

A thermophile, Thermus scotoductus SA-01, was cultured within a constant-temperature (65°C) microwave (MW) digester to determine if MW-specific effects influenced the growth and physiology of the organism. As a control, T. scotoductus cells were also cultured using convection heating at the same temperature as the MW studies. Cell growth was analyzed by optical density (OD) measurements, and cell morphologies were characterized using electron microscopy imaging (scanning electron microscopy [SEM] and transmission electron microscopy [TEM]), dynamic light scattering (DLS), and atomic force microscopy (AFM). Biophysical properties (i.e., turgor pressure) were also calculated with AFM, and biochemical compositions (i.e., proteins, nucleic acids, fatty acids) were analyzed by attenuated total reflectance-Fourier transform infrared (ATR-FTIR) spectroscopy. Gas chromatography-mass spectrometry (GC-MS) was used to analyze the fatty acid methyl esters extracted from cell membranes. Here we report successful cultivation of a thermophile with only dielectric heating. Under the MW conditions for growth, cell walls remained intact and there were no indications of membrane damage or cell leakage. Results from these studies also demonstrated that T. scotoductus cells grown with MW heating exhibited accelerated growth rates in addition to altered cell morphologies and biochemical compositions compared with oven-grown cells.

Evaluation of proliferating cell abundance and phenotypes in proliferative diabetic retinopathy.

BACKGROUND: The aim of this work is to evaluate the abundance, origins, and phenotypes of actively proliferating cells in proliferative diabetic retinopathy (PDR). METHODS: Eleven epiretinal membranes from patients undergoing surgery for PDR were evaluated by indirect immunofluorescence for evidence of cell proliferation using the nuclear cell proliferation marker Ki67 and for cell identities using glial fibrillary acidic protein (GFAP), glutamine synthetase, and α-smooth muscle actin (αSMA). RESULTS: Ki67 positivity was consistently rare in PDR epiretinal membranes at 3.02 ± 1.42 % of the total cell population. The majority of the Ki67-positive cells were also positive for GFAP (74.0 %) with lower proportions positive for αSMA (30.7 %) and glutamine synthetase (1.5 %). Co-localization studies using glial and myoid markers revealed that virtually all (92 %) of the αSMA-positive cells are also GFAP positive and thus derive from glia. CONCLUSIONS: Entry into cell cycle and thus cell proliferation appears to be a rare phenomenon in PDR involving only a small percentage of the total cell population. Glia and/or glial-derived myofibroblasts appear to be the predominate cell types in epiretinal scar tissues and also account for the majority of the actively proliferating cells.

Floater Stories: Assessing the Potential Benefits of Vitrectomy.

Symptomatic vitreous opacities (SVO, "floaters") in the mobile, aging vitreous that substantially interfere with daily visual activities (DVA) constitute degenerative vitreous syndrome (DVS). DVS is best distinguished from common "nuisance" floaters by use of "floater stories" written by presenting patients describing their symptoms. Here I discuss why vitreous opacity vitrectomy, though curative, has been adopted only belatedly and is still controversial, and I describe my long-term experience with its use for this disease.

Horse to human: Streptococcus equi septicemia presenting as endogenous endophthalmitis.

Purpose: To present a rarely reported systemic infection with streptococcus equi subspecies zooepidemicus (streptococcus equi), transmitted from a horse, and to describe successful treatment when complicated by endogenous endophthalmitis. Observations: We diagnosed suspected streptococcus equi septicemia presenting as loss of vision in the right eye of an otherwise healthy polo player/horse trainer. He received immediate intravenous antibiotics and three vitrectomies with two intravitreal antibiotic injections during the first week, to cure infection and subsequent retinal detachment. Blood and initial vitreous cultures rapidly grew streptococcus equi. The septicemia was quickly controlled by systemic antibiotics without developing commonly seen and often fatal meningitis. The right eye recovered 20/30 visual acuity three months post infection. Conclusions: Presentation of this rare septicemia as endogenous endophthalmitis illustrates the potentially lifesaving role of early diagnosis by the ophthalmologist. Immediate and recurrent vitrectomy in conjunction with intravitreal and systemic antibiotic therapy resulted in recovery of near normal vision, whereas less timely and interventional treatments have failed heretofore.

Preventing Retinal Detachment: The Encircling Laser Retinopexy Technique.

Encircling (360 degree) retinal detachment prophylaxis using indirect ophthalmoscope laser delivery recently achieved strong proof of safety and effectiveness by preventing the development of peripheral retinal tears and detachments in the eyes of patients with Stickler syndrome (syndromic eyes). Untreated, Stickler syndrome patients have a 65% lifetime risk of retinal detachment (half by age 20, 80% bilateral). This report describes an optimal technique of encircling laser retinopexy to also prevent the more common retinal detachments seen in aging (non-syndromic) eyes that share with Stickler syndrome the common pathogenesis of peripheral retinal tears caused by vitreous traction.

Vitreous Opacity Vitrectomy (VOV): Safest Possible Removal of "Floaters".

Purpose: Primary opacities that develop in the aging vitreous, commonly termed "floaters," were once considered merely a nuisance, not justifying any risk of surgical removal. However, vitreoretinal specialists are increasingly recognizing that extensive symptomatic vitreous opacities (SVO) that substantially interfere with activities that critically depend on vision (daily visual activities, DVA), constituting degenerative vitreous syndrome (DVS, see http://floaterstories.com), warrant removal albeit with minimal risk - but no description of how to reduce vitrectomy risks to least possible has been forthcoming. We here describe such a method. Patients and Methods: The safest possible removal of extensive SVO as described herein was attained by an operation specifically designed for DVS treatment (vitreous opacity vitrectomy, VOV), rather than as only a means of achieving subsequent retinal surgery in the same procedure, as is usually the case. We retrospectively reviewed the outcomes of 100 consecutive VOV operations (in 81 patients, average age 66) performed with ultra-high speed, 27-gauge vitrectomy probes. Results: All eyes rapidly achieved continuously clear vision, and no eye developed a clinically significant complication during a year of follow-up. Three small, existent retinal breaks were discovered prior to peripheral vitrectomy and one apparently iatrogenic retinal tear was found at VOV completion, when each was treated. In the eyes that were not pseudophakic, postoperative nuclear sclerosis progression was successfully managed by subsequent cataract extraction. Conclusion: The goals of VOV for DVS are to safely restore continuously clear vision by performing tractionless vitreous removal with respect to the retina and to reduce the lifetime risk of retinal detachment, both by such vitreous removal and by microscopic examination of the peripheral retina under anesthesia (MEPRUA), guiding appropriate prophylactic retinopexy. The otherwise healthy DVS eyes so treated warrant this specific form of vitrectomy, continually focused on achieving least possible risk, to maintain an acceptable risk/benefit ratio.

Preventing Retinal Detachment: Where are We? Implications from Stickler Syndrome.

Stickler syndrome, a rare inherited disease, carries a lifetime risk of rhegmatogenous retinal detachment (RRD) of up to 65%, higher than any other predisposing condition known. Both syndromic and non-syndromic eyes suffer RRD predominately from the same pathogenesis, vitreous tractional tears in the peripheral retina. Consequently, extraordinary publications in 2021-2022, each reporting successful prevention of RRD in Stickler syndrome, using 360-degree (encircling) laser retinopexy, provide the first strong evidence upon which similar prophylaxis in non-syndromic eyes at high risk of RRD from peripheral retinal tears can confidently go forward.

Complete and early vitrectomy for endophthalmitis.

We recently co-authored a report on the ten-year (2007-2017) results achieved at our center (Retina Specialists of Alabama) in the treatment of Acute Post-Cataract Endophthalmitis (APCE). Of all eyes, 77.4% were initially treated with Complete and Early Vitrectomy for Endophthalmitis (CEVE). Visual acuity of ≥ 20/40 was restored in 79% of all eyes versus 53% of eyes reported in the Endophthalmitis Vitrectomy Study. We believe that CEVE is the initial treatment of choice whenever the fundus is obscured by endophthalmitis vitreous opacity.

NECROSIS OF THE RETINA AND UVEAL TRACT SECONDARY TO EXPANDING GAS TAMPONADE.

PURPOSE: To present a case of retinal and uveal necrosis caused by expanding gas tamponade after pars plana vitrectomy. METHODS: Single case report. RESULTS: An otherwise healthy 66-year-old woman underwent pars plana vitrectomy with intended 20% sulfur hexafluoride (SF6) tamponade for macular hole repair of her pseudophakic left eye. She developed intractable nausea, emesis and increasing left eye pain in association with gas expanded to totally fill the left eye, just hours after surgery. Extremely elevated intraocular pressure was lowered with a successful paracentesis but recurred within a few hours. She then underwent vitrectomy evacuation of all vitreous cavity gas, reformation of the anterior chamber, and silicone oil placement, normalizing intraocular pressure. Three weeks later, the left eye had no light perception, and devitalization of the retina, choroid, and iris was evident. CONCLUSION: We present a case of blindness and intraocular tissue dissolution/disorganization after vitrectomy with intended 20% SF6. To our knowledge, this is the most detailed report of the under-recognized complication of expanding gas tamponade. Institutions hosting vitrectomy surgery should consider enacting a formal "Time Out" that requires all team members to witness accurate fractionation of potentially expansile gas. In the event of acute postoperative glaucoma in such eyes, a single small volume paracentesis cannot be relied upon to protect against continued gas expansion.

Stickler Syndrome (SS): Laser Prophylaxis for Retinal Detachment (Modified Ora Secunda Cerclage, OSC/SS).

PURPOSE: To introduce a novel technique of encircling laser prophylaxis (ora secunda cerclage Stickler syndrome, OSC/SS) to prevent rhegmatogenous retinal detachment (RRD) in Stickler syndrome eyes. PATIENTS AND METHODS: After first eye RRD at age 50 and at age 18, respectively, a 53-year-old father and his 22-year-old son with type 2 SS (STL2) gave informed consent and underwent OSC/SS prophylaxis, performed in each fellow eye. A 26-year-old STL2 daughter then suffered first eye retinal detachment and similarly chose fellow eye OSC/SS prophylaxis. A second son, 28 years of age with STL2, chose OSC/SS prophylaxis in both eyes. RESULTS: The three OSC/SS treated fellow eyes have gone 12 years, 11 years, and 8 years without RRD. STL1 and less common STL2 eyes are known to have a similar rate of RRD, and 80% of STL1 fellow eyes develop RRD at a median of 4 years in the absence of prophylaxis. Moreover, five of six (83%) known STL2 family members suffered RRD, only the STL2 son with bilateral OSC/SS remaining bilaterally attached. All five OSC/SS treated eyes (average 8.7 years post-prophylaxis) retained preoperative visual acuity of 20/20 to 20/30, with an average, asymptomatic reduction of meridional field in each eye to 50 degrees. In contrast, in the three eyes having suffered RRD prior to presentation, visual acuity ranged from 20/125 to 8/200 and average meridional field was 29 degrees. CONCLUSION: Encircling grid laser (OSC) modified in Stickler eyes to encompass the ora serrata and extend posteriorly to and between the vortex vein ampullae (OSC/SS) is a reasonable RRD prophylaxis option to offer STL1 and STL2 patients as an alternative to no treatment or less effective prophylaxis. Because of rarity and severity, the ultimate proof of safety and efficacy will likely come not from randomized trials, but from a non-randomized, prospective, cohort comparison study of such individual efforts.

Nitrogen Compound Characterization in Fuels by Multidimensional Gas Chromatography.

Certain nitrogen-containing compounds can contribute to fuel instability during storage. Hence, detection and characterization of these compounds is crucial. There are significant challenges to overcome when measuring trace compounds in a complex matrix such as fuels. Background interferences and matrix effects can create limitations to routine analytical instrumentation, such as GC-MS. In order to facilitate specific and quantitative measurements of trace nitrogen compounds in fuels, a nitrogen-specific detector is ideal. In this method, a nitrogen chemiluminescence detector (NCD) is used to detect nitrogen compounds in fuels. NCD utilizes a nitrogen-specific reaction that does not involve the hydrocarbon background. Two-dimensional (GCxGC) gas chromatography is a powerful characterization technique as it provides superior separation capabilities to one-dimensional gas chromatography methods. When GCxGC is paired with a NCD, the problematic nitrogen compounds found in fuels can be extensively characterized without background interference. The method presented in this manuscript details the process for measuring different nitrogen-containing compound classes in fuels with little sample preparation. Overall, this GCxGC-NCD method has been shown to be a valuable tool to enhance the understanding of the chemical composition of nitrogen-containing compounds in fuels and their impact on fuel stability. The % RSD for this method is <5% for intraday and <10% for interday analyses; the LOD is 1.7 ppm and the LOQ is 5.5 ppm.

Complete and Early Vitrectomy for Endophthalmitis After Cataract Surgery: An Alternative Treatment Paradigm.

PURPOSE: In this study, we report the treatment outcomes of complete and early vitrectomy for endophthalmitis (CEVE) after cataract surgery as the predominate initial treatment, accompanied by systemic antibiotics and retreatment of persistent or recurrent purulence (CEVE+). PATIENTS AND METHODS: Clinical features and microbiological factors were retrospectively reviewed in 62 eyes of 62 patients who were treated for acute postcataract endophthalmitis (APCE) occurring within three weeks of cataract surgery at Retina Specialists of Alabama, between 2007 and 2017. RESULTS: Visual acuity on presentation included light perception (LP) in 18 eyes (29%) and hand motion (HM) in 23 eyes (37%). Initial treatment was maximum possible vitrectomy in 48 eyes (77%) and tap-and-inject in 14 eyes (23%), with 38 eyes (61%) receiving two or more treatments. Cultures for the first intervention were positive in 49 eyes (79%) and virulent in 18 eyes (29%). At a median follow-up time of five months, final visual acuity was ≥20/40 in 49 eyes (79%), between 20/50 and 5/200 in seven eyes (11%), and <5/200 in six eyes (10%). Virulence was the strongest predictor of poor visual outcome. Retinal detachment occurred in four eyes (6%), likely from necrotic retinal defects in each case. CONCLUSION: Complete and early vitrectomy is a safe and effective initial treatment for APCE. When accompanied by systemic antibiotics and retreatment (CEVE+) of recurrent media opacification, it improves recovery of 20/40 or better visual acuity by approximately 50% compared to a predominantly tap-and-inject treatment paradigm. We recommend CEVE for fundus-obscuring APCE (~75% of all cases) whenever the view is inadequate to rule out macular distress.

Optic disc pit maculopathy: tamponade of maculoschisis.

PURPOSE: To present rapid and safe closure of the pit-macula communication (PMC) by core vitrectomy and adequate duration gas tamponade as our preferred method of resolving optic disc pit (ODP) maculopathy and to define the term "maculoschisis" in ODP maculopathy as an alternative to the term "schisis-like." PATIENT AND METHODS: A twenty-four-year-old female presented with an optical coherence tomography (OCT) confirmed ODP and a "giant" communicating maculoschisis cavity. Central macular thickness (CMT) measured 906 microns, and macular volume was twice normal, at 20.8 mm3. Snellen corrected visual acuity was 20/70. Two months after initial vitrectomy performed elsewhere with short-term gas tamponade (SF6 20%), CMT and visual acuity were not significantly improved. Combined lens extraction/intraocular lens placement and repeat vitrectomy with C3F8 15% gas tamponade were performed, with one supplemental (office) gas injection. RESULTS: OCT imaging six weeks postoperatively showed definitive closure of the PMC with CMT reduced by 405 microns. Sequestered from its ODP source, foveal schisis fluid then resolved by 12 weeks postoperatively. At final follow-up 3.4 years postoperatively, the macula remained dry with a CMT of 322 microns and a concave foveal contour. Macular volume was reduced to (a normal) 10.2 mm3 and visual acuity had improved to 20/25. CONCLUSION: No report heretofore has documented rapid, sustained closure of the PMC by gas tamponade as the preferred method of expeditiously resolving ODP maculopathy. However, tamponade PMC closure sequesters ODP fluid and uniquely provides early assurance of ultimate maculopathy resolution. In all other techniques, PMC closure is a trailing phenomenon and success remains uncertain during months to a year or more of (unsequestered) fluid resolution. We suggest that more invasive techniques (laser barrier application to the peripapillary choroid, vitreoretinal interface maneuvers, and pit-plugging) be withheld unless a recurrence is detected during subsequent examinations.

Evolving window factor analysis-multivariate curve resolution with automated library matching for enhanced peak deconvolution in gas chromatography-mass spectrometry fuel data.

Fuel chromatography is inherently limited by the high complexity of petroleum fuel compositions. In practice, almost no fuel components are fully resolved in gas chromatography. This is due to both insufficient peak capacity for the large number of individual components within time and chromatographic efficiency constraints, and insufficient resolving power of the stationary phase in the gas chromatography column relative to the many structurally similar isomers or homologs present in petrochemical fuels. Multidimensional approaches, longer columns and slower heating rates can offer some benefits but will not necessarily fully resolve co-eluting fuel compounds, especially within reasonable analysis times. The following work details how deconvolved mass spectral loadings, combined with library matching, provide a quality metric against which to automatically evaluate results obtained from an experimental evolving window factor analysis-multivariate curve resolution deconvolution algorithm applied to gas chromatography-mass spectrometry data. This algorithm was evaluated in the context of trace component detection in synthetic fuel data sets, dodecane and tetradecane detection in petrochemical fuels, and the detection of natural products unlikely to be present in petrochemical fuels. In the case of the trace component detection challenge, the experimental algorithm outperformed a control algorithm that utilized a singular value-based quality metric. Meanwhile, when detecting dodecane, tetradecane, and natural products in petrochemical fuels, the experimental algorithm allowed for higher-quality compound identification results than could be obtained without peak deconvolution, thus reliably improving fuel component resolution in an automated fashion.

Juvenile Incarceration and Health.

Addressing the health status and needs of incarcerated youth represents an issue at the nexus of juvenile justice reform and health care reform. Incarcerated youth face disproportionately higher morbidity and higher mortality compared to the general adolescent population. Dental health, reproductive health, and mental health needs are particularly high, likely as a result of lower access to care, engagement in high-risk behaviors, and underlying health disparities. Violence exposure and injury also contribute to the health disparities seen in this population. Further, juvenile incarceration itself is an important determinant of health. Juvenile incarceration likely correlates with worse health and social functioning across the life course. Correctional health care facilities allow time for providers to address the unmet physical and mental health needs seen in this population. Yet substantial challenges to care delivery in detention facilities exist and quality of care in detention facilities varies widely. Community-based pediatricians can serve a vital role in ensuring continuity of care in the postdetention period and linking youth to services that can potentially prevent juvenile offending. Pediatricians who succeed in understanding and addressing the underlying social contexts of their patients' lives can have tremendous impact in improving the life trajectories of these vulnerable youth. Opportunities exist in clinical care, research, medical education, policy, and advocacy for pediatricians to lead change and improve the health status of youth involved in the juvenile justice system.