Vitreous Humor Levels Research Articles

Estimation of Time Since Death From Potassium Levels in Vitreous Humor in Cases of Unnatural Death: A Facility-Based Cross-Sectional Study.

Background Estimation of time since death/postmortem interval (PMI) forms a crucial component for all autopsy surgeons. With the subjectivity that is prevalent with conventional morphological and physical signs of death, newer-age modalities such as chemical analysis providebetter precision. The easy accessibility and the resistance to putrefactionmakevitreous humor the best choice for such chemical analysis. Thus, the present study's aim is to estimate the time since death in cases of unnatural death by investigating the potassium level changes in the vitreous humor. Methodology This is a facility-based cross-sectional study conducted in the mortuary under the Department of Forensic Medicine in a public tertiary healthcare teaching hospital in South India between August and September 2022. Deceased individuals fulfilling the inclusion and exclusion criteria were recruited in the study. Vitreous samples were collected from a single eye and analyzed using an autoanalyzer for potassium values. After due derivations, postmortem intervals were calculated from potassium values, then they were compared with the PMIs estimated using physical signs and those determined using official police records. Data were entered using MS Excel 20 (Microsoft Corporation, Redmond, Washington) and analyzed using the Statistical Package for the Social Sciences (SPSS) software, version 20 (IBM Corp., Armonk, NY). Results Of the 100 deceased individuals included in the study, 68%were men, and the majority (24%) belonged to the age group of 53-62 years. A linear relationship is said to exist between vitreous potassium concentration and postmortem interval. No correlation was seen between the ambient temperature and the potassium levels of the vitreous humor. PMI confirmed by the potassium levelsseconded the PMI given by the police records andphysical signs (Rigor mortis) (Spearman's rho was statistically significant at the two-tailed level or at the 0.01 level with a kappa value of 0.88). Conclusion Potassium measurements in the vitreous humor to estimate the PMI are associated with improved accuracy and precision in determining the time since death. They are not affected by external factors, makingthem a reliable marker for the same.

Role of Vitreous Humor and Synovial Fluid Potassium Levels in Estimating Postmortem Interval: A Study

Determining the time since death is a crucial aspect of a forensic autopsy as it helps establish the sequence ofevents leading to death, narrow down the list of potential suspects, and aid in legal investigations. The postmorteminterval can be estimated using various indicators such as body temperature, rigor mortis, and biochemicalchanges in bodily fluids, and this information can provide valuable insights into the circumstances surroundingthe death. This study aimed to investigate the correlation between post-mortem interval and the levels of sodiumand potassium in vitreous humor and synovial fluid. The study included 100 cases, with 71% males and 29%females, and poisoning cases were the most prevalent. The results indicated a linear correlation between time sincedeath and potassium levels in both vitreous humor and synovial fluid, suggesting that potassium concentrationvalues could be useful for estimating time since death. However, sodium levels showed a negative correlation,indicating they are not significant for this purpose. These findings could be valuable for forensic investigationsand the determination of the time since death. Additionally, the study found that alcohol could be detected fromvitreous humor, further highlighting its potential as a forensic tool.

Evaluation of the Dose-Dependent Inflammatory Response and No-Observable Adverse Effect Level of Intravitreal Endotoxin in the African Green Monkey.

PurposeTo evaluate the inflammatory effects and no-observed adverse effect level (NOAEL) of intravitreal endotoxin in an African green monkey model of uveitis.MethodsFifteen green monkeys were administered intravitreal endotoxin ranging from 0.005 to 0.08 endotoxin unit (EU)/eye. Inflammation was evaluated by slit-lamp biomicroscopy, indirect fundoscopy, tonometry, color fundus photography, ocular coherence tomography, laser flare photometry, and histopathology, with analysis of cytokine levels in aqueous and vitreous humor. The inter-rater reliability of a refined nonhuman primate ophthalmic scoring system was evaluated.ResultsA dose-dependent inflammatory response was observed beginning at 0.02 EU/eye; no inflammatory response exceeding the vehicle was observed at 0.005 EU/eye. Retinal pathology was minimal, and posterior visualization degraded with increasing inflammation. Inflammation was observed by histopathology at 0.04 EU/eye. Inter-rater reliability of the scoring system was high, with 99.2% of individual scores differing by 1 scale unit or less and 87.2% of summary scores differing by 2 scale units or less.ConclusionsThe NOAEL for intravitreal endotoxin in the green monkey is 0.005 EU/eye, with inflammation increasing with increasing dose beginning at 0.02 EU/eye. This updated nonhuman primate ophthalmic scoring system allows for high inter-rater reliability for the quantification of mild to severe inflammation in the green monkey eye.Translational RelevanceValidation of the ophthalmic inflammation scoring system enables application of the green monkey as a valuable translational model. Candidate therapeutics should be confirmed to have endotoxin levels below this threshold before safety testing in this species to enable interpretation of inflammation and minimize impact on animal welfare.

Intact quantitative bioanalytical method development and fit-for-purpose validation of a monoclonal antibody and its related fab fragment in human vitreous and aqueous humor using LC-HRMS.

Ranibizumab is an FDA-approved drug used to treat wet age-related macular degeneration (AMD), diabetic retinopathy, macular edema, and myopic choroidal neovascularization. Bevacizumab is another drug often used off-label to treat wet AMD. In order to reduce unwanted angiogenesis, ranibizumab and bevacizumab target circulating VEGF-A in the eye. Concentration levels in human vitreous and aqueous humor can be used to provide valuable efficacy information. However, vitreous and aqueous humor's aqueous environment, and vitreous humor's viscosity, as well as the stickiness of the analytes can provide bioanalytical challenges. In this manuscript, we describe the development, optimization, and fit-for-purpose validation of an LC-HRMS method designed for intact quantitative bioanalysis of ranibizumab and bevacizumab in human vitreous and aqueous humor following intravitreal administration. In order to fully develop this method, evaluations were conducted to optimize the conditions, including the data processing model (extracted ion chromatograms (XICs) vs deconvolution), carryover mitigation, sample preparation scheme optimization for surrogate and primary matrices, use of internal standard/immunocapture/deglycosylation, and optimization of the extraction and dilution procedure, as well as optimization of the liquid chromatography and mass spectrometry conditions. Once the method was fully optimized, a fit-for-purpose validation was conducted, including matrix parallelism, with a linear calibration range of 10 to 200µg/mL. The development of this intact quantitative method using LC-HRMS provides a proof-of-concept template for challenging, but valuable new and exciting bioanalytical techniques.

Self-sealing hyaluronic acid-coated 30-gauge intravitreal injection needles for preventing vitreous and drug reflux through needle passage

Self-sealing hyaluronic acid (HA)-coated self-sealing 30-gauge needles exhibiting instant leakage prevention of intravitreal humor and injected drug were developed in this study. Ninety New Zealand rabbits were used in this study. We assessed dye regurgitation in intravitreal ICG dye injections using HA-coated needles (HA needle group) and conventional needles (control group). Vitreous humor levels of anti-vascular endothelial growth factor (VEGF) were compared between groups one, three, and seven days after intravitreal bevacizumab (0.016 mL) injections. Expression levels of inflammatory cytokines in the aqueous humor and vitreous humor, including prostaglandin E2 (PGE2), interferon-γ, tumor necrosis factor-α, interleukin (IL)-1β, IL-4, IL-6, IL-17, and IL-8, were compared between HA needle, control, and normal (in which intravitreal injection was not performed) groups following 12 intravitreal injections over a period of one week. In the HA needle group, HA remained at the injection site and blocked the hole after intravitreal injection. Dye regurgitation occurred significantly less frequently in the HA needle group (16.7%) than the control group (55.6%) after intravitreal ICG dye injection. Meanwhile, vitreous anti-VEGF levels were markedly higher in the HA needle group than the control group one and three days after intravitreal bevacizumab injections. After 12 intravitreal injections, expression levels of aqueous and vitreous IL-8 significantly increased in the control group compared to the HA needle and normal groups. Conversely, there were no significant differences in the expression of the other seven cytokines among the three groups. Intravitreal injections using HA-coated self-sealing 30-gauge needles can block the outflow of vitreous humor and drugs through the needle passage.

Sensitization of ON-bipolar cells with ambient light activatable multi-characteristic opsin rescues vision in mice.

Gene therapy-based treatment such as optogenetics offers a potentially powerful way to bypass damaged photoreceptors in retinal degenerative diseases and use the remaining retinal cells for functionalization to achieve photosensitivity. However, current approaches of optogenetic treatment rely on opsins that require high intensity light for activation thus adding to the challenge for use as part of a wearable device. Here, we report AAV2 assisted delivery of highly photosensitive multi-characteristic opsin (MCO1) into ON-bipolar cells of mice with retinal degeneration to allow activation by ambient light. Rigorous characterization of delivery efficacy by different doses of AAV2 carrying MCO1 (vMCO1) into targeted cells showed durable expression over 6 months after delivery as measured by reporter expression. The enduring MCO1 expression was correlated with the significantly improved behavioral outcome, that was longitudinally measured by visual water-maze and optomotor assays. The pro/anti-inflammatory cytokine levels in plasma and vitreous humor of the vMCO1-injected group did not change significantly from baseline or control group. Furthermore, biodistribution studies at various time points after injection in animal groups injected with different doses of vMCO1 showed non-detectable vector copies in non-targeted tissues. Immunohistochemistry of vMCO1 transfected retinal tissues showed bipolar specific expression of MCO1 and the absence of immune/inflammatory response. Furthermore, ocular imaging using SD-OCT showed no change in the structural architecture of vMCO1-injected eyes. Induction of ambient light responsiveness to remaining healthy bipolar cells in subjects with retinal degeneration will allow the retinal circuitry to gain visual acuity without requiring an active stimulation device.

Vitreous potassium concentration as a predictor of postmortem interval in severe burn deaths at Alexandreia mortuary

ABSTRACT Background: Postmortem interval (PMI) estimation is an important goal in forensic medicine. After death, many physiochemical changes occur in a regular sequence and thanatochemistry is the chemistry of death. They can be used to arrive at an approximate time of death. Aim: to estimate the time since death using a scoring method for three postmortem changes; hypostasis, rigidity and corneal turbidity in sever burn cases. Also, to evaluate the use of thanatochemistry; potassium (K+) in vitreous humor (VH) and serum in determination of (PMI) and compare the accuracy of thanatochemistry and the scoring method for postmortem changes in estimation of PMI. Methods: The study was conducted on 100 adult autopsy cases of known postmortem interval presented to the mortuary of Alexandria from May 2017 to May 2018, 50 burn cases where autopsy confirmed the cause of death as severe burns and another 50 control cases. The development of postmortem rigidity, hypostasis and corneal turbidity was assessed and numerically scored. The potassium (K+) levels in vitreous humor (VH) and serum were measured. The data were statistically analyzed and linear regression analysis was used to obtain equations for calculation of PMI .Results: All the studied variables in the present study were significantly correlated with PMI; highest correlation coefficient in control and burn groups was for K+ level in VH, followed by corneal turbidity and serum K+ then rigidity in burn groups, but in control groups the highest correlation coefficient was for K+ level in VH and serum, followed by rigidity then corneal turbidity and lastly hypostasis. All equations obtained from the present study can predict PMI but with different levels of accuracy. Conclusion: The most accurate equation in control cases was that concerning with all the five studied variables. Furthermore, the scoring method for the physical postmortem changes was proved to be more valuable in PMI estimation than thanatochemistry. No much difference between accuracy of equations in burn cases was that concerning with all the five studied variables.

Association of Cognitive Function with Amyloid-β and Tau Proteins in the Vitreous Humor.

The eye may serve as source for diagnostic testing for early detection of Alzheimer's disease (AD). Examination of amyloid-β (Aβ) and tau protein content in human vitreous and its correlation to neuro-cognition may improve ocular-based AD detection methods. To evaluate levels of Aβ and tau protein in human vitreous humor and investigate the clinical predictive role of these proteins as early diagnostic markers of AD. A prospective, single-center, multi-surgeon cohort study. Vitreous humor samples from 80 eyes were measured quantitatively for Aβ40-42, pTau, and tTau. Linear regression was used to test associations between AD biomarker levels, Mini-Mental State Exam (MMSE), and serum apolipoprotein E (APOE) allele status, with adjustment for age, sex, and education level of patients. Lower MMSE scores were significantly associated with lower levels of vitreous Aβ40 (p = 0.015), Aβ42 (p = 0.0066), and tTau (p = 0.0085), and these biomarkers were not associated with any pre-existing eye conditions. Presence of the ɛ4 allele and the ɛ2 allele approached significance with reduced Aβ40 level (p = 0.053) and increased p-Tau level (p = 0.056), respectively. Patients with poor cognitive function have significantly lower vitreous humor levels of AD-related biomarkers Aβ40, Aβ42, and tTau. These biomarkers do not correlate with underlying eye conditions, suggesting their specificity in association with cognitive change. This is the first study to our knowledge to correlate cognition with AD-related proteins in the vitreous humor. Results suggest ocular proteins may have a role for early dementia detection in individuals at risk for AD.

Relationship Between Neutralizing Antibodies Against Adeno-Associated Virus in the Vitreous and Serum: Effects on Retinal Gene Therapy.

PurposeWe determine the prevalence of neutralizing antibodies (NAbs) to adeno-associated virus (AAV) in the vitreous humor and serum of patients with vitreoretinal diseases and investigate the relationship between NAb titers in the vitreous humor and serum.MethodsWe analyzed NAbs to AAV serotypes 2, 5, 8, and 9 via in vitro neutralization in the vitreous humor and serum from 32 patients requiring vitrectomy for vitreoretinal diseases. The blood–retinal barrier (BRB) was evaluated for integrity based on preoperative examinations, with vitreous hemorrhage (VH) on funduscopy or dye leakage on fluorescein angiography observed indicating disruption.ResultsNAb levels were much lower in the vitreous humor than in the serum regardless of serotype. Patients with VH had higher levels of NAbs in the vitreous humor than those without VH. The NAb ratio (ratio between NAb titers in the serum and vitreous humor) was much lower in patients with epiretinal membrane with than in those without leakage. A significantly lower NAb ratio was noticed in patients with than in those without BRB disruptions.ConclusionsThe NAb ratio between levels in serum and vitreous humor varies according to the condition of the BRB. Therefore, in addition to measuring the serum NAb level, physicians should examine BRB integrity when planning retinal gene therapy.Translational RelevanceThis study provides substantial basis for retinal gene therapy using AAVs and how maintenance of BRB integrity in target diseases should be considered.

Analysis of hypoxanthine and lactic acid levels in vitreous humor for the estimation of post-mortem interval (PMI) using LC–MS/MS

Hypoxanthine (Hx) is produced during terminal stages of purine catabolism in humans. The concentrations of Hx and l-lactic acid in vitreous humor highly correlate with post-mortem interval (PMI). In this study, we measured the concentrations of Hx and l-lactic acid in uncontrolled authentic vitreous humor from cadavers, and investigated the correlation between these molecules and PMI. A liquid chromatography–tandem mass spectrometry (LC–MS/MS) was used for the quantitative analysis of Hx and l-lactic acid in vitreous humor. These concentrations were also corrected by four seasons such as spring, summer, autumn, and winter and temperatures on the day of death such as −10 to 5 °C, 6–15 °C, 16–25 °C, and 26–32 °C that may affect the biomarker concentrations. Vitreous humors were collected from cadavers with known time of death at the National Forensic Service (NFS), Republic of Korea. The correlation between the concentrations of Hx and l-lactic acid in vitreous humors and PMI was evaluated using 79 corpses (53 males and 26 females), with sampling time ranging from 13 to 103 h after death. The average daily ambient temperature at the time of death of each sample was investigated to calibrate the correlation with PMI. Following correction of the concentrations of Hx and l-lactic acid with temperature, the correlation of Hx and l-lactic acid with PMI increased from 0.53 to 0.59 for Hx and 0.38 to 0.42 for l-lactic acid. The highest correlation of Hx and l-lactic acid concentrations with PMI was observed in the winter season, with an R2 value of 0.80 and 0.71 for Hx and l-lactic acid, respectively. The correlation of Hx and l-lactic acid with PMI was corrected by ambient temperature for each season, resulting in an increase in the R2 value to 0.88 for Hx and 0.72 for l-lactic acid. The best correlation was observed when the temperature was corrected after dividing by season.

Transscleral Delivery of Bevacizumab-Loaded Chitosan Nanoparticles.

Purpose: The aim of this study was to synthesize bevacizumab-loaded nanoparticles and evaluate their effects on the treatment of posterior segment diseases via subtenon injections. Methods: Bevacizumab-loaded chitosan nanoparticles (BLCNs) were synthesized by the ionic gelation method, and their physicochemical characteristics and in vitro release profile were studied. The BLCNs were characterized using atomic force microscopy (AFM), FTIR spectroscopy, dynamic light scattering, and scanning electron microscopy. The BLCNs were delivered into rabbits' eyes via posterior subtenon injections. An immunohistochemical evaluation of the ocular tissues was performed, and the vitreous humor and serum bevacizumab levels were measured by ELISA. Results: Bevacizumab-loaded chitosan nanoparticles with a diameter of 80 to 380 nm were prepared and characterized. In vitro studies showed that after the first 5 days of the experiment, a significant increase in the drug release maintained the desired drug dosage for 3 weeks. Immunohistochemical in vivo studies revealed that there were BLCNs penetrating through the sclera. Furthermore, the intravitreal bevacizumab concentration reached a maximum concentration of 18 μg/ml, and it decreased to 6 μg/ml after only a week. Conclusion: The results revealed that subtenon injection of BLCNs is a promising alternative to intravitreal injections. In addition to the ELISA studies, immunohistochemical experiments confirmed that BLCNs enable transscleral bevacizumab penetration, and BLCN usage may provide the required bevacizumab levels for the treatment of posterior segment diseases.

The Relationship Between the Renin-Angiotensin-Aldosterone System and NMDA Receptor-Mediated Signal and the Prevention of Retinal Ganglion Cell Death.

Excitotoxicity, which is due to glutamate-induced toxic effects on the retinal ganglion cell (RGC), is one of several mechanisms of RGC loss. The renin-angiotensin-aldosterone system (RAAS) has also been implicated in RGC death. Therefore, it is important to determine the exact relationship between the RAAS and N-methyl-d-aspartate (NMDA) receptor-mediated signal in order to prevent RGC death. N-methyl-d-aspartate or aldosterone was injected into the vitreous body. After intravitreal injection of NMDA or aldosterone, animals were treated with spironolactone or memantine. Retinal damage was evaluated by measuring the number of RGCs at 4 weeks after local administration of aldosterone or at 2 weeks after local administration of NMDA. Vitreous humor levels of aldosterone were measured using enzyme immunoassay kits. A significantly decreased number of RGCs were observed after intravitreal injection of NMDA. Although spironolactone did not show any neuroprotective effects, memantine significantly reduced NMDA-induced degeneration in the retina. Furthermore, a significant decrease in the number of RGCs was observed after an intravitreal injection of aldosterone. While memantine did not exhibit any neuroprotective effects, spironolactone caused a significant reduction in the aldosterone-induced degeneration in the retina. There was no change in the aldosterone concentration in the vitreous humor after an NMDA injection. Our findings indirectly show that there is no relationship between the RAAS and NMDA receptor-mediated signal with regard to RGC death.

Panretinal Photocoagulation Using Short-Pulse Laser Induces Less Inflammation and Macular Thickening in Patients with Diabetic Retinopathy.

We compared the effect of panretinal photocoagulation (PRP) using short-pulse laser (SPL) and conventional laser, regardless of the number of spots, in terms of their effect on the progression of diabetic macular edema (DME) and anterior flare intensity (AFI) in patients with high-risk nonproliferative diabetic retinopathy (non-PDR). Forty-two eyes of 42 patients were subjected to PRP using the conventional argon laser (Conv group) or SPL (SPL group). CRT and AFI levels in the SPL group were significantly lower than those in the Conv group (CRT at 4, 6, and 10 weeks; AFI at 6, 10, and 18 weeks). Eyes of rabbits were photocoagulated using conventional laser with 500 spots (Conv 500s), SPL with 500 spots (SPL 500s), or 1000 spots (SPL 1000s). Vascular endothelial growth factor (VEGF), interleukin-6 (IL-6), intercellular adhesion molecule-1 (ICAM-1), and monocyte chemotactic protein-1 (MCP-1) levels in vitreous humor were measured using an immunoassay. Compared to conventional laser, VEGF, IL-6, and MCP-1 levels were significantly lower in the SPL 1000s and SPL 500s groups. In patients with high-risk non-PDR, SPL has a greater preventive effect on the progression of DME and AFI and produces less inflammatory cytokines than conventional lasers.

Sustained Delivery of Timolol Maleate for Over 90 Days by Subconjunctival Injection.

Medical treatment of glaucoma relies on intraocular pressure (IOP)-lowering medications, typically administered daily by the patient. While these medications are effective when applied correctly, patient adherence is a major obstacle in glaucoma treatment. We have developed a sustained-release formulation of timolol maleate that can be injected subconjunctivally to avoid patient noncompliance. A biodegradable microsphere formulation for timolol maleate was injected subconjunctivally in normal rabbits. We measured timolol levels in tears, aqueous humor, vitreous humor, and serum of study rabbits. Furthermore, IOP profiles were recorded longitudinally. Tissue compatibility and side effects were evaluated using histochemistry. The microsphere formulation led to measureable amounts of timolol in the aqueous humor and the tear film for up to 90 days. Timolol was not detectable in the serum at any time. A significant reduction of IOP was observed in treated eyes. Clinically, the subconjunctival administration of the microspheres was well tolerated with no signs of inflammation or infection. The absence of local inflammation was confirmed by histology. A single subconjunctival administration of timolol microspheres achieved delivery and IOP reduction in rabbits for up to 90 days without local or systemic inflammation or toxicity. This approach has the potential to improve the management of glaucoma in patient populations, who are challenged to adhere to a regimen of daily eye drops.

Effects of dexamethasone and superoxide dismutase instillations on clinical course of uveitis and local biochemical processes (experimental study)

to evaluate and compare the effect of topical superoxide dismutase (SOD), which is an antioxidant enzyme, dexamethasone, and a combination of these on the course of experimental uveitis in rabbits as well as biochemical parameters of aqueous and vitreous humor. Acute uveitis was induced in 16 rabbits by a double injection (subcutaneous and intravitreal) of normal horse serum. Of them 12 animals, divided into 3 groups of 4 each, received topical SOD, dexamethasone, or both daily for 7 days. The remaining 4 rabbits (8 eyes) were treated with placebo and, thus, constituted the control group. On day 8 the following parameters were measured in aqueous humor: protein concentration, antioxidant activity, SOD activity, α2-macroglobulin level, and leukocyte number. Total protein and albumin levels in vitreous humor were also determined. The effects of SOD and dexamethasone instillations were considered similar in many parameters. However, SOD was associated with a greater increase in antioxidant activity and a greater decrease in aqueous humor leukocytes, while dexamethasone was more effective in decreasing aqueous humor α2-macroglobulin and vitreous humor protein and albumin. The substances had a synergistic effect on iridal edema as well as aqueous humor leukocyte number and α2-macroglobulin level. CONCLUSION. Adding SOD to the complex therapy of uveitis results in lower inflammation intensity and enhanced dexamethasone effect.

Urea nitrogen, creatinine, and uric acid levels in postmortem serum, vitreous humor, and pericardial fluid.

Urea nitrogen, creatinine, and uric acid are relatively stable in postmortem serum and may, therefore, be used for diagnostic purposes when chronic kidney disease and end-stage renal failure are investigated as causes of death. Nevertheless, uncertainties remain in defining the best alternative to postmortem serum for the identification and assessment of significantly decreased kidney function. In this study, we investigated urea nitrogen, creatinine, and uric acid levels in postmortem serum, pericardial fluid, and vitreous humor in a series of medico-legal cases (500 autopsies) with various causes of death. No postmortem interval-related differences were observed in any of the investigated fluids for any analyzed parameter, confirming the biochemical stability of all compounds after death. Data analysis failed to reveal statistically significant differences between postmortem serum and pericardial fluid urea nitrogen, creatinine, and uric acid concentrations. Conversely, statistically significant differences were observed in all analyzed biomarkers between postmortem serum and vitreous humor levels, with lower concentrations of all markers measured in vitreous. The results of this study suggest that, in order to estimate as accurately as possible blood analyte concentrations at the time of death, pericardial fluid should be preferred to vitreous humor.

Blood and vitreous humor cytokine profile in patients with proliferative diabetic retinopathy and post-vitrectomy hemophthalmia

Aim. To study vascular endothelial growth factor (VEGF), tumor necrosis factor alpha (TNF-α), interleukin-1β (IL-1β) and interleukin-1 receptor antagonist (IL-1RA) blood and vitreous humor levels in patients with proliferative diabetic retinopathy (PDRP) and post-vitrectomy hemophthalmia. Methods. 82 patients (82 eyes) with PDRP and post-vitrectomy hemophthalmia present 2 months (from 55 to 78 days) after performed vitrectomy were examined. Results. In patients with proliferative diabetic retinopathy (PDRP) and post-vitrectomy hemophthalmia VEGF blood level remained normal in 92.7% of cases, TNF-α blood level was normal at all times, blood level of IL-1β was within normal ranges in 93.8% of cases, and IL-1RA blood level was decreased in 74.4% of cases. Vitreous humor level was above normal ranges for VEGF - in 84% of cases, for TNF-α - in 9,9% of cases, IL-1β vitreous humor level was within reference ranges at all times, and IL-1RA vitreous humor level was decreased in 84.1% of cases. Conclusion. The gained data indicates further vascular proliferation in the eye cavity as a leading factor for hemorrhage relapses, despite the vitrectomy performed.

A case of intraocular lymphoma with central nervous system involvement and high interleukin-10 levels in both vitreous humor and cerebrospinal fluids: successful treatment with a combination of intravitreal, intrathecal, and systemic therapy

A 70-year-old man with diffuse large B cell lymphoma, who had been in complete remission without treatment, presented with a visual disorder in the right eye. Vitreous biopsy was performed, although the results were not typically suggestive of lymphoma. The concentration of interleukin-10 (IL-10) in the vitreous humor was markedly elevated, suggesting intraocular lymphoma (IOL). Weekly intravitreal injections of methotrexate (MTX) resulted in remission of the visual disorder. During this remission, 10 months after the last intravitreal MTX treatment, a cerebral tumor was observed in the corpus callosum and atypical lymphocytes were detected in the cerebrospinal fluid. The concentration of IL-10 in the CSF was markedly elevated and the IL-6 level was slightly elevated, suggesting central nervous system (CNS) involvement. The patient was treated with intrathecal MTX, systemic rituximab, high-dose cytarabine, and high-dose methotrexate. After this therapy, the cerebral tumor disappeared, atypical lymphocytes were undetectable in the CSF, and the CSF IL-10 level was significantly reduced. IL-10 and IL-6 concentrations in the vitreous humor and CSF are important for diagnosis of IOL with CNS involvement and for monitoring the efficacy of therapy.

Transporter Targeted Gatifloxacin Prodrugs: Synthesis, Permeability, and Topical Ocular Delivery

In this work, we aim to design and synthesize prodrugs of gatifloxacin targeting organic cation transporter (OCT), monocarboxylate transporter (MCT), and ATB (0, +) transporters and to identify a prodrug with enhanced delivery to the back of the eye. Dimethylamino-propyl, carboxy-propyl, and amino-propyl(2-methyl) derivatives of gatifloxacin (GFX), DMAP-GFX, CP-GFX, and APM-GFX, were designed and synthesized to target OCT, MCT, and ATB (0, +) transporters, respectively. An LC-MS method was developed to analyze drug and prodrug levels in various studies. Solubility and log D (pH 7.4) were measured for prodrugs and the parent drug. The permeability of the prodrugs was determined in the cornea, conjunctiva, and sclera-choroid-retinal pigment epitheluim (SCRPE) and compared with gatifloxacin using an Ussing chamber assembly. Permeability mechanisms were elucidated by determining the transport in the presence of transporter specific inhibitors. 1-Methyl-4-phenylpyridinium iodide (MPP+), nicotinic acid sodium salt, and α-methyl-DL-tryptophan were used to inhibit OCT, MCT, and ATB (0, +) transporters, respectively. A prodrug selected based on in vitro studies was administered as an eye drop to pigmented rabbits, and the delivery to various eye tissues including vitreous humor was compared with gatifloxacin dosing. DMAP-GFX exhibited 12.8-fold greater solubility than GFX. All prodrugs were more lipophilic, with the measured log D (pH 7.4) values ranging from 0.05 to 1.04, when compared to GFX (log D: -1.15). DMAP-GFX showed 1.4-, 1.8-, and 1.9-fold improvement in permeability across the cornea, conjunctiva, and SCRPE when compared to GFX. Moreover, it exhibited reduced permeability in the presence of MPP+ (competitive inhibitor of OCT), indicating OCT-mediated transport. CP-GFX showed 1.2-, 2.3-, and 2.5-fold improvement in permeability across the cornea, conjunctiva, and SCRPE, respectively. In the presence of nicotinic acid (competitive inhibitor of MCT), the permeability of CP-GFX was reduced across the conjunctiva. However, the cornea and SCRPE permeability of CP-GFX was not affected by nicotinic acid. APM-GFX did not show any improvement in permeability when compared to GFX across the cornea, conjunctiva, and SCRPE. Based on solubility and permeability, DMAP-GFX was selected for in vivo studies. DMAP-GFX showed 3.6- and 1.95-fold higher levels in vitreous humor and CRPE compared to that of GFX at 1 h after topical dosing. In vivo conversion of DMAP-GFX prodrug to GFX was quantified in tissues isolated at 1 h after dosing. The parent drug-to-prodrug ratio was 8, 70, 24, 21, 29, 13, 55, and 60% in the cornea, conjunctiva, iris-ciliary body, aqueous humor, sclera, CRPE, retina, and vitreous humor, respectively. In conclusion, DMAP-GFX prodrug enhanced solubility, log D, as well as OCT mediated delivery of gatifloxacin to the back of the eye.

Estimation of postmortem interval using thanatochemistry and postmortem changes

IntroductionEstimation of postmortem interval is an important goal in forensic medicine. After death, many physiochemical changes occur in a regular sequence and can be used to arrive at an approximate time of death. Thanatochemistry is the chemistry of death. It can give a quantitative measurement to determine the postmortem interval (PMI). The aim of the present work was to estimate the time since death using a scoring method for three postmortem changes; hypostasis, rigidity and corneal turbidity. Also, to evaluate the use of thanatochemistry; potassium (K+) and hypoxanthine (Hx) levels in vitreous humor (VH) in determination of (PMI) and compare the accuracy of thanatochemistry and the scoring method for postmortem changes in estimation of PMI. Subjects and methodsThe study was conducted on 70 adult autopsy cases, of known postmortem interval. The development of postmortem rigidity, hypostasis and corneal turbidity was assessed and numerically scored. The potassium (K+) and hypoxanthine (Hx) levels in vitreous humor (VH) were measured. The data were statistically analyzed and linear regression analysis was used to obtain equations for calculation of PMI. ResultsAll the studied variables in the present study were significantly correlated with PMI; the highest correlation coefficient was for corneal turbidity, followed by K+ level in VH then hypostasis, rigidity and lastly hypoxanthine level in VH. Five equations obtained from the present study can predict PMI but with different levels of accuracy. ConclusionThe most accurate equation was that concerning with all the five studied variables (the three postmortem changes in addition to K+ and Hx levels in VH). Furthermore, the scoring method for the physical postmortem changes was proved to be more valuable in PMI estimation than thanatochemistry within the studied range of PMI that was up to 60h.