Assessing humoral immune response after two doses of an inactivated SARS-CoV-2 vaccine (CoronaVac) in healthcare workers.

OBJECTIVES: During COVID-19 pandemic, the absence of immunity in the population left them susceptible to infection with SARS-CoV-2; healthcare workers (HCWs) being in the highest risk group. This study intends to assess and follow up the humoral immunity in HCWs vaccinated with an inactive virus vaccine (CoronaVac). STUDY DESIGN: This is a prospective observational study. METHODS: A total of 1072 HCWs were investigated for the presence of immunoglobulin G antibodies to the receptor-binding domain of the S1 subunit of the spike protein of SARS-CoV-2 after vaccination. Blood samples were obtained after 28 days of the first dose, 21 days of the second dose, and 3 months after the second dose. Detection of antispike antibodies was performed by the chemiluminescent microparticle immunoassay method (SARS-CoV-2 IgG II Quant, Abbott, Ireland). The results greater than or equal to the cutoff value of 50.0 AU/mL were reported as positive. RESULTS: Four weeks after the first dose of vaccine, antispike antibodies were detected in 834/1072 (77.8%) of HCWs. Seropositivity was higher among females (84.6%) than males (70.6% p < 0.001) and was found to be highest in both women and men between the ages of 18-34 years. Antispike antibodies were detected in 1008 of 1012 (99.6%) after 21 days of the second dose and in 803 of 836 (96.1%) after 3 months of the second dose. CONCLUSIONS: CoronaVac was found to be highly immunogenic after two consecutive doses performed 28 days apart to HCWs; however, the immunogenicity declined significantly (p < 0.001) after 3 months following the second dose of vaccine.

Oxidative DNA damage in retinopathy of prematurity.

PURPOSE: This study examines the levels of oxidative damage in patients with retinopathy of prematurity (ROP). METHODS: Fifty patients were recruited with a birthweight below 1500 g or gestational age below 32 weeks. The cases were classified into those who developed ROP (n=25) and those without ROP (n=25). The authors obtained blood and urine samples from each infant, for measuring 8-hydroxy 2-deoxyguanosine (8-OHdG) and malondialdehyde (MDA) levels, at the time of the first examination at 4-6 postnatal weeks. RESULTS: A significant difference was observed in leukocyte and urine 8-OHdG levels in patients with ROP compared to those without ROP (p<0.001 for both). Similarly, a significant difference was observed in plasma and urine MDA levels in patients with ROP compared to those without ROP (p<0.001 for both). In addition, significant correlations were found between levels of 8-OHdG in leukocyte DNA and plasma MDA (r=0.859, p<0.001), and between levels of urine 8-OHdG excretion and urine MDA (r=0.563, p<0.001). CONCLUSIONS: 8-OHdG in leukocyte DNA and urine levels in premature infants can be useful as an indicator for ROP screening.

Protective role of intramuscularly administered vitamin E on the levels of lipid peroxidation and the activitiesof antioxidant enzymes in the lens of rats made cataractous with gamma-irradiation.

PURPOSE: To determine the antioxidant role of vitamin E (VE) (10 mg/kg/day) against radiation-induced cataract in lens after total-cranium irradiation of rats with a single dose of 5 Gy. METHODS: Sprague-Dawley rats were divided into three groups. Group 1 did not receive VE or irradiation but received both 0.1 ml physiologic saline intraperitoneally and sham irradiation (control group). Group 2 received to total cranium 5 Gy of gamma irradiation as a single dose (RT group) plus 0.1 ml physiologic saline intraperitoneally. Group 3 received irradiation to total cranium plus 10 mg/kg/day VE (RT+VE group). The rats were irradiated using a cobalt-60 teletherapy unit. Chylacks cataract classification (1) was used in this study. At the end of 10 days, the rats were killed and their eyes were enucleated to measure the antioxidant enzymes (the activity of superoxide dismutase [SOD], glutathione peroxidase [GSH-Px]) and lipid peroxidation level (malondialdehyde [MDA]). RESULTS: While grade 1 cataract development was detectable in seven rats in the RT group, it was detectable only in two rats in the RT+VE group, whereas none of the rats in the control group exhibited any biomicroscopic change in their lenses. MDA level and GSH-Px activity in the rat lens in the RT group was significantly higher than in the control group. SOD activity in the RT group was lower than in the control group. The activity of SOD and GSH-Px enzymes was higher in the RT+VE group, but MDA level was lower in the RT+VE group when compared with the RT group. CONCLUSIONS: Vitamin E has a protective effect on radiation-induced cataract by decreasing oxidative stress. (Eur J Ophthalmol 2004; 14: 478-85).

Protective role of intramuscularly administered vitamin E on the levels of lipid peroxidation and the activities of antioxidant enzymes in the lens of rats made cataractous with gamma-irradiation.

PURPOSE: To determine the antioxidant role of vitamin E (VE) (10 mg/kg/day) against radiation-induced cataract in lens after total-cranium irradiation of rats with a single dose of 5 Gy. METHODS: Sprague-Dawley rats were divided into three groups. Group 1 did not receive VE or irradiation but received both 0.1 ml physiologic saline intraperitoneally and sham irradiation (control group). Group 2 received to total cranium 5 Gy of gamma irradiation as a single dose (RT group) plus 0.1 ml physiologic saline intraperitoneally. Group 3 received irradiation to total cranium plus 10 mg/kg/day VE (RT+VE group). The rats were irradiated using a cobalt-60 teletherapy unit. Chylack's cataract classification (1) was used in this study. At the end of 10 days, the rats were killed and their eyes were enucleated to measure the antioxidant enzymes (the activity of superoxide dismutase [SOD], glutathione peroxidase [GSH-Px]) and lipid peroxidation level (malondialdehyde [MDA]). RESULTS: While grade 1 cataract development was detectable in seven rats in the RT group, it was detectable only in two rats in the RT+VE group, whereas none of the rats in the control group exhibited any biomicroscopic change in their lenses. MDA level and GSH-Px activity in the rat lens in the RT group was significantly higher than in the control group. SOD activity in the RT group was lower than in the control group. The activity of SOD and GSH-Px enzymes was higher in the RT+VE group, but MDA level was lower in the RT+VE group when compared with the RT group. CONCLUSIONS: Vitamin E has a protective effect on radiation-induced cataract by decreasing oxidative stress.

Protection of the retina from ischemia-reperfusion injury by L-carnitine in guinea pigs.

PURPOSE: To investigate the efficacy of L-carnitine in preventing retinal injury followed by ischemia-reperfusion. METHODS: The eyes of 34 guinea pigs were used in this experiment. The guinea pigs were divided into two groups: the first group (n=17) was given L-carnitine intraperitoneally (500 mg/kg) and second group (n=17) received the same dose of saline solution. Under general anesthesia, peritomy was performed. Retro-orbital tissues were ligated for 90 minutes and ischemia was induced, followed by 4 hours of reperfusion. One of the enucleated eye was stained with hematoxylin and eosin (H&E) and retinal thicknesses were evaluated. Thiobarbituric acid reactive substances (TBARS) levels were determined in the retina of the other eye. RESULTS: Mean TBARS levels in retinal tissue were found lower in L-carnitine group (2.77 +/- 0.55 microM) than in the control group (6.57 +/- 1.19 microM), (p<0.01). On the other hand, mean retinal thickness was found to be increased in the control group (47.47 +/- 5.62 microm) when compared to the L-carnitine group (26.52 +/- 4.65 microm), (p<0.01). In correlation analysis, significantly positive relationships were found between retinal TBARS level and retinal thickness both in the control and L-carnitine groups (r=0.981, p<0.01 and r= 0.967, p<0.01 respectively). CONCLUSIONS: L-carnitine is effective in preventing retinal injury followed by ischemia-reperfusion.

Diabetic cataract and the total antioxidant status in aqueous humor.

Some mechanisms have been proposed for cataract formation in diabetes mellitus such as excessive tissue sorbitol concentrations, abnormal glycosylation of lens proteins and increased free radical production in the intraocular region. We measured total antioxidant status and uric acid levels in aqueous humor from diabetic (n=20) and non-diabetic subjects (n=16) with cataracts. The patients with diabetes and cataract had significantly lower aqueous humor total antioxidant status than those with senile cataract (p = 0.001). Serum and aqueous humor uric acid levels were significantly lower in the diabetic cataract group compared to the senile cataract group. In the diabetic cataract group, the aqueous humor antioxidant status correlated positively with the aqueous humor uric acid levels (p < 0.05). The results of this study suggest that reduced aqueous humor antioxidant status might be associated with reduced aqueous humor uric acid in patients with diabetic cataract. This decrease in aqueous humor uric acid levels might lead to the acceleration of cataract formation.

A case of a large dentigerous cyst containing a canine tooth in the maxillary antrum leading to epiphora.

A case of a large dentigerous cyst containing a canine tooth in the maxillary antrum is presented. This case is of interest due because of its extensiveness and the presence of a canine tooth in the roof of the maxillary sinus. In addition, this caused a right-sided epiphora. Enucleation of the cyst containing the ectopic tooth was made.