Contribution of infection and vaccination to population-level seroprevalence through two COVID waves in Tamil Nadu, India.

This study employs repeated, large panels of serological surveys to document rapid and substantial waning of SARS-CoV-2 antibodies at the population level and to calculate the extent to which infection and vaccination separately contribute to seroprevalence estimates. Four rounds of serological surveys were conducted, spanning two COVID waves (October 2020 and April-May 2021), in Tamil Nadu (population 72 million) state in India. Each round included representative populations in each district of the state, totaling ≥ 20,000 persons per round. State-level seroprevalence was 31.5% in round 1 (October-November 2020), after India's first COVID wave. Seroprevalence fell to 22.9% in round 2 (April 2021), a roughly one-third decline in 6 months, consistent with dramatic waning of SARS-Cov-2 antibodies from natural infection. Seroprevalence rose to 67.1% by round 3 (June-July 2021), with infections from the Delta-variant induced second COVID wave accounting for 74% of the increase. Seroprevalence rose to 93.1% by round 4 (December 2021-January 2022), with vaccinations accounting for 63% of the increase. Antibodies also appear to wane after vaccination. Seroprevalence in urban areas was higher than in rural areas, but the gap shrunk over time (35.7 v. 25.7% in round 1, 89.8% v. 91.4% in round 4) as the epidemic spread even in low-density rural areas.

Wound Healing Potential of Couroupita guianensis Aubl. Fruit Pulp Investigated on Excision Wound Model.

Wound care management aims at stimulating and improving healing process without scar formation. Although various plants have been reported to possess wound healing properties in tribal and folklore medicines, there is a lack of scientific data to validate the claim. In this aspect, it becomes inevitable to prove the efficacy of naturally derived products at pharmacological levels. Couroupita guianensis as a whole plant has been reported to exhibit wound healing activity. The leaves and fruit of this plant have been utilized in folkloric medicine to cure skin diseases and infections for many years. However, to the best of our knowledge, no scientific studies have been conducted to verify the wound healing properties of C. guianensis fruit pulp. Therefore, the present study seeks to investigate the wound healing potential of C. guianensis fruit pulp using an excision wound model in Wistar albino male rats. This study indicated that the ointment prepared from crude ethanolic extract of C. guianensis fruit pulp facilitated wound contraction that were evidenced by a greater reduction in the wound area and epithelialization period and increased hydroxyproline content. The experimental groups treated with low and mid dose of C. guianensis ethanol extract (CGEE) ointments had shown a wound closure of 80.27% and 89.11% respectively within 15 days, which is comparable to the standard betadine ointment which showed 91.44% healing in the treated groups. Further, the extract influenced the expression of genes VEGF and TGF-ß on post wounding days that clearly explained the strong correlation between these genes and wound healing in the experimental rats. The animals treated with 10% CGEE ointment showed a significant upregulation of both VEGF and TGF-ß as compared with other test and standard groups. These findings provide credence to the conventional application of this plant in the healing of wounds and other dermatological conditions, and may represent a therapeutic strategy for the treatment of wounds.

Comparison of epidural analgesia with ultrasound-guided bilateral erector spinae plane block in aorto-femoral arterial bypass surgery.

OBJECTIVE: Thoracic Epidural Analgesia (TEA) was compared with ultrasound-guided bilateral erector spinae plane (ESP) block in aorto-femoral arterial bypass surgery for analgesic efficacy, hemodynamic effects, and pulmonary rehabilitation. DESIGN: Prospective randomized. SETTING: Tertiary care centre. PARTICIPANTS: Adult patients, who were scheduled for elective aorto-femoral arterial bypass surgery. INTERVENTIONS: It was a prospective pilot study enrolling 20 adult patients who were randomized to group A (ESP block = 10) and group B (TEA = 10). Monitoring of heart rate (HR) and mean arterial pressure (MAP) and pain assessment at rest and deep breathing using visual analog scale (VAS) were done till 48-h post-extubation. Rescue analgesic requirement, Incentive spirometry, oxygenation, duration of ventilation and stay in Intensive Care Unit (ICU) were reported as outcome measures. Statistical analysis was performed using unpaired Student T-test or Mann-Whitney U test. A value of P < 0.05 was considered significant. RESULTS: HR was lower in group B than group A at 1 and 2 h post- surgery and at 0.5, 16, 20, and 32 h post-extubation (P < 0.05). MAP were lower in group B than A at 60, 90, 120, 150, 180, 210, 240, 270 minutes and at 0 hour post-surgery and at 4 hours, every 4 hours till 32 hours post-extubation (P < 0.05). Intraoperative midazolam and fentanyl consumption, ventilatory hours, VAS at rest, incentive spirometry, oxygenation, and ICU stay were comparable between the two groups. VAS during deep breathing was more in group A than B at 0.5, 4 hours and every 4 hours till 44 hours post-extubation. The time to receive the first rescue analgesia was shorter in group A than B (P < 0.05). CONCLUSION: Both ESP block and TEA provided comparable analgesia at rest. Further studies with larger sample size are required to evaluate whether ESP block could be an alternative to TEA in aorto-femoral arterial bypass surgery.

Seroprevalence in Tamil Nadu through India's two COVID waves: Evidence on antibody decline following infection and vaccination

Four rounds of serological surveys were conducted, spanning two COVID waves (October 2020 and April-May 2021), in Tamil Nadu (population 72 million) state in India. Each round included representative populations in each district of the state, totaling [≥]20,000 persons per round. State-level seroprevalence was 31.5% in round 1 (October-November 2020), after Indias first COVID wave. Seroprevalence fell to 22.9% in 2 (April 2021), consistent with waning of antibodies from natural infection. Seroprevalence rose to 67.1% by round 3 (June-July 2021), reflecting infections from the Delta-variant induced second COVID wave. Seroprevalence rose to 93.1% by round 4 (December 2021-January 2022), reflecting higher vaccination rates. Antibodies also appear to wane after vaccination. Seroprevalence in urban areas was higher than in rural areas, but the gap shrunk over time (35.7 v. 25.7% in round 1, 89.8% v. 91.4% in round 4) as the epidemic spread even in low-density rural areas. Article Summary LineAntibodies waned after Indias first COVID wave and both vaccination and infection contributed its roughly 90% seroprevalence after its second wave.

Insecticidal compounds from Rhizophoraceae mangrove plants for the management of dengue vector Aedes aegypti.

BACKGROUND & OBJECTIVES: Mosquito control is facing a threat due to the emergence of resistance to synthetic insecticides. Insecticides of botanical origin could serve as potential alternatives in future. Larvicidal efficacies of different parts of mangrove plants belonging to Rhizophoraceae family were tested against the late IV instar larvae of dengue vector, Aedes aegypti. METHODS: Different plant parts (leaf, bark, root, stilt root, hypocotyl and flower) of Rhizophoraceae family mangrove plants (Bruguiera cylindrica, Ceriops decandra, Rhizophora mucronata and R. apiculata) were collected from Karangadu southeast coast of India. The larval mortality was observed after 24 h exposure. Repellency bioassays were carried out in a 10 Χ 10 Χ 3 m room at 27- 35°C and 60- 80% RH. The bark (A3 and E1) and stilt root (A3 and E4) fractions of R. mucronata with different concentrations (0.25, 0.50, 0.75, 1, 2 and 4 mg/cm) were applied on one arm. RESULTS: The stilt root crude extract of R. mucronata showed maximum larvicidal activity (LC50 value 0.0275 ± 0.0066 µg/ml and LC90 = 0.0695 ± 0.156 µg/ml) followed by the bark extract (LC50 value of 0.03 ± 0.0076 µg/ml and LC90 = 0.0915 ± 0.156 µg/ml). Column chromatographic fractions of R. mucronata bark extracts (E1) showed maximum larvicidal activity (LC50 = 0.0496 ± 0.0085 µg/ml and LC90 = 0.1264 ± 0.052 µg/ml) followed by the acetone extract (LC50 = 0.0564 ± 0.0069 µg/ml and LC90 = 0.1187 ± 0.05 µg/ml). Ethanolic fraction (E4) of R. mucronata stilt root extracts showed maximum larvicidal activity (LC50 = 0.0484 ± 0.0078 µg/ml and LC90 = 0.1191 ± 0.025 µg/ml) followed by acetone fraction (A3) (LC50 = 0.0419 ± 0.0059 µg/ml and LC90 = 0.0955 ± 0.069 µg/ml). Repellent activity of R. mucronata stilt root and bark extracts (A3) showed maximum percentage of protection (97.5%) with 9.1 h protection time at 4 mg concentration of the stilt root extract. Moreover, ethanolic fraction of the stilt root (E4) extract showed maximum percentage of protection (100%) with 10 h protection time at 4 mg concentration. GC-MS analysis revealed that R. mucronata possesses variety of biopesticidal compounds. INTERPRETATION & CONCLUSION: The results as well as the significance of this preliminary investigation highlight the importance of R. mucronata as a novel source for natural insecticidal products.