An update and perspectives on the use of promoters in plant genetic engineering

Genetically engineered plants have varied applications in agriculture for enhancing the values of food and feed.Genetic engineering aims to introduce selected genetic regions with desirable traits into target plants for bothspatial and temporal expressions. Promoters are the key elements responsible for regulating gene expressionsby modulating the transcription factors (TFs) through recognition of RNA polymerases. Based on theirrecognition and expression, RNA polymerases were categorized into RNA pol II and pol III promoters.Promoter activity and specificity are the two prime parameters in regulating the transgene expression. Since theuse of constitutive promoters like Cauliflower mosaic virus (CaMV) 35S may lead to adverse effects on nontarget organisms or ecosystem, inducible/tissue specific promoters and/or the RNA pol III promoters providemyriad opportunities for gene expressions with controlled regulation and with minimum adverse effects.Besides their role in transgene expression, their influence in synthetic biology and genome editing are alsodiscussed. This review provides an update on the importance, current prospects, and insight into the advantagesand disadvantages of promoters reported thus far would help to utilize them in the endeavour to developnutritionally and agronomically improved transgenic crops for commercialization.

Effect of a combination of oral midazolam and low-dose ketamine on anxiety, pain, swelling, and comfort during and after surgical extractions of mandibular third molars.

Purpose: To assess the clinical efficacy of a combination of oral midazolam plus low-dose ketamine for reducing anxiety during surgery and in preventing postoperative pain and swelling after the surgical extraction of third molars. Materials and Methods: Thirty patients requiring bilateral surgical extraction of mandibular third molars were included in this study. Prior to extraction of the tooth on the right side, a combination of oral midazolam and low-dose ketamine was given to the patient, while this protocol was not followed for extraction of the tooth on the left side. Anxiety levels were checked before surgery. The postoperative pain and swelling and patient's comfort with and without the premedication were compared. Results: Facial swelling on the postoperative days was lower on the right side than on the left. Pain scores at 30 minutes and 24 hours after surgery were significantly higher on the left side. Also, anxiety during the surgery was less and comfort levels were higher postoperatively when the combination of oral midazolam plus low-dose ketamine was used. Conclusions: Premedication with midazolam plus low-dose ketamine prior to surgical extraction of third molars can provide the patient with a comfortable procedure and good postoperative analgesia, with less swelling and significantly less pain.