Role of Signaling Molecules Sodium Nitroprusside and Arginine in Alleviating Salt-Induced Oxidative Stress in Wheat.

Nitric oxide (NO) is a well-accepted signaling molecule that has regulatory effects on plants under various stresses. Salinity is a major issue that adversely affects plant growth and productivity. The current study was carried out to investigate changes in the growth, biochemical parameters, and yield of wheat plants in response to NO donors, namely sodium nitroprusside (SNP) (2.5 and 5.0 mM) and arginine (10 and 20 mM), under two salinity levels (1.2 mM and 85.5 mM NaCl). Salinity stress significantly decreased the lengths and weights of plant parts (shoot, tiller, and root) and reduced the flag leaf area, photosynthetic pigments, indole acetic acid (IAA), and yield and its components. Moreover, salt stress induced a significant accumulation of some osmoprotectants (total soluble sugars (TSS) and amino acids, especially proline) and triggered the accumulation of hydrogen peroxide (H2O2) and lipid peroxidation in wheat leaves. In contrast, arginine and SNP treatments significantly mitigated the negative impacts of salinity on growth and productivity via enhancing photosynthetic pigments, nitrate reductase, phenolic compounds, IAA, TSS, free amino acids, and proline. In addition, SNP and arginine potentially reduced oxidative damage by decreasing H2O2 and lipid peroxidation through the induction of antioxidant enzymes. The individual amino acid composition of wheat grains under the interactive effect of salinity and NO sources has been scarcely documented until now. In this study, the NO sources restrained the reduction in essential amino acids (isoleucine and lysine) of wheat grains under salinity stress and further stimulated the contents of non-essential and total aromatic amino acids. Interestingly, the applied protectants recovered the decrease in arginine and serine induced by salinity stress. Thus, SNP or arginine at the levels of 5.0 and 20 mM, respectively, had a profound effect on modulating the salt stress of wheat throughout the life cycle.

Strategy of Salt Tolerance and Interactive Impact of Azotobacter chroococcum and/or Alcaligenes faecalis Inoculation on Canola (Brassica napus L.) Plants Grown in Saline Soil.

A pot experiment was designed and performed in a completely randomized block design (CRBD) to determine the main effect of two plant growth-promoting rhizobacteria (PGPR) and their co-inoculation on growth criteria and physio-biochemical attributes of canola plants (Brassica napus L.) plant grown in saline soil. The results showed that inoculation with two PGPR (Azotobacter chroococcum and/or Alcaligenes faecalis) energized the growth parameters and photosynthetic pigments of stressed plants. Moreover, soluble sugars' and proteins' contents were boosted due to the treatments mentioned above. Proline, malondialdehyde (MDA), and hydrogen peroxide (H2O2) contents were markedly declined. At the same time, antioxidant enzymes, viz. superoxide dismutase (SOD), ascorbate peroxidase (APX), and peroxidase (POD), were augmented due to the inoculation with Azotobacter chroococcum and/or Alcaligenes faecalis. Regarding minerals' uptake, there was a decline in sodium (Na) and an increase in nitrogen (N), potassium (K), calcium (Ca), and magnesium (Mg) uptake due to the application of either individual or co-inoculation with the mentioned bacterial isolates. This study showed that co-inoculation with Azotobacter chroococcum and Alcaligenes faecalis was the most effective treatment and could be considered a premium tool used in facing environmental problems, especially saline soils.

Mechanistic Insight of Allantoin in Protecting Tomato Plants Against Ultraviolet C Stress.

Allantoin ((AT) a purine metabolite)-mediated ultraviolet C (UVC) stress mitigation has not been studied to date. Here, we reported the physicochemical mechanisms of UVC-induced stress in tomato (Solanum lycopersicum L.) plants, including an AT-directed mitigation strategy. UVC stress reduced plant growth and photosynthetic pigments. Heatmap and principal component analysis (PCA) revealed that these toxic impacts were triggered by the greater oxidative damage and disruption of osmolyte homeostasis. However, pre-treatment of AT noticeably ameliorated the stress-induced toxicity as evident by enhanced chlorophyll, soluble protein, and soluble carbohydrate contents in AT-pretreated UVC-stressed plants relative to only stressed plants leading to the improvement of the plant growth and biomass. Moreover, AT pre-treatment enhanced endogenous AT and allantoate content, phenylalanine ammonia-lyase, non-enzymatic antioxidants, and the enzymatic antioxidants leading to reduced oxidative stress markers compared with only stressed plants, indicating the protective effect of AT against oxidative damage. Moreover, PCA displayed that the protective roles of AT strongly associate with the improved antioxidants. On the other hand, post-treatment of AT showed less efficacy in UVC stress mitigation relative to pre-treatment of AT. Overall, this finding illustrated that AT pre-treatment could be an effective way to counteract the UVC stress in tomato, and perhaps in other crop plants.

Polyneuropathy Associated with Severe Iron Overload and Oxidative Stress in ß-Thalassemia Patients.

To investigate the frequency of peripheral neuropathy in patients with ß-thalassemia, and to assess its relation to iron overload and oxidative stress. Sixty ß-thalassemia patients with mean age of 19 ± 4.9 years were recruited. Serum ferritin was quantitatively assessed by enzyme-linked immunoassay and biomarkers of oxidative stress were estimated calorimetrically. Electrophysiological studies using NEMUS 2, Galileu Software were carried out. The patients were separated into two groups: those with abnormal nerve conduction studies (NCS) {Group A; N = 38} and those with normal NCS {Group B; N = 22}. Thirty-eight (63.3%) patients had axonal motor neuropathy as evidenced by abnormal NCS (group A), they showed higher mean serum ferritin (p < 0.01), higher mean malondialdehyde (MDA) (p < 0.01), and lower mean nitrous oxide, total antioxidant capacity, paraoxonase-1 (PON1) (p < 0.01) compared to group B. Bivariate analysis of NCS data demonstrated that abnormal NCS were more frequent in splenectomized patients (p = 0.002), and poorly-chelated patients with serum ferritin ≥ 2000 ng/ml (p = 0.001). Significant variables associated with abnormal motor NCS were entered in stepwise regression analysis and only elevated serum ferritin (p = 0.01) was independently associated with abnormal motor NCS (p = 0.02; 95% CI 1.433-51.791). None of the studied patients had sensory neuropathy or myopathy. Peripheral motor neuropathy may occur in ß-thalassemia patients at a high frequency, regardless of their age and gender. Severe iron overload may contribute to the pathogenesis of neuropathy. Other factors including chelation therapy, splenectomy, and oxidative stress might have an enhancing effect that couldn't be proved in this study.

Does the surgical approach for treating mandibular condylar fractures affect the rate of seventh cranial nerve injuries? A systematic review and meta-analysis based on a new classification for surgical approaches.

PURPOSE: The purpose of this study was to determine the rate of facial nerve injury (FNI) when performing (ORIF) of mandibular condylar fractures by different surgical approaches. MATERIALS AND METHODS: A systematic review and meta-analysis were performed that included several databases with specific keywords, a reference search, and a manual search for suitable articles. The inclusion criteria were all clinical trials, with the aim of assessing the rate of facial nerve injuries when (ORIF) of mandibular condylar fractures was performed using different surgical approaches. The main outcome variable was transient facial nerve injury (TFNI) and permanent facial nerve injury (PFNI) according to the fracture levels, namely: condylar head fractures (CHFs), condylar neck fractures (CNFs), and condylar base fractures (CBFs). For studies where there was no delineation between CNFs and CBFs, the fractures were defined as CNFs/CBFs. The dependent variables were the surgical approaches. RESULTS: A total of 3873 patients enrolled in 96 studies were included in this analysis. TFNI rates reported in the literature were as follows: A) For the transoral approach: a) for strictly intraoral 0.72% (1.3 in CNFs and 0% for CBFs); b) for the transbuccal trocar instrumentation 2.7% (4.2% in CNFs and 0% for CBFs); and c) for endoscopically assisted ORIF 4.2% (5% in CNFs, and 4% in CBFs). B) For low submandibular approach 15.3% (26.1% for CNFs, 11.8% for CBFs, and 13.7% for CNFs/CBFs). C) For the high submandibular/angular subparotid approach with masseter transection 0% in CBFs. D) For the high submandibular/angular transmassetric anteroparotid approach 0% (CNFs and CBFs). E) For the transparotid retromandibular approach a) with nerve facial preparation 14.4% (23.9% in CNFs, 11.8% in CBFs and 13.7% for CNFs/CBFs); b) without facial nerve preparation 19% (24.3% for CNFs and 10.5% for CBFs). F) For retromandibular transmassetric anteroparotid approach 3.4% in CNFs/CBFs. G) For retromandibular transmassetric anteroparotid approach with preauricular extension 2.3% for CNFs/CBFs. H) For preauricular approach a) deep subfascial dissection plane 0% in CHFs b) for subfascial approach using traditional preauricular incision 10% (8.5% in CHFs and 11.5% in CNFs). I) For retroauricular approach 3% for CHFs. PFNI rates reported in the literature were as follows: A) for low submandibular approach 2.2%, B) for retromandibular transparotid approach 1.4%; C) for preauricular approach 0.33%; D) for high submandibular approach 0.3%; E) for deep retroparotid approach 1.5%. CONCLUSION: According to published data for CHFs, a retroauricular approach or deep subfascial preauricular approach was the safest to protect the facial nerve. For CNFs, a transmassetric anteroparotid approach with retromandibular and preauricular extension was the safest approach to decrease risk of FNI. For CBFs, high submandibular incisions with either transmassetric anteroparotid approach with retromandibular or transmassetric subparotid approach, followed by intraoral (with or without endoscopic/transbuccal trocar) were the safest approaches with respect to decreased risk of FNI.

Stability of large maxillary advancements using a combination of prebent and conventional plates for fixation.

OBJECTIVE: The purpose of this study was to determine the stability of one and two jaw maxillary advancements fixed with prebent plates and "L"-shaped plates. STUDY DESIGN: Twenty-six patients met the inclusion criteria (group 1: one jaw [14]; group 2: two jaws [12]). Radiographs were digitized before surgery (T1), immediately after surgery (T2), at 6 weeks (T3), and at 6 months (T4). Stability was assessed comparing A-point movement and change in palatal plane. t tests were used for comparisons between groups, and linear regression analysis was used to assess the stability of A-point T2-T4 versus A-point movement T1-T2 and changes in the palatal plane T1-T2. RESULTS: Initial A-point movement between the two groups was significant (group 1 = 7.61 ± 1.73; group 2 = 5.22 ± 1.67) (P = .0002). Both showed relapse (group 1 = 0.78 ± 0.95; group 2 = 0.04 ± 0.49). Although there was no significant relationship between initial A-point movement and relapse, there was a significant negative relationship between change in palatal plane and relapse in group 1. When initial A-point movement and change in palatal plane were combined, as both increased, relapse also increase (P = .007; R2 = 0.41). CONCLUSIONS: Prebent plates used with "L" plates are a stable fixation technique. Relapse increases with large advancements and change in palatal plane (posterior impaction).

A Modified Technique for Placing Prebent Plates during a Le Fort I Osteotomy: A Technical Note.

Prebent plates have gained popularity in recent years as a fixation appliance for large maxillary advancements. They are larger than standard plates used for maxillary procedures and appear to give greater stability. Due to their size and configuration, they have the potential to be more palpable than standard plates, possibly causing discomfort following placement. With a simple "box" osteotomy of the maxilla at the site of placement and a minor modification of the plate, the plate is less palpable and better tolerated by the patient.