A subsequent 2017 multicenter RCT of 100 patients in the same groups also found similar pancreatitis rates but a 29.3% higher cost in the pancreatic duct stenting group, suggesting that early precut may be more cost-effective. The relationship between endoscopist experience and the success rates of pre-cut techniques were explored in six studies. Three found a positive correlation between cannulation success rates and endoscopist experience while the other three did not . In the meta-analysis by Sundaralingam et al, it was noted that only studies that involved expert endoscopists and not trainees showed a significant reduction in the risk of pancreatitis in the precut group compared with standard technique. Taken together, these studies suggest that in the hands of experienced endoscopists, early pre-cut techniques may facilitate SBC with lower PEP rates when compared to repeated attempts at standard cannulation. The TPS technique warrants additional discussion as this technique was not specifically evaluated in the studies included in the meta-analysis mentioned above. Through 5 studies, biliary cannulation success rates using TPS ranged from 85% to 100% and adverse events ranging from 3.5% to 20.5% and PEP rates ranging from 3.5% to 22.4% of cases. More recently, a meta-analysis comparing TPS to needle knife PP found significantly a lower success rate and a higher rate of bleeding complication for the needle-knife group but no difference in PEP, perforation, or total complication rates when compared to TPS. The authors conclude that TPS may have a higher SBC success rate with less bleeding but does not reduce the risk of PEP.Another type of rendezvous technique is the percutaneous rendezvous technique , pots with drainage holes in which access to the bile duct is achieved percutaneously , after which a guide wire is threaded anterograde through the needle into the bile duct and out through papilla.
This technique has been used in cases of difficult anatomy, e.g., patients with large, infiltrative tumors involving the papilla or cases of post-operative anatomy, such as Roux-en-Y anastomosis, Billroth II gastrectomy, where the location of the papilla may be difficult to access conventionally or via EUS. Case reports combining the Perc-RV technique with the placement of a hydrophilic guiding angiocatheter at the papilla to facilitate entry of the ST and/or percutaneous balloon dilation of the papilla via the anterograde direction prior to SBC have also been described. A retrospective analysis that looked at 24 patients with SBC failure due to many reasons found a 96% success rate with the perc-RV technique with a 2.4% complication rate . Perc-RV involves increased technical difficulty and training required to obtain percutaneous access to the biliaryducts, however, it allows a percutaneous transhepatic biliary drain to be inserted to alleviate biliary obstruction if other methods of obtaining biliary access fails . There are other methods of performing rendezvous-based SBC such as enteroscopy-assisted EUS or Perc-RV techniques for Roux-en-Y or Billroth II anatomy or intraoperative rendezvous technique where a guide wire is surgically inserted into the biliary ducts. These techniques are beyond the scope of this review, are generally reserved for advanced cases, and are typically performed in specialized endoscopy centers by endoscopists who have had extensive training and experience with difficult cannulation.ERCP has rapidly grown in its therapeutic abilities since its advent 50 years ago. One aspect that has stayed constant that both the first endoscopist to successfully cannulate the papilla, and most endoscopists today, would likely both agree is that successful ERCP hinges on adequate training, careful preparation in selecting the right patient for procedure, ensuring proper positioning and deciding initial techniques. Even with the ideal patient, up to 20% of SBC still fail when using conventional methods of contrast-assisted or WGC and are labelled difficult cannulation.
Although definitions vary, cannulation attempts of a duration over 5-10 min, over 5 attempts, or more than one unintentional MPD cannulation or opacification are the most widely used definitions for difficult cannulation. In this review, we have described steps to be considered and employed when difficult SBC is encountered. If the MPD has been cannulated, then a PD stent or CBD cannulation can be considered to reduce the risk of PEP. When the anatomy of the papilla is unfavorable or a difficult cannulation is anticipated, endoscopists can choose to perform a variety of early precut or rendezvous techniques, the choice of which depends on the experience of the endoscopist, disease being treated, and anatomy of the patient. The decision of which technique to pursue when difficult cannulation is encountered should include consideration of endoscopist experience, patient anatomy, and the disorder being treated, among other factors.Bunch grapes , notably European , are considered among the major fruit crops worldwide, producing roughly 70–80 million tons each year . Cultivars of V. vinifera L. are used for wine, juice, and table grape production. Grape berries are classified as nonclimacteric fruits, exhibiting a double-sigmoid developmental pattern with two rapid growth phases: the berry formation and the ripening phase , separated by an intermediate lag phase called the green plateau . The exponential increase in berry size characterizes both growth stages , but not the lag one . During phases and , also known as immature stages, organic acids, mainly tartrate and malate, accumulate leading to induction of acidity levels . At the end of the lag phase, a step-change point takes place known as veraison, where acidity starts to decline while sugars, mostly glucose and fructose, as well as anthocyanins in colored varieties, increase. Of particular interest are phenolic compounds, which are major and ubiquitous plant secondary metabolites derived from the shikimate/phenylpropanoid and polyketide pathways, with three utmost categories: proanthocyanidins , also known as condensed tannins, the gallo- and ellagitannins , and the phlorotannins . Such diversity of polyphenols, with more than 8000 structural variants, bestows them a wide range of biological functions ranging from growth, development, and protection inside the plant to, to some extent, human-related issues . In grapevines, the accumulation pattern of phenolic compounds, along with the aforementioned berry attributes, distinguishes each of the berry phases throughout berry development . Indeed, berry quality and sensory characteristics are notably defined by its polyphenol content . Remarkably, astringency is among the hardest sensory traits to depict and interpret as many intricate processes underpinning its perception . For instance, a sensory characterisation of the astringency of 11 varietals of Italian red wine revealed that neither total phenols nor PAs can predict how all astringency subtleties will be perceived . It is worth noting that the amounts, compositions, and proportions of polyphenols in a given species may vary widely depending on several factors, such as genotypic variations, developmental stages, and environmental circumstances . Scarlet Royal is a mid-season ripening table grape variety, producing seedless, red-skinned, oval-shaped, firm, and moderate to large berries with a sweet to neutral flavor .
In the San Joaquin Valley, California, it typically ripens in mid to late August, filling the harvest window between Flame Seedless and Crimson Seedless, and has thus become a very popular red table grape variety in California. However, an undesirable astringent taste has been observed occasionally in some cases. In fact, the economic value of grapevines depends substantially on the environmental conditions, including climate, soil, cultural practices, cultivar, and rootstock. Hence, the term “terroir” is used in viticulture to describe the effect of such an interactive ecosystem on grapevine and wine quality . The current study aimed to understand the underlying mechanism of astringency development in Scarlet Royal berries at two contrasting vineyards . The first location produces well-colored, non-astringent berries; however, drainage pot the second site yields astringent taste, poorly colored berries . The data showed a large variation in berry astringency within the same vineyard and from year to year. The data illustrated that the divergence in berry astringency stemmed from alterations in its polyphenol composition , most notably tannins. Additionally, the ripening stage was the most distinguishing platform for such variation between both vineyards. We were able to determine the tannins’ threshold level that causes the Scarlet Royal astringency taste to be ~ 400 mg/L. Given the changes in the levels of polyphenols during berry ripening, the question was raised: what is the mechanism governing the distinctive tannins accumulation pattern between V7-berries and V9-berries, and hence astringency diversity? To answer this question, RNA-seq data generated at one ripening time point was associated to the changes in polyphenolic levels using a systems biology approach, WGCNA . The module-trait association analysis positively correlated the key flavonoid/PAs biosynthetic genes with the accumulation of tannins, catechin, and quercetin glycosides exclusively in V9-berries. The modulation of the berry’s transcriptomic profile is concomitant with its polyphenols’ composition, which finally disturbs berry quality, including astringency levels.Five-year-old V. vinifera cv. Scarlet Royal grafted on Freedom rootstock was chosen for its berry astringency diversity at two commercial vineyards located in Delano, San Joaquin Valley, California, USA. Vineyards were located at a close distance of 10 km, and the local weather conditions during the two seasons were collected from the Delano CIMIS weather station . Both vineyards were planted at the spacing of 2.44 and 3.66 m in an open gable trellis supporting system with East-West row orientation. Vines were pruned in a Quadrilateral cordon training with 7–8 spurs left on each cordon during the winter pruning. In addition, general UC guidelines practices were applied in both vineyard. Starting from veraison and until the end of the season, during two consecutive years . During the first year, sampling dates were July 8th , August 1st , August 10th , September 9th , September 15th , and October 19th ; and for the second year, sampling dates were: July 15th , August 10th , August 25th , September 10th , September 29th , and October 21st . Sampling dates varied from the first to the second year due to the vineyard’s accessibility. At each sampling point, two sets of fifty berries were collected periodically. The first set was used to measure the berry weight, and then these berries were macerated in an electric blender, filtered through a paper towel, and an aliquot of juice was used to determine soluble solids , pH, and titratable acidity . Soluble solids were determined using a tabletop Milwaukee MA871-BOX digital refractometer . The TA and pH were determined by titrating a 40 mL aliquot of juice with 0.1 N NaOH to a pH of 8.2 using an automatic titrator Excellence T5 . Another random 50 berries from each replicate were collected for color, tannins, and phenolic compounds and sent immediately in a cooler to EST laboratories. At harvest, which was during the month of September, an extra set of samples was collected and promptly frozen in liquid nitrogen and stored at −80°C for subsequent analysis, including RNA extraction and gene expression studies. Harvest time was determined by the growers, and the marketable clusters were picked based on the color, and yield was determined from the three harvest dates.At bloom, fifty leaves from each replicate were collected, resulting in a total of 200 leaves from each vineyard, for nutrient analysis. The leaf positioned at the front of the cluster was specifically selected, and the petiole was immediately separated from the blade. The petioles were transported to the laboratory, where they were triple-washed with distilled water to remove any impurities before being sent to a private laboratory for nutrient analysis. In the winter, soil samples were collected at a depth of 30 cm and at a distance of 30 cm from the vine. These samples were transported immediately to the laboratory for analysis. The nutrient content was determined using the methods described in US Salinity Laboratory Staff .The taste panel evaluation of Scarlet Royal table grapes was conducted with the participation of twelve nonprofessional panelists. Astringent taste perception was assessed using a scale ranging from one, representing an extremely low level of astringency, to seven, indicating an extremely high level of astringency. The taste evaluation was performed on 24 clusters from each vineyard. Phenolic compounds analysis. Total phenolic analysis was performed on 250 grams of whole berries by ETS laboratory using a reversed-phase HPLC method adapted from Price et al. .Total RNA was isolated from whole berry samples following the protocol described by Boss et al. . To remove any residual DNA, RNase-free RQI treatment was performed according to the manufacturer’s instructions , and the samples were further purified using the RNeasy mini kit .