Enhancing climate change resilience in agricultural crops.

Climate change threatens global food and nutritional security through negative effects on crop growth and agricultural productivity. Many countries have adopted ambitious climate change mitigation and adaptation targets that will exacerbate the problem, as they require significant changes in current agri-food systems. In this review, we provide a roadmap for improved crop production that encompasses the effective transfer of current knowledge into plant breeding and crop management strategies that will underpin sustainable agriculture intensification and climate resilience. We identify the main problem areas and highlight outstanding questions and potential solutions that can be applied to mitigate the impacts of climate change on crop growth and productivity. Although translation of scientific advances into crop production lags far behind current scientific knowledge and technology, we consider that a holistic approach, combining disciplines in collaborative efforts, can drive better connections between research, policy, and the needs of society.

Atrazine and nicosulfuron affect the reproductive fitness of the predator Podisus nigrispinus (Hemiptera: Pentatomidae).

Herbicides can impact non-target metabolic pathways in natural enemies and lead to the reduction of these populations in the field. Behavioral characteristics, morphology and histology of reproductive structures and reproduction of females of Podisus nigrispinus (Dallas) (Hemiptera: Pentatomidae) were evaluated under the effect of the herbicides atrazine, nicosulfuron and the mixture of both. The number of mature oocytes per ovary was lower in females exposed to the herbicides atrazine, nicosulfuron and the mixture of both. Herbicides did not affect the longevity and mortality of P. nigrispinus, therefore, they are selective for this predator. On the other hand, herbicides can cause sublethal effects by affecting the reproduction of predators.

Persistence of auxinic herbicides applied on pasture and toxicity for succeeding crops.

The aim of this work was to determine the persistence of auxinic herbicides applied on tropical pasture and toxicity for succeeding crops. The herbicides were applied in an area of dystrophic red‒yellow latosol with pasture infested of weeds. At 40, 80, and 280 days after application of herbicide, the soil samples were collected at depths of 0 to 20 cm. Soil with residues of 2,4-D, 2,4-D + picloram, triclopyr, and a soil without herbicide application were analyzed with six replicates. Seven crops were cultivated in these soils: cucumber (Cucumis sativus L.), velvet bean [Mucuna pruriens (L.) DC.], pigeon pea [Cajanus cajan (L.) Millsp.], alfalfa (Medicago sativa L.), lablab bean [Lablab purpureus (L.) Sweet], corn (Zea mays L.), and sorghum [Sorghum bicolor (L.) Moench]. The plants of cucumber, pigeon pea, and alfalfa were the most susceptible to the auxinic herbicide residues. However, the lablab bean was the only one among the dicot evaluated that showed tolerance to the 2,4-D + picloram residual when cultivated in soils at 280 days after application of herbicide. Corn and sorghum showed lower chlorophyll content in soils with 2,4-D + picloram residual up to 80 days after application of herbicide.

Mechanical effect of the Angelchik prosthesis on the competency of the gastric cardia: pathophysiologic implications and surgical perspectives.

The Angelchik prosthesis appears to be effective in preventing gastroesophageal reflux, although its precise mechanism of action remains controversial. In a unique in vitro model, 10 freshly harvested canine esophagogastric specimens were tested for their ability to remain competent against challenges of intragastric pressure under controlled conditions of intra-abdominal pressure, longitudinal esophageal tension, lower esophageal sphincter pressure and overall length and circumference of the cardia (measure of gastric dilatation). Competency of the specimen was assessed by stepwise variation in the overall length of the sphincter, while keeping constant intraabdominal pressure (20 cm H2O), intragastric pressure (20 cm H2O), esophageal tension (physiologic), lower esophageal sphincter pressure (15 cm H2O) and degree of gastric dilatation (3 cm). With each specimen serving as its own control, the effect produced by the application of an Angelchik prosthesis was evaluated. Results consistently demonstrated that at any lower esophageal sphincter length the percent of competency was increased when the prosthesis was applied (P < 0.01). The findings indicate that the Angelchik prosthesis controls reflux by preventing unfolding of the lower esophageal sphincter when challenged by intragastric pressure.

Splenic and gastro-duodenal vein occlusion--influence on the pancreatic gland and on the outcome of experimental pancreatitis.

The observation that splenic vein thrombosis results in pancreatic changes similar to haemorrhagic pancreatitis initiated the present investigation. The influence of splenic and/or gastroduodenal vein occlusion on the pancreatic gland was evaluated and compared to that obtained after induction of experimental pancreatitis (EP). The influence of splenic vein occlusion on EP was also investigated. An approximately 4-fold increase in serum amylase activity was obtained after simultaneous ligation of the splenic and gastroduodenal veins. This increase was comparable to that obtained after EP. On the other hand, amylase activity in ascites was considerably lower after vein occlusion than after EP. Splenic vein occlusion in rats with EP more moderately increased the amylase activity but did not influence mortality rate 24 h postoperatively. Venous thromboses were observed in all groups with occluded veins but not in rats with EP. Vein occlusion alone did not result in fat necroses. Although occlusion of the splenic and gastroduodenal veins results in macromorphologic and biochemical changes resembling those in EP, the microscopic findings of the two conditions differ. Thus, the results do not support the hypothesis that pancreatic vein thromboses are of etiologic significance for the development of acute haemorrhagic pancreatitis.

Plasmapheresis and haemodialysis in a case of septic cholangitis complicated by hepatic and renal failure. Case report.

Plasmapheresis was used as a complement to conventional therapy in a patient with multiorgan failure and disseminated intravascular coagulation (DIC) following biliary obstruction and septic cholangitis. The patient's remarkable improvement after plasmapheresis suggests a beneficial influence on the pathophysiologic mechanisms. Plasmapheresis is concluded to inhibit DIC and eliminate endotoxins.

Major liver resection for hilar cholangiocarcinoma.

Between 1968 and 1984 liver resection with curative attempt was performed in 22 patients with hilar cholangiocarcinoma. Right lobectomy was performed in 4 patients, extended right lobectomy in 7, left lobectomy in 8, and excision of the median segment segment of the left lobe (segment IV) in 3. Bilio-enteric continuity was restored by hepatocholedochostomy in 17 patients and hepatojejunostomy in 4. (One patient had external transhepatic catheter drainage and no internal bile drainage.) Operative mortality rate was 27% and caused by excessive intraoperative bleeding, sepsis, or liver insufficiency. Postoperative complications occurred in 57% of patients surviving the operation and were due mainly to leakage from the hepatocholedochostomy. Median survival was 6 months, and one third of the patients survived 1 year. Three patients survived 10 years and were among the four patients in whom a tumor-free resection margin was obtained (one of them died in the postoperative phase). It is concluded that resection of hilar cholangiocarcinoma may give long-term survival if a free resection margin is obtained. The importance of a free resection margin indicates that surgery should be aggressive and include liver resection.

Composition of the refluxed material determines the degree of reflux esophagitis in the dog.

To evaluate the influence of the composition of refluxed material in the pathogenesis of esophagitis, a dog model was used to allow esophageal reflux of gastric secretions, duodenal pancreaticobiliary secretions, and a combination of both. Control dogs had only an esophageal incision. Incompetence of the cardia was established in five other groups by transecting the distal sphincter and creating a hiatal hernia. Two groups received moderate or maximal histamine stimulation of gastric secretion. A gastrojejunostomy, pyloromyotomy, and duodenal closure distal to the papilla were added in the other three groups, creating duodenogastric reflux; two were stimulated with histamine and one had a truncal vagotomy and no histamine. Radiologic, manometric, and pH studies showed that incompetence of the cardia was obtained. The dogs were killed 4 wk postoperatively and evaluated for gross and microscopic evidence of esophagitis. Erosive esophagitis was found only in dogs with reflux of gastric juice following maximal acid stimulation. Microscopic reflux changes in esophageal mucosa were seen in all groups; again, changes were most pronounced in dogs with maximal gastric stimulation. The combination of duodenogastric reflux and moderate gastric stimulation produced more significant alterations in microscopic reflux criteria than did moderate gastric stimulation alone. Our conclusions are as follows: In a dog model of gastroesophageal reflux of various combinations of gastric and duodenal secretory components, erosive esophagitis occurred only with maximal gastric stimulation in the absence of duodenogastric reflux. All reflux combinations, however, produced some degree of microscopic changes, suggesting they could eventually cause gross changes with a lengthened experimental time span.

The value of preoperative imaging techniques in patients with chronic pancreatic pleural effusions.

Four patients with chronic pancreatitis and internal pancreatic fistulae to the left pleura are presented. ERCP was done in three of the patients and demonstrated the fistulae in all. In the forth patient CT gave valuable information. In patients with suspicion of internal pancreatico-pleural fistulae we recommend preoperative ERCP for demonstration of the internal demarcations of the ductal and fistula systems and CT for delineation of the external boundaries and relationships of the pathological lesions.

Influence of peritoneal lavage on objective prognostic signs in acute pancreatitis.

In 39 patients with severe attacks of acute pancreatitis, a longitudinal study was done with respect to the influence of peritoneal lavage on objective prognostic signs (WBC, blood-glucose, serum-calcium, hematocrit, serum-creatinine, arterial pO2, base deficit); amylase activities in peritoneal fluid, serum, and urine; serum-hemoglobin, serum-Na, serum-K, and plasma-insulin. In addition to standard care in the ICU, half of the patients (N = 19) were randomly treated with peritoneal lavage. Peritoneal lavage did not influence overall mortality (13%), incidence of major complications (36%), or hospital stay (23 +/- 7 days). None of the prognostic signs was significantly influenced by lavage. Amylase concentration in peritoneal fluid was significantly reduced in the lavaged group after 6 hours compared to 24 hours in controls. Serum and urinary amylase decreased 12 hours earlier in the lavaged group, indicating an efficiency of the lavage procedure per se. Still, this study did not reveal any beneficial clinical effects of peritoneal lavage in acute pancreatitis.

Esophagojejunostomy with the EEA stapler.

Esophagojejunostomy after total gastrectomy was attempted in 27 operations with the EEA stapling device (U.S. Surgical Corp., Norwalk, Conn.). After removal of the specimen the anastomosis is performed with an end-to-side technique with insertion of the cartridge and its central rod through the open jejunal end. The 28 mm wide cartridge was used in 24 anastomoses and the 25 mm wide cartridge was used in two. In one case the 25 mm cartridge tore the distal esophagus, and the anastomosis had to be sutured manually. The median operation time was 305 minutes (range, 205 to 560 minutes), and the time to perform the anastomosis was 20 minutes (range, 15 to 60 minutes). Anastomotic leakage occurred in three patients, two of whom were stapled with the 25 mm cartridge. All healed with conservative treatment. One patient developed a stricture at the anastomotic site due to recurrence of the tumor. There was one hospital death. Median hospital stay was 16 days (range, 8 to 71 days) and median survival time was 11 months. It is concluded that the EEA stapler allows the construction of a fast and reliable esophagojejunostomy with good functional results after total gastrectomy for gastric cancer.

Physiologic evaluation of esophageal function in patients with achalasia and diffuse esophageal spasm.

To evaluate function of the normal and pathologic esophageal body under more physiologic conditions than those utilized for traditional laboratory testing, manometry was performed before and during eating using a catheter assembly containing three peripheral transducers. Studies were evaluated from seven normal volunteers, 18 typical achalasia patients (eight before and 10 after esophagomyotomy), and eight patients with diffuse esophageal spasm (DES) as characterized by frequent simultaneous and repetitive contractions. In the preprandial period, all had similar frequencies of esophageal contractions, although there was a wide range. During eating, the frequency of contractions increased in all groups; however, the contraction frequency in unoperated achalasia patients, 12.7 +/- 5.0 contractions/min, significantly exceeded the frequency in normal volunteers of 4.9 +/- 1.3 contractions/min, p less than 0.01. The frequency was lower in operated achalasia patients, 9.4 +/- 6.5 contractions/min, but still exceeded that of normal volunteers, p less than 0.01. Patients with DES also had more frequent contractions, 10.5 +/- 9.7 contractions/min, than did the normal volunteers, p less than 0.01. The mean pressure of esophageal contractions for both achalasia groups was similar and was significantly lower than for the normal volunteers. Pressure in the DES patients was intermediate. It is concluded that patients with achalasia have lower pressure but more frequent contractions than normal volunteers during eating, and this spasm-like activity may be a more important pathophysiologic factor in their dysphagia than previously recognized. Esophagomyotomy does decrease the frequency of these contractions. Frequency, but not pressure, of contractions differs from normal in patients with DES.

Healing of esophagojejunal anastomoses after experimental total gastrectomy. A comparative study using manually sutured or stapled anastomoses.

In construction of the eosphagojejunostomy after total gastrectomy, the EEA stapled (US Surgical Corporation, Norwalk, CT) and the two-layer interrupted 3-0 Dexon anastomoses are compared concerning the radiological appearance, breaking strength, circulation, and collagen concentration. Thirty female pigs were used. After total gastrectomy and Roux-en-Y preparation, the pigs were randomized to achieve sutured or stapled anastomoses. 141Ce-labeled microspheres were used for measurements of anastomotic blood flow. After the pigs were killed, the breaking strength of the anastomosis was recorded, the collagen content determined, and an anastomotic index calculated comparing two perpendicular diameters in the anastomosis and 5 cm above. Breaking strength, leakage frequency, and anastomotic index were the same in the two groups. One week after surgery, there was a significant increase in anastomotic circulation (p less than 0.05) in both the sutured and the stapled anastomoses compared to controls. Collagen increased equally with time in the two groups (p less than 0.01). The stapled esophagojejunostomy was faster to perform (20 min) than the sutured (28 min) (p less than 0.05).

Length of the distal esophageal sphincter and competency of the cardia.

Pressure and abdominal length of the distal esophageal sphincter are important factors in maintaining competency of the cardia against challenges of intraabdominal pressure. Some patients with normal distal esophageal sphincter pressure and position may have reflux which could be due to the inability of the cardia to overcome challenges of intragastric pressure. Three experimental studies and one clinical study were designed to evaluate this problem. The results showed that the resistance to flow through the cardia is related to the integrated effect of distal esophageal sphincter pressure and length; the ratio of distal esophageal sphincter to intragastric pressure necessary to maintain competency is inversely related to the length of sphincter present; gastric dilatation has an adverse effect on the degree of competency achieved by a given distal esophageal sphincter length; and patients with an overall distal esophageal sphincter length of 2 cm or less measured at rest in the fasting state are subject to reflux caused by gastric dilatation, increased intragastric pressure independent of intraabdominal pressure, or both.

Influence of morphine on the distal oesophagus and the lower oesophageal sphincter--a manometric study.

Basal pressure and relaxation of the lower oesophageal sphincter (LOS) as well as amplitude, duration and propagation velocity of peristaltic waves in the distal third of oesophagus were measured in 15 healthy adults (nine men and six women). A highly standardised technique was used employing manometric equipment including a low-compliance pneumohydraulic infusion system and a triple lumen recording catheter. After establishment of baseline manometry values the catheter was positioned with its distal orifice in the lower oesophageal sphincter. In 10 subjects 0.2 mg/kg body weight of morphine sulphate was then injected subcutaneously. In five others equal volume of saline was given. The manometric data were analysed blindly. Repeated manometric evaluations were carried out 15, 30, 45, 60, and 75 minutes after the injection. Morphine increased slightly LOS-pressure and significantly (p less than 0.001) decreased LOS-relaxation, the maximal effect occurring 30 minutes after the injection. Amplitude of peristaltic waves increased slightly but insignificantly, whereas propagation velocity and duration were uninfluenced. The results of this study suggest that pharmacologic doses of morphine influence normal function of the LOS and possibly the distal oesophagus. The role of endogenous opiates in this respect, however, awaits further studies. It is suggested that abnormalities in opioid neurotransmission may explain some of the non-specific oesophageal motility disorders.

Influence of intraluminal trypsin activity on the course of acute experimental pancreatitis.

In short-term experiments (25 or 72 h) oral trypsin inhibitor administration to pancreatitic rats significantly decreased survival rate, whereas oral trypsin administration had no effect in this respect. Neither treatment influenced the activities of amylase in serum, pancreatic tissue or ascites. Trypsin given in excess together with the trypsin inhibitor abolished the deleterious effects on survival caused by the trypsin inhibitor. In a long-term experiment in healthy rats oral trypsin inhibitor ingestion caused a significant increase in pancreatic wet weight, protein concentration and activities of amylase, lipase and trypsinogen in pancreatic tissue; again, trypsin administration had no effect. The data support the idea that oral trypsin inhibitor administration causes release of cholecystokinin (CCK) or CCK-like factors from the intestine by interfering with the negative feedback regulation exerted by intraluminal trypsin. The results of the short-term experiments further indirectly suggest that even small amounts of trypsin within the intestine - as in acute pancreatitis - can exert the feedback regulation. Finally, the results of the long-term experiment suggest that oral administration of trypsin does not exert any suppressive effects on pancreatic wet weight and pancreatic enzyme content.

Hormonal and cholinergic effects on amylase and lysosomal enzyme activities in pancreatic tissue and ascites of rats with acute experimental pancreatitis.

The effects of hormonal or cholinergic stimulation on survival and on activities of lysosomal enzymes and amylase in pancreatic tissue and ascites were studied in rats with induced pancreatitis. Pancreatitis per se caused an increase of the activities of cathepsin D, N-acetyl-beta-D-glucosaminidase and amylase, and a decrease of acid phosphatase in pancreatic tissue. Pancreatic protein concentration was not influenced. In pancreatitic rats administration of cerulein or carbachol markedly decreased survival rate. Cerulein increased the activities of cathepsin D and amylase in ascites and cathepsin D and acid phosphatase in pancreatic tissue. Carbachol increased the activities of cathepsin D and amylase in ascites and acid phosphatase in pancreatic tissue. Both cerulein and carbachol decreased the activity of amylase in pancreatic tissue. Administration of secretin or the anticholinergic drug Pro-Banthine did not influence survival rate or the activities of lysosomal enzymes and amylase in ascites. In pancreatic tissue the activity of acid phosphatase was slightly increased by secretin or Pro-Banthine. In conclusion, the results show a nonparallel alteration of lysosomal enzyme activities in pancreatic tissue in rats with pancreatitis. Cerulein and cholinergic stimulation decreased survival rate and brought about a marked increase of cathepsin D activity in ascites and, in the case of cerulein, also in pancreatic tissue. The implication of lysosomes and especially the catheptic proteases in the pathogenesis and outcome of acute pancreatitis deserves further attention.

Percutaneous transhepatic cholangiography and drainage. Risks and complications.

An analysis of 237 consecutive PTC/PTD procedures revealed radiographically demonstrable complications in 21 per cent (50/237 cases: bile-contrast medium leakage 24 cases, haemobilia 18 cases) and clinically registered complications in 11% (26/237 cases: bile or blood leakage with or without peritonitis in 10 cases). Two deaths occurred. When possible, a drainage catheter was inserted for decompression. This was performed on 184 occasions in 139 patients--failure rate was 5 per cent. Unsuccessful attempt to introduce a drainage catheter constituted a major complication risk occurring in 5/13 cases (38%). Signs of infection were frequent though these complications were not a major problem in this series. Various possibilities to reduce complications and infections are discussed.