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Being able to adapt our movements to changing circumstances allows people to maintain performance across a wide range of tasks throughout life, but it is unclear whether visuomotor learning abilities are fully developed in young children and, if so, whether they remain stable in the elderly. There is limited evidence of changes in motor adaptation ability throughout life, and the findings are inconsistent. Therefore, our goal was to compare visuomotor learning abilities throughout the lifespan. We used a shorter, gamified experimental task and collected data from participants in 5 age groups. Young children (M = 7 years), older children (M = 11 years), young adults (M = 20 years), adults (M = 40 years) and older adults (M = 67 years) adapted to a 45° visuomotor rotation in a centre-out reaching task. Across measures of rate of adaptation, extent of learning, rate of unlearning, generalization, and savings, we found that all groups performed similarly. That is, at least for short bouts of gamified learning, children and older adults perform just as well as young adults., Competing Interests: The authors have declared that no competing interests exist., (Copyright: © 2024 Clayton et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)

It has been suggested that people with Ehlers-Danlos syndrome (EDS), or other similar connective tissue disorders, may have proprioceptive impairments, the reason for which is still unknown. We recently found that EDS patients were less precise than healthy controls when estimating their felt hand's position relative to visible peripheral reference locations, and that this deficit was positively correlated with the severity of joint hypermobility. We further explore proprioceptive abilities in EDS by having patients localize their non-dominant left hand at a greater number of workspace locations than in our previous study. Additionally, we explore the relationship between chronic pain and proprioceptive sensitivity. We found that, although patients were just as accurate as controls, they were not as precise. Patients showed twice as much scatter than controls at all locations, but the degree of scatter did not positively correlate with chronic pain scores. This further supports the idea that a proprioceptive impairment pertaining to precision is present in EDS, but may not relate to the magnitude of chronic pain.

In the United States, the proportion of foodborne illness outbreaks associated with consumption of contaminated domestic and imported fresh fruits and vegetables (produce) has increased over the past several decades. To address this public health concern, the goal of this work was to identify and quantify factors associated with microbial contamination of produce in pre- and postharvest phases of the farm-to-fork continuum. From 2000 to 2003, we collected 923 samples of 14 types of produce (grown in the southern United States or in the northern border states of Mexico) from 15 farms and eight packing sheds located in the southern United States. To assess microbial quality, samples were enumerated for Escherichia coli, total aerobic bacteria, total coliforms, and total Enterococcus. Most produce types had significantly higher microbial concentrations when sampled at the packing shed than when sampled at the farm. In addition, we observed seasonal differences in the microbial concentrations on samples grown in the United States, with higher mean indicator concentrations detected in the fall (September, October, and November). We developed a predictive, multivariate logistic regression model to identify and quantify factors that were associated with detectable concentrations of E. coli contamination on produce. These factors included produce type (specifically, cabbage or cantaloupe), season of collection (harvested in the fall), and packing step (bin, box, conveyor belt, or turntable). These results can be used to identify specific mechanisms of produce contamination and propose interventions that may decrease the likelihood of produce-associated illness.

Objective: To assess the safety and efficacy of islet autotransplantation (IAT) combined with total pancreatectomy (TP) to prevent diabetes., Summary Background Data: There have been recent concerns regarding the safety of TP and IAT. This is thought to be related to the infusion of large volumes of unpurified pancreatic digest into the portal vein. Minimizing the volume of islet tissue by purifying the pancreatic digest has not been previously evaluated in terms of the postoperative rate of death and complications, pain relief, and insulin independence., Method: During a 54-month period, 24 patients underwent pancreas resection with IAT. Islets were isolated using collagenase and a semiautomated method of pancreas digestion. Where possible, islets were purified on a density gradient and COBE processor. Islets were embolized into the portal vein, within the spleen and portal vein, or within the spleen alone. The total median volume of digest was 9.9 mL., Results: The median number of islets transplanted was 140,419 international islet equivalents per kilogram. The median increase in portal pressure was 8 mmHg. Early complications included duodenal ischemia, a wedge splenic infarct, partial portal vein thrombosis, and splenic vein thrombosis. Intraabdominal adhesions were the main source of long-term problems. Eight patients developed transient insulin independence. Three patients were insulin-independent as of this writing. Patients had significantly decreased insulin requirements and glycosylated hemoglobin levels compared with patients undergoing TP alone. Of the patients alive and well as of this writing, four had failed to gain relief of their abdominal pain and were still opiate-dependent., Conclusion: Combined TP and IAT can be a safe surgical procedure. Unfortunately, almost all patients were still insulin-dependent, but they had decreased daily insulin requirements and glycosylated hemoglobin levels compared with patients undergoing TP alone. A prospective randomized study is therefore needed to assess the long-term benefit of TP and IAT on diabetic complications.

Nitric oxide synthase, induced by cytokines in insulin-containing cells, produces nitric oxide which inhibits function and may promote cell killing. Since glucagon was shown to prevent inducible nitric oxide synthase (iNOS) expression in rat hepatocytes it was of interest to examine the action of glucagon (and cyclic AMP) on iNOS induction in insulin-producing cells. Cultured RIN5F cells and primary rat and human islets of Langerhans were treated with interleukin 1beta (IL-1beta) or a combination of cytokines, and were co-treated or pre-treated with glucagon. In RIN5F cells, the activity of iNOS induced by IL-1beta (10 pM, 24 h), was significantly reduced by glucagon (1000 nM), which raises cyclic AMP, and by forskolin (1-10 microM), a non specific activator of adenylate cyclase. Glucagon and forskolin also decreased iNOS expression in RIN5F cells, and rat and human islets, as shown by Western blotting. The inhibitory action of IL-1beta (100 pM, 24 h) on rat islet insulin secretion was partially reversed by 1-h pre-treatment with glucagon (10-1000 nM), while the contrasting stimulatory effect of 48-h treatment with cytokines on insulin secretion from human islets was similarly prevented by glucagon (1000 nM) pre-treatment. These results suggest that glucagon inhibits iNOS expression in insulin-containing cells and imply that glucagon could modulate the inhibitory effects of cytokines., (Copyright 1999 Academic Press.)

Tumour cell membrane fatty acid composition was investigated using an animal model of colorectal carcinogenesis. Eighty six male Wistar rats were fed experimental diets containing either 5% saturated fat or 20% saturated fat. Colorectal tumours were induced by intraperitoneal injection of azoxymethane, and control rats received saline. Animals were killed at intervals up to 26 weeks after the last injection of carcinogen for histology and lipid analysis. Cell membrane fatty acids in colonic mucosa and colorectal tumours were determined by gas liquid chromatography. Animals fed the 20% fat diet developed more carcinomas (28 cancers in 14 rats) than those fed the 5% fat diet (14 cancers in 15 rats; chi 2 = 8.03, p = 0.0046) but they did not develop significantly more adenomas (28 and 24 respectively). Cell membrane fatty acid analysis showed a considerable increase in the content of arachidonic acid (20:4, n-6) in the tumours (mean (SEM) 11.7 (1.5)%) compared with colonic mucosa (4.2 (0.4)%; p less than 0.05). Dietary fatty acid composition was also found to influence the profile of fatty acids in the colonic mucosa. This study suggests that a high saturated fat diet promotes the malignant transformation of colorectal adenomas. The colorectal tumours were characterised by an increased cell membrane arachidonic acid, the precursor of putative cancer promoting prostaglandins.