Jugular Catheter Research Articles

Glucose measurements in sheep using a long-term continuous glucose monitor designed for humans

This study evaluated the feasibility of utilizing a continuous glucose monitors (CGM) designed for use in humans to measure glucose levels in sheep. Four Suffolk x Dorset sheep were fitted with jugular catheters and FreeStyle Libre 2 (Abbott®) glucose monitors. Glucose concentration from the CGM were compared with those from a glucometer and traditional assays during a hyperglycemic clamp, aiming to explore a broader range of physiological glucose concentrations in a controlled manner. Measurements were taken every five minutes during the infusion and every ten minutes post-infusion until baseline levels were restored. Relationships were analyzed using a linear mixed-effects model with glucometer readings as the response variables, GCM reading as fixed effects, and animal as random effect with significant level of p < 0.05. The results demonstrated a significant linear correlation between the CGM and glucometer readings both during the infusion (p = 0.0003) and afterward (p = 0.006). A glucose calorimetric test was used to confirm glucose concentrations on samples and used as gold standard. Although the glucometer and CGM did not differ from the assay method, they did differ from one another (p = 0.045). Upon more in-depth analysis, the random intercepts for animal were highly significant and one CGM showed values numerically much higher than other CGM and other glucose analysis methods. No difference among methods was observed (p = 0.715) when the outlier animal was omitted. While promising, CGM demands confirmation of initial readings and standardization against established methods before wider adoption in research or clinical applications.

A simple calculation formula for the insertion depth of catheter of the central venous access port in Chinese patients

BackgroundThe catheter tip placed between the T6 and T7 vertebrae is recognized as an optimal position for the totally implantable venous access ports (TIVAPs). This study aimed to propose a simple formula for calculating the optimal insertion depth of the right internal jugular central venous catheter (CVC) of TIVAP in Chinese patients. MethodsThis was a prospective observational study. The medical records of 151 patients with TIVAPs placement were retrospectively analyzed. Patient's height and actual insertion depth of CVC were used to build a simple linear regression model. The Peres’ formula was revised to better calculate the optimal insertion depth of the right internal jugular CVC of TIVAPs, accounting for population-specific anatomical variations observed in Chinese patients. A total of 158 patients scheduled for TIVAPs placement were prospectively recruited. The insertion depth of catheter was preoperatively determined according to the established formula, and postoperative chest X-ray was performed to determine the position of catheter tip. The rate of proper position of catheter (the catheter tip within T6 or T7 vertebrae) was calculated to assess the clinical feasibility and effectiveness of the new formula. ResultsThe proper position rate was 64.24% (97/151) in the retrospective group. According to patients’ height and insertion depth of CVC of these 97 cases with proper position, Peres’ formula was revised to ‘insertion depth = 0.1*height – 4 (cm)’. Based on insertion depth predicted by the new formula, the proper position rate in the prospective group reached 86.08% (136/158). ConclusionThe simple formula for calculating the insertion depth of right internal jugular CVC of TIVAPs is clinically feasible for Chinese patients.

Bridging the procedures skill gap from medical school to residency: a simulation-based mastery learning curriculum.

The transition from medical student to intern is a recognized educational gap. To help address this, the Association of American Medical Colleges developed the Core Entrustable Professional Activities for entering residency. As these metrics outline expectations for all graduating students regardless of specialty, the described procedural expectations are appropriately basic. However, in procedure-heavy specialties such as emergency medicine, the ability to perform advanced procedures continues to contribute to the disconnect between undergraduate and graduate medical education. To prepare our graduating students for their internship in emergency medicine, we developed a simulation-based mastery learning curriculum housed within a specialty-specific program. Our overall goal was to develop the students' procedural competency for central venous catheter placement and endotracheal intubation before graduation from medical school. Twenty-five students participated in a simulation-based mastery learning procedures curriculum for ultrasound-guided internal jugular central venous catheter placement and endotracheal intubation. Students underwent baseline assessment, deliberate practice, and post-test assessments. Both the baseline and post-test assessments used the same internally developed checklists with pre-established minimum passing scores. Despite completing an emergency medicine rotation and a critical care rotation, none of the students met the competency standard during their baseline assessments. All twenty-five students demonstrated competency on both procedures by the end of the curriculum. A second post-test was required to demonstrate achievement of the central venous catheter and endotracheal intubation minimum passing scores by 16% and 28% of students, respectively. Students demonstrated procedural competency for central venous catheter placement and endotracheal intubation by engaging in simulation-based mastery learning procedures curriculum as they completed their medical school training. With three instructional hours, students were able to achieve basic procedural competence for two common, high-risk procedures they will need to perform during emergency medicine residency training.

Cephalad Positioning of Internal Jugular Vein Central Venous Catheter – No Need to Worry!

Cephalad Positioning of Internal Jugular Vein Central Venous Catheter – No Need to Worry!

Monitoring Blood-Brain Barrier Opening in Rats with a Preclinical Focused Ultrasound System.

The brain has a highly selective semipermeable blood barrier, termed the blood-brain barrier (BBB), which prevents the delivery of therapeutic macromolecular agents to the brain. The integration of MR-guided low-intensity pulsed focused ultrasound (FUS) with microbubble pre-injection is a promising technique for non-invasive and non-toxic BBB modulation. MRI can offer superior soft-tissue contrast and various quantitative assessments, such as vascular permeability, perfusion, and the spatial-temporal distribution of MRI contrast agents. Notably, contrast-enhanced MRI techniques with gadolinium-based MR contrast agents have been shown to be the gold standard for detecting BBB openings. This study outlines a comprehensive methodology involving MRI protocols and animal procedures for monitoring BBB opening in a rat model. The rat model provides the added benefit of jugular vein catheter utilization, which facilitates rapid medication administration. A stereotactic-guided preclinical FUS transducer facilitates the refinement and streamlining of animal procedures and MRI protocols. The resulting methods are characterized by reproducibility and simplicity, eliminating the need for specialized surgical expertise. This research endeavors to contribute to the optimization of preclinical procedures with rat models and encourage further investigation into the modulation of the BBB to enhance therapeutic interventions in neurological disorders.

Pharmacokinetics of methadone after intravenous and subcutaneous administration in domestic ferrets (Mustela putorius furo)

ObjectiveTo determine the pharmacokinetic profile of methadone after intravenous (IV) and subcutaneous (SC) administration in domestic ferrets (Mustela putorius furo). Study designCrossover experimental study. AnimalsA group of eight healthy adult ferrets weighing 1.01 ± 0.23 kg (mean ± standard deviation). MethodsMethadone hydrochloride (0.3 mg kg–1) was injected IV or SC to each ferret with a 3 week washout period. Blood samples were collected via a jugular catheter before and 5, 10, 15, 20, 30, 45, 60, 90, 120, 180, 240, 360 and 480 minutes after drug administration. Liquid chromatography–tandem mass spectrometry was used to determine plasma methadone concentrations. A nonlinear mixed effects model was used to analyze the data. ResultsAfter IV injection, systemic clearance (Clss) and volume of distribution (Vdss) were 78.9 mL min–1 kg–1 and 9.8 L kg–1, respectively. Elimination half-life was 2.0 hours and SC bioavailability was fixed at 1. The maximum observed plasma concentration after SC injection was 92.1 ± 76.8 ng mL–1. Behavioral changes were observed after both routes. Conclusions and clinical relevanceThe pharmacokinetic profile of IV methadone was characterized by a high Clss and large Vdss, with high bioavailability and absorption rate after SC administration. Half-life was short and mean plasma methadone concentrations stayed above the minimum effective concentration (MEC) reported in humans only after SC administration for 5 minutes, but remained above that reported in dogs for 45 minutes following both routes. Further studies investigating the MEC and pharmacodynamics of methadone in ferrets are warranted.

Abstract MP25: Buprenorphine pharmacotherapy reduces somatic signs of withdrawal in neonates but may not prevent cardiovascular risk in adult offspring with prenatal fentanyl exposure

Long-term effects on the cardiovascular system of offspring exposed to fentanyl in utero are one of the understudied aspects of the opioid crisis. Previously, we have shown that offspring exposed to opioids in utero display exacerbated somatic signs of withdrawal compared to vehicle-exposed offspring. We also showed that prenatal opioid exposure induce long lasting effects increasing blood pressure (BP) in the adult offspring. Buprenorphine (BUP) is one of the most effective FDA-approved standard-of-care therapies used to treat mothers with opioid use disorder and their newborns with neonatal opioid withdrawal syndrome (NOWS). Yet, long-term effects of BUP in the pediatric population is limited. This study aimed to determine the efficacy of BUP in reducing somatic signs of withdrawal in rat neonates and the long-term effects on BP control. Female Sprague-Dawley rat breeders were implanted with a chronic jugular vein catheter and subjected to 2-hr self-administration (SA) sessions of vehicle (VEH, 0.9% NaCl, n=3) or fentanyl (FEN, 2.5 μg/kg/infusion/lever press, n=3). After rats developed dependence, they were paired during proestrus with males for breeding. SA sessions continued until delivery. There were no changes in maternal weight gain and pup weights at birth. At postnatal day 1, a subset of FEN-SA pups was treated with BUP for 5 consecutive days (1 mg/kg, sc). Video recording was performed daily to quantify somatic signs of withdrawal, including body curls, head movements, and spasms. FEN-SA increased withdrawal at postnatal days 1-3. This effect was attenuated in FEN-SA offspring treated with BUP (p<0.05).14-week-old male offspring were implanted with radiotelemetry (n=4 per group). Compared to VEH-SA, FEN-SA offspring showed: 1) increased BP in response to phenylephrine (PE, 40 µg/kg ip), 2) tachycardic response to 1-hour restraint stress followed by impaired BP recovery (p<0.05, respectively), 3) similar acute responses to AngII (30 µg/kg, sc), 4) exacerbated BP and delayed heart rate recovery in response to acute FEN (20 µg/kg, sc, p<0.05), although plasma clearance was similar between groups. BUP treatment in FEN-SA offspring did not influence acute changes in BP or heart rate to different hypertensive stimuli. Taken together our data suggests that an opioid-based therapy effectively reduced somatic signs of withdrawal; however, it does not seem effective in attenuating the acute and chronic BP responses in prenatal fentanyl-exposed offspring.

Biological sex modulates the efficacy of 2,5-dimethoxy-4-iodoamphetamine (DOI) to mitigate fentanyl demand

BackgroundOverdose deaths remain high for opioid use disorder, emphasizing the need to pursue innovative therapeutics. Classic psychedelic drugs that engage many monoamine receptors mitigate opioid use. Here, we tested the hypothesis that the preferential serotonin 5-HT2AR agonist, 2,5-dimethoxy-4-iodoamphetamine (DOI) could reduce the demand for fentanyl in a preclinical model of fentanyl self-administration. MethodsMale and female Sprague-Dawley rats (n = 25–29) were implanted with indwelling jugular catheters and allowed to self-administer fentanyl (3.2μg/kg/infusion). Rats progressed to a novel low price twice within-session threshold procedure where rats sampled the lowest price twice before decreasing the dose of fentanyl by a ¼ log every 10minutes across 11 doses. Once stable, rats were pretreated with saline or DOI (0.01, 0.03, 1mg/kg). Fentanyl consumption was analyzed using an exponentiated demand function to extract the dependent variables, Q0 and α. ResultsMale and female rats acquired fentanyl self-administration in the lowest price twice within-session threshold procedure. DOI dose-dependently altered fentanyl intake such that 5-HT2AR activation decreased Q0 in female rats but increased Q0 in male rats. For demand elasticity, DOI increased α in male rats but did not alter α in female rats. DOI did not alter inactive lever presses or latency. ConclusionDOI reduces consumption at minimally constrained costs but did not affect the reinforcement value of fentanyl in female rats. Alternatively, DOI significantly reduced the reinforcement value of fentanyl in male rats. Biological sex alters the therapeutic efficacy of DOI and 5-HT2AR activation sex-dependently alters opioid reinforcement.

Gut Microbiota and DTI Microstructural Brain Alterations in Rodents Due to Morphine Self-Administration.

The opioid epidemic is an evolving health crisis in need of interventions that target all domains of maladaptive changes due to chronic use and abuse. Opioids are known for their effects on the opioid and dopaminergic systems, in addition to neurocircuitry changes that mediate changes in behavior; however, new research lines are looking at complementary changes in the brain and gut. The gut-brain axis (GBA) is a bidirectional signaling process that permits feedback between the brain and gut and is altered in subjects with opioid use disorders. In this work, we determine longitudinal, non-invasive, and in-vivo complementary changes in the brain and gut in rodents trained to self-administer morphine for two weeks using MRI and 16S rDNA analysis of fecal matter. We assess the changes occurring during both an acute phase (early in the self-administration process, after two days of self-administration) and a chronic phase (late in the self-administration process, after two weeks of self-administration), with all measurements benchmarked against baseline (naïve, non-drug state). Rats were surgically implanted with an intravenous jugular catheter for self-administration of morphine. Rats were allowed to choose between an active lever, which delivers a single infusion of morphine (0.4 mg/kg/infusion), or an inactive lever, which had no consequence upon pressing. Animals were scanned in a 7T MRI scanner three times (baseline, acute, and chronic), and before scanning, fecal matter was collected from each rat. After the last scan session, a subset of animals was euthanized, and brains were preserved for immunohistochemistry analysis. We found early changes in gut microbiota diversity and specific abundance as early as the acute phase that persisted into the chronic phase. In MRI, we identified alterations in diffusivity indices both within subjects and between groups, showing a main effect in the striatum, thalamus, and somatosensory cortex. Finally, immunohistochemistry analyses revealed increased neuroinflammatory markers in the thalamus of rats exposed to morphine. Overall, we demonstrate that morphine self-administration shapes the brain and gut microbiota. In conclusion, gut changes precede the anatomical effects observed in MRI features, with neuroinflammation emerging as a crucial link mediating communication between the gut and the brain. This highlights neuroinflammation as a potential target in addressing the impacts of opioid use.

An abysmal conundrum associated with a misplaced dialysis catheter.

A 25-year-old female patient with chronic glomerulonephritis, initiated on haemodialysis presented with high-grade fever, a dysfunctional catheter, low oxygen saturation and unstable blood pressure. Upon evaluation, the patient was febrile with elevated white blood cell counts. She was intubated, started on inotropes and transferred to the intensive care unit. Chest radiography showed that the tunnelled internal jugular dialysis catheter had migrated to the inferior vena cava. Echocardiography and transoesophageal echocardiography showed severe heart dysfunction with a large thrombus attached to the catheter, indicating catheter-related atrial thrombus (CRAT). CT pulmonary angiography revealed blockage of the segmental pulmonary arteries, suggesting pulmonary embolism. Blood and tracheal cultures revealed Methicillin-resistant Staphylococcus aureus (MRSA). The patient was administered appropriate antibiotics and anticoagulants and underwent surgical removal of the thrombus and the catheter. This case demonstrates the risks associated with improper placement of dialysis catheters and highlights the brief management of CRAT.

Guidewire entrapment in the Chiari network during the insertion of a hemodialysis catheter: a case report

BackgroundThe Chiari network, a remnant of fetal anatomy, consists of a mesh-like structure within the right atrium. With advancements in cardiac interventions, complications associated with the Chiari network have increasingly been reported. However, there are few reports about guidewire or catheter entrapment in the Chiari network during the insertion of a dialysis catheter.Case presentationA 46-year-old male with end-stage renal disease was hospitalized and underwent a digital subtraction angiography-assisted catheterization of the right internal jugular vein tunnel-cuffed dialysis catheter. When the guide wire entered a depth of about 20 cm, it was difficult to advance, manifested as resistance when twisting the guide wire and inability to enter the inferior vena cava. After the peelable sheath was inserted, it was difficult to pull out the guide wire. After repeated attempts to rotate the guide wire, the guide wire was finally pulled out. A fibrous tissue was wrapped around the tip of the guide wire. Its length was 6 cm, with a smooth surface and tough texture. We considered that the tissue we pulled out was most likely a part of a Chiari network.ConclusionsThis case highlights the potential for the Chiari network to complicate surgical procedures, including difficulty with guidewire and catheter manipulation. Attention should be paid to Chiari networks. Echocardiography can be used to identify the Chiari network. During the surgery, forcefully pulling out a stuck guidewire is not suggested, to avoid the risk of tearing the atrial wall and causing pericardial tamponade. An urgent consultation with ultrasound doctors and cardiac surgeons might be helpful in such cases.

Prediction of internal jugular vein catheter length inserted through the posterior approach of the sternocleidomastoid muscle.

This study aimed to determine an equation to estimate the optimal insertion length for catheter placement via the posterior approach of the sternocleidomastoid muscle in cancer patients. This retrospective study included patients with cancer who underwent infusion port implantation surgery in the Oncology Department of the 900th Hospital of Joint Logistic Support Force of the Chinese People Liberation Army from April 2017 to September 2023. Patient height (H), weight (W), chest length (C), and length of the internal jugular vein catheter (L) were collected from medical records. The patients were randomized 7:3 to the training and validation sets. Linear regression analyses were used in the training set to determine formulas to predict catheter length. The formula predictive value was analyzed using the Bland-Altman method in the validation set. This study included 336 patients, with a mean age of 58.27 ± 11.70 years, randomized in the training (n = 235) and validation (n = 101) sets. Linear regression analysis revealed that the equations for catheter length relative to H, body mass index (BMI), and C are L = 0.144 × H - 8.258 (R² = 0.608, P < .001), L = -0.103 × B + 17.384 (R² = 0.055, P < .001), and L = 0.477 × C + 1.769 (R² = 0.342, P < .001), respectively. The multivariable linear regression analysis showed that the equation between the length of the catheter and H and C was L = 0.131 × H + 0.086 × C-8.515 (R² = 0.614, P < .001). The Bland-Altman analysis in the validation set showed that the predicted values of internal jugular vein catheter length and the actual values showed good agreement. The optimal L might be determined by simple formulas based on patients H and C.

Reinforcing effects of fentanyl analogs found in illicit drug markets

RationaleThe potent synthetic opioid fentanyl, and its analogs, continue to drive opioid-related overdoses. Although the pharmacology of fentanyl is well characterized, there is little information about the reinforcing effects of clandestine fentanyl analogs (FAs).ObjectivesHere, we compared the effects of fentanyl and the FAs acetylfentanyl, butyrylfentanyl, and cyclopropylfentanyl on drug self-administration in male and female rats. These FAs feature chemical modifications at the carbonyl moiety of the fentanyl scaffold.MethodsSprague-Dawley rats fitted with intravenous jugular catheters were placed in chambers containing two nose poke holes. Active nose poke responses resulted in drug delivery (0.2 mL) over 2 s on a fixed-ratio 1 schedule, followed by a 20 s timeout. Acquisition doses were 0.01 mg/kg/inj for fentanyl and cyclopropylfentanyl, and 0.03 mg/kg/inj for acetylfentanyl and butyrylfentanyl. After 10 days of acquisition, dose-effect testing was carried out, followed by 10 days of saline extinction.ResultsSelf-administration of fentanyl and FAs was acquired by both male and female rats, with no sex differences in acquisition rate. Fentanyl and FAs showed partial inverted-U dose-effect functions; cyclopropylfentanyl and fentanyl had similar potency, while acetylfentanyl and butyrylfentanyl were less potent. Maximal response rates were similar across drugs, with fentanyl and cyclopropylfentanyl showing maximum responding at 0.001 mg/kg/inj, acetylfentanyl at 0.01 mg/kg/inj, and butyrylfentanyl at 0.003 mg/kg/inj. No sex differences were detected for drug potency, efficacy, or rates of extinction.ConclusionsOur work provides new evidence that FAs display significant abuse liability in male and female rats, which suggests the potential for compulsive use in humans.

Pulmonary Arterial Hypertension as a Predictor of Severity of Chronic Kidney Disease and Correlation with Its Various Stages

Abstract Background: Pulmonary arterial hypertension (PAH) pulmonary hypertension (PH) presents a complex pathobiology. Individuals with end-stage kidney disease, particularly those undergoing hemodialysis (HD), face an elevated risk of PH development. Early identification of PH severity in chronic kidney disease (CKD) can facilitate timely interventions to mitigate cardiovascular mortality. Our study aimed to determine the prevalence of PAH in CKD patients and explored its association with different CKD stages. Materials and Methods: A hospital-based cross-sectional study involving 60 CKD patients was conducted. Pulmonary arterial pressures were assessed using Doppler echocardiography, and patients were stratified into groups based on PH severity. Results: In our study, 86.7% of CKD patients had PAH, and their mean pulmonary arterial systolic pressure (PASP) was 50.83 ± 9.779 mmHg. There was a significant increase in PH prevalence with advancing CKD stages (P &lt; 0.001). Patients undergoing HD exhibited a substantial PH prevalence (63.5%) (P &lt; 0.001) as compared to those receiving conservative treatment. Furthermore, pulmonary arterial pressures were greater in HD patients with an arteriovenous fistula (AVF) (44.2%) (P &lt; 0.001) than in individuals with a femoral or jugular vein HD catheter. Conclusion: Nearly four-fifth of CKD patients had PAH. In addition, individuals undergoing dialysis with an AVF demonstrated significantly elevated pulmonary arterial pressures compared to those using a femoral or jugular vein HD catheter.

Evaluate Nurses' Application to Infection Control Measures in Total Parenteral Nutrition Administration via Neonatal Jugular Central Venous Catheter

Evaluate Nurses' Application to Infection Control Measures in Total Parenteral Nutrition Administration via Neonatal Jugular Central Venous Catheter

Effects of improved right subclavian vein catheterization on the direction of the catheter tip in children

Background. Catheter tip malposition is commonly observed during subclavian vein catheterization. This study was to investigate whether position and partially retracted the guide wire could reduce catheter malposition. Methods. The children needing right subclavian venipuncture catheterization were randomly divided into two groups: test group A (82 patients) and control group B (82 patients). In group A, catheterization was performed with the patient in a supine position and the guide wire partially retracted during placement. In contrast, in group B, catheterization was done with the patient in Trendelenburg without partial retraction of the guide wire. The catheter tip direction was examined using intraoperative ultrasound, and a postoperative chest X-ray was obtained. Results. The rate of correct catheter tip direction at first insertion was higher in group A compared to group B (86.2% vs. 66.7%, P &lt; 0.05). There were no significant differences in incidence and general data between the two groups. The repeated vascular puncture was unsuccessful in three patients (2 cases in group A and 1 case in group B), and right internal jugular vein catheter instead. Conclusions. The guide wire can be partially retracted in the supine position to reduce catheter tip malposition during right subclavian venipuncture in children.

(051) METHAMPHETAMINE-INDUCED VAGINAL LUBRICATION IN RATS AND THE ESTROUS CYCLE

Abstract Introduction In an interview-based study performed by our lab of women who use methamphetamine (meth), we previously found that the drug, when delivered intravenously (IV), produces a feeling indistinguishable from an orgasm, which is accompanied by a flushing sensation and the production of excessive vaginal lubrication. We have also reported meth-induced vaginal lubrication in an anesthetized animal model. This production of vaginal transudate was dependent on the dose of meth used and the potent vasodilator nitric oxide. Objective The objective of the current study was to assess meth-induced vaginal lubrication across different stages of the estrous cycle and following ovariectomy (ovx) in anesthetized rats, and to assess plasma levels of two signaling molecules associated with sexual arousal. Methods Anesthetized rats, each previously implanted with a chronic indwelling jugular catheter, were anesthetized and given one IV infusion of meth (0.24 mg/kg) and vaginal lubrication was measured. A pre-weighed cotton-tipped swab, inserted into the vaginal canal, collected fluid secreted following the administration of meth. Blood was withdrawn before and at ten and fifteen minutes after meth administration either via the jugular catheter or via a small tail snip to measure plasma levels of estradiol and nitric oxide. Testing was completed at each stage of the estrous cycle as well as before and after ovariectomy. Results Estradiol and nitric oxide increased following meth infusion similarly across all stages of the estrous cycle. Vaginal lubrication increased more with meth treatment than with saline treatment. This was true across all stages of the estrous cycle and despite ovariectomy. Conclusions These findings have far-reaching implications for those who suffer from vaginal dryness. The mechanism underlying this phenomenon may present a novel pharmacotherapeutic target to treat vaginal dryness. Since meth still produced vaginal secretions in anesthetized rats, these results suggest that targeting this mechanism may even prove beneficial in post-menopausal women, a patient group likely at highest risk for experiencing vaginal dryness. Disclosure Any of the authors act as a consultant, employee or shareholder of an industry for: Embera Neuurotherapeutics &amp; JanOne.

Association of postabsorptive glucose and acetate metabolism with feed intake, growth, and efficiency in finishing beef heifers

The objective of this experiment was to determine whether acetate and glucose metabolism and insulin response to glucose are associated with the growth, feed intake, and feed efficiency of finishing heifers. Charolais heifers ( n = 18; initial body weight = 415.7 ± 45.17 kg) were acclimated to restraint with a halter and fed a finishing diet ad libitum using an Insentec feeding system. Following a 12 h fast, a jugular catheter was inserted, and an acetate clearance test was performed followed by a glucose clearance test. Four days after the metabolic tests, heifers began an 84-day DMI and ADG test period. Heifers gained 1.69 ± 0.03 kg/day and consumed 10.4 ± 0.19 kg/day. Acetate and glucose clearance rates were not associated with any production trait ( P ≥ 0.40). Insulin time to peak concentration after the glucose challenge was associated ( r = 0.69; P = 0.003) with G:F, but not peak concentration ( P = 0.45). The increased time to insulin peak could indicate that efficient heifers have pancreatic β-cell dysfunction, which is a contributor to insulin resistance. These data indicate that insulin resistance early in the finishing period could be related to improved feed efficiency in finishing heifers.

Two Cases of Malpositioning of Internal Jugular Central Venous Catheters: A Review of Literature and Current Treatment Recommendations

Two Cases of Malpositioning of Internal Jugular Central Venous Catheters: A Review of Literature and Current Treatment Recommendations

237 Disrupted insulin signaling due to an acute immune response in swine

Abstract Insulin is an anabolic hormone involved in glucose uptake and synthesis of fats, proteins, and glycogen. Altered insulin signaling can occur due to metabolic state, pathogen exposure, and autoimmune disorders. Lipopolysaccharide (LPS), an endotoxin secreted produced by gram-negative bacteria, can induce a severe, systemic immune response. In pigs, chronic LPS exposure has induced insulin resistance. However, the effects of acute exposure to LPS on insulin signaling and resistance have not been elucidated. Crossbred nursery pigs [n = 58, initial body weight (BW) = 12.1 kg ± 0.23 kg] were randomly assigned into two experimental subsets, where 10 animals were designated for repeated blood sampling and 48 animals underwent timed euthanasia for tissue collection. For repeated blood sampling, jugular catheters were placed under anesthesia and the animals were given 48 h to recover before being randomly assigned to treatments. These treatments were an intraperitoneal injection of either 15µg/kg BW LPS or an equal volume of 0.9% Saline (n = 5 pigs/treatment). Blood was collected for 48 h followed by euthanasia. The other 48 pigs were randomly assigned to the same treatments, and then randomly assigned to euthanasia timepoints of 0, 3, 6, 12, 24 or 48 h post injection for tissue collection. Among the catheterized pigs, 2-h post LPS challenge there was a decrease in serum insulin concentration (P &amp;lt; 0.05) and mild hyperglycemia (P &amp;lt; 0.05) post challenge. At 12- and 24-h post LPS challenge there was a decrease in insulin (P &amp;lt; 0.05) and a trend hyperglycemia was also apparent at 24 h (P = 0.063). In liver tissue, insulin related genes exhibited alterations post LPS injection. Phosphoinositide 3-kinase (pi3k) and insulin receptor substrate 1 (irs1) expression were decreased at 3 and 6 h (p&amp;lt; 0.05) and protein kinase b (akt) expression were decreased at 3 h (P &amp;lt; 0.05) post challenge. The expression of insulin inhibitor growth factor receptor bound protein 10 (grb10) was decreased at 6-, 12-, and 24-h after challenge (P &amp;lt; 0.05). Fructose-1-6-bisphosphatase (f16bp) expression was reduced at 3-, 6-, and 12-h (P &amp;lt; 0.05) in the liver while phosphoenolpyruvate carboxykinase (pepck) expression was decreased at 3- and 6-h (P &amp;lt; 0.01) post challenge. Other metabolic genes were decreased at 3-, 6-, and 12-h post LPS challenge, including fatty acid synthase (fas; P &amp;lt; 0.05), carbohydrate response element binding protein (chrebp; P &amp;lt; 0.05), and acetyl CoA carboxylase (acc; P &amp;lt; 0.05). Protein abundance of Akt 3 h after LPS injection was decreased in the liver (P &amp;lt; 0.05). In skeletal muscle 6 h post LPS injection, insulin receptor (insr), insulin-like growth factor receptor (igfr) and fas were all increased (P &amp;lt; 0.05) These results indicate disrupted insulin signaling at various levels after an acute immune response.