Neonatal Hypoxic-Ischemic Encephalopathy Yields Permanent Deficits in Learning Acquisition: A Preclinical Touchscreen Assessment

Neonatal hypoxic-ischemic encephalopathy (HIE) remains a common problem world-wide for infants born at term. The impact of HIE on long-term outcomes, especially into adulthood, is not well-described. To facilitate identification of biobehavioral biomarkers utilizing a translational platform, we sought to investigate the impact of HIE on executive function and cognitive outcomes into adulthood utilizing a murine model of HIE. HIE mice (unilateral common carotid artery occlusion to induce ischemia, followed by hypoxia with a FiO₂ of 0.08 for 45 min) and control mice were tested on discrimination and reversal touchscreen tasks (using their noses) shown to be sensitive to loss of basal ganglia or cortical function, respectively. We hypothesized that the HIE injury would result in deficits in reversal learning, revealing complex cognitive and executive functioning impairments. Following HIE, mice had a mild discrimination impairment as measured by incorrect responses but were able to learn the paradigm to similar levels as controls. During reversal, HIE mice required significantly more total trials, errors and correction trials across the paradigm. Analysis of specific stages showed that reversal impairments in HIE were driven by significant increases in all measured parameters during the late learning, striatal-mediated portion of the task. Together, these results support the concept that HIE occurring during the neonatal period results in abnormal neurodevelopment that persists into adulthood, which can impact efficient associated learning. Further, these data show that utilization of an established model of HIE coupled with touchscreen learning provides valuable information for screening therapeutic interventions that could mitigate these deficits to improve the long-term outcomes of this vulnerable population.

Impact of Sampling and Storage Techniques on Beef Muscle Measurements During Aging

ObjectivesThis objective was to determine if variations in beef sampling techniques utilized by meat researchers have a significant impact on beef muscle measurements during aging.Materials and MethodsTen beef short loins (IMPS 180) were purchased from a commercial packing plant within 48 h of slaughter. Loins were transported to the NDSU Meat Science laboratory where they were mapped into four sections from most anterior (1) to most posterior (4). Within sections, two, 40-g samples were removed; one sample was vacuum packaged (SMALL-VAC) and the other sample was stored in a wire-closure sealed bag (SMALL-BAG). The remaining whole short loin was vacuum packaged. All samples and whole short loins were stored at 4°C for 10 d. At 10 d, the short loins were sampled again where one, 40-g sample was removed from each mapped section (WHOLE-VAC). Purge loss was measured by weighing each sample prior to packaging treatment and at the end of the 10-d aging period; percentage change in weight was calculated. Troponin-T degradation was determined by western blot. Briefly, protein was extracted in an SDS-phosphate buffer, separated by SDS-PAGE under reducing conditions, and transferred to PVDF membranes. Western analysis was done using an anti-troponin-T antibody (clone JLT 12), and immunoreactive bands (Band 1 = doublet ∼42 to 45 kDa; Band 2 = doublet ∼ 36 to 38 kDa, Band 3 = 30 kDa) were analyzed for differences in density. Sarcomere length was determined using HeNe laser diffraction. Thinly sliced samples (∼50 to 100 mg) were placed in a sucrose-phosphate buffer and subjected to beadmill homogenization. A drop of the homogenate was placed on a glass slide, diffraction patterns were measured, and sarcomere length was calculated. Thiobarbituric acid reactive substances (TBARS) were assessed using a colorimetric assay. Analysis was conducted using Proc Mixed procedure of SAS where storage type, section location, and their interaction were used as fixed effects.ResultsThere was a storage type by section interaction (P = 0.017) that occurred with purge loss. SMALL-VAC samples released more purge than SMALL-BAG from the more posterior samples. Troponin-T Band 1 tended to be less (P = 0.07) in WHOLE-VAC samples compared with SMALL-VAC and SMALL-BAG. There was a storage type by section interaction (P = 0.02) where the most posterior SMALL-BAG samples had greater Band 2. There were no differences (P ≥ 0.25) in Band 3 between treatments. There was no difference (P = 0.29) in sarcomere length due storage type. However, there was a difference (P = 0.01) in sarcomere length between sections, where the shortest sarcomeres were in the center of the strip loin and longest sarcomeres on either end. There was a storage type by section interaction (P = 0.02) for TBARS where concentration was greatest in the most posterior portion of SMALL-BAG compared with WHOLE-VAC.ConclusionCollection of smaller samples for aging studies may not be representative of samples aged in a whole primal cut and may influence research outcomes.

Effect of Feeding a Low Vitamin a Diet to Beef Steers on Calpain 1 Activation during Meat Aging

ObjectivesThe objective of the study was to determine if a vitamin A deficient diet during beef finishing influences calpain 1 activation during meat aging.Materials and MethodsSixty-four steers of approximately 7 mo of age were subjected to a 14-d acclimation period followed by a 95-d growing period on a low vitamin A diet (1017 IU vitamin A/kg DM) designed to deplete liver vitamin A stores. Steers were assigned to a randomized complete blocked design with a 2 × 2 arrangement of treatments (breed: commercial Angus, n = 32, and purebred Simmental, n = 32; and a Low Vitamin A diet or a control diet). The low Vitamin A (LVA) treatment was a finishing diet with no supplemental vitamin A (723 IU vitamin A/kg DM). The control (CON) treatment was the LVA diet plus supplementation with 2200 IU vitamin A/kg DM for a total of 2923 IU vitamin A/kg DM. Serum retinol concentrations were monitored at the beginning and end of treatment. Upon completion of finishing, steers were slaughtered in two groups at a commercial plant. After fabrication, boneless strip loins (IMPS 180) were collected and transported to NDSU. Samples (approximately 40 g) were collected from the anterior portion of the strip loin on d-2 and d-7 of aging and immediately frozen. Protein was extracted from meat samples in fractionation buffers to yield sarcoplasmic and myofibrillar portions, separated by SDS-PAGE, and transferred to PVDF membranes. Immunoblot analysis was done using anti-desmin (d-2 and d-7) and anti-calpain 1 (d-2) antibodies, and results were visualized and documented. A pooled control was run on all membranes and set to a value of one for normalizing results. All experimental data were analyzed using the Proc Mixed procedure of SAS with breed of steers, dietary treatments, their interaction and slaughter date used as a fixed effect.ResultsCalpain 1 autolysis in the sarcoplasmic protein fraction of the d-2 aged loin samples were not affected by treatment or breed. The myofibrillar protein fraction from Angus loins had greater (P = 0.02) accumulation of the 76 kDa calpain 1 autolysis product than that from the Simmental loins; the myofibrillar fraction of the loins from the LVA treatment tended (P = 0.07) to have more 76 kDa calpain 1 autolysis product than that from the CON. There were not any differences (P > 0.19) in the 80 kDa calpain 1 band or the 78 kDa calpain 1 intermediate autolysis product in the myofibrillar fraction. There was a treatment by breed interaction (P = 0.01) for desmin in the d-7 aged loins where Angus loins from the CON treatment had less accumulation of the 46 kDa band than Angus loins on the LVA treatment and Simmental loins from either treatment.ConclusionVitamin A restriction increased protein proteolysis in Angus but not in Simmental steers. The increased calpain 1 autolysis in Angus vs. Simmental, regardless of Vitamin A treatment, indicates a genetic difference that may be the driver for the increased protein degradation in steers a restricted vitamin A diet.

Competency assessments: perceptions at follow-up

OBJECTIVES

To report on the perceptions of assessment of competency and its consequences on a group of clients and significant others at follow-up.

METHODS

Ninety-five interviews were conducted using a carefully developed semistructured telephone interview of 24 clients and 71 family/caregivers, representing the perceptions of about 80 clients.

RESULTS

There was general satisfaction in the competency assessment process. There was a perception that interests and rights were protected. Clients were seen to be less involved in all spheres of decision making regardless of capacity outcome. Clients and families were satisfied with how decisions were made.

CONCLUSIONS

Follow-up study of competency assessment does not support the conclusions previously drawn based on court record studies that assessments are deleterious and frequently result in violations of rights.

Genesis and acid/base

Perhaps the enigmatic etiology of cell specialization ultimately leading to organogenesis can be explained by the unusual combine application of some common mechanisms. Perhaps the combination of control of variable pH through compartmentalization, dialysis/diffusion gradients, and an electrophoresis plane impacts cells in zones causing the developmental patterns. Possibly pH is even manipulated at times to change the charge on molecules in order that attraction of opposite charges can be utilized.

A possible explanation for growth hormone resistance in chronic renal failure

Perhaps the liver in renal failure significantly alters its pH in order to attempt to maintain homeostasis. This alteration might explain the growth hormone resistance found in children with chronic renal failure.

Could the defect in type II diabetes mellitus be the absence of a postprandial alkalosis?

Perhaps the liver following a meal has a significant change in pH. Insulin binding and several enzymes important in the postprandial state for processing lipids, proteins and carbohydrates all appear to have alkaline optimal pH levels. Diabetes mellitus type II could be due to the liver failing to obtain the optimum pH for insulin binding.

Diseased cells and pH

Diseased cells may alter their intracellular pH. This could explain such diverse activities as resistance to hormones, resistance to medications, and preferential metastasis to the same locations.

A study of diet and breast cancer prevention in Canada: why healthy women participate in controlled trials

Little research has been undertaken to determine why healthy people agree to enroll in randomized controlled trials of cancer prevention. This study describes the beliefs of Canadian women participating in a trial designed to determine the effect of reducing dietary fat on the development of breast cancer. Healthier eating, nutritional counseling, contributing to science, and helping others were the most frequently cited advantages of participation. Weight control and general better health were specifically associated with the dietary regimens. Attending appointments and difficulties when eating out were the main disadvantages of participation. Suggestions that would promote adherence to the trial protocol also were elicited. Responses cited most often included opportunities to meet other participants, more nutritional counseling (particularly psychological tips), updates about the trial, and more recipes. Attention should be paid to these suggestions as they characterize some of the major determinants of adherence behavior.

Acid/base may be more variable than previously thought

Organ systems in the human body may not be homogeneous in regard to pH. Possibly specific organ systems under certain conditions maintain a pH level significantly different than the systemic pH.

Possible etiology for euthyroid sick syndrome

Euthyroid sick syndrome is possibly due to an increase in Triac (a T3 analogue) and/or Tetrac (a T4 analogue). Triac and/or Tetrac possibly feed back on the pituitary/hypothalamus region and cause a secondary hypothyroidism. This is possibly analogous to such diverse conditions as fetal thyroid function and black bear hibernation.

Hypothyroid induced hypometabolic state as a possible diagnostic and therapeutic maneuver

Diseased cells possibly function autonomously without as much dependence upon metabolic cues such as thyroid hormone by comparison to normal cells. Therefore if reversible hypothyroidism can be induced briefly in euthyroid patients, conceivably normal cells can be induced into a hypometabolic state while the diseased cells continue at their baseline or near baseline metabolic level. This induced difference could be utilized to isolate and target abnormal cells better.