Evolutionarily conserved prefrontal-amygdalar dysfunction in early-life anxiety.

Some individuals are endowed with a biology that renders them more reactive to novelty and potential threat. When extreme, this anxious temperament (AT) confers elevated risk for the development of anxiety, depression and substance abuse. These disorders are highly prevalent, debilitating and can be challenging to treat. The high-risk AT phenotype is expressed similarly in children and young monkeys and mechanistic work demonstrates that the central (Ce) nucleus of the amygdala is an important substrate. Although it is widely believed that the flow of information across the structural network connecting the Ce nucleus to other brain regions underlies primates' capacity for flexibly regulating anxiety, the functional architecture of this network has remained poorly understood. Here we used functional magnetic resonance imaging (fMRI) in anesthetized young monkeys and quietly resting children with anxiety disorders to identify an evolutionarily conserved pattern of functional connectivity relevant to early-life anxiety. Across primate species and levels of awareness, reduced functional connectivity between the dorsolateral prefrontal cortex, a region thought to play a central role in the control of cognition and emotion, and the Ce nucleus was associated with increased anxiety assessed outside the scanner. Importantly, high-resolution 18-fluorodeoxyglucose positron emission tomography imaging provided evidence that elevated Ce nucleus metabolism statistically mediates the association between prefrontal-amygdalar connectivity and elevated anxiety. These results provide new clues about the brain network underlying extreme early-life anxiety and set the stage for mechanistic work aimed at developing improved interventions for pediatric anxiety.

Growing and finishing performance of steers when fed recycled poultry bedding during the growing period.

Sixty Angus-cross steers were used to compare the effects of recycled poultry bedding (RPB) stacking method and the inclusion of monensin in growing diets on performance. Steers were individually fed balanced, growing diets for a period of 84 d. The diets were control (CON), CON + monensin (CON+M), deep-stacked RPB (DS), DS+M, shallow-stacked RPB (SS), and SS+M. The CON diets contained corn, soybean meal, corn silage, and cottonseed hulls. In the RPB diets, 35% of the silage, cottonseed hulls, and soybean meal was replaced with RPB (as-fed basis). At the end of the growing period, 30 steers, representing all treatment groups, had liver biopsies for trace mineral analysis and ruminal fluid samples to assess pH, VFA, and ammonia concentrations. All steers had blood samples drawn at the end of the growing period for analysis of Se and urea N. Steers were transported 466.6 km to simulate shipping stress and started on a finishing diet for a 120-d period. Intake, ADG, and G:F were monitored throughout the trial. Steers fed CON diets had higher ADG, DMI, and G:F than SS, and higher ADG and G:F than DS (P < 0.05) during the growing period. Steers fed DS diets had higher DMI than SS (P < 0.05) during the growing period. Inclusion of monensin in the growing diets increased G:F and decreased DMI (P < 0.05). Steers from the RPB treatments started the finishing period at lighter BW than steers fed CON diets (P < 0.05). During the finishing period, steers fed SS diets had higher DMI than steers fed CON diets (P < 0.06), whereas steers fed DS diets were intermediate. At slaughter, steers fed CON diets had higher hot carcass weights and quality grades than steers fed SS diets (P < 0.07), whereas steers fed DS diets were intermediate. Results indicate that steers fed RPB consumed it better when processed by deep stacking before consumption, that carryover effects of RPB into the finishing phase were minimal, and inclusion of monensin did not affect consumption of RPB diets.

Prevention of lameness in cow-calf operations.

Lameness is a significant cause of economic loss, premature culling, and loss of genetics in cow-calf operations. In recent years, attention to treatment and prevention of lameness has increased. Veterinarians must be aware of factors associated with lameness such as genetics, environment, and nutrition so that preventive measures can be instituted in consultation with ranchers.

Dental wear and growth performance in steers fed sweetpotato cannery waste.

OBJECTIVE: To determine whether feeding sweetpotato cannery waste (SPCW) to cattle had adverse effects on dental wear, growth performance, or ruminal tissues. DESIGN: Clinical trial. ANIMALS: 36 Holstein steers. PROCEDURE: Steers were assigned to 1 of 3 groups. All steers received ryegrass hay ad libitum. In addition, steers in group 1 were fed 3.2 kg of corn and soybean meal/steer/d, steers in group 2 were fed 0.45 kg of soybean meal/steer/d and SPCW ad libitum, and steers in group 3 were fed a mixture of SPCW and broiler litter ad libitum. Samples of rumen fluid were collected on day 56. Steers were slaughtered on day 84, and samples of rumen were submitted for histologic examination. Teeth from control steers were removed, and calcium ion loss in response to etching with 2.28% lactic acid solutions buffered to pH of 3.75, 4.0, 4.25, 4.5, and 4.75 was determined. RESULTS: Average daily gain was lower for steers fed SPCW than for steers in the other 2 groups. Steers fed the SPCW-broiler litter mixture had only mild increases in tooth wear and tooth color scores, compared with control steers, whereas steers fed unbuffered SPCW had substantial increases in tooth wear and tooth color scores. Histologic abnormalities were detected in rumens from steers fed diets containing SPCW. Calcium ion loss decreased as pH of the etching solution increased. CLINICAL IMPLICATIONS: Results indicate that feeding cattle unbuffered SPCW can cause dental erosion, ruminal epithelial changes, and poor growth; however, SPCW buffered with broiler litter can be used as a cattle feed.

In vitro effects of an acidic by-product feed on bovine teeth.

OBJECTIVE: To evaluate in vitro erosive effects of sweet potato cannery waste (SPCW) on bovine incisor enamel. SAMPLE POPULATION: 20 bovine mandibles. PROCEDURE: Mandibles were collected and incisors were classified into 3 categories: lacking observable wear, advanced normal wear, or abnormal wear associated with feeding SPCW. Intact mandibles were radiographed. Contralateral normal teeth from the same jaw were used to compare Ca2+ loss (etching) with SPCW, lactic acid (pH 3.2), or SPCW neutralized with NaOH to pH 5.0 or 5.5. Scanning electron microscopy was performed to compare etched and unetched specimens. Two abnormally worn teeth were evaluated histologically. Knoop hardness testing was conducted on unexposed areas of surface enamel and enamel exposed to SPCW. RESULTS: Radiography revealed large periapical abscesses in the mandibles exposed to SPCW. Nearly identical amounts of Ca2+ were removed by SPCW and lactic acid solution at the same pH. Scanning electron microscopy did not indicate consistent differences between etch patterns resulting from exposure to SPCW or lactic acid. Mean rate of calcium removal was 56% higher in deciduous than permanent teeth. Knoop hardness data suggested that softening occurred in enamel exposed to SPCW. Neutralizing SPCW to pH 5.5 eliminated calcium removal. Histologic examination of sections indicated that SPCW degraded and removed some dentin matrix proteins. CONCLUSIONS: Exposure to SPCW results in enamel erosion in vitro; low pH is the most likely cause of erosion. Neutralizing SPCW to pH 5.5 eliminated erosive effects. CLINICAL RELEVANCE: Confirmation of SPCW's erosive effects on enamel in vitro supported the field diagnosis.

Effect of cataract extraction on automated fields in chronic open-angle glaucoma.

OBJECTIVE: To evaluate the influence of cataract extraction on the results of visual field testing in chronic open-angle glaucoma. DESIGN: We performed automated perimetry within 6 months before and after phacoemulsification and combined trabeculectomy in 24 consecutive patients with chronic open-angle glaucoma. Eyes were pharmacologically dilated and were tested with their best corrected refraction for each visual field performed. RESULTS: After surgery, the average mean defect, pattern SD, and total decibel loss within any visual field cluster (as determined by the Glaucoma Hemifield Test, Humphrey Field Analyzer, Humphrey Instruments, San Leandro, Calif) did not change significantly (P > .05, paired t test). These findings did not vary on the basis of the amount of preoperative damage in the visual field. The power of this study to exclude a 4-dB change in the mean defect after surgery was 86.5%. CONCLUSION: This study suggests that cataract extraction in patients with chronic open-angle glaucoma has minimal effect on the visual field test results after surgery.

Correlation of pattern discrimination perimetry to the optic disc and visual field in ocular hypertensive and chronic open-angle glaucoma patients.

We evaluated 19 ocular hypertensive and 32 chronic open-angle glaucoma patients to determine the correlation of pattern discrimination field loss to known markers of glaucomatous damage on the visual field and the optic nerve head. This study found no statistical association of the findings on the pattern discrimination perimeter to the areas of the optic disc, peripapillary halo, peripapillary atrophy, neural rim, or cup/pallor discrepancy (P > 0.05). In addition, no statistical relationship was observed to the diameters of the largest vein or artery in the inferior- or superior-temporal quadrant adjacent to the optic disc (P > 0.05). Between pattern discrimination and automated perimetry no agreement was observed in any visual field cluster (Glaucoma Hemifield Test) greater than that expected by chance alone (P > 0.05). When both visual function tests disagreed, the proportion of abnormal diagnoses in any cluster did not differ statistically between tests in chronic open-angle glaucoma patients (P > 0.05). However, in ocular hypertensive patients a greater proportion of abnormal diagnoses was observed with pattern discrimination perimetry (P < 0.03). This study suggests that pattern discrimination perimetry appears to measure a different physiologic property of the retina than does automated perimetry.

Lipid peroxidation in pregnancy: new perspectives on preeclampsia.

Basic research during the past two decades has led to increased awareness of the role of lipid peroxidation in various physiologic and pathophysiologic processes. A number of reports indicate that preeclampsia is associated with elevated blood levels of lipid peroxidation products. In view of its potentially destructive character, uncontrolled lipid peroxidation has been suggested as an etiologic factor in preeclampsia. The present article summarizes current information regarding the occurrence of lipid peroxidation in normal and preeclamptic pregnancy. Recent progress concerning our understanding of the process of lipid peroxidation and its role in cardiovascular disease is also reviewed. This information is used to discuss potential mechanisms by which lipid peroxidation might contribute to the pathogenesis of preeclampsia.