Relationship between total ghrelin and inflammation in hemodialysis patients

In hemodialysis (HD) patients studies have shown that plasma ghrelin is increased and it has been speculated that ghrelin levels might be related to systemic inflammation. The present study attempted to correlate the serum levels of total ghrelin with serum TNF-α and IL-6, and with nutritional status and body composition in HD patients. Forty-seven HD patients from a single dialysis unit (18 women, mean age 55.3 ± 12.2 yr; BMI 24.4 ± 4.2 kg/m²; % body fat 29.4 ± 7.4%) were studied and compared to 21 healthy subjects (12 women, 50.7 ± 15.7 yr and BMI 25.6 ± 4.0 kg/m²; % body fat 30.0 ± 5.7%). Biochemical data, serum total ghrelin, TNF-α and IL-6 levels were measured. The body composition was evaluated by dual energy X-ray absortiometry (DEXA) and energy and protein intake were evaluated. Patients showed elevated plasma ghrelin levels when compared to healthy subjects (1.14 ± 1.0 ng/mL vs 0.58 ± 0.4; p < 0.001). There was a positive correlation between ghrelin levels and TNF-α (r = 0.25; p < 0.04), IL-6 (r = 0.42; p < 0.02), and a negative correlation between TNF-α and protein intake (r = −0.28; p < 0.03), and energy intake (r = −0.34; p < 0.01). No correlation was observed with any aspect of body composition. Plasma ghrelin levels are elevated in HD patients and associated with the state of systemic inflammation. We suggest that the inflammatory state may affect ghrelin bioactivity and metabolism in hemodialysis patients.     

Human plasma phospholipid transfer protein specific activity is correlated with HDL size: Implications for lipoprotein physiology

To gain further insights into the relationship between plasma phospholipid transfer protein (PLTP) and lipoprotein particles, PLTP mass and phospholipid transfer activity were measured, and their associations with the level and size of lipoprotein particles examined in 39 healthy adult subjects. No bivariate correlation was observed between PLTP activity and mass. PLTP activity was positively associated with cholesterol, triglyceride, apo B and VLDL particle level (r_s = 0.40–0.56, p ≤ 0.01) while PLTP mass was positively associated with HDL-C, large HDL particles, and mean LDL and HDL particle sizes (r_s = 0.44–0.52, p < 0.01). Importantly, plasma PLTP specific activity (SA) was significantly associated with specific lipoprotein classes, positively with VLDL, IDL, and small LDL particles (r_s = 0.42–0.62, p ≤ 0.01) and inversely with large LDL, large HDL, and mean LDL and HDL particle size (r_s = − 0.42 to − 0.70, p ≤ 0.01). After controlling for triglyceride levels, the correlation between PLTP mass or SA and HDL size remained significant. In linear models, HDL size explained 45% of the variability of plasma PLTP SA while triglyceride explained 34% of the PLTP activity. Thus, in healthy adults a significant relationship exists between HDL size and plasma PLTP SA (r_s = − 0.70), implying that HDL particle size may modulate PLTP SA in the vascular compartment.     

Increased urinary glucocorticoid metabolites are associated with metabolic syndrome, hypoadiponectinemia, insulin resistance and β cell dysfunction

Metabolic syndrome (MetS) may have increased cortisol (F) production caused by 11β-hydroxysteroid dehydrogenase 1 (11β-HSD1) in liver and adipose tissue and/or by HPA axis dysregulation. F is then mainly metabolized by liver reductases into inactive tetrahydrometabolites (THMs). We measured THM levels in patients with or without MetS and evaluate the correlation between THMs and anthropometric and biochemical parameters. We recruited 221 subjects, of whom 130 had MetS by ATP III. We evaluated F, cortisone (E), adipokines, glucose, insulin and lipid profiles as well as urinary (24 h) F, E and THM levels. β Cell function was estimated by the HOMA Calculator. We observed that patients with MetS showed higher levels of THMs, HOMA-IR and leptin and lower levels of adiponectin and HOMA-β but no differences in F and E in plasma or urine. THM was associated with weight (r = +0.44, p < 0.001), waist circumference (r = +0.38, p < 0.01), glycemia (r = +0.37, p < 0.01), and triglycerides (r = +0.18, p = 0.06) and negatively correlated with adiponectin (r = −0.36, p < 0.001), HOMA-β (r = −0.21, p < 0.001) and HDL (r = −0.29, p < 0.01). In a logistic regression model, THM levels were associated with hypertension, hyperglycemia and dyslipidemia. We conclude that MetS is associated with increased urinary THMs but not with F and E levels in plasma or urine. Increased levels of THM, reflecting the daily cortisol production subsequently metabolized, are correlated with hypoadiponectinemia, hypertension, dyslipidemia, insulin resistance and β cell dysfunction. A subtle increased in glucocorticoid production may further account for the phenotypic and biochemical similarities observed in central obesity and Cushing’s syndrome.     

Odours and volatile organic compounds emitted from municipal solid waste at different stage of decomposition and relationship with biological stability

Odours (OU_E) and volatile organic compounds (VOC) emission during biological process used to treat MSW were studied under standardized conditions in order to detect potential risk for workers and population. Results obtained indicated that odours and VOCs emitted depend on the biological stability of waste measured by the dynamic respiration index (DRI) and a very good correlation were found between these parameters (OU_E vs. DRI, r = 0.96, p < 0.001, n = 6; VOC vs. DRI, r = 0.97, p < 0.001, n = 6).GC-MS study of the VOCs indicated the presence of a group of molecules that were degraded during the process. On the other hand, a second group of molecules, i.e. aromatic and halogenated compounds, and furan persisted in the waste sample, although molecule concentrations were always lower than Threshold Limit Value-Time Weighted Average (TLV-TWA).     

Estrogen receptor expression and vessel density in the vagina wall in postmenopausal women with prolapse

After menopause, critically estrogen low levels result in modifications in vaginal wall. This cross-sectional study aims to determine whether there is a change in the number of vessels in the lamina propria of the vagina after menopause in parallel to the ER-alpha expression on the vaginal wall. Twelve women who underwent a genital surgery for genital prolapse up to grade II were selected. They were divided into two groups: a premenopausal group (PG) consisting of six women who were 18–40 years old with FSH levels =12 mIU/ml and regular cycles, and a menopausal group (MG) consisting of six women at least one year after menopause who were <65 years old with FSH levels =40 mIU/ml. Slides were stained for ER-alpha immunohistochemistry, and an endothelial cell marker CD3 was used to label vessels which were identified by using a system for morphometry. The number of vessels was significantly higher in the PG than in the MG both on the anterior wall (PG: 1.055 ± 145.8 vessels/mm², MG: 346.6 ± 209.9 vessels/mm², p < 0.0001) and on the posterior wall (PG: 1064 ± 303.3 vessels/mm², MG: 348.6 ± 167.3 vessels/mm², p = 0.0005). The ER-alpha score was significantly higher in the PG than the score for the MG on both the anterior and posterior walls (PG: 6.0 ± 0.52, MG: 2.5 ± 0.89, p = 0.007; PG: 5.8 ± 0.79, MG: 2.7 ± 0.95, p = 0.03, respectively). There was a positive correlation between the ER-alpha score and the vessel concentration on the anterior (r = 0.6656, p = 0.018) and posterior (r = 0.6738, p = 0.016) vaginal walls. Age was strongly negatively correlated with vessel concentration on the vaginal walls (respectively r = -0.9033, p < 0.0001, r = -0.7440, p = 0.0055). Therefore, postmenopausal women with genital prolapse have a smaller number of vessels on the vaginal wall compared to normoestrogenic controls with the same pathological condition. Hypoestrogenism and advancing age are factors that are associated to these changes.     

Long-term changes in macrophyte vegetation after reduction of fish stock in a shallow lake

Starting in the middle of the 1970s, submerged macrophytes began to disappear from shallow Lake Warniak due to feeding pressure by grass carp (Ctenopharyngodon idella). In the middle of the 1980s, the lake was stocked with seston-feeding silver carp (Hypophthalmichthys molitrix) and bighead carp (Aristichthys nobilis). By 1993, the biomass of silverhead carp and bighead carp had declined. This allowed charophytes to recolonize the bottom of the lake. The main charophyte species at this time were Chara globularis and Chara rudis. Since then, five other stonewort species have been found: Chara contraria, C. filiformis, C. tomentosa, C. aspera and Nitellopsis obtusa. Seventeen species of aquatic angiosperms have also been found. There were distinct changes in the relative abundance and spatial distribution of particular species. C. rudis developed most intensely in the shallow parts of the lake near the southern and western shores. C. globularis gradually took over the deeper central part of the lake. In 2001, C. rudis began to retreat again. The relative abundance and spatial distribution of charophytes was correlated to water clarity (r = 0.87, p < 0.05), total phosphorus level (r = −0.78; p < 0.05), and chlorophyll a content (r = −0.79; p < 0.05).     

Factors affecting the performance of membrane bioreactor for piggery wastewater treatment

This study was conducted to identify the factors affecting the performance of membrane bioreactor (MBR) for piggery wastewater treatment. The change of organic and nitrogen concentrations in piggery wastewater was studied to investigate the treatment efficiency. The increase of COD, BOD and NH₃–N from 1150 to 2050 mg/L, 683 to 1198 mg/L and 154 to 248 mg/L has led to the decrease of treatment efficiency. Removal efficiencies of COD, BOD and NH₃–N have decreased from 96.0% to 92.0%, 97.0% to 92.7% and 93.2% to 69.5%, respectively. The effects of biomass characteristics on membrane fouling were determined based on Pearson’s correlation coefficient (r_p). It was found that MLSS had a negative correlation with permeate flux (r_p = −0.745, at significant level of 0.05) while sludge floc size a positive correlation (r_p = 0.731, at significant level of 0.05). MLSS and sludge floc size were found to be the dominant factors that controlled the membrane filterability while sludge viscosity, EPS, SMP and SV₃₀ have taken as the sub-factors affecting membrane fouling.     

2d:4d, sex steroid hormones and human psychological sex differences

Studies on 2d:4d, the ratio between the second and the fourth digit, as a possible indicator of prenatal androgen exposure, have failed to produce consistent results. This paper analyzes the relation between 2d:4d, sex steroids and well-documented sex differences in characteristics such as depression, dominance, and aggressive (ART) and non-aggressive adolescent risk-taking (NART) in a comparatively large sample of adolescent boys (N = 301, mean age: 14.4 years) and girls (N = 298, mean age: 14.3 years). Boys had on average a lower 2d:4d than girls (F = 42.15; p < 0.001). With respect to boys, controlling for age and pubertal development (PD), a small but marginally significant positive association was found between 2d:4d and total testosterone (TT) (r = 0.11; p < 0.05). In girls a significant association was found between 2d:4d and SHBG (r = 0.18; p < 0.01). However, relationships between 2d:4d and hormones depended on the phase of the menstrual cycle, with 2d:4d being negatively associated with FT (B = − 0.013; p < 0.05) once a positive association between 2d:4d and FT for girls in the mid-cycle group (B = 0.019; p < 0.01) is taken into account. With respect to sex differences in characteristics, we found evidence of a relationship between 2d:4d and depression in boys (r = − 0.14; p < 0.05) but not between 2d:4d and dominance, ART or NART. No relationships were found between 2d:4d and any of these variables in girls.     

A model to estimate growth in young-of-the-year tautog, Tautoga onitis, based on RNA/DNA ratio and seawater temperature

This study presents an indirect method for estimating growth rates of young-of-the-year (YOY) tautog, Tautoga onitis, based on laboratory calibration experiments and nucleic acid-based indices. Field-collected tautog were held in the laboratory at 3 temperatures over a 17-day period. Four feeding levels were used to produce a range of growth rates. An ultraviolet absorption assay was used to measure nucleic acid concentrations in white muscle tissue. The strength of the relationship between growth rate and three nucleic acid-based parameters (RNA concentration, DNA concentration, RNA/DNA ratio (R/D)) was tested. Correlation results indicated a significant positive relationship between R/D and weight-based instantaneous growth rate (G) (r = 0.68; p < 0.001). Both R/D (r = − 0.55; p < 0.006) and RNA (r = − 0.56; p < 0.005) were highly negatively correlated with temperature (T). Multiple linear regression showed that R/D and temperature explained 61% of the variability in growth, resulting in the model G = 0.01285(R/D) + 0.00057(T) − 0.03205 (p < 0.0001). This R/D-temperature model can be used to evaluate recent growth rates in YOY tautog under field conditions and has applications for aquaculture when comparing growth rates of fish held under different culture conditions.     

Biomass accumulation and energy conversion efficiency in aromatic rice genotypes

A field experiment was conducted to evaluate photosynthetic efficiency along with different growth parameters of aromatic rice genotypes. Forty genotypes including three non-aromatic checks exhibited enormous variations for leaf area index (LAI), crop growth rate (CGR), relative growth rate (RGR), net assimilation rate (NAR), grain yield, total dry matter, harvest index and photosynthetic efficiency or energy use efficiency (Eμ) at panicle initiation and heading stages. Minimum LAI-value was 0.52 in Khazar at PI stage and maximum was 4.91 in Sakkor khora at heading stage. The CGR-value was in the range of 4.80−24.11 g m⁻² per day. The best yielder BR39 produced grain of 4.21 t ha⁻¹ and the worst yielder Khazar gave 1.42 t ha⁻¹. Total dry matter (TDM) yield varied from 4.04 to 12.26 t ha⁻¹ where genotypes proved their energy use efficiency a range between 0.58 to 1.65%. Eμ showed a significant positive relation with TDM (r = 0.80^**), CGR (r = 0.72^**) and grain yield (r = 0.66^**). A negative correlation was established between TDM and harvest index and LAI and RGR. Path analysis result showed that NAR at heading stage exerted highest positive direct effect (0.70) on Eμ.     

Effect of meal size on the specific dynamic action of the juvenile snakehead (Channa argus)

The effect of meal size on the specific dynamic action (SDA) of the juvenile snakehead (Channa argus) was assessed at 25 °C. The fish were fed with test diets at meal sizes of 0.5, 1, 2, 3, 4, and 5% body mass and the postprandial oxygen consumption rate was determined at 1-h intervals until it returned to the pre-prandial level. The peak metabolic rate increased from 237.4 to 283.2 mg O₂ kg^− 1 h^− 1 as the relative meal size increased from 0.5% to 3% and leveled off at 4% and 5%. Factorial metabolic scope increased from 1.53 to 1.99 and SDA duration increased from 11.7 to 32.3 h as the relative meal size increased from 0.5% to 5%. The relationship between SDA duration (D) and relative meal size (M) was described as: D = 4.28 M + 10.62 (r² = 0.752, P < 0.05, n = 50). The energy expended on SDA increased while the SDA coefficient decreased with increasing meal size. The results of the present study suggest that the snakehead may adopt different feeding strategies when taking in different amounts of food.     

Significant correlations of dermal total carotenoids and dermal lycopene with their respective plasma levels in healthy adults

Carotenoids in skin have been known to play a role in photoprotection against UV radiation. We performed dermal biopsies of healthy humans (N = 27) and collected blood samples for pair-wise correlation analyses of total and individual carotenoid content by high performance liquid chromatography (HPLC). The hydrocarbon carotenoids (lycopene and beta-carotene) made up the majority of carotenoids in both skin and plasma, and skin was somewhat enriched in these carotenoids relative to plasma. Beta-cryptoxanthin, a monohydroxycarotenoid, was found in similar proportions in skin as in plasma. In contrast, the dihydroxycarotenoids, lutein and zeaxanthin, were relatively lacking in human skin in absolute and relative levels as compared to plasma. Total carotenoids were significantly correlated in skin and plasma (r = 0.53, p < 0.01). Our findings suggest that human skin is relatively enriched in lycopene and beta-carotene, compared to lutein and zeaxanthin, possibly reflecting a specific function of hydrocarbon carotenoids in human skin photoprotection.     

Pharmacology and selectivity of various natural and synthetic bombesin related peptide agonists for human and rat bombesin receptors differs

The mammalian bombesin (Bn)-receptor family [gastrin-releasing peptide-receptor (GRPR-receptor), neuromedin B-receptor (NMB receptor)], their natural ligands, GRP/NMB, as well as the related orphan receptor, BRS-3, are widely distributed, and frequently overexpressed by tumors. There is increased interest in agonists for this receptor family to explore their roles in physiological/pathophysiological processes, and for receptor-imaging/cytotoxicity in tumors. However, there is minimal data on human pharmacology of Bn receptor agonists and most results are based on nonhuman receptor studies, particular rodent-receptors, which with other receptors frequently differ from human-receptors. To address this issue we compared hNMB-/GRP-receptor affinities and potencies/efficacies of cell activation (assessing phospholipase C activity) for 24 putative Bn-agonists (12 natural, 12 synthetic) in four different cells with these receptors, containing native receptors or receptors expressed at physiological densities, and compared the results to native rat GRP-receptor containing cells (AR42J-cells) or rat NMB receptor cells (C6-glioblastoma cells). There were close correlations (r = 0.92-99, p < 0.0001) between their affinities/potencies for the two hGRP- or hNMB-receptor cells. Twelve analogs had high affinities (≤1 nM) for hGRP receptor with 15 selective for it (greatest = GRP, NMC), eight had high affinity/potencies for hNMB receptors and four were selective for it. Only synthetic Bn analogs containing β-alanine¹¹ had high affinity for hBRS-3, but also had high affinities/potencies for all GRP-/hNMB-receptor cells. There was no correlation between affinities for human GRP receptors and rat GRP receptors (r = 0.131, p = 0.54), but hNMB receptor results correlated with rat NMB receptor (r = 0.71, p < 0.0001). These results elucidate the human and rat GRP-receptor pharmacophore for agonists differs markedly, whereas they do not for NMB receptors, therefore potential GRP-receptor agonists for human studies (such as Bn receptor-imaging/cytotoxicity) must be assessed on human Bn receptors. The current study provides affinities/potencies on a large number of potential agonists that might be useful for human studies.     

In vivo passages of heterologous Beauveria bassiana isolates improve conidial surface properties and pathogenicity to Nilaparvata lugens (Homoptera: Delphacidae)

In entomopathogenic hyphomycetes, desired candidates against the brown planthopper, Nilaparvata lugens (a sap-sucking rice pest in Asia), are lacking. In this study, 21 Beauveria bassiana isolates from heterologous host insects showed low pathogenicity to third-instar nymphs sprayed at the high concentration of ∼1000 conidia/mm², causing only 2-23% mortalities. Of those, three isolates killed significantly more nymphs (up to 45-62%) after two in vivo passages but no more after further passage. Conidial hydrophobicity rates (H_r), zeta potentials (P_z), and subtilisin-like protease (Pr1) activities (A_p) of these isolates showed the same trends in the three host passages (N: 0-3). In multivariate correlation, the variables N, H_r and P_z were found contributing 89% to the mortality variation (r² = 0.89). Significant positive correlations were also found between H_r and N (r² = 0.64), P_z and N (r² = 0.52), A_p and N (r² = 0.51), H_r and A_p (r² = 0.45), and P_z and A_p (r² = 0.57), respectively. However, irregular changes of H_r and P_z occurred in four other isolates, whose pathogenicity to N. lugens was not enhanced by repeated host passages, resulting in no correlation between the variables. Our data indicate that the conidial surface properties H_r and P_z associated with cuticle adhesion reflect the heterologous host-induced adaptation and help to select fungal candidates against N. lugens from repeated in vivo passages.     

Suppression of QRFP 43 in the hypothalamic ventromedial nucleus of Long-Evans rats fed a high-fat diet

QRFP 43 is a RFamide peptide present in the ventromedial nucleus (VMN) and lateral hypothalamus. It stimulates food intake in mice and its chronic infusion induces hyperphagia, reduced thermogenesis, and obesity. In this experiment, we measured it in the VMN and lateral hypothalamus of Long-Evans rats fed either a high-fat (HF), control, or low-fat (LF) diet in parallel with plasma leptin, adiposity, and energy intake. After 8 weeks of ad libitum diet intake, energy intake of HF rats was similar to that of control rats. In the VMN, QRFP 43 was completely undetectable in HF rats and its tissue concentration in control rats was significantly lower than in LF rats (p < 0.03). HF rats had higher levels of leptin than control rats (+24%; p < 0.03) and than LF rats (+42%; p < 0.002). The QRFP 43 concentration in the VMN was inversely correlated with plasma leptin (r = −0.34; P < 0.04) and with the adipogenic index of the diet (p < 0.02) but not with insulin. We conclude that the decrease of the orexigenic drive mediated by QRFP 43 could contribute to the normalization of caloric intake in HF diet fed rats. QRFP 43 might play a role downstream of leptin in the regulation of feeding behavior.     

Factors controlling vegetation structure in peatland lakes—Two conceptual models of plant zonation

Two conceptual models of plant zonation in peatland lakes are given. The first represents vegetation on slightly sloping substrate (N < 0.2) in shallow and relatively large lakes. The vegetation is not diverse (H′ = 0.0 ± 0.01). The frequency and biomass of the dominant (Sphagnum denticulatum) correlate positively with lake size, and negatively with depth and substrate slope. They are also correlated with water transparency and water color (r = −0.53), concentrations of total organic carbon (r = −0.43), Ca²⁺ (r = 0.40) and humic acids (r = −0.46), and redox potential (r = 0.44). The second model represents vegetation on steep peat walls (N > 0.3) in deep, usually small lakes. Plants occur only on the upper part of the peat wall or form a multispecies curtain hanging from the lip of peat at the top. Species diversity in this scenario is higher (H′ = 0.18 ± 0.17). The curtains usually are composed of mosses such as Warnstorfia exannulata, S. cuspidatum and S. riparium, and vascular plants are rare. The frequency and biomass of bryophytes in this type of structure are related to substrate slope (r = 0.56), lake depth (r = 0.56), Ca²⁺ concentration (r = −0.69) and water color (r = −0.51). In both models, plant biomass is correlated with temperature (r = −0.78), irradiance (r = −0.64) and water oxygenation (r = −0.54).     

Oxidative DNA damage and influence of genetic polymorphisms among urban and rural schoolchildren exposed to benzene

Traffic related urban air pollution is a major environmental health problem in many large cities. Children living in urban areas are exposed to benzene and other toxic pollutants simultaneously on a regular basis. Assessment of benzene exposure and oxidative DNA damage in schoolchildren in Bangkok compared with the rural schoolchildren was studied through the use of biomarkers.Benzene levels in ambient air at the roadside adjacent to Bangkok schools was 3.95-fold greater than that of rural school areas. Personal exposure to benzene in Bangkok schoolchildren was 3.04-fold higher than that in the rural schoolchildren. Blood benzene, urinary benzene and urinary muconic acid (MA) levels were significantly higher in the Bangkok schoolchildren. A significantly higher level of 8-hydroxy-2′-deoxyguanosine (8-OHdG) in leukocytes and in urine was found in Bangkok children than in the rural children. There was a significant correlation between individual benzene exposure level and blood benzene (r_s = 0.193, P < 0.05), urinary benzene (r_s = 0.298, P < 0.05), urinary MA (r_s = 0.348, P < 0.01), and 8-OHdG in leukocyte (r_s = 0.130, P < 0.05). In addition, a significant correlation between urinary MA and 8-OHdG in leukocytes (r_s = 0.241, P < 0.05) was also found. Polymorphisms of various xenobiotic metabolizing genes responsible for susceptibility to benzene toxicity have been studied; however only the GSTM1 genotypes had a significant effect on urinary MA excretion.Our data indicates that children living in the areas of high traffic density are exposed to a higher level of benzene than those living in rural areas. Exposure to higher level of benzene in urban children may contribute to oxidative DNA damage, suggesting an increased health risk from traffic benzene emission.     

Species-specificity of oospore dimensions in three ecorticate species of Chara (Charales,Charophyceae)

Dimensions of oospores such as length, width, fossa-breadth, length-to-width ratio and number of striae were considered for morphological identification of the members of Charales. Oospores were collected from natural stands of three species, viz. Chara braunii, C. corallina and C. wallichii in ponds in West Bengal (India). Oospore dimensions (length, width and fossa-breadth) correlated well: though the fossa breadth–length relation of C. braunii showed lower correlation coefficient (r² = 0.076, p < 0.001), all other five breadth or width–length relationships showed r² ≥ 0.23, p < 0.001. These bivariate patterns were significantly different among the species (one-way ANCOVA of length–width ratio to fossa-breadth: adjusted means and slopes both p < 0.001), C. braunii and C. corallina has similar length to width ratios, C. wallichii and C. corallina were similar in width, whereas the species differed in breadth and length in the order C. braunii, C. wallichii, and C. corallina.     

Establishing a model for assessing DNA damage in murine brain cells as a molecular marker of chemotherapy-associated cognitive impairment

Aims

Chemotherapy-associated cognitive impairment often follows cancer chemotherapy. We explored chemotherapy-induced DNA damage in the brain cells of mice treated with 5-fluorouracil (5FU), an antineoplastic agent, to correlate the extent of DNA damage to behavioral functioning in an autoshaping-operant mouse model of chemotherapy-induced learning and memory deficits (Foley et al., 2008).

Main methods

Male, Swiss-Webster mice were injected once with saline or 75 mg/kg 5FU at 0, 12, and 24 h and weighed every 24 h. Twenty-four h after the last injection, the mice were tested in a two-day acquisition and the retention of a novel response task for food reinforcement. Murine brain cells were analyzed for the presence of single- and double-strand DNA breaks by the single cell gel electrophoresis assay (the Comet assay).

Key findings

We detected significant differences (p < 0.0001) for all DNA damage characteristics (DNA “comet” tail shape, migration pattern, tail moment and olive moments) between control mice cohort and 5FU-treated mice cohort: tail length – 119 vs. 153; tail moment – 101 vs. 136; olive moment – 60 vs. 82, correspondingly. We found a positive correlation between increased response rates (r = 0.52, p < 0.05) and increased rate of errors (r = 0.51, p < 0.05), and DNA damage on day 1. For all 15 mice (saline-treated and 5FU-treated mice), we found negative correlations between DNA damage and weight (r = − 0.75, p < 0.02).

Significance

Our results indicate that chemotherapy-induced DNA damage changes the physiological status of the brain cells and may provide insights to the mechanisms for cognitive impairment after cancer chemotherapy.     

Genetic and non-genetic factors associated with milking order in lactating dairy cows

The ability to rapidly identify temporal deviations of an animal from its norm will be important in the management of individual cows in large herds. Furthermore, predictors of genetic merit for especially health traits are useful to augment the accuracy of selection, and thus genetic gain, in breeding programs. The objective of this study was to estimate the repeatability of milking order and to quantify the contribution of differences in additive genetic variation to phenotypic differences (i.e., heritability). The data used in this study included 9813 herd milk recording test-day records with time of milking from 85,532 cows in 1143 herds across an 8-year period. Milking order was available for both morning and evening milking for each cow with, on average, 3.33 milk test-day records (i.e., 6.66 milking events) per lactation, and on average 1.62 lactations per cow. Variance components for milking order were estimated using animal linear mixed models; covariance components between milking order and milk yield, milk composition and somatic cell score (i.e., logarithm₁₀ somatic cell count) were estimated also using animal linear mixed models. The heritability of milking order was 0.20 indicating partial genetic control of milking order. The repeatability of milking order within test-day, within lactation, and across lactations was 0.63, 0.51, and 0.47, respectively. Milking order was positively (P < 0.001), but weakly, phenotypically correlated with milk yield (r = 0.04), and milk fat concentration (r = 0.01) and negatively (P < 0.001), but weakly, correlated with milk protein concentration (r = −0.02) and somatic cell score (r = −0.05). Milking order was positively (P < 0.05), although weakly, genetically correlated with milk yield (r = 0.07) and negatively (P < 0.05), but also weakly, genetically correlated with somatic cell score (r = −0.08). This study is the first to show a contribution of additive genetics to milking order in dairy cattle but the genetic correlation between milking order and somatic cell score was weak.