Short communication: Effect of maternal heat stress in late gestation on blood hormones and metabolites of newborn calves

Maternal heat stress alters immune function of the offspring, as well as metabolism and future lactational performance, but its effect on the hormonal and metabolic responses of the neonate immediately after birth is still not clear. The objective of this study was to investigate the blood profiles of hormones and metabolites of calves born to cows that were cooled (CL) or heat-stressed (HS) during the dry period. Within 2 h after birth, but before colostrum feeding, blood samples were collected from calves [18 bulls (HS: n=10; CL: n=8) and 20 heifers (HS: n=10; CL: n=10)] born to CL or HS dry cows, and hematocrit and plasma concentrations of total protein, prolactin, insulin-like growth factor-I, insulin, glucose, nonesterified fatty acid, and β-hydroxybutyrate were measured. Compared with CL, HS calves had lower hematocrit and tended to have lower plasma concentrations of insulin, prolactin, and insulin-like growth factor-I. However, maternal heat stress had no effect on plasma levels of total protein, glucose, fatty acid, and β-hydroxybutyrate immediately after birth. These results suggest that maternal heat stress desensitizes a calf's stress response and alters the fetal development by reducing the secretion of insulin-like growth factor-I, prolactin, and insulin.

Household air pollution and personal exposure risk of polycyclic aromatic hydrocarbons among rural residents in Shanxi, China

Polycyclic aromatic hydrocarbons (PAHs) are a group of pollutants of widespread concerns. Gaseous and size-segregated particulate-phase PAHs were collected in indoor and outdoor air in rural households. Personal exposure was measured and compared to the ingestion exposure. The average concentrations of 28 parent PAHs and benzo(a)pyrene (BaP) were 9000 ± 8390 and 131 ± 236 ng/m(3) for kitchen, 2590 ± 2270 and 43 ± 95 ng/m(3) for living room, and 2800 ± 3890 and 1.6 ± 0.7 ng/m(3) for outdoor air, respectively. The mass percent of high molecular weight (HMW) compounds with 5-6 rings contributed 1.3% to total 28 parent PAHs. Relatively higher fractions of HMW PAHs were found in indoor air compared to outdoor air. Majorities of particle-bound PAHs were found in the finest PM0.25 , and the highest levels of fine PM0.25 -bound PAHs were in the kitchen using peat and wood as energy sources. The 24-h personal PAH exposure concentration was 2100 ± 1300 ng/m(3) . Considering energies, exposures to those using wood were the highest. The PAH inhalation exposure comprised up to about 30% in total PAH exposure through food ingestion and inhalation, and the population attributable fraction (PAF) for lung cancer in the region was 0.85%. The risks for inhaled and ingested intakes of PAHs were 1.0 × 10(-5) and 1.1 × 10(-5) , respectively.

HLA-B allele dropout in PCR sequence-specific oligonucleotide probe typing due to intronic polymorphism in the novel B*58:01:01:02 allele

Currently, Luminex technology based on the PCR sequence-specific oligonucleotide (SSO) probe method has been widely used for HLA genotyping in the immunogenetics laboratories. Here, we reported a case with HLA-B allele dropout by Luminex technology. The initial HLA-B result of the Luminex method with a commercial agent kit was inconclusive, and then, the result of PCR-SBT technology indicated the dropout as a HLA-B*58 allele. Subsequently, the full-length sequence of HLA-B allele was determined by TOPO-TA cloning, and a novel allele B*58:01:01:02 was identified in the individual. Compared with HLA-B*58:01:01:01, the novel allele showed some nucleotides difference at 509 C>T, 521 T>G and CCC insertion in position 503 of intron 2. According to the full-length sequence, the new mutations of intron 2 were contributed to HLA-B locus allele dropout in the sample. Our results indicated multiplatform should be used to improve the HLA typing accuracy when a conclusive HLA genotype cannot be determined.

HLA-A, -B and -DRB1 allele and haplotype frequencies of 8333 Chinese Han from the Zhejiang province, China

The distribution of human leucocyte antigen (HLA) allele and haplotype is varied among different ethnic populations. In this study, HLA-A, -B and -DRB1 allele and haplotype frequencies were determined in 8333 volunteer bone marrow donors of Zhejiang Han population using the polymerase chain reaction sequence-based typing. A total of 52 HLA-A, 96 HLA-B and 61 HLA-DRB1 alleles were found. Of these, the top three frequent alleles in HLA-A, HLA-B and HLA-DRB1 loci, respectively, were A*11:01 (24.53%), A*24:02 (17.35%), A*02:01 (11.58%); B*40:01 (15.67%), B*46:01 (11.87%), B*58:01 (9.05%); DRB1*09:01 (17.54%),DRB1*12:02 (9.64%) and DRB1*08:03 (8.65%). A total of 171 A-B-DRB1 haplotypes with a frequency of >0.1% were presented and the five most common haplotypes were A*33:03-B*58:01- DRB1*03:01, A*02:07-B*46:01-DRB1*09:01, A*30:01-B*13:02-DRB1*07:01, A*33:03-B*58:01-RB1*13:02 and A*11:01-B*15:02-DRB1*12:02. The information will be useful for selecting unrelated bone marrow donors and for anthropology studies and pharmacogenomics analysis.

Effects of late-gestation heat stress on immunity and performance of calves

Lactating cows that experience heat stress will have reduced dry matter intake and milk yield and shift metabolism, which ultimately reduces the efficiency of milk production. Dry cows that are heat stressed similarly experience lower intake, reduced mammary growth, and compromised immune function that ultimately results in a poorer transition into lactation and lower milk yield in the next lactation. A recent focus in our laboratory is on the effects of late gestation, in utero heat stress on calf survival and performance. We have completed a series of studies to examine preweaning growth and health, and later reproductive and productive responses, in an attempt to quantify acute and persistent effects of in utero heat strain. Late gestation heat stress results in calves with lower body weight at birth, shorter stature at weaning, and failure to achieve the same weight or height at 12 mo of age observed in calves from dams that are cooled when dry. A portion of the reduced growth may result from the lower immune status observed in calves heat stressed in utero, which begins with poorer apparent efficiency of immunoglobulin absorption and extends to lower survival rates through puberty. Heat-stressed calves, however, have permanent shifts in metabolism that are consistent with greater peripheral accumulation of energy and less lean growth relative to those from cooled dams. Comparing reproductive performance in calves heat stressed versus those cooled in utero, we observe that the cooled heifers require fewer services to attain pregnancy and become pregnant at an earlier age. Tracking the milk production in calves that were heat stressed in utero versus those cooled in late gestation revealed a significant reduction of yield in the first lactation, approximately 5 kg/d through 35 wk of lactation, despite similar body weight and condition score at calving. These observations indicate that a relatively brief period of heat stress in late gestation dramatically alters the health, growth, and ultimate performance of dairy calves. Thus, it is critical to effectively manage heat stress of dry cows to avoid negative effects on the calf.

Noise-induced damage to ribbon synapses without permanent threshold shifts in neonatal mice

Recently, ribbon synapses to the hair cells (HCs) in the cochlea have become a novel site of interest in the investigation of noise-induced cochlear lesions in adult rodents (Kujawa and Liberman, 2009; Lin et al., 2011; Liu et al., 2012; Shi et al., 2013). Permanent noise-induced damage to this type of synapse can result in subsequent degeneration of spiral ganglion neurons (SGNs) in the absence of permanent changes to hearing sensitivity. To verify whether noise exposure during an early developmental period produces a similar impact on ribbon synapses, the present study examined the damaging effects of noise exposure in neonatal Kunming mice. The animals received exposure to broadband noise at 105-decibel (dB) sound pressure level (SPL) for 2h on either postnatal day 10 (P10d) or postnatal day 14 (P14d), and then hearing function (based on the auditory brainstem response (ABR)) and cochlear morphology were evaluated during either postnatal weeks 3-4 (P4w) or postnatal weeks 7-8 (P8w). There were no significant differences in the hearing threshold between noise-exposed and control animals, which suggests that noise did not cause permanent loss of hearing sensitivity. However, noise exposure did produce a significant loss of ribbon synapses, particularly in P14d mice, which continued to increase from P4w to P8w. Additionally, a corresponding reduction in the amplitude of compound action potential (CAP) was observed in the noise-exposed groups at P4w and P8w, and the CAP latency was elongated, indicating a change in synaptic function.