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1.
J Dairy Sci ; 106(11): 7861-7879, 2023 Nov.
Article in English | MEDLINE | ID: mdl-37641276

ABSTRACT

The physiological stress caused by excessive heat affects dairy cattle health and production. This study sought to investigate the effect of heat stress on test-day yields in US Holstein and Jersey cows and develop single-step genomic predictions to identify heat tolerant animals. Data included 12.8 million and 2.1 million test-day records, respectively, for 923,026 Holstein and 153,710 Jersey cows in 27 US states. From 2015 through 2021, test-day records from the first 5 lactations included milk, fat, and protein yields (kg). Cow records were included if they had at least 5 test-day records per lactation. Heat stress was quantified by analyzing the effect of a 5-d hourly average temperature-humidity index (THI5d¯) on observed test-day yields. Using a multiple trait repeatability model, a heat threshold (THI threshold) was determined fowr each breed based on the point that the average adjusted yields started to decrease, which was 69 for Holsteins and 72 for Jerseys. An additive genetic component of general production and heat tolerance production were estimated using a multiple trait reaction norm model and single-step genomic BLUP methodology. Random effects were regressed on a function of 5-d hourly average (THI5d¯) and THI threshold. The proportion of test-day records that occurred on or above the respective heat thresholds was 15% for Holstein and 10% for Jersey. Heritability of milk, fat, and protein yields under heat stress for Holsteins increased, with a small standard error, indicating that the additive genetic component for heat tolerance of these traits was observed. This was not as evident in Jersey traits. For Jersey, the permanent environment explained the same or more of the variation in fat and protein yield under heat stress indicating that nongenetic factors may determine heat tolerance for these Jersey traits. Correlations between the general genetic merit of production (in the absence of heat stress) and heat tolerance genetic merit of production traits were moderate in strength and negative. This indicated that selecting for general genetic merit without consideration of heat tolerance genetic merit of production may result in less favorable performance in hot and humid climates. A general genomic estimated breeding value for genetic merit and a heat tolerance genomic estimated breeding value were calculated for each animal. This study contributes to the investigation of the impact of heat stress on US dairy cattle production yields and offers a basis for the implementation of genomic selection. The results indicate that genomic selection for heat tolerance of production yields is possible for US Holsteins and Jerseys, but a study to validate the genomic predictions should be explored.

2.
Phys Chem Chem Phys ; 22(4): 2466-2474, 2020 Jan 28.
Article in English | MEDLINE | ID: mdl-31939962

ABSTRACT

The perovskite oxide SrFeO3 has favourable redox properties for oxygen exchange applications, including oxygen separation and oxygen production chemical looping cycles. For such applications, lower temperature operation can improve the energy demand and feasibility of the process, but can also lead to kinetic limitations. Here we investigate the oxidation and reduction reaction kinetics of SrFeO3 in the temperature range 450-750 K. Isothermal relaxation techniques are used to observe the reaction rates across this temperature range, using a thermogravimetric analysis system. Experimental data are analysed according to an isoconversional method and fit with a simple power law model to extract activation energies. The apparent activation energy of oxidation and reduction was found to be 92 ± 16 and 144 ± 17 kJ mol-1 respectively. Comparison of oxidation and reduction kinetics together with considerations of particle size indicate that the oxidation reaction rate may be limited by diffusion in the bulk, while the reduction reaction rate is limited by the surface reaction. Furthermore, we also investigated the mixed perovskite Sr0.93Ca0.07Fe0.9Co0.1O3, which exhibited a 4-fold increase in the oxidation rate.

3.
Phys Chem Chem Phys ; 18(33): 23147-54, 2016 Aug 17.
Article in English | MEDLINE | ID: mdl-27494765

ABSTRACT

The thermodynamic redox properties of ceria and ceria zirconia solid solutions are analysed with a new methodology for modelling such systems based on the statistical mechanics of lattice configurations. Experimental thermogravimetric equilibrium data obtained for small non-stoichiometry measurements are combined with literature data to cover a large range of non-stoichiometry (CeO2-δ, δ = 0.001-0.32), temperature (1073-1773 K) and oxygen partial pressure (1-10(-13) bar). A dilute species model of defect clusters , obeying the law of mass action, was sufficient to describe the system over the whole range of conditions, leading to a simple analytical equation of state for the system. This offers new physical insight into the redox properties of ceria based materials, and the theoretical methods developed should also be of great interest for other materials which exhibit continuous oxygen non-stoichiometry similar to ceria, such as perovskite oxides.

4.
Clin Pharmacol Ther ; 97(3): 215-7, 2015 Mar.
Article in English | MEDLINE | ID: mdl-25670498

ABSTRACT

A biosimilar is designed to match the reference product--to be as close to the reference as the reference is to itself considering batch-to-batch variability and manufacturing changes over its lifetime. Interchangeability will require additional data, however, the interchangeable biologic itself will be the same as that approved for biosimilarity.


Subject(s)
Biosimilar Pharmaceuticals/standards , Drug Approval , Drug Discovery/standards , Humans
5.
J Gen Virol ; 93(Pt 5): 1076-1080, 2012 May.
Article in English | MEDLINE | ID: mdl-22258865

ABSTRACT

Although ORF23 is conserved among gammaherpesviruses, its role during infection is unknown. Here, we studied the expression of ORF23 of murine gammaherpesvirus 68 (MHV-68) and its role during infection. ORF23 mRNA was detected in infected cells as a late transcript. The ORF23 protein product could be expressed and detected as an N-terminally FLAG-tagged protein by Western blot and indirect immunofluorescence. To investigate the role of ORF23 in the infection cycle of a gammaherpesvirus, we constructed an ORF23 deletion mutant of MHV-68. The analysis of the ORF23 deletion mutant suggested that ORF23 of MHV-68 is neither essential for replication in cell culture nor for lytic or latent infection in vivo. A phenotype of the ORF23 deletion mutant, reflected by a moderate reduction in lytic replication and latency amplification, was only detectable in the face of direct competition to the parental virus.


Subject(s)
Open Reading Frames , Rhadinovirus/pathogenicity , Viral Proteins/metabolism , Virus Replication , Animals , Blotting, Western , Coronaviridae Infections/pathology , Coronaviridae Infections/virology , Gene Deletion , Gene Expression Profiling , Lung/virology , Mice , Mice, Inbred BALB C , Mice, Inbred C57BL , Protein Biosynthesis , Rhadinovirus/growth & development , Spleen/virology , Transcription, Genetic , Viral Load , Viral Proteins/genetics
6.
Dement Geriatr Cogn Disord ; 32(3): 171-7, 2011.
Article in English | MEDLINE | ID: mdl-22005607

ABSTRACT

BACKGROUND: Personality traits contribute to cognitive functioning. We present a study comparing personality traits in normal ageing and mild cognitive impairment (MCI). METHODS: We conducted a representative longitudinal study including 222 subjects from a cohort born between 1930 and 1932 (n = 500) examined at three examination waves (t1: 1993/1994; t2: 1997/1998; t3: 2005/2007). Personality traits were assessed with the NEO-Five-Factor Inventory questionnaire. RESULTS: Healthy controls and patients with MCI showed a significant (p < 0.05) decrease concerning their levels of neuroticism and extraversion over time. MCI subjects scored significantly higher on neuroticism at baseline and lower on openness at all examinations compared to healthy controls. Subjects with higher baseline neuroticism showed a 2.24 times higher risk of developing MCI at the third follow-up (odds ratio = 2.24, 95% confidence interval = 1.12-4.45 - scores adjusted for education and sex). CONCLUSIONS: MCI subjects differ in their premorbid personality traits compared to healthy controls. According to our study, higher neuroticism should be considered a risk factor for the development of MCI.


Subject(s)
Cognitive Dysfunction/psychology , Personality , Aged , Aging/psychology , Cognitive Dysfunction/epidemiology , Confidence Intervals , Data Interpretation, Statistical , Educational Status , Female , Germany/epidemiology , Humans , Logistic Models , Longitudinal Studies , Male , Neuropsychological Tests , Neurotic Disorders/psychology , Odds Ratio , Population , Predictive Value of Tests , Prospective Studies , Risk Factors , Sex Factors
7.
Radiologe ; 51(4): 278-84, 2011 Apr.
Article in German | MEDLINE | ID: mdl-21461705

ABSTRACT

A variety of neurodegenerative diseases can underlie dementia syndromes. In addition to Alzheimer's disease (AD) and its prodromal stages, these include in particular frontotemporal degeneration, Lewy body dementia and Parkinson's dementia, progressive supranuclear paresis, corticobasal degeneration and chorea Huntington. Although not classified as a neurodegenerative brain disease, for all clinical diagnoses there must be a differential diagnostic separation from vascular forms of dementia. Furthermore an exclusion of affective disorders, such as minor depression is necessary from a clinical psychiatric perspective. Moreover the preclinical stages of AD often present with uncharacteristic symptoms. Especially affective symptoms can occur in addition to initial cognitive deficits such as memory decline. In summary, clinical and neuropsychological procedures together with functional imaging techniques allow a detailed diagnostic assessment of neurodegenerative dementia syndromes which can be additionally supported by neurochemical biomarkers and innovative imaging procedures, such as diffusion imaging or magnetic resonance spectroscopy.


Subject(s)
Brain/diagnostic imaging , Brain/pathology , Dementia/complications , Dementia/diagnosis , Diagnostic Imaging/methods , Neurodegenerative Diseases/complications , Neurodegenerative Diseases/diagnosis , Diagnosis, Differential , Humans , Radionuclide Imaging
9.
J Dairy Sci ; 92(7): 3402-10, 2009 Jul.
Article in English | MEDLINE | ID: mdl-19528618

ABSTRACT

The objectives of this study were to compare alternative mastitis definitions and to estimate genetic correlations of producer-recorded mastitis with somatic cell score (SCS) and yield. Cow health events and lactation records from June 2002 through October 2007 were provided by Dairy Records Management Systems (Raleigh, NC). First- through fifth-lactation records from cows calving between 20 and 120 mo of age and that calved in a herd-year with at least 1% of cows with a clinical mastitis event were retained. The edited data contained 118,516 lactation records and 1,072,741 test-day records of 64,893 cows. Mastitis occurrence (1 = at least one mastitis event during lactation or test-day interval, 0 = no mastitis events), number of mastitis events during lactation, SCS, and yield were analyzed with animal models (single trait) or sire-maternal grandsire models (multiple trait) in ASREML. Comparisons were made among models assuming a normal distribution, a binary distribution, or Poisson distribution (for total episodes). The overall incidence of clinical mastitis was 15.4%; and heritability estimates ranged from 0.73% (test-day interval mastitis with a linear model) to 11.07% (number of mastitis episodes with a Poisson model). Increased mastitis incidence was genetically correlated with higher SCS (range 0.66 to 0.88) and was generally correlated with higher yield (range -0.03 to 0.40), particularly during first lactation (0.04 to 0.40). Significant genetic variation exists for clinical mastitis; and health events recorded by producers could be used to generate genetic evaluations for cow health. Sires ranked similarly for daughter mastitis susceptibility regardless of how mastitis was defined; however, test-day interval mastitis and a total count of mastitis episodes per lactation allow a higher proportion of mastitis treatments to be included in the genetic analysis.


Subject(s)
Cattle/physiology , Mastitis, Bovine/genetics , Milk/cytology , Animals , Cattle/genetics , Fats/analysis , Female , Lactation/physiology , Mastitis, Bovine/physiopathology , Milk/chemistry , Milk Proteins/analysis
10.
Allergy ; 63(11): 1438-47, 2008 Nov.
Article in English | MEDLINE | ID: mdl-18925880

ABSTRACT

BACKGROUND: There is strong evidence that reduced exposures to microbial compounds triggering innate immune responses early in life are critical for the development of allergic illnesses. The underlying mechanisms remain unknown, but will include T-cell responses either along T helper type 1 (Th1)/Th2 pathways or via T regulatory and Th17 cells. Yet, little is known about innate immune responses and the function of T regulatory/Th17 cells at birth. The aim of this study was to investigate T-cell responses to innate (Lipid A/LpA, peptidoglycan/Ppg) and adaptive (phytohemagglutinin) stimuli at birth and to compare these findings with adult immune responses. METHODS: Cord and peripheral blood mononuclear cells including T regulatory and Th17 cells from 25 neonates and 25 adults were examined for proliferation, cytokine secretion, surface, mRNA expression and functional suppression assays. RESULTS: Proliferation and cytokine responses to innate stimuli were less mature at birth than in adulthood. T regulatory and Th17 cells were less expressed in cord than in adult blood (Ppg-induced Foxp3, P = 0.001, LpA-induced CD4(+) CD25(+) high, P = 0.02; Th17 : P < 0.0001). Mitogen-induced suppression of T-regulatory cells on T-effector cell function was less efficient in cord than in adult blood (P = 0.01). At both ages, Th17 cells were correlated with Th1/Th2 cells (P < 0.01), but not with interleukin-10 secretion following innate-stimulation. CONCLUSION: Innate immune responses are immature at birth. Furthermore, the function of T regulatory and Th17 cells is impaired. Th17 cells in association with Th1/Th2 cells may be involved in early immuno-modulation. Potent innate immune stimulation early in life can potentially contribute to protection from allergic diseases.


Subject(s)
Cytokines/blood , Fetal Blood/immunology , Leukocytes, Mononuclear/immunology , Parturition/immunology , T-Lymphocytes, Helper-Inducer/immunology , T-Lymphocytes, Regulatory/immunology , Adult , Fetal Blood/metabolism , Humans , Immunity, Innate , Infant, Newborn , Interleukin-17/immunology , Interleukin-17/metabolism , Leukocytes, Mononuclear/metabolism , Lipid A/immunology , Lipid A/metabolism , Middle Aged , Peptidoglycan/immunology , Peptidoglycan/metabolism , Phytohemagglutinins/immunology , Phytohemagglutinins/metabolism , T-Lymphocytes, Helper-Inducer/metabolism , T-Lymphocytes, Regulatory/metabolism
11.
Cereb Cortex ; 17(10): 2468-77, 2007 Oct.
Article in English | MEDLINE | ID: mdl-17204821

ABSTRACT

The cortical mechanisms of feature-selective attention to color and motion cues were studied in humans using combined electrophysiological, magnetoencephalographic, and hemodynamic (functional magnetic resonance imaging) measures of brain activity. Subjects viewed a display of random dots that periodically either changed color or moved coherently. When attention was directed to the color change it elicited enhanced neural activity in visual area V4v, previously shown to be specialized for processing color information. In contrast, when dot movement was attended it produced enhanced activity in the motion-specialized area human MT. Parallel recordings of event-related electrophysiological and magnetoencephalographic responses indicated that the attention-related facilitation of neural activity in these specialized cortical areas occurred rapidly, beginning as early as 90-120 ms after stimulus onset. We conclude that selection of an entire feature dimension (motion or color) boosts neural activity in its specialized cortical module much more rapidly than does selection of one feature value from another (e.g., one color from another), as reported in previous electrophysiological studies. By combining methods with high spatial and temporal resolution it is possible to analyze the precise time course of feature-selective processing in specialized cortical areas.


Subject(s)
Attention/physiology , Brain/physiology , Visual Perception , Adult , Brain Mapping , Evoked Potentials , Female , Humans , Magnetic Resonance Imaging , Magnetoencephalography , Male , Motion Perception , Reference Values , Space Perception , Time Perception
12.
J Dairy Sci ; 90(2): 1073-9, 2007 Feb.
Article in English | MEDLINE | ID: mdl-17235187

ABSTRACT

A survey was mailed to approximately 4,000 herds participating in a young sire progeny test program to estimate the percentage of herds that selectively alter the voluntary waiting period (VWP) for individual cows or groups of cows. Responses were received from 673 herds (17%; 583 Holsteins, 55 Jerseys, 35 other dairy breeds). The mean VWP cited by respondents was 56 +/- 0.6 d (range = 30 to 90 d) and did not differ by breed. Among responding herds, 64% (432/673) indicated the VWP was selectively altered for one or more reasons. The most frequently cited reasons for altering the VWP were postpartum health (50%), season (18%), milk yield (18%), parity (14%), and other reasons (14%). In Holstein herds that altered the VWP based on milk yield, the highest production group averaged 14 more days to first service than the lowest production group (> or =40 vs. <20 kg of energy-corrected milk, respectively). In contrast, days to first service were nearly identical for all production groups in Holstein herds that did not vary the VWP based on milk yield. In conclusion, management decisions to selectively alter the VWP led to differences in days to first service and may have a confounding effect on genetic estimates of daughter fertility. Opportunities to improve the accuracy of daughter pregnancy rate estimates may reside in models that adjust for VWP management decisions on a within-herd basis.


Subject(s)
Breeding/methods , Dairying/methods , Animals , Female , Health Status , Insemination, Artificial/veterinary , Lactation , Male , Parity , Postpartum Period , Pregnancy , Seasons , Surveys and Questionnaires , Time Factors
13.
Clin Exp Immunol ; 142(2): 260-7, 2005 Nov.
Article in English | MEDLINE | ID: mdl-16232212

ABSTRACT

Increased expression of CD44 variant isoforms have been shown on the inflammatory infiltrates in human and mouse colitis and blockade or deletion of CD44 isoforms inhibit experimental colitis. The objective of this study was to find out if short-term treatment of CD44 antibodies specific to CD44v7, but not to other variant isoforms, suppresses leucocyte-endothelial interaction in chronic dextran sodium sulphate (DSS)-induced colitis in mice. Chronic colitis was induced by oral administration of four cycles of 5% DSS in BALB/c mice. Expression of CD44 was investigated on isolated mononuclear cells of the gut immune system. In established colitis, mice were treated with antibodies against CD44v7 or CD44v4 three times in 7 days. Intravital microscopy was used to study leucocyte-endothelial interactions and leucocyte extravasation. As a marker of inflammatory infiltrates myeloperoxidase was quantified in gut tissue. CD44-induced apoptosis was determined by fluorescence staining of hypodiploidic cell nuclei. In chronic DSS-induced colitis both CD44 variant isoforms, v4 and v7 were significantly up-regulated on mononuclear cells. However, whereas anti-CD44v7 antibody treatment induced a marked restoration of the gut mucosa and significantly reduced endothelial sticking and extravasation of circulating leucocyte in vivo (P < 0.01), application of anti-CD44v4 or an isotype control antibody had no anti-inflammatory effect. A significant reduction of myeloperoxidase activity was detected after blockade of CD44v7, but not v4. Short-term treatment with anti-CD44v7 antibody blocks T cell extravasation and recruitment to the intestinal mucosa and cures established experimental colitis.


Subject(s)
Antibodies, Monoclonal/therapeutic use , Colitis/therapy , Hyaluronan Receptors/immunology , Intestinal Mucosa/immunology , Animals , Cell Adhesion/immunology , Chronic Disease , Colitis/chemically induced , Colitis/immunology , Dextran Sulfate , Disease Models, Animal , Down-Regulation/immunology , Endothelial Cells/immunology , Female , Hyaluronan Receptors/metabolism , Immunity, Mucosal , Leukocytes/immunology , Lymph Nodes/immunology , Lymphocyte Activation/immunology , Mesentery , Mice , Mice, Inbred BALB C , Peroxidase/metabolism , Protein Isoforms/immunology , Protein Isoforms/metabolism
14.
Water Sci Technol ; 49(4): 189-93, 2004.
Article in English | MEDLINE | ID: mdl-15077970

ABSTRACT

In the WATER project the German Aerospace Center, and the Universidade Federal de Uberlândia, analyse the possibilities of treating paper mill effluents by solar photocatalysis for the paper mill of the Brazilian paper producer Votorantim Celulose e Papel, VCP, at Luiz Antônio, SP, Brazil. The degradation of the bio-polymer lignin is a vast problem in paper production. The tests have shown that treatment by the photocatalyst TiO2 and solar radiation is an ecological future oriented approach to solve this problem. The treatment of lignin containing process water by solar photocatalysis was optimised and the economics for solar treatment plants of different sizes was estimated to check the possibilities for implementing the technology in industrial processes.


Subject(s)
Waste Disposal, Fluid/methods , Water Purification/methods , Catalysis , Coloring Agents/chemistry , Industrial Waste , Photochemistry , Sunlight , Titanium/chemistry
15.
Proc Natl Acad Sci U S A ; 100(20): 11806-11, 2003 Sep 30.
Article in English | MEDLINE | ID: mdl-12960369

ABSTRACT

Objects in the environment may be attended selectively and perceived as unified ensembles of their constituent features. To investigate the timing and cortical localization of feature-integration mechanisms in object-based attention, recordings of event-related potentials and magnetic fields were combined with functional MRI while subjects attended to one of two superimposed transparent surfaces formed by arrays of dots moving in opposite directions. A spatiotemporal analysis revealed evidence for a rapid increase in neural activity localized to a color-selective region of the fusiform gyrus when the surface moving in the attended direction displayed an irrelevant color feature. These data provide support for the "integrated-competition" model of object-selective attention and point to a dynamic neural substrate for the rapid binding process that links relevant and irrelevant features to form a unified perceptual object.


Subject(s)
Attention/physiology , Visual Perception/physiology , Adult , Evoked Potentials , Humans , Magnetic Resonance Imaging , Male
16.
J Dairy Sci ; 86(4): 1513-25, 2003 Apr.
Article in English | MEDLINE | ID: mdl-12741578

ABSTRACT

Progeny-test (PT) programs of US artificial-insemination (AI) organizations were examined to determine timeliness of sampling, PT daughter distribution, rate of return of PT bulls to widespread service, and genetic merit of PT bulls compared with AI-proven and natural-service (NS) bulls. Bull age at semen release and at birth and calving of PT daughters was documented by breed (Ayrshire, Brown Swiss, Guernsey, Holstein, Jersey, and Milking Shorthorn) for bulls that entered AI service since 1960. Mean Holstein bull age at semen release (16 mo) changed little over time, but standard deviations (SD) decreased from 4.0 mo during the 1960s to 2.4 mo during the 1990s. Most Holstein bulls (80%) had semen released by 18 mo. Mean age of Holstein bulls at birth and calving of PT daughters during the 1990s was 29 and 56 mo, respectively (a decline of 4 mo from the 1960s); SD decreased from 6 to 3 mo. Bulls of other breeds usually were older at birth and calving of PT daughters, and SD were larger. Mean Holstein bull age when 80% of PT daughters had been born declined from 36 mo during the 1960s to 31 mo during the early 1990s; for other breeds, bulls showed the same trend but at older ages. Mean Holstein bull age when 80% of PT daughters had calved declined from 65 mo during the 1960s to 59 mo during the 1990s; for other breeds, bulls were older. Percentage of herds with PT daughters has increased over time. For Holsteins, herds with five or more usable first-parity records that had PT daughters with usable records increased from 15% during 1965 to 61% during 1998; percentage of herds with from 1 to 19% PT records increased from 11 to 38%, and percentage of herds with >50% PT daughters increased from 1 to 5%. Percentage of Holstein PT bulls returned to AI service declined to about 12% for bulls with PT entry around 1990; for other breeds, 12 to 23% of most recent PT bulls were returned to service. Percentage of milking daughters that had records usable for genetic evaluation that were sired by PT bulls increased steadily from 10 to 18%, whereas percentage of daughters with usable records that were sired by NS bulls declined from 14 to 7%. Milk yield of daughters of AI-proven bulls was 107 to 200 kg greater than for daughters of PT bulls and 366 to 444 kg greater than for daughters of NS bulls for all years. More extensive and rapid sampling and increased selection intensity of PT programs have led to more rapid genetic progress. More extensive use of AI could increase US producer income by millions of dollars annually.


Subject(s)
Cattle/genetics , Insemination, Artificial/veterinary , Aging , Animals , Breeding , Dairying/economics , Dairying/methods , Female , Lactation/genetics , Linear Models , Male , Parity , Selection, Genetic , Time Factors
17.
Water Sci Technol ; 44(5): 271-8, 2001.
Article in English | MEDLINE | ID: mdl-11695470

ABSTRACT

Solar photocatalytic detoxification of non-biodegradable chlorinated hydrocarbon solvents (NBCS) is carried out in different concentrating and non concentrating devices using TiO2 as a photocatalyst fixed on the inner surface of the reaction tubes or as a slurry catalyst which has to be removed from the treated water. The reaction is most effective using 200 mg/l of TiO2 as a slurry in a non concentrating CPC reactor. The concentrating parabolic trough reactor has a poor activity because of its minor irradiated reactor surface. Catalyst coated glass tubes are less efficient then the used slurry catalyst. Their advantage is that no catalyst has not to be removed from the treated water and there is no loss of activity during treatment. Yet their physical stability is not sufficient to be competitive to the slurry catalyst. Nevertheless the degradation results are very promising and will possibly lead to commercial applications of this technology.


Subject(s)
Hydrocarbons, Chlorinated/chemistry , Solvents/chemistry , Catalysis , Coloring Agents/chemistry , Equipment Design , Photochemistry , Titanium/chemistry , Ultraviolet Rays , Water Purification/methods
18.
Toxicol Appl Pharmacol ; 175(2): 121-9, 2001 Sep 01.
Article in English | MEDLINE | ID: mdl-11543644

ABSTRACT

Human exposure to the environmental toxin 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) produces a severe skin pathology known as chloracne. In these studies we employed a three-dimensional, organotypic model system to study the effects of TCDD on human skin. This model uses the spontaneously immortalized human keratinocyte cell line NIKS and recapitulates both the three-dimensional microenvironment and epithelial-mesenchymal interactions found in intact human skin. Treatment of the organotypic cultures with TCDD causes alterations in the pattern of keratinocyte terminal differentiation. Analysis at both the light and electron microscope levels reveals a fully differentiated cornified layer in TCDD-treated organotypic cultures at earlier time points than observed in vehicle (dimethyl sulfoxide)-treated controls. Furthermore, TCDD-treated organotypic cultures exhibit aberrant distribution of several differentiation-specific protein markers. Basal cells in TCDD- and DMSO-treated organotypic cultures show no differences in proliferation as measured by quantification of 5-bromo-2'-deoxyuridine (BrdU)-positive nuclei. No aberrant BrdU uptake was detected outside of the basal layer. Neither TUNEL labeling nor immunohistochemical staining with an antibody to active caspase-3 revealed increased apoptosis in TCDD-treated organotypic cultures relative to controls. These data clearly indicate that TCDD modulates homeostasis in a model of human stratifying epithelium independent of changes in proliferation and apoptosis, exclusively by impacting keratinocyte terminal differentiation. This TCDD-induced effect on differentiation-specific proteins results in profound changes in the tissue architecture.


Subject(s)
Cryoprotective Agents/pharmacology , Dimethyl Sulfoxide/pharmacology , Environmental Pollutants/pharmacology , Keratinocytes/drug effects , Polychlorinated Dibenzodioxins/pharmacology , Antimetabolites/metabolism , Bromodeoxyuridine/metabolism , Cell Line , Cells, Cultured , Humans , Keratinocytes/metabolism , Microscopy, Electron
19.
J Dairy Sci ; 84(8): 1899-912, 2001 Aug.
Article in English | MEDLINE | ID: mdl-11518316

ABSTRACT

Characteristics of progeny-test (PT) programs of artificial insemination (AI) organizations in the United States were examined for changes since 1960. Mean number of bulls that were progeny tested annually by major AI organizations during the mid 1990s was 11 for Ayrshires, 24 for Brown Swiss, 21 for Guernseys, 1261 for Holsteins, 112 for Jerseys, and 3 for Milking Shorthorns. Mean parent age at progeny-test (PT) bull birth decreased except for Milking Shorthorns; mean age of maternal grandsire at bull birth decreased for Holsteins and Jerseys but increased for other breeds. For Holsteins, mean ancestor ages at PT bull birth were 85 mo for sires, 47 mo for dams, and 136 mo for maternal grandsires during the mid 1990s. Percentage of PT bulls that resulted from embryo transfer increased to 78% for Brown Swiss and 80% for Holsteins by 1999. Inbreeding in PT bulls increased over time and ranged from 3.8% for Brown Swiss to 6.4% for Jerseys (5.6% for Holsteins) during the mid 1990s. Mean numbers of daughters and herds per PT bull generally declined except for Holsteins, which increased during the early 1990s to 61 daughters and 44 herds. Mean number of states in which PT daughters are located increased; for Holstein PT bulls during 1994, 22% of daughters were in California, 13% in Wisconsin, 12% in New York, and 10% in Pennsylvania and Minnesota. Percentage of first-lactation cows that were PT daughters increased and ranged from 6% for Milking Shorthorns to 22% for Ayrshires (14% for Holsteins) during 1998. Percentage of PT daughters that were registered declined and was 19% for Holsteins and around 80% for other breeds.


Subject(s)
Cattle/genetics , Insemination, Artificial/veterinary , Age Factors , Animals , Breeding , Cattle/physiology , Female , Lactation/genetics , Male , Pedigree , Reproduction/genetics , United States
20.
J Dairy Sci ; 84(5): 1246-54, 2001 May.
Article in English | MEDLINE | ID: mdl-11384052

ABSTRACT

Stillbirth, defined as a calf that dies just prior to, during, or within 48 h of parturition, represents a reoccurring concern among breeders of dairy cattle in the United States. About 11% of parturitions of primiparous Holstein cows result in the death of a calf; 5.7% in multiparous cows. Genetic evaluations can be reported as perinatal survival to 48 h to emphasize the positive information about the trait. The purpose of this research was to: 1) estimate genetic parameters by restricted maximum likelihood for perinatal survival rates; 2) characterize the genetic evaluation of sires for the perinatal survival of their progeny and maternal grandsires for the perinatal survival of their daughters progeny; and 3) estimate genetic trends from 1984 to 1994. Data (n = 666,339) were from the National Association of Animal Breeders calving ease database. Over 600 new young sires were available each year. The binomial response variable, 1 = alive, 0 = stillborn within 48 h of parturition was analyzed by using a sire-maternal grandsire linear mixed model. The model included fixed effects for sex of calf, dystocia, and season of birth, and gestation length as a covariate; correlated random effects of sire and maternal grandsire; and uncorrelated random effects of herd-years. Parturitions of primiparous and multiparous cows were analyzed separately. In primiparous cows, heritability estimates were 1.1 and 2.2% for sire of the calf and maternal grandsire, respectively. The genetic correlation between sire and maternal grandsire predicted transmitting ability (PTA) for perinatal survival, was 0.31; simple product moment correlations among sire-MGS PTA were 0.43 and 0.46 for primiparous and multiparous cows, respectively. The PTA for sire of the calf ranged from -2.9 (lower survival) to 2.8% (higher survival). Mean PTA from 1984 to 1994 was quite variable from year to year. Evidence showed a slightly negative, but nonsignificant, genetic trend in perinatal survival (-0.04% per year for sires and -0.02% per year for maternal grandsires). Estimates of genetic parameters and genetic trends for data from multiparous cows are also reported. Correlations among PTA for perinatal survival, milk yield, and calving ease are given.


Subject(s)
Breeding/statistics & numerical data , Cattle Diseases/epidemiology , Cattle/genetics , Cattle/physiology , Fetal Death/veterinary , Animals , Cattle Diseases/mortality , Databases as Topic , Dystocia/epidemiology , Dystocia/mortality , Dystocia/veterinary , Female , Fetal Death/epidemiology , Gestational Age , Incidence , Male , Models, Genetic , Parity , Pregnancy , Seasons , Sex Factors , United States
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