Estimation of dominance variance in purebred Yorkshire swine

We used 179,485 Yorkshire reproductive and 239,354 Yorkshire growth records to estimate additive and dominance variances by Method Fraktur R. Estimates were obtained for number born alive (NBA), 21-d litter weight (LWT), days to 104.5 kg (DAYS), and backfat at 104.5 kg (BF). The single-trait models for NBA and LWT included the fixed effects of contemporary group and regression on inbreeding percentage and the random effects mate within contemporary group, animal permanent environment, animal additive, and parental dominance. The single-trait models for DAYS and BF included the fixed effects of contemporary group, sex, and regression on inbreeding percentage and the random effects litter of birth, dam permanent environment, animal additive, and parental dominance. Final estimates were obtained from six samples for each trait. Regression coefficients for 10% inbreeding were found to be -.23 for NBA, -.52 kg for LWT, 2.1 d for DAYS, and 0 mm for BF. Estimates of additive and dominance variances expressed as a percentage of phenotypic variances were, respectively, 8.8 +/- .5 and 2.2 +/- .7 for NBA, 8.1 +/- 1.1 and 6.3 +/- .9 for LWT, 33.2 +/- .4 and 10.3 +/- 1.5 for DAYS, and 43.6 +/- .9 and 4.8 +/- .7 for BF. The ratio of dominance to additive variances ranged from .78 to .11.     

Different MRF4 knockout alleles differentially disrupt Myf-5 expression: cis-regulatory interactions at the MRF4/Myf-5 locus

Three different null alleles of the myogenic bHLH gene MRF4/herculin/Myf-6 were created recently. The three alleles were similar in design but were surprisingly different in the intensity of their phenotypes, which ranged from complete viability of homozygotes to complete lethality. One possible explanation for these differences is that each mutation altered expression from the nearby Myf-5 gene to a different extent. This possibility was first raised by the observation that the most severe MRF4 knockout allele expresses no Myf-5 RNA and is a developmental phenocopy of the Myf-5 null mutation. Furthermore, initial studies of the two weaker alleles had shown that their differences in viability correlate with the intensity of rib skeletal defects, and the most extreme version of this rib defect is the hallmark phenotype of Myf-5 null animals. In the present study we tested this hypothesis for the two milder MRF4 alleles. By analyzing compound heterozygous animals carrying either the intermediate or the weakest MRF4 knockout allele on one chromosome 10 and a Myf-5 knockout allele on the other chromosome, we found that both of these MRF4 alleles apparently downregulate Myf-5 expression by a cis-acting mechanism. Compound heterozygotes showed increased mortality of the normally viable MRF4 allele, together with intensified rib defects for both MRF4 alleles and increased deficits in myotomal Myf-5 expression. The allele-specific gradation in phenotypes also suggested that rib morphogenesis is profoundly sensitive to quantitative differences in Myf-5 function if Myf-5 products drop below hemizygous levels. The mechanistic basis for cis interactions at the MRF4/Myf-5 locus was further examined by fusing a DNA segment containing the entire MRF4 structural gene, including all sequences deleted in the three MRF knockout alleles, with a basal promoter and a lacZ reporter. Transgenic embryos showed specific LacZ expression in myotomes in a pattern that closely resembles the expression of Myf-5 RNA. cis-acting interactions between Myf-5 and MRF4 may therefore play a significant role in regulating expression of these genes in the early myotomes of wildtype embryos.     

Molecular cloning of cDNA encoding porcine interleukin-15

Interleukin-15 (IL-15) is a recently identified growth and differentiation factor with an important potential role in the initial immune responses to infection. To enable the study of the role of this cytokine in the protective immune-mechanisms generated against parasitic diseases of swine, cDNA was generated from a macrophage enriched adherent cell population from peripheral blood mononuclear cells (PBMC). This cDNA was used for the enzymatic amplification of the porcine IL-15 sequence using human IL-15-derived primers. The open-reading frame of the porcine IL-15 cDNA is 486 base pairs (bp) in length and encodes a 162-amino-acid (aa) protein. Comparisons of the predicted swine protein sequence with those predicted from human, bovine and mouse IL-15 sequences indicate similarities of 82.1, 84.6, and 71.6%, respectively.     

A leucine zipper motif in the ectodomain of Sendai virus fusion protein assembles in solution and in membranes and specifically binds biologically-active peptides and the virus

We have detected a leucine zipper-like motif in the ectodomain of the Sendai virus fusion protein (aa 269-307) which is extremely conserved in the family of Sendai viruses. To find a possible role for this motif, we synthesized SV-269, a 39 amino acid peptide corresponding to this domain, and a mutant peptide, MuSV-269, with an amino acid pair interchanged their positions. The peptides were labeled with fluorescent probes at their N-terminal amino acid and functionally and structurally characterized. The data show that SV-269, but not MuSV-269, specifically binds Sendai virus. Expectedly, SV-269 is more active than the mutant MuSV-269 in inhibiting Sendai virus-mediated hemolysis. Fluorescence studies reveal that SV-269 assembles in aqueous solution, binds to zwitterionic PC and negatively-charged PS/PC vesicles, and assembles therein. Although MuSV-269 similarly binds to both types of vesicles, it only slightly assembles in solution and not at all in membranes. Moreover, SV-269, but not MuSV-269, coassembles with the biologically-active heptad repeats SV-150 and SV-473 (Rapaport et al. , 1995) in solution as revealed by fluorescence and circular dichroism (CD) spectroscopy, and with SV-150 within negatively-charged PS/PC and zwitterionic PC vesicles. Despite these differences, both SV-269 and MuSV-269 adopt similar secondary structures in 40% TFE and 1% SDS as revealed by CD spectroscopy, and disrupt the packing of the lipid bilayers to the same extent, as shown by the dissipation of diffusion potential. The role of this leucine zipper motif is discussed in terms of the assembly of the Sendai virus fusion protein in solution and within membranes. Since most of the heptadic leucines are also conserved in the corresponding domains of other paramyxoviruses such as rinderpest, measles, SV5, and parainfluenza, it may indicate a similar role of this domain in these viruses as well.     

Seminal plasma PSA in spinal cord injured men: a preliminary report

We report the case of a 48-year-old patient who developed acute onset bilateral, peripheral motor dysfunction in the arms and forearms. Clinical history, electromyography and laboratory tests confirmed the diagnosis of peripheral neuropathy caused by lead poisoning from the domestic water supply. The EMG showed axonal alterations. Improvement was observed after treatments with chelating agents and removal of the source of poisoning. This case provides the opportunity to recall the traditional 1889 Dejerine classification of lead-related peripheral neuropathies and is a warning signal that lead poisoning remains a problem in peri-urban areas of developed countries.     

Beta-carotene concentration in buccal mucosal cells with and without dysplastic oral leukoplakia after long-term beta-carotene supplementation in male smokers

OBJECTIVE: To measure the beta-carotene concentration in buccal mucosal cells in smoking men who had received long-term beta-carotene (BC) supplementation in a controlled trial. To assess the association of cellular BC on the prevalence of dysplasia in oral leukoplakia. DESIGN: An end-of-trial examination of a part of subjects in the Alpha-Tocopherol, Beta Carotene Cancer Prevention Study. SUBJECTS AND METHODS: 343 men who for 5-7 years had received BC (20 mg/d) or alpha-tocopherol (AT) (50 mg/d), or both of these or placebo. BC concentration of buccal mucosal cells was compared in the subjects with BC supplementation (n = 173) to that of those without it (n = 170). Oral mucosae were examined clinically and lesions showing leukoplakia histopathologically. RESULTS: Mean (s.d.) BC concentration in buccal mucosal cells was 7.7 (10.3)mg/kg protein in the subjects who received BC compared to 1.1 (1.7) mg/kg protein in those who did not. The BC concentration in the cells of supplemented subjects correlated with their serum BC levels (P < 0.001). AT supplementation had no effect on BC concentration nor was daily amount of smoking statistically significantly associated with the BC concentration in buccal cells. Altogether 17 subjects showed oral leukoplakia, 7 had dysplasia. In these 7 subjects, the BC concentration in buccal mucosal cells did not differ statistically significantly compared to subjects with only hyperkeratosis (n = 10) (F-test, P = 0.74). CONCLUSIONS: After long-term BC supplementation, BC concentration in oral mucosal cells was 7-fold greater than without supplementation. There was no evidence to support an association between cellular BC concentration and precancerous lesions among the few subjects having them in their oral mucosae.     

Ethanol blocks the central action of IGF-1 to induce luteinizing hormone secretion in the prepubertal female rat

OBJECTIVE: To test the simultaneous effect of various established predictors of breast and cervical cancer screening (breast self-examination, clinical breast examination by a physician, Papanicolaou [Pap] smear, and pelvic examination) in a low-income, Mexican-American sample. MATERIAL AND METHODS: A total of 188 Mexican-American women participated in a face-to-face structured interview in their preferred language. We tested a model with four established predictors of breast and cervical cancer screening--communication skills, knowledge of cancer, access to health care (finances and availability of care), and anxiety about cancer. Simultaneous structural equations analysis was used to form latent variables and to control for the effect of all predictors concurrently. RESULTS: Screening behavior was inversely associated with anxiety about cancer when all other predictors were statistically controlled. In addition, anxiety substantially affected the relationship between communication skills and screening behavior. Unexpectedly, knowledge of cancer was positively, rather than negatively, associated with anxiety about cancer. Predictors in the model demonstrated an excellent fit of the proposed model to the data. CONCLUSION: Successful cancer screening programs for Mexican-American women must address not only access barriers but also communication skills, knowledge, and, perhaps most importantly, anxiety.     

Development of Intrinsic Fluorescent Multispectral Imagery Specific for Fat, Connective Tissue, and Myofibers in Meat

ABSTRACT: Intrinsic fluorescent properties of muscle tissue were evaluated in order to characterize the different structural components of meat. The combinations of excitation and emission wavelengths showing the best ability to distinguish the 3 components were 290/332 nm for myofiber, 322/440 (or 322/405) nm for fat, and 380/440 nm for connective tissue. Sample orientation and the mincing of meat samples affected fluorescent amplitudes but not the overall shape of the spectra. These emission spectra of meat components were used to make multispectral images to determine whether the 3 components could be distinguished. The results show that auto fluorescence can be used for selective visualization of fat, fiber, and connective tissue on digitized images of meat.     

Assessing the effect of deep inhalation on airway calibre: a novel approach to lung function in bronchial asthma and COPD

Bronchoconstriction in bronchial asthma and chronic obstructive pulmonary disease (COPD) may be due to decreased airway calibre and/or to the inability of the airways to distend after a deep inhalation (DI). The purpose of this review is to discuss the physiological and clinical relevance of this latter mechanism. During induced constriction, DI shows remarkable bronchodilatation in normal subjects, but a blunted or null effect in asthmatics. In contrast, during spontaneous bronchospasm DI tends to decrease airway calibre. From a functional point of view, airway inflammation, remodelling, and peripheral bronchoconstriction could prevent airway smooth muscle from stretching. Therapeutic intervention improving lung function may change the response to DI. For example, bronchodilators allow expiratory airflow before DI to increase more than after DI, because of decreased bronchial hysteresis. This suggest that bronchodilation might be systematically underestimated from parameters derived from maximal expiratory manoeuvres. Inhaled corticosteroids tend to increase the dilator effect of DI, likely due to decreased bronchial and peribronchial oedema. In conclusion, measuring the effects of deep inhalation on lung function is an easy and simple test able to evaluate the structural changes occurring in the airways and to monitor the effectiveness of therapy.     

Interferon alfa-2b alone or in combination with ribavirin as initial treatment for chronic hepatitis C. Hepatitis Interventional Therapy Group

BACKGROUND: Only 15 to 20 percent of patients with chronic hepatitis C have a sustained virologic response to interferon therapy. We compared the efficacy and safety of recombinant interferon alfa-2b alone with those of a combination of interferon alfa-2b and ribavirin for the initial treatment of patients with chronic hepatitis C. METHODS: We randomly assigned 912 patients with chronic hepatitis C to receive standard-dose interferon alfa-2b alone or in combination with ribavirin (1000 or 1200 mg orally per day, depending on body weight) for 24 or 48 weeks. Efficacy was assessed by measurements of serum hepatitis C virus (HCV) RNA and serum aminotransferases and by liver biopsy. RESULTS: The rate of sustained virologic response (defined as an undetectable serum HCV RNA level 24 weeks after treatment was completed) was higher among patients who received combination therapy for either 24 weeks (70 of 228 patients, 31 percent) or 48 weeks (87 of 228 patients, 38 percent) than among patients who received interferon alone for either 24 weeks (13 of 231 patients, 6 percent) or 48 weeks (29 of 225 patients, 13 percent) (P<0.001 for the comparison of interferon alone with both 24 weeks and 48 weeks of combination treatment). Among patients with HCV genotype 1 infection, the best response occurred in those who were treated for 48 weeks with interferon and ribavirin. Histologic improvement was more common in patients who were treated with combination therapy for either 24 weeks (57 percent) or 48 weeks (61 percent) than in those who were treated with interferon alone for either 24 weeks (44 percent) or 48 weeks (41 percent). The drug doses had to be reduced and treatment discontinued more often in patients who were treated with combination therapy. CONCLUSIONS: In patients with chronic hepatitis C, initial therapy with interferon and ribavirin was more effective than treatment with interferon alone.