Higher order genomic organization and epigenetic control maintain cellular identity and prevent breast cancer

Cells establish and sustain structural and functional integrity of the genome to support cellular identity and prevent malignant transformation. In this review, we present a strategic overview of epigenetic regulatory mechanisms including histone modifications and higher order chromatin organization (HCO) that are perturbed in breast cancer onset and progression. Implications for dysfunctions that occur in hormone regulation, cell cycle control, and mitotic bookmarking in breast cancer are considered, with an emphasis on epithelial-to-mesenchymal transition and cancer stem cell activities. The architectural organization of regulatory machinery is addressed within the contexts of translating cancer-compromised genomic organization to advances in breast cancer risk assessment, diagnosis, prognosis, and identification of novel therapeutic targets with high specificity and minimal off target effects.

Management of a measles outbreak among Old World nonhuman primates

BACKGROUND AND PURPOSE

A measles outbreak in a facility housing Old World nonhuman primates developed over a 2-month period in 1996, providing an opportunity to study the epidemiology of this highly infectious disease in an animal-handling setting.

METHODS

Serum and urine specimens were collected from monkeys housed in the room where the initial measles cases were identified, other monkeys with suspicious measles-like signs, and employees working in the affected areas. Serum specimens were tested for measles virus-specific IgG and IgM antibodies, and urine specimens were tested for measles virus by virus isolation or reverse transcriptase-polymerase chain reaction (RT-PCR).

RESULTS

A total of 94 monkeys in two separate facilities had evidence of an acute measles infection. The outbreak was caused by a wild-type virus that had been associated with recent human cases of acute measles in the United States; however, an investigation was unable to identify the original source of the outbreak. Quarantine and massive vaccination helped to control further spread of infection.

CONCLUSIONS

Results emphasize the value of having a measles control plan in place that includes a preventive measles vaccination program involving human and nonhuman primates to decrease the likelihood of a facility outbreak.

Nonclassic measles infections in an immune population exposed to measles during a college bus trip

This study investigated the frequency of mild or asymptomatic measles infections among 44 persons exposed to a student with measles during a 3-day bus trip using two buses. Questionnaires and serum samples were obtained 26-37 days after the trip. All participants had detectable measles-neutralizing antibodies, and none developed classic measles symptoms. Ten persons (23%) were IgM positive for measles, indicating recent infection. Among previously vaccinated IgM-negative persons, those who rode on bus A with the index case-patient had significantly higher microneutralization titers than those on bus B (P= .001), suggesting that some persons on bus A were infected but were IgM negative at the time of the study. Mild or asymptomatic measles infections are probably very common among measles-immune persons exposed to measles cases and may be the most common manifestation of measles during outbreaks in highly immune populations.

Sensory and instrument-measured ground chicken meat color

Instrument values were compared to sensory perception of ground breast and thigh meat color. Different patty thicknesses (0.5, 1.5, and 2.0) and background colors (white, pink, green, and gray), previously found to cause differences in instrument-measured color, were used. Sensory descriptive analysis scores for lightness, hue, and chroma were compared to instrument-measured L* values, hue, and chroma. Sensory ordinal rank scores for lightness, redness, and yellowness were compared to instrument-generated L*, a*, and b* values. Sensory descriptive analysis scores and instrument values agreed in two of six comparisons using breast and thigh patties. They agreed when thigh hue and chroma were measured. Sensory ordinal rank scores were different from instrument color values in the ability to detect color changes caused by white, pink, green, and gray background colors. Instrument values agreed with sensory scores for lightness only when white and pink backgrounds were used. Instrument and sensory methods agreed when a* values and redness scores were compared using each of the backgrounds. The sensory panel did not detect differences in yellowness found by the instrument when samples on white and pink backgrounds were compared to samples on green and gray backgrounds. A majority of panelists (84 of 85) preferred samples on white or pink backgrounds. Red color of breast patties was associated with freshness. Reflective lighting was compared to transmission lighting using patties of different thicknesses. Sensory evaluation detected no differences in lightness due to breast patty thickness when reflective lighting was used. Increased thickness caused the patties to appear darker when transmission lighting was used. Decreased transmission lighting penetrating the sample made the patties appear more red. Reflective lighting made thigh patties appear lighter. Lightness decreased when thigh patty thickness increased with both reflective and transmission lighting. Transmission lighting made the thigh patties appear more yellow as patty thickness increased.

Elevated plasma corticosterone concentrations influence the onset of rigor mortis and meat color in broilers

This experiment was conducted to determine the effect of elevated plasma corticosterone (CORT) levels on meat quality characteristics. Male broilers (Arbor Acres) were either 1) fed a diet containing corticosterone (CORT) prior to processing, 2) transported by truck for 3 h before processing, or 3) processed without either of the above treatments. Six crates of birds (10 birds per crate; two crates per treatment) were stunned or killed using CO2 gas. Six birds per crate were processed and blood samples were collected during exsanguination for plasma CORT analysis. Meat samples were collected from carcasses either at 20 min or at 4 h post-mortem. At each sampling time (ST), Pectoralis superficialis samples were collected and either individually quick frozen (IQF) in liquid nitrogen or aged on ice (AOI) for 24 h prior to pH, ratio of inosine to adenosine nucleotides (R-value), cooking loss, shear value, and color analyses. The IQF Biceps femoris samples were used for pH, R-value, color, and heme pigment analysis. Mean (+/- SEM) CORT concentrations were 12.9+/-2.57, 11.7+/-1.38 and 7.9+/-0.79 ng/mL, respectively, in the CORT, transported, and control groups. There were significant treatment by ST (P < 0.05) and ST (P < 0.001) effects on the R-value of IQF P. superficialis samples. The CORT group had the highest L* value (P < 0.01) and the lowest a* value (P < 0.06). There was also a significant main effect of ST on shear values (P < 0.05) of AOI P. superficialis samples, with the means higher at 4 h than at 20 min post-mortem. The R-value of IQF B. femoris samples was markedly influenced by treatment (P < 0.001) and ST (P < 0.001). The results indicate that artificially elevating circulating CORT concentrations results in lighter meat color in broilers.

Shackling of broilers: effects on stress responses and breast meat quality

1. Experiments were conducted to study the welfare and meat quality effects of shackling. In experiment 1, broilers with or without leg problems were shackled (S) for 4 min on a moving line and blood sampled; or handled (H), returned to the crate and sampled after 4 min; or sampled immediately after removal from the crate (control, C). 2. Plasma corticosterone (CORT) concentrations, as measured by radioimmunoassay, were highest in S and lowest in C, while the H group was intermediate. Leg problems had no effect on CORT. 3. In experiment 2, tonic immobility (TI) was induced in broilers after 2 min inverted handling to determine fear responses. One week later, the birds were fasted, transported and then shackled on a moving shackle line for 0, 1, 3 or 4 min, then unshackled and blood sampled. Wing flapping during shackling was also quantified. 4. Shackling time did not influence CORT concentrations. There was a negative correlation (r = -0.714) between CORT and wing flapping duration in the 1 min shackling treatment. There was no relationship between TI and wing flapping or CORT. 5. In experiment 3, broilers were exposed to two food withdrawal (FW) times (food withdrawn overnight or during crating only) and held for 4 h prior to processing, shackled (0, 2 or 4 min shackling time, ST), and then killed by exsanguination. Blood samples were collected during the neck-cut. Pectoralis superficialis and Supracoracoideus samples were either collected after 15 min and individually quick frozen (IQF) in liquid nitrogen or collected at 4 h post mortem from carcases chilled on slush ice (COI). 6. CORT increased significantly with increased ST. There was a FW x ST interaction effect on the initial pH of fillets. ST influenced the b*, chroma and Hue values of the COI fillets. FW influenced the L* and Hue values of both IQF and COI fillets as well as the a* value of the COI fillets. 7. In summary, CORT increased with shackling time when birds were held after transport. FW and ST also influenced the colour of fillets, although it is not clear whether these changes are perceptible to the consumer. The duration of wing flapping during shackling did not appear to be related to fearfulness, although it was influenced by properties of the shackle line. We suggest that there be a maximum time lapse between shackling and stunning or killing of 2 min to minimise stress and meat quality changes.

Effects of crating and transport on stress and meat quality characteristics in broilers

Experiments were conducted to determine 1) whether different crating durations influence stress responses and meat quality in broilers, and 2) whether holding crated broilers after transport influences corticosterone (CORT) levels and meat quality. In a preliminary experiment, male broilers (n = 50) were held in crates (10 birds per crate) for either 0, 1, 2, 3, or 4 h prior to processing. Crating duration did not affect plasma CORT level, cooking loss, shear value of breast or thigh muscles, or carcass skin discolorations. Crating duration also did not affect the color (L*, a*, b*, chroma, and hue angle) of breast meat, but did change the color of thigh meat, with samples from the 3 h crating group having the highest hue values (P < 0.01). Corticosterone concentrations and hue values of thigh samples were positively correlated (P < 0.05, r = 0.244). In Experiment 1, broilers (n = 36) were crated for either 1 or 3 h, with 9 birds per crate. Crating time did not influence plasma CORT, epinephrine, or norepinephrine concentrations, initial pH, color, or texture of breast and thigh meat samples. In Experiment 2, broilers were crated (nine birds per crate) early in the morning and transported 3 h to the processing facility by truck. Nine crates of birds were held in a dark quiet place for 4 h prior to processing (H) and the remaining nine crates were processed immediately (NH). Corticosterone levels were significantly lower (P < 0.01) in the H group than in the NH group. Initial pH of thigh meat of the H group was also significantly lower (P < 0.01), although breast meat pH was not affected by treatment. Holding had no effect on shear values, color (breast and thigh), or total heme concentration (thigh). There was a significant correlation (P < 0.01, r = 0.302) between CORT levels and hue values of thigh meat. These results suggest that higher preslaughter stress levels in broilers could influence the color of thigh meat, although overall meat quality was not affected under the conditions of this study.

Diagnosis of measles with an IgM capture EIA: the optimal timing of specimen collection after rash onset

The optimal timing for collection of a single serum specimen to diagnose measles by using a monoclonal antibody-capture EIA was evaluated. Results of testing paired serum samples from 166 measles cases with at least 1 IgM-positive specimen were analyzed. Among persons whose second samples were IgM-positive, the seropositivity rate for first samples was 77% when collected within 72 h and 100% when collected 4-11 days after rash onset. Among unvaccinated persons whose first samples were IgM-positive, the rate for IgM positivity of second specimens declined from 100% at 4 days to 94% at 4 weeks after rash onset, then declined further to 63% at 5 weeks. Some previously vaccinated persons became IgM-negative during the third week after rash onset. In general, a single serum specimen collected between 72 h and 4 weeks after rash onset can be used to diagnose most cases of measles with an IgM capture EIA.

Measles vaccine effectiveness and duration of vaccine-induced immunity in the absence of boosting from exposure to measles virus

BACKGROUND

It is unknown whether vaccine-induced immunity is lifelong in the absence of periodic exposure to measles virus. After 27 years of no known exposure to measles, an outbreak in Palau in 1993 offered the opportunity to study this issue and the measles vaccine effectiveness.

METHODS

Household contacts of a sample of confirmed cases were interviewed for exposure, symptoms and vaccination status verified by records. Serum from symptomatic contacts was tested for measles antibodies.

RESULTS

Among 78 contacts 4 of 5 (80%) unvaccinated, 4 of 35 (11%) 1-dose vaccine recipients and none of 38 (0%) > 1-dose recipients developed measles. Effectiveness of 1-dose vaccine was 86% (95% confidence interval, 60 to 95%). An additional dose significantly reduced the risk of measles (P = 0.048). Time since vaccination was not a significant risk factor for developing measles (relative risk, 1.6; 95% confidence interval, 0.3 to 9.4; persons vaccinated > 15 years ago vs. < 5 years ago).

CONCLUSIONS

Similar to the estimates previously obtained in the area, measles vaccine effectiveness in Palau was lower than the estimates obtained in the US. A second dose of vaccine further reduced the risk for developing measles. We found no evidence that waning immunity was an important problem in this limited population with no known previous exposure to measles virus. The small number of vaccinated contacts precludes a definitive assessment.

Effect of background color, sample thickness, and illuminant on the measurement of broiler meat color

The effects of sample thickness (0.5, 1.0, and 1.5 cm), background color (white, pink, green, and gray), and illuminant (D-65, A, and F) on color measurement of broiler tissue were determined. Color values from the anterior portions of the two Pectoralis superficialis muscles were not different from each other, allowing one to be used as a control for the other. Light penetrated the thinner posterior portions of the muscle and was reflected by the white background, producing different L*, a*, and b* values when compared to the thicker anterior portion of the muscle. These changes could alter or mask color changes in the tissue. Light penetrated 0.5 cm thick sliced breast, ground breast, and ground thigh samples and was reflected by the background in large enough quantities to cause color differences (P < 0.05) when both sample thickness and background colors were compared. White and pink backgrounds reflected the largest amount of light, followed in decreasing order by green and gray. The light reflected by background decreased as sample thickness increased from 0.5 to 1.0 cm and no differences due to reflection occurred in the 1.5 cm thick samples. Background reflection can prevent measurement of true sample color. The three illuminants produced different (P < 0.05) color values depending on the major wavelength characteristics of each illuminant. Illuminant choice should depend on wavelength characteristics of the illuminant, sample color, and the color values to be measured.

The Safe Dates Project: theoretical basis, evaluation design, and selected baseline findings

Approximately 20% of adolescents have experienced violence from a dating partner. The Safe Dates Project tests the effects of a program on the primary and secondary prevention of dating violence among adolescents living in a rural North Carolina county. The program being evaluated aims to prevent dating violence by changing dating violence norms, gender stereotyping, conflict-management skills, help-seeking, and cognitive factors associated with help-seeking. School activities include a theater production, a 10-session curriculum, and a poster contest. Community activities include special services for adolescents in violent relationships and community service provider training. A pretest-posttest experimental design with random allocation of 14 schools to treatment condition was used to test study hypotheses. Data were collected in schools using self-administered questionnaires. Eighty-one percent (n = 1,967) of the eighth- and ninth-graders in the county completed baseline questionnaires, and 91% of those adolescents completed follow-up questionnaires. The sample is 75.9% Caucasian and 50.4% female. Baseline data indicate that 25.4% and 8.0% of this sample have been victims of nonsexual and sexual dating violence, respectively, and 14.0% and 2.0% have been perpetrators of nonsexual and sexual dating violence, respectively. Consistent with other adolescent dating violence studies, both boys and girls report being victims and perpetrators of dating violence. Control and treatment groups are similar at baseline on all demographic, mediating, and outcome variables. Findings suggest that dating violence is prevalent among adolescents and that prevention programs are warranted.

Risk of infection with hepatitis A, B or C, cytomegalovirus, varicella or measles among child care providers

BACKGROUND

Employment as a child care provider has been suggested as an indication for hepatitis A virus (HAV) immunization; however, whether this occupational group is at increased risk of HAV infection is not well-defined.

METHODS

We obtained sera samples for testing for antibodies to hepatitis A, B and C, cytomegalovirus, varicella and measles from a sample of child care providers in King County, WA, and administered a questionnaire to assess employment characteristics and other potential risk factors for infection. We also compared the anti-HAV seroprevalence among providers with that of subjects in the Third National Health and Nutrition Survey, representative of the US general population.

RESULTS

Thirteen percent (48 of 360) of providers were anti-HAV-positive (46% (22 of 47) of foreign born vs. 8% (26 of 313) of US-born (P < 0.001)). In multivariate analysis anti-HAV seropositivity was associated with foreign birth, age, income and Hispanic ethnicity but was not associated with characteristics of employment. Seroprevalence among US-born providers tended to be lower than that among Third National Health and Nutrition Survey subjects of similar age, sex, race and income. Sixty-two percent of providers were seropositive to cytomegalovirus, which was associated with nonwhite race, changing diapers > or = 3 days/week while at work and having a child in the household. Antibody prevalence was 1.4% to hepatitis B core antigen, 0.6% to hepatitis C, 94% to measles and 98% to varicella.

CONCLUSIONS

The anti-HAV prevalence among US-born providers was low, and seropositivity was not associated with employment characteristics, indicating that occupational exposure to HAV is uncommon under non-outbreak circumstances.

Comparative detection of measles-specific IgM in oral fluid and serum from children by an antibody-capture IgM EIA

In vaccinated populations, the diagnosis of measles often requires laboratory confirmation. Serum tested by EIAs has proven sensitive and specific for diagnosing measles. For comparison of detection of measles-specific IgM in oral fluid and serum samples by an antibody-capture EIA, 163 Ethiopian infants who presented for routine measles vaccination were studied. Paired serum and oral fluid samples were collected before and 2 weeks after vaccination; 269 paired samples were adequate for analyses. Of the 104 serum samples that were IgM-positive, 95 (91%) of the paired oral fluid samples were IgM-positive. Of the 165 serum samples that were IgM-negative, 156 (95%) of the paired oral fluid samples were IgM-negative. The Pearson partial correlation coefficient for optical density readings from postvaccination oral fluid compared with serum was 0.81. Oral fluid appears to be an acceptable alternative to serum for measuring measles-specific IgM antibodies by an antibody-capture EIA.

Measles antibody in vaccinated human immunodeficiency virus type 1-infected children

OBJECTIVES

The goals of this study were to evaluate the proportion of previously vaccinated human immunodeficiency virus (HIV) type 1-infected children with detectable postvaccination measles antibody; to assess risk factors for vaccine failure; and to evaluate the response to reimmunization.

METHODS

A total of 81 perinatally HIV-infected children receiving medical care in the Bronx, New York who had previously received measles vaccine were enrolled. The Centers for Disease Control and Prevention (CDC) HIV class, lymphocyte subsets, and measles antibody were determined upon enrollment. Additional data abstracted from medical records included dates and number of prior measles vaccinations and CDC HIV class at the time of vaccination. Measles antibody was determined by microneutralization enzyme-linked immunosorbent assay (ELISA).

RESULTS

The median age at time of study was 42 months (range, 9 to 168 months). Overall, 58 (72%) subjects had detectable measles antibody (microneutralization ELISA titer > 1:5). Children studied within 1 year of vaccination were more likely to have detectable measles antibody than children evaluated more than 1 year after vaccination (83% vs 52%, P < .01). The proportion of children with detectable measles antibody was higher among children with no or moderate immunosuppression compared to those with severe immunosuppression when immune status was based on CD4%. Children vaccinated at 6 to 11 months of age appeared to have a higher proportion of detectable measles antibody than those who received a first measles vaccination after age 1. Only 1 (14%) of 7 previously vaccinated children who were seronegative or had very low titers experienced a four-fold rise in measles antibody when reimmunized.

CONCLUSION

These results support current recommendations to vaccinate HIV-infected children against measles. The proportion of children with detectable measles antibody among vaccinated HIV-infected children is considerably lower than in vaccinated healthy children. HIV-infected children may respond better to measles vaccine when it is administered before the first birthday. From our limited data it appears that reimmunization of previously vaccinated HIV-infected children with moderate to severe immunosuppression does not result in an antibody recall response.

Molecular epidemiology of measles virus: identification of pathways of transmission and implications for measles elimination

The nucleotide sequences of either the hemagglutinin or nucleoprotein genes from wild type measles viruses isolated in the United States between 1989 and 1992 differed by < 0.5%. This suggests that the majority of viruses associated with resurgence of measles in the United States belonged to a single indigenous genotype. In contrast, wild type viruses isolated from sporadic outbreaks of measles in the United States during 1994 were genetically heterogeneous. These viruses were more closely related to wild type viruses previously circulating in Europe, Africa, or Japan and were epidemiologically linked to importations or no known source. In addition to demonstrating the utility of genetic analysis in understanding the epidemiology of measles, these data suggest that the transmission of the indigenous virus was interrupted after the 1989-1992 epidemic. Measures to further reduce the incidence of measles in the United States should include efforts to control importation and subsequent spread of measles.

Antigenic analysis of current wild type and vaccine strains of measles virus

The antigenic properties of vaccine and wild type strains of measles virus were compared. Serum specimens from vaccinated persons, persons infected during the prevaccine era, or mice experimentally vaccinated with the hemagglutinin (H) protein from vaccine virus neutralized vaccine virus and a wild type measles virus from 1989 equally well. In contrast, serum specimens from patients with recent measles virus infection and mice experimentally vaccinated with the H protein from the wild type virus from 1989 neutralized wild type virus with titers 4-8 times higher than those to vaccine virus. Several H protein-specific monoclonal antibodies could differentially recognize vaccine or wild type virus. These data show that the H proteins of the recent wild type viruses contain both conserved and new or modified antigenic determinants and are consistent with previous studies that described genetic drift in the H proteins of recent wild type viruses.

Immunoglobulin M antibody response to measles virus following primary and secondary vaccination and natural virus infection

The use of IgM antibody detection for the classification of the primary and secondary measles antibody response in persons following primary and secondary vaccination and natural measles virus infection was examined. Of 32 nonimmune children receiving primary measles vaccination, 31 (97%) developed IgM antibodies, consistent with a primary antibody response. Of 21 previously vaccinated children with low levels of preexisting IgG antibodies who responded to revaccination, none developed detectable IgM antibodies, whereas 33 of 35 (94%) with no detectable preexisting IgG antibodies developed an IgM response. Of a sample of 57 measles cases with a prior history of vaccination, 55 (96%) had detectable IgM antibodies. Of these, 30 (55%) were classified as having a primary antibody response and 25 (45%) a secondary antibody response based on differences in their ratios of IgM to IgG antibodies. Differences in the severity of clinical symptoms between these 2 groups were consistent with this classification scheme. These findings suggest that 1) an IgM response follows primary measles vaccination in the immunologically naive, 2) an IgM response is absent on revaccination of those previously immunized, and 3) an IgM response may follow clinical measles virus infection independent of prior immunization status.

Effect of d-mannose on fimbriae of bacterial isolates from chicken carcasses

Pseudomonad-like microbial isolates were obtained from commercially processed broiler chicken carcasses for use in experiments to determine if d-mannose would interfere with their ability to form pellicles and rims and prevent agglutination of blood and yeast cells. Inhibition of agglutination, rim formation, and pellicle formation would provide evidence that d-mannose acts on the fimbriae to prevent attachment of microorganisms to surfaces. Presence of 4% d-mannose in the growth medium interfered with the formation and stability of the pellicle in some isolates. The pellicles affected by d-mannose did not cover the entire surface and were easily dispersed. Addition of d-mannose did not prevent the formation of rims to the same extent it prevented pellicle formation, and it was concluded that d-mannose did not completely prevent growth of fimbriae. The addition of d-mannose prevented the agglutination of 1% sheep blood, 1% horse blood, and yeast cells by interfering with the formation of fimbriae or the mechanism of attachment by fimbriae. These experiments provided evidence that d-mannose can be used to prevent attachment of isolates normally found on chicken carcasses to specific cell surfaces by occupying mannose-sensitive receptor sites on the cell.

Effect of D-mannose on motility, presence of flagella, and attachment of Pseudomonas aeruginosa to chicken skin cells

Treatment of Pseudomonas aeruginosa with 1 to 3% d-mannose reduced cell activity indicating the flagella were affected by d-mannose but did not decrease attachment to chicken skin cells. Distance of migration of P. aeruginosa through a hollow tube filled with 1 to 4% d-mannose was reduced when compared with 0% d-mannose. This reduced movement through the tube indicated a possible affect on the flagella. Examination of P. aeruginosa with a light microscope showed that the addition of 1, 2, 3, and 4% d-mannose to a solution containing the organism removed the flagella from 27 to 40% of the cells.

Effect of high-energy electron irradiation of chicken meat on thiobarbituric acid values, shear values, odor, and cooked yield

Experiments were conducted to determine whether electron-beam irradiation would affect shear values, yield, odor, and thiobarbituric acid (TBA) values of chicken tissues. Broiler breasts (pectoralis superficialis) and whole thighs were irradiated with an electron-beam accelerator at levels to produce adsorbed doses of 100, 200, and 300 krads on the surface of the sample. The thigh samples were stored for 2, 4, and 8 days before testing for TBA values. The depth to which the radiation had penetrated the pectoralis superficialis muscle was also determined. Radiation penetrated 22 mm into slices of pectoralis superficialis muscle when 100 krad was absorbed by the surface of the tissue. The dose absorbed beneath the tissue surface to a depth of 10 mm was larger than the dose absorbed at the surface. The absorbed dose decreased as the depth of penetration increased. For cooked breast tissue, the shear values and moisture content were not affected by the absorbed radiation. Cooking losses of aged breast tissue were not affected by irradiation, but cooking losses were reduced in breast tissue that had not been aged. Irradiating uncooked thigh and uncooked breast samples produced a characteristic odor that remained after the thighs were cooked but was not detectable after the breast samples were cooked. With two exceptions, no significantly different TBA values were found that could be attributed to irradiation.

Effects of high-energy electron irradiation of chicken meat on Salmonella and aerobic plate count

Four experiments were used to determine the effects of high-energy irradiation on the number of aerobic microorganisms and Salmonella on broiler breasts and thighs. Irradiation ranging from 100 to 700 kilorads (krads) was provided by a commercial-scale, electron-beam accelerator. Irradiation of broiler breast and thigh pieces with electron beams at levels of 100, 200, 300, 400, 500, and 600 krads showed that levels as low as 100 krads would eliminate Salmonella. When 33 thighs were tested after irradiation at 200 krads, only one thigh tested presumptive positive. The total number of aerobic organisms was reduced by 2 to 3 log10 cycles at irradiation levels of 100, 200, 300, 400, 500, 600, and 700 krads. Increasing the dose above 100 krads gave little if any additional benefit.

Effect of age, sex, and barriers in experimental pens on muscle growth

Length, width, and depth of pectoralis, supracoracoideus, peroneus longus, gastrocnemius, femorotibialis, iliotibialis, and semitendinosus did not increase proportionately with muscle weight as male broilers aged from 5 to 8 wk of age. Only peroneus longus from the drumstick and semitendinosus from the thigh had maximum percentage increases in length, width, and depth at the same age that maximum percentage weight increases occurred. Barriers 10.2, 12.7, and 15.2 cm high were placed in pens when the chicks were 1 wk old and raised 2.5 cm each week until birds were 8 wk old. Muscles were dissected from male and female broilers at 4 and 8 wk of age. Bird activity from crossing the barriers resulted in weight differences in pectoralis and peroneus longus after 3 wk of exposure and in the supracoracoideus, semitendinosus, and femorotibialis muscles after 7 wk of exposure when compared with values for controls. Differences in muscle measurements attributable to barriers in the pen were found in birds in treatment groups after 3 wk of exposure for iliotibialis (length) and femorotibialis (depth). Increases in muscle measurements in birds after 7 wk of exposure occurred in length of pectoralis, supracoracoideus, gastrocnemius pars externa, peroneus longus, and femorotibialis muscles. Alterations in width were found in pectoralis, gastrocnemius pars interna, and femorotibialis muscles and changes in depth in peroneus longus and semitendinosus muscles. These changes were found to be affected by sex, and a number of sex x barrier interactions were found.(ABSTRACT TRUNCATED AT 250 WORDS)

Growth characteristics of selected broiler muscles as affected by age and experimental pen design

Broilers were grown in conventional pens and in pens modified with barriers and ramps extending across their width. The purpose of these modifications was to increase the use (exercise) of specific muscle groups and measure changes in muscle growth. The breast (pectoralis, supracoracoideus, and gastrocnemius pars externa muscles) from birds reared in conventional pens grew at a more rapid rate than the total body weight of the live bird. Increased growth rates of the breast, pectoralis, supracoracoideus, gastrocnemius pars interna, and femorotibialis muscles were found in birds raised in pens with single ramps. The double-ramp treatment resulted in increased growth in peroneus longus and femorotibialis. Barriers in pens resulted in slower growth rates in gastrocnemius pars externa and iliotibialis, double ramps resulted in slower growth rates in gastrocnemius pars externa, and single ramps resulted in slower growth rates in gastrocnemius pars externa and semitendinosus. Modification of conventional pens caused changes in weight and measurements of many of the muscles studied. Pectoralis muscles from birds reared in pens with barriers were 12.6% heavier after 3 wk exposure than those from birds in conventional pens. The pectoralis muscle of birds after 4 wk exposure to single ramps was 7.1% heavier and the femorotibialis muscle was 19.8% heavier than respective muscles from birds grown in conventional pens. Changes in muscle dimensions showed that conformation of the muscle could be altered by pen modification.

Detection of human T cell leukemia virus type I and human immunodeficiency virus in cultured lymphocytes of a Zairian man with AIDS

We report the detection of human T cell leukemia virus type I (HTLV-I) and human immunodeficiency virus (HIV) in the cultured lymphocytes of a 45-year-old Zairian man with AIDS. HIV was successfully isolated and analyzed by SDS-PAGE and competition radioimmunoassay. However, by the culture techniques used, HTLV-I could not be separated from the HIV. Western blot analysis of the patient's serum showed the presence of both HTLV-I- and HIV-specific antibodies. The finding of this dual infection may explain reports that greater than or equal to 30% of patients with AIDS are positive for antibodies to HTLV-I.

Mutagenesis testing of acetyl-tributylcitrate and epoxidized soybean oil

Mutagenesis testing was conducted on two plasticizers commonly used in plastic wrap manufacture, acetyl-tributylcitrate and epoxidized soybean oil. There is no record of mutagenic testing using a bacterial screening method for these two compounds. The two plasticizers were screened using mutant strains of Salmonella typhimurium. The tests determined that they were not mutagenic.

Migration of acetyl-tributylcitrate from plastic film into poultry products during microwave cooking

Migration of the plasticizer acetyl-tributylcitrate from a plastic film into poultry meat and model food systems was studied. It was determined that this commonly used plasticizer migrated from the plastic film during microwave cooking by comparing the infrared spectra of the film used to cover the chicken to unused film. The peak at 1730 cm-1 was substantially reduced in the used film relative to a standard band at 2920 cm-1. Subsequent experimentation verified by chemical analysis that the compound was acetyl-tributylcitrate and that it migrated from the film into the chicken meat. Experiments using comminuted chicken meat and model food systems in a test cell indicated that the migration of the plasticizer was time related with a plateau being reached after cooking for 8 min. Studies with model food systems in the test cell indicated that the lipid portion of the system was responsible for migration and retention of acetyl-tributylcitrate in the sample. Increasing the lipid portion of the system tended to increase the amount of plasticizer found.

In vivo and in vitro metabolism of [14C]penicillic acid

In vivo and in vitro studies of the metabolism of [14C]penicillic acid showed a significant uptake of penicillic acid by red blood cells and a significant increase in radioactivity associated with the membrane fraction with time (1-4 hr); however, the majority of the red blood cell activity was intracellular. The 14C-radioactivity concentration in liver fractions (1.5 percent of the administered dose 2 hr following administration) was high in the RNA-DNA and protein fractions. The level of the 14C activity associated with these fractions increased with time (24 hr). Preliminary studies of the in vivo metabolism of [14C]penicillic acid by rats showed that a significant amount of radioactivity was excreted in the urine (82 percent of the administered dose after 7 days), of which strongly acidic urinary metabolites accounted for 23 percent; weakly to moderately acidic, 60 percent; strongly basic, 2 percent; and neutral, 15 percent. Isolation and identification studies of the neutral urinary fraction indicated that the major metabolites are non-ionic macromolecules (Mr < 5000). Biliary metabolites (10 percent of the administered dose 2 hr following administration) were 28 percent strongly acidic and 72 percent weakly to moderately acidic.

Preliminary report of the distribution of [14C]penicillic acid in rats: autoradiographic technique

The distribution of [14C]penicillic acid in rats was determined by autoradiographic technique. Adult male rats were given [14C]penicillic acid orally and IV. According to autoradiographic analyses 24 hours later, high levels of radioactivity were in liver, heart, kidneys, lungs, and caudal part of the intestine. The significance of bile as an excretory route for penicillic acid was confirmed by the results from IV administration of the compound.

Biliary excretion of [14C]penicillic acid by rats

Adult male rats were given [14C]penicillic acid by oral intubation, and the biliary excretion of the compound was monitored. The significance of bile as an excretory route was confirmed and compared by using open and recycle cannulation of the bile duct. The biological half-retention life of [14C]penicillic acid in the bile was 3.63 h.