Two types of high inductive electromagnetic stimulation and their different effects on endothelial cells.

Effects of low-frequency electromagnetic fields (LF EMF) on the activation of different tissue recovery processes have not yet been fully understood. The detailed quantification of LF EMF effects on the angiogenesis were analysed in our experiments by using cultured human and mouse endothelial cells. Two types of fields were used in the tests as follows: the LF EMF with rectangular pulses, 340-microsecond mode at a frequency of 72 Hz and peak intensity 4 mT, and the LF EMF with sinusoidal alternating waveform 5 000 Hz, amplitude-modulated by means of a special interference spectrum mode set to a frequency linear sweep from 1 to 100 Hz for 6 s and from 100 Hz to 1 Hz return also for 6 s, swing period of 12 second. Basic parameters of cultured cells measured after the LF EMF stimulus were viability and proliferation acceleration. Both types of endothelial cells (mouse and human ones) displayed significant changes in the proliferation after the application of the LF EMF under conditions of a rectangular pulse mode. Based on the results, another test of the stimulation on a more complex endothelial-fibroblast coculture model will be the future step of the investigation.

High inductive magnetic stimuli and their effects on mesenchymal stromal cells, dendritic cells, and fibroblasts.

Effects of low-frequency electromagnetic fields (LF EMF) on the activation of different tissue recovery processes have already been fully understood. Preliminary recent data demonstrated that a special case of sinusoidal electromagnetic fields, known as amplitude-modulated currents (AMC) could have a potential to accelerate the cell metabolism or cell migration. An AMC generator was designed to generate sinusoidal induced electric currents with the amplitude modulation and the harmonic carrier frequency of 5,000 Hz was modulated by frequencies of 1 to 100 Hz. The magnetic field peak was 6 mT, electric field intensity 2 V/m and the current density of induced electrical currents was approximately 1 A/m(2). The coil of the generator was adapted to easy handling and safe integration into the shelf of the CO(2) incubator. The shelf with the coil was prepared for the introduction of cells in standard plastic in vitro chambers. The tests focused on cells with migratory capacity after injury or during immunological processes and thus, mesenchymal stromal cells (MSC), dendritic cells (DC), and fibroblasts were chosen. The tests involved exposures of the cells to LF EMF (180 min/day) every day, for a period of three days, before examining them for cell death, morphology changes, and CD markers. The samples were tested by using MTT assay and the effects on the intracellular concentration of reactive oxygen species were quantified. The cell migration was finally measured with the help of the transwell migration assay. None of the cell types showed any decrease in the cell viability after the LF EMF application and the cells displayed minimum changes in reactive oxygen species. Functional changes (acceleration of cell migration) after AMC exposure were statistically significant for the MSC samples only. The acceleration of MSCs is associated with the production of MMP by these cells. The EMF has a potential to be a safe, clinically applicable selective activator of MSC homing, MSC paracrine production, and subsequent regeneration processes.

Cost-effective techniques to control human enteropathogens on fresh poultry.

Salmonella is a multi-faceted problem that must be attacked on many fronts. The results of Food Safety and Inspection Service's Puerto Rico Bacterial Control Project confirmed that there is no "silver bullet." The project showed that a combination of management commitment, process control, and specific interventions at key control points can bring about significant improvements in the bacterial quality of fresh poultry.

Effects of countercurrent scalding and postscald spray on the bacteriologic profile of raw chicken carcasses.

In June and September 1988, the USDA Food Safety and Inspection Service sampled raw chicken carcasses at a federally inspected slaughter establishment in Puerto Rico to determine the effects of changing the scalding equipment on bacterial contents of raw poultry products. The scalding equipment was changed to a countercurrent configuration, with a postscald hot-water rinse cabinet that sprayed carcasses as they exited the scalder. Analysis of 250 carcass-rinse samples collected at preevisceration, prechill, and postchill sites over 7 days indicated that carcasses had mean aerobe plate counts of log(10)3.73 before evisceration, 3.18 before chilling, and 2.87 after chilling; Enterobacteriaceae counts of log(10)2.70 before evisceration, 2.25 before chilling, and 1.56 after chilling; and Escherichia coli counts of log(10)2.09 before evisceration, 1.61 before chilling, and 0.89 after chilling. Salmonellae were found on 24% of the carcasses before evisceration, on 28% before chilling, and on 49% after chilling. Although bacterial count reductions were significant at all 3 sites, the proportion of carcasses contaminated with salmonellae in this study was higher at the postchill than prechill site (49 vs 28%). This no doubt was caused by cross-contamination in the chiller. These percentages indicated that although simple scalder changes contributed substantially to the improvement of the bacterial quality of chicken carcasses, additional interventions in the chilling process (such as chlorination of chill water) are important to control cross-contamination and to preserve the positive effects obtained by the scalder changes.

Profile of selected bacterial counts and Salmonella prevalence on raw poultry in a poultry slaughter establishment.

The USDA Food Safety and Inspection Service determined populations of bacteria on poultry during processing at a slaughter plant in Puerto Rico in November and December 1987. The plant was selected because of its management's willingness to support important changes in equipment and processing procedures. The plant was representative of modern slaughter facilities. Eight-hundred samples were collected over 20 consecutive 8-hour days of operation from 5 sites in the processing plant. Results indicated that slaughter, dressing, and chilling practices significantly decreased the bacterial contamination on poultry carcasses, as determined by counts of aerobic bacteria, Enterobacteriaceae, and Escherichia coli. Salmonella was not enumerated; rather, it was determined to be present or absent by culturing almost the entire rinse. The prevalence of Salmonella in the study decreased during evisceration, then increased during immersion chilling.

Effects of chlorination of chill water on the bacteriologic profile of raw chicken carcasses and giblets.

In March 1989, the USDA Food Safety and Inspection Service sampled raw chicken carcasses and giblets at a federally inspected slaughter establishment in Puerto Rico to determine the effects of adding chlorine to carcass and giblet chill water on bacterial contents of raw poultry products. Over four 8-hour workdays, 200 carcass rinse samples were collected at 3 sites in the establishment; 39 giblet rinse samples were collected at 1 site. Analyses of the carcass rinse samples indicated that carcasses had average aerobe plate counts of log10 3.20 before chilling and 2.51 after chilling; Enterobacteriaceae counts of log10 2.57 before chilling and 1.75 after chilling; and Escherichia coli counts of log10 2.04 before chilling and 1.20 after chilling. Salmonellae were found on 43% of the carcasses before chilling and on 46% after chilling. Analyses of the giblet and neck rinse samples indicated that raw giblets and necks after chilling had average aerobe plate count of log10 3.49, Enterobacteriaceae count of log10 2.57, and E coli count of log10 1.06. Salmonellae were found on 12% of the giblets and necks sampled. Results compared favorably with giblet and neck rinse sample results obtained during a baseline sampling study in November and December 1987. The baseline results indicated aerobe plate count of log10 3.72; Enterobacteriaceae count of log10 2.90; E coli count of log10 1.14; and salmonellae on 69% of the giblets and necks sampled. Placing raw chicken carcasses in chlorinated chill water reduced aerobe, Enterobacteriaceae, and E coli plate counts. Prevalence of carcasses with salmonellae remained nearly the same.(ABSTRACT TRUNCATED AT 250 WORDS)

[Polychlorinated biphenyls (PCB) in human adipose tissue]. / Polychlorierte Biphenyl (PCB) im menschlichen Fettgewebe.

This study describes the contamination of human adipose tissue with six selected polychlorinated biphenyls (PCB) known as "indicator congeners", with PCB no. 49 and the mixed inducer PCB nos. 156, 170, and 189. The low chlorinated biphenyls nos. 28, 49, and 52 could not be found in the tissue samples, while the average concentration of PCB no. 101 was 9.0 micrograms/kg. The content of PCB nos. 138, 153, and 180 was slightly below the values published by the "Deutsche Forschungsgemeinschaft" (DFG). The mixed inducer nos. 138, 156, 170, and 180 amounted to approximately 40% of all the PCBs measured. The PCB contamination was positively correlated with age: for the age group 61-70 years, with the exception of PCB no. 101, a distinct increase in the concentrations could be observed.

[Pollution of indoor air in large-scale kitchens and laundries by volatile halogenated hydrocarbons]. / Die Belastung der Innenraumluft in Grossküchen und Wäschereien durch leichtflüchtige halogenierte Kohlenwasserstoffe.

The study demonstrates that the agents used for dishwashing and in the central laundry are already slightly contamined with halogenated hydrocarbons and formaldehyde. Analyses of the washing lyes yield considerably higher concentrations of halogenated hydrocarbons. Especially in the dishwater a relatively high concentration of trichloromethane (chloroform) was detected. Obviously these halogenated hydrocarbons are also present in relatively high concentrations in the air of the corresponding working places. However, the concentrations of individual halogenated hydrocarbons and formaldehyde are clearly below the respective threshold limit values.

[Environmental characterization: air pollution]. / Umweltcharakterisierung: Luftverunreinigung.

During the years of the epidemiological group-diagnostic examination (1982-1986) it was attempted to characterize the atmospheric air pollution in the industrial Rhine-Main area (Wiesbaden and Frankfurt) and, in comparison, in two control areas (Freiburg with the adjacent High Black Forest and the Starnberg area). For this the measurements of the air measuring stations of the network for emissions of the German Umweltbundesamt (Federal Environmental Protection Agency) at Berlin and Frankfurt were used and well as those of the Hessische Landesanstalt für Umwelt, Wiesbaden (Hessian Office for Environmental Protection); Landesanstalt für Umweltschutz Baden-Württemberg, Karlsruhe (Regional Office for Environmental Protection of Baden-Württemberg); Bayerische Landesanstalt für Umweltschutz (Bavarian Office for Environmental Protection, Munich), were used. The comparison of the different measuring components used shows the pollutant concentration in the air at the measuring stations in Wiesbaden and Frankfurt attains the highest values. Opposed to that, the pollutant concentration in the areas Freiburg with the adjacent Black Forest and in the region of Starnberg can be judged to be relatively low. No statement can, unfortunately, be made on the heavy metal burden in the air of the Starnberg area, since heavy metal in the air have not been analysed.

[Environmental characterization: weather and climate]. / Umweltcharakterisierung: Wetter und Klima.

In order to characterize the weather and the climate in the area of industrial Rhine-Main area (Wiesbaden and Frankfurt) and in the two control areas (Freiburg with the bordering higher region of the Black Forest and the Starnberg area), relevant measuring data was provided by the German Meteorological Service, Centre of the Medicometeorological Research Establishment, Freiburg. The monthly as well as yearly climatic values of the years 1982-1985 were employed for the following stations: Frankfurt Airport; Wiesbaden South; Freiburg Meteorological Office; Munich Airport Riem which are representative for our areas under examination. For the characterization of the climate in the study areas the following parameters were used: temperature degrees C; relative humidity of the air in %; amount of rainfall in mm; duration of sunshine; wind distribution. The climatic values were interpreted for the years 1982-1985 of the epidemiological group-diagnostic examination of children.

[Heavy metal content of the children's hair]. / Schwermetallgehalt des Kinderhaares.

In the framework of the epidemiological group-diagnostic studies in the industrial areas Rhine-Main (Wiesbaden and Frankfurt) with a relatively high air pollution as well as in two control areas (Freiburg and Starnberg) with lower air pollution, hair samples from more than 2500 ten-year-old children were taken. After an appropriate washing process (removal of the exogenic load) and wet incineration, the hair samples were examined by AAS- for their heavy metal content (Cd, Pb, Fe and Zn). The evaluation of the results over the time of the examination from 1982 until 1986 shows that the hair samples from children in the burdened area Rhine-Main with high air pollution have higher lead as well as cadmium values than those of the control area Freiburg with the bordering region of the Black Forest. Furthermore it can be clearly recognized in the five years of the examination of children's hair that the contamination or the content of toxic heavy metals such as Cd and Pb in the polluted region of Wiesbaden is distinctly decreasing over the years. Surprisingly, increased zinc, cadmium and also, during the last two years, increased lead values in children's hair were detected in the Starnberg area. During the five years of examination there was a correlation between the heavy metal content in children's hair and the heavy metal content in airborne dust of the burdened area; this is particularly true for cadmium.

Type A botulism from commercially canned beef stew.

Two of three persons who ate lunch together became ill with symptoms characteristic of botulism. One died before botulism was suspected and before specimens could be collected for laboratory testing, but a serum specimen from the other patient, who survived, yielded botulinal toxin, type A. The third person remained asymptomatic, but Clostridium botulinum type A was cultured from his stool. The three persons had shared two canned foods: home-canned green beans and commercially canned beef stew. The green beans were initially assumed to be the cause of the outbreak. However, the empty stew can was recovered from the garbage, and washings from the can yielded C botulinum, type A, and its toxin.