Short-Chain Fatty Acids as Sanitizers for Beef 1, 2, 3

Formic, acetic and propionic acids in various combinations and individually were screened for antimicrobial efficacy and effect on meat color. Microorganisms tested were two pseudomonads, three coliforms, a Streptococcus sp., a Micrococcus sp., a spore-forming bottom yeast and three film yeasts which reproduced by budding. Variables tested were microorganism, pH, concentration of sanitizer and exposure time. When the 11 cultures were exposed to individual sanitizers and mixtures of them in three replications, 2% formic acid and 1% formic plus 1% acetic acid were most effective, destroying 84 and 73%, respectively, of the test cultures. Three microorganisms that were refractory to 2% acetic acid were usually killed by 2% formic acid. Addition of ascorbic acid to the sanitizer to reduce oxidation of the meat pigments resulted in lowered microbial counts. Color was not affected by addition of 1% ascorbic acid. With added 5% ascorbic acid, discoloration was noticeable but not extensive. There was no effect of pH on microbial destruction at the concentration of acid used, However, more microorganisms were killed as time of exposure to the acid was increased.

Milk Films Exposed to High Humidity: Studies with Electron Microscopy and Electrophoresis 1, 2

Stainless steel plates, which are similar to milk contact surfaces, were dipped in fresh raw milk. The residual film was dried (37 C and 10% to 20% relative humidity) for 30 min. Treated plates were then exposed to 100% relative humidity for 30 min at 37 C. Scanning electron microscopy revealed splotches of fat on surfaces of dried films and the humidified films had a more aggregated and porous appearance than films that were dried only. The incidence of granulated lactose was greater among humidified samples than among nonhumidified samples. Discontinuous polyacrylamide gel electrophoresis revealed that α- and β-caseins resisted rinsing from plates on which dried films were exposed to 100% relative humidity but not from plates on which films had been dried only.

A horseradish peroxidase study of afferent connections of the globus pallidus in Macaca mulatta

The high tonic discharge rates of globus pallidus neurons in awake monkeys suggest that these neurons may receive some potent excitatory input. Because most current electrophysiological evidence suggests that the major described pallidal afferent systems from the neostriatum are primarily inhibitory, we used retrograde transport of horseradish peroxidase (HRP) to identify possible additional sources of pallidal afferent fibers. The appropriate location was determined before HRP injection by mapping the characteristic high frequency discharge of single pallidal units in awake animals. In animals with injections confined to the internal pallidal segment, retrograde label was seen in neurons of the pedunculopontine nucleus, dorsal raphe nucleus, substantia nigra, caudate, putamen, subthalamic nucleus, parafascicular nucleus, zona incerta, medial and lateral subthalamic tegmentum, parabrachial nuclei, and locus coeruleus. An injection involving the external pallidal segment and the putamen as well resulted in additional labeling of cells in centromedian nucleus, pulvinar, and the ventromedial thalamus.

A Method for Decreasing Sampling Variance in Bacteriological Analyses of Meat Surfaces 1, 2

Viable counts of bacteria are often high in some areas and low in adjacent areas of the same surface of fresh meat. The present study indicated that rubbing meat surfaces together before sampling reduces variation among bacterial plate counts of pieces of beef plate meat. Counts before rubbing ranged from 2 to 6,187/cm², whereas counts after rubbing ranged from 15 to 2,043/cm². The reduced sample variance allowed for fewer samples to be taken in studies of cleaning and sanitizing of fresh beef.

Paraformaldehyde-induced fluorescence as a histochemical test for 5-hydroxytryptamine in the epididymis of the opossum

Epididymides of four opossums were tested histochemically for the presence of 5-hydroxytryptamine (5-HT). In addition, testes and epididymides of two opossums were analysed biochemically for the same substance. Biochemical analysis revealed a high concentration of 5-HT in the epididymis, while the amount in the testis proved to be insignificant. Fluorescence microscopy gave positive results in the apical portion of the epithelium. There was also fluorescence in the connective tissue in general, in mast cells, and in a thick subepithelial band in particular. Following treatment with 2% sodium borohydride in 1,2-propanediol for 15 minutes, the fluorescence of mast cells was removed, while there was a slight reduction in epithelial fluorescence and that in the subepithelial band and other connective tissue. The subepithelial band stained metachromatically with azure B, and this staining characteristic was removed by treatment with RNAse. Feulgen reaction revealed elongate nuclei in the band. It would seem that the 5-HT is located in both the mast cells and the epithelium. It seemed to be also present in the subepithelial band, but because of strong autofluorescence it is difficult to demonstrate. At the present time the function of 5-HT in the opossum epididymis is unknown, and is under further investigation.

Factors Influencing Tenacity of Dried Milk Films Exposed to High Humidity 1, 2

Rinsability of milk films on stainless steel was impaired by exposure to 100% relative humidity (RH). Rinsability was determined by automated Lowry protein tests of detergent used to remove films. Residue of milk films was 1% of the initial soil load when dried on stainless steel plates without humidification, but was 6.35% of the initial load after drying (30 min), humidification (15 min) and redrying (30 min) all at 37 C. Three successive exposures to 100% RH for 7.5 min at 37 C, each followed by 30 min of drying, yielded a residue of nearly 30% of the initial soil load. Exposure at 37 C produced the maximum amount of residue on plates. Experimental temperatures ranged from 0 to 75 C. Temperature of milk applied to plates was of little importance. Raw milk formed more tenacious film than skim milk or major components of milk. Milk produced during colder months yielded less soluble films than milk produced during warmer months. Lowering of milk pH to 5.7, adding soluble calcium, and aging milk at 0 C increased residues. Chelation of soluble calcium with EDTA or dissociation of milk protein with sodium dodecyl sulfate decreased soil residue levels. Exposure of instantized nonfat dry milk to the high humidity treatment decreased its solubility more than tenfold.

Microbial Growth on Plate Beef During Extended Storage After Washing and Sanitizing

Plate beef was washed and/or sanitized with cold water, hot water, steam, sodium hypochlorite, or acetic acid before being stored for up to 28 days at 3.3 C and 90% relative humidity. Microbial counts initially and at regular intervals thereafter disclosed that, compared with untreated controls, time to reach counts of 10⁸ bacteria per cm² were (a) 1 day less with steam- or water-treated samples, (b) 2 to 3 days more with hypochlorite-treated samples, (c) 5 days more with hot-water-treated samples, and (d) 16 to 17 days more with acetic acid-treated samples. Re-sanitization with acetic acid extended time to reach equivalent counts by 7 additional days.

Quadriplegia associated with narrow cervical canal, ligamentous calcification and ankylosing hyperostosis

The occurrence of three pathological entities of the cervical spine--ankylosing hyperostosis, calcification of the posterior longitudinal ligament, congenitally narrowed cervical canal--in a single patient is reported. This combination of pathology led to a severely narrowed cervical canal and a spine with abnormal mobility at non-fused levels. Minor trauma to the patient resulted in permanent quadriplegia.

Discharge patterns of basal ganglia neurons during active maintenance of postural stability and adjustment to chair tilt

Neurons in the putamen and globus pallidus were studied in awake monkeys making active postural adjustments during static and dynamic chair tilt. When the chair was held horizontal and the monkey actively maintained a restricted head position, neurons had tonic firing rats similar to those described previously, with low frequency patterns in the putamen and low frequency-burst or intermediate (IFD) to high frequency (HFD) tonic patterns in neurons in the pallidal segments. Over half of the neurons with IFD or HFD discharge rates and a smaller proportion of those with slow discharge rates showed changes in firing that were temporally correlated with chair tilt. Phase shifts of firing frequency relative to sinusoidally vaired chair position varied in units with different tonic discharge frequencies. Maximum and minimum discharge rates in IFD neurons occurred near maximum chair velocities, whereas the phase shift decreased in HFD neurons, which had higher discharge rates during the horizontal chair position. Neurons with changes in discharge during chair tilt were found in all portions of the putamen and globus pallidus studied.

Combined and Individual Effects of Washing and Sanitizing on Bacterial Counts of Meat - A Model System 1, 2

Strips of plate meat were sprayed with acetic acid, sodium hypochlorite, or tap water after they were washed with 0, 12.7, or 25.4 liters of tap water/min. Washing before sanitizing lowered bacteria counts significantly only when the higher volume of water, 1.4 ml/cm², was applied, and this difference existed for samples taken immediately but not 48 h after treatment. Reductions in counts exceeded 99.9% when samples washed with 25.4 liters/min (1.4 ml/cm²) were sanitized with 3% acetic acid. This sanitizer was sprayed at the rate of 6.8 liters/min (1.9 ml/cm²) at a pressure of 14.0 kg/cm² from a distance of 40 cm as the meat moved at 2 cm/sec through the spray. Under comparable conditions of application, both sodium hypochlorite (200 to 250 mg/liter) and tap water reduced counts by about 90%. Acetic acid had a much greater residual effect on numbers of viable bacteria than did hypochlorite. No effect of air drying was observed.

Segmental reflex inputs to motoneurons innervating dorsal neck musculature in the cat

The responses to stimulation of upper cervical muscle and cutaneous afferents were studied in motoneurons innervating splenius, complexus, and biventer cervicis dorsal neck muscles of cats. Motoneurons innervating complexus and biventer cervicis fibers, which are in the deeper, longitudinally oriented muscles, were monosynaptically excited by ipsilateral Group I afferents from each of these muscles, but they did not receive significant input from splenius Group I afferents. Likewise, splenius motoneurons were not monosynaptically excited by ipsilateral afferents from complexus anf biventer cervicis. Stimulation of ipsilateral cutaneous afferents produced predominant excitation in splenius motoneurons, predominant inhibition in biventer cervicis motoneurons, and inhibition or mixed responses in complexus motoneurons. None of the neck motoneurons studied showed postsynaptic potentials following single or multiple shock stimulation of contralateral muscle nerves at stimulus intensities expected to excite exclusively Group I afferents. Higher intensity stimulation of contralateral muscle afferents, as well as fibers in the greater auricular nerves, produced predominant inhibition in all three neck motoneuron pools. Segmentally-excited afferents to neck motoneurons, like those from supraspinal systems, appear to evoke different patterns of synaptic responses in splenius motoneurons than they do in motoneurons innervating fibers in the deeper, longitudinally oriented complexus and biventer cervicis muscles.

Saccadic eye movements and eye-head coordination in children

The eye and head movements of nine children, ages 6 through 10, were measured in order to establish quantitative characteristics of eye movements and eye-head corrdination patterns of children with normal vision and reading levels. The relationship between saccade amplitude and duration was linear, but the slope of this relationship indicated that saccades in children may have higher velocities than they do in adults. One of three temporal patterns of head and saccadic eye movement occurred during shifts of gaze to visual targets, depending on the temporal and spatial predictability of the target. It is suggested that quantitative measurements such as these could be used to examine developmental characteristics of eye and eye-head movement control.

Experiments in Sanitizing Beef With Sodium Hypochlorite 1, 2

Beef plate meat was sprayed with sodium hypochlorite (pH 6.0) from two sources, commercial and electroytically generated. Variables studied in two experiments were rate of flow of sanitizer, line pressure, speed of movement of meat through the sprays, and method and time of sanitization. Hypochlorite sprays reduced microbial counts significantly more than did water applied under the same conditions, but type of hypochlorite was unimportant. Maximum reductions in counts made immediately after sanitization approximated 97 and 93% as measured by swab and core sampling methods, respectively. Sprays were most effective when delivered in a single passage over meat at a rate of 2 rather than 10 cm/sec or in about seven successive passages at 10 cm/sec. Samples collected by coring and swabbing estimated microbial populations different from each other when the samples were taken after sanitized meat had been stored at 3 C for 48 h. Based on our findings we recommend the coring method.

Diet and cancer

Differences in food intake patterns are positively correlated with differences in the incidence of various cancers in world populations. It is postulated here that dietary factors play a vital role in the genesis of several major neoplasms, specifically gastric and colon carcinomas. In addition to the food consumed, such variables as total caloric intake, nutrtional excess or deficit, exposure to carcinogens and consumption of alcohol also increase the risk of cancer. Through recognition of these factors and subsequent long-term manipulation of diet, it should be possible to reduce cancer morbidity and mortality.

Evidence for origin of insect sex pheromones: presence in food plants

Compounds identified as sex attractant pheromones in a number of phytophagous insects were found in a variety of host plants. These agents vary in chemical composition in different plant species, which suggests that dietary factors may provide an evolutionary mechanism for diversification of certain insect species. A theoretical framework to explain this phenomenon is postulated on the basis of experiments with the oak leaf roller moth.

Detection of tetracycline resistance in Streptococcus pneumoniae

Bacteriological details are given of a patient with chronic purulent bronchitis, who was being followed up during a survey of relapse in chronic bronchitis. A strain of Streptococcus pneumoniae, serotype 10, was isolated from the sputum over a period of six months, followed by a type 47A strain and later a type 28 strain. The patient was receiving prophylactic treatment with tetracycline throughout. The type 10 strain was sensitive to tetracycline in vitro by both the disc diffusion and doubling dilution sensitivity tests and mice infected with this strain were protected by tetracycline. In contrast, both the type 47A and type 28 strains were sensitive by the disc diffusion technique, but showed a low degree of tetracycline resistance by the doubling dilution method; mice infected with both these strains were not protected by tetracycline.

Sex pheromone of the oak leaf roller: a complex chemical messenger system identified by mass fragmentography

The sex pheromone of the oak leaf roller, Archips semiferanus Walker, is composed of a complex mixture of chemical signals. The attractant component of the pheromone contains a series of tetradecenyl acetates having double bonds in positions 2 to 12. Mass fragmentography of the ozonolysis products of the attractant component was used to locate the double bonds in the various isomer.