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There has long been interest in the inheritance of malocclusion, but few studies have distinguished between skeletal (craniometric) variables and occlusal, tooth-based variables (e.g., anterior irregularity, rotations, displacements). This study was based on serial assessments of untreated persons in 30 sibships from 4 years (full deciduous dentition) to 20 years of age (full permanent dentition) in the Bolton-Brush Growth Studies of Ohio. Results define a clear dichotomy: craniometric variables (k = 29) typically show significant additive components of variance; correlations increase from age 4 to age 20; and correlations average 0.43 at adulthood. Tooth-based variables of position and relationship (k = 21) reach significance only occasionally; correlations decrease with age to the extent that few variables for subjects at age 20 have a correlation significantly different from zero. In contrast to craniometric variables, which have high heritabilities, almost all of the occlusal variability is acquired rather than inherited.

A simple high-performance liquid chromatographic method has been developed for the rapid purification and analysis of protamine components contained in insulin formulations. Only a single step is needed to separate peptides whose compositions, sizes, and unusual isoelectric points (pI 13.8) are nearly identical. The method involves their isocratic separation on a reversed-phase column using a pH 2 phosphate buffer and a low acetonitrile content as an eluant. The purified chum salmon components were analyzed by amino acid analysis, solid-phase amino acid sequencing, carboxypeptidase B digests, insulin complexation analysis, and a mass spectrophotometric procedure which gives an accurate mass of the intact peptides. This HPLC purification technique may also be applicable to protamines and other highly basic peptides isolated from other sources.

Several strains of Listeria species formed petite-sized colonies from parent stock cultures when grown on agar media containing 0.2-1% (w/v) esculin. This was observed in Listeria monocytogenes (7/22 strains), L. innocua (1/3), L. grayi (1/1), L. seeligeri (1/3), and L. welshimeri (1/1), but not in L. ivanovii (0/1) and L. murrayi (0/1). This phenomenon was only observed on agar media that contained esculin. All petite isolates had biotyping profiles identical to their larger, normal-sized counterpart isolates. Normal and petite-sized isolates from two L. monocytogenes strains, Scott A and V7, were pathogenic to immunosuppressed white mice. On media containing 0.5% (w/v) esculin + ferric iron, Listeria cultures produced colony diameters intermediate in size between those of normal and petite cultures. When pregrown in glucose broth, all petite isolates demonstrated visible beta-glucosidase (esculinase) activity within 5 min, while the normal-sized isolates showed beta-glucosidase activity only after at least 20-70 min. This evidence suggests that cells forming petite colonies are beta-glucosidase constitutive variants within the parent population, while cells that form normal-sized colonies are inducible for beta-glucosidase (esculinase) activity. A possible role for the esculin hydrolysis product, esculetin, in causing petite colony formation is discussed.

Eight hundred fifty-nine murine hybridomas were produced from eight fusions, and 27 were characterized for secretion of antibodies reactive to Listeria monocytogenes. One monoclonal antibody (MAb), P5C9, reacted with all test strains of L. monocytogenes (31 of 31), L. innocua (3 of 3), and L. welshimeri (1 of 1) but not with any strains of the other four Listeria species or with any of 22 gram-positive or 11 gram-negative species of bacteria when tested in microtiter and dot blot enzyme immunoassays. Of the other 26 antibodies, 20 reacted with either L. monocytogenes Scott A or V7 and with some or all of the other six Listeria species but also cross-reacted with some or all of the non-Listeria bacteria tested. MAb P5C9 is of the immunoglobulin G1 murine subclass. In Western blot (immunoblot) analyses, this MAb reacted with a single antigen with a molecular weight of 18,500, and it is shared in common with all three reactive species, L. monocytogenes, L. innocua, and L. welshimeri. This antigen was extracted with detergent and appeared to be cell bound.

In this study the methods of Hungate were used to quantitate the anaerobic bacteria present in commercially available ground beef, cheddar cheese, and German hand cheese. Of 235 anaerobic roll-tube isolates from ground beef and German hand cheese, all were facultative anaerobes. Of 213 anaerobic roll-tube isolates from cheddar cheese, 91% were facultative anaerobes and 9% were obligate anaerobes. Using results of biochemical tests, 14 or the 17 obligately anaerobic isolates from cheddar cheese were Propionibacterium acnes, two were strains of Propionibacterium that could not be speciated, and one was tentatively identified as a strain of Streptococcus evolutus. Obligate anaerobes were estimated to be present in the cheddar cheese at a level of about 10(6)/g. The possible significance of these levels of P. acnes in nonsterile foods is discussed.

This report describes the isolation of Cardiobacterium hominis from a patient with a history of rheumatic heart disease. Seven blood cultures yielded the organism. This investigation includes the case history, significant details of the hospital course, and the bacteriological, biochemical, and antimicrobial characteristics of Cardiobacterium hominis, integrated with a brief review of the literature.

The regional concentrations and in-vitro secretions of canine pancreatic polypeptide (cPP), insulin, and glucagon were studied. CPP is found predominantly in the uncinate process of the dog pancreas, whereas insulin and, more markedly, glucagon predominate in the body and tail of the pancreas. In-vitro secretion studies of pancreatic pieces indicate that dibutyryl cyclic AMP (dcAMP) alone can stimulate cPP release whereas glucose and arginine alone have no effect. Arginine, but not glucose, potentiates this stimulant effect of dcAMP. These studies suggest that the cAMP generating system may play a role in regulation of cPP secretion.

Pancreatic polypeptide (PP) has been isolated from rat pancreas by gel filtration, ion exchange chromatography, and high performance liquid chromatography. The isolation was monitored with a RIA, using antibody to the carboxyl-terminal hexapeptide of bovine PP. Rat PP contains 36 amino acids and is similar in composition to PP from other mammalian sources. The single methionine residue in the peptide appears to oxidize easily to the sulfoxide, thereby giving rise to two immunoactive peaks on high performance liquid chromatography. Reduction to the native peptide can be accomplished with mercaptoethanol. The PP content of rat pancreas is about 2 mg/kg. The amino acid sequence of rat PP is Ala-Pro-Leu-Glu-Pro-Met-Tyr-Pro-Gly-Asp- Tyr-Ala-Thr-His-Glu-Gln-Arg-Ala-Gln-Tyr-Glu-Thr-Gln-Leu-Arg-Arg-Tyr-Ile- Asn-Thr-Leu-Thr-Arg-Pro-Arg-Tyr-NH2. This sequence preserves characteristics necessary for stabilization of the compact globular conformation found in avian PP.

In order to determine the effect of lactogen on insulin secretion and junctional coupling among islet beta cells, ovine prolactin (oPRL) was infused by Alzet minipumps into female rats for 4 days. This treatment produced an oPRL level of 994 +/- 122 ng/ml which, combined with residual rat PRL (rPRL) (12 +/- 2 ng/ml), represented nearly a 20-fold increase from control (rPRL: 53 +/- 17 ng/ml). In addition, plasma insulin was increased nearly 50% (control: 21.9 +/- 3 microU/ml; experimental: 30.3 +/- 3 microU/ml; p less than 0.05). When pancreata from lactogen-treated and control animals were perfused with linear 30-200 mg/dl glucose gradients, the apparent glucose threshold for insulin secretion in the experimental group was nearly 33% lower than that of the controls (i.e., 70 +/- 4.6 mg/dl vs. 104 +/- 7.5 mg/dl; p less than 0.01). The oPRL treatment also increased dye coupling among beta cells. Central cells in islets isolated from lactogen-treated and control animals were injected with Lucifer Yellow CH to estimate the extent of gap junctional coupling. There was nearly a twofold increase in the projected area of dye transfer per injection in the experimental vs. the controls: 4,607 +/- 575 micron 2 vs. 2,302 +/- 474 micron 2, respectively; p less than 0.02. The effects of oPRL decreased the apparent glucose threshold for insulin release, increased the above-threshold glucose-induced insulin secretion, and increased the extent of dye coupling among beta cells. These changes in insulin secretion and dye coupling closely resemble those observed in islets from pregnant rats.

Studies using tissue homogenates have demonstrated an increase in pulmonary beta-receptors during development. However, techniques using disrupted tissue have not permitted the precise anatomic localization of pulmonary beta-receptors or identification of structures where increases occur. Using L-[3H]dihydroalprenolol, beta-receptors were radioautographically localized and quantitated in sections of newborn (NB) and adult (A) guinea pig lung. Scatchard analysis showed a single class of binding sites with a maximum binding capacity of 189 +/- 3 (NB) and 305 +/- 37 (A) fmol X mg-1 protein (P less than 0.02). Binding was of high affinity with the dissociation constant (Kd) = 1.46 +/- 0.2 (NB) and 1.26 +/- 0.3 (A) nM (NS). The majority of beta-receptors were localized in alveolar wall and airway epithelia (alveolar much greater than bronchiolar greater than bronchial) (P less than 0.0001). Airway and vascular smooth muscle had significantly fewer demonstrable beta-receptors. The increased number of beta-receptors in the adult appeared to be due primarily to a 2.0 +/- 0.12-fold increase in alveolar wall and airway epithelia as opposed to only a 1.3 +/- 0.18-fold increase in the already low number in airway and vascular smooth muscle (P less than 0.05). While apparent receptor density may not necessarily correlate with physiological response or importance, radioautographic localization of pulmonary beta-receptors may significantly enhance our understanding of their role in normal and pathologic states.

The lactoperoxidase-thiocyanate-H2O2 system (LP system), consisting of lactoperoxidase (0.37 U/ml), KSCN (0.3 mM), and H2O2 (0.3 mM), delayed but did not prevent growth of L. monocytogenes Scott A at 5, 10, 20, and 30 degrees C in broth and at 20 degrees C in milk. The net lag periods determined spectrophotometrically varied inversely with temperature and were shorter at 5 and 10 degrees C for cultures from shaken versus from statically grown inocula. Lag periods for cultures from shaken and statically grown inocula, respectively, were 73 and 98 h at 5 degrees C, 22 and 32 h at 10 degrees C, both 8.9 h at 20 degrees C, and both 2.8 h at 30 degrees C. After the lag periods, the maximum specific growth rates were similar for each of the three treatments (complete LP system, H2O2 alone, or control broth) at 5, 10, and 20 degrees C and were 0.06 to 0.08, 0.09 to 0.1, and 0.32 to 0.36/h, respectively. At 20 degrees C in sterile reconstituted skim milk, the LP system restricted growth of Scott A, with log CFU counts per ml at 0, 36, and 68 h being 5.7, 6.4 and 7.9 (versus 5.7, 9.8, and 11.2 for controls). Possible explanations for the decreased lag times observed for cultures from aerobically grown inocula are discussed.

A new operative approach for non-gangrenous cecal volvulus combining transrectal Baker tube colonic decompression with peritoneal flap cecopexy has advantages over previously described operations.

The sporulation of Clostridium perfringens NCTC 8798 was studied after exposing vegetative cells to: pH values of 1.5 to 8.0 in fluid thioglycolate broth (for 2h) and then transferring them to Duncan-Strong (DS) sporulation medium; sodium cholate or sodium deoxycholate (0.3 to 6.5 mM) in DS medium; or Rhia-Solberg medium with 0.4% (wt/wt) starch, glucose, or both added at 0 to 55 mM. At pH 1.5, no culturable heat-resistant spores were formed. For cells exposed to pH 3.0, 4.0, 5.0, or 6.0, increases in heat-resistant spores were not seen until after a lag of 12 to 13 h, whereas the lag was only 2 to 3 h for cells exposed to pH 7.0 or 8.0. Maximal spore crops were produced after only 6 to 8 h for cells exposed to pH 7 or 8, but 16 to 18 h was required for production of maximal spore crops by cells exposed to the lower-pH media. The addition of sodium cholate (3.5 to 6.5 mM) to DS medium only slightly reduced the culturable heat-resistant spore count from 1.9 X 10(7) to 3 X 10(6)/ml. The addition of 1.8 mM or more sodium deoxycholate reduced the culturable heat-resistant spore count to less than 10/ ml. When either starch or glucose alone was added to Rhia-Solberg medium there was no production of culturable heat-resistant spores, but a combination of 0.4% (wt/wt) starch and 4.4 mM glucose yielded 6 X 10(5) spores/ml. The spore production remained at this level for glucose concentrations of 6 to 22 mM, but then declined to about 3 X 10(3) spores per ml at higher concentrations.

Cells of Vibrio parahaemolyticus were stressed by heat, cold or heat-cold treatments of 45 C for 12 h, 0 C for 24 h or both. The five menstrua in which cells were stressed were 0.1 M phosphate buffer with 3% NaCl (B + 3%), 0.25 - strength Marine Broth (0.25 × MB) Trypticase Soy Broth with 3% NaCl (TSB + 3%) and Trypticase Soy Agar with 3 or 7% NaCl (TSA + 3% or TSA + 7%). The chill stress produced no cell injury, measured as the difference in colony counts in TSA+3% and TSA+7%, in the three liquid menstrua but caused more than 4 logs of cell injury in the solid menstrua compared to controls. The heat stress caused 2.5- and 1.5-log increases in the number of injured cells from B + 3% or 0.25 × MB, respectively. Cells heat-stressed in TSB + 3% showed no decline in colony counts, but those heat-stressed in TSA+ 7% produced about a 6-log lower colony count. For cells heated and then chilled in B+3% or 0.25 × MB as the liquid menstruum, the percentages of heat-injured cells that apparently regained tolerance to 7% NaCl when shifted to the cold were about 99.7 and 95.0%, respectively. Conversely, cells that were heated and then chilled in the solid menstrua did not regain tolerance to 7% NaCl. Thus, cell injury was greater and apparently less easily reversed for cells stressed in solid than liquid menstrua.

Sporulation kinetics and spore heat resistance data were compared for a lysogenic strain of Clostridium perfringens, s9, before and after curing with ultraviolet irradiation. The cured strain showed the same growth rate in broth media as the lysogenic strain but took 6 h longer to form refractile spores. For lysogenized and cured strains the percentages of refractile spores produced that were heat-resistant (80 degrees C for 15 min) were 50 and 0.2, respectively. When reinfected with the temperature phage, the cured strain produced spores in 2 to 3 h, like the original lysogenic culture, and 10% of the spores produced were heat-resistnat.

Exterior surfaces of beef plates were inoculated with aerobic mesophilic, psychrotrophic, coliform, fecal coliform and Staphylococcus aureus bacteria before spraying with city water (7.03 kg/cm 2 ) or with 100, 150 or 200 ppm hypochlorite solutions applied at 3.75, 5.25 or 7.03 kg/cm 2 ) for 12 sec. Surface strips excised from the inoculated carcass regions were analyzed for bacterial persistence at 2 hand 2,4,8,16 and 20 days after spray treatment. A one log. or greater, reduction incoliforms, fecal coliforms and S. aureus counts occurred within 4 days for each spray treatment. Initial aerobic mesophilic and psychrotrophic counts were reduced by < 1 log within 2 h but increased to original inoculum levels within 8 days for each treatment. Mesophilic and psychrotrophic counts increased to > 3.5 logs higher than inoculated levels after 16 days at 4-6 C. Spray pressure (P < .01) was more effective in reducing mesophilic, psychrotrophic and S. aureus counts than was hypochlorite concentration (P < .05) while both variables were about equally effective against coliforms (P < .01) and fecal coliforms (P < .05). Surprisingly, reductions of psychrotrophic, coliform and S. aureus counts on the beef carcass surface sprayed with hypochlorite solutions were not significantly (P < .05) different from those observed on carcasses sprayed with city water. However, a significantly (P < .05) greater reduction in aerobic mesophile and fecal coliform counts at 2 days after treatment was obtained when using the intermediate spray pressure of 5.25 kg/cm 2 containing 200 ppm hypochlorite, rather than city water. No undesirable change in beef grade, muscle shear or color property was observed for carcasses treated with the hypochlorite solutions.

Two isolates of Cunninghamella bertholletiae from confirmed cases of human zygomycosis were studied, and their sexual, asexual, and physiologic characteristics described. Minimal inhibitory concentrations for these two isolates, as well as for six other clinical isolates of C bertholletiae, were determined for amphotericin B, flucytosine, and miconazole using a standardized agar dilution technique. All isolates were found to be susceptible to miconazole, but resistant to flucytosine and amphotericin B.

Bacterial counts of "soul foods" obtained from 10 farm families and 10 supermarkets were determined. Total plate count means for farm family vegetables ranged from 1.5 × 10 6 /g to 2.9 × 10 6 /g, and 2.0 × 10 2 /g to 3.1 × 10 5 /g for vegetables purchased at the retail sales establishments. Pig offal samples with the highest total plate counts were pigtails, 4.8 × 10 8 /g and maws, 4.5 × 10 8 /g from farm families; and pigtails, 2.8 × 10 9 /g, neck bones, 2.4 × 10 9 /g from the retail sources. Fecal coliforms were not detected in any of the vegetable samples but were isolated from 24% of the pig offals. Sixty percent of all of the foods were positive for Salmonella and 96% were positive for coagulase-positive Staphylococcus aureus . Clostridium perfringens was only detected in one sample, chitterlings from a retail source.

Carbon and nitrogen assimilation for 50 yeasts isolated from White Riesling fermentation were tested by using a disk inoculum-solid medium method. This method was quicker and gave results comparable to the conventional liquid medium methods. Yeast characteristics (growth response, pigment production, morphology) could also be compared with this method.

Microbial counts of several laboratory-prepared defatted egg products and ingredients were determined. Commercial full-fat egg yolks (EY) were defatted with hexane, air dried overnight, mixed with water, homogenized, pasteurized (60°C, 5 min), and spray dried to yield a defatted egg yolk product (DEY). Egg products for scrambling (EPS) were formulated with DEY and other ingredients, processed as above, and held wet (EPS-W) or spray-dried (EPS-SD). On a dry matter basis, the log counts in colony forming units per g (log CFU/g) of EY for aerobic bacteria, yeasts and molds, and aerobic mesophilic sporeformers were low at 1.3, 1.0 and 0, respectively. For DEY these counts were 6.0, 2.4, and 4.3, respectively. These counts for DEY after pasteurization decreased by 98.6, 89.6, and 40.0%, and after spray drying decreased by 99.3, 96.1, and 83.5%, respectively, compared to the pre-pasteurization counts. For EPS-W, pasteurization reduced aerobic bacteria, yeasts and molds, and coliforms by 82.0, 86.7, and 98.7%, but did not reduce aerobic mesophilic sporeformers. Compared to pre pasteurization counts, for EPS-SD the aerobic bacteria, yeasts and molds, coliforms, and aerobic mesophilic sporeformer counts after pasteurization decreased by 99.7, 91.9, 99.3, and 50.0%, while after spray drying the count reductions were 99.9, 98.9, 99.9, and 85.8%, respectively. Microbial counts of finished products were below guidelines set by the U.S.D.A. for egg products. No Salmonella were detected in any of the ingredients or prototype products at any stage of processing. The combination treatment of pasteurization followed by spray drying significantly reduced the spore counts of DEY and EPS-SD, compared to pre-pasteurization counts.

Batch cultures of Shigella flexneri M4243 were grown at 37 degrees C in broth to early stationary phase, washed, and heated at 50 degrees C in 0.1 M phosphate buffer (pH 7.0). Cells were surface plated on a tryptic phytone glucose agar (TPGA), TPGA with 0.15 or 0.85% bile salts no. 3 (TPGA-BS 0.15 or TPGA-BS 0.85), or TPGA with 0.25 or 0.50% sodium deoxycholate (TPGA-DC 0.25 or TPGA-DC 0.50). Cells sampled after no heating produced colony counts on TPGA-BS 0.85 or on TPGA-DC 0.50 that were no more than about 0.5 log lower than for unheated cell samples plated on TPGA. Cells heated at 50 degrees C for 30 min produced colony counts on TPGA-DC 0.50 or on TPGA-BS 0.85 that were about 1.5 logs lower than on TPGA. Cells heated for 30 min and shifted to TPG broth at 37 degrees C to allow resuscitation required about 2 h to regain tolerance to 0.85% BS. However, heated cells resuscitated on solid TPGA at 35 degrees C before being challenged with overlays of TPGA-BS 0.85 or TPGA-DC 0.50 required 6 to 8 h on TPGA to regain tolerance to 0.85% BS or 0.50% DC. To regain tolerance to overlays of 0.15% BS or 0.25% DC, heated cells required resuscitation periods on TPGA of about 2 or 2 to 6 h, respectively. Cells heated in TPG broth and sampled after no heating produced colony counts on TPGA that were about 1.5 logs lower than for unheated cell suspensions, suggesting greater apparent injury when heat stressed in broth than in buffer.(ABSTRACT TRUNCATED AT 250 WORDS)

Listeria Selective Isolation Agar (LSI) and Modified Acriflavin Ceftazidime Esculin Agar (MACE) were compared to McBride Listeria Agar minus Blood (MLA-B) for ability to recover Listeria monocytogenes Scott A cells inoculated into commercial yogurt, pH 4.1, Yogurt was stored at 5 degrees C and sampled periodically over a 12 day period. LSI, MACE and MLA-B inhibited the growth of the two yogurt organisms but LSI and MACE gave better inhibition of other separately tested Gram-positive bacteria likely to be present in other fermented foods. Acid-stressed Listeria monocytogenes Scott A cells were optimally recovered by enrichment at 5 degrees C for 5-18 days in 0.1 M phosphate buffer, pH 7.2, followed by transfer to tryptic soy broth +0.5% yeast extract at 30 degrees C for 2 days. At low inoculum levels (10(2) cells/g yogurt), they were not detectable by direct plating or enrichment of yogurt after day 0. At high inoculum levels (10(7) cells/g yogurt), they were detectable up to day 6 but not at day 9 by direct plating on MLA-B, LSI or MACE with log counts per gram of yogurt being about 10 fold higher on LSI than on MACE or MLA-B. The above enrichment procedure permitted recovery on MLA-B, LSI, or MACE of viable Listeria cells from the day 9 samples found negative by direct plating.

Airborne Aspergillus flavus spores were rarely detected throughout the 1975 growing season by the agar plate method at cornfield sites in Georgia, Illinois, Maryland, South Carolina, and Virginia.

The construction and operation of a relatively inexpensive cabinet for sausage fermentation studies is described. Temperature can be controlled to +/-1 C with a relative humidity of approximately 95%.

Mass screening of the general population with the stool blood test is a costly means of increasing the incidence of colorectal cancer identification; however, the test is worthwhile as a screening tool in patients at risk. We found the incidence of positive results to increase with age, as does the risk of colorectal cancer. Further efforts to increase the incidence of colorectal cancer detection should be directed toward increasing the awareness of primary care physicians and improving their screening practices. We stress that high-risk populations should be given special attention and the use of flexible proctosigmoidoscopes should be encouraged.

A simple, quantitative radial diffusion assay for staphylocoagulase in culture fluids, using microscope slides coated with a thin layer of agar containing plasma and fibrinogen, was developed. No prior purification of the enzyme was needed, and only small quantities, 7 microliter, were required for each test. This method is particularly suitable for objectively comparing the relative amounts of coagulase produced by different cultures of Staphylococcus aureus.

A genetic variant of bovine proinsulin has been isolated using preparative reverse-phase HPLC. The new proinsulin (bovine proinsulin II) differs from the known proinsulin (bovine proinsulin I) by a single amino acid residue at position C-48 in the connecting peptide. The amino acid replacement is a leucine substitution for proline. The two proinsulins were found in a ratio of approximately 9:1, proinsulin I: proinsulin II. No chemical or biological differences were observed for the two proinsulins other than their different elution times on reverse-phase HPLC.

Impaired beta-receptor function has been postulated as one factor contributing to airway hyperreactivity in asthmatic patients. Although numerous indirect studies have cast doubt on this theory, none of these previous investigations has been able to directly measure changes in beta-receptor number on intrapulmonary structures capable of affecting the physiologic changes seen in this disease state. To help clarify the intrapulmonary location of such changes, a model of allergic bronchoconstriction was prepared by sensitizing guinea pigs to ovalbumin intraperitoneally (ip) 2 wk prior to testing (Group S). A second group of animals was sensitized to ovalbumin, then 2 wk later partially desensitized (Group D) during a 4- to 6-wk period by repeated exposure to increasing doses of nebulized ovalbumin with epinephrine rescue. Control animals received ip administered and nebulized normal saline alone. Pulmonary function assessed by plethysmography revealed an increase in airway resistance to 294 +/- 42% (SE) of control in Group S (p less than 0.005) and a decrease in dynamic compliance to 76 +/- 8% of control in Group D and 39 +/- 10% of control in Group S (p less than 0.002) after exposure to nebulized ovalbumin. Using L-[3H] dihydroalprenolol ([3H] DHA), beta-receptors were autoradiographically localized and quantitated in lung sections from all 3 groups. Significant decreases (p less than 0.02) in 3H-DHA binding were noted in alveolar and conducting airway epithelium, and bronchiolar and vascular smooth muscle in ovalbumin-exposed animals.(ABSTRACT TRUNCATED AT 250 WORDS)

Drug analyses were performed on 200 blood samples that were taken for alcohol analysis from road users in Tasmania. Alcohol at a concentration of above 0.5 g was found in 75% of the samples, and other drugs were found in 17% of the samples. Cannabis was the most prevalent of these other drugs: it was detected in 6% of road users; benzodiazepine drugs were detected in 5% of road users; and barbiturate drugs were detected in 2% of road users. Alcohol was found in 50% and other drugs were found in 25%, of drivers, riders and pedestrians who were involved in road accidents that were serious enough to cause death or injury. In addition to alcohol, other drugs may be making a significant contribution to road accidents because all the drugs that were identified are capable of impairing psychomotor performance. Of particular concern is the prevalence of cannabis, which is an illegal drug, and barbiturate drugs, which are now prescribed rarely. A well-controlled study is required to quantitate the contribution of drugs other than alcohol to road accidents. In the meantime, drivers should be warned that drugs that depress the central nervous system can be expected to impair driving ability and to increase the risk of an accident.

Diameters of surface colonies of Pseudomonas fluorescens were observed to increase linearly with time at temperatures from 30 to 0 C.

The kinetics of the decline of populations of Salmonella typhimurium inoculated into freshly reconstituted dehydrated onion and garlic powders was studied. Measurable bactericidal activity was observed for onion and garlic concentrations of 1 and 5% (w/v), respectively, with maximal death rates occurring for concentrations of 5 and 10%. At these concentrations, the decimal reduction times were 1.1 and 1.2 hr, respectively, for resting cell cultures and 1.8 and 2.1 hr, respectively, for growing cultures. Of the major volatile aliphatic disulfide compounds of onions, n-propyl allyl and di-n-propyl, at concentrations of 0.1%, showed a comparable activity against resting cells but only a bacteriostatic effect toward actively growing cultures, which overcame this effect in 2 to 6 hr. At comparable concentrations, growing cultures of Escherichia coli were as susceptible to garlic, but apparently more resistant to onion, than were those of S. typhimurium.