Fate of Listeria monocytogenes during freezing, thawing and home storage of frankfurters

Little information is available regarding the fate of Listeria monocytogenes during freezing, thawing and home storage of frankfurters even though recent surveys show that consumers regularly store unopened packages in home freezers. This study examined the effects of antimicrobials, refrigerated storage, freezing, thawing method, and post-thawing storage (7 degrees C) on L. monocytogenes on frankfurters. Inoculated (2.1 log CFU/cm(2)) frankfurters formulated without (control) or with antimicrobials (1.5% potassium lactate plus 0.1% sodium diacetate) were vacuum-packaged, stored at 4 degrees C for 6 or 30 d and then frozen (-15 degrees C) for 10, 30, or 50 d. Packages were thawed under refrigeration (7 degrees C, 24 h), on a countertop (23 +/- 2 degrees C, 8 h), or in a microwave oven (2450 MHz, 1100 watts, 220 s followed by 120 s holding), and then stored aerobically (7 degrees C) for 14 d. Bacterial populations were enumerated on PALCAM agar and tryptic soy agar plus 0.6% yeast extract. Antimicrobials completely inhibited (p < 0.05) growth of L. monocytogenes at 4 degrees C for 30 d under vacuum-packaged conditions, and during post-thawing aerobic storage at 7 degrees C for 14 d. Different intervals between inoculation and freezing (6 or 30 d) resulted in different pathogen levels on control frankfurters (2.1 or 3.9 log CFU/cm(2), respectively), while freezing reduced counts by <1.0 log CFU/cm(2). Thawing treatments had little effect on L. monocytogenes populations (<0.5 log CFU/cm(2)), and post-thawing fate of L. monocytogenes was not influenced by freezing or by thawing method. Pathogen counts on control samples increased by 1.5 log CFU/cm(2) at d-7 of aerobic storage, and reached 5.6 log CFU/cm(2) at d-14. As indicated by these results, consumers should freeze frankfurters immediately after purchase, and discard frankfurters formulated without antimicrobials within 3 d of thawing and/or opening.

Evaluation of changes in Listeria monocytogenes populations on frankfurters at different stages from manufacturing to consumption

This study evaluated the fate of inoculated Listeria monocytogenes on frankfurters stored under conditions simulating those that may be encountered between manufacturing and consumption. Frankfurters with or without 1.5% potassium lactate and 0.1% sodium diacetate (PL/SD) were inoculated (1.8 +/- 0.1 log CFU/cm(2)) with a 10-strain composite of L. monocytogenes, vacuum-packaged, and stored under conditions simulating predistribution storage (24 h, 4 degrees C), temperature abuse during transportation (7 h, 7 degrees C followed by 7 h, 12 degrees C), and storage before purchase (60 d, 4 degrees C; SBP). At 0, 20, 40, and 60 d of SBP, samples were exposed to conditions simulating delivery from stores to homes or food establishments (3 h, 23 degrees C), and then opened or held vacuum-packaged at 4 or 7 degrees C for 14 d (SHF). Pathogen counts remained relatively constant on frankfurters with PL/SD regardless of product age and storage conditions; however, they increased on product without antimicrobials. In vacuum-packaged samples, during SHF at 4 degrees C, the pathogen grew faster (P < 0.05) on older product (20 d of SBP) compared to product that was fresh (0 d of SBP); a similar trend was observed in opened packages. At 7 degrees C, the fastest growth (0.35 +/- 0.02 log CFU/cm(2)/d) was observed on fresh product in opened packages; in vacuum-packages, growth rates on fresh and aged products were similar. By day 40 of SBP the pathogen reached high numbers and increased slowly or remained unchanged during SHF. This information may be valuable in L. monocytogenes risk assessments and in development of guidelines for storage of frankfurters between package opening and product consumption.

Control of Listeria monocytogenes on frankfurters with antimicrobials in the formulation and by dipping in organic acid solutions

The antilisterial activity of sodium lactate (SL) and sodium diacetate (SD) was evaluated in a frankfurter formulation and in combination with a dipping treatment into solutions of lactic acid or acetic acid after processing and inoculation. Pork frankfurters were formulated with 1.8% SL or 0.25% SD or combinations of 1.8% SL with 0.25 or 0.125% SD. After processing, frankfurters were inoculated (2 to 3 log CFU/cm2) with a 10-strain composite of Listeria monocytogenes and left undipped or were dipped (2 min) in 2.5% solutions of lactic acid or acetic acid (23 +/- 2 degrees C) before vacuum packaging and storage at 10 degrees C for 40 days. Total microbial populations and L. monocytogenes, lactic acid bacteria, and yeasts and molds were enumerated during storage. Sensory evaluations also were carried out on frankfurters treated and/or formulated with effective antimicrobials. The combination of 1.8% SL with 0.25% SD provided complete inhibition of L. monocytogenes growth throughout storage. Dipping in lactic acid or acetic acid reduced initial populations by 0.7 to 2.1 log CFU/cm2, but during storage (12 to 20 days), populations on dipped samples without antimicrobials in the formulation reached 5.5 to 7.9 log CFU/cm2. For samples containing single antimicrobials and dipped in lactic acid or acetic acid, L. monocytogenes growth was completely inhibited or reduced over 12 and 28 days, respectively, whereas final populations were lower (P < 0.05) than those in undipped samples of the same formulations. Bactericidal effects during storage (reductions of 0.6 to 1.0 log CFU/ cm2 over 28 to 40 days) were observed in frankfurters containing combinations of SL and SD that were dipped in organic acid solutions. Inclusion of antimicrobials in the formulation and/or dipping the product into organic acid solutions did not affect (P > 0.05) the flavor and overall acceptability of products compared with controls. The results of this study may be valuable to meat processors as they seek approaches for meeting new regulatory requirements in the United States.

Effect of simulated spray chilling with chemical solutions on acid-habituated and non-acid-habituated Escherichia coli O157:H7 cells attached to beef carcass tissue

Samples (10 by 20 by 2.5 cm) of beef carcass tissue were inoculated (10(4) to 10(5) CFU/cm2) with Escherichia coli O157: H7 that was either non-acid habituated (prepared by incubating at 15 degrees C for 48 h in inoculated filter-sterilized composite [1:1] of hot and cold water meat decontamination runoff fluids, pH 6.05) or acid habituated (prepared in inoculated water fluids mixed with filter-sterilized 2% lactic acid [LA] runoff fluids in a proportion of 1/99 [vol/vol], pH 4.12). The inoculated surfaces were exposed to conditions simulating carcass chilling (- 3 degrees C for 10 h followed by 38 h at 1 degree C). Treatments applied to samples (between 0 and 10 h) during chilling included the following: (i) no spraying (NT) or spraying (for 30 s every 30 min) with (ii) water, (iii) cetylpyridinium chloride (CPC; 0.1 or 0.5%), (iv) ammonium hydroxide (AH; 0.05%), (v) lactic acid (LA; 2%), (vi) acidified sodium chlorite (ASC; 0.12%), (vii) peroxyacetic acid (PAA; 0.02%), (viii) sodium hydroxide (SH; 0.01%), or (ix) sodium hypochlorite (SC; 0.005%) solutions of 4 degrees C. Samples were taken at 0, 10, 24, 36, and 48 h of the chilling process to determine changes in E. coli O157:H7 populations. Phase 1 tested water, SH, PAA, LA, and 0.5% CPC on meat inoculated with non-acid-habituated pathogen populations, whereas phase 2 tested water, SC, AH, ASC, LA, and 0.1% CPC on meat inoculated with acid- and non-acid-habituated populations. Reductions in non-acid-habituated E. coli O157:H7 populations from phase 1 increased in the order NT = water = SH < PAA < LA < CPC. Reductions from phase 2 for acid-habituated cells increased in the order NT = water = SC < ASC = LA = AH < CPC, whereas on non-acid-habituated cells the order observed was NT = water = SC < AH = ASC < LA < CPC. Previous acid habituation of E. coli O157:H7 inocula rendered the cells more resistant to the effects of spray chilling, especially with acid; however, the trend of reduction remained spray chilling with water = non-spray chilling < spray chilling with chemical solutions.

Thermal inactivation of susceptible and multiantimicrobial-resistant salmonella strains grown in the absence or presence of glucose

The heat resistance of susceptible and multiantimicrobial-resistant Salmonella strains grown to stationary phase in glucose-free tryptic soy broth supplemented with 0.6% yeast extract (TSBYE-G; nonadapted), in regular (0.25% glucose) TSBYE, or in TSBYE-G with 1.00% added glucose (TSBYE+G; acid adapted) was determined at 55, 57, 59, and 61 degrees C. Cultures were heated in sterile 0.1% buffered peptone water (50 microl) in heat-sealed capillary tubes immersed in a thermostatically controlled circulating-water bath. Decimal reduction times (D values) were calculated from survival curves having r(2) values of >0.90 as a means of comparing thermal tolerance among variables. D(59 degrees C) values increased (P < 0.05) from 0.50 to 0.58 to 0.66 min for TSBYE-G, TSBYE, and TSBYE+G cultures, respectively. D(61 degrees C) values of antimicrobial-susceptible Salmonella strains increased (P < 0.05) from 0.14 to 0.19 as the glucose concentration increased from 0.00 to 1.00%, respectively, while D(61 degrees C) values of multiantimicrobial-resistant Salmonella strains did not differ (P > 0.05) between TSBYE-G and TSBYE+G cultures. When averaged across glucose levels and temperatures, there were no differences (P > 0.05) between the D values of susceptible and multiantimicrobial-resistant inocula. Collectively, D values ranged from 4.23 to 5.39, 1.47 to 1.81, 0.50 to 0.66, and 0.16 to 0.20 min for Salmonella strains inactivated at 55, 57, 59, and 61 degrees C, respectively. z(D) values were 1.20, 1.48, and 1.49 degrees C for Salmonella strains grown in TSBYE+G, TSBYE, and TSBYE-G, respectively, while the corresponding activation energies of inactivation were 497, 493, and 494 kJ/mol. Study results suggested a cross-protective effect of acid adaptation on thermal inactivation but no association between antimicrobial susceptibility and the ability of salmonellae to survive heat stress.

Acid adaptation does not promote survival or growth of Listeria monocytogenes on fresh beef following acid and nonacid decontamination treatments

The objective of this study was to evaluate the survival and growth of acid-adapted and nonadapted Listeria monocytogenes inoculated onto fresh beef subsequently treated with acid or nonacid solutions. Beef slices (2.5 by 5 by 1 cm) from top rounds were inoculated with acid-adapted or nonadapted L. monocytogenes (4.6 to 5.0 log CFU/cm2) and either left untreated (control) or dipped for 30 s in water at 55 degrees C, water at 75 degrees C, 2% lactic acid at 55 degrees C, or 2% acetic acid at 55 degrees C. The beef slices were vacuum packaged and stored at 4 or 10 degrees C and were analyzed after 0, 7, 14, 21, and 28 days of storage. Dipping in 75 degrees C water, lactic acid, and acetic acid resulted in immediate pathogen reductions of 1.4 to 2.0, 1.8 to 2.6, and 1.4 to 2.4 log CFU/cm2, respectively. After storage at 10 degrees C for 28 days, populations of L. monocytogenes on meat treated with 55 degrees C water increased by ca. 1.6 to 1.8 log CFU/cm2. The pathogen remained at low population levels (1.6 to 2.8 log CFU/cm2) on acid-treated meat, whereas populations on meat treated with 75 degrees C water increased rapidly, reaching levels of 3.6 to 4.6 log CFU/cm2 by day 14. During storage at 4 degrees C, there was no growth of the pathogen for at least 21 days in samples treated with 55 and 75 degrees C water, and periods of no growth were longer for acid-treated samples. There were no differences between acid-adapted and nonadapted organisms across treatments with respect to survival or growth. In conclusion, the dipping of meat inoculated with L. monocytogenes into acid solutions reduced and then inhibited the growth of the pathogen during storage at 4 and 10 degrees C, while dipping in hot water allowed growth despite initial reductions in pathogen contamination. The results of this study indicate a residual activity of acid-based decontamination treatments compared with water-based treatments for refrigerated (4 degrees C) or temperature-abused (10 degrees C) lean beef tissue in vacuum packages, and these results also indicate that this activity may not be counteracted by prior acid adaptation of L. monocytogenes.

Comparative analysis of acid resistance between susceptible and multi-antimicrobial-resistant Salmonella strains cultured under stationary-phase acid tolerance-inducing and noninducing conditions

This study compared acid resistance levels among five antimicrobial-susceptible strains of Salmonella and five strains that were simultaneously resistant to a minimum of six antimicrobial agents. The induction of a stationary-phase acid tolerance response (ATR) was attempted by both transient low-pH acid shock and acid adaptation. For acid shock induction, strains were grown for 18 h in minimal E medium containing 0.4% glucose (EG medium) and exposed to sublethal acid stress (pH 4.3) for 2 h, and subsequently, both shocked and nonshocked cultures were acid challenged (pH 3.0) for 4 h. Acid adaptation was achieved by growing strains for 18 h in tryptic soy broth containing 1.0% glucose (TSB+G), while nonadapted cultures were grown for 18 h in glucose-free tryptic soy broth (TSB-G). Acid-adapted and nonadapted inocula were acid challenged (pH 2.3) for 4 h. Initial (0 h) mean populations of nonchallenged Salmonella were 8.5 to 8.7, 8.4 to 8.8, and 8.2 to 8.3 log CFU/ml for strains grown in EG medium, TSB-G, and TSB+G, respectively. After 4 h of acid challenge, mean populations were 3.0 to 4.8 and 2.5 to 3.7 log CFU/ml for previously acid-shocked susceptible and resistant strains, respectively, while corresponding counts for nonshocked strains were 4.3 to 5.5 log CFU/ml and 3.9 to 4.9 log CFU/ml. Following 4 h of acid exposure, acid-adapted cultures of susceptible and resistant strains had mean populations of 6.1 to 6.4 log CFU/ml and 6.4 to 6.6 log CFU/ml, respectively, while corresponding counts for nonadapted cultures were 1.9 to 2.1 log CFU/ml and 1.8 to 2.0 log CFU/ml, respectively. A low-pH-inducible ATR was not achieved through transient acid shock, while an ATR was evident following acid adaptation, as adapted populations were 4.2 to 4.8 log units larger than nonadapted populations following acid exposure. Although some strain-dependent variations in acid resistance were observed, results from this study suggest no association between susceptibility to antimicrobial agents and the ability of the Salmonella strains evaluated to survive low-pH stress.

Biofilm formation by acid-adapted and nonadapted Listeria monocytogenes in fresh beef decontamination washings and its subsequent inactivation with sanitizers

The antimicrobial effects of sodium hypochlorite (SH, 200 ppm, at an adjusted pH of 6.80 +/- 0.20 and at an unadjusted pH of 10.35 +/- 0.25), quaternary ammonium compound (pH 10.20 +/- 0.12, 200 ppm), and peroxyacetic acid (PAA, pH 3.45 +/- 0.20, 150 ppm) on previously acid-adapted or nonadapted Listeria monocytogenes inoculated (10(5) CFU/ml) into beef decontamination water washings were evaluated. The effects of the sanitizers on suspended cells (planktonic or deattached) and on cells attached to stainless steel coupons obtained from inoculated washings stored at 15 degrees C for up to 14 days were studied. Cells were exposed to sanitizers on days 2, 7, and 14. The pathogen had formed a biofilm of 5.3 log CFU/cm2 by day 2 of storage (which was reduced to 4.6 log CFU/cm2 by day 14), while the total microbial populations showed more extensive attachment (6.1 to 6.6 log CFU/cm2). The sanitizers were more effective in reducing populations of cells in suspension than in reducing populations of attached cells. Overall, there were no differences between previously acid-adapted and nonadapted L monocytogenes with regard to sensitivity to sanitizers. The total microbial biofilms were the most sensitive to all of the sanitizers on day 2, but their resistance increased during storage, and they were at their most resistant on day 14. Listeria monocytogenes displayed stronger resistance to the effects of the sanitizers on day 7 than on day 2 but had become sensitized to all sanitizers by day 14. SH at the adjusted pH (6.80) (ASH) was generally more effective in reducing bacterial populations than was SH at the unadjusted pH. PAA generally killed attached cells faster at 30 to 300 s of exposure than did the other sanitizers, except for ASH on day 2. PAA was more effective in killing attached cells than in killing cells treated in suspension, in contrast to the other sanitizers.

Exposure to non-acid fresh meat decontamination washing fluids sensitizes Escherichia coli O157:H7 to organic acids

AIMS

To investigate whether Escherichia coli O157:H7 maintains acid tolerance in water meat decontamination washing fluids.

METHODS AND RESULTS

A rifampicin-resistant derivative of E. coli O157:H7 strain ATCC 43895 was inoculated (10(5) cfu ml(-1)) in spray-washings from meat sprayed with cold (10 degrees C) or hot (85 degrees C) water, stored at 10 degrees C for up to 14 days, and its acid tolerance was assessed at 2 and 8 days by exposure to broth or new washings adjusted to pH 3.5 or 3.7 with lactic or acetic acid. The pathogen survived in the water washings, but it was outgrown by the natural, Pseudomonas-like flora, and it was sensitized to acid.

CONCLUSIONS

The acid tolerance of E. coli O157:H7 decreases following exposure to non-acid, but otherwise stressful, conditions prevailing in water meat washings at 10 degrees C.

SIGNIFICANCE AND IMPACT OF THE STUDY

These findings suggest that the more intense use of water-based technologies should be included in meat decontamination strategies because they may contribute to enhanced meat safety by inducing acid sensitization in E. coli O157:H7.

A prospective, physician self-reported adverse incident audit on a general medical unit

There is some evidence that physician self-reporting is an efficient and effective way of collecting data on adverse incidents in health care. This study tested a simple prospective adverse incident audit, self-reported by physicians, on a general medical unit. A total of 158 reports were collected over a 6-month period covering a wide range of quality issues, including, but not limited to, safety issues. One-third of reported incidents occurred within 48 h of hospitalization. One-half of incidents were associated with harm or inconvenience to patients. Reported incidents fell into easily classifiable groups, and the data was used as a platform for a coordinated approach to quality improvement within the department. It is concluded that this technique is an easily implementable addition to the more traditional methods used for quality improvement within general medicine.

Ascorbic acid enhances destruction of Escherichia coli O157:H7 during home-type drying of apple slices

Destruction of Escherichia coli O157:H7 was evaluated on inoculated apple slices dehydrated at two temperatures with and without application of predrying treatments. Half-ring slices (0.6 cm thick) of peeled and cored Gala apples were inoculated by immersion for 30 min in a four-strain composite inoculum of E. coli O157:H7. The inoculated slices (8.7 to 9.4 log CFU/g) either received no predrying treatment (control), were soaked for 15 min in a 3.4% ascorbic acid solution, or were steam blanched for 3 min at 88 degrees C immediately prior to drying at 57.2 or 62.8 degrees C for up to 6 h. Samples were plated on tryptic soy (TSA) and sorbitol MacConkey (SMAC) agar media for direct enumeration of surviving bacterial populations. Steam blanching changed initial inoculation levels by +0.3 to -0.7 log CFU/g, while immersion in the ascorbic acid solution reduced the inoculation levels by 1.4 to 1.6 log CFU/g. Dehydration of control samples for 6 h reduced mean bacterial populations by 2.9 log CFU/g (TSA or SMAC) at 57.2 degrees C and by 3.3 (SMAC) and 3.5 (TSA) log CFU/g at 62.8 degrees C. Mean decreases from initial inoculum levels for steam-blanched slices after 6 h of drying were 2.1 (SMAC) and 2.0 (TSA) log CFU/g at 57.2 degrees C, and 3.6 (TSA or SMAC) log CFU/g at 62.8 degrees C. In contrast, initial bacterial populations on ascorbic acid-pretreated apple slices declined by 5.0 (SMAC) and 5.1 (TSA) log CFU/g after 3 h of dehydration at 57.2 degrees C, and by 7.3 (SMAC) and 6.9 (TSA) log CFU/g after 3 h at 62.8 degrees C. Reductions on slices treated with ascorbic acid were in the range of 8.0 to 8.3 log CFU/g after 6 h of drying, irrespective of drying temperature or agar medium used. The results of immersing apple slices in a 3.4% ascorbic acid solution for 15 min prior to drying indicate that a predrying treatment enhances the destruction of E. coli O157:H7 on home-dried apple products.

Fate of Escherichia coli O157:H7, Salmonella typhimurium DT 104, and Listeria monocytogenes in fresh meat decontamination fluids at 4 and 10 degrees C

Bacterial pathogens may colonize meat plants and increase food safety risks following survival, stress hardening, or proliferation in meat decontamination fluids (washings). The objective of this study was to evaluate the ability of Escherichia coli O157:H7, Salmonella Typhimurium DT 104, and Listeria monocytogenes to survive or grow in spray-washing fluids from fresh beef top rounds sprayed with water (10 or 85 degrees C) or acid solutions (2% lactic or acetic acid, 55 degrees C) during storage of the washings at 4 or 10 degrees C in air to simulate plant conditions. Inoculated Salmonella Typhimurium DT 104 (5.4 +/- 0.1 log CFU/ml) died off in lactate (pH 2.4 +/- 0.1) and acetate (pH 3.1 +/- 0.2) washings by 2 days at either storage temperature. In contrast, inoculated E. coli O157:H7 (5.2 +/- 0.1 log CFU/ml) and L. monocytogenes (5.4 +/- 0.1 log CFU/ml) survived in lactate washings for at least 2 days and in acetate washings for at least 7 and 4 days, respectively; their survival was better in acidic washings stored at 4 degrees C than at 10 degrees C. All inoculated pathogens survived in nonacid (pH > 6.0) washings, but their fate was different. E. coli O157:H7 did not grow at either temperature in water washings, whereas Salmonella Typhimurium DT 104 failed to multiply at 4 degrees C but increased by approximately 2 logs at 10 degrees C. L. monocytogenes multiplied (0.6 to 1.3 logs) at both temperatures in water washings. These results indicated that bacterial pathogens may survive for several days in acidic, and proliferate in water, washings of meat, serving as potential cross-contamination sources, if pathogen niches are established in the plant. The responses of surviving pathogens in meat decontamination waste fluids to acid or other stresses need to be addressed to better evaluate potential food safety risks.

Influence of the natural microbial flora on the acid tolerance response of Listeria monocytogenes in a model system of fresh meat decontamination fluids

Depending on its composition and metabolic activity, the natural flora that may be established in a meat plant environment can affect the survival, growth, and acid tolerance response (ATR) of bacterial pathogens present in the same niche. To investigate this hypothesis, changes in populations and ATR of inoculated (10(5) CFU/ml) Listeria monocytogenes were evaluated at 35 degrees C in water (10 or 85 degrees C) or acidic (2% lactic or acetic acid) washings of beef with or without prior filter sterilization. The model experiments were performed at 35 degrees C rather than lower (8.0 log CFU/ml) by day 1. The pH of inoculated water washings decreased or increased depending on absence or presence of natural flora, respectively. These microbial and pH changes modulated the ATR of L. monocytogenes at 35 degrees C. In filter-sterilized water washings, inoculated L. monocytogenes increased its ATR by at least 1.0 log CFU/ml from days 1 to 8, while in unfiltered water washings the pathogen was acid tolerant at day 1 (0.3 to 1.4 log CFU/ml reduction) and became acid sensitive (3.0 to >5.0 log CFU/ml reduction) at day 8. These results suggest that the predominant gram-negative flora of an aerobic fresh meat plant environment may sensitize bacterial pathogens to acid.

Food safety education: what should we be teaching to consumers?

Food safety education is most effective when messages are targeted toward changing behaviors most likely to result in foodborne illness. The five major control factors for pathogens are personal hygiene, adequate cooking, avoiding cross-contamination, keeping food at safe temperatures, and avoiding foods from unsafe sources. Pathogens associated with poor personal hygiene have the highest incidence and costs. Inadequate cooking and cross-contamination have lower incidence. Keeping food at safe temperatures and unsafe food sources have the lowest incidence, although costs per case are sometimes very high. We recommend that consumer food safety educators primarily focus on hand washing, adequate cooking, and avoiding cross-contamination. Secondary messages should focus on keeping food at safe temperatures and avoiding food from an unsafe source. Evaluation tools are needed to evaluate self-reported behavior changes. The evaluation questions must focus on salient behaviors that are most likely to result in foodborne illnesses and must withstand rigorous standards of reliability and validity.

Expanded health belief model predicts diabetes self-management in college students

An instrument was designed to determine relationships between constructs of the Expanded Health Belief Model and to identify characteristics of college students who successfully manage their diabetes. The Diabetes College Scale was developed to measure attitudes and behaviors pertinent to diabetes management and college life. It was tested for content validity, test-retest reliability, and internal consistency. Data were collected from college students using a cross-sectional design. Campus health care providers were invited via electronic mail to administer the survey to students with Type I diabetes. Ninety-eight questionnaires were mailed to interested providers, of which 86 (88%) were returned. Mean scores for attitude constructs, seven behaviors, and two outcomes were measured. Twenty-six experts established content validity. Instrument reliability was evaluated using paired t-tests, Cronbach's alpha, and correlation coefficients. Correlation coefficients and stepwise multiple regression analysis evaluated relationships among variables measured. Intention and emotional response were strong predictors of exercise, whereas health importance and intention were predictive of testing blood sugar. Situational factors and emotional response were substantial barriers to optimal diabetes self-care. College health care providers should address these areas in providing services to this population. Additional testing of the instrument is also recommended.

Development and evaluation of an intervention program: "Control on Campus"

PURPOSE

This study was designed to develop and test an intervention for college students with type 1 diabetes.

METHODS

A diabetes program, "Control on Campus," and guide were developed based on the Expanded Health Belief Model and Social Learning Theory. Diabetes knowledge, attitudes, and behaviors were assessed preprogram, postprogram, and at follow-up for 3 intervention cohorts and a control group.

RESULTS

Reporting of HbA1c values and diabetes knowledge improved significantly as a result of the intervention compared with no increase in the control group. Furthermore, participants reported feeling more support on campus after the intervention, appeared to have overcome their fears associated with testing their blood glucose, reported an increased frequency of blood glucose testing, and were more likely to test when they felt their blood glucose level was low.

CONCLUSIONS

Overall, this research yielded substantial insight into the characteristics of college students with diabetes and was successful in designing and evaluating an intervention trial for this population.

College students with diabetes: using focus groups and interviews to determine psychosocial issues and barriers to control

College students with diabetes are at risk for improvised diabetes care due to their age, newly acquired independence, and erratic schedules. The purpose of this study was to employ focus groups and interviews to identity factors that affect the ability of these students to engage in appropriate self-care behaviors. Focus group and interview questions were developed to address variables of the Expanded Health Belief Model. Two focus groups and fifteen interviews were conducted. Barriers to successful diabetes management were time management, stress hypoglycemic reactions, diet management constraints, and inadequate finances. Several psychosocial issues that affected successful management also were identified. These issues were grouped into three categories: (1) inconveniences of diabetes management, (2) motivators to managing diabetes, and (3) social support issues. The findings show the value of formative evaluation that can then be used to design diabetes education programs to meet clients' perceived needs.

Severe falciparum malaria with hyperparasitaemia treated with intravenous artesunate

We report a 57-year-old man with falciparum malaria contracted in Kenya who presented with a three-day history of symptoms. Despite prompt treatment with quinine and artesunate and rapid clearing of the parasitaemia, he developed multiple complications and died 28 days after presentation. This case illustrates the potential for malaria to be fatal despite appropriate treatment and is one of the first reports of the use of artesunate in a hospital in a developed country.

Consumer concerns about modern technology in agriculture: considerations for undergraduate and graduate teaching

A number of events over the last several decades have sensitized society to the possible negative impacts of technology. The majority of our population is one or more generations removed from direct experience on farms and ranches. Thus, few individuals are aware of the dramatic changes that have occurred in agriculture. Since the establishment of the land-grant university system, agriculture in the United States has changed from a system employing 10 million farmers and farm workers each feeding five people to a system in which 2.1 million farmers feed more than 100 people each and support exports of more than $35 billion annually. There are perceptions, as well as survey data, indicating society is concerned about the use and impacts of technology in the food and agriculture system. Survey data indicate 87% of people disagreed that "economic growth is more important than environmental protection." In addition, the survey data indicate society is concerned about how technology is used and who decides which applications are to be pursued. More than 8 out of 10 people (85%) surveyed believed "citizens deserve a greater role in decisions about science and technology." There seems to be concern regarding the use of technology and resultant impacts on the environment, food safety, animal well-being, and the size and numbers of farms in the United States. Education, both formal and informal, is the key to helping the public make informed decisions regarding the role of science and technology in the food and agriculture system. The colleges of agriculture need to carefully evaluate their research, teaching, and extension portfolios to "rediscover" their mission.(ABSTRACT TRUNCATED AT 250 WORDS)

Asthma knowledge in hospital patients with acute severe asthma

OBJECTIVES

To assess patient knowledge about asthma management and to assess the risk of asthma-associated morbidity in patients admitted to hospital with acute severe asthma.

SUBJECTS AND SETTING

Patients admitted to Fremantle Hospital with a primary diagnosis of acute severe asthma from July to September 1992.

RESULTS

Bronchodilator therapy has been used for more than 12 months by all 25 previously diagnosed asthmatics, with 88% knowing that the drug was a bronchodilator. Corticosteroid therapy had been used by 84% of patients but only 52% of these knew that it was anti-inflammatory or "preventive" medication. Sixty per cent of patients did not recall seeing National Asthma Campaign advertisements. Twenty-three patients (88%) were classified as being at high risk of morbidity.

CONCLUSIONS

The level of knowledge about asthma management in patients admitted to this hospital is poor. Most patients are at high risk of asthma-associated morbidity.

Effects of stage of the cycle and estradiol-17 beta on oxytocin synthesis by ovine granulosa and luteal cells

Individual ovine follicles or corpora lutea (CL) were obtained at different stages of the estrous cycle to compare the pattern of oxytocin synthesis with time in vitro. Granulosa cells from follicles in the early follicular phase produced minimal amounts of oxytocin whereas output from preovulatory (post LH surge) follicles increased to a peak of 540 pg/10(4) cells.24 h on days 4-7 in vitro declining to 180 pg/10(4) cells.24 h by day 11. Production from day 1 CL was also high, peaking at 1639 pg/10(4) cells.24 h. In contrast the capacity for oxytocin synthesis by day 2 CL had already declined, with peak output reaching only 185 pg/10(4) cells.24 h on days 3-4. Day 9 CL produced small amounts of oxytocin (50 pg/10(4) cells in the first 24 h) followed by a low output thereafter. The effect of estradiol-17 beta (E2 beta) on oxytocin synthesis was examined. The results were dependent on the stage of the cycle at which the cells were obtained. Oxytocin production was significantly stimulated in three and inhibited in four out of nine preovulatory follicles by the addition of 50 or 500 ng/ml E2 beta, whereas in days 1 and 2 CL E2 beta consistently inhibited oxytocin synthesis and in day 9 CL no response was found. These data indicate that the ovarian capacity to synthesize oxytocin varies markedly at different stages of the cycle, and that cells obtained close to ovulation do not experience the rapid down-regulation in oxytocin synthesis which occurs in vivo in the early luteal phase. E2 beta may switch from having a stimulatory to an inhibitory action on oxytocin synthesis shortly before ovulation.

Educating patients with diabetes: comparison of nutrient-based and exchange group methods

This study compared the effectiveness of a nutrient-based (diet guide) approach with that of a food-group (exchange lists) approach to menu planning for persons with noninsulin-dependent diabetes. Each method was presented to four groups in three-session workshops emphasizing meal planning to reduce risk of heart disease. The diet guide method evaluated menus specifically for calories, source of calories, cholesterol, fiber, sodium, and key vitamins and minerals. Of 105 subjects recruited, 97 completed the workshops and 83 the 6-month follow-up. Subjects responded positively to the diet guide method, finding it as easy to use as the exchange lists method. Menu planning and evaluation initially took longer using the diet guide than the exchange group method (25 vs. 16 minutes per day), but subjects indicated that time was well spent. Also, with practice, the time required to use the diet guide method decreased to 17 minutes per day. Both diet-education programs improved attitude and knowledge regarding diabetes, diet, and nutrition, with retention of knowledge gained for up to 6 months. Increases in applied nutrition knowledge scores were significantly greater, however, for diet guide than for exchange lists subjects both 3 months (24% vs. 15% increase) and 6 months postworkshop (15% vs. 8% increase). We conclude that the diet guide method can effectively serve as an alternative menu-planning system to exchange lists for patients with noninsulin-dependent diabetes who have at least a high school education.

A comparison of nutrient-based and exchange-group methods of diet instruction for patients with noninsulin-dependent diabetes

This study compared effectiveness of nutrient-based (Diet Guide) vs food-group (Exchange Lists) methods of diabetic diet evaluation in improving dietary compliance, glycemic control, and biochemical indicators of heart disease risk. Eighty-three persons with noninsulin-dependent diabetes were taught one of two diet-planning methods in a 3-session workshop. Both methods led to reductions in energy intake and percent of calories from fat and saturated fatty acids in 6 mo postworkshop. Reductions in fat intake were greater and more long lasting for persons using Diet Guide than using Exchange Lists method of diet planning. Despite dietary changes, neither diet-planning method led to significant decreases in weight or skinfold thickness. Few differences were seen in clinical measurements pre- and 6 mo postworkshop. Total and LDL cholesterol values were lower than preworkshop values for men in both groups. Suggestions are given for improving effectiveness of both diet-planning methods.

Gangrenous colitis in the haemolytic-uraemic syndrome

The cases of two children with the haemolytic-uraemic syndrome (HUS) in whom clinical signs of intussusception necessitated emergency surgical intervention are reported. Both patients had bilateral renal cortical necrosis and haemorrhagic gangrenous colitis; both subsequently died. The early recognition and appropriate management of HUS is advocated.

The effect of thiol compounds on lymphocytes stimulated in culture

The effect was studied of D-penicillamine (D-PAm) and other thiol compounds (concentration range, approximately 10(-4)-3.4 X 10(-3) M) on mouse spleen cells, stimulated in culture by concanavalin A or by mixed lymphocyte interaction. Thiols initially enhanced the rate of incorporation of [3H] thymidine into DNA of these cells. The enhanecment was typically followed by a sharp decline in activity to a level often below that of thiol-free cultures. The time which elapsed between adding the thiol and the decline in activity depended on the concentration of the particular thiol used. Exceptional among thiols studied was L-cysteine, which lacked inhibitory properties. Variation of the L-cystine content of the medium used here influenced the effect of thiols such as D-PAm on the cells, an increase in cystine content favouring the retention of high activity. It was found that D-PAm reacted slowly with a constituent of the culture medium, causing the latter eventually to lose its capacity to maintain cells. The effects of this reaction could be counteracted by adding L-cystine, L-cysteine, and certain other thiol compounds. It was concluded that DPAm combined with L-cystine in the medium to form the mixed disulphide, which evidently could not be utilized by the cells as a source of L-cystine. Deprivation of this essential nutrient accounted for the eventual inhibition of [3H] thymidine incorporation in cultures exposed to thiols. The initial, enhancing effect of thiols on stimulated lymphocytes represented a modulation of the response to the primary stimulant: there was no evidence that thiols were themselves mitogenic.