The ability of spore formers to degrade milk proteins, fat, phospholipids, common stabilizers, and exopolysaccharides.

Spore formers are common spoilage-causing microorganisms in dairy products; however, their modes of spoilage (proteolysis, lipolysis, etc.) have not been described in detail for cultured dairy products such as sour cream and yogurt. The objective of the present study was to test the ability of spore-forming strains isolated from dairy environments for their spoilage-causing activities at typical sour cream (24°C) and yogurt (42°C) fermentation temperatures. A total of 25 spore-forming strains were isolated from different sources, including raw milk, pasteurizer balance tank, biofilms formed on heat exchangers, and milk powder. These strains were tested for proteolytic and lipolytic activities and for their ability to degrade phospholipids, common stabilizers (starch, gelatin, xanthan gum, pectin), and exopolysaccharides (EPS) at sour cream and yogurt fermentation temperatures. A higher percentage of positive strains was observed for selected activities at yogurt fermentation temperature compared with sour cream fermentation temperature. Identified proteolytic spore-forming strains, based on a skim milk agar method, were subsequently quantified for their level of proteolysis using non-casein nitrogen (NCN) content and sodium dodecyl sulfate-PAGE (SDS-PAGE). The proteolytic strains that showed the highest levels of proteolysis (highest percentages of NCN content) at 24°C were Bacillus mojavensis BC, Bacillus cereus DBC, Bacillus subtilis DBC, B. mojavensis DBC1, and Paenibacillus polymyxa DBC1. At 42°C the strains with the highest levels of proteolysis (highest percentages of NCN content) were B. subtilis DBC, B. mojavensis BC, B. mojavensis DBC1, B. cereus DBC, and Bacillus licheniformis DBC6. Results of SDS-PAGE demonstrated that proteolytic strains had primarily hydrolyzed ß- and κ-CN. A viscometric method was used to evaluate the susceptibility of exopolysaccharides (EPS) to degradation by selected spore formers. This method helped to determine that EPS produced by commercial yogurt and sour cream cultures is susceptible to degradation by spore formers present in dairy environments.

Invited review: anaerobic fermentation of dairy food wastewater.

Dairy food wastewater disposal represents a major environmental problem. This review discusses microorganisms associated with anaerobic digestion of dairy food wastewater, biochemistry of the process, factors affecting anaerobic digestion, and efforts to develop defined cultures. Anaerobic digestion of dairy food wastewater offers many advantages over other treatments in that a high level of waste stabilization is achieved with much lower levels of sludge. In addition, the process produces readily usable methane with low nutrient requirements and no oxygen. Anaerobic digestion is a series of complex reactions that broadly involve 2 groups of anaerobic or facultative anaerobic microorganisms: acidogens and methanogens. The first group of microorganisms breaks down organic compounds into CO(2) and volatile fatty acids. Some of these organisms are acetogenic, which convert long-chain fatty acids to acetate, CO(2), and hydrogen. Methanogens convert the acidogens' products to methane. The imbalance among the different microbial groups can lead not only to less methane production, but also to process failure. This is due to accumulation of intermediate compounds, such as volatile fatty acids, that inhibit methanogens. The criteria used for evaluation of the anaerobic digestion include levels of hydrogen and volatile fatty acids, methane:carbon ratio, and the gas production rate. A steady state is achieved in an anaerobic digester when the pH, chemical oxygen demand of the effluent, the suspended solids of the effluent, and the daily gas production remain constant. Factors affecting efficiency and stability of the process are types of microorganisms, feed C:N ratio, hydraulic retention time, reactor design, temperature, pH control, hydrogen pressure, and additives such as manure and surfactants. As anaerobic digesters become increasingly used in dairy plants, more research should be directed toward selecting the best cultures that maximize methane production from dairy food waste.

Flavor profiles of full-fat and reduced-fat cheese and cheese fat made from aged Cheddar with the fat removed using a novel process.

Many consumers are concerned with fat intake. However, many reduced-fat foods, including reduced-fat cheese, lack robust flavors. The objectives of this study were to characterize the flavors found in full-fat cheese, cheese fat, and reduced-fat cheese made from aged Cheddar using a novel process to remove the fat (Nelson and Barbano, 2004). Two full-fat, aged cheeses (9 and 39 mo) were selected, and the fat was removed using the novel fat removal process. Full-fat cheeses, shredded and reformed full-fat cheeses, corresponding reduced-fat cheeses, and cheese fats were then analyzed using descriptive sensory and instrumental analysis followed by consumer acceptance testing. Cheeses were extracted with diethyl ether followed by isolation of volatile material by high vacuum distillation. Volatile extracts were analyzed using gas chromatography/ olfactometry with aroma extract dilution analysis. Selected compounds were quantified. The 39-mo cheese was characterized by fruity and sulfur notes, and the 9-mo-old cheese was characterized by a spicy/brothy flavor. Reduced-fat cheeses had similar flavor profiles with no difference in most sensory attributes to corresponding full-fat cheeses. Sensory profiles of the cheese fats were characterized by low intensities of the prominent flavors found in the full-fat cheeses. Instrumental analysis revealed similar trends. Consistent with sensory analysis, there were lower concentrations and log(3) flavor dilution factors for most compounds in the cheese fats compared with both the reduced- and full-fat cheeses, regardless of compound polarity. Consumers found the intensity of flavor in the reduced-fat cheese to be equal to the full-fat cheeses. This study demonstrated that when fat was removed from aged full-fat Cheddar cheese, most of the flavor and flavor compounds remained in the cheese and were not removed with the fat.

Yield and aging of Cheddar cheeses manufactured from milks with different milk serum protein contents.

Whey proteins in general and specifically beta-lactoglobulin, alpha-lactalbumin, and immunoglobulins have been thought to decrease proteolysis in cheeses manufactured from concentrated retentates from ultrafiltration. The proteins found in whey are called whey proteins and are called milk serum proteins (SP) when they are in milk. The experiment included 3 treatments; low milk SP (0.18%), control (0.52%), and high milk SP (0.63%), and was replicated 3 times. The standardized milk for cheese making of the low milk SP treatment contained more casein as a percentage of true protein and more calcium as a percentage of crude protein, whereas the nonprotein nitrogen and total calcium content was not different from the control and high SP treatments. The nonprotein nitrogen and total calcium content of the milks did not differ because of the process used to remove the milk SP from skim milk. The low milk SP milk contained less free fatty acids (FFA) than the control and high milk SP treatment; however, no differences in FFA content of the cheeses was detected. Approximately 40 to 45% of the FFA found in the milk before cheese making was lost into the whey during cheese making. Decreasing the milk SP content of milk by 65% and increasing the content by 21% did not significantly influence general Cheddar cheese composition. Higher fat recovery and cheese yield were detected in the low milk SP treatment cheeses. There was more proteolysis in the low milk SP cheese and this may be due to the lower concentration of undenatured beta-lactoglobulin, alpha-lactalbumin, and other high molecular weight SP retained in the cheeses made from milk with low milk SP content.

A microfiltration process to maximize removal of serum proteins from skim milk before cheese making.

Microfiltration (MF) is a membrane process that can separate casein micelles from milk serum proteins (SP), mainly beta-lactoglobulin and alpha-lactalbumin. Our objective was to develop a multistage MF process to remove a high percentage of SP from skim milk while producing a low concentration factor retentate from microfiltration (RMF) with concentrations of soluble minerals, nonprotein nitrogen (NPN), and lactose similar to the original skim milk. The RMF could be blended with cream to standardize milk for traditional Cheddar cheese making. Permeate from ultrafiltration (PUF) obtained from the ultrafiltration (UF) of permeate from MF (PMF) of skim milk was successfully used as a diafiltrant to remove SP from skim milk before cheese making, while maintaining the concentration of lactose, NPN, and nonmicellar calcium. About 95% of the SP originally in skim milk was removed by combining one 3 x MF stage and two 3 x PUF diafiltration stages. The final 3 x RMF can be diluted with PUF to the desired concentration of casein for traditional cheese making. The PMF from the skim milk was concentrated in a UF system to yield an SP concentrate with protein content similar to a whey protein concentrate, but without residuals from cheese making (i.e., rennet, culture, color, and lactic acid) that can produce undesirable functional and sensory characteristics in whey products. Additional processing steps to this 3-stage MF process for SP removal are discussed to produce an MF skim retentate for a continuous cottage cheese manufacturing process.

Impact of milk preacidification with CO2 on cheddar cheese composition and yield.

Preacidification of milk for cheese making may have a beneficial impact on increasing proteolysis during cheese aging. Unlike other acids, CO(2) can easily be removed from whey. The objectives of this work were to determine the effect of milk preacidification on Cheddar cheese composition, the recovery of individual milk components, and yield. Carbon dioxide was injected inline after the cooling section of the pasteurizer. Cheeses with and without added CO(2) were made simultaneously from the same batch of milk. This procedure was replicated 3 times. Carbon dioxide in the cheese milk was about 1600 ppm, which resulted in a milk pH of about 5.9 at 31 degrees C. The starter culture and coagulant addition rates were the same for both the CO(2) treatment and the control. The whey pH at draining of the CO(2) treatment was lower than the control. Total make time was shorter for the CO(2) treatment compared with the control. Cheese manufactured from milk acidified with CO(2) retained less of the total calcium and fat than the control cheese. The higher fat loss was primarily in the whey at draining. Preacidification with CO(2) did not alter the crude protein recovery in the cheese. The CO(2) treatment resulted in a higher added salt recovery in the cheese and produced a cheese that contained too much salt. Considering the higher added salt retention, the salt application rate could be lowered to achieve a typical cheese salt content. Cheese yield efficiency of the CO(2) treated milk was 4.4% lower than the control due to fat loss. Future work will focus on modifying the make procedure to achieve a normal fat loss into the whey when CO(2) is added to milk.

Impact of milk preacidification with CO2 on the aging and proteolysis of cheddar cheese.

To determine the influence of milk preacidification with CO(2) on Cheddar cheese aging and proteolysis, cheese was manufactured from milk with and without added CO(2). The experiment was replicated 3 times. Carbon dioxide (approximately 1600 ppm) was added to the cold milk, resulting in a milk pH of 5.9 at 31 degrees C in the cheese vat. The starter and coagulant usage rates were equal for the control and CO(2) treatment cheeses. The calcium content of the CO(2) treatment cheese was lower, but no difference in moisture content was detected. The higher CO(2) content of the treatment cheeses (337 vs. 124 ppm) was maintained throughout 6 mo of aging. In spite of having almost one and a half times the salt-in-moisture, proteolysis as measured by pH 4.6 and 12% trichloroacetic acid soluble nitrogen expressed as percentages of total nitrogen, was higher in the CO(2) treatment cheeses throughout aging. The ratio of alpha(s)-casein (CN) to para-kappa-CN decreased faster in the CO(2) treatment cheeses than in the control cheeses, especially before refrigerated storage. No difference was detected in the ratio of beta-CN to para-kappa-CN between the control and CO(2) treatment cheeses. Intact alpha(s)- and beta-CN were found in the expressible serum (ES) from the CO(2) treatment cheese as well as alpha(s1)-I-CN, but they were not detected in the ES from the control cheese. No CN was detected in the ES from the curd before the salting of either the control or CO(2) treatment cheese. Higher proteolysis in the cheese made from milk preacidified with CO(2) may have been due to increased substrate availability in the water phase or increased chymosin activity or retention in the cheese.

Reduced-fat cheddar cheese manufactured using a novel fat removal process.

Normally, reduced-fat Cheddar cheese is made by removal of fat from milk prior to cheese making. Typical aged flavor may not develop when 50% reduced-fat Cheddar cheese is produced by this approach. Moreover, the texture of the reduced-fat cheeses produced by the current method may often be hard and rubbery. Previous researchers have demonstrated that aged Cheddar cheese flavor intensity resides in the water-soluble fraction. Therefore, we investigated the feasibility of fat removal after the aging of Cheddar cheese. We hypothesized the typical aged cheese flavor would remain with the cheese following fat removal. A physical process for the removal of fat from full-fat aged Cheddar cheese was developed. The efficiency of fat removal at various temperatures, gravitational forces, and for various durations of applied forces was determined. Temperature had the greatest effect on the removal of fat. Gravitational force and the duration of applied force were less important at higher temperatures. A positive linear relationship between temperature and fat removal was observed from 20 to 33 degrees C. Conditions of 30 degrees C and 23,500 x g for 5 min removed 50% of the fat. The removed fat had some aroma but little or no taste. The fatty acid composition, triglyceride molecular weight distribution, and melting profile of the fat retained in the reduced-fat cheeses were all consistent with a slight increase in the proportion of saturated fat relative to the full-fat cheeses. The process of fat removal decreased the grams of saturated fat per serving of cheese from 6.30 to 3.11 g. The flavor intensity of the reduced-fat cheeses were at least as intense as the full-fat cheeses.

Faculty triage shortens emergency department length of stay.

OBJECTIVE: To determine whether faculty triage (FT) activities can shorten emergency department (ED) length of stay (LOS). METHODS: This was a comparison study measuring the impact of faculty triage vs no faculty triage on ED LOS. It was set in an urban county teaching hospital. Subjects were patients presenting to the registration desk between 9 AM and 9 PM on 16 consecutive Mondays (August 2 to November 15, 1999). On eight Mondays, an additional faculty member was stationed at the triage desk. He or she was asked to expedite care by rapid evaluation orders for diagnostic studies and basic therapeutic interventions, and by moving serious patients to the patient care areas. He or she was not provided with detailed instructions or protocols. The ED LOS, time of registration (TIMEREG), inpatient admission status (ADMIT), x-ray utilization (XRAY), total patients registered each day between 9 AM and 9 PM (TOTREG), and patients who left without being seen (LWBS) were determined using an ED information system. The LOS was analyzed in relation to FT, ADMIT, and XRAY by the Mann-Whitney U test. The LOS was related to TIMEREG and TOTREG by simple linear regression. Stepwise multiple linear regression models to predict LOS were generated using all the variables. RESULTS: Patients without FT (n = 814) had a mean LOS of 445 minutes. Patients with FT (n = 920) had a mean LOS of 363 minutes. Mean difference in LOS was -82 minutes (95% CI = -111 to -53), a reduction of 18%. The LOS was also related to: ADMIT +203 minutes (95% CI = 168 to 238), TOTREG -2.7 min/additional patient registered (95% CI = -1.15 to -4.3), and TIMEREG +0.14 min/min since 9 AM (95% CI = 0.07 to 0.21). The LWBS was reduced by 46% with FT. In multiple regression analysis, ADMIT, FT, TIMEREG, and XRAY were all related to LOS, but the model explained only a small part of variance (adjusted R(2) = 0.093). The faculty cost is estimated to be $11.98/patient. CONCLUSIONS: Faculty triage offers a moderate increase in efficiency at this ED, albeit with relatively high cost.

2-Methoxyethanol metabolism, embryonic distribution, and macromolecular adduct formation in the rat: the effect of radiofrequency radiation-induced hyperthermia.

Exposure of pregnant rats to the solvent 2-methoxyethanol (2ME) and radiofrequency (RF) radiation results in greater than additive fetal malformations (Nelson, B.K., Conover, D.L., Brightwell, W.S., Shaw, P.B., Werren, D.W., Edwards, R.M., Lary, J.M., 1991. Marked increase in the teratogenicity of the combined administration of the industrial solvent 2-methoxyethanol and radiofrequency radiation in rats. Teratology 43, 621-34; Nelson, B.K., Conover, D.L., Shaw, P.B., Werren, D.W., Edwards, R.M., Hoberman, A.M., 1994. Interactive developmental toxicity of radiofrequency radiation and 2-methoxyethanol in rats. Teratology 50, 275-93). The current study evaluated the metabolism of 14C-labeled 2ME and the distribution of methoxyacetic acid (MAA) in maternal and embryonic tissues of pregnant Sprague-Dawley rats either exposed to 10 MHz RF radiation or sham conditions. Additionally, adduct formation for both plasma and embryonic protein was tested as a possible biomarker for the observed 2ME/RF teratogenicity. Rats were administered [ethanol-1,2-(14)C]-2ME (150 mg/kg, 161 microCi/rat average) by gavage on gestation day 13 immediately before RF radiation sufficient to elevate body temperature to 42 degrees C for 30 min. Concurrent sham- and RF-exposed rats were sacrificed at 3, 6, 24 or 48 h for harvest of maternal blood, urine, embryos and extra-embryonic fluid. Tissues were either digested for determination of radioactivity or deproteinized with TCA and analyzed by HPLC for quantification of 2ME metabolites. Results show the presence of 2ME and seven metabolites, with the major metabolite, MAA, peaking at 6 h in the tissues tested. MAA, the proximal teratogen, was detectable in maternal serum, urine, embryo and extraembryonic fluid 48 h after dosing. Clearance of total body 14C was significantly reduced for the RF-exposed animals (P<0.05) for the 24-48 h period, but MAA values for serum, embryos and extraembryonic fluid were similar for both sham- and RF-exposed rats. Additionally, no difference was noted for 2ME metabolite profiles in urine or tissue for sham- or RF-exposed rats, thus eliminating an effect of RF radiation on MAA production as a possible explanation for the reported RF-2ME synergism. Subsequently, serum and embryo protein-bound adducts were evaluated by analysis of covalently bound radioactivity. Serum protein binding was significantly higher for sham than RF rats at 3- and 6-h - highest for sham rats at 6 h (519+/-95 microg as parent 2ME/g of protein) whereas RF serum values were highest at 24 h (266+/-79 microg/g protein). Embryonic protein binding was significantly higher for sham rats at 6 h, but binding was highest for both groups at 24 h (sham=229+/-71 microg/g, RF=185+/-48 microg/g). Formation of protein adducts after 2ME is thought to be related to levels of methoxyacetaldehyde, a reactive intermediate in the formation of MAA. These results suggest that no direct relationship exists for covalent binding in the embryo which would explain RF-2ME synergistic malformations. In comparison with urinary metabolites, the relatively slow elimination of adducted serum 2ME indicates that analysis of protein-bound concentrations could be a potential tool for long- term biomonitoring of worker exposure.

Developmental toxicity interactions of methanol and radiofrequency radiation or 2-methoxyethanol in rats.

This research was undertaken to determine potential interactions among chemical and physical agents. Radiofrequency (RF) radiation is used in numerous workplaces, and many workers are concurrently exposed to RF radiation and various chemicals. The developmental toxicity of RF radiation is associated with the degree and duration of hyperthermia induced by the exposure. Previous animal research indicates that hyperthermia induced by an elevation in ambient temperature can potentiate the toxicity and teratogenicity of some chemical agents. We previously demonstrated that combined exposure to RF radiation (10 MHz) and the industrial solvent, 2-methoxyethanol (2ME), enhanced teratogenicity in rats. Interactions were noted at even the lowest levels of 2ME tested, but only at hyperthermic levels of RF radiation. The purpose of the present research is to investigate if the interactive effects noted for RF radiation and 2ME are unique to these agents, or if similar interactions might be seen with other chemicals. Because methanol is widely used as a solvent as well as fuel additive, and, at high levels, is teratogenic in animals, we selected methanol as a chemical to address generalizability. Based on the literature and our pilot studies, 0, 2, or 3 g/kg methanol (twice, at 6-hour intervals) were administered on gestation day 9 or 13 to groups of 10 Sprague-Dawley rats. Dams treated on day 9 were given methanol and exposed to RF radiation sufficient to maintain colonic temperature at 41 degrees C for 60 minutes (or sham). Those treated on day 13 were given methanol plus either 0 or 100 mg/kg 2ME. Because we observed that methanol produced hypothermia, some groups were given the initial dose of methanol concurrently with the RF or 2ME, and others were given the first dose of methanol 1.5 hours prior to RF or 2ME. Dams were sacrificed on gestation day 20, and the fetuses were examined for external malformations. The results indicate that RF radiation or methanol on day 9 increased the incidence of resorbed fetuses, but no interactive effects were observed. The resorptions were highest in groups given the experimental treatments 1.5 hours apart. The higher dose of methanol also reduced fetal weights. Administration of 2ME or methanol on day 13 increased the rate of malformations, and there was evidence of a positive interaction between 2ME and methanol. Fetal weights were reduced by 2ME and methanol alone, but no interaction was observed. Also, separation of the dosing with the teratogens did not affect the results. These results point out that interactions in developmental toxicology, such as those of RF radiation, 2ME, and methanol that we have studied, are complex, and such interactions cannot be fully understood or predicted without more research. It is important that combined exposure effects be considered when developing both physical agent and chemical agent exposure guidelines and intervention strategies.

Intravenous Lorazepam versus dimenhydrinate for treatment of vertigo in the emergency department: a randomized clinical trial.

STUDY OBJECTIVE: To determine whether lorazepam is more effective than dimenhydrinate in relieving the symptom of vertigo in the emergency department setting. METHODS: A prospective, randomized, double-blind trial of intravenous lorazepam versus dimenhydrinate therapy was conducted in the ED of a county-owned, university-affiliated hospital. All adult patients who presented between January 24, 1998, and May 23, 1999, with the symptom of vertigo were eligible for inclusion. The intervention was varying the intravenous treatment between lorazepam, 2 mg, and dimenhydrinate, 50 mg. All patients received intravenous infusion of Ringer's lactate solution at a rate of 100 mL/h. Adequacy of randomization to the 2 treatment groups was assessed by comparing the patients' relevant baseline history, physical examination, and symptoms. The predetermined primary outcome measurement was the patient's sensation of "vertigo with ambulation" 1 and 2 hours after treatment. Secondary outcome measurements included vertigo while lying, sitting, and turning the head, ability to ambulate as judged by the enrolling physician, and sensation of nausea and drowsiness 1 and 2 hours after treatment, and whether the patient was "ready to go home" per patient report or physician assessment 2 hours after treatment. All patient symptoms were reported on 10-point scales. Outcome measurements were compared between the 2 treatment groups with a 2-way repeated-measures analysis of variance, Student's t test, Mann-Whitney U, and chi(2) test as appropriate. RESULTS: Ten patients refused entry into the study, 16 were excluded, and 74 were enrolled, treated, and included in the analysis. One enrolled patient had evidence of vertigo of central origin. The pretreatment values of vertigo with ambulation were strongly correlated with the patient's ability to ambulate (P <.001), suggesting good internal validity. The patients randomly assigned to the lorazepam group were sicker based on their pretreatment symptoms and ability to ambulate, and this may have biased the study results. The patients' symptom of "vertigo with ambulation" decreased 1.5 units more (95% confidence interval [CI] 0 to 3.0) on average on a 10-point scale 2 hours after treatment in the dimenhydrinate group. All other measures of vertigo also decreased more in the dimenhydrinate group, although the differences were not statistically significant. At 2 hours after treatment, the patients' ability to ambulate was better in the dimenhydrinate group (P <.001), and 17% (95% CI -2 to 36) more patients in this group were "ready to go home." Patients in the lorazepam group experienced a 1.8-unit (95% CI 0.2 to 3.4) greater increase in drowsiness 2 hours after treatment. CONCLUSION: Our results suggest that dimenhydrinate was more effective in relieving vertigo and less sedating than lorazepam at the intravenous doses administered in this study. Dimenhydrinate appears to be the preferred medicine for patients who present to the ED with vertigo likely to be of peripheral origin.

Preventive practicum training in healthcare organizations. The Meharry model.

BACKGROUND: Practicum training for preventive medicine residents often occurs in agencies whose community is geographically defined and whose governance is closely linked to public election. We were unsure about the financial ability of such departments to support training and are concerned that over-reliance on traditional health departments might not be best for either medically indigent populations or preventive medicine. We, therefore, sought to apply a public health model--based on a strategic partnership between nursing and preventive medicine--to a large health care organization. The result was formation of a mini-health department, suitable for fully accredited preventive medicine practicum training, within the Alvin C. York Veterans Affairs Medical Center, Murfreesboro, TN. This Center serves a defined population of 21,594 patients and about 1600 employees. The theoretical framework for the new department was based on demonstration of a close fit between the competencies expected of preventive medicine physicians by the American College of Preventive Medicine (ACPM) and activities required by the Joint Commission on Accreditation of Healthcare Organizations (JCAHO). Because of JCAHO requirements, many healthcare organizations already pay for preventive medicine services. CONCLUSIONS: By placing preventive medicine training faculty into existing budget slots at our institution, systemwide personnel costs for prevention decreased by about $36,000 per year, even as personnel funding for preventive medicine physicians increased from about $24,000 to $376,000 per year. Moreover, there was dramatic, sustained improvement in 17 indicators of preventive care quality as determined by an external peer review organization. In addition to providing a new venue for training, this model may also improve the quality and reach of preventive services, decreased fixed costs for service delivery, and yield new employment opportunities for preventive medicine physicians.

Utility of a single beta HCG measurement to evaluate for absence of ectopic pregnancy.

The objectives of this study were to determine the optimal cutoff value (CV) and utility of a single serum beta human chorionic gonadotropin hormone (HCG) level in assessing the likelihood of ectopic pregnancy (ECP). A retrospective chart review was performed at an urban county hospital. The optimal CV was determined by comparing all available patients diagnosed with ECP and patients diagnosed with threatened abortion (TA) in the Emergency Department (ED) who subsequently delivered a baby at the same hospital. The utility of the test was assessed in a group of all known patients who presented to the ED with lower abdominal or pelvic pain or vaginal bleeding between 6 and 13 weeks estimated gestational age (EGA). There were 212 ECPs with measured HCGs. Only nine presented after 13 weeks EGA. The mean HCG value was 5,378 mIU/mL. There was no significant correlation between HCG and EGA. There were 132 TAs with measured HCGs who subsequently delivered. Only four TAs presented before 6 weeks EGA. Regarding the TA patients who presented between 6 and 13 weeks EGA, there were 81 with a mean HCG of 83,810 mIU/mL. Between 6 and 13 weeks EGA, HCG was not significantly correlated with EGA. The entire ECP group was compared with the TA group with 6-13 week EGA. A receiver-operating characteristic curve with nine HCG cutoff values was constructed. Clinically, the optimal CV was 40K. At this level, a test for the condition "absence of ECP" had a specificity of 99%, and only two of 212 ECPs in our group would test false-positive with an HCG value over 40K. When the test was applied to a group of 175 women who presented with pain or bleeding between 6 and 13 weeks EGA, the sensitivity and positive predictive value for an intrauterine pregnancy were 24% and 99.9 %, respectively. However, if this test was applied to all patients regardless of clinical findings, and then an ultrasound (U/S) algorithm was applied to the patients who had an HCG of less than 40K, it would predictably increase the rate of ECPs falsely identified as intrauterine pregnancies (IUPs) by 1%, regardless of the false-positive rate of the U/S algorithm itself. Given the potential morbidity and mortality of undiagnosed ectopic pregnancy, ultimately neither this test nor any other that is less than 100% specific for IUP can be recommended instead of an initial U/S evaluation for patients who present at risk for ECP.

Prospective, randomized trial of template-assisted versus undirected written recording of physician records in the emergency department.

STUDY OBJECTIVE: To determine whether use of the T-System (Emergency Services Consultants, Irving, TX) template-generated medical documentation system (1) decreases physician evaluation time in the emergency department, (2) increases gross billing under the 1997 Health Care Financing Administration guidelines by minimizing downcoding caused by inadequate documentation, and (3) increases physician satisfaction with the documentation process, compared with the undirected written narrative format. METHODS: A prospective, randomized, unblinded, controlled, convenience trial of documentation with the T-System of ED templates versus undirected written documentation was conducted in the ED of a county-owned, university-affiliated hospital. All patients seen between the hours of 7 AM and 10 PM during a 16-day period were included. The intervention was varying the method of documentation of the emergency physician. Adequacy of randomization to the 2 documentation groups was assessed by comparing ED triage classification, patient disposition, level of training of the evaluating physician, and whether ED consultation with other services occurred. Outcome measurements included emergency physician total evaluation and treatment time, professional bill, and satisfaction, as evaluated by a questionnaire completed after the study period. The 2 documentation groups were compared by an intention-to-treat analysis and by Student's t test and the median test as appropriate. RESULTS: A total of 1,228 patient encounters were included. Emergency physician total evaluation and treatment time with template-directed documentation was 4.6 minutes less than with undirected recording, a difference that was not significant (95% confidence interval [CI], -9.2 to 18.3). Gross billing was $29. 60 more per patient (95% CI, $22.20 to $37.00) with the T-System, as assessed by our hospital coders. This difference was caused by a mean.50 (95% CI,.39 to.60) higher level of evaluation and management coding. Physicians preferred the T-System (P <.0005). CONCLUSION: Use of template-assisted documentation in the ED was associated with higher gross billing and physician satisfaction but no significant decrease in emergency physician total evaluation time.

Developmental toxicity interactions of salicylic acid and radiofrequency radiation or 2-methoxyethanol in rats.

Radiofrequency (RF) radiation is used in a variety of workplaces where workers are concurrently exposed to chemicals. Combined exposure to RF radiation (10 MHz) and the industrial solvent, 2-methoxyethanol (2ME), produces enhanced teratogenicity in rats. The purpose of the present research was to determine if the synergistic effects noted for RF radiation and 2ME are generalizable to other chemicals. Since salicylic acid (SA) is widely used as an analgesic and is teratogenic in animals, SA was selected to address generalizability. Based on the literature and our pilot studies, 0, 250, or 350 mg/kg SA were administered by gavage on gestation Day 9 or 13 to rats. Concurrently rats given SA on Day 9 were exposed to RF radiation sufficient to maintain colonic temperature at 41 degrees C for 60 min (or sham). Those given SA on Day 13 were also given 0 or 100 mg/kg 2ME (gavage). Dams were sacrificed on gestation Day 20, and the fetuses were examined for external malformations. The data provide no evidence of synergistic interactions between RF radiation and salicylic acid (resorptions and malformations). Limited evidence of antagonism was observed between 2ME and salicylic acid (fetal weights). This investigation highlights the importance of additional research on interactions in developmental toxicology, and emphasizes the need to consider combined exposure effects when developing both physical agent and chemical agent exposure guidelines and intervention strategies.

Effect of environmental temperature on the interactive developmental toxicity of radiofrequency radiation and 2-methoxyethanol in rats.

OBJECTIVE: This research was conducted to determine if altered environmental temperatures would affect the interactive developmental toxicity of radiofrequency (RF) radiation and the industrial solvent, 2-methoxyethanol (2ME). This is important because RF radiation is used in a variety of workplaces that have poorly controlled environmental temperatures, and many workers are concurrently exposed to various chemicals. Furthermore, we have previously demonstrated that combined exposure to RF radiation (10 MHz) and 2ME produces enhanced teratogenicity in rats. METHODS: RF radiation sufficient to maintain colonic temperatures at the control value (38degrees ), 39.0degrees or 40.0 degrees C for 2 or 4 h combined with either 0 or 100 mg/ kg 2ME at environmental temperatures of 18 degrees , 24 degrees and 30 degrees C (65 degrees , 75 degrees , and 85 degrees F) were given on gestation day 13 to Sprague-Dawley rats. Dams were killed on gestation day 20, and the fetuses were examined for external malformations. RESULTS AND CONCLUSIONS: Environmental temperature does affect the specific absorption rate (SAR) necessary to maintain a specific colonic temperature but does not affect the interactive developmental toxicity of RF radiation and 2ME in rats. These results, consistent with the literature, add to the evidence that the developmental toxicity of RF radiation (combined or alone) is associated with colonic temperature, not with SAR.

Statistical methodology: V. Time series analysis using autoregressive integrated moving average (ARIMA) models.

Most methods of defining a statistical relationship between variables require that errors in prediction not be correlated. That is, knowledge of the error in one instance should not give information about the likely error in the next measurement. Real data frequently fail this requirement. If a Durbin-Watson statistic reveals that there is autocorrelation of sequential data points, analysis of variance and regression results will be invalid and possibly misleading. Such data sets may be analyzed by time series methodologies such as autoregressive integrated moving average (ARIMA) modeling. This method is demonstrated by an example from a public policy intervention.

Analysis of the treatment of spontaneous sustained stable ventricular tachycardia.

OBJECTIVES: To determine the termination rate of spontaneous sustained stable ventricular tachycardia (SSSVT) as a function of the first and second therapeutic interventions used, and to determine factors associated with successful termination. METHODS: A multihospital, retrospective analysis of the treatment of patients with SSSVT was performed. The setting included 2 urban county hospitals, 2 urban private hospitals, and a Veterans Affairs hospital. Cases were identified by discharge diagnosis and ECG characteristics, and confirmed by electrophysiology study or ECG criteria. RESULTS: There were 40 cases of SSSVT identified. Excluding adenosine, 35 patients were treated with lidocaine as a first intervention. The rate of termination with lidocaine bolus was 17% (6 of 35) (95% CI 7-34%). Regarding the 35 patients initially treated with lidocaine, the odds of termination of SSSVT were 11 times greater in those without a history of previous myocardial infarction (MI) than in those with a history of MI (95% CI 0.96-551). Of the 29 patients who failed initial lidocaine treatment, 23 were treated with a second lidocaine bolus, with a termination rate of 18% (4 of 22) (95% CI 5-40%). Only 2 patients with sustained ventricular tachycardia had a concurrent MI, and the tachycardia was unresponsive to initial lidocaine bolus in both cases. Fifteen patients received adenosine with no tachycardia terminations and no significant adverse effects. CONCLUSIONS: The rate of SSSVT termination with lidocaine was low, particularly in patients with a history of Mi.

Paternal exposure of rabbits to lead: behavioral deficits in offspring.

Paternal exposures to exogenous agents have been reported to produce a variety of developmental defects in the offspring. In experimental animals, these effects include decreased litter size and weight, increased stillbirth and neonatal death, birth defects, tumors, and functional/behavioral abnormalities-some of these effects being transmitted to the second and third generations. The majority of experimental studies assessing nervous system function of offspring following paternal exposures have utilized rats as the experimental animal, but other species can be used. The National Toxicology Program (NTP) has initiated studies to validate the rabbit as an animal model for human reproductive toxicity, because rabbits are the smallest laboratory animal from which ejaculates can be collected repeatedly. An important part of reproductive toxicology is assessment of the reproductive ability of males following exposure, as well as developmental and functional assessment of their offspring. This article describes a pilot study and a main study to investigate the feasibility of using rabbits to assess the functional effects of paternal exposure to lead. The pilot study included seven male rabbits per group exposed for 15 weeks to lead acetate sufficient to produce 0, 50, or 110 micrograms/dl blood lead. The main study included 15 male rabbits per group exposed for 15 weeks to lead acetate to produce 0, 20, 40, and 80 micrograms/dl blood lead. At the conclusion of the exposure, male rabbits were mated with unexposed females. These females carried their litters to term, delivered, and reared their own offspring. The offspring were weighed at 5, 10, 15, 20, 25, 30, and some at 35 days of age. They were also tested for exploratory activity in a standard figure-eight "maze" for 30 min/day on days 15, 20, 25, and 30. A second assessment of exploratory behavior, along with a simple test of aversive conditioning, was attempted in the pilot study, but was judged not to be suitable for the main study. Of the 21 male rabbits that were mated in the pilot study, 16 produced viable litters (6/7, 6/7, and 4/7 in control, low- and high-lead groups, respectively), with a mean number of 6 live births/litter in each treatment group (range 2-8). Of the 60 rabbits mated in the main study, 57 produced litters, and two rabbits died giving birth. Significant postnatal deaths were observed in all groups, with about one half of the offspring dying before testing was initiated at day 15. There were no treatment-related effects on offspring weight gain through wearing. The data suggest that paternal lead exposure of rabbits may reduce figure-eight activity on day 25, the time of peak activity in the offspring.