Detergents in drainage systems for buildings.

Current soil waste vent (SWV) system design guides aim to produce ventilated drainage networks for buildings which protect attached water trap seals from unwanted air pressure effects. Such effects may cause trap seal failure that are caused by airflow induction during discharge. The ventilation design guides are based on steady-state experiments utilising cold clean water as a test media. However, most 'grey' and 'black' water sources are dosed with detergent, and are often warm, which significantly alters the behaviour when compared to clean water. Thus, current design standards provide only approximations of SWV system response. Results indicate that induced airflows in warm detergent-dosed water can be significantly higher than those measured in clean water systems, by a factor of more than 2. This paper quantifies the effect of detergents in SWV systems in terms of observed air entrainment rates and previously published research on the factors that contribute to air entrainment. Results of previous work are cast into dimensionless groupings suitable for inclusion into a mathematical simulation model based on a finite difference scheme. It utilises the method of characteristics as a solution technique to simulate drainage system operation via the equations that define unsteady partially filled or full bore pipe flows and the boundary conditions represented by water traps and other common system components.

Development of a rapid response biosensor for detection of Salmonella typhimurium.

An integrated optic interferometer for detecting foodborne pathogens was developed. The interferometer is a planar waveguide with two thin antibody-coated channels of immunochemically selective agents that interact with antigen molecules. One channel is coated with antibody to Salmonella as a sample, and the other is coated with human immunoglobulin G as a reference channel by using reductive amination. Salmonella was introduced onto the sensing channels through the flow cell on the channels. Phase shift (pi) generated by refractive index variation, as determined by interfering the perturbed sample channel with an unperturbed reference channel and observing the fringe shift, was used for detection. Salmonella Typhimurium (heat-treated or boiled) was detected by binding to antibody against Salmonella common structural antigen immobilized on a silane-derived sensor surface at concentrations in the range of 1x10(5) to 1x10(7) CFU/ml. Salmonella (1x10(7) CFU/ml) mixed with Escherichia coli (1x10(7) CFU/ml) were readily detected without any decrease in sensitivity by the direct assay. Application of a sandwich assay with a second antibody or a gold-conjugated antibody increased the detection limit to 1x10(5) CFU/ml within a 10-min reaction time. Various methods for the immobilization of the capture antibody to the biosensor channels were compared. The greatest binding response was observed in a direct reductive amination method with a long reaction period and increased the detection limit of direct binding of Salmonella antigen to 1x10(4) CFU/ml. The biosensor was able to detect Salmonella Typhimurium in chicken carcass wash fluid originally inoculated at a level of 20 CFU/ml after 12 h of nonselective enrichment. The planar optic biosensor shows promise as a fast, sensitive, reliable, and economical means of detecting food pathogens in the future.

Accuracy of two pulse oximeters during maximal cycling exercise.

This study compared the measurement of oxygen saturation of haemoglobin (SaO2) by two pulse oximeters (Ohmeda Biox 3700e and Criticare 504 USP) with the measurement of SaO2 in arterial blood samples by CO-oximetry. Unlike many previous validation studies, arterial blood was sampled in ground glass rather than plastic syringes. Twenty men, 11 well-trained cyclists (mean +/- SE, age = 23.3 +/- 1.5 years, mass = 71.4 +/- 1.1 kg VO2max = 77 +/- 1 ml.kg1.min-1) and 9 relatively untrained subjects (age = 27.1 +/- 2.8 years, mass = 78.1 +/- 2.2 kg VO2max = 51 +/- 3 ml.kg 1.min-1) performed two maximal cycle ergometer tests each in an hypobaric chamber. The tests were at 745 mm Hg or 695 mm Hg with simultaneous measurement of SaO2 by the pulse oximeters and the CO-oximeter at rest, minute 7 of exercise and at VO2max. The best correlations, to the Co-oximeter measurement (SCO-OXO2) were found when all data from rest and exercise were combined (Criticare: r = 0.94; Ohmeda: r = 0.91). The bias measurements showed the Ohmeda underestimated SCO-OXO2 at all levels (mean = -2.5 +/- 1.9%) and the Criticare overestimated SCO-OXO2 at all levels, although to a lesser degree (mean = 0.9 +/- 1.5%). In conclusion, these results highlight the need for validation of individual pulse oximeters and that the effect of dyshaemoglobins must also be considered.

Reduced performance of male and female athletes at 580 m altitude.

This study examined the effect of mild hypobaria (MH) on the peak oxygen consumption (VO2peak) and performance of ten trained male athletes [x (SEM); VO2peak = 72.4 (2.2) ml x kg(-1) x min(-1)] and ten trained female athletes [VO2peak = 60.8 (2.1) ml x kg(-1) x min(-1)]. Subjects performed 5-min maximal work tests on a cycle ergometer within a hypobaric chamber at both normobaria (N, 99.33 kPa) and at MH (92.66 kPa), using a counter-balanced design. MH was equivalent to 580 m altitude. VO2peak at MH decreased significantly compared with N in both men [-5.9 (0.9)%] and women [-3.7 (1.0)%]. Performance (total kJ) at MH was also reduced significantly in men [-3.6 (0.8)%] and women [-3.8 (1.2)%]. Arterial oxyhaemoglobin saturation (SaO2) at VO2peak was significantly lower at MH compared with N in both men [90.1 (0.6)% versus 92.0 (0.6)%] and women [89.7 (3.1)% versus 92.1 (3.0)%]. While SaO2 at VO2peak was not different between men and women, it was concluded that relative, rather than absolute. VO2peak may be a more appropriate predictor of exercise-induced hypoxaemia. For men and women, it was calculated that 67-76% of the decrease in VO2peak could be accounted for by a decrease in O2 delivery, which indicates that reduced O2 tension at mild altitude (580 m) leads to impairment of exercise performance in a maximal work bout lasting approximately 5 min.

Increased arterial desaturation in trained cyclists during maximal exercise at 580 m altitude.

This study utilized a hypobaric chamber to compare the effects of mild hypobaria (MH; 50 mmHg, approximately 580 m altitude) on blood O2 status and maximal O2 consumption (VO2max) in 9 untrained and 11 trained (T) cyclists with VO2max values of 51 +/- 3 and 77 +/- 1 ml.kg-1.min-1, respectively. In both groups, arterial O2 saturation (SaO2) decreased significantly during maximal exercise, and this effect was enhanced with MH. Both these responses were significantly greater in the T cyclists in whom the final SaO2 during MH was 86.5 +/- 0.9%. When the group data were combined, approximately 65% of the variance in SaO2 could be attributed to a widened alveolar-arterial Po2 difference. The arterial PO2 during maximal exercise at sea level in the T group was on the steeper portion of the hemoglobin-O2-loading curve (T, 68.3 +/- 1.3 Torr; untrained, 89.0 +/- 2.9 Torr) such that a similar decrease in arterial PO2 in the two groups in response to MH resulted in a significantly greater fall in both SaO2 and calculated O2 content in the T group. As a consequence, the VO2max fell significantly only in the T group (mean change, -6.8 +/- 1.5%; range, + 1.2 to - 12.3%), with approximately 70% of this decrease being due to a fall in O2 content. This is the lowest altitude reported to decrease VO2max, suggesting that T athletes are more susceptible to a fall in inspired PO2.

The desire for multiple births in couples with infertility problems contradicts present practice patterns.

Paradoxically, the attitude of infertility patients towards multiple births has never been investigated. We therefore generated a survey by questionnaire, which was sent to 3800 consecutive unselected couples with infertility problems: 582 responses were received (15% response rate) and analysed. The percentage distribution of the responses to 21 questions, addressing attitudes towards and knowledge about the risk of multiple gestations, was the main outcome. Worry about multiple births was expressed, independent of the number of multiples, although fear about multiple conceptions was rejected by a large majority (64%). The risk of a twin birth was not strongly perceived, but the perception of risk increased with increasing numbers of multiples: triplets (50-62%), quadruplets or more (71-72%). A desire for the conception of twins was expressed by 67-90% of couples, a desire for the conception of triplets was equally expressed and rejected, and for a multiple gestation beyond triplets was rejected by 73-82% of couples. Patients were educated about the risks of selective embryo reduction and responded in a bimodal fashion to the option of utilizing this procedure, with equal numbers being willing to consider or reject it. Age, parity and length of infertility did not affect the couples' worry or fear about multiples. The desire for twins and triples, however, was correlated significantly with age (twins, P = 0.032; triplets, P = 0.03); there was no such correlation for larger multiples. The length of infertility was correlated with a positive attitude towards multiples beyond triplets (P = 0.029) but was not correlated with a desire for twins or triplets. Prior parity did not affect the attitude towards multiples at all.(ABSTRACT TRUNCATED AT 250 WORDS)

Positioning hospitals: a model for regional hospitals.

In an age of marketing warfare in the health care industry, hospitals need creative strategies to compete successfully. Lately, positioning concepts have been added to the health care marketer's arsenal of strategies. To blend theory with practice, the authors review basic positioning theory and present a framework for developing positioning strategies. They also evaluate the marketing strategies of a regional hospital to provide a case example.

Employee wellness program marketing: an organizational theory perspective.

An employee wellness program (EWP) marketing system can be analyzed as an adhocracy, an organizational form proposed by Mintzberg and is characterized by sharing of power, mutual adjustment among its members, and ability to innovate. The design parameters of informal behavior, planning and control, liaison, and decentralization appear to be particularly important to the success of EWPs.

Employee decision making and the successful marketing of hospital wellness products.

Hospitals are beginning to pursue employee wellness services as a promising diversification opportunity. However, a marketing concept approach to new product development may be needed for hospitals to compete and succeed in this unique product area. A model of employee decision making relative to wellness offerings is presented here. The model can serve as a fundamental starting point in hospitals' adoption of a marketing concept approach to developing products for the employee wellness market.

Employee wellness programs: a strategy for increasing participation.

Employee wellness programs can bring dramatic reductions in organizational health insurance premiums. However, employee participation in such programs is voluntary and averages only about 20% within sponsoring companies. Higher participation rates could be achieved by using a marketing approach. The authors illustrate a consumer-oriented marketing approach that examines the influences on employees' decisions to participate in employee wellness programs.

Nontuberculous mycobacterial adenitis of childhood. The ten-year experience at a community hospital.

An increased occurrence of nontuberculous mycobacterial adenitis was observed in children admitted to the Tucson Medical Center for adenitis between 1979 and 1983. All infections were due to Mycobacterium avium-intracellulare complex (MAI). All isolates were obtained from children less than 3 years old and with symptoms of two months or less. Children with negative cultures tended to be older, had a longer interval of lymphadenopathy, and had larger glands. Factors that may have caused the separation of our two groups and the high prevalence of MAI are addressed herein. Only earlier suspected diagnosis and application of tuberculosis screening studies can define the true prevalence of MAI disease in childhood.

Structure-activity relationships for blood pressure effects of prednisolone in sheep.

This study investigated the effect of 5 day infusions of 6 alpha and 9 alpha-fluoro and 16 alpha, 17 alpha-acetal analogues of prednisolone on blood pressure in conscious sheep. In vivo mineralocorticoid (MC) and glucocorticoid (GC) activities of these steroids were also measured. Prednisolone (100 mg/d) produced a small increase in mean arterial pressure associated with increased fasting plasma [glucose] and polyuria, but had no MC activity. 9 alpha-fluoro substitution greatly enhanced both the pressor and MC activity of prednisolone. The effect of 9 alpha-fluoro substitution on pressor activity was not affected by beta-methylation at C-16 (betamethasone), but was attenuated by either alpha-hydroxylation or alpha-methylation at C-16 (triamcinolone and dexamethasone, respectively). The effect of 9 alpha-fluoro substitution on MC activity as determined by urinary Na excretion was not altered by a methyl group at C-16 in either alpha or beta configuration but the MC activity was attenuated by an alpha-hydroxyl group at C-16. In contrast, 6 alpha-fluoro substitution had little influence on pressor, MC and GC activities. 16 alpha, 17 alpha-acetonide and 16 alpha, 17 alpha-butylidenedioxy substitution increased the pressor activity of parent compounds, but had no influence on either GC or MC activity. This study demonstrates a dissociation between the pressor effects and the MC and GC activities associated with steroid administration and provides further evidence to support the concept of 'hypertensinogenic' class of steroid activity which can be distinguished from their MC and GC activity.

Characterization studies of glucose dehydrogenase.

Porcine liver beta-D-glucose dehydrogenase has been isolated using Triton X-114 to release it from the endoplasmic reticulum. The purified enzyme contains a limited amount (1.7%) of lipid material, including cholesterol, fatty acids, mono and diglycerides, phosphatidylcholine, phosphatidylethanolamine, and cholesterol esters. This enzyme is a tetrameric protein containing an extensive number of hydrophobic residues. This form of glucose dehydrogenase is capable of turning over both beta-D-glucose and alpha-D-glucose-6-phosphate in vivo as indicated from a steady state kinetic analysis at 37 degrees C.

Guanidinium- and temperature-induced conformational changes in glucose dehydrogenase.

The conformational changes in glucose dehydrogenase are studied as a function of temperature and guanidinium chloride (GdmCl) concentration. The data were analyzed assuming a two-conformer model which gave similar results using either circular dichroism or enzyme activity. The free energy of denaturation was 0.94 kcal/mol from specific activity and 1.64 kcal/mol from circular dichroism measurements. The mid-point of the denaturation curve was 0.65 or 0.63 M GdmCl, as determined by specific activity or circular dichroism, respectively. The transition temperature, 6.4 degrees C, is close to that of a microsomal membrane phase change, a result that is consistent with the fact that glucose dehydrogenase contains lipid materials when isolated with a non-ionic detergent such as Triton X-114. As the temperature increased, the amount of beta-pleated sheet increased, and the alpha-helical content decreased, suggested that glucose dehydrogenase contains a stable core of beta-pleated sheet.

Quantitative changes of serum lipoprotein-X after cholestyramine administration in infants with cholestatic biliary tract and liver disease.

Lipoprotein-X (LP-X) was determined before and after the administration of cholestyramine in fifty-five infants with persistent cholestatic jaundice to differentiate between intra- and extrahepatic disease. In twenty-seven infants with biliary atresia, serum LP-X prior to cholestyramine ranged from 0.87 to 11.42 g/l (mean: 3.43 g/l; the average concentration was significantly lower (P less than 0.001) in males. After cholestyramine, LP-X rose in twenty-three, remained the same in two, and decreased slightly in two infants. Serum LP-X was present in twenty of the twenty-eight infants with intrahepatic cholestasis prior to cholestyramine in concentrations from 0.84 to 14.19 g/l (mean: 3.13 g/l). After cholestyramine, LP-X decreased in all by an average of 78% (P less than 0.005). The other eight infants did not have LP-X before or after cholestyramine. This study shows that LP-X in the serum of infants with cholestatic jaundice indicates severe cholestasis, but is not itself diagnostic of biliary atresia. The differentiation of biliary atresia from other diseases is readily achieved, as the administration of cholestyramine for 2-3 weeks causes a marked decrease of serum LP-X in patients with patent extrahepatic bile ducts. The absence of serum LP-X excludes biliary atresia.

Identification of the jaundiced infant who is likely to recover without surgical intervention.

A series of 32 infants with persistant jaundice in whom an unequivocal differentiation between intrahepatic cholestasis and biliary atresia could not be made is reviewed. A protocol including Lipoprotein-X (LP-X) determinations before and after a short course of cholestyramine (CSM) was carried out in all. A fall in serum LP-X after CSM indicates the presence of patent extrahepatic bile ducts (even microscopic) which will function without benefit of hepatic portoenterostomy. A rise in LP-X levels after CSM means an atretic biliary system. The LP-X, CSM protocol was not able to differentiate between the anatomical variants of biliary atresia that may respond to hepatic portoenterostomy and those that will not. Patent bile ducts (even microscopic) in the porta hepatis and/or proximal hepatoduodenal ligament, which are in continuity with intrahepatic ducts, must be present if hepatic portoenterostomy is to be successful. None of our 12 infants undergoing hepatic portoenterostomy showed evidence of bile excretion after the procedure. Microscopic study of serial sections taken through the excised hepatoduodenal ligament tissues of these 12 infants revealed that none had anatomical findings conducive to the success of the operation.