Characterization of heme c peptides by mass spectrometry

Liquid secondary ion mass spectrometry, also called fast atom bombardment mass spectrometry, has been used to determine proteolytic hydrolysis sites for peptides derived from c-type cytochromes that contain covalently attached heme c. An unexpected fragmentation occurs that breaks the covalent thioether bonds between the heme and the peptide, and the heme fragment further rearranges to give rise to an intense ion at m/z of 617 that corresponds to protonated iron protoporphyrin IX. The observation of this ion fragment can be used to unambiguously identify the presence of authentic heme c in peptides or peptide mixtures at the subnanomole level.

Membranous glomerulonephritis in association with hepatitis C virus infection

Two bone marrow transplant recipients are described who developed nephrotic syndrome in association with hepatitis C virus (HCV) infection. Renal biopsies of both patients revealed stage I membranous glomerulonephritis. Detection of HCV genome was performed by nonisotopic in situ hybridization and reverse transcriptase polymerase chain reaction on paraffin-embedded renal biopsy specimens. Hepatitis C virus genome was detected by reverse transcription nested polymerase chain reaction on the RNA extracted from 15 5-microns paraffin sections. However, HCV genome was not revealed by nonisotopic in situ hybridization, which was likely due to the low copy number of HCV genomes present. These studies suggest that chronic HCV infection is associated with membranous glomerulonephritis.

Magnetization of fast and slow oxidized cytochrome c oxidase

Oxidized cytochrome c oxidase can now be prepared either to react rapidly (fast) or to react slowly (slow) with cyanide [Baker, G.M., Noguchi, M., & Palmer, G. (1987) J. Biol. Chem. 262, 595-604]. Slow oxidized cytochrome c oxidase is also characterized by an integer spin g = 12 EPR signal which is absent in the fast form. The saturation magnetization of two samples of both forms of cytochrome oxidase has been studied at four applied magnetic fields (0.3125, 1.25, 2.5, and 5.0 T) over a temperature range from 2 to 200 K using a superconducting susceptometer. The saturation magnetization data of the two preparations are readily distinguished. The data for the coupled cytochrome a3: CuB site of both preparations are most simply interpreted as exhibiting S = 2 paramagnetism with D = +13 cm-1 for the fast and D = -7 cm-1 for the slow forms, respectively. However, there is some indication that the fast form is a mixture of both S = 2 and S = 1 paramagnetic species while the slow form is only S = 2.

Comparison of hepatocyte phenotypes at the glutathione transferase and albumin loci in Sprague-Dawley and Nagase analbuminemic rats and F1 progeny after initiation and promotion

Hepatocarcinogenesis was examined in an initiation--promotion protocol with a single initiating dose of 7,12-dimethylbenz[a]anthracene (DMBA) followed by promotion with phenobarbital (PB) in the Nagase analbuminemic rat (NA), the Sprague-Dawley rat (SD) and their F1 crosses. All rats received a 70% partial hepatectomy, followed at 24 h by 30 mg DMBA/kg body wt or the solvent. After a 2 week recovery following surgery, half of the solvent control and initiated groups received either basal diet or promotion with 0.05% PB mixed into the basal NIH-07 diet. After 12 weeks of promotion, the rats were killed and the livers perfused and fixed in situ with paraformaldehyde. Liver slices were paraffin embedded and stained for the placental isozyme of glutathione S-transferase (PGST). The number of altered hepatic foci (AHF) expressing PGST per liver was determined by quantitative stereology and used as an endpoint for comparison of initiation in the rat strains. The NA rat had a lower response to this initiation-promotion protocol than did the SD rat. The F1 progeny of the male NA and female SD rats were more similar to the NA parent in their responsiveness to initiation, whereas the F1 progeny of the female NA and male SD were similar to the SD parent in this respect. Putative mutagenesis and carcinogenesis were examined in the F1 progeny of the female NA and male SD rat. In these rats, serial liver sections were stained either for albumin to detect putative mutations at that locus, or PGST to identify putatively initiated hepatocytes. In the NA/SD F1, the number of single hepatocytes with a putative mutation at the albumin locus was the same (3.7 x 10(5)/liver) as those expressing a common marker of preneoplasia (PGST). The number of AHF expressing PGST was approximately 5% that of the single cells exhibiting an altered expression of albumin or PGST, indicating a possible quantitative correlation between initiation and mutation in vivo when individual hepatocytes with altered gene expression were counted. These studies also suggest that only a subpopulation of the putatively initiated hepatocytes expands clonally in the presence of the promoting agent, PB. The progeny of the female NA rat crossed with the SD male rat appears to provide a useful model in which to compare mutation and carcinogenesis simultaneously in vivo.

The relationship of child acuity, maternal responses, nurse attitudes and contextual factors in the bone marrow transplant unit

PURPOSE

This study was designed to examine the relationships between maternal perceptions of an acutely ill child, nurse caregivers and contextual factors in a pediatric critical care unit.

METHODS

Subjects were mothers of 20 children who had had their first bone marrow transplant and the primary nurse of each child. The study was conducted on a bone marrow transplant unit. Variables included the acuity of the child, maternal satisfaction with nursing care, maternal vigilance as measured by the time spent at the child's bedside, nurses' attitudes toward family involvement with care, nursing experience and bone marrow transplant unit variables (census, unit acuity and staffing deficit).

RESULTS

Positive associations were observed between the child's acuity and maternal satisfaction with nursing care, and between maternal vigilance and staffing deficit. There was an inverse relationship between maternal vigilance and length of nursing experience of the primary nurse and between positive attitudes of nurses toward family participation and years of nursing experience.

CONCLUSION

These results show the complex nature of parental perceptions and involvement in the hospitalized child's care. They suggest that maternal attitudes about caregiving are associated with the child's acuity and that maternal vigilance is related to nursing and environmental factors, principally critical care experience of the primary nurse.

The relationship of child acuity, maternal responses, nurse attitudes and contextual factors in the bone marrow transplant unit

PURPOSE: This study was designed to examine the relationships between maternal perceptions of an acutely ill child, nurse caregivers and contextual factors in a pediatric critical care unit. METHODS: Subjects were mothers of 20 children who had had their first bone marrow transplant and the primary nurse of each child. The study was conducted on a bone marrow transplant unit. Variables included the acuity of the child, maternal satisfaction with nursing care, maternal vigilance as measured by the time spent at the child's bedside, nurses' attitudes toward family involvement with care, nursing experience and bone marrow transplant unit variables (census, unit acuity and staffing deficit). RESULTS: Positive associations were observed between the child's acuity and maternal satisfaction with nursing care, and between maternal vigilance and staffing deficit. There was an inverse relationship between maternal vigilance and length of nursing experience of the primary nurse and between positive attitudes of nurses toward family participation and years of nursing experience. CONCLUSION: These results show the complex nature of parental perceptions and involvement in the hospitalized child's care. They suggest that maternal attitudes about caregiving are associated with the child's acuity and that maternal vigilance is related to nursing and environmental factors, principally critical care experience of the primary nurse.

High-calcium diet in spontaneously hypertensive rats: intervention with calcium antagonist verapamil

A number of studies have shown an antihypertensive effect for high-calcium diets, but others have found no effect or, even a prohypertensive effect. Because of these disparate results, studies were conducted in spontaneously hypertensive rats (SHR) fed either a normal calcium diet (1.0% calcium) or a high-calcium diet (4.0% calcium) with or without verapamil HCl (50 mg/kg body weight) from ages 5 to 12 weeks. Systolic blood pressure (SBP) and heart rate (HR) were measured by indirect tail cuff method. During the analysis of the electrolytes and vasoactive hormones monitored in this study, it was found that rats fed high-calcium diet had significantly elevated serum ionized and total calcium and calcium excretion. Systolic blood pressure for the verapamil-normal calcium diet (week 5, 148 +/- 4 mm Hg; week 7, 162 +/- 4 mm Hg) did not differ significantly from that of normal calcium diet (week 5, 152 +/- 2 mm Hg; week 7, 160 +/- 1 mm Hg). The high-calcium diet potentiated the development of hypertension, i.e., SBP was (157 +/- 2 mm Hg) on the 5th week and (174 +/- 4 mm Hg) on the 7th week. Conversely, verapamil high-calcium diet prevented the development of hypertension (week 5, SBP was 139 +/- 4 mm Hg; week 7, SBP was 146 +/- 3 mm Hg).(ABSTRACT TRUNCATED AT 250 WORDS)

Diffusion imaging of experimental allergic encephalomyelitis

Diffusion-weighted magnetic resonance imaging (MRI) was compared with T2-weighted MRI in longitudinal studies of experimental allergic encephalomyelitis (EAE), an animal model of multiple sclerosis, in five monkeys (Macaca fascicularis). In a region of the brain that had highly directional myelinated fibers (internal capsule) sequential changes were identified on diffusion-weighted images on and before the day these changes were detected on conventional T2-weighted images. Changes were also identified on diffusion-weighted images in brain areas that did not develop T2-weighted abnormalities. This result suggests that diffusion-weighted image intensities are sensitive to pathologic conditions of the brain that can not be seen on T2-weighted images.

Prevalence of AIDS-related risk factors and condom use in the United States

A national probability survey of human immunodeficiency virus (HIV)-related risk factors among the general heterosexual population, the National AIDS (acquired immunodeficiency syndrome) Behavioral Surveys, has obtained data from 10,630 respondents. Data are presented on the prevalence of HIV-related risks in the general heterosexual population, on the distribution of the three largest risk groups across social strata, and on the prevalence and distribution of condom use among heterosexuals reporting a risk factor. Between 15 and 31 percent of heterosexuals nationally and 20 and 41 percent in cities with a high prevalence of AIDS reported an HIV risk factor. Condom use was relatively low. Only 17 percent of those with multiple sexual partners, 12.6 percent of those with risky sexual partners, and 10.8 percent of untested transfusion recipients used condoms all the time. Overall, the results suggest that current HIV prevention programs have, to a very limited extent, reached those heterosexuals with multiple sexual partners but have failed to reach many other groups of the heterosexual population at risk for HIV. New public health strategies may be needed for these specific risk groups.

Identification of heme macrocycle type by near-infrared magnetic circular dichroism spectroscopy at cryogenic temperatures

The electron paramagnetic resonance (EPR) and near-infrared magnetic circular dichroism (MCD) spectra of the azide and cyanide adducts of nitrimyoglobin and hydroperoxidase II from Escherichia coli have been measured at cryogenic temperatures. For the first time, ligand-to-metal charge-transfer transitions in the near-infrared have been observed for an Fe(III)-chlorine system. It is shown that near-ultraviolet-to-visible region electronic spectra of 'green' hemes such as these are an unreliable indicator of macrocycle type. However, the combined application of EPR and near-infrared MCD spectroscopies clearly distinguishes between the porphyrin-containing nitrimyoglobin and the chlorine-containing hydroperoxidase II.

Human lipoprotein lipase: relationship of activity, heparin affinity, and conformation as studied with monoclonal antibodies

The objective of this study was to investigate how a conformational change in lipoprotein lipase (LPL) affects its molecular functions. Monoclonal antibodies (MAbs) were raised against purified bovine milk lipoprotein lipase. MAb 5D2 bound to human and bovine LPL both before and after denaturation of LPL. MAb 5F9 also recognized LPL from both species, but only after denaturation of the antigen, suggesting that a conformational change led to exposure of a previously hidden epitope. The MAbs were used in two sandwich enzyme-linked immunosorbent assays (ELISAs). One ELISA used the same MAb (5D2) to coat the plate and detect the bound antigen. This ELISA thus required the same epitope to be present in duplicate for detection (as would be the case with a dimeric antigen). The second ELISA used MAb 5F9 to coat the plate and MAb 5D2 to detect the antigen. This ELISA detected LPL only after it had been denatured. By measuring the same sample before and after denaturation with guanidine hydrochloride (GuHCl) in the 5F9 ELISA, and subtracting one from the other, a measure of native LPL was obtained. In inactivation experiments using human LPL, activity and the measure of LPL mass obtained in the 5D2 ELISA decreased and were related inversely to the measured mass obtained in the 5F9 ELISA which increased, indicating that loss of activity is closely linked to dimer dissociation and loss of native conformation. The effect of conformation and dimeric structure on LPL-heparin interaction was studied by heparin-Sepharose chromatography.(ABSTRACT TRUNCATED AT 250 WORDS)

Risk for AIDS in multiethnic neighborhoods in San Francisco, California. The population-based AMEN Study

To examine the actual and potential spread of human immunodeficiency virus (HIV) from an acquired immunodeficiency syndrome (AIDS) epicenter to surrounding neighborhoods, we studied the prevalence of the viral infection and AIDS risk behaviors from 1988 to 1989 in a representative sample of unmarried whites, African Americans, and Hispanics living in San Francisco. We surveyed 1,770 single men and women aged 20 to 44 years (a 64% response rate) in a random household sample drawn from 3 neighborhoods of varying geographic and cultural proximity to the Castro District where the San Francisco epidemic began. Of 1,369 with blood tests, 69 (5%) had HIV antibodies; all but 5 of these reported either homosexual activity (32% HIV-positive; 95% confidence interval [CI] = 23%, 41%), injection drug use (5% HIV-positive; CI = 1%, 14%), or both (59% HIV-positive; CI 42%, 74%). Homosexual activity was more common among white men than among African-American or Hispanic men, but the proportion of those infected was similar in the 3 races. Both the prevalence of homosexually active men and the proportion infected were much lower in the 2 more outlying neighborhoods. Risk behaviors in the past year for acquiring HIV heterosexually--sex with an HIV-infected person or homosexually active man or injection drug user, unprotected sexual intercourse with more than 4 partners, and (as a proxy) having a sexually transmitted disease--were assessed in 1,573 neighborhood residents who were themselves neither homosexually active men nor injection drug users. The prevalence of reporting at least 1 of these risk behaviors was 12% overall, and race-gender estimates ranged from 5% among Hispanic women to 21% among white women. We conclude that in San Francisco, infection with HIV is rare among people who are neither homosexually active nor injection drug users, but the potential for the use spread of infection is substantial, as 12% of this group reported important risk behaviors for acquiring the virus heterosexually.

Peripheral anterior synechiae formation with anterior chamber intraocular lenses

In a cross-sectional study, 88 eyes with anterior chamber intraocular lenses (AC-IOLs) were evaluated by goniophotography by one masked observer for the presence of peripheral anterior synechiae (PAS) and by another masked observer for the length of the AC-IOL. Sixty-eight of the 88 lenses had PAS which were strongly correlated with the lens being oversized (P less than .001). However, differences in haptic style or lens rigidity were not associated with the presence of PAS.

Human lipoprotein lipase. Analysis of the catalytic triad by site-directed mutagenesis of Ser-132, Asp-156, and His-241

Lipoprotein lipase (LPL) plays a central role in normal lipid metabolism as the key enzyme involved in the hydrolysis of triglycerides present in chylomicrons and very low density lipoproteins. LPL is a member of a family of hydrolytic enzymes that include hepatic lipase and pancreatic lipase. Based on primary sequence homology of LPL to pancreatic lipase, Ser-132, Asp-156, and His-241 have been proposed to be part of a domain required for normal enzymic activity. We have analyzed the role of these potential catalytic residues by site-directed mutagenesis and expression of the mutant LPL in human embryonic kidney-293 cells. Substitution of Ser-132, Asp-156, and His-241 by several different residues resulted in the expression of an enzyme that lacked both triolein and tributyrin esterase activities. Mutation of other conserved residues, including Ser-97, Ser-307, Asp-78, Asp-371, Asp-440, His-93, and His-439 resulted in the expression of active enzymes. Despite their effect on LPL activity, substitutions of Ser-132, Asp-156, and His-241 did not change either the heparin affinity or lipid binding properties of the mutant LPL. In summary, mutation of Ser-132, Asp-156, and His-241 specifically abolishes total hydrolytic activity without disrupting other important functional domains of LPL. These combined results strongly support the conclusion that Ser-132, Asp-156, and His-241 form the catalytic triad of LPL and are essential for LPL hydrolytic activity.

Condom use in multi-ethnic neighborhoods of San Francisco: the population-based AMEN (AIDS in Multi-Ethnic Neighborhoods) Study

We examined the prevalence and correlates of condom use in a community-based sample of unmarried heterosexual and gay/bisexual Whites, Blacks, and Hispanics (aged 20 to 44 years) in San Francisco (n = 1229). Only 9% of heterosexual males reported always using condoms, and fewer of those with multiple sexual partners (6%) reported always using condoms compared with those in monogamous relationships (12%). Much higher proportions of gay/bisexual men reported always using condoms (48%). Racial differences in condom use were observed only among women. Sexual communication and the sexual enjoyment value of condoms were consistent correlates of condom use across gender and sexual orientation, while other condom-related beliefs were significant predictors of condom use only for men. In general, condom promotion programs should build sexual communication skills, teach people how to enhance enjoyment with condoms, and reduce psychological barriers to condom acquisition and use.

Retinal oxygenation and laser treatment in patients with diabetic retinopathy

The oxygen tension in the preretinal vitreous cavity was measured in human patients undergoing vitreous operations for proliferative diabetic retinopathy. The oxygen tension was significantly higher (P = .004) over areas of retina that had been treated with panretinal photocoagulation than it was over untreated areas in the same retina. This confirmed previous results in animals that showed that panretinal photocoagulation increases the inner retinal oxygen tension. We concluded that panretinal photocoagulation improves the oxygen supply to the inner retina and thereby minimizes the influence of retinal ischemia in diabetic retinopathy.

Marathon running: physiological and chemical changes accompanying late-race functional deterioration

Twenty-one experienced runners were studied before, during and immediately after a marathon race to ascertain whether either depletion of energy substrate or rise in body temperature, or both, contribute to late-race slowing of running pace. Seven runners drank a glucose/electrolyte (GE) solution ad libitum (Na+ 21 mmol l-1, K+ 2.5 mmol l-1, Cl- 17 mmol l-1, PO4(2-) 6 mmol l-1, glucose 28 mmol l-1) throughout the race; 6 drank water and 8 drank the GE solution diluted 1:1 with water. Although average running speeds for the three groups were not significantly different during the first two-thirds (29 km) of the race, rectal temperature was significantly higher (P < 0.05) and reduction of plasma volume was greater (P < 0.05) in runners who replaced sweat losses with water. During the last one-third of the race, the average running pace of the water-replacement group slowed by 37.2%; the pace slowed by 27.9% in the 8 runners who replaced their sweat loss with GE diluted 1:1 with water (1/2 GE) and 18.2% in runners who replaced fluid loss with full-strength solution (GE). Eleven runners (5 in the water group, 4 in the 1/2 GE group and 2 in the GE group) lapsed into a walk/run/walk pace during the last 6 miles of the race. Ten of these had a rectal temperature of 39 degrees C or greater after 29 km of running, and plasma volume in these runners was reduced by more than 10%.(ABSTRACT TRUNCATED AT 250 WORDS)

The use of transcutaneous electrical nerve stimulation during the biliary lithotripsy procedure

Transcutaneous electrical nerve stimulation (TENS) has been suggested as a means to reduce the amount of intravenous analgesia/sedation in patients undergoing extracorporeal shock wave lithotripsy (ESWL). A retrospective analysis of 79 ESWL procedures on 73 consecutive unselected patients was done in an attempt to determine the effectiveness of TENS in reducing the amount of intravenous fentanyl citrate and/or midazolam HCl needed to control pain and anxiety during the ESWL procedure. The study was divided into two parts: (1) all patients receiving TENS (n = 44) versus a non-TENS group (n = 35), and (2) comparison of the early (n = 22) and late non-TENS (n = 22) groups against each other; separately the late non-TENS group was compared to the entire TENS group. In the study, TENS reduce the amount of fentanyl citrate needed to control anxiety by 22.9% (P less than 0.025). No difference was noted when the early and late non-TENS group of patients were compared to each other. A gender difference was noted with a significant reduction in the dose of fentanyl citrate only in female patients receiving TENS (45.4%). Likewise, there was a significant reduction in the dose of midazolam HCl only in males who had TENS (38.9%). The data suggests that TENS may be a useful addition to reduce the amount of sedation and analgesia during ESWL.

Flecainide toxicity in a neonate with supraventricular tachycardia

Class IC antiarrhythmic drugs, specifically encainide and flecainide, have been used with increasing frequency in children and young adults with both atrial and ventricular tachyarrhythmias. As a result of the recent findings from the Cardiac Arrhythmia Suppression Trial (CAST) study, their use in adults as well as children has been questioned. Because of their potential and often dangerous side effects, the child receiving a class IC drug must be monitored very closely. We report a case of flecainide toxicity in a 2 1/2-week-old neonate who was being treated for incessant supraventricular tachycardia.

Magnetization of manganese superoxide dismutase from Thermus thermophilus

The ground state magnetic properties of manganese superoxide dismutase from Thermus thermophilus in its native and reduced forms have been determined using saturation magnetization data. Parallel EPR measurements were used to verify that commonly encountered paramagnetic impurities were at low concentration relative to the metalloprotein. The native enzyme contains high spin Mn(III) (S = 2) with D = +2.44(5) cm-1 and E/D = 0. The reduced enzyme contains high spin Mn(II) (S = 5/2) with D = +0.50(5) cm-1 and E/D = 0.027. These results are in keeping with the suggestions of several previous groups of workers concerning the permissible oxidation and spin states of the manganese, but the zero field splitting parameters are unlike those of known manganese model compounds. In addition, the extinction coefficient for the visible region absorption maximum of the native enzyme and the corresponding difference extinction coefficient (native minus reduced) have been measured using saturation magnetization data to quantitate Mn(III) present. The result, epsilon 480 = 950(80) M-1 cm-1 (delta epsilon 480 = 740(60) M-1 cm-1) agrees with the previously reported value of epsilon 480 = 910 M-1 cm-1 found by total manganese determination (Sato, S. and Nakazawa, K. (1978) J. Biochem. 83, 1165-1171). The wide variation in the reported visible region extinction coefficients of manganese superoxide dismutases from different sources is discussed.

Virulent human strains of group G streptococci express a C5a peptidase enzyme similar to that produced by group A streptococci

Specific proteolytic destruction of the human chemotaxin, C5a, is a property of group A and B streptococcal pathogens. Here we show that virulent group G streptococci from human sources also express C5a peptidase activity. The enzyme responsible for this activity is approximately the same size as and is antigenically similar to that produced by group A streptococci. On the basis of Southern hybridization analysis with an internal fragment of the group A C5a peptidase gene (scpA) as a probe, a copy of this gene was found in the genome of all group G human isolates tested. Comparison of partial restriction maps of scpA and scpG revealed significant similarity between the two genes. Group G strains isolated from dogs and cows were found to lack C5a peptidase activity and did not hybridize to the scpA-specific probe. The association of this activity with three streptococcal species suggests that elimination of phagocyte chemotactic attractants is a more universal virulence mechanism than originally anticipated.

Amino acid substitution (Ile194----Thr) in exon 5 of the lipoprotein lipase gene causes lipoprotein lipase deficiency in three unrelated probands. Support for a multicentric origin

Studies on the molecular biology of lipoprotein lipase (LPL) deficiency have been facilitated by the availability of LPL gene probes and the recent characterization of gene mutations underlying human LPL deficiency. Typically, missense mutations have predominated and show a preferential localization to exons 4 and 5. This distribution supports earlier studies attributing functional significance to residues encoded by these exons. We now report a further missense mutation within exon 5 of the LPL gene in three unrelated patients. Amplification of individual exons by the polymerase chain reaction and direct sequencing revealed a T----C transition at codon 194 of the LPL cDNA which results in a substitution of threonine for isoleucine at this residue. The catalytic abnormality induced by this mutation was confirmed through in vitro mutagenesis studies in COS-1 cells. Transfection with a LPL cDNA containing the codon 194 transition resulted in the synthesis and secretion of a catalytically defective protein. The Thr194 substitution was associated with two different DNA haplotypes, consistent with a multicentric origin for this mutation.

Intradermal hepatitis B vaccination

The availability of vaccine since 1982 for immunization against hepatitis B virus (HBV) has had minimal impact on the disease; mass immunization has been suggested. Intradermal vaccination, which has precedent in prophylaxis of other infectious diseases, has been investigated as a low-cost alternative to traditional intramuscular HBV vaccination. Results of open and comparative trials indicate similar seroconversion rates for intradermal and intramuscular HBV vaccination routes in healthy adults. However, antibody titers and, presumably, duration of antibody protection appear to be decreased with intradermal HBV vaccination. Limited data suggest that demographic factors such as age and gender may affect vaccine responsiveness to intradermal HBV vaccine. Adverse skin reactions are common but do not represent a deterrent to continued intradermal HBV vaccination. There is a need for large-scale prospective comparative trials to substantiate the value of intradermal HBV vaccination. Nevertheless, the potential economic and epidemiologic benefit of intradermal vaccination justifies continued investigation for prevention of HBV infection.

The role of the nurse manager in a case management delivery system

Change and innovative nursing practice models are more the norm rather than the exception in today's acute care hospitals. Some hospitals are redesigning the workplace. A common thread in most new models of delivery include some form of managed care.