Pharmacokinetics and pharmacodynamics of GS-9350: a novel pharmacokinetic enhancer without anti-HIV activity

GS-9350 is a new chemical entity under development as a potent, mechanism-based inhibitor of human cytochrome P450 3A (CYP3A) isoforms. Its intended use is to increase the systemic exposure of coadministered agents that are metabolized by CYP3A enzymes. Unlike ritonavir, which is in current clinical use for this purpose, GS-9350 is devoid of anti-HIV activity. The pharmacokinetics of GS-9350 and its efficacy in increasing systemic exposure of the probe CYP3A substrate midazolam were examined in a study involving single- and multiple-dose escalations of GS-9350 from 50 to 400 mg. Single-dose escalation from 50 to 400 mg resulted in a 164-fold increase in GS-9350 exposure, whereas multiple-dose escalation in the dosage range of 50-300 mg resulted in a 47-fold increase in exposure. GS-9350 potently inhibited midazolam apparent clearance (95% reduction), similar in effect to ritonavir 100 mg. GS-9350 was generally well tolerated at all doses, and there was no evidence of dose-limiting toxicity. Establishing proof-of-concept, GS-9350 is currently under phase II development as a potential alternative to ritonavir for use with antiretroviral agents (including the HIV integrase inhibitor elvitegravir) that are often prescribed along with a "booster" drug.

Evidence for the neural crest origin of turtle plastron bones

The migrating cranial neural crest cells of birds, fish, and mammals have been shown to form the membranous bones of the cranium and face. These findings have been extrapolated to suggest that all the dermal bones of the vertebrate exoskeleton are derived from the neural crest ectomesenchyme. However, only one group of extant animals, the Chelonians, has an extensive bony exoskeleton in the trunk. We have previously shown that the autapomorphic carapacial and plastron bones of the turtle shell arise from dermal intramembranous ossification. Here, we show that the bones of the plastron stain positively for HNK-1 and PDGFRalpha and are therefore most likely of neural crest origin. This extends the hypothesis of the neural crest origin of the exoskeleton to include the turtle plastron.

Development of an evolutionarily novel structure: fibroblast growth factor expression in the carapacial ridge of turtle embryos

The turtle shell, an evolutionarily novel structure, contains a bony exoskeleton that includes a dorsal carapace and a ventral plastron. The development of the carapace is dependent on the carapacial ridge (CR), a bulge in the dorsal flank that contains an ectodermal structure analogous to the apical ectodermal ridge (AER) of the developing limb (Burke. 1989a. J Morphol 199:363-378; Burke. 1989b. Fortschr Zool 35:206-209). Although the CR is thought to mediate the initiation and outgrowth of the carapace, the mechanisms of shell development have not been studied on the molecular level. Here, we present data suggesting that carapace formation is initiated by co-opting genes that had other functions in the ancestral embryo, specifically those of limb outgrowth. However, there is divergence in the signaling repertoire from that involved in limb initiation and outgrowth. In situ hybridizations with antisense riboprobes derived from Trionyx spiniferous fibroblast growth factor-10 (tfgf10) and Trachemys scripta (T. scripta) fibroblast-growth factor 8 (tfgf8) cDNAs were performed on sections of early T. scripta embryos (< 30 days). Expression of tfgf10 was localized to the mesenchyme subjacent to the ectoderm of the CR. In the chick limb bud, FGF10 is known to be expressed in the early limb-forming mesenchyme and is capable of inducing FGF8 in the AER to initiate the outgrowth of the limb bud. Although the expression of tfgf8 was found in the AER of the developing turtle limb, it was not seen in the CR. Thus, the initiation of the carapace is in agreement with FGF10 expression in the CR, but FGF8 does not appear to have a role in mediating early carapace outgrowth.

Ubiquitin-dependent 26S proteasomal pathway: a role in the degradation of native human liver CYP3A4 expressed in Saccharomyces cerevisiae?

Cytochrome P450, CYP3A4, is the dominant human liver endoplasmic reticulum (ER) hemoprotein enzyme, responsible for the metabolism of over 60% of clinically relevant drugs. We have previously shown that mechanism-based suicide inactivation of CYP3A4 and its rat liver ER orthologs, CYPs 3A, via heme-modification of their protein moieties, results in their ubiquitin (Ub)-dependent 26S proteasomal degradation (Korsmeyer et al. (1999) Arch. Biochem. Biophys. 365, 31; Wang et al. (1999) Arch. Biochem. Biophys. 365, 45). This is not surprising given that the heme-modified CYP3A proteins are structurally damaged. To determine whether the turnover of the native enzyme similarly recruited this pathway, we heterologously expressed this protein in wild-type Saccharomyces cerevisiae and mutant strains (hrd1Delta, hrd2-1, and hrd3Delta) previously shown to be deficient in the Ub-dependent 26S proteasomal degradation of the polytopic ER protein 3-hydroxy-3-methylglutaryl-CoA reductase (isoform Hmg2p), the rate-limiting enzyme in sterol biosynthesis, as well as in strains deficient in ER-associated Ub-conjugating enzymes, Ubc6p and/or Ubc7p (Hampton et al. (1996) Mol. Biol. Cell 7, 2029; Hampton and Bhakta (1997) Proc. Natl. Acad. Sci. USA 94, 12,944). Our findings reveal that in common with the degradation of Hmg2p, that of native CYP3A4 also requires Hrd2p (a subunit of the 19S cap complex of the 26S proteasome) and Ubc7p, and to a much lesser extent Hrd3p, a component of the ER-associated Ub-ligase complex. In contrast to Hmg2p-degradation, that of native CYP3A4 does not appear to absolutely require Hrd1p, another component of the ER-associated Ub-ligase complex. Furthermore, studies in a S. cerevisiae pep4Delta strain proven to be deficient in the vacuolar degradation of carboxypeptidase Y indicated that CYP3A4 degradation is also largely independent of vacuolar (lysosomal) proteolytic function. The degradation of two other native ER proteins, Sec61p and Sec63p, normal components of the ER translocon, were also examined in parallel and found to be stabilized to some extent in HRD2- and UBC7-deficient strains. Together these findings attest to the remarkable mechanistic diversity in the normal degradation of ER proteins.

Structure--function relationships of rat hepatic tryptophan 2,3-dioxygenase: identification of the putative heme-ligating histidine residues

The liver cytosolic enzyme tryptophan 2,3-dioxygenase (TDO) catalyzes the oxidation of L-tryptophan to formylkynurenine and controls the physiological flux of tryptophan into both the serotonergic and kynureninic pathways. This hemoprotein enzyme is composed of four noncovalently bound subunits of equivalent mass and contains two heme moieties per molecule. Electron paramagnetic resonance analyses have indicated that a histidyl nitrogen is involved in heme ligation [Henry et al., (1976) J. Biol. Chem. 251, 1578], but the identity of the His residue(s) is unknown. In an attempt to characterize the active site of the enzyme we have substituted each of the 12 His residues in the rat TDO subunit with Ala, to determine their relative importance in heme binding. Sequence alignment of the rat liver protein with that of known or putative TDO sequences from other organisms reveals that four of the His residues are conserved in eukaryotes, two of which are also conserved in prokaryotes. Our findings indicate that replacement of the evolutionarily conserved His 76 and 328 residues resulted in a dramatic reduction of TDO activity, whereas that of the eukaryotically conserved His70 resulted in a significant reduction relative to that of the wild-type enzyme. On the other hand, replacement of the other eukaryotically conserved His273 residue, while affecting the relative expression of the enzyme, had little effect on its specific activity. Size-exclusion analyses revealed that the His76Ala and His328Ala mutants retained little or no heme, suggesting that these may be key residues in ligating the prosthetic heme moieties. Whether these His residues are both provided by the same TDO subunit or a different TDO subunit remains to be determined.

Porcine enteric spirochete infections in the UK: surveillance data and preliminary investigation of atypical isolates

Investigations into the possible causes of colitis and typhlocolitis were carried out on 98 pig units in the United Kingdom between 1997 and 1999. Brachyspira pilosicoli was identified most commonly, occurring as the suggested primary agent in 18% of the outbreaks but forming part of mixed infections in another 24% of outbreaks. The equivalent figures for other bacterial pathogens were: B. hyodysenteriae, 13% and 16%; Lawsonia intracellularis, 10% and 15%: Salmonella species, 6% and 12%; and Yersinia species, 4% and 10%. Unclassified Brachyspira species of unknown pathogenicity were identified in 12% of outbreaks. The 24 unclassified isolates divided into three groups on the basis of their phenotypic characteristics. In addition, there were 50 atypical Brachyspira species isolates that showed differences between their phenotypic characteristics and genetic identity based on sequence analysis of a section of the 23S rDNA gene. Four representative atypical isolates were found to be pathogenic as a result of an experimental oral challenge study in pigs.

Inhibition of human CYP1A2 activity in vitro by methylxanthines: potent competitive inhibition by 8-phenyltheophylline

1. Humans are exposed in vivo to methylxanthines by dietary ingestion, as well as from their use as therapeutic agents. The inhibitory effect of a series of these compounds on high-affinity phenacetin O-deethylase activity in the human liver microsomal fraction, a measure of CYP1A2 activity, has been evaluated. 2. Paracetamol, the product of phenacetin O-deethylase activity, was analysed by gas chromatography/negative-ion mass spectrometry using a novel bistrifluoromethylbenzoyl/ trimethylsilyl derivative, and incubation conditions for assessing high-affinity phenacetin O-deethylase activity were examined and optimized. 3. 1-Methylxanthine, caffeine, theophylline, 8-methylxanthine, pentoxyfylline and 3isobutyl-1-methylxanthine caused moderate inhibition with IC50 = 260, 140, 120, 100, 62 and 36 microM respectively. 4. 8-Phenyltheophylline was a potent competitive inhibitor of high-affinity phenacetin O-deethylase activity with an IC50 = 0.7 microM and Ki = 0.11 microM. 5. The specificity of inhibition by 8-phenyltheophylline was assessed by measuring its effect on debrisoquine 4-hydroxylase (CYP2D6), terfenadine hydroxylase (CYP3A4), chlorzoxazone 6-hydroxylase (CYP2E1) and tolbutamide 4-hydroxylase (CYP2C9) activities in human liver microsomal fraction. No inhibition of any of these activities was observed. 6. The potency and specificity of 8-phenyltheophylline as an inhibitor of human hepatic CYP1A2 indicate that the compound may be useful as a chemical inhibitor of this enzyme for further in vitro studies.

An opportunity for HMOs to use marketing to increase enrollee satisfaction

PURPOSE

To identify the combination of marketing components (i.e., service, price, access, and promotion) of commercial health maintenance organizations (HMOs) that are related to overall enrollee satisfaction. The researchers focus on factors that commercial HMOs control directly--specifically, health care organization and financing.

DESIGN

Descriptive (mail order).

METHODOLOGY

This study uses national data provided by a major health benefits consulting firm, which collected data from a 1997 calendar year mail survey of HMO administrators. The administrators responded to an extensive survey, which tapped selected HMO marketing-mix components and the percentage of surveyed members who indicated satisfaction with their HMOs. To test hypotheses, researchers treated marketing-mix components as independent variables and enrollee satisfaction as the dependent variable.

PRINCIPAL FINDINGS

This study found statistically significant relationships between overall satisfaction and HMO providers' quality; access, particularly to specialists and out-of-network providers; waiting times for physician services; customer service; and disease prevention/health promotion programs. The researchers did not find significant relationships between overall satisfaction and accreditation by the National Committee for Quality Assurance (NCQA), the presence of physician gatekeepers, numbers of providers, or financial indicators. The relationship between overall satisfaction and utilization was mixed. This study's findings are largely consistent with the literature, consumer- and professional-group position papers, and the President's Advisory Commission on Consumer Protection and Quality in the Health Care Industry.

CONCLUSIONS

HMOs can use marketing as a way to address problems and pursue opportunities identified by enrollees. As these findings demonstrate, certain features of HMO design are more appealing to patients. By focusing on these preferences, HMOs can adopt a responsive market orientation that gives rise to more effective marketing mixes and hence improves enrollee satisfaction. With improved satisfaction, enrollees generate less need for government intervention through regulation or legislation.

Enrollee satisfaction with HMOs and its relationship with disenrollment

Relying on 1997 data from a universe of 740 HMOs, this study uniquely documented, from the perspective of health plan administrators, rates of enrollee satisfaction and disenrollments. On the basis of various reporting totals per variable or indicator, the average level of satisfaction was 83.9%; the average number of disenrollments was 20,996 per plan. Among different datasets, an average of 18.9% members disenrolled per plan; an average of 10.2% were voluntary disenrollments; and an average of 18.3% were involuntary disenrollments. Plans with higher satisfaction enrollees had predominantly lower disenrollment rates, more enrollees likely to recommend plans to family or friends, fewer older enrollees, fewer male enrollees, and higher overall plan performance. To enhance the gaining and retaining of enrollees, plan administrators should closely monitor the various dimensions of satisfaction, such as services complement, quality of care, administrative efficiency, care management, enrollees' complaints, plan performance, appointment convenience, and waiting times.

Integration of nurse executives into executive level administration in Utah hospitals

Nurse executives (NEs) in Utah acute care hospitals perceive that they are integrated into executive level administration. This perception is shared by NEs' career supporters and hinderers. To integrate NEs, influential colleagues used active methods, especially involvement. NEs add value to the administrative team by combining clinical and managerial expertise. NE integration is manifest in decision making, participation and interaction. Continued integration depends upon commitment from the chief executive officer (CEO), leadership in organizational change, addressing "glass ceiling" issues, and NEs' continuous demonstration of competence.

Room at the top?

Nurse executives have joined hospital administrative teams, but are they accepted as fully integrated team executives? Learn how nurse executives and their influential colleagues view integration and its influences.

Academic preparation for healthcare executive-track personnel

This study focuses on career aspirations of executive-track health care administrative personnel and their perceptions of the competencies required to become hospital chief executive officers (CEOs). This article examines these topics using the results of a 1994 survey of 162 junior- and mid-level healthcare managers who work in hospitals in a western state. Respondents included 34 CEO aspirants and 128 CEO nonaspirants. The majority of both groups reported high satisfaction with several work-related activities. Significantly more CEO nonaspirants than CEO aspirants perceived a need for additional self-development in several work areas. CEO aspirants reported that CEOs five years from now would need improved strategy formulation and negotiation skills. CEO aspirants also perceived that in the future, successful CEOs will have to be more proficient in several areas, such as interpersonal skills and medical staff relations. Three lists of academic subject matter considered important to career preparation were generated from (1) the Association of University Programs in Health Administration (AUPHA) undergraduate standards, combined with curriculum graduate standards of the Accrediting Commission on Education for Health Services Administration (ACEHSA); (2) study participants' responses; and (3) professional literature. When compared for relatedness, the contents of the three lists were not significantly different statistically. The implications of these findings for health administration education are discussed.

Job satisfaction of selected categories of Utah hospital managers

In a survey of managers in Utah hospitals, 85 percent responded overall satisfaction with their jobs. Surprisingly, women in the survey reported significantly greater satisfaction with their jobs than other respondents.

Nurse executives' leadership roles. Perceptions of incumbents and influential colleagues

The authors present a leadership profile of employed nurse executives (NEs). Interviews and survey data show that the typical NE is a married, middle-aged woman who has a masters degree in clinical nursing and extensive clinical experience. When comparing NEs' and influential colleagues' perceptions of the effectiveness of NEs leadership skills, the former rate themselves higher than the latter, and both groups perceive that NEs' leadership styles are more "task motivated" than "relationship motivated." The authors apply these findings to the career planning of NEs, chief executive officers, and educators in healthcare fields.

Investigations into field cases of porcine colitis with particular reference to infection with Serpulina pilosicoli

Investigations into the possible causes of colitis and typhlocolitis were carried out on 85 pig units in the United Kingdom between 1992 and 1996. Serpulina pilosicoli was identified most commonly, occurring as the suggested primary agent on 21 (25 per cent) of the units but forming part of mixed infections on another 23 (27 per cent) of the units, the main co-infections being Yersinia pseudotuberculosis (eight units), proliferative enteropathy (six units), Salmonella species (four units) or Serpulina hyodysenteriae (two units). 'Atypical' Serpulina species, S hyodysenteriae, Salmonella typhimurium, Y pseudotuberculosis and Lawsonia intracellularis (proliferative enteropathy) were the suggested primary agents on seven, six, four, four and three units, respectively. Various combinations of mixed infections involving the latter organisms and other possibly incidental agents were recorded on another 10 units. Investigations on a further six units failed to detect any recognised pathogens. On units where S pilosicoli was the suggested primary agent, pigs ranging between 20 to 40 kg (eight to 16 weeks of age), but occasionally up to 50 kg, had diarrhoea and grew poorly over a period of two to three weeks. The prevalence was estimated to be between 5 and 15 per cent in affected batches, with a mortality of approximately 1 per cent. The clinical signs usually developed seven to 14 days after the moving and mixing of pigs. At postmortem examination, affected pigs had liquid contents in their colon, which contained accumulations of mucus in some chronic cases. Gross and histological lesions of colitis were prominent in the mid-spiral region of the colon. In mixed infections with Y pseudotuberculosis, Salmonella typhimurium or S hyodysenteriae, lesions were more extensive and affected the caecum as well as the colon. In the colon, lesions of proliferative enteropathy were usually confined to the proximal half of the ascending spiral but mixed infection with S pilosicoli caused more extensive colitis. Mixed infections were reported to prolong the time taken for pigs to recover naturally and to have a more detrimental effect on growth rates than S pilosicoli infection alone. Despite the successful treatment of batches of pigs with tiamulin or lincomycin, S pilosicoli infection persisted as a chronic problem on many units, with diarrhoea and colitis in successive batches of pigs unless prophylactic medication was used.

Hospital CEOs, CFOs, and nurse executives: opportunities for a new alliance

This article examines the involvement of Utah acute care hospital nurse executives (NEs) in financial management roles. The authors surveyed NEs and their career supporters and hinderers. Findings suggest that NFs: 1. lack financial management skills, support, involvement, and satisfaction; 2. recognize financial management's importance and desire to improve performance; and 3. consider chief executive officers (CEOs) as their major supporters and chief financial officers (CFOs) their major hinderers in financial management. These "supporters" and "hinderers" of NEs showed consensus regarding the primacy of NEs' leadership and patient advocacy roles. These findings contrast with major professional association policy directives and expert opinions that advocate expanded financial management roles for NEs that will enable them to fully realize their executive potential. CEOs are positioned to establish norms that balance the traditional leadership-patient advocacy roles of NEs with newer financial management roles. CEOs can offer NEs and CFOs opportunities to improve NEs' financial management participation and performance. CEOs can provide empowerment and encourage CFOs to offer NEs "power tools" (for example, information, expertise, resources, and support). The three groups, however, must negotiate reasonable expectations for NEs in financial management and adequate preparation for these consequent responsibilities. Together, CEOs, CFOs, and NEs can successfully take hospitals into the future by leading them in ongoing learning and change.

Hospital administrators' career paths: which way to the top?

This article examines career paths of aspirants to hospital administrator positions. It focuses on successful career objectives, barriers, and paths. The 1994 survey data from 162 hospital-employed executive track personnel in a western state facilitate comparisons with nonaspirants. Only 34 (21 percent) self-reported a goal to become an administrator. Aspirants require institutional and mentor support, and need to follow more proactive and diverse career paths than they have done previously.

Pathogenicity of three strains of Serpulina pilosicoli in pigs with a naturally acquired intestinal flora

Serpulina pilosicoli is an anaerobic spirochete which has been isolated from the colons of pigs with enteric disease. The clinical and pathologic features of experimental infections of conventional pigs (born by normal farrowing with a naturally acquired intestinal flora) with three strains of S. pilosicoli were determined in order to confirm the enteropathogenicity of this species. Strains were derived from the colons of British pigs with colitis and passaged 8 to 10 times during expansion and purification in vitro. Eighteen ten-week-old Large White-Landrace cross pigs were each inoculated once orally with 0.7 x 10(9) to 1.6 x 10(9) of one of three strains of S. pilosicoli. Six pigs were challenged with each strain. Control pigs were dosed with uninfected broth medium or with 1.8 x 10(7) cells of the nonpathogenic Serpulina innocens. Eight pigs (two to four per S. pilosicoli challenge group) developed soft or diarrheic feces (fecal dry matter < 24%) between 3 and 8 days after challenge, which persisted for 7 to 8 days or until necropsy at 14 days after challenge. Average weight gains in two of the three groups challenged with S. pilosicoli were significantly less than controls. The feed conversion ratios of all the groups challenged with S. pilosicoli were impaired compared to controls. The mean values for daily liveweight gain (and feed conversion ratio) for the three groups challenged with S. pilosicoli were 0.799 (2.13), 0.783 (2.05), and 0.844 kg (2.10), respectively, while that of the uninoculated controls was 0.944 kg (1.70). Gross lesions with slight mucosal thickening, congestion, and multifocal erosions were evident in seven of eight diarrheic pigs. The relative weights of the large intestines of pigs challenged with S. pilosicoli were significantly less than controls. Histologic lesions with an increase in mucosal height, infiltration of the lamina propria with mononuclear cells, mucosal erosion with mixed inflammatory cell infiltration, and goblet cell hyperplasia in colonic glands were evident in 15 of the 18 challenged pigs. S. pilosicoli was recovered on bacterial culture of the colon from all except one of the pigs with these histologic lesions. Serpulina sp. was clearly visible within the colonic glands of these affected pigs in silver-stained sections of the gut. Clinical and pathologic findings in control pigs were unremarkable, with no diarrhea or colonic lesions evident. The results provide further evidence that S. pilosicoli is a specific enteric pathogen for conventional pigs. It is capable of colonizing the large intestine and causing mucosal damage, which although mild is sufficient to result in significant adverse effects on growth.

Heterocyclic amines: evaluation of their role in diet associated human cancer

1. Heterocyclic amines are formed in parts per billion levels when meat is cooked. 2. The heterocyclic amines MeIQx and PhIP are efficiently absorbed into the systemic circulation after ingestion of cooked food. 3. We have shown that MeIQx and PhIP, both in vitro and in vivo, are substrates for human hepatic CYP1A2, which exclusively and efficiently catalyses their conversion to genotoxic hydroxylamines. 4. MeIQx and PhIP are promutagens. MeIQx is a very powerful bacterial mutagen whereas PhIP is a more potent mammalian cell mutagen. Using a mammalian cell target gene, hprt, we have shown that PhIP induces a characteristic mutational 'fingerprint'. 5. MeIQx and PhIP are carcinogenic in bioassays. The PhIP mutational 'fingerprint' has been detected in the Apc gene of 5/8 colonic tumours induced by PhIP in rats.

A comparison of Utah hospital CEO turnover between 1973-1987 and 1988-1992

This 1988-1992 study follows up on research on Utah hospital CEO turnover between 1973-1987. For both periods, the highest turnover rate was transfer/promotion, followed by force out, retirement, death, and quitting. There was one change: For-profits had significantly higher turnover than nonprofits. For both periods, the lowest rates of turnover and involuntary turnover were in the largest hospitals, all urban, all but one in a multihospital system, and one for-profit.

Short synthetic peptides exploited for reliable and specific targeting of antibodies to the C-termini of cytochrome P450 enzymes

An antibody was raised against a synthetic peptide (Ser-Glu-Asn-Tyr-Lys-Asp-Asn) corresponding to residues 290-296 of the cytochrome P450 enzyme, CYP1A2, of both rat and mouse. A cysteine residue attached to the N-terminus of the peptide during synthesis allowed coupling in a specific orientation via the thiol group to the carrier protein, keyhole limpet haemocyanin. Antiserum raised in rabbits bound specifically to CYP1A2 in the rat and mouse. To determine those amino acid residues involved in binding of the antibody, related peptides of various lengths were synthesised and the binding of the antibody was determined by an enzyme-linked immunosorbent assay. These studies show that the minimum epitope is the C-terminal tripeptide sequence, Lys-Asp-Asn. Other than in rat and mouse CYP1A2, this tripeptide is found as an internal sequence in a large number of proteins including bovine fibronectin, chicken gizzard myosin heavy chain, and the P450 enzymes, rabbit CYP3A6 and human CYP3A4, but the antibody did not bind to any of these proteins. However, the antibody did bind to yeast glucose-6-phosphate dehydrogenase in which the tripeptide sequence is the C-terminus. Antibodies raised against a truncated peptide (Tyr-Lys-Asp-Asn), representing the C-terminal half of the peptide, also bound to glucose-6-phosphate dehydrogenase, but failed to bind to CYP1A2; thus although the C-terminal region of the peptide 290-296 is strongly immunogenic, it appears that it is not this population of antibodies that binds to CYP1A2. As antibodies were found to bind strongly to the C-terminus of glucose-6-phosphate dehydrogenase, the C-termini of proteins as targets for anti-peptide antibodies were investigated further by immunising rabbits with four 5-residue peptides which represent the C-termini of the P450 enzymes, CYP1A1, CYP1A2, CYP2E1 and CYP2A6. The peptides were coupled to keyhole limpet haemocyanin through their N-termini via cysteine residues added to the sequences. All four antisera bound specifically to their respective target proteins, as demonstrated by immunoblotting using hepatic microsomal fractions from rat, rabbit and human. It is suggested that this method of antibody production could be of general use for the reliable production of antisera against proteins where their sequence at the C-terminus is known, and such antibodies can be highly specific as they do not bind to internal sequences.

Revenue enhancement through total quality management/continuous quality improvement (TQM/CQI) in outpatient coding and billing

To survive and thrive, rural hospitals are seeking enhanced revenues. This study focuses on outpatient laboratory and radiology coding and billing accuracy in a nonrandom sample of seven rural hospitals in a Western state. Information was gathered on (1) procedures incorrectly coded, (2) potential revenue increases from correct coding and billing, (3) barriers to implementing changes, and (4) perceived audit value. The identified major source of potential revenue enhancement was increased fees from private payers. Correct coding and billing to Medicare and Medicaid offered the potential of additional revenue. Participating administrators appreciated the validation of coding and billing practices and identification of potential enhanced revenues. Five of seven hospitals (71.4%) selectively implemented recommended changes. Complete compliance with recommended changes was limited by barriers of tradition, competition, and reimbursement, which must be overcome to realize successful implementation. Joint Commission on Accreditation of Healthcare Organization's (JCAHO) new Total Quality Management/Continuous Quality Improvement (TQM/CQI) emphasis provides an opportunity for revenue enhancement through coding/billing assessments and interdepartmental focus and coordination.

The new nurse executive. An emerging role

In recent years, the nurse executive (NE) has become an integral part of the hospital administrative team. The position has taken on a higher profile, and many questions are surfacing about every facet of NE administration. Since 1991, the literature is replete with articles discussing the new NE role. This article is a review summary and consolidation of 19 recently published articles, selected from a much broader list of periodical articles. It also reflects the results of six focus groups with hospital administrators and NEs in both urban and rural healthcare delivery settings. The summary pinpoints attributes identified as essential to an NE and those areas in which more research is needed. It also discloses that to function effectively, the new NE must have flexible and action-oriented personality qualities, possess executive level business management skills, have completed some graduate level degree work, and be an expert on clinical affairs. Future research should concentrate on the diverse educational needs of NEs and how to best meet those needs.

Contribution of CYP1A1 and CYP1A2 to the activation of heterocyclic amines in monkeys and human

The activation of heterocyclic amines to mutagenic products by hepatic microsomal fractions from cynomolgus monkey, marmoset monkey and man was compared with the respective levels of cytochrome P450 enzymes CYP1A1 and CYP1A2. The rate of activation of 2-amino-3,8-dimethylimidazo[4,5-f] quinoxaline (MeIQx), 2-amino-3-methylimidazo[4,5-f]quinoline (IQ) and 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP) to mutagens by hepatic microsomal fraction from cynomolgus monkey was very low. This was associated with a lack of constitutive expression of CYP1A1 and CYP1A2. In contrast, human hepatic microsomal fraction readily activates these heterocyclic amines and this is associated with constitutive expression of CYP1A2. Treatment of cynomolgus monkey with 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) causes a very modest induction of CYP1A2, and a small increase in the activation of MeIQx and IQ. However, there was marked induction of CYP1A1 which was accompanied by > 10-fold increases in PhIP activation and 7-ethoxyresorufin O-deethylase (EROD), 7-methoxyresorufin O-demethylase (MROD) and aryl hydrocarbon hydroxylase activities. Following treatment of cynomolgus monkey with 3-methylcholanthrene, induction of CYP1A1, but not CYP1A2, was evident. In untreated marmoset monkey the activations of MeIQx and PhIP, as well as phenacetin O-deethylase, EROD, MROD and aryl hydrocarbon hydroxylase activities, are similar to those in man, although the activations of IQ and coumarin 7-hydroxylase activity are lower than in man. The presence of constitutive CYP1A2, and the absence of CYP1A1, in the liver of this species correspond to the situation in man. Treatment of marmoset monkey with TCDD results in increased CYP1A2 levels (4-fold), accompanied by proportional increases in the activation of MeIQx and IQ and phenacetin O-deethylase, EROD and MROD activities. The activation of PhIP is increased disproportionately, by 8-fold, most likely due to the activity of CYP1A1 which is also induced by TCDD in this species. Overall, the hepatic metabolism of heterocyclic amines by CYP1A enzymes in the untreated marmoset monkey resembles that in human more closely than that in the cynomolgus monkey. Therefore, marmoset monkey may be a more suitable model than the cynomolgus monkey for carcinogenicity studies involving MeIQx and PhIP, but not IQ.

Methods for optimizing revenue in rural hospitals

Rural hospitals have been failing over the last two decades, and one of the biggest reasons has been lack of attention paid to detail and accuracy in the coding and pricing of services rendered. Most research that has explored the problems of coding accuracy and its impact on reimbursement has focused on coding by medical record professionals, but many coding procedures are performed by "front line" lower-level employees working in a hospital's laboratory, radiology department, pharmacy, or other ancillary service departments. This article explains how rural hospitals can optimize their reimbursement and adhere to Medicare/Medicaid and other third-party payer regulations by training coders properly and by reviewing their pricing policies to make sure that prices charged accurately reflect the true cost of services.

Identification of the epitope of an anti-peptide antibody which binds to CYP1A2 in many species including man

An anti-peptide antibody was raised against the sequence Thr-Gly-Ala-Leu-Phe-Lys-His-Ser-Glu-Asn-Tyr-Lys which occurs at positions 283-294 in the rat cytochrome P450 enzyme CYP1A2. Compared with its binding to the peptide used for immunization, the antibody bound with only slightly reduced affinity to the truncated peptides Thr-Gly-Ala-Leu-Phe-Lys-His-Ser and Leu-Phe-Lys-His-Ser. However, binding to the peptide Ser-Glu-Asn-Tyr-Lys-Asp-Asn, which overlaps with the C-terminal region of the immunizing peptide, was very low. Thus, a major epitope for the anti-peptide antibody is Leu-Phe-Lys-His-Ser, which corresponds to a region of CYP1A2 that is conserved in many species. The antibody was tested by immunoblotting for its ability to bind to hepatic microsomal fractions from a number of species. Where possible animals were treated with compounds which induce CYP1A2 and the results compared with those with untreated animals. It was found that the antibody bound to rat, mouse, rabbit, hamster, guinea pig, pig, marmoset monkey and human CYP1A2. No evidence was found for binding to dog CYP1A2. The region corresponding to the major epitope at residues 286-290 of rat CYP1A2 was identical in mouse, hamster, rabbit and human CYP1A2. The sequence of marmoset and guinea pig CYP1A2 are not known but are predicted to be very similar to the sequence in the rat. The lack of binding of the antibody to dog CYP1A2 may be explained by two differences in this region compared with rat CYP1A2. Maximum inhibition of CYP1A2 activity by this antibody, as measured by high-affinity phenacetin O-deethylase activity, was 20%. This is in contrast to a previously described anti-peptide antibody directed to an adjacent region which caused 65% inhibition of this activity. Thus, the edge of an inhibitory region on the surface of cytochrome P450 has been identified. The ability of the antibody to bind to CYP1A2 from a number of animals should make this antibody of use for studying the levels of CYP1A2 apoprotein in many species.

Human hepatic CYP1A1 and CYP1A2 content, determined with specific anti-peptide antibodies, correlates with the mutagenic activation of PhIP

Mono-specific antibodies targeted to human CYP1A1 and CYP1A2 have been produced by immunizing rabbits with protein conjugates of short synthetic peptides corresponding to residues 290-297 and 284-296 respectively, of these enzymes. The antibody targeted to CYP1A1 bound in immunoblotting to the recombinant protein expressed in yeast but did not bind to any human hepatic microsomal protein, whereas the antibody targeted to CYP1A2 bound only to this enzyme in immunoblotting of human hepatic microsomal fractions and did not recognize recombinant human CYP1A1. The intensity of hepatic microsomal CYP1A2 immunoreactivity (n = 5) correlated significantly with a number of activities characteristic of this enzyme: phenacetin O-deethylase (POD), ethoxyresorufin O-deethylase (EROD) and methoxyresorufin O-demethylase activities and the ability to activate the dietary carcinogen 2-amino-3,8-dimethylimidazo[4,5-f]quinoxaline (MeIQx), to a mutagen. The anti-CYP1A2 anti-peptide antibody consistently inhibited both POD and EROD activities, but inhibition was incomplete (28%). In view of the known (> 90%) contribution of CYP1A2 to these activities and the correlation with antibody binding, this is consonant with an epitope for the anti-CYP1A2 anti-peptide antibody that forms the edge of a functionally important proinhibitory surface region previously identified in rat cytochromes CYP1A. CYP1A2 immunoreactivity determined by immunoblotting correlated significantly with the ability of human hepatic microsomal fractions to activate 2-amino-1-methyl-6-phenylimidazo[4,5-b] pyridine (PhIP), another dietary carcinogen, to a mutagen. It is concluded that CYP1A1 is absent from human liver and that CYP1A2 is likely to be a major catalyst in the hepatic activation of PhIP.

An inhibitory monoclonal anti-protein antibody and an anti-peptide antibody share an epitope on rat cytochrome P-450 enzymes CYP1A1 and CYP1A2

A monoclonal antibody, 12/2/3/2, which was raised against purified rat CYP1A1 recognises specifically rat and mouse CYP1A1 and CYP1A2, but not any cytochrome P-450 present in hepatic microsomal fractions from rabbit, guinea pig, hamster or human. By comparing the primary sequences of cytochromes P-450 to which 12/2/3/2 does and does not bind, 10 possible locations for its epitope were found. Of these, one was extremely hydrophilic and, hence, predicted to be the most antigenic in the native protein. An antibody was produced against the synthetic peptide corresponding to this region (Gly-Arg-Asp-Arg-Gln-Pro-Arg-Leu: residues 356-363 and 350-357 of rat CYP1A1 and CYP1A2, respectively). The antibody bound to rat, mouse and hamster CYP1A1 and to rat and mouse CYP1A2, but did not bind to any protein present in hepatic microsomal fractions from the rabbit, guinea pig or human. The binding of the anti-peptide antibody to CYP1A1 or CYP1A2 was partially antagonised by the monoclonal antibody. However, whereas the monoclonal antibody inhibited both CYP1A1- (aryl hydrocarbon hydroxylase) and CYP1A2-(high-affinity phenacetin O-deethylase) dependent monooxygenase activity, the anti-peptide antibody was without effect on these activities. Antigen denaturation by 8 M urea or 0.05% (w/v) SDS had no effect on binding of the anti-peptide antibody to cytochrome P-450, whilst binding of the monoclonal antibody was reduced by more than 1000-fold. The anti-peptide antibody partially antagonised the binding of 12/2/3/2 to urea-denatured but not native cytochrome P-450. These data suggest that whilst the complete binding site for the monoclonal antibody is discontinuous, sufficient of the epitope is linear, so that when the antigen is denatured the monoclonal antibody is still able to bind and this binding is antagonised by the anti-peptide antibody. However, inhibition of catalytic activity by the monoclonal antibody must require binding to discontinuous residues.

N-hydroxy-MeIQx is the major microsomal oxidation product of the dietary carcinogen MeIQx with human liver

2-Amino-3,8-dimethylimidazo[4,5-f]quinoxaline (MeIQx), one of the most abundant of the heterocyclic aromatic amines formed during the cooking of meat, is genotoxic and carcinogenic in rodents. MeIQx requires metabolic activation by P450 before it can exert these effects. Whilst there is indirect evidence that the mutagenic product is N-hydroxy-MeIQx (N-OHMeIQx), we have now identified this unequivocally following incubation of the amine with human hepatic microsomal fraction. A mixture of unlabelled MeIQx, [13C,15N2]MeIQx and [14C]MeIQx was used as substrate and the products analysed by HPLC-thermospray mass spectrometry. Characteristic doublet ions, 3 mass units apart, were found at m/z 214/217 ([M+H]+) from the parent compound, MeIQx and at 230/233 ([M+H]+) from N-OHMeIQx. The presence of a doublet ion at m/z 214/217 with the doublet at 230/233 [M+H+] provided additional evidence that this was N-OHMeIQx, as facile loss of 'O' is characteristic of N-hydroxylamines. Further evidence for the identity of the major metabolite, which accounted for approximately 90% of all microsomal metabolism, was obtained by comparing the mutagenicity of the HPLC eluate using Salmonella typhimurium YG1024, which is particularly sensitive to N-hydroxylamines, and TA98/1,8-DNP6 which is resistant to most N-hydroxylamines. Ninety-five per cent of direct-acting mutagenicity present in the reaction mixture was associated with a single peak, which co-eluted with N-OHMeIQx, as indicated by mass spectrometry. In the presence of a metabolic activation system, only one additional mutagenic peak, corresponding to unchanged MeIQx, could be detected. MeIQx (5 microM) was N-hydroxylated at a rate of 77 +/- 11 pmol/mg/min (mean +/- SEM, n = 4) by human liver microsomes. The specific inhibitor of human CYP1A2, furafylline (5 microM) inhibited the N-hydroxylation of MeIQx by > 90%. These data show that N-OHMeIQx is both the major oxidation product and the major genotoxic product of MeIQx generated by microsomal fractions of human liver and that the reaction is catalysed almost exclusively by CYP1A2.

Identification of the epitope of a monoclonal antibody which binds to several cytochromes P450 in the CYP1A subfamily

The monoclonal antibody, 3/4/2, which was raised against purified rat cytochrome P450 isoenzyme 1A1 (CYP1A1) binds to cytochromes P4501A in many species. It was shown by immunoblotting that the antibody binds to CYP1A1 in microsomal fractions prepared from rat, mouse, rabbit, hamster and human. The antibody also binds to cytochrome P450 isoenzyme 1A2 in microsomal fractions prepared from rabbit and human, but not rat or mouse. Using purified isoenzymes in an enzyme-linked immunosorbent assay it was found that the affinity of binding to the two rabbit hydrocarbon-inducible isoenzymes is reduced compared with that for rat CYP1A1. Binding is not affected by denaturation of the antigens. The effects of chemical and enzymatic treatments on rat CYP1A1 showed that the epitope contains a trypsin-sensitive site that includes arginine, but lacks lysine. The epitope does not contain methionine, cysteine, aspartic acid or glutamic acid residues. In addition, digestion of the protein with cyanogen bromide produces a fragment of Mr 20,000 which contains the antibody binding site. By comparing the cross-reactivity of the antibody with the primary structures of CYP1A1 and 1A2 from the rat, mouse, rabbit and human, and by considering the results of the chemical and enzymatic treatments, it was possible to deduce the likely location and structure of the binding site of 3/4/2 on members of the CYP1A subfamily. It is concluded that the epitope for this antibody is Phe-Arg-His-Ser-Ser-Phe, which lies at positions 380-385 in rat CYP1A1. Further, it is predicted from a model of the tertiary structure of eukaryotic cytochrome P450 that a part of this binding site lies within a helix in the native protein.

Identification of a functionally conserved surface region of rat cytochromes P450IA

A region of rat cytochrome P450IA1 at residues 294-301 (Gln-Asp-Arg-Arg-Leu-Asp-Glu-Asn), equivalent to a proinhibitory region of cytochrome P450IA2, was identified by sequence alignment. Anti-peptide antibodies were successfully raised when the peptide was coupled through either its N- or its C-terminus to carrier protein, but no antibodies were produced against the so-called multiple peptide antigen, which consisted of eight copies of the peptide attached through its C-terminus to a synthetic base. Both of the anti-peptide antibodies bound specifically to cytochrome P450IA1 in the rat, as shown by e.l.i.s.a. and immunoblotting. They inhibited microsomal aryl hydrocarbon hydroxylase activity and the mutagenic activation of 2-acetylaminofluorene (these reactions are catalysed by cytochrome P450IA1), but not high-affinity phenacetin O-de-ethylation activity, which is catalysed by cytochrome P450IA2. However, there was differences in the properties of the two antisera in their binding to cytochromes P450IA1 in species other than the rat, their relative binding to the multiple peptide antigen, the yield of antibody following affinity purification using peptide coupled through its N-terminus to CNBr-activated Sepharose, and the binding of the purified preparations to N- and C-terminal-coupled peptide conjugates. These observations indicated that the antibodies were directed to the region of the peptide opposite to the end which was coupled to the carrier protein. Nevertheless, both of the antibody preparations bound equally well to the target cytochrome P450, thus indicating that, in the native protein, the whole of the peptide region is exposed on the surface of cytochrome P450IA1 and is available for binding by the antibodies. The role of this region appears to be the same in both cytochromes P450IA1 and P450IA2, despite the difference in its primary structure in the two cytochromes P450.

Orientation of cytochromes P450 in the endoplasmic reticulum

The orientation of eukaryotic cytochromes P450, with respect to the membrane of the endoplasmic reticulum, has been investigated. There is now good evidence that the tertiary structure of these proteins is essentially the same as that of the soluble bacterial isoenzyme cytochrome P450CI, with the exception of an extension at the N-terminus which is thought to form a membrane-anchoring sequence. The remainder of the molecule protrudes from the cytosolic face of the membrane so that it can interact with substrates and electron-donating proteins. Two models based on this structure have been considered, in which the plane of the heme of cytochrome P450 is oriented either parallel with or perpendicular to the plane of the membrane of the endoplasmic reticulum. The validity of these models has been assessed from the results of studies involving the binding of antipeptide antibodies directed toward known regions of cytochromes P450, modeling of the interaction of cytochrome P450 with cytochrome b5, proposed intramolecular movements of cytochrome P450 during its catalytic cycle, and the partitioning of substrates for cytochrome P450 between the cytosol and membrane. It is concluded that cytochrome P450 is most likely oriented such that the heme is not fixed horizontal to the plane of the membrane of the endoplasmic reticulum and may well lie with the heme perpendicular to the membrane.

Species variation in the response of the cytochrome P-450-dependent monooxygenase system to inducers and inhibitors

1. In the safety evaluation of drugs and other chemicals it is important to evaluate their possible inducing and inhibitory effects on the enzymes of drug metabolism. 2. While many similarities exist between species in their response to inducers and inhibitors, there are also important differences. Possible mechanisms of such variation are considered, with particular reference to the cytochrome P-450 system. 3. Differences in inhibition may be due to differences in inhibitory site of the enzyme involved, which is not always the active site of the enzyme, in competing pathways or in the pharmacokinetics of the inhibitor. 4. Differences in induction could be due to differences in the nature of the induction mechanism, in the isoenzyme induced, in tissue- or age-dependent regulation, in competing pathways for the substrate or its products, or in the pharmacokinetics of the inducing agent. 5. Examples of each of these possible differences are considered, often from our own work on the P450 IA subfamily, and results in animals are compared with those in humans, where possible. 6. At present, the differences between species in their response to inducers and inhibitors make extrapolation to humans from the results of animal studies difficult, so that ultimately such effects should be studied in the species of interest, humans.

Furafylline is a potent and selective inhibitor of cytochrome P450IA2 in man

1. Furafylline (1,8-dimethyl-3-(2'-furfuryl)methylxanthine) is a methylxanthine derivative that was introduced as a long-acting replacement for theophylline in the treatment of asthma. Administration of furafylline was associated with an elevation in plasma levels of caffeine, due to inhibition of caffeine oxidation, a reaction catalysed by one or more hydrocarbon-inducible isoenzymes of P450. We have now investigated the selectivity of inhibition of human monooxygenase activities by furafylline. 2. Furafylline was a potent, non-competitive inhibitor of high affinity phenacetin O-deethylase activity of microsomal fractions of human liver, a reaction catalysed by P450IA2, with an IC50 value of 0.07 microM. 3. Furafylline had either very little or no effect on human monooxygenase activities catalysed by other isoenzymes of P450, including P450IID1, P450IIC, P450IIA. Of particular interest, furafylline did not inhibit P450IA1, assessed from aryl hydrocarbon hydroxylase activity of placental samples from women who smoked cigarettes. 4. It is concluded that furafylline is a highly selective inhibitor of P450IA2 in man. 5. Furafylline was a potent inhibitor of the N3-demethylation of caffeine and of a component of the N1- and N7-demethylation. This confirms earlier suggestions that caffeine is a selective substrate of a hydrocarbon-inducible isoenzyme of P450 in man, and identifies this as P450IA2. Thus, caffeine N3-demethylation should provide a good measure of the activity of P450IA in vivo in man. 6. Although furafylline selectively inhibited P450IA2, relative to P450IA1, in the rat, this was at 1000-times the concentration required to inhibit the human isoenzyme, suggesting a major difference in the active site geometry between the human and the rat orthologues of P50IA2.

Turnover at the top: Utah hospital CEOs in a turbulent era

This retrospective study describes the rate and causes of CEO turnover between 1973 and 1987 in Utah community and noncommunity hospitals. Both voluntary (i.e., self-initiated) and involuntary (i.e., organization-initiated) turnover were examined. For the overall period, the annual average turnover rate was 16.6 percent; the major component was the category "taking another hospital administration position or promoted within a multihospital system." In recent years, the turnover rate has been increasing, and the category of those being forced out has been comprising an increasing percentage of the turnover. For the 15-year period, the lowest rate of turnover and turnover due to force out were in the largest hospitals--all of which are urban, all but one of which belongs to a multihospital system, and none of which is for profit. Future research should incorporate retrospective and prospective studies to better understand, predict, and control hospital CEO turnover.

An anti-peptide antibody targeted to a specific region of rat cytochrome P-450IA2 inhibits enzyme activity

An anti-peptide antibody has been produced which binds to and specifically inhibits the activity of cytochrome P-450IA2 in rat hepatic microsomes. This was achieved by raising an antibody against a synthetic peptide (Ser-Glu-Asn-Tyr-Lys-Asp-Asn), the sequence of which occurs in cytochrome P-450IA2 at positions 290-296. The selection of this region of cytochrome P-450IA2 was based on several criteria, including prediction of surface and loop areas, identification of variable regions between cytochromes P-450IA2 and P-450IA1, and consideration of a site on cytochrome P-450IA1 where chemical modification has been shown to cause substantial enzyme inactivation. The specificity of antibody binding was determined by enzyme-linked immunosorbent assay and by immunoblotting using hepatic microsomal preparations and purified cytochrome P-450 isoenzymes. This showed that the antibody binds specifically to rat and mouse cytochrome P-450IA2 and to no other cytochrome P-450, as was predicted from the amino acid sequences of the peptide and the cytochromes P-450. The effect of the antibody upon enzyme activity was studied in hepatic microsomes from rats treated with 3-methylcholanthrene. The antibody was shown to inhibit specifically the activity of reactions catalysed by cytochrome P-450IA2 (phenacetin O-de-ethylase and 2-acetylaminofluorene activation), but had no effect on aryl hydrocarbon hydroxylase activity, which is catalysed by cytochrome P-450IA1, or on aflatoxin B1 activation.

Identification and location of alpha-helices in mammalian cytochromes P450

A model of the alpha-helical structure of mammalian cytochromes P450 is proposed. The location and sequence of alpha-helices in mammalian cytochromes P450 were predicted from their homology with those of cytochrome P450cam, and these sequences were generally confirmed as helical in nature by using a secondary structure prediction method. These analyses were applied to 26 sequences in 6 gene families of cytochrome P450. Mammalian cytochromes P450 consist of approximately 100 amino acid residues more than cytochrome P450cam. This difference was accounted for by three major areas of insertion: (1) at the N-terminus, (2) between helices C and D and between helices D and E, and (3) between helices J and K. Insertion 1 has been suggested by others as a membrane anchoring sequence, but the apparent insertions at 2 and 3 are novel observations; it is suggested that they may be involved in the binding of cytochrome P450 reductase. Only the mitochondrial cytochrome P450 family appeared to show a major variation from this pattern, as insertion 2 was absent, replaced by an insertion between helices G and H and between helices H and I. This may reflect the difference in electron donor proteins that bind to members of this cytochrome P450 family. Other than these differences the model of mammalian cytochromes P450 proposed maintains the general structure of cytochrome P450cam as determined by its alpha-helical composition.

Hospital administrators in a market environment: the case of Utah

This study describes selected characteristics of hospital administrators in Utah, who are implementing a market strategy of cost containment. A mail survey was used to query hospital administrators concerning their personal backgrounds, professional practice patterns, and perceived role performance. The questionnaire elicited a 75.6 percent return from a limited universe sample. Analytical results disclose that Utah hospital administrators are relatively young, professionally dynamic, well educated, and subject to frequent career-motivated moves. Using Mintzberg's ten administrative roles, respondents identified two as key: "Leader" ranks as the role performed best, the role second most critical to survival, second best prepared for, second most time-consuming, and second most satisfying. "Entrepreneur" ranks as the role most critical to survival, most satisfying, most deserving of improvement, second least prepared for, and second best performed. Suggestions for innovative ways in which administrators can develop their skills to be better prepared to meet future challenges are listed.

Satisfaction with care and the utilization of dental services at a neighborhood health center

The purpose of this research was to develop further information relevant to the problem of utilization of dental services at neighborhood health centers. The research objectives were: (1) A descriptive assessment of the utilization trends of the population served by a neighborhood health center; (2) Some determination of any possible correlation between failed appointments and patients' satisfaction with dental care; and, (3) Some exploration of possible reasons for non-utilization of scheduled dental appointments by a sample of patients from the neighborhood health center who report a history of previous dental treatment. From dental clinic daily appointment sheets, an assessment of utilization trends of a neighborhood health center population for a seven-month period (jon trends of a neighborhood health center population for a seven-month period (June 1, 1973 to December 31,1973) was obtained. In addition, analyses of patient treatment records and information obtained from personal interviews with 40 individuals from the health center population facilitated the completion of the second and third research objectives. The results indicated: (1) Compared to the findings of earlier research,-3 the reported ratio of broken to total appointments scheduled for this study population was substantially lower; (2) There is a rather strong relation between satisfaction with care and the utilization of dental services at the neighborhood health center studied; (3) Satisfaction with care is dependent upon a number of factors; and (4) Reasons given for nonutilization of scheduled dental services are practical ones, of which some are also reflected in the reasons given ofr dissatisfaction with dental care.