Neurological damage and duodenopancreatic reflux in the pathogenesis of alcoholic pancreatitis.

OBJECTIVE: To present a new theory on the pathogenesis of acute alcoholic pancreatitis based on experimental data, the significance of which has not been recognized, and on evidence from the current literature. HYPOTHESIS: That chronic alcoholism damages muscarinic receptors in the pancreas, duodenum, and Oddi sphincter, producing heightened sensitivity to acetylcholine, stimulation of protein-rich pancreatic juice, hypertonicity of the duodenum and esophagus, relaxation of the Oddi sphincter, and intraduodenal pressures exceeding those shown to cause duodenopancreatic reflux and acute pancreatitis in humans and experimental animals. OUTCOME: The duodenopancreatic reflux mechanism can explain all of the clinical features of acute alcohol pancreatitis, including the intraductal site and rapid activation of zymogens by enterokinase, the recurrent episodes of pancreatitis, the precipitation of protein plugs by partial proteolytic hydrolysis, the severe vascular changes, the relation to infection by the most direct route, and the progression to chronic pancreatitis via the necrosis-fibrosis sequence. CONCLUSIONS: Damage to the nervous system, with a time lag of 5 to 15 years between the onset of heavy drinking and the development of neurological disorders (peripheral neuropathy and cerebellar degeneration), is a characteristic complication of chronic alcoholism. The similarity to events in alcoholic pancreatitis is striking.

Exploring dimensions of access to medical care.

This paper examines the dimensions of the access concept with particular attention to the extent to which more parsimonious indicators of access can be developed. This process is especially useful to health policy makers, planners and researchers in need of cost-effective social indicators of access to monitor the need for and impact of innovative health care programs. Three stages of data reduction are used in the analysis, resulting in a reduced set of key indicators of the concept. Implication for subsequent data collection and measurement of access are discussed.

Antibiotic screening of medicinal plants of the British Columbian native peoples.

One hundred methanolic plant extracts, 96 of which had documented medicinal uses by British Columbian native peoples, were screened for antibiotic activity against 11 bacterial strains. Eighty-five percent were found to have significant antibiotic activity against at least two of the bacteria tested. Ninety-five percent of the plants categorized as potential antibiotics based on their ethnobotanical usage were found to exhibit significant antibiotic activity. Seventy-five were found to be active against methicillin-resistant Staphylococcus aureus, 46 were active against an antibiotic supersusceptible strain of Pseudomonas aeruginosa and 18 of these were also active against a wild type strain. The extracts with the broadest spectra of activity were prepared from: Alnus rubra bark and catkins, Fragaria chiloensis leaves, Moneses uniflora aerial parts, and Rhus glabra branches.

Antifungal screening of medicinal plants of British Columbian native peoples.

One hundred methanolic plant extracts were screened for antifungal activity against 9 fungal species. Eighty-one were found to have some antifungal activity and 30 extracts showed activity against 4 or more of the fungi assayed. The extracts with the greatest fungal inhibition were prepared from Alnus rubra catkins, Artemisia ludoviciana aerial parts, Artemisia tridentata aerial parts, Geum macrophyllum roots, Mahonia aquifolium roots and Moneses uniflora aerial parts. In addition to these, extracts prepared from the following plants also exhibited antifungal activity against all 9 fungi: Asarum caudatum whole plant, Balsamorhiza sagittata roots, Empetrum nigrum branches, Fragaria chiloensis leaves, Gilia aggregata aerial parts and roots, Glehnia littoralis roots, Heracleum lanatum roots, Heuchera cylindrica roots and Rhus glabra branches.

Antimicrobial constituents of Rhus glabra.

The antimicrobial activity of the methanol extract and isolated constituents of Rhus glabra (Anacardiaceae), a species used in folk medicine by North American native people, was evaluated against 11 microorganisms, including gram-positive and gram-negative bacteria. The extract was subsequently fractionated and monitored by bioassays leading to the isolation of three antibacterial compounds, the methyl ester of 3,4,5-trihydroxybenzoic acid (methyl gallate) (minimal inhibition concentration (MIC) 12.5 micrograms/ml), 4-methoxy-3,5-dihydroxybenzoic acid (MIC 25 micrograms/ml) and gallic acid (MIC > 1000 micrograms/ml). The first two compounds are reported here for the first time from Rhus glabra. Their structures were established using spectroscopic and chemical methods.

Antiviral screening of British Columbian medicinal plants.

One hundred methanolic plant extracts were screened for antiviral activity against seven viruses. Twelve extracts were found to have antiviral activity at the non-cytotoxic concentrations tested. The extracts of Rosa nutkana and Amelanchier alnifolia, both members of the Rosaceae, were very active against an enteric coronavirus. A root extract of another member of the Rosaceae, Potentilla arguta, completely inhibited respiratory syncytial virus. A Sambucus racemosa branch tip extract was also very active against respiratory syncytial virus while the inner bark extract of Oplopanax horridus partially inhibited this virus. An extract of Ipomopsis aggregata demonstrated very good activity against parainfluenza virus type 3. A Lomatium dissectum root extract completely inhibited the cytopathic effects of rotavirus. In addition to these, extracts prepared from the following plants exhibited antiviral activity against herpesvirus type 1: Cardamine angulata, Conocephalum conicum, Lysichiton americanum, Polypodium glycyrrhiza and Verbascum thapsus.

Testing the effects of an empowerment-based leadership development programme: part 1 - leader outcomes.

AIM: To determine if a leadership development programme based on an empowerment framework significantly increased leaders' use of empowering behaviours. BACKGROUND: Leadership programmes are effective ways to prepare nurse leaders for their complex roles. Relational competencies, such as leader empowering behaviours, are associated with improved leader, staff and practice environment outcomes. METHODS: A quasi-experimental, pre-test-post-test design was used to compare perceptions and self-reported behaviours of leaders who participated in a year-long leadership programme with those of similar leaders who did not attend the programme. Multiple regression analyses were used to evaluate a conceptual framework of leader empowerment. RESULTS: The leadership programme was directly associated with leaders' perceptions of using more empowering behaviours. Leader empowering behaviours were also associated with feelings of being structurally empowered, mediated through feelings of being psychologically empowered, although the source of empowerment needs further investigation. CONCLUSIONS: Leaders' use of empowering behaviours can be increased through focused training and through a workplace empowerment process. IMPLICATIONS FOR NURSE MANAGEMENT: Leader empowering behaviours have been shown to be associated with more engaged staff and healthier work environments. Based on study results, we suggest that these behaviours are teachable, and they should be emphasized in leadership development programmes.

Testing the effects of an empowerment-based leadership development programme: part 2 - staff outcomes.

AIM: To determine if nurse leaders' attendance at a leadership development programme based on an empowerment framework would increase staff perceptions of organisational support and organisational commitment. BACKGROUND: Leadership empowering behaviours are teachable relational competencies that have been associated with quality leader-staff relationships and positive staff outcomes. METHODS: A quasi-experimental, pre-test-post-test design was used to compare perceptions of staff whose leaders participated in a year-long leadership programme with staff of similar leaders who did not attend the programme. A series of multiple regression analyses were used to test the conceptual model of programme effects. RESULTS: Leaders' programme participation was directly associated with greater staff organisational commitment 1 year after the programme. Both programme attendance and leader-empowering behaviours were found to act as independent catalysts for staff empowerment, with structural empowerment partially mediating the effects of leader empowering behaviours on organisational commitment. CONCLUSIONS: Leader participation in a development programme based on an empowerment framework may be an important means of increasing staff organisational commitment, a key predictor of staff turnover. IMPLICATIONS FOR NURSE MANAGEMENT: Leadership development programmes should emphasize relational competencies, including leader empowering behaviours, given their potential for enhancing organisational commitment.

Structural-chemical evolution within exfoliated clays.

The exfoliated (delaminated) structures of lamellar clays offer potential as precursors for the formation of various nanostructured materials. In this article, Lucentite and Laponite phyllosilicate clays, which both have empirical formulas of Na(0.33)[Mg(2.67)Li(0.33)Si4O10(OH)2] but differ in nanodimensions, have been exfoliated. Experiments were carried out for mixtures containing approximately 1 wt % phyllosilicate in a 5% aqueous solution of poly(acrylic acid) at different temperatures. X-ray diffraction and photoemission spectroscopy measurements for the solid products recovered after stirring the mixtures at 20 degrees C showed that the fully extended chains of poly(acrylic acid) were intercalated within the interlayer spaces between the silicate plates of the clays. At 85 degrees C, however, the clays were exfoliated and/or partially exfoliated. Photoemission spectroscopy also indicated that the exfoliated structures primarily consisted of silica nanoplates. 29Si nuclear magnetic resonance and oxygen K-edge near-edge X-ray absorption fine structure indicated that the surfaces of the plates were terminated by high concentrations of the silanol (-SiOH) groups, which created structural branches during intercalation. A model was developed in which intercalation and the removal of ions from the clays after the poly(acrylic acid) interactions reduced the electrostatic van der Waals forces between the plates. It was also shown that the formation of branches created a steric effect that inhibited the stacking of the plates. Together these resulted in exfoliation.

Multiple group association models with latent variables: an analysis of secular trends in abortion attitudes, 1972-1988.

This paper examines methods for integrating latent class models with association and conditional association models, including those in multiple groups. These methods are shown to be generalizable to a wide range of association models in which one or more variables is latent and shown to be especially well suited to modeling temporal changes (tends) in latent structures. Like the usual association model, association models with latent variables utilize the information inherent in the ordering of the categories. Consequently, these models require the estimation of fewer parameters and are preferred to loglinear models that may require the estimation of substantial numbers of parameters even for models with a moderate number of observed variables. Following a discussion of the formal model, an example is considered. This example focuses on the American public's approval (disapproval) of legalized abortion from 1972 to 1988.

Patterns of drug use among white institutionalized delinquents in Georgia: evidence from a latent class analysis.

Previous research by Kandel [1] and others indicates that adolescent drug use follows a progression from legal drugs, through marijuana, to hard drugs. In this study of drug use patterns, institutionalized delinquents were found to follow a similar progression of drug use. Unlike previous studies which used "rule of thumb" methods of model assessment, this study uses probabilistic assessment of the models. Importantly, the present study supports a modified gate-way sequence, where cocaine use appears as an intermediate step between marijuana use and use of other hard drugs. It is suggested that widespread availability of cocaine in the late 1980's may have resulted in a new "step" in the drug use sequence.

DSM-III major depressive disorder in the community. A latent class analysis of data from the NIMH epidemiologic catchment area programme.

The fit of the structure of DSM-III major depressive disorder to data from two large epidemiological surveys is assessed by latent class analysis. The surveys were conducted at the Baltimore and Raleigh-Durham sites of the National Institute of Mental Health (NIMH) Epidemiologic Catchment Area Program. Three classes are required to fit the data, and the third class bears a strong resemblance to major depressive disorder, although it requires slightly more symptoms to be present than DSM-III. The derived structure replicates successfully for Baltimore and Raleigh-Durham, with a prevalence of the major depression category of 0.9% for both sites.

Mammalian reovirus M3 gene sequences and conservation of coiled-coil motifs near the carboxyl terminus of the microNS protein.

Nucleotide sequences of the mammalian orthoreovirus (reovirus) type 1 Lang and type 2 Jones M3 gene segments were newly determined. The nucleotide sequence of the reovirus type 3 Dearing M3 segment also was determined to compare with a previously reported M3 sequence for that isolate. Comparisons showed Lang and Dearing M3 to be more closely related than either was to Jones M3, consistent with previous findings for other reovirus gene segments. The microNS protein sequences deduced from each M3 segment were shown to be related in a similar pattern as the respective nucleotide sequences and to contain several regions of greater or less than average variability among the three isolates. Identification of conserved methionine codons near the 5' ends of the Lang, Jones, and Dearing M3 plus strands lent support to the hypothesis that microNSC, a smaller protein also encoded by M3, arises by translation initiation from a downstream methionine codon within the same open reading frame as microNS. Other analyses of the deduced protein sequences indicated that regions within the carboxyl-terminal third of microNS and microNSC from each isolate have a propensity to form alpha-helical coiled coils, most likely coiled-coil dimers. The new sequences will augment further studies on microNS and microNSC structure and function.

Endoscopic balloon dilatation of biliary strictures.

The case of a 67-year-old woman who had a long history of recurrent cholangitis after repeated biliary tract surgery, and whose clinical course was complicated by the development of multiple biliary strictures and secondary biliary cirrhosis, is reported. Nasobiliary drainage was used to successfully decompress the biliary system and to control infection during an acute episode of cholangitis. Subsequent endoscopic, hydrostatic balloon dilatation of the major bile-duct strictures resulted in an improvement in her clinical condition which was supported by the results of biochemical tests.

Reovirus nonstructural protein muNS binds to core particles but does not inhibit their transcription and capping activities.

Previous studies provided evidence that nonstructural protein muNS of mammalian reoviruses is present in particle assembly intermediates isolated from infected cells. Morgan and Zweerink (Virology 68:455-466, 1975) showed that a subset of these intermediates, which can synthesize the viral plus strand RNA transcripts in vitro, comprise core-like particles plus large amounts of muNS. Given the possible role of muNS in particle assembly and/or transcription implied by those findings, we tested whether recombinant muNS can bind to cores in vitro. The muNS protein bound to cores, but not to two particle forms, virions and intermediate subvirion particles, that contain additional outer-capsid proteins. Incubating cores with increasing amounts of muNS resulted in particle complexes of progressively decreasing buoyant density, approaching the density of protein alone when very large amounts of muNS were bound. Thus, the muNS-core interaction did not exhibit saturation or a defined stoichiometry. Negative-stain electron microscopy of the muNS-bound cores revealed that the cores were intact and linked together in large complexes by an amorphous density, which we ascribe to muNS. The muNS-core complexes retained the capacity to synthesize the viral plus strand transcripts as well as the capacity to add methylated caps to the 5' ends of the transcripts. In vitro competition assays showed that mixing muNS with cores greatly reduced the formation of recoated cores by stoichiometric binding of outer-capsid proteins mu1 and sigma3. These findings are consistent with the presence of muNS in transcriptase particles as described previously and suggest that, by binding to cores in the infected cell, muNS may block or delay outer-capsid assembly and allow continued transcription by these particles.

Mammalian reovirus L2 gene and lambda2 core spike protein sequences and whole-genome comparisons of reoviruses type 1 Lang, type 2 Jones, and type 3 Dearing.

The reovirus L2 genome segment encodes the core spike protein lambda2, which mediates enzymatic reactions in 5' capping of the viral plus-strand transcripts. Complete nucleotide-sequence determinations were made for the L2 genome segments of eight mammalian reoviruses, including the prototype isolates of serotypes 1 and 2: Lang (T1L) and Jones (T2J), respectively. Each L2 segment was found to be 3912 or 3915 bases in length. Partial nucleotide-sequence determinations were also made for the 3916-base L2 segment of reovirus type 3 Dearing (T3D), the prototype isolate of serotype 3. The whole-genome sequence of reovirus T3D was reported previously. The T1L L2 analysis represents completion of the whole-genome sequence of that isolate as well. The T2J L2 analysis leaves only the sequence of the M1 segment yet to be reported from the genome of that isolate. The T2J M1 sequence made available from analysis in another lab was used for initiating whole-genome comparisons of reoviruses T1L, T2J, and T3D in this report. The nine L2 gene sequences and deduced lambda2 protein sequences were used to gain further insights into the biological variability, structure, and functions of lambda2 through comparisons of the sequences and reference to the crystal structure of core-bound lambda2. Phylogenetic comparisons suggest the presence of three evolutionary lines of divergent L2 alleles among the nine isolates. Localized regions of conserved amino acids in the lambda2 crystal structure include active-site clefts of the RNA capping enzyme domains, sites of interactions between lambda2 domains within the pentameric spike structure, and sites of interaction between lambda2 subunits and other proteins in viral particles.