The establishment of an integrated skills training centre for undergraduate nursing education.

AIM: This paper details the experience of establishing an integrated skills training centre for use in undergraduate nursing education in The Open University of Hong Kong. BACKGROUND: Skills training is an essential element in undergraduate nursing education. Owing to the increasing complexity of the health-care system and patient health needs, undergraduate nursing students should be well prepared for integrated skills competency, critical thinking and rapid decision-making. To achieve this goal, the use of simulation as a skills training tool is being recommended. CONCLUSION: The Clinical Nursing Education Centre is established. It adopts simulation as a teaching and learning tool. It has four specific education units, namely: (1) clinical simulation education unit, (2) virtual reality education unit, (3) nursing skills education unit, and (4) Chinese medicinal education unit. These units are specifically designed for the teaching and learning of nursing skills related to general, mental and Chinese medicinal nursing from elementary to advanced level. Experiences pertaining to the conceptualization, exploration and actualization phases of the establishment are presented. Details of the structure and specific functions of the centre are also illustrated. Finally, there is discussion on the challenges encountered during the establishment process and how they were overcome.

Predictors of important neurological causes of dizziness among patients presenting to the emergency department.

OBJECTIVES: Dizziness is a common presenting complaint in the emergency department (ED). This prospective study describes the incidence, causes and outcome of ED patients presenting with dizziness and tries to identify predictors of central neurological causes of dizziness. METHODS: Single-centre prospective observational study in a university teaching hospital ED in Hong Kong. All ED patients (> or = 18 years old) presenting with dizziness were recruited for 1 month. Symptoms, previous health, physical findings, diagnosis and disposition were recorded. The outcome at 3 months was evaluated using hospital records and telephone interviews. Follow-up was also performed at 55 months using computerised hospital records to identify patients with subsequent stroke and those who had died. RESULTS: 413 adults (65% female, mean 57 years) were recruited. The incidence of dizziness was 3.6% (413/11 319). Nausea and/or vomiting (46%) and headache (20%) were the commonest associated findings. Hypertension (33%) was the commonest previous illness. Central neurological causes of dizziness were found in 6% (23/413) of patients. Age > or = 65 years (OR=6.13, 95% CI 1.97 to 19.09), ataxia symptoms (OR=11.39, 95% CI 2.404 to 53.95), focal neurological symptoms (OR=11.78, 95% CI 1.61 to 86.29), and history of previous stroke (OR=3.89, 95% CI 1.12 to 13.46) and diabetes mellitus (OR=3.57, 95% CI 1.04 to 12.28) predicted central causes of dizziness. CONCLUSIONS: Most dizzy patients had benign causes. Several clinical factors favoured a diagnosis of central neurological causes of dizziness.

Estimating the rate of re-expansion of spontaneous pneumothorax by a formula derived from computed tomography volumetry studies.

BACKGROUND: Available evidence suggesting that the rate of re-expansion of spontaneous pneumothorax is 1.25%/day is based on a small sample and mathematical modelling-based estimates. AIM: To estimate the rate of re-expansion of spontaneous pneumothoraces by a formula derived from computed tomography volumetry studies. METHODS: This retrospective study included adult patients with spontaneous pneumothorax, identified from patient management databases, who were treated conservatively. Medical records were reviewed to confirm that no intervention such as aspiration or catheter drainage had occurred. Radiographs were reviewed independently by two researchers and measured according to the method described by Collins et al. Their formula was used to estimate pneumothorax size on each date. The rate of re-expansion was defined as the change in size (%)/number of days between radiographs. Patients were excluded if they did not have at least two radiographs taken, at least 1 day apart. Data were analysed using cluster analysis by patient to minimise the effect of repeated measures from an individual patient. RESULTS: 88 episodes were identified in 57 patients. 82% were men and the patients had a median age of 22 years. The average rate of re-expansion was 2.2%/day (95% confidence interval 1.4% to 3.0%), but varied between -7.5% and 13.4%/day. CONCLUSION: Spontaneous pneumothoraces treated conservatively re-expand at an average rate of 2.2%/day.

Niacin-positive Mycobacterium kansasii isolated from immunocompromised patients.

Niacin-positive Mycobacterium kansasii was isolated from three patients, two with respiratory infections and one with a perirectal abscess. The isolates were phenotypically similar to other strains of M. kansasii, differing only in their ability to produce niacin. This phenotype has been reported only twice in the literature, during the 1960s.

Activity of antimicrobial agents against Mycobacterium avium-intracellulare complex (MAC) strains isolated in Italy from AIDS-patients.

Twenty-five strains of Mycobacterium avium-intracellulare (MAC) isolated from acquired immunodeficiency syndrome (AIDS) patients in three medical centres in Italy have been studied. Serotyping performed on eighteen strains showed various serovars within either M. avium or M. intracellulare serotypes and with serovars 1 and 21 being the most prevalent (four strains for each serovar). Among fourteen drugs used for testing the antibiotic sensitivity, rifapentine, rifabutin and clofazimine showed to have the best in vitro activity. In an ex vivo model of infection using peritoneal resting macrophages from the C57BL/6 mouse, the intracellular viability of a strain of M. avium (strain 489, serovar 3) was reduced by clofazimine, amikacin, ciprofloxacin, rifabutin and clarithromycin (99, 98, 93, 89 and 69%, respectively), thus indicating for clofazimine a good correlation between in vitro and ex vivo activity.

Comprehensive approach to identification of serovars of Mycobacterium avium complex.

Serotyping of nontuberculous mycobacteria, especially those of the Mycobacterium avium complex, provides important epidemiological information, particularly in tracing origins of infections. Seroagglutination with whole cells and polyclonal rabbit antibodies was the original way of identifying serovars and is still commonly used. The discovery of the glycolipid nature of the typing antigens allows differentiation of serovars on the basis of thin-layer chromatography of whole antigens and gas chromatography-mass spectrometry of the characteristic sugars of the oligosaccharide haptens of these antigens. In particular, the generation of monoclonal antibodies to the glycolipid antigens allows facile differentiation of serovars through enzyme-linked immunosorbent assay. All of these protocols were applied in developing a comprehensive approach to the typing of members of the M. avium complex.

Clinical and epidemiological importance of typing of Mycobacterium avium complex isolates.

The results of the application of a range of typing procedures to the identification and classification of 6,264 cultures of nontuberculous mycobacteria from human sources and the environment are reported. Seroagglutination, an enzyme-linked immunosorbent assay applied to whole bacteria or the glycolipid typing antigens and based on serovar-specific polyclonal or monoclonal antibodies, thin-layer chromatography of these antigens, and gas chromatography of their specific sugar determinants were used to arrive at identifications. As a result of this comprehensive approach, 4,452 (71%) of all cultures and 88% of those of samples from patients with AIDS proved to be typeable. The rank order of frequency of occurrence of individual organisms within the entire group of isolates was Mycobacterium avium complex serovar 4 greater than serovar 8 greater than serovar 1 greater than serovar 9 greater than serovar 6 greater than serovar 14 greater than serovar 2 greater than M. fortuitum greater than M. kansasii greater than M. xenopi greater than an apparent mixture of serovar 4 and M. xenopi greater than a mixture of serovar 4 and serovar 8. These results were similar but not identical to the pattern observed for isolates obtained from patients with AIDS; the order was M. avium complex serovar 4 greater than serovar 8 greater than serovar 1 greater than a mixture of serovar 4 and M. xenopi, a mixture of serovar 4 and serovar 8 greater than serovar 9 greater than serovar 2 greater than serovar 6. Serotyping was also used to demonstrate the possible clinical significance of nontuberculous mycobacteria recovered from different body sites. Other information on the distribution of M. avium serovars in patients from different geographical environments is provided.

Serovars of Mycobacterium avium complex isolated from patients in Sweden.

The serovars of clinical isolates of Mycobacterium avium complex from 24 acquired immunodeficiency syndrome (AIDS) and 140 non-AIDS patients in Sweden were studied by using type-specific antisera. A wide distribution of serovars was seen. Serovar 6 was predominant in both groups of patients, isolated from 33 and 16% of the AIDS and non-AIDS patients, respectively. The results indicate geographical as well as disease-related differences in the distribution of M. avium complex serovars of clinical importance.

Development of an automated human sperm quality system.

A computer-automated system, including hardware and software components, is developed for objective assessment of human sperm density and other characteristics, including morphological abnormalities and motility. The hardware component essentially consists of an IBM AT, a relatively low-cost image processing board and other inexpensive commercially available instruments. On the other hand, the software component is developed through the incorporation of image analysis, pattern recognition and modelling techniques with the knowledge of human reproduction from the available literature. The whole system is expected to produce a practical and cost-effective means for the routine assessment of human semen quality.

Generation of monoclonal antibodies to the specific sugar epitopes of Mycobacterium avium complex serovars.

Monoclonal antibodies have been generated to the unique distal sugar epitopes on the oligosaccharide haptens of the glycopeptidolipid antigens of clinically prominent members of the Mycobacterium avium serocomplex. Thus, antibodies are described that recognize the distal O-acetyl-alpha-L-rhamnopyranosyl residue of the specific glycopeptidolipid of M. avium serovar 1, the 4-O-acetyl-2,3-di-O-methyl-alpha-L-fucopyranose of serovar 2, the 4-O-methyl-alpha-L-rhamnopyranosyl-(1----4)-2-O-methyl-alpha-L- fucopyranosyl unit of serovar 4, the 4,6-(1'-carboxyethylidene)-3-O-methyl-beta-D-glucopyranosyl unit of serovar 8 [and the 4,6-(1'-carboxyethylidene)-beta-D-glucopyranosyl residue of serovar 21], and the 4-O-acetyl-2,3-di-O-methyl-alpha-L-fucopyranosyl-(1----4)-beta-D- glucuronopyranosyl unit of serovar 9. Epitope definition was arrived at through use of the pure, chemically defined glycopeptidolipid antigens and neoglycoproteins containing the chemically synthesized distal sugars of some select serovars. These monoclonal antibodies combined with the already published information on the structure of the antigen determinants and the tools used to arrive at these structures provide powerful means for fundamental studies on the role of these antigens in immunopathogenesis and for the precise mapping of the epidemiology of opportunistic infections caused by M. avium.

Speciation of organisms within the Mycobacterium avium-Mycobacterium intracellulare-Mycobacterium scrofulaceum (MAIS) complex based on restriction fragment length polymorphisms.

A DNA probe which hybridizes to all pathogenic species of slow-growing mycobacteria has been used to identify restriction-fragment-length-polymorphisms (RFLPs) in Bam Hl digests of chromosomal DNA from members of the Mycobacterium avium-Mycobacterium intracellulare-Mycobacterium scrofulaceum complex. The RFLP patterns so produced were found to fall into distinct categories which were representative of each of the three species. Except for two doubtful isolates, strains of M. avium were found to fall into two related RFLP-types, one of which contained the vast majority of the strains tested. In contrast, M. intracellulare strains were found to be more heterogeneous. For these strains, we found one major RFLP-type and one subsidiary type which appears to be a sub-set of the first. We also found two further RFLP-types which contained serovars 7 and 18 respectively. We conclude from this that M. avium, M. intracellulare and M. scrofulaceum are three distinct species and that serovars belonging to the 'intermediate group' of Meissner and Anz belong to the species M. avium. Utilizing these criteria, we examined a number of isolates from the 'ambiguous' serovar 9 and found that of eight strains tested, six typed as M. avium and two typed as M. intracellulare.

Concentration of Mycobacterium avium by hospital hot water systems.

Water from 34 sites on two temporarily vacant hospital floors was analyzed for the presence of mycobacteria. These sites included 18 cold water taps and 16 hot water taps, including shower heads. A total of 14 sites (41%) demonstrated the presence of Mycobacterium avium as confirmed by biochemical characterization, DNA/rRNA probe analysis, and seroagglutination. Of positive sites, 11 were hot water sources with an average temperature of 55 degrees C and yielding up to 500 colony-forming units per 100 mL. Seven of 11 strains analyzed for glycolipid antigens were identified with the type 4 serovar, the preponderant serovar of M avium in patients with acquired immunodeficiency syndrome from the Boston area. Potable hot water systems, particularly those that generate aerosols, may contain concentrations of M avium greater than those found in cold water systems and could serve as an environmental source for colonization and infection of immunocompromised persons.

Mycobacterium avium complex pseudobacteriuria from a hospital water supply.

From July 1983 through November 1985, organisms belonging to Mycobacterium avium complex were isolated from the urine of 29 patients. Strains recovered from the urine of nine patients from July 1983 through August 1984 were serotyped. Eight of the nine samples belonged to serovar 4. M. avium complex was isolated from the urine of 21 patients during the period from November 1984 through November 1985. While the possibility of a point source contamination was investigated, M. avium complex was recovered from the phenol red solution used for processing urine specimens in the mycobacteriology laboratory and the deionized tap water of that laboratory that is used to make the reagent. M. avium complex serovar 4 was subsequently recovered from the tap water of the laboratory and four hospital wards. During the year following the installation of a microbiological filter for the mycobacteriology laboratory deionized tap water, 2 urine isolates were recovered, compared to 26 the previous year. This study demonstrates the importance of filtration devices at tap water sites that are used to make laboratory reagents and the value of serotyping as a marker for the detection of a specific source of M. avium complex contamination.

Definition of the surface antigens of Mycobacterium malmoense and use in studying the etiology of a form of mycobacteriosis.

Mycobacterium malmoense is the latest of a roster of atypical mycobacteria implicated in pulmonary infections. Yet it lacks recognizable phenotypic features to allow its ready identification. Some 23 clinical isolates of M. malmoense were examined for homologous seroagglutination reactions and characteristic surface antigens. One group showed concordant agglutination interreactions and an identical spectrum of glycolipids and are regarded as M. malmoense sensu stricto. The glycolipids are of the newly found, trehalose-containing lipooligosaccharide class. De-O-acylation followed by high-pressure liquid chromatography revealed one major and several minor oligosaccharides. Partial acidic cleavage to release glycosidically linked trehalose, alpha-mannosidase digestion to demonstrate the presence of a non-reducing-end mannobiose, perdeuteriomethylation, partial acid hydrolysis, reduction, and O ethylation, combined with 1H nuclear magnetic resonance and electron impact and fast-atom bombardment mass spectrometry revealed the structure of the major oligosaccharide as alpha-D-Manp-(1----3) -alpha-D-Manp-(1----[2-alpha-L-Rhap-(1--]4--3)-alpha-L-Rh ap- (1----3)-alpha-D-Glcp-(1----1)-alpha-D-Glcp, in which two of the 2-alpha-L-Rhap residues are O methylated at C-3. (Man, mannose; Rha, rhamnose; Glc, glucose; p, pyranosyl). The structures of the minor oligosaccharides were also determined; they differ at the distal nonreducing end. The dominant oligosaccharide was acylated by octanoate, 2-methyleicosanoate, and 2,4-dimethylpentacosanoate to yield the major species-specific surface antigen of M. malmoense, which we regard as the most characteristic feature of the pathogen.

Structure and antigenicity of the specific oligosaccharide hapten from the glycopeptidolipid antigen of Mycobacterium avium serotype 4, the dominant Mycobacterium isolated from patients with acquired immune deficiency syndrome.

A large number of patients with acquired immune deficiency syndrome develop disseminated infections due to member serotypes of the Mycobacterium avium complex. Seroagglutination on 181 such isolates followed by enzyme-linked immunosorbent assay and thin layer chromatography of the type-specific glycopeptidolipid (GPL) antigens demonstrated that the majority of serotypes were M. avium serotype 4. The specific GPL of serotype 4 was isolated in both the native, acetylated, and the deacetylated forms and its oligosaccharide hapten released as the oligosaccharide alditol by reductive beta-elimination. A comprehensive structural analytical approach developed for more complex carbohydrates was applied to the oligosaccharide alditol in order to reveal glycosyl and glycosyl-linkage composition, sequence arrangements, ring forms, and enantiomeric and anomeric configurations. The structure of the triglycosyl alditol was established as, 4-O-Me-L-Rhap-(alpha 1----4)-2-O-Me-L-Fucp-(alpha 1----3)-L-Rhap- (alpha 1----2)-6-deoxytalitol, in which the nonreducing-end disaccharide unit is unique to serotype 4. The native GPL antigen is diacetylated, presumably at other than the terminal disaccharide, since the antigenicity of both the acetylated and deacetylated antigens are comparable. The structure of the epitope of the type-specific antigen of serotype 4 will serve as the basis for synthetic antigen probes and the target for the monoclonal antibodies required to trace the origins in the environment of the infectious agent and study the epidemiology of human infections.

Mycobacterium avium-M. intracellulare isolates from patients with or without acquired immunodeficiency syndrome.

Susceptibility testing and serotyping were performed on 57 isolates of Mycobacterium avium-M. intracellulare from patients with acquired immunodeficiency syndrome (AIDS) and 75 isolates from patients without AIDS. Susceptibility patterns and serotypes of AIDS isolates were significantly different from those of non-AIDS isolates. These results may partially explain the poor therapeutic response of M. avium-M. intracellulare infections in AIDS patients.

Comparison of 15 laboratory and patient-derived strains of Mycobacterium avium for ability to infect and multiply in cultured human macrophages.

Mycobacterium avium is a cause of nontuberculous chronic granulomatous infections which is attracting increased attention as a frequent opportunistic pathogen in acquired immunodeficiency syndrome. Some important aspects of its human pathogenicity were investigated by using cultured human macrophages infected with it. The uptake and replication of various strains of M. avium in the macrophages could be measured by CFU counts of the bacteria in samples of lysed, sonicated macrophages. Microscopic counts of acid-fast bacilli were not useful because the bacteria multiplying in the macrophages were usually not acid fast. Electron microscopy showed the intracellular bacilli to multiply by transverse fission, to be surrounded in individual vacuoles by a broad electronlucent zone, and to have thinner cell walls than extracellularly grown M. avium. Fifteen strains, including examples of serovars 1, 2, 4, 8, and 9, were studied for uptake and rate of replication in cultured macrophages from three normal subjects. The strains were isolates from patients with nontuberculous granulomatous infection, acquired immunodeficiency syndrome, or unrelated problems, or they were laboratory reference cultures. There were no differences among them in phagocytosis, but there were differences in intracellular replication. Laboratory strains tended to be avirulent, that is, they did not replicate in the macrophages. Patient isolates usually were virulent and could be compared for virulence by intracellular replication rates. Virulence correlated with flat, transparent bacterial colony morphology on nutrient agar but not with serovar or kind of patient from whom the bacteria were isolated. However, among strains of transparent colony morphology there were wide differences in virulence. A virulent bacilli generally produced domed, opalescent colonies on nutrient agar. A virulent bacilli predominated in populations of M. avium conditioned to growth in bacteriologic culture medium. Bacilli of virulent colony morphology predominated in populations passaged through cultured macrophages. The model described here presents a new approach to the investigation of the pathogenicity of M. avium for human subjects and may be more patient relevant than animal models.