Role of Thin Fimbriae in Adherence and Growth of Acinetobacter calcoaceticus RAG-1 on Hexadecane

Acinetobacter calcoaceticus RAG-1, a hydrocarbon-degrading bacterium which adheres avidly to hydrocarbons and other hydrophobic surfaces, possesses numerous thin fimbriae (ca. 3.5-nm diameter) on the cell surface. MR-481, a nonadherent mutant of RAG-1 which is unable to grow on hexadecane under conditions of limited emulsification and low initial cell density, lacks these fimbriae. Prolonged incubation of MR-481 in hexadecane medium enriched for partial adherence revertants. The reappearance of thin fimbriae was observed in all such revertant strains. RAG-1 cells and partial revertant strains were agglutinated in the presence of antibody, whereas MR-481 cells were not. Another mutant, AB15, which was previously isolated on the basis of its nonagglutinability in the presence of antibody, also lacked thin fimbriae and was conditionally nonadherent. Furthermore, strain AB15 was unable to grow on hexadecane medium. Adherence of RAG-1 cells to hexadecane was considerably reduced after shearing treatment. The material removed from the cell surface by shearing of RAG-1 and the partial revertant strains yielded a single antigenic band in RAG-1 and partial revertant strains, as observed by crossed immunoelectrophoresis. This band was absent in both fimbriae-less mutants, MR-481 and AB15. The data demonstrate that the thin fimbriae of RAG-1 (i) are a major factor in adherence to polystyrene and hydrocarbon, (ii) may be crucial in enabling growth of cells on hexadecane, and (iii) constitute the major cell surface agglutinogen.

Emulsan in Acinetobacter calcoaceticus RAG-1: Distribution of Cell-Free and Cell-Associated Cross-Reacting Material

Emulsan is an extracellular polymeric bioemulsifier produced by Acinetobacter calcoaceticus RAG-1. Antibodies prepared against purified emulsan inhibited the activity of the polymer in a standard emulsification test. These antibodies were used to develop a sensitive enzyme-linked immunosorbent assay to monitor changes in cell-free emulsan throughout the growth cycle. This assay was also used to detect emulsan associated with the cell surface and to monitor changes in the distribution of cell-free and cell-associated emulsan throughout the growth cycle. Cells in the early exponential phase exhibited relatively large amounts of cell-associated emulsan which decreased rapidly between the midexponential and early stationary phases. This drop in cell-associated material was accompanied by a rise in the concentration of extracellular polymer. Moreover, in agreement with previous results (C. Rubinovitz, D. L. Gutnick, and E. Rosenberg, manuscript in press), production of cell-free emulsan was enhanced in the presence of chloramphenicol. The release of this material from the cell surface in the presence of chloramphenicol apparently involved the synthesis of cell-associated cross-reacting material since the relative amount of such cell-bound polymer remained constant during the treatment with the drug.

Interruptions and resistance: a comparison of medical consultations with family and trained interpreters

While working with trained interpreters in health care is strongly recommended, few studies have looked at the subtle differences in communication processes between trained and "ad hoc" interpreters, such as adult family members. Using Habermas' Communicative Action Theory (CAT) which distinguishes between the Lifeworld (contextually grounded experiences) and the System (decontextualized rules), we analysed 16 family practice consultations with interpreters, 10 with a trained interpreter and 6 with a family member. We found clear differences in communication patterns between consultations with a trained interpreter and consultations with a family member as interpreter. In both cases the Lifeworld is frequently interrupted and the outcomes are similar: the Lifeworld is rarely heard and acknowledged by the physician. Physicians interrupt the Voice of the Lifeworld significantly more with a trained interpreter than with a family member. Family members and trained interpreters also interrupt the Voice of the Lifeworld just as much. However, these interruptions differ in their functions (both physicians and interpreters interrupt to keep the interview on track to meet the biomedical goals; family interpreters interrupt to control the agenda). We have identified patients' resistance when physicians ignore their Lifeworld, but this resistance is usually only transmitted by professional interpreters (and not by family interpreters). We identified specific risks of working with family interpreters: imposing their own agenda (vs. the patient's one) and controlling the consultation process. Even if the collaboration with trained interpreters becomes more widespread, work with "ad hoc" interpreters will continue to occur. Therefore, institutions should provide training and organizational support to help physicians and patients to achieve communication in all situations.

Uranium binding by emulsan and emulsanosols

Emulsan, the extracellular bioemulsifier of Acinetobacter RAG-1, bound up to 0.9 microm of uranium per 1 mg emulsan. The dissociation constant for the emulsan-uranium complex, K(app) (I) was 1.2 x 10(-4)M. Much larger amounts of uranium were bound to emulsan when the biopolymer occurred on hexadecane-water interfaces. Under these conditions, more than 3.5 microm uranium were bound per 1 mg emulsan and the dissociation constant K(app) (II) was 5.1 x 10(-5)M. At pH 2, more than 90% of the uranium bound to emulsan on the hexadecane-water interface was desorbed, while less than 10% bioemulsifier was released from the interface. The different binding parameters of emulsan when free in solution and while adsorbed onto the hexadecane water interface are discussed in view of potential applications and as a model system for studying the properties of an extracellular amphipathic polymer bound to a hydrophobic surface.

Deviation from Archie's law in partially saturated porous media: Wetting film versus disconnectedness of the conducting phase

We experimentally study the electrical transport in partially water-saturated pore network. The porous medium under investigation is a Fontainebleau sandstone, characterized by x-ray tomography. We show the existence of two electrical conductivity regimes. At high water saturation, the electric resistivity follows a well-known Archie law. Below a water saturation S_{w} approximately 0.2 , a strong negative deviation from this Archie law is observed. We attribute this transition to the existence of "a thick liquid film," assuring the ionic conduction in the low saturation regime. A numerical simulation is proposed to confirm this scenario. Two possible protocols are used to distribute the brine phase in the pore network of a three-dimensional microtomography image. The first one is based on a minimization of the interfacial energy. The second takes into account a quasistatic capillary displacement. The classical random-walk algorithm is used to compute the electric conductivity at various water saturations. Without the "thick film," both of the two fluid-placing protocols show a disconnectedness transition of the brine phase when S_{w}<0.2 . Adding this "film" to solid surface, the electrical continuity is maintained. The bending down trend is correctly reproduced, showing that in this range, the electric response cannot be described by a power law as usual.

Healthy Israel 2020: a visionary national health targeting initiative

This article describes the development of a national health targeting initiative entitled 'Healthy Israel 2020' which was created to enhance the health and wellbeing of Israelis through a variety of health promotion and disease prevention interventions. This initiative builds upon the experience of two major worldwide targeting efforts, "Health People 2010" of the US and the World Health Organization's Health21', as well as lessons learned from other countries. Important philosophical underpinnings are highlighted, particularly the evidence-based nature of the process. Real-world organizational and policy challenges and creative solutions are presented. It is hoped that this report will be of value to others in Israel and elsewhere who are interested in improving the health of their nations.

The Experience of Abused Women With Their Children's Law Guardians

In-depth unstructured interviews are conducted with previously abused divorced mothers about their experience with law guardians of their children. Interviews are transcribed and their content analyzed using ATLAS.ti software. Nine themes clustered in the following three groups emerge: perceived performance of law guardians; perceived shortcomings of the system, which provides a context for interaction with law guardians; and emotional effects on women. These themes are discussed and illustrated, and implications for practice are suggested.

Through interpreters' eyes: comparing roles of professional and family interpreters

OBJECTIVE

We describe and compare the perceptions of professional and family member interpreters concerning their roles and tasks as interpreters in primary care clinical encounters.

METHODS

Encounters between physicians (19) and patients (24) accompanied by a professional (6) or a family (9) interpreter were videotaped. Stimulated recall was used to elicit interpreters' perceptions of their role in the clinical encounter. We analyzed transcriptions of the interpreter interviews using Atlas-ti software.

RESULTS

The roles professional interpreters identified were: information transfer; creating a safe environment for the patient; mediation between cultures; maintaining professional boundaries. Family interpreters perceived their roles (facilitating understanding; ensuring diagnosis and treatment; interacting with the health care system) as part of their responsibilities as a family member.

CONCLUSION

Professional interpreters act mainly to ensure information transfer. Family interpreters act mainly as a third participant often speaking as themselves rather than rendering the words of doctor and patient into the other's language.

PRACTICE IMPLICATIONS

To obtain the maximum benefit from a professional interpreter the physician must invite the interpreter to act as an advocate for the patient and a culture broker. Physicians should always use a professional interpreter to ensure accurate information transfer. A family member should often be included in encounters to serve as a valuable patient advocate.

Doctor-patient communication in primary care with an interpreter: physician perceptions of professional and family interpreters

OBJECTIVE

This paper explores physician perceptions of the ways professional and family interpreters affect their performance of doctor-communication tasks described in the Calgary-Cambridge Framework.

METHODS

Physicians' (19) encounters with patients (24) accompanied by an interpreter were videotaped. Stimulated recall was used to elicit each of the participants' perceptions of the clinical encounter. We analyzed transcriptions of the physician interviews using Atlas-ti software.

RESULTS

Physicians perceived all communication tasks to be more difficult using an interpreter than when one was not needed. Physicians perceived family interpreters to be less skilled translators than professional interpreters. Physicians expected professional interpreters to serve as culture brokers at least some of the time. Although only some family interpreters were also caregivers, physicians assumed that all of them fulfilled caregiver roles.

CONCLUSION

With professional interpreters, physicians follow communication rules they were taught. In contrast, physicians act as though these rules are not relevant with family interpreters who they treat as caregivers.

PRACTICE IMPLICATIONS

Guidelines to working with an interpreter should include directives on working with both professional and family interpreters, describing the similarities and differences with each type, and modifying the clinical encounter process to correspond to those attributes.

21. Optimal care in rheumatoid arthritis: Preliminary findings from a focus group study

The objective of our work was to identify facilitators of optimal care, as well as potential barriers, for patients with rheumatoid arthritis (RA). The design was a focus group study. Individuals with established RA were identified through invitation letters sent using a random sample of the Quebec Arthritis Society mailing list. Patients were eligible for participation if they had a diagnosis of RA confirmed by a rheumatologist and if they had sought care within the McGill Réseau Universitaire Intégré de Santé network. We planned a series of focus group meetings (90 minutes each) to obtain sufficient data in terms of spectrum of ideas. In each moderator-led group, participants were asked to discuss five questions related to quality care. A co-moderator was available to document non-verbal communication, with audio-taping of all sessions and professional transcription for data analysis. Qualitative content analysis, based on grounded theory, was the chosen means of identifying recurring themes and categories. Two focus group sessions have been completed with two more scheduled. Preliminary findings indicate the importance of good communication between family physicians, specialists, and allied health care workers. Final coding of transcripts and computer-assisted content analysis is being completed. However it appears that focus group may be useful in studying optimal care for chronic diseases such as RA. Our preliminary findings emphasize the necessity of good communication among health care providers. Ultimately we hope to generate knowledge that can be transformed into better health for Canadians with arthritis and other chronic diseases.

GPs' strategies in intercultural clinical encounters

BACKGROUND

In North America and Europe, patients and physicians are increasingly likely to come from non-Western cultural backgrounds. The expectations of these patients may not match those of physicians.

OBJECTIVE

To identify strategies used by GPs with patients from cultures other than their own.

METHODS

We conducted a qualitative inductive study based on 25 semi-structured interviews with family physicians practising in Montreal, Canada. We elicited physicians' strategies when dealing with patients from a cultural background different from their own. We began by asking physicians to describe an encounter they found difficult and one they found easy.

RESULTS

Physicians reported three types of strategies: (i) insistence on patient adaptation to local beliefs and behaviours; (ii) physician adaptation to what he or she assumed patients wanted; and (iii) negotiation of a mutually acceptable plan. Individual physicians did not adopt the same strategy in all situations. Their choice of strategy depended on the topic. When dealing with issues they felt deeply about, such as the autonomy of women, many physicians insisted on patient adaptation. Physicians used a patient-centred model of care, but had no framework to elicit information about patients' culture.

CONCLUSIONS

A patient-centred model of care enables physicians to consult effectively despite a wide range of cultural differences between themselves and their patients. However, their lack of a conceptual framework for addressing cultural difference prevents systematic data collection and consideration of challenges to respect for individual autonomy. Physician training should include the provision of an explicit conceptual framework for approaching patients from a different culture.