bluuebunny/crossref_metadata_2025 huggingface dataset:
Genetic divergence among East Icelandic and Faroese populations of Atlantic cod provides evidence for historical imprints at neutral and non-neutral markers
Authors: Pampoulie Christophe , Steingrund Pétur , Stefánsson Magnus Ö. , Daníelsdóttir Anna K.
Published: December 2007

Pampoulie, C., Steingrund, P., Stefánsson, M. Ö., and Daníelsdóttir, A. K. 2008. Genetic divergence among East Icelandic and Faroese populations of Atlantic cod provides evidence for historical imprints at neutral and non-neutral markers. – ICES Journal of marine Science, 65: 65–71. During the past decade, genetic markers have been used increasingly to improve stock discrimination and to aid fisheries management. Today, the Icelandic and Faroese Plateau cod (Gadus morhua) are managed as separate units, belonging to ICES Subareas Va and Vb1, respectively. There is little information on the genetic connectivity of the two units, however, except in terms of tagging experiments which revealed limited adult migration between the two areas, and few genetic studies describing genetic differentiation among Faroese and East Icelandic cod. Here, previously published data on the genetic structure of Icelandic cod were combined with new data from the Faroe Plateau to assess the level and the source of genetic variability of Atlantic cod around the Iceland–Faroe Ridge and the potential sources of genetic variation. In all, 771 cod were genotyped at nine microsatellite loci and at the Pantophysin locus (Pan I). The genetic markers employed were congruent and showed that South Icelandic and East Icelandic–Faroese Plateau populations have limited genetic connectivity. Diversifying selection associated with restricted gene flow is likely to explain the observed pattern with the Pan I locus. Further analyses detected historical imprints in the microsatellite data, suggesting that the divergence could be due to isolation of different cod populations during the last glacial maximum.
Gut‐specific genes from the black fly Simulium vittatum encoding trypsin‐like and carboxypeptidase‐like proteins
Authors: Ramos A. , Mahowald A. , Jacobs‐Lorena M.
Published: December 2007

In haematophagous insects digestion of the blood meal provides nutrients for survival and essential components for egg production. We have isolated and partially characterized two gut‐specific genes from the black fly Simulium vittatum. Sequence analysis revealed that both are highly similar to digestive proteases, one to trypsins and the other to carboxypeptidases. RNA blot analysis indicates that the expression of these two genes is regulated in a sexspecific manner; when fed the same sucrose‐based diet, expression in males is substantially lower than in females. In females, expression of both genes is strongly induced by a blood meal. At 6 h after the blood meal the trypsin‐like gene product was immunolocalized to the midgut epithelium and to the outer layers of the peritrophic matrix.
Molecular characterization of a strain‐specific repeated DNA sequence in the fall armyworm Spodoptera frugiperda (Lepidoptera: Noctuidae)
Authors: Lu Y.‐J. , Kochert G. D. , Isenhour D. J. , Adang M. J.
Published: December 2007

The fall armyworm moth, Spodoptera frugiperda, is a migratory species composed of sympatric corn and rice strains. The strains are indistinguishable in morphology but can be recognized by molecuiar markers. We have cloned and characterized seven monomer units of a repeated DNA sequence, called FR, which is found exclusively in the genome of the rice strain individuals. The 189 bp FR units are tandemly organized in arrays longer than 30 kb. Female individuals possess over 100‐fold more of the FR sequence than male individuals. The repeated sequence is not methylated at GGCC sites, and shows high sequence similarity among repeat units.
Mycetome endosymbionts of tsetse flies constitute a distinct lineage related to Enterobacteriaceae
Authors: Aksoy S. , Pourhosseini A. A. , Chow A.
Published: December 2007

Tsetse flies (Diptera: Glossinidae) harbour two morphologically different endosymbionts intracellularly associated with gut tissue: a primary (P) and a secondary (S) organism. The P‐endosymbiont is a gram‐negative rod, 8–10 μm in size, and resides intracellularly within specialized cells, mycetocytes which are organized into an organelle (mycetome), in the anterior portion of the gut. The S‐endosymbiont is a smaller (1–2 μm) gram‐negative rod and is harboured in the epithelial sheath cells in midgut. Phylogenetic characterization of S‐endosymbionts from taxonomically distant insects including tsetse flies has shown that they are related to the free‐living bacterium, Escherichia coli, and are members of the family Enterobacteriaceae within the γ‐3 subdivision of Proteobacteria. In this study, a polymerase chain reaction (PCR) based assay was designed utilizing the conserved sequences of 16S rDNA in order to phylogenetically characterize the mycetome‐associated P‐endosymbionts directly from tsetse mycetome tissue. Analysis from five species of flies representing the three major subgenera of genus Glossina indicates that P‐endosymbionts constitute a distinct lineage within the γ‐3 subdivision of Proteobacteria. Mycetome endosymbiont phylogeny appears to parallel the classic taxonomic assignments independently developed for their insect host species. This suggests an ancient association for this symbiosis, which may have subsequently radiated with time, giving rise to the current species of tsetse flies and their modern‐day endosymbionts. Based on endosymbiont phylogeny, the fusca flies constitute the most ancient subgenus, followed by the morsitans and palpalis groups.
Evaluation of a viral thymidine kinase gene for suicide selection in transfected mosquito cells
Authors: Mazzacano C. A. , Fallon A. M.
Published: December 2007

An Aedes albopictus cell line previously shown to be deficient in thymidine kinase activity was transfected with a thymidine kinase gene (tk) from Herpes simplex virus. Survival of the transfected lines in a TK+selective medium' indicated that the viral gene was actively expressed at a level sufficient to rescue the TK‐deficient phenotype of the parent line. Unlike the parental cells, TK+transformants (TK6:hsv cells) were sensitive to 5–bromodeoxyuridine, and contained DNA corresponding to the constructs introduced by trans‐fection. This TK selection system will facilitate recovery of other cotransfected, non‐selectable mosquito genes in cultured cells. Transformed cells were treated with several antiviral drugs to define conditions for a suicide selection' system, in which cells expressing the viral thymidine kinase enzyme (TK) under the control of an inducible promoter would be selectively destroyed, whereas cells expressing the endogenous mosquito enzyme would remain relatively unaffected. The anti‐herpetic drug (E)‐5‐(2‐bromovinyl)‐2'‐deoxyuridine (BVDU) showed greater cytotoxicity against transformed cells expressing the viral enzyme, and less toxicity to wild‐type mosquito cells. This cell culture system provides a model for initial evaluation of suicide selection systems that may ultimately be adapted to the mosquito using sex‐ or tissue‐specific promoters to drive expression of heterologous genes.
Phylogeny of the Coleoptera based on mitochondrial cytochrome oxidase I sequence data
Authors: Howland D. E. , Hewitt G. M.
Published: December 2007

A 400 base pair region of the mitochondrial cytochrome oxidase I gene (COI) was sequenced for thirty‐seven species of beetle, representing fifteen families. The sequence was found to be highly variable, with 12–18% divergence within families, and up to 27% divergence between families. Phylogenetic analysis using the neighbour‐joining method shows the Carabidae (Adephaga) as a distinct clade, but also shows that all other beetles (Polyphaga) diverged soon after the Adephaga/Polyphaga split. Whilst some species are grouped within their respective families, others are too diverged for easy resolution. The main disagreement with trees constructed using comparative morphology and the fossil record is the position of the Coccinelli‐dae. Whilst COI may be an informative gene for molecular systematics at lower taxonomic levels, or in other insects, improved resolution of this particular phylogeny will require a more highly conserved sequence.
Issues of reliability and validity in the measurement of challenging behaviour (behavioural difficulties) in learning disability: a discussion of implications for nursing research and practice
Authors: GATES BOB
Published: December 2007

The purpose of this paper is to contribute to the debate on issues related to the reliability and validity of measurement of challenging behaviour (behavioural difficulties) in learning disability. A number of practical, theoretical and methodological issues are discussed that have significance for the nurse both as practitioner and/or researcher in learning disability. These issues are equally important to both provider and purchaser of health care in order that resources can be most effectively targeted.

The term ‘challenging behaviour’ would appear to be used both in literature and research synonymously with behavioural difficulties, this has implications for nurses in both their clinical practice and/or research. The author concludes by identifying a need to replace the term challenging behaviour, with ‘behavioural difficulties’. It is argued that such a term is much more explicit in meaning and amenable to operational definition, thus enabling empirical study. Such a proposal will not be accepted by all as justifiable; this is because some might argue that adopting the term behavioural difficulties may be a retrograde step that perpetuates negative imagery and inappropriate labelling of people with a learning disability.
The effects of patient suicide on nursing staff
Authors: MIDENCE KENNY , GREGORY SARAH , STANLEY REA
Published: December 2007

Attitudes towards patient suicide, and the effects that this has on nursing staff are rather complex, and should not be viewed on a simple negative/positive continuum.

Suicide is a difficult but inevitable incident that affects psychiatric units, and the limited literature on nurses' attitudes to suicide, and the effects that patient suicide has on them has highlighted the need for emotional and professional support from their colleagues, including senior nurses, psychiatrists and managers, to cope better after a patient has committed suicide. Furthermore, the importance of regular meetings and reviews of assessment and prevention policies has also been emphasized.

The present study looked at the effects that suicide has on nursing staff, their attitudes, and ways of improving their coping skills. Major findings include the lack of emotional support, the need for training, formal assessment of patients at risk, regular multidisciplinary meetings following a suicide and nursing staff's acceptance of suicide as the patient's personal choice.

Recommendations for helping nursing staff during the post‐suicide period are suggested.
Health, health promotion and the elderly
Authors: YOUNG KATE
Published: December 2007

Health promotion is a mode of practice which is being increasingly examined by policymakers (DHSS, 1987; DoH, 1992).

Although practitioners are being required to screen people over 75 years of age and are exhorted to reduce accidents in the elderly by 33% between 1990 and 2005 (DoH, 1992), there is evidence that they do not value this sort of work (Pursey & Luker, 1993).

This paper looks at the findings from 178 interviews with people aged over 75 years, examining the importance of health and health promotion to the elderly.

Further to the work of Cox et al. (1987), it is clear that people aged over 75 years continue to engage in a wide variety of activities which are designed to keep or improve their health.

Elderly people's accounts of their health suggest that the real influence of social circumstances and environment must be assessed and planned for if health promotion activity is to have relevance and meaning to this group of people.

Evidence is presented which indicates that the elderly are a group of people who would welcome health‐promotion activity provided it is given in easily accessible forms.

The notion of client participation is highlighted as a difficult area, which is likely to require particular skill in working with elderly clients. In the light of these findings, practitioners may need to examine their own attitudes to their work with the elderly.
Research in intensive care nursing
Authors: LEINO‐KILPI HELENA , SUOMINEN TARJA
Published: December 2007

The results of a questionnaire study about intensive care nursing in Finland indicate that the chief problems in intensive care nursing are concerned with staff coping resources, quality development and patient experiences.

Questions on staff stress and coping have been researched quite extensively. Earlier studies have described intensive care nursing as highly stressful and pointed to numerous problems related to coping.

It is clear that intensive care nursing warrants closer attention in research.
‘To be or not to be’– an ethical debate on the not‐for‐resuscitation (NFR) status of a stroke patient
Authors: HERBERT CAROLINE L.
Published: December 2007

Nursing has been described as a moral endeavour (Seedhouse, 1988; Berger et al., 1991), the art of dealing with ethical issues of right and wrong.

Within the nursing literature, ethical issues are a major topic for discussion. Berger et al. (1991) explain that this reflects larger societal concerns about ethics in business, industry and government.

The development of advanced technology and life‐sustaining treatments such as cardiopulmonary resuscitation (CPR) has heightened the dilemmas of moral decision making. CPR was developed in the 1960s as an emergency life‐saving procedure, although it is currently used on anyone who does not have a not‐for‐resuscitation status (Anon., 1980).

In this paper, an ethical issue involving the decision of whether or not to resuscitate a stroke patient is discussed. An overview of the main ethical theories is presented because they provide a framework for an explication of ethical decision‐making. The options available to those involved are then discussed in relation to relevant research. Finally, a conclusion is drawn from the ensuing situation.
The experiences of mothers caring for a child with severe atopic eczema
Authors: ELLIOTT BARBARA E. , LUKER KAREN
Published: December 2007

Atopic eczema is a relatively common disease which frequently occurs during childhood.

This paper reports the findings of a research study which explored the effects upon family life of caring for a child with severe atopic eczema.

Seventy‐seven accounts written by mothers of preschool children with this disease were analysed using qualitative latent content analysis.

The focus of this paper is on the implications of the disease for the mothers' role and the additional work generated by the disease.

The implications of these findings for nursing practice, in particular the work of health visitors and paediatric community nurses, is discussed.

Throughout this paper the term ‘nurse’ is used to describe both nurses and health visitors.
‘A thorny problem for feminism’: an analysis of the subjective work experiences of enrolled nurses
Authors: MACKENZIE JENNIFER
Published: December 2007

Feminist methodology has been used in this study to investigate the subjective work experiences of 19 enrolled nurses.

Reflexive conversational techniques enabled participants to relate autobiographical narratives examining their experiences of working in a nursing hierarchy.

Two themes are reported: ‘nursing identity’ and ‘exploitation’. Through an analysis of these themes insight has been gained into the manner in which nurses inter‐relate.

The study demonstrates how the correlation between rank, status and expertise within the nursing hierarchy may have negative consequences for patient care.
The challenges of improving discharge planning in Sweden and the UK: different but the same
Authors: LUNDH ULLA , WILLIAMS SION
Published: December 2007

Discharge of older people from hospital has been an area of concern for over 20 years.

The present emphasis on rapid throughput of patients in acute care settings is likely to exacerbate existing problems.

Improving current practice will mean addressing a number of complex issues to do with communication between agencies and professions.

Despite different welfare systems, many of the challenges of discharge planning are shared in different countries.

This paper describes attempts to involve patients and carers in discharge planning in Sweden and the UK and identifies a number of areas which require attention if the ideals of patient and carer empowerment are to be achieved.
The Total Health Care Audit System: a systematic methodology for clinical practice evaluation and development in NHS provider organizations
Authors: Miles Andrew , Bentley Paul , Price Nicholas , Polychronis Andreas , Grey Joseph , Asbridge Jonathan
Published: December 2007

Writing in Medical Education in 1982, Fowkes (1982) noted the lack of general agreement within the medical profession on methods of audit, a deficiency previously articulated by Shaw (1980) and later emphasized by McIntyre (1985). More recently, a study by Black & Thompson (1993) of consultant and junior medical staff in four London district general hospitals revealed that ‘many doctors did not understand how to undertake audit’, and major research by both Hopkins (1993, 1994) and Buttery et al. (1994) described a multiplicity of methodological deficiencies in the general approaches to audit adopted by clinicians since the promulgation of the White Paper definition in 1989. Soundness of methodological approach is fundamental to securing the success of clinical audit within Provider organizations and is thus central to the generation of measurable improvements in the quality of clinical care being delivered to patients. It is therefore disturbing that methodological deficiencies may still be observed in general approaches to audit (Buttery et al. 1994), with no author yet recommending a formal system for critical inquiry into clinical practice. It was the recognition of the unsatisfactory nature of this situation which led us to develop a system aimed at assessing, in a critical fashion, the quality of the totality of care dispensed within NHS provider organizations. The system is presented here for the first time.
Professionals perceptions of psychotropic medication in residential facilities for individuals with mental retardation
Authors: Singh N. N. , Ellis C. R. , Donatelli L S. , Williams D. E. , Ricketts R. W. , Goza A. B. , Perlman N. , Everly D. E. , Best A. M. , Singh Y. N.
Published: December 2007

Professional staff in four state facilities for individuals with mental retardation were surveyed to determine their perceptions, knowledge and opinions regarding the use of psychotropic medication. A large majority of the 377 respondents indicated that the physicians in their facilities were primarily responsible for medication‐related decisions. Under ideal conditions, however, all professional staff and parents were seen as having a greater influence in the decision‐making process. Aggression, delusions and hallucinations, self‐injury, other psychiatric disorders, and anxiety were rated as disorders most likely to result in medication therapy. Behaviour modification was viewed as a suitable alternative to drug treatment for acting out and aggression. The professionals indicated that behavioural observation was the most influential assessment technique in current usage, followed by global impressions and informal diaries. Over 80% of the respondents perceived their preservice and inservice training on issues related to the use of psychotropic medication to treat behaviour problems as inadequate, with 96% of them desiring continuing education. These findings were compared to data from similar studies of populations with other disabilities, and suggestions for modifications in the current decision‐making processes related to the use of psychotropic medication in institutionalized individuals with mental retardation are discussed.
Visual acuity and accommodation in infants and young children with Down's syndrome
Authors: Woodhouse J. M. , Pakeman V. H. , Saunders K. J. , Parker M. , Fraser W. I. , Lobo S. , Sastry P.
Published: December 2007

Accommodation and visual acuity were measured in 53 children with Down's syndrome aged between 12 weeks and 57 months. Results were compared With data for 136 control (typically developing) children aged between 4 weeks and 48 months. Whereas the control children accommodated accurately on near targets, accommodation was defective in 92% of the children with Down's syndrome, and there was no change in accommodative ability with age. On the other hand, visual acuity lay within normal limits for the younger children. Children over the age of 2 years showed a below‐normal visual acuity, which is not explained either by refractive error or by the effect of poor accommodation. The data suggest a sudden change in the rate of development of visual acuity which may be associated with physiological changes in the visual cortex. Previously reported defects of accommodation and visual acuity in older children and adults with Down's syndrome are confirmed by our findings in infants and young children.
The molecular pathogenesis of hepatocellular carcinoma
Authors: Moradpour D. , Wands J. R.
Published: December 2007

SUMMARY. Some of the multiple factors involved in the molecular pathogenesis of hepatocellular carcinoma have been elucidated in recent years but no clear picture of how and in what sequence these factors interact at the molecular level has emerged yet. Transformation of hepatocytes to the malignant phenotype may occur irrespective of the aetiological agent through a pathway of chronic liver injury, regeneration and cirrhosis. The activation of cellular oncogenes, the inactivation of tumour suppressor genes and overexpression of certain growth factors contribute to the development of HCC. There is increasing evidence that the hepatitis B virus may play a direct role in the molecular pathogenesis of HCC. Aflatoxins have been shown to induce specific mutations of the p53 tumour suppressor gene thus providing a clue to how an environmental factor may contribute to tumour development at the molecular level.
Contribution of HEV and HCV in causing fulminant non‐A, non‐B hepatitis in western India
Authors: Arankalle V. A. , Jha J. , Favorov M. O. , Chaudhari A. , Fields H. A. , Banerjee K.
Published: December 2007

Summary. During 1990, 38 patients with fulminant non‐A, non‐B hepatitis (NANB) died in Government Medical College Hospital, Aurangabad. Serum samples from these patients were tested for antibodies to hepatitis C virus (anti‐HCV) and IgM antibodies to hepatitis E virus (IgM‐anti‐HEV). All samples were also subjected to polymerase chain reaction (PCR) for the detection of HBV DNA, HCV RNA and HEV RNA. None of the patients had circulating anti‐HCV antibodies; three had HCV RNA. Based on anti‐HEV‐IgM positivity 14 patients (37%) could be diagnosed as suffering from hepatitis E. None was positive for HEV RNA. In the absence of serological markers, HBV DNA was present in three cases. None of the HBV DNA positive patients had anti‐δ antibodies. Dual infections (HBV with HEV, and HBV with HCV) were seen in two cases. The aetiology of half of the NANB cases could not be assigned to the known hepatitis viruses using current techniques.
Prevalence of hepatitis C antibody in patients with chronic liver disease and hepatocellular carcinoma in Korea
Authors: Park B. C. , Han B. H. , Ahn S. Y. , Lee S. W. , Lee D. H. , Lee Y. N. , Sec J. H. , Kim K. W.
Published: December 2007

Summary. To investigate the contribution of hepatitis C virus (HCV) to chronic liver disease and hepatocellular carcinoma (HCC) in Korea, antibodies to HCV (anti‐HCV) were tested by enzyme immunoassay in 1759 patients with chronic liver disease and HCC, and in 808 healthy adults. The prevalence of anti‐HCV was 1.6% in 808 controls. Anti‐HCV was present in 32 (7.7%) of 418 hepatitis B surface antigen (HBsAg)‐positive and 128 (53.1%) of 241 HBsAg‐negative patients with chronic hepatitis, 16 (6.0%) of 265 HBsAg‐positive and 90 (30.5%) of 295 HBsAg‐negative patients with liver cirrhosis, and 16 (4.8%) of 330 HBsAg‐positive and 61 (29.0%) of 210 HBsAg‐negative patients with HCC. Antibodies to hepatitis B core antigen (anti‐HBc) were present in 80–88% of patients who were seropositive for anti‐HCV and seronegative for HBsAg. Among the sera from 114 patients with HBsAg‐negative and anti‐HCV‐positive chronic liver diseases, HBV DNA and HCV RNA were detected by polymerase chain reaction (PCR) in 54 (47.4%) and 61 (53.3%), respectively. Both HBV DNA and HCV RNA were detected in 4 (4.4%) samples. The mean age of the patients with both HBsAg and anti‐HCV was not different from that of patients who were seropositive for HBsAg alone. These findings indicate that current and/or past HBV infection is still the main cause of chronic liver disease in Korea. Although multivariate analysis showed that anti‐HCV is a risk factor for chronic hepatitis, cirrhosis of the liver and HCC, PCR data for HBV DNA and HCV RNA indicate that HCV infection plays only a minor role in HBsAg‐positive as well as in HBsAg‐negative liver disease and does not accelerate the development of HCC in HBV carriers.
Clinical relevance of hepatitis C virus quasispecies
Authors: Enomoto N. , Sato C.
Published: December 2007

Summary. It has been shown that hepatitis C virus (HCV) populations in infected individuals are composed of quasispecies with diverse mutations. The analysis of these variants may reveal mechanisms of the persistence of HCV infection, carcinogenesis and resistance to antiviral therapy. Recently, genetic features of interferon‐resistant HCV have been elucidated through the analysis of interferon‐resistant quasispecies, making it possible to predict interferon efficacy by detecting interferon‐resistant strains.
Clinical and serological courses of a newborn with post‐transfusion hepatitis C
Authors: Maniwa H. , Miyake Y. , Hamada M. , Oda T. , Li R. , Yokoyama T. , Sugiyama K. , Wada Y.
Published: December 2007

Summary. The clinical and serological course of a haemophilic baby who was transfused with 160 ml of blood containing the hepatitis C virus (HCV) (0.70 Meq. ml‐1) on the sixth post‐natal day is described. He is the infant of an HCV‐negative mother. One month after the transfusion, there was a marked increase in HCV RNA and a small amount of HCV antibody was detected. This case provides evidence that a newborn is capable of producing HCV antibodies.
Hepatitis C virus infection in patients with clinically diagnosed alcoholic liver diseases
Authors: Sata M. , Fukuizumi K. , Uchimura Y. , Nakano H. , Ishii K. , Kumashiro R. , Mizokami M. , Lau J. Y. N. , Tanikawa K.
Published: December 2007

Summary To determine the incidence of hepatitis C virus (HCV) infection in patients with alcoholic liver disease (AID), serum samples from 252 patients with AID were tested for anti‐HCV and HCV RNA. Serial sera of these patients were collected and stored under optimal conditions to allow exact quantification of HCV RNA. Fifteen patients who visited our hospital during the same period of time with chronic HCV infections served as controls. In those with AID, anti‐HCV and HCV RNA were positive in 55.5% and 41.2%, respectively. Patients with histologically diagnosed chronic hepatitis and hepatocellular carcinoma had much higher prevalence rates of HCV RNA (84% and 100%, respectively) compared to those with fatty liver (4.3%), hepatic fibrosis (10.1%) and alcoholic hepatitis (22.2%) (P < 0.01). Although no difference in serum HCV RNA levels was observed between the patients with both AID and chronic HCV infection and those with chronic HCV infection alone, HCV RNA levels significantly (10‐fold) dropped after abstinence in nearly half of the patients (P < 0.01). These data indicate that HCV infection in patients with AID promotes progression of liver disease, and abstinence from alcohol is associated with a reduction in serum HCV RNA levels.
Interferon accumulation in cirrhotic rat liver
Authors: Miyajima I. , Sata M. , Gondo K. , Suzuki H. , Tantkawa K.
Published: December 2007

SUMMARY. In patients with chronic hepatitis C, the therapeutic effect of interferon (IFN) is influenced by the progression of liver disease. In a previous study, we showed that 2′,5′‐oligoadenylate synthetase activity in the liver homogenate was significantly lower in cirrhotic rats than in controls after injection of murine IFN. To determine the reason for this decrease, we injected IFN into rats with thioacetamide‐induced cirrhosis and used microautoradiography with human lymphoblastoid interferon ([125I]LyIFN). Accumulation of [125I]LyIFN in cirrhotic rat livers was approximately half of that in control rats (2880±900 vs 5770±600mm2, P<0.01). In the cirrhotic rat livers there were few grains on the hepatocytes, but many on collagen fibres. These results suggest that binding of IFN to its hepatocyte receptors is hindered in the presence of cirrhosis. The decreased amount of IFN reaching hepatocytes may contribute to the poor responses to IFN seen in patients with cirrhosis.
Longitudinal genotype analysis and quantification of hepatitis C virus in haemophilia patients receiving interferon‐α therapy
Authors: Devereux H. , Telfer P. , Brown D. , Morris A. , Dusheiko G. , Emery V. , Lee C.
Published: December 2007

SUMMARY. Haemophilic patients have a high prevalence of hepatitis C virus (HCV) infection because of the use of unsterilized clotting factor concentrates. Six major genotypes of HCV have been distinguished so far, with epidemiological evidence suggesting that genotypes 1–3 are common in the indigenous UK and US populations. The aim of this study was to analyse the changes in viral load and composition of the HCV quasispecies in haemophilic patients receiving therapy with interferon‐α (IFN‐α) using the four major methods currently available for HCV genotyping. The most consistent genotype results were obtained using restriction fragment‐length polymorphism (RFLP) analysis when compared with the DNA sequence analysis, and showed that the dominant genotype can change in patients with mixed genotype infections treated with IFN‐α. This study indicates the difficulties in studying this group of patients with mixed HCV genotype infections, and that frequent sampling is necessary, together with viral load measurement to monitor response to IFN‐α therapy.
Aminopeptidase activity in strains of oral streptococci
Authors: Floderus Eugenie , Andersson Carita , Linder Lars , Sund Marie‐Louise
Published: December 2007

Ten strains of oral streptococci were analyzed for aminopeptidase activity by isoelectric focusing and crossed immunoelectrophoresis together with enzyme staining procedures. Substrate specificities were determined using 15 aminoacyl‐β‐naphthylamides. All 10 strains tested showed enzyme activity with the arginine and leucine substrates. None of the strains exhibited activity with the glycine, cystine, or proline substrates. Some strains had multiple enzyme bands with some of the substrates. All strains had aminopeptidase bands located in the pi range 4.1–4.3, except Streptococcus mutans IB and Streptococcus milleri NCTC 10708. The isoelectric profiles of these strains, having enzyme bands in the range 4.45–4.9, differed markedly from the others. These were also the only strains where no arginine aminopeptidase cross‐reactivity occurred with the Streptococcus mitis ATCC 903 antiserum.
Human serum antibody responses to oral microorganisms IV. Correlation with homologous infection
Authors: Ebersole J. L. , Taubman M. A. , Smith D. J. , Frey D. E. , Haffajee A. D. , Socransky S. S.
Published: December 2007

Recent microbiological studies of periodontal disease in humans have supported the concept of a specific bacterial etiology. While individual agents have not been unequivocally identified, numerous Gram‐negative members of the subgingival microflora have been implicated. In addition, elevations in systemic antibody responses have been consistent with certain oral microorganisms being involved in an infectious process associated with the disease. This report delineates the relationship between elevated systemic antibody levels and oral colonization with the homologous microorganism at active disease sites. Thirty‐four patients with various types of periodontal disease were examined. Using ELISA, each patient was shown to have an elevated antibody response to at least one organism from a battery of 18 oral microorganisms that were tested. Subsequently, subgingival plaque was cultured from disease‐active and inactive sites of each subject. The results demonstrated that the same microorganism to which the individual exhibited elevated serum antibody responses was detected in nearly 55% of the disease‐active sites, while only 18% of the inactive sites showed the microorganism. Certain microorganisms including Actinobacillus actinomycetemcomitans, Bacteroides gingivalis, Eikenella corrodens and Wolinella recta were primarily or exclusively correlated with active disease lesions. These findings support the hypothesis that elevated systemic antibodies to periodontopathic bacteria are reflective of subgingival colonization and exist as a response to a bacterial infection at disease‐active sites.
Chlorhexidine affects arginine metabolism as well as glycolysis in a strain of Streptococcus sanguis
Authors: Rogers A. H. , Zilm P. S. , Gully N. J. , Pfennig A. L.
Published: December 2007

Abstract The effect of Chlorhexidine digluconate (CHX) on the uptake and catabolism of arginine (arg) by Streptococcus sanguis P4A7 was investigated since the ability to use this amino acid may play a role in its existence in dental plaque. Organisms were grown glucose‐limited in continuous culture in a chemically‐defined medium. Washed cells, resuspended in a salt solution, were exposed to various concentrations of CHX prior to the addition of arg. Uptake of arginine and the appearance of its catabolites were monitored by HPLC analysis of cell suspension filtrates. At pH 7.0 and 5.5, both uptake and breakdown were progressively reduced by 0.06 and 0.12 mM CHX and these effects were even more marked in the presence of 0.24 mM CHX, which also reduced cell viability. The glycolytic rate was also progressively reduced as the level of CHX was raised from 0.06 to 0.24 mM. The arginine deiminase pathway, as well as glycolysis, is thus depressed by sub‐inhibitory concentrations of CHX and it is suggested that this could have far‐reaching effects on overall plaque metabolism.
Media for cultivation of Eikenella corrodens and formate‐ and fumarate‐requiring species of oral bacteria
Authors: Tanner Anne
Published: December 2007

Abstract Different cultivation media were tested for growth of Eikenella corrodens, Wolinella recta, Wolinella curva, Campylobacter concisus, Bacteroides gracilis, and Bacteroides ureolyticus. Most basal media included sodium formate (1 g/1), sodium fumarate (1.5 g/1), potassium nitrate (1 g/1) (FFN), and hemin (5 mg/1). B. gracilis, C. concisus and W. curva grew optimally in microtiter plate wells and test tubes with yeast extract (YE) (15 g/1) as the basal medium. E. corrodens grew better in YE (15 g/1) in microtiter plates, and better in trypticase soy with YE (8 g/1) in tubes. The opposite pattern was observed for B. ureolyticus. W. recta grew optimally in brain heart infusion with YE (5 g/1), sodium formate (2 g/1), and sodium fumarate (3 g/1) in microtiter plates and in test tubes. An agar medium consisting of brain heart infusion agar, YE (10 g/1), sodium formate (2 g/1), sodium fumarate (3 g/1), hemin (5 mg/1), and 5% sheep blood yielded excellent agar growth of the formate‐ and fumarate‐requiring species.
Comparison of different methods for detection of urease activity in oral Actinomyces species
Authors: Kalfas Sotirios
Published: December 2007

Abstract The urease activity of oral Actinomyces strains was examined by 4 different methods. Detection of urease was performed most easily and with the highest sensitivity by using a modified lessen test.
Cell surface mutants of Streptococcus sanguis with altered adherence properties
Authors: Jenkinson Howard F. , Carter Deidre A.
Published: December 2007

Two mutants of Streptococcus sanguis (Challis) with altered cell‐surface hydrophobicities were isolated after mutagenesis with ethyl methanesulphonate. Cells of one mutant were more hydrophobic than those of the parent strain and they adhered better to hexadecane, octyl‐Sepharose, hydroxylapatite, saliva‐treated hydaroxylapatite, and to Actinomyces viscosus. The second mutant had reduced hydrophobicity, and cells adhered less well to all the above surfaces except the actinomycetes, adsorption to which was similar to that of the wild‐type strain. The differences in hydrophobicity of the mutants were associated with alterations in amount and exposure of surface proteins, in particular two envelope proteins (Mr 43,000 and 45,000). The properties of the mutants support the contention that hydrophobic forces are determinants in S. sanguis adherence.
Associations between microbial species in subgingival plaque samples
Authors: Socransky S. S. , Haffajee A. D. , Dzink J. L. , Hillman J. D.
Published: December 2007

Samples of subgingival plaque were taken from 275 active and inactive sites in 35 subjects with destructive periodontal diseases. The predominant cultivable microbiota was determined in each of the samples by characterizing 50 randomly selected isolates recovered on anaerobically incubated Trypticase soy agar supplemented with 5% sheep blood. Microbial associations between species were determined by computing the odds ratio of a site being infected by a “target” species in the presence of an “effector” species. Data are presented for 22 numerically dominant “effector” species and 8 “target” species which consisted of suspected periodontal pathogens. These included Actinobacillus actinomycetemcomitans, Bacteroides forsythus, Bacteroides gingivalis, Bacteroides intermedicus, Bacteroides melaninogenicus, Peptostreptococcus micros, Streptococcus intermedius and Wolinella recta. Positive associations were considered to be relationships in which the odds ratio of detecting a “target” species was >2:1 in the presence of the “effector” species, while negative associations were defined as those in which the odds ratio of detecting the “target” species was < 0.5:1 in the presence of the “effector” species. In general, species of streptococci, an unnamed Actinomyces sp. and Propionibacterium acnes showed a negative association with the 8 suspected pathogens, while many Gram‐negative species tended to show a positive association with these suspected pathogens. There appeared to be specificity in the associations observed. For example, S. intermedius was positively associated with Streptococcus mitis and Streptococcus sanguis I, but negatively associated with Bacteroides forsythus. In contrast, W. recta was negatively associated with S. mitis and Streptococcus sanguis I, but positively associated with Bacteroides forsythus. S. sanguis II, Streptococcus uberis, P. acnes, Capnocytophaga ochracea and an unnamed Actinomyces sp. showed negative associations with 4 of the suspected periodontal pathogens, while B. gingivalis, Fusobacterium nucleatum and the Eubacterium sp. showed only positive or “neutral” associations with the “target” species. Data from this and other investigations suggest that microbial associations might play an important role in controlling the composition of subgingival plaque and, thus, be a major determinant of health or destructive periodontal diseases.
Predominant cultivable microflora of plaque on removable dentures in patients with denture‐induced stomatitis
Authors: Theilade Else , Budtz‐Jørgensen Ejvind
Published: December 2007

Plaque from the fitting surface of upper full dentures in 8 patients with denture‐induced stomatitis was sampled with curettes for study. To characterize the predominant cultivable flora, 1249 isolates (138–196 from each sample) were sub‐cultured from anaerobic roll tubes. Streptococci constituted 17–76% of the isolates in each sample (median 29%) and were identified asS. mitior, S. milleri, S. mutans, S. salivarius, andS. sanguis.Staphylococci (mainlyS. aureus) made up 2–15%, median 6%. Gram‐positive rods constituted 5–72% (median 45%), mainlyLactobacillusspp. (0–72%, median 19%) andActinomycesspp. (0–43%, median 9%). Gram‐negative cocci made up 0–28% (median 15%) and Gram‐negative rods only 0–1.8% (median 0%). Yeast viable counts on Sabouraud agar corresponded to 0–1.7% (median 0.27%) of the total viable counts. Stomatitis‐inducing denture plaque has a similar complex and variable, mainly Gram‐positive, bacterial flora as that of denture plaque in subjects with healthy oral mucosa. Yeasts and lactobacilli are, however, in greater evidence in stomatitis.
Competition between Streptococcus mutans and Lactobacillus casei in mixed continuous culture
Authors: Bowden G. H. W. , Hamilton I. R.
Published: December 2007

In natural oral ecosystems, succession of Streptococcus mutans and Lactobacillus species occurs in bacterial communities which can be associated with the development of carious lesions. The objective of this study was to explore the interaction between 2 strains of S. mutans (SF2452) and Lactobacillus casei (RB1014) when grown together in continuous culture under conditions of varying environmental pH and in the presence of fluoride. When the strains, isolated from approximal carious lesions, were grown initially at a dilution rate of 0.1 h‐1 under a glucose limitation at pH 7.0, a stable mixed community developed (Days 5–10) with S. mutans as the dominant population. When the pH control was removed (Day 10), the binary culture lowered the pH to 5.1 causing a small reduction in the numbers of S. mutans and allowing L. casei to predominate. A more dramatic effect was seen when the environmental pH was rapidly lowered to 4.8 by the addition of acid. In this case, the S. mutans population was significantly reduced and the L. casei population rose to the level previously held by S. mutans. Re‐adjustment of the pH to 7.0 resulted in a re‐establishment of the population ratios prior to the addition of acid. The possibility that S. mutans was capable of aciduric adaptation during a biologically‐generated pH reduction was examined by mixing cultures of both organisms after each had been grown to steady slate at pH 5.5 in separate chemostats. In this case S. mutans maintained its population and was dominant in the community at pH 5.5 indicating that adaptation by S. mutans had given it an ecological advantage over L. casei at this pH. The addition of fluoride (20 mM) to the mixed culture favored L. casei since the growth of S. mutans was greatly inhibited al this fluoride level. Nevertheless S. mutans was able to survive at low levels in the chemostat, presumably in surface films, for at least 5 days, since removal of fluoride from (he medium resulted in the re‐establishment of S. mutans in a competitive position with L. casei. These experiments indicate that S. mutans possesses adaptive and survival characteristics which would be of considerable advantage in an ecological system such as dental plaque.
Relationship between mutans streptococci in saliva and their colonization of the tooth surfaces
Authors: Lindquist B. , Emilson C. G. , Wennerholm K.
Published: December 2007

The relationship between the salivary concentration of mutans streptococci and their prevalence on different tooth surfaces was studied in 114 subjects. Plaque samples were obtained from all tooth surfaces in the dentition and the infection magnitude of mutans streptococci was determined. The salivary concentrations of mutans streptococci correlated significantly with the number of colonized tooth surfaces and with the infection level of mutans streptococci for individual teeth or groups of tooth surfaces. The highest correlation values were found for buccal and approximal surfaces and for molars followed by premolars and anterior teeth. The 10 tooth surfaces best reflecting the salivary levels of mutans streptococci were 5 buccal and 5 approximal sites, 6 of them localized on maxillary posterior teeth. A significant positive relationship was noted between the prevalence of mutans streptococci in saliva and on the dorsum of the tongue.
Interaction between surface protein antigens of Streptococcus mutans and human salivary components
Authors: Russell Michael W. , Mansson‐Rahemtulla Britta
Published: December 2007

The potential involvement of surface antigens (Ags) I/II and III of Streptococcus mutans in its adherence to salivary pellicle‐coated tooth surfaces was investigated. The binding of radiolabelled Ag I/II to hydroxyapatite was increased by pretreating the mineral with human parotid saliva, and binding was maintained in the continuous presence of saliva. Binding of Ag III to hydroxyapatite was inhibited by pretreatment with, or in the presence of, saliva. Various aminohexoses, and also tris, inhibited the binding of Ag I/II. When Ags I/II and III were tested for their ability to bind to salivary components separated by SDS gel electrophoresis, several proteins capable of binding Ag I/II were identified, notably 2 proteins of apparent relative molecular mass 28,000 and 38,000. Analysis of these proteins, isolated by micro‐preparative electrophoresis, indicated high proportions of proline, glycine, and glutamic acid, and overall compositions similar to basic prolinerich salivary proteins.
The expression and function of a Bacteroides gingivalis hemagglutinin gene in Escherichia coll
Authors: Progulske‐Fox Ann , Tumwasorn Somying , Holt Stanley C.
Published: December 2007

Eight Escherichia coli JM 109 transformants generated from a clone bank of Bacteroides gingivalis 381 genomic DNA, were found to express B. gingivalis antigens. Quantitation of antigen expression by ELISA indicated that isopropyl‐B‐D‐thiogalactopyranoside (1PTG) was not necessary for antigen expression for any of the clones but that expression in 2 of the clones, ST 2 and ST 3, was increased in cells grown in the presence of IPTG. Western blot analysis revealed that the expressed protein of clone ST 2 has a molecular weight of 125,000 Dal. and that clone ST 3 contains multiple bands of 30 to 50 kdal which react with the anti‐, B. gingivalis antiserum. Three of the transformants were found to agglutinate sheep erylhrocytes. Polyclonal monospecific antiserum to one of the transformants, clone ST 2, was found to react to 2 major bands of MWs 43,000 and 38,000 and minor bands of 115,000, 105,000, 32,000, and 30,000 Dal. present in B. gingivalis cell lysale preparations. Adsorption of anti B. gingivalis antiserum with cells of clone ST 2 reduced the hemagglutination inhibition activity of the antiserum 4‐fold whereas antiserum to the clone itself inhibited B. gingivalis hemagglutination at a titer of 8 times that of normal rabbit serum. Immunoelectronmicroscopic studies using the antiserum to clone ST 2 indicate that the product of the cloned gene (hemagglutinin) is located on the B. gingivalis cell surface. A restriction map generated of the cloned B. gingivalis DNA fragment confirms the insert to be 3.2 kbases and indicates the possibility of a repeated sequence in the fragment.