Defining quality of preventive oral health services in a northern First Nations community: a concept mapping study

INTRODUCTION

In partnership with the Norway House Cree Nation (NHCN) in Manitoba, Canada, this study developed a framework based on how Indigenous parents/caregivers of young children and community-based oral health decision-makers perceive 'quality of preventive oral health services'.

METHODS

Concept mapping was used to develop the 'quality of preventive oral health services' framework. This involved brainstorming/idea generation, sorting and rating, visual representation, and interpretation sessions with parents/caregivers (CG) and decision-makers (DM) in Norway House, Manitoba. Using the Concept System's GlobalMax software, a conceptual framework was created that was modified from input from CG and DM groups, which can be visualized through the concept map.

RESULTS

The final concept map revealed seven domains of quality preventive oral health services: dental staff character and skills, working with community, responsibilities in preventive education, inclusive preventive oral health strategies, accessibility to appointments, logistics of providing services, and dental environment.

CONCLUSION

This study provides insight into the existing gap in oral health services for Indigenous populations. Based on conversations and the concept mapping process, the developed framework can inform the steps to be taken to improve preventive oral health services for Indigenous peoples. The framework has been used to develop a quantitative scale to inform sustainable and impactful change in the quality of preventive oral health services that are meaningful to Indigenous peoples.

Using Concept Mapping to Define Indigenous Housing First in Hamilton, Ontario

BACKGROUND

The lasting impact of colonization contributes to the disproportionate rates of homelessness experienced by Indigenous people in Canada.

METHODS

This study used participatory mixed methods to evaluate an urban, Indigenous-led Housing First program in Ontario to fill knowledge gaps on wise practices addressing the unique dimensions of Indigenous homelessness. Using concept mapping, staff perspectives were engaged to generate 65 unique statements describing program delivery and their interrelationships using a six-cluster map.

RESULTS

'Team's Professional Skills' and 'Spiritual Practices' rated high in importance (mean = 4.75 and 4.73, respectively), and feasibility (mean = 4.31 and 4.33, respectively). While fairly important, 'Partnerships and Agency Supports' was ranked least feasible (mean = 3.89). On average, clusters rated higher in importance than feasibility.

CONCLUSION

Concept mapping draws from local knowledge, elicits strong engagement, and captured the holistic and client-centred approach of an Indigenous Housing First Model.

Evaluation of prognostic risk models for postoperative pulmonary complications in adult patients undergoing major abdominal surgery: a systematic review and international external validation cohort study

BACKGROUND

Stratifying risk of postoperative pulmonary complications after major abdominal surgery allows clinicians to modify risk through targeted interventions and enhanced monitoring. In this study, we aimed to identify and validate prognostic models against a new consensus definition of postoperative pulmonary complications.

METHODS

We did a systematic review and international external validation cohort study. The systematic review was done in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. We searched MEDLINE and Embase on March 1, 2020, for articles published in English that reported on risk prediction models for postoperative pulmonary complications following abdominal surgery. External validation of existing models was done within a prospective international cohort study of adult patients (≥18 years) undergoing major abdominal surgery. Data were collected between Jan 1, 2019, and April 30, 2019, in the UK, Ireland, and Australia. Discriminative ability and prognostic accuracy summary statistics were compared between models for the 30-day postoperative pulmonary complication rate as defined by the Standardised Endpoints in Perioperative Medicine Core Outcome Measures in Perioperative and Anaesthetic Care (StEP-COMPAC). Model performance was compared using the area under the receiver operating characteristic curve (AUROCC).

FINDINGS

In total, we identified 2903 records from our literature search; of which, 2514 (86·6%) unique records were screened, 121 (4·8%) of 2514 full texts were assessed for eligibility, and 29 unique prognostic models were identified. Nine (31·0%) of 29 models had score development reported only, 19 (65·5%) had undergone internal validation, and only four (13·8%) had been externally validated. Data to validate six eligible models were collected in the international external validation cohort study. Data from 11 591 patients were available, with an overall postoperative pulmonary complication rate of 7·8% (n=903). None of the six models showed good discrimination (defined as AUROCC ≥0·70) for identifying postoperative pulmonary complications, with the Assess Respiratory Risk in Surgical Patients in Catalonia score showing the best discrimination (AUROCC 0·700 [95% CI 0·683-0·717]).

INTERPRETATION

In the pre-COVID-19 pandemic data, variability in the risk of pulmonary complications (StEP-COMPAC definition) following major abdominal surgery was poorly described by existing prognostication tools. To improve surgical safety during the COVID-19 pandemic recovery and beyond, novel risk stratification tools are required.

FUNDING

British Journal of Surgery Society.

Classism and Everyday Racism as Experienced by Racialized Health Care Users: A Concept Mapping Study

In Toronto, Canada, 51.5 % of the population are members of racialized groups. Systemic labor market racism has resulted in an overrepresentation of racialized groups in low-income and precarious jobs, a racialization of poverty, and poor health. Yet, the health care system is structured around a model of service delivery and policies that fail to consider unequal power social relations or racism. This study examines how racialized health care users experience classism and everyday racism in the health care setting and whether these experiences differ within stratifications such as social class, gender, and immigration status. A concept mapping design was used to identify mechanisms of classism and everyday racism. For the rating activity, 41 participants identified as racialized health care users. The data analysis was completed using concept systems software. Racialized health care users reported “race”/ethnic-based discrimination as moderate to high and socioeconomic position-/social class-based discrimination as moderate in importance for the challenges experienced when receiving health care; differences within stratifications were also identified. To improve access to services and quality of care, antiracist policies that focus on unequal power social relations and a broader systems thinking are needed to address institutional racism within the health care system.

Experiences of everyday racism in Toronto's health care system: a concept mapping study

BACKGROUND

In Canada, there is longstanding evidence of health inequities for racialized groups. The purpose of this study is to understand the effect of current health care policies and practices on racial/ethnic groups and in particular racialized groups at the level of the individual in Toronto's health care system.

METHODS

This study used a semi-qualitative study design: concept mapping. A purposive sampling strategy was used to recruit participants. Health care users and health care providers from Toronto and the Greater Toronto Area participated in all four concept mapping activities. The sample sizes varied according to the activity. For the rating activity, 41 racialized health care users, 23 non-racialized health care users and 11 health care providers completed this activity. The data analysis was completed using the concept systems software.

RESULTS

Participants generated 35 unique statements of ways in which patients feel disrespect or mistreatment when receiving health care. These statements were grouped into five clusters: 'Racial/ethnic and class discrimination', 'Dehumanizing the patient', 'Negligent communication', 'Professional misconduct', and 'Unequal access to health and health services'. Two distinct conceptual regions were identified: 'Viewed as inferior' and 'Unequal medical access'. From the rating activity, racialized health care users reported 'race'/ethnic based discrimination or everyday racism as largely contributing to the challenges experienced when receiving health care; statements rated high for action/change include 'when the health care provider does not complete a proper assessment', 'when the patient's symptoms are ignored or not taken seriously', 'and 'when the health care provider belittles or talks down to the patient'.

CONCLUSIONS

Our study identifies how racialized health care users experience everyday racism when receiving health care and this is important to consider in the development of future research and interventions aimed at addressing institutional racism in the health care setting. To support the elimination of institutional racism, anti-racist policies are needed to move beyond cultural competence polices and towards addressing the centrality of unequal power social relations and everyday racism in the health care system.

Association between Bacillus Calmette-Guérin vaccination and lymphoma: a population-based birth cohort study

BACKGROUND

Most risk factors for lymphoma identified so far relate to immunosuppression, but its aetiology remains unclear.

OBJECTIVES

We investigated whether Bacillus Calmette-Guérin (BCG) vaccination is associated with lymphoma, overall and separately for Hodgkin's lymphoma (HL) and non-Hodgkin's lymphoma (NHL).

METHODS

A cohort of 400 611 subjects born in the province of Québec, Canada, between 1970 and 1974 was used. Information on BCG vaccination was extracted from the Quebec BCG Vaccination Registry. Lymphomas cases were individuals who had ≥2 health encounters, medical visits or hospitalizations, for lymphoma within 2 months or who were identified through the Quebec Tumor Registry. Cox proportional hazard regression was used to estimate hazard ratios (HRs) and 95% confidence interval (CI), adjusting for potential confounders.

RESULTS

A total of 178 335 (46.0%) subjects were BCG-vaccinated, and 1478 (0.38%) cases of lymphomas were ascertained. Amongst them, 922 were identified as NHL and 421 as HL. After adjustment, no association was observed between BCG vaccination and either lymphoma (any type) (HR = 1.03, 95% CI: 0.96-1.11) or NHL (HR = 0.99, 95% CI: 0.86-1.13). For HL, nonproportional hazards were observed. Before the age of 18, the risk of HL was elevated amongst vaccinated individuals (HR = 2.26, 95% CI: 1.39-3.69). However after 18 years of age, no association was found (HR = 0.93, 95% CI: 0.75-1.15).

CONCLUSION

Bacillus Calmette-Guérin vaccination may increase the risk of HL before 18 years of age, but residual confounding cannot entirely be excluded. Given the benefits of BCG vaccination, these results need to be reproduced in other populations before firm conclusions can be drawn.

Cassava flour slurry as a low-cost alternative to commercially available gel for obstetrical ultrasound: a blinded non-inferiority trial comparison of image quality

OBJECTIVE

To evaluate the quality of ultrasound images obtained with cassava flour slurry (CFS) compared with conventional gel in order to determine objectively whether CFS could be a true low-cost alternative.

DESIGN

Blinded non-inferiority trial.

SETTING

Obstetrical ultrasound unit in an academic medical centre.

POPULATION OR SAMPLE

Women with a singleton pregnancy, undergoing anatomy ultrasounds.

METHODS

Thirty pregnant women had standard biometry measures obtained with CFS and conventional gel. Images were compared side-by-side in random order by two blinded sonologists and rated for image resolution, detail and total image quality using a 10-cm visual analogue scale. Ratings were compared using paired t-tests. Participant and sonographer experience was measured using five-point Likert scales.

MAIN OUTCOME MEASURES

Image resolution, detail, and total image quality. Participant experience of gel regarding irritation, messiness, and ease of removal.

RESULTS

We found no significant difference between perceived image quality obtained with CFS (mean = 6.2, SD = 1.2) and commercial gel (mean = 6.4, SD = 1.2) [t (28) = -1.1; P = 0.3]. Images were not rated significantly differently for either reviewer in any measure, any standardized image or any view of a specific anatomic structure. All five sonographers rated CFS as easy to obtain clear images and easy for patient and machine cleanup. Only one participant reported itching with CFS.

CONCLUSIONS

CFS produces comparable image quality to commercial ultrasound gel. The dissemination of these results and the simple CFS recipe could significantly increase access to ultrasound for screening, monitoring and diagnostic purposes in resource-limited settings.

FUNDING

This study was internally funded by our department.

TWEETABLE ABSTRACT

Low-cost homemade cassava flour slurry creates images equal to commercial ultrasound gel, improving access.

Gender differences in felt stigma and barriers to help-seeking for problem gambling

Background

Men and women differ in their patterns of help-seeking for health and social problems. For people experiencing problem gambling, feelings of stigma may affect if and when they reach out for help. In this study we examine men's and women's perceptions of felt stigma in relation to help-seeking for problematic gambling.

Methods

Using concept mapping, we engaged ten men and eighteen women in group activities. We asked men and women about their perceptions of the pleasurable aspects and negative consequences of gambling; they generated a list of four hundred and sixteen statements. These statements were parsed for duplication and for relevance to the study focal question and reduced to seventy-three statements by the research team. We then asked participants to rate their perceptions of how much felt stigma (negative impact on one's own or family's reputation) interfered with help-seeking for gambling. We analyzed the data using a gender lens.

Findings

Men and women felt that shame associated with gambling-related financial difficulties was detrimental to help-seeking. For men, the addictive qualities of and emotional responses to gambling were perceived as stigma-related barriers to help-seeking. For women, being seduced by the 'bells and whistles' of the gambling venue, their denial of their addiction, their belief in luck and that the casino can be beat, and the shame of being dishonest were perceived as barriers to help-seeking.

Conclusions

Efforts to engage people who face gambling problems need to consider gendered perceptions of what is viewed as stigmatizing.

5 DISRUPTION OF THE HIGH MOBILITY GROUP AT-HOOK 2 (HMGA2) GENE IN SWINE REDUCES POSTNATAL GROWTH

The high mobility group AT-hook 2 (HMGA2) protein has been shown to be a crucial gene for cell growth, proliferation, and apoptosis; HMGA2 is also a strong biological candidate for growth, because mutations in this gene alter body size in mice and humans. Compared with wild-type controls, adult mice lacking HMGA2 are 60% smaller, and adult heterozygous mutants are 20% smaller. In humans, HMGA2 has been associated with adult and childhood height without any other deleterious effect. Additionally, a microdeletion in the HMGA2 gene in a human patient resulted in short stature, with no dysmorphologies and normal puberty. In order to determine the effect of HMGA2 on fetal and adult growth in pigs, a transgenic pig line deficient in HMGA2 expression was generated by gene targeting in fetal fibroblasts (FF). Using a targeting vector carrying a reporter gene, and homology arms specific to HMGA2, heterozygous mutant cell lines were generated. The cell lines were then used to generate 6 heterozygous females by somatic cell nuclear transfer (SCNT). Bodyweights and lengths from snout to base of tail were measured every 2 weeks for a year for mutant (n = 6) and wild-type farm gilts (n = 6). Data were analysed by one-way ANOVA. As in mice, disruption of one allele of the HMGA2 gene resulted in 25% reduction in weight (P < 0.0001) and 14% reduction in length (P < 0.0001). Early in postnatal growth (2 months), weights of mutants were not different than wild-type. However, mutants were 20 to 35% lighter (P < 0.05) during mid stages (6 months) and 25 to 30% (P < 0.0001) in late stages (3 months). The same insertional mutation generated 8 heterozygous male clones by SCNT. In addition, 7 nontransgenic males from the same FF line were generated as SCNT controls. Bodyweights and lengths were measured every 2 weeks for 30 weeks for HMGA2 heterozygous mutants (n = 8), control SCNT (n = 7) and wild-type farm boars (n = 5). The weight curve of boars showed similar pattern as for mutant gilts. At 30-week postnatal stage, mutants were 17% (P < 0.05) and 16% (P < 0.05) lighter in weight compared with littermate and wild-type animals, respectively. We are presently developing homozygous HMGA2 mutant lines. Currently, 3 of 6 heterozygous gilts have been bred with heterozygous boars, with 1 confirmed pregnancy. The expectation is that the homozygous animals will, like mice, be 60% smaller than the wild-type animals. The approach described here will result not only in a valuable large-animal model of dwarfism, but also in a tool to reduce the size of existing transgenic and nontransgenic swine lines. This, in turn, will increase the receptivity of valuable transgenic lines by the biomedical community. Funding for this work was provided by NIH grant R21-OD010553 to JP.

[CSF otorrhea: case report and management]

Mr G, sixty-seven years old, was admitted to our hospital for a liver transplant. He suffered from a cirrhosis due to an HBV infection, complicated by an hepatocellular carcinoma. During the perioperative care, a left otorrhea was discovered. According to the clinical history, this otorrhea had been present for six weeks and followed the completion of a myringotomy. The myringotomy had been performed with a view to place a transtympanic ventilation tube for the treatment of a serous otitis media inducing a conductive hearingloss. Clinical, biological, and radiological explorations revealed a CSF leak caused by the fact that the myringotomy had been done in a temporal meningo-encephalocele. A conservative treatment allowed to stop the otorrhea. We present a short discussion about temporal meningoencephalocele and, more generally, about CSF otorrhea.

Are residents of downtown Toronto influenced by their urban neighbourhoods? Using concept mapping to examine neighbourhood characteristics and their perceived impact on self-rated mental well-being

Background

There is ample evidence that residential neighbourhoods can influence mental well-being (MWB), with most studies relying on census or similar data to characterize communities. Few studies have actively investigated local residents’ perceptions.

Methods

Concept mapping was conducted with residents from five Toronto neighbourhoods representing low income and non-low income socio-economic groups. These residents participated in small groups and attended two sessions per neighbourhood. The first session (brainstorming) generated neighbourhood characteristics that residents felt influenced their MWB. A few weeks later, participants returned to sort these neighbourhood characteristics and rate their relative importance in affecting residents’ ‘good’ and ‘poor’ MWB. The data from the sorting and rating groups were analyzed to generate conceptual maps of neighbourhood characteristics that influence MWB.

Results

While agreement existed on factors influencing poor MWB (regardless of neighbourhood, income, gender and age), perceptions related to factors affecting good MWB were more varied. For example, women were more likely to rank physical beauty of their neighbourhood and range of services available as more important to good MWB, while men were more likely to cite free access to computers/internet and neighbourhood reputation as important. Low-income residents emphasized aesthetic attributes and public transportation as important to good MWB, while non-low-income residents rated crime, negative neighbourhood environment and social concerns as more important contributors to good MWB.

Conclusion

These findings contribute to the emerging literature on neighbourhoods and MWB, and inform urban planning in a Canadian context.

Narcotic analgesic utilization amongst injured workers: using concept mapping to understand current issues from the perspectives of physicians and pharmacists

Background

Work-related injuries result in considerable morbidity, as well as social and economic costs. Pain associated with these injuries is a complex, contested topic, and narcotic analgesics (NA) remain important treatment options. Factors contributing to NA utilization patterns are poorly understood. This qualitative study sought to characterize the factors contributing to NA utilization amongst injured workers from the perspectives of physicians and pharmacists.

Methods

The study employed concept mapping methodology, a structured process yielding a conceptual framework of participants' views on a particular topic. A visual display of the ideas/concepts generated is produced. Eligible physicians and pharmacists (n = 22) serving injured workers in the province of Ontario (Canada) were recruited via purposive sampling, and participated in concept mapping activities (consisting of brainstorming, sorting, rating, and map exploration). Participants identified factors influencing NA utilization, and sorted these factors into categories (clusters). Next, they rated the factors on two scales: 'strength of influence on NA over-utilization' and 'amenability to intervention'. During follow-up focus groups, participants refined the maps and discussed the findings and their implications.

Results

82 factors were sorted into 7 clusters: addiction risks, psychosocial issues, social/work environment factors, systemic-third party factors, pharmacy-related factors, treatment problems, and physician factors. These clusters were grouped into 2 overarching categories/regions on the map: patient-level factors, and healthcare/compensation system-level factors. Participants rated NA over-utilization as most influenced by patient-level factors, while system-level factors were rated as most amenable to intervention. One system-level cluster was rated highly on both scales (treatment problems - e.g. poor continuity of care, poor interprofessional communication, lack of education/support for physicians regarding pain management, unavailability of multidisciplinary team-based care, prolonged wait times to see specialists).

Conclusions

Participants depicted factors driving NA utilization among injured workers as complex. Patient-level factors were perceived as most influential on over-utilization, while system-level factors were considered most amenable to intervention. This has implications for intervention design, suggesting that systemic/structural factors should be taken into account in order to address this important health issue.

Pathways connecting neighborhood influences and mental well-being: socioeconomic position and gender differences

Few studies have explored how participant socioeconomic position (SEP) and gender is related to perceptions of the pathways connecting neighborhood influences and mental well-being. This research used the concept mapping method, an intensive structured conceptualization process that produces pictorial views of how concepts are connected and interrelated. Thirty-six low and non-low SEP men and women from Toronto, Canada participated in the concept mapping sessions. One hundred and twenty unique neighborhood characteristics were felt to be related to mental well-being and those items were grouped into six distinct clusters. Notable differences in cluster importance by participant SEP status were found. While no overall differences were observed for males verses females, further stratification by both participant SEP and gender suggested that gendered perceptions are not uniform. Participant-created diagrams illustrated how the cluster domains are related to each other and to good mental well-being. These findings are important for uncovering the mechanisms by which neighborhoods differentially affect the mental health of residents from different SEPs and genders.

Is formal training necessary for capsule endoscopy? The largest gastroenterology trainee study with controls

BACKGROUND

Little is known about the infrastructure to train gastroenterologists in capsule endoscopy. The level of capsule endoscopy exposure among trainees in the United Kingdom or Europe has also not been quantified.

AIMS AND METHODS

To assess the ability of 10 gastroenterology trainees with endoscopy experience to interpret 10 capsule endoscopy videos against five medical students, with an expert in capsule endoscopy as the gold standard. Parameters assessed included gastric emptying time, small bowel transit and the diagnosis made. A questionnaire survey assessed the level of capsule endoscopy exposure among United Kingdom trainees.

RESULTS

Trainees were better at determining the gastric emptying time (p=0.013) and more likely to record true positives compared to the students (p=0.037). They were also less likely to record false positives (p=0.005) and more likely to reach the correct diagnosis (p=0.001, OR 3.6, CI 1.8-7.4). Our survey found that, 65% of trainees had prior exposure to capsule endoscopy but only 13% had done capsule endoscopy reporting. Sixty seven percent felt capsule endoscopy should be incorporated into their training.

CONCLUSION

This study has shown that prior endoscopic experience enables trainees to interpret capsule endoscopy more accurately than medical students. However, there is a demand for focussed training which would enable trainees to reliably interpret pathology on capsule endoscopy.

Neighbourhoods and mental well-being: what are the pathways?

The last decade has seen an acceleration in research examining the impact of neighbourhood characteristics on a health outcomes. Yet, identifying specific pathways by which neighbourhoods affect mental well-being has received less attention. The article describes findings from a qualitative study conducted in Toronto, Ont., Canada, examining the pathways by which neighbourhood characteristics are related to mental well-being. Methods of concept mapping were used to answer our research questions. Participants identified over 100 neighbourhood characteristics grouped into six cluster that were important for either good or poor mental well-being. Clusters were rated in terms of their importance to mental well-being. Finally, participants drew diagrams describing how the neighbourhood factors and domains were contributing to poor and good mental well-being. Concept mapping provides unique contributions and challenges and may provide a useful means of examining specific pathways from neighbourhood to health outcomes.

Research note: ethics of drug treatment research with court-supervised subjects

The last two decades have seen an acceleration of clinical research on, and treatment advances in, addictive illness. Much important research in this area requires the participation of subjects who themselves suffer from drug dependence and have a strong likelihood of becoming involved in the criminal justice system at some point. However, using court-supervised persons with addictive disorders in drug research raises a number of significant ethical issues. These include, among others, worries about the individual's ability to provide capable, voluntary, informed consent and the obligation of researchers to safeguard sensitive clinical information. A variety of potentially coercive factors can influence court-supervised persons in their decision whether to enter research and can compromise their ability to provide informed consent. In this paper, we explore the ethical issues arising in this research and offer some suggestions for approaches to address these concerns.

[Prader-Willi syndrome: specific management by a multidisciplinary team]

Prader Willi syndrome can be viewed as a physiopathological model of obesity. Such patients deserve specific management, preferably in a multidisciplinary setting. The paper reports on 6 patients followed in the paediatric endocrine service at the University of Liege.

Duality of gonadotropins in gnathostomes

The glycoprotein hormone alpha subunit and two beta subunits were cloned from the ventral lobe of the pituitary gland of an elasmobranch fish, Scyliorhinus canicula. The mature alpha subunit was 96 amino acids long and showed 64-76 amino acid residues in common with alpha subunit sequences of representatives of sarcopterygians (tetrapods and dipnoi) and actinopterigyans (chondrostei and teleostei). The Scyliorhinus beta 1 subunit was 115 amino acid long and had characteristics specific to FSH beta subunits and, in particular, the two potential N-linked glycosylation sites in conserved positions. The beta 2 sequence was 112 amino acids long. The Scyliorhinus beta 2 subunit had only one potential N-linked glycosylation site at the same position as that in LH. None of the two beta subunits from Scyliorhinus displayed the two amino acid insertions shared by TSH beta subunit sequences between the fifth and the sixth cysteines as compared to actinopterygian and sarcopterygian gonadotropins. These data indicate that Scyliorhinus beta 1 and beta 2 subunits are orthologous to FSH and LH beta subunits, respectively. It is concluded that the two FSH and LH lineages were already individualized at the emergence of chondrichthyans.

Phylogenetic analysis of the vertebrate glycoprotein hormone family including new sequences of sturgeon (Acipenser baeri) beta subunits of the two gonadotropins and the thyroid-stimulating hormone

The beta subunits of the two gonadotropins (GTH1 and GTH2) and of the thyroid-stimulating hormone (TSH) of a chondrostean fish, Acipenser baeri, were cloned. These new sequences and selected representative members of beta subunits of vertebrate glycoprotein hormones, including tetrapod follicle-stimulating hormones (FSH) and luteinizing hormones (LH), allowed us to infer the phylogenetic relationships within this family. Both distance matrix and maximum parsimony methods were used on both nucleotide and amino acid sequences, with bootstrapping evaluation over 1000 replicates. The four trees obtained had highly similar topologies. In each case, three monophylogenetic lineages, TSH, GTH1-FSH, and GTH2-LH were clearly identified. The three monophylogenetic lineages were supported by 21-23 specific characters at the amino acid level, out of a total of 121 characters. The resolved topologies within each monophyletic hormone cluster were congruent with the known phylogenetic relationships between the related species. The inferred parental relationships within gonadotropins are in agreement with data concerning their biological functions. The present study demonstrates that GTH1 and GTH2 are the actinopterygian homologues of tetrapod FSH and LH, respectively.

Heterogeneity of eel thyrotropin beta mRNAs is due to a minisatellite in the 3' untranslated region of the gene

The aim of this study was to determine the causes of the high heterogeneity, in the number and the length, of the thyrotropin (TSH) beta mRNA in the European eel. Northern blot analysis showed that removal of the poly(A) tail did not affect this heterogeneity. PCR amplification on reverse-transcribed pituitary RNAs (RT) showed the main source of heterogeneity to be a highly variable region in the 3' untranslated region (UTR). PCR amplification of the 3' UTR from RTs and genomic DNAs demonstrated that the high variability reflected polymorphism within the eel TSH beta gene. Isolation and sequencing of 3' UTR amplification fragments showed that the variable region comprised more or less exact repetitions of a 26-42-bp fragment. The number of repetitions varied from one allele to another. This variable region could be characterized as a minisatellite. In conclusion, instability of a minisatellite in the 3' UTR of the TSH beta gene generated the multiple and widely differing TSH beta mRNAs.

Modeling studies of binding of sea raven type II antifreeze protein to ice

Certain plants, insects, and fish living in cold environments prevent tissue damage due to freezing by producing antifreeze proteins or antifreeze glycoproteins that inhibit ice growth below the normal equilibrium freezing point of water in a noncolligative fashion. In polar fish these macromolecules, taking into account their structural characteristics, are grouped into three broad classes, namely Type I, Type II, and Type III. In this paper we report the results of our studies on the stereospecific binding of sea raven, a Type II antifreeze protein (AFP) to (111) hexagonal bipyramidal faces of ice. Earlier studies of Type I and Type III AFPs have shown that stereospecific binding of these proteins, recognizing specific planes of ice, is essential for their noncolligative antifreeze point depression. Moreover, as it has been shown for the AFT of Type I, this binding also occurs along specific vectors on these planes and also is enantioselective, distinguishing between the mirror related directions. In this study we will show, by using molecular modeling, that the fold of Type II AFP could facilitate a stereospecific mode of interaction with (111) planes of ice. Similar to Type I AFP, preferential directionality of binding was also observed in the simulations.

Down-regulation of TSH subunit mRNA levels by thyroid hormones in the European eel

The effects of 3,5,3'-triiodothyronine (T3) and thyroxine (T4) on alpha and thyroid-stimulating hormone (TSH) beta subunit mRNA pituitary levels were examined in a teleost, the European silver eel. Northern blot analysis showed that the number and length of mRNAs encoding TSH beta varied among individuals, a variability apparently not related to thyroidal status. When several bands were present, their intensities were summed for quantitative analysis. Increasing circulating thyroid hormones (THs) by implantation of T3 or T4 significantly decreased TSH beta mRNA levels. Depression of circulating THs by thiourea treatment increased alpha and TSH beta mRNA levels. In vitro studies showed that T3 and T4 decrease TSH beta mRNA levels in primary cultures of eel pituitary cells. In conclusion, in vivo and in vitro experiments indicate that T3 and T4 exert a negative feedback action on pituitary TSH beta mRNA level in the European eel and that this effect might be exerted, at least partly, through a direct action on the pituitary.

[Cloning and sequence of thyrotropin beta subunit of a teleost fish: the eel (Anguilla anguilla L.)]

We obtained the sequence of eel thyrotropin beta-subunit cDNA. About 1,100 bp long, it encodes a 147-amino acid protein including a 20-residue signal peptide. We analyse homologies between angTSH beta and the other known beta-subunits taking in account the ability of mammal gonadotropins (GTH) to stimulate teleost thyroid. A peptide corresponding to mammalian CAGYC (implicated in subunit association) is original and different from its eel beta GTH2 counterpart.

[Passive immunotherapy in AIDS: transfusion of plasma rich in anti-p25 antibody (phase I trial)]

The present study is a therapeutic trial of phase I, based on the principle of passive immunotherapy in acquired immunodeficiency syndrome (AIDS). Eighteen patients with full blown AIDS (stage IV C2 of CDC) were subdivided into two groups: nine receiving every two weeks 300 ml of plasma collected from HIV-1 seropositive symptomless (stage II or III of CDC) individuals, and nine (control group) receiving 300 ml of seronegative plasma at the same rythm and for the same period. Each patient received seven transfusions. Clinical and biological results during the transfusional and post-transfusional periods are reported.

No evidence of frequent human immunodeficiency virus type 1 infection in seronegative at-risk individuals

The possible existence of human immunodeficiency virus type 1 (HIV-1) infection in asymptomatic seronegative at-risk individuals was investigated in a prospective study of 55 seronegative high-risk individuals (42 homosexual men and 13 heterosexual individuals) and 32 seronegative hemophiliacs treated with factor VIII or IX concentrates before viral inactivation by heat treatment and systematic screening of blood donations. Tests used include the polymerase chain reaction assay with three primer pairs (one in the gag region and two in the pol region) and tests for serum p24 antigen, anti-nef serology (Western blot), and five biologic markers frequently altered by HIV infection (CD4 lymphocyte count, serum beta 2-microglobulin and neopterin concentration, and serum IgG and IgA concentration). Although 91 of 92 HIV-1-seropositive persons were positive in testing with at least one primer pair, no positive result was observed in seronegative at-risk individuals or in 117 seronegative low-risk controls. No nef antibody was found in seronegative at-risk individuals or seronegative controls, but 44 (47%) of 92 HIV-1-seropositive persons had nef antibodies. These findings do not support the existence of frequent HIV-1 infection in seronegative at-risk individuals.