Outcomes of Hallux Amputation Versus Partial First Ray Resection in People with Non-Healing Diabetic Foot Ulcers: A Pragmatic Observational Cohort Study

There are few data comparing outcomes after hallux amputation or partial first ray resection after diabetic foot ulcer (DFU). In a similar context, the choice to perform one of these two surgeries is attributable to clinician preference based on experience and characteristics of the patient and the DFU. Therefore, the purpose of this study was to determine the more definitive surgery between hallux amputation and partial first ray resection. We abstracted data from a cohort of 70 patients followed for a 1-year postoperative period to support clinical practice. We also attempted to identify patient characteristics leading to these outcomes. Our results suggested no statistical difference between the type of surgery and outcomes such as recurrence of DFU and amputation at 3, 6, and 12 months or death. However, there was a statistically significantly increased likelihood of re-ulceration for patients with CAD who underwent hallux amputation (p = 0.02). There was also a significantly increased likelihood of re-ulceration for people with depression or a history when the partial ray resection was performed (p = 0.02). Patients with prior amputation showed a higher probability of undergoing another re-amputation with partial ray resection (p = 0.01). Although the trends that emerge from this project are limited to what is observed in this statistical context, where the number of patients included and the number of total observations per outcome were limited, it highlights interesting data for future research to inform clinical decisions to support best practices for the benefit of patients.

La contribution des Acadiens au peuplement des régions du Québec1

Les Acadiens sont des descendants d’immigrants français qui se sont établis principalement au xviie siècle en Nouvelle-Écosse et au Nouveau-Brunswick. En 1755, les autorités britanniques ont ordonné la déportation des Acadiens qui ont été dispersés dans les colonies anglaises d’Amérique, en France et en Angleterre. On estime que de 2 000 à 4 000 Acadiens se sont établis au Québec. L’objectif de cette étude est de mesurer et de caractériser l’impact de l’apport migratoire acadien sur le pool génique québécois contemporain. Les données utilisées proviennent d’un corpus généalogique comprenant 2 340 ascendances. Les lieux d’origine des ancêtres, la fréquence de leurs mentions dans les généalogies ainsi que leur contribution génétique aux différentes populations régionales du Québec ont été analysés. Les résultats révèlent que de 46 % à 100 % des ascendances, selon la région, comprennent au moins un ancêtre d’origine acadienne. La contribution des fondateurs acadiens est particulièrement élevée aux Îles-de-la-Madeleine, où 86 % du pool génique leur est attribuable. Les populations de la Gaspésie (27 %) et de la Côte-Nord (14 %), affichent aussi une importante contribution acadienne.

Contribution of hierarchical clustering techniques to the modeling of the geographic distribution of genetic polymorphisms associated with chronic inflammatory diseases in the Québec population

OBJECTIVES

The purpose of this project was to evaluate the potential of the downward hierarchical clustering analysis (DHCA) for studying genetic heterogeneity, i.e. differences in allele frequency in subpopulations, such as the 15 public health regions of the province of Québec (Canada).

METHODS

The study relied on an anonymized sample of 1,680 individuals who had participated in the Québec Heart Health Survey in 1990-1991. The genotyping of 11 variants in 8 candidate genes known to be involved in chronic inflammatory diseases, namely asthma and cardiovascular diseases, was performed using the amplification refractory mutation system and restriction fragment length polymorphism techniques. Only variants showing an allelic frequency >2% in the Québec Heart Health Survey (n = 8) were selected. DHCA techniques were then applied to model the geographical distribution of these 8 genetic variants in 15 Québec public health regions and to study genetic heterogeneity.

RESULTS

The DHCA allowed to group public health regions and gene variants on the basis of genetic variability. For both asthma and cardiovascular diseases, 3 significant clusters of public health regions and 1 cluster of gene variants were identified.

DISCUSSION

This study suggests that DHCA might be useful in studying genetic heterogeneity at the population level and for public health activities.

Origines et contributions génétiques des fondatrices et des fondateurs de la population québécoise

Cette étude présente une analyse des origines géographiques et de la contribution génétique des ancêtres fondateurs de la population du Québec. À l’aide de données tirées du ficher BALSAC et du Registre de la population du Québec ancien, un corpus de 2223 généalogies ascendantes couvrant l’ensemble du territoire québécois a été construit. Ces généalogies remontent jusqu’au 17e siècle et couvrent en moyenne plus de neuf générations. Tous les liens généalogiques unissant l’ensemble des individus identifiés dans les ascendances ont été établis. Les résultats indiquent qu’environ 81 pour cent du pool génique québécois s’explique par des fondatrices et fondateurs venus de France au 17e siècle. Des différences importantes existent toutefois selon le lieu d’origine en France et selon le sexe des fondateurs. Les résultats ont aussi mis en évidence la présence de nombreux liens d’apparentement éloigné dans cette population.

Evaluation of BRCA1 and BRCA2 mutation prevalence, risk prediction models and a multistep testing approach in French-Canadian families with high risk of breast and ovarian cancer

BACKGROUND AND OBJECTIVE

In clinical settings with fixed resources allocated to predictive genetic testing for high-risk cancer predisposition genes, optimal strategies for mutation screening programmes are critically important. These depend on the mutation spectrum found in the population under consideration and the frequency of mutations detected as a function of the personal and family history of cancer, which are both affected by the presence of founder mutations and demographic characteristics of the underlying population. The results of multistep genetic testing for mutations in BRCA1 or BRCA2 in a large series of families with breast cancer in the French-Canadian population of Quebec, Canada are reported.

METHODS

A total of 256 high-risk families were ascertained from regional familial cancer clinics throughout the province of Quebec. Initially, families were tested for a panel of specific mutations known to occur in this population. Families in which no mutation was identified were then comprehensively tested. Three algorithms to predict the presence of mutations were evaluated, including the prevalence tables provided by Myriad Genetics Laboratories, the Manchester Scoring System and a logistic regression approach based on the data from this study.

RESULTS

8 of the 15 distinct mutations found in 62 BRCA1/BRCA2-positive families had never been previously reported in this population, whereas 82% carried 1 of the 4 mutations currently observed in > or =2 families. In the subset of 191 families in which at least 1 affected individual was tested, 29% carried a mutation. Of these 27 BRCA1-positive and 29 BRCA2-positive families, 48 (86%) were found to harbour a mutation detected by the initial test. Among the remaining 143 inconclusive families, all 8 families found to have a mutation after complete sequencing had Manchester Scores > or =18. The logistic regression and Manchester Scores provided equal predictive power, and both were significantly better than the Myriad Genetics Laboratories prevalence tables (p<0.001). A threshold of Manchester Score > or =18 provided an overall sensitivity of 86% and a specificity of 82%, with a positive predictive value of 66% in this population.

CONCLUSION

In this population, a testing strategy with an initial test using a panel of reported recurrent mutations, followed by full sequencing in families with Manchester Scores > or =18, represents an efficient test in terms of overall cost and sensitivity.

Demogenetic study of three populations within a region with strong founder effects

OBJECTIVES

The population of the Saguenay-Lac-St-Jean (SLSJ) region (Quebec, Canada) is known to have a relatively high prevalence of certain hereditary disorders, which can be explained by the consequences of founder effects. This study aims at providing new insights on the origins and subregional stratification of these founder effects.

METHODS

The genealogies of 300 individuals were reconstructed and analyzed using the BALSAC population register.

RESULTS

Inbreeding and kinship levels are higher in Lower Saguenay than in Upper Saguenay and Lac-St-Jean. The population of Lower Saguenay also distinguishes itself because of a fewer number of distinct ancestors.

CONCLUSION

Beyond the genetic features that characterize the whole region, SLSJ also displays intraregional variability. Thus it is important to take into account the settlement patterns and the demographic history of this population for a better appraisal of its contemporary genetic structure.

A "Fille du Roy" introduced the T14484C Leber hereditary optic neuropathy mutation in French Canadians

The predominance of the T14484C mutation in French Canadians with Leber hereditary optic neuropathy is due to a founder effect. By use of genealogical reconstructions of maternal lineages, a woman married in Quebec City in 1669 is identified as the shared female ancestor for 11 of 13 affected individuals, who were previously not known to be related. These individuals carry identical mitochondrial haplogroups. The current geographic distribution of French Canadian cases overlaps with that of the founder's female descendants in 1800. This is the first example of genealogical reconstruction to identify the introduction of a mitochondrial mutation by a woman in a founder population.

Anatomy of a founder effect: myotonic dystrophy in Northeastern Quebec

Founder effects are largely responsible for changes in frequency profiles of genetic variants in local populations or isolates. They are often recognized by elevated incidence of certain hereditary disorders as observed in regions of Charlevoix and Saguenay-Lac-Saint-Jean (SLSJ) in Northeastern Quebec. Dominantly transmitted myotonic dystrophy (DM1) is highly prevalent in SLSJ where its carrier rate reaches 1/550, compared with 1/5,000 to 1/50,000 elsewhere. To shed light on the origin of DM1 in this region, we have screened 50 nuclear DM1 families from SLSJ and studied the genetic variation in a 2.05 Mb (2.9 cM) segment spanning the site of the expansion mutation. The markers analyzed included 22 biallelic SNPs and two microsatellites. Among 50 independent DM1 chromosomes, we distinguished ten DM1-associated haplotypes and grouped them into three haplotype families, A, B and C, based on the relevant extent of allele sharing between them. To test whether the data were consistent with a single entry of the mutation into SLSJ, we evaluated the age of the founder effect from the proportion of recombinant haplotypes. Taking the prevalent haplotype A1_21 (58%) as ancestral to all the disease-associated haplotypes in this study, the estimated age of the founder effect was 19 generations, long predating the colonization of Nouvelle-France. In contrast, considering A1_21 as ancestral to the haplotype family A only, yielded the estimated founder age of nine generations, consistent with the settlement of Charlevoix at the turn of 17th century and subsequent colonization of SLSJ. We conclude that it was the carrier of haplotype A (present day carrier rate of 1/730) that was a "driver" of the founder effect, while minor haplotypes B and C, with corresponding carrier rates of 1/3,000 and 1/10,000, respectively, contribute DM1 to the incidence level known in other populations. Other studies confirm that this might be a general scenario in which a major "driver" mutation/haplotype issued from a founder effect is found accompanied by distinct minor mutations/haplotypes occurring at background population frequencies.

Molecular and genealogical characterization of the R1443X BRCA1 mutation in high-risk French-Canadian breast/ovarian cancer families

The Quebec population contains about six-million French Canadians, descended from the French settlers who colonized "Nouvelle-France" between 1608 and 1765. Although the relative genetic contribution of each of these founders is highly variable, altogether they account for the major part of the contemporary French-Canadian gene pool. This study was designed to analyze the role of this founder effect in the introduction and diffusion of the BRCA1 recurrent R1443X mutant allele. A highly conserved haplotype, observed in 18 French-Canadian families and generated using 17 microsatellite markers surrounding the BRCA1 locus, supports the fact that the R1443X mutation is a founder mutation in the Quebec population. We also performed haplotyping analysis of R1443X carriers on 19 other families from seven different nationalities; although the same alleles are shared for three markers surrounding the BRCA1 gene, distinct haplotypes were obtained in four families, suggesting multiple origins for the R1443X mutation. Ascending genealogies of the 18 French Canadian families and of controls were reconstructed on an average depth of 10 generations. We identified the founder couple with the highest probability of having introduced the mutation in the population. Based on the descending genealogy of this couple, we detected the presence of geographical concentration in the diffusion pattern of the mutation. This study demonstrates how molecular genetics and demogenetic analyses can complement each other to provide findings that could have an impact on public health. Moreover, this approach is certainly not unique to breast cancer genetics and could be used to understand other complex traits.

A genealogical study of essential hypertension with and without obesity in French Canadians

OBJECTIVES

To investigate genetic homogeneity in a set of hypertensive families and in subsets chosen for high and low prevalence of obesity; and to compare fasting insulin and lipids, ion transport, and water homeostasis in the obese and lean families.

RESEARCH METHODS AND PROCEDURES

The study was carried out in a relative population isolate of the Saguenay/Lac St. Jean region in Canada. Genetic homogeneity was evaluated with the mean coeffigcients of kinship (phi) and inbreeding (F) computed with ascending genealogies. Serum insulin and lipids were measured after overnight fasting. Total body water was estimated with bioelectrical impedance. Sodium-lithium countertransport and sodium-potassium co-transport were determined in freshly isolated erythrocytes.

RESULTS

F and phi were increased in hypertensive families compared with families selected at random. F and phi were further increased within the subsets of obese and lean families. In addition, fasting insulin, total body water, sodium-lithium countertransport, and sodium-potassium co-transport were higher in the obese than in the lean families. The two subsets of families did not differ by fasting lipids.

DISCUSSION

In the Saguenay/Lac St. Jean population, the degree of genetic homogeneity was increased in families selected for hypertension, and it was further increased in subsets of hypertensive families with high and low prevalence of obesity. This suggests that hypertension in lean and obese individuals may represent, at least in part, separate genetic entities. Some of the extra genes shared in common within the subsets may contribute to their differences in body weight, insulin sensitivity, ion transport, and water homeostasis.

Quebec child mental health survey: prevalence of DSM-III-R mental health disorders

The Quebec Child Mental Health Survey (QCMHS) was conducted in 1992 on a representative sample of 2400 children and adolescents aged 6 to 14 years from throughout Quebec. Prevalences of nine Axis-I DSM-III-R (American Psychiatric Association, 1987) mental health disorders were calculated based on each informant (for 6-11-year-olds: child, parent, and teacher; for 12-14-year-olds: child and parent). Informant parallelism allows the classification of results of the demographic variables associated with disorders in the logistic regression models. This strategy applies to group variables (correlates of disorders) whereas informant agreement applies to individual diagnoses. Informant parallelism implies that results for two informants or more are in the same direction and significant. In the QCMHS, informant parallelism exists for disruptive disorders, i.e. in two ADHD regression models (child and parent) higher rates among boys and young children, and in three oppositional/conduct disorders regression models (child, parent, and teacher) higher rates among boys. No informant parallelism is observed in the logistic regression models for internalizing disorders, i.e. the patterns of association of demographic variables with anxiety and depressive disorders vary across informants. Urban-rural residence does not emerge as a significant variable in any of the logistic regression models. The overall 6-month prevalences reach 19.9% according to the parent and 15.8% according to the child. The implications of the results for policy makers and clinicians are discussed.

Alzheimer's disease: preliminary study of spatial distribution at birth place

Alzheimer's disease (AD) is a neurodegenerative disorder which is characterized by a progressive loss of memory and the alteration of cognitive functions. At least three chromosomal segments have been associated with early-onset AD in genetic linkage studies. These results argue for a certain degree of heterogeneity in the genetic origin of some forms of AD, although environmental risk factors cannot be ruled out in late-onset AD. In this preliminary study, we analyzed the geographical distribution of the birth places of a sample of 235 AD cases born in a defined region of Quebec (Canada), between 1895 and 1935. We wished to test the hypothesis that risk factors acting at, or around birth place and time play a role in the etiology of AD. The field of study was divided into rural and urban areas. A reference population of live births was used to compute a measure of odds ratio (OR). The OR results showed a statistically significant excess of AD cases in the rural area as compared to the reference population. When stratified for sex, the OR results showed a global excess of female AD cases in both the rural and the urban areas. For men, only the urban area presented a statistically significant deficit. We also analyzed the structures of the genealogical kinships of the rural and urban sub-groups. Although AD cases from the rural sub-group were more closely related to each other than those from the urban one, removal of the kin pairs from the OR analysis seemed to have little effect on the rural/urban distribution of cases. Therefore, the OR results would not appear to be due primarily to a difference in the kinship structures of the two sub-groups. This could mean that some risk factors for AD afflict women more strongly than men, the effect being different depending on the urban or rural origin. However, potential biases such as a higher rate of report for women, differential migration between birth places or a differential mortality ratio between sexes could produce spurious results in the direction of what we have observed in this preliminary study.

Season of birth and Alzheimer's disease: a population-based study in Saguenay-Lac-St-Jean/Québec (IMAGE Project)

The birth distribution of 399 cases of Alzheimer's disease (AD) identified in the region of Saguenay-Lac-St-Jean (Québec) was compared with that of: (a) the population currently living in the area; and (b) the population born during the same period in the same area. AD cases have been recruited since 1986 by the IMAGE Project. Cases and controls were grouped according to the month of birth and according to the day of birth using density estimation. Analyses showed a significant deficit of births in the month of May. We believe these preliminary results deserve further attention and we suggest two possible explanations that could lead to a deficit of AD births at specific periods during the year.

Do children aged 9 through 11 years understand the DISC Version 2.25 questions?

OBJECTIVE

To assess the understanding of Diagnostic Interview Schedule for Children-Version 2.25 (DISC-2.25) questions by children aged 9 through 11 years.

METHOD

Two hundred forty children were recruited from four public schools. The cognitive appraisal of 280 questions from the most prevalent DSM-III-R diagnoses was evaluated. The collaboration of four children was necessary to cover one DISC. Sixty DISCs, evenly distributed according to age and sex, were completed. Two child psychiatrists evaluated the children's answers. Nonparametric tests were used to assess understanding of questions as a whole, of time concepts (overall, categories, number), and of questions based on the number of words.

RESULTS

Children aged 9, 10, and 11 years understood 38%, 38%, and 42% of the questions as a whole, respectively, and 26%, 24%, and 30% of the overall time concepts, respectively. The understanding rates of questions as a whole were significantly higher than those of overall time concepts. Durations were significantly better understood than periods and frequencies, and questions having one time component were significantly better grasped than those with two or more. Shorter questions were significantly better understood than longer ones.

CONCLUSION

Although the DISC has been greatly improved since the initial version, the results suggest that additional revision is needed before clinicians or researchers use the DISC with younger children.

[Communication in a child psychiatric training center]

This paper indicates the special needs for communication of information in a Hospital Department of Child Psychiatry, where the main activities are: clinical services, consultation with the community, teaching, training and research. In the organization of information three areas must be considered: orientations and policies of the Department, the community and its facilities and the scientific data necessary for clinical teaching and research activities.

The importance for scientific information being made easily available to users is stressed, as well as the necessity to develop motivation for an active search for information. Emphasis is also placed on the quality which must determine the choice of technical means to deal with this information. Finally, certain specialized means of information in the Department of Psychiatry of Hôpital Sainte-Justine are briefly described.

[The team examination of learning disorders of school children]

This paper describes a method for the examination of learning disorders. The examination of a child and his parents is carried out simultaneously by a team including a social worker, a psychiatrist, a specialized educator in remedial teaching, a psychologist and a neurologist. Each specialist examines the child alone but observes the examinations by other team members through a one-way mirror. This procedure favours a more unified and refined comprehensive diagnosis while permitting the use of more specific examination techniques and tests whose limitations can be immediately compensated and complemented by the other team members. Each professional discipline develops means of elucidating more and more definite aspects of the studied learning disorders. Patients can thus obtain more complete services in a single visit to the hospital. In most cases, this examination is sufficient to permit immediate recommendations to the child and his parents for precise and practical therapeutic measures. Also extremely valuable is the enrichment each professional team member derives through observing the work of his co-workers. Repeated confrontation of working methods refines observation skills, widens scientific perspectives, increases mutual understanding and respect, and gives everyone a deeper knowledge of his own specialization.