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Biomedical subjects

A Kong

Publications and source records attributed to A Kong.

At least 19 recordsLinked to original sources
PubMed2006

The genetic spectrum of a population-based sample of familial hemiplegic migraine.

Familial hemiplegic migraine (FHM) is a rare subtype of migraine with aura and transient hemiplegia. FHM mutations are known in three genes, the CACNA1A (FHM1) gene, the ATP1A2 (FHM2) and the SCN1A (FHM3) gene and seem to have an autosomal-dominant mode of inheritance. The aim of this study was to search for FHM mutations in FHM families identified through a screen of the Danish population of 5.2 million people. FHM patients were diagnosed according to the International Classification of Headache Disorders and all FHM patients had a physical and neurological examination by a physician. A total of 147 FHM patients from 44 different families were identified; 43 FHM families participated in this study. Linkage analysis of these families shows clear linkage to the FHM locus (FHM1) on chromosome 19, supportive linkage to the FHM2 locus whereas no linkage was found to the FHM3 locus. Furthermore, we sequenced all exons and promoter regions of the CACNA1A and ATP1A2 genes and screened for the Q1489K mutation in the SCN1A gene. CACNA1A gene mutations were identified in three of the FHM families, two known FHM mutations, R583Q and T666M and one novel C1369Y mutation. Three FHM families were identified with novel mutations in the ATP1A2 gene; a family with a V138A mutation, a family with a R202Q mutation and a family with a R763C mutation. None of the Danish FHM families have the Q1489K mutation in the SCN1A gene. Our study shows that only 14% (6/42) of FHM families in the general Danish population have exonic FHM mutations in the CACNA1A or ATP1A2 gene. The families we identified with FHM mutations in the CACNA1A and ATP1A2 genes were extended, multiple affected families whereas the remaining FHM families were smaller. The existence of many small families in the Danish FHM cohort may reflect less bias in FHM family ascertainment and/or more locus heterogeneity than described previously.

Adolescent↗
PubMed2005

Association between the gene encoding 5-lipoxygenase-activating protein and stroke replicated in a Scottish population.

Cardiovascular diseases, including myocardial infarction (MI) and stroke, most often occur on the background of atherosclerosis, a condition attributed to the interactions between multiple genetic and environmental risk factors. We recently reported a linkage and association study of MI and stroke that yielded a genetic variant, HapA, in the gene encoding 5-lipoxygenase-activating protein (ALOX5AP), that associates with both diseases in Iceland. We also described another ALOX5AP variant, HapB, that associates with MI in England. To further assess the contribution of the ALOX5AP variants to cardiovascular diseases in a population outside Iceland, we genotyped seven single-nucleotide polymorphisms that define both HapA and HapB from 450 patients with ischemic stroke and 710 controls from Aberdeenshire, Scotland. The Icelandic at-risk haplotype, HapA, had significantly greater frequency in Scottish patients than in controls. The carrier frequency in patients and controls was 33.4% and 26.4%, respectively, which resulted in a relative risk of 1.36, under the assumption of a multiplicative model (P=.007). We did not detect association between HapB and ischemic stroke in the Scottish cohort. However, we observed that HapB was overrepresented in male patients. This replication of haplotype association with stroke in a population outside Iceland further supports a role for ALOX5AP in cardiovascular diseases.

5-Lipoxygenase-Activating Proteins↗
PubMed2005

Sclerosing mesenteritis.

Sclerosing mesenteritis is a rare benign process involving mesenteric fat that has non-specific histology and imaging characteristics, which are critical to the diagnosis. It has two different pathological variants: mesenteric panniculitis (acute or subacute) and retractile mesenteritis (chronic). This case study illustrates the radiological findings of sclerosing mesenteritis, describes certain signs that suggest the diagnosis and reviews recent published literature.

Biopsy↗
PubMed2005

Computed tomography diagnosis of tracheobronchopathia osteochondroplastica.

Tracheobronchopathia osteochondroplastica (TO) is a rare benign disease characterized by the presence of osseous and cartilaginous submucosal nodules projecting into the tracheobronchial tree. Most cases are asymptomatic and discovered incidentally at post-mortem. We identified a case of TO on thoracic spiral CT and confirmed the diagnosis of bronchoscopy. This article reviews the imaging characteristics of TO, and shows the 3-D virtual bronchoscopic and multiplanar reconstruction appearances of TO.

Bronchial Diseases↗
PubMed2005

Rates of diabetes mellitus-related complications in a contemporary adolescent cohort.

BACKGROUND: Ten years after the Diabetes Control and Complications Trial there is a paucity of data as to what are current rates of diabetes-related complications in adolescence. OBJECTIVE: To assess the incidence of diabetes-related complications in a contemporary cohort of adolescents with type 1 diabetes mellitus. DESIGN: Retrospective cross-sectional survey. PATIENTS: Adolescents aged >10 years with type 1 diabetes mellitus for >5 years from the Royal Children's Hospital, Melbourne Diabetes Clinic. RESULTS: 382 patients were studied (191 male). The mean HbA1c for males was 8.72% and for females was 8.80%. The rates of hypothyroidism and hypercholesterolaemia were 1.5% and 22% respectively. Twenty-five patients (8%) had intermittent microalbuminuria and six (2%) had persistent microalbuminuria. Only one patient had macroalbuminuria (0.3%). Only two patients (0.7%) with mild non-were diagnosed proliferative diabetic retinopathy. Coeliac disease was diagnosed in 6% of patients. CONCLUSIONS: In this representative and contemporary cohort of diabetic adolescents the incidence of microvascular diabetes-related complications is quite low.

Adolescent↗
PubMed2002

Temozolomide as second-line chemotherapy for relapsed gliomas.

BACKGROUND: Temozolomide, an imidazotetrazine prodrug has shown activity in phase II studies in patients with high-grade glioma at first recurrence. We assessed the efficacy of temozolomide as second-line therapy following failure of PCV chemotherapy in patients with recurrent/progressive gliomas. PATIENTS AND METHODS: Between September 1994 and November 2000, 32 patients with high-grade gliomas at second recurrence/progression received temozolomide as salvage therapy and results were reviewed retrospectively. RESULTS: Of 32 assessable patients 7 had clinical improvement; there were no imaging responses. Median survival of the cohort was 4 months, with 28% alive at 6 months. Age, performance status, histology and previous response to PCV chemotherapy did not predict for clinical response to temozolomide. CONCLUSION: In the small cohort of patients with recurrent malignant glioma who failed PCV chemotherapy temozolomide demonstrated limited activity as second-line treatment although this remains within the confidence intervals of response seen in patients with glioblastoma.

Adult↗
PubMed2002

Assessing critical care unit performance: a global measure using graphical analysis.

Outcome measurement in critical care is difficult because of the wide variety of patients treated and the diverse therapeutic options and pathways available. Individual outcome measures for critical care are available but are naturally limited to only a single aspect of performance. Most importantly, better performance in one aspect of care may compromise the standard of care in another. A global measure of performance would be helpful. For the year 1999-2000, the five hospitals in the East Anglian Critical Care Network provided data on capacity, workload and performance. The data was transformed and displayed graphically on a radar chart so that the area of the polygon within the radar chart was proportional to each unit's overall performance. The results from the five hospitals suggest that there is little overall difference in the units' global performance but the graphical representation highlighted some individual deficiencies. Graphical analysis of complex processes such as critical care delivery may facilitate performance assessment, providing that the measures chosen, weightings assigned and scales used are standardised with care.

Bed Occupancy↗
PubMed2002

Genetic factors contribute to the risk of developing endometriosis.

BACKGROUND: Endometriosis is known to cluster within nuclear families. The extent of familial clustering can be evaluated in Iceland with its large population-based genealogical database. METHODS AND RESULTS: Applying several measures of familiality we demonstrated that 750 women with endometriosis were significantly more interrelated than matched control groups. The risk ratio for sisters was 5.20 (P < 0.001) and for cousins 1.56 (P = 0.003). The average kinship coefficient for the patients was significantly higher than that calculated for 1000 sets of 750 matched controls (P < 0.001) and this remained significant when contribution from first-degree relatives was excluded (P < 0.05). The minimum number of ancestors required to account for the group of patients was compared with the minimum number of ancestors required to account for the control groups at different time points in the past. The minimum number of founders for the group of patients was significantly smaller than for the control groups. Affected cousin pairs were as likely to be paternally connected as maternally connected. CONCLUSIONS: This is the first population-based study using an extensive genealogy database to examine the genetic contribution to endometriosis. A genetic factor is present, with a raised risk in close and more distant relatives, and a definite kinship factor with maternal and paternal inheritance contributing.

Cluster Analysis↗
PubMed2001

Allelic frequencies and patterns of single-nucleotide polymorphisms in candidate genes for asthma and atopy in Iceland.

Numerous asthma and atopy loci have been reported in studies demonstrating associations of the asthma-related phenotypes atopy, elevated IgE levels, and bronchial hyperresponsiveness with alleles of microsatellite markers and single-nucleotide polymorphisms (SNPs) within specific cytokine/chemokine and IgE-regulating genes. Although the studies reporting these observations are compelling, most of them lack statistical power. We assessed the nature, pattern, and frequency of SNPs in 24 candidate genes in Iceland and looked for associations with asthma and atopy. We identified 42 SNPs with an average minor allele frequency of 20.3% (asthma) and 20.7% (control). Twenty SNPs (48%) were within coding sequences and 90% of those led to a predicted change in protein sequence. No differences were detected in the allelic frequencies of SNPs in any of these candidate genes between control subjects and the patients with atopic asthma. Moreover, linkage analysis that included 269 patients with atopic asthma uncovered no evidence of linkage to markers associated with these genes. We conclude that this study has failed to produce evidence in support of the notion that variations within these 24 candidate atopy and asthma genes significantly influence the expression of the atopic asthmatic phenotype or contribute to the susceptibility of atopic asthma.

Adolescent↗
PubMed2001

The role of linkage studies for common diseases.

Linkage analysis when applied to common diseases has had limited success in mapping the genes contributing to them. We present a genealogic approach applied to the relatively isolated population of Iceland. We use an affecteds-only, allele-sharing method--which does not specify any particular inheritance model--implemented in the new statistical program, Allegro, which calculates lod scores based on multipoint calculations. We describe how this approach has helped us to map a gene contributing to the common late-onset form of Parkinson's disease to statistical significance.

Case-Control Studies↗
PubMed2001

A genome-wide scan for preeclampsia in the Netherlands.

Preeclampsia, hallmarked by de novo hypertension and proteinuria in pregnancy, has a familial tendency. Recently, a large Icelandic genome-wide scan provided evidence for a maternal susceptibility locus for preeclampsia on chromosome 2p13 which was confirmed by a genome scan from Australia and New Zealand (NZ). The current study reports on a genome-wide scan of Dutch affected sib-pair families. In total 67 Dutch affected sib-pair families, comprising at least two siblings with proteinuric preeclampsia, eclampsia or HELLP-syndrome, were typed for 293 polymorphic markers throughout the genome and linkage analysis was performed. The highest allele sharing lod score of 1.99 was seen on chromosome 12q at 109.5 cM. Two peaks overlapped in the same regions between the Dutch and Icelandic genome-wide scan at chromosome 3p and chromosome 15q. No overlap was seen on 2p. Re-analysis in 38 families without HELLP-syndrome (preeclampsia families) and 34 families with at least one sibling with HELLP syndrome (HELLP families), revealed two peaks with suggestive evidence for linkage in the non-HELLP families on chromosome 10q (lod score 2.38, D10S1432, 93.9 cM) and 22q (lod score 2.41, D22S685, 32.4 cM). The peak on 12q appeared to be associated with HELLP syndrome; it increased to a lod score of 2.1 in the HELLP families and almost disappeared in the preeclampsia families. A nominal peak on chromosome 11 in the preeclampsia families showed overlap with the second highest peak in the Australian/NZ study. Results from our Dutch genome-wide scan indicate that HELLP syndrome might have a different genetic background than preeclampsia.

Chromosome Mapping↗
PubMed2001

Seasonal variation in admission rates to intensive care units.

Intensive care physicians perceive that there is seasonal variation in the number of admissions to critical care services. There is, however, little published evidence to support this belief. Data were therefore collected from five adjacent critical care units in the eastern region over a period of 8 years, in order to quantify any seasonal variation that may exist. Data on 16 355 critically ill patients were obtained between 1992 and 2000. Analysis showed clear winter peaks; December had a 30% higher admission rate than the quietest month, February. There was a small, but increasing, summer peak. The admission rate also exhibits an increasing linear trend, equivalent to a 6.6% annual increase in admissions per critical care bed. We conclude that there is significant seasonal variation in critical care activity, and that this is important to consider when planning services.

Adult↗
PubMed2000

Familial aggregation of Parkinson's disease in Iceland.

BACKGROUND: The role of genetics in early-onset Parkinson's disease has been established, but whether there is a genetic contribution to the more common, late-onset form remains uncertain. METHODS: We reviewed the medical records and confirmed the diagnosis of Parkinson's disease in 772 living and deceased patients in whom the disease had been diagnosed during the previous 50 years in Iceland. With the use of an extensive computerized data base containing genealogic information on 610,920 people in Iceland during the past 11 centuries, several analyses were conducted to determine whether the patients were more related to each other than random members of the population (control subjects). RESULTS: Patients with Parkinson's disease, including a subgroup of 560 patients with late-onset disease (onset at >50 years of age), were significantly more related to each other than were subjects in matched groups of controls, and this relatedness extended beyond the nuclear family. The risk ratio for Parkinson's disease was 6.7 (95 percent confidence interval, 4.3 to 9.6) for siblings, 3.2 (95 percent confidence interval, 1.2 to 7.8) for offspring, and 2.7 (95 percent confidence interval, 1.6 to 3.9) for nephews and nieces of patients with late-onset Parkinson's disease. CONCLUSIONS: Late-onset Parkinson's disease has a genetic component as well as an environmental component.

Age of Onset↗
PubMed2000

Lumpectomy margins, reexcision, and local recurrence of breast cancer.

BACKGROUND: The diagnosis of breast cancer is often made by excisional biopsy without margin assessment for mammographic findings or palpable masses. Many patients treated with breast conservation undergo reexcision to obtain clear margins although the relationship between clear margins and local recurrence remains controversial. METHODS: Patients undergoing breast conservation and adjuvant radiation therapy with complete follow-up over 5 years were studied. Factors associated with obtaining clear histopathologic margins and undergoing reexcision to obtain clear margins were studied in relation to the risk of local recurrence. RESULTS: Clear biopsy margins were associated with diagnosis by fine-needle aspiration cytology (fine-needle aspiration 42%, spot localization 11%, excisional biopsy 10%; P <0.001). Reexcision was significantly related to diagnostic method (spot localization 63%, excisional biopsy 36%, fine-needle aspiration 10%; P <0.001), first margin status (clear 0%, close 11%, positive 46%, unknown 48%; P <0.001), patient age (54 years for reexcised patients and 58 for non-reexcised patients; P <0.001), and tumor size (mean tumor size 1. 4 cm for reexcised patients and 1.7 cm for non-reexcised patients; P = 0.003). Patients undergoing reexcision were significantly more likely to be diagnosed by spot localization, have nonnegative excisional biopsy margins, be younger, and have smaller tumors than patients not undergoing reexcision. Local recurrence was not significantly related to margin status (8% with clear margins, 7% with positive margins, 19% with close margins, and 11% with unknown margins) or reexcision (10% local recurrence rate for patients with negative final margins after reexcision and 12% with positive, close or unknown first margin without reexcision). Estrogen receptor status was the only variable related to local recurrence in Cox proportional hazards model (P = 0.009). Estrogen receptor negative patients with nonnegative margins experienced a 20% rate of local recurrence compared with 10% for estrogen receptor negative patients with negative margins and 7% for estrogen receptor positive patients regardless of margin status (P = 0.021). CONCLUSIONS: Clear excision margins are facilitated by preoperative diagnosis by fine-needle cytology. For patients with nonnegative margins, reexcision was more commonly performed in young patients with small tumors diagnosed by spot localization biopsy. The relationship of local recurrence to margins and reexcision was not statistically significant. Estrogen receptor negative tumors with nonnegative margins had a significantly higher rate of local recurrence than estrogen receptor negative tumors with clear margins and estrogen receptor positive tumors regardless of margin status.

Adult↗
PubMed1999

Loci on chromosomes 2 (NIDDM1) and 15 interact to increase susceptibility to diabetes in Mexican Americans.

Complex disorders such as diabetes, cardiovascular disease, asthma, hypertension and psychiatric illnesses account for a large and disproportionate share of health care costs, but remain poorly characterized with respect to aetiology. The transmission of such disorders is complex, reflecting the actions and interactions of multiple genetic and environmental factors. Genetic analyses that allow for the simultaneous consideration of susceptibility from multiple regions may improve the ability to map genes for complex disorders, but such analyses are currently computationally intensive and narrowly focused. We describe here an approach to assessing the evidence for statistical interactions between unlinked regions that allows multipoint allele-sharing analysis to take the evidence for linkage at one region into account in assessing the evidence for linkage over the rest of the genome. Using this method, we show that the interaction of genes on chromosomes 2 (NIDDM1) and 15 (near CYP19) makes a contribution to susceptibility to type 2 diabetes in Mexican Americans from Starr County, Texas.

Chromosomes, Human, Pair 15↗