Associations between epigenome-wide DNA methylation and height-related traits among Sub-Saharan Africans: the RODAM study

Human height and related traits are highly complex, and extensively research has shown that these traits are determined by both genetic and environmental factors. Such factors may partially affect these traits through epigenetic programing. Epigenetic programing is dynamic and plays an important role in controlling gene expression and cell differentiation during (early) development. DNA methylation (DNAm) is the most commonly studied epigenetic feature. In this study we conducted an epigenome-wide DNAm association analysis on height-related traits in a Sub-Saharan African population, in order to detect DNAm biomarkers across four height-related traits. DNAm profiles were acquired in whole blood samples of 704 Ghanaians, sourced from the Research on Obesity and Diabetes among African Migrants study, using the Illumina Infinium HumanMethylation450 BeadChip. Linear models were fitted to detect differentially methylated positions (DMPs) and regions (DMRs) associated with height, leg-to-height ratio (LHR), leg length, and sitting height. No epigenome-wide significant DMPs were recorded. However we did observe among our top DMPs five informative probes associated with the height-related traits: cg26905768 (leg length), cg13268132 (leg length), cg19776793 (height), cg23072383 (LHR), and cg24625894 (sitting height). All five DMPs are annotated to genes whose functions were linked to bone cell regulation and development. DMR analysis identified overlapping DMRs within the gene body of HLA-DPB1 gene, and the HOXA gene cluster. In this first epigenome-wide association studies of these traits, our findings suggest DNAm associations with height-related heights, and might influence development and maintenance of these traits. Further studies are needed to replicate our findings, and to elucidate the molecular mechanism underlying human height-related traits.

Malaria deaths as sentinel events to monitor healthcare delivery and antimalarial drug safety

OBJECTIVES

To identify case management, health system and antimalarial drug factors contributing to malaria deaths.

METHOD

We investigated malaria-related deaths in South Africa's three malaria endemic provinces from January 2002 to July 2004. Data from healthcare facility records and a semi-structured interview with patients' contacts were reviewed by an expert panel, which sought to reach consensus on factors contributing to the death. This included possible health system failures, adverse reactions to antimalarials, inappropriate medicine use and failing to respond to treatment.

RESULTS

Approximately 177 of 197 cases met inclusion criteria for the study. Delay in seeking formal health care was significantly longer for patients who sought traditional health care [median 4; inter-quartile range (IQR) 3-7 days] than for patients who did not (median 3; IQR 1-5 days; P = 0.033). Patients with confirmed or suspected HIV/AIDS were significantly more likely to use traditional approaches (25%) than those with other comorbidities (0%; P = 0.002). Malaria was neither suspected nor tested for at a primary care facility in 23% of cases with adequate records. Initial hospital assessment was considered inadequate in 74% of cases admitted to hospital and in-patient monitoring and management was adequate in only 27%. There were 32 suspected adverse reactions to antimalarial therapy.

CONCLUSION

A confidential enquiry into malaria-related deaths is a useful tool for identifying preventable factors, health system failures and adverse events affecting malaria case management.

Transformation-defective adenovirus 5 E1A mutants exhibit antioncogenic properties in human BLM melanoma cells

Adenoviral E1 A proteins exhibit a strong tumor-suppressive activity in human tumor cells. However, E1 A is capable of transforming rodent and human cells in cooperation with other oncoproteins, such as activated RAS. Thus, the therapeutic use of wild-type E1A harbors the principal risk of enhancing tumor malignancy. This prompted us to construct E1A 13S cDNA-derived mutants that were unable to transform baby mouse kidney cells in cooperation with E1B and to test their tumor-suppressive activity in BLM human melanoma cells. Anchorage-independent growth in soft agar was reduced for those cell lines expressing the E1AdelCR2 mutant, which lacks the entire conserved region 2 (CR2) sequences, or for cells expressing the E1AcR3Ex2 mutant, which contains CR3 plus exon 2 sequences. In contrast, cell lines expressing the entire E1A wild-type (E1AWT) or only the exon 2 sequences (E1AEx2) grew like the parental BLM cells. Moreover, inoculation of nude mice with BLM cells or cells expressing E1AEx2 revealed large tumors after 2 weeks. In contrast, tumors derived from E1AdelCR2- or E1ACR3Ex2-expressing cells exhibited a substantial delay in tumor growth accompanied by a loss of E1A expression in the outgrown tumors. Cell lines expressing E1AWT showed an intermediate phenotype. Thus, expression of CR3 plus exon 2 sequences is sufficient to enhance both the antioncogenic properties and the therapeutic safety of E1A in our system.

A survey of Canadians enrolled in American Emergency Medicine residencies

Despite the existence of Emergency Medicine (EM) residency programs in Canada, Canadian physicians continue to pursue EM training in the United States. To determine the factors that may influence these Canadian physicians to return to practice in Canada, a survey was sent to all Canadians enrolled in U.S. EM training programs. Seventeen of 22 (77%) post-graduate trainees responded. Residents said they had chosen U.S. training mainly because of the low number of residents in Canadian EM specialty programs, and they also had the perception that U.S. EM training was superior. Lower salaries, restrictions on location of practice, and an inability to obtain Royal College certification were the factors most likely to prevent a return to Canada. Six of the 17 respondents (35%) said they were definitely or probably returning to Canada. Given the limited number of Canadian training positions and the Canadian Emergency Physician workforce shortfall, the U.S. training route appears to be underutilized.

A standardized letter of recommendation for residency application

Emergency medicine (EM) program directors have expressed a desire for more evaluative data to be included in application materials. This is consistent with frustrations expressed by program directors of multiple specialties, but mostly by those in specialties with more competitive matches. Some of the concerns about traditional narrative letters of recommendation included lack of uniform information, lack of relative value given for interval grading, and a perception of ambiguity with regard to terminology. The Council of Emergency Medicine Residency Directors established a task force in 1995 that created a standardized letter of recommendation form. This form, to be completed by EM faculty, requests that objective, comparative, and narrative information be reported regarding the residency applicant.

Acute myocardial infarction complicated by hemodynamically unstable bradyarrhythmia: prehospital and ED treatment with atropine

The purpose of this study was to investigate the therapeutic response to atropine of patients experiencing hemodynamically compromising bradyarrhythmia related to acute myocardial infarction (AMI) in the prehospital (PH) setting and the therapeutic impact of the PH response to atropine on further Emergency Department (ED) care. In addition, the prevalence of AMI in patients presenting with atrioventricular block (AVB) is noted. Retrospective review of PH, emergency department (ED), and hospital records. PH patients, with hemodynamically compromising bradycardia or AVB with evidence of spontaneous circulation, who received atropine as delivered by emergency medical services (EMS) personnel, were used. Urban/suburban fire department-based emergency medical services (EMS) system with on-line medical control serving a population of approximately 1.6 million persons. Hemodynamic instability was defined as the presence of any of the following: ischemic chest pain, dyspnea, syncope, altered mental status, and systolic blood pressure less than 90 mm Hg. Bradycardia was defined as sinus bradycardia, junctional bradycardia, or idioventricular bradycardia (grouped as bradycardia), whereas AVB included first-, second- (types I and II), or third-degree (grouped as AVB). The response that occurred within 1 minute of atropine dosing was recorded as none, partial, complete, or adverse. Comparisons were made between patients with AMI and non-AMI hospital discharge diagnoses. The diagnosis of AMI was confirmed by abnormal elevations in creatinine phosphokinase MB fraction. One hundred seventy-two patients meeting entry criteria were identified. Of these, 131 (76.1%) had complete PH, ED, and hospital records and were used for data analysis. Forty-five patients (34.3%) had a primary hospital discharge diagnosis of AMI; the remaining patients had a non-AMI discharge diagnosis. AMI patients were significantly younger (67 +/- 12 v 73 +/- 13 years, P = .025), were less likely to have a history of heart disease (35.5% v54.7%, P = .038), and were more likely to present with chest pain (68.9% v24.4%, P < .001) or hypotension (60% v37.2%, P = .013) compared with non-AMI patients. Forty-five of 131 patients presented with AVB, of which 25 had a hospital discharge diagnosis of AMI (55.6%). The mean time from first dose of atropine to ED arrival and the total dose of atropine received in the PH setting did not differ between AMI and non-AMI groups (15.2 +/- 7.7 v 16.2 +/- 8.7 minutes, P= .5; and 0.9 +/- 0.49 v 1.0 +/- 0.58 mg, P = .25). The likelihood of achieving normal sinus rhythm in the PH setting did not differ between AMI and non-AMI groups (40% v 18.6%, P = .07). No differences were found between AMI and non-AMI groups in the amount of additional atropine given (1.2 +/- 0.58 v 1.3 +/- 1.1 mg, P = .58) or the use of other resuscitative therapies after ED arrival (isoproterenol, 13.3% v12.8%, P = .93; dopamine, 28.9% v26.7% P = .79; transcutaneous pacing, 26.7% v26.7%, P = .99; transvenous pacing, 8.9% v5.8%, P = .51), with the exception of thrombolytic therapy (24.4% v 0%, P< .001) and cardiac catheterization (22.2% v3.4%, P = .001). Despite a lack of significant difference in achieving a normal sinus rhythm in the prehospital or ED setting, AMI patients were more likely to achieve a normal sinus rhythm over the total course of PH and ED care than non-AMI patients (44.4% v24.4%, P = .019). Hemodynamically unstable (by ACLS criterion) AVB presenting in the PH setting is associated with a hospital diagnosis of AMI in most (55.6%) patients in this study. AMI patients with hemodynamically unstable AVB or bradycardia are no more likely to respond to atropine therapy in the PH setting than patients with non-AMI hospital diagnoses. Finally, although there is no difference in the treatment of compromising AVB or bradycardia received by AMI versus non-AMI patients in the PH or ED setting, AMI patients are more likely to achieve a normal sinus rhythm over the t

The efficacy of atropine in the treatment of hemodynamically unstable bradycardia and atrioventricular block: prehospital and emergency department considerations

OBJECTIVE

To determine the efficacy of atropine therapy in patients with hemodynamically compromising bradycardia or atrioventricular block (AVB) in the prehospital and emergency department settings.

METHODS

DESIGN

Retrospective review of prehospital, emergency department, and hospital records.

PARTICIPANTS

Prehospital patients with hemodynamically compromising bradycardia or AVB with evidence of spontaneous circulation who received atropine as delivered by emergency medical services personnel (advanced life support level).

SETTING

Urban/suburban fire department-based emergency medical service system with on-line medical control serving a population of approximately 1.6 million persons.

DEFINITIONS

Hemodynamic instability was defined as the presence of any of the following: ischemic chest pain, dyspnea, syncope, altered mental status, and systolic blood pressure less than 90 mmHg. Bradycardia was defined as sinus bradycardia, junctional bradycardia, or idioventricular bradycardia (grouped as bradycardia) while AVB included first-, second- (types I and II), or third-degree (grouped as AVB). The response that occurred within one minute following each dose of atropine was defined as none, partial, complete, or adverse.

MAIN RESULTS

Of 172 patients meeting entry criterion complete data was available for 131 (76.1%) and constitutes the study population. The mean age was 71 years. Fifty-one percent were female. Forty-five patients had AVB and 86 bradycardia. Patients with AVB were more likely to have a presenting systolic blood pressure less than 90 mmHg than those with bradycardia. In the 131 patients, responses to atropine were as follows: 26 (19.8%) = partial, 36 (27.5%) = complete, 65 (49.6%) = none, and 4 (2.3%) = adverse. Patients presenting with bradycardia (compared to AVB) more commonly: (1) received a single dose of atropine; (2) a lower total dose of atropine in the prehospital interval; (3) were more likely to arrive in the ED with a normal sinus rhythm; and (4) were less likely to receive additional atropine or isoproterenol in the ED. Those patients who achieved normal sinus rhythm over the total course of care were likely to have achieved that rhythm during the prehospital interval. There was no difference between groups in the likelihood of leaving the ED with a normal sinus rhythm achieved during the ED interval. Acute myocardial infarction was more common in patients presenting with AVB (55.5%) than with bradycardia (23.2%, P = 0.001).

CONCLUSIONS

Approximately one-half of patients who received atropine in the prehospital setting for compromising rhythms had either a partial or complete response to therapy. Adverse responses were uncommon. Those patients who presented with hemodynamically unstable bradycardia to EMS personnel responded more commonly to a single dose and a lower total dose of atropine compared to similar patients with AVB. Those patients who achieve normal sinus rhythm by ED discharge were likely to have achieved it during the prehospital interval.

The liver-specific transcription factor LF-B1 contains a highly diverged homeobox DNA binding domain

The nuclear protein LF-B1 (also referred to as HNF-1) is a transcription activator required for the expression of several liver-specific genes. LF-B1 has been purified to homogeneity from rat liver nuclear extracts. The sequence of the protein has been partially determined and, subsequently, overlapping cDNA clones containing the entire open reading frame of LF-B1 were isolated. The full-length cDNA encodes a 628 amino acid protein and directs the synthesis in vitro of a protein capable of binding DNA with the same specificity as LF-B1. The cDNA was recombined into a vaccinia virus vector and active LF-B1 was obtained from infected HeLa cells. Addition of the vaccinia recombinant protein to rat spleen extracts results in activation of transcription of an LF-B1-dependent promoter. The DNA binding domain of LF-B1 is located in the amino-terminal part of the protein and displays distant structural similarity to the homeobox domain. The distribution of LF-B1 mRNA is restricted to liver, which correlates with the tissue-specific expression of its target genes.