Measurement of lumefantrine and its metabolite in plasma by high performance liquid chromatography with ultraviolet detection

Artemether-lumefantrine (ARM-LUM) has in recent years become the first-line treatment for uncomplicated malaria in many Sub-Saharan African countries. Vigorous monitoring of the therapeutic efficacy of this treatment is needed. This requires high-quality studies following standard protocols; ideally, such studies should incorporate measurement of drug levels in the study patients to exclude the possibility that insufficient drug levels explain an observed treatment failure. Several methods for measuring lumefantrine (LUM) in plasma by HPLC are available; however, several of these methods have some limitations in terms of high costs and limited feasibility arising from large required sample volumes and demanding sample preparation. Therefore, we set out to develop a simpler reversed phase high performance liquid chromatography (RP-HPLC) method based on UV detection for simultaneous measurement of LUM and its major metabolite the desbutyl LUM (DL) in plasma. Halofantrine was used as an internal standard. Liquid–liquid extraction of samples was carried out using hexane–ethyl acetate (70:30, v/v). Chromatographic separation was carried out on a Synergi Polar-RP column (250 mm × 300 mm, particle size 4 μm). The mobile phase consisted of acetonitrile–0.1 M ammonium acetate buffer adjusted to pH 4.9 (85:15%, v/v). Absorbance of the compounds was monitored at 335 nm using a reference wavelength of 360 nm. Absolute extraction recovery for LUM and DL were 88% and 90%, respectively. Inter- and intraday coefficients of variation for LUM and DL were ≤10%. The lower limits of quantification for LUM and DL were 12.5 and 6.5 ng/ml, respectively. After validation, the methodology was transferred to a local laboratory in Tanga Tanzania and samples from a small subset of malaria patients were analysed for LUM. The method appears to be applicable in settings with limited facilities.     

Hypertension Is a Risk Factor for Fractures

To study the effects of hypertension and other cardiovascular risk factors on risk of fractures, we carried out a case-control study including 124,655 fracture cases and 373,962 age- and gender-matched controls. The main exposure was hypertension, stroke, acute myocardial infarction, ischemic heart disease, atrial fibrillation, peripheral arterial disease, and deep venous thromboembolism, and the main confounders were use of diuretics, antihypertensive drugs, organic nitrates, vitamin K antagonists, and cholesterol lowering drugs along with other confounders. Hypertension and stroke were the only significant risk factors in both the short-term (OR = 1.27, 95% CI = 1.20–1.34 and 1.24, and 95% CI = 1.16–1.31 for ≤3 years since diagnosis of hypertension and stroke, respectively) and the long-term (OR = 1.11, 95% CI = 1.00–1.23 and 1.09, and 95% CI = 1.02–1.18 for > 6 years since diagnosis of hypertension and stroke, respectively) perspective. Acute myocardial infarction, atrial fibrillation, and deep venous thromboembolism were all associated with a transient increase in the risk of fractures within the first 3 years following diagnosis. Peripheral arterial disease and ischemic heart disease were not associated with an increased risk of fractures. In conclusion, hypertension and stroke seem to be the major cardiovascular risk factors for fractures, whereas acute myocardial infarction, atrial fibrillation, and deep venous thromboembolism seem to be only minor risk factors. The fracture risk in hypertension may explain why antihypertensive drugs as a class effect are associated with a decreased risk of fractures. These drugs may counter some of the deleterious effects of high blood pressure.     

Diabetes and Its Complications and Their Relationship with Risk of Fractures in Type 1 and 2 Diabetes

This case–control study sought to assess the effects of diabetes and its complications on the risk of fractures. There were 124,655 fracture cases and 373,962 age- and sex-matched controls. The main exposure was diabetes and its complications, and the main confounders were use of insulin and oral antidiabetic agents, presence of cardiovascular disease, and use of drugs for cardiovascular disease, along with a number of other confounders. In the crude analysis, diabetes and all complications was associated with a statistically significantly increased overall risk of fractures. The increase in risk of fractures was higher in type 1 diabetes (T1D) than in type 2 diabetes (T2D). However, after adjustment for confounders, the difference between T1D and T2D disappeared, and only diabetic kidney disease in T1D retained a significantly increased risk of fractures. There was a time dependency in the risk of fractures with an early increase at <2.5 years after diagnosis. followed by a decrease to the level of the background population from 2.5 to 5 years after diagnosis, and a limited increase in T1D but not T2D at >5 years after diagnosis. We conclude that diabetes, whether T1D or T2D, seems to carry an increased risk of fractures, and complications to diabetes except for diabetic kidney disease add little to the overall risk of fracture, perhaps pointing at a common risk factor linked to the high blood glucose levels, which may weaken bone strength.     

Validation of epilepsy diagnoses in the Danish National Hospital Register

PURPOSE: To validate the diagnosis of epilepsy in the Danish National Hospital Register. METHODS: We randomly selected 200 patients registered with epilepsy in the Danish National Hospital Register between 1977 and 2002 and validated the diagnosis according to the guidelines developed by the International League Against Epilepsy. RESULTS: We reviewed the medical records of 188 (94%) persons from 57 departments at 41 hospitals. The epilepsy diagnoses were confirmed in 153 patients, providing a positive predictive value for epilepsy of 81% (95% confidence interval (95% CI): 75-87%). Among the 35 patients who did not fulfill the criteria for epilepsy, 14 were admitted after a single, unprovoked seizure. Among patients registered with epilepsy the positive predictive value of seizure disorder was 89% (95% CI: 83-93%). Among patients classified with epilepsy syndromes, the positive predictive value for syndrome classification was 60% (95% CI: 44-74%) for epilepsy with complex focal seizures and 35% (95% CI: 22-51%) for primary generalized epilepsy. CONCLUSION: The validity of the epilepsy diagnoses in the Danish National Hospital Register has a moderate to high positive predictive value for epilepsy, but a relatively low predictive value for epilepsy syndromes.     

The ghrelin response to exercise before and after growth hormone administration

CONTEXT: We have previously shown that exercise-induced GH release is not mediated by ghrelin, but it remains to be studied whether the increase in GH may suppress postexercise ghrelin levels. OBJECTIVE: The objective of this study was to characterize systemic ghrelin levels after exercise with and without concomitant GH administration. DESIGN, PARTICIPANTS, AND INTERVENTION: Group A: Twenty-nine elite athletes (age, 18-37 yr) were studied after a maximal exercise test. Group B: In a double blind, placebo-controlled, parallel study, 32 healthy subjects (age, 18-33 yr) were randomized to placebo, GH 0.1 IU/kg per day, or GH 0.2 IU/kg per day for 4 wk. These subjects performed a multistage fitness test to assess maximum oxygen uptake at baseline and after 4 wk. We measured total circulating ghrelin levels before and immediately after exercise and at 15, 30, 60, 90, and 120 min after exercise. RESULTS: Group A: Serum ghrelin levels after exercise decreased significantly (P < 0.01). Group B: Exercise at baseline was associated with a significant lowering of ghrelin levels after exercise (P < 0.0001). In addition, 4 wk of high-dose GH were followed by a further approximately 20% reduction in basal and after exercise serum ghrelin (micrograms per liter): 0.78 (range 0.52-1.17) vs. 0.63 (range 0.50-0.91), P < 0.05. CONCLUSIONS: 1) Ghrelin levels decrease significantly after exercise in elite athletes and healthy subjects. 2) High-dose GH suppresses ghrelin levels. 3) These data support the hypothesis that GH feedback inhibits ghrelin secretion.     

Epilepsy and risk of suicide: a population-based case-control study

BACKGROUND: Studies have linked epilepsy with an increased suicide risk, but the association might be modified by psychiatric, demographic, and socioeconomic factors. METHODS: Suicide cases were identified in the Cause of Death Register in Denmark from 1981 to 1997. Up to 20 controls, matched by sex, birth year, and calendar date, were assigned to each suicide case. FINDINGS: We identified 21 169 cases of suicide and 423 128 controls. 492 (2.32%) individuals who committed suicide had epilepsy compared with 3140 (0.74%) controls, corresponding to a three times higher risk (rate ratio [RR] 3.17 [95% CI 2.88-3.50]; p<0.0001). The RR remained high after excluding those with a history of psychiatric disease and adjusting for socioeconomic factors (1.99, 1.71-2.32; p<0.0001). The highest risk of suicide was identified in patients with epilepsy and comorbid psychiatric disease, even after adjusting for socioeconomic factors (13.7, 11.8-16.0; p<0.0001). In individuals with epilepsy, the highest risk of suicide was found during the first half year after diagnosis was made (5.35, 3.43-8.33; p<0.0001), and was especially high in those with a history of comorbid psychiatric disease (29.2, 16.4-51.9; p<0.0001). INTERPRETATION: Individuals with epilepsy have a higher risk of suicide, even if coexisting psychiatric disease, demographic differences, and socioeconomic factors are taken into account. Our study identifies people with newly diagnosed epilepsy as a vulnerable group that require special attention.     

Validation of MCADD newborn screening

Medium‐chain acyl‐CoA dehydrogenase deficiency (MCADD) represents a potentially fatal fatty acid β‐oxidation disorder. Newborn screening (NBS) by tandem mass spectrometry (MS/MS) has been implemented worldwide, but is associated with unresolved questions regarding population heterogeneity, burden on healthy carriers, cut‐off policies, false‐positive and negative rates. In a retrospective case‐control study, 333 NBS samples showing borderline acylcarnitine patterns but not reaching recall criteria were genotyped for the two most common mutations (c.985A>G/c.199C>T) and compared with genotypes and acylcarnitines of 333 controls, 68 false‐positives, and 34 patients. c.985A>G was more frequently identified in the study group and false‐positives compared to controls (1:4.3/1:2.3 vs. 1:42), whereas c.199C>T was found more frequently only within the false‐positives (1:23). Biochemical criteria were devised to differentiate homozygous (c.985A>G), compound heterozygous (c.985A>G/c.199C>T), and heterozygous individuals. Four false‐negatives were identified because our initial algorithm required an elevation of octanoylcarnitine (C₈) and three secondary markers in the initial and follow‐up sample. The new approach allowed a reduction of false‐positives (by defining high cut‐offs: 1.4 μmol/l for C₈; 7 for C₈/C₁₂) and false‐negatives (by sequencing the ACADM gene of few suspicious samples). Our validation strategy is able to differentiate healthy carriers from patients doubling the positive predictive value (42→88%) and to target NBS to MCADD‐subsets with potentially higher risk of adverse outcome. It remains controversial, if NBS programs should aim at identifying all subsets of all diseases included. Because the natural course of milder variants cannot be assessed by observational studies, our strategy could serve as a general model for evaluation of MS/MS‐based NBS.     

Dermatosis in children with oedematous malnutrition (Kwashiorkor): a review of the literature

Children with oedematous malnutrition, known as kwashiorkor, may develop a characteristic skin lesion, named ‘Dermatosis of Kwashiorkor’ (DoK). Only a few studies have been concerned with this condition, and the reason for the development of DoK remains unexplained. This study review the existing studies concerning DoK, including its clinical manifestations, histopathology, suggested pathophysiology, current treatment and prognosis for children of the age of 6 months to 5 years. Standardized clinical studies are needed to further understand the implications of DoK. Such studies would suffer from the lack of consistency concerning the terminology and scoring of the lesions in DoK. We therefore stress the need for a standardized scoring of the degree of DoK. This would facilitate valid and comparable studies and the development of better treatment for this vulnerable group of patients.