A boy with autosomal recessive hypercholesterolaemia

We describe a 9-year-old Iranian boy with tuberous xanthomas, elevated LDL-cholesterol levels of 15.5 mmol/l, and vague complaints of chest pain while playing soccer. The consanguineous parents of the boy had normal cholesterol concentrations, which indicated an autosomal recessive disorder rather than autosomal dominant familial hypercholesterolaemia. The diagnosis of autosomal recessive hypercholesterolaemia (ARH) was confirmed by the presence of a mutation in the phosphotyrosine binding domain of a putative adaptor protein, which prevents normal internalisation of the LDL receptor (LDLR) in the liver. The clinical phenotype of ARH is similar to that of classical homozygous familial hypercholesterolaemia caused by defects in the LDLR gene, but it is more variable, generally less severe, and more responsive to lipid-lowering therapy. The patient's complaints of chest pain were not caused by ischaemia as was tested by an exercise and 24-hour electrocardiogram and by a myocardial perfusion scan. His LDL-C dropped by about 6o% after being treated with a combination of 40 mg atorvastatin and 10 mg ezetimibe.     

Plant sterols lower LDL cholesterol without improving endothelial function in prepubertal children with familial hypercholesterolaemia

In adults with familial hypercholesterolaemia (FH), cholesterol lowering with statins has been shown to improve the endothelial function, a hallmark of early atherogenesis. Currently, therapeutic options for treating high cholesterol levels in FH children are limited. Plant sterols safely and effectively reduce serum cholesterol concentrations by inhibiting cholesterol absorption. Therefore, we evaluated the effect of plant sterols on cholesterol and vascular function in prepubertal children with FH. We included 41 children (5–12 years old) with FH in a double-blind crossover trial using spreads containing 2.3 g of plant sterols (mainly sitosterol and campesterol) per 15 g spread and a placebo spread for a 4-week period, separated by a 6-week washout period. Lipid levels and endothelial function were assessed after both 4-week treatment periods. Endothelial function was assessed as flow-mediated dilation (FMD) of the brachial artery using a wall tracking system. Data were compared to those of 20 healthy controls. Intake of 2.3 g plant sterols per day decreased total cholesterol (-11%) and low-density cholesterol (-14%) as compared to placebo spread in FH children. FH children treated with placebo spread were characterized by an impaired FMD compared to healthy control children (7.2 %± 3.4% versus 10.1%±4.2%, p < 0.005). However, the reduction of LDL in FH children did not improve FMD (placebo: 7.2% ± 3.4% versus plant sterols: 7.7% ± 4.1%). In conclusion, the present study shows a clear reduction of LDL cholesterol by plant sterol treatment. However, short-term plant sterol treatment does not improve the endothelial function in FH children. This revised version was published online in August 2006 with corrections to the Cover Date.     

Selective persistence of dermal CD8+ T cells in lesional plaque psoriasis after clobetasol-17 propionate treatment

In psoriasis, T-cell infiltration and epidermal hyperproliferation are key phenomena which are closely related. Our aim was to investigate the dynamics among T-cell subsets in relation to epidermal proliferation and clinical severity in psoriasis during treatment with an ultra-potent corticosteroid. Seven psoriasis patients were treated twice daily for 14 days with clobetasol-17 propionate ointment. Punch biopsies were taken at day 0, 3, 7 and 14. Epidermal proliferation marker Ki-67 and CD4+, CD8+, CD45RO+, CD2+ T cells were quantified by immunohistochemical techniques and image analysis. The clinical score declined significantly (60%; p<0.01) and a 47% reduction of Ki-67+ nuclei was observed after only 3 days (p<0.01). In the epidermis all investigated T-cell subsets were significantly reduced at day 14 (p<0.05). In the dermis, treatment resulted in a significant decrease of CD4+, CD45RO+ and CD2+ T cells, but dermal CD8+ T cells persisted. In psoriasis, reduction of clinical severity and epidermal proliferation during the early phase of topical corticosteroid therapy cannot primarily be the result of decreased T-cell subsets. Furthermore, selective persistence of dermal CD8+ T cells was observed, which might be associated with disease relapse.     

Ovotestes and XY sex reversal in a female with an interstitial 9q33.3-q34.1 deletion encompassing NR5A1 and LMX1B causing features of Genitopatellar syndrome

We describe our findings in a 46,XY female with a clinical features of Genitopatellar syndrome (GPS) and confirmed hermaphroditism with ovotestes, and five additional patients with GPS. GPS is a genetic disorder characterized by renal and genital anomalies, joint dislocation, aplastic or hypoplastic and often displaced patellae, minor facial anomalies, and mental retardation. The genital anomalies clearly distinguish GPS from nail-patella syndrome (NPS) that has similar features, but additionally shows hypoplastic finger- and toenails as found in the 46,XY female. In our patients no mutation was found in the coding regions of WNT4, WNT7A, TBX4, and LMX1B. Fluorescent in situ hybridization (FISH) and array-based comparative genome hybridization (aCGH) analysis showed a 3 Mb deletion of LMX1B, NR6A1, and NR5A1 (SF1) in the 46,XY female. This is the first report of a microdeletion causing haploinsuffiency of LMX1B and NR5A1. The deletion of LMX1B is responsible for the knee anomalies and the deletion of NR5A1 likely causes the sex reversal. Cytogenetic analysis of the five additional patients with diagnosed GPS failed to identify a similar microdeletion, or inversion of a potentially regulatory element between the two genes. This suggests that the locus 9q33-9q34 can be excluded for GPS and that the presented case is unique in its combination of GPS and NPS features caused by a microdeletion associated with loss of function of LMX1B and NR5A1.     

Protein breakdown on whole-body and organ level in non-cachectic tumour-bearing mice undergoing surgery

BACKGROUND & AIMS: Since both cancer and surgery are known to alter protein turnover, we investigated how the presence of tumour affects post-operative protein breakdown. METHODS: Controls and tumour-bearing non-cachectic mice were studied, both with and without laparotomy (n=8 per group). One day after laparotomy, stable isotopes of phenylalanine and 3-methylhistidine were used in a steady-state protocol to assess total protein breakdown on whole-body level and in muscle, intestines, liver and kidney, in addition to whole-body myofibrillar protein breakdown and body composition. Proteasomal chymotrypsin-like activity was measured to determine activity of the ATP-dependent ubiquitin pathway. RESULTS: On whole-body level, the presence of tumour increased total protein breakdown from 47+/-6 to 58+/-4 nmol/10 g/min (p<0.05) and myofibrillar protein breakdown from 0.70+/-0.04 to 1.22+/-0.14 nmol/10 g/min (p<0.05) without affecting protein breakdown in organs, body composition or proteasomal activity. Laparotomy increased myofibrillar protein breakdown in controls (from 0.70+/-0.04 to 0.98+/-0.12 nmol/10 g/min, p<0.05) and tumour-bearing mice (from 1.22+/-0.14 to 1.54+/-0.22 nmol/10 g/min, p=0.15) to a similar extent. CONCLUSIONS: Whole-body total protein breakdown, total protein breakdown across organs, body composition or proteasomal activity were not affected by laparotomy. Tumour-bearing mice had increased total and myofibrillar protein breakdown on whole-body level even before weight loss was obvious. However, this did not affect the post-operative response in protein breakdown or body composition.     

Cleavage and inactivation of alpha 1-antitrypsin by metalloproteinases released from neutrophils.

Human neutrophils, when stimulated with phorbol myristate acetate or fMet-Leu-Phe in the presence or absence of cytochalasin B, released metalloproteinases that catalytically inactivated the plasma serine proteinase inhibitor, alpha 1-antitrypsin. Inactivation, measured as loss of elastase inhibitory capacity, was accompanied by cleavage of a Mr 4,000 peptide from the COOH-terminus. Cleavage of alpha 1-antitrypsin by cell supernatants was inhibited by EDTA, o-phenanthroline, and DTT, but not by inhibitors of serine or thiol proteinases. Gelatinase and collagenase were separated from the medium of stimulated neutrophils. Both preparations cleaved and inactivated alpha 1-antitrypsin, with cleavage occurring close to the reactive center, at the Phe-Leu bond between positions P7 and P6. Cleavage by purified gelatinase was very slow and could account for only a minor fraction of the activity of neutrophil supernatants. The collagenase preparation was more active. However, the unusual cleavage site, and the ability of fMet-Leu-Phe-stimulated neutrophils to cleave alpha 1-antitrypsin without releasing collagenase, suggests that collagenase is not responsible for cleavage by the cells, which, by implication, is due to an as yet uncharacterized metalloenzyme. Our results demonstrate that by releasing metalloproteinases, neutrophils could proteolytically inactivate alpha 1-antitrypsin at sites of inflammation. This provides an alternative to the previously documented mechanism of inactivation by neutrophil-derived oxidants.     

Are metformin,statin and aspirin use still associated with overall mortality among colorectal cancer patients with diabetes if adjusted for one another?

Background:

Metformin, statin and aspirin use seem associated with decreased mortality in cancer patients, though, without adjusting for one another. Independent associations of these drugs with overall mortality after colorectal cancer (CRC) diagnosis within glucose-lowering drugs (GLDs) users were assessed.

Methods:

Patients starting GLDs before CRC diagnosis (1998–2011) were selected from the Eindhoven Cancer Registry linked with the PHARMO Database Network. The Cox regression model, with time since CRC diagnosis, included time-dependent variables of cumulative exposure to metformin, statins and aspirin after cancer diagnosis and time-dependent ever-never terms for drug exposure.

Results:

A total of 1043 patients used GLDs before CRC diagnosis; 666 (64%) used metformin, 639 (61%) used statins and 490 (47%) used aspirin after CRC diagnosis. Multivariable analyses revealed that longer cumulative exposure to metformin was not associated with overall mortality (HR_{Cumulative exposure/6 months} 1.02; 95% CI 0.97–1.07), whereas the favourable effect of statins increased with cumulative exposure (HR_{Cumulative exposure/6 months} 0.93; 95% CI 0.89–0.98). No association between aspirin use and overall mortality was seen (HR_{Cumulative exposure/6 months} 0.98; 95% CI 0.93–1.03).

Conclusions:

No independent association between cumulative exposure to metformin, aspirin and overall mortality was found. Cumulative exposure to statins after CRC diagnosis was associated with lower overall mortality, supporting a drug effect of statins among GLDs users.