The GIST of Targeted Therapy for Malignant Melanoma

The high response rates to the tyrosine kinase inhibitor imatinib in KIT-mutated gastrointestinal stromal tumors (GIST) has led to a paradigm shift in cancer treatment. In a parallel fashion, the field of melanoma is shifting with the utilization of targeted therapy to treat BRAF-mutated melanoma. We reviewed published literature in PubMed on GIST and melanoma, with a focus on both past and current clinical trials. The data presented centers on imatinib, vemurafenib, and most recently dabrafenib, targeting KIT and BRAF mutations and their outcomes in GIST and melanoma. The BRAF^V600E melanoma mutation, like the KIT exon 11 mutation in GIST, has the highest response to therapy. High response rates with inhibition of KIT in GIST have not been recapitulated in KIT-mutated melanoma. Median time to resistance to targeted agents occurs in ~7 months with BRAF inhibitors and 2 years for imatinib in GIST. In GIST, the development of secondary mutations leads to resistance; however, there have been no similar gatekeeper mutations found in melanoma. Although surgery remains an important component of the treatment of early GIST and melanoma, surgeons will need to continue to define the thresholds and timing for operation in the setting of metastatic disease with improved targeted therapies. Combination treatment strategies may result in more successful clinical outcomes in the management of melanoma in the future.     

Disease patterns and causes of death of hospitalized HIV-positive adults in West Africa: a multicountry survey in the antiretroviral treatment era

Objective

We aimed to describe the morbidity and mortality patterns in HIV-positive adults hospitalized in West Africa.

Method

We conducted a six-month prospective multicentre survey within the IeDEA West Africa collaboration in six adult medical wards of teaching hospitals in Abidjan, Ouagadougou, Cotonou, Dakar and Bamako. From April to October 2010, all newly hospitalized HIV-positive patients were eligible. Baseline and follow-up information until hospital discharge was recorded using standardized forms. Diagnoses were reviewed by a local event validation committee using reference definitions. Factors associated with in-hospital mortality were studied with a logistic regression model.

Results

Among 823 hospitalized HIV-positive adults (median age 40 years, 58% women), 24% discovered their HIV infection during the hospitalization, median CD4 count was 75/mm³ (IQR: 25–177) and 48% had previously received antiretroviral treatment (ART). The underlying causes of hospitalization were AIDS-defining conditions (54%), other infections (32%), other diseases (8%) and non-specific illness (6%). The most frequent diseases diagnosed were: tuberculosis (29%), pneumonia (15%), malaria (10%) and cerebral toxoplasmosis (10%). Overall, 315 (38%) patients died during hospitalization and the underlying cause of death was AIDS (63%), non-AIDS-defining infections (26%), other diseases (7%) and non-specific illness or unknown cause (4%). Among them, the most frequent fatal diseases were: tuberculosis (36%), cerebral toxoplasmosis (10%), cryptococcosis (9%) and sepsis (7%). Older age, clinical WHO stage 3 and 4, low CD4 count, and AIDS-defining infectious diagnoses were associated with hospital fatality.

Conclusions

AIDS-defining conditions, primarily tuberculosis, and bacterial infections were the most frequent causes of hospitalization in HIV-positive adults in West Africa and resulted in high in-hospital fatality. Sustained efforts are needed to integrate care of these disease conditions and optimize earlier diagnosis of HIV infection and initiation of ART.     

Temperature-Acclimated Brown Adipose Tissue Modulates Insulin Sensitivity in Humans

In rodents, brown adipose tissue (BAT) regulates cold- and diet-induced thermogenesis (CIT; DIT). Whether BAT recruitment is reversible and how it impacts on energy metabolism have not been investigated in humans. We examined the effects of temperature acclimation on BAT, energy balance, and substrate metabolism in a prospective crossover study of 4-month duration, consisting of four consecutive blocks of 1-month overnight temperature acclimation (24°C [month 1] → 19°C [month 2] → 24°C [month 3] → 27°C [month 4]) of five healthy men in a temperature-controlled research facility. Sequential monthly acclimation modulated BAT reversibly, boosting and suppressing its abundance and activity in mild cold and warm conditions (P < 0.05), respectively, independent of seasonal fluctuations (P < 0.01). BAT acclimation did not alter CIT but was accompanied by DIT (P < 0.05) and postprandial insulin sensitivity enhancement (P < 0.05), evident only after cold acclimation. Circulating and adipose tissue, but not skeletal muscle, expression levels of leptin and adiponectin displayed reciprocal changes concordant with cold-acclimated insulin sensitization. These results suggest regulatory links between BAT thermal plasticity and glucose metabolism in humans, opening avenues to harnessing BAT for metabolic benefits.     

Corticosteroid treatment exacerbates nephrotic syndrome in a zebrafish model of magi2a knockout

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Endoscopic Duodenal–Jejunal Bypass Liner Rapidly Improves Type 2 Diabetes

Background

Bariatric procedures excluding the proximal small intestine improve glycemic control in type 2 diabetes within days. To gain insight into the mediators involved, we investigated factors regulating glucose homeostasis in patients with type 2 diabetes treated with the novel endoscopic duodenal–jejunal bypass liner (DJBL).

Methods

Seventeen obese patients (BMI 30–50 kg/m²) with type 2 diabetes received the DJBL for 24 weeks. Body weight and type 2 diabetes parameters, including HbA_1c and plasma levels of glucose, insulin, glucagon-like peptide-1 (GLP-1), glucose-dependent insulinotropic polypeptide (GIP), and glucagon, were analyzed after a standard meal before, during, and 1 week after DJBL treatment.

Results

At 24 weeks after implantation, patients had lost 12.7?±?1.3 kg (p?<?0.01), while HbA_1c had improved from 8.4?±?0.2 to 7.0?±?0.2 % (p?<?0.01). Both fasting glucose levels and the postprandial glucose response were decreased at 1 week after implantation and remained decreased at 24 weeks (baseline vs. week 1 vs. week 24: 11.6?±?0.5 vs. 9.0?±?0.5 vs. 8.6?±?0.5 mmol/L and 1,999?±?85 vs. 1,536?±?51 vs. 1,538?±?72 mmol/L/min, both p?<?0.01). In parallel, the glucagon response decreased (23,762?±?4,732 vs. 15,989?±?3,193 vs. 13,1207?±?1,946 pg/mL/min, p?<?0.05) and the GLP-1 response increased (4,440?±?249 vs. 6,407?±?480 vs. 6,008?±?429 pmol/L/min, p?<?0.01). The GIP response was decreased at week 24 (baseline—115,272?±?10,971 vs. week 24—88,499?±?10,971 pg/mL/min, p?<?0.05). Insulin levels did not change significantly. Glycemic control was still improved 1 week after explantation.

Conclusions

The data indicate DJBL to be a promising treatment for obesity and type 2 diabetes, causing rapid improvement of glycemic control paralleled by changes in gut hormones.     

Regulation of human skeletal stem cells differentiation by Dlk1/Pref-1.

Dlk-1/Pref-1 was identified as a novel regulator of human skeletal stem cell differentiation. Dlk1/Pref-1 is expressed in bone and cultured osteoblasts, and its constitutive overexpression led to inhibition of osteoblast and adipocyte differentiation of human marrow stromal cells. INTRODUCTION: Molecular control of human mesenchymal stem cell (hMSC) differentiation into osteoblasts and adipocytes is not known. In this study, we examined the role of delta-like 1/preadipocyte factor-1 (Dlk1/Pref-1) in regulating the differentiation of hMSCs. MATERIALS AND METHODS: As a model for hMSCs, we have stably transduced telomerase-immortalized hMSC (hMSC-TERT) with the full length of human Dlk1/Pref-1 cDNA and tested its effect on hMSC growth and differentiation into osteoblasts or adipocytes as assessed by cytochemical staining, FACS analysis, and real time PCR. Ex vivo calvaria organ cultures assay was used to confirm the in vitro effect of Dlk/Pref-1 on bone formation. RESULTS: Dlk1/Pref-1 was found to be expressed in fetal and adult bone, hMSCs, and some osteoblastic cell lines. A retroviral vector containing the human Dlk1/Pref-1 cDNA was used to create a cell line (hMSC-dlk1) expressing high levels of Dlk1/Pref-1 protein. Overexpression of Dlk1/Pref-1 did not affect the proliferation rate of hMSC, but the ability to form mature adipocytes, mineralized matrix in vitro, and new bone formation in neonatal murine calvariae organ cultures was reduced. These effects were associated with inhibition of gene expression markers of late stages of adipocyte (adipocyte fatty acid-binding protein [aP2], peroxisome proliferator-activated receptor-gamma2 [PPARgamma2], and adiponectin [APM1]) and osteoblast differentiation (alkaline phosphatase [ALP], collagen type I [Col1], and osteocalcin [OC]). Lineage commitment markers for adipocytes (adipocyte determination and differentiation factor -1 [ADD1]) and osteoblasts (core binding factor/runt-related binding factor 2 [Cbfa1/Runx2]) were not affected. CONCLUSION: During hMSC differentiation, Dlk1/Pref-1 maintains the size of the bipotential progenitor cell pool by inhibiting the formation of mature osteoblasts and adipocytes.     

How compensation breaks down in Parkinson's disease: Insights from modeling of denervated striatum

The bradykinesia and other motor signs of Parkinson's disease (PD) are linked to progressive loss of substantia nigra dopamine (DA) neurons innervating the striatum. However, the emergence of idiopathic PD is likely preceded by a prolonged subclinical phase, which may be masked by a variety of pre‐ and postsynaptic compensatory mechanisms. It is often considered self‐evident that the signs of PD manifest only when nigrostriatal degeneration has proceeded to such an extent that putative compensatory mechanisms fail to accommodate the depletion of striatal DA levels. However, the precise nature of the compensatory mechanisms, and the reason for their ultimate failure, has been elusive. In a recent computational study we modeled the effects of progressive denervation, including changes in the dynamics of interstitial DA and also adaptive or compensatory changes in postsynaptic responsiveness to DA signaling in the course of progressive nigrostriatal degeneration. In particular, we found that failure of DA signaling can occur by different mechanisms at different disease stages. We review these results and discuss their relevance for clinical and translational research, and we draw a number of predictions from our model that might be tested in preclinical experiments. © 2016 The Authors. Movement Disorders published by Wiley Periodicals, Inc. on behalf of International Parkinson and Movement Disorder Society.     

Epidemiology of adult ankle fractures in Sweden between 1987 and 2004: a population-based study of 91,410 Swedish inpatients

Background and purpose

Previous national epidemiological data on the characteristics and trends of patients with ankle fractures have been limited. We therefore analyzed data on Swedish inpatients with ankle fractures in this nationwide population study, based on data from 1987 through 2004.

Patients and methods

Data on all inpatients aged 15 years and older with ankle fracture were extracted from the Swedish National Patient Register for the period 1987–2004.

Results

We identified 91,410 hospital admissions with ankle fracture, corresponding to an annual incidence rate of 71 per 10⁵ person-years. During the study period, the number of hospital admissions increased by 0.2% annually, mainly from increase in fracture incidence in the elderly women. Mean age at admission was 45 (SD 19) years for men and 58 (18) for women. The major mechanism of injury was falling at the same level (64%).

Interpretation

This nationwide study of inpatients with ankle fractures showed an increase in fracture incidence, particularly in elderly women.Ankle fractures are among the most common fractures treated in orthopaedic surgery today. They are also a significant source of morbidity in both the young and the elderly (Donaldson et al. 1990, Jones et al. 1994, van Staa et al. 2001). Previous epidemiological studies have shown trends of increasing incidence over time, mainly in elderly women (Bengnér et al. 1986, Daly et al. 1987, Baron et al. 1996, Kannus et al. 1996, Court-Brown et al. 1998, van Staa et al. 2001, Kannus et al. 2002). However, most of these studies have included limited numbers of patients, and mostly originated from single hospitals or limited areas.Basic epidemiological data such as incidence, fracture type, age and sex distribution, mechanisms of injury, and surgical procedures can provide estimates when discussing disease burden and in the planning and provision of healthcare.The purpose of this study was to perform an epidemiological analysis of all adult ankle fractures requiring hospital admission in Sweden from 1997 through 2004, including incidence, causes of fracture, surgical procedures, patient characteristics, and trends over time.     

Automatic prediction of infarct growth in acute ischemic stroke from MR apparent diffusion coefficient maps

RATIONALE AND OBJECTIVES: We introduce a new approach to the prediction of final infarct growth in human acute ischemic stroke based on image analysis of the apparent diffusion coefficient (ADC) maps obtained from magnetic resonance imaging. Evidence from multiple previous studies indicate that ADC maps are likely to reveal brain regions belonging to the ischemic penumbra, that is, areas that may be at risk of infarction in the few hours following stroke onset. MATERIALS AND METHODS: In a context where "time is brain," and contrarily to the alternative-and still-debated-perfusion-diffusion weighted image (PWI/DWI) mismatch approach, the DWI magnetic resonance sequences are standardized, fast to acquire, and do not necessitate injection of a contrast agent. The image analysis approach presented here consists of the segmentation of the ischemic penumbra using a fast three-dimensional region-growing technique that mimics the growth of the infarct lesion during acute stroke. RESULTS: The method was evaluated with both numerical simulations and on two groups of 20 ischemic stroke patients (40 patients total). The first group of patient data was used to adjust the parameters of the model ruling the region-growing procedure. The second group of patient data was dedicated to evaluation purposes only, with no subsequent adjustment of the free parameters of the image-analysis procedure. Results indicate that the predicted final infarct volumes are significantly correlated with the true final lesion volumes as revealed by follow-up measurements from DWI sequences. CONCLUSION: The DWI-ADC mismatch method is an encouraging fast alternative to the PWI-DWI mismatch approach to evaluate the likeliness of infarct growth during the acute stage of ischemic stroke.