Clinical improvement of DM1 patients reflected by reversal of disease-induced gene expression in blood

BACKGROUND

Myotonic dystrophy type 1 (DM1) is an incurable multisystem disease caused by a CTG-repeat expansion in the DM1 protein kinase (DMPK) gene. The OPTIMISTIC clinical trial demonstrated positive and heterogenous effects of cognitive behavioral therapy (CBT) on the capacity for activity and social participations in DM1 patients. Through a process of reverse engineering, this study aims to identify druggable molecular biomarkers associated with the clinical improvement in the OPTIMISTIC cohort.

METHODS

Based on full blood samples collected during OPTIMISTIC, we performed paired mRNA sequencing for 27 patients before and after the CBT intervention. Linear mixed effect models were used to identify biomarkers associated with the disease-causing CTG expansion and the mean clinical improvement across all clinical outcome measures.

RESULTS

We identified 608 genes for which their expression was significantly associated with the CTG-repeat expansion, as well as 1176 genes significantly associated with the average clinical response towards the intervention. Remarkably, all 97 genes associated with both returned to more normal levels in patients who benefited the most from CBT. This main finding has been replicated based on an external dataset of mRNA data of DM1 patients and controls, singling these genes out as candidate biomarkers for therapy response. Among these candidate genes were DNAJB12, HDAC5, and TRIM8, each belonging to a protein family that is being studied in the context of neurological disorders or muscular dystrophies. Across the different gene sets, gene pathway enrichment analysis revealed disease-relevant impaired signaling in, among others, insulin-, metabolism-, and immune-related pathways. Furthermore, evidence for shared dysregulations with another neuromuscular disease, Duchenne muscular dystrophy, was found, suggesting a partial overlap in blood-based gene dysregulation.

CONCLUSIONS

DM1-relevant disease signatures can be identified on a molecular level in peripheral blood, opening new avenues for drug discovery and therapy efficacy assessments.

Insulin Signaling as a Key Moderator in Myotonic Dystrophy Type 1

Myotonic dystrophy type 1 (DM1) is an autosomal dominant genetic disease characterized by multi-system involvement. Affected organ system includes skeletal muscle, heart, gastro-intestinal system and the brain. In this review, we evaluate the evidence for alterations in insulin signaling and their relation to clinical DM1 features. We start by summarizing the molecular pathophysiology of DM1. Next, an overview of normal insulin signaling physiology is given, and evidence for alterations herein in DM1 is presented. Clinically, evidence for involvement of insulin signaling pathways in DM1 is based on the increased incidence of insulin resistance seen in clinical practice and recent trial evidence of beneficial effects of metformin on muscle function. Indirectly, further support may be derived from certain CNS derived symptoms characteristic of DM1, such as obsessive-compulsive behavior features, for which links with altered insulin signaling has been demonstrated in other diseases. At the basic scientific level, several pathophysiological mechanisms that operate in DM1 may compromise normal insulin signaling physiology. The evidence presented here reflects the importance of insulin signaling in relation to clinical features of DM1 and justifies further basic scientific and clinical, therapeutically oriented research.

Those Who Don't Return: Improving Efforts to Address Tuberculosis Among Former Miners in Southern Africa

Despite increasing awareness regarding the role of oscillating migration in the mining industry as a major driving force in the spread of tuberculosis (TB) throughout southern Africa, very little work has focused on the historical and contextual factors which may contribute to former migrant miners' present-day risk of TB. Most research regarding migration-related and occupational influences on TB has been done on current miners still employed by the mining industry. Through both a historical and contemporary lens, this paper explores and elucidates the need to address the TB epidemic among former migrant mine workers and provides considerations to improve current interventions among this critical population.

Lower levels of plasma 25-hydroxyvitamin D among young adults at diagnosis of autoimmune type 1 diabetes compared with control subjects: results from the nationwide Diabetes Incidence Study in Sweden (DISS)

AIMS/HYPOTHESIS

Low plasma vitamin D concentrations may promote the development of type 1 diabetes. To test this hypothesis, we measured plasma 25-hydroxyvitamin D (25OHD) in young adults with type 1 diabetes.

METHODS

The nationwide Diabetes Incidence Study in Sweden (DISS) covers 15- to 34-year-old people with newly diagnosed diabetes. Blood samples at diagnosis were collected during the 2-year period 1987/1988. Patients with islet antibodies (islet cell antibodies, GAD antibodies or tyrosine phosphatase-like protein antibodies) were defined as having autoimmune type 1 diabetes. Plasma 25OHD was measured in samples taken from 459 patients at the time of diagnosis, and in 138 of these subjects 8 years later. The results were compared with age- and sex-matched control subjects (n=208).

RESULTS

At diagnosis, plasma 25OHD levels were significantly lower in patients with type 1 diabetes than in control subjects (82.5+/-1.3 vs 96.7+/-2.0 nmol/l; p<0.0001). Eight years later, plasma 25OHD had decreased in patients (81.5+/-2.6 nmol/l; p=0.04). Plasma 25OHD levels were significantly lower in diabetic men than in diabetic women at diagnosis (77.9+/-1.4 vs 90.1+/-2.4 nmol/l; p<0.0001) and at follow-up (77.1+/-2.8 nmol/l vs 87.2+/-4.5 nmol/l; p=0.048).

CONCLUSIONS/INTERPRETATION

The plasma 25OHD level was lower at diagnosis of autoimmune type 1 diabetes than in control subjects, and may have a role in the development of type 1 diabetes. Plasma 25OHD levels were lower in men than in women with type 1 diabetes. This difference may be relevant to the high incidence of type 1 diabetes among young adult men.

Organic thin-film electronics from vitreous solution-processed rubrene hypereutectics

Electronic devices based on single crystals of organic semiconductors provide powerful means for studying intrinsic charge-transport phenomena and their fundamental electronic limits. However, for technological exploitation, it is imperative not to be confined to the tedious growth and cumbersome manipulation of molecular crystals-which generally show notoriously poor mechanical properties-but to be able to process such materials into robust architectures by simple and efficient means. Here, we advance a general route for facile fabrication of thin-film devices from solution. The key beneficial feature of our process-and the principal difference from existing vapour deposition and solution-processing schemes-is the incorporation of a glass-inducing diluent that enables controlled crystallization from an initial vitreous state of the organic semiconductor, formed in a selected area of the phase diagram of the two constituents. We find that the vitrifying diluent does not adversely affect device performance. Indeed, our environmentally stable, discrete rubrene-based transistors rival amorphous silicon devices, reaching saturated mobilities of up to 0.7 cm2 V-1 s-1, ON-OFF ratios of >or=10(6) and subthreshold slopes as steep as 0.5 V per decade. A nearly temperature-independent device mobility, indicative of a high crystalline quality of our solution-processed, rubrene-based films, corroborates these findings. Inverter and ring-oscillator structures are also demonstrated.

Design, synthesis, and evaluation of N-aroyloxy-2-thiopyridones as DNA photocleaving reagents

N-Benzoyloxy-2-thiopyridone (12) was shown to induce single-strand nicks in duplex DNA upon irradiation with visible light (lambda&350 nm). This finding led to the design of a series of compounds, in which an acridinyl nucleus was covalently linked to the N-benzoyloxy-2-thiopyridone unit. These conjugates (15, 16, 17 and 18) were synthesized and evaluated as novel DNA photocleaving reagents. Optimal photocleaving activity was observed for conjugate 16, in which a flexible polymethylene spacer of 4 carbons was used to connect the aminoacridine entity to the thiopyridone. This compound was shown to cleave DNA at low microM concentrations and was approximately two-orders of magnitude more efficient than the parent N-benzoyloxy-2-thiopyridone (12). Furthermore, the DNA cleavage ladders induced by 16 and 12 were found to be identical and of no significant sequence selectivity. These data suggest that the N-aroyloxy-2-thiopyridones can be used for the design of new DNA photocleaving reagents with potential use as 'photofootprinting agents' or as 'site-directed photonucleases'.

Increased plasminogen activator inhibitor and tissue plasminogen activator levels in subjects with electrocardiographic abnormality indicative of ischaemic heart disease: a cross-sectional study in Norsjö, Sweden

The plasma levels of tissue plasminogen activator (tPA) antigen concentration and plasminogen activator inhibitor (PAI) activity were measured in a random sample of 260 subjects, 30, 40, 50, or 60 years of age. Electrocardiographic Q, ST and/or ST-T changes, suggestive of definite or possible ischaemic heart disease (IHD), were found in 21% of the 50-year-old and 37% of the 60-year-old subjects. As compared to subjects lacking such signs, plasma tPA and PAI levels were significantly increased in the 60-year-old group, and PAI tended to be increased in the 50-year-old group. Previous case-control studies, usually performed at specialized centres and liable to sampling biases, have suggested an association between increased PAI levels and ischaemic heart disease. This cross-sectional population study provides independent data that patients with electrocardiographic signs of IHD have increased levels of both PAI and tPA antigen.

Testicular histology after treatment with LH-RH analogue for carcinoma of the prostate

Orchiectomy was performed in 16 patients because of progression of prostatic cancer despite adequate medical castration with goserelin (Zoladex, ICI) over a mean period of 17.6 months. Severe tubular atrophy was seen in the testes. The Leydig cells also showed signs of atrophy, a fact that may indicate a direct effect of goserelin on these cells. In 1 patient, however, orchiectomy was postponed for 3 months after cessation of medical castration. The serum testosterone had resumed almost normal values and testicular histology revealed intact spermatogenesis and apparently normal Leydig cells.

Primary retroperitoneal sarcomas. A review of 36 cases

A retrospective study of 36 patients with primary retroperitoneal sarcomas treated at The Norwegian Radium Hospital is presented. The median age at presentation was 57 years. The most common presenting symptom was abdominal pain. Leiomyosarcoma and liposarcoma were the most common histologic subtypes. The median survival in the whole series was 25 months. Patients with completely resected tumors had a longer median survival (59 months) than patients with incomplete resection (16 months) but the difference was not statistically significant. The malignancy grade seemed to be the most important prognostic factor and patients with low grade tumors had a significantly better outlook than those with high grade tumors.

Intramuscular fluid pressure during isometric contraction of human skeletal muscle

Intramuscular fluid pressures were recorded in the vastus medialis of seven healthy male volunteers. Pressures were measured simultaneously at three different sites in the muscle by a catheter-tip transducer with extremely low volume-displacement characteristics and by two extracorporeal transducers connected to slit catheters. All three recording systems gave qualitatively similar results provided the catheters had inner diameters exceeding 0.53 mm and allowed measurement of pressures lasting as short as 1 s. Wick catheters yielded slower responses than slit catheters. At any position intramuscular fluid pressure increased linearly with force up to maximal voluntary contraction (MVC). However, slopes of these curves varied greatly mainly because the pressure was also a linear function of the distance from the fascia. The highest recorded pressure was 570 Torr. At prolonged submaximal contractions intramuscular fluid pressure oscillated independent of contraction force. The linearity of both the pressure-force relationship and the pressure-depth relationship is compatible with a simple model based on the law of Laplace because the muscle fibers are curved during contraction in this muscle. It is hypothesized that blood flow is first compromised deep in the muscle where pressure is highest and in general at lower stress or tension in short bulging muscles with great curvature of the fibers compared with long slender ones.

Subcutaneous bronchogenic anomalies

Two cases of congenital anomalies, one cyst and one sinus, presenting in the suprasternal notch are reported. No communication with deeper structures was found at surgery, and histology was compatible with previous descriptions of subcutaneous bronchogenic cysts. The literature is reviewed, and the similarity between these lesions and many cases of branchial fistula is stressed.