WOUND CLOSURE BY DERMATOTRACTION AFTER FASCIOTOMY FOR ACUTE COMPARTMENT SYNDROME

Intramuscular pressure (IMP) was measured in 16 patients during secondary wound closure by dermatotraction with external tissue extension (ETE®). Secondary wound closure was done 4-16 days after fasciotomy for acute compartment syndrome. The traction between wound edges was 2.5 N in the first six patients and 3.5 N in the following 10 patients. Mean (SD) IMP was 6.9 (3.5) mmHg before wound closure. It increased to 12.3 (1.4) mmHg in the 2.5 N group and to 24.7 (7.0) mmHg in the 3.5 N group when dermatotraction was applied. Mean (SD) leg perfusion pressure in the 2.5 N group decreased by 7% to 69.3 (10.9) mmHg and in the 3.5 N group by 23% to 62.2 (7.4) mmHg. None of the patients needed a skin graft. We conclude that dermatotraction by ETE® raises IMP intraoperatively sufficiently to preserve adequate limb perfusion pressures.     

Dominant ARL3-related retinitis pigmentosa

Purpose: To clinically and genetically characterise a second family with dominant ARL3-related retinitis pigmentosa due to a specific ARL3 missense variant, p.(Tyr90Cys).

Methods: Clinical examination included optical coherence tomography, electroretinography, and ultra-wide field retinal imaging with autofluorescence. Retrospective data were collected from the registry of inherited retinal diseases at Oslo university hospital. DNA was analysed by whole-exome sequencing and Sanger sequencing. The ARL3 missense variant was visualized in a 3D-protein structure.

Results: The phenotype was non-syndromic retinitis pigmentosa with cataract associated with early onset of decreased central vision and central retinal thinning. Sanger sequencing confirmed the presence of a de novo ARL3 missense variant p.(Tyr90Cys) in the index patient and his affected son. We did not find any other cases with rare ARL3 variants in a cohort of 431 patients with retinitis pigmentosa-like disease. By visualizing Tyr90 in the 3D protein structure, it seems to play an important role in packing of the α/β structure of ADP-ribosylation factor-like 3 (ARL3). When changing Tyr90 to cysteine, we observe a loss of interactions in the core of the α/β structure that is likely to affect folding and stability of ARL3.

Conclusion: Our study confirms that the ARL3 missense variant p.(Tyr90Cys) causes retinitis pigmentosa. In 2016, Strom et al. reported the exact same variant in a mother and two children with RP, labelled ?RP83 in the OMIM database. Now the questionmark can be removed, and ARL3 should be added to the list of genes that may cause non-syndromic dominant retinitis pigmentosa.     

Decreased migration with locally administered bisphosphonate in cemented cup revisions using impaction bone grafting technique

Background and purpose — Impaction bone grafting (IBG) in revision hip surgery is an established method in restoring bone stock deficiencies. We hypothesized that local treatment of the morsellized allograft with a bisphosphonate in cemented revision would, in addition to increased bone density, also reduce the early migration of the cup as measured by radiostereometry (RSA).

Patients and methods — 20 patients with aseptic cup loosening underwent revision using the IBG technique. The patients were randomized to either clodronate (10 patients) or saline (10 patients, control group) as local adjunct to the morsellized bone. The outcome was evaluated by dual-energy X-ray absorptiometry (DXA) during the first year regarding periacetabular bone density and with radiostereometric analysis (RSA) for the first 2 years regarding cup migration.

Results — 2 patients were lost to follow-up: 9 patients remained in the clodronate and 9 in the control group. Less proximal migration was found in the clodronate group compared with the controls, measured both over time (mixed-models analysis, p = 0.02) as well as at the specified time points up to 2 years (0.22?mm and 0.59?mm respectively, p = 0.02). Both groups seemed to have stabilized at 1 year. We found similar bone mineral density measured by DXA, and similar RSA migration in the other directions. No cups were re-revised.

Interpretation — Local treatment of the allograft bone with clodronate reduced early proximal migration of the revised cup but without any measurable difference in periacetabular bone density.     

Correction of hypospadias with a vertical preputial island flap: the Göteborg experience of 47 patients

We report the follow-up of 47 patients with penile hypospadias who were treated by the Scuderi procedure between 1988 and 1998 at Sahlgrenska University Hospital, Göteborg, Sweden. Forty of the patients (85%) had had no previous operations, while the remaining seven had had meatotomy with chordectomy only, or an unsuccessful Dennis-Browne procedure. Hypospadias was distal in 35 (74%), mediopenile in 8 (17%), and proximal in 4 (9%); 21 (45%) showed signs of curvature. After a Scuderi urethroplasty one patient developed a fistula (2%) and 4 developed mild stenosis. The early success rate was therefore 42/47 (89%) and this later increased to 46/47 (98%) after non-surgical treatment of the stenoses. The results support the use of the Scuderi procedure for correction of primary and secondary penile hypospadias with a low complication rate.     

Cotranslational folding of membrane proteins probed by arrest-peptide–mediated force measurements

Polytopic membrane proteins are inserted cotranslationally into target membranes by ribosome–translocon complexes. It is, however, unclear when during the insertion process specific interactions between the transmembrane helices start to form. Here, we use a recently developed in vivo technique to measure pulling forces acting on transmembrane helices during their cotranslational insertion into the inner membrane of Escherichia coli to study the earliest steps of tertiary folding of five polytopic membrane proteins. We find that interactions between residues in a C-terminally located transmembrane helix and in more N-terminally located helices can be detected already at the point when the C-terminal helix partitions from the translocon into the membrane. Our findings pinpoint the earliest steps of tertiary structure formation and open up possibilities to study the cotranslational folding of polytopic membrane proteins.     

Declining Coronary Heart Disease Mortality in Iceland: Contribution by Incidence,Recurrence and Case Fatality Rate

Objective : To analyse to what extent the recent decline in coronary heart disease mortality in Iceland is due to changes in incidence, recurrence and case fatality rates. Design : A countrywide registration of myocardial infarction (MI) in people aged 25-74 was performed in Iceland during 1981-1999 according to the MONICA protocol. Possible cases were found by review of all hospital discharge records, autopsy records and death certificates. Results : MI death rate declined by 63% in males and 51% in females, most in the youngest age groups in men (86%) and least in the oldest (49%). In women there was not a significant difference in age groups. Overall the age-adjusted reduction in MI death rate was 55.4% in both sexes combined; of this 23.1% was due to incidence reduction, 22.8% to recurrence reduction and 11.6% to case fatality reduction. In the youngest age groups the decline in incidence contributed most to the decline in MI death rate (62% in men and 71% in women), but thereafter the decline in case fatality in men. In the older age groups decline in recurrence rate has greater weight. Conclusion : The recent decline in MI mortality under the age of 75 years in Iceland is due to reduction in incidence and recurrence rate by about 40% each and to reduction in case fatality by 20%.     

Economics of nuclear power and climate change mitigation policies

The events of March 2011 at the nuclear power complex in Fukushima, Japan, raised questions about the safe operation of nuclear power plants, with early retirement of existing nuclear power plants being debated in the policy arena and considered by regulators. Also, the future of building new nuclear power plants is highly uncertain. Should nuclear power policies become more restrictive, one potential option for climate change mitigation will be less available. However, a systematic analysis of nuclear power policies, including early retirement, has been missing in the climate change mitigation literature. We apply an energy economy model framework to derive scenarios and analyze the interactions and tradeoffs between these two policy fields. Our results indicate that early retirement of nuclear power plants leads to discounted cumulative global GDP losses of 0.07% by 2020. If, in addition, new nuclear investments are excluded, total losses will double. The effect of climate policies imposed by an intertemporal carbon budget on incremental costs of policies restricting nuclear power use is small. However, climate policies have much larger impacts than policies restricting the use of nuclear power. The carbon budget leads to cumulative discounted near term reductions of global GDP of 0.64% until 2020. Intertemporal flexibility of the carbon budget approach enables higher near-term emissions as a result of increased power generation from natural gas to fill the emerging gap in electricity supply, while still remaining within the overall carbon budget. Demand reductions and efficiency improvements are the second major response strategy.