The interface between tapasin and MHC class I: identification of amino acid residues in both proteins that influence their interaction

Prior to the binding of antigenic peptide, a complex of chaperone proteins associates with the Major Histocompatibility Complex (MHC) class I heavy chain/β₂m heterodimer. Although each dornain of the MHC class I heavy chain contains amino acid resid uses that influence chaperone binding, there are several pieces of evidence that point to an interaction between the MHC clas 1α2/α3 domains and tapasin. In egard to the site on tapasin involved in the tapasin/MHC interface, we have found that a particular region of tapasin (containing amino acid residues 334–342) is necessary for the binding of tapasin to the MHC class I heavy chain. Our results also indicate that amino acids in this region of tapasin also affect the proportion of MHC class I open forms expressed at the cell surface and MHC class I egress from the endoplasmic reticulurn. Based on these results and those obtained by other laboratories, a model for MHC class I/tapasin interaction is proposed.     

Prognostic value of renal vein renin determination in suspected renovascular hypertension

Surgical correction of unilateral renal artery stenosis was performed in 31 hypertensive patients. Preoperative renal vein renin ratios (RVRR) before and after dihydralazine stimulation were measured in all patients. Postoperative blood pressure were normal in 12, improved in 17 and unchanged in 2 patients. Six patients did not have renin lateralization, but all were cured or improved after surgery. RVRR was a poor predictor of the results of surgery in patients with unilateral renal artery stenosis.     

The “Scandinavian Star” ferry disaster 1990 -a challenge to forensic odontology

Summary With 158 victims, the fire on board the Scandinavian Star was one of the world's worst ferry disasters. A team of identification experts, including dentists, were employed to secure evidence for identification and to remove the victims from the ferry. Four parallel teams, each with 2 dentists, examined and autopsied the victims at the Institute of Forensic Medicine, University of Oslo. Using the INTERPOL Disaster Victim Identification forms and aided by computers, all victims were identified within 17 days. Dental identity could be established in 107 cases (68%).     

Aorto-Caval Fistula Due to Rupture of Abdominal Aneurysm

Abstract

Two operated cases of aorto-caval fistula due to ruptured abdominal aneurysm are reported. This is a rare and real surgical emergency and is fatal without operation. The classical symptoms of high-output failure occurring simultaneously with the findings of an expansible abdominal mass with thrill and bruit should facilitate clinical diagnosis.     

Intra-rater variability in low-grade glioma segmentation

Assessment of size and growth are key radiological factors in low-grade gliomas (LGGs), both for prognostication and treatment evaluation, but the reliability of LGG-segmentation is scarcely studied. With a diffuse and invasive growth pattern, usually without contrast enhancement, these tumors can be difficult to delineate. The aim of this study was to investigate the intra-observer variability in LGG-segmentation for a radiologist without prior segmentation experience. Pre-operative 3D FLAIR images of 23 LGGs were segmented three times in the software 3D Slicer. Tumor volumes were calculated, together with the absolute and relative difference between the segmentations. To quantify the intra-rater variability, we used the Jaccard coefficient comparing both two (J2) and three (J3) segmentations as well as the Hausdorff Distance (HD). The variability measured with J2 improved significantly between the two last segmentations compared to the two first, going from 0.87 to 0.90 (p?=?0.04). Between the last two segmentations, larger tumors showed a tendency towards smaller relative volume difference (p?=?0.07), while tumors with well-defined borders had significantly less variability measured with both J2 (p?=?0.04) and HD (p?<?0.01). We found no significant relationship between variability and histological sub-types or Apparent Diffusion Coefficients (ADC). We found that the intra-rater variability can be considerable in serial LGG-segmentation, but the variability seems to decrease with experience and higher grade of border conspicuity. Our findings highlight that some criteria defining tumor borders and progression in 3D volumetric segmentation is needed, if moving from 2D to 3D assessment of size and growth of LGGs.

     

Single‐dose administration of clenbuterol is detectable in dried blood spots

Clenbuterol is a β₂‐agonist prescribed for asthmatic patients in some countries. Based on its anabolic and lipolytic effects observed in studies on rodents and in livestock destined for food production, clenbuterol is abused by bodybuilders and athletes seeking leanness. Urinary clenbuterol analysis is part of routine doping analysis. However, the collection of urine samples is time‐consuming and can be intimidating for athletes. Dried blood spot (DBS) appears attractive as an alternative matrix, but the detectability of clenbuterol in humans through DBS has not been investigated. This study evaluated if clenbuterol could be detected in DBS and urine collected from six healthy men after oral intake of 80 μg clenbuterol. The DBS and urine samples were collected at 0, 3, 8, 24, and 72 h post‐ingestion, with additional urine collections on days 7 and 10. Using LC–MS/MS, it was shown that clenbuterol could be detected in all DBS samples for 24 h post‐ingestion and with 50% sensitivity 3 days after ingestion. The DBS method was 100% specific. Evaluation of analyte stability showed that clenbuterol is stable in DBS for at least 365 days at room temperature when using desiccant and avoiding light exposure. In urine, clenbuterol was detectable for at least 7–10 days after ingestion. Urinary clenbuterol concentrations below 5 ng/mL were present in some subjects 24 h after administration. Collectively, these data indicate that DBS are suitable for routine doping control analysis of clenbuterol with a detection window of at least 3 days after oral administration of 80 μg.     

Results at 10 to 14 years after osteochondral autografting (mosaicplasty) in articular cartilage defects in the knee

PurposeThe aim of this study was to evaluate the medium-term (5–9 years) and long-term (10–14 years) outcomes of mosaicplasty in the knee and identify possible risk factors for poor outcome.MethodsWe included patients 60 years or younger with symptomatic focal full-thickness chondral lesions. Seventy-three patients (87%) with median age of 34 years were available for analyses. Clinical outcome was evaluated by Lysholm score and VAS of pain.ResultsBoth the mean Lysholm score and mean VAS pain score improved significantly from baseline, 49 (SD 17) and 58 (SD 23), respectively, to both the mid-term follow-up, 72 (SD18, p < 0.001) and 27 (SD 20, p < 0.001), respectively, and the long-term follow-up, 72 (SD 21, p < 0.001) and 33 (SD 23, p < 0.001), respectively. A poor outcome at the long-term follow-up – defined as a Lysholm score of 64 or less or having had a knee replacement – was found in 40%. A poor outcome was more frequent in patients 40 years or older (59%), in women (61%) and in defects with an area of 3 cm² or more (57%). Conversely, in a subgroup of male individuals younger than 40 years with defect size less than 3 cm² the failure rate was 12.5% and the mean Lysholm score was 82 (SD 16).ConclusionWe conclude that the long-term clinical outcome after mosaicplasty varies greatly depending on age, gender and the size of the lesion.Level of evidenceIV-Retrospective Case Series.     

Surgical strategy in grade II astrocytoma: a population-based analysis of survival and morbidity with a strategy of early resection as compared to watchful waiting

Background

We recently demonstrated a survival benefit of early resection in unselected diffuse low-grade gliomas (LGG). However, heterogeneity within the LGG entity warrants investigation in a homogenous subgroup. Astrocytoma represents the largest subgroup of LGG, and is characterized by diffuse growth and inferior prognosis. We aimed to study the effects of early resection compared to biopsy and watchful waiting in this subgroup.

Methods

Patient data was retrospectively reviewed in two neurosurgical departments with regional referral practice. In one hospital, initial diagnostic biopsies and watchful waiting was favored, while early resections guided with three-dimensional (3D) ultrasound were advocated in the other hospital. This created a natural experiment with patient management heavy influenced by residential address. In the hospitals’ histopathology databases, all adult patients diagnosed with supratentorial LGG from 1998 through 2009 were screened (n?=?169) and underwent blinded histopathological review. Histopathological review concluded with 117 patients with grade II astrocytomas that were included in the present study. The primary end-point was overall survival assessed by a regional comparison.

Results

Early resections were performed in 51 (82 %) versus 12 (22 %) patients in the respective hospitals (p?<?0.001). The two patient populations were otherwise similar. Median survival was 9.7 years (95 % CI 7.5–11.9) if treated in the hospital favoring early resections compared to 5.6 years (95 % CI 3.5–7.6) if treated at the hospital favoring biopsy and watchful waiting (p?=?0.047). No difference in surgical-related neurological morbidity was seen (p?=?0.843).

Conclusions

Early 3D ultrasound guided resections improve survival, apparently without increased morbidity, compared to biopsy and watchful waiting in patients with diffuse World Health Organization (WHO) grade II astrocytomas.