Transanal total mesorectal excision for rectal cancer has been suspended in Norway.

BACKGROUND: Transanal total mesorectal excision (TaTME) for rectal cancer has emerged as an alternative to the traditional abdominal approach. However, concerns have been raised about local recurrence. The aim of this study was to evaluate local recurrence after TaTME. Secondary aims included postoperative mortality, anastomotic leak and stoma rates. METHODS: Data on all patients who underwent TaTME were recorded and compared with those from national cohorts in the Norwegian Colorectal Cancer Registry (NCCR) and the Norwegian Registry for Gastrointestinal Surgery (NoRGast). Kaplan-Meier estimates were used to compare local recurrence. RESULTS: In Norway, 157 patients underwent TaTME for rectal cancer between October 2014 and October 2018. Three of seven hospitals abandoned TaTME after a total of five procedures. The local recurrence rate was 12 of 157 (7·6 per cent); eight local recurrences were multifocal or extensive. The estimated local recurrence rate at 2·4 years was 11·6 (95 per cent c.i. 6·6 to 19·9) per cent after TaTME compared with 2·4 (1·4 to 4·3) per cent in the NCCR (P < 0·001). The adjusted hazard ratio was 6·71 (95 per cent c.i. 2·94 to 15·32). Anastomotic leaks resulting in reoperation occurred in 8·4 per cent of patients in the TaTME cohort compared with 4·5 per cent in NoRGast (P = 0·047). Fifty-six patients (35·7 per cent) had a stoma at latest follow-up; 39 (24·8 per cent) were permanent. CONCLUSION: Anastomotic leak rates after TaTME were higher than national rates; local recurrence rates and growth patterns were unfavourable.

ANTECEDENTES: La resección total del mesorrecto transanal (transanal total mesorectal excision, TaTME) para el cáncer de recto se ha propuesto como una alternativa al abordaje abdominal tradicional. Sin embargo, la recidiva local (local recurrence, LR) después de este procedimiento es motivo de preocupación. El objetivo de este estudio fue evaluar la LR en pacientes operados mediante TaTME. Los objetivos secundarios incluyeron la mortalidad postoperatoria, las fugas anastomóticas y el porcentaje de estomas. MÉTODOS: Se registraron los datos de todos los pacientes operados mediante TaTME y se compararon con las cohortes nacionales del Registro Noruego de Cáncer Colorrectal (Norwegian Colorectal Cancer Registry, NCCR) y del Registro Noruego de Cirugía Gastrointestinal (Norwegian Registry for Gastrointestinal Surgery, NoRGast) utilizando estimaciones de Kaplan-Meier y la prueba de log-rank para comparar curvas de LR. RESULTADOS: En Noruega, 157 pacientes se sometieron a TaTME por cáncer de recto entre octubre de 2014 y octubre de 2018. Tres de siete hospitales abandonaron el TaTME después de un total de cinco procedimientos. La LR observada fue 12/157 (7,6%), siendo ocho de ellas multifocales o extensas. La tasa estimada de LR a 2,4 años fue de 11,6 % (i.c. del 95% 6,6 a 19,9) versus 2,4 % (1,4 a 4,3) en el NCCR (log rank P < 0,001). El cociente de riesgos instantáneos (hazard ratio, HR) ajustado fue 6,7 (i.c. del 95% 2,9 a 15,3). Las fugas anastomóticas que precisaron una reintervención después de TaTME ocurrieron en un 8,4% versus 4,5% en el registro NoRGast (P = 0,047). Cincuenta y seis pacientes (35,7%) tenían un estoma en el último seguimiento; 39 (24,8%) eran permanentes. CONCLUSIÓN: Las tasas de fuga anastomótica tras una TaTME fueron más altas que los datos nacionales con tasas de LR y patrones de crecimiento desfavorables.

MR scanning, tattoo inks, and risk of thermal burn: An experimental study of iron oxide and organic pigments: Effect on temperature and magnetic behavior referenced to chemical analysis.

BACKGROUND: Tattooed persons examined with magnetic resonance imaging (MRI) can develop burning sensation suggested in the literature to be thermal burn from the procedure. MRI-induced thermal effect and magnetic behavior of known tattoo pigments were examined ex vivo. MATERIALS AND METHODS: Magnetic resonance imaging effects on 3 commonly used commercial ink stock products marketed for cosmetic tattooing was studied. A main study tested 22 formulations based on 11 pigment raw materials, for example, one line of 11 called pastes and another called dispersions. Samples were spread in petri dishes and tested with a 0.97 T neodymium solid magnet to observe visual magnetic behavior. Before MRI, the surface temperature of the ink was measured using an infrared probe. Samples were placed in a clinical 3T scanner. Two scans were performed, that is, one in the isocenter and one 30 cm away from the center. After scanning, the surface temperature was measured again. Chemical analysis of samples was performed by mass spectroscopy. RESULTS: Mean temperature increase measured in the isocenter ranged between 0.14 and 0.26°C (P < .01) and in the off-center position from -0.16 to 0.21°C (P < .01). Such low increase of temperature is clinically irrelevant. Chemical analysis showed high concentrations of iron, but also nickel and chrome were found as contaminants. High concentration of iron was not associated with any increase of temperature or any physical draw or move of ink. CONCLUSION: The study could not confirm any clinically relevant temperature increase of tattoo pigments after MRI.

Novel mutation in ATP13A2 widens the spectrum of Kufor-Rakeb syndrome (PARK9).

Kufor-Rakeb syndrome (KRS) is a rare autosomal recessive inherited juvenile parkinsonian syndrome caused by mutations in ATP13A2. We describe six patients from a consanguineous Greenlandic Inuit family, homozygous for a novel frame-shift mutation in exon 22 of ATP13A2 (c.2473C>AA, p.Leu825AsnfsX32). Disease onset varied from 10 to 29 years of age, the latest reported, and the clinical features were highly variable within a wide spectrum of an extrapyramidal-pyramidal syndrome with cognitive/psychiatric features. Ataxia was seen in two patients and axonal neuropathy in one, features not previously related to KRS. Dopamine transporter scans showed symmetrical, severely reduced uptake in striatum in two patients. Magnetic resonance imaging was without atrophy in one patient despite disease duration of 17 years, and cerebral and cerebellar atrophy was seen in another patient after 4 years of disease duration. The molecular pathogenic mechanisms of ATP13A2 mutations are discussed. The observation that the mutant transcript is not degraded by nonsense-mediated RNA decay and the fact that none of the eight heterozygous carriers from the family have KRS symptoms suggest that the mutant protein does not interfere and destroy the function of the wild-type ATP13A2 protein.

Hepatitis D outbreak among children in a hepatitis B hyper-endemic settlement in Greenland.

Hepatitis B virus (HBV) infection is endemic in Greenland with 5-10% of the population being HBsAg-positive (chronic carriers). Surprisingly, despite of the high prevalence of HBV infection, acute and chronic hepatitis B, liver cirrhosis and primary hepatocellular carcinoma appear much less frequently than expected. The reasons for the low frequencies are unknown, but as a consequence implementation of a childhood HBV vaccination programme, though debated for years, has never been instituted. We describe an outbreak of hepatitis D (HDV) infection among children in a hepatitis B hyper-endemic settlement of 133 inhabitants on the west coast of Greenland. In 2006 a total of 27% of the inhabitants were HBsAg-positive (chronic carriers) and 83% were HBcAb-positive (previously exposed). Forty-six percent of the HBsAg-positive persons were below 20 years of age. On follow-up 1 year later a total of 68% of the HBsAg-positive persons were HDV-IgG positive. Five children, who were HBsAg-positive in 2006, had HDV-seroconverted from 2006 to 2007, indicating a HDV-super-infection. Most of the HDV-IgG positive children had markedly elevated liver enzymes. In the multivariate analysis, among the HBV and HDV markers, presence of HDV-IgG was most strongly associated with elevation of liver enzymes. In conclusion, the HBV-HDV super-infection and presumed HDV outbreak in this settlement challenges the notion that HBV infection may not be as harmless in Greenland as previously anticipated. The findings strongly suggest that HBV vaccination should be included in the child-immunization program in Greenland.

Antenatal ultrasound and postnatal autopsy findings in terminations after 12 weeks' gestation due to fetal abnormality: population-based study in Western Norway, 1988-2002.

BACKGROUND: Ultrasound screening has been part of antenatal care for several decades, and warrants high expertise to meet the criteria for a worthwhile screening program. In particular, the rate of false positives should be low. PURPOSE: To examine time trends of pregnancy terminations for fetal abnormality after 12 weeks' gestation, and to assess the agreement between antenatal ultrasound and post-termination autopsy findings for the main pathologies leading to termination. MATERIAL AND METHODS: During the period 1988 to 2002, 198 pregnancies were terminated for fetal abnormality after 12 weeks' gestation. We reviewed the case notes for those 151 who were autopsied (male/female/undetermined ;= ;91/56/4). Annual rates of live births and stillbirths were retrieved from the Medical Birth Registry of Norway. RESULTS: Antenatal ultrasound provided a correct diagnosis of the major abnormality in 149/151 cases (99%), based on post-termination autopsy findings. The annual rate of terminations after 12 weeks' gestation varied between 0.6 and 3.4 (mean 1.8) per 1000 live births, with a trend toward higher rates over the study period (P=0.001, chi-square test for linear-by-linear association). CONCLUSION: The specificity of antenatal ultrasound for major abnormalities was high, as compared to postnatal autopsy findings. The mean annual rates of termination after 12 weeks' gestation tended to increase over the 14-year study period.

Familial Currarino syndrome presenting with peripheral primitive neuroectodermal tumour arising with a sacral teratoma.

This report illustrates a rare genetic disorder, Currarino syndrome, in association with an unusual malignant transformation to a peripheral primitive neuroectodermal tumour within a sacral teratoma. The triad of features consists of a presacral mass, partial sacral agenesis and anorectal anomalies. The most common presentation is constipation. In this case there was a history of constipation, teratomas and spinal abnormalities in many of the family members over three generations. Detailed family history taken at time of initial presentation may have prevented delay in diagnosis and averted the need for intensive treatment, which may well cause late sequelae.

Preventing injuries in female youth football--a cluster-randomized controlled trial.

A set of exercises--the "11"--have been selected to prevent football injuries. The purpose of this cluster-randomized controlled trial was to investigate the effect of the "11" on injury risk in female youth football. Teams were randomized to an intervention (n=59 teams, 1091 players) or a control group (n=54 teams, 1001 players). The intervention group was taught the "11," exercises for core stability, lower extremity strength, neuromuscular control and agility, to be used as a 15-min warm-up program for football training over an 8-month season. A total of 396 players (20%) sustained 483 injuries. No difference was observed in the overall injury rate between the intervention (3.6 injuries/1000 h, confidence interval (CI) 3.2-4.1) and control group (3.7, CI 3.2-4.1; RR=1.0, CI 0.8-1.2; P=0.94) nor in the incidence for any type of injury. During the first 4 months of the season, the training program was used during 60% of the football training sessions, but only 14 out of 58 intervention teams completed more than 20 prevention training sessions. In conclusion, we observed no effect of the injury prevention program on the injury rate, most likely because the compliance with the program was low.

Molecular mechanisms of membrane polarity in renal epithelial cells.

Exciting discoveries in the last decade have cast light onto the fundamental mechanisms that underlie polarized trafficking in epithelial cells. It is now clear that epithelial cell membrane asymmetry is achieved by a combination of intracellular sorting operations, vectorial delivery mechanisms and plasmalemma-specific fusion and retention processes. Several well-defined signals that specify polarized segregation, sorting, or retention processes have, now, been described in a number of proteins. The intracellular machineries that decode and act on these signals are beginning to be described. In addition, the nature of the molecules that associate with intracellular trafficking vesicles to coordinate polarized delivery, tethering, docking, and fusion are also becoming understood. Combined with direct visualization of polarized sorting processes with new technologies in live-cell fluorescent microscopy, new and surprising insights into these once-elusive trafficking processes are emerging. Here we provide a review of these recent advances within an historically relevant context.

Endosperm Development in Barley: Microtubule Involvement in the Morphogenetic Pathway.

An immunofluorescence study of sectioned barley endosperm imaged by confocal laser scanning microscopy provided three-dimensional data on the relationship of microtubules to the cytoplasm, nuclei, and cell walls during development from 4 to 21 days after pollination (DAP). Microtubules play an important role throughout endosperm ontogeny. The syncytium is organized into units of nuclear-cytoplasmic domains by nuclear-based radial microtubule systems that appear to control the pattern of the first anticlinal walls at 5 to 6 DAP. After 7 DAP, phragmoplasts of two origins (interzonal and cytoplasmic) guide wall formation. Large compartments formed by the "free growing" walls in association with cytoplasmic phragmoplasts formed adventitiously at interfaces of opposing microtubule systems are subsequently subdivided by interzonal phragmoplast/cell plates to give rise to the starchy endosperm. During development of the aleurone layer from 8 to 21 DAP, the microtubule cycle is typical of plant histogenesis; cortical microtubules are hooplike, and preprophase bands of microtubules predict the division plane.

Expression of a novel factor, com1, is regulated by 1,25-dihydroxyvitamin D3 in breast cancer cells.

Tumor cells and their surrounding microenvironment produce a variety of factors that promote tumor growth and metastasis. We recently identified a nuclear factor, termed com1, that is up-regulated in human breast carcinoma cells on formation of experimental metastatic tumors and is assumed to act as a growth-promoting factor in breast cancer. 1,25-Dihydroxyvitamin D3 [1,25(OH)2D3] is a potent inhibitor of growth in breast cancer both in vitro and in vivo. We compared the growth-regulatory mechanisms of nontumorigenic and estrogen-dependent MCF-7 cells with those of the tumorigenic and tamoxifen-resistant subline MCF7/ LCC2 in the presence of 1,25(OH)2D3. Proliferation of MCF7/LCC2 cells, which revealed constitutive com1 expression, was inhibited by 1,25(OH)2D3 (10(-7) M). This was strongly associated with cell cycle arrest in G1 phase, consistent with accumulation of the hypophosphorylated form of the retinoblastoma protein as well as the induction of the cyclin-dependent kinase inhibitor p21. These cell cycle events were preceded by a transient up-regulation (5-8-fold) of com1 mRNA. Furthermore, clonal growth of the MCF7/LCC2 cells was also inhibited by 1,25(OH)2D3 (10(-7) M), and when the com1-negative MCF-7 cells were stably transfected with com1, the resulting MCF7/com1 cells showed a significant decrease in colony formation. These results seem to indicate that rather than promoting growth, com1 may participate in the regulatory pathway involved in cellular growth inhibition when recruited by inhibitory signals.

Cavity mutants of Savinase. Crystal structures and differential scanning calorimetry experiments give hints of the function of the buried water molecules in subtilisins.

The subtilisin molecule possesses several internal water molecules, which may be characterised as an integral part of the protein structure. We have introduced specific mutations (T71I, T71S, T71V, T71A and T71G) at position 71 in the subtilisin variant Savinase from Bacillus lentus. This position is involved in a hydrogen bonded network with several internal water molecules, forming a water channel. The water channel and most of the other internal water molecules are positioned in the interface between two half-domains of the subtilisin molecule. The data presented here indicate that the internal water molecules are structural, and may be the result of trapping during the folding process.

The 1.6 A structure of Kunitz-type domain from the alpha 3 chain of human type VI collagen.

The C-terminal Kunitz-type domain from the alpha 3 chain of human type VI collagen (C5), a single 58 amino acid residue chain with three disulfide bridges, was cloned, expressed and crystallized in a monoclonic form, space group P2(1), with a = 25.7 A, b = 38.2 A, c = 28.8 A and beta = 109 degrees. The structure was resolved by molecular replacement, using Alzheimer's protein precursor inhibitor and bovine pancreatic trypsin inhibitor three-dimensional structures as search models. The molecule with one sulfate ion and 43 associated water molecules was refined by XPLOR to an R-factor of 18.9% at 1.6 A. The molecule was not degraded by trypsin and did not inhibit trypsin or tested serine proteases. As opposed to the other Kunitz family members, C5 demonstrates left-handed chirality of the Cys14-Cys38 disulfide bond. Inversion of the Thr13 carbonyl and bulky side-chains at the interface with trypsin in a model of the C5-trypsin complex may explain the lack of inhibition of trypsin.

Research approaches to describe the mechanisms of injuries in sport: limitations and possibilities.

A number of different methodological approaches have been used to describe the inciting event for sports injuries. These include interviews of injured athletes, analysis of video recordings of actual injuries, clinical studies (clinical findings of joint damage are studied to understand the injury mechanism, mainly through plain radiography, magnetic resonance imaging, arthroscopy, and computed tomography scans), in vivo studies (ligament strain or forces are measured to understand ligament loading patterns), cadaver studies, mathematical modelling and simulation of injury situations, and measurement/estimation from "close to injury" situations. In rare cases, injuries have even occurred during biomechanical experiments. This review describes each research approach and assesses its strengths and weaknesses in contributing to the understanding and prevention of sports injuries.

Tissue factor activates allosteric networks in factor VIIa through structural and dynamic changes.

BACKGROUND: Tissue factor (TF) promotes colocalization of enzyme (factor VIIa) and substrate (FX or FIX), and stabilizes the active conformation of FVIIa. Details on how TF induces structural and dynamic changes in the catalytic domain of FVIIa to enhance its efficiency remain elusive. OBJECTIVE: To elucidate the activation of allosteric networks in the catalytic domain of the FVIIa protease it is when bound to TF. METHODS: Long-timescale molecular dynamics simulations of FVIIa, free and in complex with TF, were executed and analyzed by dynamic network analysis. RESULTS: Allosteric paths of correlated motion from the TF contact point, Met306, in FVIIa to the active site triad can be described and quantified. In particular, the shortest paths from Met306 to Ser344 and His193 are 16% and 8% longer in free FVIIa than in TF-FVIIa, and they encompass previously undiscovered residue-residue interactions that are not likely to be inferred from mutagenesis studies. Furthermore, paths from Met306 to Ile153 (N-terminus) and Trp364, both representing hallmark residues of allostery, are 7% and 37% longer, respectively, in free FVIIa. Thus, there is significantly weaker coupling between the TF contact point and key residues in the catalytic domain of FVIIa, causing the active site triad to disintegrate in the simulation when TF is not present. CONCLUSIONS: These findings complement our current understanding of how the protease FVIIa is stimulated by TF. We demonstrate allosteric networks in the catalytic domain that are activated by TF and help to make FVIIa an efficient catalyst of FIX and FX activation.

Structural changes in factor VIIa induced by Ca2+ and tissue factor studied using circular dichroism spectroscopy.

Factor VIIa (fVIIa) is composed of four discrete domains, a gamma-carboxyglutamic acid (Gla)-containing domain, two epidermal growth factor (EGF)-like domains, and a serine protease domain, all of which appear to be involved, to different extents, in an optimal interaction with tissue factor (TF). All except the second EGF-like domain contain at least one Ca2+ binding site and many properties of fVIIa, e.g., TF and phospholipid binding and amidolytic activity, are Ca(2+)-dependent. A CD study was performed to characterize and locate the conformational changes in fVIIa induced by Ca2+ and TF binding. In addition to intact fVIIa, derivatives lacking the Gla domain or the protease domain were used. Assignment of the Ca(2+)-induced changes in the far-UV region of the fVIIa spectrum to the Gla domain could be made by comparing the CD spectra obtained with these fVIIa derivatives. The changes primarily appeared to reflect a Ca(2+)-induced ordering of alpha-helices existing in the apo state of fVIIa. This was corroborated by models of the apo and Ca2+ forms of fVIIa, obtained as difference spectra between fVIIa derivatives, were very similar to those of isolated Gla peptides from other vitamin K-dependent plasma proteins. The near-UV CD spectrum of fVIIa was dominated by aromatic residues residing in the protease domain and specific bands affected by Ca2+ were indicative of tertiary structural alterations. The formation of a fVIIa:TF complex led to secondary structural changes that appeared to be restricted to the catalytic domain, possibly shedding light on the mechanism by which TF induces an enhancement of fVIIa catalytic activity.

Binding of Zn2+ to a Ca2+ loop allosterically attenuates the activity of factor VIIa and reduces its affinity for tissue factor.

The protease domain of coagulation factor VIIa (FVIIa) is homologous to trypsin with a similar active site architecture. The catalytic function of FVIIa is regulated by allosteric modulations induced by binding of divalent metal ions and the cofactor tissue factor (TF). To further elucidate the mechanisms behind these transformations, the effects of Zn2+ binding to FVIIa in the free form and in complex with TF were investigated. Equilibrium dialysis suggested that two Zn2+ bind with high affinity to FVIIa outside the N-terminal gamma-carboxyglutamic acid (Gla) domain. Binding of Zn2+ to FVIIa, which was influenced by the presence of Ca2+, resulted in decreased amidolytic activity and slightly reduced affinity for TF. After binding to TF, FVIIa was less susceptible to zinc inhibition. Alanine substitutions for either of two histidine residues unique for FVIIa, His216, and His257, produced FVIIa variants with decreased sensitivity to Zn2+ inhibition. A search for putative Zn2+ binding sites in the crystal structure of the FVIIa protease domain was performed by Grid calculations. We identified a pair of Zn2+ binding sites in the Glu210-Glu220 Ca2+ binding loop adjacent to the so-called activation domain canonical to serine proteases. Based on our results, we propose a model that describes the conformational changes underlying the Zn2+-mediated allosteric down-regulation of FVIIa's activity.

Assignment of side-chain conformation using adiabatic energy mapping, free energy perturbation, and molecular dynamic simulations.

NMR spectroscopic analysis of the C-terminal Kunitz domain fragment (alpha3(VI)) from the human alpha3-chain of type VI collagen has revealed that the side chain of Trp21 exists in two unequally populated conformations. The major conformation (M) is identical to the conformation observed in the X-ray crystallographic structure, while the minor conformation (m) cannot structurally be resolved in detail by NMR due to insufficient NOE data. In the present study, we have applied: (1) rigid and adiabatic mapping, (2) free energy simulations, and (3) molecular dynamic simulations to elucidate the structure of the m conformer and to provide a possible pathway of the Trp21 side chain between the two conformers. Adiabatic energy mapping of conformations of the Trp21 side chain obtained by energy minimization identified two energy minima: One corresponding to the conformation of Trp21 observed in the X-ray crystallographic structure and solution structure of alpha3(VI) (the M conformation) and the second corresponding to the m conformation predicted by NMR spectroscopy. A transition pathway between the M and m conformation is suggested. The free-energy difference between the two conformers obtained by the thermodynamic integration method is calculated to 1.77+/-0.7 kcal/mol in favor of the M form, which is in good agreement with NMR results. Structural and dynamic properties of the major and minor conformers of the alpha3(VI) molecule were investigated by molecular dynamic. Essential dynamics analysis of the two resulting 800 ps trajectories reveals that when going from the M to the m conformation only small, localized changes in the protein structure are induced. However, notable differences are observed in the mobility of the binding loop (residues Thr13-Ile18), which is more flexible in the m conformation than in the M conformation. This suggests that the reorientation of Trp2 might influence the inhibitory activity against trypsin, despite the relative large distance between the binding loop and Trp21.

A (His)6-tagged recombinant barley (Hordeum vulgare L.) endosperm ADP-glucose pyrophosphorylase expressed in the baculovirus-insect cell system is insensitive to allosteric regulation by 3-phosphoglycerate and inorganic phosphate.

ADP-glucose pyrophosphorylase from photosynthetic tissue is allosterically regulated by 3-phosphoglycerate and inorganic phosphate. In contrast, data from our laboratory indicated that the major AGPase from barley seeds is insensitive to these regulators. Verification of this conclusion has, however, been hindered by the proteolytic degradation of the enzyme from seeds. This report characterizes the barley seed AGPase expressed in the baculovirus-insect cell system, confirming that lack of allosteric regulation by 3-PGA/Pi is an intrinsic property of the enzyme. Purification of the enzyme was by Ni2+-NTA agarose chromatography using a (His)6 tag attached to the N-terminus of the small AGPase subunit.

Protein secondary structure and homology by neural networks. The alpha-helices in rhodopsin.

Neural networks provide a basis for semiempirical studies of pattern matching between the primary and secondary structures of proteins. Networks of the perceptron class have been trained to classify the amino-acid residues into two categories for each of three types of secondary feature: alpha-helix or not, beta-sheet or not, and random coil or not. The explicit prediction for the helices in rhodopsin is compared with both electron microscopy results and those of the Chou-Fasman method. A new measure of homology between proteins is provided by the network approach, which thereby leads to quantification of the differences between the primary structures of proteins.