bluuebunny/crossref_metadata_2025_split huggingface dataset:
Limited tolerance towards folded elements during secretion of the autotransporter Hbp
Authors: Jong Wouter S. P. , Ten Hagen‐Jongman Corinne M. , Den Blaauwen Tanneke , Jan Slotboom Dirk , Tame Jeremy R. H. , Wickström David , De Gier Jan‐Willem , Otto Ben R. , Luirink Joen 
Published: February 2007

SummaryMany virulence factors secreted by pathogenic Gram‐negative bacteria belong to the autotransporter (AT) family. ATs consist of a passenger domain, which is the actual secreted moiety, and a β‐domain that facilitates the transfer of the passenger domain across the outer membrane. Here, we analysed folding and translocation of the AT passenger, using Escherichia coli haemoglobin protease (Hbp) as a model protein. Dual cysteine mutagenesis, instigated by the unique crystal structure of the Hbp passenger, resulted in intramolecular disulphide bond formation dependent on the periplasmic enzyme DsbA. A small loop tied off by a disulphide bond did not interfere with secretion of Hbp. In contrast, a bond between different domains of the Hbp passenger completely blocked secretion resulting in degradation by the periplasmic protease DegP. In the absence of DegP, a translocation intermediate accumulated in the outer membrane. A similar jammed intermediate was formed upon insertion of a calmodulin folding moiety into Hbp. The data suggest that Hbp can fold in the periplasm but must retain a certain degree of flexibility and/or modest width to allow translocation across the outer membrane.
An experimentalist's guide to computational modelling of the Min system
Authors: Kruse Karsten , Howard Martin , Margolin William 
Published: February 2007

SummarySpatio‐temporal oscillations of the Min proteins are essential for selecting the cell division site in Escherichia coli. These oscillations are a key example of a biological phenomenon that can only be understood on a systems level rather than on the level of its individual components. Here, we review the key concepts that mathematical modelling has added to our understanding of the Min system. While several different mechanisms have been proposed, in all cases the oscillations emerge from a dynamic instability of a uniform protein distribution. To generate this instability, however, the various mechanisms rely on different features of Min protein interactions and transport. We critically evaluate these mechanisms in light of recent experimental evidence. We also review the effects of fluctuations caused by low cellular concentration of Min proteins, and describe how stochastic effects may potentially influence Min protein dynamics.
MerR family transcription activators: similar designs, different specificities
Authors: Hobman Jon L. 
Published: February 2007

SummaryLiving organisms use metals for a variety of essential functions, and face the problems of how to acquire and regulate the intracellular levels of those metals they need, differentiate between essential and toxic metals, and remove from the cell or detoxify metals that are toxic. In bacteria, cytoplasmic metal ion responsive transcriptional regulators are important in regulating the expression of genes involved in metal ion homeostasis and efflux systems. The MerR family of transcriptional activators are metal sensing regulators that are found in different bacteria and have a common design, but have evolved to recognize and respond to different metals. In this issue of Molecular Microbiology, work by Checa and colleagues describes for the first time a gold‐specific MerR family regulator named GolS from Salmonella enterica serovar Typhimurium that controls the production of an efflux pump and a metal chaperone protein that confer resistance to Au salts.
Specificity determinants of conjugative DNA processing in the Enterococcus faecalis plasmid pCF10 and the Lactococcus lactis plasmid pRS01
Authors: Chen Yuqing , Staddon Jack H. , Dunny Gary M. 
Published: February 2007

SummaryThe DNA‐processing region of the Enterococcus faecalis pheromone‐responsive plasmid pCF10 is highly similar to that of the otherwise unrelated plasmid pRS01 from Lactococcus lactis. A transfer‐proficient pRS01 derivative was unable to mobilize plasmids containing the pCF10 origin of transfer, oriT. In contrast, pRS01 oriT‐containing plasmids could be mobilized by pCF10 at a low frequency. Relaxases PcfG and LtrB were both capable of binding to single‐stranded oriT DNAs; LtrB was highly specific for its cognate oriT, whereas PcfG could recognize both pCF10 and pRS01 oriT. However, pcfG was unable to complement an ltrB insertion mutation. Genetic analysis showed that pcfF of pCF10 and ltrF of pRS01 are also essential for plasmid transfer. Purified PcfF and LtrF possess double‐stranded DNA binding activities for the inverted repeat within either oriT sequence. PcfG and LtrB were recruited into their cognate F–oriT DNA complex through direct interactions with their cognate accessory protein. PcfG also could interact with LtrF when pCF10 oriT was present. In vivo cross‐complementation analysis showed that ltrF partially restored the pCF10ΔpcfF mutant transfer ability when provided in trans, whereas pcfF failed to complement an ltrF mutation. Specificity of conjugative DNA processing in these plasmids involves both DNA–protein and protein–protein interactions.
Crystal structure of a novel prokaryotic Ser/Thr kinase and its implication in the Cpx stress response pathway
Authors: Zheng Jimin , He Chunhua , Singh Vinay Kumar , Martin Nancy L. , Jia Zongchao 
Published: February 2007

SummaryThe Cpx signalling system of Escherichia coli and Salmonella enterica senses extracytoplasmic stress and controls expression of factors that allow the bacterium to adapt to these stressors and thereby enhance survival. Many of the Cpx‐responsive genes products are of unknown function. We determined the crystal structure of one of these gene products, called YihE in E. coli, which exhibits a eukaryotic kinase fold. Functional assays established that both YihE and the S. enterica YihE homologue, RdoA, undergo autophosphorylation and phosphorylate protein substrates at Ser/Thr residues in vitro, demonstrating that YihE/RdoA is a novel Ser/Thr protein kinase in prokaryotic cells. Phenotypic analysis of yihE/rdoA null strains indicates that this kinase is most abundant in stationary phase, and is important for long‐term cell survival and for expression of surface appendages in both a Cpx‐independent and ‐dependent manner. YihE/RdoA is therefore a previously unknown kinase component of a new type of bacterial phosphorelay mechanism, adding kinase activity as another response to the Cpx sensing system that functions to maintain cellular homeostasis.
Long‐term functional outcome of macular hole surgery correlated to optical coherence tomography measurements
Authors: Haritoglou Christos , Neubauer Aljoscha S , Reiniger Ingrid W , Priglinger Siegfried G , Gass Carolin A , Kampik Anselm 
Published: February 2007

AbstractObjective:  Evaluation of long‐term functional outcome after macular hole surgery and its correlation with postoperative optical coherence tomography (OCT).Methods:  Before and after surgery a complete clinical examination and OCT were performed in 38 patients. Best corrected postoperative visual acuity (VA) was correlated to the following OCT parameters: preoperative base and minimum diameter of the hole, hole height, hole form factor, retinal thickness and nerve‐fibre layer measurements postoperatively, postoperative foveal contour, appearance of retinal pigment epithelium layer and photoreceptor layer.Results:  Over a mean follow up of 67 months, VA improved significantly (P = 0.01). Retinal thickness and retinal thickness and nerve‐fibre layer measurements of the operated eye did not differ from fellow eye. A negative correlation was seen between final VA and preoperative base diameter of the hole (r = −0.41, P = 0.02) and hole height (r = −0.45, P = 0.01). The correlation between hole form factor values and final VA (r = 0.36, P = 0.04) was weak. Appearance of the photoreceptor band was the only OCT parameter significantly correlating with final VA (r = −0.42, P = 0.01) and explaining the observed increase (r = −0.32, P = 0.05) in VA.Conclusion:  Appearance of the photoreceptor layer on postoperative OCT correlates to functional outcome and may help to explain cases of unsatisfactory postoperative VA despite successful hole closure.
Alterations of retinal pigment epithelium in central serous chorioretinopathy
Authors: Hirami Yasuhiko , Tsujikawa Akitaka , Sasahara Manabu , Gotoh Norimoto , Tamura Hiroshi , Otani Atsushi , Mandai Michiko , Yoshimura Nagahisa 
Published: February 2007

AbstractBackground:  To examine with en face optical coherence tomography (OCT) the alterations of retinal pigment epithelium (RPE) in central serous chorioretinopathy (CSC) and their role in the pathophysiology of CSC.Methods:  We examined retrospectively 30 consecutive eyes of 30 patients with various phases of CSC. All patients underwent fluorescein angiography, indocyanine green angiography, and en face and longitudinal OCT examinations.Results:  Of 25 eyes with acute CSC, en face OCT showed RPE abnormalities in 22 eyes (88%) with pigment epithelial detachment (PED) in nine eyes (36%) and a small bulge of RPE in the posterior pole in 15 eyes (60%). Of four eyes with chronic CSC, OCT showed PED in one eye (25%) and a small bulge of RPE in other three eyes (75%). Of 29 eyes with acute or chronic CSC, fluorescein angiography showed characteristic pinpoint leakage in 20 eyes (69%). Of these 20 eyes, a leaking point was located within PEDs in five eyes (25%) and was consistent with the bulge of RPE in nine eyes (45%). With indocyanine green angiography, 28 (97%) eyes showed choroidal vascular hyperpermeability. Ten of the 11 eyes with PED (91%) showed PED within the areas of choroidal vascular hyperpermeability. Sixteen of the 18 eyes with a bulge of RPE (89%) showed the bulge within areas of choroidal vascular hyperpermeability. The one eye in the quiescent CSC exhibited multiple small PEDs within the areas of choroidal vascular hyperpermeability by en face OCT.Conclusions:  En face OCT enables us to detect alterations of RPE in eyes with CSC. Most alterations of RPE were associated with choroidal abnormalities.
Blepharophimosis–ptosis–epicanthus inversus syndrome: objective analysis of surgical outcome in patients from a single unit
Authors: Taylor Alexandra , Strike Paul W , Tyers Anthony G 
Published: February 2007

AbstractBackground:  The aim was to objectively assess surgical outcome in blepharophimosis–ptosis–epicanthus inversus syndrome (BPES).Method:  Retrospective review of 14 consecutive patients with BPES. Mustardé double z plasty (at about age 4) and autogenous fascia lata Crawford brow suspension (9–12 months later) were used in all. One consultant performed all operations. Patient photographs were scanned and magnified for analysis. Preoperative and postoperative intercanthal distance, vertical palpebral aperture and cosmetic outcome were measured. Values were converted into ratios.Results:  Bilateral (mildly asymmetrical) ptosis and symmetrical epicanthic folds were found in all preoperatively. Seventy‐one per cent had severe folds. Preoperative intercanthal distance ratio range was 1.26–1.60 (non‐BPES = 1.0). Median reduction post surgery was 26% (P = 0.001, Wilcoxon’s signed ranks test). Patients with largest preoperative ratio displayed greatest correction (P = 0.029). Mustardé technique completely abolished all epicanthic folds and unmasked prominent caruncles in all. Fifty per cent had mild scarring postoperatively in the medial canthal region. Median change in marginal reflex distance ratio (right) = 22.2% (P = 0.012), left = 18.2% (P = 0.008), Wilcoxon’s signed ranks tests. Postoperatively all had formed eyelid creases with improved upper lid position symmetry.Conclusions:  This is the first known study objectively assessing surgical outcome in BPES. Mustardé double z plasty and Crawford autogenous fascia lata brow suspension are an effective surgical combination in the treatment of this syndrome, with overall cosmetic benefit.
Traumatic intralenticular abscess: a case series
Authors: Salman Amjad , Parmar Pragya , Philip Vinitha R , Thomas Philip A , Jesudasan Christdas AN 
Published: February 2007

AbstractPurpose:  To report the clinical presentation, management and outcome of eyes with traumatic intralenticular abscess.Methods:  In this interventional case series, records of eight patients (eight eyes) with intralenticular abscess developing following trauma were reviewed. All patients underwent extracapsular cataract extraction with intracameral antibiotics with or without pars plana vitrectomy. Main outcome measures studied were resolution of infection and final visual outcome.Results:  Lens abscess developed in six eyes following penetrating injury and in two eyes following intraocular penetration of caterpillar hair. Gram positive cocci were cultured from the lens aspirate in five eyes and Staphylococcus epidermidis was the most common organism isolated. Cataract extraction resulted in control of the infection in all eyes and seven eyes (87.5%) had a favourable visual outcome.Conclusion:  Early lens extraction with intracameral antibiotics in eyes with intralenticular abscess allows control of infection with good visual outcome.
SKIN GRAFT FAILURE IS PREDICTED BY WAIST–HIP RATIO: A MARKER FOR METABOLIC SYNDROME
Authors: Penington Anthony J. , Morrison Wayne A. 
Published: February 2007

Background:  Obesity is recognized as a risk factor for wound healing problems in surgery, but the reason for this increased risk is unclear. It is now recognized that truncal obesity, as measured by either the waist circumference or the waist–hip ratio (WHR), is a strong risk factor for an array of metabolic problems termed ‘metabolic syndrome’. It was suggested that increased WHR would be a sensitive marker of obesity‐related wound healing impairment and therefore would predict skin graft failure.Method:  Consecutive patients undergoing full‐thickness skin graft of the head and neck region in a private practice setting were enrolled prospectively. The body mass index and WHR were recorded at the time of surgery and skin graft take was assessed at 1–2 weeks.Results:  There was a strong correlation between increased WHR and graft failure; all four patients in the study having a WHR greater than 1 showed partial or total graft loss compared with only one patient having a 10% loss in the remainder (r = −0.76, P = 0.002).Conclusion:  There is a strong correlation between truncal obesity as measured by the WHR and skin graft failure. WHR or waist circumference should be considered as a preoperative assessment tool in identifying patients at risk of surgical complications.
CHANGES IN THE ABDOMINAL FAT DISTRIBUTION AFTER GASTRECTOMY: COMPUTED TOMOGRAPHY ASSESSMENT
Authors: Yoon Dae Young , Kim Hyeon Kyu , Kim Ju Ae , Choi Chul Soon , Yun Eun Joo , Chang Suk Ki , Lee Yu‐Jin , Park Chan Heun 
Published: February 2007

Background:  We investigated the postoperative changes in visceral fat, as compared with subcutaneous fat in patients who underwent total gastrectomy (TG) or subtotal gastrectomy (STG).Methods:  Thirty‐eight patients of gastric cancer who underwent abdominal and pelvic computed tomography scans before and after STG (n = 28) or TG (n = 10) were examined. The volumes of the total, visceral and subcutaneous adipose tissues (TAT, VAT and SAT, respectively) were calculated in each scan using the multislice method. Changes between the preoperative data and results obtained at 6 and 12 months after surgery were evaluated.Results:  In the first 6 months, there were significant decreases in TAT, VAT and SAT values in the TG (−2424 ± 1309, −1535 ± 1056 and −889 ± 613 cm3, respectively) and STG (−1590 ± 1309, −1024 ± 645, and −578 ± 659 cm3, respectively) groups. From 6 to 12 months after surgery, a further significant reduction in VAT (−351 ± 196 cm3) in the TG group and significant regains in TAT and SAT (850 ± 1205 and 757 ± 1032 cm3, respectively) in the STG group were observed. The ratio of VAT to SAT calculated in both groups decreased continuously in all periods of observation.Conclusion:  Patients who underwent gastrectomy lost TAT, VAT and SAT during the postoperative period up to 6 months and the decrease in VAT was greater and more persistent than the decrease in SAT, particularly in the TG group.
MEDULLARY THYROID CARCINOMA: A 20‐YEAR EXPERIENCE FROM A CENTRE IN SOUTH INDIA
Authors: Finny Philip , Jacob Jubbin J , Thomas Nihal , Philip Jim , Rajarathnam Simon , Oommen Regi , Nair Aravindan , Seshadri Mandalam S 
Published: February 2007

Background:  Management of medullary thyroid carcinoma (MTC) remains controversial despite many advances over the past five decades. We attempt to review the presentation, management and prognosis of MTC at our institution over the last two decades.Methods:  We conducted a retrospective review of the records of 40 patients with MTC over a period of 20 years.Results:  Ten patients had hereditary MTC and 30 had sporadic MTC. The mean age of presentation was 41 years. Sixty‐five per cent of the patients had a definite thyroid swelling and 43% had lymphadenopathy at the time of presentation. Total thyroidectomy with a central neck dissection was carried out in 82.5% of patients. Adjuvant therapy was given in 75% of patients because of extensive/residual disease. Postoperative hypercalcitoninaemia was seen 73% of patients. 131I metaiodobenzylguanidine scanning was carried out in 16 patients with persistent hypercalcitoninaemia; the uptake was positive in 10 and negative in 6, indicating a positivity of 62%.Conclusion:  Medullary thyroid carcinoma accounts for 2.5% of thyroid carcinomas. There is a small male preponderance. In our series 131I metaiodobenzylguanidine scan had a better positivity than what has been reported in the published work. Persistent postoperative hypercalcitoninaemia was associated with a poorer prognosis that did not reach statistical significant.
RISK FACTORS FOR POSTOPERATIVE PULMONARY COMPLICATIONS IN UPPER ABDOMINAL SURGERY
Authors: Kanat Fikret , Golcuk Ayse , Teke Turgut , Golcuk Murat 
Published: February 2007

Background:  Pulmonary complications are the most frequent cause of postoperative morbidity and mortality in upper abdominal surgery (UAS). We aimed to examine the influence of possible preoperative, operative and postoperative risk factors on the development of early postoperative pulmonary complications (POPC) after UAS.Methods:  A prospective study of 60 consecutive patients was conducted who underwent elective UAS in general surgical unit. Each patient’s preoperative respiratory status was assessed by an experienced chest physician using clinical examination, chest radiographs, spirometry and blood gas analysis . Anaesthetical risks, surgical indications, operation time, incision type, duration of nasogastric catheter and mobilization time were noted. Forty‐eight hours after the operation, pulmonary examinations of the patients were repeated.Results:  Postoperative pulmonary complications were observed in 35 patients (58.3%). The most common complication was pneumonia, followed by pneumonitis, atelectasis, bronchitis, pulmonary emboli and acute respiratory failure. The presence of preoperative respiratory symptoms and the spirometric parameter of forced expiratory volume in 1 s/forced vital capacity were the most valuable risk factors for early prediction of POPC. The sensitivity, specificity and diagnostic efficiency of the presence of preoperative respiratory symptoms in the POPC prediction were 70, 61 and 66%, respectively.Conclusion:  We recommend a detailed pulmonary examination and spirometry in patients who will undergo UAS by chest physicians to identify the patients at high risk for POPC, to manage respiratory problems of the patients before surgery and also to help surgeons to take early measures in such patients before a most likely POPC occurrence. Improvement of lung function in those patients at risk for POPC before operation may decrease morbidity in surgical patients.
EMERGENCY THORACIC SURGERY FOR PENETRATING, NON‐MEDIASTINAL TRAUMA
Authors: Loogna Peter , Bonanno Fabrizio , Bowley Douglas M. , Doll Dietrich , Girgensohn Roland , Smith Martin D. , Glapa Miriam , Degiannis Elias 
Published: February 2007

Background:  Penetrating thoracic injury is commonly found in South Africa. A review of our recent experience was undertaken to assess the effectiveness of our protocols for this type of injury.Methods:  A retrospective study of 61 consecutive patients with penetrating, non‐mediastinal trauma to the chest was conducted over 32 months at a single trauma unit. Patient details, mechanism of injury, operative procedure and in‐hospital mortality and morbidity rates were recorded.Results:  Two thousand and nineteen patients presented with penetrating chest injury of which 61 patients (3%) underwent thoracic surgery for non‐mediastinal injury. Twenty‐six patients had stab wounds and 35 had gunshot wounds. Overall mortality was 17/61 (28%). Gunshot wounds were more likely to result in death than stab wounds (relative risk = 11.9; 95% confidence interval 1.7–84.0) and thoracoabdominal injury resulted in death more commonly than chest injury (relative risk = 4.8; 95% confidence interval 2.2–10.3) resulted in death.Conclusion:  Penetrating chest injury is common and most patients can be managed without formal thoracic surgical intervention. However, the patients who do merit surgical intervention have a relatively high mortality and a rapid and practised operative approach is required to achieve acceptable results.
RISK FACTORS FOR MICROVASCULAR TUMOUR THROMBI IN HEPATOCELLULAR CARCINOMA: A UNIVARIATE AND MULTIVARIATE ANALYSIS
Authors: Ibrahim Salleh , Roychowdhury Anupama , Khoon Hean Tay 
Published: February 2007

Background:  Microvascular tumour thrombi in hepatocellular carcinoma (HCC) predict poor outcome and are a risk factor for intrahepatic and extrahepatic metastases. Survival after liver transplantation is also affected. Our aim was to predict the risk factors for the presence of microvascular tumour thrombi.Methods:  Seventy‐six patients who had undergone hepatectomy for HCC in our hospital were included in a retrospective analysis from a prospective database.Results:  Thirty‐one patients (40.8%; mean age 50.7 ± 12.2 years, P < 0.021) had microvascular tumour thrombi (group T) and 54 patients (group NT; mean age 58.6 ± 15.4 years) did not. Using logistic regression analysis, we found that more than one HCC nodule, a large tumour, chronic hepatitis C infection and high serum aspartate aminotransferaselevels were significant risk factors for microvascular tumour thrombi. Age, preoperative serum bilirubin level and sex were not significant risk factors.Conclusion:  Patients with chronic hepatitis C infection having multiple HCC nodules, large tumour size and high preoperative aspartate aminotransferase levels are at high risk for microvascular tumour thrombi.