The injury patterns, management and outcomes of retroperitoneal haemorrhage caused by lumbar arterial bleeding at a Level-1 Trauma Centre: A 10-year retrospective review.

PURPOSE: Haemorrhagic shock remains a leading preventable cause of death amongst trauma patients. Failure to identify retroperitoneal haemorrhage (RPH) can lead to irreversible haemorrhagic shock. The arteries of the middle retroperitoneal region (i.e., the 1st to 4th lumbar arteries) are complicit in haemorrhage into the retroperitoneal space. However, predictive injury patterns and subsequent management implications of haemorrhage secondary to bleeding of these arteries is lacking. MATERIALS AND METHODS: We performed a retrospective cohort study of patients diagnosed with retroperitoneal haemorrhage who presented to our Level-1 Trauma Centre (2009-2019). We described the associated injuries, management and outcomes relating to haemorrhage of lumbar arteries (L1-4) from this cohort to assess risk and management priorities in non-cavitary haemorrhage compared to RPH due to other causes. RESULTS: Haemorrhage of the lumbar arteries (LA) is associated with a higher proportion of lumbar transverse process (TP) fractures. Bleeding from branches of these vessels is associated with lower systolic blood pressure, increased incidence of massive transfusion, higher shock index, and a higher Injury Severity Score (ISS). A higher proportion of patients in the LA group underwent angioembolisation when compared to other causes of RPH. CONCLUSION: This study highlights the injury patterns, particularly TP fractures, in the prediction, early detection and management of haemorrhage from the lumbar arteries (L1-4). Compared to other causes of RPH, bleeding of the LA responds to early, aggressive haemorrhage control through angioembolisation. These injuries are likely best treated in Level-1 or Level-2 trauma facilities that are equipped with angioembolisation facilities or hybrid theatres to facilitate early identification and management of thoracolumbar bleeds.

Maternal hypomagnesemia alters hippocampal NMDAR subunit expression and programs anxiety-like behaviour in adult offspring.

It is well established that maternal undernutrition and micronutrient deficiencies can lead to altered development and behaviour in offspring. However, few studies have explored the implications of maternal Mg deficiency and programmed behavioural and neurological outcomes in offspring. We used a model of Mg deficiency (prior to and during pregnancy and lactation) in CD1 mice to investigate if maternal Mg deficiency programmed changes in behaviour and NMDAR subunit expression in offspring. Hippocampal tissue was collected at postnatal day 2 (PN2), PN8, PN21 and 6 months, and protein expression of NMDAR subunits GluN1, GluN2A and GluN2B was determined. At 6 months of age, offspring were subject to behavioural tasks testing aspects of anxiety-like behaviour, memory, and neophobia. Maternal hypomagnesemia was associated with increased GluN1, GluN2A and GluN2B subunit expression in female offspring at 6 months, but decreased GluN1 and GluN2A expression in males. The GluN2B:GluN2A expression ratio was increased in both sexes. Male (but not female) offspring from Mg-deficient dams showed anxiety-like behaviour, with reduced head dips (Suok test), and reduced exploration of open arms (elevated plus maze). Both male and female offspring from Mg-deficient dams also showed impaired recognition memory (novel object test). These findings suggest that maternal Mg deficiency can result in behavioural deficits in adult life, and that these changes may be related to alterations in hippocampal NMDA receptor expression.

Two distinct superconducting phases in LiFeAs.

A non-trivial temperature evolution of superconductivity including a temperature-induced phase transition between two superconducting phases or even a time-reversal symmetry breaking order parameter is in principle expected in multiband superconductors such as iron-pnictides. Here we present scanning tunnelling spectroscopy data of LiFeAs which reveal two distinct superconducting phases: at = 18 K a partial superconducting gap opens, evidenced by subtle, yet clear features in the tunnelling spectra, i.e. particle-hole symmetric coherence peak and dip-hump structures. At Tc = 16 K, these features substantiate dramatically and become characteristic of full superconductivity. Remarkably, the distance between the dip-hump structures and the coherence peaks remains practically constant in the whole temperature regimeT ≤ . This rules out the connection of the dip-hump structures to an antiferromagnetic spin resonance.

Maternal hypomagnesemia alters renal function but does not program changes in the cardiovascular physiology of adult offspring.

Maternal undernutrition is known to adversely impact fetal health and development. Insults experienced in utero alter development of the fetus as it adapts to microenvironment stressors, leading to growth restriction and subsequent low birth weight. Infants born small for gestational age have significantly increased risk of developing cardiovascular and renal disease in later life, an effect that is often characterized by hypertension and reduced glomerular number. Maternal magnesium (Mg2+) deficiency during pregnancy impairs fetal growth, however, the long-term health consequences for the offspring remain unknown. Here, we used a mouse model of dietary Mg2+ deficiency before and during pregnancy to investigate cardiovascular and renal outcomes in male and female adult offspring at 6 months of age. There were no differences between groups in 24-h mean arterial pressure or heart rate as measured by radiotelemetry. Cardiovascular responses to aversive (restraint, dirty cage switch) and non-aversive (feeding response) stressors were also similar in all groups. There were no differences in nephron number, however, Mg2+-deficient offspring had increased urine flow (in both males and females) and reduced Mg2+ excretion (in males only). Despite evidence suggesting that maternal nutrient restriction programs for hypertension in adult offspring, we found that a moderate level of maternal dietary Mg2+ deficiency did not program for a nephron deficit, or alter cardiovascular function at 6 months of age. These data suggest there are no long-term adverse outcomes for the cardiovascular health of offspring of Mg2+ deficient mothers.

Maternal hypomagnesemia causes placental abnormalities and fetal and postnatal mortality.

INTRODUCTION: Magnesium (Mg(2+)) is essential for cellular growth and the maintenance of normal cellular processes. However, little is known about how maternal hypomagnesemia during pregnancy affects fetal growth and development. This study investigated the effects of maternal hypomagnesemia on the late gestation placenta and fetus, and postnatal outcomes until weaning. METHODS: Female CD1 mice consumed a control (0.2% w/w Mg(2+)), moderately Mg(2+) deficient (MMD; 0.02% w/w Mg(2+)) or severely Mg(2+) deficient (SMD; 0.005% w/w Mg(2+)) diet for 4 weeks prior to mating and throughout pregnancy. Dams were killed at E18.5 for embryonic studies or allowed to litter naturally and the offspring studied up to postnatal day 21. RESULTS: At E18.5, both Mg(2+) deficient diets decreased maternal plasma and bone Mg(2+) but only the SMD diet decreased fetal plasma Mg(2+). Maternal hypomagnesemia led to fetal loss and fetal growth restriction. Maternal Mg(2+) deficiency increased placental glycogen cell area and decreased spongiotrophoblast cell area while upregulating mRNA expression of the MagT1 Mg(2+) transporter in spongiotrophoblast cells. The SMD animals also displayed instances of gross placental abnormalities. After birth, pups in the SMD group had increased early postnatal mortality and failed to thrive. Pups in the MMD group underwent catch-up growth but remained shorter than controls at PN21 and were hypomagnesemic and hypoglycemic. CONCLUSIONS: These changes suggest that maternal Mg(2+) deficiency during pregnancy impairs placental development and fetal growth, which may have long-term health consequences for offspring. Collectively, these results have important implications for women who are Mg(2+) deficient during pregnancy.

Observation of the waveguide resonance in a periodically patterned high refractive index broadband antireflection coating.

Grating waveguide structures have been prepared by the deposition of a high refractive index broadband antireflection coating onto a patterned fused silica substrate. Aluminum oxide and hafnium oxide as well as mixtures thereof have been used as coating materials. Optical reflection measurements combined with atomic force microscopy have been used to characterize the structures. Upon illumination with a TE wave, the best structure shows a narrow reflection peak located at 633 nm at an incidence angle of about 17°. The peak reflectance of that sample accounts for more than 89%. Off-resonance interference structures appear strongly suppressed in the spectrum between 450 and 800 nm because of the characteristics of the designed antireflection layer. The structure thus possesses a notch filter spectral characteristic in a broad spectral range.

Design and properties of a cryogenic dip-stick scanning tunneling microscope with capacitive coarse approach control.

We present the design, setup, and operation of a new dip-stick scanning tunneling microscope. Its special design allows measurements in the temperature range from 4.7 K up to room temperature, where cryogenic vacuum conditions are maintained during the measurement. The system fits into every (4)He vessel with a bore of 50 mm, e.g., a transport dewar or a magnet bath cryostat. The microscope is equipped with a cleaving mechanism for cleaving single crystals in the whole temperature range and under cryogenic vacuum conditions. For the tip approach, a capacitive automated coarse approach is implemented. We present test measurements on the charge density wave system 2H-NbSe2 and the superconductor LiFeAs which demonstrate scanning tunneling microscopy and spectroscopy data acquisition with high stability, high spatial resolution at variable temperatures and in high magnetic fields.

Dual resonance excitation system for the contact mode of atomic force microscopy.

We propose an improved system that enables simultaneous excitation and measurements of at least two resonance frequency spectra of a vibrating atomic force microscopy (AFM) cantilever. With the dual resonance excitation system it is not only possible to excite the cantilever vibrations in different frequency ranges but also to control the excitation amplitude for the individual modes. This system can be used to excite the resonance frequencies of a cantilever that is either free of the tip-sample interactions or engaged in contact with the sample surface. The atomic force acoustic microscopy and principally similar methods utilize resonance frequencies of the AFM cantilever vibrating while in contact with the sample surface to determine its local elastic modulus. As such calculation demands values of at least two resonance frequencies, two or three subsequent measurements of the contact resonance spectra are necessary. Our approach shortens the measurement time by a factor of two and limits the influence of the AFM tip wear on the values of the tip-sample contact stiffness. In addition, it allows for in situ observation of processes transpiring within the AFM tip or the sample during non-elastic interaction, such as tip fracture.

Imaging macrophages in trehalose with SIMS.

Phagocytosis is a major component of the animal immune system where apoptotic cellular material, metabolites, and waste are safely processed. Further, efficient phagocytosis by macrophages is key to maintaining healthy vascular systems and preventing atherosclerosis. Single-cell images of macrophage phagocytosis of red blood cells, RBCs, and polystyrene microspheres have been chemically mapped with TOF-SIMS. We demonstrate here cholesterol and phosphocholine localizations as relative to time and activity.

HPV-16 E5 oncoprotein upregulates lipid raft components caveolin-1 and ganglioside GM1 at the plasma membrane of cervical cells.

High-risk human papillomaviruses (HPVs), especially HPV-16, play a primary role in the pathogenesis of cervical cancer. HPV-16 encodes the E5, E6 and E7 oncoproteins. Although the biological functions of E5 are poorly understood, recent studies indicate that its expression correlates with papillomavirus oncogenicity. In this study we demonstrate that the HPV-16 E5 oncoprotein increases plasma membrane expression of caveolin-1, which is a constituent of lipid rafts and regulator of cell signaling, and that this phenotype is mediated by the C-terminal 10 amino acids of E5. Moreover, E5 (but not mutant E5) induces a 23- to 40-fold increase in the lipid raft component, ganglioside GM1, on the cell surface and mediates a dramatic increase in caveolin-1/GM1 association. Since gangliosides strongly inhibit cytotoxic T lymphocytes, block immune synapse formation and are expressed at high levels on the surface of many tumor cells, our results suggest a potential mechanism for immune evasion by the papillomaviruses. Additionally, surface gangliosides are known to enhance proliferative signaling by the epidermal growth factor (EGF) receptor, providing a possible mechanistic basis for observations that EGF signaling is enhanced in E5-expressing cells. Finally, the upregulation of caveolin-1 and ganglioside GM1 at the plasma membrane of E5-expressing cervical cells provides potential new therapeutic targets and diagnostic markers for high-risk HPV infections.

RING finger-dependent ubiquitination by PRAJA is dependent on TGF-beta and potentially defines the functional status of the tumor suppressor ELF.

In gastrointestinal cells, biological signals for transforming growth factor-beta (TGF-beta) are transduced through transmembrane serine/threonine kinase receptors that signal to Smad proteins. Smad4, a tumor suppressor, is often mutated in human gastrointestinal cancers. The mechanism of Smad4 inactivation, however, remains uncertain and could be through E3-mediated ubiquitination of Smad4/adaptor protein complexes. Disruption of ELF (embryonic liver fodrin), a Smad4 adaptor protein, modulates TGF-beta signaling. We have found that PRAJA, a RING-H2 protein, interacts with ELF in a TGF-beta-dependent manner, with a fivefold increase of PRAJA expression and a subsequent decrease in ELF and Smad4 expression, in gastrointestinal cancer cell lines (P < 0.05). Strikingly, PRAJA manifests substantial E3-dependent ubiquitination of ELF and Smad3, but not Smad4. Delta-PRAJA, which has a deleted RING finger domain at the C terminus, abolishes ubiquitination of ELF. A stable cell line that overexpresses PRAJA exhibits low levels of ELF in comparison to a Delta-PRAJA stable cell line, where ELF expression is high compared to normal controls. The alteration of ELF and/or Smad4 expression and/or function in the TGF-beta signaling pathway may be induced by enhancement of ELF degradation, which is mediated by a high-level expression of PRAJA in gastrointestinal cancers. In hepatocytes, half-life (t(1/2)) and rate constant for degradation (k(D)) of ELF is 1.91 h and 21.72 min(-1) when coupled with ectopic expression of PRAJA in cells stimulated by TGF-beta, compared to PRAJA-transfected unstimulated cells (t(1/2) = 4.33 h and k(D) = 9.6 min(-1)). These studies reveal a mechanism for tumorigenesis whereby defects in adaptor proteins for Smads, such as ELF, can undergo degradation by PRAJA, through the ubiquitin-mediated pathway.

Regions of allelic imbalance in the distal portion of chromosome 12q in gastric cancer.

AIMS: To define regions of loss on the distal portion of chromosome 12q in gastric adenocarcinoma. METHODS: Microsatellite analysis on chromosome 12 was performed on 19 human gastric cancer cell lines using 77 markers, 71 of which were within or distal to 12q21; some portions of this region showed extended regions of homozygosity (ERHs) in 10 of 19 gastric cancer cell lines. In addition, microdissected tumour cells from 76 primary gastric adenocarcinomas were examined using 13 markers of interest implicated by the cell line data; 70% of these showed allelic imbalance (AI) at one or more markers in or distal to 12q21. RESULTS: Mapping ERHs in the cell lines and sites of AI in the tumours identified three regions that contain putative tumour suppressor genes: region A is located within 2.8 Mb between markers D12S1667 and D12S88; region B, within 1.9 Mb between markers D12S1607 and D12S78; and region C, in 0.74 Mb between markers D12S342 and D12S324. Fluorescence in situ hybridisation (FISH) analysis in two cell lines confirmed that two of the ERHs reflected deletions, not amplifications, of D12S81 in region A and D12S340 in region C. FISH analysis of marker D12S1075 within an ERH containing region B in one cell line showed neither amplification nor deletion. AI on 12q was not associated with prognosis, but was associated with ethnicity of the patient. CONCLUSIONS: These results identify regions on chromosome 12 that appear to contain tumour suppressor genes important in the development of gastric cancer.

Expression of the bovine papillomavirus type 1 E5B gene reveals a protein-protein interaction of the E5A and E5B gene products.

The bovine papillomavirus type 1 (BPV-1) genome has been shown to contain a small open-reading frame designated E5B (nucleotides 4013-4167) which is predicted to encode a hydrophobic, 52 amino acid protein. In order to detect and characterize the E5B protein, an 18 nucleotide sequence encoding a 6 amino acid epitope was added to the 3' end of the E5B open-reading frame which was then expressed in COS-1 cells using a SV40 vector. Immunoprecipitation, immunofluorescence, and cell fractionation studies identified the E5B protein as a 4-kDa protein and localized it primarily to membranes of the endoplasmic reticulum and nucleus. Unlike the E5A protein of BPV-1, E5B did not form dimers (despite containing a cysteine residue) or form complexes with growth factor receptors such as the PDGF receptor or erb B-2 receptor. Interestingly, the E5B protein formed physical complexes with the hydrophobic E5A oncoprotein, apparently via transmembrane interactions. Additionally, expression of E5B inhibited the transforming capability of BPV-1 E5A. These observations suggest that the expression of this viral protein may play a significant role in BPV/host cell interactions.

Coagulation changes in individuals with sickle cell trait.

Sickle cell disorders, such as Hb SS and Hb SC, are associated with a hypercoagulable state that may contribute to the vaso-occlusive episodes observed in the disorders. To what extent increased coagulation activity occurs in individuals with sickle cell trait has had limited study. Because such information may help clarify clinical and pathologic findings that may occur in these individuals and may be useful in clarifying the hypercoagulable state in sickle cell disease, we have examined individuals with Hb AS to determine the extent that increased coagulation activity does occur. We measured d-dimers, thrombin-antithrombin (TAT) complexes, prothrombin fragment 1.2 (F1.2), absolute blood monocyte levels, proteins C and S, and isotypes of antiphospholipid antibodies in individuals with Hb AS and in matched controls (Hb AA). Results showed that d-dimers, TAT, and F1.2 were increased significantly above normal levels. Absolute blood monocyte levels were increased. The d-dimers, TAT, F1.2, and monocyte counts showed significant increasing trends through groups of increasing severity (Hb AA, Hb AS, Hb SC, and Hb SS). Our study shows that individuals with Hb AS have increased coagulation activity, with d-dimers, TAT, and F1.2 being consistent indicators. The measures of coagulation activity in Hb AS are lower than in patients with Hb SC and Hb SS disease. These results extend our previous observation that the degree of coagulation activation parallels the degree of disease severity among sickle cell genotypes. The findings suggest that monocytosis, with the possible expression of monocyte-derived tissue factor, and the associated hypercoagulable state are driven by disease severity.

Results of reoperations in colorectal anastomotic strictures.

PURPOSE: The incidence of colorectal anastomotic strictures varies from 3 to 30 percent. Most of these anastomotic strictures are simple narrowings shorter than 1 cm that can be successfully treated by dilation or endoscopic alternatives. However, up to 28 percent of patients will require surgical correction. This can be technically difficult, with the possibility of a permanent colostomy. This study reports the outcomes after operative treatment of severe strictures of colorectal anastomoses. METHODS: From August 1992 to October 1996, 27 patients were referred for surgical treatment of severe rectal anastomotic strictures. The reasons for the initial surgery were as follows: rectal cancer (13), diverticular disease (7), Hirschsprung's disease (2), rectal endometriosis (2), uterine carcinoma with rectal invasion (1), ruptured abdominal aortic aneurysm with rectosigmoid necrosis (1), and rectovaginal fistula (1). There were 15 (56 percent) stapled anastomoses, and 21 (78 percent) patients had developed a postoperative leak. RESULTS: The median time between initial surgery and diagnosis of the stenosis was 7.2 (range, 1-24) months and between the last operation and referral was 15.1 (range, 1-44) months. Stenosis was located at a mean distance of 9.5 (range, 4-15) cm from the anal verge. Eleven patients (41 percent) had been unsuccessfully dilated before referral. Surgical correction of the stenosis required 7 colorectal anastomoses for upper rectal anastomotic strictures and 20 coloanal anastomoses for middle and lower rectal strictures (19 Soave's procedures and 1 colon J-pouch-anal anastomosis). Intestinal continuity was restored in all cases. After a mean follow-up of 28.7 +/- 14 months, no recurrences were detected and functional results were satisfactory. CONCLUSIONS: Resection of the stenosis and construction of a new colorectal anastomosis can be performed successfully for upper rectal anastomotic stricture. For a stenosis located in the middle and lower rectum, Soave's procedure offers a good alternative, with satisfactory long-term functional results. Whichever technique is used, a permanent colostomy should rarely be required.

Phosphatidylserine, a death knell.

Virtually every cell in the body restricts phosphatidylserine (PS) to the inner leaflet of the plasma membrane by energy-dependent transport from the outer to the inner leaflet of the bilayer. Apoptotic cells of all types rapidly randomize the asymmetric distribution, bringing PS to the surface where it serves as a signal for phagocytosis. A myriad of phagocyte receptors have been implicated in the recognition of apoptotic cells, among them a PS receptor, yet few ligands other than PS have been identified on the apoptotic cell surface. Since apoptosis and the associated exposure of PS on the cell surface is probably over 600 million years old, it is not surprising that evolution has appropriated aspects of this process for specialized purposes such as blood coagulation, membrane fusion and erythrocyte differentiation. Failure to efficiently remove apoptotic cells may contribute to inflammatory responses and autoimmune diseases resulting from chronic, inappropriate exposure of PS.

Cation selective ion channels formed by macrodiolide antibiotic elaiophylin in lipid bilayer membranes.

The macrodiolide antibiotic elaiophylin (1) forms stable, long-lasting cation selective ion channels in planar lipid bilayer membranes prepared from soybean phosphatidylcholine. Current of the single ion channel displayed two sublevels corresponding to the two substates of the channel conductance: a slow substate, with about 5 s of mean dwell time in the open state at 40% level of the total amplitude conductance, and a fast substate of higher conductance with dwell times in the open and closed state of about 0.1 s. Amplitude conductances of the single ion channels in 200 mM of LiCl, NaCl, KCl, RbCl and CsCl were 75, 140, 220, 240 and 226 pS, and the conductance was linear function of the electrolyte concentration. Ratios of cation to anion permeabilities of the channel for NaCl and KCl were 8+/-2 and >24, respectively. A molecular model of the channel structure is suggested.