Emergency general surgery in a public hospital in Malaysia.

INTRODUCTION: Patients undergoing emergency general surgery (EGS) are at risk for death and complications. Information on the burden of EGS is critical for developing strategies to improve the outcomes. METHODS: In this retrospective cohort study, medical records of all general surgical operations in a public hospital were reviewed for the period 1st January 2017 to 31st December 2017. Data on patient demographics, operative workload, case mix, time of surgery and outcomes were analysed. RESULTS: Of the 2960 general surgical operations that were performed in 2017, 1720 (58.1%) of the procedures were performed as emergencies. The mean age for the patients undergoing emergency general surgical procedures was 37.9 years (Standard Deviation, ±21.0), with male preponderance (57.5%). Appendicitis was the most frequent diagnosis for the emergency procedures (43%) followed by infections of the skin and soft tissues (31.6%). Disorders of the colon and rectum ranked as the third most common condition, accounting for 6.7% of the emergency procedures. Majority of emergency surgery (59.3%) took place after office hours and on weekends. Post-operative deaths and admissions to critical care facilities increased during EGS when compared to elective surgery, p<0.01. CONCLUSIONS: EGS constitutes a major part of the workload of general surgeons and it is associated significant risk for death and post-operative complications. The burden of EGS must be recognised and patient care systems must evolve to make surgery safe and efficient.

Subvolt electro-optical modulator on thin-film lithium niobate and silicon nitride hybrid platform.

A low voltage operation electro-optic modulator is critical for applications ranging from optical communications to an analog photonic link. This paper reports a hybrid silicon nitride and lithium niobate electro-optic Mach-Zehnder modulator that employs 3 dB multimode interference couplers for splitting and combining light. The presented amplitude modulator with an interaction region length of 2.4 cm demonstrates a DC half-wave voltage of only 0.875 V, which corresponds to a modulation efficiency per unit length of 2.11 V cm. The power extinction ratio of the fabricated device is approximately 30 dB, and the on-chip optical loss is about 5.4 dB.

High-performance racetrack resonator in silicon nitride - thin film lithium niobate hybrid platform.

In this paper, we propose an electro-optic modulator design in a hybrid Si3N4-X-cut LiNbO3. The modulator is based on a modified racetrack resonator and performs at both DC and heightened frequencies. Here the driving electrodes are defined along the straight section of the racetrack. This is done to maximize modulation and minimize modulation-cancelation that occurs in a conventional X-cut LiNbO3-based resonator due to the directional change of the electric field in the micro-ring. The single bus racetrack resonator is formed in a hybrid Si3N4-LiNbO3 platform, to guide the optical mode. The fabricated device is characterized and has a measured tunability and intrinsic quality factor (Q) of 2.9 pm/V and 1.3 × 105, respectively. In addition, the proposed racetrack device exhibits enhanced electro-optic conversion efficiency at modulation frequencies that match with the racetrack's optical free spectral range (FSR). For example, at the modulation frequency of 25 GHz, which corresponds to the fabricated device's optical FSR frequency, a ∼10 dB increase in electro-optic conversion efficiency is demonstrated. With the enhancement, our measured device demonstrates a conversion efficiency comparable to non-resonant thin-film LiNbO3 devices that possess RF electrodes that are 10 times longer in length.

Tunable hybrid silicon nitride and thin-film lithium niobate electro-optic microresonator.

This Letter presents, to the best of our knowledge, the first hybrid Si3N4-LiNbO3-based tunable microring resonator where the waveguide is formed by loading a Si3N4 strip on an electro-optic (EO) material of X-cut thin-film LiNbO3. The developed hybrid Si3N4-LiNbO3 microring exhibits a high intrinsic quality factor of 1.85×105, with a ring propagation loss of 0.32 dB/cm, resulting in a spectral linewidth of 13 pm, and a resonance extinction ratio of ∼27 dB within the optical C-band for the transverse electric mode. Using the EO effect of LiNbO3, a 1.78 pm/V resonance tunability near 1550 nm wavelength is demonstrated.

Vertical mode transition in hybrid lithium niobate and silicon nitride-based photonic integrated circuit structures.

This Letter presents an optical mode transition structure for use in Si3N4/LiNbO3-based hybrid photonics. A gradual modal transition from a Si3N4 waveguide to a hybrid Si3N4/LiNbO3 waveguide is achieved by etching a terrace structure into the sub-micrometer thick LiNbO3 film. The etched film is then bonded to predefined low pressure chemical vapor deposition Si3N4 waveguides. Herein we analyze hybrid optical devices both with and without the aforementioned mode transition terrace structure. Experimental and simulated results indicate that inclusion of the terrace significantly improves mode transition compared to an abrupt transition, i.e., a 1.78 dB lower mode transition loss compared to the abrupt transition. The proposed transition structure is also applied to the design of hybrid Si3N4-LiNbO3 micro-ring resonators. A high-quality factor (Q) resonator is demonstrated with the terrace transition which mitigates undesired resonances.

Polyetherimide hollow fiber membranes for CO2 absorption and stripping in membrane contactor application.

Porous asymmetric polyetherimide (PEI) hollow fiber membranes with various non-solvent additives, e.g. lithium chloride, methanol and phosphoric acid (PA) were prepared for CO2 absorption and stripping process in a membrane contractor. The PEI membranes were characterized via gas permeation, liquid entry pressure of water (LEPw), contact angle and field emission scanning electronic microscopy analysis. The CO2 absorption and stripping performance was evaluated via the membrane contactor system. Addition of non-solvent additives increased the LEPw and membrane porosity of the PEI membrane with the formation of various membrane microstructures and contact angles. Absorption test was performed at 40 °C showed that the PEI-PA membrane produced the highest absorption flux of 2.7 × 10-2 mol m-2 s-1 at 0.85 m s-1 of liquid velocity. Further testing on PEI-PA membrane was conducted on CO2 stripping at 60 °C, 70 °C to 80 °C and the results indicated that the stripping flux was lower compared to the absorption flux. Stripping tests at 80 °C produced the highest stripping flux which might due to the increase in equilibrium partial pressure of CO2 in the liquid absorbent. Modification of PEI membrane via incorporation of additive can enhanced the performance of a membrane contactor via increasing the absorption and stripping flux.

Surveillance of antibiotic and analgesic use in the Oral Surgery Department of the University Dentistry Clinical Center of Kosovo.

BACKGROUND: Because Kosovo has no reliable information on antimicrobial and analgesic use in dental practice, the survey reported here evaluated the antibiotic and analgesic prescriptions in the Oral Surgery Department of the University Dentistry Clinical Center of Kosovo (UDCCK). METHODS: The data of 2,442 registered patients for a 1-year period were screened and analyzed concerning antibiotic and analgesic use as per standards of rational prescription. RESULTS: Dentistry doctors prescribed antibiotics significantly more often than analgesics. Antibiotics were prescribed in 8.11% of all cases, while only 1.35% of total prescriptions were for analgesics. The total consumption of antibiotic drugs in the UDCCK was 4.53 Defined Daily Doses [DDD]/1,000 inhabitants/day, compared with only 0.216 DDD/1,000 inhabitants/day for analgesics. From a total number of 117 patients, 32 patients received combinations of two antibiotics. CONCLUSION: Pharmacotherapy analysis showed that the prescription rates of antibiotics and analgesics in the UDCCK are not rational in terms of the qualitative aspects of treatment. For the qualitative improvement of prescription of these drug groups, we recommend the implementation of treatment guidelines following rational standards.

Perturbed threat monitoring following a traumatic event predicts risk for post-traumatic stress disorder.

BACKGROUND: Post-traumatic stress disorder (PTSD) is a chronic and difficult to treat psychiatric disorder. Objective, performance-based diagnostic markers that uniquely index risk for PTSD above and beyond subjective self-report markers could inform attempts to improve prevention and early intervention. We evaluated the predictive value of threat-related attention bias measured immediately after a potentially traumatic event, as a risk marker for PTSD at a 3-month follow-up. We measured the predictive contribution of attentional threat bias above and beyond that of the more established marker of risk for PTSD, self-reported psychological dissociation. METHOD: Dissociation symptoms and threat-related attention bias were measured in 577 motor vehicle accident (MVA) survivors (mean age = 35.02 years, 356 males) within 24 h of admission to an emergency department (ED) of a large urban hospital. PTSD symptoms were assessed at a 3-month follow-up using the Clinician-Administered PTSD Scale (CAPS). RESULTS: Self-reported dissociation symptoms significantly accounted for 16% of the variance in PTSD at follow-up, and attention bias toward threat significantly accounted for an additional 4% of the variance in PTSD. CONCLUSIONS: Threat-related attention bias can be reliably measured in the context of a hospital ED and significantly predicts risk for later PTSD. Possible mechanisms underlying the association between threat bias following a potentially traumatic event and risk for PTSD are discussed. The potential application of an attention bias modification treatment (ABMT) tailored to reduce risk for PTSD is suggested.

Effect of polymer concentration on the structure and performance of PEI hollow fiber membrane contactor for CO2 stripping.

A series of polyetherimide (PEI) hollow fiber membranes with various polymer concentrations (13-16 wt.%) for CO2 stripping process in membrane contactor application was fabricated via wet phase inversion method. The PEI membranes were characterized in terms of liquid entry pressure, contact angle, gas permeation and morphology analysis. CO2 stripping performance was investigated via membrane contactor system in a stainless steel module with aqueous diethanolamine as liquid absorbent. The hollow fiber membranes showed decreasing patterns in gas permeation, contact angle, mean pore size and effective surface porosity with increasing polymer concentration. On the contrary, wetting pressure of PEI membranes has enhanced significantly with polymer concentration. Various polymer concentrations have different effects on the CO2 stripping flux in which membrane with 14 wt.% polymer concentration showed the highest stripping flux of 2.7 × 10(-2)mol/m(2)s. From the performance comparison with other commercial membrane, it is anticipated that the PEI membrane has a good prospect in CO2 stripping via membrane contactor.

Transforming growth factor-beta1-antisense modulates the expression of hepatocyte growth factor/scatter factor in keloid fibroblast cell culture.

Abnormal wound healing processes can result in hypertrophic scars and keloids. Transforming growth factor-beta1 (TGF-beta1) and hepatocyte growth factor/scatter factor (HGF/SF) are biphasic growth factor cytokines in physiologic and pathophysiologic conditions. Findings have shown TGF-beta1 to be pivotal in the formation of keloid tissue. Therefore, neutralizing antibodies may allow wound healing without keloid formation. As reported, TGF-beta1 is antagonized by HGF/SF. Some authors have reported that exogenous administration of HGF/SF prevented scar formation. Hence, this study targeted TGF-beta1 and determined the levels of HGF/SF in fibroblast cell culture. Keloid tissue was taken from seven patients. Another seven patients with mature nonhypertrophic scar served as controls. All tissues were cultured, and fibroblast cultures were used for further experiments. The TGF-beta1 antisense was administered at 3 and 6 micromol/ml, and HGF/SF levels were determined after 16, 24, and 48 h of incubation. The levels of HGF/SF showed significant differences after incubation with antisense oligonucleotides. The increasing antisense levels resulted in increased HGF/SF levels (up to 87.66 pg/ml after 48 h of incubation). In conclusion, targeting TGF-beta1 resulted in significantly increased levels of HGF/SF. The clinical relevance could include the use of locally administered HGF/SF in protein or gene form to minimize formation of keloids. Nevertheless, wound healing is the result of many interacting cytokines, so neutralizing or targeting one protein could result in no significant effect.

Serotonergic enhancement of a 4-AP-sensitive current mediates the synaptic depression phase of spike timing-dependent neuromodulation.

The mechanism underlying spike timing-dependent neuromodulation (STDN) was investigated in the opisthobranch mollusc Tritonia diomedea. The serotonergic dorsal swim interneurons (DSIs) dynamically modulated the synaptic output of ventral swim interneuron B (VSI); immediately after DSI stimulation, there was a potentiation of VSI synaptic strength followed by a longer-lasting synaptic depression. The potentiation phase of STDN was unaffected by spike broadening produced by the potassium channel blocker 4-aminopyridine (4-AP). In contrast, the depression phase was eliminated by 4-AP. Bath-applied serotonin (5-HT) decreased VSI spike duration and increased the magnitude of the A-current (IA), a voltage-dependent, transient, outward current. 4-AP preferentially blocked IA and prevented the spike narrowing caused by 5-HT, uncovering the full extent of 5-HT-induced synaptic potentiation. A consistent correlation was observed between IA and spike duration, but the correlation between synaptic strength and spike duration differed between preparations. Conductance-based simulations showed that the magnitude of A-current conductance could affect spike duration and gave an estimation of the change needed to produce spike narrowing. An artificial IA introduced into the VSI in the presence of 4-AP by means of the dynamic-clamp technique restored spike duration and gave a further approximation of the magnitude of modulation needed for spike narrowing. Together, these results suggest a mechanism for STDN: the DSIs release 5-HT, which causes a spike duration-independent enhancement of synaptic strength and a longer-lasting enhancement of IA that narrows the VSI spike and hence decreases VSI synaptic strength. Thus, STDN arises from the dynamics of independent intracellular signaling events.

[Middle-ear adenoma]. / Adenom des Mittelohres.

In our case we present a 47-year old female patient, who had a history of one year of right-sided recurrent ear pain without any signs of ear-infections. A computer tomography (CT) imaging was carried out. At the mid-modiolar level, the axial CT-scan showed a small contrast-enhancing density in the middle ear space. She refused further investigation until the ear-pain increased and slight hearing loss was present. Again, six months later a CT-scan was performed, and the hyperdense tissue formation engaged the entire middle ear cleft of the right temporal bone. Typical of MEA, no osteolytic signs were present; the skull-base was intact, the air-cell system of the temporal bone showed no osteolysis or deficiency. In the case presented here, we show a MEA which has filled the middle ear with fluid retention in the mastoid with absent destruction of any structure clinically resulting in ear pain and slight conductive hearing loss. These lesions are contrast-enhancing on CT and on magnetic resonance imaging (MRI) have brain-like signal intensity T2-weighted images. In this case, the lesion was exenterated.

[Angiogenic factors in external auditory canal cholesteatoma-fibroblast cell culture]. / Angiogene Faktoren in der Fibroblastenzellkultur des Gehörgangcholesteatoms.

BACKGROUND: The external auditory canal cholesteatoma (EACC) is characterized by hyperproliferation of the epithelial and subepithelial tissue. Compared to normal meatal skin, strong expression of FGF-2 and VEGF had previously been detected. Many authors reported that FGF-2 acts via VEGF and is induced by hypoxia. Hypoxia seems to be pivotal for establishing EACC. Therefore, human EACC fibroblasts were investigated by incubating with FGF-2 and determining VEGF. PATIENTS AND METHODS: We harvested fibroblasts from human EACC and normal meatal skin and incubated the fibroblast culture with 50 ng/ml FGF-2 and determined VEGF concentrations after 1-4 days. RESULTS: Compared to untreated fibroblast cultures, there was a significant increase of VEGF concentration (p<0.05). However, there was no significant difference between the proliferation quantities. CONCLUSION: VEGF and FGF-2 are possibly involved in a cascade of growth factor activities, which modulates their concentration in human-derived EACC fibroblast culture. Exogenous FGF-2 increased fibroblast expression for VEGF, which is a major autocrine mediator of FGF-2-induced angiogenesis and proliferation.

[Cell adhesion proteins in external auditory canal cholesteatoma]. / Expression von Zell-Zell-Adhäsionsproteinen im Gehörgangscholesteatom.

BACKGROUND: External auditory canal cholesteatoma (EACC) is a rare entity in otolaryngology, which is histomorphologically identical with middle ear cholesteatoma. The cause of EACCt is, however, still not clear. The aim of this study was to describe the expression of beta-catenin, MMP-2, and MMP-9 in EACC matrix compared to the normal auditory meatal skin (AMS). METHODS: Thirteen specimens were obtained during surgical procedure. EACC and AMS specimens were immunostained with antibodies for beta-catenin, MMP-2, and MMP-9. RESULTS: Only the basal layers of the EACC specimens were positive for beta-catenin. The suprabasal layers showed diminished or negative immunostaining for beta-catenin. In all layers, AMS was homogeneously positive for beta-catenin. In contrast, the immunostaining for the gelatinases was equally increased in all layers of EACC, whereas AMS was weekly positive. CONCLUSION: The reduced immunoreactivity for beta-catenin may have been present because of the lessened cell-cell adhesion in the suprabasal layers of EACC. The increased expression of the metalloproteinases might point at an increased lack of integrity of EACC matrix. Recent studies revealed a balance between disintegrating and stabilising factors in normal tissue, which is disturbed in inflamed and neoplastic tissue. In EACC matrix, an imbalance of these factors, represented by reduced beta-catenin and increased gelatinase expression, is possible. Increased desquamation, the accumulation of keratin debris, and loss of tissue-stability support our findings.

Filamentous phage associated with recent pandemic strains of Vibrio parahaemolyticus.

A group of pandemic strains of Vibrio parahaemolyticus has recently appeared in Asia and North America. We demonstrate that a filamentous phage is specifically associated with the pandemic V. parahaemolyticus strains. An open reading frame unique to the phage is a useful genetic marker to identify these strains.

Monodansylcadaverine inhibits cytotoxicity of Vibrio parahaemolyticus thermostable direct hemolysin on cultured rat embryonic fibroblast cells.

The mechanism of action of Vibrio parahaemolyticus thermostable direct hemolysin (TDH) on cultured cells still remains unclear. We show that addition of osmotic stabilizers, such as polyethylene glycol and dextran, could not protect cultured rat embryonic fibroblast cells (Rat-1) against cytotoxicity induced by TDH, unlike their protection against the hemolytic activity of TDH. By contrast, 100 microM monodansylcadaverine, as well as the presence of 1 mM ethylene glycol-bis(beta-aminoethyl ether)-N,N,N',N'-tetraacetic acid (EGTA) in medium, protected the cells against cytotoxicity of TDH. Binding of TDH to Rat-1 cells and intracellular localization of TDH were affected by monodansylcadaverine and EGTA as analyzed by flow cytometry and confocal microscopy. On the hemolytic activity of TDH, monodansylcadaverine and EGTA had no effect. These results suggest that the mechanism of cytotoxicity of TDH on Rat-1 cells was different from that of hemolytic activity of TDH on red blood cells.

Vibrio parahaemolyticus thermostable direct hemolysin can induce an apoptotic cell death in Rat-1 cells from inside and outside of the cells.

Rat-1 cells exposed to Vibrio parahaemolyticus thermostable direct hemolysin (TDH) developed morphological changes including shrinkage of the cells and reduction in the size of nuclei. Cells either microinjected with TDH or transfected with the tdh gene also showed morphological changes similar to those induced by externally added toxin. Furthermore, TDH-exposed or tdh-transfected cells both showed chromatin condensation and DNA fragmentation which suggest cells undergoing apoptosis. In contrast, expression of a TDH mutant (R7) did not reveal any cytotoxic effects. We demonstrate that expressed TDH was distributed in the cytoplasm. The interleukin-1beta-converting enzyme-related protease inhibitor ZVAD-FMK did not inhibit TDH cytotoxicity. Our results suggest that TDH can induce its cytotoxicity both from outside and from inside the cells and killed the cells through apoptosis.