High-Throughput Contractile Measurements of Hydrogel-Embedded Intact Mouse Muscle Fibers Using an Optics-Based System.

In vitro cell culture is a powerful tool to assess cellular processes and test therapeutic strategies. For skeletal muscle, the most common approaches involve either differentiating myogenic progenitor cells into immature myotubes or the short-term ex vivo culture of isolated individual muscle fibers. A key benefit of ex vivo culture over in vitro is the retention of the complex cellular architecture and contractile characteristics. Here, we detail an experimental protocol for the isolation of intact flexor digitorum brevis muscle fibers from mice and their subsequent ex vivo culture. In this protocol, muscle fibers are embedded in a fibrin-based and basement membrane matrix hydrogel to immobilize the fibers and maintain their contractile function. We then describe methods to assess the muscle fiber contractile function using an optics-based, high-throughput contractility system. The embedded muscle fibers are electrically stimulated to induce contractions, after which their functional properties, such as sarcomere shortening and contractile velocity, are assessed using optics-based quantification. Coupling muscle fiber culture with this system allows for high-throughput testing of the effects of pharmacological agents on contractile function and ex vivo studies of genetic muscle disorders. Finally, this protocol can also be adapted to study dynamic cellular processes in muscle fibers using live-cell microscopy.

The factors affecting mortality in intensive care unit of a burns center.

OBJECTIVE: To determine the characteristics of patients, mortality-affecting factors and mortality rate in follow-up burn-injured patients in an intensive care setting at a burns treatment centre. Methods: The retrospective study was conducted between May and November 2014 at Kocaeli Derince Training and Research Hospital Burn Treatment Centre, Kocaeli, Turkey, and comprised data from January 2008 to January 2013 of in-patients who had been treated at the intensive care unit. The therapy outcomes and the follow-up processes were evaluated. Data was analysed using SPSS 17. RESULTS: Of the 381 patients, 105(27.6%) were females and 276(72.4%) were males. The overall mean age was 28.4±21.1 years. There were 52(13.6%) mortalities, while 329(86.4%) survived. The mean total body surface area was 18.3±12.9% in those who survived compared to 52±24.3% in those who died (p<0.000). The highest rate of death was observed in those aged >66 years (p<0.000). The impact of flame burns on mortality was statistically significant (p<0.05). The impact of inhalation burns, suicide, abuse, operational requirements and systemic disease on mortality was statistically significant (p<0.05). CONCLUSIONS: Older age, higher total body surface area, flame burns, presence of inhalation burn, third degree burn, suicide attempt, presence of systemic disease, duration of prolonged mechanical ventilation and operation requirements were found to be poor prognostic factors for survival in burn patients.

Airway patency in children undergoing magnetic resonance imaging using neck collars: a single center, randomized, double-blind, prospective study.

BACKGROUND AND OBJECTIVES: Maneuvers precluding the downward shift of the mandibula and providing slight extension of the head have been shown to increase upper airway dimensions. This study aimed to investigate the role of Neck Collars (NC) in maintaining airway patency during Magnetic Resonance Imaging (MRI) examination in a pediatric population aged between 0 and 16 years. METHODS: One hundred twenty-five children were recruited in this prospective study. Subjects were randomly assigned to NC group (NC+) or standard imaging group (NC-). Measurements of anteroposterior and transverse dimensions and cross-sectional area were performed to determine the upper airway size at three distinct levels: soft palate, base of the tongue, and tip of the epiglottis. RESULTS: The anteroposterior diameter and cross-sectional area at the levels of base of the tongue and soft palate were significantly higher in NC+ patients compared to NC- patients. However, anteroposterior dimensions and cross-sectional areas at the epiglottis level were similar in the two groups. When patients were analyzed according to age groups of 0-2, 2-8, and 8-16 years, the anteroposterior diameter and cross-sectional area at the levels of base of the tongue and soft palate were significantly higher in NC+ patients compared to NC- patients in all age groups. CONCLUSIONS: This study clearly demonstrates that the application of a NC may improve retropalatal end and retroglossal airway dimensions in a pediatric population undergoing MRI examination and receiving sedation in supine position.

Uncoupling growth and succinic acid production in an industrial Saccharomyces cerevisiae strain.

This study explores the relation between biomass-specific succinic acid (SA) production rate and specific growth rate of an engineered industrial strain of Saccharomyces cerevisiae, with the aim to investigate the extent to which growth and product formation can be uncoupled. Ammonium-limited aerobic chemostat and retentostat cultures were grown at different specific growth rates under industrially relevant conditions, that is, at a culture pH of 3 and with sparging of a 1:1 CO2 -air mixture. Biomass-specific SA production rates decreased asymptotically with decreasing growth rate. At near-zero growth rates, the engineered strain maintained a stable biomass-specific SA production rate for over 500 h, with a SA yield on glucose of 0.61 mol mol-1 . These results demonstrate that uncoupling of growth and SA production could indeed be achieved. A linear relation between the biomass-specific SA production rate and glucose consumption rate indicated the coupling of SA production rate and the flux through primary metabolism. The low culture pH resulted in an increased death rate, which was lowest at near-zero growth rates. Nevertheless, a significant amount of non-viable biomass accumulated in the retentostat cultures, thus underlining the importance of improving low-pH tolerance in further strain development for industrial SA production with S. cerevisiae.

Perioperative hypothermia in pediatric patients operated in a tertiary care center: Incidence and correlates.

BACKGROUND & OBJECTIVES: Hypothermia, described as temperature < 35°C, is a frequent condition encountered in patients operated under general anesthesia. It is associated with significant morbidity and mortality. We aimed to estimate its incidence and to investigate the conditions associated with hypothermia in pediatric patients. METHODS: This prospective clinical study was carried out in the operating theatre of a tertiary care center between August 2015 and September 2015. A total of 108 pediatric patients who underwent various surgical procedures that lasted for more than 30 minutes were enrolled. Baseline demographic data, types of surgical procedures, duration of operations, preoperative and perioperative body temperatures were recorded. The incidence of hypothermia and its possible correlates were sought. RESULTS: Our series consisted of 108 children (77 males, 71.3%; 31 females, 28.7%) with an average age of 6.08±5.09 years were included in the study. There was no case diagnosed with hypothermia in the preoperative, perioperative and postoperative periods. Patients in American Society of Anesthesiologists classification (ASA) three group had significantly higher preoperative body temperatures compared to those in ASA-1 and ASA-2 groups (p = 0.027). The postoperative body temperature in patients receiving intravenous fluid replacement was significantly lower (p=0.017). CONCLUSION: For pediatric patients scheduled for surgical interventions, we recommend close monitorization and follow-up of body temperature, implementation of preventive measures to avoid hypothermia and routine perioperative heating. Avoidance of hypothermia may prevent hazardous consequences of postoperative hypothermia.

Successful cryoablation of incessant fast-slow atypical atrioventricular nodal reentrant tachycardia in a child with tachycardia-induced cardiomyopathy.

A 15-year-old female patient presented at the clinic with heart failure (HF). A 12-lead electrocardiogram showed a heart rate of 170 bpm; negative P waves in leads DII, DIII, aVF; and long RP tachycardia (LRPT). Echocardiography demonstrated a shortening fraction (SF) of 20%. An electrophysiology study during tachycardia revealed an atrial-His time of 52 milliseconds and a His-atrial interval of 295 milliseconds. During ventricular entrainment, the postpacing interval-tachycardia cycle length was measured at 225 milliseconds. There was a pseudo V-A-A-V response. These findings confirmed the diagnosis of atypical atrioventricular nodal re-entrant tachycardia (aAVNRT). Successful slow pathway cryoablation was performed with an 8-mm-tip cryocatheter. After 2 weeks, the SF was measured as 34%. During a 2-year follow-up period, no recurrence was observed. In conclusion, fast-slow aAVNRT should be a part of the differential diagnosis of incessant LRPT leading to HF. Cryoablation can be used successfully in cases of aAVNRT.

Factors affecting mortality among victims of electrical burns.

BACKGROUND: The aim of this study was to determine the factors affecting mortality rate among patients with an electrical burn. METHODS: A total of 115 patients admitted to the emergency department and hospitalized in the Burn Treatment Center or Intensive Care Unit (ICU) due to the electrical burn, were included in the study. RESULTS: A total of 115 patients (4 female and 111 male) with a mean age of 32.88±12.87 years were included in the study. The mean hospitalization period was 25.03±20.50 days, and the mean total body surface area burned (% TBSA) was 22.83±15.54%. Among those patients, 9 (8.5%) expired, and the remaining 106 were discharged after treatment. In a logistic regression analysis, TBSA >20% (p=0.02, OR: 11.7, CI: 1.38-99.16); ICU requirement (p=0.005, OR: 1.28, CI: 1.08-1.58); erythrocyte transfusion requirement (p=0.02, OR: 12.48, CI: 1.44-107.83); fresh frozen plasma (FFP) requirement (p=0.03, OR: 10.23, CI: 1.18-88.17); albumin requirement (p=0.02, OR: 12.60, CI: 1.44-109.85); admission serum albumin level <3.5 mg/dl (p=0.04, OR: 7.25, CI: 0.82-63.64); and admission hemoglobin level <12 mg/dl (p=0.01, OR: 8.29, CI: 1.57-43.61) were determined as risk factors for mortality in patients with electrical burns. CONCLUSION: In clinical practice, defining a mortality risk analyzer using these factors may be helpful in the management of patients with electrical burns. Additional, more comprehensive studies are required to define the risk factors for mortality and long-term morbidities in patients with electrical burns.

General characteristics of paint thinner burns: Single center experience.

BACKGROUND: The aim of the present study was to present characteristic features and risk factors of paint thinner burns in order to raise awareness and help prevent these injuries. METHODS: Records of patients admitted to the burn unit due to paint thinner burns were retrospectively reviewed, and patients with comprehensive data available were included in the study. Total of 48 patients (3 female and 45 male) with mean age of 27.79±11.49 years (range: 4-58 years) were included in the study. RESULTS: Mean total hospitalization period was 30.25±27.11 days (range: 3-110 days), and mean total burn surface area was 32.53±24.06% (range: 3.0-90.0%). In 31 cases (64.6%), intensive care unit admission was required. Among all 48 patients, 9 (18.8%) died in hospital and remaining 38 were discharged after treatment. Primary cause of death was septicemia (n=7) or respiratory failure (n=6). Inhalation injury was present in 12 of the patients, 6 of whom died (50%). Statistically significant differences were found between expired and discharged patients when compared for presence of inhalation injury (p=0.01) and septicemia (p=0.031). CONCLUSION: Ignition of paint thinner is an important cause of burn injuries that may result in very severe clinical picture. Patients require prompt and careful treatment. Clinicians should be aware that inhalation injury and sepsis are the 2 main factors affecting mortality rate in this group of patients. With increased awareness, preventive measures may be defined. Further studies are warranted to decrease mortality rate in this subgroup of burn patients.

Retroperitoneal Ganglioneuroma: Mimicking an ovarian mass in a child.

UNLABELLED: Ganglioneuroma are rare, benign neural tumor of sympathetic nervous system originating from neural crest sympathogonia. Pelvic ganglioneuromas may mimic ovarian masses. We present a patient operated with the diagnosis of ovarian tumor which had a pelvic gangliuoneuroma. CASE: An eleven-year old female patient complaining of abdominal pain and a mass was seen at our hospital. On examination a 10×10 cm mass was palpable in the pelvis. Laboratory parameters were all normal and the tumor markers such as ß-HCG, AFP, CEA, serum catecholamines were negative. Abdominal ultrasonography and computed tomography showed an 11×6×9 cm solid mass containing calcification. The preoperative diagnosis was an adnexal mass of ovary. The patient was operated under general anesthesia and we found a retroperitoneal mass attached to the spine at L5. The tumoral mass was completely excised. Histopathological examination of tumor was reported as ganglioneuroma. The patient was discharged on seventh day of hospitalization with no neurological deficit. Retroperitoneal ganglioneuromas are usually present with local mass a benign tumoral course. The preoperative diagnosis may be difficult in pelvic ganglioneuromas due to close similarity with the ovarian masses. The treatment of the ganglioneuroma is total surgical excision and histology provides a confirmatory diagnosis.