Effect of warmed irrigation solution on core body temperature during hip arthroscopy for femoroacetabular impingement.

PURPOSE: To determine the effect of warming arthroscopic irrigation solution on core body temperature during hip arthroscopic surgery in patients with femoroacetabular impingement. METHODS: An analytical, prospective, observational study was performed in a cohort of 166 consecutive patients. All patients underwent hip arthroscopy for treatment of femoroacetabular impingement. Two groups were studied: patients operated on with arthroscopic irrigation solution warmed up to 32°C ± 2°C (89.6°F ± 3.6°F) and a control group comprising patients operated on with irrigation solution used at room temperature. Relevant information was collected regarding the patients (age, sex, body mass index, and blood pressure) and the procedure (volume and temperature of saline solution, pressure of fluid pump, surgery time, and room temperature). Corresponding statistical analysis was performed with STATA 11.0 (StataCorp, College Station, TX), by use of descriptive statistics, parametric and nonparametric tests, and a generalized estimating equation model for repeated measurements. RESULTS: Both groups were comparable in terms of age, sex, systolic and diastolic blood pressure, body mass index, volume of irrigation solution used, and room temperature. The mean age of the cohort was 33 years (range, 14 to 60 years); mean body mass index, 23.7 kg/m(2) (range, 17.2 to 34 kg/m(2)); mean volume of irrigation solution, 26 L (range, 12 to 39 L); mean systolic blood pressure, 97 mm Hg; mean diastolic blood pressure, 51 mm Hg; and mean surgical time, 110 minutes. A decrease in core body temperature by 0.5°C (0.9°F) or greater occurred during the course of surgery in 66% of patients in the control group versus 28% in the warmed-solution group (P < .001). At least 1 core body temperature measurement of less than 36°C (96.8°F) was recorded in 48% of patients in the control group versus 14% in the warmed-solution group (P < .001). The trend toward a decrease in core body temperature was 4 times greater in the control group than in the warmed-solution group (P < .001). CONCLUSIONS: Use of arthroscopic irrigation solution warmed up to 32°C (89.6°F) reduces the risk of a decrease in core body temperature during hip arthroscopy in patients with femoroacetabular impingement. LEVEL OF EVIDENCE: Level II, analytical, prospective, comparative study in a cohort of consecutive patients.

Deep Gluteal Pain Syndrome: Endoscopic Technique and Medium-Term Functional Outcomes.

BACKGROUND: Sciatic nerve entrapment is an entity that generates disabling pain, mainly when the patient is sitting on the involved side. According to some studies, the presence of fibrovascular bands has been described as the main cause of this pathology, and the sciatic nerve's decompression by endoscopic release has been described as an effective treatment generally associated with a piriformis tenotomy. The aim of this study was to present the medium-term functional results of endoscopic release of the sciatic nerve without resection of the piriformis tendon. METHODS: This prospective, observational study included 57 patients who underwent an endoscopic operation for sciatic nerve entrapment between January 2014 and January 2019. In all cases, a detailed medical history was obtained and a physical examination and a functional evaluation were performed using the modified Harris hip score (mHHS), the 12-item International Hip Outcome Tool (iHOT-12), and the visual analog scale (VAS) for pain. All patients had pelvic radiographs and magnetic resonance imaging (MRI) scans of the hip on the involved side and underwent a prior evaluation by a spine surgeon. RESULTS: This study included 20 male and 37 female patients with a mean age of 43.6 years (range, 24 to 88 years) and a mean follow-up of 22.7 months. The median mHHS improved from 59 to 85 points. The median iHOT-12 improved from 60 to 85 points. The median VAS decreased from 7 to 2. Postoperative complications occurred in 12% of patients: 1 patient with extensive symptomatic hematoma, 3 patients with hypoesthesia, and 3 patients with dysesthesia. CONCLUSIONS: Endoscopic release of the sciatic nerve by resection of fibrovascular bands without piriformis tenotomy is a technique with good to excellent functional results comparable with those of techniques in the literature incorporating piriformis tenotomy. LEVEL OF EVIDENCE: Therapeutic Level IV . See Instructions for Authors for a complete description of levels of evidence.

Hip arthroscopy and hypothermia.

PURPOSE: To determine the incidence of and factors that contribute to the development of hypothermia during hip arthroscopic surgery. METHODS: An analytic observational study was carried out in a cohort of 73 consecutive patients. All patients underwent hip arthroscopy for the treatment of femoroacetabular impingement. The patients' core temperature (esophageal) was measured throughout the surgery. Relevant information was collected on the patients (age, gender, body mass index, blood pressure) and on the procedure (volume and temperature of saline solution, pressure of fluid pump, surgery time, room temperature). The corresponding statistical analysis was performed with Stata 10.0 (StataCorp, College Station, TX), by use of a repeated-measures generalized estimating equations model. RESULTS: The patients' mean age was 33 years, and there were 39 female and 34 male patients. The mean body mass index was 23.9; systolic blood pressure, 97.5 mm Hg; and diastolic blood pressure, 52.2 mm Hg. The incidence of hypothermia below 35°C (95°F) was 2.7%. The multivariate statistical analysis of the results showed a direct relation between hypothermia and surgery time of more than 120 minutes (P < .001). There was an inverse relation between core body temperature and surgery time (P < .001), with a drop of 0.19°C/h (32.342°F/h). Of the patients, 68.22% had a decrease in temperature of more than 0.5°C (32.9°F) until the end of surgery. There was also a direct relation between core body temperature and saline solution temperature (P < .001), body mass index (P < .01), and diastolic blood pressure (P < .03). CONCLUSIONS: The incidence of hypothermia below 35°C (95°F) in patients who underwent hip arthroscopy for the treatment of femoroacetabular impingement is 2.7%. The factors that contribute toward the development of hypothermia during hip arthroscopic surgery are prolonged surgery time, low body mass index, low blood pressure during the procedure, and low temperature of the arthroscopic irrigation fluid.

Correction to: Proximity ligation scaffolding and comparison of two Trichoderma reesei strains genomes.

[This corrects the article DOI: 10.1186/s13068-017-0837-6.].

Proximity ligation scaffolding and comparison of two Trichoderma reesei strains genomes.

BACKGROUND: The presence of low complexity and repeated regions in genomes often results in difficulties to assemble sequencing data into full chromosomes. However, the availability of full genome scaffolds is essential to several investigations, regarding for instance the evolution of entire clades, the analysis of chromosome rearrangements, and is pivotal to sexual crossing studies. In non-conventional but industrially relevant model organisms, such as the ascomycete Trichoderma reesei, a complete genome assembly is seldom available. RESULTS: The chromosome scaffolds of T. reesei QM6a and Rut-C30 strains have been generated using a contact genomic/proximity ligation genomic approach. The original reference assembly, encompassing dozens of scaffolds, was reorganized into two sets of seven chromosomes. Chromosomal contact data also allowed to characterize 10-40 kb, gene-free, AT-rich (76%) regions corresponding to the T. reesei centromeres. Large chromosomal rearrangements (LCR) in Rut-C30 were then characterized, in agreement with former studies, and the position of LCR breakpoints used to assess the likely chromosome structure of other T. reesei strains [QM9414, CBS999.97 (1-1, re), and QM9978]. In agreement with published results, we predict that the numerous chromosome rearrangements found in highly mutated industrial strains may limit the efficiency of sexual reproduction for their improvement. CONCLUSIONS: The GRAAL program allowed us to generate the karyotype of the Rut-C30 strain, and from there to predict chromosome structure for most T. reesei strains for which sequence is available. This method that exploits proximity ligation sequencing approach is a fast, cheap, and straightforward way to characterize both chromosome structure and centromere sequences and is likely to represent a popular convenient alternative to expensive and work-intensive resequencing projects.

High-quality genome (re)assembly using chromosomal contact data.

Closing gaps in draft genome assemblies can be costly and time-consuming, and published genomes are therefore often left 'unfinished.' Here we show that genome-wide chromosome conformation capture (3C) data can be used to overcome these limitations, and present a computational approach rooted in polymer physics that determines the most likely genome structure using chromosomal contact data. This algorithm--named GRAAL--generates high-quality assemblies of genomes in which repeated and duplicated regions are accurately represented and offers a direct probabilistic interpretation of the computed structures. We first validated GRAAL on the reference genome of Saccharomyces cerevisiae, as well as other yeast isolates, where GRAAL recovered both known and unknown complex chromosomal structural variations. We then applied GRAAL to the finishing of the assembly of Trichoderma reesei and obtained a number of contigs congruent with the know karyotype of this species. Finally, we showed that GRAAL can accurately reconstruct human chromosomes from either fragments generated in silico or contigs obtained from de novo assembly. In all these applications, GRAAL compared favourably to recently published programmes implementing related approaches.

Kinetic transcriptome analysis reveals an essentially intact induction system in a cellulase hyper-producer Trichoderma reesei strain.

BACKGROUND: The filamentous fungus Trichoderma reesei is the main industrial cellulolytic enzyme producer. Several strains have been developed in the past using random mutagenesis, and despite impressive performance enhancements, the pressure for low-cost cellulases has stimulated continuous research in the field. In this context, comparative study of the lower and higher producer strains obtained through random mutagenesis using systems biology tools (genome and transcriptome sequencing) can shed light on the mechanisms of cellulase production and help identify genes linked to performance. Previously, our group published comparative genome sequencing of the lower and higher producer strains NG 14 and RUT C30. In this follow-up work, we examine how these mutations affect phenotype as regards the transcriptome and cultivation behaviour. RESULTS: We performed kinetic transcriptome analysis of the NG 14 and RUT C30 strains of early enzyme production induced by lactose using bioreactor cultivations close to an industrial cultivation regime. RUT C30 exhibited both earlier onset of protein production (3 h) and higher steady-state productivity. A rather small number of genes compared to previous studies were regulated (568), most of them being specific to the NG 14 strain (319). Clustering analysis highlighted similar behaviour for some functional categories and allowed us to distinguish between induction-related genes and productivity-related genes. Cross-comparison of our transcriptome data with previously identified mutations revealed that most genes from our dataset have not been mutated. Interestingly, the few mutated genes belong to the same clusters, suggesting that these clusters contain genes playing a role in strain performance. CONCLUSIONS: This is the first kinetic analysis of a transcriptomic study carried out under conditions approaching industrial ones with two related strains of T. reesei showing distinctive cultivation behaviour. Our study sheds some light on some of the events occurring in these strains following induction by lactose. The fact that few regulated genes have been affected by mutagenesis suggests that the induction mechanism is essentially intact compared to that for the wild-type isolate QM6a and might be engineered for further improvement of T. reesei. Genes from two specific clusters might be potential targets for such genetic engineering.