Safety and Preliminary Efficacy of Cervical Paraspinal Interfascial Plane Block for Postoperative Pain after Pediatric Chiari Decompression.

BACKGROUND: Surgery for lesions of the posterior fossa is associated with significant postoperative pain in pediatric patients related to extensive manipulation of the suboccipital musculature and bone. In this study, we assess the preliminary safety, effect on neuromonitoring, and analgesic efficacy of applying a cervical paraspinal interfascial plane block in pediatric patients undergoing posterior fossa surgery. METHODS: In this prospective case series, we enrolled five patients aged 2-18 years undergoing surgery for symptomatic Chiari type I malformation. An ultrasound-guided cervical cervicis plane (CCeP) block was performed prior to the incision. A local anesthetic agent (bupivacaine) and a steroid adjuvant (dexamethasone) were injected into the fascial planes between the cervical semispinalis capitis and cervical semispinalis cervicis muscles at the level of the planned suboccipital decompression and C1 laminectomy. Motor-evoked and somatosensory-evoked potentials were monitored before and after the block. Patients were assessed for complications from the local injection in the intraoperative period and for pain in the postoperative period. RESULTS: No adverse events were noted intraoperatively, and there were no changes in neuromonitoring signals. Pain scores were low in the immediate postoperative period, and rescue medications were minimal. No complaints of incisional pain or need for narcotics were noted at the time of the 3-month postsurgical follow-up. CONCLUSIONS: In this study, we demonstrate the preliminary safety and analgesic efficacy of a novel application of a CCeP block to pediatric patients undergoing suboccipital surgery. Larger studies are needed to further validate the use of this block in children.

Rare median and musculocutaneous nerve fusion with intraoperative electrical confirmation: illustrative case.

BACKGROUND: Nerve transfer is a surgical technique in which a redundant or expendable fascicle is transferred or coapted to an injured nerve distal to the site of injury for the purpose of reinnervation. Successful nerve transfer is dependent on correct intraoperative identification of donor and recipient nerves. OBSERVATIONS: An 8-year-old male was recommended for ulnar nerve fascicle to biceps branch of musculocutaneous nerve transfer to restore elbow flexion weakness after a demyelinating spinal cord injury. The biceps branch was identified approximately midway along the upper arm. Proximal musculocutaneous nerve stimulation induced hand movement and electromyography activity in the median nerve muscles. Neurolysis of the thickened proximal structure revealed fusion of the musculocutaneous and median nerves. Because of the proximity of the median and musculocutaneous nerves, median rather than ulnar nerve fascicles were used as donors for transfer. LESSONS: The authors provide the first reported intraoperative finding of an anatomical variant in which the musculocutaneous nerve and median nerve were fused in the upper arm, confirmed through intraoperative electrical stimulation. Surgeons should be aware of this rare anatomical variant to ensure correct nerve identification when performing nerve transfers in the proximal upper extremity.

Multivariate links between the developmental timing of adversity exposure and white matter tract integrity in adulthood.

Early-life adversity is pervasive worldwide and represents a potent risk factor for increased mental health burden across the lifespan. However, there is substantial individual heterogeneity in associations between adversity exposure, neurobiological changes, and mental health problems. Accounting for key features of adversity such as the developmental timing of exposure may clarify associations between adversity, neurodevelopment, and mental health. The present study leverages sparse canonical correlation analysis to characterize modes of covariation between age of adversity exposure and the integrity of white matter tracts throughout the brain in a sample of 107 adults. We find that adversity exposure during middle childhood (ages 5-6 and 8-9 in particular) is consistently linked with alterations in white matter tract integrity, such that tracts supporting sensorimotor functions display higher integrity in relation to adversity exposure while tracts supporting cortico-cortical communication display lower integrity. Further, latent patterns of tract integrity linked with adversity experienced across preschool age and middle childhood (ages 4-9) were associated with trauma-related symptoms in adulthood. Our findings underscore that adversity exposure may differentially affect white matter in a function- and developmental-timing specific manner and suggest that adversity experienced between ages 4-9 may shape the development of global white matter tracts in ways that are relevant for adult mental health.

Using Polygraph to Detect Passengers Carrying Illegal Items.

The present study examined the effectiveness of a Modified-Comparison Questions Technique, used in conjunction with the polygraph, to differentiate between common travelers, drug traffickers, and terrorists at transportation hubs. Two experiments were conducted using a mock crime paradigm. In Experiment 1, we randomly assigned 78 participants to either a drug condition, where they packed and lied about illicit drugs in their luggage, or a control condition, where they did not pack or lie about any illegal items. In Experiment 2, we randomly assigned 164 participants to one of the two conditions in Experiment 1 or an additional bomb condition, where they packed and lied about a bomb in their luggage. For both experiments, we assessed participants' RR interval, heart rate, peak-to-peak amplitude of Galvanic Skin Response (GSR) and all three combined, using Discriminant Analyses to determine the classification accuracy of participants in each condition. In both experiments, we found decelerated heart rates and increased peak-to-peak amplitude of GSR in guilty participants when lying in response to questions regarding their crime. We also found accurate classifications of participants, in both Experiment 1 (drug vs. control: 84.2% vs. 82.5%) and Experiment 2 (drug vs. control: 82:1% vs. 95.1%; bomb vs. control: 93.2% vs. 95.1%; drug vs. bomb: 92.3% vs. 90.9%), above chance level. These findings indicate that Modified-CQT, combined with a polygraph test, is a viable method for investigating suspects of drug trafficking and terrorism at transportation hubs such as train stations and airports.

Morphology of the archaellar motor and associated cytoplasmic cone in Thermococcus kodakaraensis.

Archaeal swimming motility is driven by archaella: rotary motors attached to long extracellular filaments. The structure of these motors, and particularly how they are anchored in the absence of a peptidoglycan cell wall, is unknown. Here, we use electron cryotomography to visualize the archaellar basal body in vivo in Thermococcus kodakaraensis KOD1. Compared to the homologous bacterial type IV pilus (T4P), we observe structural similarities as well as several unique features. While the position of the cytoplasmic ATPase appears conserved, it is not braced by linkages that extend upward through the cell envelope as in the T4P, but rather by cytoplasmic components that attach it to a large conical frustum up to 500 nm in diameter at its base. In addition to anchoring the lophotrichous bundle of archaella, the conical frustum associates with chemosensory arrays and ribosome-excluding material and may function as a polar organizing center for the coccoid cells.

Asymmetric Enzymatic Synthesis of Allylic Amines: A Sigmatropic Rearrangement Strategy.

Sigmatropic rearrangements, while rare in biology, offer opportunities for the efficient and selective synthesis of complex chemical motifs. A "P411" serine-ligated variant of cytochrome P450(BM3) has been engineered to initiate a sulfimidation/[2,3]-sigmatropic rearrangement sequence in whole E. coli cells, a non-natural function for any enzyme, providing access to enantioenriched, protected allylic amines. Five mutations in the enzyme substantially enhance its activity toward this new function, demonstrating the evolvability of the catalyst toward challenging nitrene transfer reactions. The evolved catalyst additionally performs the highly enantioselective imidation of non-allylic sulfides.

Structural conservation of chemotaxis machinery across Archaea and Bacteria.

Chemotaxis allows cells to sense and respond to their environment. In Bacteria, stimuli are detected by arrays of chemoreceptors that relay the signal to a two-component regulatory system. These arrays take the form of highly stereotyped super-lattices comprising hexagonally packed trimers-of-receptor-dimers networked by rings of histidine kinase and coupling proteins. This structure is conserved across chemotactic Bacteria, and between membrane-bound and cytoplasmic arrays, and gives rise to the highly cooperative, dynamic nature of the signalling system. The chemotaxis system, absent in eukaryotes, is also found in Archaea, where its structural details remain uncharacterized. Here we provide evidence that the chemotaxis machinery was not present in the last archaeal common ancestor, but rather was introduced in one of the waves of lateral gene transfer that occurred after the branching of Eukaryota but before the diversification of Euryarchaeota. Unlike in Bacteria, the chemotaxis system then evolved largely vertically in Archaea, with very few subsequent successful lateral gene transfer events. By electron cryotomography, we find that the structure of both membrane-bound and cytoplasmic chemoreceptor arrays is conserved between Bacteria and Archaea, suggesting the fundamental importance of this signalling architecture across diverse prokaryotic lifestyles.

Quick preparation of genomic DNA from Drosophila.

This protocol describes a standard miniprep for Drosophila melanogaster that requires very few flies and produces high-quality DNA. This method can also be used to isolate RNA when RNase-free conditions are utilized; an extra step must be taken to rid the sample of genomic DNA (e.g., RNase-free DNase digestion).

Recovery of DNA sequences flanking P-element insertions in Drosophila: inverse PCR and plasmid rescue.

The Drosophila melanogaster P-transposable element is a powerful and widely used research tool. Sequences flanking the P-element can be recovered and the site of insertion can be mapped to the nucleotide, to connect the genetic and physical maps and facilitate molecular analysis of the gene of interest. The Berkeley Drosophila Genome Project (BDGP) has assembled a well-characterized collection of lethal mutations induced by single P-element insertions generated by a number of laboratories. The genomic DNA sequences adjacent to these insertions have been recovered by either plasmid rescue or inverse polymerase chain reaction (PCR). The combination of a complete genomic DNA sequence and relatively fast and easy molecular methods for mapping P-element insertion sites to the nucleotide enhances the use of P-elements as tools in Drosophila research. This protocol provides detailed procedures for isolating DNA flanking P-element insertions.