Treating Hypertrophic Burn Scar With 2940-nm Er:YAG Laser Fractional Ablation Improves Scar Characteristics as Measured by Noninvasive Technology.

Their group previously demonstrated high-patient satisfaction for the treatment of hypertrophic burn scar (HBS) with the erbium: yttrium aluminum garnet (Er:YAG) laser, but this and other literature supporting the practice suffer from a common weakness of a reliance on subjective assessments by patients or providers. Herein, they sought to prospectively study the effects of Er:YAG fractional ablation on HBS using noninvasive, objective technologies to measure outcomes. Patients with HBS had identical regions of scar designated for treatment by the Er:YAG laser (TREAT) or to be left untreated (CONTROL). They prospectively collected scar measurements of TREAT and CONTROL regions preoperatively, 3 weeks, and 3 months after Er:YAG treatment. Scar measurements included viscoelastometry, transepidermal water loss, optical coherent tomography, and high-frequency ultrasound. Outcomes were measured for the aggregate difference between the TREAT group vs the CONTROL group, as well as within each group in isolation. Seventeen patients were seen preoperatively, followed by n = 15 at 3 weeks and n = 11 at 3 months. A mixed-model repeated measures analysis showed no significant effect of fractional ablation when comparing the overall TREAT group measurements with those of the CONTROL group. However, when considered as within-group measurements, TREAT scars showed significant improvement in viscoelastic deformity (P = .03), elastic deformity (P = .004), skin roughness (P = .05), and wrinkle depth (P = .04) after fractional ablation, whereas CONTROL scars showed no such within-group changes. HBS treated by the Er:YAG laser showed objective improvements, whereas no such changes were seen within the untreated scars over the same time frame.

Cannabis Use Has Negligible Effects Following Severe Traumatic Injury.

Nearly half of all states have legalized medical marijuana or recreational-use marijuana. As more states move toward legalization, the effects on injured patients must be evaluated. This study sought to determine effects of cannabis positivity at the time of severe injury on hospital outcomes compared with individuals negative for illicit substances and those who were users of other illicit substances. A Level I trauma center performed a retrospective chart review covering subjects over a 2-year period with toxicology performed and an Injury Severity Score (ISS) of more than 16. These individuals were divided into the negative and positive toxicology groups, further divided into the marijuana-only, other drugs-only, and mixed-use groups. Differences in presenting characteristics, hospital length of stay, intensive care unit (ICU) stays, ventilator days, and death were compared. A total of 8,441 subjects presented during the study period; 2,134 (25%) of these had toxicology performed; 843 (40%) had an ISS of more than 16, with 347 having negative tests (NEG); 70 (8.3%) substance users tested positive only for marijuana (MO), 323 (38.3%) for other drugs-only, excluding marijuana (OD), and 103 (12.2%) subjects showed positivity for mixed-use (MU). The ISS was similar for all groups. No differences were identified in Glasgow Coma Scale (GCS), ventilator days, blood administration, or ICU/hospital length of stay when comparing the MO group with the NEG group. Significant differences occurred between the OD group and the NEG/MO/MU groups for GCS, ICU length of stay, and hospital charges. Cannabis users suffering from severe injury demonstrated no detrimental outcomes in this study compared with nondrug users.

Small N-terminal deletion by splicing in cerebellar alpha 6 subunit abolishes GABAA receptor function.

Sequence variation was found in cDNA coding for the extracellular domain of the rat gamma-aminobutyric acid type A (GABAA) receptor alpha 6 subunit. About 20% of polymerase chain reaction (PCR)-amplified alpha 6 cDNA prepared from rat cerebellar mRNA lacked nucleotides 226-255 as estimated by counting single-stranded phage plaques hybridized specifically to the short (alpha 6S) and long (wild-type) forms of the alpha 6 mRNA. Genomic PCR revealed an intron located upstream of the 30-nucleotide sequence. Both splice forms were detected in the cerebellum by in situ hybridization. Recombinant receptors, resulting from coexpression of the alpha 6S subunit with the GABAA receptor beta 2 and gamma 2 subunits in human embryonic kidney 293 cells, were inactive at binding [3H]muscimol and [3H]Ro 15-4513. In agreement, injection of complementary RNAs encoding the same subunits into Xenopus oocytes produced only weak GABA-induced currents, indistinguishable from those produced by beta 2 gamma 2 receptors. Therefore, the 10 amino acids encoded by the 30-nucleotide fragment may be essential for the correct assembly or folding of the alpha 6 subunit-containing receptors.

Heteromeric NMDA receptors: molecular and functional distinction of subtypes.

The N-methyl D-aspartate (NMDA) receptor subtype of glutamate-gated ion channels possesses high calcium permeability and unique voltage-dependent sensitivity to magnesium and is modulated by glycine. Molecular cloning identified three complementary DNA species of rat brain, encoding NMDA receptor subunits NMDAR2A (NR2A), NR2B, and NR2C, which are 55 to 70% identical in sequence. These are structurally related, with less than 20% sequence identity, to other excitatory amino acid receptor subunits, including the NMDA receptor subunit NMDAR1 (NR1). Upon expression in cultured cells, the new subunits yielded prominent, typical glutamate- and NMDA-activated currents only when they were in heteromeric configurations with NR1. NR1-NR2A and NR1-NR2C channels differed in gating behavior and magnesium sensitivity. Such heteromeric NMDA receptor subtypes may exist in neurons, since NR1 messenger RNA is synthesized throughout the mature rat brain, while NR2 messenger RNA show a differential distribution.