Efficacy and Safety of Intrathecal Morphine for Cesarean Delivery: A Narrative Review.

PURPOSE OF REVIEW: Pain management is a critical aspect of care during and following a cesarean delivery. Without proper control of pain, individuals can experience poor mobility, increased thromboembolic events, and difficulty caring for the neonate in the postpartum period. There have been multiple methods for pain management for cesarean delivery and intrathecal morphine (ITM) has emerged as a prominent option for post-operative analgesia due to its efficacy, safety, and potential benefits over other treatments. This review analyzes data on efficacy, side effects, and safety of ITM and the pain control alternatives. RECENT FINDINGS: A comprehensive literature review was conducted to compare ITM with other analgesic techniques in post-cesarean patients. ITM was found to be as effective or better than other analgesic options, including bilateral quadratus lumborum block (QLB), opioid-free epidural analgesia (CSEA-EDA), and intravenous fentanyl. One study found that both ITM and oral analgesia were effective in pain control and that ITM caused fewer breakthrough pain events but had a longer duration and a greater rate of side effects than oral opioid analgesia. Commonly observed side effects of intrathecal opioids include nausea, vomiting, pruritus, and urinary retention, and it is thought that the adverse effects from intrathecal administration of opioids are short-lived. ITM may provide a decreased risk of DVT and coagulation by decreasing lower extremity weakness and numbness, thereby decreasing recovery time and increasing mobility. ITM is a safe and effective option for post-cesarean analgesia, with comparable pain relief to alternative forms of pain control, and side effects that are generally manageable. Further research is warranted to explore beneficial combinations with other methods of pain management and optimal dosing strategies.

Expansion of the genetic code through reassignment of redundant sense codons using fully modified tRNA.

Breaking codon degeneracy for the introduction of non-canonical amino acids offers many opportunities in synthetic biology. Yet, despite the existence of 64 codons, the code has only been expanded to 25 amino acids in vitro. A limiting factor could be the over-reliance on synthetic tRNAs which lack the post-transcriptional modifications that improve translational fidelity. To determine whether modified, wild-type tRNA could improve sense codon reassignment, we developed a new fluorous method for tRNA capture and applied it to the isolation of roughly half of the Escherichia coli tRNA isoacceptors. We then performed codon competition experiments between the five captured wild-type leucyl-tRNAs and their synthetic counterparts, revealing a strong preference for wild-type tRNA in an in vitro translation system. Finally, we compared the ability of wild-type and synthetic leucyl-tRNA to break the degeneracy of the leucine codon box, showing that only captured wild-type tRNAs are discriminated with enough fidelity to accurately split the leucine codon box for the encoding of three separate amino acids. Wild-type tRNAs are therefore enabling reagents for maximizing the reassignment potential of the genetic code.

Cell numbers, cell ratios, and developmental plasticity in the rod pathway of the mouse retina.

The precise specification of cellular fate is thought to ensure the production of the correct number of neurons within a population. Programmed cell death may be an additional mechanism controlling cell number, believed to refine the proper ratio of pre- to post-synaptic neurons for a given species. Here, we consider the size of three different neuronal populations in the rod pathway of the mouse retina: rod photoreceptors, rod bipolar cells, and AII amacrine cells. Across a collection of 28 different strains of mice, large variation in the numbers of all three cell types is present. The variation in their numbers is not correlated, so that the ratio of rods to rod bipolar cells, as well as rod bipolar cells to AII amacrine cells, varies as well. Establishing connectivity between such variable pre- and post-synaptic populations relies upon plasticity that modulates process outgrowth and morphological differentiation, which we explore experimentally for both rod bipolar and AII amacrine cells in a mouse retina with elevated numbers of each cell type. While both rod bipolar dendritic and axonal arbors, along with AII lobular arbors, modulate their areal size in relation to local homotypic cell densities, the dendritic appendages of the AII amacrine cells do not. Rather, these processes exhibit a different form of plasticity, regulating the branching density of their overlapping arbors. Each form of plasticity should ensure uniformity in retinal coverage in the presence of the independent specification of afferent and target cell number.

Distinct critical behaviors from the same state in quantum spin and population dynamics perspectives.

There is a deep connection between the ground states of transverse-field spin systems and the late-time distributions of evolving viral populations-within simple models, both are obtained from the principal eigenvector of the same matrix. However, that vector is the wave-function amplitude in the quantum spin model, whereas it is the probability itself in the population model. We show that this seemingly minor difference has significant consequences: Phase transitions that are discontinuous in the spin system become continuous when viewed through the population perspective, and transitions that are continuous become governed by new critical exponents. We introduce a more general class of models that encompasses both cases and that can be solved exactly in a mean-field limit. Numerical results are also presented for a number of one-dimensional chains with power-law interactions. We see that well-worn spin models of quantum statistical mechanics can contain unexpected new physics and insights when treated as population-dynamical models and beyond, motivating further studies.

Unroofed Coronary Sinus in a Patient With Prior Surgical Closure of Secundum Atrial Septal Defect.

An unroofed coronary sinus is an uncommon congenital cardiac anomaly. It leads to a left to right shunt like an atrial septal defect (ASD) and comprises <1% of all ASDs. It can also additionally create a pathway for paradoxical embolization to the brain and other attendant complications. Here, we present the case of an asymptomatic 40-year-old-male with a history of prior surgical closure of an ostium secundum ASD who was referred for preoperative evaluation for non-cardiac surgery. An unroofed coronary sinus with persistent left superior vena cava (PLSVC) was suspected on transthoracic echocardiography and confirmed by transesophageal echocardiography.

Variation of stress levels, burnout, and resilience throughout the academic year in first-year medical students.

Medical student wellness is of great concern in the health care field. A growing number of studies point to increases in suicide, depression, anxiety, mood disorders, and burnout related to physician lifestyles. Mental health issues commencing in medical school have been suggested to have a significant impact on future physician lifestyle and burnout. Tracking the mental health of medical students at the University of Toledo College of Medicine and Life Sciences (UTCOMLS) with standardized indices will help elucidate triggers of poor mental health. Anonymous surveys were developed and distributed to preclinical medical students at five strategic time points throughout the 2018 2019 academic year. Surveys collected basic demographic information as well as inventories measuring perceived stress, burnout, resilience, and mindfulness. 172 M1s (83 males and 89 females) were included in the study and average response rate for the first 4 (out of 5) surveys averaged 74.8%. M1 males and females had on average increased personal burnout over time with females consistently scoring higher. Both males and females had an increase in stress from August to each subsequent month (p<0.05). Females reported a higher level of perceived stress than males in the beginning and middle of the academic year (p<0.05). Both males and females report a gradual decrease in resiliency throughout the academic year. These surveys demonstrated over half of males and females in medical school reported higher perceived stress scores than their gender-matched peers in the general United States population. Our study strengthens documented trends in resiliency, perceived stress, and burnout amongst medical students. More study in designing targeted approaches to ameliorate these findings in the medical student population is warranted.

Bacterial adherence to cotton and silk sutures.

BACKGROUND: Silk and cotton sutures are the most commonly used materials for skin closure, the choice being largely based on tradition. We undertook this study to compare the bacterial adherence in vitro to these two materials because it is well known that the physicochemical characteristics of a suture material influence its ability to attract bacteria and consequently promote wound infection. METHODS: We determined the bacterial adherence in vitro to cotton and silk for Staphylococcus aureus and Escherichia coli, common organisms found in postoperative infection at our institute, using three inoculum strengths. The sutures were incubated with the organisms and bacterial counts per suture material calculated after 20, 60, 120 and 180 hours of incubation. The bacterial counts for the sutures were then compared at these intervals. RESULTS: The bacterial adherence for both organisms at all time intervals was significantly greater to silk than to cotton, except at 60 hours for Staphylococcus aureus. The bacterial count for each suture material appeared to be an intrinsic property of the suture and did not vary with the concentration of the bacteria in the initial inoculum. The cost of an equivalent thickness of silk is 50 times that of cotton. CONCLUSION: We suggest that cotton should be the preferred suture for skin closure because bacterial adherence to it is lower and it is much cheaper than silk.