The Efficacy and Safety of Transversus Abdominis Plane Blocks After Open Cholecystectomy in Low- and Middle-Income Countries

BACKGROUND

Postoperative pain management is challenging in low- and middle-income countries (LMICs). This study assesses the safety and efficacy of transversus abdominis plane (TAP) blocks as an adjunct for postoperative pain control after an open cholecystectomy in LMICs during short-term surgical missions (STSMs). TAP block is a regional anesthesia technique that has been shown to be effective in providing supplementary analgesia to the anterolateral wall post abdominal surgery.

METHODS

A retrospective chart review of patients undergoing open cholecystectomy during STSMs was performed. STSMs took place in Guatemala, the Philippines, and Peru from 2009 to 2019. Measured outcomes including pain scores, presence of postoperative nausea or vomiting, and opioid consumption were compared between TAP block and non-TAP block groups.

RESULTS

Of the 48 patients analyzed, 28 underwent TAP block (58%). Non-TAP block patients received, on average, 8 mg of oral morphine equivalents more than the TAP patients (P = 0.035). No significant difference was noted in pain scores, which were taken immediately after surgery, 2 h after surgery, and at multiple times between these time points to calculate an average. Of the patients who received a TAP block, 11% reported nausea or vomiting compared with 45% in the standard group (P < 0.01). There were no reported procedure-related complications.

CONCLUSIONS

TAP blocks are safe and effective adjuncts for postoperative pain management on STSMs to LMICs. Additional studies are needed to investigate the potential advantages and disadvantages of more widespread use of TAP blocks in LMICs.

A Retrospective Review of Spinal Radiofrequency Neurotomy Procedures in Patients with Metallic Posterior Spinal Instrumentation – Is it Safe?

Background: Recent studies have shown that medial branch radiofrequency neurotomy (RFN) procedures done at the level of a pedicle screw can increase pedicle screw temperature, and it has been speculated that pedicle screw heating may cause thermal injury. There has been a limited amount of investigation into the real-world safety profile of RFN procedures in patients with pedicle screws. Objectives: We aim to demonstrate that the occurrence of serious adverse events is rare for a medial branch RFN procedure completed at a level with metallic spinal hardware when performed according to the Spine Intervention Society practice standards. Study Design: This study involved retrospective chart reviews of every patient who received an RFN procedure for spinal facet joint pain during the 5-year time period from 2012-2016. Setting: The research took place within a single university-based interventional pain management center. Methods: The study sample included 507 patient charts. Data collection included patient demographics, RF denervation sites at a level with metallic hardware, and all serious RF-related complications that could be attributable to heated metallic hardware. The research team developed medical-chart abstraction criteria for each of the following categorized complications: a) superficial burns, b) deep burns, c) denervation of dorsal ramus, d) denervation of ventral ramus, and e) coagulation of a spinal vascular structure. Results: Of the 36 patients who met the inclusion criteria for this study, 43.6% were men and 56.4% were women. The mean age was 59.5 years old, with an age range of 25 to 87 years. There were a total of 56 ablations performed at a level with metallic spinal hardware, of which 11 were cervical, 44 were lumbar, and 1 was thoracic . There were zero documented complications found among our patient population in any of the 5 categories of serious complications. Limitations: As a retrospective chart review, this study was dependent on the availability and accuracy of medical records. Chart abstraction criteria for each outcome measure were developed by the research team without scientific testing. Conclusions: There have been no reported complications attributable to hardware temperature increases when performing medial branch RFNs at the level of a pedicle screw. For safety, it is important to use multiplanar fluoroscopic imaging techniques to ensure that the RFN cannula is not in contact with the pedicle screw. Key Words: Radiofrequency neurotomy, medial branch nerve ablation, safety, thermal injuries, metallic spinal hardware, pedicle screws, lateral mass screws, cervical facet joints, severe complications, adverse events

A Retrospective Review of Spinal Radiofrequency Neurotomy Procedures in Patients with Metallic Posterior Spinal Instrumentation - Is it Safe?

BACKGROUND

Recent studies have shown that medial branch radiofrequency neurotomy (RFN) procedures done at the level of a pedicle screw can increase pedicle screw temperature, and it has been speculated that pedicle screw heating may cause thermal injury. There has been a limited amount of investigation into the real-world safety profile of RFN procedures in patients with pedicle screws.

OBJECTIVES

We aim to demonstrate that the occurrence of serious adverse events is rare for a medial branch RFN procedure completed at a level with metallic spinal hardware when performed according to the Spine Intervention Society practice standards.

STUDY DESIGN

This study involved retrospective chart reviews of every patient who received an RFN procedure for spinal facet joint pain during the 5-year time period from 2012-2016.

SETTING

The research took place within a single university-based interventional pain management center.

METHODS

The study sample included 507 patient charts. Data collection included patient demographics, RF denervation sites at a level with metallic hardware, and all serious RF-related complications that could be attributable to heated metallic hardware. The research team developed medical-chart abstraction criteria for each of the following categorized complications: a) superficial burns, b) deep burns, c) denervation of dorsal ramus, d) denervation of ventral ramus, and e) coagulation of a spinal vascular structure.

RESULTS

Of the 36 patients who met the inclusion criteria for this study, 43.6% were men and 56.4% were women. The mean age was 59.5 years old, with an age range of 25 to 87 years. There were a total of 56 ablations performed at a level with metallic spinal hardware, of which 11 were cervical, 44 were lumbar, and 1 was thoracic . There were zero documented complications found among our patient population in any of the 5 categories of serious complications.

LIMITATIONS

As a retrospective chart review, this study was dependent on the availability and accuracy of medical records. Chart abstraction criteria for each outcome measure were developed by the research team without scientific testing.

CONCLUSIONS

There have been no reported complications attributable to hardware temperature increases when performing medial branch RFNs at the level of a pedicle screw. For safety, it is important to use multiplanar fluoroscopic imaging techniques to ensure that the RFN cannula is not in contact with the pedicle screw.

KEY WORDS

Radiofrequency neurotomy, medial branch nerve ablation, safety, thermal injuries, metallic spinal hardware, pedicle screws, lateral mass screws, cervical facet joints, severe complications, adverse events.

Broad-spectrum mildew resistance in Arabidopsis thaliana mediated by RPW8

Plant disease resistance (R) genes control the recognition of specific pathogens and activate subsequent defense responses. We show that the Arabidopsis thaliana locus RESISTANCE TO POWDERY MILDEW8 (RPW8) contains two naturally polymorphic, dominant R genes, RPW8.1 and RPW8.2, which individually control resistance to a broad range of powdery mildew pathogens. Although the predicted RPW8.1 and RPW8.2 proteins are different from the previously characterized R proteins, they induce localized, salicylic acid-dependent defenses similar to those induced by R genes that control specific resistance. Apparently, broad-spectrum resistance mediated by RPW8 uses the same mechanisms as specific resistance.

Comparison of Erysiphe cichoracearum and E. cruciferarum and a survey of 360 Arabidopsis thaliana accessions for resistance to these two powdery mildew pathogens

In previous work, UEA1 and UCSC1, two geographically distinct, powdery mildew isolates, were recognized for their ability to infect Arabidopsis thaliana. We have clarified the identity of these isolates by determining their host ranges, reexamining their morphology, and comparing their DNA sequences for the 5.8S ribosomal RNA and two flanking internal transcribed spacer sequences. These experiments confirm that UEA1 is a member of Erysiphe cruciferarum and that UCSC1 belongs to E. cichoracearum. Interactions of the two Erysiphe isolates with 360 A. thaliana accessions were examined to provide a comprehensive profile of naturally occurring powdery mildew resistance in this weedy species. The majority of A. thaliana accessions (213) were susceptible to both isolates. Among the accessions exhibiting some degree of resistance, most (84) responded differentially to UEA1 and UCSC1 and the remainder were resistant to both isolates. Notably, resistance to UCSC1 cosegregated with RPW7, a locus previously demonstrated to confer resistance to UEA1 in Ms-0 x Landsberg (erecta) crosses. With this large collection of resistant accessions, questions about species specificity, genetic diversity and the evolution of resistance to powdery mildews can be addressed.

Characterization of three loci controlling resistance of Arabidopsis thaliana accession Ms-0 to two powdery mildew diseases

Arabidopsis thaliana accession La-er was susceptible, and accession Ms-0 was resistant, to powdery mildew diseases caused by Erysiphe cruciferarum UEA1 and E. cichoracearum UCSC1. The resistance reaction phenotype of A. thaliana Ms-0 to both pathogens was characterized, and the resistance loci were genetically mapped. Growth of E. cruciferarum UEA1 on Ms-0 leaves was arrested after formation of the first appressorium: the underlying host epidermal cell collapsed, and occasionally there was necrosis of one or two host mesophyll cells. Growth of E. cichoracearum UCSC1 on Ms-0 leaves was arrested after emergence of several germ tubes from the conidium, and there was necrosis of host mesophyll cells at the sites of infection. Examination of F2 progeny of a cross La-er x Ms-0 indicated that two independently-segregating dominant loci were required for resistance to E. cruciferarum UEA1. One locus, named RPW6, was genetically mapped to chromosome 5, in a 5.6 cM interval flanked by pCITf16 and PI. The other locus, named RPW7, mapped to chromosome 3 in a 8.5 cM interval flanked by CDC2A and AFC1. Independent effects of RPW6 and RPW7 on E. cruciferarum UEA1 could be detected by quantitative measurements of growth of mycelium and production of conidia. Resistance to E. cichoracearum UCSC1 mapped to a single locus, named RPW8, at a location on chromosome 3 which we could not distinguish from RPW7. Evidently, RPW7 and RPW8 define either a complex resistance locus, or a common resistance gene with dual specificity.

Pricing in the NHS

Since the introduction of the NHS internal market, it has been necessary to price health care for contracts and extra contractual referrals. Internal markets, like conventional markets, operate via a pricing mechanism. This article describes the NHS pricing principles and the development of NHS pricing for acute hospital services in the first 5 years of the market.

The poster presentation as an educational tool

The authors describe their experiences in using the poster presentation to develop undergraduate nursing students in the scholarly role of professional nursing practice. The posters were used as a means for students to communicate their accomplishments in implementation and evaluation of an innovative clinical project. Methods for development, exhibition, and evaluation of the poster project are described.

Defective viral DNA ameliorates symptoms of geminivirus infection in transgenic plants

Nicotiana benthamiana was transformed with a single copy of a tandem repeat of subgenomic DNA B isolated from plants infected with a Kenyan isolate of the bipartite geminivirus African cassava mosaic virus. Symptoms in transformed plants were less severe than in nontransformed controls when challenged with virus or cloned DNA of Kenyan or Nigerian isolates. Symptom amelioration was associated with the mobilization and amplification of the subgenomic DNA, producing a comparable reduction in the amount of DNA specific to each genomic component. The disproportionate reduction in the levels of full-length components (DNA A, 20%; DNA B, 70%) indicates that the episomally replicating subgenomic DNA has been amplified at the expense of full-length DNA B to three times the level of the latter. Serial infection of transformants resulted in a further decrease in symptom severity and viral DNA levels. No differences were observed in the severity of symptoms or levels of viral DNA when transformants and controls were challenged with the related geminiviruses beet curly top virus and tomato golden mosaic virus, demonstrating the specific nature of the interaction. Analysis of infected tissue showed that tomato golden mosaic virus was unable to amplify the subgenomic DNA. However, since the production of subgenomic DNA is possibly a common feature of the bipartite geminiviruses, this approach might contribute to the production of plants showing increased tolerance to a number of economically important viral diseases.

Delimitation of essential genes of cassava latent virus DNA 2

Insertion and deletion mutagenesis of both extended open reading frames (ORFs) of cassava latent virus DNA 2 destroys infectivity. Infectivity is restored by coinoculating constructs that contain single mutations within different ORFs. Although frequent intermolecular recombination produces dominant parental-type virus, mutants can be retained within the virus population indicating that they are competent for replication and suggesting that rescue can occur by complementation of trans acting gene products. By cloning specific fragments into DNA 1 coat protein deletion vectors we have delimited the DNA 2 coding regions and provide substantive evidence that both are essential for virus infection. Although a DNA 2 component is unique to whitefly-transmitted geminiviruses, the results demonstrate that neither coding region is involved solely in insect transmission. The requirement for a bipartite genome for whitefly-transmitted geminiviruses is discussed.