Variations in Student Approaches to Problem Solving in Undergraduate Biology Education

Existing research has investigated student problem-solving strategies across science, technology, engineering, and mathematics; however, there is limited work in undergraduate biology education on how various aspects that influence learning combine to generate holistic approaches to problem solving. Through the lens of situated cognition, we consider problem solving as a learning phenomenon that involves the interactions between internal cognition of the learner and the external learning environment. Using phenomenography as a methodology, we investigated undergraduate student approaches to problem solving in biology through interviews. We identified five aspects of problem solving (including knowledge, strategy, intention, metacognition, and mindset) that define three qualitatively different approaches to problem solving; each approach is distinguishable by variations across the aspects. Variations in the knowledge and strategy aspects largely aligned with previous work on how the use or avoidance of biological knowledge informed both concept-based and nonconcept-based strategies. Variations in the other aspects revealed intentions spanning complete disengagement to deep interest with the course material, different degrees of metacognitive reflections, and a continuum of fixed to growth mindsets. We discuss implications for how these characterizations can improve instruction and efforts to support development of problem-solving skills.

Promoting student interest in plant biology through an inquiry-based module exploring plant circadian rhythm, gene expression, and defense against insects

We present a weeklong curricular module for high school biology students that promotes knowledge of phytohormones, the circadian clock, and the Central Dogma. The module, which relies on easily accessible items and requires minimal space, integrates a hands-on experiment that guides students through replicating research examining circadian entrainment in postharvest cabbage from groceries. This work found that plants have cyclical, circadian expression of genes that produce phytohormones, and that such cyclical expression influences herbivory by caterpillars. Such cyclical patterns were found in plants both in situ and in postharvest cabbage. This work thus provides an ideal platform to shape student conceptions of circadian rhythms, gene expression, and plant herbivory by having students use light timers to entrain postharvest cabbage to alternating light and dark cycles and then measuring herbivory in these plants. The results should replicate previous work and demonstrate less herbivory when both plant and caterpillar are entrained to the same light and dark cycles since the expression of phytohormones involved in plant defense will be greatest when caterpillars are active. The module then concludes with a discussion of gene regulation and how this influences phytohormones. This module was field tested at four public schools, reaching over 600 students, and we present data demonstrating that the module led to learning gains and likely increases in interest in plant biology and self-efficacy.

Exploring pathways to food science careers in Southern California: A case study in food science career development

Southern California is a diverse region that is home to a high concentration of food science companies, with an increasing demand for additional food scientists and technologists to join this workforce. Despite this abundance of food science companies and the high demand for jobs, there is currently a shortage in the number of qualified food scientists and technologists in the region. This shortage is also observed within higher education, with declining enrollments in the food science graduate and undergraduate programs across Southern California. Here, we conduct a case study to explore the factors that influence students from Southern California to pursue or not pursue careers in food science. We surveyed both undergraduate and graduate students currently enrolled in food science as well as industry professionals in the region to determine sources of knowledge about the discipline, and motivations and barriers for pursuing careers in food science. We also surveyed high school educators in the region to gain additional perspectives on how food science is being introduced at the secondary level, if at all. Our results demonstrate that many students and high school educators are not knowledgeable about career options within food science and that students who are pursuing food science largely report similar motivations for pursuing the discipline as those currently working in the food science industry. We conclude by discussing implications for the food science education community within Southern California and beyond.

Investigating the Influence of Assessment Question Framing on Undergraduate Biology Student Preference and Affect

Nearly all undergraduate biology courses rely on quizzes and exams. Despite their prevalence, very little work has been done to explore how the framing of assessment questions may influence student performance and affect. Here, we conduct a quasi-random experimental study where students in different sections of the same course were given isomorphic questions that varied in their framing of experimental scenarios. One section was provided a description using the self-referential term "you", placing the student in the experiment; another section received the same scenario that used classmate names; while a third section's scenario integrated counterstereotypical scientist names. Our results demonstrate that there was no difference in performance throughout the semester between the sections, nor were there differences in students' self-reported stress and identity. However, students in all three sections indicated that they most preferred the self-referential framing, providing a variety of reasons that suggest that these variants may influence how well a student reads and processes the question. In addition, our results also indicate that the framing of these scenarios can also have a large impact on some students' affect and attitude toward the question. We conclude by discussing implications for the biology education research community and biology instructors.

Reading Primary Scientific Literature: Approaches for Teaching Students in the Undergraduate STEM Classroom

Teaching undergraduate students to read primary scientific literature (PSL) is cited as an important goal for many science, technology, engineering, and math (STEM) classes, given a range of cognitive and affective benefits for students who read PSL. Consequently, there are a number of approaches and curricular interventions published in the STEM education literature on how to teach students to read PSL. These approaches vary widely in their instructional methods, target student demographic, required class time, and level of assessment demonstrating the method's efficacy. In this Essay, we conduct a systematic search to compile these approaches in an easily accessible manner for instructors, using a framework to sort the identified approaches by target level, time required, assessment population, and more. We also provide a brief review of the literature surrounding the reading of PSL in undergraduate STEM classrooms and conclude with some general recommendations for both instructors and education researchers on future areas of investigation.

Neutral theory and beyond: A systematic review of molecular evolution education

Molecular evolution-including the neutral theory of molecular evolution-is a major sub-discipline of evolution and is widely taught in undergraduate evolution courses. However, despite its ubiquity, there have not been any previous attempts to compile and review the molecular evolution education literature. Here, we draw upon the framework proposed in a past literature review examining the broader evolution education landscape to conduct a literature review of papers related to molecular evolution education, classifying the contributions of such papers to evolution pedagogy as well as evolution education research. We find that there remains very limited coverage of molecular evolution in the education literature, with existing papers focusing primarily on providing new instructional modules and strategies for teaching molecular evolution. Our work suggests several areas of critical need as well as opportunities to advance evolution education and evolution education research, including compiling instructional goals for the sub-discipline, developing validated assessments, and investigating student thinking related to molecular evolution. We conclude by providing general strategies, advice, and a novel curricular activity for teaching molecular evolution and the neutral theory of molecular evolution.

Insight from Biology Program Learning Outcomes: Implications for Teaching, Learning, and Assessment

Learning goals and objectives are a key part of instruction, informing curricular design, assessment, and learning. These goals and objectives are also applied at the programmatic level, with program learning outcomes (PLOs) providing insight into the skills that undergraduate biology programs intend for their students to master. PLOs are mandated by all major higher education accreditation agencies and play integral roles in programmatic assessment. Despite their importance, however, there have not been any prior attempts to characterize PLOs across undergraduate biology programs in the United States. Our study reveals that many programs may not be using PLOs to communicate learning goals with students. We also identify key themes across these PLOs and differences in skills listed between institution types. For example, some Vision & Change core competencies (e.g., interdisciplinary nature of science; connecting science to society; quantitative reasoning) are highlighted by a low percentage of programs, while others are shared more frequently between programs. Similarly, we find that biology programs at 4-year institutions likely emphasize PLOs relating to computational skills and research more than at 2-year institutions. We conclude by discussing implications for how to best use PLOs to support student learning, assessment, and curricular improvements.

Characterizing First-Year Biology Majors' Motivations and Perceptions of the Discipline

Understanding why students choose to major in biology provides important insight into the motivations of biology majors. It is similarly important to investigate how biology majors perceive the discipline, including associated activities, such as independent research, which can influence students' interests in the field and likelihood to persist in science, engineering, technology, and math. However, there has been little work done examining biology student motivations and perceptions, particularly at non-research-intensive universities or after the COVID-19 pandemic started. To address this gap, we surveyed the first-year cohort of biology majors at a private, comprehensive university. We found that students largely reported choosing the major because of interest in the field and/or the fact that the major would prepare them for specific careers. We also found that students had skewed conceptions of several major subdisciplines of biology (ecology and evolution; cell and molecular biology; and anatomy and physiology). Finally, most students reported not knowing what independent research is or presented naive conceptions of research. Our work offers a characterization of how first-year students at our university perceive the discipline, and we conclude by discussing changes that our program has made to address these results as well as implications for instructors and biology administrators.

Exploring physiology instructors' use of core concepts: pedagogical factors that influence choice of course topics

The physiology core concepts are designed to guide instructors in undergraduate physiology courses. However, although past work has characterized the alignment of physiology programs with the core concepts, it is unclear to what extent these core concepts have influenced instructors' pedagogical decisions or how represented these core concepts are across physiology courses. We surveyed undergraduate physiology instructors to determine their familiarity with the core concepts, the impact of the core concepts on their teaching, as well as the alignment of their courses with these core concepts. Instructors report predominantly relying on textbooks and past syllabi of their courses as resources that influence their instructional decisions on which topics to include in a course. However, many instructors report reorganizing their physiology courses in subsequent iterations or reducing the number of concepts covered to allow more time for critical thinking and active learning. In addition, we find that the majority of instructors indicate that they are not knowledgeable about the list of physiology core concepts and that the influence of these core concepts is limited even for those who report familiarity with the list of core concepts. Finally, we find that instructors report uneven coverage of physiology core concepts in their courses, with some core concepts ubiquitous while others are sparsely covered. We conclude by discussing implications of our work for the physiology education community and call for the continued development of resources to support new physiology instructors and the need to promote coverage of certain core concepts in physiology courses.NEW & NOTEWORTHY The physiology core concepts are a critical resource for undergraduate physiology instructors. Despite this, little past work has investigated the impact of these core concepts across institutions. We find that most instructors are unfamiliar with these core concepts and instead rely on other resources when developing and revamping their physiology courses. We also identify uneven coverage of the core concepts in the curriculum and offer implications for the physiology education community.

Student Motivations and Barriers toward Online and In-Person Office Hours in STEM Courses

Office hours are one of the most common support mechanisms found in courses. Despite the prevalence of office hours in life sciences classes, there has been little investigation of how science, technology, engineering, and math (STEM) students perceive office hours, particularly at non-research intensive universities or other institutions where a majority of students attend office hours. We surveyed more than 500 students, representing most life sciences majors at a comprehensive university, to investigate their motivations and barriers for attending office hours. We then compared instructors' perceptions to students' conceptions of office hours. We identified key themes in student and instructor comments using inductive, grounded theory, finding that students view a more limited range of benefits for office hours than instructors. Students likewise cited a larger number of barriers for attending than instructors perceived. In addition, while there were minimal differences in rates of office hours attendance and perception of office hours based on key demographic factors, we identify areas where students of different class years and gender perceive differences, suggesting areas of future research. Finally, we explored students' views of in-person versus online office hours, providing insight for instructors to better reach all students.

Setting college students up for success Kelly A. Hogan and Viji Sathy West Virginia University Press, 2022. 272 pp

A pair of researchers outline strategies for ensuring that postsecondary courses are inclusive.

Characterizing Biology Education Research: Perspectives from Practitioners and Scholars in the Field

Biology education research (BER) is a recently emerging field mainly focused on the learning and teaching of biology in postsecondary education. As BER continues to grow, exploring what goals, questions, and scholarship the field encompasses will provide an opportunity for the community to reflect on what new lines of inquiry could be pursued in the future. There have been top-down approaches at characterizing BER, such as aims and scope provided by professional societies or peer-reviewed journals, and literature analyses with evidence for current and historical research trends. However, there have not been previous attempts with a bottom-up approach at characterizing BER by directly surveying practitioners and scholars in the field. Here, we share survey results that asked participants at the Society for the Advancement of Biology Education Research (SABER) annual meeting what they perceive as current scholarship in BER as well as what areas of inquiry in the field that they would like to see pursued in the future. These survey responses provide us with information directly from BER practitioners and scholars, and we invite colleagues to reflect on how we can collectively and collaboratively continue to promote BER as a field.

Promoting Academic Integrity and Student Learning in Online Biology Courses

The COVID-19 pandemic has caused an abrupt shift in biology courses, with many transitioning to online instruction. This has led to an increased concern about academic integrity and cheating in online courses. Here, I draw upon the peer-reviewed literature to provide evidence-based answers to four questions concerning cheating and online biology courses: (i) What types of cheating are prevalent with the shift to online instruction? (ii) Should instructors make assessments open book and open notes? (iii) How does cheating occur in biology lab courses? (iv) Finally, what strategies can biology instructors take to uphold academic integrity with online learning? I frame these answers not only around academic integrity but on the potential impacts on student learning and discuss some strategies that may not only deter cheating but also promote greater student learning.

Instructor Strategies to Alleviate Stress and Anxiety among College and University STEM Students

While student stress and anxiety are frequently cited as having negative effects on students' academic performance, the role that instructors can play in mitigating these challenges is often underappreciated. We provide summaries of different evidence-based strategies, ranging from changes in instructional strategies to specific classroom interventions, that instructors may employ to address and ameliorate student stress and anxiety. While we focus on students in science, technology, engineering, and mathematics, the strategies we delineate may be more broadly applicable. We begin by highlighting ways in which instructors can learn about and prepare to act to alleviate stress and anxiety. We then discuss how to better connect with students and build an inclusive, equitable, and empowering classroom environment. When coupled with strategies to change student evaluation and assessment, these approaches may collectively reduce student stress and anxiety, as well as improve student performance. We then discuss the roles that instructors may play in empowering students with skills that improve their time management, studying, and approach toward learning, with an eye toward ensuring their success across all their academic endeavors. We conclude by noting areas in which further research is needed to determine best practices for alleviating student stress and anxiety.

Student perceptions of an inquiry-based molecular biology lecture and lab following a mid-semester transition to online teaching

The transition to online learning in spring 2020 was abrupt for both students and instructors. While many instructors moved to asynchronous classes, some institutions relied more heavily on synchronous online courses. Here, we evaluate student perceptions of an inquiry-based molecular biology lecture and lab course following this transition by comparing student survey responses from spring 2019, when the lecture and lab were fully in person, to spring 2020, when the lecture and lab started in person before transitioning to a synchronous online format. Students were asked to identify the main factors that supported their learning in lecture and lab, characterize the main barriers to learning in those courses, and discuss their preference of having an inquiry-based lab or a traditional "cookbook" lab with pre-determined answers. We coded these responses and provide one of the first studies to examine the impact of this online transition on student perceptions of learning in an inquiry-based molecular biology lecture and lab course.

Using primary literature on SARS-CoV-2 to promote student learning about evolution

The ongoing COVID-19 pandemic caused by SARS-CoV-2 has caused widespread deaths, illnesses, and societal disruption. I describe here how I pivoted a discussion-based senior biology capstone course to include a multiweek module surrounding one primary literature paper on the evolution of SARS-CoV-2 and the subsequent scientific discourse about the paper. Using a gradual reveal of the paper following the CREATE method (consider, read, elucidate, and think of the next experiment), I challenged students to learn new evolutionary principles and critically analyze the data surrounding the evolution and transmission of SARS-CoV-2 presented in the paper. I also provide general advice for implementing this module in future courses.

A "Choose-Your-Own" Classroom-Based Activity That Promotes Scientific Inquiry about RNA Interference

RNA interference (RNAi), the process that results in the degradation of a target gene's mRNA, is a fundamental part of eukaryotic gene regulation and is also an important molecular technique that allows for experimental manipulation of gene expression without altering DNA sequences. Despite the importance of RNAi, there have been relatively few lecture-based activities designed to teach about the consequences of this process and counter common misconceptions. I present here an inquiry-based activity that is centered around a "choose your own experiment" design where students generate hypotheses and critically evaluate their ideas by choosing several simulated experiments. The activity presents students with one of the original puzzling observations, the discovery that triggering overexpression of a given gene in a flower resulted in an opposite change in phenotype than expected, and the subsequent discovery that there was a dramatic decrease of that gene's mRNA, that sparked the discovery of RNAi. Students then propose a molecular mechanism for these results before using a limited budget of funding to simulate their choice of experiments. Simulated results are provided for these experiments, and students must work together to interpret and discuss these results before deciding on the next experiment. I provide a guide for instructors on how to implement this activity, with suggestions on how to vary the activity to fit different class sizes as well as an abbreviated version for instructors who are short on time. Finally, I include an aligned assessment so that instructors may check student learning about the impacts of RNAi.

Aspergillus-related pulmonary diseases in lung transplantation

While lung transplantation is an attractive treatment option for many end stage lung diseases, the relatively high 5-year mortality continues to be a significant limiting factor. Among the foremost reasons for this is the eventual development of obstructive chronic lung allograft dysfunction. Infections, which the lung allograft is especially prone to, are a major risk factor. Specifically, the Aspergillus species cause a higher burden of disease among lung transplant recipients, due to unique risk factors, such as relative hypoxemia. However, these risk factors also provide unique opportunities for treatment and preventative strategies, as outlined in this review.

Targeted complement inhibition and microvasculature in transplants: a therapeutic perspective

Active complement mediators play a key role in graft-versus-host diseases, but little attention has been given to the angiogenic balance and complement modulation during allograft acceptance. The complement cascade releases the powerful proinflammatory mediators C3a and C5a anaphylatoxins, C3b, C5b opsonins and terminal membrane attack complex into tissues, which are deleterious if unchecked. Blocking complement mediators has been considered to be a promising approach in the modern drug discovery plan, and a significant number of therapeutic alternatives have been developed to dampen complement activation and protect host cells. Numerous immune cells, especially macrophages, develop both anaphylatoxin and opsonin receptors on their cell surface and their binding affects the macrophage phenotype and their angiogenic properties. This review discusses the mechanism that complement contributes to angiogenic injury, and the development of future therapeutic targets by antagonizing activated complement mediators to preserve microvasculature in rejecting the transplanted organ.

Stereoselective synthesis of delta-lactones from 5-oxoalkanals via one-pot sequential acetalization, Tishchenko reaction, and lactonization by cooperative catalysis of samarium Ion and mercaptan

By the synergistic catalysis of samarium ion and mercaptan, a series of 5-oxoalkanals was converted to (substituted) delta-lactones in efficient and stereoselective manners. This one-pot procedure comprises a sequence of acetalization, Tishchenko reaction and lactonization. The deliberative use of mercaptan, by comparison with alcohol, is advantageous to facilitate the catalytic cycle. The reaction mechanism and stereochemistry are proposed and supported by some experimental evidence. Such samarium ion/mercaptan cocatalyzed reactions show the feature of remote control, which is applicable to the asymmetric synthesis of optically active delta-lactones. This study also demonstrates the synthesis of two insect pheromones, (2S,5R)-2-methylhexanolide and (R)-hexadecanolide, as examples of a new protocol for asymmetric reduction of long-chain aliphatic ketones.

Epstein-barr virus-associated malignancies: epidemiologic patterns and etiologic implications

Epstein-Barr virus (EBV), a ubiquitous B-lymphotrophic herpesvirus, has been found in the tumor cells of a heterogeneous group of malignancies (Burkitt's lymphoma, lymphomas associated with immunosuppression, other non-Hodgkin's lymphomas, Hodgkin's disease, nasopharyngeal carcinoma, gastric adenocarcinoma, lymphoepithelioma-like carcinomas, and immunodeficiency-related leiomyosarcoma). As the epidemiologic characteristics of these cancers have not been considered together, this review seeks to relate their incidence patterns and risk factors to EBV biology and virus-host interaction in an attempt to help elucidate factors involved in EBV-related carcinogenesis. We include a brief review of EBV virology and primary infection to provide a biologic context for considering the epidemiology, summarize the most salient epidemiologic features of each malignancy, synthesize epidemiologic data by risk factor to uncover commonalities and informative contrasts across the diseases, and propose hypotheses regarding etiologic mechanisms, based on the possible effect of the risk factors at various stages in the viral life cycle.

In vivo architecture of the manganese superoxide dismutase promoter

Mitochondrial manganese superoxide dismutase (Mn-SOD) is the primary cellular defense against damaging superoxide radicals generated by aerobic metabolism and as a consequence of inflammatory disease. Elevated expression of Mn-SOD therefore provides a potent cytoprotective advantage during acute inflammation. Mn-SOD contains a GC-rich and TATA/CAAT-less promoter characteristic of a housekeeping gene. In contrast, however, Mn-SOD expression is dramatically regulated in a variety of cells by numerous proinflammatory mediators, including lipopolysaccharide, tumor necrosis factor-alpha, and interleukin-1. To understand the underlying regulatory mechanisms controlling Mn-SOD expression, we utilized DNase I-hypersensitive (HS) site analysis, which revealed seven hypersensitive sites throughout the gene. Following high resolution DNase I HS site analysis, the promoter was found to contain five HS subsites, including a subsite that only appears following stimulus treatment. Dimethyl sulfate in vivo footprinting identified 10 putative constitutive protein-DNA binding sites in the proximal Mn-SOD promoter as well as two stimulus-specific enhanced guanine residues possibly due to alterations in chromatin structure. In vitro footprinting data implied that five of the binding sites may be occupied by a combination of Sp1 and gut-enriched Kr uppel-like factor. These studies have revealed the complex promoter architecture of a highly regulated cytoprotective gene.

Absence of Epstein-Barr virus EBER-1 transcripts in an epidemiologically diverse group of breast cancers

Epstein-Barr virus (EBV), a ubiquitous herpesvirus associated with certain lymphomas and carcinomas, has been identified within the malignant cells of a small proportion of breast tumors. As breast cancer is a very common malignancy in women, a pathogenetic role of EBV for even a subgroup of patients could have important implications for etiology and prevention. Therefore, we attempted to confirm the EBV-breast cancer association by exploring it in a representative case series stratified by characteristics that modify breast cancer risk. We studied a sample of 97 female and 28 male patients identified from a US population-based cancer registry. Patients were selected randomly within age, sex, ethnicity and tumor estrogen-receptor status groups. With their archived tumor tissues, we examined EBV presence using in situ hybridization for the EBER-1 transcript. In the 107 technically adequate specimens, we did not detect this viral transcript in any tumors, including one from a woman who also had an EBER-positive nasopharyngeal carcinoma. Our uniformly negative findings are extremely unlikely to have occurred by chance and cannot be attributed to selective sampling, as our study group included persons at diverse risk for breast cancer. We conclude that the EBV EBER-1 transcript is not commonly expressed in breast cancer, based on a broadly representative case series, though we cannot exclude an association of EBV within a particular population subgroup.

Absence of Epstein-Barr virus EBER-1 transcripts in an epidemiologically diverse group of breast cancers

Epstein-Barr virus (EBV), a ubiquitous herpesvirus associated with certain lymphomas and carcinomas, has been identified within the malignant cells of a small proportion of breast tumors. As breast cancer is a very common malignancy in women, a pathogenetic role of EBV for even a subgroup of patients could have important implications for etiology and prevention. Therefore, we attempted to confirm the EBV-breast cancer association by exploring it in a representative case series stratified by characteristics that modify breast cancer risk. We studied a sample of 97 female and 28 male patients identified from a US population-based cancer registry. Patients were selected randomly within age, sex, ethnicity and tumor estrogen-receptor status groups. With their archived tumor tissues, we examined EBV presence using in situ hybridization for the EBER-1 transcript. In the 107 technically adequate specimens, we did not detect this viral transcript in any tumors, including one from a woman who also had an EBER-positive nasopharyngeal carcinoma. Our uniformly negative findings are extremely unlikely to have occurred by chance and cannot be attributed to selective sampling, as our study group included persons at diverse risk for breast cancer. We conclude that the EBV EBER-1 transcript is not commonly expressed in breast cancer, based on a broadly representative case series, though we cannot exclude an association of EBV within a particular population subgroup.

Catalytic properties of human manganese superoxide dismutase

The depletion of superoxide catalyzed by human manganese superoxide dismutase (MnSOD) was observed spectrophotometrically by measuring the absorbance of superoxide at 250-280 nm following pulse radiolysis and by stopped-flow spectrophotometry. Catalysis showed an initial burst of activity lasting approximately 1 ms followed by the rapid emergence of a greatly inhibited catalysis of zero-order rate. These catalytic properties of human MnSOD are qualitatively similar to those reported for MnSOD from Thermus thermophilus (Bull, C., Niederhoffer, E. C., Yoshida, T., and Fee, J. A.(1991) J. Am. Chem. Soc. 113, 4069-4076). However, there are significant quantitative differences; the emergence of the inhibited form is approximately 30-fold more rapid for human MnSOD. The turnover number for human MnSOD at pH 9.4 and 20 degrees C was kcat = 4 x 10(4) s-1 and kcat/Km = 8 x 10(8) M-1 s-1, determined by a simulated fit of the model of Bull et al. (1991) to the pulse radiolysis data. We also report that the maximum of the visible absorption spectrum of human MnSOD (epsilon480 = 525 M-1 cm-1) showed a strong dependence on pH that could be described by an ionization of pKa 9.4 +/- 0.1 with a maximum at low pH.

[Pre- and intra-operative administration of epidural morphine provides good postoperative pain relief after laminectomy]

BACKGROUND

To evaluate the postoperative analgesic effect of epidural morphine administered at different timing in lumbar spine surgery.

METHODS

Eighty-four patients who were scheduled for elective lumbar spine surgery were randomized in three groups. Seventeen patients in group I who received non-steroid analgesics postoperatively (diclophenac sodium 50 mg, iv, q4h) served as control while thirty-six patients in group II who received single dose epidural morphine 3 mg in combination with 10 ml 2% lidocaine given at the lesion site (L4-5 or L5-S1) just before general anesthesia and thirty-one patients in group III who received 3 mg morphine in combination with 3 ml 2% lidocaine administered to the targeted epidural space by means of slow drippings just before wound closure were studied subjects.

RESULTS

During the first 24 h postoperatively, the patients in group II and group III suffered a pain which was significantly less in intensity as compared with those in group I (p < 0.05). We used the 10 cm visual analog pain score (VAS) to scale post-operative pain with "no pain" and "worst pain" respectively anchored at 0 and 10 cm. The incidence of side effects such as pruritus, nausea and vomiting was higher in group II and III than in group I. We did not evaluate the occurrence of urinary retention because routine retention urinary catheterization in all patients hampered us to do so. There were no significant differences in the quality and duration of analgesia between group II and III. Respiratory depression of clinical significance was not observed. Neither decrease in oxygen saturation below 92% registered on pulse oximetry nor decrease in respiratory rate below 12 cycles/min was found in the PACU.

CONCLUSIONS

Preoperative or intraoperative administration of epidural morphine could provide satisfactory analgesia in lumbar spine surgery during the first 24 h postoperatively.

[Disseminated intravascular coagulation--a case report]

A 31 year-old T1PoAoL1 female developed the early Disseminated Intravascular Coagulation (DIC) signs after cesarean section. The patient had recovery completely after transabdomen total hysterectomy (TAH) and blood products transfusion. Case presentation, literature review, possible pathogenetic mechanism and treatment of DIC were discussed.

Rat copper/zinc superoxide dismutase gene: isolation, characterization, and species comparison

A 13 kb rat Cu/ZnSOD genomic clone has been purified from a rat liver genomic library and completely characterized by restriction mapping, detailed sequencing and Southern blot analysis. This gene spans approximately 6 kb and contains five exons and four introns. Comparison of rat, mouse, and human Cu/ZnSOD genes reveals a high conservation in genomic organization and exon-intron junctions, including an unusual 5'GC donor sequence at the first intron. The gene contains a TATA box as well as an inverted CCAAT box, a feature common to both the mouse and human genes. Furthermore, several repeats were identified in the 5' promoter region of this gene, and these regulatory elements are also strikingly conserved in these three species.

Multiple mRNA species generated by alternate polyadenylation from the rat manganese superoxide dismutase gene

The mitochondrial enzyme, manganese superoxide dismutase (MnSOD) is an integral component of the cell's defense against superoxide-mediated cellular damage. We have isolated and characterized four cDNA clones and the structural gene for rat MnSOD. Northern analyses using MnSOD cDNA probes detected at least five mRNAs in all tissues and cell types examined. Southern and Northern analysis using a 3' non-coding sequence probe, common to all the cDNAs, showed hybridization only to genomic restriction fragments that correspond to our genomic clone and the five MnSOD mRNAs. These data demonstrate that all of the rat MnSOD transcripts are derived from a single functional gene. Primer extension data indicate that transcription initiation is clustered within a few bases. Northern analysis using intron probes demonstrates that all five transcripts are fully processed. Northern analysis using cDNA and genomic probes from sequences progressively 3' to the end of the coding sequence indicates that size heterogeneity in the MnSOD transcripts results from variations in the length of the 3' non-coding sequence. From this data and the location of potential polyadenylation signals near the expected sites of transcript termination, we conclude that the existence of multiple MnSOD mRNA species originate as the result of alternate polyadenylation.

[Effects of lidocaine cervical epidural blockade on respiratory function]

Cervical epidural anesthesia with 2% lidocaine has been shown to reduce ventilatory capacity in patients with normal lungs by Dr. Bromage. It is important to evaluate the respiratory effect of this technique which may induce intercostal and phrenic nerve paralysis. After institutional approval and informed content had been obtained, 50 patients undergoing OR & IR of upper limbs, mean age 24 +/- 4 yrs mean weight 65 +/- 6 kg, ASA status I-II without preoperative pulmonary dysfunction were studied. C7-T1 intervertebral space was identified by the hanging-drop technique using a 16G Tuochy needle. A catheter was inserted cranially to a distance of 12 cm. Pulmonary function measurement and arterial blood gas data were obtained before and 20', 50', 105' min after injection of 12 ml 2% plain lidocaine. The anesthesia levels were between C3-T3 and obtained at 13 +/- 2 min. Mean arterial blood gas analysis showed mild respiratory acidosis at 20 min (PaCO2: 46.0 +/- 3.5 mmHg). The measured values of IVC, VC, FVC, FEV1, PEF, when compared with control values were decreased over 15.60% of control values and 20% of predicted data at 20 min. The ratio of FEV1/VC, FEV1/FVC were still within normal limit (greater than 80%). The result was significantly compatible to the criteria of mild type of pulmonary function test. No respiratory distress was complained of and only cause little change of arterial blood gas.(ABSTRACT TRUNCATED AT 250 WORDS)

Hepatitis type B virus DNA in patients receiving hemodialysis: correlation with other HBV serological markers

Possible presence of hepatitis type B virus (HBV) was assessed in 239 end-stage renal failure patients who were receiving long-term maintenance hemodialysis (average 30.8 months; duration: 1-94 months), and who had not shown any other symptom of HBV infection. Their HBV serological markers, including HBV DNA, were evaluated together with those of normal control individuals. HBV surface antigen (HBsAg) was detected in 42 of the 239 dialysis patients, 15 of whom also positive for HBV DNA (mean +/- SD = 56.2 +/- 23.7 pg/100 microliters of serum). HBV DNA was also found in 22 of the 197 (11.2%) dialysis patients who were negative for HBsAg, with an average of 36.2 +/- 19.0 pg/100 microliters of serum. This rate of detecting HBV DNA in HBV seronegative dialysis individuals was significantly higher than the rate of 1.83% found among healthy HBsAg(-) individuals. Among these 22 dialysis patients who were HBsAg(-) but HBV DNA(+), 15 were found to possess antibodies against HBsAg (anti-HBs) and/or antibody against HBV e antigen (anti-HBe). These data suggested that the absence of serum HBV antigen or the presence of antibodies against HBV markers might not be sufficient to identify possible HBV infection in immunocompromised hosts such as hemodialysis patients.