Transitioning from intrathecal bupivacaine to mepivacaine for same-day discharge total joint arthroplasty: a quality improvement study.

INTRODUCTION: Same-day discharge total knee and hip arthroplasty is becoming more common. Anesthetic approaches that optimize readiness for discharge are important. Based on an institutional change from low-dose bupivacaine to mepivacaine, we aimed to assess the impact on postanesthesia care unit (PACU) recovery in a quaternary care, academic medical center. METHODS: In this quality improvement retrospective study, a single surgeon performed 96 combined total knee and hip arthroplasties booked as same-day discharge from September 20, 2021 to December 20, 2021. Starting on November 15, 2021 the subarachnoid block was performed with isobaric mepivacaine 37.5-45 mg instead of hyperbaric bupivacaine 9-10.5 mg. We compare these cohorts for time to discharge from PACU, perioperative oral morphine milligram equivalent (OMME) administration, PACU pain scores, conversion to general anesthesia (GA), and overnight admission. RESULTS: We found the use of isobaric mepivacaine as compared with hyperbaric bupivacaine for intrathecal block in same-day discharge total joint arthroplasty was associated with decreased length of PACU stay at our academic center (median 4.03 vs 5.33 hours; p=0.008), increased perioperative OMME (mean 22.5 vs 11.4 mg; p<0.001), increased PACU pain scores (mean 6.29 vs 3.41; p<0.01) and no difference in conversion to GA or overnight admission. CONCLUSIONS: Intrathecal mepivacaine was associated with increased perioperative OMME consumption and PACU pain scores, but still realized a decreased PACU length of stay.

Word differences in news media of lower and higher peace countries revealed by natural language processing and machine learning.

Language is both a cause and a consequence of the social processes that lead to conflict or peace. "Hate speech" can mobilize violence and destruction. What are the characteristics of "peace speech" that reflect and support the social processes that maintain peace? This study used existing peace indices, machine learning, and on-line, news media sources to identify the words most associated with lower-peace versus higher-peace countries. As each peace index measures different social properties, they can have different values for the same country. There is however greater consensus with these indices for the countries that are at the extremes of lower-peace and higher-peace. Therefore, a data driven approach was used to find the words most important in distinguishing lower-peace and higher-peace countries. Rather than assuming a theoretical framework that predicts which words are more likely in lower-peace and higher-peace countries, and then searching for those words in news media, in this study, natural language processing and machine learning were used to identify the words that most accurately classified a country as lower-peace or higher-peace. Once the machine learning model was trained on the word frequencies from the extreme lower-peace and higher-peace countries, that model was also used to compute a quantitative peace index for these and other intermediate-peace countries. The model successfully yielded a quantitative peace index for intermediate-peace countries that was in between that of the lower-peace and higher-peace, even though they were not in the training set. This study demonstrates how natural language processing and machine learning can help to generate new quantitative measures of social systems, which in this study, were linguistic differences resulting in a quantitative index of peace for countries at different levels of peacefulness.

Overview of Rate and Risk Factors of Surgical Site Infection in a Tertiary Hospital in Liberia: A Prospective Cohort Study.

Background: Surgical site infection (SSI) is accountable for a third of postoperative deaths and for 8% of all deaths due to hospital-acquired infections. There is a wide disparity in the incidence and burden of SSI in low and high-income countries. Objectives: To assess the rates and risk factors of SSI in a tertiary hospital in a resource-limited sub-Saharan African country and generate institutional baseline data for future monitoring and interventions. Materials and Methods: This was a descriptive prospective cohort study done at John F Kennedy Memorial Hospital, a tertiary hospital in Monrovia, Liberia, from October 18 to December 18, 2021. Consecutive participants, including children and adults that had surgical operations within the study period, were recruited. Criteria for diagnosis of SSI were as defined by the Centre for Disease Control (1999). Data were collected on the demography of the participants, type of surgery done, presence of SSI, comorbidities, and risk factors for SSI. Results: Of the 111 patients analyzed, thirty-two patients had SSI giving a hospital incident rate of 28.8%. This comprises superficial SSI (22/31; 71.0%), deep SSI (6/31; 19.4%), and organ/space SSI (3/31; 9.7%). Twelve out of 42 females (28.6%) and 20 of 69 males (29.0%) had SSI. There is no statistically significant difference in gender SSI rate (P = 0.963). SSI occurred more in dirty wounds (13/23; 56.5%), compared to contaminated wounds (6/11, 54.6%), clean contaminated (7/22; 31.8%), and clean wounds (6/55, 10.9%). There is a statistical difference in the rate of SSI among the wound classes (P = 0.001). The infection rate is also more in emergency surgeries (18/39, 46.2%) compared to elective surgeries (14/72, 19.4%), and it is significant (P = 0.003). Statistically, there was no significant difference between the two skin preparation agents used (P = 0.351). The abdomen was the most common site of surgical incision and had the highest rate of SSI (24/79; 30.4%) (P = 0.045). There was no statistical difference in SSI rate between those whose hairs were removed in the ward or in the theatre (P = 0.114); length of incision (P = 0.297), or duration of surgery (P = 0.715) (see table for classification and rates). Conclusion: The SSI rate in our study is high at 28.8%. Abdominal surgeries, emergencies, and wound class accounted for the majority of the SSIs. The baseline data will be useful in developing infection control strategies.

Cancer's camouflage: Microvesicle shedding from cholesterol-rich tumor plasma membranes might blindfold first-responder immunosurveillance strategies.

Intermediary metabolism of tumors is characterized, in part, by a dysregulation of the cholesterol biosynthesis pathway at its rate-controlling enzyme providing the molecular basis for tumor membranes (mitochondria, plasma membrane) to become enriched with cholesterol (Bloch, 1965; Feo et al., 1975; Brown and Goldstein, 1980; Goldstein and Brown, 1990). Cholesterol enriched tumor mitochondria manifest preferential citrate export, thereby providing a continuous supply of substrate precursor for the tumor's dysregulated cholesterogenesis via a "truncated" Krebs/TCA cycle (Kaplan et al., 1986; Coleman et al., 1997). Proliferating tumors shed elevated amounts of plasma membrane-derived extracellular vesicles (pmEV) compared with normal tissues (van Blitterswijk et al., 1979; Black, 1980). Coordination of these metabolic phenomena in tumors supports the enhanced intercalation of cholesterol within the plasma membrane lipid bilayer's cytoplasmic face, the promotion of outward protrusions from the plasma membrane, and the evolution of cholesterol enriched pmEV. The pmEV shed by tumors possess elevated cholesterol and concentrated cell surface antigen clusters found on the tumor cells themselves (Kim et al., 2002). Upon exfoliation, saturation of the extracellular milieu with tumor-derived pmEV could allow early onset mammalian immune surveillance mechanisms to become "blind" to an evolving cancer and lose their ability to detect and initiate strategies to destroy the cancer. However, a molecular mechanism is lacking that would help explain how cholesterol enrichment of the pmEV inner lipid bilayer might allow the tumor cell to evade the host immune system. We offer a hypothesis, endorsed by published mathematical modeling of biomembrane structure as well as by decades of in vivo data with diverse cancers, that a cholesterol enriched inner bilayer leaflet, coupled with a logarithmic expansion in surface area of shed tumor pmEV load relative to its derivative cancer cell, conspire to force exposure of otherwise unfamiliar membrane integral protein domains as antigenic epitopes to the host's circulating immune surveillance system, allowing the tumor cells to evade destruction. We provide elementary numerical estimations comparing the amount of pmEV shed from tumor versus normal cells.

Warburg's Ghost-Cancer's Self-Sustaining Phenotype: The Aberrant Carbon Flux in Cholesterol-Enriched Tumor Mitochondria via Deregulated Cholesterogenesis.

Interpreting connections between the multiple networks of cell metabolism is indispensable for understanding how cells maintain homeostasis or transform into the decontrolled proliferation phenotype of cancer. Situated at a critical metabolic intersection, citrate, derived via glycolysis, serves as either a combustible fuel for aerobic mitochondrial bioenergetics or as a continuously replenished cytosolic carbon source for lipid biosynthesis, an essentially anaerobic process. Therein lies the paradox: under what conditions do cells control the metabolic route by which they process citrate? The Warburg effect exposes essentially the same dilemma-why do cancer cells, despite an abundance of oxygen needed for energy-generating mitochondrial respiration with citrate as fuel, avoid catabolizing mitochondrial citrate and instead rely upon accelerated glycolysis to support their energy requirements? This review details the genesis and consequences of the metabolic paradigm of a "truncated" Krebs/TCA cycle. Abundant data are presented for substrate utilization and membrane cholesterol enrichment in tumors that are consistent with criteria of the Warburg effect. From healthy cellular homeostasis to the uncontrolled proliferation of tumors, metabolic alterations center upon the loss of regulation of the cholesterol biosynthetic pathway. Deregulated tumor cholesterogenesis at the HMGR locus, generating enhanced carbon flux through the cholesterol synthesis pathway, is an absolute prerequisite for DNA synthesis and cell division. Therefore, expedited citrate efflux from cholesterol-enriched tumor mitochondria via the CTP/SLC25A1 citrate transporter is fundamental for sustaining the constant demand for cytosolic citrate that fuels the elevated flow of carbons from acetyl-CoA through the deregulated pathway of cholesterol biosynthesis.

How to live in peace? Mapping the science of sustaining peace: A progress report.

Despite good faith attempts by countless citizens, civil society, governments, and the international community, living in a sustainably peaceful community continues to be an elusive dream in much of our world. Among the challenges to sustaining peace is the fact that few scholars have studied enduringly peaceful societies, or have examined only narrow aspects of them, leaving our understanding of the necessary conditions, processes and policies fragmented, and deficient. This article provides a work-in-progress overview of a multidisciplinary, multimethod initiative, which aims to provide a holistic, evidence-based understanding of how peace can be sustained in societies. The Sustaining Peace Project, launched in 2014, uses complexity science as an integrative platform for synthesizing knowledge across disciplines, sectors and communities. This article introduces the multiple components of the project and shares preliminary findings. (PsycInfo Database Record (c) 2022 APA, all rights reserved).

Fetal MRI in the Identification of a Fetal Ventral Wall Defect Spectrum.

Objective To ascertain if useful criteria for prenatal diagnosis of fetal ventral body wall defects (VBWDs) exists by reviewing published literature on diagnosis of VBWD as compared with our own diagnostic experience. Study Design A comprehensive literature review of diagnostic criteria of fetal VBWD including pentalogy of Cantrell (POC), omphalocele, exstrophy, imperforate anus, spina bifida (OEIS), cloacal exstrophy, limb-body wall complex (LBWC), and body stalk anomaly was performed followed by a retrospective review of all fetal magnetic resonance imaging (MRI) examinations from our medical center over a 2-year period. Results Classically, OEIS is omphalocele, bladder exstrophy, imperforate anus, and spina bifida. POC is defects of the supraumbilical abdomen, sternum, diaphragm, pericardium, and heart. LBWC is two of the following: exencephaly or enencephaly with facial clefts, thoracoschisis or abdominoschisis, and limb defects. Twenty-four cases of VBWD on MRI over a 24-month period were identified with seven cases involving defects of additional organ systems. Six of these seven cases demonstrated findings from two or more of the traditional diagnoses POC, OEIS, and LBWC making diagnosis and counseling difficult. Conclusion There is a lack of consensus on useful diagnostic criteria within the published literature which is reflected in our own diagnostic experience and poses a challenge for accurate prenatal counseling.

Radiation-Induced Cerebral Microbleeds in Pediatric Patients With Brain Tumors Treated With Proton Radiation Therapy.

PURPOSE: Proton beam radiation therapy (PBT) has been increasingly used to treat pediatric brain tumors; however, limited information exists regarding radiation-induced cerebral microbleeds (CMBs) among these patients. The purpose of this study was to evaluate the incidence, risk factors, and imaging appearance of CMBs in pediatric patients with brain tumors treated with PBT. MATERIALS AND METHODS: A retrospective study was performed of 100 pediatric patients with primary brain tumors treated with PBT. CMBs were diagnosed by examination of serial magnetic resonance imaging scans, including susceptibility-weighted imaging. Radiation therapy plans were analyzed to determine doses to individual CMBs. Clinical records were used to determine risk factors associated with the development of CMBs in these patients. RESULTS: The mean age at time of PBT was 8.1 years. The median follow-up duration was 57 months. The median time to development of CMBs was 8 months (mean, 11 months; range, 3-28 months). The percentage of patients with CMBs was 43%, 66%, 80%, 81%, 83%, and 81% at 1 year, 2 years, 3 years, 4 years, 5 years, and >5 years from completion of proton radiation therapy. Most of the CMBs (87%) were found in areas of brain exposed to ≥30 Gy. Risk factors included maximum radiation therapy dose (P = .001), percentage and volume of brain exposed to ≥30 Gy (P = .0004, P = .0005), and patient age at time of PBT (P = .0004). Chemotherapy was not a significant risk factor (P = .35). No CMBs required surgical intervention. CONCLUSIONS: CMBs develop in a high percentage of pediatric patients with brain tumors treated with proton radiation therapy within the first few years after treatment. Significant risk factors for development of CMBs include younger age at time of PBT, higher maximum radiation therapy dose, and higher percentage and volume of brain exposed to ≥30 Gy. These findings demonstrate similarities with CMBs that develop in pediatric patients with brain tumor treated with photon radiation therapy.

Fear of Cancer Recurrence: What Radiologists Should Know.

OBJECTIVE: Fear of cancer recurrence is both more common and more complex than many radiology personnel may suspect. CONCLUSION: By gaining a deeper understanding of such fears, radiologists and other health care professionals can provide care that better reflects and meets the needs of such patients.

Morton Deutsch (1920-2017).

Presents an obituary for Morton Deutsch, who died March 13, 2017, at 97 years old. Deutsch believed in the power of ideas to rectify serious social problems, and in the role of science to refine our understanding of those ideas. Ranked among the 100 most eminent psychologists of the 20th century, he was a distinguished theorist and pioneer in the study of cooperation, conflict resolution and social justice, as well as a remarkably warm, wise and respectful mentor. Deutsch held numerous leadership positions, including faculty positions at Teachers College, Columbia University and New York University and various presidencies, and accumulated dozens of awards, including eight lifetime achievement awards and the creation of four awards in his name. He also trained as a psychoanalyst and had a private practice for many years. In 1986, he founded the International Center for Cooperation and Conflict Resolution at Columbia, where he continued to work and welcome students well into his 90s. (PsycINFO Database Record

Living well with dementia groups: changes in participant and therapist verbal behaviour.

OBJECTIVES: This paper reports two related analyses of verbal material from seven Living Well with Dementia groups: the first examines changes in the verbal behaviours of participants across the course of the sessions in all seven groups; while the second contrasts therapist behaviour in two groups. METHODS: In the first analysis, recordings of three sessions from each group were transcribed and participant descriptions of dementia were analysed using the Markers of Assimilation of Problematic Experiences of Dementia (MAPED) rating procedure. In the second analysis, therapist behaviour in weeks 2 and 8 from two groups (F and G) was analysed using the Hill Counsellor Verbal response rating scale. Inter-rater reliabilities for the two sets of ratings were 'good' and 'very good', respectively. RESULTS: For the MAPED ratings, a five by four contingency table was analysed using chi-squared, which indicated a highly significant change in assimilation. There were significant higher levels of level 1 and 2 markers in the first two sessions and level 4 for sessions 5 and 6. Facilitators used significantly more direct guidance and information giving behaviour in the second session at Location F compared to Location G. CONCLUSIONS: The results suggest that important changes occurred in the way that dementia was described across the seven LivDem groups: this includes both reductions in the avoidance of direct references to dementia after the first two sessions, as well as an increase in 'insight' statements. Directive facilitator behaviour may be associated with poorer outcomes.

Supporting activity engagement by family carers at home: maintenance of agency and personhood in dementia.

An explorative paper to describe how family carers, through the caregiving journey, reaffirm and promote the agency of people with dementia. Agency is an important concept in dementia care and is crucial to the promotion of wellbeing and the delivery of person-centred care. This article is based on one of the key findings of a study that explored family carers' experiences of engaging their relatives in daily activities in domestic settings. Following research governance and ethical approval, 30 in-depth interviews (initial and follow-up) were carried out with 15 resident-carers of people with dementia who were recruited via local community mental health teams. Then five focus groups were conducted with 21 participants accessed through carers support groups. Interviews and focus groups were transcribed, coded and analysed using a grounded theory method. Findings showed the process in which family carers encouraged and sustained a sense of autonomy and control (agency) in their relative's daily activities. Key strategies used by carers included: being non-judgemental; facilitating a sense of worth; taking calculated risks; maintaining the continuity of their relative's identity; enhancing a sense of connection with their relative's role and identity using enjoyable activities; preventing inactivity and attending to the bodily source of the agency. Lack of support for carers could ultimately pose a risk to the maintenance of the agency of people with dementia. This study provides a deeper insight into the process used by home carers to support the agency of people with dementia. This is essential if practitioners are to identify and develop more realistic intervention strategies and to work in effective partnership with family carers. The implications for the creation of dementia-friendly communities are discussed.

Moving on or digging deeper: Regulatory mode and interpersonal conflict resolution.

Conflict resolution, in its most basic sense, requires movement and change between opposing motivational states. Although scholars and practitioners have long acknowledged this point, research has yet to investigate whether individual differences in the motivation for movement from state-to-state influence conflict resolution processes. Regulatory Mode Theory (RMT) describes this fundamental motivation as locomotion. RMT simultaneously describes an orthogonal motivational emphasis on assessment, a tendency for critical evaluation and comparison. We argue that this tendency, in the absence of a stronger motivation for locomotion, can obstruct peoples' propensity to reconcile. Five studies, using diverse measures and methods, found that the predominance of an individual's locomotion over assessment facilitates interpersonal conflict resolution. The first two studies present participants with hypothetical conflict scenarios to examine how chronic (Study 1) and experimentally induced (Study 2) individual differences in locomotion predominance influence the motivation to reconcile. The next two studies investigate this relation by way of participants' own conflict experiences, both through essay recall of previous conflict events (Study 3) and verbal narratives of ongoing conflict issues (Study 4). We then explore this association in the context of real-world conflict discussions between roommates (Study 5). Lastly, we examine results across these studies meta-analytically (Study 6). Overall, locomotion and assessment can inform lay theories of individual variation in the motivation to "move on" or "dig deeper" in conflict situations. We conclude by emphasizing the importance of using RMT to go beyond instrumental approaches to conflict resolution to understand fundamental individual motivations underlying its occurrence. (PsycINFO Database Record

Markers of assimilation of problematic experiences in dementia within the LivDem project.

This study aimed to determine whether the Markers of Assimilation of Problematic Experiences in Dementia scale (MAPED) can be used to identify whether the way in which participants talk about dementia changed during the group. All eight sessions of a LivDem group, which were attended by participants were recorded and transcribed. An initial analysis identified 160 extracts, which were then rated using the MAPED system. Inter-rater reliability was 61% and following a resolution meeting, 35 extracts were discarded, leaving 125 extracts with an agreed marker code. All of the participants were identified as producing a speech marker relating to dementia, and these varied between 0 (warding off) to 6 (problem solution). Examples of these markers are provided. The proportion of emergence markers (indicating the initial stages of assimilation) compared to later markers changed significantly between the first four sessions and the final sessions. This difference was still significant even when the markers produced by the most verbal participant, Graham, were excluded. The use of process measures within psychotherapy complements more conventional outcome measures and has both theoretical and clinical implications.

Integrating Buprenorphine Into an Opioid Treatment Program: Tailoring Care for Patients With Opioid Use Disorders.

OBJECTIVES: This report identifies the institutional barriers to, and benefits of, buprenorphine maintenance treatment (BMT) integration in an established hospital-based opioid treatment program (OTP). METHODS: This case study presents the authors' experiences at the clinic, hospital, and corporation levels during efforts to integrate BMT into a hospital-based OTP in New York City and a descriptive quantitative analysis of the characteristics of hospital outpatients treated with buprenorphine from 2006 to 2013 (N=735). RESULTS: Integration of BMT into an OTP offered patients the flexibility to transition between intensive structured care and primary care or outpatient psychiatry according to need. Main barriers encountered were regulations, clinical logistics of dispensing medications, internal cost and reimbursement issues, and professional and cultural resistance. CONCLUSIONS: Buprenorphine integration offers a model for other OTPs to facilitate partnerships among primary care and mental health clinics to better serve diverse patients with varying clinical needs and with varying levels of social support.

A pilot randomised controlled trial to compare changes in quality of life for participants with early diagnosis dementia who attend a 'Living Well with Dementia' group compared to waiting-list control.

OBJECTIVES: The aim of this paper is to report a pilot study in which participants who had recently received a diagnosis of dementia were randomised to either a 10-week group intervention or a waiting-list control. METHOD: Memory clinic staff with limited previous experience of group therapy were trained to lead a 10-week group therapy intervention called 'Living Well with Dementia'. Fifty-eight participants, all of whom had received a diagnosis of Alzheimer's disease, vascular or Lewy body dementia within the previous 18 months, were randomised to receive either the intervention or treatment as usual (waiting-list control). Data collection occurred at baseline, within two weeks after the intervention finished and at 10-week follow-up. RESULTS: The study met its recruitment targets, with a relatively low attrition rate for the intervention arm. The acceptability of the intervention and research methods was examined qualitatively and will be reported on elsewhere. For the primary outcome, measure of quality of life in Alzheimer's disease (QoL-AD), and secondary outcome, self-esteem, there was some evidence of improvement in the intervention group compared to the control group. There was, also, evidence of a reduction in cognitive functioning in the treatment group compared to the control. Such reported differences should be treated with caution because they are obtained from a pilot and not a definitive study. CONCLUSION: This pilot study succeeded in collecting data to inform a future definitive cost effectiveness clinical trial of Living Well with Dementia group therapy.

Behavioral and emotional dynamics of two people struggling to reach consensus about a topic on which they disagree.

We studied the behavioral and emotional dynamics displayed by two people trying to resolve a conflict. 59 groups of two people were asked to talk for 20 minutes to try to reach a consensus about a topic on which they disagreed. The topics were abortion, affirmative action, death penalty, and euthanasia. Behavior data were determined from audio recordings where each second of the conversation was assessed as proself, neutral, or prosocial. We determined the probability density function of the durations of time spent in each behavioral state. These durations were well fit by a stretched exponential distribution, [Formula: see text] with an exponent, [Formula: see text], of approximately 0.3. This indicates that the switching between behavioral states is not a random Markov process, but one where the probability to switch behavioral states decreases with the time already spent in that behavioral state. The degree of this "memory" was stronger in those groups who did not reach a consensus and where the conflict grew more destructive than in those that did. Emotion data were measured by having each person listen to the audio recording and moving a computer mouse to recall their negative or positive emotional valence at each moment in the conversation. We used the Hurst rescaled range analysis and power spectrum to determine the correlations in the fluctuations of the emotional valence. The emotional valence was well described by a random walk whose increments were uncorrelated. Thus, the behavior data demonstrated a "memory" of the duration already spent in a behavioral state while the emotion data fluctuated as a random walk whose steps did not have a "memory" of previous steps. This work demonstrates that statistical analysis, more commonly used to analyze physical phenomena, can also shed interesting light on the dynamics of processes in social psychology and conflict management.

Cell-specific gene expression in Anabaena variabilis grown phototrophically, mixotrophically, and heterotrophically.

BACKGROUND: When the filamentous cyanobacterium Anabaena variabilis grows aerobically without combined nitrogen, some vegetative cells differentiate into N2-fixing heterocysts, while the other vegetative cells perform photosynthesis. Microarrays of sequences within protein-encoding genes were probed with RNA purified from extracts of vegetative cells, from isolated heterocysts, and from whole filaments to investigate transcript levels, and carbon and energy metabolism, in vegetative cells and heterocysts in phototrophic, mixotrophic, and heterotrophic cultures. RESULTS: Heterocysts represent only 5% to 10% of cells in the filaments. Accordingly, levels of specific transcripts in vegetative cells were with few exceptions very close to those in whole filaments and, also with few exceptions (e.g., nif1 transcripts), levels of specific transcripts in heterocysts had little effect on the overall level of those transcripts in filaments. In phototrophic, mixotrophic, and heterotrophic growth conditions, respectively, 845, 649, and 846 genes showed more than 2-fold difference (p < 0.01) in transcript levels between vegetative cells and heterocysts. Principal component analysis showed that the culture conditions tested affected transcript patterns strongly in vegetative cells but much less in heterocysts. Transcript levels of the genes involved in phycobilisome assembly, photosynthesis, and CO2 assimilation were high in vegetative cells in phototrophic conditions, and decreased when fructose was provided. Our results suggest that Gln, Glu, Ser, Gly, Cys, Thr, and Pro can be actively produced in heterocysts. Whether other protein amino acids are synthesized in heterocysts is unclear. Two possible components of a sucrose transporter were identified that were upregulated in heterocysts in two growth conditions. We consider it likely that genes with unknown function represent a larger fraction of total transcripts in heterocysts than in vegetative cells across growth conditions. CONCLUSIONS: This study provides the first comparison of transcript levels in heterocysts and vegetative cells from heterocyst-bearing filaments of Anabaena. Although the data presented do not give a complete picture of metabolism in either type of cell, they provide a metabolic scaffold on which to build future analyses of cell-specific processes and of the interactions of the two types of cells.