Multiorgan MRI findings after hospitalisation with COVID-19 in the UK (C-MORE): a prospective, multicentre, observational cohort study

INTRODUCTION

The multiorgan impact of moderate to severe coronavirus infections in the post-acute phase is still poorly understood. We aimed to evaluate the excess burden of multiorgan abnormalities after hospitalisation with COVID-19, evaluate their determinants, and explore associations with patient-related outcome measures.

METHODS

In a prospective, UK-wide, multicentre MRI follow-up study (C-MORE), adults (aged ≥18 years) discharged from hospital following COVID-19 who were included in Tier 2 of the Post-hospitalisation COVID-19 study (PHOSP-COVID) and contemporary controls with no evidence of previous COVID-19 (SARS-CoV-2 nucleocapsid antibody negative) underwent multiorgan MRI (lungs, heart, brain, liver, and kidneys) with quantitative and qualitative assessment of images and clinical adjudication when relevant. Individuals with end-stage renal failure or contraindications to MRI were excluded. Participants also underwent detailed recording of symptoms, and physiological and biochemical tests. The primary outcome was the excess burden of multiorgan abnormalities (two or more organs) relative to controls, with further adjustments for potential confounders. The C-MORE study is ongoing and is registered with ClinicalTrials.gov, NCT04510025.

FINDINGS

Of 2710 participants in Tier 2 of PHOSP-COVID, 531 were recruited across 13 UK-wide C-MORE sites. After exclusions, 259 C-MORE patients (mean age 57 years [SD 12]; 158 [61%] male and 101 [39%] female) who were discharged from hospital with PCR-confirmed or clinically diagnosed COVID-19 between March 1, 2020, and Nov 1, 2021, and 52 non-COVID-19 controls from the community (mean age 49 years [SD 14]; 30 [58%] male and 22 [42%] female) were included in the analysis. Patients were assessed at a median of 5·0 months (IQR 4·2-6·3) after hospital discharge. Compared with non-COVID-19 controls, patients were older, living with more obesity, and had more comorbidities. Multiorgan abnormalities on MRI were more frequent in patients than in controls (157 [61%] of 259 vs 14 [27%] of 52; p<0·0001) and independently associated with COVID-19 status (odds ratio [OR] 2·9 [95% CI 1·5-5·8]; padjusted=0·0023) after adjusting for relevant confounders. Compared with controls, patients were more likely to have MRI evidence of lung abnormalities (p=0·0001; parenchymal abnormalities), brain abnormalities (p<0·0001; more white matter hyperintensities and regional brain volume reduction), and kidney abnormalities (p=0·014; lower medullary T1 and loss of corticomedullary differentiation), whereas cardiac and liver MRI abnormalities were similar between patients and controls. Patients with multiorgan abnormalities were older (difference in mean age 7 years [95% CI 4-10]; mean age of 59·8 years [SD 11·7] with multiorgan abnormalities vs mean age of 52·8 years [11·9] without multiorgan abnormalities; p<0·0001), more likely to have three or more comorbidities (OR 2·47 [1·32-4·82]; padjusted=0·0059), and more likely to have a more severe acute infection (acute CRP >5mg/L, OR 3·55 [1·23-11·88]; padjusted=0·025) than those without multiorgan abnormalities. Presence of lung MRI abnormalities was associated with a two-fold higher risk of chest tightness, and multiorgan MRI abnormalities were associated with severe and very severe persistent physical and mental health impairment (PHOSP-COVID symptom clusters) after hospitalisation.

INTERPRETATION

After hospitalisation for COVID-19, people are at risk of multiorgan abnormalities in the medium term. Our findings emphasise the need for proactive multidisciplinary care pathways, with the potential for imaging to guide surveillance frequency and therapeutic stratification.

FUNDING

UK Research and Innovation and National Institute for Health Research.

Clinical characteristics with inflammation profiling of long COVID and association with 1-year recovery following hospitalisation in the UK: a prospective observational study

BACKGROUND

No effective pharmacological or non-pharmacological interventions exist for patients with long COVID. We aimed to describe recovery 1 year after hospital discharge for COVID-19, identify factors associated with patient-perceived recovery, and identify potential therapeutic targets by describing the underlying inflammatory profiles of the previously described recovery clusters at 5 months after hospital discharge.

METHODS

The Post-hospitalisation COVID-19 study (PHOSP-COVID) is a prospective, longitudinal cohort study recruiting adults (aged ≥18 years) discharged from hospital with COVID-19 across the UK. Recovery was assessed using patient-reported outcome measures, physical performance, and organ function at 5 months and 1 year after hospital discharge, and stratified by both patient-perceived recovery and recovery cluster. Hierarchical logistic regression modelling was performed for patient-perceived recovery at 1 year. Cluster analysis was done using the clustering large applications k-medoids approach using clinical outcomes at 5 months. Inflammatory protein profiling was analysed from plasma at the 5-month visit. This study is registered on the ISRCTN Registry, ISRCTN10980107, and recruitment is ongoing.

FINDINGS

2320 participants discharged from hospital between March 7, 2020, and April 18, 2021, were assessed at 5 months after discharge and 807 (32·7%) participants completed both the 5-month and 1-year visits. 279 (35·6%) of these 807 patients were women and 505 (64·4%) were men, with a mean age of 58·7 (SD 12·5) years, and 224 (27·8%) had received invasive mechanical ventilation (WHO class 7-9). The proportion of patients reporting full recovery was unchanged between 5 months (501 [25·5%] of 1965) and 1 year (232 [28·9%] of 804). Factors associated with being less likely to report full recovery at 1 year were female sex (odds ratio 0·68 [95% CI 0·46-0·99]), obesity (0·50 [0·34-0·74]) and invasive mechanical ventilation (0·42 [0·23-0·76]). Cluster analysis (n=1636) corroborated the previously reported four clusters: very severe, severe, moderate with cognitive impairment, and mild, relating to the severity of physical health, mental health, and cognitive impairment at 5 months. We found increased inflammatory mediators of tissue damage and repair in both the very severe and the moderate with cognitive impairment clusters compared with the mild cluster, including IL-6 concentration, which was increased in both comparisons (n=626 participants). We found a substantial deficit in median EQ-5D-5L utility index from before COVID-19 (retrospective assessment; 0·88 [IQR 0·74-1·00]), at 5 months (0·74 [0·64-0·88]) to 1 year (0·75 [0·62-0·88]), with minimal improvements across all outcome measures at 1 year after discharge in the whole cohort and within each of the four clusters.

INTERPRETATION

The sequelae of a hospital admission with COVID-19 were substantial 1 year after discharge across a range of health domains, with the minority in our cohort feeling fully recovered. Patient-perceived health-related quality of life was reduced at 1 year compared with before hospital admission. Systematic inflammation and obesity are potential treatable traits that warrant further investigation in clinical trials.

FUNDING

UK Research and Innovation and National Institute for Health Research.

Patient experiences of fertility clinic closure during the COVID-19 pandemic: appraisals, coping and emotions

STUDY QUESTION

What are appraisals, coping strategies and emotional reactions of patients to coronavirus disease 2019 (COVID-19) fertility clinic closures?

SUMMARY ANSWER

Clinic closure was appraised as stressful due to uncertainty and threat to the attainability of the parenthood goal but patients were able to cope using strategies that fit the uncertainty of the situation.

WHAT IS KNOWN ALREADY

Psychological research on COVID-19 suggests that people are more anxious than historical norms and moderately to extremely upset about fertility treatment cancellation owing to COVID-19.

STUDY DESIGN, SIZE, DURATION

The study was of cross-sectional design, comprising a mixed-methods, English language, anonymous, online survey posted from April 09 to April 21 to social media. Eligibility criteria were being affected by COVID-19 fertility clinic closure, 18 years of age or older and able to complete the survey in English. In total, 946 people clicked on the survey link, 76 did not consent, 420 started but did not complete survey, and 450 completed (48% completion, 446 women, four men).

PARTICIPANTS/MATERIALS, SETTING, METHODS

Overall 74.7% (n = 336) of respondents were residents in the UK with an average age of 33.6 years (SD = 4.4) and average years trying to conceive, 3.5 years (SD = 2.22). The survey comprised quantitative questions about the intensity of cognitive appraisals and emotions about clinic closure, and ability to cope with clinic closure. Open-text questions covered their understanding of COVID-19 and its effect on reproductive health and fertility plans, concerns and perceived benefits of clinic closure, and knowledge about closure. Sociodemographic information was collected. Descriptive and inferential statistics were used on quantitative data. Thematic qualitative analysis (inductive coding) was performed on the textual data from each question. Deductive coding grouped themes from each question into meta-themes related to cognitive stress and coping theory.

MAIN RESULTS AND THE ROLE OF CHANCE

Most patients (81.6%, n = 367) had tests or treatments postponed, with these being self (41.3%, n = 186) or publicly (46.4%, n = 209) funded. Patients appraised fertility clinic closure as having potential for a more negative than positive impact on their lives, and to be very or extremely uncontrollable and stressful (p ≤ .001). Most reported a slight to moderate ability to cope with closure. Data saturation was achieved with all open-text questions, with 33 broad themes identified and four meta-themes linked to components of the cognitive stress and coping theory. First, participants understood clinic closure was precautionary due to unknown effects of COVID-19 but some felt clinic closure was unfair relative to advice about getting pregnant given to the public. Second, closure was appraised as a threat to attainability of the parenthood goal largely due to uncertainty of the situation (e.g., re-opening, effect of delay) and intensification of pre-existing hardships of fertility problems (e.g., long time waiting for treatment, history of failed treatment). Third, closure taxed personal coping resources but most were able to cope using thought-management (e.g., distraction, focusing on positives), getting mentally and physically fit for next treatments, strengthening their social network, and keeping up-to-date. Finally, participants reported more negative than positive emotions (p ≤  .001) and almost all participants reported stress, worry and frustration at the situation, while some expressed anger and resentment at the unfairness of the situation. Overall, 11.9% were not at all able to cope, with reports of intense feelings of hopelessness and deteriorating wellbeing and mental health.

LIMITATIONS, REASONS FOR CAUTION

The survey captures patient reactions at a specific point in time, during lockdown and before clinics announced re-opening. Participants were self-selected (e.g., UK residents, women, 48% starting but not completing the survey), which may affect generalisability.

WIDER IMPLICATIONS OF THE FINDINGS

Fertility stakeholders (e.g., clinics, patient support groups, regulators, professional societies) need to work together to address the great uncertainty from COVID-19. This goal can be met proactively by setting up transparent processes for COVID-19 eventualities and signposting to information and coping resources. Future psychological research priorities should be on identifying patients at risk of distress with standardised measures and developing digital technologies appropriate for the realities of fertility care under COVID-19.

STUDY FUNDING/COMPETING INTEREST(S)

University funded research. Outside of the submitted work, Professor Boivin reports personal fees from Merck KGaA, Merck AB, Theramex, Ferring Pharmaceuticals A/S; grants from Merck Serono Ltd; and that she is co-developer of the Fertility Quality of Life (FertiQoL) and MediEmo apps. Outside of the submitted work, Dr. Mathur reports personal or consultancy fees from Manchester Fertility, Gedeon Richter, Ferring and Merck. Outside of the submitted work, Dr. Gameiro reports consultancy fees from Ferring Pharmaceuticals A/S, Access Fertility and SONA-Pharm LLC, and grants from Merck Serono Ltd. The other authors declare no conflicts of interest.

TRIAL REGISTRATION NUMBER

N/A

Determination of Fluoride in Wine by Fluoride Selective Ion Electrode, Standard Addition Method: Collaborative Study

The accuracy, precision, and reproducibility of a rapid method for determination of fluoride in wine, using a fluoride selective ion electrode, were established by a collaborative study involving 12 laboratories, 5 in Europe and 7 in the United States. The laboratories assayed 6 Youden pairs of fluo-ride-fortified, red and white wine samples with fluoride concentrations ranging from 0.2 to 3.0 mg/L. The relative standard deviations of repeatability ranged from 1.94 to 4.88%; relative standard deviations of reproducibility ranged from 4.15 to 18.40%. HORRAT values ranged from 0.30 to 0.97. The average recovery was 99.97%. Based on the statistical results of this collaborative study, the Study Director recommends that this method be adopted First Action.

Determination of Ochratoxin A in Wine and Beer by Immunoaffinity Column Cleanup and Liquid Chromatographic Analysis with Fluorometric Detection: Collaborative Study

The accuracy, repeatability, and reproducibility characteristics of a liquid chromatographic method for the determination of ochratoxin A (OTA) in white wine, red wine, and beer were established in a collaborative study involving 18 laboratories in 10 countries. Blind duplicates of blank, spiked, and naturally contaminated materials at levels ranging from ≤0.01 to 3.00 ng/mL were analyzed. Wine and beer samples were diluted with a solution containing polyethylene glycol and sodium hydrogen carbonate, and the diluted samples were filtered and cleaned up on an immunoaffinity column. OTA was eluted with methanol and quantified by reversed-phase liquid chromatography with fluorometric detection. Average recoveries from white wine, red wine, and beer ranged from 88.2 to 105.4% (at spiking levels ranging from 0.1 to 2.0 ng/mL), from 84.3 to 93.1% (at spiking levels ranging from 0.2 to 3.0 ng/mL), and from 87.0 to 95.0% (at spiking levels ranging from 0.2 to 1.5 ng/mL), respectively. Relative standard deviations for within-laboratory repeatability (RSDr) ranged from 6.6 to 10.8% for white wine, from 6.5 to 10.8% for red wine, and from 4.7 to 16.5% for beer. Relative standard deviations for between-laboratories reproducibility (RSDR) ranged from 13.1 to 15.9% for white wine, from 11.9 to 13.6% for red wine, and from 15.2 to 26.1% for beer. HORRAT values were ≤0.4 for the 3 matrixes.

P666Anti-platelet therapy in the primary prevention of cardiovascular disease in patients with chronic obstructive pulmonary disease: randomised controlled proof of concept trial (APPLE COPD-ICON 2)

Acknowledgement/Funding

Astra Zeneca (Funder reference number ISSBRIL0303)

Regulation of IL-12p40 by HIF controls Th1/Th17 responses to prevent mucosal inflammation

Intestinal inflammatory lesions are inherently hypoxic, due to increased metabolic demands created by cellular infiltration and proliferation, and reduced oxygen supply due to vascular damage. Hypoxia stabilizes the transcription factor hypoxia-inducible factor-1α (HIF) leading to a coordinated induction of endogenously protective pathways. We identified IL12B as a HIF-regulated gene and aimed to define how the HIF-IL-12p40 axis influenced intestinal inflammation. Intestinal lamina propria lymphocytes (LPL) were characterized in wild-type and IL-12p40^-/- murine colitis treated with vehicle or HIF-stabilizing prolyl-hydroxylase inhibitors (PHDi). IL12B promoter analysis was performed to examine hypoxia-responsive elements. Immunoblot analysis of murine and human LPL supernatants was performed to characterize the HIF/IL-12p40 signaling axis. We observed selective induction of IL-12p40 following PHDi-treatment, concurrent with suppression of Th1 and Th17 responses in murine colitis models. In the absence of IL-12p40, PHDi-treatment was ineffective. Analysis of the IL12B promoter identified canonical HIF-binding sites. HIF stabilization in LPLs resulted in production of IL-12p40 homodimer which was protective against colitis. The selective induction of IL-12p40 by HIF-1α leads to a suppression of mucosal Th1 and Th17 responses. This HIF-IL12p40 axis may represent an endogenously protective mechanism to limit the progression of chronic inflammation, shifting from pro-inflammatory IL-12p70 to an antagonistic IL-12p40 homodimer.

Thirteen years of oxcarbazepine exposures reported to US poison centers

Objectives:

Oxcarbazepine (OXC) is a 10-keto analogue of carbamazepine used in patients with partial and secondary generalized seizures. We evaluated ingestions of OXC reported to US poison centers for adverse effects from supratherapeutic doses and/or overdose.

Method:

Retrospective analysis of data reported to National Poison Data System from single-substance OXC ingestions between January 2000 and December 2012.

Results:

There were 18,867cases with a mean of 1451 exposures/year. The patients were predominantly adults with 5464 exposures in children <6 years (29%). The most commonly reported clinical effects were drowsiness ( n = 4703, 25%), vomiting ( n = 1559, 8%), tachycardia ( n = 590, 3%), agitated ( n = 342, 1.8%), hypotension ( n = 178, 0.9%), electrolyte disturbance ( n = 153, 0.8%), coma (n = 156, 0.8%), and seizures ( n = 121, 0.6%). There were 176 patients with a major effect of which 31 involved were children and 1728 (9%) patients with moderate effects of which 300 involved were children. Five deaths were reported in adults. Intentional exposure (e.g. suicide) was the reason for exposure in 68% of patients with major effects and in all fatalities. Fifty-three percent of adults and 38% of children were managed in a health-care facility (HCF). HCF utilization levels remained consistent.

Discussion:

Severe outcomes appear to be infrequent (<1%). Unlike other anticonvulsants OXC does not appear to be proconvulsant in overdose.

Conclusion:

Serious outcomes for OXC overdoses are unlikely in the pediatric patient. With only mild symptoms likely, observation at home may be appropriate for the majority of cases. In the adult population there appears to be few neurologic and cardiovascular complications even in the intentional exposure.

Age-related thermal response: the cellular resilience of juveniles

Understanding species' responses to environmental challenges is key to predicting future biodiversity. However, there is currently little data on how developmental stages affect responses and also whether universal gene biomarkers to environmental stress can be identified both within and between species. Using the Antarctic clam, Laternula elliptica, as a model species, we examined both the tissue-specific and age-related (juvenile versus mature adult) gene expression response to acute non-lethal warming (12 h at 3 °C). In general, there was a relatively muted response to this sub-lethal thermal challenge when the expression profiles of treated animals, of either age, were compared with those of 0 °C controls, with none of the "classical" stress response genes up-regulated. The expression profiles were very variable between the tissues of all animals, irrespective of age with no single transcript emerging as a universal biomarker of thermal stress. However, when the expression profiles of treated animals of the different age groups were directly compared, a very different pattern emerged. The profiles of the younger animals showed significant up-regulation of chaperone and antioxidant transcripts when compared with those of the older animals. Thus, the younger animals showed evidence of a more robust cellular response to warming. These data substantiate previous physiological analyses showing a more resilient juvenile population.

105 BOVINE EMBRYO TYPE, GRADE AND RECIPIENT SYNCHRONY, BUT NOT CORPUS LUTEUM QUALITY, INFLUENCED PREGNANCY RATES IN COMMERCIAL EMBRYO TRANSFER

Embryo transfer is a tool that enables progressive cattle producers to reach their reproductive, genetic and financial goals. The complexity of pregnancy establishment increases with any reproductive technology, especially with one with many variables. This clinical analysis employed a statistical model capable of explaining factors that affect pregnancy probability resulting from over 8000 embryo transfers. These data included corpus luteum (CL) quality score, embryo stage (morula to blastocyst) and grade (1–3), recipient synchrony (relative to the embryo age) and pregnancy rate (≥45 days). The CL score was an amalgamation of the palpable diameter of the CL, whether or not a crown was present and the overall quality of the reproductive tract (size of the uterine horns and perceived patency of the cervix). Embryos produced by IVF were transferred fresh and in vivo–produced embryos were transferred fresh (VIVO FRESH) or following cryopreservation (VIVO FROZ). Statistical methods were used to compare types of embryos transferred and pregnancy rates. All data were analysed using JMP 2009 software by logistic regression with the Logit link. Analysis for the odds of pregnancy occurring among groups using contrasts was conducted. Fisher's exact test showed significant differences (P < 0.05) among groups for pregnancy rate, with the VIVO FRESH embryos group having the highest rate (68.5 ± 1.5%) and the VIVO FROZ the lowest (54.7 ± 1.6%) and the IVF embryos were intermediate (62.1 ± 3.3%). Synchrony, stage, embryo grade and CL quality were analysed for their predictive ability of pregnancy rates in the IVF, VIVO FRESH and VIVO FROZ groups using effect tests with a P < 0.05. Interestingly, the CL quality had no predictive ability for any of the groups. Effectors that had an influence on the VIVO FROZ group included synchrony, stage and embryo grade. However, for the IVF and VIVO FRESH groups, pregnancy rates were affected by only embryo grade. Retrospective, observational analysis of commercial embryo transfer data represents a challenge to meaningful interpretation. Because of the nature of the business, experimental treatments cannot always be developed and implemented. Nonetheless, valuable information is gained by using appropriate statistical methods. As anticipated, these data suggested that the type of embryo transferred, grade and synchrony of the recipient are all important factors, particularly for cryopreserved embryos. Unexpectedly, the score of the CL did not influence pregnancy outcome regardless of embryo type. Evaluation of clinical data allows adjustment of embryo transfer protocols, facilitates genetic gain via enhanced reproductive success and provides a unique opportunity to analyse large, real-world data sets.

Radiation Defect-Induced Lattice Contraction of InP

We studied the lattice strain induced in the MeV ion bombarded InP crystals and the annealing behaviors of lattice strain, Raman line shift, and linewidth. The lattice spacing for the planes parallel to the surface decreases as a result of irradiation, and amounts to a strain of −0.061% for (100) face, −0.056% for (110) face, and −0.050% for (111) face for 15 MeV Cl bombarded samples to a dose of 1.25E15 ions/cm2. The negative lattice strain, Raman line shift, and line width completely recover at 450°C, and show a major recovery stage at 250°C – 350°C.

248 PRODUCTION OF FLAGGED RECOMBINANT BOVINE BMP15 TO IMPROVE BOVINE IN VITRO EMBRYO PRODUCTION SYSTEMS

Current in vitro systems for bovine embryo production are inefficient and produce embryos with lower viability than their in vivo-derived counterparts. Recent reports demonstrate that in vitro bovine oocyte maturation systems could benefit from the addition of oocyte-secreted factors, specifically GDF9 and BMP15 (Gilchrist et al. 2007 Theriogenology 67, 6–15). The long-term goal of this work is to produce species-specific recombinant oocyte-secreted factors capable of improving bovine embryo production in vitro. In the current project, the objective was to produce a cell line that expresses recombinant bovine BMP15. This protein is first translated as a large precursor peptide consisting of propeptide and mature regions, which are enzymatically cleaved to form the active mature protein. The wild-type BMP15 gene was cloned using reverse transcriptase PCR with RNA obtained from bovine ovarian tissue. For improved detection and purification of the active form of the recombinant protein, a detectable FLAG tag sequence (DYKDDDDK) was incorporated into the wild-type BMP15 gene by PCR and cloned into pCDNA expression vector. The FLAG tag was introduced immediately 3′ of the cleavage site at the N-terminal portion of the mature protein to produce recombinant FLAG-tagged BMP15 (rbFL-BMP15). To ensure efficient production of the mature protein, a Kozak sequence was inserted 5′ of the start ATG and the cleavage site altered to be recognised by PACE/furin enzymes, which are endogenously expressed in most mammalian cells including HEK-293 cells (Li et al. 2009 Mol. Hum. Reprod. 15, 779–788). Following sequencing to verify transcript fidelity, pCDNA-rbFL-BMP15 was transfected into HEK-293 cells, and mature protein production was detected by Western blot analysis. Cells plated at 85% confluency were transfected with Lipofectamine 2000, and lysates were harvested 48 h post-transfection. The presence of bovine rbFL-BMP-15 in cell lysates was confirmed by Western blot using the anti-FLAG antibody. Ongoing experiments will test the bioactivity of the purified rbFL-BMP15 by evaluating activation of the SMAD 1/5 pathway via Western blot for phosphorylated SMAD 1/5. After a biologically active protein is confirmed, purified protein will be collected for testing during in vitro maturation of bovine oocytes. We anticipate the species-specific form of oocyte-secreted factors will further enhance in vitro embryo production systems beyond that reported using heterologous factors.

Transcription profiling of acute temperature stress in the Antarctic plunderfish Harpagifer antarcticus

Harpagifer antarcticus (the Antarctic plunderfish), a shallow-water benthic fish distributed around the Antarctic Peninsula, is a member of the notothenioid family, one of whose adaptations to the cold waters of Antarctica has been the loss of the classic heat shock response. In order to gain a more comprehensive understanding of the effects of temperature stress on H. antarcticus, we constructed a liver cDNA library and a 10,371 feature microarray. This was hybridized with material from a time course series of animals held at 6°C for 48h. The resulting expression profiles show that this fish displays the classical vertebrate acute inflammatory response. There was also a pronounced signal for increased energy requirements via up-regulation of genes involved in the β oxidation of fatty acids and also a strong signature of response to oxidative stress. Genes in the latter category did not include the "classic" antioxidants such as glutathione S-transferase, but genes involved in the production of reducing potential in the form of NADPH, peroxisome proliferation via peroxisomal acyl co-enzyme A oxidase 1 and genes known to be up-regulated by hypoxia-inducible factor 1 (HIF1). These identifications provide clear support for oxygen being the whole animal limiting factor at least in acute short-term temperature challenges. The classical heat shock proteins were not up-regulated during this trial, although numerous clones for each were present on the gene chip, confirming the lack of this response in this species. These data significantly increase our knowledge of the cellular stress response from animals in this unique environment.

Gene expression associated with changes in cold tolerance levels of the Antarctic springtail, Cryptopygus antarcticus

The ability of the Antarctic microarthropod Cryptopygus antarcticus (Collembola, Isotomidae) to survive low temperatures has been well studied at the physiological level, with recent investigations indicating the importance of the moulting process in conferring this ability. This study investigated gene expression in groups of C. antarcticus that have distinct differences in their ability to survive low temperatures. A microarray containing c. 5400 C. antarcticus expressed sequence tags was used to investigate gene expression differences between groups of animals with different supercooling points (SCP), and to low temperatures close to their SCP. By demonstrating the involvement of moult-related genes in the differential survival of two groups of C. antarcticus with distinct SCP profiles, the results of this investigation add support to the suggestion that moulting plays a role in conferring cold tolerance in C. antarcticus.

266 BIRTH OF CANINE OFFSPRING FOLLOWING INSEMINATION OF A BITCH WITH FLOW-SORTED SPERMATOZOA

Different traits and temperaments that are sex-related often underlie the selection of guide dogs used for auditory and/or visually impaired humans. The objective of this project was to select X-chromosome-bearing canine sperm by means of flow cytometry/cell sorting based on DNA content (X chromosome- bearing canine sperm contain 3.7% more DNA than Y-chromosome-bearing sperm) and use the sorted sperm for artificial insemination (AI) to produce live offspring. This technology has proven reliable for sex selecting offspring using AI in a number of species and is of great commercial value to food animal livestock production. To test the efficacy of sorted canine sperm, a 2-year-old nulliparous Labrador retriever bitch in observed heat was monitored for plasma progesterone levels for a baseline rise to 2.8 ng mL–1, indicative of the LH surge. Progesterone levels more than doubled (5.8 ng mL–1) 2 days later, suggesting ovulation. One ejaculate was collected from a proven Labrador retriever stud on each of Days 2, 5, and 6 following the estimated LH peak. Sperm (200 million) were diluted in TRIS buffer without egg yolk (pH 7.4) and stained with 97.4 µm Hoechst 33342 in 1-mL aliquots for 45 min in a 34.5�C water bath and then diluted to 100 million sperm mL–1 with 4% egg yolk TRIS (pH 6.2) containing 0.002% food coloring dye (FD&C #40). Sperm were sex-sorted using an SX MoFlo™ sperm sorter (Dako, Fort Collins, CO, USA), operated at 40 psi and using a TRIS-based medium (pH = 6.8, 370 mOsm kg–1 water) as sheath fluid: 10 000–20 000 events s–1 and sort rates of 800–2000 sperm s–1. Sorted sperm were concentrated by centrifugation for 20 min at 850g and, after the supernatant was removed, were extended with 20% egg yolk TRIS extender (pH 6.8) to a total volume of 2 mL. Transcervical insemination of fresh, sorted sperm occurred within 9 h of the semen collection. An additional 1 mL of 20% egg yolk TRIS extender was used to flush the insemination catheter. The respective number of X-chromosome-bearing sperm inseminated per day was 46.2, 20.3, and 18.2 million, totaling 84.7 million sperm, and the weighted purity mean across the 3 sort days was 82%. Pregnancy was ascertained by ultrasound 30 days post-AI. Five puppies (3 female and 2 male) were delivered via natural birth 62 days after first AI. Only 60% of the offspring were of the predicted sex due to an 18% probability of chance, given the weighted mean purity of the sorted sperm and for a litter of 5 puppies. This demonstrates that fresh canine sperm can be separated by sex on the basis of DNA content, and transcervical insemination of low numbers of non-frozen sorted canine sperm can be used to produce live offspring. This work was funded by XY, Inc.

Analysis of veterinary drug residues in fish and shrimp composites collected during the Canadian Total Diet Study, 1993–2004

Thirty shrimp, marine fish, freshwater fish, and canned fish composite samples collected and prepared as part of the Canadian Total Diet Study were analysed for 39 different veterinary drug residues. The analyses were undertaken to obtain baseline data that could be used to estimate the dietary exposure of Canadians to these residues. The most frequently observed residue was AOZ (four out of 30 samples), the metabolite of furazolidone, at a range of 0.50 to 2.0 ng g(-1) wet weight. Other residues detected included enrofloxacin (three samples; 0.3-0.73 ng g(-1)), leucomalachite green (three samples; 0.73-1.2 ng g(-1)), oxolinic acid (two samples; 0.3-4.3 ng g(-1)), AMOZ (the metabolite of furaltadone; one sample; 0.40 ng g(-1)), chloramphenicol (one sample; 0.40 ng g(-1)), and SEM (the metabolite of nitrofurazone; one sample; 0.8 ng g(-1)). The results of this survey indicate that Canadians are exposed to low ng g-1 concentrations of some banned and unapproved veterinary drug residues via the consumption of certain fish and shrimp.

Complications Common to Ventricular Assist Device Support Are Rare with 90 Days of DeBakey VAD® Support in Calves

The DeBakey VAD is a miniaturized, electromagnetically driven axial flow pump intended for long-term ventricular assist. Safety and performance data from six calves implanted with the complete DeBakey VAD system are reported elsewhere; here we describe complications and necropsy findings for these same six animals, all of which survived 90 days. The study was conducted according to a uniform protocol, which included anticoagulation and antibiotic prophylaxis. Clinical complications tracked included bleeding, cardiovascular abnormalities (e.g., arrhythmias, tachycardia unrelated to pain, bradycardia), hemolysis, hepatic dysfunction, renal dysfunction, thromboembolism (neurologic or peripheral), or infection. Each adverse event was retrospectively categorized with regard to severity (mild, moderate, severe) and relationship to device. Clinical findings were confirmed by necropsy. There was no evidence of systemic infection, thromboembolism, hemolysis, or renal or hepatic dysfunction in these six animals during the study period. A single adverse event was noted in each of two of the calves. Both events were considered mild according to the predefined criteria. Bleeding related to the surgical implantation procedure and requiring reoperation occurred in one animal. The other animal had evidence of a superficial infection at the exit site of the cables on the left lateral thoracic wall; the infection did not extend into the thoracic cavity. Chronic, healed small renal infarct scars were present in several animals. Mild valvular endocardiosis was observed in two calves and mild fibroelastosis was present in the endocardium at the site of the inflow cannula in three calves; however, these lesions were not considered clinically significant. No other gross or histologic abnormalities were noted at necropsy. In conclusion, calves implanted with the complete DeBakey VAD for 90 days demonstrated few complications and had no significant necropsy findings. Complications common to ventricular assist device (VAD) support (i.e., hemolysis, infection, bleeding, thromboembolism) were rare during long-term support (90 days) with the DeBakey VAD.

A simple turbidimetric assay designed for the routine screening as well as therapeutic monitoring of native LDL particles

We describe the development and performance of a homogeneous assay for the direct turbidimetric determination of LDL particles in human serum. The assay is based upon the specific agglutination of LDL particles by the polyanion PAMPS. The co-agglutination of VLDL is avoided by the addition of a zwitterionic detergent. Yielding results within 10 min, the assay requires only a small sample volume taken directly from primary serum tubes, i.e., no pretreatment of the sample is necessary. It can be easily applied to routine clinical chemistry analyzers. The results are highly correlated with LDL cholesterol determinations by ultracentrifugation (r>0.95) and dextran sulfate precipitation (r>0.95), but an increased recovery of small, high density LDL particles is observed, which more adequately reflects the atherogenic risk of LDL. The assay provides excellent intra- and inter-assay CVs in the range of 0.6--1.6 and 1.7--2.4%, respectively, on Roche Diagnostics/Hitachi analyzers. The method is well suited to the high-throughput screening of LDL cholesterol levels.

Glucose absorption in acute peritoneal dialysis

OBJECTIVE

During acute peritoneal dialysis (APD), it is known that glucose found in the dialysate solution contributes to the provision of significant calories. It has been well documented in continuous ambulatory peritoneal dialysis (CAPD) that glucose absorption occurs. In APD, however, it remains unclear how much glucose absorption actually does occur. Therefore, the purpose of this study was to determine whether it is appropriate to use the formula used to calculate glucose absorption in CAPD (Grodstein et al) among patients undergoing APD.

METHODS

Actual measurements of glucose absorption (Method I) were calculated in 9 patients undergoing APD treatment for >24 hours who were admitted to the intensive care unit. Glucose absorption using the Grodstein et al formula (Method II) was also determined and compared with the results of actual measurements. The data was then further analyzed based on the factors that influence glucose absorption, specifically dwell time and concentration.

RESULTS

The mean total amount of glucose absorbed was 43% +/- 15%. However, when dwell time and concentration were further examined, significant differences were noted. Method I showed a cumulative increase over time. Method II showed that absorption was fixed. This suggests that with the variation in dwell time commonly seen in the acute care setting, the use of Method II may not be accurate. In each of the 2 methods, a significant difference in glucose absorption was noted when comparing the use of 1.5% and 4.25% dialysate concentrations.

CONCLUSION

The established formula designed for CAPD should not be used for calculating glucose absorption in patients receiving APD because variation in dwell time and concentration should be taken into account. Because of the time constraints and staffing required to calculate each exchange individually, combined with the results of the study, we recommend the use of the percentage estimate of 40% to 50%.

Chronic survival of calves implanted with the DeBakey ventricular assist device

The DeBakey ventricular assist device (VAD) is a miniaturized, electromagnetically driven axial flow pump capable of generating in excess of 10 L/min output. The VAD was evaluated in 19 calves during experiments designed to test iterative modifications in the system and to determine the safety of the DeBakey VAD for intermediate to long-term implant. Five of the animals died or were euthanized during the perioperative period (i.e., Days 1-5) due to complications associated with bleeding (n = 3), sudden cardiac arrest (n = 1), or pump occlusion due to a muscle remnant associated with coring (n = 1). The remaining 14 animals survived from 7-145 days. Ten of the 14 animals survived 30 or more days, and 2 animals survived 93 and 145 days before elective euthanasia. Pump function was evaluated in the 14 calves that survived beyond the perioperative period. Pump output at implantation averaged 3 L/min while output at 100 days (n = 2) averaged 4.22 L/min. The electrical current did not change across time during the study, indicating normal operation of the bearings. Pumps consumed less than 10.5 W of power for all support durations. Hemolysis did not occur; the average daily plasma free hemoglobin varied from 2.0 to 8.0 mg/dl. Evaluation of serum biochemical data showed that implantation of the DeBakey VAD in calves with normal hearts did not impair end organ function; BUN, creatinine, and total bilirubin varied minimally within the normal range. The white blood cell count of implanted animals remained within the normal range throughout the study.

Dilatational percutaneous tracheostomy: modification of technique

BACKGROUND

Major inherent risks associated with percutaneous dilatational tracheostomy include loss of airway during endotracheal tube manipulation, inability to cannulate the trachea below the endotracheal tube, and difficulties related to neck anatomy.

METHOD

Percutaneous dilatational tracheostomy technique was modified to make the incision in the suprasternal area, and the use of air leak technique confirmed tracheal penetration below the endotracheal cuff. Bronchoscopy was not used.

RESULTS

One hundred patients underwent percutaneous dilatational tracheostomy using the modification mentioned above. Although three patients had minor bleeding complications, there was no loss of airway; nor were there other complications.

CONCLUSION

This technique provides improved safety from loss of airway and illuminates the need for concomitant bronchoscopy.

Management of blunt splenic trauma in patients older than 55 years. Southern Connecticut Regional Trauma Quality Assurance Committee

BACKGROUND

Many experts have suggested that blunt splenic trauma in patients older than 55 years should not be managed by observation because of supposed increased fragility of the spleen and decreased physiologic reserve in elderly patients. We sought to determine the outcome of nonoperative management of blunt splenic trauma in patients older than 55 years.

METHODS

For the years 1994 through 1996, data for patients with splenic injury older than 55 years from seven trauma centers in a single state were reviewed.

RESULTS

Blunt splenic trauma occurred in 41 patients older than 55 years. Eight patients were excluded from further analysis because of death from massive associated injuries within 24 hours of admission. The remaining 33 patients (mean age, 72+/-10 years) were divided into two groups: immediate exploration (10 patients) and observation (23 patients). Observation of blunt splenic injury failed in 4 of 23 patients (17%). No patient deaths were related to the method of management of the splenic injury.

CONCLUSIONS

Observation of the elderly patient with blunt splenic trauma has an acceptable failure rate of 17%.

Organ failure, infection, and the systemic inflammatory response syndrome are associated with elevated levels of urinary intestinal fatty acid binding protein: study of 100 consecutive patients in a surgical intensive care unit

BACKGROUND

Intestinal mucosal ischemia and subsequent barrier dysfunction have been related to the development of organ dysfunction and death in the critically ill. We hypothesized that urine concentrations of intestinal fatty acid binding protein (IFABP), a sensitive marker of intestinal ischemia, might predict the development of the systemic inflammatory response syndrome (SIRS) and organ dysfunction.

METHODS

One hundred consecutive critically ill patients were prospectively studied for the development of infectious complications, organ dysfunction, and SIRS. Urine was collected daily for measurement of IFABP.

RESULTS

A total of 58 males and 42 females (mean age, 56 years; range,16-85 years) were studied. Of these 100 patients, 40 patients developed complications and 5 patients developed SIRS. IFABP was significantly elevated in all patients with SIRS, and IFABP levels peaked an average of 1.4 days (range, 0-7 days) before the diagnosis of SIRS.

CONCLUSION

Elevated concentrations of urine IFABP correlated with the clinical development of SIRS. Studies to assess the utility of IFABP as a predictor of organ dysfunction and SIRS in the critically ill are warranted.

Computed tomography in the initial evaluation of hemodynamically stable patients with blunt abdominal trauma: impact of severity of injury scale and technical factors on efficacy

BACKGROUND

Although computed tomography is used widely in evaluating injuries from blunt abdominal trauma, grading of injuries does not reliably predict the need for intervention. Objective reporting is essential to evaluate accuracy and facilitate patient triage. We established and tested a five-point grading system for overall severity of injury.

METHODS

A total of 392 computed tomographic trauma cases were objectively classified according to the type and severity of abdominal injuries, by two experienced radiologists. Interobserver variability between the original interpretation and the consensus of the film reviewers was evaluated. The computed tomographic grading system was measured against rate of admission, exploratory laparotomy, and further imaging.

RESULTS

Patients with higher grades of injury on computed tomography were increasingly likely to have surgical management (odds ratio, 3.99; 95% confidence interval, 1.86-8.58; p < 0.0006), with sensitivity 100%, specificity 89.5% for level 2 injuries and higher. Although there was almost perfect agreement between the official interpretation and the reviewers' blinded consensus interpretation (raw agreement 84%, weighted kappa 0.86), indeterminate studies were reduced from 23% (16 of 67) to 12% (8 of 67) on review: these were more likely to have metallic or motion artifacts (5 of 16 vs. 1 of 51 p < 0.002).

CONCLUSIONS

Standardizing reporting of injuries enhances accuracy, and grading eliminates equivocation. Diagnostic certainty in computed tomography of blunt abdominal trauma is reduced by motion and metallic artifacts.

Purification of active E1 alpha 2 beta 2 of Pseudomonas putida branched-chain-oxoacid dehydrogenase

Active E1 component of Pseudomonas putida branched-chain-oxoacid dehydrogenase was purified from P. putida strains carrying pJRS84 which contains bkdR (encoding the transcriptional activator) and bkdA1 and bkdA2 (encoding the alpha and beta subunits). Expression was inducible, however, 45-, 39- and 37-kDa proteins were produced instead of the expected 45-kDa and 37-kDa proteins. The 45-kDa protein was identified as E1 alpha and the 37-kDa and 39-kDa proteins were identified as separate translational products of bkdA2 by their N-terminal sequences. The N-terminal amino acid of the 39-kDa protein was leucine instead of methionine. The 45-, 39- and 37-kDa proteins were also produced in wild-type P.putida. Translation of bkdA1 and bkdA2 from an Escherichia coli expression plasmid produced only 45-kDa and 39-kDa proteins, with N-terminal methionine on the 39-kDa protein. The insertion of guanine residues 5' to the first ATG of bkdA2 did not affect expression of E1 beta in P. putida including the N-terminal leucine which appears to eliminate the possibility of ribosome jumping. The Z-average molecular mass of the E1 component was determined by sedimentation equilibrium to be 172 +/- 9 kDa compared to a calculated value of 166 kDa for the heterotetramer and a Stokes radius of 5.1 nm. E1 alpha Ser313, which is homologous to the phosphorylated residue of rat liver E1 alpha, was converted to alanine resulting in about a twofold increase in Km, but no change in Kcat. S315A and S319A mutations had no effect on Km or Kcat indicating that these residues do not play a major part in catalysis of E1 alpha beta 2.

Non-metric multidimensional scaling in the analysis of neuroanatomical connection data and the organization of the primate cortical visual system

Neuroanatomists have established that the various gross structures of the brain are divided into a large number of different processing regions and have catalogued a large number of connections between these regions. The connectional data derived from neuroanatomical studies are complex, and reliable conclusions about the organization of brain systems cannot be drawn from considering them without some supporting analysis. Recognition of this problem has recently led to the application of a variety of techniques to the analysis of connection data. One of the techniques that we previously employed, non-metric multidimensional scaling (NMDS), appears to have revealed important aspects of the organization of the central nervous system, such as the gross organization of the whole cortical network in two species. We present here a detailed treatment of methodological aspects of the application of NMDS to connection data. We first examine in detail the particular properties of neuroanatomical connection data. Second, we consider the details of NMDS and discuss the propriety of different possible NMDS approaches. Third, we present results of the analyses of connection data from the primate visual system, and discuss their interpretation. Fourth, we study independent analyses of the organization of the visual system, and examine the relation between the results of these analyses and those from NMDS. Fifth, we investigate quantitatively the performance of a number of data transformation and conditioning procedures, as well as tied and untied NMDS analysis of untransformed low-level data, to determine how well NMDS can recover known metric parameters from artificial data. We then re-analyse real connectivity data with the most successful methods at removing the effects of sparsity, to ensure that this aspect of data structure does not obscure others. Finally, we summarize the evidence on the connectional organization of the primate visual system, and discuss the reliability of NMDS analyses of neuroanatomical connection data.

Kringle 4 of human apolipoprotein[a] shares a linear antigenic site with human catalase

Monoclonal antibody (mab) 1A2, directed against human apolipoprotein[a] (apo[a]), revealed a strong reaction with peroxisomes as shown by immuno-gold labeled cryosections of human liver biopsies. This reactivity was not due to the presence of apo[a] in peroxisomes but to a cross-reactivity of mab 1A2. Immunoblot analysis of peroxisomal fractions and purified human catalase demonstrated that mab 1A2 reacts with catalase. Conversely, an anti-catalase antibody also recognized apo[a]. By sequence comparison we identified a 4-amino acid motif (Y-Y-P-N) that is shared between the highly repetitive kringle 4 motif of apo[a] and the carboxy-terminal third of the peroxisomal marker enzyme catalase. No other identical sequences were identified in these proteins. Results from the following experiments indicated that 1A2 recognizes this short linear epitope. i) Mab 1A2 reacted only with the 4 amino acid peptide sequence in a pin-ELISA using immobilized overlapping peptides. ii) A synthetic peptide including this sequence completely inhibited the 1A2 immunoreactivity to apo[a] and catalase. iii) A recombinant fusion protein tagged with the putative epitope was recognized by mab 1A2. Our findings demonstrate that unknown linear epitopes in native proteins can be identified by sequence comparison between known proteins. The practical implication is that antibodies against apo[a] must be controlled for this cross-reactivity before using them for immunohistochemical studies of intracellular apo[a] in tissues or cells.

Cytokines in Crohn's colitis

BACKGROUND

Increasing evidence points to a pathologic role for cytokines in Crohn's colitis. Levels of cytokines are increased in diseased segments of colon in Crohn's colitis, but no one has studied the concentration of cytokines in clinically and histologically nondiseased segments.

METHODS

Mucosal biopsies were obtained from 7 patients with active segmental Crohn's colitis and from 7 controls without inflammatory bowel disease. The concentration of Interleukin (IL)-1 beta, IL-2, IL-6, and IL-8 in patients and controls were determined using enzyme linked immunosorbent assay and compared. Histologic sections were also performed to confirm diseased and nondiseased segments of colon.

RESULTS

The concentrations of IL-1 beta, IL-6, and IL-8 were significantly higher in the involved segments of colon (10.3 +/- 4.1, 3.7 +/- 1.0, 34.4 +/- 6.9 picograms [pg] per mg) when compared to controls (1.8 +/- 0.5, 1.1 +/- 0.5, 5.3 +/- 1.0 pg/mg). The concentrations of IL-1 beta, IL-2, and IL-8 (8.5 +/- 2.9, 5.3 +/- 1.2, 26.3 +/- 8.8 pg/mg) in normal appearing segments of colon of patients with Crohn's colitis were also significantly higher than in controls, whose IL-2 level was 2.0 +/- 0.5 pg/mg. IL-1 beta and IL-8 were significantly more concentrated in both the involved and uninvolved colonic segments of patients with Crohn's colitis compared to controls. IL-2 and IL-6 were also more concentrated in Crohn's patients than in controls, but not significantly. The differences in interleukin concentrations between involved and uninvolved segments of colon in patients with segmental Crohn's colitis were not significant.

CONCLUSIONS

Although Crohn's colitis is often a segmental disease, concentrations of IL-1 beta and IL-8 are increased throughout the entire colon. These observations reinforce the hypothesis that Crohn's colitis involves the whole colon even when this is not apparent clinically or histologically.

Determination of ethyl carbamate in alcoholic beverages and soy sauce by gas chromatography with mass selective detection: collaborative study

A method using gas chromatography with mass selective detection for the determination of ethyl carbamate (EC; also known as urethane) in alcoholic beverages and soy sauce was collaboratively studied by 17 laboratories including authors' laboratories. The method uses prepacked columns for extraction of liquids with methylene chloride, and n-propyl carbamate as the internal standard. A practice sample and 6 samples of distilled spirits, fortified wines, table wines, and soy sauces were analyzed by each collaborator. Each matrix included blind duplicates of incurred and fortified EC at 3 levels. Distilled spirits contained 50-330 ng EC/g (ppb), fortified wine 40-160 ppb, table wine 10-50 ppb, and soy sauce 15-70 ppb. The ranges of the repeatability relative standard deviations, excluding outliers, were 4.03-6.63% for distilled spirits, 4.01-5.05% for fortified wine, 3.94-6.73% for table wine, and 4.70-8.49% for soy sauce. The ranges of the reproducibility relative standard deviations, excluding outliers, were 8.53-9.49% for distilled spirits, 6.84-12.02% for fortified wine, 8.86-18.47% for table wine, and 13.87-27.37% for soy sauce. Recoveries of added EC ranged from 87 to 93%. Recoveries relative to reference values, labeled as the internal standard, obtained by using gas chromatography/tandem mass spectrometry with a triple quadrupole mass spectrometer ranged from 89 to 100%.

O6-methylguanine-DNA methyltransferase in normal and malignant tissue of the breast

An important component of high-dose chemotherapy/autologous bone marrow support regimens for adjuvant treatment of breast cancer is carmustine. Preclinical studies have shown that the level of the DNA repair protein O6-methylguanine-DNA methyltransferase is correlated with the resistance of cultured human tumor cells to this drug, but little is known about transferase levels of breast tissue in vivo. We measured the DNA repair activity in 80 tissue samples from 65 patients, including normal, abnormal, benign, and malignant specimens. Wide interindividual variations was observed and average transferase levels were similar in normal and benign tissue. However, transferase levels were significantly elevated in stage I-IV disease. In addition, the frequency of samples with no detectable transferase was greatly reduced in this malignant group, and transferase was positively correlated with the presence of positive nodes, a marker for disease progression. In contrast, transferase levels were not correlated with age or estrogen receptor status, and the levels in normal tissue did not vary between patients with benign or malignant disease. These results suggest that this DNA repair activity may be increased in breast cancer relative to normal tissue and encourage further study of the predictive value of transferase measurements in high-dose chemotherapy/autologous bone marrow transplant for breast cancer.

Construction of chromosomal recA mutants of Pseudomonas putida PpG2

The recA gene of Pseudomonas putida PpG2 was cloned by complementation of the recA mutations of Escherichia coli strains DH5 alpha and HB101. The nucleotide sequence of the DNA fragment was determined and shown to contain recA and a downstream partial open reading frame. Two mutants of P. putida PpG2, strains JS387 and JS388, were constructed by insertional inactivation of recA with a tetracycline-resistance gene in both orientations. Both mutants acquired sensitivity to methyl methanesulfonate (MMS) and both failed to undergo homologous recombination. While the recA mutation of P. putida JS388 was complemented in trans by recA of P. putida, the JS387 mutant was difficult to transform and transformants exhibited varying degrees of sensitivity to MMS. Therefore, P. putida JS388 can be used as a carrier of recombinant plasmids, but JS387 is not a suitable host for this purpose.

Transforming growth factor beta 1-like immunoreactivity in the pituitary gland of the rat: effect of estrogen

We have recently shown that transforming growth factor-beta 1 (TGF beta 1) is produced in the rat pituitary gland and inhibits the secretion of PRL and the estrogen-induced growth of lactotropes. In this study, we sought to ascertain whether TGF beta 1 inhibits lactotropic functions by an autocrine or paracrine mechanism. Our techniques consisted of localizing the pituitary distribution of the growth factor immunoreactivity and measuring changes in pituitary TGF beta 1 and PRL levels in the presence and absence of estrogen in ovariectomized animals. With the use of standard immunohistochemical techniques, we observed that in cyclic females and ovariectomized rats, 60 +/- 7% of the cells exhibiting TGF beta 1-like immunoreactivity in the anterior pituitary were lactotropes. In addition, the melanotropes in the intermediate lobe appeared to be TGF beta 1 immunopositive. Treatment with estrogen for 7 days reduced the number of TGF beta 1-immunoreactive lactotropes. Immunoreactive TGF beta 1 was also detectable in anterior pituitary extracts using a specific RIA. Estrogen treatment decreased the level of TGF beta 1 in the anterior pituitary extracts from ovariectomized rats. TGF beta 1 immunoreactivity was inversely proportional to the overall size of the anterior pituitary and the concentrations of PRL, as measured in both the anterior lobe extracts and plasma. These results suggest that lactotropes may serve as a site of TGF beta 1 synthesis and that the production of TGF beta 1 in these cells can be negatively influenced by PRL stimulation through the action of the lactotrope-proliferating hormone, estrogen. Furthermore, these data support the notion that TGF beta 1 controls lactotropic function by an autocrine mechanism.

Transcriptional analysis of the promoter region of the Pseudomonas putida branched-chain keto acid dehydrogenase operon

Branched-chain keto acid dehydrogenase is a multienzyme complex produced by Pseudomonas putida when it is grown in a minimal medium containing branched-chain amino acids. A 1.87-kilobase (kb) DNA fragment was cloned and sequenced which contained 0.24 kb of the E1 alpha structural gene and 1.6 kb of upstream DNA. There were 854 base pairs (bp) of noncoding DNA upstream of bkdA1, the first gene of the bkd operon, and 592 bp between the transcriptional and translational starts. The G + C content of the noncoding region was 56.7% compared with 65.2% for all the structural genes of the operon. A partial open reading frame was found on the strand opposite that of the bkd operon beginning at base 774. When the bkd promoter was cloned into the promoter probe vector pKT240, streptomycin resistance was obtained in P. putida but not Escherichia coli with the promoter in both orientations, which indicates either that the bkd promoter is bidirectional or that there are two promoters in this region. A series of ordered deletions on both sides of the proposed site of the start of transcription revealed that almost 700 bp upstream of the start of translation were required for expression. Streptomycin resistance was also obtained in an rpoN mutant of P. putida KT2440 containing constructs with the intact bkd promoter, indicating that the bkd operon does not require the rpoN sigma factor for expression. Another construct containing the bkd promoter, bkdA1, and bkdA2 in pKT240 was used to transform P. putida JS113, a mutant which was unable to produce the E1 subunits of the branched-chain keto acid dehydrogenase. In this case, very high inducible expression of the bkd operon was obtained.