Gastric bypass surgery contributing to hyperammonaemic encephalopathy: an under-reported cause of severe nutritional deficiency and significant patient mortality.

Gastric-bypass associated hyperammonaemia (GaBHA) is an under-recognised cause of non-hepatic encephalopathy that is associated with significant mortality and has limited reporting in published literature. GaBHA has been reported predominately in middle-aged females with a past surgical history of Roux-En-Y surgical procedure. Individuals may present at any stage post-surgery and an important minority may have an undiagnosed inherited metabolic disorder. We report a case of a 49 year old woman who presented acutely with encephalopathy, a significantly elevated plasma ammonia level, and substantial multifactorial nutritional deficiency which required correction with intensive enteral and parenteral nutritional support. This case represented a diagnostic and management challenge for acute medical physicians and the multidisciplinary team involved.

Do Pulmonary Cavity Shapes Influence Lung Function?

Distribution of lung tissue within the chest cavity is a key contributor to delivery of both blood and air to the gas exchange regions of the lung. This distribution is multifactorial with influences from parenchyma, gravity, and level of inflation. We hypothesize that the manner in which lung inflates, for example, the primarily diaphragmatic nature of normal breathing, is an important contributor to regional lung tissue distribution. To investigate this hypothesis, we present an organ-level model of lung tissue mechanics, which incorporates pleural cavity change due to change in lung volume or posture. We quantify the changes using shape and density metrics in ten healthy subjects scanned supine at end-inspiratory and end-expiratory volumes and ten subjects scanned at both supine and prone end-inspiratory volumes. Comparing end-expiratory to end-inspiratory volume, we see primarily a change in the cranial-caudal dimension of the lung, reflective of movement of diaphragm. In the diaphragmatic region, there is greater regional lung expansion than in the cranial aspect, which is restricted by the chest wall. When moving from supine to prone, a restriction of lung was observed anteriorly, resulting in a generally reduced lung volume and a redistribution of air volume posteriorly. In general, we see the highest in lung tissue density heterogeneity in regions of the lung that are most inflated. Using our computational model, we quantify the impact of pleural cavity shape change on regional lung distribution and predict the impact on regional elastic recoil pressure.

A smartphone application for treating depressive symptoms: study protocol for a randomised controlled trial.

BACKGROUND: Depression is a commonly occurring disorder linked to diminished role functioning and quality of life. The development of treatments that overcome barriers to accessing treatment remains an important area of clinical research as most people delay or do not receive treatment at an appropriate time. The workplace is an ideal setting to roll-out an intervention, particularly given the substantial psychological benefits associated with remaining in the workforce. Mobile health (mhealth) interventions utilising smartphone applications (apps) offer novel solutions to disseminating evidence based programs, however few apps have undergone rigorous testing. The present study aims to evaluate the effectiveness of a smartphone app designed to treat depressive symptoms in workers. METHODS: The present study is a multicentre randomised controlled trial (RCT), comparing the effectiveness of the intervention to that of an attention control. The primary outcome measured will be reduced depressive symptoms at 3 months. Secondary outcomes such as wellbeing and work performance will also be measured. Employees from a range of industries will be recruited via a mixture of targeted social media advertising and Industry partners. Participants will be included if they present with likely current depression at baseline. Following baseline assessment (administered within the app), participants will be randomised to receive one of two versions of the Headgear application: 1) Intervention (a 30-day mental health intervention focusing on behavioural activation and mindfulness), or 2) attention control app (mood monitoring for 30 days). Participants will be blinded to their allocation. Analyses will be conducted within an intention to treat framework using mixed modelling. DISCUSSION: The results of this trial will provide valuable information about the effectiveness of mhealth interventions in the treatment of depressive symptoms in a workplace context. TRIAL REGISTRATION: The current trial is registered with the Australian and New Zealand Clinical Trials Registry ( ACTRN12617000547347 , Registration date: 19/04/2017).

Feasibility and acceptability of introducing routine antenatal contraceptive counselling and provision of contraception after delivery: the APPLES pilot evaluation.

OBJECTIVE: To determine the feasibility and acceptability of routine antenatal contraceptive counselling and contraception provision including long-acting reversible contraception (LARC) postpartum. DESIGN: Health service research evaluation. SETTING: Community antenatal clinics and hospital maternity settings in National Health Service, Scotland UK. POPULATION: Women booked for antenatal care. METHODS: Contraceptive counselling with a community midwife (22 weeks' gestation) and provision of contraception (with facilitated access to LARC methods) prior to discharge from maternity hospital. Evaluation consisted of (i) self administered questionnaire (32-34 weeks) of women's views of antenatal contraceptive counselling, (ii) database review of contraceptive methods provided at discharge, and (iii) focus groups with midwives and obstetricians. MAIN OUTCOME MEASURES: Women's views on antenatal contraceptive counselling. Secondary outcomes included (i) uptake of LARC methods and (ii) barriers and facilitators to providing antenatal counselling and contraception. RESULTS: There were 1369 women in the cohort. Questionnaires were distributed to 1064 women (78%) and completed by 794 (75%). In all, 78% of respondents (n = 621) discussed contraception antenatally with a community midwife and 74% (n = 461) found this helpful. Although 43% of respondents (n = 341) were planning to use LARC, only 9% of the cohort (118 of 1369) received LARC prior to discharge. Community midwives indicated that antenatal contraceptive counselling was now embedded in their role, but hospital staff indicated that workloads impacted upon ability to provide contraception for women. CONCLUSIONS: Antenatal contraceptive counselling, delivered by community midwives, is feasible and highly acceptable to women. However, providing contraception and LARC for women before they are discharged home remains a challenge. TWEETABLE ABSTRACT: Giving contraceptive advice antenatally is feasible and acceptable.

Provision of contraception after emergency contraception from the pharmacy: evaluating the acceptability of pharmacy for providing sexual and reproductive health services.

OBJECTIVES: Community pharmacies in the United Kingdom (UK) provide sexual and reproductive health (SRH) services such as emergency contraception (EC), although there is scope for provision of additional services. We conducted a pilot study of pharmacy based interventions for initiating effective contraception after EC. By determining the views of participating women and pharmacists we aimed to identify barriers and facilitators to providing interventions from pharmacies routinely. STUDY DESIGN: In the pilot study, women presenting for levonorgestrel EC to community pharmacies, were provided with either standard care or one of two interventions: one packet of progestogen-only pills (POPs); or an invitation to present the empty EC packet to a local family planning clinic for contraception. A sample of women participating were asked to undergo a further interview. Operational difficulties with research in the community pharmacy were also documented by the research team. METHODS: Semi-structured interviews were conducted with 12 women, four from each arm of the pilot study, using a standardised topic guide. Pre- and post-study interviews were conducted with the pharmacists involved. RESULTS: All women welcomed the interventions indicating the benefit of having different options available. They also identified possible advantages and disadvantages of each intervention. All pharmacists were positive about their involvement in the study. Methodological problems included difficulty in retention of participating pharmacists, slow recruitment and failure to accurately complete study paperwork. CONCLUSIONS: Women welcomed the interventions offered. Pharmacists viewed their participation in the study positively. The problems encountered provide valuable feedback to inform the development larger scale studies of such interventions.

Failed tracheal intubation in obstetric anaesthesia: 2 yr national case-control study in the UK.

BACKGROUND: There are few national figures on the incidence of failed tracheal intubation during general anaesthesia in obstetrics. Recent small studies have quoted a rate of one in 250 general anaesthetics (GAs). The aim of this UK national study was to estimate this rate and identify factors that may be predictors. METHODS: Using the UK Obstetric Surveillance System (UKOSS) of data collection, a survey was conducted between April 2008 and March 2010. Incidence and associated risk factors were recorded in consultant-led UK delivery suites. Units reported the details of any failed intubation (index case) and the two preceding GA cases (controls). Predictors were evaluated using multivariable logistic regression, significance P<0.05 (two-sided). RESULTS: We received 57 completed reports (100% response). The incidence using a unit-based estimation approach was one in 224 (95% confidence interval 179-281). Univariate analyses showed the index cases to be significantly older, heavier, with higher BMI, with Mallampati score recorded and score >1. Multivariate analyses showed that age, BMI, and a recorded Mallampati score were significant independent predictors of failed tracheal intubation. The classical laryngeal mask airway was the most commonly used rescue airway (39/57 cases). There was one emergency surgical airway but no deaths or hypoxic brain injuries. Gastric aspiration occurred in four (8%) index cases. Index cases were more likely to have maternal morbidities (P=0.026) and many babies in both groups were admitted to the neonatal intensive care unit: 21 (37%) vs 29 (27%) (NS). Three babies died--all in the control group.

Socioeconomic deprivation, readmissions, mortality and acute exacerbations of bronchiectasis.

BACKGROUND: Bronchiectasis is known to cause significant morbidity in children in New Zealand. Little is known of the disease in adults. AIM: Our objective was to characterise a cohort of adults who presented to hospital with acute exacerbations of the disease. METHODS: We retrospectively collected information on all exacerbations treated as inpatients from a single hospital in South Auckland, New Zealand during 2002. RESULTS: We collected information on 307 exacerbations in 152 patients. Twenty-seven per cent were of Maaori ethnic origin, and 44% Pacific. Seventy per cent lived in areas categorised as the 20% most deprived in New Zealand. Comorbid conditions were present in 80% of patients - most commonly chronic obstructive pulmonary disease, asthma, diabetes and cardiac disease. Seventy (46%) patients had at least one readmission and 32 patients (21%) died within 12 months of admission to hospital. Greater deprivation was associated with increased mortality at 12 months after admission after adjusting for other factors (OR 11, 95% CI 2.0-61, P= 0.006). In the subgroup who underwent high-resolution computed tomographic scanning (93), increasing severity of bronchiectasis (modified Bhalla score) was associated with readmission within 12 months (P= 0.004), but not mortality (P= 0.419). CONCLUSIONS: We have shown that exacerbations of bronchiectasis in South Auckland are more common in patients who are predominantly of Maaori or Pacific descent and are socioeconomically deprived. Admission to hospital for an exacerbation is associated with high readmission and mortality rates.

Diagnostic yield of bronchoscopic sampling in febrile neutropenic patients with pulmonary infiltrate and haematological disorders.

BACKGROUND: The development of pulmonary infiltrate in neutropenic patients is potentially life-threatening, and requires early diagnosis and treatment. Bronchoscopic sampling is an established form of investigation in such patients. AIM: The aim of the study is to determine the diagnostic yield and complication rate of bronchoscopic sampling in patients with a haematological disorder presenting with febrile neutropenia and pulmonary infiltrate. METHODS: Medical records and laboratory investigations were retrospectively reviewed for all patients with a haematological disorder who underwent flexible bronchoscopy and bronchoalveolar lavage (BAL) or bronchial washing (BW) at Auckland City Hospital, New Zealand, after presenting with febrile neutropenia and pulmonary infiltrate between January 2008 and December 2009. Demographic, clinical, radiological and microbiological data, procedure-related complications and treatment were recorded. Modifications to treatment regimens as a result of bronchoscopy and 30-day mortality were recorded. RESULTS: Out of 678 bronchoscopies performed during this period, 26 were in patients with a haematological disorder presenting with febrile neutropenia and pulmonary infiltrate. Most patients had a haematological malignancy (19/26). Two (7.7%) patients reported minor haemoptysis. No biopsies were performed. Positive microbiological samples were obtained with BAL/BW in 23% of patients. The most common organisms identified were Aspergillus species (15.4%); other organisms were Candida (11.6%) and Streptococcus pneumoniae (3.9%). The bronchoscopic results altered the clinical management of 10 (38.4%) patients. The 30-day mortality rate was 19.2%, but no deaths were related to the procedure. CONCLUSIONS: In haematology patients presenting with febrile neutropenia and pulmonary infiltrate, bronchoscopy is a safe procedure that plays a significant role in management.

Public health response to an outbreak of Legionnaires' disease in Edinburgh, United Kingdom, June 2012.

We report an outbreak comprising 50 confirmed cases of Legionnaires' disease in Edinburgh, Scotland, June 2012. In addition, there were 49 suspected cases. Epidemiological evidence suggests that a common outdoor airborne exposure occurred over south-west Edinburgh. This probably emanated from cooling towers in the north-east of the affected area, although not yet clearly linked by scientific evidence. The co-ordinated public health, environmental and clinical response helped prevent ongoing exposure and mitigated associated mortality and morbidity.

Does CT scanning predict the likelihood of a positive transbronchial biopsy in sarcoidosis?

BACKGROUND: Transbronchial lung biopsy (TBB) has a variable diagnostic yield in sarcoidosis. It was hypothesised that the extent and pattern of parenchymal disease on CT scanning would predict the likelihood of a positive TBB result. METHODS: Patients with sarcoidosis (n = 77) were included if they had undergone a CT scan within 6 weeks of TBB. Ethnicity, symptoms, pulmonary function and site and results of TBB and bronchoalveolar lavage (BAL) were recorded. CT scans were scored quantitatively for patterns of parenchymal disease (nodular, reticular, consolidation and ground glass) on a lobar basis. RESULTS: 39 patients (50.6%) had a positive TBB. Symptoms, ethnicity, treatment, lung volumes and chest radiographic stage were not predictors of a positive biopsy. Female gender, reduced percentage predicted carbon monoxide transfer factor and a higher percentage of lymphocytes in the BAL fluid were associated with a positive biopsy, as were higher total lung score, reticular pattern and ground-glass opacity. The associations were more significant for the total lobar score and the lobar ground-glass score of the lobe biopsied. On multivariate analysis gender, percentage of lymphocytes in the BAL fluid and total lung score were independent predictors of a positive TBB. CONCLUSION: The total extent of parenchymal disease on the CT scan in addition to the pattern and lobar distribution predicts the likelihood of a positive TBB at bronchoscopy.

Growth effects of vanadium in the rat.

Vanadium is necessary for growing rats raised inside trace elementcontrolled, all plastic isolators on a highly purified amino acid diet. Addifion of vanadium to the diet enhances growth by over 40 percent. A nearly optimum effect is obtained with 10 micrograms of vanadium per 100 grams of diet in (0.1 part per million), supplied in the form of sodium orthovanadate, as seen from series of tests with levels ranging from 1 to 5 micrograms per 100 grams of diet. Different vanadium compounds show different potencies: sodium orthovanadate was effective, metavanadate less active, and pyrovanadate without activity. Tetravalent vanadium, supplied as vanadyl sulfate or acetate, was utilized but produced smaller responses. The amounts of vanadium required are those normally found in tissues and nutrients.

Single fibers of cat optic nerve: "thresholds" to light.

Absolute thresholds of 39 single fibers of the optic nerves of 20 cats were determined by inspection of post-stimulus time histograms, each com puted from the responses to 60 to 100 identical flashes of white light. The values found-from 1.1 x 10(-7) to 6.8 x 10(-6) candella per square meter (nits)-agree well with psychophysi cal thresholds found in previous in vestigations.

Plasma trace elements and cognitive function in older men and women: the Rancho Bernardo study.

OBJECTIVE: This study examines the sex-specific associations of plasma concentrations of iron, copper, and zinc with cognitive function in older community-dwelling adults. DESIGN: Cross-sectional study. SETTING: 1988-92 follow-up clinic visit. PARTICIPANTS: 602 men and 849 women (average age=75 +/- 8 years) who were community-dwelling and not clinically demented. MEASUREMENTS: Blood samples were assayed for trace elements and 12 cognitive function tests were administered. Sex-specific analyses were adjusted for age, education, alcohol consumption, smoking, exercise, and estrogen use in women. RESULTS: Men and women differed significantly in education and alcohol intake (p's < 0.001), concentrations of plasma iron, copper and zinc (p's < 0.001) and scores on 11 of 12 cognitive function tests (p=0.04 to < 0.001). Regression analyses showed significant inverted U-shaped associations in men; both low and high iron levels were associated with poor performance on total and long-term recall and Serial 7's (p's=0.018, 0.042 and 0.004, respectively) compared to intermediate concentrations. In women, iron and copper concentrations had inverse linear associations with Buschke total, long and short-term recall and Blessed scores (p's < 0.05). Zinc was positively associated with performance on Blessed Items (p=0.008). Analyses comparing cognitive function using categorically defined mineral concentrations yielded similar sex specific results. CONCLUSION: Optimal trace element concentrations may exist for optimal cognitive function in older adults, and these levels may differ by sex and cognitive function domain.

The discovery and comparative expression analysis of three distinct type I interferons in the perciform fish, meagre (Argyrosomus regius).

Type I interferons (IFN) play an important role in anti-viral responses. In teleost fish multiple genes exist, that are classified by group/subgroup. That multiple subgroups are present in Acanthopterygian fish has only become apparent recently, and 3 subgroups are now known to be expressed, including a new subgroup termed IFNh. However, the potential to express multiple IFN subgroups and their interplay is not well defined. Hence this study aims to clarify the situation and undertook the first in-depth analysis into the nature and expression of IFNc, IFNd and IFNh in the perciform fish, meagre. Constitutive expression was analysed initially during larval development and in adult tissues (gills, mid-gut, head kidney, spleen). During early ontogeny IFNc was the highest expressed IFN, and this was also the case in adult tissues with the exception of gills where IFNd was highest. However, comparison between tissues for individual isoforms showed that spleen had high transcript levels of all three IFNs, IFNd/IFNh were also highly expressed in gills. The expression of each sub-group was increased significantly in the four tissues following injection of poly I:C, however, this increase was only seen in the mid-gut for IFNh. Following in vitro stimulation with poly I:C again all three isoforms were upregulated, although with differences in kinetics and the cell source used. For example, early induction was seen for IFNc/IFNh in gill cells, IFNd/IFNh in splenocytes and all three isoforms in head kidney cells. Induction was sustained in splenocytes and head kidney cells, but in gut cells only a late induction was seen. These results demonstrate a complex pattern of regulation between the different IFN isoforms present in meagre and highlights potential sub-functionalisation of these IFN subgroups during perciform anti-viral responses.

c-Abl phosphorylates Hdm2 at tyrosine 276 in response to DNA damage and regulates interaction with ARF.

The p53 tumour-suppressor protein is tightly regulated through its association with the Hdm2 E3 ligase. Activation of p53 by DNA strand breaks is orchestrated by the ataxia-telangiectasia mutated (ATM) protein kinase and involves interruption of Hdm2-mediated p53 degradation. As part of this mechanism ATM itself, and the ATM-activated protein tyrosine kinase, c-Abl, inhibit Hdm2 function through phosphorylation of serine 395 and tyrosine 394 (Y394), respectively. In the present study, we have identified a novel target of c-Abl in the Hdm2 protein, tyrosine 276 (Y276). We show that c-Abl phosphorylates this residue in vitro and confirm that Y394 is a target of c-Abl. We also show that Y276 is phosphorylated in a c-Abl-dependent manner in cultured cells and provide evidence that Y276 is phosphorylated in response to DNA damage coincident with the activation of c-Abl. Finally, we show that Y276 phosphorylation stimulates interaction with ARF, leading to increased levels of nucleolar Hdm2 and decreased turnover of p53. These data establish Y276 as a physiological target of c-Abl that contributes functionally to the induction of p53.

Enhanced Pest Ant Control With Hydrophobic Bait.

The red imported fire ant, Solenopsis invicta (Buren), left most of its natural enemies behind in South America when it arrived in Mobile, AL, in the 1930s and spread rapidly throughout the southeastern United States, reaching population levels up to 10 times those found in South America. The large population densities and propensity for disturbed habitats led to direct conflict with human activities. Bait control methods were first developed for fire ants in the early 1960s and little has changed in the subsequent decades, despite the drawback that the bait carrier rapidly breaks down when wet. The southeast United States is wet; thus, bait labels have various guidance-restricting applications based on potential wet conditions. Here we compare a hydrophobic fire ant bait to the equivalent standard bait formulation and demonstrate in a paired-mound field experiment under natural wet conditions in Florida (heavy dew on ground), a significant advantage for the hydrophobic bait. An effective hydrophobic ant bait would extend the utility of current bait insecticides to wet conditions and also fill an important gap in our ability to control invasive pest ant species that thrive in wet tropical and subtropical habitats, e.g., Wasmannia auropunctata (Roger), the little fire ant.

Two types of TNFα in meagre (Argyrosomus regius): Discovery, distribution and expression modulation.

TNFα is a key cytokine involved in systemic inflammation and regulation of immune cells and is important during development. In the present study, 2 isoforms of TNFα were discovered in meagre, an emerging species in aquaculture. Phylogenetic analysis suggests these isoforms represent the type I and type II TNFα classes previously described in other teleost species. This study is the first to compare how these 2 types of TNFα behave in meagre and aims to provide insights into their expression in teleost fish by interrogating expression in whole tissues and isolated cell populations in four immunologically important sites (gills, intestine, head kidney and spleen) following PAMP stimulation, as well as monitoring gene expression during meagre development. Differential expression was seen in head kidney and gills, where TNFα1 was more highly expressed. Both isoforms increased in head kidney of meagre following injection with LPS, but this was not seen in other tissues or after injection with other PAMPs. However, in vitro studies hinted at a possible mucosal bias for TNFα1, which was more highly induced in gill and intestinal cell suspensions by PAMPs. In contrast TNFα2 was more highly induced in cells from systemic tissues. Through early development expression of both types of TNFα decreased as the meagre matured, with the exception of a transient increase shortly after the move to a dry feed diet. However, during the later stages of development expression of both isoforms increased in the gills. This data demonstrates a degree of differential expression of TNFα1 and TNFα2 in meagre with regard to expression regulation, and highlights the importance of TNFα during early development of teleost fish.

Post-treatment residual thrombus increases the risk of recurrent deep vein thrombosis and mortality.

BACKGROUND: Recurrent thromboembolic events after an initial deep vein thrombosis (DVT) are relatively frequent. Residual thrombus in the affected veins on ultrasound scan at the completion of anticoagulant therapy has been described as a recurrence risk factor, and may have utility in stratifying those patients at risk. OBJECTIVES: The aims of the study were to correlate the risk of recurrence of DVT with the results of ultrasound at completion of oral anticoagulant therapy. A secondary aim was to review the mortality in this population. PATIENTS: A cohort of 316 DVT patients was included. The patients were divided into those with completely clear vessels on follow-up scan (45%) and those with residual thrombus identified (55%). RESULTS: The cumulative incidence of recurrence was 10% by 2 years and 23% by 5 years. Patients with residual thrombus on follow-up ultrasound were at higher risk of recurrence (hazard ratio [HR] 2.2, 1.19-4.21; P = 0.012) which remained significant after multivariate adjustment for age, gender and malignancy (HR 2.2, 1.15-4.17; P = 0.018). During follow-up, the cumulative mortality was 12% at 2 years and 27% by 5 years. The risk of death was increased in patients with residual thrombus on follow-up scan (HR 3.9, 1.93-7.71; P < 0.001) and this risk persisted after multivariate analysis of age, gender and malignancy (2.8, 1.37-5.72; P = 0.005). The majority of deaths were due to malignancy (68%) however 10 (18%) died from vascular causes. There was a trend towards increased vascular death in the patients with residual thrombus on follow-up ultrasound scan, which did not reach significance (HR 4.1, 0.87-19.33; P = 0.13). CONCLUSIONS: Consistent with previous cohort studies, recurrence risk is increased in patients with residual thrombus on ultrasound. The increased risk of death in patients with residual thrombus, with a trend towards increased vascular death, may suggest that failure of thrombus resolution is a marker of more global vascular dysfunction.

p53 N-terminus-targeted protein kinase activity is stimulated in response to wild type p53 and DNA damage.

The p53 tumour suppressor protein plays a central role in the cellular defence against agents which cause genetic damage. The activity of p53 is regulated at different levels and is subject to multi-site phosphorylation by a variety of different protein kinases. In this paper we have characterised p53 N-terminus-targeted protein kinase (p53NK) activities, present in a range of cell lines, following fractionation of cellular lysates by ion exchange chromatography on HiTrap Q and Mono Q resins. Three peaks of p53NK activity were observed following fractionation of HeLa cell lysates; these activities were each able to catalyse phosphorylation of up to three residues (serines 4, 6 and 9 in murine p53) within the N-terminus of the p53 protein. Similarly, multiple p53NK activities were detected in the MethAp53(ts) cell line (which expresses the valine 135 temperature-sensitive p53 protein). Strikingly, when these cells were shifted from 38 degrees C (the non-permissive temperature) to 28 degrees C, at which the p53 adopts a wild type conformation, a fivefold stimulation of kinase activity was detected. Moreover, when the DNA damage-inducing drugs etoposide or camptothecin were added to the cells, a further stimulation of kinase activity was observed following growth at 28 degrees C, but not 38 degrees C. These data are consistent with a regulatory model in which p53 is sensitive to stress or DNA damage through phosphorylation at its N-terminus.

Phosphorylation of the p53 tumour-suppressor protein at three N-terminal sites by a novel casein kinase I-like enzyme.

Wild-type mouse p53, expressed in Escherichia coli, was phosphorylated by highly purified casein kinase I (CKI) from rabbit muscle. The major site of phosphorylation in the p53 was identified as serine 6, which is known to be phosphorylated in vivo. Serines 4 and 9 were also phosphorylated. To determine whether CKI is likely to be a physiological p53 kinase, SV3T3 cell lysates were fractionated on a Mono Q column and assayed for p53 kinase and casein kinase activities. Four p53 kinase activities were detected, one of which co-purified with CKI activity. This p53 kinase (designated PK270) further co-purified with CKI on sucrose gradients and had a native molecular weight, like CKI, in the range of 35,000-45,000. However, PK270 was separated from the bulk of CKI activity on a phosvitin-Sepharose affinity column, and was therefore likely to be a CKI-related kinase. In support of these conclusions, phosphorylation of p53, by both CKI and PK270, was inhibited by a peptide corresponding to a consensus CKI target sequence, but not by a non-specific peptide. Moreover, phosphopeptide analyses of p53 phosphorylated by CKI or by PK270 gave similar results, indicating that these two kinases phosphorylate the same sites in p53.