The impacts of seasonal variation and climate on food utilization in a population of critically endangered cotton-top tamarins (Saguinus oedipus) in Colombia: A 22-year longitudinal study

To examine how precipitation patterns and climate change impact feeding choices made by a population of critically endangered cotton-top tamarins (Saguinus oedipus), we examined 22 years of feeding data (1999-2020) from 21 groups collected at Parque Natural Regional Bosque Seco El Ceibal Mono Tití in Santa Catalina, Colombia. We describe the diet and examine the role of seasonal rainfall and annual variation in rainfall on diet. Rainfall is highly seasonal (mean annual rainfall 1562 mm [range 940-2680 mm]) with a dry, early rainy, and late rainy season in each year. Over 80 species of plants formed part of the fruit, nectar, and exudate components of the diet. Fruits, although available year-round, were more commonly available and consumed during the late rainy seasons (August-November). Exudates were consumed more frequently in the dry season (December-March) and invertebrate consumption was stable across the year. Nectar feeding from a single species (Combretum fruticosum) peaked in November. Rainfall varied over the years, with 13 years exceeding the 99% confidence intervals for mean rainfall. Ten of these extreme years (both drought and extremely wet) occurred in the last 11 years. Fruit consumption did not vary between extreme and average years, but cotton-top tamarins consumed more invertebrates and exudates in wet years. Presently, cotton-top tamarins appear to be able to cope with these extreme variations in rainfall due to their highly varied diet. However, the forests that these primates depend upon for survival are threatened by human exploitation making it critically important to maintain a generalist feeding strategy for survival as many fruiting trees that compose a large proportion of the diet are removed. As conservation efforts continue, plant species consumed by cotton-top tamarins provide useful data when selecting species for habitat restoration programs.

International Collaboration as an interdisciplinary approach for the development of a Cultural Competency online module

Introduction

Culture is a concept most people instinctively understand, but may struggle to fully articulate. Culture is not limited to ethnicity and religion, but encompasses age, gender, sexual orientation, occupation, socioeconomic status, ethnic origin or migrant experience, religious or spiritual belief, and dis/ability. Given the breadth and complexity of culture, healthcare professionals in particular are challenged to interact with an increasingly multicultural world and various cultural groups. There is a growing need for appropriate training models to enhance cultural awareness, and cultural competence, including in pharmacy schools.

“Interdisciplinary” can be defined as “relating to more than one branch of knowledge” [1], and international collaboration allows the connection of knowledge of different cultures. Developing a teaching intervention internationally, across three continents allows wider exposure to different cultures and can help students appreciate what culture may mean in different countries and how different ways of living are accepted and/or perceived in different societies.

Aim

To design and disseminate an online cultural communication module for use by pharmacy students across three countries and continents

Methods

A team from the Schools of Pharmacy at University College London (UCL), UK; Monash University, Australia and University of North Carolina (UNC), USA worked collaboratively to build an online module to help pharmacy students understand the importance of cultural awareness when communicating with patients. The Schools identified a range of cultural groups and scenarios in which pharmacist led communications could occur. Each School designed and filmed three scenarios, with two versions: one relatively good demonstration of communication and one poor. A range of actors, patients and pharmacists from different cultural groups (e.g. ethnic background, disability, LGBTQi, gender etc.) were involved in the design and filming. The module required students to reflect on the roleplays and provided feedback in the form of summary key points for each topic area. This module was embedded into the existing curricula for all Year 1 (Monash and UCL) and Year 2 (UNC) students in 2019. Students were informed as part of their regular course communication. A Likert style evaluation survey, including free text responses about the module was included, Questions were adapted from previous teaching evaluations. This data was recorded via each School’s Learning Management System. Descriptive statistics and a basic thematic analysis were conducted.

Results

Across the three Schools, a total of 525 students were offered the online module and 208 completed it. At UNC, 72.2% of students who completed would recommend the module to others, at UCL 83% and Monash 88%. Students’ feedback fell under three themes as seen in Table 1.

Conclusion

The innovation and strength of this learning intervention comes from the international collaboration. The online module allows students to identify and be culturally aware of a diverse group of people across three continents, allowing a unique and rich experience for all students through this collaboration and developing them not only as culturally competent healthcare professionals but also global citizens.

References

1. Oxford Dictionaries, Oxford University Press, Definition of Interdisciplinary in English, Oxford, 2020. [Accessed 11th October 2020]. Available from: https://premium-oxforddictionaries-com.libproxy.ucl.ac.uk/definition/english/interdisciplinary

Verification and Validation of Digital Pathology (Whole Slide Imaging) for Primary Histopathological Diagnosis: All Wales Experience

Aims:

The study is aimed to verify Aperio AT2 scanner for reporting on the digital pathology platform (DP) and to validate the cohort of pathologists in the interpretation of DP for routine diagnostic histopathological services in Wales, United Kingdom.

Materials, Methods and Results:

This was a large multicenter study involving seven hospitals across Wales and unique with 22 (largest number) pathologists participating. 7491 slides from 3001 cases were scanned on Leica Aperio AT2 scanner and reported on digital workstations with Leica software of e-slide manager. A senior pathology fellow compared DP reports with authorized reports on glass slide (GS). A panel of expert pathologists reviewed the discrepant cases under multiheader microscope to establish ground truth. 2745 out of 3001 (91%) cases showed complete concordance between DP and GS reports. Two hundred and fifty-six cases showed discrepancies in diagnosis, of which 170 (5.6%) were deemed of no clinical significance by the review panel. There were 86 (2.9%) clinically significant discrepancies in the diagnosis between DP and GS. The concordance was raised to 97.1% after discounting clinically insignificant discrepancies. Ground truth lay with DP in 28 out of 86 clinically significant discrepancies and with GS in 58 cases. Sensitivity of DP was 98.07% (confidence interval [CI] 97.57–98.56%); for GS was 99.07% (CI 98.72–99.41%).

Conclusions:

We concluded that Leica Aperio AT2 scanner produces adequate quality of images for routine histopathologic diagnosis. Pathologists were able to diagnose in DP with good concordance as with GS.

Strengths and Limitations of this Study:

Strengths of this study – This was a prospective blind study. Different pathologists reported digital and glass arms at different times giving an ambience of real-time reporting. There was standardized use of software and hardware across Wales. A strong managerial support from efficiency through the technology group was a key factor for the implementation of the study.

Limitations:

This study did not include Cytopathology and in situ hybridization slides. Difficulty in achieving surgical pathology practise standardization across the whole country contributed to intra-observer variations.

Prevalence of underweight, wasting and stunting among young children with a significant cognitive delay in 47 low-income and middle-income countries

BACKGROUND

Undernutrition in early childhood is associated with a range of negative outcomes across the lifespan. Little is known about the prevalence of exposure to undernutrition among young children with significant cognitive delay.

METHOD

Secondary analysis of data collected on 161 188 three- and four-year-old children in 47 low-income and middle-income countries in Rounds 4-6 of UNICEF's Multiple Indicator Cluster Surveys. Of these, 12.3% (95% confidence interval 11.8-12.8%) showed evidence of significant cognitive delay.

RESULTS

In both middle-income and low-income countries, significant cognitive delay was associated with an increased prevalence of exposure to three indicators of undernutrition (underweight, wasting and stunting). Overall, children with significant cognitive delay were more than twice as likely than their peers to be exposed to severe underweight, severe wasting and severe stunting. Among children with significant cognitive delay (and after controlling for country economic classification group), relative household wealth was the strongest and most consistent predictor of exposure to undernutrition.

CONCLUSIONS

Given that undernutrition in early childhood is associated with a range of negative outcomes in later life, it is possible that undernutrition in early childhood may play an important role in accounting for health inequalities and inequities experienced by people with significant cognitive delay in low-income and middle-income countries.

The impact of flow PRA on outcome in pediatric heart recipients in modern era: An analysis of the Pediatric Heart Transplant Study database

Data from patients in the Pediatric Heart Transplant Study (PHTS) registry transplanted between 2010 and 2014 were analyzed to determine the association between HLA antibody (PRA) determined by SPA using Luminex or flow cytometry with a positive retrospective cross-match and the post-transplant outcomes of acute rejection and graft survival. A total of 1459 of 1596 (91%) recipients had a PRA reported pretransplant; 26% had a PRA > 20%. Patients with a PRA > 20% were more likely to have CHD, prior cardiac surgery, ECMO support at listing, and waited longer for transplantation than patients with a PRA <20%. Patients with higher PRA% determined by SPA were predictive of a positive retrospective cross-match determined by flow cytometric method (P < .001). A PRA > 50% determined by SPA was independently associated with worse overall graft survival after first month of transplant in both unadjusted and adjusted for all other risk factors. In this large multicenter series of pediatric heart transplant recipients, an elevated PRA determined by SPA remains a significant risk factor in the modern era.

Microtubule-Targeting Agents Eribulin and Paclitaxel Differentially Affect Neuronal Cell Bodies in Chemotherapy-Induced Peripheral Neuropathy

Chemotherapy-induced peripheral neuropathy (CIPN) is a common side effect of anticancer treatment with microtubule-targeted agents (MTAs). The frequency of severe CIPN, which can be dose limiting and even life threatening, varies widely among different MTAs. For example, paclitaxel induces a higher frequency of severe CIPN than does eribulin. Different MTAs also possess distinct mechanisms of microtubule-targeted action. Recently, we demonstrated that paclitaxel and eribulin differentially affect sciatic nerve axons, with paclitaxel inducing more pronounced neurodegenerative effects and eribulin inducing greater microtubule stabilizing biochemical effects. Here, we complement and extend these axonal studies by assessing the effects of paclitaxel and eribulin in the cell bodies of sciatic nerve axons, housed in the dorsal root ganglia (DRG). Importantly, the microtubule network in cell bodies is known to be significantly more dynamic than in axons. Paclitaxel induced activating transcription factor 3 expression, a marker of neuronal stress/injury. Paclitaxel also increased expression levels of acetylated tubulin and end binding protein 1, markers of microtubule stability and growth, respectively. These effects are hypothesized to be detrimental to the dynamic microtubule network within the cell bodies. In contrast, eribulin had no significant effect on any of these parameters in the cell bodies. Taken together, DRG cell bodies and their axons, two distinct neuronal cell compartments, contain functionally distinct microtubule networks that exhibit unique biochemical responses to different MTA treatments. We hypothesize that these distinct mechanistic actions may underlie the variability seen in the initiation, progression, persistence, and recovery from CIPN.

Overweight and obesity among children at risk of intellectual disability in 20 low and middle income countries

BACKGROUND

Children with intellectual disability (ID) in high income countries are at significantly greater risk of obesity than their non-disabled peers. We aimed to estimate the prevalence of overweight and obesity in 3 to 4-year-old children who are/are not at risk of ID in low and middle income countries.

METHOD

Secondary analysis of Round 4 and 5 UNICEF Multiple Indicator Cluster Surveys (MICS) from 20 low and middle income countries that included a total of 83 597 3 to 4-year-old children.

RESULTS

Few differences in risk of overweight or obesity were apparent between 3 and 4-year-old children identified as being at risk/not at risk of ID in 20 low and middle income countries. In the two countries where statistically significant differences were observed, prevalence of overweight/obesity was lower among children at risk of ID.

CONCLUSIONS

These results stand in stark contrast to evidence from high income countries which suggest that children with ID are at significantly increased risk of obesity when compared to their non-intellectually disabled peers.

Increased intracranial pressure in mini-pigs exposed to simulated solar particle event radiation

Changes in intracranial pressure (ICP) during space flight have stimulated an area of research in space medicine. It is widely speculated that elevations in ICP contribute to structural and functional ocular changes, including deterioration in vision, which is also observed during space flight. The aim of this study was to investigate changes in OP occurring as a result of ionizing radiation exposure (at doses and dose-rates relevant to solar particle event radiation). We used a large animal model, the Yucatan mini-pig, and were able to obtain measurements over a 90 day period. This is the first investigation to show long term recordings of ICP in a large animal model without an invasive craniotomy procedure. Further, this is the first investigation reporting increased ICP after radiation exposure.

From financial hardship to child difficulties: main and moderating effects of perceived social support

BACKGROUND

There is an unequivocal relationship between socio-economic status and child well-being. The Family Stress Model of economic hardship proposes that this relationship is mediated by financial hardship, parenting stress and parenting behaviours. In this study, the Family Stress Model is tested and analysis is extended to examine main and moderating effects of social support.

METHODS

A survey incorporating well-validated measures of financial hardship, parenting stress, parenting behaviours and child difficulties was sent to 1296 parents who had utilized universal family support services in Alberta, Canada. A total of 923 parents (71%) responded. Hierarchical linear regression was employed to investigate the mediating roles of financial hardship, parenting stress and parenting behaviours, and to investigate main and moderating influences of parental social support.

RESULTS

The study findings generally support the Family Stress Model. The relationship between socio-economic status and child difficulties was mediated by financial hardship and parenting stress. Higher levels of parental social support were associated with lower levels of parenting stress, ineffective parenting and child difficulties. Parental social support was important irrespective of parenting stress levels.

CONCLUSIONS

The study findings add to the now critical mass of data showing that parent-child health and well-being is inextricably linked with parental social support. While there is a burgeoning literature on parent training, far less research attention has been given to the development and evaluation of strategies to strengthen parents' social relationships. This is an important direction for future research.

A phase Ib trial of IPI-504 (retaspimycin hydrochloride), a novel Hsp90 inhibitor, in combination with docetaxel

3547

Background: IPI-504 is a water-soluble heat shock protein 90 (Hsp90) inhibitor. IPI-504 causes the degradation of a variety of mutated or amplified oncoproteins, including epidermal growth factor receptor (EGFR) and human epidermal growth factor receptor 2 (HER2). The combination of IPI-504 and docetaxel demonstrates additive efficacy in murine xenograft models. This Phase 1b trial was undertaken to identify the maximum tolerated dose (MTD) of IPI-504 in combination with docetaxel. Methods: Eligible patients (pts) had advanced solid tumors that were either refractory to available therapies or for which docetaxel alone was an appropriate therapy. Intravenous (IV) 75 mg/m2 docetaxel was given once every three weeks (q 3- weekly). IPI-504 was administered IV q 3-weekly, with 3 pts per cohort and inter-cohort dose escalation. All pts were evaluated for safety, pharmacokinetics (PK), and tumor response. Results: 16 pts have been enrolled at 3 dose levels of IPI-504 (7 at 300 mg/m2, 6 at 450 mg/m2, and 3 at 550 mg/m2). 6 pts had non-small cell lung cancer (NSCLC). Median age was 59 yrs (range 33–77). Median number of cycles received was 3 (1–11), with 5 pts currently on study. There have been 4 dose-limiting toxicities (DLTs): 1 at 300 mg/m2 (Grade 3 febrile neutropenia); 1 at 450 mg/m2 (Grade 3 fatigue); and 2 at 550 mg/m2 (Grade 1 asymptomatic sinus bradycardia requiring hospitalization for observation, and Grade 3 elevated AST with Grade 3 acute respiratory distress syndrome). All DLTs resolved on trial. No PK interactions between docetaxel and IPI-504 have been observed. The regimen of IPI-504 450 mg/m2 with docetaxel 75 mg/m2 has been identified as the recommended phase 2 dose on a q 3-weekly schedule. Conclusions: In this Phase 1b trial, the MTD of IPI-504 plus docetaxel q 3-weekly was identified. Toxicities were reversible and similar to those seen with docetaxel or IPI-504 alone in this patient population. Given the activity of single-agent IPI-504 against NSCLC and the standard use of docetaxel in that disease, an expanded evaluation of this regimen in pts with previously treated NSCLC is on-going. The combination of IPI-504 and docetaxel on a weekly schedule is also being explored.

[Table: see text]

Health beliefs of the urban Pare tribe living in Moshi, Tanzania

This study aimed to explore and describe the health beliefs and practices of urban Pares, living in Moshi, Tanzania. No previously documented studies of the health beliefs of the Pare were identified. This transcultural qualitative study utilised semistructured interviews conducted with nine informants, followed by thematic analysis of the interview data. Unlike professional health care workers functioning within the scientific paradigm, urban Pare health beliefs arise from magico-religious, holistic and scientific paradigms. Beliefs and behaviour patterns are however changing. Nurses caring for urban Pares can use the findings and recommendations from this study to enhance culturally congruent care.

UV Raman spectroscopy of hydrocarbons

In this paper, the UV Raman spectra of a large number of saturated and alkyl-substituted monocyclic, bicyclic and polycyclic aromatic hydrocarbons are obtained at 220 and 233 nm excitation wavelengths. Also included are nitrogen- and sulphur-containing hydrocarbons. The spectra obtained are fluorescence free, even for such highly fluorescent compounds as perylene, consistent with earlier reports of UV Raman spectra of hydrocarbons. The hydrocarbon UV Raman spectra exhibit greatly improved signal-to-noise ratio when in the neat liquid or solution state compared with the neat solid state, suggesting that some surface degradation occurs under the conditions used here. Assignments are given for most of the bands and clear marker bands for the different classes of hydrocarbons are readily observable, although their relative intensities vary greatly. These results are discussed in the context of structure and symmetry to develop a consistent, molecular-based model of vibrational group frequencies.

Quantifying remaining forested habitat within the historic distribution of the cotton-top tamarin (Saguinus oedipus) in Colombia: Implications for long-term conservation

Landsat Thematic Mapper (TM) data were used to classify forested areas within the historic distribution of the endangered cotton-top tamarin (Saguinus oedipus) in Colombia. This species continues to be threatened by habitat destruction, and we observed a 31% decrease of the forested habitat within the tamarins' historic distribution in 1990-2000. It is estimated that since the establishment of some protected areas for cotton-top tamarins and other native Colombian wildlife (Parque Nacional Natural Paramillo, Santuario de Fauna y Flora Los Colorados, and Reserva Forestal de Montes de Maria), almost 43% of the original forested area has been lost. Given that the human population of Colombia increases annually by 1.6% [Patel, 2002], it is important to target specific areas for tamarin protection while creating mitigation strategies to compensate for economic growth. The results of this study provide valuable information to assist in the long-term development of effective conservation strategies for this endangered primate.

The use of low-frequency vocalizations in African elephant(Loxodonta africana) reproductive strategies

Fertility-advertisement calls in females are predicted to occur in nonmonogamous species where males and females are widely separated in space. In African elephants, low-frequency vocalizations have thus been suggested as a reproductive strategy used by fertile females to attract mates. This study examined the use of low-frequency vocalizations with respect to different phases of the estrous cycle in African elephants by simultaneously monitoring vocalizations, behavior, and hormonal profiles. Subjects were one male and six female African elephants housed at Disney's Animal Kingdom. No acoustically distinct vocalizations were restricted to the ovulatory follicular phase. However, overall rate of low-frequency vocalization as well as the rate of one acoustically distinct vocalization changed over the estrous cycle, with highest rates of calling related to the first period of follicular growth, or anovulatory follicular phase. Elevated rates of vocalization thus were not restricted to behavioral estrus and occurred much earlier in the estrous cycle than in most species that produce fertility-advertisement calls. Both herd composition and elephant identity also affected rates of vocalization. Vocalizations therefore may not be reliable signals of actual fertility. However, the increase in vocalizations in advance of estrus may attract males to the herd prior to ovulation, facilitating both male-male competition and female choice. Once present in the herd, males may then switch strategies to use more reliable chemical and visual cues to detect ovulating females.

Prevalence of hospital-acquired infections in a tertiary referral hospital in northern Tanzania

Hospital-acquired infections (HAI) are a major and largely preventable cause of morbidity and morbidity worldwide. Very few reports on the prevalence of HAI in sub-Saharan Africa have been published and most of those that have appeared in the press have focused on surgical-wound infection. In the present, questionnaire-based, point-prevalence study, in which the doctor on the ward round was used as the primary informant, the prevalences of all HAI among all the inpatients at a tertiary referral hospital in northern Tanzania were estimated. On the day of the study, there were 412 inpatients (in 15 ward areas) and 61 cases of HAI were identified, giving an overall HAI prevalence of 14.8%. The prevalences of HAI were particularly high in the medical intensive-care unit (40%), the surgical (orthopaedic and general surgery) wards (36.7%), and one of the general medical wards (22.2%). Factors associated with a patient having a HAI were hospitalization for >30 days [odds ratio (OR) = 4.07; 95% confidence interval (CI) = 2.07-7.99]; being a patient on the orthopaedic and general surgical ward known as 'Surgical 2' (OR = 2.14; CI = 1.02-4.46); and being referred from another health facility (OR = 1.90; CI = 1.02-3.42). The most commonly identified HAI in the hospital were urinary-tract infections (14 cases), followed by surgical-wound infections (10 cases) and then lower respiratory-tract infections (six cases). Twenty HAI were 'unspecified'. The study was rapid and cheap to carry out. The results not only gave a baseline estimate of HAI in the study setting but also identified key areas for interventions to reduce HAI.

A phase I dose-ranging trial of monthly infusions of zoledronic acid for the treatment of osteolytic bone metastases

Bisphosphonates are potent inhibitors of bone resorption and provide a therapeutic benefit for patients with bone metastases. Zoledronic acid is a highly potent, nitrogen-containing bisphosphonate. In the present trial, we assessed the safety and tolerability of increasing doses of zoledronic acid and its effects on urinary markers of bone resorption in cancer patients with bone metastases. Fifty-nine cancer patients with bone metastases were enrolled sequentially into one of 8 treatment groups in the core protocol. Each patient received a 5-min i.v. infusion of 0.1, 0.2, 0.4, 0.8, 1.5, 2, 4, or 8 mg zoledronic acid monthly for 3 months. Patients were monitored for clinical findings, adverse events, electrocardiograms, markers of bone resorption, as well as routine hematology, blood chemistries, and urinalysis. Thirty patients who demonstrated a radiographic response to treatment or stable disease in the core protocol were enrolled in a humanitarian extension protocol and continued to receive monthly infusions. Zoledronic acid was well tolerated at all dose levels. Adverse events reported by >10% of patients included skeletal pain, nausea, fatigue, upper respiratory tract infection, constipation, headache, diarrhea, and fever. Three patients in the core protocol and one patient in the extension protocol experienced grade 3 skeletal pain, "flu-like" symptoms, or hypophosphatemia, which were possibly related to treatment; all recovered completely. Adverse events were reported with similar frequency across all of the dosage groups. Zoledronic acid resulted in sustained, dose-dependent decreases in urinary markers of bone resorption. Zoledronic acid was safe and well tolerated and demonstrated potent inhibition of bone resorption.

Reproductive events of wild cotton-top tamarins (Saguinus oedipus) in Colombia

Reproductive patterns of wild cotton-top tamarin (Saguinus oedipus) females located in La Reserva Forestal Protectora Serranía de Coraza-Montes de María in Colosó, Colombia, were examined using long-term behavioral observations and fecal steroid analysis. Using an enzyme immunoassay, we analyzed fecal samples for E1C and PdG. Comparisons of reproductive cycles of a reproductively active female and her daughters were made. An inhibition of ovarian cycles has been observed in daughters living in their families. However, daughters also exhibited normal ovarian cycling that subsequently resulted in pregnancy. Factors influencing the fertility are discussed as they relate to the reproductive strategies of wild cotton-top tamarin females.

Sequential sib-pair and association studies to detect genes in quantitative traits

We applied sib-pair and association methods to a GAW data set of nuclear families with quantitative traits. Our approaches included 1) preliminary statistical studies including correlations and linear regressions, 2) sib-pair methods, and 3) association studies. We used a single data set to screen for linkage and association and, subsequently, additional data sets to confirm the preliminary results. Using this sequential approach, sib-pair analysis provided evidence for the genes influencing Q1, Q2, and Q4. We correctly predicted MG1 for Q1, MG2 for Q2, and MG4 for Q4. We did not find any false positives using this approach. Association studies identified chromosomes 8 and 9 to be associated with Q4; however these are assumed to be false positives as no associations were modeled into the data.

Resistance to replication of human immunodeficiency virus challenge in SCID-Hu mice engrafted with peripheral blood mononuclear cells of nonprogressors is mediated by CD8(+) T cells and associated with a proliferative response to p24 antigen

High levels of resistance to challenge with human immunodeficiency virus type 1 SF162 were observed in animals engrafted with peripheral blood mononuclear cells of four long-term nonprogressors (LTNPs). Resistance was abrogated by depletion of CD8(+) T cells in vivo and was observed only in LTNPs with proliferative responses to p24. In a subgroup of nonprogressors, CD8(+) T cells mediated restriction of challenge viruses, and this response was associated with strong proliferative responses to p24 antigen.

Bcl-2 protein expression: association with p53 and prognosis in colorectal cancer

Bcl-2 expression in colorectal carcinomas was studied in a series of 224 patients and the relation to p53 expression, stage and survival assessed. Bcl-2 expression was down-regulated compared with normal mucosa in 67% (151) of the cases. In 144 cases staining was positive for p53 (MAB DO7), and 41 of these 144 p53-positive cases were also bcl-2 positive (28%) compared with 32 of the remaining 80 p53-negative cases (40%). Survival was significantly worse (P = 0.01) in the p53-positive cases. Bcl-2-positive cases, including patients in all Dukes' stages, had a slightly better prognosis which was not statistically significant. However, cases at an early stage (Dukes' stages A and B) and with negative p53 status, had a much better prognosis if they showed bcl-2 protein expression, suggesting that the bcl-2 status itself has an effect on prognosis (P = 0.01). Neither bcl-2 nor p53 alone was correlated with stage, but when examined by both p53 and bcl-2 status a group [bcl-2(+)/p53(-)] with better prognosis was defined. The last group was significantly lower Dukes' stage, with 26 out of 32 cases (81%) being A or B compared with 22 (11%) of the 202 remaining cases (P = 0.004). Thus, either loss of bcl-2 expression or gain of abnormal p53 expression is associated with high stage and poor prognosis. The bcl-2(+)/p53(-) phenotype is similar to that of normal mucosa, and these results suggest that such cases represent an indolent group at an early stage in the progression of colorectal cancer.