Approaches for enhancing patient-reported experience measurement with ethnically diverse communities: a rapid evidence synthesis

BACKGROUND

Patient-reported experience measures (PREMs) are used to drive and evaluate unit and organisational-level healthcare improvement, but also at a population level, these measures can be key indicators of healthcare quality. Current evidence indicates that ethnically diverse communities frequently experience poorer care quality and outcomes, with PREMs data required from this population to direct service improvement efforts. This review synthesises evidence of the methods and approaches used to promote participation in PREMs among ethnically diverse populations.

METHODS

A rapid evidence appraisal (REA) methodology was utilised to identify the disparate literature on this topic. A search strategy was developed and applied to three major electronic databases in July 2022 (Medline; PsycINFO and CINAHL), in addition to websites of health agencies in Organisation for Economic Co-operation and Development countries via grey literature searches. A narrative evidence synthesis was undertaken to address the review question.

RESULTS

The review resulted in 97 included studies, comprised 86 articles from electronic database searches and 11 articles from the grey literature. Data extraction and synthesis identified five strategies used in PREM instruments and processes to enhance participation among ethnically diverse communities. Strategies applied sought to better inform communities about PREMs, to create accessible PREMs instruments, to support PREMs completion and to include culturally relevant topics. Several methods were used, predominantly drawing upon bicultural workers, translation, and community outreach to access and support communities at one or more stages of design or administration of PREMs. Limited evidence was available of the effectiveness of the identified methods and strategies. PREMs topics of trust, cultural responsiveness, care navigation and coordination were identified as pertinent to and frequently explored with this population.

CONCLUSIONS

The findings provide a basis for a maturity model that may guide change to increase participation of ethnically diverse communities in PREMs. In the short-medium term, health systems and services must be able to recognise and respond to cultural and linguistic diversity in the population when applying existing PREMs. In the longer-term, by working in collaboration with ethnically diverse communities, systems and services may co-create adapted or novel PREMs that tackle the factors that currently inhibit uptake and completion among ethnically diverse communities.

From Detractors to Promoters: A comparative analysis of patient experience drivers across Net Promoter Score subcategories

BACKGROUND

The utilization of patient experience surveying by health care institutions has become increasingly prevalent, yet its effectiveness in promoting quality improvement remains uncertain. To enhance the utility of patient feedback, the examination of free-text comments may provide valuable insights to guide patient experience strategy.

AIMS

This study aims to explore the utility of free-text comments and identify key differences for patient experience drivers between Net Promoter Score (NPS) subcategories of Detractors, Passives, and Promoters.

METHODS

Evaluation and classification of comments was conducted using the eight Picker Principles of Person Centred Care, with descriptive analysis of patient comments performed on the NPS data.

RESULTS

Analysis of patient NPS comments can be classified into three key drivers: "feeling well-treated" (for Detractors), "feeling comfortable" (for Passives), and "feeling valued" (for Promoters). Specifically, Detractor comments provided the most comprehensive and detailed feedback to guide patient experience improvement activities.

CONCLUSION

This study highlights differences between NPS subcategories, particularly regarding aspects of safety, comfort, and feeling valued. Comments from Detractor respondents may be especially useful for guiding quality improvements due to increased specificity and insights. These results also emphasize the essential nature of empathy and compassionate interactions between patients and clinicians to achieve the highest level of patient satisfaction and experience.

Characterising consumer engagement in virtual models of care: A systematic review and narrative synthesis

BACKGROUND

Widespread adoption of digital tools and technologies now support the delivery of virtual healthcare. Although, consumer engagement is central to care processes in virtual care models, there is paucity of evidence regarding the nature and outcomes of consumer engagement. This study aimed to determine the nature of consumer engagement used in virtual models of care, and its impact on quality and safety of care.

METHODS

A systematic review was undertaken with a narrative synthesis, with a search strategy applied to five electronic databases (CINAHL, EMBASE, MEDLINE, PsycINFO and Web of Science) RESULTS: Fifty-eight studies were included in the review that utilised a variety of virtual models of care across care services. Consumer engagement, such as patients' active involvement in monitoring, capturing and reporting their health data, was a common feature of the identified virtual models.

CONCLUSION

Increasing use of virtual models of care requires consideration of the role of patients and their support persons in the use of technology and in wider care processes that occur at a distance from health professionals. Ensuring consumers are equipped with necessary support to effectively engage in virtual care is important to ensure equity in access to, and outcomes of, virtual care models.

EXPLORING THE KNOWLEDGE AND PRACTICES OF AUSTRALIAN MEDICAL STUDENTS REGARDING INFECTION PREVENTION AND CONTROL IN HOSPITALS: A PILOT STUDY

Objective: To assess the knowledge and practice of medical students regarding standard precautions in an Australian undergraduate medical programme. Study Design: Cross sectional study. Place and Duration of Study: University of New South Wales, Australia, duration of study was six-years. Methodology: Fifty medical students who were involved in clinical practice, were invited to complete a comprehensive questionnaire on standard precautions. Results: The majority of participants agreed that hand hygiene was the most important factor in infection control. Only 32 (16%) knew to use a full personal protective equipment for Ebola. Regarding sharps disposal, 46 (92%) students always disposed used needles in the recommended bin, 27 (54%) indicated they sometimes recapped used needle while 25 (20%) sometimes bent used needles. Conclusion: This study showed that there is a gap between knowledge and practice of medical students regarding hand hygiene and other infection control measures. There is a need for standardized and regular student training in the use of standard precautions in infection prevention and control.

Factors Determining Medical Students' Experience in an Independent Research Year During the Medical Program

BACKGROUND

There is ongoing debate about best practice models to support active learning by encouraging medical students to conduct independent research projects. This study explored student satisfaction, experiences, and learning outcomes of a unique, mandatory research program in an Australian medical school.

METHODS

Students were invited to complete an anonymous survey ranking statements using Likert scales and completing open-ended questions. Factors predicting student satisfaction with the research year were analysed using a generalised linear regression model. A content analysis of open-ended questions was conducted.

RESULTS

The survey was completed in October 2019 by 117 of 252 students (46%). The majority (84%) reported satisfaction with the research year. Factors associated with satisfaction were research skills learnt (OR 2.782, 95% CI 1.428-5.421; p < 0.003), supervision and support (OR = 2.587, 95% CI 1.237-5.413; p < 0.012), and meaningfulness and experience (OR = 2.506, 95% CI 1.100-5.708; p < 0.029). Qualitative results confirmed support from the faculty and supervisors, perceiving their research as meaningful, and the opportunity to learn research skills were highly regarded by students.

CONCLUSIONS

This study has shown that learning outcomes for basic research skills and high satisfaction rates can be achieved in a mandatory undergraduate research programme when students have dedicated time for their research, opportunities to negotiate their own project, and good support from faculty and mentors.

SUPPLEMENTARY INFORMATION

The online version contains supplementary material available at 10.1007/s40670-021-01340-9.

A retrospective review of primary care research projects completed by medical students at University of New South Wales Medicine

BACKGROUND AND OBJECTIVES

It is important for medical students to learn how to conduct sound medical research by implementing their own research projects. This study describes the primary care research projects conducted by fourth-year medical students for their Independent Learning Project/Honours (ILP/Honours) at University of New South Wales (UNSW) Medicine.

METHOD

A review was conducted of research projects undertaken by medical students at UNSW to determine the number and themes of projects on primary care topics, and the departments that supervised these projects.

RESULTS

Of 3116 student research projects, 482 (15.5%) were on primary care topics. Major themes were mental health and substance abuse (90; 18.7%), aged care issues (67; 13.7%), common chronic diseases (63; 13.1%), and issues facing Aboriginal and Torres Strait Islander people or people from culturally and linguistically diverse communities (59; 12.2%). Only 134 (4.3% of the total 3116) research projects were supervised through departments with primary care academics.

DISCUSSION

The ILP/Honours program gives medical students at UNSW Medicine an opportunity to conduct research on primary care topics. There needs to be more attention given to growing the research capacity of primary care academic departments.

Clinicians' experience of providing care: a rapid review

BACKGROUND

Health care services internationally are refocussing care delivery towards patient centred, integrated care that utilises effective, efficient and innovative models of care to optimise patient outcomes and system sustainability. Whilst significant efforts have been made to examine and enhance patient experience, to date little has progressed in relation to provider experience. This review aims to explore this knowledge gap by capturing evidence of clinician experience, and how this experience is defined and measured in the context of health system change and innovation.

METHODS

A rapid review of published and grey literature review was conducted utilising a rapid evidence assessment methodology. Seventy-nine studies retrieved from the literature were included in the review. Fourteen articles were identified from the grey literature search and one article obtained via hand searching. In total, 94 articles were included in the review. This study was commissioned by and co-designed with the New South Wales, Ministry of Health.

RESULTS

Clinician experience of delivering health care is inconsistently defined in the literature, with identified articles lacking clarity regarding distinctions between experience, engagement and work-related outcomes such as job satisfaction. Clinician experience was commonly explored using qualitative research that focused on experiences of discrete health care activities or events in which a change was occurring. Such research enabled exploration of complex experiences. In these contexts, clinician experience was captured in terms of self-reported information that clinicians provided about the health care activity or event, their perceptions of its value, the lived impacts they experienced, and the specific behaviours they displayed in relation to the activity or event. Moreover, clinician's experience has been identified to have a paucity of measurement tools.

CONCLUSION

Literature to date has not examined clinician experience in a holistic sense. In order to achieve the goals identified in relation to value-based care, further work is needed to conceptualise clinician experience and understand the nature of measurement tools required to assess this. In health system application, a broader 'clinician pulse' style assessment may be valuable to understand the experience of clinical work on a continuum rather than in the context of episodes of change/care.

The collaborative learning development exercise (CLeD-EX): an educational instrument to promote key collaborative learning behaviours in medical students

BACKGROUND

Modern clinical practice increasingly relies on collaborative and team-based approaches to care. Regulatory bodies in medical education emphasise the need to develop collaboration and teamwork competencies and highlight the need to do so from an early stage of medical training. In undergraduate medical education, the focus is usually on collaborative learning, associated with feedback and reflection on this learning This article describes a novel educational instrument, the Collaborative Learning Development Exercise (CLeD-EX), which aims to foster the development of key collaborative learning competencies in medical students. In this article we report on the effectiveness, feasibility and educational impact of the CLeD-EX.

METHODS

In this study, the "educational design research" framework was used to develop, implement and evaluate the CLeD-EX. This involved adopting a systematic approach towards designing a creative and innovative instrument which would help solve a real-world challenge in developing collaborative learning skills. The systematic approach involved a qualitative exploration of key collaborative learning behaviours which are influential in effective collaborative learning contexts. The identified competencies were employed in the design of the CLeD-EX. The design of the CLeD-EX included features to facilitate structured feedback by tutors to students, complemented by self-evaluation and reflection. The CLeD-EX was field-tested with volunteer junior medical students, using a controlled pre-test post-test design. Analysis of the completed CLeD-EX forms, self-perception surveys (i.e. pre-test and post-test surveys) and analyses of reflective reports were used to explore the educational impact of CLeD-EX, as well as its utility and practicality.

RESULTS

After using the CLeD-EX, students showed a significant improvement in critical thinking and group process as measured by a previously validated instrument. Both students and tutors recognised CLeD-EX as an effective instrument, especially as a structured basis for giving and receiving feedback and for completing the feedback loop. CLeD-EX was also found to be feasible, practical and focused, while promoting learning and effective interactions in small group learning.

CONCLUSION

The findings of this study support the introduction of an effective and feasible educational instrument such as the CLeD-EX, to facilitate the development of students' skills in collaborative learning.

Developing the competency of ‘collaborative clinical practice’

This article was migrated. The article was not marked as recommended. With the increasing complexity of healthcare delivery and patient case mix, and the aging population, health professionals are expected to function more often and more effectively as members of multidisciplinary teams. Competency based medical education (CBME) advocates that the professional development of doctors should be fostered from the start of medical school through to medical practice and with continuing professional development. Strategies for developing teamwork among health professionals and students range from minimal, implicit to explicit (Earnest et al., 2017). Considering this continuum of medical education and the spectrum of educational strategies, we propose a framework for the programmatic approach which can be used in developing competence in 'collaborative clinical practice'.

Urban and rural comparison of vitamin D status in Pakistani pregnant women and neonates

We undertook a cross-sectional study in rural Jehlum and urban Karachi to evaluate the prevalence of vitamin D deficiency in Pakistani pregnant women and neonates and to assess any association of serum 25(OH) vitamin D [25(OH)D] concentration with vitamin D binding protein (Gc) genotypes. Altogether, 390 women and 266 neonates were recruited from urban and rural sites, respectively. Serum 25(OH)D was measured by an immunoassay, while Gc genotypes were identified using polymerase chain reaction followed by restriction fragment length polymorphism or PCR-RFLP. One-way analysis of variance or ANOVA and linear regression were used for statistical analysis. In urban Karachi, 99.5% of women and 97.3% of neonates were vitamin D deficient (< 50 nmol/L), while 89% of women and 82% of neonates were deficient in rural Jehlum. Gc genotypes were not associated with serum 25(OH)D concentrations in both women and their neonates. We conclude that vitamin D deficiency is highly prevalent in Pakistani women and their neonates, and Gc genotypes are not associated with serum 25(OH)D concentrations.

Role of vitamins B6, B12 and folic acid on hyperhomocysteinemia in a Pakistani population of patients with acute myocardial infarction

BACKGROUND AND AIM

Pakistani people belong to an ethnic group which has the highest rate of coronary artery disease (CAD). We investigated the possible correlation between deficiency of vitamins B6, B12 or folic acid and hyperhomocysteinemia in Pakistani patients with acute myocardial infarction (AMI). A case-control study was carried out involving 224 AMI patients (age 30-70 years; 55 females and 169 males) and 126 normal healthy subjects (age 31-70 years; 35 females and 91 males).

METHODS AND RESULTS

Fasting venous blood was obtained from cases and controls. Serum was analyzed for folic acid and B12 using radioassays. Plasma was analyzed for pyridoxal phosphate (PLP; coenzymic form of B6) using a radioenzymatic assay and for total homocysteine using a fluorescence polarization immunoassay. Mean serum B12 concentration in AMI patients was found to be significantly lower than the mean for controls (241+/-185 pg/ml vs 608+/-341 pg/ml; p < 0.001). Mean serum folate level in patients was also found to be lower than controls (3.35+/-3.78 ng/ml vs 4.93+/-2.93 ng/ml), however, the differences were not statistically significant. Similarly, mean PLP concentration in plasma of cases (19.4+/-24.4 nmol/l) was lower than the concentration in controls (23.2+/-17.6 nmol/l), but the difference was not statistically significant. Mean plasma homocysteine level in AMI cases (18+/-8.36 micromol/l) was higher than the mean level in controls (16.4+/-4.9 micromol/l), but not to a significant extent. However, this mean homocysteine concentration in normal healthy subjects was among the highest reported in the literature and was significantly more than mean values reported in most Eastern and Western studies. Compared to controls, there was significantly greater deficiency of folate (32.5% vs 67.1%), B12 (3.2% vs 63.4%) and PLP (49.2% vs 74.1%) in AMI patients. Deficiencies of folate, B12 and PLP were defined as serum folate levels less than 3.5 ng/ml, serum levels of B12 less than 200 pg/ml and plasma PLP levels less than 20 nmol/l. Mean plasma homocysteine levels in smokers were found to be significantly higher in both cases and controls. Similarly, mean serum folate levels in smokers (compared to nonsmokers) were significantly lower in both cases and controls.

CONCLUSIONS

Substantial nutritional deficiencies of these three vitamins along with mild hyperhomocysteinemia, perhaps through an interplay with the classical cardiovascular risk factors (highly prevalent in this population), could be further aggravating the risk of CAD in the Pakistani population.

Variability in lipid profile in patients with acute myocardial infarction from two tertiary care hospitals in Pakistan

OBJECTIVE

To investigate changes in total cholesterol, high density lipoprotein (HDL)-cholesterol, low density lipoprotein (LDL)-cholesterol and triglycerides in serum of Pakistani patients with AMI due to age, gender, body mass index (BMI), diabetes, hypertension, and smoking, and also find out the prevalence of hypercholesterolemia, hypertriglyceridemia, "low HDL-cholesterol" and "isolated low-HDL cholesterol" in them.

PATIENTS AND METHODS

Serum samples from 451 consecutive AMI patients (250 from National Institute of Cardiovascular Diseases, Karachi and 201 from Armed Forces Institute of Cardiology, Rawalpindi) were analyzed for total cholesterol, HDL-cholesterol and triglycerides using kit methods. LDL-cholesterol was determined using the Friedewald formula.

RESULTS

Mean serum concentrations of total cholesterol, HDL-cholesterol, LDL-cholesterol and triglycerides in AMI patients were found to be 181 +/- 50 mg/dl, 35.7 +/- 11.3 mg/dl, 110 +/- 47 mg/dl and 177 +/- 127 mg/dl, respectively. Mean levels of total cholesterol and HDL-cholesterol were not significantly affected by age, gender, BMI, diabetes mellitus, hypertension and smoking. Mean LDL-cholesterol concentration, however, was found to be significantly increased in diabetes mellitus (p=0.047), while age, gender, BMI, hypertension and smoking had no significant effect on the levels of this lipoprotein. Mean levels of triglycerides were significantly decreased in older patients (>50 years) compared to younger (<50 years) ones (p=0.019). Gender, BMI, diabetes mellitus, hypertension and smoking, however, had no effect on triglyceride levels The frequencies of hypercholesterolemia, hypertriglyceridemia, "low HDL-cholesterol" and "isolated low-HDL-cholesterol" were found to be 30.6%, 30.1%, 48.6% and 34.1%, respectively.

CONCLUSION

High prevalence of hypertriglyceridemia and low HDL-cholesterol (which constitute a component of metabolic syndrome) in Pakistani AMI patients is suggestive that these two lipid abnormalities could be playing a major role in the development of atherosclerosis in Pakistani population.

Increased levels of erythrocyte glutathione in acute myocardial infarction: an antioxidant defence

OBJECTIVE

Glutathione (GSH) has a central role in the defence against oxidative damage. This study was carried out to investigate any change in erythrocyte GSH levels in a population of patients with acute myocardial infarction (AMI) and compare them with levels in normal healthy subjects.

METHOD

GSH levels were determined in erythrocytes of one hundred and seventy six patients with AMI (age: 30-70 years; 131 males and 45 females) admitted to the National Institute of Cardiovascular Diseases, Karachi. These levels were compared with eryrocyte GSH levels obtained from 95 normal healthy subjects (controls).

RESULTS

Mean +/- SD erythrocyte GSH levels in AMI patients and controls were found to be 2.34 +/- 0.62 micromol/ml of packed cells and 2.08+/- 0.62 micromol/ml of packed cells, respectively. The two values when compared with one way ANOVA were found to be significantly different (p=0.001). Age had little effect on erythrocyte GSH levels in both AMI patients and normal healthy subjects.

CONCLUSION

Increased production of reactive oxygen species is a feature of cardiovascular disease, such as AMI and cells can respond to mild oxidative stress by upregulating antioxidant defence in terms of increased production of GSH.

Effect of methotrexate and folinic acid on skeletal growth in mice

AIM

To investigate whether chronic administration of medium doses of methotrexate (MTX) causes suppression of skeletal growth in young mice and to determine whether folinic acid supplementation could reverse this effect.

METHODS

Four equal groups of Balb/c young male mice (6 animals in each group; mean body weight 11.9 +/- 0.25 g, in their rapid growth phase) were subjected to the following drug treatment for a period of 3 wk. Group 1 was given intraperitoneal MTX (3.5 mg kg(-1) body weight) every second day. Group 2 received folinic acid (7.0 mg kg(-1) body weight) intraperitoneally every second day. Group 3 was given both drugs (MTX every second day and folinic acid 8 h post-MTX injection). Group 4 was injected with physiological saline every other day to serve as a control group. Total body weight of the animals in each group was monitored every second day for the entire study period. The animals were sacrificed, the bilateral femurs and tibias of each animal were harvested and X-rays of the bones were taken. The length of each femur and tibia was measured using a micrometer. Measurements from the radiographs were also recorded using image analysis software. The MTX concentrations in the plasma and the folate levels in erythrocytes were determined. The heights of the distal femoral and the proximal tibial growth plate for each animal were measured on histological tissue sections.

RESULTS

Mean lengths of both the tibia and femur of animals were compared in the four treatment groups. A significant decrease in the mean lengths (one-way ANOVA, p < 0.005) was observed in the group receiving MTX alone. Similarly, there was a significant decrease (p < 0.001) in the height of the femoral and tibial growth plate in this group when compared with the other groups. The main effect of MTX seemed to be on the hypertrophic proliferative zone of chondrocytes in the growth plate. Furthermore, animals in this MTX-treated group also showed increased levels of MTX in plasma and low levels of erythrocyte folate.

CONCLUSION

These data show that chronic administration of MTX induces suppression of skeletal growth in mice, possibly through the inhibition of the pathway of de novo DNA synthesis. Folinic acid treatment following MTX administration appears to reverse this growth inhibition. Based on these observations, children suffering from juvenile rheumatoid arthritis, osteosarcoma or acute lymphoblastic leukaemia and receiving MTX over long periods of time could be at risk of short-term suppression of skeletal growth. If this is the case, it is possible that they could benefit from dietary supplementation with folinic acid.

Effect of methotrexate and folinic acid on accumulation of iron in mice

A mouse-model was used to investigate the effect of methotrexate (MTX) and folinic acid on accumulation of iron in young growing mice. Four equal groups of Balb/c young male mice were treated (subcutaneously) with either MTX, or folinic acid, or MTX plus folinic acid, or physiological saline on every second day. After 3 weeks of treatment, liver, spleen, kidney, small intestine, brain, skeletal muscle and heart were removed and analyzed for iron contents using a spectrophotometric method. When the mean values of iron in liver of four groups were compared using one way ANOVA followed by Tukey's HSD test, the group receiving MTX alone was found to have significantly (p=0.004) more accumulation of iron in liver. The group receiving MTX plus folinic acid had iron accumulation in the liver similar to the placebo group. However, the mean values of iron in brain, kidney, small intestine, skeletal muscle, heart and spleen in all the groups, were not found to be statistically different. The data indicate that MTX shifts iron from being utilized in hemoglobin synthesis to liver stores. Folinic acid administration 8 h post-MTX, however, prevents this shift of iron to liver. Decreased levels of iron in plasma in mice treated with MTX alone suggest decreased availability of iron to other tissues for their normal growth and development.

Folinic acid protects against suppression of growth by methotrexate in mice

The objective of this study was to investigate whether folinic acid supplementation would protect young mice against suppression of growth by methotrexate (MTX). Four equal groups of Balb/c young male mice (5 animals in each group; mean+/-SD body weight 9.64+/-0.85 g, in their rapid growth phase) were subjected to the following drug treatment: One group was given MTX (3.5 mg/kg body weight) intraperitoneally on every 2nd day, another received folinic acid (7.0 mg/kg body weight) intraperitoneally every 2nd day. The third group was given both of these drugs (MTX on every 2nd day and folinic acid 8 h post-MTX injection). The fourth group was injected with physiological saline every other day to serve as a control group. Total body weight, food and water consumption by animals in each group were monitored every second day for a period of 3 weeks. After this period mice were sacrificed and liver, spleen and kidneys were excised, weighed and analyzed for MTX and dihydrofolate reductase activity. A small segment of the proximal part of small intestine and small pieces of liver and kidney were also removed to study morphological changes. Compared to the groups, which received folinic acid alone, folinic acid plus MTX or physiological saline, mean increase in body weight (6.8+/-0.8 g) of mice over a period of 3 weeks was minimal in the group receiving MTX alone (one-way ANOVA p=0.0001). The mean weights of liver and kidney in this group receiving MTX alone were also found to be significantly less than the mean weights of these organs in the 3 groups (p<0.001). The negative effect on growth of animals appears not only due to malabsorption but inhibition of pathway of de novo DNA synthesis may also be involved. This is supported by loss of villous pattern in small intestine of mice treated with MTX alone and increased accumulation of free MTX and decreased dihydrofolate reductase in the liver of the group receiving MTX alone as compared with the group receiving MTX plus folinic acid. The data indicate that the administration of folinic acid protects mice against suppression of growth by MTX. On the basis of these observations it can be deduced that patients suffering from juvenile rheumatoid arthritis or acute lymphoblastic leukaemia receiving MTX over a long period of time might be at a risk of experiencing short-term suppression of growth, however they could benefit from supplementation with folinic acid.

Induction of white cell proliferation due to haematopoietic growth factors is associated with an increase in multiple forms of dihydrofolate reductase in non-neutropenic cancer patients

OBJECTIVE

Granulocyte-colony stimulating factor (G-CSF) and granulocyte macrophage-colony stimulating factor (GM-CSF) are frequently used in cancer patients to overcome the granulocytopenic effects of chemotherapy, and also to mobilize the stem cells. The mobilized stem cells are collected from the peripheral blood and used for transplantation following high doses of chemotherapy. However, the molecular mechanism by which these colony stimulating factors (CSFs) bring about proliferation of myeloid precursor cells is not clearly known. Dihydrofolate reductase (DHFR), which has an established role in DNA synthesis, could be a link between administration of CSF and stem cell proliferation. The purpose of this study was to investigate whether CSFs induce white cell proliferation by producing multiple forms of DHFR.

METHODS

Twelve patients with non-haematological malignancies were treated with either G-CSF or GM-CSF to mobilize stem cells. Nine healthy subjects were treated with placebo as controls. Blood samples were obtained before and after stimulation with CSFs or placebo. White blood cells were separated and concentrations of both active DHFR and immunoreactive nonfunctional form of DHFR were determined in their cytoplasm using methotrexate-binding assay and enzyme-linked immunosorbent assay, respectively. Total leucocytes count (TLC) was also monitored before and after stimulation with CSFs or placebo.

RESULTS

There was a significant (P < 0.05) increase in concentration of immunoreactive nonfunctional form of DHFR and TLC following stimulation with CSFs. There was an increase in concentration of active DHFR as well, however, this did not reach statistical significance. In the placebo-treated subjects, no significant increase in active DHFR, immunoreactive nonfunctional form of enzyme or TLC was observed. However, it was noticed that the base-line values of active DHFR and immunoreactive nonfunctional form of enzyme in leucocytes of cancer patients were higher than the base-line values in leukocytes of normal healthy subjects.

CONCLUSION

Our data suggest that colony stimulating factors induce white cell proliferation by increasing levels of multiple forms of DHFR.

Increased levels of multiple forms of dihydrofolate reductase in peripheral blood leucocytes of cancer patients receiving haematopoietic colony-stimulating factors: interim analysis

The precise mechanism whereby granulocytes proliferate when haematopoietic colony stimulating factors (CSFs) are used in neutropenic cancer patients is poorly understood. The purpose of this study was to investigate whether these cytokines bring about leucocyte proliferation by increasing the levels of multiple forms of dihydrofolate reductase (DHFR). Blood samples were collected from 36 cancer patients (25 males and 11 females) with chemotherapy-induced neutropenia. One sample of blood from each patient was obtained before therapy either with CSF, such as granulocyte colony stimulating factor (G-CSF) and granulocyte-macrophage colony stimulating factor (GM-CSF) or with placebo, and another one at the time of resolution of neutropenia. Peripheral blood leucocytes in these blood samples were counted, separated and lysed. From lysates, cytoplasmic samples were prepared and analyzed for active DHFR by a methotrexate-binding assay and for total immunoreactive DHFR by an enzyme linked immunosorbent assay. The increase in total leucocyte count (TLC) was most prominent (P < 0.005) in the CSF group and less so (P < 0.05) in the placebo group. The mean +/- SD concentration values of active DHFR before and after stimulation with GM-CSF found were to be 0.34 +/- 0.4 ng/mg protein and 0.99 +/- 0.82 ng/mg protein, respectively, and in the group treated with G-CSF, 0.24 +/- 0.32 ng/mg protein and 1.18 +/- 2.4 ng/mg protein, respectively. This increase in active DHFR after stimulation with CSF was statistically significant (P < 0.05). Similarly, concentration values of immunoreactive but nonfunctional form of DHFR (IRE) were 110 +/- 97 ng/mg protein and 605 +/- 475 ng/mg protein before and after stimulation with GM-CSF, and 115 +/- 165 ng/mg protein and 1,054 +/- 1,095 ng/ mg protein before and after stimulation with G-CSF. This increase in concentration of IRE after stimulation with GM-CSF or G-CSF was statistically significant (P < 0.005). In the control group, there was an increase in the concentration of both active DHFR and IRE after treatment with placebo. However, this was not statistically significant. Resolution of neutropenia was quicker in the groups treated with CSF compared to the control group. Results of this study indicate that colony stimulating factors (G-CSF and GM-CSF) induce white cell proliferation by increasing the levels of multiple forms of DHFR.

Additive effect of indomethacin and methotrexate on suppression of growth in rats

The purpose of this study was to investigate the medium-term effects of methotrexate (MTX) and indomethacin on the growth of young rats. Four equal groups of Sprague-Dawley male rats (four animals in each group; mean+/-S.D. body weight, 183+/-13 g, in their rapid growth phase) were subjected to the following drug treatment: one group was given MTX (0.2 mg kg(-1) body weight) subcutaneously on every fourth day, another received indomethacin (2.5 mg kg(-1) body weight) subcutaneously daily and the third group was given both of these drugs (MTX on every fourth day and indomethacin daily). The fourth group was injected subcutaneously with physiological saline every day to serve as a control group. Total body weight, food and water consumption by animals in each group were monitored every second day for a period of 10 weeks. After this period, liver, spleen and kidneys were excised, weighed and analysed for MTX and dihydrofolate reductase activity. Compared with the groups, which received MTX alone, indomethacin alone, or physiological saline, mean increase (17+/-11 g) in body weight of rats was minimal in the group receiving both MTX and indomethacin. The difference was statistically significant (p=0.001) when the values of mean increase in body weight of rats in different treatment groups after a 10-week treatment were compared. The mean weights of liver and spleen in this group receiving both MTX and indomethacin were also found to be significantly less than the weights of these organs in the control group (p<0.01). There also appears to be a decline in food consumption in this group (p<0.05). This negative effect on growth of animals in this group appears to be not only due to decreased food consumption but also due to increased inhibition of de novo pathway of DNA synthesis. This is supported by increased accumulation of MTX and decreased dihydrofolate reductase activity in this group receiving both MTX and indomethacin, as compared with the group receiving MTX alone. The data indicate an additive effect of MTX and indomethacin on the suppression of growth in young rats, alluding to the notion that patients suffering from juvenile rheumatoid arthritis or acute lymphoblastic leukaemia receiving these two drugs concomitantly over a long period of time might be at a risk of experiencing short-term suppression of growth.

Accumulation of methotrexate in human tissues following high-dose methotrexate therapy

Methotrexate concentration was analyzed in a number of tissues of a patient of osteogenic sarcoma who had been on high-dose methotrexate therapy for nearly 6 months. Gall bladder and kidney contained the highest concentration of the drug, followed by testis, small intestine, skeletal muscle, bone marrow, lung, spleen, heart and liver. Although, compared to kidney the liver contained relatively small amount of the drug, yet nearly 1/5th of the total drug in liver was in bound form. This bound form of methotrexate is most likely associated with multiple forms of dihydrofolate reductase. The total concentration of methotrexate in kidney is 80 fold higher than the concentration of the drug in liver and 28 fold higher than the concentration in bone marrow. This suggests that in high-dose methotrexate therapy, nephrotoxicity is the more immediate threat to the patient than hepatotoxicity and bone marrow suppression.

Urinary N-acetyl-beta-D-glucosaminidase in rheumatoid arthritis

Excretion of urinary N-acetyl beta-D-glucosaminidase (NAG) and its isoenzyme patterns were studied in two groups of patients with rheumatoid arthritis (RA) and in normal control subjects. Urine samples were collected from 30 seropositive RA patients, 19 seronegative RA patients, and 15 normal healthy subjects. All the patients and normal subjects were assessed to have normal liver and kidney functions. A small portion of the urine sample was dialyzed against 0.01 M phosphate buffer, pH 7.0 and NAG activity was monitored. Mean +/- SD values of urinary NAG in seropositive RA patients, in seronegative RA patients and in normal healthy subjects were found to be 4.20 +/- 3.73 U/g creatinine, 2.96 +/- 2.11 U/gm creatinine, and 1.71 +/- 0.6 U/g creatinine, respectively. The mean urinary, NAG value in RA patients was found to be significantly higher (P < 0.05) in seropositive RA compared to the mean NAG value in normal healthy subjects and patients with seronegative RA when analyzed by one way ANOVA and Tukey-HSD test. The mean proportion of isoenzyme form B to isoenzyme form A in seropositive RA patients was also found to be significantly different (P < 0.05) from the mean proportion of these forms in normal healthy subjects and seronegative RA patients. There also appears to be a correlation between the concentration of urinary NAG and severity of the disease in seropositive RA.

The effects of non-steroidal anti-inflammatory drugs on the disposition of methotrexate in patients with rheumatoid arthritis

We have studied the pharmacokinetics of methotrexate in patients with rheumatoid arthritis concurrently taking the most commonly used non-steroidal anti-inflammatory drugs (NSAIDs), aspirin, diclofenac, naproxen, indomethacin, and ibuprofen. The area under the curve, the total systemic clearance, the distribution volume, and the half-life of methotrexate in patients receiving concurrent NSAID therapy did not change significantly (at p < 0.05). Concurrent treatment with NSAIDs resulted in increased inter-patient variability of methotrexate concentration, possibly as a result of biochemical interactions; however, it does not appear clinically relevant. The data suggest that the NSAIDs do not significantly affect the disposition of methotrexate, contrary to some of the earlier reports.

Methotrexate in rheumatoid arthritis: a 2 year experience at a university hospital in Pakistan

In this study we report our two years experience of methotrexate (MTX) in the management of rheumatoid arthritis (RA) at the Aga Khan University Hospital, Karachi. We studied the clinical course of 124 RA patients. The mean age was 44 +/- 11 years (range 19-72) and mean duration of RA was 5 +/- 4 years (range 0.3-25). Female to male ratio was 10:2.4 (100F:24M). All of them were diagnosed according to the criteria set by American Rheumatism Association. The mean value of ESR was 60 +/- 30 (Range 3-128). Fifty one percent had severe disease (> 10 joints involved and evidence of erosions and deformities). Twenty-one patients had extra-articular manifestations. None of them had received MTX previously. Their kidney and liver functions were assessed to be normal. Patients were divided into two groups. One group (n = 92) received MTX (7.5-10 mg/week) as initial treatment, while the other group (n = 32) was given other disease modifying anti-rheumatic drugs (penicillamine, salazopyrin, gold, or chloroquine) followed by MTX. Assessment of the treatment outcome and development of any adverse reactions was carried out at 3-month interval over an average period of 1 year. Assessment of the treatment outcome in the group which received MTX as initial drug revealed the response to be excellent in 13%, good in 70%, fair in 11% and variable in 4%. In the group which received MTX as second-line of therapy, 59% of the patients had the response from good to excellent, while 25% of the patients exhibited poor to fair response. Regarding side-effects of MTX treatment, 57% exhibited none, while 35% had nausea and vomiting. Alopecia was the next common toxicity in these patients. Two individuals had abnormal liver function tests (value twice more than normal), while one developed lung fibrosis. MTX despite its adverse effects in some of the patients is still an effective, well tolerated and inexpensive disease modifying drug in RA.

Effect of ifosfamide on intracellular glutathione levels in peripheral blood lymphocytes and its correlation with therapeutic response in patients with advanced ovarian cancer

The successful outcome of ovarian cancer therapy with alkylating agents and cisplatin is seriously hampered by the development of acquired drug resistance. An increase in intracellular glutathione (GSH) levels in cancer cells is one of the major mechanisms involved. Depletion of GSH overcomes drug resistance and restores the chemosensitivity of malignant cells. Ifosfamide (IFEX), an alkylating agent, has been demonstrated to decrease intracellular GSH levels in vitro in malignant cell lines and in vivo in peripheral blood lymphocytes (PBL) obtained from patients with cancer. We studied the effect of IFEX on intracellular GSH levels in PBL isolated from patients with advanced ovarian cancer who were receiving chemotherapy. A total of 14 patients received IFEX plus mesna as a continuous infusion (1 g/m2 per day) for 6 consecutive days and cisplatin (100 mg/m2) as a 24-h continuous infusion on the 6th day. PBL were isolated prior to the initiation of chemotherapy and on the 3rd and 6th days of IFEX infusion. Intracellular GSH levels were determined by a modification of Tietze's method. IFEX caused a 20% or greater suppression of intracellular GSH levels in nine patients, eight of whom achieved complete remission of their disease. Six patients responded poorly to this chemotherapeutic regimen, five of whom showed no significant suppression of GSH levels. These data suggest that IFEX suppresses intracellular GSH levels in PBL from patients with ovarian cancer and that this suppression correlates closely with the subsequent clinical outcome.

Ty1-copia group retrotransposon sequences in amphibia and reptilia

We have isolated sequences belonging to Ty1-copia group retrotransposons from the genomes of an amphibian (Pyxicephalus adspersa) and three reptiles (Conolophus subscristatus, Amblyrynchus cristatus and Pytas mucosus). Two different sequences were found in the amphibian (Tpa1 and Tpa2). Each is present in several copies per genome and absent from the genomes of two other amphibian species. The C. subcristatus sequence Tcs1 is present in multiple copies in both its host genome (Galapagos land iguana) and the genome of the related Galapagos marine iguana (A. cristatus). There is little or no polymorphism in Tcs1 insertions between different individual animals, suggesting that this sequence is not transposing rapidly in either iguana genome. The P. mucosus sequence Tpm1 shows a discontinuous distribution in snake species, suggesting that it has either been lost from many lineages during vertical germline transmission or has been transferred horizontally in some snake species. Phylogenetic comparisons of all these sequences with each other and with other members of this retrotransposon group from other animals and plants show that sequences within a particular vertebrate species are most closely related to each other, consistent with a vertical transmission model for their evolution.

Pharmacokinetics of aditoprim and trimethoprim in buffalo calves

Pharmacokinetic parameters of two antifolates, trimethoprim and aditoprim, were studied in buffalo calves. The elimination half-life of aditoprim (6.14 h) was nearly twice as long as that of trimethoprim (3.08 h) and compares well with values observed in heifers. This longer half-life of aditoprim is a result of its much larger distribution volume (four to five times larger) because the clearance of aditoprim was about twice as high as that of trimethoprim. The longer half-life of aditoprim is expected to give a longer duration of in vivo bacteriostatic activity than that of trimethoprim.

Evidence for kinetic and immunologic heterogeneity of dihydrofolate reductase in L1210 leukemia cells

Two species of DHFR were identified in wild-type L1210 murine leukemia cells by analysis of the kinetics of the binding of MTX and dissociation of the MTX-enzyme complex at pH 5.0 and pH 7.2. The two forms of DHFR were also distinguished by immunoinhibition of the binding of MTX and the catalytic reduction of FH2 to FH4 using an antiserum raised to the purified high affinity form of DHFR. The Ka for the binding of MTX by the low affinity form of the enzyme is 4.5 x 10(7) M-1, substantially lower than the reported Ka for the binding of this drug by the high affinity enzyme. The low affinity form of the enzyme catalyzed the reduction of FH2 to FH4 at a rate slower than the high affinity form of DHFR.

Heterogeneity of methotrexate binding in human colon tumor cells

[3H]-methotrexate binding at pH 5.0 and pH 7.2 by the cytosol of tumor tissues and the surrounding normal areas of the gastrointestinal tract of patients suffering from colon or gastric cancer has been used to identify in these cells the presence of a binder of methotrexate having low-affinity for this drug in addition to the enzyme dihydrofolate reductase. Scatchard analysis of the [3H]-methotrexate binding data by a colon tumor sample also reveals that there are two binders of this drug present in the cytosol of these cells. The association constant (Kass) for one binder of methotrexate is = 5.6 x 10(7) M-1 while the Kass for the second binder is = 1.0 x 10(6) M-1. The two binders do not differ very much in their apparent molecular weight. Upon isoelectric focusing, the tumor cell cytosol resolves into 4 major isoproteins each having the ability not only to bind [3H]-methotrexate but also reduce [3H]-pteroylglutamic acid to [3H]-tetrahydropteroylglutamic acid. This suggests that the two binders of methotrexate may be the two forms of dihydrofolate reductase having different affinities for this anticancer drug.

Pharmacokinetics of aditoprim in goats using a radioassay

A simple, highly sensitive radioassay was developed for the activity of a newly discovered inhibitor of dihydrofolate reductase (DHFR), aditoprim. The procedure is based on the inhibition of binding of [3H]-methotrexate ([3H]MTX) with bacterial dihydrofolate reductase by the antifolate, aditoprim. The analytic sensitivity using this binding inhibition method was less than 5 ng in plasma. The procedure developed requires no extraction of the drug from the plasma. The variation of simultaneous duplicate determinations was 6.3 per cent, whereas the variability of plasma samples assayed on different days was less than 11 per cent. The assay developed was applied to study the pharmacokinetics of aditoprim in the goat. In comparison with trimethoprim (TMP), the new inhibitor of DHFR, aditoprim, had a longer half-life and a larger volume of distribution, suggesting enhanced and prolonged antibacterial activity of aditoprim over TMP.

Methotrexate clearance and clinical toxicity in osteosarcoma following high-dose methotrexate therapy

Two patients with osteogenic sarcoma were treated with high-dose methotrexate (MTX) followed by leucovorin 'rescue'. Profiles of MTX clearance from plasma and erythrocytes were obtained. Clearance of the drug from plasma during the first 36 hours appears to be biphasic with the first phase of elimination of the drug being appreciably more rapid than the second phase. The drug had also incorporated into the bone marrow precursor cells and reappeared after a few days in the circulating mature erythrocytes which may later serve as a slow-changing compartment for MTX. Nonspecific binding of the drug to plasma proteins may have been one of the causes of delayed clearance of plasma MTX observed in one of the patients. However, delayed clearance does not appear to correlate with the severity of clinical toxicity which was found to be more pronounced in a patient with a better clearance of the drug. Our results support the more recent concept that enhanced clinical toxicity may not be predictable by monitoring plasma MTX alone.

Mouse brain contains a high molecular weight nonfunctional protein with antigenic homology to dihydrofolate reductase

The cytosol of brain tissue from mature BDF1 mice contains very little dihydrofolate reductase activity but it does contain a high molecular weight nonfunctional protein which cross-reacts in a radioimmunoassay for the active enzyme. Liver cytosol contains less of this high molecular weight cross-reacting protein and more of the functional dihydrofolate reductase. The cytosol from kidney contains very little of the high molecular weight cross-reacting protein, 95% of the immunoreactive proteins being the functional form of dihydrofolate reductase. The modification of dihydrofolate reductase into a nonfunctional form may be an intrinsic property of some cells and this finding could explain the variability in measuring the activity of this enzyme in brain tissue of mature animals.