Screening for poverty and related social determinants to improve knowledge of and links to resources (SPARK): development and cognitive testing of a tool for primary care

BACKGROUND

Healthcare organizations are increasingly exploring ways to address the social determinants of health. Accurate data on social determinants is essential to identify opportunities for action to improve health outcomes, to identify patterns of inequity, and to help evaluate the impact of interventions. The objective of this study was to refine a standardized tool for the collection of social determinants data through cognitive testing.

METHODS

An initial set of questions on social determinants for use in healthcare settings was developed by a collaboration of hospitals and a local public health organization in Toronto, Canada during 2011-2012. Subsequent research on how patients interpreted the questions, and how they performed in primary care and other settings led to revisions. We administered these questions and conducted in-depth cognitive interviews with all the participants, who were from Saskatchewan, Manitoba, Ontario, and Newfoundland and Labrador. Cognitive interviewing was used, with participants invited to verbalize thoughts and feelings as they read the questions. Interview notes were grouped thematically, and high frequency themes were addressed.

RESULTS

Three hundred and seventy-five individuals responded to the study advertisements and 195 ultimately participated in the study. Although all interviews were conducted in English, participants were diverse. For many, the value of this information being collected in typical healthcare settings was unclear, and hence, we included descriptors for each question. In general, the questions were understood, but participants highlighted a number of ways the questions could be changed to be even clearer and more inclusive. For example, more response options were added to the question of sexual orientation and the "making ends meet" question was completely reworded in light of challenges to understand the informal phrasing cited by English as a Second Language (ESL) users of the tool.

CONCLUSION

In this work we have refined an initial set of 16 sociodemographic and social needs questions into a simple yet comprehensive 18-question tool. The changes were largely related to wording, rather than content. These questions require validation against accepted, standardized tools. Further work is required to enable community data governance, and to ensure implementation of the tool as well as the use of its data is successful in a range of organizations.

O050 A ten-year review of methodological trends and outcomes in riskreducing mastectomy and associated reconstruction at a tertiary referral centre

Introduction

Risk-reducing mastectomy (RRM) is the removal of breast tissue to substantially decrease the risk of developing breast cancer in individuals with higher breast cancer susceptibility due to strong family history or genetic mutations. This retrospective study evaluates cases of RRM, and subsequent reconstruction performed at a tertiary referral centre over the last decade, with emphasis on mastectomy and reconstructive trends.

Methods

A retrospective review of all cases of RRM performed between January 2010 and January 2020, divided into two groups corresponding to the first half (group 1) and second half (group 2) of the decade was conducted. Data collected included demographics, genetic test results, family and personal history of breast cancer, co-morbidities, mastectomy type, reconstruction type, surgical histopathology findings and complications.

Results

A total of 167 patients (group 1=76, group 2=91) underwent RRM, with a significant increase in cases of RRM despite negative genetic test results (p=0.047). The proportion of nipple sparing techniques for RRM compared to more traditional skin-sparing techniques. Concomitantly, post-RRM reconstruction has progressively become solely implant-based, to coincide with a rise in ADM usage. This is consistent with national trends towards fewer complex autologous procedures.

Take-home message

Emergent trends in risk-reducing mastectomy and reconstructive techniques are occurring against a background of broadened indications for RRM and more frequent patient requests for RRM in the absence of any documented pathogenic gene mutation. As breast surgery continues to evolve, it is important to evaluate specific trends such as more conservative forms of mastectomy and novel techniques/devices for breast reconstruction to ensure optimal patient care and levels of satisfaction.

The Newcomer Health Clinic in Nova Scotia: A Beacon Clinic to Support the Health Needs of the Refugee Population

Refugees tend to have greater vulnerability compared to the general population reporting greater need for physical, emotional, or dental problems compared to the general population. Despite the importance of creating strong primary care supports for these patients, it has been demonstrated that there is a significant gap in accessing primary care providers who are willing to accept the refugee population. These have resulted in bottlenecks in the transition or bridge clinics and have left patients orphaned without a primary care provider. This in turn results in higher use of emergency service and other unnecessary costs to the healthcare system. Currently there are few studies that have explored these challenges from primary care provider perspectives and very few to none from patient perspectives. A novel collaborative implementation initiative in primary healthcare (PHC) is seeking to improve primary medical care for the refugee population by creating a globally recommended transition or beacon clinic to support care needs of new arrivals and transitions to primary care providers. We discuss the innovative elements of the clinic model in this paper.

An International Survey Evaluating Factors Influencing the Use of Total Intravenous Anaesthesia

The purpose of this study was to evaluate factors influencing the use of propofol-based total intravenous anaesthesia (TIVA) since despite TIVA being a well-established technique, it is used far less frequently than volatile anaesthesia. Questions were formulated after reviewing the literature for perceived disadvantages of TIVA and meeting with a focus group consisting of both senior and junior anaesthestists from our department. Once the survey had been formulated, specialist anaesthetists from professional colleges and societies from several countries were invited to complete the survey on an electronic web-based platform to allow evaluation of the respondent's rating of the importance of a range of factors in their decision not to use TIVA for a particular case. Basic descriptive statistics were determined using SPSS statistical software, while graphical depictions of data were handled using R for statistical analysis. A total of 763 survey responses were included in the final analysis and stratified according to the frequency of TIVA use. Among the infrequent users, issues such as additional effort, institutional preference, lack of real-time monitoring of propofol concentration, risk of missing drug delivery failure and increased turnaround time were among the top reasons mentioned. Interestingly, these issues were considered far less important among the frequent users when not choosing TIVA. We concluded that frequent and infrequent users respond quite differently to similar technical TIVA-related factors. Non-technical factors may play an important role in the infrequent user's decision not to use TIVA for a particular case.

Abstract P5-11-02: Impact of pre-operative exercise and mind-body interventions on patient-reported outcomes in women with newly diagnosed breast cancer

Background: Breast cancer diagnosis has a number of adverse psychological effects. The Pre-Operative Health and Body (PreHAB) Study tested the impact of exercise and mind-body interventions upon on mood, quality of life, and patient-reported outcomes in women with newly diagnosed breast cancer.

Methods: Women with newly diagnosed Stage I-III breast cancer were enrolled through Dana-Farber Cancer Institute and Yale University breast cancer clinics prior to surgery. Participants were randomized 1:1 to an aerobic and strength-training exercise intervention, comprised of twice-weekly meetings with an exercise trainer and home based aerobic exercise, or to a self-directed mind-body relaxation intervention, comprised of a book and CD focused on relaxation and visualization. Participants engaged in the interventions between enrollment and surgery. The EORTC QLQ C-30, Hospital Anxiety and Depression Scale, and Perceived Stress Scale were collected at enrollment and prior to surgery.

Results: 49 women were randomized (27 exercise and 22 control). Mean time between enrollment and surgery was 4.2 weeks. At baseline, patients reported moderate levels of anxiety, stress, insomnia, and lack of appetite, as well as diminished emotional and cognitive functioning (Table). Exercise participants significantly increased minutes of weekly exercise vs. mind-body participants (increase of 203 vs. 23 min/wk, p<0.0001). Mind body participants engaged in the intervention on average 69% of days during the intervention period. Pre-post changes demonstrated that participation in the mind-body intervention led to improvements in emotional and cognitive functioning and a reduction in anxiety and stress, and participation in the exercise intervention led to improvements in global quality of life, insomnia, appetite, and stress (Table). Women in the mind-body group experienced a significantly greater improvement in cognitive functioning as compared to women in the exercise group.

Conclusions: Women with newly diagnosed breast cancer reported a number of physical and psychological symptoms in the pre-operative period. Exercise and mind-body interventions demonstrated promising benefits in improving functioning and reducing symptoms. More work is needed to develop pre-operative programs to help reduce the distress imparted by a cancer diagnosis in the critical time between diagnosis and surgery.

Table*

 Exercise Mind Body Between Groups BaselineChangep valueBaselineChangep valuep valueEmotional Functioning68.6 (23.3)4.7 (18.3)0.2966.3 (24.2)10.0 (20.5)0.050.64Cognitive Functioning79.5 (24.6)-3.3 (24.1)0.6273.8 (22.1)11.7 (15.4)0.0020.03QOL74.0 (15.3)9.7 (15.9)0.00569.0 (21.1)7.5 (18.5)0.110.78Insomnia35.9 (32.6)-16.7 (32.6)0.0334.9 (35.7)-8.3 (21.3)0.060.52Lack of Appetite17.9 (27.0)-13.3 (27.2)0.0311.1 (19.2)-5.0 (22.4)0.530.29Anxiety8.3 (3.4)-0.6 (2.9)0.259.2 (2.5)-1.6 (2.3)0.0060.35Stress14.7 (7.2)-2.2 (4.9)0.0618.4 (5.5)-3.1 (6.8)0.060.77

*Results reported as means (SD). Positive scores on functional and QOL measures indicate improvements; negative scores on symptom measures indicate a decrease in symptoms.

Citation Format: Ligibel JA, Giobbie-Hurder A, Dillion D, Shockro L, Campbell N, Rhei E, Troyan S, Dominici L, Golshan M, Chagpar A, Yung R, Freedman R, Tolaney S, Winer E, Frank E, McTiernan A, Irwin M. Impact of pre-operative exercise and mind-body interventions on patient-reported outcomes in women with newly diagnosed breast cancer [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P5-11-02.

Abstract S5-05: Impact of pre-operative exercise on breast cancer gene expression

Background: Exercise is linked to a lower risk of developing and dying from breast cancer, but the biological mechanisms through which exercise could impact breast cancer are unclear. In animal models, exercise impacts tumor formation and progression, but there are few data regarding direct effects of exercise on tumor tissue in humans. The Pre-Operative Health and Body (PreHAB) Study was a randomized window of opportunity trial designed to explore the impact of exercise on molecular pathways in women with breast cancer.

Methods: Inactive women with Stage I-III breast cancer were enrolled through Dana-Farber Cancer Institute and Yale University prior to surgery. Participants were randomized 1:1 to an aerobic and strength training exercise intervention or mind body control intervention and participated in the interventions between enrollment and the time of surgery. Tumor tissue was collected at enrollment and surgery; samples were reviewed by a breast pathologist and were macrodissected to include sections of tumor with at least 10% cellularity. Capture RNA-sequencing of the transcriptome coding regions was performed using the Illumina Truseq RNA access platform.

Results: 49 women were randomized (27 exercise and 22 control). At baseline, mean age was 52.6, BMI was 30.2kg/m2 and exercise was 49 min/wk. Mean time between enrollment and surgery was 4.2 weeks. Participants in the exercise arm significantly increased exercise vs. controls (increase of 203 vs. 23 min/wk, p<0.0001). Transcriptomic analysis was performed on the tumors from the pre and post intervention biopsies from 32 patients (16 exercise and 16 control). Quality Control analysis of the RNA-sequencing data showed an average read depth of 25 million reads per sample, mapping ∼79% to exonic regions. Principal Component Analysis revealed no read bias or batch effects and unsupervised clustering showed that pre- and post-operative samples clustered together by patient. Differential gene expression analysis by DEseq2 revealed a limited number of individual genes with significant changes after the intervention. KEGG pathway analysis, however, of 214 KEGG pathways using the bioconductor package GAGE (Generally Applicable Gene-Set Enrichment for Pathway Analysis) demonstrated upregulation of 13 unique pathways between the baseline biopsy and surgical excision in exercise participants and none in mind body participants (q<0.1). The top ranked upregulated pathway was cytokine-cytokine receptor interactions (q=6.93E-05, set size=238 genes). Il6, CCL3 and other cytokines are among the genes upregulated in this pathway. Analysis also demonstrated downregulation of 13 unique pathways (q<0.1) including cell cycle, RNA transport and DNA replication pathways, in exercise participants over the intervention period.

Conclusions: A pre-operative exercise intervention led to alterations in gene expression in tumor tissue in women with breast cancer. Validation in additional data sets and an analysis of which cellular compartments within the tumor are responsible for the changes is needed. These findings demonstrate that exercise may have a direct effect on breast tumor tissue in humans, providing new insights into the biologic mechanisms through which exercise could lower the risk of developing and dying from breast cancer.

Citation Format: Ligibel JA, Irwin M, Dillon D, Barry W, Giobbie-Hurder A, Frank E, Winer EP, McTiernan A, Cornwell M, Pun M, Brown M, Jeselsohn R. Impact of pre-operative exercise on breast cancer gene expression [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr S5-05.

Socioeconomic status and lifestyle behaviours in cancer survivors: smoking and physical activity

PURPOSE

Smoking cessation and increased physical activity (pa) have been linked to better outcomes in cancer survivors. We assessed whether socioeconomic factors influence changes in those behaviours after a cancer diagnosis.

METHODS

As part of a cross-sectional study, a diverse group of cancer survivors at the Princess Margaret Cancer Centre (Toronto, ON), completed a questionnaire about past and current lifestyle behaviours and perceptions about the importance of those behaviours with respect to their health. The influence of socioeconomic indicators on smoking status and physical inactivity at 1 year before and after diagnosis were assessed using multivariable logistic regression with adjustment for clinico-demographic factors.

RESULTS

Of 1222 participants, 1192 completed the smoking component. Of those respondents, 15% smoked before diagnosis, and 43% of those smokers continued to smoke after. The proportion of survivors who continued to smoke increased with lower education level (p = 0.03). Of the 1106 participants answering pa questions, 39% reported being physically inactive before diagnosis, of whom 82% remained inactive afterward. Survivors with a lower education level were most likely to remain inactive after diagnosis (p = 0.003). Lower education level, household income, and occupation were associated with the perception that pa had no effect or could worsen fatigue and quality of life (p ≤ 0.0001).

CONCLUSIONS

In cancer survivors, education level was a major modifier of smoking and pa behaviours. Lower socioeconomic status was associated with incorrect perceptions about pa. Targeting at-risk survivors by education level should be evaluated as a strategy in cancer survivorship programs.

Abstract P3-08-01: Randomized controlled trial of weight loss vs. usual care on telomere length in women with breast cancer: The lifestyle, exercise and nutrition (LEAN) study

PURPOSE: Some studies suggest that telomere shortening due to repeated cell divisions may be associated with increased breast cancer risk and mortality. Obesity is also associated with increased breast cancer risk and mortality. Few studies have examined telomere length as a potential mechanism/biomarker mediating the obesity-breast cancer association. One study published of a diet, physical activity and support intervention in prostate cancer patients found a positive association between lifestyle changes and relative lengthening of telomeres, and another study of weight loss in healthy postmenopausal women observed no effect of weight loss on leukocyte telomere length. The purpose of our study was to examine the effect of a 6-month diet- and exercise-induced weight loss intervention vs. usual care on telomere length in 100 breast cancer survivors.

METHODS: 100 breast cancer survivors with BMI≥25 kg/m2 were randomly assigned to a weight loss counseling intervention with either telephone or in-person counseling (n = 67) or usual care group (n=33). Weight loss counseling included eleven 30-minute counseling sessions over 6 months, focusing on reducing caloric intake, increasing physical activity and behavioral therapy. Body composition (height, weight, and DEXA scans), physical activity and diet were measured at baseline and 6-months. Fasting blood samples were also collected at baseline and 6 months. Relative telomere length (T/S: telomere length/single copy of gene albumin) was measured by quantitative-polymerase chain reaction (qPCR) done on buffy coat extracted genomic DNA. Mean baseline to 6-month changes were compared between groups (intent-to-treat) using generalized estimating equations and Pearson correlation coefficients.

RESULTS: Baseline characteristics were similar for women randomized to each group. Women were 59±7 years, with BMI 33.1±6.6 kg/m2 and were 2.9±2.1 years from diagnosis; 91% were non-Hispanic white, and 51% were diagnosed with Stage I breast cancer. Average 6-month weight loss was 6.2% and 2.0% for weight loss and usual care groups, respectively (p=0.0004). At baseline, higher % body fat was associated with shorter T/S (r = -0.31, P=0.012). After 6 months, women randomized to weight loss experienced a 4% T/S lengthening compared to a 5% T/S shortening in the usual care group (P=0.10) (Table 1).

Effect of weight loss vs. usual care on leukocyte telomere lengthLEAN VariableUsual Care  Weight Loss Group  TelomereNMeanSDNMeanSDBaseline330.850.26630.750.216 Month Change26-0.040.21540.030.18  (-5%)  (+4%)p=.10SD=Standard Deviation

CONCLUSION: Our results indicate that higher % body fat is associated with shorter leukocyte telomere length, and weight loss was associated with an increase in leukocyte telomere length, suggesting that telomere length may be a mechanism mediating the relationship between obesity and breast cancer risk and mortality.

Citation Format: Sanft T, Lu L, Harrigan M, Cartmel B, Zhou Y, Chagpar A, Pusztai L, Irwin M. Randomized controlled trial of weight loss vs. usual care on telomere length in women with breast cancer: The lifestyle, exercise and nutrition (LEAN) study. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P3-08-01.

Astronomical algorithms for automated analysis of tissue protein expression in breast cancer

BACKGROUND

High-throughput evaluation of tissue biomarkers in oncology has been greatly accelerated by the widespread use of tissue microarrays (TMAs) and immunohistochemistry. Although TMAs have the potential to facilitate protein expression profiling on a scale to rival experiments of tumour transcriptomes, the bottleneck and imprecision of manually scoring TMAs has impeded progress.

METHODS

We report image analysis algorithms adapted from astronomy for the precise automated analysis of IHC in all subcellular compartments. The power of this technique is demonstrated using over 2000 breast tumours and comparing quantitative automated scores against manual assessment by pathologists.

RESULTS

All continuous automated scores showed good correlation with their corresponding ordinal manual scores. For oestrogen receptor (ER), the correlation was 0.82, P<0.0001, for BCL2 0.72, P<0.0001 and for HER2 0.62, P<0.0001. Automated scores showed excellent concordance with manual scores for the unsupervised assignment of cases to 'positive' or 'negative' categories with agreement rates of up to 96%.

CONCLUSION

The adaptation of astronomical algorithms coupled with their application to large annotated study cohorts, constitutes a powerful tool for the realisation of the enormous potential of digital pathology.

Tissue expanders: early experience of a novel treatment option for perineal herniation

PURPOSE

Acquired perineal hernias through the reconstructed pelvic floor can complicate radical pelvic operations including abdominoperineal resection of rectum. Operative intervention is indicated for symptomatic hernias. There is a lack of consensus as to the best operative technique. Here we present a novel method for repairing perineal herniation using saline-filled tissue expanders.

METHODS

Perineal hernia repair may be affected either via an abdominal or via a perineal approach. After adhesiolysis to remove small bowel from the pelvis, a Natrelle™ 150SH tissue expander (Allergan Inc., California, USA) or Siltex™ Round Becker (Mentor Medical Systems, Holland) of appropriate size is inserted in the pelvis and the button placed in a subcutaneous pocket in the perineal skin. The tissue expander is then filled with saline until it fills the true anatomical pelvis without bladder compression. The volume may be increased or decreased postoperatively by accessing the subcutaneous button.

RESULTS

We have performed this procedure in three patients with some success, all of whom have experienced symptomatic relief. The tissue expander may subsequently be removed without recurrence of symptoms, due to the fibrous capsule which forms. One patient required re-operation to elevate a herniating tissue expander. The tissue expander was removed earlier than anticipated to avoid deep pelvic infection in another.

CONCLUSION

Our early experience suggests that using saline-filled tissue expanders to fill dead space in the pelvis after radical surgery may prove to be a valuable approach to perineal herniation, particularly if adjuvant radiotherapy is planned.

A review of web-based weight loss interventions in adults

Unprecedented obesity rates are changing the burden of disease worldwide and obesity-related health complications are increasing healthcare costs. In response, researchers, clinicians and public health practitioners are seeking new and effective tools such as the Internet to effect weight loss. This review highlights peer-reviewed literature on randomized controlled trials that examine Internet-delivered weight loss and maintenance programmes. The scope of this review is broader than previous reviews, including more males and non-Caucasian participants. The reviewed studies show intervention results ranging from no weight loss to an average loss of 7.6 kg. It is difficult to draw a definitive conclusion on the potential impact of Internet-based weight loss as study methods are highly variable between papers, low adherence was recorded and not all studies include a control group. As the demand for low-cost, efficacious interventions that yield statistically significant and/or clinically relevant results grows, more rigorous, population-specific research is needed to determine if Internet-delivered interventions may slow or reverse with weight gain and obesity and the associated health consequences.

CERTAIN EFFECTS OF SALTS ON THE PENETRATION OF BRILLIANT CRESYL BLUE INTO NITELLA

The effect of various substances on living cells may be advantageously studied by exposing them to such substances and observing their subsequent behavior in solutions of a basic dye, brilliant cresyl blue. The rate of penetration of the basic dye, brilliant cresyl blue, is decreased when cells are exposed to salts with monovalent cations before they are placed in the dye solution (made up with borate buffer mixture). This inhibiting effect is assumed to be due to the effect of the salts on the protoplasm. This effect is not readily reversible when cells are transferred to distilled water, but it is removed by salts with bivalent or trivalent cations. In some cases it disappears in dye made up with phosphate buffer mixture, or with borate buffer mixture at the pH value in which the borax predominates, and in the case of NaCl it disappears in dye containing NaCl. No inhibiting effect is seen when cells are exposed to NaCl solution containing MgCl₂ before they are placed in the dye solution. The rate of penetration of dye is not decreased when cells are previously exposed to salts with bivalent and trivalent cations. The rate is slightly increased when cells are placed in the dye solution containing a salt with monovalent cation and probably with bivalent or trivalent cations. In the case of the bivalent and trivalent salts the increase is so slight that it may be negligible.

ON THE NATURE OF THE DYE PENETRATING THE VACUOLE OF VALONIA FROM SOLUTIONS OF METHYLENE BLUE

When uninjured cells of Valonia are placed in methylene blue dissolved in sea water it is found, after 1 to 3 hours, that at pH 5.5 practically no dye penetrates, while at pH 9.5 more enters the vacuole. As the cells become injured more dye enters at pH 5.5, as well as at pH 9.5. No dye in reduced form is found in the sap of uninjured cells exposed from 1 to 3 hours to methylene blue in sea water at both pH values. When uninjured cells are placed in azure B solution, the rate of penetration of dye into the vacuole is found to increase with the rise in the pH value of the external dye solution. The partition coefficient of the dye between chloroform and sea water is higher at pH 9.5 than at pH 5.5 with both methylene blue and azure B. The color of the dye in chloroform absorbed from methylene blue or from azure B in sea water at pH 5.5 is blue, while it is reddish purple when absorbed from methylene blue and azure B at pH 9.5. Dry salt of methylene blue and azure B dissolved in chloroform appears blue. It is shown that chiefly azure B in form of free base is absorbed by chloroform from methylene blue or azure B dissolved in sea water at pH 9.5, but possibly a mixture of methylene blue and azure B in form of salt is absorbed from methylene blue at pH 5.5, and azure B in form of salt is absorbed from azure B in sea water at pH 5.5. Spectrophotometric analysis of the dye shows the following facts. 1. The dye which is absorbed by the cell wall from methylene blue solution is found to be chiefly methylene blue. 2. The dye which has penetrated from methylene blue solution into the vacuole of uninjured cells is found to be azure B or trimethyl thionine, a small amount of which may be present in a solution of methylene blue especially at a high pH value. 3. The dye which has penetrated from methylene blue solution into the vacuole of injured cells is either methylene blue or a mixture of methylene blue and azure B. 4. The dye which is absorbed by chloroform from methylene blue dissolved in sea water is also found to be azure B, when the pH value of the sea water is at 9.5, but it consists of azure B and to a less extent of methylene blue when the pH value is at 5.5. 5. Methylene blue employed for these experiments, when dissolved in sea water, in sap of Valonia, or in artificial sap, gives absorption maxima characteristic of methylene blue. Azure B found in the sap collected from the vacuole cannot be due to the transformation of methylene blue into this dye after methylene blue has penetrated into the vacuole from the external solution because no such transformation detectable by this method is found to take place within 3 hours after dissolving methylene blue in the sap of Valonia. These experiments indicate that the penetration of dye into the vacuole from methylene blue solution represents a diffusion of azure B in the form of free base. This result agrees with the theory that a basic dye penetrates the vacuole of living cells chiefly in the form of free base and only very slightly in the form of salt. But as soon as the cells are injured the methylene blue (in form of salt) enters the vacuole. It is suggested that these experiments do not show that methylene blue does not enter the protoplasm, but they point out the danger of basing any theoretical conclusion as to permeability on oxidation-reduction potential of living cells from experiments made or the penetration of dye from methylene blue solution into the vacuole, without determining the nature of the dye inside and outside the cell.

THE PENETRATION OF DYES AS INFLUENCED BY HYDROGEN ION CONCENTRATION

When cells of Nitella are placed in buffer solutions at pH 9, there is a very slow and gradual increase in the pH of the sap from pH 5.6 to 6.4 (when death of the cells takes place). If the living cells are placed in 0.002 per cent dye solutions of brilliant cresyl blue at different pH values (from pH 6.6 to pH 9), it is found that the rate of penetration of the dye, and the final equilibrium attained, increases with increase in pH value, which can be attributed to an increase in the active protein (or other amphoteric electrolyte) in the cell which can combine with the dye.

SPECTROPHOTOMETRIC STUDIES OF PENETRATION : V. RESEMBLANCES BETWEEN THE LIVING CELL AND AN ARTIFICIAL SYSTEM IN ABSORBING METHYLENE BLUE AND TRIMETHYL THIONINE

The rate of diffusion through the non-aqueous layer of the protoplasm depends largely on the partition coefficients mentioned above. Since these cannot be determined we have employed an artificial system in which chloroform is used in place of the non-aqueous layer of the protoplasm. The partition coefficients may be roughly determined by shaking up the aqueous solutions with chloroform and analyzing with the spectrophotometer (which is necessary with methylene blue because we are dealing with mixtures). This will show what dyes may be expected to pass through the protoplasm into the vacuole in case it behaves like the artificial system. From these results we may conclude that the artificial system and the living cell act almost alike toward methylene blue and azure B, which supports the notion of non-aqueous layers in the protoplasm. There is a close resemblance between Valonia and the artificial system in their behavior toward these dyes at pH 9.5. In the case of Nitella, on the other hand, with methylene blue solution at pH 9.2 the sap in the artificial system takes up relatively more azure B (absorption maximum at 650 mµ) than the vacuole of the living cell (655 mµ). But both take up azure B much more rapidly than methylene blue. A comparison cannot be made between the behavior of the artificial system and that of the living cell at pH 5.5 since in the latter case there arises a question of injury to cells before enough dye is collected in the sap for analysis.

THE BEHAVIOR OF CHLORIDES IN THE CELL SAP OF NITELLA

1. A method is given for determining the chloride content in a drop (less than 0.03 cc.) of the cell sap of Nitella. 2. Chlorides accumulate in the sap to the extent of 0.128 M; this accumulation can be followed during the growth of the cell. The chloride content does not increase when the cell is placed for 2 days in solutions (at pH 6.2) containing chlorides up to 0.128 M. 3. The exosmosis of chlorides from injured cells can be followed quantitatively. When one end of the cell is cut off a wave of injury progresses toward the other end; this is accompanied by a progressive exosmosis of chlorides.

MECHANISM OF THE ACCUMULATION OF DYE IN NITELLA ON THE BASIS OF THE ENTRANCE OF THE DYE AS UNDISSOCIATED MOLECULES

The rate of penetration of brilliant cresyl blue into the living cells of Nitella indicates that the dye enters only in the form of the undissociated molecule. At equilibrium the total concentration of the dye in the sap is proportional to the concentration of the free base in the outside solution.

STUDIES ON PENETRATION OF DYES WITH GLASS ELECTRODE : V. WHY DOES AZURE B PENETRATE MORE READILY THAN METHYLENE BLUE OR CRYSTAL VIOLET?

Glass electrode measurements of the pH value of the sap of cells of Nitella show that azure B in the form of free base penetrates the vacuoles and raises the pH value of the sap to about the same degree as the free base of the dye added to the sap in vitro, but the dye salt dissolved in the sap does not alter the pH value of the sap. It is concluded that the dye penetrates the vacuoles chiefly in the form of free base and not as salt. The dye from methylene blue solution containing azure B free base as impurity penetrates and accumulates in the vacuole. This dye must be azure B in the form of free base, since it raises the pH value of the sap to about the same extent as the free base of azure B dissolved in the sap in vitro. The dye absorbed by the chloroform from methylene blue solution behaves like the dye penetrating the vacuole. These results confirm those of spectrophotometric analysis previously published. Crystal violet exists only in one form between pH 5 and pH 9.2, and does not alter the pH value of the sap at the concentrations used. It does not penetrate readily unless cells are injured. A theory of "multiple partition coefficients" is described which explains the mechanism of the behavior of living cells to these dyes. When the protoplasm is squeezed into the sap, the pH value of the mixture is higher than that of the pure sap. The behavior of such a mixture to the dye is very much like that of the sap except that with azure B and methylene blue the rise in the pH value of such a mixture is not so pronounced as with sap when the dye penetrates into the vacuoles. Spectrophotometric measurements show that the dye which penetrates from methylene blue solution has a primary absorption maximum at 653 to 655 mµ (i.e., is a mixture of azure B and methylene blue, with preponderance of azure B) whether we take the sap alone or the sap plus protoplasm. These results confirm those previously obtained with spectrophotometric measurements.

ACCUMULATION OF BRILLIANT CRESYL BLUE IN THE SAP OF LIVING CELLS OF NITELLA IN THE PRESENCE OF NH(3)

When the living cells of Nitella are placed in a solution of brilliant cresyl blue containing NH(4)Cl, the rate of accumulation of the dye in the sap is found to be lower than when the cells are placed in a solution of dye containing no NH(4)Cl and this may occur without any increase in the pH value of the cell sap. This decrease is found to be primarily due to the presence of NH(3) in the sap and seems not to exist where NH(3) is present only in the external solution at the concentration used.

THE EFFECT OF ACETATE BUFFER MIXTURES, ACETIC ACID, AND SODIUM ACETATE, ON THE PROTOPLASM, AS INFLUENCING THE RATE OF PENETRATION OF CRESYL BLUE INTO THE VACUOLE OF NITELLA

When living cells of Nitella are exposed to a solution of sodium acetate and are then placed in a solution of brilliant cresyl blue made up with a borate buffer mixture at pH 7.85, a decrease in the rate of penetration of dye is found, without any change in the pH value of the sap. It is assumed that this inhibiting effect is caused by the action of sodium on the protoplasm. This effect is not manifest if the dye solution is made up with phosphate buffer mixture at pH 7.85. It is assumed that this is due to the presence of a greater concentration of base cations in the phosphate buffer mixture. In the case of cells previously exposed to solutions of acetic acid the rate of penetration of dye decreases with the lowering of the pH value of the sap. This inhibiting effect is assumed to be due chiefly to the action of acetic acid on the protoplasm, provided the pH value of the external acetic acid is not so low as to involve an inhibiting effect on the protoplasm by hydrogen ions as well. It is assumed that the acetic acid either has a specific effect on the protoplasm or enters as undissociated molecules and by subsequent dissociation lowers the pH value of the protoplasm. With acetate buffer mixture the inhibiting effect is due to the action of sodium and acetic acid on the protoplasm. The inhibiting effect of acetic acid and acetate buffer mixture is manifested whether the dye solution is made up with borate or phosphate buffer mixture at pH 7.85. It is assumed that acetic acid in the vacuole serves as a reservoir so that during the experiment the inhibiting effect still persists.

SPECTROPHOTOMETRIC STUDIES OF PENETRATION : IV. PENETRATION OF TRIMETHYL THIONIN INTO NITELLA AND VALONIA FROM METHYLENE BLUE

Spectrophotometric measurements show that it is chiefly the trimethyl thionin that is present in the sap extracted from the vacuoles of uninjured cells of Nitella or Valonia which have been placed in methylene blue solution at a little above pH 9. Whether these measurements were made immediately or several hours later the same results were obtained. Methylene blue is detected in the sap (1) when the cells are injured or (2) when the contamination of the sap from the stained cell wall occurs at the time of extraction. The sap is found to be incapable of demethylating methylene blue dissolved in it even on standing for several hours. It is somewhat uncertain as to whether the trimethyl thionin penetrated as such from the external methylene blue solution which generally contains this dye as impurity (in too small concentration for detection by spectrophotometer but detectable by extraction with chloroform), or whether it has formed from methylene blue in the protoplasm. The evidences described in the text tend to favor the former explanation. Theory is discussed on basis of more rapid penetration of trimethyl thionin (in form of free base) than of methylene blue, or of trimethyl thionin in form of salt.

ON THE ACCUMULATION OF DYE IN NITELLA

Living cells of Nitella were placed in different concentrations of brilliant cresyl blue solutions at pH 6.9. It was found that the greater the concentration of the external dye solution, the greater was the speed of accumulation of the dye in the cell sap and higher was the concentration of dye found in the sap at equilibrium. Analysis of the time curves showed that the process may be regarded as a reversible pseudounimolecular reaction. When the concentration in the sap is plotted as ordinates and the concentration in the outside solution as abscissae the curve is convex toward the abscissae. There is reason to believe that secondary changes involving injury take place as the dye accumulates and that if these changes did not occur the curve would be concave toward the abscissae. The process may be explained as a chemical combination of the dye with a constituent of the cell. This harmonizes with the fact that the temperature coefficient is high (about 4.9). Various other possible explanations are discussed.

THE PENETRATION OF BASIC DYE INTO NITELLA AND VALONIA IN THE PRESENCE OF CERTAIN ACIDS, BUFFER MIXTURES, AND SALTS

When living cells of Nitella are exposed to an acetate buffer solution until the pH value of the sap is decreased and subsequently placed in a solution of brilliant cresyl blue, the rate of penetration of dye into the vacuole is found to decrease in the majority of cases, and increase in other cases, as compared with the control cells which are transferred to the dye solution directly from tap water. This decrease in the rate is not due to the lowering of the pH value of the solution just outside the cell wall, as a result of diffusion of acetic acid from the cell when cells are removed from the buffer solution and placed in the dye solution, because the relative amount of decrease (as compared with the control) is the same whether the external solution is stirred or not. Such a decrease in the rate may be brought about without a change in the pH value of the sap if the cells are placed in the dye solution after exposure to a phosphate buffer solution in which the pH value of the sap remains normal. The rate of penetration of dye is then found to decrease. The extent of this decrease is the greater the lower the pH value of the solution. It is found that hydrochloric acid and boric acid have no effect while phosphoric acid has an inhibiting effect at pH 4.8 on stirring. Experiments with neutral salt solutions indicate that a direct effect on the cell (decreasing penetration) is due to monovalent base cations, while there is no such effect directly on the dye. It is assumed that the effect of the phosphate and acetate buffer solutions on the cell, decreasing the rate of penetration, is due (1) to the penetration of these acids into the protoplasm as undissociated molecules, which dissociate upon entrance and lower the pH value of the protoplasm or to their action on the surface of the protoplasm, (2) to the effect of base cations on the protoplasm (either at the surface or in the interior), and (3) possibly to the effect of certain anions. In this case the action of the buffer solution is not due to its hydrogen ions. In the case of living cells of Valonia under the same experimental conditions as Nitella it is found that the rate of penetration of dye decreases when the pH value of the sap increases in presence of NH₃, and also when the pH value of the sap is decreased in the presence of acetic acid. Such a decrease may be brought about even when the cells are previously exposed to sea water containing HCl, in which the pH value of the sap remains normal.

COMPARATIVE STUDIES ON RESPIRATION : VI. INCREASED PRODUCTION OF CARBON DIOXIDE ACCOMPANIED BY DECREASE OF ACIDITY

In petals of Salvia high concentrations of ether cause an increase in oxygen consumption and in the production of CO(2), while at the same time a decrease occurs in the acidity of the cell contents.

THE PERMEABILITY OF LIVING CELLS TO DYES AS AFFECTED BY HYDROGEN ION CONCENTRATION

1. An accurate quantitative method of measuring the penetration of dye into the living cell is described. 2. Cresyl blue is unable to penetrate rapidly unless the pH outside the cell is decidedly greater than that inside. The rate of penetration increases with increasing pH. 3. Around pH 9 penetration of the dye is rapid while the reverse is true of exosmosis. At low pH values (5.9) exosmosis is rapid and penetration is very slow.

EXIT OF DYE FROM LIVING CELLS OF NITELLA AT DIFFERENT pH VALUES

Experiments on the exit of brilliant cresyl blue from the living cells of Nitella, in solutions of varying external pH values containing no dye, confirm the theory that the relation of the dye in the sap to that in the external solution depends on the fact that the dye exists in two forms, one of which (DB) can pass through the protoplasm while the other (DS) passes only slightly. DB increases (by transformation of DS to DB) with an increase in the pH value, and is soluble in substances like chloroform and benzene. DS increases with decrease in pH value and is insoluble (or nearly so) in chloroform and benzene. The rate of exit of the dye increases as the external pH value decreases. This may be explained on the ground that DB as it comes out of the cell is partly changed to DS, the amount transformed increasing as the pH value decreases. The rate of exit of the dye is increased when the pH value of the sap is increased by penetration of NH(3).

COUNTERACTION OF THE INHIBITING EFFECTS OF VARIOUS SUBSTANCES ON NITELLA

When living cells of Nitella are first exposed to (1) phosphate buffer mixture, or (2) phosphoric acid, or (3) hydrochloric acid, or (4) sodium chloride, or (5) sodium borate, and are then placed in a solution of brilliant cresyl blue made up with a borate buffer mixture at pH 7.85, the rate of penetration of the dye into the vacuole is decreased as compared with the rate in the case of cells transferred directly from tap water to the same dye solution. When cells exposed to any one of these solutions are placed in the dye solution made up with phosphate buffer solution at pH 7.85, the rate of penetration of dye into the vacuole is the same as the rate in the case of cells transferred from the tap water to the same dye solution. It is probable that this removal of the inhibiting effect is due primarily to the presence of certain concentration of sodium and potassium ions in the phosphate buffer solution. If a sufficient concentration of sodium ions is added to the dye made up with a borate buffer mixture the inhibiting effect is removed just as it is in the case of the dye made up with the phosphate buffer mixture. The inhibiting effect of some of these substances is found to be removed by the dye containing a sufficient concentration of bivalent cations, or by washing the cells with salts of bivalent cations. The inhibiting effect and its removal are discussed from a theoretical standpoint.

STUDIES ON PENETRATION OF DYES WITH GLASS ELECTRODE : IV. PENETRATION OF BRILLIANT CRESYL BLUE INTO NITELLA FLEXILIS

Glass electrode measurements of the pH value of the sap of Nitella show that cresyl blue in form of free base penetrates the vacuoles and raises pH value of the sap to about the same degree as the free base of the dye added to the sap in vitro, while the dye salt dissolved in the sap does not alter its pH value. It is proved conclusively that the increase in the pH value of the sap is due only to the presence of the dye and not to some other alkaline substance. Spectrophotometric measurements show that the dye which penetrates the vacuole is chiefly cresyl blue. When the protoplasm is squeezed into the sap, the pH value of the sap is higher than that of the pure sap. Such a mixture behaves very much like the sap in respect to the dye.

Early introduction of clinical skills teaching in a medical curriculum--factors affecting students' learning

OBJECTIVE

To evaluate the effects of the early introduction of clinical skills teaching on students' learning following an overhaul of the curriculum of a traditional Asian medical school.

METHODS

Randomly selected medical students in Year I and II were invited to participate in 30 focus group interviews while all students were asked to assist with the questionnaire survey. Most students were contacted personally to help them understand the objectives of the study. Confidentiality was emphasised and a non-faculty interviewer was recruited for the interviews.

RESULTS

Two hundred and eight of Year I/Year II students attended the lunchtime focus group interviews (response rate=86.7%) while 252 (73.5%) students returned the questionnaire. The majority of them (87%) agreed or strongly agreed that it was good to introduce clinical skills in the early years of the curriculum. They reflected that the course enhanced their learning interest and made them feel like doctors. They also made many constructive suggestions on how the course could be improved during the interactive focus group interviews so that the negative effects could be minimised.

CONCLUSION

It is useful to introduce clinical skills in the early years of a medical curriculum. A comprehensive course evaluation, using both quantitative and qualitative methods, helps to collect useful information on how the course can be improved.

Suppression of interleukin-6 to interleukin-10 ratio in chronic alcoholics: association with postoperative infections

OBJECTIVE

To investigate the interleukin-6 (IL-6) to interleukin-10 (IL-10) ratio and levels of sE-selectin in patients undergoing elective surgery of the upper digestive tract and to define the differences in the perioperative immune response between chronic alcoholic and non-alcoholic patients.

DESIGN

Prospective pilot study.

SETTING

Single center, interdisciplinary intensive care unit (ICU) at a university hospital.

MEASUREMENT AND MAIN RESULTS

The study compared chronic alcoholics ( n=25) and non-alcoholics ( n=20) before and after surgery for resection of upper digestive tract tumors. White blood cell counts, C-reactive protein and circulating levels of sE-selectin, the pro-inflammatory cytokine IL-6 and the inhibitory cytokine IL-10, were obtained at hospital admission, preoperatively, postoperatively at ICU admission and 2 and 4 days later. Rates of postoperative infectious complications including pneumonia and sepsis were determined. sE-selectin only differed between chronic alcoholics and non-alcoholics preoperatively. Compared to non-alcoholics, chronic alcoholic patients showed a fourfold increase in circulating levels of IL-10 ( p<0.01) and a suppression of the IL-6/IL-10 ratio ( p=0.001) immediately after surgery. Coincident with the immune alterations, chronic alcoholics had a prolonged ICU stay ( p<0.01) and a threefold increased rate of wound infections ( p<0.05) and pneumonia ( p<0.01). Lower IL-6/IL-10 ratios were associated with increased rates of infectious complications ( p<0.05).

CONCLUSION

Chronic alcoholics had decreased IL-6/IL-10 ratios at ICU admission and increased rates of infectious complications in the postoperative ICU course. This may indicate immediate postoperative immune suppression before the onset of infections and may help to identify chronic alcoholic patients at risk.

Neuroimmunology of disordered sleep in depression and alcoholism

The specific functions of sleep are not known, although sleep is commonly considered a restorative process that is important for the proper functioning of the immune system. Severity of disordered sleep in depressed and alcoholic subjects correlates with declines in natural and cellular immunity and is associated with alterations in the complex cytokine network. Despite evidence that sleep and sleep loss have effects on immune processes and nocturnal secretion of cytokines, the physiological significance of these immune changes is not known. Moreover, in view of basic evidence of a reciprocal interaction between sleep and cytokines, further research is needed to understand whether alterations in cytokines contribute to disordered sleep.

Providing hospice care in rural Texas

Hospice organizations in rural areas face many logistical and financial challenges. The authors review their experiences in offering hospice care to a widely dispersed population of patients. Crown of Texas Hospice, headquartered in Amarillo, Texas, provides hospice care throughout most of the vast and sparsely populated Texas panhandle. In the United States, patients typically are not referred to hospice care until the very end of the terminal phase of their disease process. Late referrals limit the opportunities for optimal symptom management and also limit the ability of a hospice organization to meet the psychosocial and spiritual needs of patients and their families. Recommendations to improve the timeliness of hospice referral are suggested.

A giant stream of metal-rich stars in the halo of the galaxy M31

Recent observations have revealed streams of gas and stars in the halo of the Milky Way that are the debris from interactions between our Galaxy and some of its dwarf companion galaxies; the Sagittarius dwarf galaxy and the Magellanic clouds. Analysis of the material has shown that much of the halo is made up of cannibalized satellite galaxies, and that dark matter is distributed nearly spherically in the Milky Way. It remains unclear, however, whether cannibalized substructures are as common in the haloes of galaxies as predicted by galaxy-formation theory. Here we report the discovery of a giant stream of metal-rich stars within the halo of the nearest large galaxy, M31 (the Andromeda galaxy). The source of this stream could be the dwarf galaxies M32 and NGC205, which are close companions of M31 and which may have lost a substantial number of stars owing to tidal interactions. The results demonstrate that the epoch of galaxy building still continues, albeit at a modest rate, and that tidal streams may be a generic feature of galaxy haloes.

Melatonin modulation of lymphocyte proliferation and Th1/Th2 cytokine expression

Melatonin is hypothesized to play a role in neuroimmunomodulation. This study investigated the in vitro effects of melatonin (10(-12) - 10(-6) M) on human peripheral blood mononuclear cell (PBMC) proliferation and T helper type 1 and T helper type 2 (Th1/Th2) cytokine expression. In vitro doses of melatonin significantly increased PBMC proliferation (p<0.05) and decreased IL-10 production in culture supernatants (p<0.05). However, there was no effect of melatonin on the stimulated production of IFN-gamma or on the intracellular accumulation of the activation antigen CD69, IFN-gamma, or IL-10 as measured by flow cytometry. These data support the notion that physiologic doses of melatonin increase lymphocyte proliferation possibly due to decreases in production of the inhibitory cytokine IL-10.

The use of focus group interviews in Asian medical education evaluative research

OBJECTIVE

To evaluate the use of focus group interviews in Asian medical education evaluative research.

METHODS

Randomly selected medical students were invited to participate in 30 focus group interviews to provide in-depth data about the effect on their learning of the introduction of early clinical skills. Efforts were made to meet all the students to help them understand the objectives of the focus group. Confidentiality was emphasised and a non-faculty interviewer was recruited for the interviews.

RESULTS

The students considered the use of focus groups to be a more meaningful way of collecting students' opinions than other methods, for example structured questionnaire, because it allowed an interactive discussion. They also felt that having an independent non-faculty interview moderator had encouraged them to express their opinions more candidly during the interviews.

CONCLUSION

The use of focus group interviews among Asian medical students for evaluative research is practical and efficient.

Oncogenes induce and activate endogenous p73 protein

The identification of upstream pathways that signal to TP73 is crucial for understanding the biological role of this gene. Since some evidence suggests that TP73 might play a role in tumorigenesis, we asked whether oncogenes can induce and activate endogenous TP73. Here, we show that endogenous p73 alpha and beta proteins are up-regulated in p53-deficient tumor cells in response to overexpressed E2F1, c-Myc, and E1A. E2F1, c-Myc, and E1A-mediated p73 up-regulation leads to activation of the p73 transcription function, as shown by p73-responsive reporter activity and by induction of known endogenous p73 target gene products such as p21 and HDM2. Importantly, E2F1-, c-Myc-, and E1A-mediated activation of endogenous p73 induces apoptosis in SaOs-2 cells. Conversely, inactivation of p73 by a dominant negative p73 inhibitor (p73DD), but not by a mutant p73DD, inhibits oncogene-induced apoptosis. These data show that oncogenes can signal to TP73 in vivo. Moreover, in the absence of p53, oncogenes may enlist p73 to induce apoptosis in tumor cells.