Physician-patient interaction in reproductive counseling

OBJECTIVE

To review the scientific and clinical bases for effective patient counseling in contraceptive care.

DATA SOURCES

All articles and chapters in the Annotated Bibliography of Doctor Patient Communication of the Task Force on Doctor and Patient of the American Academy on Physician and Patient were searched and included. This is an expert-derived data base based on MEDLINE review from 1969 to 1994 and including expert-selected additions from PsychLit and a variety of other social science data bases, books, and reviews.

METHODS OF STUDY SELECTION

Expert consensus was used from the Committee on Bibliography of the American Academy on Physician and Patient.

TABULATION, INTEGRATION, AND RESULTS

The doctor-patient interaction is the main determinant of the accuracy and completeness of patient data, diagnostic accuracy, efficiency in the encounter, compliance, patient understanding of problems, and patient and physician satisfaction. Yet this critical skill is inadequately taught and practiced, with serious consequences for patient care and physician job satisfaction. Use of the 14 structural elements (preparing the environment, preparing oneself, observation, greeting, introduction, detecting and overcoming barriers to communication, surveying problems, negotiating a priority problem, developing a narrative thread, establishing the life context of the patient, establishing a safety net, presenting findings and options, negotiating plans, and closing) and three functions (gathering information, developing a therapeutic relationship, and patient education) and their associated behaviors improves encounter results significantly. Other helpful activities are patient activation, facilitating partnership, review of findings and plans, eliciting and responding to patients' attitudes and emotions about contraception and fertility, and use of empathy and positive regard.

CONCLUSIONS

The use of scientifically derived, empirically validated interview skills substantially improves outcomes in contraceptive and other patient education and counseling. Use of appropriate structure and functions of the encounter, patient participation and partnership, review of patient understanding and reactions, and relating to the patients' attitudes and emotions about the subject each improve the outcomes of contraceptive care.

Absence of germline mutations in exons 5-9 of the p53 gene in patients with Li-Fraumeni-like (SBLA) and familial adenomatous polyposis heritable cancer syndromes

Although acquired mutations in the human p53 gene occur in many tumor types, germline mutations are rare. An exception is the occurrence of germline p53 mutations in a fraction of families afflicted with the Li-Fraumeni syndrome (LFS). Previous studies from our laboratory demonstrated increased levels of wild type p53 protein in skin fibroblasts (SF) of patients from heritable cancer syndrome, including familial adenomatous polyposis (FAP), neurofibromatosis type 1 (NF1), and bilateral retinoblastoma (bRB) (Kopelovich and DeLeo, 1984,1986). Here, we further address the association between germline p53 alterations and genetic predisposition to cancer in the SBLA syndrome and in FAP. DNA sequencing and single-stranded conformational polymorphism analysis (SSCP) were utilized to screen for the presence of mutations within exons 5-9 of the p53 gene in SF and in benign tumors. Thus we observed no germline mutations in exons 5-9 of the p53 gene in SF from SBLA or FAP patients, including the Gardner variant. In addition, we observed no acquired mutations in exons 5-9 of the p53 gene in benign tumors from FAP patients. In conclusion, we found no association between germline p53 mutations and SBLA or FAP. How mechanisms that involve nonmutational activation of the p53 protein might affect genetic predisposition to cancer remains to be established.

Genetic screening for colorectal cancer and intervention

There is a complex interaction between environmental/dietary factors and genetics underlying the pathogenesis of colon carcinogenesis. Little data exist concerning the impact of diet on the phenotypic expression of genetically linked colon cancer. As a result, it has been difficult to develop rationally designed dietary intervention studies in first-degree relatives of patients with established familial adenomatous polyposis (FAP), hereditary nonpolyposis colorectal cancer (HNPCC) and other familial colon cancer syndromes. Only 2 double-blinded, placebo-controlled trials have been published concerning the use of preventive strategies in patients with genetically inherited colorectal cancer syndromes, both in patients with FAP. One study evaluated the effects of vitamin C plus vitamin E with or without a high-dose wheat bran fiber supplement on the recurrence of rectal adenomas. Over a 48-month intervention period, only the wheat bran fiber intervention significantly reduced polyp growth. A second study reported that intervention with the NSAID sulindac for 9 months in young patients with FAP resulted in a significant reduction in both polyp number and size in the rectosigmoid colon. All of the large-scale (i.e., >500 randomized participants) phase III nutrient or chemopreventive agent intervention studies thus far have targeted participants with a history of non-familial, sporadic colorectal adenomas. Current clinical adenoma trials do not measure whether the regimen being tested can prevent genotoxic events occurring in early stages of abnormal cell development that contribute to the eventual formation of adenomas nor whether the agent(s) can inhibit events occurring during the progression of adenomas to carcinomas. Therefore, future clinical trial designs may have to consider (i) lengthening the clinical trial period before adenomas develop, (ii) testing at early patient ages and/or (iii) measuring the growth of adenomas as they progress to carcinomas.

Strategies for intervention with chemopreventive agents

Different mechanisms of activity have led to the development of a wide variety of intermediate biomarkers to measure the efficacy of chemopreventive agents. Chemopreventive agents are now being used in pre-clinical models that have targeted mutations or normal cells. Based on pre-clinical findings, clinical chemoprevention studies have progressed to measure the possible modulation of dysplastic lesions, including adenomas. Human studies are best carried out where the study design matches the known activity of the agents on cells in early, mid- or late stages of abnormal cellular development, previously determined in pre-clinical studies.

Inherited and acquired risk factors in colonic neoplasia and modulation by chemopreventive interventions

The progressively abnormal development of epithelial cells prior to tumor development leads to widely differing chemopreventive approaches. The diversity of these approaches has resulted in different assays to measure the activities of the agents. To apply these assays to preclinical studies, we have developed rodent models in which different stages of evolution of colonic neoplasia are expressed. In one model mice carrying a truncated Apc allele with a nonsense mutation in exon 15 have been generated by gene targeting and embryonic stem cell technology (Apc 1638 mice). These mice develop multiple gastrointestinal lesions including adenomas and carcinomas, focal areas of high grade dysplasia (FAD) and polypoid hyperplasias with FADS. The incidence of inherited colonic neoplasms has now been modulated by a chemopreventive regimen. Colonic lesions significantly increased in Apc 1638 mice on a Western-style diet, compared to Apc 1638 mice on AIN-76A diet which has lower fat content and higher calcium and vitamin D. These studies have also been carried out in normal mice, and have demonstrated without any chemical carcinogen that a Western-style diet induced colonic tumorigenesis. Modulation of cell proliferation has also been induced by Western-style diets in other organs including mammary gland, pancreas and prostate. These findings are leading to the development of new preclinical models for evaluating the efficacy of many classes of chemopreventive agents.

Model of mouse mammary gland hyperproliferation and hyperplasia induced by a western-style diet

Mammary glands of female C57BL/6J mice were analyzed after they were fed a Western-style diet or control AIN-76A diet. The Western-style diet contained several risk factors found in human diets in geographic regions having increased risk for breast cancer: high fat and phosphate and low calcium and vitamin D. After they were fed these diets for 8, 14, and 20 weeks, mice were sacrificed, and mammary glands were removed for morphometric and radioautographic measurements. Although after the animals were fed the Western-style diet for 8 weeks the number of terminal ducts per mouse mammary gland (NTDMG) was similar in the Western-style and control diet groups, after they were fed the Western-style diet for 14 weeks (p < 0.05) and 20 weeks (p < 0.01) the NTDMG significantly increased compared with the control group. Moreover, there was a significant increase (p < 0.01) in the tritiated thymidine labeling index of mammary terminal ductal epithelial cells after 14 and 20 weeks of Western-style diet administration. Thus the Western-style diet induced increased epithelial cell proliferation and increased NTDMG in female mice when fed during young adult growth and development. The findings raise the possibility that the ingestion of a diet with Western-style fat and phosphate content and with low calcium and vitamin D may induce similar changes during the early development of the human mammary gland.

Patient education and counseling in the context of modern patient-physician-family communication

The modern understanding of patient education derives from a robust literature from public health and clinical medicine that started to become empirical and rigorous in the mid-1960s. Patient education is one of three functions of the medical interview, each of which must each be accomplished skillfully if the others are to be maximally effective. This article discusses the new conceptualization of patient education and provides examples of how it works. The rule of patient activation is discussed and implications for future research are presented.

Inhibition of Western-diet induced hyperproliferation and hyperplasia in mouse colon by two sources of calcium

A Western-style diet containing high-fat and phosphate, and low calcium and vitamin D was fed to mice for 20 weeks. Starting at week 8, subgroups of animals received the Western-style diet supplemented by two different calcium sources: tricalcium phosphate and calcium citrate malate. Hyperproliferation (increased [3H]thymidine-labelled cells/colonic crypt) and hyperplasia (increased total epithelial cells/crypt) developed in the sigmoid colon after 8 weeks of feeding the Western-style diet confirming previous results, and these were reversed at later periods by the addition of the two calcium sources to the Western-style diet. Findings indicate that the modified colonic epithelial cell hyperproliferation and hyperplasia which have been associated with subsequent development of colonic neoplasia, are induced in mice fed a Western-style diet, and the addition of calcium to the diet inhibited their development in the colonic mucosa.

Learners as teachers: the conflicting roles of medical residents

OBJECTIVE

To explore the impact of internal medicine residents' roles as learners, teachers, and physicians on their performance in teaching and supervising interns; to generate insights for educational policy and research.

DESIGN

Qualitative analysis of in-depth, semistructured, recorded interviews with a cohort of second-postgraduate-year (PGY-2) residents. Questions elicited their accounts of differences in the learning process between the first and second residency years, their responses to situations in which they lacked sufficient clinical knowledge, their views of their supervisory relationship with interns, and their assessments of changes in their role in patient care since their internships. Transcripts were independently analyzed by the interdisciplinary team of authors.

SETTING

New York University/Bellevue Hospital Center's internal medicine residency (New York City), a highly competitive program in a major public hospital and a university medical center, emphasizing housestaff autonomy and self-reliance.

PARTICIPANTS

A cohort of 18 of 21 medical residents at Bellevue Hospital Center during the last rotation of PGY-2.

RESULTS

Intense conflicts confound residents' roles as teachers. These conflicts fall into three categories: 1) as learners, residents' own needs frequently coincide with those of interns in ways that may undermine their teaching--they are expected to nurture others despite their own considerable needs for emotional support, teach material that they barely grasp, and exert authority while feeling ignorant; 2) as team leaders, residents must ensure that interns get the hospital's work done, sometimes at the expense of teaching them; and 3) as clinicians, residents' first priority is to address the medical needs of patients--the learning needs of interns are secondary.

CONCLUSION

Second-year internal medicine residents experience conflicts inherent in their simultaneous commitment to learning, teaching, and service that may undermine both their effectiveness in supervising interns and their own professional development. Potential remedies are to restructure residency programs so as to equip residents with training and support for their role as teachers, reduce the tension between training and service by delegating tasks to nonphysician personnel, and provide graded responsibility to housestaff as physicians and teachers.

Abnormal cell proliferation and p52/p35-CSK expression in the colons of aging rats

In rodents and in humans, aging is associated with increased gastrointestinal epithelial cell proliferation and an expanded crypt proliferative compartment similar to that seen in the preneoplastic bowel. We have compared the distribution of a series of cytoskeletal antigens that are modified when colonic cancer cells differentiate in vitro in the colon of young (4-7 month) and aging (22-26 month) Fischer 344 rats. Two such proteins, p52 and p35, (that are increased in cultured senescent cells) differ in their position in the crypt axis and subcellular localization between young and aging rats. In young rats, immunoreactive p52 protein is present solely near the colonic crypt surface epithelium but in aging rats p52 expressing cells are found deeper in crypts. The intracellular localization of p35 also differs markedly in young and aging animals. The distribution of these proteins appears to be a reproducible biomarker of aging. Antigenic changes similar to those observed in aging colons also are seen in crypt cells of patients with ulcerative colitis and in the flat colonic mucosa of patients with adenomatous polyps and colon cancer. The combination of proliferative and differentiation changes suggest that the flat mucosa of the colon of aging rats has preneoplastic features.

Calcium and the prevention of colon cancer

Chemoprevention studies utilizing calcium have now progressed from basic measurements to clinical trials. Calcium's effects on epithelial cells have demonstrated decreased proliferation and induced cell differentiation with increasing levels of calcium in vitro, similar in vivo effects in rodent and human colon, and decreased carcinogen-induced colonic tumor formation in rodents. Current studies are attempting to inhibit colonic adenoma formation in human subjects. Most but not all epidemiologic studies also link increased dietary calcium with a decreased risk of colon cancer. In animal models, supplemental dietary calcium has decreased mammary epithelial cell hyperplasia and hyperproliferation and colonic cell hyperproliferation when the latter was induced by bile acids, fatty acids, and partial resection of the small intestine. Supplemental dietary calcium also decreased carcinogen-induced colonic tumors in several rodent models. In normal mice, and in mice carrying a targeted apc gene mutation, we recently increased colonic polypoid hyperplasias by a Western-style diet containing low calcium and vitamin D. In human subjects at increased risk for colon cancer, oral calcium supplementation significantly reduced colonic epithelial cell proliferation in most of the studies, including four randomized clinical trials. These studies have now progressed to short-term human clinical trials, including trials that measure the regrowth of transformed adenoma cells. Short-term adenoma-regrowth clinical trials, however, are limited in their ability to measure whether chemopreventive agents inhibit early genotoxic events, abnormal cellular metabolic activities involved in tumor promotion over many years, or the progression of adenoma cells to carcinoma.

Mammary ductal epithelial cell hyperproliferation and hyperplasia induced by a nutritional stress diet containing four components of a western-style diet

We have studied effects of several nutrients on the proliferation of mammary ductal epithelial cells in C57BL/6J virgin female mice, using morphometry and [3H]dT in vivo labeling. A nutritional stress diet was given based on the AIN-76A semi-synthetic diet modified to contain four significant risk factors of a Western-style diet: high fat and phosphate and decreased calcium and vitamin D. The numbers of large, intermediate and terminal ducts and proliferating epithelial cells in mammary glands were assayed in control and stress diet groups. An increased number of mammary ducts and increased number of proliferating cells were found at the level of the small terminal ducts, a cancer-prone region in the mammary gland in the stress diet group compared to the control group after 20 weeks of diet administration. Thus, mammary terminal ductal hyperproliferation, expansion in the size of the proliferative epithelial cell compartment and excessive duplication of mammary ductal epithelial cells were found after this Western-style diet containing decreased dietary calcium and vitamin D. These changes are similar to those developing in colonic epithelium of mice maintained on the same diets and during chemically induced colonic carcinogenesis.

A targeted chain-termination mutation in the mouse Apc gene results in multiple intestinal tumors

Germ-line mutations in the human adenomatous polyposis coli (APC) gene result in familial adenomatous polyposis, an autosomal dominant disorder characterized by the early onset of multiple adenomatous polyps in the large bowel with a high likelihood of developing colorectal carcinomas. To understand the role of APC in intestinal tumor formation, we have introduced a chain-termination mutation in the 15th exon of the mouse Apc gene and employed it to modify the endogenous gene by homologous recombination in embryonic stem cells. Mice which are heterozygous for the Apc gene modification progressively develop intestinal tumors in a manner that is similar to that observed in patients with familial adenomatous polyposis and in mice which carry a mutation called multiple intestinal neoplasia (Min). Our results indicate that the Apc gene modification is a critical event in the initiation of intestinal tumor formation and results in an autosomal dominant predisposition toward development of spontaneous colonic and intestinal tumors in mice.

General internal medicine

Internists advanced toward a patient care model based on critical, qualitative, and quantitative assessment of clinical care processes and outcomes. The complete internist must consider social context as well as traditional risk factors in promoting the health of patients.

Effects of vitamin/mineral supplementation on the proliferation of esophageal squamous epithelium in Linxian, China

Abnormalities of epithelial proliferation have been proposed as an early step in gastrointestinal carcinogenesis. To determine whether micronutrient supplementation may reduce squamous epithelial proliferation in the esophagus, we evaluated proliferation in subjects participating in a randomized nutrition intervention trial in Linxian, China, where esophageal cancer rates are among the highest in the world. After 30 months of intervention involving daily supplementation with multiple vitamins and minerals, an endoscopic survey was performed and squamous biopsies from 512 subjects were labeled with tritiated thymidine and autoradiographed. Analysis showed no treatment effect on the overall amount of squamous epithelial proliferation measured by the total labeling index. However, a measure of the vertical distribution of labeled cells showed lower values with supplementation: a 14% reduction in all subjects (P = 0.29), and a 29% reduction in nonsmokers (P = 0.03). These results suggest a potential modest benefit for short-term intervention with multiple vitamins and minerals on squamous epithelial cell proliferation of the esophagus in this high-risk population.

Expression of plasminogen activator inhibitor type 1 (PAI-1) by HT-29di human large bowel carcinoma cells is modulated as a function of epithelial differentiation

Highly differentiated epithelial populations (36% mucin-producing cells; sixfold increase in alkaline phosphatase activity; development of flat, substrate-adherent, entero-cytic foci) were induced upon in vitro exposure of HT-29di human colon carcinoma cells to sodium butyrate (NaB). 1,25-dihydroxyvitamin D3 [1,25-(OH)2D3] (10(-7) M) and the ionophore A23187 (0.5 microM) significantly augmented (two to threefold) NaB-induced HT-29di differentiation, whereas 1,25-(OH)2D3 or A23187 alone were not effective. Induction reflected specific changes in protein abundance, involving, most notably, a differentiation-associated increase in the expression and substrate-deposition of a 47-kDa protein with pI/mw two-dimensional map coordinates and immunochemical properties identical to that of plasminogen activator inhibitor type 1 (PAI-1), a major regulator of the pericellular proteolytic cascade. Culture of HT-29di cells in medium of either high (2.5 mM) or low (0.25 mM) Ca2+ concentration did not affect the incidence of 'spontaneous' differentiation, although NaB-induced goblet cell and enterocytic maturation was Ca(2+)-dependent. The inability of 1,25-(OH)2D3, A23187 or modulated Ca2+ levels alone (i.e., in the absence of NaB) to effect differentiation of HT-29di cells and the Ca(2+)-dependence of the NaB response indicate that NaB and Ca2+ act co-operatively to induce colonic epithelial maturation in vitro.

A comparison of work-sampling and time-and-motion techniques for studies in health services research

OBJECTIVE

This study compares results and illustrates trade-offs between work-sampling and time-and-motion methodologies.

DATA SOURCES

Data are from time-and-motion measurements of a sample of medical residents in two large urban hospitals.

STUDY DESIGN

The study contrasts the precision of work-sampling and time-and-motion techniques using data actually collected using the time-and-motion approach. That data set was used to generate a simulated set of work-sampling data points.

DATA COLLECTION/EXTRACTION METHODS

Trained observers followed residents during their 24-hour day and recorded the start and end time of each activity performed by the resident. The activities were coded and then grouped into ten major categories. Work-sampling data were derived from the raw time-and-motion data for hourly, half-hourly, and quarter-hourly observations.

PRINCIPAL FINDINGS

The actual time spent on different tasks as assessed by the time-and-motion analysis differed from the percent of time projected by work-sampling. The work-sampling results differed by 20 percent or more of the estimated value for eight of the ten activities. As expected, the standard deviation decreases as work-sampling observations become more frequent.

CONCLUSIONS

Findings indicate that the work-sampling approach, as commonly employed, may not provide an acceptably precise approximation of the result that would be obtained by time-and-motion observations.

Physician satisfaction with primary care office visits. Collaborative Study Group of the American Academy on Physician and Patient

To study encounter-specific physician satisfaction we collected exit questionnaires from patients and physicians following 550 primary care office visits. The physicians' questionnaire included 20 items pertaining to satisfaction with the visit, one of which was an assessment of global satisfaction. Using a boot-strap technique, we factor analyzed the satisfaction questions in 10 repeated samples. Four distinct dimensions of physician satisfaction emerged: satisfaction with the patient-physician relationship, with the data collection process, with the appropriateness of the use of time, and with the absence of excessive demands on the part of the patient. Each scale was found to be reliable; global satisfaction was most closely related to the relationship factor. Satisfaction with use of time and the adequacy of data collection tended to be stable for individual physicians across a range of patients whereas global satisfaction and satisfaction with the relationship and the demanding nature of the patient and were more variable, hence most unique to each encounter. This study of physician satisfaction represents an effort to incorporate knowledge about physicians' subjective experiences into a systematic understanding of the dynamics of the medical interview.

Correlation of epithelial proliferation and squamous esophageal histology in 1185 biopsies from Linxian, China

Epithelial proliferation is an active area of research in gastrointestinal cancer, but only a few studies have examined the relationship of esophageal epithelial proliferation and squamous histologic findings in populations with high rates of squamous esophageal cancer. In order to study this correlation, tritiated thymidine labeling was performed on 1185 esophageal biopsies from 745 residents of Linxian, China, a county with some of the highest esophageal-cancer rates in the world. Total labeling index (TLI = total labeled cells/total cells counted) was used to measure the amount of proliferation, and the proportion of labeled cells found in cell layers 4 to 10 (labeled cell fraction 4 plus, LF4+ = labeled cells in layers 4-10/total labeled cells) was used to measure the vertical distribution of proliferation. Of the biopsies, 979 were histologically normal, 51 showed acanthosis, 35 showed esophagitis, 116 showed squamous dysplasia, and 6 showed invasive squamous cancer. The mean values of both proliferation variables, stratified by histologic diagnosis, showed the following relationships: normal = acanthosis < esophagitis = dysplasia < cancer. The ranges of proliferation values overlapped extensively in all biopsy categories, so that measuring proliferation could not substitute for histologic diagnosis. It remains to be seen whether proliferation values, histologic diagnoses, or some combination of these methods is most predictive of subsequent esophageal cancer.

Morphological and morphometric measurements in colorectal mucosa of subjects at increased risk for colonic neoplasia

Measurements of intermediate biomarkers have recently increased, attempting to provide useful information about cancer risk. We report morphological findings in rectal mucosal biopsies from patients at low risk and at high risk for colorectal cancer. Rectal biopsies were analyzed from fourteen Seventh-Day Adventist (SDA) subjects at low risk and from twenty-seven members of families with hereditary nonpolyposis colonic cancer (HNPCC) at higher risk. The following measurements were made on rectal crypts: length of crypts, numbers of cells, diameter of the surface, middle and base of the crypts and infiltration of inflammatory cells into the lamina propria. Findings indicated morphological differences in normal-appearing rectal mucosa of individuals in the HNPCC group compared with SDA subjects (P < 0.05). They included shorter crypts with fewer epithelial cells and increased cellular infiltration in the mucosa of HNPCC subjects compared with SDA subjects, suggesting minimal inflammation, and an early stage of crypt atrophy in the rectal mucosa of subjects at higher risk for colonic neoplasia.

Effects of sennosides and nonanthranoid laxatives on cytochemistry of epithelial cells in rat colon

The cytochemical effects of laxatives on rat colonic epithelial cells were studied. A total of 32 rats was divided into four groups. Three groups were treated with bisacodyl, picosulfate and sennosides for 12 weeks, and a fourth group served as control. The rectum, midcolon and cecum were studied for acidic mucins, lectin soybean agglutinin (SBA) and cytokeratin AE1. Most striking and consistent changes were found in the rectum including total acidic mucin content which significantly increased, with sulfomucin decreased and sialomucin increased in the three treatment groups. Cytokeratin AE1 expression increased on picosulfate and sennosides. SBA total binding increased on bisacodyl and picosulfate. The present findings were thought to be of functional origin and do not represent early precancerous lesions.

Abnormal rectal cell proliferation and p52/p35 protein expression in patients with ulcerative colitis

We evaluated the presence of cell proliferation and antigenic abnormalities in rectal biopsies from 37 patients affected by ulcerative colitis and 15 controls. The study was carried out by thymidine labeling and immunochemistry, using antibodies against specific cytoskeletal-associated proteins (p52, p35, alpha-actinin). Among ulcerative colitis patients, 24 had an immunofluorescence pattern similar to that of controls, while 13 showed an abnormal distribution of one or more proteins (p52 alone or p52 and either p35 or alpha-actinin) within the rectal crypts. Patients showed a shift of the proliferative compartment towards the top of the rectal crypts compared with controls. This finding was more evident in patients with p52 or p35 abnormalities. Proliferative and antigenic defects were not related either to age or the duration of colitis. These phenotypic changes might be a biomarker of increased risk of colon cancer in ulcerative colitis.

Doctors as workers: work-hour regulations and interns' perceptions of responsibility, quality of care, and training

OBJECTIVE

To study residents' perceptions of their responsibility for patients, the quality of patient care, and their learning experiences in light of new work-hour regulations.

DESIGN

Inductive analysis of in-depth, semistructured, recorded interviews with a cohort of interns in internal medicine in the last month of their first postgraduate year. Questions were grounded in an examination of issues related to going off duty and delegating tasks to colleagues. Transcripts were independently analyzed by an interdisciplinary team.

SETTING

New York University/Bellevue Hospital Center's residency program in internal medicine (in New York City).

PARTICIPANTS

A cohort of 21 of a possible 24 interns in medicine on rotation at Bellevue Hospital Center.

RESULTS

The interviews revealed: 1) intense concern harbored by interns for their patients with resulting difficulty in maintaining realistic boundaries between work and personal lives; 2) an open-ended workday and competing considerations confronting interns when deciding to leave the hospital--including concerns about leaving patients at critical junctures in their care, confidence in the colleague to whom they were signing out, regard for the workload of this colleague, and uneasiness about the educational consequences; 3) deterrents to acknowledging and acting on one's limits in performing medical work; and 4) a recurrent conflict between delegating responsibility and retaining control over patient care.

CONCLUSION

Values traditionally learned in training emphasize autonomy and individual accountability. They may conflict with the shared decision making and collective responsibility among peers necessitated by work-hour limitations and associated changes in program structure.

Effects of caloric restriction and dietary fat on epithelial cell proliferation in rat colon

Epidemiological studies indicate that caloric intake and dietary fat content influence colonic carcinogenesis. In rodents, caloric restriction reduces, and some fats increase, carcinogen-induced colon cancer incidence. The present study was designed to investigate the effects of caloric restriction on colonic cell proliferation (CCP) in carcinogen-treated or control rats fed low- or high-fat diets. F344 rats were treated with azoxymethane (15 mg/kg x2) and then fed an isocaloric AIN 76A diet containing either 5 or 23% corn oil, ad libitum or calorie-restricted to 70 or 80% of the kilocalories consumed by ad libitum rats. Biopsies of the distal colon were taken at 10 and 20 weeks, and rats were sacrificed at 21 or 34 weeks on the experimental diets. Distal CCP was determined by microautoradiography after [3H]thymidine labeling in vitro or presacrifice administration in vivo. The labeling index and number of labeled cells per crypt column were significantly reduced by caloric restriction at all time points (10, 20, 21, 34 weeks). Caloric restriction reduced CCP in high fat- and low fat-fed rats and in azoxymethane-treated and control rats. High fat resulted in decreased CCP in the distal colon compared to low fat at 34 weeks but not earlier. The findings indicate that: (a) caloric restriction is effective in favorably modulating CCP, an intermediate biomarker of colon cancer risk; (b) a high fat ad libitum diet, which increased tumor yield, does not increase distal colon proliferation; (c) dietary fat intake alters proliferation in a manner differing from that induced by changing dietary caloric intake.

Proliferation and differentiation biomarkers in colorectal mucosa and their application to chemoprevention studies

Colorectal cancer is one of the leading causes of morbidity and mortality in Western countries. Because its prognosis is relatively unaffected by improvements in surgery and chemotherapy, increasing interest has recently been directed toward chemoprevention. Intermediate biomarkers of abnormal cell proliferation, differentiation, and gene expression have recently been identified and have served to measure effects of chemopreventive agents in rodent models and in short-term human clinical trials. Alterations in cell proliferation and differentiation have been found in preneoplastic diseases and in normal-appearing colorectal mucosa of patients at increased risk for malignancy. Several techniques are available for measuring these alterations, and standardization and comparison of different methods are underway to assess the utility of various intermediate biomarkers in chemoprevention studies.

Expansion of the epithelial cell proliferative compartment and frequency of adenomatous polyps in the colon correlate with the strength of family history of colorectal cancer

Expansion of the proliferative compartment of epithelial cells in colonic crypts and colonic adenomas have been described as phenotypic precursors to colon cancer in individuals affected with hereditary or sporadic colon cancer. This study measured the size of the proliferative compartment in colonic crypts and the frequency of adenomas in asymptomatic members of families having sporadic colorectal cancer. The subjects were divided into 2 groups according to the frequency of colorectal cancer in their families. A shift of the compartment of proliferating epithelial cells toward the lumenal surface of colonic crypts was seen in the group of subjects with a stronger family history of colorectal cancer, with significant differences in the numbers of proliferative cells in the upper and the lower crypt compartments (P < 0.05) and in the fraction of proliferative cells at the highest compartment at the lumenal surface of the crypts (P < 0.05). Cell proliferation patterns in normal-appearing mucosa of the 2 groups revealed no difference in whole crypt [3H]thymidine labeling index. Colonoscopic examination of the 56 subjects revealed an overall prevalence of adenomas of 21%; when stratified by frequency of colorectal cancer in their families, 3 of 22 subjects (14%) with a weaker family history had adenomas, while 9 of 34 (26%) with a stronger family history had adenomas. Thus, parallel abnormalities of colonic epithelial cell proliferation and neoplasia were seen in individuals with a family history of colorectal cancer, both of which were more pronounced with increasing strength of family history. This observation provides further evidence of relationships among these factors in the etiology of "sporadic" colorectal cancer.

A randomized double-blind intervention study on the effect of calcium supplementation on esophageal precancerous lesions in a high-risk population in China

To determine whether dietary calcium supplementation affects esophageal precancerous lesions, 200 subjects with esophageal lesions in a high-risk area for esophageal cancer in China (Huixian, Henan) were randomly divided into 2 groups (100 subjects/group). Subjects in one group received an oral supplementation of calcium carbonate tablets (1200 mg of calcium daily), and subjects in the other group received placebo pills for 11 months. At the entry and the end of the trial, esophagoscopy was performed, and 2 or 3 biopsy specimens were taken from the middle and lower thirds of the esophagus and from macroscopic lesions, if any, of each subject for histopathology and cell proliferation analysis with deoxythymidine labeling. In comparison to normal epithelium, increased proliferative compartment size was observed in epithelia with hyperplasia or dysplasia. After the intervention, the percentage of individuals with "normal epithelium," "basal cell hyperplasia," "basal cell hyperplasia II," and "basal cell hyperplasia III and dysplasia" were 44, 31, 13, and 11% in the calcium group and 35, 39, 17, and 6% in the placebo group, respectively. The labeling index was 0.046 in the calcium group and 0.044 in the placebo group. After the intervention, the labeling index in basal cell layers 1 to 5, the major zone of cell proliferation, fell 38% in the calcium group and 44% in the placebo group from before the intervention. Therefore, in this study, calcium supplementation was not shown to have beneficial effects in alleviating precancerous lesions and abnormal cell proliferation patterns.

Modulation of colonic epithelial cell proliferation, histone acetylation, and luminal short chain fatty acids by variation of dietary fiber (wheat bran) in rats

The effect of increasing amounts of wheat bran (0, 5, 10, 20%) in AIN-76 semisynthetic diet on colonic luminal short chain fatty acids, epithelial cell histone acetylation, and cytokinetics, was studied for 2 weeks in groups of 10 male Sprague-Dawley rats. Luminal contents were removed from the colon at sacrifice, quick frozen, and analyzed for short chain fatty acids by gas-liquid chromatography. Histone acetylation was assessed in cells isolated from the same animals. Cell proliferation was measured after a short pulse in vivo with [3H]thymidine. Colonic luminal butyrate levels were lower in the 0 and 20% fiber groups, and higher in the 5 and 10% fiber groups. In contrast, cell proliferation, as determined by labeling index, was higher in the 0 and 20% fiber groups, and lower in the 5 and 10% fiber groups. This resulted in a significant inverse correlation between luminal butyrate levels and colonic cell proliferation. In addition, there was a positive linear correlation between luminal butyric acid levels and colon epithelial cell histone acetylation. From these data it was concluded that colonic butyrate levels can be modulated by the addition of wheat bran to the diet and that butyrate can modulate DNA synthesis (calculated as labeling index) in the proliferative compartments of colonic crypts. The localization of dividing cells was unchanged and no induction of terminal differentiation was detectable (contrary to what has been observed for transformed cells in culture).

Cell proliferation in rat colon measured with bromodeoxyuridine, proliferating cell nuclear antigen, and [3H]thymidine

Epithelial cell proliferation was studied in the normal colonic mucosa of 5-week-old Sprague-Dawley rats, comparing [3H]thymidine incorporation (group 1) with two newer proliferation markers, bromodeoxyuridine (group 2) and proliferating cell nuclear antigen (group 3). Microautoradiography (group 1) or immunoperoxidase assays (groups 2 and 3) were carried out. Cells were counted for positive reaction and position along 50 colonic crypt columns/animal. No significant differences were found in number or distribution of labeled epithelial cells in proliferative compartments in crypt columns of normal colonic mucosa; labeled cells were mainly in the lower 60% of colonic crypts. Thus, in this model, bromodeoxyuridine and proliferating cell nuclear antigens were comparable to [3H]thymidine as reliable markers of proliferating epithelial cells in rat colon.

Calcium, vitamin D, and colon cancer

Calcium contributes to the progression of epithelial cells through all phases of the proliferative cycle and into stages of cell differentiation; intracellular concentrations of calcium that are required for cell renewal, however, are lower than those required for epithelial-cell differentiation. These effects of calcium are modulated by interactions with 1,25-dihydroxy-vitamin D3, phosphate, and fatty acids, all of which are partly dependent on dietary intake. In rodent models, increased dietary calcium inhibited hyperproliferation of colon epithelial cells induced by increased levels of fatty acids or bile acids present in the colon. When carcinogens induced hyperproliferation of colon epithelial cells the hyperproliferation was decreased by added dietary calcium, and in several animal models the occurrence of carcinogen-induced carcinomas of the colon decreased with increased dietary calcium. A nutritional stress diet, designed to represent human Western dietary intake of calcium, phosphate, vitamin D, and fat, produced hyperproliferation and hyperplasia in the colons of rodents; these effects were reduced by increasing dietary levels of calcium. Decreased levels of ornithine decarboxylase also were reported in human and rodent colon mucosa exposed to increasing levels of calcium. In human subjects at increased risk for familial colon cancer, hyperproliferation of colon epithelial cells was reduced after oral dietary supplementation with calcium. In epidemiological studies, several investigators reported inverse correlations between levels of dietary calcium intake and the incidence of colon cancer. Extrapolation of the data have suggested a protective effect of total calcium intakes above 1500 to 1800 mg/day.

Intermediate biomarkers of increased risk for colorectal cancer: comparison of different methods of analysis and modifications by chemopreventive interventions

Intermediate biomarkers of abnormal cell growth and development have recently been used in chemoprevention trials in attempts to identify the efficacy of chemopreventive agents in human subjects. Measurements carried out include those related to cell proliferation, differentiation, and gene structure and expression in the colon. Among modified patterns of cell proliferation identified by microautoradiographic or immunoperoxidase assays, a characteristic expansion in the size of the proliferative compartment has been observed in normal-appearing colorectal mucosa of human subjects with disease increasing cancer risk; the same patterns have been induced by chemical carcinogens in rodents. Moreover, this intermediate biomarker has been modulated by chemopreventive agents in both rodents and humans. Newer intermediate biomarkers being studied for application to human chemopreventive programs include normal and abnormal patterns of expression of mucins, intermediate filaments and cytoskeletal proteins, and the structure and expression of a variety of genes associated with normal and abnormal cell development. The application of these various intermediate biomarkers to chemoprevention studies is increasing the ability of investigators to analyze the effects of novel chemopreventive agents in the colon and in other organs.

Gastrointestinal cancer: pathogenesis, risk factors and the development of intermediate biomarkers for chemoprevention studies

Dietary, environmental and genetic factors contribute to the etiology, pathogenesis and risk for gastrointestinal cancers. Measurements of cell proliferation and differentiation further identify abnormal cellular properties associated with increased susceptibility to gastrointestinal cancer. In precancerous esophagus, the proliferative compartment increases in size, increased ploidy and dysplasia develop, and epithelial cells express abnormal cytokeratins and ectopic tumor-associated antigens. In precancerous stomach, increased proliferative activity and metaplasia develop. Intestinal enzymes and mucins are expressed and normal gastric antigens are replaced by intestinal or embryonic antigens. In flat colonic mucosa and in colonic adenomas, expansions of the proliferative compartment occur. Gene expression is modified, gene deletions occur and blood group-related antigens are modified as the cells undergo abnormal differentiation and develop into adenomas and carcinomas. Chemopreventive regimens are now being tested to determine whether they modify such intermediate biomarkers toward normal levels characteristic of lower risk for neoplasia. It is anticipated that the utilization of intermediate biomarkers in chemoprevention studies may permit more novel chemopreventive regimens to be tested in human subjects than heretofore was possible.

Precancerous lesions of the human esophagus: multiparametric study of esophageal biopsies from a high-risk population in Linxian, China

Histopathology, morphometry, tritiated thymidine incorporation and immunohistochemistry were studied in 221 esophageal biopsies from subjects with cytologica hyperplasia in Linxian, China. A spectrum of 7 morphologic entities were found: (1) normal/near normal (NN); (2) basal cell hyperplasia 0 (BHO); (3) simple hyperplasia (SH); (4) mixed basal and spinous cell hyperplasia (MBS); (5) basal cell hyperplasia 1 (BH1); (6) dysplasia (D); and (7) non-proliferative lesion (NP). Forty percent of the biopsies had combinations of histologic types. The thickness of the epithelium was increased in SH, MBS, and BH1, but not in BHO and NP. Elongation of papillae was frequently seen in SH, MBS, BH1, and D. Papillary bleeding was very prevalent in the esophageal specimens studied. A variety of cellular changes were found in peripapillary areas especially when bleeding occurred. [3H]-thymidine labeling index was dramatically increased in the entire epithelium in dysplasia, and also increased in cell layer 3 of MBS, BH1 and D. Blood group antigen LeY and lectin WGA showed consistent positivity in cellular membranes of the squamous cells, and these changes occurred before gross morphologic alterations. These findings provide a hypothesis for the sequence of pathogenetic events leading to esophageal carcinoma, and define each step with corresponding biomarkers for cancer prevention studies.

Sex differences in patients' and physicians' communication during primary care medical visits

This study reports on the analysis of audiotapes of 537 adult, chronic disease patients and their 127 physicians (101 men and 26 women) in a variety of primary care practice settings to explore differences attributable to the effects of the patient's and the physician's sex on the process of communication during medical visits. Compared to male physicians, women conducted longer medical visits (22.9 vs 20.3 minutes; F(1,515) = 7.9, P less than .005), with substantially more talk F(1,518) = 19.5, P less than .000. Differences were especially evident during the history segment of the visit when female physicians talked 40% more than male physicians (F(1,518) = 20.1, P less than .000) and when patients of female physicians talked 58% more than male physicians' patients (F(1,448) = 24.4, P less than .000). Compared to male physicians, female physicians engaged in more positive talk, partnership-building, question-asking, and information-giving. Similarly, when with female compared to male physicians, patients engaged in more positive talk, more partnership-building, question-asking, and information-giving related to both biomedical and psychosocial topics.

Application of intermediate biomarkers to studies of cancer prevention in the gastrointestinal tract: introduction and perspective

In this article, abnormalities in the proliferation and differentiation of gastrointestinal cells are described in diseases that increase predisposition to gastrointestinal cancer. Recent findings related to the effects of calcium on gastrointestinal cell proliferation, differentiation, and tumor occurrence in rodent models and in human subjects are summarized.

Colonic hyperproliferation induced in rats and mice by nutritional-stress diets containing four components of a human Western-style diet (series 2)

In a previous study colonic hyperplasia and hyperproliferation were induced in mice and rats by a nutritional-stress diet, based on the AIN-76A semisynthetic diet modified to contain four suggested high-risk components of the human Western-style diet: increased fat and phosphate and decreased calcium and vitamin D contents. In this study the effect of raising calcium alone to near the median level (0.22 mg/kcal) and to a high level (1.3 mg/kcal), comparable to adult human dietary intake, was tested in mice and rats while retaining the three other high-risk components. With median calcium intake the nutritional-stress diet induced hyperproliferation of epithelial cells in colonic crypts, with increased numbers of proliferating cells in crypt columns in sigmoid colon of mice (P less than 0.001) and rats (P = 0.02) and in the ascending colon of mice (P = 0.01). With high calcium intake, hyperproliferation was reduced almost to control amounts in the presence of unchanged fat, phosphate, and vitamin D.