The role of family physicians in cancer care: perspectives of primary and specialty care providers.

BACKGROUND: Currently, the specific role of family physicians (fps) in the care of people with cancer is not well defined. Our goal was to explore physician perspectives and contextual factors related to the coordination of cancer care and the role of fps. METHODS: Using a constructivist grounded theory approach, we conducted telephone interviews with 58 primary and cancer specialist health care providers from across Canada. RESULTS: The participants-21 fps, 15 surgeons, 12 medical oncologists, 6 radiation oncologists, and 4 general practitioners in oncology-were asked to describe both the role that fps currently play and the role that, in their opinion, fps should play in the future care of cancer patients across the cancer continuum. Participants identified 3 key roles: coordinating cancer care, managing comorbidities, and providing psychosocial care to patients and their families. However, fps and specialists discussed many challenges that prevent fps from fully performing those roles: ■ The fps described communication problems resulting from not being kept "in the loop" because they weren't copied on patient reports and also the lack of clearly defined roles for all the various health care providers involved in providing care to cancer patients.■ The specialists expressed concerns about a lack of patient access to fp care, leaving specialists to fill the care gaps. The fps and specialists both recommended additional training and education for fps in survivorship care, cancer screening, genetic testing, and new cancer treatments. CONCLUSIONS: Better communication, more collaboration, and further education are needed to enhance the role of fps in the care of cancer patients.

Multigene expression profile testing in breast cancer: is there a role for family physicians?

BACKGROUND: Family physicians (fps) play a role in aspects of personalized medicine in cancer, including assessment of increased risk because of family history. Little is known about the potential role of fps in supporting cancer patients who undergo tumour gene expression profile (gep) testing. METHODS: We conducted a mixed-methods study with qualitative and quantitative components. Qualitative data from focus groups and interviews with fps and cancer specialists about the role of fps in breast cancer gep testing were obtained during studies conducted within the pan-Canadian canimpact research program. We determined the number of visits by breast cancer patients to a fp between the first medical oncology visit and the start of chemotherapy, a period when patients might be considering results of gep testing. RESULTS: The fps and cancer specialists felt that ordering gep tests and explaining the results was the role of the oncologist. A new fp role was identified relating to the fp-patient relationship: supporting patients in making adjuvant therapy decisions informed by gep tests by considering the patient's comorbid conditions, social situation, and preferences. Lack of fp knowledge and resources, and challenges in fp-oncologist communication were seen as significant barriers to that role. Between 28% and 38% of patients visited a fp between the first oncology visit and the start of chemotherapy. CONCLUSIONS: Our findings suggest an emerging role for fps in supporting patients who are making adjuvant treatment decisions after receiving the results of gep testing. For success in this new role, education and point-of-care tools, together with more effective communication strategies between fps and oncologists, are needed.

Do current cancer follow-up care practices meet the needs of young adult cancer survivors in Canada? A qualitative inquiry.

PURPOSE: The purpose of the present study was to assess whether current cancer follow-up care practices meet the needs of young adult cancer survivors in Canada. METHODS: This qualitative study used a constructivist grounded theory framework to analyze telephone interviews with cancer survivors from across Canada diagnosed between the ages of 18 and 39 years. The focus was specifically on cancer follow-up care (cfc). RESULTS: Interviews were conducted with 55 participants, and 53 interviews were used for the analysis. The overall theme that emerged from the data was the lack of age-specific cfc. Some of the subthemes that emerged were the absence or inadequacy of fertility and infertility treatment options; of psychological services such as family, couples, and sexuality counseling; of social supports such as assistance with entry or re-entry into the education system or workplace; of access to supplemental health insurance; and of survivorship care plans. Based on the data resulting from the interviews, we developed a conceptual model of young-adult cfc incorporating the major themes and subthemes that emerged from our study. The proposed model aims to ensure a more age-appropriate and comprehensive approach to cfc for this group of cancer patients. CONCLUSIONS: Current Canadian cfc practices are inadequate and do not provide comprehensive care for young adult cancer survivors in Canada. The conceptual model presented here aims to ensure a more comprehensive approach to cfc that meets the needs of this unique cancer population and reduces further possible physical, psychological, or social cancer sequelae.

Transgastric biologic mesh delivery and abdominal wall hernia repair in a porcine model.

BACKGROUND AND STUDY AIMS: Incisional abdominal wall hernias currently require repair with open or laparoscopic surgery, which is associated with wound complications and recurrent hernia formation. Natural orifice transluminal endoscopic surgery (NOTES) techniques may have the potential to decrease the morbidity associated with hernia repair. The aim of this study was to repair a chronic ventral hernia with a biologic mesh placed transgastrically in a porcine model. MATERIALS AND METHODS: Six pigs underwent creation of an incisional abdominal wall hernia. At least 4 weeks later, transgastric repair was done using an underlay biologic mesh with at least 5 cm of overlap from the hernia fascial edge. The mesh was secured with transfascial sutures and the stomach was closed with a sutured gastropexy. Pigs were evaluated 2 weeks later by laparoscopy. Pigs were sacrificed and necropsy wa s performed 4 weeks after the repair. RESULTS: Six pigs underwent hernia repair lasting a mean (+/- SD) of 204 +/- 123 minutes, with one perioperative death. At 2 weeks after hernia repair, laparoscopy showed significant adhesions in all pigs; one pig had extensive mesh infection and was sacrificed. Necropsy on one pig at 2 weeks and four pigs at 4 weeks showed complete coverage of the hernia defect in all pigs. All pigs had mesh abscesses or a positive mesh culture. CONCLUSION: Transgastric repair of a chronic ventral hernia is technically feasible. Difficulties with mesh delivery and infection need to be overcome before this approach can be used in humans.

"This is a kind of betrayal": a qualitative study of disability after breast cancer.

OBJECTIVE: We proposed to document the effect of arm morbidity and disability in 40 Canadian women who were 12-24 months post breast cancer surgery. METHODS: We completed 40 qualitative interviews as one component of a multidisciplinary national longitudinal study of arm morbidity after breast cancer (n = 745) involving four research sites (Fredericton/Saint John, Montreal, Winnipeg, Surrey). During semi-structured interviews, participants who had reported arm morbidity and disability in earlier surveys were asked to discuss the effects of these conditions on everyday life. RESULTS: The interviewees reported making major adjustments to paid and unpaid work, which often involved the assistance of family members, thus demonstrating the effect of disability. Interview data resulted in the creation of a model that addresses arm morbidity and disability, and that holds implications for health care professionals. CONCLUSIONS: Based on the interview findings, we conclude that a robust measure of disability after breast cancer should be developed. In the absence of a validated measure of the effect of disability, evaluating qualitative responses to questions about everyday activities could provide the impetus for provision of physical therapy and emotional support.

Endoscopic colotomy closure after full thickness excision: comparison of T fastener with multiclip applier.

BACKGROUND AND STUDY AIMS: Safe, reliable, and efficient endoscopic closure of a colotomy is paramount for endoscopic full thickness excision of the colon. Two newly developed devices, the Tissue Apposition System (TAS) and the InScope Multi-Clip Applier (IMCA), may help to achieve this. The aim of this study was to determine the feasibility of using each device to close colotomies after full thickness wall excisions. MATERIAL AND METHODS: 12 pigs were used in the study. After laparoscopic full thickness excision of the colonic wall, the defect was closed using either the TAS or the IMCA. Closure was performed under laparoscopic vision. Success of colotomy closure, time taken for colotomy closure, postoperative infections, and complication rates were recorded. RESULTS: Complete closure was achieved in 6/6 pigs in the TAS group. In 5/6 pigs in the IMCA group closure was successful; in one pig laparoscopic assistance was used. Median closure time (range) was significantly lower in the TAS group at 48 minutes (15 - 51) vs. 76 minutes (43 - 145) in the IMCA group. There were no postoperative infections or complications. CONCLUSIONS: Endoscopic closure after full thickness colonic wall excision is feasible with both the TAS and the IMCA. Closure times are significantly shorter and handling is easier with the TAS. Combined use of both systems might be beneficial.

Evaluation of a novel endoluminal stapling procedure to restrict the lower esophageal sphincter and reduce reflux.

BACKGROUND AND STUDY AIMS: An effective, safe, and long-lasting endoluminal treatment for gastroesophageal reflux disease (GERD) would be an attractive prospect. We developed an endoluminal technique to restrict and tighten the lower esophageal sphincter (LES), by using a transoral endoscopic stapling device in a porcine model. PATIENTS AND METHODS: Pre-interventional evaluation comprised endoscopy, manometry, and 48-hour pH measurement of the distal esophagus using the catheterless BRAVO pH capsule. By placing the endoluminal stapling device at the LES and firing a 2.5-cm staple line, a vertical plication was created. In five pilot pigs (phase 1), plications were placed in various locations at the LES. In another five pigs (phase 2), plications were placed uniformly at the mid level of the LES on the lesser curvature side. Measurements were repeated 2 weeks after the procedure. Necropsy and histological analysis were performed. RESULTS: Endoluminal stapling was successfully completed in all animals. In phase 2, the median procedure time was 15 minutes (range 10-55 minutes). LES pressure increased from 10.5 mmHg (+/- 2.5 mmHg) to 14.3 mmHg (+/- 3.8 mmHg) (P = 0.038). Median percentage of time with pH below 4 decreased from 6.6% (range 2.9%-48.8%) to 2.2% (range 0%-10.4%) (P = 0.043). Histology showed the staple line involving the muscular layer in all pigs. A gap was present in the central part of the staple line in three pigs resulting in a mucosa-muscular bridge of tissue. This bridge did not influence the results. CONCLUSION: This novel endoluminal technique is feasible and safe in a porcine model over 2 weeks. It is appealing due to its simplicity and ease of application. Further studies aimed at eliminating the gap in the staple line and investigating more animals over longer survival periods are needed.

The economic impact on families when a child is diagnosed with cancer.

OBJECTIVE: In a study conducted in New Brunswick and Newfoundland and Labrador, we examined the economic impact on families caring for a child with cancer. METHODS: We undertook semi-structured interviews with 28 French and English families with a child diagnosed with cancer in the last 10 years. RESULTS: Families who care for a child with cancer incur considerable costs during the diagnostic, treatment, and follow-up care phases of the disease. Four major themes emerged from this qualitative study as contributing factors for these expenses: necessary travel; loss of income because of a reduction or termination of parental employment; out-of-pocket treatment expenses; and inability to draw on assistance programs to supplement or replace lost income. In addition, many of the decisions with regard to the primary caregiver were gendered. Typically, the mother is the one who terminated or reduced work hours, which affected the entire family's financial well-being. CONCLUSIONS: For families with children diagnosed with cancer, financial issues emerged as a significant concern at a time when these families were already consumed with other challenges. This economic burden can have long-term effects on the financial security, quality of life, and future well-being of the entire family, including the siblings of the affected child, but in particular the mother. Financial assistance programs for families of seriously ill children need to be revisited and expanded.

Guidelines 2000 for colon and rectal cancer surgery.

BACKGROUND: Oncologic resection techniques affect outcome for colon cancer and rectal cancer, but standardized guidelines have not been adopted. The National Cancer Institute sponsored a panel of experts to systematically review current literature and to draft guidelines that provide uniform definitions, principles, and practices. METHODS: Methods were similar to those described by the American Society of Clinical Oncology in developing practice guidelines. Experts representing oncology and surgery met to review current literature on oncologic resection techniques for level of evidence (I-V, where I is the best evidence and V is the least compelling) and grade of recommendation (A-D, where A is based on the best evidence and D is based on the weakest evidence). Initial guidelines were drafted, reviewed, and accepted by consensus. RESULTS: For the following seven factors, the level of evidence was II, III, or IV, and the findings were generally consistent (grade B): anatomic definition of colon versus rectum, tumor-node-metastasis staging, radial margins, adjuvant R0 stage, inadvertent rectal perforation, distal and proximal rectal margins, and en bloc resection of adherent tumors. For another seven factors, the level of evidence was II, III, or IV, but findings were inconsistent (grade C): laparoscopic colectomy; colon lymphadenectomy; level of proximal vessel ligation, mesorectal excision, and extended lateral pelvic lymph node dissection (all three for rectal cancer); no-touch technique; and bowel washout. For the other four factors, there was little or no systematic empirical evidence (grade D): abdominal exploration, oophorectomy, extent of colon resection, and total length of rectum resected. CONCLUSIONS: The panel reports surgical guidelines and definitions based on the best available evidence. The availability of more standardized information in the future should allow for more grade A recommendations.

Uroguanylin treatment suppresses polyp formation in the Apc(Min/+) mouse and induces apoptosis in human colon adenocarcinoma cells via cyclic GMP.

The enteric peptides, guanylin and uroguanylin, are local regulators of intestinal secretion by activation of receptor-guanylate cyclase (R-GC) signaling molecules that produce cyclic GMP (cGMP) and stimulate the cystic fibrosis transmembrane conductance regulator-dependent secretion of Cl- and HCO3-. Our experiments demonstrate that mRNA transcripts for guanylin and uroguanylin are markedly reduced in colon polyps and adenocarcinomas. In contrast, a specific uroguanylin-R-GC, R-GCC, is expressed in polyps and adenocarcinomas at levels comparable with normal colon mucosa. Activation of R-GCC by uroguanylin in vitro inhibits the proliferation of T84 colon cells and elicits profound apoptosis in human colon cancer cells, T84. Therefore, down-regulation of gene expression and loss of the peptides may interfere with renewal and/or removal of the epithelial cells resulting in the formation of polyps, which can progress to malignant cancers of the colon and rectum. Oral replacement therapy with human uroguanylin was used to evaluate its effects on the formation of intestinal polyps in the Min/+ mouse model for colorectal cancer. Uroguanylin significantly reduces the number of polyps found in the intestine of Min/+ mice by approximately 50% of control. Our findings suggest that uroguanylin and guanylin regulate the turnover of epithelial cells within the intestinal mucosa via activation of a cGMP signaling mechanism that elicits apoptosis of target enterocytes. The intestinal R-GC signaling molecules for guanylin regulatory peptides are promising targets for prevention and/or therapeutic treatment of intestinal polyps and cancers by oral administration of human uroguanylin.

Pacing the human stomach.

The aim of this study was to document the pattern of human gastric pacesetter potentials after abdominal operation and to determine whether the potentials could be paced by electrical stimuli. Ten patients undergoing cholecystectomy had temporary serosal electrodes positioned along the greater curvature of the stomach. Bipolar myoelectric recordings and attempts at electrical pacing were made after operation. On postoperative day 1, the pacesetter potentials had a regular frequency (3.2 +/- 0.1 cycles/min), and no gastric dysrhythmias were evident. The distal stomach of nine of ten patients could be entrained by pacing the proximal electrodes (forward pacing) to a maximal rate of 4.3 +/- 0.3 cycles/min (p less than 0.05 versus nonpacing) without a change in propagation velocity or direction. Backward pacing (maximum rate, 3.9 +/- 0.2 cycles/min) was possible in six patients. Forward pacing was successful by day 3 in only four of ten patients, and backward pacing was successful in none of ten patients. A meal given a median of 3.5 days after operation did not change the pacesetter potential frequency, rhythm, or direction of propagation, and three of ten patients had successful forward pacing after a meal. In conclusion, a regular pattern of gastric pacesetter potentials is present after cholecystectomy. The gastric pacesetter potentials can be paced with electrical stimuli, although refinements of the pacing electrodes or stimuli will be needed to achieve long-term pacing. Pacing holds promise as a potential treatment for gastric myoelectrical disorders.

The Roux stasis syndrome. Treatment by pacing and prevention by use of an 'uncut' Roux limb.

Ectopic pacemakers in the Roux limb are associated with delayed gastric emptying after Roux gastrectomy. The aim herein was to suppress the ectopic pacemakers by electrical pacing or to prevent them by maintaining enteric myoneural continuity with an "uncut" Roux limb, and so improve the delayed emptying. Among eight dogs with truncal vagotomy and Roux hemigastrectomy, four dogs had a pacing electrode applied to the proximal end of the Roux limb. The other four dogs had a gastrojejunostomy to an uncut Roux limb. In them, the afferent jejunal limb was occluded by staples but not divided, and a diverting jejuno-jejunostomy was performed. Roux pacing and the uncut Roux operation abolished ectopic pacemakers in the Roux limb and speeded the slow gastric emptying present in unpaced control tests. At autopsy, however, dehiscences were found in the staple line in the dogs with the uncut Roux procedures. In conclusion, electrical pacing and the uncut Roux limb show promise as techniques to prevent ectopic jejunal pacemakers and gastric stasis after Roux gastrectomy. Both must be improved before they can be used in patients.

Complications following pancreaticoduodenectomy. Current management.

From 1980 to 1989, 279 patients underwent pancreaticoduodenectomy at a single institution with a postoperative mortality of 4%. The aim of this study was to determine incidence, origin, and present management strategy of early complications following this operation. Significant morbidity occurred in 46% of the patients, including delayed gastric emptying (23%), pancreaticojejunal anastomotic leak (17%), intra-abdominal sepsis (10%), biliary-enteric anastomotic leak (9%), gastrointestinal tract bleeding (5%), and intra-abdominal hemorrhage (3%). Complications were associated with advanced age, prolonged operations, and increased operative blood loss. Most complications were managed nonoperatively. Mortality was increased when a reoperation was required, a biliary-enteric leak occurred, or an intra-abdominal abscess developed. Pancreaticoduodenectomy continues to carry a high postoperative morbidity; however, operative mortality is low, and management of complications has been made simpler with more sophisticated, nonoperative therapeutic options.

The Roux operation for postgastrectomy syndromes.

The aim of this paper is to describe the technique, indications, and results of the Roux operation as used in the treatment of postgastrectomy syndromes. A Roux gastrojejunostomy with a 40-cm Roux limb is the procedure of choice for alkaline reflux gastritis, because it virtually eliminates reflux of bile and pancreatic juice into the stomach. The slow transit through a Roux limb can also be used to good advantage to slow gastric emptying in patients with dumping. Patients with delayed gastric emptying respond to the combination of near-total gastric resection, which removes the atonic gastric remnant and speeds emptying, and Roux-Y gastrojejunostomy, which prevents reflux esophagitis and provides a reservoir for ingesta in the upper gut. After all Roux operations, however, the Roux limb may slow emptying so much that pain, fullness, nausea, and food vomiting result, the so-called Roux stasis syndrome. Prevention of the Roux stasis syndrome with an "uncut" Roux limb and the treatment of the syndrome by using electrical pacing to suppress the ectopic pacemakers that emerge in the limb offer possible new solutions to this vexing problem.

Electrical dysrhythmias in the Roux jejunal limb: cause and treatment.

Electrical dysrhythmias in the Roux limb after Roux gastrojejunostomy are associated with upper gut stasis of food. The aim of this study was to determine the cause of the dysrhythmias and whether they could be eliminated with pacing. A set of four dogs (Group A) underwent three sequential operations: placement of jejunal electrodes at sites corresponding to the Roux limb; construction of a Roux limb without vagotomy, gastrectomy, or gastrojejunostomy; and transthoracic truncal vagotomy. A second set of five dogs (Group B) underwent truncal vagotomy, distal gastrectomy, and Roux gastrojejunostomy with recording electrodes placed on the Roux limb and a pacing electrode situated at the proximal end of the limb. Electrical recordings were obtained on four separate occasions after each operation. In Group A dogs, orad and disordered propagation of jejunal pacesetter potentials occurred in the Roux limb 56 +/- 5% of the time after limb construction but never before construction. The pattern was not changed with vagotomy. In Group B dogs, electrical dysrhythmias in the Roux limb also occurred and were corrected with electrical pacing. We concluded that electrical dysrhythmias in the canine Roux limb are secondary to the jejunal transection done during Roux limb construction, and are not due to gastrectomy, gastroenterostomy, or vagotomy. The dysrhythmias can be corrected with pacing.

Proximal gastric vagotomy in the emergency treatment of bleeding duodenal ulcer.

Proximal gastric vagotomy for bleeding duodenal ulcer was performed in 52 low-risk patients between 1973 and 1986. Duodenotomy without violation of the pylorus was done in all patients to allow inspection and control of the bleeding site. The median duration of operation was 3 hours and 20 minutes, although 25% of the procedures required 4 or more hours. There was no postoperative mortality and no early reoperations. Among the six patients with postoperative complications, one rebled from the ulcer and two developed prolonged gastric atony. At the time of follow-up (median, 2.9 years), 48 of the patients were alive and 4 had died of non-ulcer causes. No patient had significant postvagotomy sequelae. Ulcer recurrence was documented in six patients, and three required reoperation. Proximal gastric vagotomy is a safe, effective therapy for bleeding duodenal ulcer. Because of the length of the operation, it should be restricted to low-risk patients who are hemodynamically stable at the time of operation.

Postgastrectomy syndromes.

Anatomic and physiological changes introduced by gastric surgery result in postgastrectomy syndromes in approximately 20% of patients. Most of these disorders are caused by operation-induced abnormalities in the motor functions of the stomach, including disturbances in the gastric reservoir function, the mechanical-digestive function, and the transporting function. Division of the vagal innervation to the stomach and ablation or bypass of the pylorus are the most significant factors contributing to postgastrectomy syndromes. Either rapid or slow emptying may result, depending on the relative importance of lack of a compliant gastric reservoir, loss of an effective contractile force, and loss of controlling factors that slow or speed gastric emptying and result in duodenal-gastric reflux. Clearly defining which syndrome is present in a given patient is critical to developing a rational treatment plan. In syndromes with slow gastric emptying, bilious vomiting, or alkaline reflux gastritis, the use of endoscopy is essential to rule out mechanical causes of the syndrome. Contrast radiography and scintigraphic gastric emptying studies are useful to document rapid or delayed gastric emptying. Postgastrectomy syndromes often abate with time. Conservative measures, including medical, dietary, and behavioral therapy, should be given at least a 1-year trial. If these nonoperative measures fail, surgical therapy is recommended. The Roux-en-Y gastrojejunostomy is useful for patients with dumping, because it slows gastric emptying and the transit of chyme through the Roux limb. The same operation helps patients with alkaline reflux gastritis, because it diverts pancreaticobiliary secretions away from the gastric remnant. Near-total gastrectomy, which reduces the size of a flaccid gastric reservoir, can be used to treat delayed gastric emptying. This operation should be combined with the Roux procedure to prevent postoperative reflux gastritis and esophagitis. Newer techniques, such as gastrointestinal pacing and the uncut Roux operation, may improve the treatment of the postgastrectomy syndromes in the future.

Acrometastases. A study of twenty-nine patients with osseous involvement of the hands and feet.

We studied the records of twenty-nine patients with forty-one metastatic lesions of the hand or foot. In five patients the lesions mimicked a benign condition, and inappropriate treatment was given. In eleven patients the acrometastases were the first indication of malignant disease, and four other patients had no known primary malignant lesion. Amputation of a phalanx, digit, or ray is recommended for most solitary phalangeal, metacarpal, or metatarsal lesions when the expected period of survival of the patient exceeds a few months.

Role of basement membrane collagen and elastin in the autofluorescence spectra of the colon.

BACKGROUND: Autofluoresence can be used to detect neoplasia in the colon. Two known fluorophores, collagen and elastin, are probably partly responsible for colonic emission spectra. Their contribution to colonic autofluorescence was investigated. METHODS: Autofluorescence spectra of normal, dysplastic, and malignant colonic tissue were studied by using excitation wavelengths from 280 nm to 350 nm. The wavelengths of peak emission and their widths at half maximum intensity were measured. Similar measurements were performed on collagen types I, III, IV, V, IX, and elastin. Colonic spectra were compared to those of collagen and elastin. Spectral differences between collagen types IV (basement membrane) I, III, V, and IX were studied. RESULTS: Four major emission peaks were noted whose wavelength of peak emission and full widths at half maximum intensity were independent of tissue histology. The emission spectra of type IV collagen differed markedly from that of nonbasement membrane collagens and elastin. CONCLUSIONS: Type IV (basement membrane) collagen is most likely responsible for the emission peak at 365 nm. The spectra of basement membrane collagen and not other types of collagen should be used in studies of epithelial tissue spectra. Elastin did not appear to be responsible for any of the four autofluorescence peaks observed in colonic tissue.

Emission spectra of colonic tissue and endogenous fluorophores.

Autofluorescence emission spectra of normal, adenomatous, and malignant tissues of the colon were compared to that of known fluorophores to indicate the possible causes of tissue fluorescence. Data were collected from normal mucosa (n = 18), adenomatous polyps (n = 32), and adenocarcinoma (n = 18) of the colon. A range of cellular and extracellular fluorophores (elastin, collagen, flavin adenine dinucleotide, nicotinamide adenine dinucleotide, phenylalanine, pyridoxal 5' phosphate, tryptophan, and tyrosine) were similarly examined using a spectrofluorometer with emission and excitation spectrometers. Emission intensities were plotted against wavelength. Wavelengths of peak emission and the width of each peak at half its maximum intensity were measured. Colonic tissue gave four major emission peaks, the wavelengths of which were independent of tissue histology. Tryptophan and collagen type IV appeared to be responsible for two of the peaks. It is possible that NADH may be the cause of a third emission maxima.