Healing the Professional Culture of Medicine

The past decade has been a time of great change for US physicians. Many physicians feel that the care delivery system has become a barrier to providing high-quality care rather than facilitating it. Although physician distress and some of the contributing factors are now widely recognized, much of the distress physicians are experiencing is related to insidious issues affecting the cultures of our profession, our health care organizations, and the health care delivery system. Culture refers to the shared and fundamental beliefs of a group that are so widely accepted that they are implicit and often no longer recognized. When challenges with culture arise, they almost always relate to a problem with a subcomponent of the culture even as the larger culture does many things well. In this perspective, we consider the role of culture in many of the problems facing our health care delivery system and contributing to the high prevalence of professional burnout plaguing US physicians. A framework, drawn from the field of organizational science, to address these issues and heal our professional culture is considered.

Aciculin interacts with filamin C and Xin and is essential for myofibril assembly, remodeling and maintenance

Filamin C (FLNc) and Xin actin-binding repeat-containing proteins (XIRPs) are multi-adaptor proteins that are mainly expressed in cardiac and skeletal muscles and which play important roles in the assembly and repair of myofibrils and their attachment to the membrane. We identified the dystrophin-binding protein aciculin (also known as phosphoglucomutase-like protein 5, PGM5) as a new interaction partner of FLNc and Xin. All three proteins colocalized at intercalated discs of cardiac muscle and myotendinous junctions of skeletal muscle, whereas FLNc and aciculin also colocalized in mature Z-discs. Bimolecular fluorescence complementation experiments in developing cultured mammalian skeletal muscle cells demonstrated that Xin and aciculin also interact in FLNc-containing immature myofibrils and areas of myofibrillar remodeling and repair induced by electrical pulse stimulation (EPS). Fluorescence recovery after photobleaching (FRAP) experiments showed that aciculin is a highly dynamic and mobile protein. Aciculin knockdown in myotubes led to failure in myofibril assembly, alignment and membrane attachment, and a massive reduction in myofibril number. A highly similar phenotype was found upon depletion of aciculin in zebrafish embryos. Our results point to a thus far unappreciated, but essential, function of aciculin in myofibril formation, maintenance and remodeling.

Phase II study of trimetrexate, fluorouracil, and leucovorin for advanced colorectal cancer

PURPOSE

A phase II study to evaluate the response rate and toxicities of a trimetrexate, fluorouracil (5FU), and leucovorin regimen in patients with advanced incurable colorectal cancer.

PATIENTS AND METHODS

Thirty-six patients with unresectable or metastatic colorectal cancer who had not been treated for advanced disease received the following chemotherapy regimen weekly for six courses every 8 weeks: trimetrexate 110 mg/m2 intravenously (I.V.) on day 1, leucovorin 200 mg/m2 I.V. on day 2 (24 hours later), 5FU 500 mg/m2 on day 2 immediately following leucovorin, and oral leucovorin 15 mg every 6 hours for seven doses starting 6 hours after 5FU. Patients were treated until progression or unacceptable toxicity.

RESULTS

Thirty patients were assessable for response, and all 36 were assessable for toxicity. Two patients (7%) achieved a complete response (CR) and 13 (43%) a partial response (PR), for an overall response (OR) rate of 50% (95% confidence interval [CI], 32% to 68%). Analysis by intent to treat demonstrated a 42% OR rate (95% CI, 26% to 58%). At final analysis, 16 patients were alive. The median survival duration for the entire cohort was 53.4 weeks. Gastrointestinal toxicity was most common, with 21 patients (58%) having grade 3/4 diarrhea and 12 patients (34%) grade 3/4 nausea. Hematologic toxicity was generally low grade, although two patients died of sepsis.

CONCLUSION

The combination of trimetrexate with 5FU and leucovorin is active in metastatic colorectal cancer. Gastrointestinal toxicity with this regimen is most prominent, but is manageable.

Preclinical evaluation of WR-151327: an orally active chemotherapy protector

Clinical trials are in progress to evaluate radio- and chemoprotection by the aminothiol 2-[(3-aminopropyl)amino]ethanethiol-dihydrogen phosphate ester (WR-2721; amifostine). Phase II and III clinical studies have demonstrated that i.v. administered WR-2721 protects against the toxicities of cis-diamminedichloroplatinum (II) and cyclophosphamide. In preclinical murine studies, we have now further characterized the chemoprotective properties of WR-2721, and have evaluated the protective ability of the related aminothiol S-3-(3-methylaminopropylamino)propylphosphorothioic acid (WR-151327) following p.o. administration. The P388 leukemia (i.p. tumor-i.p. cytotoxic drug on Day 1 after tumor) was used to determine antitumor efficacy. Single dose pretreatment with i.p. WR-2721 protects normal mouse tissues against the chemotoxicities of mitomycin C, cis-diammine(cyclobutanedicarboxylato)platinum (II), and doxorubicin. Bone marrow suppression and cytotoxic drug-induced lethality were reduced, without compromising P388 antitumor activity. Pretreatment with a single p.o. dose of WR-151327 was as effective as i.p. WR-2721 in protecting against the myelotoxicity and lethality of mitomycin C, cis-diamminedichloroplatinum (II), and cis-diammine(cyclobutanedicarboxylato)platinum (II), while P388 antitumor activity was maintained. These data support the clinical development of WR-151327 as a p.o. administered chemotherapy protector.

Randomized clinical trial of mitomycin-C with or without pretreatment with WR-2721 in patients with advanced colorectal cancer

The use of mitomycin for metastatic colorectal cancer has been limited by mitomycin's myelosuppressive potential. The objective of this randomized study was to determine whether WR-2721 would decrease the hematologic toxicity of mitomycin in patients with colorectal cancer resistant to fluorouracil-based therapy. Ninety-seven patients with refractory colorectal cancer were randomized to receive either mitomycin 20 mg/m2 only or the same dose of mitomycin after pretreatment with WR-2721, 910 mg/m2. The principal toxicity in both groups was thrombocytopenia. The platelet nadirs were lower in patients receiving single-agent mitomycin (P = 0.026). Surprisingly, no clinical complete or partial responses were noted in either group, and survival was not different between the two groups. Thus, while WR-2721 decreased the thrombocytopenia associated with mitomycin therapy, mitomycin was ineffective in the treatment of refractory colorectal carcinoma.

Analysis of prognostic factors and survival in patients with ovarian cancer treated with second-line hexamethylmelamine (altretamine)

Hexamethylmelamine (altretamine, HMM) 260 mg/m2/day p.o. for 14 days followed by a 14-day drug-free interval was administered to 52 outpatients with advanced ovarian cancer who had previously been treated with chemotherapy. Prior to HMM, 92% (48/52) of these patients had received cisplatin and cyclophosphamide with or without doxorubicin. Two more patients received other cisplatin-based regimens. At the completion of HMM therapy, 15% (8/52) displayed no evidence of disease (NED). Of these eight patients, five are still alive 32 to 82 months after altretamine therapy (median follow-up of 46 months). At 41 months, one patient died of intercurrent illness with no clinical evidence of recurrence; the other two patients died of their disease at 21 and 31 months following HMM therapy. The median survival of the total group was 11 months: nine months for patients who did not respond to altretamine and 46+ months for patients with NED after altretamine (p less than 0.05). Intermittent oral administration of single-agent altretamine was well tolerated: eight patients reported moderate gastrointestinal symptoms, and only one patient reported severe gastrointestinal symptoms. Moderate neurologic toxicity was reported by five patients. No WBC fell below 2000 mm3 and platelet counts fell below 100,000 mm3 in only three patients; no patient experienced severe hematologic toxicity. In this series of patients, the overall response (15%) was comparable to or better than those reported for more toxic chemotherapeutic regimens. On the basis of these data and those reported by other investigators, HMM warrants consideration as a reasonable option in the management of recurrent or persistent ovarian cancer.

Hexamethylmelamine as a single second-line agent in ovarian cancer

Fifty-two patients with advanced ovarian cancer were treated with single-agent hexamethylmelamine (HMM), 260 mg/m2 po per day for 14 days followed by 14 days off drug. All patients had been previously treated with chemotherapy. Of these patients, 92% (48/52) received cisplatin and cyclophosphamide +/- doxorubicin prior to hexamethylmelamine. Two additional patients received other cisplatin-based regimens. Fifteen percent (8/52) were found to have no evidence of disease (NED) at the completion of treatment with HMM. Five of these patients are alive at 12 to 65 months (median follow-up of 32 months); one patient died at 41 months of an intercurrent illness with no clinical evidence of recurrence; two patients died of recurrent tumor at 21 and 31 months. The median survival of the series of 52 patients is 11 months: 9 months for patients who did not respond versus 41 months for patients with NED post-HMM (P less than 0.05). The regimen was well tolerated: moderate gastrointestinal toxicity was reported by 8 patients; only one patient reported severe gastrointestinal toxicity. Moderate neurologic toxicity (primarily sensory) was reported by 5 patients, 3 patients experienced white counts less than 2000 or platelet counts less than 100,000, and no patient sustained severe hematologic toxicity. This moderate-dose intermittent regimen was associated with moderate toxicity and was well accepted by patients. The overall response is comparable to or higher than that reported for more toxic chemotherapy regimes. Based on these data and those recently reported by other authors, hexamethylmelamine should be considered in the treatment of recurrent ovarian cancer.

Phase II study of daunorubicin in previously untreated patients with advanced colorectal carcinoma

Fourteen patients with advanced measurable colorectal cancer were treated with daunorubicin hydrochloride (DNR). The drug was administered at a dose of 15 mg/m2 on day 1 through 3 and 8 through 10. After a 4-day rest period DNR was given in weekly injections of 15 mg/m2. There were no partial or complete responses. This study failed to confirm the previously reported therapeutic activity of this agent in colorectal carcinoma, using an identical dose and schedule. We have initiated a phase 1 study of daunorubicin to identify a maximum tolerated dose using an every 3-week schedule for future phase II trials in solid tumors.

Comparison of the experimental antitumor activities of three nitrosourea derivatives chlorozotocin, RFCNU and CNCC encapsulated in liposomes with those in the free state

L1210 leukemia was used to compare the antitumor activities of three nitrosoureas (chlorozotocin, RFCNU and CNCC) encapsulated in liposomes with those in the free state. The results obtained varied according to the chemical structure of the compound, its solubility in oil or water, the route of administration into the body, and the treatment dose. The application of liposomes in the chemotherapy of malignant disease deserves further investigations.

Cellular and molecular mechanisms of the bone marrow sparing effects of the glucose chloroethylnitrosourea chlorozotocin

1,(2-Chloroethyl)-3-cyclohexyl-1-nitrosourea (CCNU) and other chloroethylnitrosourea anticancer agents in clinical use produce severe and cumulative bone marrow toxicity. Chlorozotocin, a glucose analogue, has demonstrated reduced hematologic toxicity while retaining full antitumor activity. The biochemical-pharmacologic properties of chlorozotocin and CCNU were compared in human bone marrow. After a 2-hr incubation with a 0.1-mM drug concentration, total cellular uptake of chlorozotocin in whole marrow was 2.47 +/- 0.80 pmole/10(4) cells and was not significantly different compared to the uptake of 1.94 +/- 0.53 pmole/10(4) cells with CCNU. The quantitative alkylation of bone marrow DNA by chlorozotocin, 22.8 +/- 1.2 pmole/mg DNA, was equivalent to that produced by CCNU, 22.9 +/- 0.5 pmole/mg DNA. Bone marrow was separated into 14 fractions by centrifugal elutriation. CCNU uptake was found to be greater than that of chlorozotocin in 3 fractions that were primarily composed of lymphocytes, monocytes, and normoblasts. Chlorozotocin uptake was greater than CCNU in 6 fractions that contained primarily mature and immature myeloid cells as well as the highest CFU-GM activity. The two drugs produced a comparable degree of DNA strand breakage and DNA-protein cross-linking as measured by alkaline elution of pooled fractions of elutriated bone marrow. DNA interstrand crosslinking was not found with either drug. The most significant finding of this study is the differences in the site of drug alkylation by chlorozotocin and CCNU in bone marrow chromatin. Endonuclease digestions with MCN, DNase I, and DNase II showed nonrandom alkylation of specific regions of chromatin by the two drugs: CCNU demonstrated a preferential binding to the transcriptionally active regions of chromatin, whereas chlorozotocin predominantly alkylated the transcriptionally inactive regions. These data suggest that the lethal damage of nitrosourea alkylation in human bone marrow is principally expressed in transcriptionally active regions of chromatin.

Phase-II study of cis-diammine-dichloro platinum (cis-platinum), bleomycin and methotrexate for advanced squamous cell carcinoma of head and neck

Twenty-one patients with head and neck carcinomas relapsing after radiotherapy were treated with a combination of cis-platinum, bleomycin, and methotrexate. Four patients (19%) achieved a partial response. Toxicity was significant in selected cases; three patients developed WBC counts less than 1,000/mm3 and one of these patients died with sepsis. Severe mucositis was present in three of the twenty-one patients. Considering the toxicity of this combination and the limited therapeutic activity with the dose and schedule used in this study, this regimen is not recommended for the treatment of squamous head and neck carcinomas relapsing after radiotherapy.

CEA monitoring among patients in multi-institutional adjuvant G.I. therapy protocols

The Gastrointestinal Tumor Study Group (GITSG) has since 1975 included protocols for monitoring carcinoembryonic antigen (CEA) levels in its colorectal cancer adjuvant trials. Among the 563 patients on the colon cancer study (GI 6175) and the 207 patients on the rectal cancer study (GI 7175), one third had preoperative CEA determinations and more than 90% had some postoperative CEA monitoring. Colon cancer patients whose preoperative CEA was greater than 5 ng/ml had a greater probability of recurring than those whose values were lower (33% versus 18% recurrence with 21 months minimum follow-up; p < 0.05). The prognostic value of preoperative CEA was apparent only in patients with Dukes' C1 colon tumors. Preoperative CEA values were not of prognostic significance among the rectal adenocarcinoma patients. Although elevated levels of CEA after resection of either colon or rectum cancers were strongly associated with subsequent tumor recurrence, no single CEA value, arbitrarily defined as "elevated", provided an adequate screening test with both high sensitivity and high specificity. Postoperative CEA elevations were more strongly predictive of recurrence when part of a steadily rising trend. In the colon cancer study, the median monthly increase in CEA for disease-free patients was estimated to be zero, and for the relapsed patients 5.8%. The corresponding estimates for patients on the rectal cancer protocol were zero and 7.8%. Only 36 of the 344 disease-free patients on the colon protocol and 14 of the 94 disease-free patients on the rectal protocol (15%) exhibited a rate of increase of CEA as high as 3% per month over the entire period of observation. Two thirds of the relapsed patients on both studies showed a rate of increase this high or higher. The patterns of CEA rise in individual patients were quite varied, however, and monthly rates of increase as established in our study are not to be used as guidelines in patient management.

Unexplained increase in serum creatine kinase isoenzyme MB activity in a lung cancer patient

In this case of mixed small cell--large cell cancer of the lung in an elderly woman, creatine kinase (EC 2.7.3.2) isoenzymes were assayed serially because of chest pain. The proportions of serum CK-BB and CK-MB isoenzyme activities were persistently above normal (CK-MB 10-18%, normal less than 5%). Electrocardiograms revealed no signs of ischemia or infarction. At autopsy no gross or microscopic infarction or inflammation of the heart was seen. There was also no infarction of smooth or skeletal muscle. The tumor was the probable source of most of the circulating CK-MB isoenzyme. Future cases may pose a similar diagnostic dilemma: differentiating creatine kinase that is present as a result of myocardial infarction from tumor-related CK-MB. Whether or not CK-MB assay could be useful in detecting tumors remains to be investigated.

Prognostic factors in Burkitt's lymphoma: importance of total tumor burden

In 42 patients with African Burkitt's lymphoma, we have studied biochemical and clinical correlations with prognosis. Clinical stage and anti-EA titer were the best predictive factors, but lactic dehydrogenase (LDH) and uric acid (UA) concentrations also correlated with stage and prognosis, whereas lactic acid (LA), which was significantly elevated in Stage D, did not significantly correlated with prognosis or with LDH and UA levels. All of these factors with the possible exception of LA reflect the total body burden of tumor. We conclude that the tumor burden is the single most important prognostic factor in Burkitt's lymphoma, and that this is reflected directly by LDH and UA concentrations, and probably indirectly by anti-EA titer.

Prediction of clinical response to 5-fluorouracil-containing chemotherapy: preliminary results of in vitro assay in human breast cancer

An in vitro assay system measuring the production of phosphorylated nucleotide products of 5-FU by human tumor cytosols is described. Samples from 11 patients with breast cancer treated with 5-FU-containing chemotherapy regimens were assayed. Significant differences were seen in quantitative and qualitative patterns of phosphorylation between samples from chemotherapy responding and nonresponding patients. The rate of 5-fluorodeoxyuridylate production and the amount of nucleotide triphosphate produced were significantly P < 0.05 increased in chemotherapy-responding patients. This in vitro assay system is a simple, reproducible procedure that requires further evaluation as a potential system for prospectively predicting clinical response to fluorinated pyrimidines.

Immunological and plasma protein changes in cancer patients following a single plasmapheresis

Serial serum protein determinations and immunological monitoring were performed prior to and following a single 4 to 5 liter plasma exchange in 10 patients with disseminated cancer. The most consistent changes were observed for two initially elevated alpha globulins, acid glycoprotein and haptoglobin, which declined rapidly in all patients 1 hour after plasmapheresis and began to rise again as early as 24 hours post-plasmapheresis to reach initial levels by 72 hours. Among the immunological parameters T and B cell counts, and phytohemaglutinin-induced lymphocyte transformation showed little change. In 4 out of 10 patients C3 levels dropped at 1 hour post-plasmapheresis and continued to decline to 24 hours, suggesting that consumption of C3 possibly by macrophages may have occurred. In view of our earlier reports that repeated plasmapheresis induced partial tumor regressions in patients with disseminated cancer and that these regressions may have been related to depletion of immunosuppressive serum proteins, it is suggested that to maintain levels of these rapidly renewed proteins at a minimum for as long as possible, it is most appropriate to perform plasmapheresis every 48 hours rather than every 72 or 96 hours as was the case in the earlier study.

Phase I studies on chlorozotocin

A phase I investigation of chlorozotocin, a new-water soluble chloroethylnitrosourea, was undertaken to define its pharmacologic effects in man. Forty-three patients received single intravenous doses ranging from 5 to 175 mg/m2 every 6 wk. No signs of toxicity were observed at doses of under 120 mg/m2, but thrombocytopenia occurred at higher doses. The thrombocytopenic nadir appeared to be dose-dependent and occurred 4 wk after treatment. Platelet transfusions were required in 2 patients who had previously received intensive chemotherapy. No significant leukopenia occurred. A mild reversible and delayed elevation of hepatic transaminases was found in 25% of courses of 120 mg/m2 or more. No renal toxicity was observed and gastrointestinal toxicity was mild. Investigation of clinical pharmacology revealed a rapid triphasic plasma clearance with initial t1/2S of 3, 15, and 30 min. The concentration of N-nitroso intact drug at 1 hr was 10% of the initial peak level. Renal excretion accounted for half of the dose. No significant concentration of N-nitroso intact or radiolabeled drug was detected in the cerebrospinal fluid of 2 patients in whom it was examined. There were objective signs of therapeutic activity in 5 patients, 3 of whom had melanoma. Based on these studies, the recommended dose for phase II investigation of chlorozotocin is 120 mg/m2 every 6 wk.

Fanconi syndrome associated with cephalothin and gentamicin therapy

A case is reported of Fanconi syndrome and nonliquric renal failure, following a brief course of cephalothin and gentamicin, in a patient with diffuse histiocytic lymphoma. These drugs, especially when used in combination, have been associated with nephrotoxicity manifested as acute tubular necrosis and altered proximal tubular function, but biochemical evidence for generalized proximal tubular dysfunction has not been accurately defined. Thus far, only two other antibiotics, degraded tetracycline and streptozotocin, have been implicated in producing an acquired Fanconi syndrome.

A putative role for nicotinamide adenine dinucleotide-promoted nuclear protein modification in the antitumor activity of N-methyl-N-nitrosourea

Incubation of HeLa cells with the anticancer agent N-methyl-N-nitrosourea (MNU) results in: (a) depression of intracellular nicotinamide adenine dinucleotide levels; (b) stimulation of the chromatin-associated, chromosomal protein-modifying enzyme polyadenosine diphosphoribose [poly(ADP-ribose)] polymerase, which uses nicotinamide adenine dinucleotide as substrate; and (c) some fragmentation of cellular DNA. DNase treatment of HeLa nuclei in vitro also stimulates poly(ADP-ribose) polymerase activity, but not in nuclei derived from MNU-treated cells unless they have been subsequently incubated to allow for recovery from MNU damage. DNA polymerase activity is stimulated in vitro by poly(ADP) ribosylation of nuclear proteins. By using intact nuclei derived from MNU-treated HeLa cells, the repair via elongation of single-strand DNA breaks is demonstrated in vitro. This repair is dependent on DNA polymerase activity and is enhanced by adenosine diphosphate ribosylation of histones. Inhibition of poly(ADP-ribose) polymerase with nicotinamide results in extensive degradation of MNU-damaged DNA. Taken as a whole, these results suggest that poly(ADP-ribose) polymerase may play a role in the repair of alkylation damage to cellular DNA and that the inhibition of this enzyme in vivo might be exploited to potentiate the antitumor and carcinogenic activities of MNU.

Cutaneous T-cell lymphomas: the Sézary syndrome, mycosis fungoides, and related disorders

Substantial evidence has accumulated to indicate not only that mycosis fungoides and the Sézary syndrome are closely related malignancies, but to suggest that they are part of a larger spectrum of cutaneous lymphomas. The neoplastic cells of these disorders have membrane features of thymus-derived (T) lymphocytes, a characteristic tissue distribution (skin infiltration, marrow sparing, localization in T-cell regions of lymphoid tissue), and distinctive morphology. For these reasons, we suggest that these lymphoproliferative disorders be grouped together as "cutaneous T-cell lymphomas". The anergy noted in patients of this group with leukemia probably is related to both decreased percentages of normal T cells and presence in the serum of macrophage migration inhibitory activity. Leukapheresis has been particularly effective in the management of selected patients. The homogeneous T-cell populations in the patients with leukemia also provide important opportunities to study many aspects of lymphocyte physiology that are of broad biologic significance.

Advanced diffuse histiocytic lymphoma, a potentially curable disease

Twenty-seven patients with advanced diffuse histiocytic lymphoma (reticulum-cell sarcoma) were treated with combination chemotherapy utilising nitrogen mustard (or cyclophosphamide), procarbazine, vincristine, and prednisone. Elven (41%) achieved a complete remission and only one of these has had a recurrence of tumour. The remaining ten complete responders were free of all evidence of tumour when last seen 26-105 months from the end of treatment. In contrast, all non-responders or partial responders have died. An interpretation of published survival data suggests that this virulent disease evolves quickly and is usally rapidly fatal if treatment is unsuccessful. Survival free of disease beyond 2 years from the end of treatment may be considered tantamount to cure. This definition of cure, previously applied only to patients treated with radiotherapy, seems applicable to patients who acheive complete remissions with modern drug treatment.