Ethical guideposts to clinical trials in oncology

Clinical research with human subjects is an ethically challenging task requiring ultimate trust on the part of patients and ultimate respect for persons on the part of clinical researchers. The author provides a simple framework to help researchers ensure the ethical integrity of a clinical trial in oncology.

Pelvic growth: Ontogeny of size and shape sexual dimorphism in rat pelves

The mammalian pelvis is sexually dimorphic with respect to both size and shape. Yet little is known about the differences in postnatal growth and bone remodeling that generate adult sexual dimorphism in pelvic bones. We used Sprague-Dawley laboratory rats (Rattus norvegicus), a species that exhibits gross pelvic size and shape dimorphism, as a model to quantify pelvic morphology throughout ontogeny. We employed landmark-based geometric morphometrics methodology on digitized landmarks from radiographs to test for sexual dimorphism in size and shape, and to examine differences in the rates, magnitudes, and directional patterns of shape change during growth. On the basis of statistical significance testing, the sexes became different with respect to pelvic shape by 36 days of age, earlier than the onset of size dimorphism (45 days), although visible shape differences were observed as early as at 22 days. Males achieved larger pelvic sizes by growing faster throughout ontogeny. However, the rates of shape change in the pelvis were greater in females for nearly all time intervals scrutinized. We found that trajectories of shape change were parallel in the two sexes until age of 45 days, suggesting that both sexes underwent similar bone remodeling until puberty. After 45 days, but before reproductive maturity, shape change trajectories diverged because of specific changes in the female pelvic shape, possibly due to the influence of estrogens. Pattern of male pelvic bone remodeling remained the same throughout ontogeny, suggesting that androgen effects on male pelvic morphology were constant and did not contribute to specific shape changes at puberty. These results could be used to direct additional research on the mechanisms that generate skeletal dimorphisms at different levels of biological organization.

The detection of an unidentified type of adenovirus in the stools of calves with weak calf syndrome by use of a commercial kit designed for the detection of human adenoviruses

An outbreak of polyarthritis in newborn calves in a large collective dairy herd was characterized by intra‐articular blood‐tinged synoviae, blood tainted faeces and massive subcorneal haemorrhages. Faecal samples from eight clinical newborn cases, 10 from unrelated dairy farms and 10 faecal samples from healthy calves were examined by the Rida^® Quick rotavirus/adenovirus‐combi test . A specific adenovirus antigen precipitin‐line was seen in the reaction in all the faecal samples from the diseased calves (n = 8), while all the others (n = 20) were negative. In addition, the same positive reaction was noted when one aqueous humor and two synovial samples were tested with this kit. Several other enteropathogens were found sporadically, but no conclusive significance could be attributed to their presence. Bovine viral diarrhoea and infectious bovine rhinothracheitis viruses as well as Chlamydia spp. and Mycoplasma spp. were not involved in this episode.

Results of an unrelated transplant search strategy using partially HLA-mismatched cord blood as an immediate alternative to HLA-matched bone marrow

Cord blood (CB) is an alternative to other sources of stem cells for transplantation. However, the impact of including CB in the initial strategy of unrelated graft search in a cohort of patients has been the object of limited analysis. Here, we report the results of such a strategy in 91 consecutive children. Absence of mismatch was required for adult donors, and up to two mismatches were allowed for CB grafts, with a nucleated cell dose over 2.5 x 10(7) cells/kg. A graft was found for 84 of the 85 children who remained available for a 3-month search. In all, 64 patients were transplanted, 36 with CB and 28 with bone marrow (BM). Primary graft failure, acute grade II-IV and extensive chronic graft-versus-host disease occurred in five, five and zero CB, and in three, one and two BM patients, respectively. The 3-year survival was 59% in CB and 57% in BM patients. Accepting CB as a source of stem cells offers a graft to almost every child in need of an unrelated transplantation, with a probability of survival similar to that of unrelated BM transplantation.

Kinesin-like proteins in the flagella of Chlamydomonas

The flagella of the biflagellate unicellular alga Chlamydomonas have long been known to contain the microtubule-dependent motor protein dynein, but recent findings indicate they also contain multiple members of the kinesin superfamily. Two of these kinesin-like proteins are restricted to a single central-pair microtubule, raising the question of how proteins are targeted to specific microtubules within the flagellum. The kinesin-like proteins on the central-pair microtubules may cause the central-pair apparatus to rotate or twist during flagellar beating. Other kinesins within the flagellum may participate in movements associated with the flagellar membrane.

Are there reliable predictors of postoperative pain?

BACKGROUND

The purpose of this study was to identify the preoperative determinants of severe postoperative pain.

METHODS

Potential predictors were assessed using a questionnaire submitted on the day before surgery. Pain at rest, and pain during coughing/mobilization, were measured using visual analog scales on the day of surgery and on the following 2 days. The type of postoperative pain management was not standardized and was prescribed by the anesthesiologist in charge. Multivariate logistic regression models explaining postoperative pain were developed in Group I, comprising 304 consecutive patients undergoing orthopedic or intraperitoneal surgery, and validated in Group II, comprising 145 independent patients.

RESULTS

Of the 62 variables examined by univariate analysis, only five were found to increase the risk of severe postoperative pain in Group I at rest and six factors during cough/mobilization. In the multivariate model for pain at rest, general anesthesia, expectation of postoperative pain, and chronic sleeping difficulties increased the risk of severe postoperative pain. In Group II, only chronic sleeping difficulties remained (OR: 3.97, 95% Cl: 1.69-9.29). In the multivariate model during cough/mobilization, intraperitoneal surgery, fear of postoperative pain, and having a relative with a history of pain increased the risk of severe postoperative pain in Group I. Intraperitoneal surgery OR 2.45 (95% Cl = 1.01-4.50) and having a relative with a history of pain OR 2.06 (95% Cl = 1.005-4.50) remained in Group II.

CONCLUSION

Of the many factors that may influence postoperative pain, chronic sleeping difficulties emerge in this population of patients as the strongest determinant of pain at rest. Intraperitoneal surgery and having a relative with a history of pain are the strongest determinants of pain during cough/mobilization. These findings make physiological sense and deserve more attention by anesthesiologists.

Access to intensive care unit beds for neurosurgery patients: a qualitative case study

OBJECTIVES

The purpose of this study was to describe the process used to decide which patients are admitted to the intensive care unit (ICU) at a hospital with special focus on access for neurosurgery patients, and evaluate it using "accountability for reasonableness".

METHODS

Qualitative case study methodology was used. Data were collected from documents, interviews with key informants, and observations. The data were subjected to thematic analysis and evaluated using the four conditions of "accountability for reasonableness" (relevance, publicity, appeals, enforcement) to identify good practices and opportunities for improvement.

RESULTS

ICU admissions were based on the referring physician's assessment of the medical need of the patient for an ICU bed. Non-medical criteria (for example, family wishes) also influenced admission decisions. Although there was an ICU bed allocation policy, patient need always superceded the bed allocation policy. ICU admission guidelines were not used. Admission decisions and reasons were disseminated to the ICU charge nurse, the bed coordinator, the ICU resident, the intensivist, and the requesting physician/surgeon by word of mouth and by written documentation in the patient's chart, but not to the patient or family. Appeals occurred informally, through negotiations between clinicians. Enforcement of relevance, publicity, and appeals was felt to be either non-existent or deficient.

CONCLUSIONS

Conducting a case study of priority setting decisions for patients requiring ICU beds, with a special focus on neurosurgical patients, and applying the ethical framework "accountability for reasonableness" can help critical care units improve the fairness of their priority setting.

Improving patient safety: just do it!

Clinicians must celebrate and study medical errors. The dark culture of blame must be replaced by a scholarly culture of safety. This commentary presents six cases that show what we can learn from errors. The first step to identifying and understanding patient safety problems is to develop a common language for discussing patient safety. Latent unsafe conditions are ongoing circumstances of daily practice that reduce the safety of patients. An error is the failure ofa planned action to be completed as intended (error of execution), or the use of a wrong plan to achieve an aim (error of planning). Errors can be intercepted by appropriate action that minimizes the threat to patient safety. An adverse event is any unintended result of medical treatment that results in prolonged hospital stay, morbidity or mortality. If an adverse event is caused by an error, or series of errors, then it is a preventable adverse event. The teaching hospital is the first place where students (physicians, nurses, pharmacists and all other disciplines) are exposed to the culture of healthcare. It is essential to expose students to a culture of safety early in their training. Clinicians can make safety an academically important activity. Clinicians will find it difficult to undertake major safety initiatives given the existing constraints on time and energy. Although clinicians can identify the safety problems,there must also be a commitment to understand safety problems and make improvements. It is strongly recommended that hospitals train, implement and support Patient Safety Consultation Teams.

Surgical teaching: how should neurosurgeons handle the conflict of duty to today's patients with the duty to tomorrow's?

The author examines the problem of tension in neurosurgical teaching between the duty to train residents by providing various levels of unsupervised surgery and the duty to patient care. The duty to train the residents also translates into ensuring the provision of good care for patients of tomorrow by producing competent surgeons. The author contends that both duties can be fulfilled simultaneously, but the surgical tension inherent in this situation must not be ignored or taken for granted.

Distribution of therapeutic response in asthma control between oral montelukast and inhaled beclomethasone

The distribution of responses in study populations provides a novel method of comparing the benefit of two treatments. This 6-week, randomised, placebo-controlled, double-blind study compared the effectiveness of oral montelukast with inhaled beclomethasone in chronic asthma by assessing the distribution and overlap of patient responses to therapy, as measured by a clinical outcome (asthma control days). A total of 730 adult patients with asthma, age 15-65 yrs, with a forced expiratory volume in one second (FEV1) at baseline of 50-85% of predicted and > or = 15% improvement in FEV1 after inhaled beta-agonist were enrolled. After a 2-week placebo run-in period, patients were randomly allocated to receive montelukast (10 mg once daily), inhaled beclomethasone (200 microg twice daily) or placebo. The primary end-point (per cent of asthma control days) was compared between treatments as the overlap in the response distributions. The overlap of the distribution of responses between the montelukast and beclomethasone groups was 89% for per cent asthma control days and 96% for change from baseline in FEV1. The mean (+/-SD) per cent asthma control days in the montelukast and beclomethasone groups was significantly higher than that in the placebo group (placebo 40.0+/-35.8, montelukast 50.7+/-37.1, beclomethasone 57.9+/-36.1). The mean differences between montelukast and placebo, beclomethasone and placebo, and montelukast and beclomethasone were significant. The mean per cent change (+/-SD) from baseline in FEV1 was 12.1+/-18.7 and 13.9+/-20.8 in the montelukast and beclomethasone groups, respectively, and significantly greater than that in the placebo group (6.4+/-20.1); there was no significant difference between the montelukast and beclomethasone groups in mean values or response distribution. There was also no difference among treatment groups in the frequency of adverse experiences. A comparison of the response distribution is an important approach to comparing therapies; montelukast and beclomethasone provided similar response distributions for the end-point of per cent asthma control days over a 6-week treatment period.

Influence of occupational exposure to latex on the prevalence of sensitization and allergy to latex in a Swiss hospital

BACKGROUND

Replacement of powdered latex gloves has been recommended in order to prevent the development of latex allergy in health care workers. The conclusion that occupational exposure to latex gloves represents a risk factor for latex allergy is mainly based on studies without exposure controls. Atopy is also thought to be a risk factor for the development of latex allergy.

OBJECTIVE

To determine the prevalence of atopy, sensitization to latex, and symptoms following latex exposure in professionally exposed and nonexposed hospital personnel by means of a cross-sectional study.

METHODS

Six hundred randomly sampled individuals working in medicine and surgery departments and in surgery theaters and 300 sex- and age-matched individuals classified as administrative personnel were selected from the employee data base of the Geneva University Hospital. A questionnaire about exposure to latex and symptoms following this exposure was sent to all individuals. Skin prick test reactions and serum IgE to latex as well as standard environmental allergens were determined in both groups.

RESULTS

Respiratory and skin (local) symptoms but not objective tests of latex sensitization (positive skin prick test and specific IgE to latex) were significantly associated with occupational exposure to latex (p < 0.001). Only among atopics subjects was 15 years or more of occupational exposure associated with a significantly higher prevalence of local symptoms than among those who were exposed from 1 to 9 years (odds ratio: 3.2; 95% confidence interval: 1.6-6.5). Atopy was significantly associated with sensitization to latex (odds ratio: 10.3; 95% confidence interval: 4.0-26.6) but not with local symptoms. Tests of latex sensitization were both frequently positive, less frequently negative, resulting in low kappa values.

CONCLUSION

These results support the current preventive health care recommendation to replace powdered latex gloves. In atopics, increasing years of occupational exposure increase the risk of developing latex allergy. In contrast to questionnaires about local symptoms, skin prick tests and specific serum IgE to latex are of limited value in epidemiologic studies of latex allergy.

In vivo analysis of mammary and non-mammary tumorigenesis in MMTV-cyclin D1 transgenic mice deficient in p53

Overexpression of the cyclin D1 oncogene and inactivation of the p53 tumor suppressor have both been implicated in substantial proportions of sporadic human breast cancers. Transgenic mice with cyclin D1 overexpression targeted to mammary tissue by the MMTV enhancer-promoter have been shown to develop mammary cancers. To investigate the relationship between pathways driven by cyclin D1 overexpression and p53 loss during the development of breast cancers, we crossed MMTV-cyclin D1 mice with p53 heterozygous null (p53+/-) mice. In such crossed mice, cyclin D1-driven mammary neoplasia would need to be substantially accelerated by p53 loss in order for mammary tumors to develop prior to the expected onset of non-mammary tumors characteristic of the p53-deficient background alone. Instead, in mice heterozygous or homozygous for p53 deficiency and simultaneously carrying the MMTV-cyclin D1 transgene, only tumors typically found in p53-deficient mice developed and mammary tumors were not observed. Interestingly, MMTV-cyclin D1/p53+/- mice appeared to develop these non-mammary tumors more rapidly than p53+/- mice, and a majority of the sampled non-mammary tumors from MMTV-cyclin D1/p53+/- mice showed 'ectopic' expression of the MMTV-driven cyclin D1 transgene. Within the constraints of possible genetic background effects and limited sensitivity due to the early emergence of non-mammary tumors, these observations provide no evidence that inactivation of p53 confers a major additional selective advantage to mammary cells overexpressing cyclin D1 in this animal model of human breast cancer. Interestingly, the results do raise the possibility that p53 inactivation might complement or cooperate with cyclin D1 deregulation during the development of some types of non-mammary tumors.

Brain necrosis after permanent low-activity iodine-125 implants: case report and review of toxicity from focal radiation

Focal irradiation has emerged as a useful modality in the management of malignant brain tumors. Its main limitation is radiation necrosis. We report on the radiation dose distribution in the cerebellum of a patient who developed imaging and autopsy diagnosis of radiation necrosis after permanent iodine-125 implants for a solitary osseous plasmacytoma of her left occipital condyle. A 55-year-old woman initially presented with neck and occipital pain and a lytic lesion of her left occipital condyle. A cytological diagnosis of solitary osseous plasmacytoma was made by transpharyngeal needle biopsy. After an initial course of external beam radiation, the patient required further treatment with systemic chemotherapy 21 months later for clinical and radiographic progression of her disease. She ultimately required subtotal surgical resection of an anaplastic plasmacytoma with intracranial extension. Permanent low-activity iodine-125 seeds were implanted in the tumor cavity. Satisfactory local control was achieved. However, clinical and imaging signs of radiation damage appeared 28 months after iodine-125 seed implantation. Progressive systemic myeloma led to her death 11 years after presentation and 9 years after seed implantation. Radiation dose distribution is described, with a discussion of toxicity from focal radiation dose escalation.

Amino acid, glucose, and lipid kinetics after palliative resection in a patient with glucagonoma syndrome

Glucagon excess causes catabolic changes, including enhanced glucose production, lipolysis, and amino acid oxidation. In this study, we evaluate the metabolic effects of debulking surgery on a patient with glucagon-producing tumor. Stable isotope tracer methods were used to measure glucose, glycerol, and alpha-ketoisocaproic acid (alpha KICA) rates of appearance (Ra) into plasma. Measurements were obtained 25 days after surgery in the basal state and during hormonal suppression of glucagon production by infusing somatostatin with insulin replacement. Basal plasma glucagon concentration (14,100 pg/mL) remained high after debulking surgery. Somatostatin infusion decreased plasma glucagon concentration to 6,735 pg/mL and basal substrate kinetics (alpha-KICA Ra from 1.97 to 1.48 micromol/kg/min; glucose Ra from 16.89 to 11.56 micromol/kg/min; and glycerol Ra from 3.33 to 2.74 micromol/kg/min). We conclude that debulking surgery fails to adequately suppress glucagon production and the alterations in substrate metabolism associated with excess glucagon. In these patients, somatostatin therapy can be an effective method to suppress secretion of glucagon and help attenuate its catabolic effects.

Outpatient craniotomy for brain tumor: a pilot feasibility study in 46 patients

BACKGROUND

Since 1991 the author has routinely performed awake craniotomy for intra-axial brain tumors with low complication rate and low resource utilization. In late 1996 a pilot study was initiated to assess the feasibility of performing craniotomy for tumor resection as an outpatient procedure.

METHODS

A rigorous protocol was developed and adhered to, based around the patient's arrival at hospital at 6:00 a.m, undergoing image-guided awake craniotomy with cortical mapping, and being discharged by 6:00 p.m.

RESULTS

During the 48 month period from December 1996 to December 2000, 245 awake craniotomies were performed and of those, 46 patients were entered into the outpatient craniotomy protocol. Pathology in the 46 intent-to-treat group was: 21 metastasis, 19 glioma, and six miscellaneous. Four patients required conversion to inpatients and one patient was readmitted later the same evening due to headache. Thus 41/46 patients successfully completed the protocol (89%). There were five complications in the 46 intent-to-treat group (10.9%).

CONCLUSIONS

Outpatient craniotomy for brain tumor is a feasible option which appears safe and effective for selected patients. Besides being resource-friendly, the procedure may be psychologically less traumatic to patients than standard craniotomy for brain tumor. Proper prospective studies including satisfaction surveys would help resolve these issues and will be the next step.