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Biomedical subjects

M M Stevens

Publications and source records attributed to M M Stevens.

At least 37 records · Page 2Linked to original sources
PubMed1997

Risk of squamous cell carcinoma of the skin in relation to plasma selenium, alpha-tocopherol, beta-carotene, and retinol: a nested case-control study.

We conducted a nested case-control study of squamous cell skin cancer (SCC) to determine whether risk was related to plasma concentrations of selenium, alpha-tocopherol, beta-carotene, and retinol. We derived the study sample from participants in our Skin Cancer Prevention Study, all of whom had at least one basal cell or squamous cell skin cancer before study entry. Those who developed a new squamous cell skin cancer during the 3-5-year follow-up period were selected as cases (n = 132). Controls (n = 264) were chosen at random, with matching by age, sex, and study center, from among those who did not develop SCC but were being followed actively at the time the SCC case was diagnosed. Prediagnostic plasma samples were analyzed for alpha-tocopherol, beta-carotene, and retinol using high-performance liquid chromatography. Selenium determinations were made using instrumental neutron activation analysis. Odds ratios were computed using conditional logistic regression for matched samples. We found no consistent pattern of SCC risk associated with any of the nutrients examined. The odds ratios (95% confidence intervals) for the highest versus the lowest quartiles of beta-carotene, retinol, alpha-tocopherol, and selenium were 0.73 (0.38-1.41), 1.43 (0.77-2.64), 0.89 (0.43-1.85), and 0.86 (0.47-1.58), respectively. Thus, our data add to the growing body of evidence that these nutrients, at the concentrations we evaluated, are not related strongly to SCC risk.

Adult↗
PubMed1996

Risk of basal cell and squamous cell skin cancers after ionizing radiation therapy. For The Skin Cancer Prevention Study Group.

BACKGROUND: Human evidence that ionizing radiation is carcinogenic first came from reports of nonmelanoma skin cancers (NMSCs) on the hands of workers using early radiation devices. An increased risk of NMSC has been observed among uranium miners, radiologists, and individuals treated with x rays in childhood for tinea capitis (ringworm of the scalp) or for thymic enlargement; NMSC is one of the cancers most strongly associated with the atomic bombing of Hiroshima and Nagasaki. Although exposure to ionizing radiation is a known cause of NMSC, it is not yet clear whether therapeutic radiation causes both major histologic types of NMSC, basal cell carcinoma (BCC) and squamous cell carcinoma (SCC). Additionally, the potentially modifying effects, such as latency, age when treated, and type of treatment, are not well understood. PURPOSE: We investigated the relative risks of BCC and SCC associated with previous radiation therapy and evaluated these risks in relation to age and time since initial treatment and the medical condition for which radiation therapy was given. METHODS: The study group comprised individual diagnosed with at least one BCC or SCC from January 1980 through February 1986, who were recruited to participate in a skin cancer prevention trial designed to test whether oral beta-carotene supplementation would reduce the risk of new NMSCs. Patients were identified through the dermatology and pathology records of academic medical centers in Hanover, NH; Los Angeles, CA; San Francisco, CA; and Minneapolis, MN. Each participant completed a questionnaire detailing lifetime residence, pigmentary characteristics, occupational and recreational sun exposure, and history of radiation therapy. At enrollment, a study dermatologist assessed skin type (tendency to burn or tan) and extent of actinic skin damage. Participants were followed with an annual dermatologic examination for an average of 4 years. Of the 5232 potentially eligible individuals, 1805 were enrolled in the trial. We excluded 112 patients who reported previous radiation therapy for skin cancer only and three with missing information on whether they were ever treated with radiation therapy, leaving 1690 patients for the analysis. Approximately 4% of the patients died or discontinued participation for other reasons during each study year. We examined time to occurrence of first new histopathologically confirmed BCC and SCC during the follow-up period in relation to history of radiation therapy (for reasons other than NMSC) using a proportional hazards model. A multiple end points survival model was used to compare the rate ratios (RRs) for BCC and SCC. We also used a longitudinal method of analysis to compute the RR of total new BCC and SCC tumors per person per study year associated with radiation therapy. Using this method, we additionally assessed the potential modifying effects of age at treatment, latency, and type of therapy. All P values were derived from two-sided statistical tests of significance. RESULTS: Among the participants we studied, 597 developed a new BCC (n = 1553 tumors) and 118 developed a new SCC (n = 179 tumors). The time to first new BCC, but not SCC, was associated with prior radiation therapy (RR = 1.7; 95% confidence interval [CI] = 1.4-2.0 and RR = 1.0; 95% CI = 0.6-1.7, respectively; P = .03 for the difference between the RRs). The RR of total BCC tumors was slightly higher (RR = 2.3; 95% CI = 1.7-3.1), but it was still unity for SCC (RR = 1.0; 95% CI = 0.5-1.9). BCC risk appeared to increase with younger age at exposure and time since initially treated, although these effects were only marginally statistically significant (P for trend = .06 and .07, respectively). Also, risk of BCC was more strongly related to treatment for acne (RR = 3.3; 95% CI = 2.1-5.2) than other conditions. CONCLUSIONS AND IMPLICATIONS: Our data suggest that exposure to therapeutic radiation is associated with BCC but not with SCC.

Adult↗
PubMed1996

Mortality associated with low plasma concentration of beta carotene and the effect of oral supplementation.

OBJECTIVE: To examine the relationship between beta carotene plasma concentration and beta carotene supplementation and risk of death from major disease causes. DESIGN: Cohort study of plasma concentrations; randomized, controlled clinical trial of supplementation. SETTING: Medical school-affiliated dermatology practices. PATIENTS: A total of 1188 men and 532 women with mean age of 63.2 years, who had enrolled in a randomized clinical trial of beta carotene supplementation to prevent nonmelanoma skin cancer. INTERVENTION: Oral beta carotene, 50 mg per day for a median of 4.3 years. MAIN OUTCOME MEASURES: All-cause mortality and mortality from cardiovascular disease and cancer. RESULTS: During a median follow-up period of 8.2 years, there were 285 deaths. Persons whose initial plasma beta carotene concentrations were in the highest quartile (>0.52 micromol/L [27.7 microg/dL]) had a lower risk of death from all causes (adjusted relative rate [RR], 0.52; 95% confidence interval [CI] 0.44 to 0.87) and from cardiovascular diseases (adjusted RR, 0.57; 95% CI, 0.34 to 0.95) compared with persons with initial concentrations in the lowest quartile (<0.21 micromol/L [11.2 microg/dL]). Patients randomly assigned to beta carotene supplementation showed no reduction in relative mortality rates from all causes (adjusted RR, 1.03; 95% CI, 0.82 to 1.30) or from cardiovascular disease (adjusted RR, 1.16; 95% CI, 0.82 to 1.64). There was no evidence of lower mortality following supplementation among patients with initial beta carotene concentrations below the median for the study group. CONCLUSIONS: These analyses provide no support for a strong effect of supplemental beta carotene in reducing mortality from cardiovascular disease or other causes. Although the possibility exists that beta carotene supplementation produces benefits that are too small or too delayed to have been detected in this study, noncausal explanations should be sought for the association between plasma concentrations of beta carotene and diminished risk of death.

Administration, Oral↗
PubMed1996

Three-year results of prevention programs on marijuana use: the New Hampshire study.

The effects on marijuana use of 1) a drug prevention curriculum, or 2) this curriculum with added parent and other adult community activities in comparison with 3) a control community were investigated. Baseline information on drug-related behaviors from a sample of fourth, fifth, and sixth graders aged nine to fourteen years in rural New Hampshire (N = 1200) were obtained. The children completed these initial questionnaires in classrooms in 1987. In the comprehensive community intervention regular marijuana use was reduced by over 50 percent. No program had a significant effect on the initiation of marijuana use. The predictors of initiation were being in a higher grade, low school satisfaction, poor academic achievement, feeling unloved by one's family, feeling unpopular, and being part of a drug-using peer group. The baseline predictors of subsequent regular marijuana use were poor academic achievement, feeling unpopular, and being part of a drug-using peer group. In interviews the cultural and social contexts of marijuana use were explored. Strategies to prevent marijuana use need to take into account the profile of the marijuana-using child, the adult community's attitudes and beliefs about drugs, and the access of drug sellers and users to children.

Adolescent↗
PubMed1996

Harmony in hygiene.

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Dental Equipment↗
PubMed1995

Use of granulocyte colony stimulating factor to reduce the toxicity of super-VAC chemotherapy in advanced solid tumours in childhood.

Children with advanced solid tumours at the Royal Alexandra Hospital for Children (RAHC) receive an intensive four drug chemotherapy combination, Super-VAC (cyclophosphamide, 500 mg/m2, adriamycin, 30 mg/m2, actinomycin-D, 0.5 mg/m2, all daily for 3 days, and vincristine, 1.5 mg/m2 weekly). The majority of patients respond well to three courses of such therapy, but with considerable morbidity, including fever, neutropenia, and mucositis. In an attempt to reduce the morbidity of Super-VAC, G-CSF was added. We documented various parameters in 12 patients who received 28 cycles with G-CSF and compared them to an historical control group of 37 cycles in the preceding 14 patients who received Super-VAC. The median duration of each cycle was 23 days with G-CSF and 28 days without G-CSF (P = 0.004). However, differences in requirements for inpatient care (median 16 v. 20 days), intravenous antibiotics (median 9 v. 10 days), amphotericin (median 5 v. 3 days), morphine (median 8.5 v. 7 days), or TPN (median 6.5 v. 8 days) did not reach statistical significance. As expected, a significant difference in neutrophil recovery was demonstrated between the two groups (median 11 v. 16 days, P < 0.0001) but not in platelet recovery (median 13 v. 13 days). The use of G-CSF with Super-VAC resulted in a shorter cycle length, so increasing the dose intensity. A reduction in morbidity could not be demonstrated. No toxic side effects from G-CSF were noted.

Adolescent↗
PubMed1995

Control of chironomid larvae (Diptera: Chironomidae) in establishing rice crops using starch-based chlorpyrifos pellets.

Starch-based pellets containing 10% (w/w) chlorpyrifos were evaluated for control of chironomid larvae in rice crops immediately after flooding. Chlorpyrifos pellets at rates of 2.0, 3.5, and 6.0 kg/ha (0.2, 0.35, and 0.6 kg AI/ha), and, as a reference treatment, 150 ml/ha of 500 g/liter chlorpyrifos emulsifiable concentrate (EC) (0.075 kg AI/ha) were evaluated in New South Wales, Australia. The pellets reduced total midge larvae by 93-94% over the initial 36 days posttreatment, with some indication of residual control 50 days posttreatment at all rates. Chironominae were reduced by 80-85%, and other chironomids (predominantly Tanypodinae) by 98% during the first 36 days posttreatment. Increasing the pellet application rate above 2.0 kg/ha did not improve control. Although the EC formulation provided 100% control of all larvae for 12 days, control declined thereafter. The EC formulation reduced total larval numbers by 55% over the first 36 days posttreatment, with Chironominae increasing by 28% and other chironomids being reduced by 84%. Significantly (P < 0.05) higher water column toxicity levels were recorded for the EC formulation in the first 3 days after application.

Animals↗
PubMed1994

Acute myeloid leukaemia in patients with trisomy 21 (Down syndrome) treated by bone marrow transplantation.

Patients with trisomy 21 have an increased incidence of haematological disorders, including neonatal 'leukaemoid reaction' (transient myeloproliferative disorder [TMD]), and acute leukaemias. In the past it has been felt that patients with trisomy 21 and acute leukaemia do not tolerate, and hence may not warrant, therapy as intensive as those without the syndrome. The present authors' experience and the current literature do not support this view. Two cases are reported of acute myeloid leukaemia in children with trisomy 21, successfully treated with intensive chemotherapy and bone marrow transplantation.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1994

Childhood acute myeloid leukemia: outcome in a single center using chemotherapy and consolidation with busulfan/cyclophosphamide for bone marrow transplantation.

PURPOSE: To report the impact of bone marrow transplantation (BMT) with busulfan/cyclophosphamide (BuCy) as end consolidation in a cohort of consecutively diagnosed children with acute myeloid leukemia (AML). PATIENTS AND METHODS: Between May 1987 and November 1992, 43 patients were diagnosed with AML. Tissue typing at diagnosis determined whether patients would proceed to autologous or allogeneic BMT as end consolidation after six cycles of chemotherapy. Conditioning for BMT was with BuCy, followed by allogeneic or unpurged autologous marrow infusion. RESULTS: Of 37 patients who received chemotherapy, 35 achieved remission (95%) after one to six courses of treatment and 34 (92%) were transplanted. Five relapsed before BMT, four were subsequently transplanted in second complete remission (CR2) (n = 3) or untreated first relapse (n = 1), and one failed to respond to further therapy. All other patients proceeded to BMT in first complete remission (CR1). Eleven patients received allografts: one relapsed and one died of graft-versus-host disease (GvHD), for a leukemia-free survival rate of 90% at a median of 41 months after BMT (range, 3 to 60). For 23 autografts, there were two toxic deaths and eight relapses, with a leukemia-free survival rate of 61% at a median of 11 months after BMT (range, 0 to 66). The high relapse rate following autologous BMT led us to escalate the dose of Bu from 16 mg/kg to 600 mg/m2 using a single daily dose of Bu. CONCLUSION: With modern supportive therapy, most newly diagnosed children with AML will enter remission and are eligible for intensification therapy. BuCy is well tolerated in children, which allowed us to escalate the dose of Bu in recent patients. Further follow-up is needed to determine whether this has an impact on the relapse rate following autologous BMT.

Adolescent↗
PubMed1994

Pain and symptom control in paediatric palliative care.

Important differences become evident in a comparison of cancer pain between children and adults. Management of pain in children is commonly multidisciplinary, is less dependent on invasive measures and relies more on systemic therapy. Children are not little adults: their immaturity, developing cognition and dependence all influence their experience and interpretation of pain. Much progress has been made in altering practices such as under-prescribing and underdosing that have adversely affected adequate control of pain in children. The challenge for paediatric health care providers in the mid 1990s is not only to be informed of current practices in pain and symptom control in paediatric palliative care, but also to remember to establish those practices in day to day management. Even though pain and its effects in children are now better understood, it is often still not managed optimally. Good management of pain in children depends on accurate assessment. In the past 10 years, assessment of pain in children has advanced considerably. However, assessment of pain in the preverbal child is still inadequate and in need of attention. Sedation, tolerance and involuntary movements may occur as side effects of opioids in children and may cause significant problems in management of the dying child. Psychostimulants can diminish sedation to some extent, but there is little information as yet on the value of these drugs in children. Tolerance to opioids may develop quickly, leading to poor control of pain and distress for the child. Strategies to improve management of tolerance include use of regional anaesthetic techniques such as the epidural/intrathecal route for opioid administration. Involuntary movements induced by opioids are uncommon but have the potential to cause significant distress. The mechanisms underlying these side effects of opioids need to be established. Strategies are needed for the effective treatment and prevention of these side effects. Neuropathic pain can be severe, distressing and difficult to treat. Experience of its treatment in terminally ill children is limited. Effective use of tricyclic antidepressants and systemically administered local anaesthetics is still to be determined. Regional anaesthetic techniques may be of great benefit when neuropathic pain cannot be controlled with systemic therapy. Procedural pain is more common than pain related to disease in the management of paediatric cancer. Further research is needed to identify the best approach to its management. We have found nitrous oxide to be of great benefit in management of procedural pain in children. Non-pharmacological methods of treatment of pain in children, such as transcutaneous electrical nerve stimulation or acupuncture, may also be useful and should receive continuing evaluation. There are significant and current issues in paediatric palliative care besides management of pain. There are difficulties in the provision of home nursing care for children with cancer in the terminal phase of their illness, including lack of community nursing services at night and on weekends and lack of adequate home help for parents. Attitudes of staff involved in the care of the child and family and their commitment to working as a multidisciplinary team strongly influence the quality and success of care given. Pain control and palliative medicine are evaluable by measures of quality assurance or outcome, and adoption of such evaluations should improve standards of care. Euthanasia in children is even more difficult as an ethical dilemma than in adults. Optimum symptom control with current techniques should almost always obviate its consideration. We are opposed to euthanasia. Psychosocial and cultural issues all influence the family's experience of palliative care. Further research is necessary in all of these areas.(ABSTRACT TRUNCATED)

Adolescent↗
PubMed1993

Gallium-67 and technetium-99m-methylene diphosphonate skeletal scintigraphy in determining prognosis for children with stage IV neuroblastoma.

Thirty-five children (aged 0-9 yr) who had presented with Stage IV neuroblastoma were studied to see if avidity for 67Ga or 99mTc-methylene diphosphonate (MDP) uptake in both primary and secondary sites at diagnosis conferred any prognostic significance. Twenty-three percent of the patients were disease free and off treatment at the time of study. Crude survival did not differ between groups. Duration of survival and the likelihood of completing treatment were related to the scintigraphic appearance at the time of diagnosis, after adjustment for potential confounding effects, using Cox's proportional hazards regression and multiple logistic regression. After adjustment for confounding influences, neither 67Ga avidity nor uptake of 99mTc-MDP was associated with a significantly worse prognosis, both in terms of adjusted survival and likelihood of completing treatment. Patients with 67Ga-avid scans at diagnosis did not demonstrate significantly worse survival (HR 1.47, 95% CI 0.43-5.11) than those without 67Ga avidity. They were somewhat less likely to complete treatment (OR 0.23, 95% CI 0.03-1.63), but this did not reach statistical significance. Similarly, although patients with 99mTc-MDP positive scans demonstrated somewhat worse survival (HR 2.47, 95% CI 0.45-13.54), this result did not reach statistical significance, nor were they less likely to complete treatment (OR 0.69, 95% CI 0.07-6.67) than those with 99mTc-MDP negative scans. Uptake of 99mTc-MDP into extraosseous sites was also not associated with worse survival (HR 1.45, 95% CI 0.58-3.62) nor with decreased likelihood of completing treatment (OR 0.78, 95% CI 0.12-5.09). Other than indicating disease stage, these results do not support the hypothesis that the scintigraphic appearance at diagnosis confers prognostic information in children with advanced neuroblastoma.

Bone Neoplasms↗
PubMed1992

"Shuttle sheet": a patient-held medical record for pediatric oncology families.

A patient-held medical record used by a pediatric oncology unit is described. Each patient's family is provided with a folder containing detailed information about the patient's current treatment. The record helps orient all health care workers involved in the patient's management to the treatment schedule, including exact doses of drugs. Details of blood counts and treatment given are entered by health care workers at each consultation, but the record is always retained by the family. The benefits of this record are that it saves time, reduces the likelihood of errors in scheduling and doses of cytotoxic drugs, and facilitates continuation of therapy at locations away from the supervising oncology unit. It reduces the amount of correspondence required for patient care, is a useful diary and treatment planner for the patient's family and hospital staff, and is an educational resource for the patient's family. It is a useful adjunct to the hospital's medical record for clinical trial data, is easily replaced if lost, and is inexpensive. It also assists surveillance of long-term survivors. The record is particularly valuable when used with patients who are being treated or assessed at more than one institution or by multiple health care workers. The record is in its 12th year of service and is used by more than 95% of patients on therapy attending the unit.

Australia↗
PubMed1991

Bulbar and pseudobulbar palsy complicating therapy with high-dose cytosine arabinoside in children with leukemia.

Three of 38 children given high-dose cytosine arabinoside therapy developed a previously undescribed complication. Neurological problems are a frequent occurrence in patients given this therapy, particularly cerebellar ataxia, but the development of bulbar and pseudobulbar palsy has not been reported. In two of these cases, it was sufficiently marked for the course of treatment to be curtailed and occurred at a relatively low cumulative dose of the drug. Neurotoxicity can occur at any time using high-dose cytosine therapy.

Adolescent↗
PubMed1991

Cognitive effects of childhood leukemia therapy: a case for four specific deficits.

Prophylactic treatment of the central nervous system (CNS) with cranial irradiation and antineoplastic drugs has made childhood acute lymphoblastic leukemia (ALL) a survivable disease, but at the same time there have been many reports of iatrogenic effects, including deficits in cognitive functioning. Previous research suggests a particular effect on the Freedom from Distractibility factor of the WISC-R, memory, and attention. These particular abilities are tested in a group of 43 ALL survivors, with comparisons against solid tumor as well as sibling controls. The results indicate that four cognitive processes are affected by CNS prophylaxis for ALL: short-term memory, speed of processing, visuomotor coordination, and sequencing ability. Younger children have a more severe speed of processing deficit and children treated with a less rigorous protocol appear to be slightly less affected generally. The specific cognitive deficits found are related to neurological evidence on both theoretical and empirical grounds. Results suggest that children who have received CNS prophylaxis are able to learn, but may be slower to acquire new material and may benefit from bimodal presentation.

Antineoplastic Agents↗