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Biomedical subjects

R Dodge

Publications and source records attributed to R Dodge.

At least 55 records · Page 3Linked to original sources
PubMed1991

Malignant melanoma in black Americans. A trend toward improved survival.

A search of patients seen at the Duke University Melanoma Clinic (Durham, NC) identified 79 black patients. Five- and 10-year survival was 35% and 26%, respectively. Patients presenting in the recent decade had less advanced disease, resulting in an improved 5-year survival of 49%. Five-year survival for white patients was 74%. Black patients had more negative prognostic indicators when compared with white patients. In a multivariate analysis, however, race was not a prognostic indicator, suggesting melanoma is not inherently more aggressive in black patients. The trend during the past decade has been for black patients to present with less advanced disease, with improved survival. This may be related to better appreciation of the disease by patients and physicians alike. Continued emphasis on education and early diagnosis may result in further improvement for black patients with melanoma.

Actuarial Analysis↗
PubMed1990

Overexpression of HER-2/neu is associated with poor survival in advanced epithelial ovarian cancer.

Previous studies have suggested that overexpression of HER-2/neu oncogene occurs in 15-40% of breast cancers and that overexpression is associated with poor prognosis. In the present report, we have used an immunohistochemical technique involving a monoclonal antibody specifically reactive with the external domain of HER-2/neu to study expression of HER-2/neu in frozen sections of normal ovary and advanced epithelial ovarian cancer. The intensity of staining for HER-2neu was always moderate or less (0-2+) in normal ovarian epithelium. Among 73 ovarian cancers, 50 (68%) had staining similar to that for normal ovarian epithelium (0-2+) while 23 (32%) stained heavily (3+). Survival of the 23 patients with high HER-2/neu expression (median, 15.7 months) was significantly worse (P = 0.001) than that of the 50 patients (median, 32.8 months) with normal HER-2/neu expression. In addition, patients whose tumors had high HER-2/neu expression were significantly less likely to have a complete response to primary therapy (P less than 0.05) or have a negative second-look laparotomy when serum CA 125 levels were normal preoperatively (P less than 0.05). These findings suggest that HER-2/neu deserves further evaluation as a prognostic marker in epithelial ovarian cancer.

Female↗
PubMed1987

Efficacy of benzathine penicillin G in group A streptococcal pharyngitis: reevaluation.

The rate of streptococcal eradication after intramuscular administration of benzathine penicillin G in 66 children with acute group A streptococcal pharyngitis was determined and possible reasons for treatment failure explored. Bacteriologic treatment failure, defined as isolation of the same serotype at 3- or 6-weeks follow-up, occurred in eight (12%) patients. The treatment failure rate was 21% in those with immunologically significant infection, versus 8% in those without antibody rises (P greater than 0.1). All group A beta-hemolytic streptococcal (GABS) strains isolated from patients with treatment failure, both before and after benzathine penicillin G therapy, were exquisitely susceptible to penicillin G (minimum inhibitory concentration less than or equal to 0.02 microgram/mL), and none showed evidence of tolerance (minimum bactericidal concentration less than or equal to 0.04 microgram/mL). Thus, we found GABS eradication rates to exceed 10% in children given benzathine penicillin G. The failure rate did not appear to be related to enrichment of the patient population with a high proportion of asymptomatic carriers nor to the presence of penicillin-tolerant GABS.

Child↗
PubMed1987

Pharmacokinetics and toxicity of methotrexate in children with Down syndrome and acute lymphocytic leukemia.

Children with Down syndrome and acute lymphocytic leukemia (ALL) have poor tolerance to antineoplastic drugs, including methotrexate (MTX). We evaluated MTX pharmacokinetics and toxicity in five patients with Down syndrome and ALL who had received multiple high doses of MTX (1 g/m2). Three control patients without Down syndrome were matched to each case according to sex, race, age, and initial leukocyte count. Median MTX plasma concentrations, measured 42 hours after infusion, were significantly higher in patients with Down syndrome versus control patients (average 0.47 vs 0.24 mumol/L, respectively, P = 0.03). When a 42-hour MTX concentration of 0.5 mumol/L was used to identify patients at risk for toxicity, more courses were considered at high risk for toxicity among patients with Down syndrome (31 of 62, 50%) than in control patients (13 of 214, 6.1%, P less than 0.0001). The average MTX clearance was 64.1 mL/min/m2 in Down syndrome vs an average control value of 80.6 mL/min/m2 (P = 0.13). Toxicity after each high-dose MTX course was graded according to standardized criteria. Grades 2 through 4 gastrointestinal toxicity and grades 3 and 4 hematologic toxicity occurred more frequently in the patients with Down syndrome (36% and 13.4% of courses, respectively) vs the control patients (3.6% and 0.9% respectively, P less than 0.0001 for both). This higher frequency of toxicity occurred despite higher doses and prolonged duration of leucovorin given to all patients with Down syndrome. We conclude that altered MTX pharmacokinetics may contribute to the higher incidence of MTX-induced toxicity seen in patients with Down syndrome.

Adolescent↗
PubMed1987

Clinical pharmacodynamic studies of high-dose methotrexate in acute lymphocytic leukemia.

As the intensity of cancer chemotherapy has been reported to influence clinical response for several drug-sensitive cancers, we have investigated the relation between systemic exposure to high-dose methotrexate (HDMTX) and clinical response in childhood acute lymphocytic leukemia (ALL). A total of 108 consecutive, previously untreated children with "standard-intermediate risk" ALL were randomized to receive postinduction therapy with HDMTX (1000 mg/m2 iv over 24 hours weekly for 3 weeks, then every 6 weeks for 72 weeks), superimposed on conventional therapy with low-dose 6-mercaptopurine (6MP; 50 mg/m2 orally per day) and methotrexate (MTX; 25 mg/m2 orally per week). The systemic clearance of HDMTX ranged from 40 to 131 ml/minute/m2 among these patients, yielding MTX steady-state plasma concentrations (Cpss) ranging from 9.3 to 25.4 microM during the infusion. The group of patients (n = 59) with median MTX Cpss less than 16 microM during the HDMTX infusion had a higher probability of having any relapse than patients (n = 49) with MTX Cpss greater than 16 microM (P less than 0.05). In a previously reported univariate analysis, patients with MTX Cpss less than or equal to 16 microM were 3.2 times more likely to relapse on therapy (P = 0.01) and 6.9 times more likely to have a hematologic relapse on therapy (P = 0.001). Multivariate and stepwise Cox's regression analyses indicated that MTX Cpss retains its prognostic importance even when other prognostic variables (i.e., DNA Index, WBC, hemoglobin) are considered.(ABSTRACT TRUNCATED AT 250 WORDS)

Child↗
PubMed1986

Clinical pharmacodynamics of high-dose methotrexate in acute lymphocytic leukemia. Identification of a relation between concentration and effect.

High-dose methotrexate (500 to 33,600 mg per square meter of body-surface area) with leucovorin rescue is a common component of therapy for acute lymphocytic leukemia. To increase understanding of the relation between the serum concentration and the effect of methotrexate, we conducted a randomized, prospective study of 108 children with "standard-risk" acute lymphocytic leukemia who were treated with 15 doses of methotrexate (1000 mg per square meter) that were infused over 24 hours. The median length of follow-up was 3.5 years from diagnosis for patients still in remission. Variability between patients in methotrexate clearance produced steady-state serum concentrations that ranged from 9.3 to 25.4 microM. Patients with median methotrexate concentrations of less than 16 microM (n = 59) had a lower probability of remaining in remission (P less than 0.05) than patients with concentrations of 16 microM or more (n = 49). Multivariate analyses indicated that patients with methotrexate concentrations of less than 16 microM were 3 times more likely to have any kind of relapse during therapy (P = 0.01) and 7 times more likely to have a hematologic relapse during therapy (P = 0.001). Stepwise Cox's regression identified leukemic-cell DNA content, methotrexate concentration, and hemoglobin as significant prognostic variables for hematologic relapse (P = 0.0005). We conclude that there is a concentration-effect relation for high-dose methotrexate in acute lymphocytic leukemia and that 1000 mg per square meter infused over a period of 24 hours may not be optimal for patients with relatively fast drug clearance.

Adolescent↗
PubMed1986

Use of the automatic interaction detector method to identify patient characteristics related to methotrexate clearance.

Systemic methotrexate (MTX) clearance was determined in 108 children who received 15 courses of MTX, 1000 mg/m2 iv over 24 hours, as a component of therapy for acute lymphocytic leukemia. The median MTX clearance was used as the representative value for each patient, and these values ranged from 44.7 to 132.1 ml/min/m2 (X = 78.4 ml/min/m2). The automatic interaction detector approach was used to determine the patient characteristics that correlated with MTX clearance. Characteristics examined were sex, age, estimated creatinine clearance, SGPT, and body surface area. The initial splits were based on creatinine clearance, and mean MTX clearances in three subgroups (50 to 100, 100 to 150, and greater than 150 ml/min/m2) were 73.1, 78.3, and 90.5 ml/min/m2, respectively. For patients with the slowest creatinine clearance, abnormal SGPT concentrations (greater than 35 IU/L) were associated with slower MTX clearance (77.6 vs. 67.8 ml/min/m2). In the latter subgroup, boys had faster clearance than girls (77.4 vs. 60.9 ml/min/m2). These results demonstrate that for children with normal serum creatinine concentrations, interpatient variability in MTX clearance can partly be explained by measures of renal and hepatic function, which indicates that the observed variability in MTX clearance is not totally random.

Adolescent↗
PubMed1986

Comparisons of asthma, emphysema, and chronic bronchitis diagnoses in a general population sample.

This report is an analysis of cases of obstructive lung disease diagnosed during the first 8 yr of a community study. Of 351 subjects who received a new diagnosis of asthma, emphysema, or chronic bronchitis from community physicians, 152 (44.5%) had a prior or concomitant diagnosis of another obstructive disease. Asthma developed most often in young subjects, emphysema in older subjects, and chronic bronchitis occurred in all age groups. Among older subjects, disease groups were surprisingly similar, with wheeze, dyspnea, and attacks of shortness of breath with wheeze all occurring frequently in diagnosed subjects, including those with emphysema. The majority of subjects who developed emphysema were males. In contrast, 72.8% of the asthma and chronic bronchitis subjects were females. These results suggest that physician bias may result in labeling male patients as emphysematous and female patients as asthmatic or bronchitic.

Adolescent↗
PubMed1985

A longitudinal study of children exposed to sulfur oxides.

This study is a longitudinal comparison of the health of children exposed to markedly different concentrations of sulfur dioxide (SO2) and moderately different concentrations of particulate sulfate (SO4=). The four groups of subjects lived in two areas of one smelter town and in two other towns, one of which was also a smelter town. In the area of highest pollution, children were intermittently exposed to high SO2 levels (peak three-hour average concentration exceeded 2,500 micrograms/m3) and moderate particulate SO4= levels (average concentration was 10.1 micrograms/m3). When the children were grouped by the four gradients of pollution observed, the prevalence of cough (measured by questionnaire) correlated significantly with pollution levels (trend chi-square = 5.6, p = 0.02). No significant differences in the incidence of cough or other symptoms occurred among the groups of subjects over three years, and pulmonary function and lung function growth over the study were roughly equal among all the groups. These results suggest that intermittent elevations in SO2 concentration, in the presence of moderate particulate SO4= concentration, produced evidence of bronchial irritation in the subjects, but no chronic effect on lung function or lung function growth was detected.

Air Pollutants↗
PubMed1985

Detection of fever with infrared thermometry: a feasibility study.

Fever is a remarkably sensitive indicator of infectious disease. The thermometer in clinical use today is basically that developed over a century ago, measuring heat conducted from skin or mucous membranes to an adjacent probe. In dealing with immunosuppressed granulocytopenic patients, the need was realized for an instrument by which temperature might be determined without a probe contact. Infrared pyrometers have been used in industry to record the temperature of mechanical objects at a distance. We tested the feasibility of using such an instrument to detect fever in humans. In a controlled and blinded fashion, infrared measurements from the eyes, axillae, and areas below the ear lobes (E spot) of 140 febrile and afebrile patients were compared with rectal temperatures recorded by a standard thermometer. The eye and E spot provided the most accurate readings. Infrared measurements of the right eye identified 57 (95%) of 60 febrile and 72 (90%) of 80 afebrile patients correctly. Overall, 92% of all patients were correctly categorized by use of the infrared thermometer at this site. We conclude that this approach is feasible and, with further technical developments, may be applicable for routine clinical use.

Child↗
PubMed1985

The epidemiology of asthma.

Significant strides have been made in recent years in the epidemiologic study of obstructive lung diseases including asthma. Community population samples are being evaluated prospectively and followed up longitudinally to document the appearance of morbidity and clinical diagnoses. Also, a variety of environmental, physiologic, and immunologic variables are being collected on a serial basis to correlate changes with the appearance (or disappearance) of recognizable disease. Unfortunately, until the semantics and diagnostic labeling of airway abnormalities becomes more precise, especially in the older population, the incidence and prevalence of disease will lack the precision it should have.

Adolescent↗
PubMed1983

The respiratory health and lung function of Anglo-American children in a smelter town.

Cooper smelters are large, usually isolated, sources of air pollution. Arizona has several such plants on the periphery of small communities. The smelters emit predominantly sulfur oxides and particulates, and the residents of these communities intermittently are exposed to high concentrations (24-h sulfur dioxide (SO2) = 250 to 500 micrograms/m3) of smelter smoke but little other pollution. This study compared the respiratory health of Anglo-American school children who lived in one smelter community with children living in another small community in Arizona that was free of smelter air pollution. The prevalence of cough, as determined by questionnaire, was 25.6% in the smelter town children and 14.3% in the nonsmelter town children (p less than 0.05). Pulmonary function at the study onset was equal in the two groups. Over the course of the 4 yr of study, lung function growth (measured as actual forced expiratory volume in one second (FEV1) after 4 yr of study minus predicted FEV1) was also equal in the smelter town and nonsmelter town children. These results suggest that children in smelter communities have slightly more cough when compared with children living in other communities, but no differences in initial lung function or lung function at yearly testing over the period of the study.

Air Pollutants↗
PubMed1983

A comparison of the respiratory health of Mexican-American and non-Mexican-American white children.

This study compares the respiratory health of Mexican-American and non-Mexican-American white school children. Using responses to questionnaires, the point prevalences of physician-confirmed asthma, attacks of shortness of breath with wheeze (without a diagnosis of asthma), and cough were compiled for each ethnic group. Using the results of yearly pulmonary function testing, initial and serial pulmonary function were also calculated. Asthma was reported by 6.5 percent of the non-Mexican-American children and 1.9 percent of the Mexican-American subjects (p less than 0.01 by chi 2). The rates of respiratory symptoms were nearly equal in the two groups. Initial and serial testing of pulmonary function showed non-Mexican-American children had significantly lower maximum expiratory flows (Vmax50%) in each year of testing. These results confirm other reports of differences in both rates of asthma and pulmonary function in Mexican-Americans and non-Mexican-Americans. Inherent differences in the size of the airways could explain these findings.

Arizona↗
PubMed1982

Chlamydial prostatitis in dogs: an experimental study.

Ten adult male mongrel dogs were inoculated with Chlamydia trachomatis by injections of 10(6) or 10(7) organisms directly into the prostate. We were able to recover Chlamydia 3 to 7 days later in three of four dogs receiving injections of 10(7) organisms. Eight of ten dogs developed detectable serum antibody to Chlamydia 14 to 68 days following inoculation. All dogs receiving 10(7) Chlamydia and two of six dogs receiving 10(6) organisms developed histological signs of prostatic hyperplasia. Thus, the dog may be a model for establishment of chlamydial prostatitis and may be used for further investigations of this disease.

Animals↗
PubMed1982

Circadian rhythms and fatigue: a discrimination of their effects on performance.

Different effects between circadian rhythms and fatigue have been discriminated. The discrimination was based on human performance changes. It was shown that such changes, not related to loss of sleep, are more easily attributable to either circadian rhythm or fatigue effects. However, when they follow loss of sleep, discrimination becomes difficult. Consequently, a new, more direct way of describing them and their cause has been formulated. This type of change is then related to the jet-lag-by-time-zone myth.

Aerospace Medicine↗
PubMed1980

The respiratory health of school children in smelter communities.

This study compares the pulmonary function and prevalence of respiratory symptoms and disorders among school children living in smelter towns and other communities of Arizona. The rate of asthma was found to be significantly higher in whites than Mexican-Americans, although differences in related problems, such as wheezing, were not significant. When the subjects were grouped by area of residence, the children living in areas with relatively high particulate levels had significantly lower pulmonary function than children living in areas with low particulate levels. No relation between symptoms or pulmonary function and sulfur dioxide levels was observed.

Adult↗