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PubMedDate not supplied

The incidence of traumatic brain injury among children in the United States: differences by race.

OBJECTIVE: This report summarizes the epidemiology of traumatic brain injury (TBI) deaths, hospitalizations, and emergency department (ED) visits by race among children aged 0-14 years in the United States. Few other studies have reported the incidence of TBI in this population by race. METHODS: Data from 3 nationally representative sources maintained by the National Center for Health Statistics were used to report the annual numbers and rates of TBI-related deaths, hospitalizations, and ED visits during 1995-2001 by race, age, and external cause of injury. RESULTS: An estimated 475,000 TBIs occurred among children aged 0-14 each year. Rates were highest among children aged 0-4. For children aged 0-9 years, both death and hospitalization rates were significantly higher for blacks than whites for motor vehicle-traffic-related TBIs. CONCLUSION: With nearly half a million children affected each year, TBI is a serious public health problem. Variation in rates by race suggest the need to more closely examine the factors that contribute to these differences, such as the external causes of the injury and associated modifiable factors (e.g., the use of seatbelts and child safety seats).

Accidents, Traffic↗
PubMed1995

Effects of noise exposure, race, and years of service on hearing in U.S. Army soldiers.

Over the last two decades the U.S. Army has instituted a comprehensive hearing conservation program (HCP) to reduce the prevalence of hearing loss in soldiers and civilian employees. As a component of this program, hearing threshold levels (HTLs) are stored in a central computerized Army-wide hearing conservation data registry. The aim of this study was to analyze the hearing threshold data to compare the hearing loss among soldiers representing different (1) race groups, (2) noise exposure groups, and (3) duration of military service. HTLs were age-corrected using data base B values from ISO 1999 (1990). As may be expected, soldiers exposed to high noise levels had significantly poorer hearing than the group of soldiers with limited noise exposure. On the average, results indicated a significant difference in HTLs among the race groups with black soldiers having the most sensitive hearing and white soldiers having the poorest. Also, subjects with greater durations of military service had the least sensitive hearing. Finally, race and years of service factors were found to interact in their effect on HTL. The findings are discussed in terms of implications of race differences, normative data, and effectiveness of the U.S. Army HCP.

Adolescent↗
PubMed1994

Aggression, social acceptance, and race as predictors of negative adolescent outcomes.

OBJECTIVE: The current study examined a mixed-race, longitudinal sample of 114 boys to assess the relative power of aggression, low peer acceptance, and race in predicting a broad range of adolescent outcomes and behaviors. METHOD: Outcomes were assessed through self-report and through peer, teacher, and independent observer ratings. RESULTS: Results indicate that preadolescent levels of aggression are predictive of boys' subsequent adolescent involvement in marijuana, drugs, and alcohol and in delinquent activity. Aggression and low peer acceptance served as predictors of teacher, peer, and independent observer ratings of externalizing and internalizing behavior at follow-up. Results also indicate that peer ratings of social acceptance and of aggressive behavior operate differently across racial groups, when predicting to self-reported follow-up behaviors. CONCLUSIONS: Aggressive and socially disliked boys are at risk for engaging in a progressive series of behaviors that increase their engagement in contranormative behavior. The moderating effects of race may be due to biases in elementary school peer ratings in mixed-race samples, or they may represent actual differences in how early risk markers operate with boys of different racial status.

Adolescent↗
PubMedDate not supplied

Acetabular depth and race in young adults: a potential explanation of the differences in the prevalence of slipped capital femoral epiphysis between different racial groups?

Slipped capital femoral epiphysis (SCFE) is known to have a higher prevalence in blacks and Polynesians. It has been postulated that a deeper acetabulum increases the shearing forces on the proximal femoral physis, resulting in a higher incidence of SCFE. It was the purpose of this study to investigate acetabular depth in the normal adult population as a function of race. Anteroposterior pelvis radiographs from young polytrauma adults (<35 years) were identified. Race was classified according as white, black, Amerindian (Hispanic and Native American), and Asian. Acetabular depth was measured by Visser's modification of the center-edge (CE) angle and Sharp's angle. All measurements were made by one observer with the same goniometer and Mose circle. There were 167 patients with an average age of 24 +/- 4 years; there were 65 female (39%) and 102 male (61%) patients. There were 57 (34%) Amerindian, 50 (30%) white, 47 (28%) black, and 13 (8%) Asian people. The CE angle was 30.6 +/- 4.8 degrees for the Asian, 28.7 +/- 5.7 degrees for the black, 30.3 +/- 5.1 degrees for the Amerindian, and 28.0 +/- 4.3 degrees for the white racial groups. Sharp's angle was 39.8 +/- 3.0 degrees for the Asian, 39.9 +/- 3.6 degrees for the black, 37.4 +/- 3.4 degrees for the Amerindian, and 39.2 +/- 3.2 degrees for the white racial groups. These differences by race were statistically significant for both Sharp's and Visser's angles. If racial variation in acetabular depth is an explanation for the racial variability of SCFE, then the CE and Sharp's angle should vary by race. In this study of healthy adults without any underlying hip pathology, racial variability in the CE or Sharp's angle did not follow the racial prevalence of SCFE.

Acetabulum↗
PubMed1994

The effect of gender and race on the measurement properties of the CES-D in older adults.

Having observed a three-fold difference in the prevalence of significant symptoms of depression among four race-gender groups of elderly adults attending an urban primary care practice, we investigated the extent to which these differences might be explained by variability in the measurement properties of the Centers for Epidemiologic Studies depression scale (CES-D). Although the internal consistency of the CES-D was acceptable for all groups, 5% of our patients were excluded for inability to complete the minimum required number of CES-D items, and nearly 40% of patients required response imputation for the allowable one to four items that they could not answer. Imputation was most frequently required for items tapping positive affect. Principal components factor analysis was performed separately for respondents answering all items and for respondents with imputed values. In both analyses we found important race-gender differences in factor structure. Moreover, the factor structure for those with imputed values was markedly different from that of respondents answering all items, including a dissolution of the positive affect dimension. Neither the race-gender differences in factor structure nor the differences among those with and without imputed data were resolved by eliminating respondents with poor education, cognitive impairment, or alcoholism, or by varying the assumptions for data imputation. However, the disparities in factor structure were essentially resolved by eliminating five CES-D items, suggesting the need to modify the CES-D in populations like ours. Although eliminating these five items results in a more pure factor structure, it does not resolve the differences in prevalence of depressive symptoms. These differences may, however, be partially due to differential response tendencies among the race-gender groups.

Black or African American↗
PubMed1999

Plasma-electrolytes in natives to hypoxia after marathon races at different altitudes.

PURPOSE: It is well known that altitude natives differ from sea level natives in aspects of fluid and electrolyte homeostasis. METHODS: To evaluate exercise and environmental influences on the electrolyte and water status in hypoxia adapted subjects, we investigated 11 well-trained marathon runners (33.7 +/- 0.7 yr, 60.5 +/- 1.9 kg), native to an altitude above 2600 m, before and after two marathon races. One competition was held at moderate altitude (AM, 2650 m, 14 degrees C, 55% RH, running time 3 h 6 min +/- 22 min) and another under tropical conditions (HM, 470 m, 28 degrees C, 70% RH, running time 2 h 54 min +/- 30 min). Blood samples were taken 3 d before, immediately after, 1 h after, and 24 h after the races. RESULTS: The loss in body fluid was calculated to be 2.15 L during AM and 5.05 L during HM, respectively. It was compensated mostly by ingested fluids without electrolyte content and by metabolically produced water, which led to hyponatremia during AM (plasma [Na+] from 144.3 +/- 0.7 to 131.7 +/- 2.1 mmol x L(-1)). Severe dehydration without significant changes in plasma [Na+] could be detected after HM. Serum antidiuretic hormone concentrations and serum aldosterone concentrations significantly increased during both races and remained at a high level for at least 1h after both competitions. Serum atrial natriuretic peptide (ANP) concentrations were at a high level at rest, increasing during HM, and decreasing during AM. CONCLUSION: Under tropical conditions, we found a severe state of dehydration characterized by an extended ANP-response, which was not prevented by water intake during the race. Under hypoxic conditions, however, we found that hyponatremia had developed. This can be partly explained by pure water intake and metabolically produced water, and also, possibly, by a special hypoxia-induced effect.

Adult↗
PubMedDate not supplied

Race and sex differences in cutaneous pain perception.

OBJECTIVE: The purpose of this study was to determine race and sex differences in cutaneous pain perception. METHODS: Pain perception was measured using a suprathreshold evaluation of pain intensity and pain unpleasantness to a series of thermal stimuli in 27 whites (14 men and 13 women) and 24 African Americans (12 men and 12 women). Blood pressure, depressive symptoms, anxiety state levels, and negative mood were assessed before pain testing to examine whether they might account for any sex or race differences in pain perception that emerged. RESULTS: African Americans rated the stimuli as more unpleasant and showed a tendency to rate it as more intense than whites. Women showed a tendency to rate the stimuli as more unpleasant and more intense than men. In addition, systolic blood pressure was inversely related to pain intensity. After statistically adjusting for systolic blood pressure, sex differences in pain unpleasantness were reduced and sex differences in pain intensity were abolished; race differences were unaltered. CONCLUSIONS: These differences in pain perception may be associated with different pain mechanisms: in the ease of sex, differences in opioid activity and baroreceptor-regulated pain systems; in the case of race, unmeasured psychological characteristics are suggested by the larger differences in ratings of pain unpleasantness than pain intensity.

Adult↗
PubMed2001

Successful long-term kidney-pancreas transplants regardless of C-peptide status or race.

BACKGROUND: We have previously shown that our patient population of 60% minority races has end-stage renal disease primarily as a result of diabetes mellitus and hypertension. It therefore was logical to explore the restoration of normal insulin production and renal function by simultaneous pancreas-kidney (SPK) transplantation, without regard to race. This study represents new analyses integrating race with C-peptide status and reports the outcome of 136 SPK transplantations performed over the last 10 years. RESULTS: Of the 49 African-Americans with diabetes mellitus and end-stage renal disease, 60% were type I and 40% were type II, based on C-peptide levels. In comparison, only 16% of Caucasians were type II. The average age at onset of diabetes mellitus was 15.7 years for type I compared with 20.7 years for type II (P>0.05). The actuarial 10-year survival rates for the 136 SPKs were 91.79% (patient), 85.07% (pancreas), and 83.58% (kidney). The type I and type II survival rates were similar in the two diabetic groups. CONCLUSIONS: The data strongly suggest that pretransplant C-peptide status does not influence the outcome of SPK transplantation in patients with renal failure from diabetes mellitus. SPK transplants should be offered to all suitable diabetic patients with renal failure regardless of C-peptide status or race.

Black People↗
PubMed2003

Are there gender and race differences in cellular immunity patterns over age in infected and uninfected children born to HIV-infected women?

This study investigated whether age-related patterns of immunologic markers in 1488 uninfected (9789 measurements) and 186 infected (3414 measurements) children differed by gender and race. CD4+, CD8+, and absolute lymphocytes by HIV infection status, gender, and race were assessed using linear mixed-effects natural cubic spline models, allowing for prematurity and maternal CD4+ cell count. In uninfected children, levels of all 3 markers peaked twice in the first few months of life, declining to adult levels by around 8 years of age; uninfected boys and uninfected black children had significantly reduced CD4+ and absolute lymphocyte counts; the gender difference was especially pronounced in black children. Infected children had substantially lower levels and distinctly different patterns; with, e.g., by age 6 months CD4+ cell counts nearly 1200 per mm3 lower than in uninfected infants. Levels also significantly differed by gender and race for infected children, although for gender in the opposite direction. The gender and race differences in CD4+ levels were not explained by a general lymphocytosis nor were they confounded by treatment. These substantial differences in immunologic markers may reflect underlying genetic influence on the cellular immune system and may have implications for clinical decisions about therapeutic management.

Age Factors↗
PubMed2006

The influence of physician race and gender on obstetrician-gynecologists' annual incomes.

OBJECTIVE: A study using 1998 data concluded that incomes of male and female obstetrician-gynecologists were essentially equivalent, after considering only differences in productivity. We examined the association between gender, race, and obstetrician-gynecologists' incomes, after correcting for productivity and other important practice and provider characteristics. METHODS: Survey responses obtained from 1992 to 2001 from 962 actively practicing obstetrician-gynecologists and linear regression modeling were used to estimate the influence of race and gender on physicians' annual incomes after controlling for work effort, provider characteristics, and practice characteristics. RESULTS: Compared with white male and black female obstetrician-gynecologists, black men reported seeing 5% more patient visits and working 18% more hours, while white women reported seeing 18% fewer visits and working 10% fewer annual hours. Women were more likely to be nonowner employees than men. White female obstetrician-gynecologists were less likely than the other groups to be board certified. After adjustment for work effort, provider characteristics, and practice characteristics, black men's mean reported annual income was 210,859 dollars, or 78,905 dollars (27%) lower than that for white men (95% confidence interval [CI] 120,082 dollars to 37,729 dollars lower; P < .001); white women's was 242,721 dollars, or 47,043 dollars (16%) lower (95% CI 70,127 dollars to 23,958 dollars lower; P < .001); and black women's was 246,355 dollars, or 43,409 dollars (15%) lower (95% CI 92,296 dollars to 5,478 dollars higher, P = .08). CONCLUSION: During the 1990s, both black race and female gender were associated with substantially lower annual incomes among obstetrician-gynecologists. These findings warrant further exploration to ensure that income differences among physicians are not unjustly driven by race or gender.

Adult↗
PubMed2003

The relation of race to outcomes and the use of health care services for acute low back pain.

STUDY DESIGN: Four strata of randomly selected health care providers in North Carolina (primary care MDs, Doctors of Chiropractic, orthopedic surgeons, and group model HMO primary care providers) enrolled 1633 consecutive patients with low back pain into a cohort study. OBJECTIVE: To determine whether race had an independent effect on rate of recovery from low back pain, and whether there was any racial disparity in the treatments provided to patients with low back pain. SUMMARY OF BACKGROUND DATA: Little research to date has examined the relation between patient race and recovery from an episode of acute low back pain. METHODS: Consecutive patients were enrolled in the provider's office and contacted by telephone at baseline, at 2, 4, 8, 12, and 24 weeks, and at 22 months. RESULTS: Blacks (n = 238) at baseline had higher pain scores on a 10-point scale (5.92 vs 5.25; P< 0.01) and worse functional disability (12.1 vs 11; P= 0.04), as assessed by the 23-point Roland-Morris scale, yet were considered by their health provider as having less severe pain and less likely to have disc disease than white patients (P < 0.05 for all comparisons). Blacks had worse functional disability at most follow-up interviews. Blacks were shown to be less likely to receive radiographs (49% vs 40%) or advanced imaging studies (10% vs 6%), even after controlling for income, education, baseline severity of low back pain, and insurance status (P < 0.05). Doctors of Chiropractic had different practice approaches than MDs, and there was an interaction with patient race. CONCLUSIONS: The relation of patient race to outcomes from and care for low back pain is complex. Blacks have slightly worse functional status than whites on presentation and at follow-up assessment. Blacks receive less intense diagnostic and treatment approaches from MDs, although the severity of their impairment is at least as great.

Activities of Daily Living↗
PubMed2005

The relationship between obesity and race on inhibin B during the menopause transition.

OBJECTIVE: Data are lacking on the effects of obesity and race on inhibin B levels during the menopause transition. The purpose of this study was to determine the relationship among inhibin B levels, body mass index (BMI), and race during the menopause transition. DESIGN: In the Penn Ovarian Aging Study, a prospective cohort study of reproductive aging, 436 women aged 35 to 47 years were followed up with serial hormones, anthropometric measures, and questionnaires for 6 years. Univariate and multivariable analyses were performed comparing mean log transformed inhibin B levels among menopause stages, age groups, BMI categories, races, and smoking groups. RESULTS: In the univariate analyses, mean inhibin B levels were negatively associated with menopause stage, age, and BMI, but not significantly with race or smoking. Interactions of menopause status and BMI were significant (P < 0.001). Premenopausal women with a BMI of 25 or higher had significantly lower inhibin B levels compared with women with a BMI of less than 25 (41.8 pg/mL vs 58.4 pg/mL, P < 0.001), whereas postmenopausal women with a BMI of 30 or higher had significantly higher inhibin B levels compared with the postmenopausal women with a BMI of less than 25 (29.1 pg/mL vs 26.7 pg/mL, P < 0.001). CONCLUSIONS: Although BMI is a significant independent predictor of inhibin B levels, the relationship between BMI and inhibin B changes with advancing menopause stage. These data provide additional evidence that obesity influences hormones during the menopause transition.

Adult↗
PubMed2005

Camel racing injuries among children.

OBJECTIVE: The aim of this study is to determine the frequency and severity of camel racing injuries among children aged 5 to 15 years during the period 1992 to 2003 in the State of Qatar. DESIGN: Case series. SETTING: The study was conducted in the Hamad General Hospital, State of Qatar, from January 1992 to December 2003. PATIENTS AND METHODS: A total of 275 subjects aged 5 to 15 years with camel racing injuries who were seen at the Accident Emergency Department, Critical Care, and Physiotherapy Departments of the Hamad General Hospital were studied. The sociodemographic information and the details of the injury of the studied subjects were collected. The Abbreviated Injury Scale system was used to determine the severity of injury. RESULTS: Overall, 275 camel racing injuries were reported among boys aged 5 to 15 years. The majority of patients were Sudanese (91.3%). The most commonly injured locations were upper limb (23.2%), lower limb (21.1%), and head (20.7%), followed by other injury locations. Seventeen patients were disabled as a result of their injury, and another 3 injuries were fatal. This study revealed that 34% of injuries were considered to be minor, 22.1% moderate, 18.1% serious, 11.6% critical, and 6.4% maximum. CONCLUSIONS: The injury severity caused by the camel racing significantly affected the length of hospital stay. At present, the government is serious about this problem, and there is a draft of proposed legislation intended to prevent the employment of children below the age of 12 as camel jockeys.

Abbreviated Injury Scale↗
PubMed2004

Race is not a predictor of prostate cancer detection on repeat prostate biopsy.

PURPOSE: We evaluated men undergoing repeat prostate biopsies for persistently increased serum prostate specific antigen (PSA) levels to determine if race was a predictor of cancer detection. MATERIALS AND METHODS: Between July 1995 and June 2002, 401 men had undergone 2 or more transrectal ultrasound guided prostate biopsies at our institutions. Clinical information was gathered using our prostate biopsy database and retrospectively reviewed. Race, age, serum PSA, PSA velocity, total number of biopsies performed, total number of previous negative cores and the presence of high grade prostatic intraepithelial neoplasia (HGPIN) or atypical small acinar proliferation (ASAP) on prior biopsy were evaluated to determine if they were predictors of subsequent cancer detection. Multivariate analysis was performed using a time dependent covariate Cox proportional hazards model. RESULTS: Of the 401 men undergoing repeat prostate biopsy, 91 (22.7%) were diagnosed with prostate cancer. In total there were 180 (44.9%) black men and 221 (55.1%) white men. Cancer was diagnosed in 49 black men (27.2%) and 42 white men (19.0%, p = 0.06). On multivariate analysis serum PSA, HGPIN, ASAP and PSA velocity were predictors of prostate cancer detection (p = 0.006, <0.0001, 0.001 and 0.0004, respectively). Race was not found to be a predictor of prostate cancer detection on repeat prostate biopsy (p = 0.16). In the evaluation of clinical data for racial differences, black men had a significantly higher incidence of HGPIN on prior biopsy compared to white men (p = 0.02). Serum PSA, PSA velocity, presence of ASAP on prior biopsy, age, number of biopsies performed and number of previous negative cores were not statistically different between black and white men. CONCLUSIONS: Race is not a predictor of prostate cancer detection in men undergoing repeat prostate biopsies. With the exception of HGPIN, all other clinical parameters were similar between black and white men. Serum PSA, PSA velocity, HGPIN and ASAP were found to be significant predictors of subsequent prostate cancer detection.

Biopsy↗
PubMed2003

Race and gender disparities in rates of cardiac revascularization: do they reflect appropriate use of procedures or problems in quality of care?

BACKGROUND: Numerous studies have documented substantial differences by race and gender in the use of coronary artery bypass graft surgery and percutaneous coronary angioplasty. However, few studies have examined whether these differences reflect problems in quality of care. METHOD: We selected a random sample stratified by gender, race, and income of 5026 Medicare beneficiaries aged 65 to 75 who underwent inpatient coronary angiography during 1991 to 1992 in 1 of 5 states. We compared the frequency of 2 problems in quality by race and gender: underuse or the failure to receive a clinically indicated revascularization procedure and receipt of revascularization when it was not clinically indicated. We used 2 independent sets of criteria developed by the RAND Corporation and the American College of Cardiology/American Hospital Association (ACC/AHA). We also examined survival of the cohort through March 31, 1994. RESULTS: Revascularization procedures were clinically indicated more frequently among whites than blacks and among men than women. Failure to receive revascularization when it was indicated was more common among blacks than among whites (40% vs. 23-24%, depending on the criteria, both P<0.001) but similar among men and women (25% vs. 22-24%, P>0.05). Racial disparities remained similar after adjusting for patient and hospital characteristics. Among patients rated inappropriate, use of procedures was greater for whites than blacks using RAND criteria (10.5% vs. 5.8%, P<0.01) and greater for men than for women (14.2% vs. 5.3% by RAND criteria, P=0.001; 8.2% vs. 4.0%% by ACC/AHA criteria, P=0.04). After multivariate adjustment, the disparities for race and gender remained similar and were statistically significant using RAND criteria. Mortality rates tended to validate our appropriateness criteria for underuse. CONCLUSIONS: Racial differences in procedure use reflect higher rates of clinical appropriateness among whites, greater underuse among blacks, and more frequent revascularization when it was not clinically indicated among whites. Underuse is associated with higher mortality. In contrast, men had higher rates of clinical appropriateness and were more likely to receive revascularization when it was not clinically indicated. There was no evidence of greater underuse among women.

Black or African American↗
PubMed2006

Variation in pediatric intensive care therapies and outcomes by race, gender, and insurance status.

CONTEXT: The differential allocation of medical resources to adult patients according to characteristics such as race, gender, and insurance status raises the serious concern that such issues apply to critically ill children as well. OBJECTIVE: This study examined whether medical resources and outcomes for children admitted to pediatric intensive care units differed according to race, gender, or insurance status. DESIGN: An observational analysis was conducted with use of prospectively collected data from a multicenter cohort. Data were collected on 5,749 consecutive admissions for children from three pediatric intensive care units located in large urban children's hospitals. PARTICIPANTS: Children aged </=18 years admitted over an 18-month period beginning in June 1996 formed the study sample. MAIN OUTCOME MEASURES: Hospital mortality, length of hospital stay, and overall resource use were examined in relation to severity of illness. Standardized ratios were formed with generalized regression analyses that included the Pediatric Index of Mortality for risk adjustment. RESULTS: After adjustment for differences in illness severity, standardized mortality ratios and overall resource use were similar with regard to race, gender, and insurance status, but uninsured children had significantly shorter lengths of stay in the pediatric intensive care unit. Uninsured children also had significantly greater physiologic derangement on admission (mortality probability, 8.1%; 95% confidence interval [CI], 6.2-10.0) than did publicly insured (3.6%; 95% CI, 3.2-4.0) and commercially insured patients (3.7%; 95% CI, 3.3-4.1). Consistent with greater physiologic derangement, hospital mortality was higher among uninsured children than insured children. CONCLUSIONS: Risk-adjusted mortality and resource use for critically ill children did not differ according to race, gender, or insurance status. Policies to expand health insurance to children appear more likely to affect physiologic derangement on admission rather than technical quality of care in the pediatric intensive care unit setting.

Adolescent↗
PubMed2004

Genomic evidence for divergence with gene flow in host races of the larch budmoth.

Ecological divergence in the face of gene flow has recently become implicated as a potentially important cause of speciation and adaptive radiation. Here, we develop a genomic approach to test for divergent selection in sympatric host races of the larch budmoth Zeiraphera diniana (Lepidoptera: Tortricidae). We analysed hundreds of amplified fragment length polymorphism markers in 92 individuals in sympatric and allopatric populations, and in two backcross broods used to map the markers to individual chromosomes. The results directly confirm the existence of natural hybridization and demonstrate strong heterogeneity between chromosomes in terms of molecular divergence between host races (the average level of divergence was FST = 0.216). However, genomic heterogeneity was not found when we analysed divergence between geographically separated populations of the same host race. We conclude that the variance of the level of sympatric divergence among chromosomes is the footprint of divergent selection acting on a few linkage groups, combined with appreciable gene flow that homogenizes between-race variation at the remaining linkage groups. These results, coupled with other recent multilocus analyses of sister species pairs, demonstrate that selection-driven sympatric phase of genetic divergence in the presence of gene flow is a likely feature of speciation.

Analysis of Variance↗
PubMed1977

Evaluation of a Chemical Method for Assay of Helminthosporium maydis Race T Toxin.

A chemical test reported by Karr et al. (Plant Physiol. 55:727) to assay for host-specific toxin produced by Helminthosporium maydis race T was evaluated. Preparations from culture filtrates of both race T isolates, containing host-specific toxin, and similar preparations from race O isolates, containing no detectable host-specific toxin, gave positive reactions in the chemical assay. Also, preparations containing active or inactive toxin gave equal responses in this test. The procedure does not provide a reliable method for assaying H. maydis race T toxin.

Journal Article↗