Biomedical subjects

E H Johnson

Publications and source records attributed to E H Johnson.

At least 19 recordsLinked to original sources

PubMed1992

Psychological and physiological predictors of lipids in black males.

The association between lipids and both psychological and physiological measures were examined in this study of healthy black males. The results revealed that certain psychological measures, namely, State and Trait Curiosity and Trait Anger, explained a significant proportion of the variance in high-density lipoproteins (HDL), low-density lipoproteins (LDL), and triglycerides. Although psychological factors accounted for a significant proportion of the variance in lipids (29% for HDL, 25% for LDL, 64% for LDL/HDL, 29% for triglyceride), the amount of explained variance was significantly increased by the inclusion of both psychological and physiological variables in the regression equation. However, neither of the psychological variables explained any of the variance for total cholesterol when physiological variables were included in the regression analysis. The overall pattern of the findings suggests that black males who are at increased risk for elevated lipid levels may be identified by their level of mental vigilance, the frequency at which their anger is experienced, and the presence of other traditional risk factors.

Adult↗

PubMed1992

Onchocerca volvulus: immunization of chimpanzees with X-irradiated third-stage (L3) larvae.

To provide a theoretical basis for the potential development of vaccines against Onchocerca volvulus (Ov) a trial has been conducted to assess the protective efficacy of immunization of chimpanzees with X-irradiated L3 larvae. Approximately 1000 larvae were injected at 0, 1, and 7 months. The immunized animals, and unimmunized controls, were then challenged with 250 live L3. In order to provide possibly protective exposure to the immunologically distinct L4 epicuticle, a radiation dose (45 krad) was chosen which preserved about 50% of the molting ability of unirradiated larvae. Despite the presence of a strong immune response to crude adult worm extracts, and to cloned Ov antigens, at the time of challenge little or no significant protection against patent infection was observed: three of four immunized animals developed patent infection as compared to four of four controls. One immunized animal failed to become patent or to manifest the late antibody response to adult worm antigens seen in both subpatent and patent infections in this model, and may have been protected from infection. The implications of these studies for future attempts to immunize against O. volvulus are discussed.

Animals↗

PubMed1992

Prognostic significance of histopathologic subtype and stage in small cell lung cancer.

A study of 149 light microscopic tissue slides from 147 patients with recorded initial diagnoses of small cell lung cancer (SCLC) (114 cases) and undifferentiated carcinoma (35 cases) was undertaken to test the reproducibility and prognostic impact of a new histopathologic subclassification of SCLC proposed by the Pathology Panel of the International Association for the Study of Lung Cancer (IASLC). This study was further designed to test the impact of clinical stage, age, sex, and race on survival. The tissue slides were blindly reclassified as SCLC or non-SCLC by a panel of five pathologists with no knowledge of the initial diagnosis. The SCLCs were divided into the three subtypes outlined by the IASLC pathology panel: small (classic or pure), mixed (small cell/large cell), and combined (small cell/squamous carcinoma or small cell/adenocarcinoma). Small cell lung cancer was clinically staged as local, regional, or distant. Consensus diagnosis (defined as agreement by at least three of the five pathologists) was achieved in 144 (96.6%) of the 149 cases. Of these 144 cases, 124 were reclassified as SCLC (115 [92.8%] small, five [4.0%] mixed, and four [3.2%] combined) and 20 were classified as non-SCLC. The median lengths of survival for the small, mixed, and combined subtypes were 225, 1,110, and 203 days, respectively (P = .025). Adequate staging data were available in 123 of the 124 SCLC cases. Of the 123 SCLC cases, 27 (21.9%) were local, 22 (17.9%) were regional, and 74 (60.2%) were distant stage. The median lengths of survival for the local, regional, and distant stages were 428, 251, and 111 days, respectively. This association was highly significant (P = .0001). We conclude that stage is the major determinant of survival in SCLC. Mixed subtypes had significantly longer survival times than the small or combined subtypes (P = .025). Survival times were longer for women than for men, and the survival time difference between men and women was significant (P = .0028). We found no significant differences in survival according to age or race.

Carcinoma, Small Cell↗

PubMed1992

Identification and characterization of an Onchocerca volvulus cDNA clone encoding a microfilarial surface-associated antigen.

The identification and characterization of a recombinant cDNA clone (OV103) expressing a microfilarial surface-associated antigen of Onchocerca volvulus is described. OV103 was identified and isolated from a lambda gt11 cDNA expression library derived from adult O. volvulus mRNA using a chimpanzee antiserum, taken 2 years after infection with third-stage larvae of O. volvulus. The cDNA clone encodes a 12.5-kDa protein that corresponds to a 15-kDa parasite protein present in microfilariae and adult female worms. The antigen encoded by this clone is located in the basal layer of the cuticle and the hypodermis of the female adult worm, and on the surface of microfilariae. OV103 fusion polypeptide is recognized only by some sera from onchocerciasis infected subjects (57%), but more significantly (89%) by sera from individuals that have low levels of patent infection. In addition, the antibody response to this protein developed before appearance of microfilariae in the skin of chimpanzees that had developed non-patent or low level patent infections, while the antibody response in chimpanzees with high levels of microfilariae appeared later at the time of appearance of microfilariae. Preliminary experiments indicated that affinity purified antibodies directed against OV103 fusion polypeptide mediated killing of nodular microfilariae in vitro in the presence of normal peripheral blood granulocytes.

Amino Acid Sequence↗

PubMed1992

The influence of pulsatile perfusion on the vascular properties of the newborn lamb lung.

It is not known how the mode of flow alters the resistance properties of the newborn pulmonary circulation. Therefore, we compared the pressure responses of the perfused left pulmonary circulation of 16 newborn lambs with step changes in either pulsatile or steady flow. The slope of the pressure-flow curve differed significantly according to mode of perfusion. The slope of the pressure-flow curve was 0.125 +/- 0.115 mm Hg.mL-1.kg.min for pulsatile flow and 0.484 +/- 0.350 mm Hg.mL-1.kg.min for steady flow perfusion (p less than 0.05). The intercept pressure at zero flow was similar for both modes of flow, being 21.3 +/- 4.9 mm Hg for pulsatile flow compared with 23.8 +/- 11.3 mm Hg for steady flow perfusion. All perfusions with either mode of flow demonstrated flow-dependent decreases in pulmonary vascular resistance. However, the decreases in resistance were greater for pulsatile than for steady flow perfusion. In addition, the steady-perfused lungs demonstrated a significantly greater left lung wet/dry weight ratio than either the left lungs of pulsatile-perfused animals or the intact left lungs of 13 control animals not undergoing experimental perfusion (p less than 0.05). Thus, the mode of flow appears to play a major role in modulating the magnitude and distribution of pulmonary vascular resistance. This factor must be considered when interpreting the physiologic significance of hemodynamic experiments.

Animals↗

PubMed1992

Morphometric quantitation of tumor necrosis in stage 1 non-small cell carcinoma of lung: prognostic implications.

We objectively examined the extent of tumor necrosis by computer-assisted morphometry in 28 patients with surgically resected Stage I non-small cell carcinoma of lung. Fourteen of the 28 patients were long-term survivors (mean survival after diagnosis 94 mo) and 14 were short-term survivors (up to 62 mo after diagnosis). The extent of tumor necrosis was determined by means of a computer assisted digitizing system. The two sample t test and the two-tailed Wilcoxon rank score tests were used for statistical analysis of comparison of the extent of tumor necrosis between the two groups of patients. This morphometric study showed that the extent of tumor necrosis was significantly associated to the probability of long-term survival, with long surviving patients having a lesser degree of tumor necrosis (t = 2.75, p < 0.02, 2 sample t test, two-tailed, df = 26). These findings reaffirm previous subjective data, derived from pathologist assessment of tumor necrosis, and suggest that morphometric evaluation of tumor necrosis may play a useful adjunct role in predicting prognosis of carcinoma of lung.

Carcinoma, Non-Small-Cell Lung↗

PubMed1992

Similarities in cardiovascular reactivity to behavioral stressors in African-American and white males.

This study examines the influence of ethnicity (African-American vs white) and family history of hypertension on the blood pressure and heart rate responses of healthy, unmedicated men, aged 21 to 39 years, to a variety of stressors that are hypothesized to elicit beta-adrenergic or alpha-adrenergic reactivity. Cardiovascular reactivity data were also obtained in response to ischemic exercise (handgrip), and a structured interview was designed to measure anger. On the basis of previous research, we predicted that African Americans would show greater responses to the alpha-adrenergic tasks (cold pressor test) and smaller cardiovascular responses to the beta-adrenergic tasks (math challenge) compared to whites. The results indicated no significant differences between African-American and white blood pressure or heart rate responses to either of the tasks. On the other hand, both African-American and white men with family histories of hypertension had significantly higher systolic and diastolic blood pressure responses during exposure to each of the stressors than did men with negative family histories of hypertension. Parental history did not significantly influence heart rate responses to the stressors or resting plasma catecholamine levels in either group. African Americans had significantly lower erythrocyte lithium-sodium exchange rates and significantly higher intracellular sodium concentration compared to whites; parental history of hypertension did not influence these measures. Finally, the blood pressure responses to stress were not modified by the erythrocyte lithium-sodium exchange rate, intracellular sodium concentration, or plasma concentrations of catecholamines.

Adult↗

PubMed1992

Black males who always use condoms: their attitudes, knowledge about AIDS, and sexual behavior.

One hundred six black males completed a questionnaire concerning attitudes and knowledge about the use of condoms and acquired immunodeficiency syndrome (AIDS). Of the 106 males in the study, 27 (26%) reported that they "always" used condoms, 31 (29%) did not use condoms and had low intentions of using them, and 48 (45%) reported high intentions to use condoms. Results indicated that knowledge about AIDS was exceptionally high for black males in all three groups. Black males with low intentions to use condoms reported significantly more negative attitudes about the use of condoms (eg, using condoms is disgusting) and reacted with more intense anger when their partners asked about previous sexual contacts, when a partner refused sex without a condom, or when they perceived condoms as interfering with foreplay and sexual pleasure. A significantly larger percentage of low intenders were treated for gonorrhea, syphilis, herpes, and genital warts than males in the other groups. Drug use did not differentiate the three groups, although marijuana was used more often by males in the low-intender group. Finally, a larger percentage of black males in the low-intender group reported experiences with anal intercourse and sex with a prostitute, but considered themselves at lower risk for AIDS than did their high-intender or steady-user counterparts.

Acquired Immunodeficiency Syndrome↗

PubMed1992

Do African-American men and women differ in their knowledge about AIDS, attitudes about condoms, and sexual behaviors?

This study identified a sample of young African-American men and women classified as having multiple sex partners or one sex partner. Of the 149 men, 71 (47%) were classified as having multiple sex partners and 78 (53%) as having one sex partner. Of the 165 women, 29 (19%) were classified as having multiple sex partners and 126 (81%) as having one sex partner. Results indicated that the groups did not differ in their knowledge about acquired immunodeficiency syndrome (AIDS). However, attitudes about condom use differed significantly by gender (P less than .01) and by multiple sex status (P less than .001). Angry reactions regarding the negotiation of condom use occurred more with men than with women (P less than .05). Men and members of the multiple sex partners group tended to engage in more risky sexual behavior. These two groups also had a significantly (P less than .001) higher incidence of gonorrhea. While the multiple sex partners group had significantly more smokers (P less than .01), drinkers (P less than .01), and crack users (P less than .05), men were significantly higher consumers of marijuana (P less than .001) and alcohol (P less than .01). Overall, the results indicate that African Americans are knowledgeable about AIDS, but there appears to be a gap between knowledge and risky sexual behaviors. Prospective studies are needed to clarify the factors that determine the relationship (or lack of) between knowledge and risky sexual behaviors. Without such studies, a major part of the foundation that is needed for the development of sensitive and effective AIDS prevention programs for African Americans will be missing.

Acquired Immunodeficiency Syndrome↗

PubMed1991

Hyperkinetic borderline hypertension in Tecumseh, Michigan.

Of 691 healthy (untreated) villagers of Tecumseh, Michigan (average age 32.6 years), 99 had a clinical blood pressure exceeding 140/90 mmHg. Thirty-seven per cent of these borderline hypertensives had increased heart rate, cardiac index, forearm blood flow and plasma norepinephrine. These subjects had elevated self-determined home blood pressure (average of 14 measurements). The present hyperkinetic borderlines had elevated blood pressure at 5, 8, 21 and 23 years of age and their parents also had higher blood pressure. The prevalence of high blood pressure in Tecumseh, its long history, elevated blood pressure readings outside the physician's office and family background of hypertension, suggests that the hyperkinetic state is a significant clinical condition. Previous studies on hospital-based populations proved that the hyperkinetic state is caused by an excessive autonomic drive. The association of the hyperkinetic state with elevated norepinephrine in this study suggests that a sympathetic hyperactivity is present in a large proportion of unselected subjects with mild blood pressure elevation.

Adult↗

PubMed1991

Onchocerca volvulus: in vitro killing of microfilaria by neutrophils and eosinophils from experimentally infected chimpanzees.

Peripheral blood leukocytes from chimpanzees experimentally infected with third stage larvae, or with nodular microfilaria (mf) of Onchocerca volvulus, were evaluated for their ability to kill nodular mf in vitro. Inoculation of chimpanzees with third stage larvae, and prospective follow up, permitted each animal to be classified as patent, infected but not patent, or post-patent. Neither lymphocytes nor monocytes significantly adhered to, immobilized, or killed mf. However, neutrophils or eosinophils killed mf effectively in the presence of immune serum. Neutrophil and eosinophil enriched cell preparations from control animals were able to kill mf with serum from infected animals, but to a significantly lesser degree than when both cells and serum were taken from infected animals. Chimpanzees inoculated with mf showed a progressive increase in cellular killing of mf after a second inoculation which surpassed that seen with animals inoculated with third stage larvae. Antibody-mediated killing of mf by neutrophils and eosinophils may be important in the termination of patency in this infection.

Animals↗

PubMed1991

Familial and psychological correlates of smoking in black and white adolescents.

Cigarette smoking is considered to be the single most preventable contributor to chronic diseases, but there is still great controversy about the initiation and maintenance of smoking among adolescents. The goal of this study was to examine familial and psychological factors that contribute to the initiation and maintenance of smoking among black and white adolescents. To accomplish this, we tested 602 male (275 black and 327 white) and 460 female (174 black and 286 white) adolescent students enrolled in health classes in Tampa, Florida. Among blacks, 15.6% were currently smoking cigarettes, compared to 34.8% of the white students. Blacks who initiated smoking were most influenced by having a sister who smoked, while maintenance was most influenced by an older brother who smoked. In contrast, white adolescents who initiated smoking were more likely to have an older brother who smoked, while maintenance of smoking was predicted by having a father who smoked. Furthermore, the data show that both the initiation and the maintenance of smoking among blacks is related to the experience of intense feelings of anger and irritability, while among white adolescents, these emotions contribute only to the initiation of smoking. These data indicate that smokers and nonsmokers differ in their emotional reactions to stress, and that ethnicity (black vs white) is an important determinant in the association between smoking and emotional reactions to stress. The overall pattern of the findings in this inquiry suggests that the efficacy of antismoking treatment procedures could be enhanced by targeting exaggerated emotional reactions for modification. The data also suggest that smoking prevention programs for adolescents should take into consideration pressures to smoke that may arise from having family members who smoke. Given the inherent problems of a cross-sectional research design, future research is needed to clarify the interrelationships between smoking, ethnicity, and measures of the experience and expression of anger.

Adaptation, Psychological↗

PubMed1990

Interrelationships between psychological factors, overweight, and blood pressure in adolescents.

Relationships between psychological factors and physical factors such as body mass, overweight, and blood pressure were examined in a sample of black and white adolescents enrolled in health science courses. Black female adolescents were significantly more overweight and obese than either other group. Psychological factors were not significantly associated with body mass (weight/height) for females. A small percentage of the variance in body mass for black (6%) and white (4%) males was explained by Trait Anger, the frequent experience of anger and the intensity of anger (S-Anger-Reaction/TP) in pressure situations. Trait Anger also significantly (p less than 0.01) discriminated between black male adolescents who were normal weight and those 20% overweight for age and height. The relationships between traditional risk factors and blood pressure among adolescents who were 20% underweight, normal weight, and 20% overweight for age and height suggest that few traditional risk factors contribute significantly to the prediction of blood pressure in overweight adolescents. In contrast, psychological measures of suppressed anger (Anger-In, Anger Expression) were significantly (p less than 0.001) associated with blood pressure among overweight adolescents. The findings regarding the associations between overweight and psychological factors are complex. Prospective studies using better measures of overweight are needed to clarify the processes involved.

Adolescent↗

PubMed1990

Gallstones and obesity: observations from 352 autopsied patients.

Obesity has been considered a risk factor for gallstones, but the association remains controversial. To test this possible association we studied autopsy reports of 352 adult patients. These included 248 obese and 104 non-obese patients. The body mass index, defined as body weight in kg/m2, was used to assess and measure the degree of obesity and to divide patients into two groups: Group 1 (normal weight and mildly obese individuals) and Group 2 (moderately and severely obese individuals). The comparative frequency of gallstones in these two groups was statistically analyzed by the Mantel-Haenzel method with stratification for age, sex, and diabetes mellitus. No significant association between gallstones and obesity (p less than 0.2) was found.

Adult↗

PubMed1989

Guanine nucleotide binding regulatory proteins and adenylate cyclase in livers of streptozotocin- and BB/Wor-diabetic rats. Immunodetection of Gs and Gi with antisera prepared against synthetic peptides.

Adenylate cyclase in liver plasma membranes from streptozotocin-diabetic (STZ) or BB/Wor spontaneously diabetic rats showed increased responsiveness to GTP, glucagon, fluoroaluminate, and cholera toxin. Basal or forskolin-stimulated activity was unchanged in STZ rats, but increased in BB/Wor rats. No change in the alpha-subunit of Gi (alpha i) was observed in STZ or BB/Wor rats using pertussis toxin-stimulated [32P]ADP-ribosylation. Immunodetection using antibodies against the COOH-terminal decapeptides of alpha T and alpha i-3 showed no change in alpha i in STZ rats and a slight decrease in BB/Wor rats. Angiotensin II inhibition of hepatic adenylate cyclase was not altered in either diabetic rat. In both models of diabetes, Gs alpha-subunits were increased as measured by cholera toxin-stimulated [32P]-ADP-ribosylation of 43-47.5-kD peptides, reconstitution with membranes from S49 cyc- cells or immunoreactivity using antibodies against the COOH-terminal decapeptide of alpha s. These data indicate that STZ-diabetes increases hepatic Gs but does not change Gi or adenylate cyclase catalytic activity. In contrast, BB/Wor rats show increased hepatic Gs and adenylate cyclase. These changes could explain the increase in hepatic cAMP and related dysfunctions observed in diabetes.

Adenosine Diphosphate Ribose↗

PubMed1989

Psychiatric morbidity and health problems among black Americans: a national survey.

This study examined the relationship between symptoms of psychiatric morbidity and health problems among a nationally representative, cross-sectional sample of 2107 black adults from the National Survey of Black Americans. Subjects experiencing a high level of psychiatric symptomatology had a significantly higher number of health problems and reported a lower level of satisfaction with their overall health than blacks with low levels of psychiatric symptoms or those who never experienced emotional problems. Individuals with the highest level of psychiatric symptomatology were more likely to have been physician-diagnosed as having ulcers, hypertension, diabetes, kidney problems, nervous-emotional problems, and circulatory system difficulties. These relationships persisted after controlling for age, gender, socioeconomic factors, and traditional risk factors for health problems, such as smoking and alcohol use. Although generally consistent with previous research on predominantly white samples, these specific findings underscore the complexities involved in drawing inferences from associations between psychiatric symptomatology and health problems observed in cross-sectional surveys. Prospective psychiatric epidemiologic studies, utilizing better measures of psychological distress and objective health outcome measures, are needed to clarify the relationship between psychiatric difficulties and health problems among black Americans.

Black or African American↗

PubMed1989

The role of the experience and expression of anger and anxiety in elevated blood pressure among black and white adolescents.

Differences between black and white adolescents in the experience and expression of anger and anxiety, traditional risk factors for hypertension, and blood pressure were examined among adolescents enrolled in a health science course in Tampa, Florida. Relationships between blood pressure and anger/anxiety and traditional risk factors were also examined. Black adolescents of both genders experienced feelings of anxiety more frequently and with greater intensity than did their white counterparts. Although black and white adolescents did not differ in their ability to experience anger, blacks experienced more intense reactions in situations involving unfair criticism and time pressure. More importantly, black males and females suppressed the expression of their anger more often than did their white counterparts. The blood pressure of black adolescent males and females was found to be significantly higher than their white counterparts. Blacks were also more likely to have a family history of hypertension, but were less likely to smoke cigarettes. Racial differences on other risk factors were found only among black females who were heavier and consumed more salty junk foods than white females. Although a number of the personality and risk factor measures were significantly correlated with blood pressure, measures of suppressed anger were more strongly correlated with blood pressure for both black and white adolescents. Findings from the multiple regression analyses showed that suppressed anger was the best independent predictor of blood pressure for all groups except white females. Overall, the findings from this study demonstrate that adolescents with elevated blood pressure can be identified by emotional/psychological factors, which are predictive of high blood pressure for both blacks and whites.

Adolescent↗

PubMed1988

Pruritus in psoriasis. A prospective study of some psychiatric and dermatologic correlates.

Among 82 inpatients with psoriasis, 67% (55 patients) reported moderate or severe pruritus. The degree of depressive psychopathology discriminated between the mild, moderate, and severe pruritus groups at admission. Prospectively, the change in depression scores correlated with the change in pruritus pretreatment to posttreatment. Pruritus severity did not correlate significantly with stress due to life events, age at onset, ethyl duration of psoriasis, age, sex, marital status, and average reported daily alcohol (ethanol) consumption. Among the objective dermatologic measures, including extent and severity of lesions, only the degree of perilesional irritation discriminated between the mild, moderate, and severe pruritus groups at admission, and prospectively, change in this measure correlated with the change in pruritus pretreatment to posttreatment. This finding was most likely related to the self-excoriation associated with pruritus. Intrapsychic factors (eg, the severity of depression) rather than external psychosocial or well-defined dermatologic factors, were the most significant correlates of pruritus in psoriasis.

Adult↗