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Biomedical subjects

J Mayer

Publications and source records attributed to J Mayer.

At least 235 records · Page 13Linked to original sources
PubMed1991

Blood pressure and sleep apnea: results of long-term nasal continuous positive airway pressure therapy.

Arterial blood pressure patterns in 12 men with sleep apnea and arterial hypertension were studied at baseline and after 6 months' therapy with nasal continuous positive airway pressure (nCPAP). Preexisting antihypertensive medication was discontinued 1 week before baseline measurements. Weight did not change during the study period; body mass index was 29.3 (range, 25.4-38.5) vs. 29.3 (25.0-38.5). During therapy the apnea index decreased from 58 (range 30-73) to 2 (range 0-7) apneic episodes per hour (p less than 0.01). Intra-arterial systolic (BP sys.) and diastolic (BP dias.) blood pressure and heart rate decreased during therapy (p less than 0.001). Mean values +/- 95% confidence intervals were as follows: BP sys., 147.1 (+/- 1.6) mm Hg vs. 126.4 (+/- 1.5) mm Hg; BP dias., 81.6 (+/- 0.8) mm Hg vs. 69.4 (+/- 0.6) mm Hg; heart rate, 68.8 (+/- 0.7) beats/min vs. 65.4 (+/- 0.7) beats/min. Furthermore, the variability of these parameters decreased during therapy: variability BP sys., 53.8 (+/- 1.1) mm Hg vs. 25.6 (+/- 1.1) mm Hg; variability BP dias., 35.6 (+/- 0.7) mm Hg vs. 17.9 (+/- 0.7) mm Hg; variability of heart rate, 28.1 (+/- 0.7) beats/min vs. 14.9 (+/- 0.7) beats/min (p less than 0.001). During treatment we found that blood pressure scores already dropped during the awake phase, with a further decrease during non-REM and REM sleep (p less than 0.001). Our results, which demonstrate the reversibility of high blood pressure upon treatment of sleep apnea, indicate that sleep apnea can be an etiological factor in hypertension. Sleep apnea should therefore be considered in the differential diagnosis of arterial hypertension.

Adult↗
PubMed1991

Biologic markers in risk assessment for environmental carcinogens.

The potential of biologic markers to provide more timely and precise risk assessments for environmental carcinogens is viewed against the current state-of-the-art in biological monitoring/molecular epidemiology. Biologic markers such as carcinogen-DNA adducts and oncogene activation are currently considered valid qualitative indicators of potential risk, but for most chemical exposures research is needed to establish their validity as quantitative predictors of cancer risk. Biologic markers have, however, already provided valuable insights into the magnitude of interindividual variation in response to carcinogenic exposures, with major implications for risk assessment.

Bias↗
PubMed1991

First experience with cilazapril in the treatment of sleep apnoea-related hypertension.

Sleep-related breathing disorders are associated with considerably impaired vitality and reduced life expectancy. In this respect, a particularly important role is played by obstructive snoring and obstructive or mixed sleep apnoea. Because of the often underestimated prevalence of sleep-related breathing disorders and their association with hypertension in greater than 50% of patients, it is important to introduce antihypertensive drug therapy that does not exacerbate the effects and the degree of these disorders, and that above all produces an adequate lowering of blood pressure by night. In the present study in 12 patients, it has been shown that the new ACE inhibitor, cilazapril, achieves a good reduction in blood pressure over 24 hours and during all stages of sleep, without any negative influence on the ratio of REM: nonREM sleep. The apnoea index was reduced from 40 (range 12 to 84) to 27 (range 0 to 72) apnoeas per hour of sleep (p less than 0.01). It will be increasingly important to take into account the effects of antihypertensive therapy on other clinical parameters, especially the nocturnal blood pressure profile and its association with sleep-related breathing disorders.

Angiotensin-Converting Enzyme Inhibitors↗
PubMed1991

DNA adducts and other biological markers in risk assessment for environmental carcinogens.

In order to validate a number of biologic markers as indicators of effective dose or potential risk, we have applied them in related cross-sectional, longitudinal and case-control studies. Biologic markers such as carcinogen-DNA adducts and activated oncogenes have already provided insights into mechanisms of chemical carcinogenesis. They have also given information regarding the extent of interindividual variation in biologic response within the human population. These results are directly relevant to quantitative risk assessment. However, more research is needed to establish quantitative links between biologic markers and human risk of cancer.

Biomarkers↗
PubMed1991

[Increase in blood pressure due to continuous obstructive snoring].

Sleep-related breathing disorders can strain the cardiovascular system. Link-ups with arterial hypertension have been confirmed in obstructive or mixed sleep apnoea which is characterised by discontinuous nocturnal snoring. On the other hand, it is known that arterial hypertension is very frequently seen in snorers. The present study deals with short-term, breathing-related blood pressure patterns and blood pressure changes during the snoring phase. 18 obstructive snoring phases were identified in 4 male patients aged 50 years (42-65), Broca index 136 (119-171). Polysomnographic measurements were carried out in the sleep laboratory and the blood pressure was continuously recorded via the a. brachialis. The short-term breathing-dependent blood pressure changes were systolic 10.8 (10-30) mmHg at the beginning and 17.5 (10-30) mmHg at the end of the snoring phase (P less than 0.01). Diastolically there was a difference of 9.4 (5-15) mmHg versus 13.9 (5-25) mmHg (P less than 0.01). During the snoring phases the systolic blood pressure increased from 140.3 (120-190) mmHg to 170.0 (145-235) mmHg and the diastolic pressure from 69.7 (50-110) mmHg to 93.1 (70-120) mmHg. The study proves that blood pressure increases occur not only in apnoeic snoring but also in continuous obstructive snoring. It is suspected that these changes are responsible for the high frequency of arterial hypertension among continuous snorers.

Adult↗
PubMed1991

Peripheral chemoreceptor reflex in obstructive sleep apnea patients; a relationship between ventilatory response to hypoxia and nocturnal bradycardia during apnea events.

15 patients with obstructive sleep apnea syndrome and arterial hypertension (H-OSAS), 25 normotensive patients with sleep apnea syndrome (N-OSAS) and 20 healthy age-matched controls (C) were included in this study. Ventilatory responses to activation (hypoxia) and inactivation (hyperoxia) of carotid chemoreceptors were studied in all subjects. Relationship between hypoxic ventilatory reactivity and nocturnal bradycardia during apnea-phases was analysed in both groups of patients. Results and conclusions. 1. We found an impairment of ventilatory response to hypoxia in H-OSAS and N-OSAS patients. However, the increase in ventilation in response to hypoxia was significantly greater in H-OSAS as compared to N-OSAS patients. 2. An augmented ventilatory response to inactivation of carotid chemoreceptors (the decrease in ventilation), observed in H-OSAS patients, indicates an increase in resting peripheral chemoreceptors drive in this group of patients. 3. The relationship between ventilatory response to hypoxia and nocturnal bradycaria in obstructive sleep apnea patients suggests, that hypoxic reactivity of arterial chemoreceptors might be involved in the origin of bradycardia during apnea events.

Bradycardia↗
PubMed1990

Restriction fragment length polymorphism of chromosome 3 (3p) and the epidermal growth factor receptor gene in human non-small cell lung carcinomas.

We have examined the possible loss of 3p alleles in lung tumor samples from 28 patients with non-small cell lung cancers (non-SCLC), using tumor adjacent lung tissue from the same patients as controls. Of the 14 patients with squamous cell carcinoma only 2 (14%) displayed constitutional heterozygosity at the 3p locus and the tumors of both of these cases did not show reduction to homozygosity. Of the 14 patients with adenocarcinomas, 50% had constitutional heterozygosity, and two of the tumors displayed a loss of heterozygosity. We have also examined restriction fragment length polymorphisms (RFLPs) of the epidermal growth factor (EGF) receptor gene in 29 non-SCLC tumor samples and in the tumor adjacent lung tissue samples obtained from the same cases. Digestion of the DNA samples with the BstEII enzyme and hybridization to a HER-A64-3 probe revealed four different types of polymorphic patterns. We did not, however, detect significant differences in the specific polymorphic bands between tumor and paired non-tumor lung tissues or between the different types of carcinomas.

Blotting, Southern↗
PubMed1990

Association of the eosinophilia-myalgia syndrome with the ingestion of tryptophan.

We report on a series of three patients with an unusual syndrome of eosinophilia and myalgia associated with the oral ingestion of tryptophan that was recognized in New Mexico in October 1989. All three patients, who were women 37 to 44 years of age, had severe muscle pain, muscle weakness, mouth ulcers, and striking eosinophilia (more than 8 X 10(9) cells per liter). Other manifestations included fever, abdominal pain, dyspnea, skin rash, and elevated serum concentrations of aminotransferase and aldolase. The women had been taking tryptophan in doses of 1.2 to 2.4 g a day for three weeks to 2 1/2 years. The discontinuation of tryptophan and the initiation of glucocorticoid treatment resulted in improvement, but all three women were still symptomatic three to five months later. Tests for trichinosis and other parasites and for allergic and connective-tissues disorders were negative, and serum immunoglobulin concentrations and erythrocyte sedimentation rates were normal. A muscle biopsy in one patient and biopsies of the vagina, liver, and other abdominal organs in another revealed eosinophilic infiltration, as well as the extracellular deposition of eosinophil-granule major basic protein. All three patients had elevated serum and urinary levels of this protein and eosinophil-derived neurotoxin, indicative of eosinophil degranulation. The syndrome of eosinophilia and myalgia in association with the ingestion of tryptophan that was seen in these three patients is a newly recognized adverse effect of tryptophan ingestion. Our identification of this association in these patients led to the discovery of an epidemic of what is now called the eosinophilia-myalgia syndrome.

Adult↗
PubMed1990

Hunger and undernutrition in the United States.

In the United States, where food is plentiful nationwide, detection of populations at risk of hunger and malnutrition must rely more on social and economic indicators than on physiological indices, important as these are. Large federal programs expanded or created after the 1969 White House Conference on Food, Nutrition, and Health were shown to be successful during the 1970s in reducing hunger and malnutrition as a massive social phenomenon, even though poverty conditions remained the same. Studies that apply our knowledge of nutritional and dietary requirements to construct a "market basket" of inexpensive, commonly used foods that meet the Recommended Dietary Allowances (RDA) and that set estimated minimum incomes as a multiple of the cost of such an "RDA-based market basket" plus the costs of other necessities would identify populations and families at risk and permit better targeting of food programs.

Child, Preschool↗
PubMed1990

Influence of metoprolol and cilazapril on blood pressure and on sleep apnea activity.

Up to 50% of hypertensive men are subject to sleep apnea (SA). With a prevalence in men of up to 10%, SA is a common illness and hypertension (HT) one of its early symptoms. It is important to have available a drug treatment that will effectively control blood pressure (BP) without exacerbating symptoms of SA. Twelve patients with SA and HT were investigated in a double-blind, comparative trial. Patients were randomly allocated to either metoprolol (M) 100 mg daily or cilazapril (C) 2.5 mg daily. Polysomnographic measurements under standardized conditions including intraarterial BP monitoring were taken on two consecutive nights each before and after the 1-week treatment. Values in the M group were (mean +/- 95% CI) systolic BP 161 +/- 2.1 vs. 148 +/- 2.2 mm Hg (p less than 0.01); diastolic BP 98 +/- 1.8 vs. 93 +/- 1.8 mm Hg (p less than 0.01); and HR 73 +/- 1.2 vs 65 +/- 1.1 beats/min (p less than 0.01). Corresponding figures for the C group were systolic BP 140 +/- 2.1 vs. 127 +/- 2.1 mm Hg (p less than 0.01); diastolic BP 95 +/- 1.7 vs. 78 +/- 1.7 mm Hg (p less than 0.01); and HR 82 +/- 1.1 vs. 79 +/- 1.2 beats/min (p less than 0.01). Whereas C reduced both BP and HR in all sleep phases, M produced no changes during REM sleep. SA activity was 45 (range 15-91) vs. 34 (range 2-57) apneas per hour of sleep in the M group and 54 (range 21-84) vs. 40 (range 8-72) apneas per hour in the C group (p less than 0.01). There were no changes in total sleep time or in the proportions of non-REM to REM sleep. Both M and C reduce nocturnal BP in SA patients, but the effect of C is seen in all sleep phases. C has a more favorable effect on the disturbed nocturnal blood pressure of SA patients.

Adult↗
PubMed1990

The role of molecular epidemiology in cancer prevention.

Risk of cancer is determined by the complex interaction between "environmental" exposures and genetic and nutritional factors that modulate response to carcinogenic insults. Here, the term "environmental" encompasses lifestyle, occupation, and the ambient environment. As a promising approach in cancer prevention, a number of biologic markers are currently being evaluated in terms of their ability to identify harmful exposures and populations at risk in time to effectively intervene. These biomarkers are reflective of the molecular dose or early effect of carcinogens (such as DNA or protein adducts, gene or chromosomal alterations and oncogene activation) or they provide information on potential susceptibility (such as the genetically or nutritionally determined handling of carcinogens). Techniques as diverse as immunoassays, 32P-postlabelling and gas chromatography-mass spectroscopy (GC/MS) are being deployed to measure DNA and protein adducts in cells and tissues from persons with occupational, community or lifestyle-related exposure to chemical carcinogens. Signal changes in target oncogenes and tumor suppressor genes are also being investigated in heavily exposed, "healthy" populations and in lung cancer cases and controls using current molecular biologic techniques. Inherited predisposition to lung cancer is being evaluated through such assays as aryl hydrocarbon hydroxylase (AHH), glutathione activity and restriction fragment length polymorphism. A review of recent studies using a panoply of biomarkers provides a departure point for recommendations for future, integrated molecular epidemiologic studies of cancer.

Animals↗
PubMed1990

[2 new finds in the old German delivery of the rosemary treatise].

Rosemary monographs are known in three versions. In two of these, wine is the basic ingredient of the remedies. Texts in the third group comprise medicines, in which all the different parts of the plant are used. This group is represented by a Dutch text of 29 paragraphs and two shorter German ones, which are here compared to the Dutch text.

Europe↗
PubMed1990

Macromolecular adducts and related biomarkers in biomonitoring and epidemiology of complex exposures.

In order to evaluate the potential of biological markers in epidemiology and risk assessment of complex exposures, we review recent studies of macromolecular adducts and oncogene activation in human populations. Results are discussed in terms of the strengths and weaknesses of various study designs in order to identify the most promising approaches for future research.

Biomarkers, Tumor↗
PubMed1989

Effects of cilazapril on hypertension, sleep, and apnea.

Epidemiologic studies revealed that up to 10 percent of middle-aged men show more than 10 cessations of breathing of more than 10 seconds' duration. In these patients, increased morbidity and mortality rates have been proved. More than 50 percent of apnea patients exhibit arterial hypertension, and up to 50 percent of hypertensive patients experience sleep apnea. Patients with sleep apnea and essential hypertension need special attention paid to their antihypertensive therapy because the following side effects of drugs have to be avoided: increases of cardiac insufficiency, hyperviscosity of the blood, intensification of the hypersomnia by central sedation, intensification of a pre-existing tendency towards arrhythmias, and deprivation of deep and rapid eye movement sleep. In this study, the effects of angiotensin-converting enzyme inhibitors in patients with sleep apnea and hypertension are examined. An interim evaluation of six patients (aged 50 to 57) yielded the following results: Average Broca index, 124; average blood pressure before therapy, 159/102 mm Hg; average blood pressure after therapy, 132/78; a decrease of the apnea and hypopnea index from x = 31 (range, 12 to 77) to x = 20 (range, two to 54). Therapy did not influence sleep structure: before therapy, an average of 19 percent of sleep episodes were of the rapid eye movement type (range, 11 to 32 percent); after therapy, 23 percent were of this type on average (range, 21 to 25 percent). A final evaluation will be carried out after the second study phase for 12 patients who have been treated in a double-blind scheme with metropolol versus cilazapril.

Adult↗
PubMed1989

Comparison of DNA adducts and sister chromatid exchange in lung cancer cases and controls.

In a molecular epidemiological study of lung cancer cases (n = 81) and noncancer controls (n = 67), polycyclic aromatic hydrocarbon (PAH)-DNA adducts were evaluated in peripheral blood leukocytes from all subjects and in a smaller number of lung tissue specimens collected prior to or at surgery. Sister chromatid exchanges (SCE) in lymphocytes were also studied in a subset of cases and controls. Questionnaire, medical record, or tumor registry data provided a family history of cancer, as well as information on cigarette smoking, dietary and occupational exposure to PAHs, and other factors related to SCEs. In both cases and controls PAH-DNA adducts in leukocytes measured by an enzyme-linked immunosorbent assay were not significantly related to age, sex, ethnicity, amount of cigarette smoking, passive smoking, dietary charcoal, or caffeine consumption. Nor did family history of cancer or histological type of cancer significantly affect adduct levels. However, when subjects were stratified by smoking status (current, former, and nonsmoker), lung cancer cases who were current smokers had significantly higher levels of covalent adducts than current smoker controls. A seasonal variation was observed in PAH-DNA binding, with a peak in adduct levels during July-October. This peak corresponds to that seen in a prior study of aryl hydrocarbon hydroxylase inducibility by other investigators. The finding of significant levels of PAH-DNA adducts in former smokers and non-smokers supports an earlier observation that this marker is not smoking specific but reflects a pervasive and variable "background" exposure to PAH. These results are consistent with a genetically determined enhancement of PAH-DNA adduct formation in leukocytes of lung cancer cases which is evident in current smokers. The results in lung tissue are limited by the small number of samples. Adduct levels were not significantly increased in lung tissue of smokers compared with nonsmokers. An inverse linear correlation was seen between adduct values in lung tissue and age of the donors. SCEs were significantly related to pack years of smoking. However, there was no difference in the frequency of SCE between cases and controls; nor were SCE and DNA adducts significantly correlated in this small sample.

DNA, Neoplasm↗