Developmental influences across the life span.
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Animals↗
Biomedical subjects
T Seeman
Publications and source records attributed to T Seeman.
Urinary excretion of urodilatin in healthy children and children with renal disease.
Urodilatin (URO) is a natriuretic peptide isolated from human urine which is thought to be produced by distal tubular cells. We measured urinary URO excretion in 50 healthy children and 23 children with acute (ARF), chronic renal failure (CRF), or hereditary tubular disorders, using a specific radioimmunoassay. The mean URO excreted in these four groups was 56, 45, 94, and 121 fmol/min per 1.73 m2, respectively (differences between first three groups not significant). The variation in URO excretion was larger in patients with kidney disease than in controls. There were significant correlations between urinary URO and sodium excretion in controls and CRF, but not in ARF. URO excretion also correlated with urine flow rate in CRF. Although no correlation was found between URO excretion and creatinine clearance, urinary URO was increased in some patients with advanced CRF, which suggests stimulated tubular production to compensate for reduced sodium excretion. In view of the therapeutic potential of URO in renal insufficiency, further study of the renal handling of URO is warranted.
Acute Kidney Injury↗
Do medical conditions affect cognition in older adults?
Analyses of a nationally representative sample who completed a list recall task (weighted n = 6,446) and 2 mental status tasks (weighted n = 6,646) were conducted to determine whether specific medical conditions such as high blood pressure and diabetes as well as general health ratings predict cognitive performance in adults aged 70 to 103. Presence of stroke and poorer health ratings predicted poorer performance on the 3 tasks. Presence of diabetes predicted poorer performance on recall and 1 mental status task. Age interacted with medical conditions including high blood pressure and diabetes in predicting mental status, with condition-related deficits confined to the younger end of the age continuum. Global health ratings interacted with age, with poorer ratings associated with worse mental status in the younger participants. Findings suggest that stroke and diabetes are associated with cognitive deficits. Some deficits are more pronounced in younger old adults with high blood pressure and poorer health ratings.
Aged↗
Blood pressure and renal function in autosomal dominant polycystic kidney disease.
The purpose of this study was to identify hypertension in children and adolescents in an early stage of autosomal dominant polycystic kidney disease (ADPKD) by the application of ambulatory blood pressure monitoring (ABPM) over 24 h; 32 children and adolescents (mean age 12.3 +/- 4.7 years) were examined. The diagnosis was based on family history and ultrasound examination. In 21 children ADPKD was confirmed by molecular genetic analysis. At the time of the study, 45% patients were asymptomatic and all had glomerular filtration rates (GFRs) > or = 65 ml/min per 1.73 m2. By ABPM, 11 patients (34%) were defined as hypertensive (systolic or diastolic blood pressure > 95th percentile), including 4 with an exclusive nocturnal hypertension. Of 7 patients with daytime hypertension, 4 had normal blood pressure by casual measurements. The nocturnal dip in blood pressure was reduced in 2 patients. Blood pressure correlated with renal size, but not with GFR, concentrating capacity, proteinuria, and plasma renin activity. The study reveals an early trend for increased blood pressure in children with ADPKD, requiring close supervision.
Adolescent↗
Factors related to current and subsequent psychotropic drug use in an elderly cohort.
AIMS OF THE STUDY: The purpose of this study was to estimate the prevalence of psychotropic drug use in a cohort of elderly persons and to examine factors related to current and subsequent drug use. POPULATION: A representative cohort of non-institutionalized subjects aged 65 and over living in New Haven, Connecticut, was interviewed in 1982, and again in 1985 and 1988. Psychotropic drug use during the prior two weeks was assessed at each home interview. RESULTS: At the baseline interview in 1982, 12.3% of the subjects reported using psychotropic drugs, half of them (6.25%) benzodiazepines. In multivariate analyses, psychotropic drug use was significantly associated with female gender and white ethnicity but not with older age. Psychotropic drug use and depressive symptomatology were strongly correlated in both genders. However, less than 5% of the subjects reporting high depressive symptomatology were using antidepressants. Psychotropic drug use was also associated with sleep problems in men and medical conditions in women. Psychotropic drug consumption increased slightly to 15.1% in 1988. Continuous use (use reported in 1982, 1985 and 1988) was found in 4.5% of the sample; it was strongly related to both depressive symptomatology and sleep problems reported at baseline. New use, beginning either in 1985 or in 1988, was observed in 12.6% of the sample; it was related to female gender, older age, and, among baseline health variables, to depressive symptomatology. CONCLUSIONS: Prevalence of psychotropic drug use in this cohort of elderly people was lower than in other studies conducted in the U.S. The reasons for this variation are discussed. Continuous use was not higher for benzodiazepines than for other psychotropic drugs.
Aged↗
Circadian blood pressure changes in untreated children with kidney disease and conserved renal function.
Ambulatory blood pressure monitoring over 24 h was applied in 31 children with kidney disease, aged 3-19 (median 11) years, in the absence of renal insufficiency and without antihypertensive therapy. Median creatinine clearance was 112 ml/min/1.73m2. Ambulatory blood pressure monitoring revealed that eight patients (26%) were hypertensive during the daytime, compared to 62% through casual recordings obtained in the office and 38% when blood pressure was taken at home. Nocturnal hypertension was detected by ambulatory monitoring in six patients, two of whom had normal blood pressure in the daytime. Median nocturnal dipping was 13% for systolic and 21% for diastolic blood pressure, i.e. similar to healthy children. Rhythm analysis recognized a distorted circadian pattern for systolic and/or diastolic blood pressure in eight patients. In conclusion, ambulatory blood pressure monitoring allows the evaluation of hypertension more reliably than casual recordings in the office. Nocturnal hypertension, as a major risk factor for renal deterioration, is detected in a similar proportion as daytime hypertension in almost 20% of untreated children with kidney disease and normal renal function.
Adolescent↗
Health psychology: what is an unhealthy environment and how does it get under the skin?
This review explores the role of environments in creating chronic and acute health disorders. A general framework for studying the nesting of social environments and the multiple pathways by which environmental factors may adversely affect health is offered. Treating socioeconomic status (SES) and race as contextual factors, we examine characteristics of the environments of community, work, family, and peer interaction for predictors of positive and adverse health outcomes across the lifespan. We consider chronic stress/allostatic load, mental distress, coping skills and resources, and health habits and behaviors as classes of mechanisms that address how unhealthy environments get "under the skin," to create health disorders. Across multiple environments, unhealthy environments are those that threaten safety, that undermine the creation of social ties, and that are conflictual, abusive, or violent. A healthy environment, in contrast, provides safety, opportunities for social integration, and the ability to predict and/or control aspects of that environment.
Behavioral Medicine↗
Psychotropic drug use and cognitive decline among older men and women.
This epidemiological study focuses on cognitive change related to psychotropic drug use in a population-based sample of subjects aged 65 and over. Cognitive functioning was assessed in 1982 and 1988 by the Short Portable Mental Status by Pfeiffer, and cognitive decline was defined as an increase of more than 2 errors in 1988 relative to the 1982 assessment. Psychotropic drugs were classified into benzodiazepines and non-benzodiazepines. For both medications, four patterns of intake were considered: no use reported at both interviews, continuous use at both interviews, temporary use at the 1982 interview and new use at the 1988 interview. Depressive symptomatology was assessed by the Center for Epidemiologic Studies Depression Scale. The analysis was performed on 1200 subjects with no or minimal impairment at baseline for whom complete data were available. Univariate analyses showed cognitive decline associated with gender, level of education and new medical condition; it was also related to depressive symptomatology and psychotropic drug use. These two factors were the most strongly associated with decrease in performance in multivariate analyses. Cognitive decline differed according to class of psychotropic drugs and pattern of use: benzodiazepine temporary users exhibited a lower risk compared with never users (OR = 0.23, p = 0.056), non-benzodiazepine new users a higher risk (OR = 5.02, p < 0.001). Despite the simple measures of cognitive functioning and psychopathology, and the approximation in pattern of psychotropic drug use, these results emphasize the importance of considering psychotropic drugs in studies of cognitive decline in elderly subjects.
Aged↗
Self-efficacy beliefs and change in cognitive performance: MacArthur Studies of Successful Aging.
Data from a cohort of relatively high functioning, older men and women were used to test the hypothesis that stronger self-efficacy beliefs predict better maintenance of cognitive performance. Structural equation modeling revealed that stronger baseline instrumental efficacy beliefs predicted better verbal memory performance at follow-up among men but not among women, controlling for baseline verbal memory score and sociodemographic and health status characteristics. For both men and women there were no significant associations between either type of self-efficacy beliefs and measures of nonverbal memory, abstraction, or spatial ability. Consistent with previous research showing relationship between baseline cognitive performance and change in self-efficacy beliefs, better abstraction ability was also predictive of increase in instrumental efficacy beliefs among the men.
Age Factors↗
Predictors of cognitive change in older persons: MacArthur studies of successful aging.
This study used a linear structural relations modeling technique (LISREL) to examine longitudinal data for 1,192 persons from a community-based population. The goal was to test the ability of an a priori model to predict cognitive change over a 2.0- to 2.5-year period in older adults aged 70-79 at the initial evaluation. The model included 22 demographic, physical, and psychosocial variables as predictors of cognitive function and cognitive change. The study used an exploratory-confirmatory design, enabling cross-validation of the model developed in the exploratory set in the confirmatory sample. Structural equation modeling analyses identified 4 endogenous model variable (education, strenuous activity, peak pulmonary expiratory flow rate, and self-efficacy) as direct predictors of cognitive change over the study period.
Aged↗
Risk factors for coronary heart disease among older men and women: a prospective study of community-dwelling elderly.
Data from a community-based sample of 2,812 men and women aged 65 years and over, living in New Haven, Connecticut, were used to examine the associations between blood pressure, smoking, diabetes, anginal chest pain, and relative weight and 6-year incidence (1982-1988) of myocardial infarction and coronary heart disease mortality. Multivariate logistic regression analyses revealed that history of diabetes was associated with increased risk of incident myocardial infarction among women (odds ratio (OR) = 3.20; 95% confidence interval 1.46-7.01), while higher relative weight was a significant risk factor among men (OR = 3.46, 95% confidence interval 1.34-8.95 for middle vs. lowest tertile and OR = 3.24; 95% confidence interval 1.10-9.53 for highest versus lowest tertile). For coronary heart disease mortality, age and diabetes (OR = 4.47, 95% confidence interval 1.85-10.79) were associated with increased risk among women, as was current smoking (OR = 3.96; 95% confidence interval 1.66-9.45). Among men, age, prevalent heart disease, and use of antihypertensive medication (OR = 1.84; 95% confidence interval 1.13-3.00) were risk factors for coronary heart disease mortality. These risk estimates and the relatively high prevalences of these risk factors suggest that attributable risks may be substantial. Observed sex differences as well as differences in patterns of risk factor associations for the two endpoints suggest that there may be different risk profiles for older men and women and for different coronary heart disease endpoints.
Aged↗
Combined angioplasty with the Kensey catheter and balloon angioplasty in occlusive arterial disease. A preliminary report.
The Kensey dynamic angioplasty catheter is an instrument for mechanical intravascular atherectomy using a rotating cam to recanalize occluded arteries. Twelve dynamic angioplasties were performed in 11 patients. The procedure was followed by an additional balloon dilatation in all cases. A technical success, i.e., a restored lumen, was recorded in 7 patients but only 4 had a functional improvement. No distal embolization or other serious complication occurred. This preliminary report shows that the therapeutic potential with this technique must be further investigated.
Adult↗
Pressure wave injuries to the nervous system caused by high-energy missile extremity impact: Part I. Local and distant effects on the peripheral nervous system--a light and electron microscopic study on pigs.
Pigs were used for studies of effects on the peripheral nervous tissue of pressure waves induced by impact and passage through the left thigh of high-energy missiles. The short-lasting pressure waves were demonstrated to move close to the speed of sound and to have a spectrum of high frequencies and large amplitudes. The sciatic nerve in the contralateral leg showed no hemorrhage or major deformation. Both immediately after the missile impact and after 48 hr the myelin sheaths in the contralateral sciatic nerve showed deformation. Myelin was bulging into the axon, dislocating the axoplasm. The nodes of Ranvier could be exposed to an increased extent. Electron microscopic examination revealed decreased number of microtubules immediately after the trauma, persisting even after 48 hr in the largest axon. Schwann cells showed, especially after 48 hr, signs of damage and swelling. Similar changes, although less extensive, were noticed in the phrenic nerves as well as in unmyelinated axons in both sciatic and phrenic nerves. It is concluded that a high-energy missile hit in the thigh of a pig, caused structurally demonstrable dislocations of myelin sheaths, and disarrangement of cytoskeleton and endoplasmic reticulum in axons as well as other signs of damage. The changes may interfere with the normal functions of peripheral and autonomic nerves.
Abdomen↗
Pressure wave injuries to the nervous system caused by high-energy missile extremity impact: Part II. Distant effects on the central nervous system--a light and electron microscopic study on pigs.
The aim of the present study was to investigate if distant effects could be detected within the central nervous system after impact of a high-energy missile in the left thigh of young pigs. Pressure transducers implanted in various parts of the body of the animal, including the brain, recorded a short-lasting burst of oscillating pressure waves with high frequencies and large amplitudes, traversing the body tissue with a velocity of about that of sound in water (1,460 m/s). The distance between the point of impact and the brain and cervical spinal cord is in the range of 0.5 m. Macroscopic examination revealed that there was no gross brain tissue disruption or visible blood-brain barrier dysfunction. Light microscopic examination demonstrated myelin invaginations in the largest axons and shrinkage of axoplasm. Electron microscopic examination revealed a reduction in the number of microtubules, especially in the larger axons in the brainstem. Disintegration of Nissl substance, i.e., chromatolysis, was noticed after 48 hr in many Purkinje nerve cells in the cerebellum, concomitantly with the appearance of an increased frequency of association between lamellar bodies and mitochondria. Changes could also be observed in the cervical spinal cord and, at reduced frequency and extent, in the optic nerve and in other parts of the brain. These effects were evident within a few minutes after the trauma and persisted even 48 hr after the extremity injury. It is concluded that distant effects, likely to be caused by the oscillating high-frequency pressure waves, appear in the central nervous system after a high-energy missile extremity impact.
Abdomen↗
Hemodynamic effects in dogs of nitrous oxide-meperidine and meperidine, respectively, in comparison with nitrous oxide.
The aim of this investigation on dogs, was to examine the hemodynamic effects of nitrous oxide (N2O) plus meperidine and of meperidine with room air ventilation, respectively, compared with those of N2O on its own. When meperidine (bolus dose 3 mg.kg-1 and continued infusion 4 mg.kg-1.h-1) was added to 80% N2O, mean arterial blood pressure fell from about 20 to 10 kPa (150 to 75 mmHg), as a result of a decrease in peripheral vascular resistance, but no compensatory changes in cardiac output were seen. When N2O was withdrawn, during continued meperidine infusion, cardiac output and stroke volume increased, while peripheral resistance remained low. Coronary vasodilation was noted when meperidine was added to N2O, and persisted when N2O was withdrawn. In the pulmonary circulation a different response was found. Here, no effects were observed when meperidine was added to N2O, while pressure and resistance decreased when N2O was withdrawn and meperidine continued.
Animals↗
Pressure waves caused by high-energy missiles impair respiration of cultured dorsal root ganglion cells.
High-energy missile extremity impact causes short-lasting pressure waves which traverse the body with a velocity close to that of sound in water. In order to elucidate mechanisms for distant damage in a living body to the peripheral and central nervous system, a model system was designed aimed to create pressure waves with amplitudes, frequency spectrum, and duration fairly comparable to those recorded in situ. Our model system enabled exposure of tissue cultures of dorsal root ganglion (DRG) and endothelial cells under strictly controlled conditions to a burst of oscillating pressure waves and to determine possible influence on oxygen consumption. Oscillating pressure waves caused by high-energy missile impact (velocity 1,200 m/s) reduced the oxygen consumption by more than 80%. However, in spite of this drastic, acute effect the ganglion cells and the feeder layer cells did not reveal any immediate plasma membrane dysfunctions as revealed by cytoplasmic uptake of Evans blue protein marker complexes. It is concluded that pressure waves fairly similar to those demonstrable in vivo in the vicinity of the peripheral and central nervous system after high-energy missile extremity impact in pigs reduce the respiration of DRG cells and endothelial cells in culture. The mitochondrial impairment is not associated with concomitant plasma membrane dysfunction for macromolecules. Nerve cells seem to be more vulnerable than the other type of cultured cells examined.
Animals↗
Pressure wave injuries to rat dorsal root ganglion cells in culture caused by high-energy missiles.
A high-energy missile impact in an extremity of an animal creates a shock wave which is rapidly dispersed as a burst of oscillating pressure waves that traverses the entire body causing local, regional, and distant injuries. The present study was performed on dorsal root ganglion (DRG) cells, cultured for 3 weeks, to elucidate the cellular mechanism for damage of nerve cells, using a simplified test system. A model system was developed allowing exposure of DRG cultures to a burst of high-frequency oscillating pressure waves, comparable to those recorded in animals after high-energy missile extremity impact. The pressure waves were induced by impact of a high-energy missile in a rubber tube filled with water, in which nerve cell cultures were kept in a closed rubber glove filled with tissue culture medium. The pressure waves had a duration of 0.5-1.5 ms and a frequency spectrum ranging from 0-250 kHz. Within minutes the neurites showed changes in their microtubules. In addition, varicosities, enriched with tubulin immunoreactive material, became irregularly studded along the nerve cell processes. Scattered DRG cells were initially permeable to the marker complex Evans-blue albumin (EBA), used as an indicator of the ability of the plasma membranes to exclude proteins. After 6 hr, however, almost every DRG neuron was intensely stained by EBA. Concomitantly, there was swelling of the nerve cell cytoplasm and organelles, and, to a variable extent, neurofilament tangles were observed.(ABSTRACT TRUNCATED AT 250 WORDS)
Animals↗
A new incision for retroperitoneal approach to the aorta.
A new incision for retroperitoneal approach to the abdominal aorta is described. The incision extends from alongside the rectus abdominis muscle across the costal arch over the 7-8th intercostal space. In the upper part only the skin and muscles are divided, allowing wide opening of the incision. The approach is muscle-sparing, since fibers of the transverse abdominal muscle are incised only in the upper part. It permits a good approach even for high aortic reconstruction.
Aorta, Abdominal↗