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Biomedical subjects

M Preston

Publications and source records attributed to M Preston.

At least 19 recordsLinked to original sources
PubMed1999

Types of conflicts and tensions between older parents and adult children.

What are the most common themes of conflict between aging parents and their adult children? Six types emerged in a qualitative analysis of Longitudinal Study of Generations survey data: conflicts over (1) communication and interaction style; (2) habits and lifestyle choices; (3) child-rearing practices and values; (4) politics, religion, and ideology; (5) work habits and orientations; and (6) household standards or maintenance. There were generational differences: parents most often listed conflicts over habits and lifestyle choices, whereas children cited communication and interaction style. These results suggest a new agenda for gerontological research: intergenerational conflict in the context of solidarity within aging families.

Adult↗
PubMed1999

Cystic fibrosis transmembrane conductance regulator-mediated corneal epithelial cell ingestion of Pseudomonas aeruginosa is a key component in the pathogenesis of experimental murine keratitis.

Previous findings indicate that the cystic fibrosis transmembrane conductance regulator (CFTR) is a ligand for Pseudomonas aeruginosa ingestion into respiratory epithelial cells. In experimental murine keratitis, P. aeruginosa enters corneal epithelial cells. We determined the importance of CFTR-mediated uptake of P. aeruginosa by corneal cells in experimental eye infections. Entry of noncytotoxic (exoU) P. aeruginosa into human and rabbit corneal cell cultures was inhibited with monoclonal antibodies and peptides specific to CFTR amino acids 108 to 117. Immunofluorescence microscopy and flow cytometry demonstrated CFTR in the intact murine corneal epithelium, and electron microscopy showed that CFTR binds to P. aeruginosa following corneal cell ingestion. In experimental murine eye infections, multiple additions of 5 nM CFTR peptide 103-117 to inocula of either cytotoxic (exoU+) or noncytotoxic P. aeruginosa resulted in large reductions in bacteria in the eye and markedly lessened eye pathology. Compared with wild-type C57BL/6 mice, heterozygous DeltaF508 Cftr mice infected with P. aeruginosa had an approximately 10-fold reduction in bacterial levels in the eye and consequent reductions in eye pathology. Homozygous DeltaF508 Cftr mice were nearly completely resistant to P. aeruginosa corneal infection. CFTR-mediated internalization of P. aeruginosa by buried corneal epithelial cells is critical to the pathogenesis of experimental eye infection, while in the lung, P. aeruginosa uptake by surface epithelial cells enhances P. aeruginosa clearance from this tissue.

Animals↗
PubMed1999

Age, renal perfusion and function in island-dwelling indigenous Kuna Amerinds of Panama.

BACKGROUND/AIMS: Among possible contributors to a progressive fall in renal perfusion and function with increasing age, some hypotheses have invoked the rise in blood pressure that occurs with age, and a high-protein diet typical of urban cultures. Kuna Amerinds residing in isolated islands off the Panamanian Coast have a very low protein intake and show no tendency for blood pressure to rise with age, thus providing an opportunity to test these hypotheses. METHODS: We measured renal plasma flow and glomerular filtration rate (PAH and inulin clearance) in 16 Kuna Indians ranging in age from 18 to 86 years (51 +/- 6 years) who have resided on Ailigandi, an isolated Panamanian island for all of their lives. Inulin and PAH were infused with a battery-driven pump for 60 min, and a metabolic clearance rate used to calculate inulin and PAH clearance. For comparison, we employed identical techniques in 29 residents of Boston, ranging in age from 19 to 79 years (52 +/- 4 years), all normotensive and free of disease or medication use. Twenty-four were Caucasian. RESULTS: The Bostonian controls showed the anticipated fall in PAH clearance with age (y = 806 - 4.9 x; r = -0.82; f = 38.0; p < 0.0001). Our hypothesis was that the absence of a blood pressure rise with age and the low protein intake would flatten the slope relating renal perfusion to Kuna age. Our finding was a numerically steeper slope relating age and renal plasma flow in the Kuna (y = 936 - 6.48x; r = -0.81; p < 0.001). Filtration fraction rose with age in both populations, and again the rise was steeper in the Kuna. GFR in the Kuna, on the other hand, was very much higher at any age (139 +/- 4 ml/min/1.73 m2) than in Bostonians (112 +/- 3 ml/min/1.73 m2; p < 0.001). CONCLUSION: The findings are not in accord with the hypothesis that age-related changes in renal perfusion and glomerular filtration rate reflect an important contribution from blood pressure rise and a high protein intake, typical of modern, urban life.

Adolescent↗
PubMed1998

A community outbreak of Salmonella berta associated with a soft cheese product.

In September 1994, a complaint was registered at a public health unit concerning a cheese product. In addition, public health laboratories in Ontario reported an increase in the number of isolates of Salmonella berta from patients with diarrhoeal illness. A clinical, environmental and laboratory investigation was initiated to determine the nature of this outbreak. Isolates of Salmonella berta were compared using large fragment genomic fingerprinting by pulsed-field gel electrophoresis (PFGE). By late October, 82 clinical cases had been identified including 35 confirmed, 44 suspected and 3 secondary. The investigation linked illness to consumption of an unpasteurized soft cheese product produced on a farm and sold at farmers' markets. Subtyping results of patient, cheese and chicken isolates were indistinguishable, suggesting that the cheese was contaminated by chicken carcasses during production. The outbreak illustrates the potential role of uninspected home-based food producers and of cross-contamination in the transmission of foodborne bacterial pathogens.

Adolescent↗
PubMed1997

Aging, acculturation, salt intake, and hypertension in the Kuna of Panama.

The indigenous Kuna who live on islands in the Panamanian Caribbean were among the first communities described with little age-related rise in blood pressure or hypertension. Our goals in this study were to ascertain whether isolated island-dwelling Kuna continue to show this pattern, whether migration to Panama City and its environs changed the patterns, and whether the island-dwelling Kuna have maintained their normal blood pressure levels despite partial acculturation, reflected in an increased salt intake. We enrolled 316 Kuna participants who ranged in age from 18 to 82 years. In 50, homogeneity was confirmed by documentation of an O+ blood group. In 92 island dwellers, diastolic hypertension was not identified and blood pressure levels were as low in volunteers over 60 years of age as in those between 20 and 30 years of age. In Panama City, conversely, hypertension prevalence was 10.7% and exceeded 45% in those over 60 years of age (P < .01), blood pressure levels were higher in the elderly, and there was a statistically significant positive relationship between age and blood pressure (P < .01). In Kuna Nega, a Panama City suburb designed to maintain a traditional Kuna lifestyle but with access to the city, all findings were intermediate. Sodium intake and excretion assessed in 50 island-dwelling Kuna averaged 135 +/- 15 mEq/g creatinine per 24 hours, exceeding substantially other communities free of hypertension and an age-related rise in blood pressure. Despite partial acculturation, the island-dwelling Kuna Indians are protected from hypertension and thus provide an attractive population for examining alternative mechanisms.

Acculturation↗
PubMed1995

Radiology/pathology conference from Robert Wood Johnson Medical School.

Inflammatory pseudotumor of the heart is a benign tumor-like lesion consisting of reparitive granulation tissue with fibroblasts, myofibroblasts, and plasma cells predominating. This lesion is commonly seen in the lungs. The authors present this case report to stimulate discussion.

Child↗
PubMed1992

In vivo and in vitro toxicity of phospholipase C from Pseudomonas aeruginosa.

Pseudomonas aeruginosa produces phospholipase C (PLC), a heat-labile hemolysin. Histopathological analysis of PLC-treated mice revealed that the primary target organs involved in PLC-induced toxicity were the liver and kidney. Mice treated i.v. with PLC demonstrated significant tubular epithelial necrosis of the kidney with hematuria, while when given i.p. they exhibited hepatonecrosis with cellular infiltration. Splenomegaly was also a consistent finding. Results from in vitro studies indicate that PLC is toxic for mouse peritoneal cells and human leukocytes.

Animals↗
PubMed1987

Relationships between IQ and neuropsychological measures in neuropsychiatric populations: within-laboratory and cross-cultural replications using WAIS and WAIS-R.

Several studies have reported positive correlations between measures of intelligence (a quasi-subject variable) and level of performance on neuropsychological tests; few, however, have presented test results by IQ grouping, which could be useful for comparative purposes. The present study examined the relationships of WAIS and WAIS-R Full Scale IQ to performance on a neuropsychological battery consisting of the Halstead-Reitan Battery (HRB), the Wide Range Achievement Test (WRAT), and the Wechsler Memory Scale (WMS). Four mixed neuropsychiatric samples provided cross-cultural and within-laboratory replications, two tested with WAIS and two with WAIS-R. Means and standard deviations for each measure were presented by five IQ levels within each sample. IQ was strongly related to scores on problem-solving tasks, auditory and linguistic measures, memory tasks, academic achievement levels, and tactual imperceptions, while motor functioning and sensory suppressions were less strongly related to IQ. IQ level was related to educational level in all samples. Correlations of years of education with dependent variables in the two WAIS-R samples were strong and replicable for WRAT scores, verbal memory measures, linguistic errors on the Aphasia Screening Test, and finger-tapping speeds but not for other HRB measures. Finally, IQ-HRB relationships were compared to those reported for other populations.

Achievement↗
PubMed1986

Multiple roles and women's mental and physical health: what have we learned?

Research on the effects of multiple roles on women's health has in the past been conducted within the context of two competing hypotheses: the scarcity hypothesis and the expansion hypothesis. Empirical evidence is more supportive of the expansion than the scarcity hypothesis, i.e., women who occupy several roles are healthier than those with few. However, this generalization obscures important health differentials related to types of roles occupied and attributes of those roles. Research on multiple roles is now shifting from examining numbers of roles to analyzing the effects of specific role combinations, patterns, and characteristics. Further research is needed to identify ways in which rewards and stresses within each role interact to produce health outcomes.

Adaptation, Psychological↗