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Biomedical subjects

D DeAngelis

Publications and source records attributed to D DeAngelis.

16 recordsLinked to original sources
PubMed2001

Ecological conceptual models: a framework and case study on ecosystem management for South Florida sustainability.

The Everglades and South Florida ecosystems are the focus of national and international attention because of their current degraded and threatened state. Ecological risk assessment, sustainability, and ecosystem and adaptive management principles and processes are being used nationally as a decision and policy framework for a variety of types of ecological assessments. The intent of this study is to demonstrate the application of these paradigms and principles at a regional scale. The effects-directed assessment approach used in this study consists of a retrospective, eco-epidemiological phase to determine the causes for the current conditions and a prospective predictive risk-based assessment using scenario analysis to evaluate future options. Embedded in these assessment phases is a process that begins with the identification of goals and societal preferences which are used to develop an integrated suite of risk-based and policy relevant conceptual models. Conceptual models are used to illustrate the linkages among management (societal) actions, environmental stressors, and societal/ecological effects, and provide the basis for developing and testing causal hypotheses. These models, developed for a variety of landscape units and their drivers, stressors, and endpoints, are used to formulate hypotheses to explain the current conditions. They are also used as the basis for structuring management scenarios and analyses to project the temporal and spatial magnitude of risk reduction and system recovery. Within the context of recovery, the conceptual models are used in the initial development of performance criteria for those stressors that are determined to be most important in shaping the landscape, and to guide the use of numerical models used to develop quantitative performance criteria in the scenario analysis. The results will be discussed within an ecosystem and adaptive management framework that provides the foundation for decision making.

Animals↗
PubMed2001

The role of bacteriologic infection in the etiology of nasolacrimal duct obstruction.

BACKGROUND: In patients with nasolacrimal duct obstruction, the inflammation and fibrosis may be secondary to coexisting infectious colonization within the lumen of the lacrimal sac. We examined the bacterial flora within the lacrimal sac at the sac-duct junction to explore the possibility of a primary bacteriologic etiology of the inflammatory response. METHODS: The study included 114 consecutive patients (132 sides) with epiphora undergoing routine external dacryocystorhinostomy (DCR) at a tertiary care hospital in Toronto between November 1999 and April 2000. A lacrimal sac tissue biopsy specimen was acquired intraoperatively from the inferior posterior lacrimal sac near the sac-duct junction. Microbiologic analysis was carried out to determine the presence and identification of infectious organisms. RESULTS: Culture gave positive results in 51 patients (44.7%) (41.7% of specimens). A total of 65 isolates were cultured, of which 78.5% were gram-positive bacteria and 21.5% gram-negative bacteria. Of the gram-positive organisms 76.5% were Staphylococcus sp. The presence of a positive culture result was independent of a history of dacryocystitis or the presence of a mucocele. INTERPRETATION: Using direct biopsy methods, we found culture-positive lacrimal sac specimens in a large proportion of patients undergoing DCR surgery. These organisms were found to be present in patients with and without a history of infection.

Bacterial Typing Techniques↗
PubMed2000

Primary localized conjunctival amyloidosis presenting with recurrence of subconjunctival hemorrhage.

PURPOSE: To report the ocular presentation and histopathology of a patient with primary localized conjunctival amyloidosis. METHODS: A 38-year-old woman presented with a recurrence of episodes of severe bilateral subconjunctival hemorrhage. Ocular examination revealed yellowish, marked folding and redundancy of the conjunctiva in the inferior cul-de-sac of each eye. RESULTS: After two initial conjunctival biopsies that showed only chronic inflammation, a third biopsy revealed the presence of amyloid in the substantia propria of the conjunctiva. CONCLUSION: Primary localized conjunctival amyloidosis is rare and usually diagnosed histologically instead of clinically. Recurrence of subconjunctival hemorrhage may be the initial presentation. Evaluation for systemic diseases is advised, though the results of the examination are almost always negative.

Adult↗
PubMed2000

Outcome of lacrimal surgery in older patients.

BACKGROUND: Performance of lacrimal surgery under neuroleptic (local) anesthesia has greatly facilitated the procedure and decreased the associated morbidity. We reviewed the outcome of lacrimal surgery in older patients to determine whether such surgery can be performed safely in the outpatient setting in this group. METHODS: Review of the office and hospital charts and the surgical and anesthetic records of 120 patients (84 women and 36 men) aged 70 to 90 years who underwent lacrimal drainage procedures (dacryocystorhinostomy [DCR], canaliculodacryocystorhinostomy, DCR with insertion of a Jones tube, or a revision endonasal procedure with probing and tube insertion) at a university-affiliated hospital in Toronto in 1996. The interval between surgery and data collection ranged from 10 to 22 months. RESULTS: Of the 120 patients 65 were aged 70 to 75 years, 38 were 76 to 80 years, 11 were 81 to 85 years, and 6 were 86 to 90 years. Ninety-six patients had a unilateral procedure, and 24 (22 of whom were aged 70 to 80) had a bilateral procedure. Concomitant conditions, such as hypertension and cardiac disorders, were found in 104 patients (87%). Of the 120 patients 98 (82%) (including all those aged 81 to 90) had local anesthesia, and 22 (18%) had general anesthesia. In one case anesthesia had to be changed from local to general during the procedure because of noncompliance. A total of 112 patients (93%) whose surgery was planned as a day procedure were able to leave the hospital the same day. Three additional patients were admitted to hospital for an overnight stay because of increased bleeding at the time of surgery (one patient) or a history of cardiac problems (two patients). Five patients who had planned overnight stays because of cardiac problems did well during surgery and were discharged the same day, without consequence. None of the patients had to be readmitted at a later date for bleeding or health problems. In 109 patients (91%) the presenting symptom(s) was completely relieved. Overall, 116 patients (97%) had a totally open system with no reflux on syringing. INTERPRETATION: The surgical goals and techniques of lacrimal surgery in older patients were not compromised by performing the surgery in the outpatient setting and under neuroleptic anesthesia in most cases.

Aged↗
PubMed1998

Lipid altering or antioxidant vitamins for patients with coronary disease and very low HDL cholesterol? The HDL-Atherosclerosis Treatment Study Design.

Evidence supports the idea that substantial benefits may derive from treatments that increase high density lipoprotein (HDL) cholesterol (HDL-C), apolipoprotein (apo) A-I, HDL2 (or 2b) or the size of HDL particles with, or without, apo A-II. HDL3 appears to be neutral in terms of coronary artery disease risk, and apo A-II appears to be adverse. Because HDL particles serve as antioxidants in vitro, the hypothesis that low HDL-C reflects an antioxidant deficiency state appears tenable. Based on these observations, a three-year angiographic study was proposed and received funding. Enrollment began in January 1995 and was completed in January 1997.

Adult↗
PubMed1994

Molecular cloning and characterization of rat brain 2',3'-cyclic nucleotide 3'-phosphodiesterase isoform 2.

We have isolated a cDNA coding for the larger isoform of the rat brain 2',3'-cyclic nucleotide 3'-phosphodiesterase (CNP2), a protein associated with myelination in the central nervous system (CNS). The complete 420 amino acid sequence was deduced from the nucleotide sequence of the cDNA. Sequence comparisons show that rat CNP shares 96% homology with mouse, 84% with bovine, and 86% with human CNP. Errors in the published sequence of rat CNP1 have now been corrected. Comparisons with other proteins reveal several interesting conserved motifs, including two leucine repeat heptads, and two consensus motifs for phosphorylation in the N-terminal domain of CNP2.

3',5'-Cyclic-AMP Phosphodiesterases↗
PubMed1989

2,4-Diamino-5-benzylpyrimidines as antibacterial agents. 13. Some alkenyl derivatives with high in vitro activity against anaerobic organisms.

A series of 2,4-diamino-5-(3,5-dialkenyl-4-methoxy- or -4-hydroxybenzyl)pyrimidines was prepared from [(allyloxy)benzyl]pyrimidines by Claisen rearrangements, and the resulting allyl phenols were further modified by methylation and rearrangement to 1-propenyl analogues. Analogous 3,4-dimethoxy-5-alkenyl derivatives were prepared by similar techniques. High in vitro antibacterial activity was obtained against certain anaerobic organisms, such as Bacteroides species and Fusobacterium, which was equal to or better than the control, metronidazole, in several cases. The profile was similar against Neisseria gonorrhoeae and Staphylococcus aureus. The 3,5-bis(1-propenyl)-4-methoxy derivative 8 was 1 order of magnitude more active against Escherichia coli dihydrofolate reductase than its saturated counterpart, and it was also more active than trimethoprim, 1. However, it was considerably less active in vitro against the Gram-negative organisms. The 3,4-dimethoxy-5-alkenyl, -5-alkyl, and -5-alkoxy analogues had very high broad-spectrum antibacterial activity. However, pharmacokinetic studies of four of the compounds in dogs and rats and in vivo studies with an abdominal sepsis model in rats showed no advantages over trimethoprim.

Alkenes↗
PubMed1981

Pharmacokinetics of trimethoprim and sulfadiazine in the dog: urine concentrations after oral administration.

Serial blood samples were obtained from 12 healthy adult dogs given equivalent subcutaneous and oral doses of the antibacterial combination, trimethoprim-sulfadiazine (1:5). By using a 1-compartment open model, pharmacokinetic parameters for both drugs were estimated from the mean serum concentration data after oral administration. Trimethoprim and sulfadiazine were rapidly absorbed, reaching maximum concentrations in 1 and 4 hours with serum elimination half-lives of 2.5 and 9.9 hours, respectively. After a single oral dose (30 mg/kg, combined ingredients) was given, both drugs were present in urine for up to 24 hours at concentrations exceeding the minimum inhibitory concentrations for common pathogenic bacteria.

Administration, Oral↗
PubMed1981

Serum concentrations of trimethoprim and sulfadiazine following oral paste administration to the horse.

Two fasted and 2 fed horses were dosed orally with a combined trimethoprim and sulfadiazine paste formulation at a dose of 35 mg (1:5 combined active ingredients)/kg. Serum concentrations of each drug were determined periodically for 3 consecutive days for the 4 horses. The extent and rate of absorption for trimethoprim were variable, but peak serum concentrations occurred generally within 3 hours; sulfadiazine absorption was slower, reaching peak concentrations by 6 hours. Fasting did not have a consistent effect on the serum concentration profiles for either drug. Both drugs achieved serum concentrations that equaled or exceeded the minimum inhibitory concentrations necessary to inhibit the growth of certain pathogens common to the horse. Thus, the paste formulation provides an effective means of dose administration of horses.

Animals↗