Biomedical subjects

S E Marcus

Publications and source records attributed to S E Marcus.

5 recordsLinked to original sources

PubMed1990

Statistical methods in SUPPORT.

The analysis and interpretation of the data collected in SUPPORT provide great potential for understanding the relationships among treatment choices, patient and physician values and preferences, perceptions about the risks and benefits of treatments, institutional characteristics, and outcomes (as measured by quality of life, survival, and satisfaction). The complicated analyses required to elucidate these relationships will pose many technical challenges in dealing with longitudinal observational data collected from seriously ill patients at multiple sites. Major challenges include the handling of incomplete data, proper parameterization of treatment effects, strategies to avoid various potential biases, validating predictive models, and constructing endpoints that combine survival with quality of life. Within the structure of the SUPPORT study, mechanisms have been established to guide the analyses and to ensure their quality and validity.

Confounding Factors, Epidemiologic↗

PubMed1987

Psychiatric consultations in short-term general hospitals.

We investigated the use of psychiatric consultations in short-term general hospitals using a national sample of 327 hospitals and examining the hospital experience of approximately 263,000 patients discharged from these hospitals. We found that the demographic characteristics of patients receiving psychiatric consultations in the national sample were roughly similar to those reported for patients receiving consultations in earlier, single-hospital studies. Rates of consultation were considerably lower, however: 0.9%, compared with a median rate of 3.3% reported in the literature. We also found that patients receiving psychiatric consultations used more hospital resources than other patients.

Adult↗

PubMed1986

Posttranslational processing of concanavalin A precursors in jackbean cotyledons.

Metabolic labeling of immature jackbean cotyledons with 14C-amino acids was used to determine the processing steps involved in the assembly of concanavalin A. Pulse-chase experiments and analyses of immunoprecipitated lectin forms indicated a complex series of events involving seven distinct species. The structural relatedness of all of the intermediate species was confirmed by two-dimensional mapping of 125I-tryptic peptides. An initial glycosylated precursor was deglycosylated and cleaved into smaller polypeptides, which subsequently reannealed over a period of 10-27 h. NH2-terminal sequencing of the abundant precursors confirmed that the intact subunit of concanavalin A was formed by the reannealing of two fragments, since the alignment of residues 1-118 and 119-237 was reversed in the final form of the lectin identified in the chase and the precursor first labeled. When the tissue was pulse-chased in the presence of monensin, processing of the glycosylated precursor was inhibited. The weak bases NH4Cl and chloroquine were without effect. Immunocytochemical studies showed that monensin treatment caused the accumulation of immunoreactive material at the cell surface and indicated that the ionophore had induced the secretion of a component normally destined for deposition within the protein bodies. Consideration of the tertiary structure of the glycosylated precursor and mature lectin showed that the entire series of processing events could occur without significant refolding of the initial translational product. Proteolytic events included removal of a peptide from the surface of the precursor molecule that connected the NH2- and COOH-termini of the mature protein. This processing activated the carbohydrate-binding activity of the lectin. The chase data suggest the occurrence of a simultaneous cleavage and formation of a peptide bond, raising the possibility that annealment of the fragments to give rise to the mature subunit involves a transpeptidation event rather than cleavage and subsequent religation.

Amino Acid Sequence↗

PubMedDate not supplied

Factors associated with the use of psychiatric consultations in short-term general hospitals.

A significant number of patients in general hospitals suffer from psychiatric distress or illness, but not all receive psychiatric consultation. This study examined several potential predictors of such consultation. These included patient characteristics (age, sex, race, insurance, disease stage, and number of medical diagnoses), characteristics of hospital stay (number of procedures, other consultations, length of stay, discharge destination), hospital characteristics (size, percent occupancy, teaching status, presence of a psychiatric unit, type of control), and community characteristics (region, urban/rural setting). Data were derived from a national sample of 327 hospitals. Parallel analyses using stepwise logistic regression were carried out across four samples: patients determined at discharge to have been hospitalized for diabetes, hip fracture, chronic obstructive pulmonary disease, and coronary artery bypass surgery. Results show a wide variation in the use of psychiatric consultations across different subgroups. Longer lengths of stay, urban setting. Northeast region, younger patient age, and other consultations were the most consistent predictors of the probability of psychiatric consultation. These variations may reflect differences in the need for consultation, differential recognition of these needs by providers, or differential availability of psychiatric consultation services. Moreover, they may have implications for equity and/or quality of hospital care.

Female↗

PubMedDate not supplied

Do objective estimates of chances for survival influence decisions to withhold or withdraw treatment? The French Multicentric Group of ICU Research.

The authors studied the impact on clinical decision making of providing feedback of objective prognostic information describing the probability of survival for ICU patients with multiple organ system failure (OSF). The prognostic estimates, derived from a control period (1), were to be provided on a daily basis to physicians providing treatment in 25 French ICUs during a subsequent experimental period (2). The types of, frequencies of, and reasons for decisions to limit or stop treatment in the two periods were compared. In the experimental period 2, 17 ICUs participated in the feedback study. Within these 17 units, there was a small but significant (p less than 0.05) increase in decisions to stop active treatment and provide comfort care that was limited to patients with three or more OSFs. There was no change in decision making in the eight units that did not participate in the feedback study. Although these results suggest a direct causal relationship between the provision of objective prognostic data and changes in physician decision making, the small increase in comfort care decisions (n = 14) between period 1 and period 2 and the fact that only 17 of the 25 original units participated in the feedback study make it difficult to eliminate other influences. There was no indication in this study, however, that explicit provision of prognostic data led to a sense of therapeutic futility.

Critical Care↗