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Biomedical subjects

C Caldwell

Publications and source records attributed to C Caldwell.

At least 37 records · Page 2Linked to original sources
PubMed1997

Regulatory differences among avian ecto-ATPases.

Extracellular ATP is found to produce a variety of important biological responses. Ecto-ATPases are located on numerous cell types in many different species, regulate extracellular ATP levels and can be a key step in generating adenosine. Studies conducted on chicken ecto-ATPases from liver and cardiac and smooth muscle show a variety of differing properties including (1) different apparent Km's, (2) lectin sensitivity, (3) responses to detergents, (4) responses to lipid mediators, and (5) responsiveness to nucleotide-mimetic affinity labels. These results suggest that although each enzyme hydrolyzes extracellular ATP, they should each be viewed as a distinct subtype of the whole ecto-ATPase family due to their differential responses, largely linked to proposed regulatory phenomenon.

Adenosine Triphosphatases↗
PubMed1997

The phosphorylation state of translation initiation factors is regulated developmentally and following heat shock in wheat.

Several translation initiation factors in mammals and yeast are regulated by phosphorylation. The phosphorylation state of these factors is subject to alteration during development, environmental stress (heat shock, starvation, or heme deprivation), or viral infection. The phosphorylation state and the effect of changes in phosphorylation of the translation initiation factors of higher plants have not been previously investigated. We have determined the isoelectric states for the wheat translation initiation factors eIF-4A, eIF-4B, eIF-4F, eIF-iso4F, and eIF-2 and the poly(A)-binding protein in the seed, during germination, and following heat shock of wheat seedlings using two-dimensional gel electrophoresis and Western analysis. We found that the developmentally induced changes in isoelectric state observed during germination or the stress-induced changes were consistent with changes in phosphorylation. Treatment of the phosphorylated forms of the factors with phosphatases confirmed that the nature of the modification was due to phosphorylation. The isoelectric states of eIF-4B, eIF-4F (eIF-4E, p26), eIF-iso4F (eIF-iso4E, p28), and eIF-2alpha (p42) were altered during germination, suggesting that phosphorylation of these factors is developmentally regulated and correlates with the resumption of protein synthesis that occurs during germination. The phosphorylation of eIF-2beta (p38) or poly(A)-binding protein did not change either during germination or following a thermal stress. Only the phosphorylation state of two factors, eIF-4A and eIF-4B, changed following a heat shock, suggesting that plants may differ significantly from animals in the way in which their translational machinery is modified in response to a thermal stress.

Blotting, Western↗
PubMed1997

Liver transplantation after jejunoileal bypass for morbid obesity.

BACKGROUND: Jejunoileal (JI) bypass was developed as a therapy for morbid obesity in the late 1960s but has since been abandoned because of a high rate of complications, including cirrhosis. The need for liver transplantation after JI bypass has been infrequent, with only four previous patients reported in the literature; however, because the time to develop symptomatic end-stage liver disease after JI bypass may be quite long (25 years or more), the incidence of patients who will require liver transplantation may only now be increasing. STUDY DESIGN: We reviewed our experience with JI bypass and liver transplantation in 380 consecutive adult patients since 1985. RESULTS: Four patients underwent liver transplantation for cirrhosis after JI bypass, all within the last 48 months. The mean duration of time from JI bypass to transplantation was 22.3 years. All patients had complications, in addition to their liver disease, which were related to the JI bypass, which included nephrolithiasis, cholelithiasis, vitamin deficiencies, renal insufficiency, and d-lactic acidosis. One patient had the JI bypass taken down before transplantation, which precipitated acute liver and renal failure, necessitating urgent transplantation. One patient, who had the JI bypass taken down at the time of transplant, has developed recurrent morbid obesity, while the other three patients have not. The one patient who has not had the JI bypass taken down has not developed evidence of recurrent liver disease and is followed with monthly liver function tests and yearly biopsies. CONCLUSIONS: The incidence of patients who require liver transplantation after JI bypass may be on the increase. Take down of the JI bypass may precipitate acute liver failure in the cirrhotic patient. JI bypass should be accomplished either at the time of transplantation or if signs of liver dysfunction occur after transplantation. Liver transplant recipients can be at risk for recurrent obesity after takedown of the JI bypass. Transplantation for those patients with decompensated cirrhosis after JI bypass has demonstrated excellent early results.

Aged↗
PubMed1997

Spatial- and object-based attentional deficits in Alzheimer's disease. Relationship to HMPAO-SPECT measures of parietal perfusion.

The purpose of this study was to investigate the ability of patients with Alzheimer's disease to shift attention between spatial locations and between objects, and to examine the brain regions involved in these cognitive operations using single photon emission computed tomography (SPECT) imaging. A recent study of patients with focal lesions provided evidence that the right and left parietal lobes are differentially involved in shifting selective attention from invalidly cued spatial locations and objects, respectively (Egly et al. J Exp Psychol Gen 1994; 123: 161-77). Accordingly, in Alzheimer's disease patients, we hypothesized that right parietal hypoperfusion on SPECT would be associated with deficits on the spatial-based component of a cued reaction time task, and left parietal hypoperfusion would be associated with the deficits on the object-based component. Attentional performance of Alzheimer's disease patients (n = 29) was compared with aged-matched normal controls (n = 17) using a cued reaction time task based on Egly et. al. (1994). Regions of interest were defined semi-automatically on SPECT, and were anatomically localized with the aid of co-registered MRI. As hypothesized, in Alzheimer's disease patients, reaction time costs of invalid targets eliciting shifts of attention between spatial locations were selectively correlated with SPECT hypoperfusion in the right superior parietal lobe; while reaction time costs of between-object shifts of attention were correlated with hypoperfusion in the left inferior parietal lobe. These results provide evidence for the specialized roles of the right and left parietal regions in the spatial and object components of attentional shifting respectively, and suggest that the cognitive profile associated with Alzheimer's disease includes both spatial- and object-based attentional impairments.

Aged↗
PubMed1996

Managing and redesigning the continuum of care: the value chain model.

Systems of care have to be managed, measured, and continuously improved. In the current health care environment, the integration of clinical medicine, systems thinking, and quality management disciplines provides needed tools and skills and identifies key leverage points and learning opportunities to improve the quality of services delivered. This article presents the value chain model and plan, designed to assist managers, physicians, and organizations in managing and redesigning the continuum of care.

Case Management↗
PubMed1995

Volunteer low-risk outpatient surgery for uninsured patients in San Francisco. The Ambulatory Surgery Access Coalition.

OBJECTIVE: To provide uncompensated elective low-risk outpatient surgery for uninsured patients through a coalition of volunteer physicians, nurses, and hospitals. DESIGN: Description of the process of establishing the Ambulatory Surgery Access Coalition (ASAC), the political and administrative obstacles encountered, and the clinical results of treatment of the first 25 patients in the pilot project. SETTING: The ASAC includes the Kaiser Foundation Hospital, San Francisco, Calif, the University of California, San Francisco, the San Francisco General Hospital (SFGH), the San Francisco Department of Public Health, the San Francisco Consortium of Community Clinics, the Northern California Chapter of the American College of Surgeons, and the San Francisco Medical Society. A pilot program of uncompensated outpatient surgery was performed at the Kaiser Foundation Hospital. PATIENTS: Twenty-nine patients were referred to the ASAC between January 1 and November 1, 1994. Twenty-six patients were judged to be candidates for surgery, and 25 patients met the criteria for the ASAC program. One patient was referred to SFGH for treatment because of a perceived increased risk for hospitalization after surgery. RESULTS: Twenty-one patients underwent herniorrhaphy; three, excision of large inclusion cysts; and one, anal fistulotomy. Seventeen procedures were done under local anesthesia, seven under general anesthesia, and one under spinal anesthesia. None of the patients required hospital admission. No wound infections occurred. CONCLUSION: The ASAC successfully provided uncompensated low-risk outpatient surgery to 25 low-income uninsured patients in San Francisco. The coalition hopes, first, to include other San Francisco hospitals and surgical specialties, and second, to serve as a model for other communities throughout the country.

Ambulatory Surgical Procedures↗
PubMed1994

A prospective randomized double-blind trial of bolus urokinase in the treatment of established Hickman catheter sepsis in children.

BACKGROUND: The incidence of Hickman catheter sepsis is 10% to 40%, with resultant catheter loss in one third of infections. Urokinase causes dissolution of colonized intracatheter fibrin thrombi and may improve salvage. STUDY AIMS: To evaluate the efficacy of 12-hour-interval slow-push urokinase infusion in addition to standard antibiotic therapy in the treatment of catheter sepsis in a pediatric oncology population. METHODS: A two-arm randomized double-blind trial was undertaken, with catheter salvage rate as the end point. Patients with Hickman catheter sepsis were randomized after culture data confirmed the diagnosis. The study drug was administered by a slow intravenous push and given at 12-hour intervals for a total of four doses. The catheters were aspirated after 1 hour. RESULTS AND CONCLUSIONS: The trial was stopped after 41 patients were entered into the study; 18 patients received a placebo, and 23 received the urokinase. In the placebo group, six catheters were lost; in the urokinase group, eight were lost. The rate of bacterial clearance was equivalent for both. After administration of the study drug, each group had three episodes of fever and chills; two of these resulted in hypotension (one in each group). The authors conclude that slow-push urokinase infusion during established Hickman catheter sepsis does not result in improved catheter salvage or bacterial clearance. Slow intravenous push infusions in this setting may provoke hemodynamic instability even after initiation of antibiotics.

Bacteria↗
PubMed1994

The characteristics of northern black churches with community health outreach programs.

OBJECTIVES: The Black church has a long history of addressing unmet health and human service needs, yet few studies have examined characteristics of churches involved in health promotion. METHODS: Data obtained from a survey of 635 Black churches in the northern United States were examined. Univariate and multivariate statistical procedures identified eight characteristics associated with community health outreach programs: congregation size, denomination, church age, economic class of membership, ownership of church, number of paid clergy, presence of other paid staff, and education level of the minister. RESULTS: A logistic regression model identified church size and educational level of the minister as the strongest predictors of church-sponsored community health outreach. The model correctly classified 88% of churches that conduct outreach programs. Overall, the model correctly classified 76% of churches in the sample. CONCLUSIONS: Results may be used by public health professionals and policy makers to enlist Black churches as an integral component for delivery of health promotion and disease prevention services needed to achieve the Year 2000 health objectives for all Americans.

Black or African American↗
PubMed1993

Mentoring: the evolving role of senior leaders in a TQM environment.

This article reviews the effort to implement total quality management (TQM) at West Paces Medical Center. The author concludes that management behavior must shift from a control-oriented style to a mentorship style. A mentor is a leader capable of instilling creative inquisitiveness at all levels of the organization through the development of a shared vision and personal dedication to the widespread use of the principles and tools of TQM.

Georgia↗