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Biomedical subjects

E Proctor

Publications and source records attributed to E Proctor.

At least 19 recordsLinked to original sources
PubMed2006

Configuration of services used by depressed older adults.

As a more comprehensive service use measure, this study identifies service use configurations based on the use of 17 services. Factors associated with service use configurations are examined guided by the Andersen and Network Episode models. Self-report data at admission and at six-month follow-up were collected, along with information from medical charts among 140 older adults hospitalized for major depression. The data document service access and levels of use in three sectors of care (psychiatric, medical, and psychosocial services) and assess need, predisposing, enabling, and social network factors associated with use. Three distinct service use configurations were identified with cluster analysis: (1) home care users; (2) moderate users of outpatient mental health services; and (3) heavy users of all formal services. Rather than psychiatric needs, post-acute service use was related to: (1) concurrent physical conditions; (2) the availability of formal and informal services; and (3) financial stability. No difference in psychiatric outcomes was found by service use configuration. It is important to understand service use patterns as a measure of service use, given the co-occurring medical, psychiatric, and psychosocial conditions of older adults and corresponding needs in multiple sectors of care.

Aftercare↗
PubMed2004

MR image-guided investigation of regional signal transducers and activators of transcription-1 activation in a rat model of focal cerebral ischemia.

BACKGROUND AND PURPOSE: STAT-1 is a member of a family of proteins called signal transducers and activators of transcription (STATs), and recent studies have shown its involvement in the induction of apoptosis. There is limited information on the role of STAT-1 following stroke. In this study we use MRI measurements of cerebral perfusion and bioenergetic status to target measurements of regional STAT-1 activity. METHODS: Rats were subjected to 60 or 90 min of middle cerebral artery occlusion with and without reperfusion. MRI maps of the apparent diffusion coefficient of water and cerebral blood flow were acquired throughout the study. After the ischemia or reperfusion period, the brain was excised and samples were analyzed by Western blots using anti-phospho-STAT1 and anti-Fas antibodies. Regions were selected for analysis according to their MRI characteristics. RESULTS: Transcriptional factor STAT-1 was enhanced in the lesion core and, to a lesser extent, in the lesion periphery, following ischemia and reperfusion. This level of activity was greater than for ischemia alone. Western blots demonstrated STAT-1 phosphorylation on tyrosine 701 and not serine 727 after ischemia and 3 h of reperfusion. Enhanced expression of the apoptotic death receptor Fas was confirmed after ischemia followed by reperfusion. CONCLUSIONS: This study demonstrates that focal ischemia of the rat brain can induce STAT-1 activation, particularly following a period of reperfusion. The activation occurs not only in the lesion core, but also in the lesion periphery, as identified using MRI. STAT-1 may play an important role in the induction of cell death following stroke.

Animals↗
PubMed2004

Characterization of Salmonella enterica subspecies I genovars by use of microarrays.

Subspecies 1 of Salmonella enterica is responsible for almost all Salmonella infections of warm-blooded animals. Within subspecies 1 there are over 2,300 known serovars that differ in their prevalence and the diseases that they cause in different hosts. Only a few of these serovars are responsible for most Salmonella infections in humans and domestic animals. The gene contents of 79 strains from the most prevalent serovars were profiled by microarray analysis. Strains within the same serovar often differed by the presence and absence of hundreds of genes. Gene contents sometimes differed more within a serovar than between serovars. Groups of strains that share a distinct profile of gene content can be referred to as "genovars" to distinguish them from serovars. Several misassignments within the Salmonella reference B collection were detected by genovar typing and were subsequently confirmed serologically. Just as serology has proved useful for understanding the host range and pathogenic manifestations of Salmonella, genovars are likely to further define previously unrecognized specific features of Salmonella infections.

DNA, Bacterial↗
PubMed2001

Moderate hypothermia ameliorates liver energy failure after intestinal ischaemia-reperfusion in anaesthetised rats.

BACKGROUND/PURPOSE: Intestinal ischaemia-reperfusion (IR) can cause liver failure. The aims of this work were to study the effects of intestinal IR on liver energy metabolism and to evaluate the effects of moderate hypothermia. METHODS: Intestinal IR (90-minute intestinal ischaemia plus 60-minute or 240-minute reperfusion) was achieved by clamping and unclamping the superior mesenteric artery in rats. Normothermia or moderate hypothermia (30 degrees to 33 degrees C) was maintained by adjusting the environmental temperature. The ratio of hepatic inorganic phosphate to adenosine triphosphate (ATP) was monitored continuously during intestinal IR using in vivo phosphorus ((31)P) magnetic resonance spectroscopy. Phosphorus metabolites also were measured in extracts prepared from freeze-clamped liver and intestine. RESULTS: Mortality occurred exclusively during normothermic intestinal IR. A progressive increase in the hepatic inorganic phosphate to ATP ratio after normothermic intestinal IR was observed. Moderate hypothermia delayed this effect. Analysis of liver extracts confirmed above findings. However, there was no difference in intestinal phosphocreatine or ATP between normothermic and hypothermic rats undergoing intestinal IR. CONCLUSIONS: Intestinal IR at normothermia was associated with liver energy failure and high mortality rate. Moderate hypothermia ameliorated liver energy failure but did not attenuate intestinal energy failure after intestinal IR. Hypothermia may prove to be useful in the management of patients with intestinal IR injuries in the future.

Adenosine Triphosphate↗
PubMed2001

How much is enough? Perspectives of care recipients and professionals on the sufficiency of in-home care.

PURPOSE OF THE STUDY: This study sought to increase knowledge about the impact of rater role on the assessment of in-home supportive care. The authors compared the perspectives of care recipients and professionals on one aspect of the broad concept of quality of care in home care-the sufficiency of the amount of care provided by informal and formal caregivers. DESIGN AND METHOD: Sufficiency of home care was assessed through concurrent elderly persons' self-report through telephone interview and nurse clinical report based on in-home interviews with the elder. Care was assessed in terms of the sufficiency of the amount of informal and formal assistance received to meet functional dependency needs. Statistical analyses compared the ratings of elder and professional. RESULTS: Professional ratings of the sufficiency of care were significantly lower than those of the elderly care recipients. From the perspective of both care recipients and professionals, sufficiency of care was significantly related to coresidence of elder and caregiver, and to caregiver health. IMPLICATIONS: Consistent with previous literature, rater role was found to influence the assessment of the sufficiency of in-home care. Researchers and providers should recognize that care recipient and professional ratings are not interchangeable.

Activities of Daily Living↗
PubMed1996

Proton nuclear magnetic resonance spectroscopy of lactate production in isolated rat liver during cold preservation.

Lactate-edited 1H NMR difference spectra have been acquired from intact rat liver tissue following flushing and preservation in ice. A peak, initially at 1.26 ppm, was seen to increase in the liver tissue with preservation time. This peak was assigned to lactate, despite the fact that its chemical shift was initially shifted by approximately -0.1 ppm relative to an externally added standard. The assignment was based on the following: (a) the peak increased over a 24-h ischemic storage period; (b) it was coupled to a signal 2.78 +/- 0.02 ppm upfield; and (c) a parallel increase in lactate was noted in perchloric acid extracts of tissue from the same liver. An additional peak, assigned to alanine, was also observed during storage and was also shifted by approximately -0.1 ppm. Inclusion of dimethyl sulfoxide, which readily permeates liver tissue, demonstrated that this chemical shift alteration was a tissue-specific effect. These results demonstrate that 1H NMR spectroscopy of intact liver tissue during hypothermic ischemia is possible, though chemical shift assignments should be made with caution.

Animals↗
PubMed1995

Hypothermic perfusion preservation of liver: the role of phosphate in stimulating ATP synthesis studied by 31P NMR.

Hypothermic perfusion of rat livers was investigated by 31phosphorus nuclear magnetic resonance (31P NMR) spectroscopy using a temperature-controlled module that allowed data acquisition at various time points during a 48-h period. The livers were perfused with an oxygenated lactobionate/raffinose-based solution containing adenosine and inorganic phosphate, and changes in tissue oedema were monitored by direct on-line measurements of liver weight changes. Liver tissue ATP concentrations, determined by fluorimetric assay, were low immediately after organ removal, probably reflecting metabolic stress during the removal period, and these increased slightly during the next 3 h. This was reflected by changes in the 31P NMR spectra. However, by 24 h ATP levels had increased significantly, and these were maintained for up to 48 h, suggesting a shift in the balance between energy production and consumption. When inorganic phosphate was replaced by another anion (citrate), ATP was maintained at a constant lower level during perfusion for 48 h. Tissue weight changes were similar in both groups, suggesting that volume control was not affected by the different ATP contents of the livers. By combining the temperature-controlled module with a separate perfusion circuit, NMR spectroscopy can provide a sensitive method for following energy metabolism in the same organ over long periods during hypothermic perfusion.

Adenosine Triphosphate↗
PubMed1995

Resuscitation of cardiac energy metabolism in the rabbit heart by brief hypothermic reperfusion after preservation studied by 31P NMR spectroscopy.

Rabbit hearts were subjected to 24-h cold ischaemic storage (at 0 degree-2 degrees C in melting ice) after initial flushing with either St Thomas' cardioplegic solution (STS) or modified lactobionate/raffinose solution (LR), and the status of phosphorylated energy metabolites was measured by 31phosphorus nuclear magnetic resonance (P NMR) spectroscopy. In both groups signals for ATP and phosphocreatine (PCr) were still detectable by 31P NMR after 24 h, and there was significantly more ATP in the LR group (P < 0.01). The hearts were then subjected to coronary reperfusion via an aortic cannula using the same storage solution (either STS or LR) at 6 degrees-8 degrees C, which was oxygenated. In both groups PCr recovered within 30 min of cold reperfusion, and by 60 min PCr was significantly higher in the LR group (P < 0.001). Also, levels of ATP were maintained at higher values during cold reperfusion i the LR group. These studies suggest two important points: (1) the general supply of phosphorylated high-energy intermediates of hearts during cold ischaemic storage is better preserved using LR, and (2) brief cold reperfusion may be used to restore energy metabolism in hearts before re-implantation.

Adenosine Triphosphate↗
PubMed1994

Evaluation of cold reperfusion as an indicator of viability in stored organs: a 31P NMR study in rat liver.

Rat livers were studied during hypothermic resuscitation perfusion using 31P nuclear magnetic resonance (NMR) spectroscopy as a viability index. Livers were stored for 48 h after being flushed either with a synthetic solution containing plasma-equivalent concentrations of cations, plus citrate and including gelatin polypeptides as colloid (GC solution), or with a modified lactobionate/raffinose [University of Wisconsin (UWC)] solution. After 48 h in either solution, all NMR-detectable ATP plus ADP had disappeared, inorganic phosphate had increased markedly and pH in the livers had become acidotic. During cold reperfusion, ATP was resynthesized, inorganic phosphate declined, and pH returned toward normal values. ATP recovery and decrease in tissue inorganic phosphate were significantly greater (P < 0.02 and P < 0.005, respectively) after 1 h cold reperfusion with the modified UW compared with reperfusion with the GC. 31P NMR spectroscopy was able to detect differences in the metabolic responses of livers stored in different solutions, and coupled with cold reperfusion may be a useful indicator of viability.

Adenosine↗
PubMed1994

Discharge destinations of Medicare patients receiving discharge planning: who goes where?

This study aims to increase knowledge about factors affecting discharge destinations of Medicare patients leaving the hospital after receiving discharge planning services. Medical, social, financial, and demographic factors are tested in relation to three dispositions: home, nursing home, and rehabilitation unit. Polytomous logistic regression was used to assess the likelihood of going to one destination versus another. For both nursing home versus home and rehabilitation unit versus home, destination was a function of first medical and then financial factors, with social resources playing a lesser role in the models. The only demographic variable with a significant relationship to destination was race, with black patients less likely to enter nursing home settings.

Black or African American↗
PubMed1993

Control of intracellular pH in mammalian liver at hypothermia: evidence for a relationship with energy metabolism.

The metabolic status of rat livers during hypothermia has been studied using 31P magnetic resonance spectroscopy. Perfusion with oxygenated buffer at 6-8 degrees C allowed maintenance of ATP, while pH increased to values in the range 7.7-7.9. In organs depleted of ATP by a short (2 h) period of cold ischemia, pH fell to 6.92 +/- 0.10. If these livers were reperfused with hypoxic buffer at hypothermia, two distinct responses were noted. In one group (responders), there was evidence of ATP resynthesis and in these organs pH returned to 7.90 +/- 0.28. In the second group (non-responders), there was no recovery of ATP synthesis and pH remained depressed at 6.97 +/- 0.07. In another group, adenine nucleotides were severely depleted by 24 h of cold ischemia, and in these livers there was again no significant recovery of ATP synthesis during hypoxic reperfusion and pH remained at 7.03 +/- 0.25. These results suggest that (a) there is an apparent relationship between energy metabolism and control of intracellular pH in the hypothermic mammalian liver, and (b) that intracellular pH may shift in liver at hypothermia to values predicted by the alpha-stat hypothesis.

Adenosine Triphosphate↗
PubMed1992

Cell and tissue responses of a murine tumour to phthalocyanine-mediated photodynamic therapy.

Mice bearing a subcutaneously growing tumour (Colo 26) were injected intravenously with the photosensitiser chloroaluminum sulphonated phthalocyanine (5 mg/kg) 24 h prior to irradiating the tumour with laser light (675 nm; 50mW, 100 J/tumour). Energy status of the tumour, as assessed by the loss of high energy phosphates in the 31P-nuclear magnetic resonance spectra, was altered dramatically following treatment, such that the ATP fell to undetectable levels within 1 h of light irradiation. However, assessment of the clonogenic capacity of neoplastic cells isolated from dissociated tumours showed that these rapid changes in cellular metabolism were not reflected in similar rapid changes in cell viability. Reductions in clonogenic capacity, which fell to less than 0.1% of control values at 24h postirradiation, closely mirrored those resulting from the cessation of vascular perfusion. Evaluation of tumour blood flow, using the technique of hydrogen washout, showed that the treatment protocol evoked a gradual and selective reduction in flow within the tumour resulting in complete vascular stasis by approximately 5 h after treatment. The results indicate that while chloroaluminum sulphonated phthalocyanine-mediated photodynamic therapy caused early metabolic damage in neoplastic cells, loss of viability paralleled the induction of complete inhibition of vascular flow in the tumour.

Animals↗
PubMed1992

Patient and family satisfaction with discharge plans.

This study explored factors affecting patient and family satisfaction with discharge plans, an outcome of discharge planning provided by the hospital department of social work. Adequacy of discharge plans was rated by 126 patients and 130 family members within 24 hours before hospital discharge. Patient ratings of discharge plans were related to their degree of involvement in decision making, social support networks (sex and marital status), and physical condition (diagnosis and functional ability). Three types of factors were important to family members: 1) factors related to the discharge planning process, 2) the patient's discharge destination, and 3) length of patient hospital stay. Findings are discussed in terms of their implications on maximizing consumer satisfaction in the cost-conscious environment.

Aged↗
PubMed1992

Seroprevalence survey of borreliosis in children with chronic arthritis in British Columbia, Canada.

A seroprevalence survey using an indirect immunofluorescence assay (IFA) for IgG antibodies to Borrelia hermsii and Borrelia burgdorferi was conducted for varied pediatric chronic arthritis patients and a nonrheumatic control group in the province of British Columbia, Canada. Overall, a higher rate of sera with IFA titers > or = 1/256 was found for B. hermsii (36.6%) compared to B. burgdorferi (12.5%). There were no significant differences among the arthritis subgroups and controls for the distribution of IFA titers for either organism. IgG immunoblotting of selected high titered sera to either borrelia species confirmed the lack of specificity of the IFA assay. Serological tests for borreliosis should be cautiously interpreted in children with chronic arthritis.

Adolescent↗
PubMed1990

The combined measurement of blood flow and metabolism in RIF-1 tumours in vivo. A study using H2 flow and 31P NMR spectroscopy.

Blood flow and phosphorus metabolites have been measured simultaneously in the murine RIF-1 tumour in vivo. Blood flow was measured using the H2 washout technique and 31P NMR spectroscopy was used to measure high energy phosphates, inorganic phosphate and intracellular pH within the tumour. Following NMR and flow measurements, hydralazine was administered and the measurements repeated. There was always a decrease in blood flow, and a fall in nucleoside triphosphate detected by NMR, after administration of hydralazine. At blood flows in excess of 15 mL 100 g-1 min-1, the nucleoside triphosphate/inorganic phosphate ratio was 1.0 or greater, whereas at flows in the range of 5-12 mL 100 g-1 min-1 the ratio fell to below 0.5, and at flows below 5 mL 100 g-1 min-1 there was no detectable resonance from nucleoside triphosphate.

Animals↗