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Biomedical subjects

P Jacobs

Publications and source records attributed to P Jacobs.

At least 145 records · Page 8Linked to original sources
PubMed1995

ICU and non-ICU cost per day.

The purpose of this study was to compare the cost of a day spent in an intensive care unit and a day spent on a general nursing unit. A descriptive design was used, based on patient level data, to examine and compare unit costs per day for each of the ICU and non-ICU portions of a patient's hospital stay. Records from 386 patients who were treated in a general medical/surgical ICU were analyzed. Records for patients who received both ICU and non-ICU care during their stay were retained. Patients were categorized according to whether they had received surgical care prior to admission to the ICU (surgical group) or had no surgical care (medical group). The groups were further divided, based on whether they were discharged from hospital (survivors), or died following transfers from the ICU (non-survivors). All four groups; surgical or medical, survivors and non-survivors, were analyzed separately. The ICU direct costs per day for survivors were between six and seven times those for non-ICU care. A one day substitution of general ward for ICU care would result in a cost reduction of $1,200 per patient for survivors. The results suggest that the savings achieved by moving a patient from ICU to non-ICU care are considerable, particularly for less severe surviving patients. In making such decisions, however, clinicians must examine prospective benefits as well as costs. If the health outcomes are not influenced, the savings from substitution are considerable, and there is a strong economic argument for substitution.

Adult↗
PubMed1995

Physical and chemical properties of superparamagnetic iron oxide MR contrast agents: ferumoxides, ferumoxtran, ferumoxsil.

The bulk physiochemical properties of the active ingredients in three AMI colloidal, superparamagnetic iron oxide (SPIO), MR contrast agents are described. Ferrous content and X-Ray diffraction (XRD) of the colloids are consistent with nonstoichiometric magnetite phases in all three active ingredients. No separate maghemite (gamma-Fe2O3) phases were detected by XRD. XRD line-broadening determinations of representative samples of ferumoxides (dextran coated), Ferumoxtran (dextran covered), and ferumoxsil (siloxane coated) yielded mean crystal diameters (volume weighted distribution) of 4.8-5.6, 5.8-6.2, and 7.9-8.8 nm, respectively. Transmission electron microscopy (TEM) showed that the crystal sizes were lognormally distributed with respective mean crystal diameters (number weighted distribution) of 4.3-4.8, 4.3-4.9, and 8.0-9.5 nm, respectively. Consistent with their small crystal sizes, the three SPIO colloids are superparamagnetic with no remanence after saturation at high applied fields (< 1 T), and showed characteristic relaxed Mössbauer spectra. The Mössbauer spectra of ferumoxides and Ferumoxtran were consistent with the presence of superparamagnetic relaxation above a blocking temperature of approximately 60 K. Due to the larger crystal sizes of ferumoxsil, its Mössbauer spectra showed the presence of rapid collective magnetic excitations on the Mössbauer time scale (approximately 1-10 ns). All three colloids showed high MR relaxivities. TEM of the SPIO colloids showed that ferumoxides and ferumoxsil are composed of aggregates of nonstoichiometric magnetite crystals, while Ferumoxtran consists of single crystals of nonstoichiometric magnetite. Dynamic light scattering (PCS) measurements showed that Ferumoxtran particles have average hydrodynamic diameters of approximately 21 nm (number weighted distribution) or 30 nm (volume weighted distribution). The data indicate that Ferumoxtran crystals are coated with an 8-12 nm layer of dextran T-10. Ferumoxides aggregates have average particle sizes of approximately 35 nm (number average distribution; TEM and PCS), or approximately 50 nm (volume weighted distribution; PCS). Mean sizes of ferumoxsil aggregates are approximately 300 nm (intensity weighted distribution). A discussion of the various particle size distributions is presented.

Chemical Phenomena↗
PubMed1995

Extensive bone marrow necrosis associated with antiphospholipid antibodies.

Bone marrow necrosis (BMN), defined morphologically by destruction of hematopoietic tissue, including the stroma, with preservation of the bone, is a rare syndrome. The conditions in which it is seen include sickle cell disease, acute leukemia, metastatic neoplasia, and bacterial infection, particularly when hypovolemia and septic shock are present. BMN is also associated with disseminated intravascular coagulation (DIC) following irradiation and antineoplastic therapy. The antiphospolipid syndrome (APS) is characterized by antibodies directed against the antiphospolipid substrate. Because this substrate is prominently involved in the coagulation cascade and widely distributed on cell walls, patients present with venous or arterial thromboses, recurrent abortion, thrombocytopenia, and Coombs' positive hemolytic anemia, typically with raised anticardiolipin antibodies or a diagnostic lupus anticoagulant test. BMN does not appear to have been previously recognized in this context. We report what we believe to be the first such case and suggest that the high titers of antibodies present may have played a central role in its pathogenesis.

Adult↗
PubMed1995

Alberta's acute care funding plan: update to December 1994.

From 1990 until 1994 Alberta Health adjusted the acute care portion of hospital budgets based on a case mix index, initially called the Hospital Performance Index (HPI). The HPI formula method was a temporary measure; in November 1993, Alberta Health announced that, commencing in 1994, hospitals would be funded on a prospective basis, although they would still use the core of the HPI in the setting of funding rates. The creation of 17 health regions in June 1994 created the need for a new system of funding which would supplant the modified prospective system. In this paper we review the evolution of the HPI plan and its individual components-patient data, patient classification, funding weights, inpatient costs and adjustment factors.

Alberta↗
PubMed1995

Comparative costs for substitutable services: inpatient and day surgery episodes of care.

The authors analyze the differences in costs between inpatient and outpatient elective surgery, by case mix group*, using the University of Alberta Hospitals Patient Resource Consumption Profile database (PRCP), supplemented with additional data from other agencies. PRCP measures costs for both inpatient and outpatient cases and is linked to the hospital's medical records, so that individual case-costing and detailed cost comparisons can be made. The focus of the comparison is on cost per case, measured in terms of the entire episode of outpatient surgery.

Alberta↗
PubMed1995

Estimating the cost of outpatient hospital care.

Hospital services can be divided into inpatient, outpatient and non-patient areas; outpatient care can be further subdivided into emergency room care, general and special clinic care, day procedures and non-admitted day/night care. Using 1992-93 Statistics Canada data on expenditures and outpatient activity from the Part One form for 29 Alberta hospitals, we estimated the average cost of each of the four outpatient areas. The estimated cost per visit was $183 for clinic visits, $166 for day/night care, $69 per emergency visit and $627 per day procedure. These estimates can be used in cost-effectiveness studies and, if supplemented with outpatient case weights and volumes, in provincial funding systems.

Alberta↗
PubMed1995

Immune response of mice infected with Schistosoma mansoni is modulated by antifibrotic treatment.

Mice infected with Schistosoma mansoni treated with beta-aminopropionitrile (BAPN), an antifibrotic agent, and the antischistosomal drug praziquantel (PZQ) were resistant to challenge for up to 5 weeks post-treatment. The combined treatment resulted in profound changes to the liver granuloma cell matrix and the composition and function of the cellular infiltrate. Although granulocytes always predominated in the infiltrate, the proportion of the cells which were macrophages was higher in mice treated with BAPN alone (39.2%) than in infected mice which were untreated (15.2%) or treated with PZQ alone (12.4%), and much higher than in mice given the combined treatment (1.8%). Two products associated with macrophage activation and cytotoxicity [tumour necrosis factor-alpha (TNF-alpha) and nitric oxide] were only detected in mice harbouring a patent infection and there was a strong positive correlation between the concentrations of each. The relatively low TNF-alpha concentrations in BAPN-treated mice seemed to be associated with the relatively small granulomas observed in these mice. BAPN treatment also led to changes in the proliferative response of the treated mice's macrophages to mitogen and soluble schistosome-egg antigen and in spleen cellularity; these changes are probably associated with the resistance to challenge infection observed in mice given BAPN with PZQ. It is clear that BAPN treatment changes the dynamics of the delayed-type hypersensitivity response within the granuloma and that this impacts on other immunological sites. How this relates to the maintenance of post-treatment resistance to a challenge infection has still to be elucidated.

Aminopropionitrile↗
PubMed1995

Fe-52 imaging of intrathoracic extramedullary hematopoiesis in a patient with beta-thalassemia.

Fe-52 scintigraphy was used to confirm extramedullary hematopoiesis in a patient with beta-thalassemia and intrathoracic masses. Imaging was performed on a standard gamma camera with a high-energy collimator. Tc-99m labeled tin colloid and In-111 chloride scintigraphy failed to reveal uptake by the masses. The exclusion of malignancy obviated the need for invasive diagnostic measures.

Diagnosis, Differential↗
PubMed1995

A comparison of intensive care unit utilization in Alberta and western Massachusetts.

OBJECTIVE: To analyze differences in intensive care unit (ICU) utilization between a Canadian province and a U.S. area. DESIGN: Retrospective data analysis of hospital discharge data and existing data from an international study of severity of illness in ICU patients. SETTING: Administrative data for the province of Alberta and the four counties of western Massachusetts for the years 1990 to 1991 were used. Detailed data on consecutive ICU admissions from two Alberta hospitals, one western Massachusetts hospital, and 24 other U.S. hospitals for 3 months in 1991 were used. MEASUREMENTS AND MAIN RESULTS: ICU use and hospital mortality rates were compared for 50,030 hospital admissions divided into 11 patient groups. ICU days per million population were two to three times as great in western Massachusetts as in Alberta. The primary reason was higher ICU incidence (percent of hospitalized patients treated in the ICU) rather than a difference in hospital admission rate or length of ICU stay. ICU incidence in western Massachusetts was significantly higher in ten of 11 patient groups--for the coronary bypass surgery group, there was no difference. The hospital mortality rate in western Massachusetts was similar to, or higher than, the mortality rate in Alberta. In Alberta, a much higher proportion of ICU patients received mechanical ventilation. For elective surgery patients, the ICU severity of illness was lower in western Massachusetts and in other U.S. hospitals than in Alberta. CONCLUSIONS: Western Massachusetts hospitalized patients are more likely to be treated in an ICU than are similar patients in Alberta. There is no evidence that the greater ICU utilization in western Massachusetts led to a lower hospital mortality rate.

Aged↗
PubMed1995

Emergency care episodes: an economic profile.

A new "episode of care" definition of emergency care was developed, consisting of the emergency department encounter and all subsequent, related care delivered within 48 hrs from the initial contact. Data were analyzed by ICD-9-CM Major Diagnostic Category (MDC) and surgical intervention using 1.6 million episodes generated by 809,145 separate patients from a national claims database. Secondary/adjunct services were a major component of episode charges. For several MDCs, hospitalization and/or surgical procedures were also major determinants of overall episodic charges. Results support the premise that economic analysis and reimbursement of emergency care benefits from the use of episodic data.

Ancillary Services, Hospital↗
PubMed1995

Blunted erythropoietin response to anaemia in tuberculosis.

The precise cause of the anaemia that is commonly associated with severe pulmonary tuberculosis (PTB) has not been elucidated. The role of erythropoietin (Epo), the central hormone regulating red cell formation, still awaits clarification. We therefore determined serum Epo levels in patients with PTB; group 1, haemoglobin less than 110 g/L, group 2, haemoglobin greater than 110 g/L; group 3, controls, consisted of matched individuals with uncomplicated iron deficiency; group 4, healthy volunteers. Peripheral blood monocytes were obtained from patients with PTB and the controls, cultured, and the supernatant fluid (SNF) harvested. Tumour necrosis factor alpha (TNF alpha) levels were determined in the SNF, which were then added in various dilutions to a hepatocellular carcinoma cell line (HepG2) capable of regulated EPO synthesis in vitro. The influence of this cytokine was defined by the addition of specific neutralising anti-TNF alpha antibodies in this assay system. Patients in group 1 had significantly lower Epo levels (54 + 11 mU/mL) compared with those in group 3 (142 +/- 41 mU/mL) (p < 0.01). Monocyte supernatants from patients in the anaemic PTB group had markedly elevated TNF alpha levels and significantly suppressed Epo output by HepG2 cells in vitro (p < 0.01). This inhibition was consistently abrogated by anti-TNF alpha antibodies. Serum Epo levels were inappropriately low in untreated PTB patients when compared with corresponding haemoglobin levels in iron deficient controls. This blunted response could be ascribed to release of TNF alpha or other cytokines by activated monocytes.

Anemia↗
PubMed1995

Prognostic factors in allogeneic bone marrow transplantation for multiple myeloma.

PURPOSE: To analyze prognostic factors for allogeneic bone marrow transplantation (BMT) in multiple myeloma. PATIENTS AND METHODS: One hundred sixty-two reports of allogeneic matched sibling-donor transplants in multiple myeloma received by the European Group for Blood and Marrow Transplantation (EBMT) registry between 1983 and early 1993 were analyzed for prognostic factors. End points were complete remission, survival, and duration of complete remission. RESULTS: Following BMT, 44% of all patients and 60% of assessable patients entered complete remission. The overall actuarial survival rate was 32% at 4 years and 28% at 7 years. The overall relapse-free survival rate of 72 patients who were in complete remission after BMT was 34% at 6 years. Favorable pretransplant prognostic factors for survival were female sex (41% at 4 years), stage I disease at diagnosis (52% at 4 years), one line of previous treatment (42% at 4 years), and being in complete remission before conditioning (64% at 3 years). The subtype immunoglobulin A (IgA) myeloma and a low beta 2-microglobulin level (< 4 g/L) also tended to have a favorable prognostic impact. The most important post-transplant prognostic factor was to enter a complete remission. Grade III to IV graft-versus-host disease (GVHD) was associated with poor survival. CONCLUSION: Patients with a low tumor burden who respond to treatment before BMT and are transplanted after first-line therapy have the best prognosis following BMT.

Adult↗
PubMed1995

A comparative review of pharmacoeconomic guidelines.

We have reviewed 4 international sets of guidelines for the economic evaluation of pharmaceutical products-those of the Australian Pharmaceutical Benefits Advisory Committee, the Canadian Coordinating Office for Health Technology Assessment, the Ontario Ministry of Health, and the England and Wales Department of Health. Comparison of these guidelines reveals that there are a number of differences between them, including disparities in outcome selection, costs and perspectives. These observations were attributed to differences in study purpose, conceptual approach, measurement techniques and value judgements. Uniformity can be achieved only in conceptual approach and measurement technique. Guidelines should be flexible to accommodate differences in the study purposes and value judgements of the analysts.

Australia↗
PubMed1995

Bone marrow failure: pathophysiology and management.

Morphologically, bone marrow is made up of a relatively mature but heterogenous population, fueled by a tiny pool of microscopically unrecognizable stem and progenitor cells. This complex tissue has the responsibility of maintaining our hematopoietic and, to a large extent, immunologic integrity, both of which are indispensable for health and, indeed, survival. Perhaps not surprisingly, bone marrow is the target of genetic, autoimmune, and environmental insults. Although robust, it has only a limited number of responses, one of which is reduction in cellular output, sometimes with superimposed qualitative abnormalities, and this is defined as bone marrow failure. Bone marrow failure is a diverse entity but can be logically explained and classified on a pathophysiologic basis. Thus the major recognizable categories of bone marrow failure are congenital and acquired defects. Each of these is subdivided according to the number of cell lines involved, over and above which the severity of the damage will determine reversibility. In each case, the natural history dictates management, and this ranges from short-term growth factor support to biologic immune response modulation and finally to bone marrow transplantation. In the past, many clinicopathologic variants of bone marrow failure were described, although their etiology was obscure and effective therapy was unavailable. This changed dramatically, however, when experimental hematologists, using radiobiology models, uncovered the dynamic nature of blood formation. Cardinal observations included the way in which spontaneous recovery followed irradiation, the central role played by pluripotential stem cells, and the integral participation of stroma in modulating this entire process. Understanding was refined once bone marrow cultures became available while, in parallel, the use of in-bred mouse strains launched the era of allogeneic transplantation. These approaches were combined, and the broad principles that govern basal or constitutive production emerged. Stem cells, with their characteristic commitment to self-renewal, exist at the apex of a hierarchy and generate a tier of proliferating progenitors that, in turn, give rise to a large postmitotic compartment of precursors that mature into distinctive myeloid and lymphoid lineages. The reserve potential is enormous, and output can be induced to meet even greatly increased demands. These events reflect the interaction of growth factors with a balancing set of negative regulators. The link between such diverse functions resides, to a large extent, in accessory cells and matrix geographically organized in what is now described as the hematopoietic inductive microenvironment. Many details of these meticulously orchestrated processes are obscure.(ABSTRACT TRUNCATED AT 400 WORDS)

Agranulocytosis↗