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Biomedical subjects

J Burkhardt

Publications and source records attributed to J Burkhardt.

16 recordsLinked to original sources
PubMed1999

Financial and organizational determinants of hospital diversification into subacute care.

OBJECTIVE: To examine the financial, market, and organizational determinants of hospital diversification into subacute inpatient care by acute care hospitals in order to guide hospital managers in undertaking such diversification efforts. STUDY SETTING: All nongovernment, general, acute care, community hospitals that were operating during the years 1985 through 1991 (3,986 hospitals in total). DATA SOURCES: Cross-sectional, time-series data were drawn from the American Hospital Association's (AHA) Annual Survey of Hospitals, the Health Care Financing Administration's (HCFA) Medicare Cost Reports, a latitude and longitude listing for all community hospital addresses, and the Area Resource File (ARF) published in 1992, which provides county level environmental variables. STUDY DESIGN: The study is longitudinal, enabling the specification of temporal patterns in conversion, causal inferences, and the treatment of right-censoring problems. The unit of analysis is the individual hospital. KEY FINDINGS: Significant differences were found in the average level of subacute care offered by investor-owned versus tax-exempt hospitals. After controlling for selection bias, financial performance, risk, size, occupancy, and other variables, IO hospitals offered 31.3 percent less subacute care than did NFP hospitals. Financial performance and risk are predictors of IO hospitals' diversification into subacute care, but not of NFP hospitals' activities in this market. Resource availability appears to expedite expansion into subacute care for both types of hospitals. CONCLUSIONS: Investment criteria and strategy differ between investor-owned and tax-exempt hospitals.

Cross-Sectional Studies↗
PubMed1995

Gaining insight into a complex organelle, the phagosome, using two-dimensional gel electrophoresis.

Phagosomes are the organelles formed de novo in a variety of cells by the internalization of large particulate materials, including a wide range of pathogenic microorganisms. We present here a systematic approach that can be used to study the polypeptide composition of phagosomes/phagolysosomes and to yield analytical information on the characteristics of their proteins. A density shift approach was used to isolate pure preparations of phagosomes filled with low density latex beads from mouse J774 and human U937 macrophages. High resolution two-dimensional (2-D) gel electrophoresis was performed to generate a map of the overall [35S]methionine-labeled protein profile of the isolated phagosomes. The resulting map showed the minimal presence of over 200 polypeptides, indicating the complexity of this organelle. Comigration experiments showed that several phagosome polypeptides, among them several known proteins, are shared by the two species. Extraction with Triton X-114 and sodium carbonate was performed to distinguish between membrane and soluble proteins, and sensitivity to a panel of proteases was measured to identify proteins exposed on the cytoplasmic face of the phagosome membrane. The general value of the 2-D gel approach in the mapping of organelle proteins is discussed.

Animals↗
PubMed1994

Nursing/pharmacy interface: a TQM project.

W. Edwards Deming's seven-step quality improvement process provided a sequential pathway to facilitate problem-solving allowing the pharmacy and nursing departments to formulate a systems perspective rather than an individual point of view. Both departments identified problems with the Medication Administration Record and defined three key outcomes needed to signify process improvement.

Communication↗
PubMed1993

Trauma-hemorrhage and resuscitation in the mouse: effects on cardiac output and organ blood flow.

Although mice are widely used for the study of immune consequences of hemorrhage, the changes of cardiac output (CO) and blood flow (BF) in response to trauma and hemorrhage in this species have not been well defined. To study this, nonheparinized C3H/HeN mice (n = 6 per group) underwent laparotomy (i.e., trauma induced), were bled to a mean arterial pressure of 35 mmHg, and maintained for 90 min by withdrawing more blood or returning Ringer lactate. The animals were then resuscitated with four times the volume of maximal bleedout in the form of Ringer lactate over 60 min. Sham-operated mice underwent the same procedure but were neither bled nor resuscitated. At the end of hemorrhage, 60 min postresuscitation, or corresponding time after sham operation, CO and BF were determined by radioactive microspheres. Results indicate that CO and BF decreased significantly at the end of hemorrhage. Resuscitation, however, restored CO and BF in various organs except the brain and skeletal muscle. Despite this, 9 of 16 mice died within 6 days postresuscitation, whereas none of sham mice died (n = 16 per group in this additional study). Therefore, we have developed a nonheparinized model of trauma-hemorrhage and resuscitation in mice that is associated with late mortality. Furthermore, the microsphere technique provides a reliable method for assessing CO and BF in mice. Thus it may be possible to study the correlation between cardiovascular and immunologic alterations under such conditions.

Animals↗
PubMed1992

Measurement of hepatic blood flow after severe hemorrhage: lack of restoration despite adequate resuscitation.

Although Ringer lactate (RL) is routinely used for resuscitation, it is not known whether the volume of RL that restores cardiac output after severe hemorrhagic shock also restores the depressed effective hepatic blood flow (EHBF). To study this, a 5-cm midline laparotomy was performed in rats (i.e., trauma induced), and the animals were then bled to and maintained at a mean arterial pressure of 40 mmHg until 40% of maximum bleedout volume was returned in the form of RL. Animals were then resuscitated with four or five times the volume of maximum bleedout with RL. EHBF was determined during hemorrhage and at various intervals thereafter by an in vivo indocyanine green (ICG) clearance technique and corrected by the appropriate hepatic extraction ratio for ICG. Cardiac output was determined by ICG dilution, and hepatic microvascular blood flow (HMBF) was measured with laser Doppler flowmetry. In addition, hepatic blood flow was assessed by using radioactive microspheres. Results indicate that resuscitation markedly improved but did not restore the depressed EHBF after trauma and hemorrhagic shock despite the fact that cardiac output was restored. Similar changes in EHBF, HMBF, and hepatic blood flow as determined by microspheres were observed, suggesting that the in vivo ICG clearance is a reliable method to assess effective hepatic perfusion. Thus the lack of restoration of EHBF may be responsible for the subsequent hepatocellular dysfunction after trauma and severe hemorrhage.

Animals↗
PubMed1989

[The effect of bronchologic studies on blood gases and hemodynamics in children].

During 78 bronchological examinations in children of all age groups out of 6 centers of children bronchology of the GDR PaO2, PaCO2 and pH were registered, in a part of them additionally pulse, systolic and diastolic blood pressure. Following to the intubation--under ventilation with 100% oxygen or a halothane-NO2-oxygen mixture--there was a marked rise of PaO2, which normalized after extubation quickly. After extubation a slight hypoxemia occurred for a short period, a quick rise of PaCO2 and a slight acidosis, too. Besides, the hearth rate, systolic and diastolic blood pressure elevated following to the intubation and diminished after extubation.

Acid-Base Equilibrium↗
PubMed1988

[Acute foreign body aspiration as a respiratory emergency in childhood].

From 1957 to 1987 altogether 206 cases of tracheobronchial foreign body aspiration were diagnosed. Two third of the patients were one or two years old. Boys prevailed with 57 per cent. 55 per cent of all foreign bodies were nuts. Only 10 per cent were radiopaque (screws, nails, needles or pieces of bones). The attempt to eliminate the foreign body via the bronchoscope was successful in 96 per cent and failed in seven cases. Six children had to undergo a thoracotomy. In one third of the cases the foreign body remained two weeks or longer in the bronchial tree. 66 children with such a "chronic" foreign body were later on examined by bronchography, which showed in 29 per cent severe deformations of the bronchial wall and in 14 per cent even bronchiectasis. An acute foreign body aspiration should always be considered and handled as an emergency.

Bronchi↗
PubMed1987

Analysis of intraocularly applied silicone oils of various origins.

Complications during the intraocular use of silicone oil can be caused by two factors: first, mechanical interaction with the surrounding tissue and, second, the physiochemical properties of the oil itself. The properties of 14 oils of various origins in clinical use were investigated: 12 of the 14 oils contained various amounts of low-molecular-weight components (cyclosiloxanes and molecules with a molecular weight of less than 2,400), which are able to diffuse into the surrounding tissue and may incite toxic or inflammatory reactions. Some of the samples had a ten-fold lower volume resistivity than others, an indicator of the presence of ionic impurities, such as catalyst remnants, which may also be responsible for adverse reactions.

Chemical Phenomena↗
PubMed1986

Bronchial secretions and bronchial mucosa in children with cystic fibrosis: comparison of bronchoscopic, biochemical, bacteriological, microscopic and ultrastructural findings.

In children (mean age 12.1 +/- 2.9 years) with cystic fibrosis, 44 bronchoscopic examinations were done under general anaesthesia with muscle relaxation using a Friedel type ventilation bronchoscope. The endoscopic picture of the mucous membranes was compared with the state of the bronchial secretions, its bacteriologic findings and content of acid mucopolysaccharides and DNA fibres (semiquantitative estimations). In all patients biopsy of the mucous membrane (central part of the bronchial tree) was performed for light and electron microscopy. The degree of reddening, swelling of the mucous membrane and hypersecretion was in some agreement with the intensity of the cellular infiltration and the production of pus (microscopic investigation). Secondary ultrastructural changes were detected in nearly all children, consisting of cellular oedema, swelling of mitochondria, dilatation of the endoplasmatic reticulum, protrusion of cells and fusion of cilia, enlarged intercellular spaces, thickening of the epithelial basal membrane, increased number of goblet cells, microtubular abnormalities of the cilia, lesions of the apical cell membrane with loss of cilia and microvilli. These ultrastructural changes were not correlated with the above-mentioned signs of inflammation.

Adolescent↗
PubMed1985

Chest radiographs of near-drowned children.

From 1972 through 1983 there were 10 near-drowned children (7 boys and 3 girls) aged 1 to 4 years, treated as inpatients at the Children's Hospital of the Medical Academy Dresden. Three of them showed a severe aspiration pneumonia which in one case was complicated by bilateral pneumothoraces. In a further five children there were radiological signs of pulmonary oedema. Only in two children were the X-ray pictures of the chest normal.

Child, Preschool↗
PubMed1985

The suitability of transfer coefficients used for stochastic calculations in radioecology.

In radioecology, stochastic calculations are used to an increasing extent. It is shown that transfer coefficients which are defined as concentration ratios are not suited for stochastic calculations, at least for essential elements and their antagonists. The reason is that essential elements are regulated in plants and animals whereby their concentrations vary within narrow limits, rather independent of the concentrations in the source compartment. For a more accurate description of the transfer of radionuclides, it is proposed to include the concentrations of the essential elements in the source and target compartments into the transfer equation which leads to the specific activity model. This model has already been proposed by Comar et al. in 1956. It seems to work accurately for the transfer into animals and their products as well as into plants. Examples of its applicability are presented and discussed. Furthermore stochastic calculations seem to be more reasonable with this model.

Animals↗
PubMed1985

[Bronchial secretion and bronchial mucosa in children with mucoviscidosis: results of comparative bronchoscopic, biochemical, bacteriologic, light and electron microscopic studies].

Twenty two patients with cystic fibrosis, 7 to 17 years of age, underwent each two bronchoscopic investigations, the second six months later than the first, in general anaesthesia with muscle relaxation using a ventilation bronchoscope and taking small biopsies of the mucous membrane. The degree of reddening, swelling of the mucous membranes and hypersecretion was in some agreement with the intensity of the cellular infiltration and the production of pus (microscopic investigation). Secondary ultrastructural changes were detected in nearly all children: e.g. cellular oedema, protrusion of cells and fusion of cilia, microtubular abnormalities of the cilia, lesions of the apical cell membranes and increased number of goblet cells. These changes of ultrastructure were not correlated to the mentioned signs of inflammation.

Adolescent↗
PubMedDate not supplied

Virucidal and chlamydicidal activities of eye drops with povidone-iodine liposome complex.

Povidone-iodine (PVP-I) is a broad-spectrum microbicide with in vitro activity against bacteria, viruses, fungi and protozoans. A 5% solution of PVP-I proved to be highly effective in ophthalmic surgery for the prophylaxis of endophthalmitis. For the antiseptic treatment of eye infections a novel application form of PVP-I has been developed by using a PVP-I liposome complex which demonstrated an excellent antimicrobial efficacy. In this study it could be shown that the novel liposomal formulations containing 2.5 or 5% PVP-I were as active as the aqueous solution against herpes simplex virus type 1, adenovirus type 8, coxsackievirus A9 and Chlamydia trachomatis in cell culture referring to equal PVP-I concentrations. Long-term cytotoxicity experiments demonstrated a moderate cytotoxicity for both formulations with a better tolerability of the liposomal PVP-I formulation compared with the aqueous solution. There is no evidence for a genotoxic activity of these agents.

Adenoviruses, Human↗