Biomedical subjects

J Holm

Publications and source records attributed to J Holm.

At least 19 recordsLinked to original sources

PubMed2001

[Recurrence and survival after conventional low anterior resection for rectal cancer].

INTRODUCTION: The aim of the study was to evaluate the incidence of recurrence of local cancer, distant metastases and survival after conventional low anterior resection for cure in patients with rectal carcinoma, on the basis of the poor prognosis after colorectal cancer in Denmark. MATERIAL AND METHODS: Consecutive patients operated on in the nine Danish departments of surgical gastroenterology in 1992-1993. Retrospective collection of data on recurrence of local cancer, distant metastases, and over-all survival at the end of 1996. RESULTS: Of 268 patients, 77 (29%) developed recurrent local cancer and/or distant metastases. Forty-eight (18%) had local recurrence with a cumulative 5-year rate of 39%. Distant metastases were seen in 54 (20%). The local recurrence rate increased with increasing Dukes' tumour stage and was higher after operation by a non-specialist (30%) than by a consultant, another specialist, or a surgeon under training and supervised by a consultant (15-17%) (p = 0.04). Multiple regression showed that the recurrence rate was independent of tumour localisation, blood loss, transfusion, anastomotic leakage, and status of the surgeon. The cumulative crude 5-year survival was 50% and independent of the status of the surgeon. DISCUSSION: Our relatively high local recurrence rate and the results in the literature after total mesorectal excision (TME) indicate that the conventional technique should be replaced by TME, which has become the recommended method in recent years. Furthermore, we propose a changed strategy in the treatment of rectal cancer. The patients should be treated in fewer departments with established teams of rectal cancer specialists taking part in all operations for rectal cancer.

Adenocarcinoma↗

PubMed2001

Molecular basis of allergic cross-reactivity between group 1 major allergens from birch and apple.

Patients allergic to birch pollen often also react with fruits and vegetables, such as apple. The major cause of cross-reactivity between birch and apple is biochemical and immunological similarity between the major allergens, Bet v 1 and Mal d 1, as demonstrated by serological and cellular immunoassays. In addition, birch pollen-specific therapeutic allergy vaccination has been shown to improve allergic symptoms caused by oral ingestion of apple. Detailed analysis of molecular surface areas based on the crystal structure of Bet v 1, and primary sequence alignment, identify potential epitopes for cross-reactive antibodies. Two or more conserved patches are identified when comparing Bet v 1 and Mal d 1, thus providing a molecular model for serological cross-reactivity involving more than one IgE-binding epitope. A minimum of two epitopes would be necessary for cross-linking of receptor bound IgE in functional histamine release assays and skin test. Individual amino acid substitutions, as occurring in isoallergenic variation, may, however, have a dramatic effect on epitope integrity if critical residues are affected. Thus, one area large enough to accommodate antibody-binding epitopes shared by all known Mal d 1 isoallergens and variants is identified, as well as areas shared by Bet v 1 and individual Mal d 1 isoallergens or variants. The occurrence of limited epitope coincidence between Bet v 1 and Mal d 1 is in agreement with the observation that some, but not all, birch pollen allergic patients react with apple, and that the epitope repertoire recognised by the IgE of the individual patients determines the degree of cross-reactivity.

Allergens↗

PubMed2001

[Implementation of a new electronic patient record in surgery].

INTRODUCTION: The increasing amount of clinical data, intensified interest of patients in medical information, medical quality management and the recent cost explosion in health care systems have forced medical institutions to improve their strategy in handling medical data. In the orthopedic department (3,600 surgeries, 75 beds, 14,000 consultations) software application for comprehensive patient data management has been developed. METHOD: When implementing the electronic patient history following criteria were evaluated: 1. software evaluation, 2. implementation, 3. work flow, 4. data security/system stability. RESULTS: In the first phase the functional character was defined. Implementation required 3 months after parametrization. The expense amounted to 130,000 DM (30 clients). The training requirements were one afternoon for the secretaries and a 2-h session for the residents. The access speed on medically relevant data averaged under 3 s. The average saving in working hours was approximately 5 h/week for the secretaries and 4 h/week for the residents. The saving in paper amounted to 36,000 sheets/year. In 3 operational years there were 3 server breakdowns. CONCLUSIONS: Evaluation of the saving on working hours showed that such a system can amortize within a year. The latest improvements in hardware and software technology made the electronic medical record with integrated quality-control practicable without massive expenditure. The system supplies an extensive platform of information for patient treatment and an instrument to evaluate the efficiency of therapy strategies independent of the clinical field.

Database Management Systems↗

PubMed2001

[A new concept for integration of image databanks into a comprehensive patient documentation].

Image processing and archiving are of increasing importance in the practice of modern medicine. Particularly due to the introduction of computer-based investigation methods, physicians are dealing with a wide variety of analogue and digital picture archives. On the other hand, clinical information is stored in various text-based information systems without integration of image components. The link between such traditional medical databases and picture archives is a prerequisite for efficient data management as well as for continuous quality control and medical education. At the Department of Orthopedic Surgery, University of Berne, a software program was developed to create a complete multimedia electronic patient record. The client-server system contains all patients' data, questionnaire-based quality control, and a digital picture archive. Different interfaces guarantee the integration into the hospital's data network. This article describes our experiences in the development and introduction of a comprehensive image archiving system at a large orthopedic center.

Computer Systems↗

PubMed2001

Ionic charge, hydrophobicity and tryptophan fluorescence of the folate binding protein isolated from cow's milk.

A high-affinity folate binding protein was isolated and purified from cow's milk by a combination of cation exchange chromatography and methotrexate affinity chromatography. Chromatofocusing studies revealed that the protein possessed isoelectric points in the pH-interval 8-7. Polymers of the protein prevailing at pH values close to the isoelectric points seemed to be more hydrophobic than monomers present at pH 5.0 as evidenced by hydrophobic interaction chromatography and turbidity (absorbance at 340 nm) in aqueous buffer solutions (pH 5-8). Ligand binding seemed to induce a conformation change that decreased the hydrophobicity of the protein. In addition, Ligand binding quenched the tryptophan fluorescence of folate binding protein suggesting that tryptophan is present at the binding site and/or ligand binding induces a conformation change that affects tryptophan environment in the protein. There was a noticeable discordance between the ability of individual folate analogues to compete with folate for binding and the quenching effect.

Animals↗

PubMed2001

Influence of poststenotic collateral pressure on blood flow velocities within high-grade carotid artery stenosis: differences between morphologic and functional measurements.

PURPOSE: The driving force for blood flow through a high-grade stenosis in the internal carotid artery can be expressed as the pressure gradient over the stenosis itself, which, however, might be reduced by the back pressure exerted by distal collateral vessels. Theoretically the maximum blood flow velocity as a measure of the functional grade of obstruction may therefore be lower than what is expected from morphologic gradations of the stenosis. This study was designed to test prospectively the influence of intracranial collateral vessels on blood flow velocities within high-grade internal carotid artery stenoses. PATIENTS AND METHODS: Forty-five consecutive patients (age 66 +/- 11) with high-grade internal carotid artery stenoses were investigated before and during carotid endarterectomy. The preoperative investigations included duplex ultrasound scanning of the neck vessels, transcranial Doppler scanning for assessment of collateral flow to the middle cerebral artery and angiography. Carotid endarterectomy was performed with patients under deep general anesthesia without a shunt. Systolic and diastolic internal carotid artery blood pressures were measured before and during intraoperative cross-clamping (ie, stump pressure) of the carotid arteries. RESULTS: Within high-grade internal carotid artery stenoses, maximum systolic and end-diastolic blood flow velocities showed a significant inverse correlation to the corresponding systolic and diastolic stump blood internal carotid artery blood pressures. All patients with spontaneous collateral flow to the ipsilateral anterior part of the circle of Willis were divided into a group with relatively high and another one with low end-diastolic blood flow velocities. The stump pressure was significantly lower in patients with high end-diastolic blood flow velocities in spite of the fact that the mean angiographic grade of stenosis did not differ significantly between the groups. CONCLUSIONS: Flow velocities within a high-grade internal carotid artery stenosis are inversely dependent on the stump pressure, that is the poststenotic collateral perfusion pressure. This should be taken into consideration in case of discrepancies between angiography and ultrasound outcome.

Blood Flow Velocity↗

PubMed2001

Monitoring improvement using a patient-rated depression scale during treatment with anti-depressants in general practice. A validation study on the Goldberg Depression Scale.

OBJECTIVE: To perform a pilot study on the value of the Goldberg Depression Scale as an instrument for monitoring improvement in depressed patients treated with anti-depressants in general practice. DESIGN: A comparative study using simultaneous ratings on the observer-based 17-item Hamilton Depression Scale and the patient-rated Goldberg Depression Scale. SETTING: General practice. PATIENTS: Twenty-one patients meeting the ICD-10 criteria of a moderate depressive episode were assessed at the time of inclusion and through three follow-up visits. MAIN OUTCOME MEASURES: Scores on the Goldberg Depression Scale compared to the Hamilton Depression Scale. RESULTS: An acceptable internal and external validity of the Goldberg Depression Scale was demonstrated. The Loevinger coefficient varied from 0.25 at the time of diagnosis to 0.57, 0.65 and 0.69 by visits two, three and four. Factor analysis identified only one general factor explaining 50% or more of the variants, except at visit 1. When the Goldberg Depression Scale was correlated to the Hamilton Depression Scales, a coefficient of 0.74 was obtained (p < 0.001). CONCLUSION: This pilot study indicates that the Goldberg Depression Scale is suitable for monitoring improvement in depressed patients treated in general practice. Further studies are recommended.

Antidepressive Agents↗

PubMed2001

Production of free radicals measured by spin trapping during operations for stenosis of the carotid artery.

OBJECTIVES: To analyse production of free radicals during operations for stenosis of the internal carotid artery. SETTING: University hospital, Sweden. SUBJECTS: 10 patients operated on for carotid artery stenosis. INTERVENTIONS: Blood samples were repeatedly drawn from the sigmoid sinus through a catheter in the internal jugular vein on the same side, before, during, and after clamping of the internal carotid artery. OXANOH was added to the blood samples in vitro and the radical production calculated from the amount oxidised to OXANO as electron spin resonance. MAIN OUTCOME MEASURES: The relation between radical production and certain clinical variables investigated by partial least squares regression analysis. RESULTS: There were several significant relations. High systolic blood pressure and advanced age were associated with low, and severe degree of stenosis with increased, free radical production. Certain anaesthetic drugs as well as blood variables also influenced the production of radicals. CONCLUSIONS: The technique used seems to offer the possibility to find and study methods to reduce free radical production during this kind of operation.

Age Factors↗

PubMed2001

A new method to measure plasma levels of activated protein C in complex with protein C inhibitor in patients with acute coronary syndromes.

Our newly devised immunofluorometric sandwich assay for measuring plasma concentrations of activated protein C (APC) in complex with protein C inhibitor (PCI) was compared with testing for conventional markers of myocardial damage CKMB (creatine kinase MB), TNI (troponin I) and hypercoagulability (D-dimer, TAT) in 76 patients with suspected myocardial infarction (MI). APC-PCI complex levels in samples drawn on admission did not correlate with CKMB in the simultaneously drawn sample but correlated closely with maximal CKMB, which reflects MI size (r = 0.52). The areas under the receiver operating characteristics (ROC) curves calculated for the APC-PCI complex results obtained upon admission did not differ significantly from the corresponding values for CKMB, TNI or TAT. Our results show that in patients at risk for MI, the APC-PCI concentration is a sensitive and independent marker that can identify a subgroup of MI patients with normal CKMB but an increased APC-PCI level upon admission. It remains to be determined whether these patients would benefit from early intensive anticoagulant treatment.

Adult↗

PubMed2000

Hydrodynamic flow profiling in microchannel structures by single molecule fluorescence correlation spectroscopy

In this paper we demonstrate high spatial resolution hydrodynamic flow profiling in silicon wafer based microchannels using single molecule fluorescence correlation spectroscopy (FCS). We have used confocal fluorescence microscopy to detect single tetramethylrhodamine (TMR-4-dUTP) biomolecules traversing a approximately 1 fL volume element defined by an argon laser beam focus. By elevating a (approximately 10(-10) M) reservoir of diluted analyte, a continuous hydrodynamic flow through the microstructure could be accomplished. The microchannel was then scanned with a diffraction-limited focus in approximately 1-microm steps in both the vertical and the horizontal directions to determine the flow profile across a 50 x 50 microm2 channel. The flow profile measured was parabolic in both dimensions, thereby showing a Poiseuille laminar flow profile. Future microstructures can hereby be nondestructively investigated with the use of high spatial resolution confocal correlation microscopy.

Journal Article↗

PubMed2000

[Endoscopic treatment of colorectal obstruction with self-expandable metal endoprosthesis].

Relief of colo-rectal obstruction by means of self-expandable metal mesh stents (SEMS) has been suggested for palliation and acute decompression followed by optimization of the patients' general condition prior to definitive surgery. Twelve patients with high operative risk and/or metastatic disease were selected for stenting with a dedicated colorectal partly covered SEMS (Choo Colo-Rectal Stent, Solco Intermed Co., Seoul, Korea). Stent deployment was successful in nine, two of whom had total obstruction. In one a guidewire perforation was treated conservatively. In two patients (one benign stricture, and one rectal cancer) the stents migrated within three weeks. One re-obstructed. In the remaining six patients colonic decompression was achieved, and the stents have been patent until death (33-175 days, four patients) or are still patent (follow-up 35-80 days). These results are promising, but data from several centres should be compiled prospectively in a standardized fashion in order to allow for assessment of the method's safety and success rates before randomized trials can be initiated.

Aged↗

PubMed2000

Electroosmosis- and pressure-driven chromatography in chips using continuous beds.

The application range of microchips can be extended to any mode of chromatography by filling the narrow channels with continuous polymer beds, exemplified by electrochromatography and ion-exchange chromatography. "Wall effects" are eliminated by anchoring the bed to the wall of the channel, an arrangement which has the additional advantage that no frits to support the bed are required. The design of the equipment is based on a quartz chip with all auxiliary pieces (for example, electrode vessels and fluid transfer fittings) placed in a rack, which permits a flexibility of great importance for automation. The same resolution and van Deemter plots were obtained in experiments performed in fused-silica capillaries and in chips for both low-molecular-weight (alkyl phenones, antidepressants) and high-molecular-weight substances (proteins). A sample of uracil, phenol, and benzyl alcohol was separated by electrochromatography in less than 20 s.

Chromatography, High Pressure Liquid↗

PubMed2000

Ligand binding characteristics of a glycosylphosphatidyl inositol membrane-anchored HeLa cell folate receptor epitope-related to human milk folate binding protein.

The folate receptor (FR) in HeLa cells was characterized as to ligand binding mechanism, antigenic properties and membrane anchor in order to obtain information to be used for the design of biological agents targeting FR in malignant tumors. The receptor displayed the following binding characteristics in equilibrium dialysis experiments (37 degrees C, pH 7.4) with [3H] folate: a high-affinity type of binding that exhibited positive cooperativity with a Hill coefficient > 1.0 and an upward convex Scatchard plot, a slow radioligand dissociation at pH 7.4 becoming rapid at pH 3.5 and inhibition in the presence of other folates. The molecular size of the receptor was 100 kDa on gel filtration with Triton X-100, or similar to that of high molecular weight human milk folate binding protein (FBP). The latter protein represents a 25 kDa molecule which equipped with a hydrophobic glycosylphosphatidyl inositol (GPI) membrane anchor susceptible to cleavage by phosphatidylinositol specific phospholipase C (PI-PLC) forms micelles of 1kDa size with Triton X-100. The HeLa cell FR immunoreacted with antibodies against purified human milk FBP in ELISA, and in a fluorescence activated cell sorting system, where HeLa cells exposed to increasing concentrations of antibody showed a dose-dependent response. Exposure to PI-PLC decreased the fraction of immunolabeled cells indicating a linkage of FR to cell membranes by a GPI anchor. HeLa cells incubated with radiofolate showed a continuous uptake with time, however, with a complete suppression of uptake in the presence of an excess of cold folate. Prewash of cells at acidic pH to remove endogenous folate increased the uptake. Binding and uptake of [3H] folate was increased in cells grown in a folate-deprived medium. The HeLa FR seems to be epitope related to human milk FBP.

Binding Sites↗

PubMed2000

Middle cerebral artery circulation during carotid surgery. A transcranial Doppler study.

OBJECTIVE: Perioperative carotid cross-clamping might induce low stump pressures as well as hypoperfusion of the middle cerebral artery. In this study blood flow velocities in the middle cerebral artery were compared with intraoperative measurements of the poststenotic carotid blood pressure. DESIGN: Forty-one patients with internal carotid artery stenosis were operated on without shunting, under general anesthesia. Poststenotic carotid pressures and middle cerebral artery flow velocities were measured before and during cross-clamping. The hemodynamic responses to preoperative carotid compressions and intraoperative cross-clamping were evaluated. RESULTS: In seven patients the poststenotic carotid blood pressure decreased on clamping despite unchanged or even increased middle cerebral artery blood flow velocities. In all other patients, pressure changes were significantly correlated to the decrease in middle cerebral artery blood flow velocities. Autoregulatory blood flow velocity responses after preoperative common carotid artery compression were not reproducible by cross-clamping. CONCLUSIONS: Stump blood pressure measurements may not reflect middle cerebral artery perfusion in about 20% of thrombendarterectomies performed under general anesthesia. A possible explanation might be dimished cerebral autoregulation and changes in collateral flow distributions.

Adult↗

PubMed2000

High diastolic flow velocities in severe internal carotid artery stenosis: a sign of increased surgical risk?

PURPOSE: We reviewed the history and preoperative investigations of patients with early postoperative neurologic events after carotid thromboendarterectomy in an attempt to identify risk factors for neurologic complications. METHODS: Patients with neurologic events/complications (S group, n = 14 patients) were compared with an age- and disease-matched control group (C group, n = 42 patients) selected from the whole carotid thromboendarterectomy material between 1987 and 1996. In this retrospective study, we re-evaluated the maximum systolic and end diastolic flow velocities within the internal carotid artery (ICA) using video recordings of preoperative Duplex ultrasound scan investigations. The flow velocity variables were compared with preoperative carotid angiography and intraoperative ICA stump pressure measurement. RESULTS: S-group did not differ from C-group concerning either cardiovascular risk factors or diseases, ipsilateral and contralateral angiographic grade of ICA stenosis, or history of cerebral infarctions. Nevertheless, in contrast to control subjects, patients with early postoperative major stroke had higher end diastolic flow velocities and lower ICA stump pressures. Patients with postoperative minor stroke, transient ischemic attack, or amaurosis fugax did not differ significantly from the control subjects. Among patients with ICA stenosis of 75% or more, end diastolic flow velocities were correlated to the diastolic stump pressures. CONCLUSION: Diastolic flow velocities within severe internal carotid artery stenosis are dependent on the level of the collateral perfusion pressure distally to the stenosis (ie, high values indicate a low internal carotid artery stump pressure), which seems to be a risk factor for early postoperative strokes.

Aged↗

PubMed2000

Endoscopic placement of self-expanding metal stents for treatment of colorectal obstruction with long-term follow-up.

INTRODUCTION: Relief of colorectal obstruction by means of self-expandable metal mesh stents (SEMS) has been suggested for palliation and acute decompression followed by optimization of the patients' general condition prior to definitive surgery. METHODOLOGY: Twelve patients with high operative risk and/or metastatic disease were selected for stenting with a dedicated colorectal partly covered SEMS (Choo Colo-Rectal Stent, Solco Intermed Co., Seoul, Korea). RESULTS: Stent deployment was successful in nine, two of whom had total obstruction. In one a guidewire perforation was treated conservatively. In two patients (one benign stricture, and one rectal cancer) the stents migrated within three weeks. One re-obstructed. In the remaining six patients colonic decompression was achieved, and the stents have been patent until death after median 116 days (33-292 days). CONCLUSION: These results are promising, but data from several centres should be compiled prospectively in a standardized fashion in order to allow for assessment of the method's safety and success rates before randomised trials can be initiated.

Aged↗

PubMed1999

Changes in levels of factor VII and protein S after acute myocardial infarction: effects of low-dose warfarin.

Persistent coagulation activity after an acute myocardial infarction may increase the risk of reinfarction. We prospectively investigated the effects on plasma coagulation of a low, fixed dose of warfarin in combination with aspirin after myocardial infarction. We also evaluated the influence of coagulation activity on clinical outcome. Plasma samples from 97 patients, randomised to 1.25 mg of warfarin daily in combination with 75 mg of aspirin or aspirin alone were drawn 4 days, 1 month, and 6 months after myocardial infarction. Patients receiving warfarin had a greater reduction in factor VII coagulation activity (FVII:C) after 6 months: 0.18 vs. 0.06 U/mL,(95% CI, 0.02-0.22), whereas no differences were seen in levels of protein C, protein S, or prothrombin fragment 1+2. In the acute phase, the level of free protein S was lower than after 6 months in both groups: 25.6 vs. 28.8% (95% CI, 4.19--2.35). Cardiovascular mortality, reinfarction, and stroke were evaluated after 4 years (median). In a survival analysis, every 0.1 U/mL increase in the level of FVII:C1 month after myocardial infarction was associated with an 15% increase in risk of cardiovascular events (95% C1, 1.01-1.30). Warfarin at 1.25 mg daily reduces FVII:C but not systemic thrombin generation measured as prothrombin fragment 1 +2. Low levels of the anticoagulant protein S may contribute to a procoagulant state.

Adult↗

PubMed1999

[Hypertension in general practice].

A group of 15 Danish general practitioners performed a medical audit on hypertension control consultations consisting of three registrations of each 15 days during 1995 through 1997. Between the first and second registration an interventional programme was set up by establishing different kinds of CME activity and by publishing local guidelines for discovering, diagnosing, treating and controlling hypertension. The blood pressure reductions achieved were only moderate even though the doctors were rather compliant to the recommendations; in 1997 no less than 70% of the patients were above the recommended target value for systolic blood pressure (140 mmHg) whereas 20% were above the target value for diastolic blood pressure (90 mmHg). Present aspects of the epidemiology of hypertension and its treatment as performed by general practitioners today are described, and possible reasons for shortcomings are discussed.

Adult↗