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P Biberthaler

Publications and source records attributed to P Biberthaler.

33 records · Page 2Linked to original sources
PubMed2001

In vivo monitoring of microvessels in skin flaps: introduction of a novel technique.

Orthogonal polarization spectral (OPS) imaging was validated against intravital fluorescence microscopy (IFM) for microvascular measurements in skin flaps of hairless mice. Examinations were performed 1, 6, and 24 hours after elevation (n = 8) with both OPS imaging and IFM. A fluorescent dye was a prerequisite for IFM measurements but not for OPS imaging. Our findings show that OPS imaging can visualize the skin flap microcirculation independent from the application of fluorescent tracers. From these images, quantitative analysis of functional capillary density (FCD) was feasible. As expected, FCD was significantly lower in the distal part of the flap compared with its base (171.8 +/- 34.7 versus 62.0 +/- 25.6, mean +/- SD; 1 hour data). Comparison of OPS imaging and IFM revealed a significant correlation of FCD values (P < 0.001) at all time points. Given the success of this validation study on mouse skin flaps, clinical investigations will have to prove that OPS imaging can also successfully be used to monitor flaps in humans.

Animals↗
PubMed2001

Ischemia at 4 degrees C: a novel mouse model to investigate the effect of hypothermia on postischemic hepatic microcirculatory injury.

Hypothermia of the ischemic organ at 4 degrees C protects hepatic microcirculation from ischemia-reperfusion (IR) injury. The effect of hypothermia during ischemia was investigated in animal models using liver transplantation and storage of the harvested organ in cold preservation solutions. No investigation of the isolated influence of hypothermia at 4 degrees C of the ischemic organ on hepatic IR injury exists, due to the lack of an appropriate animal model. Therefore, the aim of our present study was to develop such a model using intravital video fluorescence microscopy (IVM). In C57BL/6 mice, a reversible isolated ischemia of the left liver lobe was induced for 90 min, followed by 240 min of reperfusion. The temperature of the ischemic organ was adjusted to either 4 degrees C or 37 degrees C by superfusion with 0.9% NaCl. Sham-operated animals without IR served as controls. The hepatic microcirculation was analyzed using IVM at 30 min and 240 min after reperfusion by quantifying sinusoidal perfusion and leukocyte-endothelial cell interaction in postsinusoidal venules. At the end of the experiment, blood and tissue samples were taken for measurement of liver enzyme activities and light and electron microscopy. Mean arterial pressure and body temperature were kept constant throughout the experiment, while the temperature of the ischemic liver lobe was adjusted to predefined levels. After normothermic ischemia, hepatic microvascular perfusion was significantly impaired compared with sham-operated animals. Perfusion failure was significantly reduced in hypothermic livers and did not differ from livers of the sham-group. Liver enzyme activities in the normotherimic group were significantly higher than in the sham and hypothermic groups. Light and electron microscopy revealed severe histological alterations at 37 degrees C ischemia, whereas at 4 degrees C ischemia only minimal lesions were encountered. Our novel model allows for isolated adjustment of ischemic liver lobe temperature without changing body temperature and systemic macrohemodynamic parameters. Hypothermia at 4 degrees C largely attenuates postischemic microvascular perfusion injury of the liver.

Animals↗
PubMed2001

[Psychiatric emergencies in preclinical emergency service; incidence, treatment and evaluation by emergency physicians and staff].

Preclinical psychiatric emergency situations (PES) rank third in frequency of calls in the German emergency medical system (EMS). However, few data exist concerning relevance and treatment of PES. The aim of this study was to investigate this relevance in preclinical EMS and its appraisal by emergency physicians and paramedics. The protocols filled in by EMS physicians on emergency duty in a German district were evaluated concerning PES. In addition, the emergency physicians and paramedics of the district were asked to complete a validated questionnaire concerning the importance, their own understanding of PES, and interest in training programs. With 9.2%, preclinical PES ranked third in frequency of all EMS calls. The most frequent case was substance abuse disorder (70%), followed by suicide attempts or ideation (33%). Specific therapy for psychiatric disorders is hardly ever performed. Emergency physicians and paramedics estimated the importance of knowledge about PES as high but rated their own knowledge as poor. Assessing five typical PES, emergency physicians gave the correct diagnoses in 71% of cases (paramedics 39%) and the correct therapy in 32% (paramedics 14%). The interest in training programs was significantly higher in experienced EMS physicians. Preclinical PES is a relevant diagnosis within EMS and correct treatment is hampered by limited knowledge. Sufficient training is not yet available, although programs are necessary and the willingness to participate in them is high.

Acute Disease↗
PubMed2001

S-100b, sE-selectin, and sP-selectin for evaluation of hypoxic brain damage in patients after cardiopulmonary resuscitation: pilot study.

S-100b is thought to be a screening marker of hypoxic brain damage in patients with cardiac arrest. However, the time-dependent occurrence and relevance of increased S-100b serum levels in out-of-hospital patients with cardiopulmonary resuscitation (CPR) is still discussed. The purpose of our study was to evaluate the diagnostic utility of S-100b measurements in comparison to that of adhesion molecules sE-selectin and sP-selectin in patients with CPR. Sixteen out-of-hospital patients (median age 69.6 years; range 59.2-82.2 years) suffering from cardiac arrest due to ventricular fibrillation, asystole, or electromechanical dissociation were recruited prospectively. Blood samples were drawn on scene after the return of spontaneous circulation (ROSC) and 12 hours after successful CPR. The reference group consisted of 10 patients with isolated severe head trauma (SHT) (Glasgow Coma Score </ or =8), and the control group comprised 20 healthy volunteers. Serum concentrations of S-100b, determined by immunoluminometric assay, were compared with serum levels of sE-selectin and sP-selectin measured by an enzyme-linked immunosorbent assay and correlated with the patients' survival. In the CPR group, S-100b serum levels (2.37 ng/ml; 1.37-4.09 ng/ml) at study entry (11.6 minutes after arriving on scene) did not significantly differ from those of SHT patients (2.88 ng/ml; 1.78-8.81 ng/ml). Both groups showed significant differences from the healthy controls (0.04 ng/ml; 0.01-0.82 ng/ml). At 12 hours after CPR the serum levels had decreased to 0.41 ng/ml (0.24-0.51 ng/ml) but continued to be significantly elevated compared to that of the control group. sE-selectin values in serum increased from 56.00 ng/ml (38.50-85.50 ng/ml) on scene to 79.00 ng/ml (52.00-127.00 ng/ml) after 12 hours (p < 0.05). The first measurements differed significantly from serum levels of the control group (22.50 ng/ml; 14.00-34.00 ng/ml) and from those of the SHT group (45.00 ng/ml; 39.00-63.75 ng/ml). At 12 hours after study entry the sE-selectin values were not significantly different from those of the SHT group (51.50 ng/ml; 39.00-95.88 ng/ml). sP-selectin serum levels increased slightly from 199.50 ng/ml (184.25-227.25 ng/ml) to 247.00 ng/ml (206.50-354.75 ng/ml). First and second measurements did not reveal any significant differences in either the SHT group or the healthy controls. When correlated with survival, S-100b measurements exhibited constantly high serum levels for patients, decreasing within the first 24 hours, whereas they decreased significantly in patients with longer survival. sP-selectin values on scene slightly increased in cases of survivals less than 24 hours after CPR. sE-selectin serum levels always remained within normal levels and revealed no significance later on. In contrast to the endothelium-derived adhesion molecules sE-selectin and sP-selectin, comparison of measurements of specific neuroprotein S-100b early after cardiac arrest and 12 hours later seem to provide an indication of the severity of hypoxic brain damage and the prognosis after CPR. Further investigations are required to better understand the CPR-related mechanisms of blood-brain barrier damage.

Aged↗
PubMed2001

Evaluation of S-100b as a specific marker for neuronal damage due to minor head trauma.

Management of patients with minor head trauma (MHT) continues to be debated in the literature. Measurement of S-100b in serum has been introduced into the discussion as an additional screening tool for intracerebral injuries because routine cranial computed tomography (CCT) of a large number of patients causes logistic difficulties, and the neurologic examination is often impaired by a high frequency of coincidental intoxication. The aim of our study was to determine the diagnostic value of measuring S-100b in the serum of MHT patients to identify risk groups. Additional validity should be aquired by a comparison with plasma levels of polymorphonuclear neutrophil (PMN) elastase an established general trauma marker. A series of 52 patients with MHT were included in the prospective study. At admission the patients underwent a routine CCT scan to detect intracerebral lesions, and blood samples were drawn to investigate circulating levels of S-100b and PMN elastase. For comparison, data for a positive control group of 10 severe head trauma patients (initial Glasgow Coma Scale score < 8) and for a negative control group with 20 healthy volunteers were obtained. The interval between MHT and admission to our hospital was 73.4 +/- 47.0 minutes. The initial S-100b serum levels of MHT patients were 0.470 +/- 0.099 ng/ml, those of the positive control group were 7.16 +/- 3.77 ng/ml, and those of the negative control group were 0.05 +/- 0.01 ng/ml. Relevant pathologic CCT scans were detected in 28.8% of MHT patients; one patient of that group was subjected to immediate surgical intervention (1.9%). At a cut-off point of 0.1 ng/ml, the sensitivity of positive S-100b levels reached 100% and the specificity 40.5%. Plasma levels of PMN elastase reached 60.52 +/- 10.75 ng/ml in the MHT group, 66.4 +/- 14.92 ng/ml in the severely head-injured group, and 23.26 +/- 1.53 ng/ml in the negative control group. Serum levels of S-100b seem to be a highly sensitive but not very specific marker for isolated neurotrauma. Measurement of this parameter may be helpful as an additional screening tool to identify high risk groups in the cohort of MHT patients.

Autoantigens↗
PubMed2001

Early cellular brain damage and systemic inflammatory response after cardiopulmonary resuscitation or isolated severe head trauma: a comparative pilot study on common pathomechanisms.

Severe neurological deficits are common characteristics of patients surviving cardiopulmonary resuscitation (CPR) or isolated severe head trauma (SHT). For comparative evaluation of underlying pathomechanisms, 22 patients with out-of-hospital cardiac arrest and successful CPR as well as 10 patients with SHT were included in our prospective study. Circulating S-100B was determined as an indicator of cellular brain damage. Interleukin-8 (IL-8), soluble E-selectin (sE-selectin) and polymorphonuclear (PMN-) elastase were measured as markers of systemic inflammation following whole body ischaemia and reperfusion injury. Venous blood samples were drawn on scene (median time 11.0 min after starting basic life support) and in the intensive care unit (median time 12.5 h thereafter) in CPR patients and at admission to hospital (median time 43.8 min after trauma) and approx. 12 h later in SHT patients. Biochemical parameters in these samples were compared with specimens taken from 20 healthy volunteers. Initial median S-100B levels of the CPR and SHT patients were both significantly increased compared with the controls. Twelve hours later, significant falls in S-100B revealed no differences between the two patient groups, but did not reach control values. Median IL-8 and sE-selectin levels entry to the study were elevated in both patient groups compared with controls and showed further rises within the following 12 h. Finally, increased initial median levels of PMN-elastase revealed significant differences between the patient groups and between patients and controls. Twelve hours later, median PMN-elastase values were equally elevated in the CPR and SHT subjects. Our preliminary data suggest similar pathomechanisms occurring after both CPR and SHT. Both clinical entities seem to be associated with early transient cellular brain damage as shown by prolonged rapidly increasing and subsequent fall in S-100B serum levels. In contrast, the prolonged elevation of circulating IL-8, sE-selectin and PMN-elastase may indicate a very similar systemic inflammatory response by endothelial cells and neutrophils initiated by ischaemia and reperfusion injury in both conditions. Further studies should be carried out to determine the cause and the prognostic value of these biochemical parameters in relation to long-term neurological outcome.

Aged↗
PubMed2001

Elevated serum levels of S-100B reflect the extent of brain injury in alcohol intoxicated patients after mild head trauma.

Elevated systemic levels of S-100B are proposed as a potential indicator of brain damage in identifying high-risk patients after mild head trauma (MHT). Although incidence of alcohol intoxication is high in these patients, the influence of alcohol intoxication on S-100B levels is unclear. Therefore, the aim of our study was to investigate serum concentrations of S-100B in intoxicated (group 1) and sober (group 2) patients after MHT in comparison with those of mild (group 3) or severely intoxicated (group 4) individuals without trauma. S-100B was significantly increased in MHT patients exhibiting posttraumatic lesions in initial cranial computed tomography scan. Alcohol intoxication did not elevate S-100B levels in group 3 or 4 subjects. Our data indicate for the first time that alcohol intoxication does not influence the diagnostic value of S-100B measurements in patients after MHT.

Alcohol Drinking↗
PubMed2000

Influence of alcohol exposure on S-100b serum levels.

Recent assessment of the glia cell-derived neuroprotein S-100b in serum has been considered as a screening method for possibly occult brain injury in patients with minor head trauma (MHT). Since MHT is associated with alcohol intoxication in up to 50% of patients requiring emergency treatment, the blood-brain barrier (BBB) as well as neuronal cell integrity may be also affected by alcohol abuse. So far, however, no valid data are available on the release of S-100b after alcohol exposure. Thus, the aim of our study was to investigate S-100b serum levels in a controlled alcohol exposure paradigm. 22 healthy volunteers were included in the study, blood samples were drawn prior to and about 90 minutes after drinking. The amount of alcohol was adjusted to the body weight. A mean of 66.7 +/- 14.81 g was consumed giving raise to a blood alcohol concentration of 0.827 +/- 0.158@1000. S-100b serum levels assayed by a luminescence immunoassay were compared with those of MHT patients. The still preliminary results suggest no increase of the serum S-100b levels (0.0509 +/- 0.048 ng/ml versus 0.0422 +/- 0.044 ng/ml) after moderate alcohol consumption. In contrast, MHT patients with alcohol intoxication (1.6 +/- 0.77@1000) revealed a significant up to 10fold elevation of S-100b serum levels. Because of the much higher blood alcohol concentration in the MHT patients compared to the control collective, a potential relationship between excessive alcohol consumption and the release of S-100b in minor head trauma can still not be excluded. Further investigations on this topic are in progress.

Adult↗
PubMed2000

S-100b as a screening marker of the severity of minor head trauma (MHT)--a pilot study.

Due to its neural tissue specificity S-100b is considered as a screening marker of cerebral injury in head trauma patients. However, the occurrence and relevance of an increased S-100b serum level in minor head trauma (MHT) is still debated. Therefore, the purpose of our study was to evaluate the diagnostic utility of S-100b measurements in a level I trauma center emergency room (ER). Eighty patients presenting with clinical symptoms of MHT (GCS score of 13-15, transitory loss of consciousness, amnesia, nausea) were prospectively recruited. Blood samples were drawn at 0 h, 6 h and 24 h after admission, and a cerebral computed tomography (CT) was performed. The reference group consisted of 10 patients with severe head injury (GCS score < 8), the control group of 20 healthy volunteers. Concentrations of S-100b in serum were determined by an immunoluminometric assay. The results were compared with the plasma levels of polymorphonuclear (PMN) elastase as an established general trauma marker. In the MHT group, the S-100b serum level revealed 1.26 +/- 0.57 ng/ml at study entry (73.46 +/- 47.53 min after trauma). In comparison, the S-100b concentration was significantly elevated in patients with severe head trauma (5.26 +/- 1.65 ng/ml, p = 0.009), but no significant difference became evident in relation to the control group (0.05 +/- 0.01 ng/ml). Starting values of PMN elastase in plasma amounted to 66.40 +/- 14.92 ng/ml in severe trauma, and to 60.52 +/- 10.75 ng/ml in MHT showing significant differences only in relation to the control group (23.36 +/- 1.53 ng/ml). When correlated with the severity of the later clinical course, the first S-100b measurements exhibited steadily increasing values as demonstrated in MHT outpatients (0.29 +/- 0.11 ng/ml), MHT in-hospital patients (0.70 +/- 0.19 ng/ml) and MHT intensive care unit patients (5.03 +/- 3.18 ng/ml). PMN elastase levels revealed no significant differences concerning the three MHT subgroups. Thus, in contrast to the general trauma marker PMN elastase, assessment of the specific neuroprotein S-100b early after traumatic insult appears to be a promising laboratory marker for the prognosis of the severity of brain injury in MHT patients. Nevertheless, further investigations are required to better understand its predictive value.

Biomarkers↗
PubMed2000

[Implementation of a quality management system for the curriculum in emergency medicine education].

Medical teaching, training and education in basic and advanced life support were improved by basic quality management procedures. 3rd year medical students (n = 276) of two consequent semesters were questionnaired about their acute emergency medicine curriculum. While Group A (n = 134) received a standard course, the new course for group B (n = 142) was reorganised on the basis of the results of group A. Interventive educational measures were an increased number of models provided for exercising the students skills, and an extension of megacode training possibilities. Participation of students in course design improved the overall performance in respect of knowledge, skills and decision-making (p < 0.05). Curriculum acceptance and intrinsic motivation of students however were not positively influenced by practical training compared to traditional knowledge transfer.

Curriculum↗
PubMed1998

[Psychiatric emergencies from the viewpoint of the emergency physician].

OBJECTIVE: In the German physician-based emergency medical system (EMS) psychiatric emergency situations (PES) rank on third place contradictory to it's importance during emergency physician training program. The aim of our study was to examine the relevance of PES and the stress which PES imposes upon EMS physicians. Further, the interest of training programs on that issue was determined. Knowledge about PES was investigated by a short test. METHODS: 952 emergency physicians were sent a questionnaire about following: demographic data, frequency of PES, strain by PES, own knowledge, interest about training programs. Further five typical PES were presented for diagnostic and therapeutic judgement. RESULTS: 222 responded (183 men/37 women/2 without gender data, average age: 40.1 +/- 6.7, qualification as emergency physician: 9.6 +/- 5.1 years, most frequent subspeciality in-hospital physicians: anaesthesiology 67.5%, in-practice physicians: general medicine 72.1%). PES frequence was estimated at 9.4%, personal knowledge judged only by 13% as sufficient, 14.2 felt incapable by PES. 73% saw importance of training, especially expressed by the more experienced (P < 0.05). Test presented 65% correct diagnoses, 33% correct therapy, 26% incorrect decision of hospital admission. CONCLUSION: PES are a frequent problem of pre-hospital patient care for emergency physicians. As personal knowledge was estimated to be insufficient, the interest for courses concerning PES issues is high.

Adult↗
PubMed1998

Endothelial prostacyclin (PGI-2) production of human and porcine valve allografts related to ischemic history.

BACKGROUND: The significance of cellular viability in human valve allografts for functional clinical longevity continues to be debated. Meaningful tests for this biological entity are therefore in demand to quantify the relative merits of graft origin and procurement techniques. The valve leaflet endothelium is recognized as a particularly sensitive target to noxes and its continued ability to produce prostacyclin (PGI-2) after explantation has been suggested as indicating viability. OBJECTIVE: Graft ischemic history and species differences were therefore studied in human and porcine valve leaflets by the measurement of endothelial prostacyclin production, post-explantational, basal and after stimulation with bradykinin. METHODS: Four groups of aortic valve donors were established. Fresh human heart-beating donors (h-HBD), cadaveric human donors (h-NHBD) processed within 24 h, fresh porcine donors (p-HBD) and cadaveric porcine donors (p-NHBD) also processed within 24 h. Leaflets were separately incubated at 37 degrees C for successive periods of 30 min up to 5 h in Earle's Medium 199. After 240 min PGI-2 production was stimulated by 10 microM bradykinin. Postincubational release was stopped with indomethacin 10 microg/ml. Prostacyclin production was measured as 6-kPGF1a using an ELISA. RESULTS: Initial PGI-2 production is significantly higher in porcine than in human grafts and in both species enhanced by previous warm ischemia. While baseline species differences disappear during progressive incubation, differences resulting from graft history are maintained. After PGI-2 stimulation species differences dominate again while ischemic history has no effect. CONCLUSION: Ischemia and surgical manipulation are stimulators of endothelial PGI-2 production in both human and porcine allografts and, therefore, a correlation of this metabolic activity with cellular integrity may be misleading. Valid data are obtained only if the natural time-course and reaction to stimulation of PGI-2 production are duely recognized and species differences in the response to mechanical and ischemic stress are considered.

Adult↗
PubMedDate not supplied

Comparison of the new OPS imaging technique with intravital microscopy: analysis of the colon microcirculation.

BACKGROUND: The OPS imaging technique has been introduced for in vivo assessment of microcirculation in humans. The aim of this study was to validate the new technique against intravital fluorescence microscopy (IFM) for the visualization of colon microcirculation in a murine model of inflammatory bowel disease (IBD). METHOD: IBD was induced in Balb/c mice by dextran sulfate sodium, controls received normal water. In each animal, both the CYTOSCAN A/R and IFM were used to image the microcirculation (n = 7 in each group). The postcapillary venular diameter was analyzed on the colon muscularis and mucosa. RESULTS: The venular diameter correlated significantly between both methods representing the good correspondence between both methods. CONCLUSION: Our study demonstrates that the new technique for visualization of microcirculation without use of fluorescent dyes, the OPS imaging, allows for quantitative measurement of a key microcirculatory parameters of the mouse colon.

Animals↗