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Biomedical subjects

R Knopp

Publications and source records attributed to R Knopp.

At least 19 recordsLinked to original sources
PubMed1992

Whole-body cesium 137 activity up to 4 years after the Chernobyl reactor accident in premature newborns, newborns, infants, and children.

Cesium 137 activity was measured after the Chernobyl incident in a whole-body radiation counter (4-pi-scintillation counter) in 85 premature and mature newborns (group 1), 174 infants and young children up to 2 11/12 years (group 2), and 48 children between 3 and 8 years (group 3) from Bonn (Germany) and surroundings. In 1987 the mean level of radioactivity in group 2, at 3.7 Bq/kg body weight corresponding to a mean radiation exposure of 11 muSv/y, was lower than that of group 1 (5.8 Bq/kg, 17 muSv/y) and 3 (9.4 Bq/kg, 28 muSv/y). Up to 1990 the values of all groups revealed a continuous decrease. The latest measurements showed mean values of 0.5 Bq/kg (1.5 muSv/y) in group 1, 0.6 Bq/kg (1.8 muSv/y) in group 2, and 0.8 Bq/kg (2.4 muSv/y) in group 3. A comparison with present cesium 137 values and determinations of the end of the 1950s and beginning of 1960s, both in adults, showed good agreement. The effective dose-equivalent rates amounted to less than 1% of that from natural radiation exposure. These levels should present no teratogenic risks to the population studied and, while there are theoretical mutagenic risks, the dose is so low that no increase in measurable mutagenic effects should be observed.

Accidents↗
PubMed1989

Comparison of five-view and three-view cervical spine series in the evaluation of patients with cervical trauma.

The three-view trauma series has been the standard screening examination for patients with cervical spine trauma. We conducted a prospective study to determine if the addition of supine oblique views to the three-view series would improve detection of fractures, subluxations, dislocations, or locked facets. All patients over a two-year period with suspected cervical spine injury had a five-view series obtained (three-view series and supine oblique views), and selected high-risk patients underwent thin-section conventional tomography of the cervical spine. Films were interpreted separately by two radiologists and an emergency physician, and the tomography results were used as the gold standard for comparison. Thirty-three of 58 high-risk patients had one or more fractures, subluxation, or dislocation demonstrated on tomography. There were no fractures or dislocations detected on the five-view series that were not detected or suspected on the three-view series. In areas of the cervical spine reported to be better visualized by supine oblique views than three-view series, our results indicate that supine oblique views did not improve detection but did, in certain cases, allow more specific diagnosis of injuries. Our data do not support the routine use of supine oblique views in the initial radiographic evaluation of patients with cervical spine trauma.

Adolescent↗
PubMed1989

Endotracheal intubation of pediatric patients by paramedics.

Although a number of studies have described endotracheal intubation of adult patients in the prehospital setting, there are few studies on prehospital endotracheal intubation of pediatric patients. The purposes of our study were to determine how frequently prehospital endotracheal intubation was used in pediatric cardiopulmonary arrests when a paramedic trained in endotracheal intubation was present, to determine the success rate and complications associated with the procedure in the field, and to compare resuscitation rates and outcome in patients with and without prehospital endotracheal intubation. Our retrospective study covered a 38-month period and included all prehospital victims of medical cardiopulmonary arrest under the age of 19 years. Data were collected from field assessment forms and validated by hospital charts, autopsy reports, coroner's reports, death certificates, and emergency medical services central dispatch logs. Of 63 victims of medical cardiorespiratory arrest, 42 had intubating paramedics present at the scene. Twenty-eight of 42 patients (66%) had endotracheal intubation attempted. Eighteen of 28 attempts (64%) were successful, associated with a major complication rate of 7% (two of 28) and a minor complication rate of 39% (11 of 28). In patients less than 1 year old, only six of 16 (38%) had endotracheal intubation attempted and only three of six (50%) attempts were successful. Of the 18 patients who were intubated successfully before arrival at the hospital, nine (50%) survived to hospital admission and one (6%) survived to discharge. The remainder died in the emergency department.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1988

[One year after Chernobyl. Cesium-137 levels in premature, newborn and nursing infants and in younger and older children of Bonn and environs].

From May to August 1987, 137Cs activity was measured in a total-body counter (4 pi counter) in 33 premature and mature newborns (group I), 40 infants and young children up to 2 4/12 years of age (group II), and 15 children between 3 and 6 8/12 years (group III), all from Bonn or its environs. The mean of measurements in group II, at 3.7 Bq/kg body-weight, was lower than that of group I (5.8 Bq) and III (9.4 Bq). Mean radiation exposure, calculated from these data, was 1.7 mrem/a for group I, 1.1 mrem/a for group II, and 2.8 mrem/a for group III. A comparison with present Cs values in adults and measurements made at the end of the 1950's and beginning of 60's showed good agreement. There were no significant differences, as regards Cs activity, between newborns or infants who had been formula-fed or breast-fed. The measured radiation exposure of the three groups is about 1% of natural radiation exposure. Thus, present-day results indicate that there will be no damage to health outside the natural scatter.

Accidents↗
PubMed1988

Mechanism of injury and anatomic injury as criteria for prehospital trauma triage.

Prehospital trauma triage should permit accurate identification and transport of patients with critical injuries to trauma centers without overloading these centers with patients having minor injuries. In most trauma systems a combination of physiologic criteria (Trauma Score [TS]), mechanisms of injury (MOI), and anatomic injury (AI) are used as prehospital trauma triage criteria. The purpose of our study was to assess the predictive value of specific MOI and AI in detecting critically injured trauma victims (Injury Severity Score [ISS] of more than 15) and determine the best combination of TS, MOI, and AI that produced the lowest percentage of undertriage and overtriage. Previous studies have examined only patients triaged to trauma centers; our study included all trauma patients regardless of destination. A total of 1,473 trauma patients was evaluated and transported by the emergency medical services system and studied prospectively during a nine-week period. Prehospital TS, specific MOI and AI, and final disposition and diagnosis were determined on all patients. The ISS was calculated on all hospital admissions. A total of 97 patients had an ISS of more than 15. Three hundred forty-one (23%) had one of the specific MOI studied; 102 (6.9%) had one of the specific AI studied. Four hundred twelve patients (28%) had at least one of the study MOI or AI.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1988

Prehospital patients refusing care.

In summary, many of the complex medicolegal and ethical issues surrounding the prehospital patient who refuses all or part of the care offered by the EMS system have been reviewed. The best outcome can be achieved using a sliding scale of capacity and a conservative approach to treatment rather than releasing the patient at the scene. Finally, the roles of collateral history, inquiries as to the origin of the patient's refusal of care, direct physician interaction with the patient, a spirit of creativity and compromise in dealing with the patient, meticulous documentation, and policy issues have been discussed.

Adult↗
PubMed1988

Magnetic resonance (MR) imaging of prostatic tumours, a comparison with X-ray CT and transrectal sonography (TRS).

A total of 7 healthy volunteers and 31 patients have been examined clinically, by MRI, TRS, and biopsy. In those patients with established carcinoma, a CT examination was also performed. For the MRI study, a superconducting MR 2000 imager (Picker International) operated at 0.15 T was used with multiplanar SE and IR sequences. SE sequences with long echo times detected prostatitis, adenoma and carcinoma of the prostate with a high degree of sensitivity. However, at present, differentiation between adenoma, prostatitis and carcinoma is not possible with sufficient accuracy. In these studies we were unable to establish a correlation between the signal pattern and staging and/or grading of the carcinoma. Reliable diagnosis of a prostate carcinoma still requires a biopsy. Because of the high soft tissue contrast and the possibility of selecting any orientation for the plane under investigation, however, MRI represents an improvement in the preoperative diagnosis of local spread.

Aged↗
PubMed1988

[Experience with a high-dose therapy concept in metastatic differentiated thyroid cancer].

Three patients with pulmonary metastases from differentiated thyroid carcinoma were treated with radioiodine. As a first treatment either 1.85 GBq (50 mCi) or 3.7 GBq (100 mCi) were given followed by doses of 11.1 GBq (300 mCi) 131I. In one patient the pulmonary metastases disappeared completely, the two other patients showed a significant regression. In one patient possibly radiation-induced pancytopenic changes appeared after the third and fourth radioiodine treatment, in the other two patients side-effects were not seen.

Adenocarcinoma↗
PubMed1986

Effect of myocardial perfusion and metabolic interventions on cardiac kinetics of phenylpentadecanoic acid (IPPA) I 123.

The effect of regional myocardial perfusion and flow-independent adrenergic stimulation, as well as lactate-mediated inhibition of cardiac lipolysis, on cardiac IPPA uptake and metabolism was examined in canine hearts (flow studies) and in the isolated perfused Langendorff rat heart (metabolic interventions). In both normal and ischaemic myocardium, local perfusion is a major determinant of cardiac IPPA uptake. In pacing-induced hyperaemia, the strict flow-dependence of cardiac IPPA uptake is not preserved. Adrenergic stimulation raises the rate of oxidation of both palmitic acid 14C and IPPA. This change is reflected by increased metabolite production released into the perfusate and radioactivity clearance recorded externally. Lactate in high concentrations exerts the opposite effect on cardiac free fatty acid oxidation. IPPA is stored in this condition preferentially in tissue phospholipids and triglycerides.

Animals↗
PubMed1985

Antishock trousers: a comparison of inflation techniques and inflation pressures.

Ten healthy male volunteers were studied to compare the effects of simultaneous versus sequential inflation of antishock trousers (AST) and simultaneous inflation pressures of 20, 40, and 100 mm Hg on blood volume displacement centrally. Radioisotope scans were used to determine the change in blood volume distribution with various inflation methods and inflation pressures of the AST. Our data suggest that the minimum inflation pressure that displaces blood centrally is 40 mm Hg, and that higher inflation pressures displace a greater percentage of the total blood volume to the central circulation than do lower pressures. The difference is small, however, and probably has no clinical effect. No difference was suggested between simultaneous and sequential inflation.

Adult↗
PubMed1985

Blood volume distribution in the Trendelenburg position.

The Trendelenburg position is used frequently in treating hypotensive patients. It is believed that placing patients in the Trendelenburg position causes an autotransfusion of blood to the central circulation. No published studies document the volume of blood displaced centrally. In our study ten volunteers were placed in the Trendelenburg position. Blood volumes were determined from body surface area, and radionuclide scanning was used to determine blood volume distribution. Placing normovolemic volunteers in the Trendelenburg resulted in a 1.8% (median) displacement of the total volume centrally. The autotransfusion of blood produced by the Trendelenburg position is small and is unlikely to have an important clinical effect.

Adult↗
PubMed1985

Captopril mediated decrease of aortic regurgitation.

The effect of captopril mediated afterload reduction on aortic regurgitation was investigated in 10 patients. Regurgitation was quantitated by means of the regurgitation fraction and the relation of regurgitant volume to end diastolic volume. These variables were derived from gated radionuclide ventriculography. After captopril treatment the blood concentration of angiotensin I rose whereas that of angiotensin II fell significantly. The conversion of angiotensin I to II was reduced to about 50% of the control value. Whereas blood pressure and heart rate did not change significantly, the regurgitation fraction and the regurgitant volume, normalised to end diastolic volume, were significantly reduced by captopril treatment. The ejection fraction remained essentially unchanged. These findings suggest that captopril reduces aortic regurgitation by reducing afterload.

Angiotensin I↗
PubMed1985

[Localization of pre-excitation in the WPW syndrome by analysis of the ventricular contraction course].

Fourier phase analysis of gated radionuclide ventriculography (RNV) was applied in 23 patient for the identification of cardiac contraction patterns in WPW syndrome (controls with normal ventricular function and sinus rhythm, n = 30). The sequence and velocity of regional ventricular wall motion was determined and correlated to the results of electrophysiological studies. In 3/23 patients the contraction pattern was not different from controls. Indicating the preexcitation in 20/23 patients the earliest ventricular contraction was localized as follows: right atrial n = 5, paraseptal right n = 2, paraseptal left n = 6 and atrial left n = 7. In 15/16 patients nuclear data corresponded with electrophysiological endocardial mapping. Phase analysis of RNV provides a reliable non-invasive method for localization of preexcitation in WPW syndrome.

Electrocardiography↗