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Biomedical subjects

G Koch

Publications and source records attributed to G Koch.

At least 667 records · Page 37Linked to original sources
PubMedDate not supplied

Bacteriological and biochemical criteria for the diagnosis of bacterial infections in chronic obstructive pulmonary disease (COPD).

In a prospective study the quantitated culture of washed sputum, the number of leukocytes and the concentration of albumin and fibrinogen in sputum were compared as diagnostic parameters for bacterial infections in patients with chronic obstructive pulmonary disease. No single criterium and no combination of criteria showed satisfactory specificity and sensitivity. Two reasons were established for the relatively loose correlation between the parameters: 1) they follow a different time course and 2) the biochemical and cellular signs of inflammation have a certain non-specificity with regard to bacterial infections. They also depend on the underlying disease. The selection of optimal criteria will become feasible only after the dynamics of bacterial and other inflammations of the respiratory tract have been studied in detail.

Albumins↗
PubMedDate not supplied

Endovascular treatment of proximal anastomotic aneurysms after aortic prosthetic reconstruction.

PURPOSE: To describe the efficacy and value of endovascular stent-grafts for the treatment of aortic anastomotic pseudoaneurysms. METHODS: Three patients with proximal aortic anastomotic pseudoaneurysms 8--15 years after prosthetic reconstruction were treated by transfemoral stent-graft implantation. In two patients the pseudoaneurysms were excluded by Talent prostheses [tube graft (n = 1), bifurcated graft (n = 1)]. In one patient an uniiliac Zenith stent-graft was implanted and an extra-anatomic crossover bypass for revascularization of the contralateral lower extremity was performed. RESULTS: All procedures were successful with primary exclusion of the pseudoaneurysms. During the follow-up (mean 16 months) one endoleak occurred due to migration of the tube stent-graft. The endoleak was sealed successfully by implanting an additional bifurcated stent-graft. CONCLUSION: Stent-graft exclusion of aortic pseudoaneurysms offers a minimally invasive and safe alternative to open surgical reconstruction.

Aged↗
PubMedDate not supplied

[Arterial complications caused by using an axillary crutch].

BACKGROUND: Of all upper extremity emboli, up to twenty percent arise from an arterial, not a cardiac source. METHOD: We report about a patient with recurrent embolism, caused by an axillary crutch-induced aneurysm of the axillary artery. RESULT: After revascularisation by embolectomy and axillo-brachial vein graft bypass, the patient was free of symptoms. CONCLUSION: Angiography and duplex scanning were necessary for the correct diagnosis.

Aged↗
PubMedDate not supplied

Lack of effect of low levels of carboxyhemoglobin on cardiovascular function in patients with ischemic heart disease.

We studied 30 patients 38-75 yr of age who had ischemic heart disease to assess the effect of acute elevation of carboxyhemoglobin (COHb) concentration. Patients were nonsmokers with ischemia defined by exercise-induced ST depression (ST decreases)--25/30, angina--23/30, or abnormal ejection fraction (EF) response--18/30. After an initial familiarization and exercise session patients were exposed to air (carboxyhemoglobin [COHb] = 1.5 +/- 0.05%) and to carbon monoxide (CO) (100 ppm-COHb-average = 3.8 +/- 0.1%) on successive days in a double blind, randomized fashion. There was no significant difference in time to onset of angina (air = 312 sec, CO = 306 sec), maximal exercise time (air = 711 sec, CO = 702 sec), maximal ST decreases (1.5 mm for both), or time to significant ST decreases (air = 474 sec, CO = 475 sec). Double product at ST decreases and maximal double products were similar for both conditions. Resting ejection fraction was slightly but nonsignificantly higher after CO exposure (air = 53.9%, CO = 55.2%). Maximal ejection fraction was similar for both conditions (air = 57.4%, CO = 57.1%). Change in ejection fraction was slightly lower for CO exposure (air = 3.5%, CO = 2%), p = .049. In conclusion, there is no clinically significant effect of 3.8% COHb (representing a 2.2% increase from resting values) on the cardiovascular system in this study.

Administration, Inhalation↗
PubMedDate not supplied

Effects of low-level carbon monoxide exposure on resting and exercise-induced ventricular arrhythmias in patients with coronary artery disease and no baseline ectopy.

The effects of acute elevation of carboxyhemoglobin (COHb) concentrations on resting and exercise-induced ventricular arrhythmias were evaluated in 10 patients who had ischemic heart disease and in whom no ectopy during baseline monitoring was noted. After an initial training session, patients were exposed to air, 100 ppm carbon monoxide (CO), or 200 ppm CO on successive days in a randomized, double-blind, cross-over fashion. After exposure to 100 and 200 ppm CO, venous COHb levels averaged 4% and 6%, respectively. Symptom-limited supine exercise was performed after exposure. Eight of the 10 patients had evidence of exercise-induced ischemia--either angina, 1.0 mm ST depression, or abnormal ejection fraction response--during 1 or more exposure days. Ambulatory electrocardiograms were obtained on each day and analyzed for arrhythmia frequency and severity. On air and CO exposure days, each patient had only 0-1 ventricular premature beat/h in the 2 h prior to exposure, during the exposure period, during the subsequent exercise test, and in the 5 h following exercise. In conclusion, low-level CO exposure is not arrhythmogenic in patients with coronary artery disease and no ventricular ectopy at baseline.

Aged↗
PubMedDate not supplied

SPECT and MR imaging in herpes simplex encephalitis.

Two cases of necrotizing herpes simplex encephalitis (HSE) were investigated with 99mTc-hexamethylpropyleneamineoxime (HMPAO) SPECT and MR. The clinical course was compared with the neuroimaging results. In the acute stage, the increased HMPAO uptake matched the MR hyperintense signal in the limbic temporal lobe and in the basal ganglia. Protracted inflammation was accompanied by persistently high HMPAO uptake. The sequelae of HSE were characterized by decreased HMPAO uptake and postnecrotic widening of the temporal horns. The "limbic" pattern recognized in both SPECT and MR reflects the basic pathophysiology and neuropathology of HSE. Both methods may be useful in the diagnosis and follow-up of HSE.

Contrast Media↗
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Effects of chronic antihypertensive treatment with acebutolol and pindolol on blood pressures, plasma catecholamines, and oxygen uptake at rest and during submaximal and maximal exercise.

The effects of 4-week periods of treatment, with equivalent doses of acebutolol (500 mg daily) and pindolol (15 mg daily), on plasma noradrenaline, adrenaline, and dopamine, and oxygen uptake at rest, during submaximal steady-state exercise and maximal exercise, and 5 min after exercise, were studied in 11 moderately hypertensive men aged 26-40 years, using a single, crossover design. The two agents had similar effects on heart rate and arterial pressures. Neither the noradrenaline nor the dopamine response to exercise was affected by acebutolol or pindolol. However, 5 min after exercise, nor adrenaline was significantly lower after pindolol. Plasma adrenaline concentration was significantly raised only by pindolol during maximal exercise (from 3.9 +/- 2.3 to 5.0 +/- 3.3 nmol/L, p less than 0.05). Neither oxygen uptake, nor ventilation during steady-state exercise were significantly different from control conditions. Maximal oxygen uptake tended to be slightly lower after acebutolol (5%), and distinctly lower after pindolol (14%). The maximal oxygen pulse was significantly increased only after acebutolol. The absence of a noradrenaline enhancement during the action of pindolol and acebutolol suggests that the increased plasma noradrenaline levels observed after some Beta-receptor blockers during work, do not reflect a compensatory response to lower blood pressure or restricted physical work capacity. The differential effects of Beta-receptor blockers appear to be due to differences in their pharmacological properties.

Acebutolol↗
PubMedDate not supplied

Immunoglobulin class distribution of systemic and mucosal antibody responses to Newcastle disease in chickens.

In serum, tracheal wash fluid, and bile from chickens that were inoculated with live or inactivated Newcastle disease virus (NDV), the kinetics and immunoglobulin (Ig) class distribution of an antibody response were demonstrated. The Ig classes (IgM, IgG, and IgA) were captured using monoclonal antibodies (MAbs) in enzyme-linked immunosorbent assays (Ig-capture ELISA). The antibody specificity of the captured Ig was confirmed by binding of NDV. After inoculation with live virus, antibodies of the IgG and IgM classes were mainly found in serum. IgM was produced early from day 4 postexposure (PE) onward, IgG was detected later from day 7 PE onward, and in the tracheal wash fluid and bile, all three Ig classes were demonstrated. After inoculation of inactivated virus, a delayed response of all three classes was observed in serum, and only IgM and IgG were recognized in the tracheal fluid and bile. The type of vaccine and the mute of antigen entrance may have determined the immunoglobulin class produced. The Ig-capture ELISA assay developed in this study can be useful for evaluating various strategies to improve the efficacy of Newcastle disease vaccines and to study the evoked immune mechanisms.

Animals↗
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Detection of antibody-forming cells directed against Newcastle disease virus and their immunoglobulin class by double immunoenzyme histochemistry.

Antibody-forming cells (AFCs) against Newcastle disease virus (NDV) and their immunoglobulin (Ig) class were demonstrated by a double immuno-enzyme histochemical technique. The AFCs were stained and quantified in spleen sections of chickens euthanatized at day 7 postexposure to the Roakin strain of NDV. The sections were incubated with NDV to determine the specificity of the AFCs. Bound virus was subsequently visualized with a primary monoclonal antibody (MAb), a secondary horseradish peroxidase-conjugated MAb, and 3-amino-9-ethylcarbazole as substrate. IgM and IgA were stained with MAbs and an alkaline phosphatase (AP)-conjugated secondary antibody. IgG class antibodies were demonstrated with an AP-conjugated rabbit serum. The final substrate for the three Igs was naphthol AS-MX-phosphate and fast blue BB. About 64-159/mm2 AFCs against NDV were detected. Of these virus-binding cells, about 55% produced IgM, 37% produced IgG, and the remaining 8% produced IgA.

Animals↗
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Measuring the diffusion of innovative health promotion programs.

Once a health promotion program has proven to be effective in one or two initial settings, attempts may be made to transfer the program to new settings. One way to conceptualize the transference of health promotion programs from one locale to another is by considering the programs to be innovations that are being diffused. In this way, diffusion of innovation theory can be applied to guide the process of program transference. This article reports on the development of six questionnaires to measure the extent to which health promotion programs are successfully disseminated: Organizational Climate, Awareness-Concern, Rogers's Adoption Variables, Level of Use, Level of Success, and Level of Institutionalization. The instruments are being successfully used in a study of the diffusion of health promotion/tobacco prevention curricula to junior high schools in North Carolina. The instruments, which measure the four steps of the diffusion process, have construct validity since they were developed within existing theories and are derived from the work of previous researchers. No previous research has attempted to use instruments like these to measure sequentially the stages of the diffusion process.

Adolescent↗
PubMedDate not supplied

Genome analysis of Marek's disease virus strain CVI-988: effect of cell culture passage on the inverted repeat regions.

The genomes of different derivatives of Marek's disease virus (MDV) strain CVI-988, a low oncogenic isolate of a serotype 1 MDV, were analyzed by restriction enzyme analyses to detect whether alterations occurred after passages in cell culture. DNA molecules of strain 988 isolated directly from blood cells contained mainly two copies of the 132-bp repeat sequence previously reported within BamH1-H and -D fragment as previously reported for more virulent MDV strains. Although a minority of virus particles showed repeat amplification was already at the fifth passage level, amplification mainly occurred between passages 17 and 34 in cell culture. In addition, a 400-bp deletion was detected within the BamH1-A fragment of two derivatives of CVI-988, 988C and 988C/R6.

Animals↗
PubMedDate not supplied

Dose-response effects of inactivated Newcastle disease vaccines: influence of serologic assay, time after vaccination, and type of chickens.

Knowledge of the dose-response relation of inactivated vaccines and of the factors that influence this relation is essential for the evaluation of existing vaccine potency assays and the development of new potency assays that are based on the antigen content of the inactivated vaccines. We quantified the relation between vaccine dose, serologic response, and clinical protection after vaccination for three different inactivated Newcastle disease (ND) vaccines. Qualitatively, similar dose-response curves were obtained for the three vaccines when either the serologic response or the clinical protection of specific-pathogen-free (SPF) chickens was plotted against the different vaccine doses applied. However, the vaccines differed quantitatively: doses of vaccines that induced similar antibody titers or clinical protection differed 2-8-fold. In contrast with the narrow range of antibody titers induced by a full vaccine dose, a very broad range of titers was obtained after dilution of the vaccines. At least 95% of the SPF chickens with detectable antibody in the serum were protected against a challenge with virulent Herts ND virus. The relation between the dosage of two different ND vaccines and the serum antibody titers remained markedly constant between 3 and 18 wk after vaccination. Vaccination of broilers instead of layers with a dilution series of inactivated ND vaccine resulted in significantly lower antibody levels and less clinical protection against virulent challenge. In conclusion, despite quantitative differences, we found comparable dose-response relations for the three inactivated ND vaccines studied.

Animals↗
PubMedDate not supplied

Results and complications in endovascular treatment of abdominal aortic aneurysms--a single center experience.

Between September 1996 and February 2000 five female and 62 male patients with an abdominal aortic aneurysm, requiring therapy, underwent endoluminal treatment. Their age ranged from 51 to 81 years (mean 72 years). Preoperative evaluation was done with spiral computed tomography (CT) and angiography. All procedures were performed under general anesthesia in a radiologically adapted operating room. Postoperative complications occurred in 28.4%. The total conversion rate was 13.4%, the 30-day lethality rate was 1.4%. During the mean follow-up of 15.1 months 19 secondary interventions were necessary in 13 patients. The results presented in this study do not justify the wide use of this method and indicate a stricter form of patient selection.

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