Biomedical subjects
Publications and source records attributed to J Witte.
We describe the development and successful use of a percutaneous lead-transsection catheter. It was used in two patients in whom removal of chronically implanted atrial pacing leads could not be accomplished by traction.
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To investigate the pacemaker syndrome (PS) presenting a mixture of signs and symptoms (syncope, presyncope, nausea, dyspnoea, vertigo, loss of physical fitness, congestive heart failure) and related to ventricular pacing, the authors measured cardiac output (CO), peripheral blood pressure (PAP) and peripheral resistance (PR) during continuous atrial and/or ventricular pacing in two groups: patients with and without PS. In both groups a significant decrease in CO was found between atrial and ventricular pacing. A significant difference between the two groups was found in the degree of PAP drop which was significant in the PS group, in the group without PS insignificant. On the other hand, the PR increase at ventricular pacing was in the PS group insignificant, in the symptomless group significant. It is concluded that ventricular pacing causes a CO decrease due to loss of normal atrial transmission. Hypotension in PS patients is connected with an atrial reflex that inhibits normal vascular tone.
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Between March, 1980 and January, 1984, computerized tomography (CT) was performed on 110 patients with proven esophageal carcinoma. In 26 patients, information obtained preoperatively by CT was compared with results of intraoperative exploration or histologic examination of resection specimen. Correlation analysis showed that accuracy of CT in assessing actual tumor size and mediastinal or abdominal lymph node involvement is rather limited, while correct results were obtained in between 84 and 100 per cent of patients as far as identification of invasion of adjacent organs is concerned. We thus advocate routine use of CT in the process of preoperative assessment of operability and staging.
The results of stimulation threshold analysis carried out in 230 patients after the initial electrode implantation, and in 188 patients during pacemaker replacement, are presented. The electrodes investigated were the IE-60K-10 (279 cases), the IE-60-K (96 cases) and the ME-50 (26 cases). The chronic stimulation threshold voltage for the electrode IE-60K-10 (electrode surface area: 10 mm2) at a pulse width of 0.5 ms, after an electrode function time of 25 months, is 2.05 +/- 0.18 V, representing 256% of the acute threshold, and is equally as high as the chronic figure for the IE-60-K electrode (surface area: 27 mm2) measured at 2.08 +/- 0.20 V. The current threshold for the IE-60K-10 increased from 0.78 +/- 0.07 mA by 299% to 2.33 +/- 0.30 mA and was thus, as expected, lower than that of the large area electrode IE-60-K, which increased from 1.11 +/- 0.22 mA to 3.23 +/- 0.43 mA (291%). On the basis of the computation of the stimulation threshold energy and the stimulation threshold charge, a reduction of pulse duration to below 0.5 ms would not appear to make such energy-saving sense.
Coagulation factors and plasma proteins are significantly decreased in patients with hyperdynamic septic shock. Besides the activation of the coagulation system, the endotoxin-induced release of granulocyte proteases is responsible for a septic disseminated intravascular coagulation. In this situation special emphasis should be placed on the levels of antithrombin III regarding application of heparin.
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The diagnosis of reflux esophagitis can be confirmed by a variety of diagnostic procedures. Beside the morphologic findings of the reflux demonstrated by X-ray, endoscopy, and histology, the degree of disturbed cardial function can be determined by manometry, pH determination, and scintiscan. Each method entails a number of errors. Therefore a distinction must be made between absolutely necessary and valuable methods for clarifying the degree of the symptoms of esophageal reflux.
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The accepted diagnostical procedures to prove a gastroesophageal reflux by direct or indirect methods do not allow any quantification and are of limited sensitivity. A quantification is possible by use of a gamma-camera with a computer-system after application of a small amount of 99m Tc-DPTA (reflux scintiscan). The high accuracy of this method could be proven by evaluation of 51 patients with suspected gastroesophageal reflux esophagitis or after total gastrectomy. The results were compared with the histological findings. With this method we found after total gastrectomy the expected high incidence of relux. The long-term results after semifundoplication were not as good as after fundoplication. The reflux scintiscan is a less invasive, but reliable method to detect the gastroesophageal reflux.
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A unique case of a metastasising choriocarcinoma, inadvertently transplanted to a man from a female cadaver kidney is reported. When the kidney was removed six days after transplantation, arterial blood vessel infiltration by chorio-carcinoma cells and high levels of human chorionic gonadotropin (HCG) in the serum of the recipient indicated an haematogenous dissemination of viable neoplastic cells. The immunosuppressive therapy was discontinued after removal of the graft and the HCG levels in the recipient gradually decreased over a periode of eight weeks, indicating a slow immunologic rejection of the tumor cells. The recipient committed suicide seven months after the transplantation had failed. No metastases were found at a legal autopsy. It seems advisable, whenever there is evidence that neoplastic cells might have been transfered by a homograft, to remove the graft and discontinue the immunosuppressive therapy. Neoplastic cells already disseminated can still be eliminated when the immunologic system is intact and not suppressed.
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The postop. aldosteronism of a control-group with a sodium intake of 1.5 mval/kg bw/d can be suppressed by increasing the sodium intake up to 5 mval/kg bw/d. A postop. increased need for sodium is supposed to be the most possible cause for this aldosteronism.
Selective proximal vagotomy (SPV) decreases the LES pressure (resting pressure and pentagastrin-stimulated pressure), significantly 6 months postoperatively without achieving LES insufficiency by clinical means. Immediately after stimulation LES pressure is identical, compared to preoperative measurements. The postoperative significantly increased concentration of basal gastrin seems not to be a major determinant of LES tone in humans.
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