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Biomedical subjects

W Horst

Publications and source records attributed to W Horst.

At least 19 recordsLinked to original sources
PubMed1986

Uptake of a monoclonal antibody against CEA (Tumak 431/31) in a human colon tumor (Co-112) xenografted in the nude mouse. Dependence on tumor size and injected dose.

A monoclonal antibody (Tumak) against carcinoembryonic antigen (CEA) was injected into nude mice bearing a human colon carcinoma (Co-112). The tumor uptake was found to be dependent on the size of the tumors: relative uptake (percentage of the injected dose/gram tumor (% i.d./g) decreased for tumors with weights up to approximately 1 g, although the absolute uptake (% i.d./tumor) still increased over the same weight range. In the constant region (greater than or equal to 1 g) mean relative tumor uptake was approximately 4% i.d./g. The same tumor size dependence was found for the relative Tumak uptake in the other mouse organs studied (e.g., blood, liver, spleen and muscle). Consequently tumor/organ ratios were found to be independent of tumor size. Tumor uptake was also studied for various doses of Tumak (0.07-120 micrograms) in tumors of approximately 1 g. Evidence was found for a threshold dose of 0.1 microgram under which no serious tumor uptake appeared. From 1 to 120 micrograms no further dependence of Tumak distribution on applied dose was found: the relative uptake of all organs remained the same but the absolute uptake increased with dose.

Animals↗
PubMed1985

A convenient method for the preparation of 99mTc(V)dimercaptosuccinic acid (99mTc(V)-DMSA).

Tc(IV)-DMSA for kidney scintigraphy has been prepared in acidic solution. Once the labeling is done in basic solution, upon addition of a small amount of NaHCO3, a mixture of 3-4 other DMSA-complexes is formed, presumably containing Tc(V). Kidney uptake in male adult rats of the 99mTc(V)-DMSA is 1.6% injected dose/g (4.9%/total organ) compared to 16.4% injected dose/g (resp. 50.3%/total organ) for 99mTc(IV)-DMSA.

Animals↗
PubMed1980

[Indication and results of radiation therapy in the treatment of astrocytomas (author's transl)].

The course of 77 patients with well-differentiated or anaplastic astrocytoma after treatment with resection and radiotherapy or radiotherapy after biopsy during the years 1954--1978 at the University hospital at Zürich is analyzed. The ten-year survival rate in patients with well-differentiated astrocytoma is about 30%. About 15% of the patients with anaplastic astrocytoma are living after 5 years, but there is no 10-year survivor in this group. Patients with mixed glioma (astrocytoma plus oligodendroglioma) show the same survival rate as patients with well-differentiated astrocytoma. Analysis of tumor dose and the size of the irradiated volume shows only in patients with anaplastic astrocytoma a trend to better survival rate after doses of at least 5000 rd in 5 weeks and irradiation fields larger than 200 cm2. In accordance with published reports, the survival rate in patients with gemistocytic astrocytoma is lower than in the other cases.

Adolescent↗
PubMed1980

[Myocardial scintigraphy with thallium 201 in assessing revascularization procedures by aortocoronary bypass or coronary dilatation].

40 patients underwent aortocoronary bypass surgery for coronary artery disease involving a single vessel in 2 cases, 2 vessels in 10 cases, and all 3 vessels in 28 cases. Preoperative exercise Thallium 201 scanning showed one or several zones of hypofixation (80 p. 100 of maximum myocardial fixation) which were not present at rest. After surgery, exercise scanning was normal in 22 out of 24 patients with normalised or improved vascularisation on control angiography, but remained pathological in 2 cases. However, comparable areas of hypoperfusion were observed in 16 patients with no improvement or worsening of vascularisation after operation. The exercise EG remained pathological in 6 out of 24 patients with normalised or improved vascularisation and in 11 out of 16 patients with identical or worsened vascularisation. In addition, 10 of the 24 patients with improved or normalised vascularisation, and 12 of 16 patients with identical or worsened vascularisation, continued to have chest pain after operation. A zone of hypoactivity was observed in the preoperative exercise scan in 18 out of 20 patients with isolated stenosis treated by catheter dilatation. Normalised exercise scans were recorded in all patients in the month following dilatation, but the exercise ECG remained pathological in 3 patients. In conclusion, 201 Thallium scanning gives a good assessment of myocardial vascularisation after revascularisation procedures. It helps identify patients with non-anginal post-operative chest pain, and detects residual ischaemia in patients without ischaemic signs on electrocardiography.

Adult↗
PubMed1980

Considerations in the radiation treatment of intracranial ependymoma. Prognosis in 24 own cases and results in published series after different techniques of radiation treatment.

The course of 24 patients with intracranial ependymomas after surgical and radiotherapeutic treatment from the years 1954 to 1978 is analysed. The survival rate after 5 and ten years is about 40%. Patients with well differentiated ependymoma, who were irradiated with tumor doses of at least 4000 rad in 4 weeks with inclusion of the whole brain for a part of the dose had a 5-year survival rate well above 50%. In patients with well-differentiated supra or infratentorial ependymomas, prophylactic irradiation of the whole spinal axis is not indicated. Patients with high-grade malignant ependymomas are irradiated by a treatment technique similar to that in patients with medulloblastomas, and additive chemotherapy is administered thereafter. Results of ongoing clinical studies should answer the question, whether this treatment can achieve higher cure rates in patients with high-grade malignant ependymomas.

Brain Neoplasms↗
PubMed1979

[Radionuclide determination of the left ventricular ejection fraction under stress: comparison with angiocardiography].

Left ventricular ejection fraction (LVEF) determined by first pass radionuclide (Nucl.) and biplane contrast angiocardiography (Angio.) was compared in 62 patients with suspected coronary artery disease under resting conditions and in 32/62 patients during bicycle ergometry at identical work load. At rest both methods correlated with r = 0.81 with similar heart rates in both determinations. The mean value of LVEF (Nucl.) was lower than the mean value of LVEF (Angio.), at 50 +/- 2 (SE) % and 58 +/- 2% respectively (p less than 0.001). During exercise a significant correlation between the two methods was again found (r = 0.76). This time no difference was detected between the mean values for LVEF (50 +/- 3% [Nucl.] vs 48 +/- 2% [Angio.], n.s.), which may be explained by the higher heart rates during the invasive study (123 +/- 5/min [Angio.] vs. 108 +/- 4/min [Nucl.], p less than 0.001), resulting in a higher degree of ischemia and hence a lower LVEF. The interobserver variability did not differ between the two methods.

Adult↗
PubMed1979

[Thallium 201 myocardial scintigraphy. Clinical use and value].

Thallium-201 exercise myocardial perfusion scintigraphy, a new, non-invasive screening method, serves to visualize stress-induced ischemic regions and scarred tissue. As compared to the exercise electrocardiogram, the method shows higher sensitivity and specificity in detecting coronary artery disease. Moreover, it makes it possible to localize the predominant defects. Even though myocardial scintigraphy cannot replace coronary arteriography in establishing the precise morphologic situation of the coronary arteries, it is of help in deciding whether an arteriogram should be carried out or not. Thus, important indications for myocardial stress scintigraphy are atypical chest pain and an abnormal electrocardiogram without pain. Furthermore, the method is useful for evaluating patients with uninterpretable electrocardiograms during exercise, and in assessing the outcome of coronary artery bypass surgery.

Coronary Artery Bypass↗
PubMed1979

[Radiotherapy of the medulloblastoma: development of methods and results of the treatment of 30 patients from 1963 to 1976 (author's transl)].

The results of the treatment of 30 patients with medulloblastoma from 1963--1976 are analysed. 20% of all patients had no evidence of disease after five years. Radiation technique and dose were subject to change in these years and the results show, that a 5 year cure rate about 40% or more can only be achieved, if the radiation dose in the fossa posterior is about 5000 rd in 5--6 weeks. The ongoing studies will show, whether the results of an optimized radiotherapy can further be enhanced by chemotherapy.

Adolescent↗
PubMed1979

[Therapy of the metastasizing adenocarcinoma of the thyroid gland using 131-I. Experiences with 103 patients from 1963 to 1977 (author's transl)].

Results of 131-I therapy in 103 patients with metastatic thyroid cancer are analyzed. Therapy included: elimination of the thyroid or residual thyroid in case of previous surgery by application of about 80 mCi of 131-I and hormone substitution. About two months later, the hormone substitution was stopped. exogenous thyrotropine wsa given and 150--300 mCi of 131-I were applicated. Two days later, the thyroid medication was reinstituted, and a week later, the patient was studied by scintigraphy and other measures. In case of an iodine-metabolizing tumorous tissue, further 131-I applications were given. In the patients with distant metastases, the ten-year survival rate is about 22%. Small masses of papillary cancer can be eradicated in the majority by means of 131-I, whereas large tumor masses (several 100 g), can not be eliminated by 131-I. In well-differentiated follicular cancer, the recovery rate obtained by 131-I is lower than in papillary cancer. Manifestations of follicular cancer with anaplastic parts, or follicular cancer with eosinophilic cells or Hürthle-cell cancers could not be eradicated by 131-I. Treatment-induced mortality lies between 2 and 3% and is acceptable in view of the recovery rate and the serious nature of the disease.

Adult↗
PubMed1979

[Results from 215 patients with laryngeal carcinoma treated with sole radiotherapy or with a combination of radiotherapy and operation (author's transl)].

Results of radiotherapy alone or in combination with surgery in 215 patients with laryngeal cancer are reported (treatment time between 1963 and 1976). In patients with glottic cancer, the cure rate is about 80% and surgical treatment for persistent/recurrent cancer was necessary only in a few cases. Analysis of tumor dose, tumor control rate and complication rate shows that in cases with glottic cancer a tumor dose between 1900 and 2000 ret is necessary and tolerable. In patients with supraglottic laryngeal cancer, the cure rate is about 55%. Early stages (T1N0M0) were mostly treated by radiotherapy alone, moderately advanced stages (T1N1,T2N0+1) mostly received radiotherapy as a primary treatment and were operated in case of irradiation failure. Advanced stages were primarily treated by a combined therapy, and by radiotherapy alone if they were inoperable. In early cases, who are to be treated by radiotherapy alone, the tumor dose should be about 1900 ret. In moderate cases, treatment by primary irradiation alone is possible, if the patient can be followed up regularly; surgery is indicated, if the patient cannot unequivocally be classified as symptomless. In some of these cases, there is no tumor demonstrable histologically in the excised larynx. In using this treatment policy, there is a better functional treatment result than in using primary combined treatment in moderately advanced cases with supraglottic laryngeal cancer.

Adult↗
PubMed1979

[The diagnosis and therapy of endocrine ophthalmopathy (author's transl)].

Radio-iodide diagnosis of the thyroid is a simple method of high security in the diagnosis of endocrine ophthalmopathy. This procedure is valuable especially, in cases where neither clinically, nor in the sero-hormonal diagnosis a disturbance of the thyroid can be found. In many cases an accelerated intrathyroidal turnover of radio-iodide can identify an unclear ophthalmopathy as an endocrine ophthalmopathy. The therapy of choice for hyperthyreoidism with endocrine ophthalmopathy is 131-iodide resection. This statement has been proven by our own experiences in more than 1000 cases in the past 15 years and by the results indicated in early literature about the course of ophthalmopathy after surgical or medical treatment. For the therapy of a malign, or imminent malign endocrine ophthalmopathy, we use percutane irradiation of the orbit with sparing of the lens in a dose of 200 rad 5 times a week. In practically all cases, this therapy eliminates the consequence of visual disturbances and avoids surgical decompression.

Graves Disease↗