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Biomedical subjects

K de Heer

Publications and source records attributed to K de Heer.

At least 19 recordsLinked to original sources
PubMed1992

Detection of colorectal carcinomas by intraoperative RIS in addition to preoperative RIS: surgical and immunohistochemical findings.

The immunoscintigraphic detection of tumour foci less than 1 cm in diameter fails even with single photon emission tomography (SPET) owing to low contrast against background activity. In an attempt to improve detection of macroscopically invisible tumour spread, intraoperative scintimetry (IOSM) with a hand-held gamma-probe was performed in addition to SPET 24-30 and 41-48 h after injection of the technetium-99m carcinoembryonic antigen (CEA MoA) on 12 patients with colorectal carcinoma and 3 patients with different neoplastic and inflammatory diseases. Tumour specimens were measured in vitro in a gamma well counter. For comparison, the presence and amount of CEA in the tumour cells were evaluated immunohistochemically. After modification, the gamma-probe originally designed for iodine-131 was 20 times more sensitive; activities of 99mTc located close to the collimator hole were measured with absolute sensitivity of 100 cps = 2.5 kBq 99mTc. The unfavourably high background activity affected both the in vitro and in vivo analysis: SPET results had been considered positive in 8 of 15 cases. In vitro tumour/non-tumour (t/nt) ratios greater than 2.0 were found in 4 cases. In vivo IOSM resulted in t/nt ratios greater than 2.0 in only 3 patients. In most cases, there was no coincidence of elevated t/nt ratios from the different methods. A correlation was derived between positive immunoscintimetric in vitro findings and immunohistochemically proven interstitial localization of CEA in tumor cells. In conclusion, the measurement technique of IOSM seems adequate, but clinical success will depend on a more specific enrichment of MoA in tumour tissue.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1989

[Perforation of gastroduodenal ulcer. Risk factors and choice of procedure].

The well known surgical risk factors, such as age, time of perforation as well as size and localisation of necrosis, were confirmed in retrospective and prospective analyses of perforation of gastroduodenal ulcers (n = 504). Incidence was unchanged in the two different time-related groups, with 3.2 or 3.7 cases in one month. There was a clear-cut need for excision of the ulcer or necrotic margin. Perforation was attributable to malignant tumours in 2.1 per cent of the cases. The authors have definitely adopted the concept of earlier primary surgery (23 per cent of all cases, as compared to 10.4 per cent before). The risk associated to it was found to be lower than linked to palliative operations. The lethality rate was as low as 7.6 per cent, once due consideration was given to the above risk factors for adequate choice of surgical methods. Particular attention was given to ulcer localisation and clinical course. Hence, lethality has clearly dropped below earlier data.

Adult↗
PubMed1989

[Identification of the recurrent laryngeal nerve in thyroid gland surgery--a status determination].

The recurrent laryngeal nerve palsy is the most important complication in thyroid surgery. It seems to be possible to reduce the rate of palsies by consequently identifying the recurrent laryngeal nerve. A comparison of statistics out of the literature with and without identification of the recurrent laryngeal nerve shows this. A follow-up of our patients of the years 1980-1982 (1312 operations) confirms this finding.

Adult↗
PubMed1987

[Metastases of the thyroid gland--morphology and clinical aspects of 25 secondary thyroid neoplasms].

Morphological and clinical findings in 25 secondary tumours of the thyroid are described. The most common sources of such lesions were the kidneys (32%), lung (28%) and breast (20%). In the majority of cases, thyroidectomy was performed prior to identification and treatment of the primary cancer. Conversely, among renal cell carcinomas, the metastatic lesion frequently appeared many years after resection of the primary tumour. This suggests that secondary thyroid tumours occasionally may be the only important malignant disease remaining. Hence, adequate surgical treatment may prove to be life-prolonging or life-saving.

Aged↗
PubMed1987

[Ethinyl estradiol and hepatocarcinogenesis. An experimental study].

The influence of ethinylostradiol on hepatocarcinogenesis was investigated in the female Dawley-rat. After 14 weekly gastric instillations of 50 mg diethylnitrosamine/kg and simultaneous administration of diet supplemented with ethinylostradiol 10 mg/l kg diet, 77.8% of the rats developed a hepatocellular carcinoma. In contrast, only 31.8% had carcinoma of the liver under similar experimental conditions. The relation of preneoplastic lesions correlated with that of carcinoma induction in both groups. If the results were to be valued on clinical relevance without difficulties a new orientation on surgical indication and transformation of the dignity of benign focal nodular hyperplasia would have to be considered.

Animals↗
PubMed1987

Increased thyrotropin binding in hyperfunctioning thyroid nodules.

The object of this study was to investigate TSH receptors in hyperfunctioning thyroid nodules (HFN). In HFN, obtained from seven patients, 125-I-TSH binding as determined by equilibrium binding analysis on particulate membrane preparations, was found to be significantly increased as compared with normal thyroid tissues (five patients; P less than 0.001). Scatchard analysis of TSH-binding revealed two kinds of binding sites for both normal thyroid tissue and HFN, and displayed significantly increased association constants of high- and low-affinity binding sites in HFN (Ka = 11.75 +/- 6.8 10(9) M-1, P less than 0.001 and Ka = 2.1 +/- 1.0 10(7) M-1, P less than 0.025; x +/- SEM) as compared with normal thyroid tissue (Ka = 0.25 +/- 0.06 10(9) M-1, Ka = 0.14 +/- 0.03 10(7) M-1; x +/- SEM). The capacity of the high-affinity binding sites in HFN was found to be decreased (1.8 +/- 1.1 pmol/mg protein, x +/- SEM) in comparison with normal thyroid tissue (4.26 +/- 1.27 pmol/mg protein; x +/- SEM). TSH-receptor autoradiography applied to cryostatic tissue sections confirmed increased TSH binding of the follicular epithelium in HFN. These data suggest that an increased affinity of TSH-receptor sites in HFN in iodine deficient areas may be an important event in thyroid autonomy.

Humans↗
PubMed1986

[Differential indications in perforation of gastroduodenal ulcer].

The differential indication of perforated peptic gastroduodenal ulcer is presented giving emergency surgical intervention preference. Simple closure after radical excision with a mortality rate of 12.1% as demonstrated in our clinical material is generally performed and in some selected cases the so-called primary definitive therapy excision, SPV or distal gastric resection. In cases of doubt simple closure is performed. An absolute acute indication for simple closure is also valid for the atypical perforation.

Aged↗
PubMed1979

[Chenodeoxycholic acid therapy and colorectal carcinoma--an experimental approach (author's transl)].

With respect to the potential significance of bile acids in the pathogenesis of colorectal cancer the effect of continuous oral administration of chenodeoxycholic acid--which is used for conservative therapy of radiolucent gallstones--on the rate of colonic tumors was examined. In rats treated with chenodeoxycholic acid a higher incidence of 1,2-dimethylhydrazine induced adenocarcinomas was detected. On the basis of these results it is postulated that all patients treated with chenodeoxycholic acid due to gallstones are registered systematically in order to gain definite information about its possible role as tumor promoter.

Animals↗
PubMed1979

[Surgical intervention in cold nodules of the thyroid gland (author's transl)].

In statistical analyses the rate of malignancy of solitary cold thyroid nodules is estimated between 3 to 50%. In our records the incidence of malignancy is 6,6%. Concerning the pathogenicity of these thyroid nodules no conclusions can be drawn which are only based on the results of such analyses. Each thyroid nodule has to be classified either according to its clinical and morphological characteristics or to its morphology alone. The condition for an optimal diagnosis and therapy is provided by the surgeon and pathologist being acquainted with the criteria for morphological classification or clinical data respectively.

Adenoma↗
PubMed1977

[Preoperative treatment of hyperthyroidism (author's transl)].

The preoperative preparation of hyperthyroidism requires the selective use of various drugs. As in the past, Plummer's iodine therapy takes precedence. Thyrostatics or beta receptor blockers, on the other hand, are only used in selected cases. The aim of preoperative preparation is euthyroidism. It is most rapidly and safely attained with Endoiodin (prolonium iodide) or combination of Endoiodine plus beta receptor blokkers. Thyrostatics appear to be less suitable for preparation, because they have a slow onset of action. Moreover, thyrostatics lead to densifications and adhesions of the thyroid gland capsule to the surrounding tissue, so that the preparation becomes complicated. 254 patients with hyperthyroidism and decompensated toxic adenoma were surgically treated without complications as a result of preparation with Endoiodin.

Adrenergic beta-Antagonists↗
PubMed1977

[An analysis of factors which can be influenced in geriatric surgery (author's transl)].

A retrospective study has been made of 1457 surgical patients over 70 years of age in three one-year periods (1960/61, 1969, 1973). While the average age remained 77, there has been changes in the frequency of diseases leading to hospitalisation. Degenerative lesions and casualties have increased. There are more elderly patients undergoing major surgery. On the contrary the mortality has reduced to 7.8%. The results of geriatric surgery are influenced by previous and concomitant diseases, the surgical lesion and the type of therapy. Suggestions for reducing the number of emergency operations are discussed. When necessary smaller palliative operation which improve the quality of life should be considered instead of major curative surgery. Surgery in the aged is a speciality and requires simultaneous consideration of various factors.

Age Factors↗
PubMed1977

[Cholecystectomy and experimental coloncarcinoma (author's transl)].

The influence of cholecystectomy on the development of carcinoma of the colon is investigated. The experimental results show a significant high rate of carcinoma of the colon induced by subcutaneous injection of 1,2-Dimethylhydrazin (DMH) in the mouse after cholecystectomy. After 10 weekly injections of 15 mg/kg DMH 70% of the animals with cholecystectomy developed carcinoma. Only 16% of the mice with similar treatment but without cholecystectomy had carcinoma. The cocarcinogenic effect of cholecystectomy is assumed to be due to the increased production of secondary bile salts by the colonic bacteria and the lacking of the resorptive function of the gall bladder for some carcinogenic substances passing through the liver. The background of this experimental studies is the clinical findings that 10% of patients with carcinoma of the large bowels had a cholecystectomy previously.

Adenocarcinoma↗
PubMed1977

Cholecystectomy and carcinoma of the colon. An experimental study.

The influence of cholecystectomy on the development of carcinoma of the colon is investigated. The experimental results show a significantly increased rate of carcinoma of the colon induced by subcutaneous injection of 1,2-Dimethylhydrazin (DMH) in the mouse after cholecystectomy. After 10 weekly injections of 15 mg/kg DMH, 70% of the animals with cholecystectomy developed carcinoma. Only 16% of the mice with similar treatment but without cholecystectomy had carcinoma. The cocarcinogenic effect of cholecystectomy is assumed to be due to the increased production of secondary bile salts by the colonic bacteria and the lacking of the resorptive function of the gallbladder for some carcinogenic substances passing through the liver. The background of this experimental studies are the clinical findings that 10% of patients with carcinoma of the large bowel had previous cholecystectomy.

Animals↗
PubMed1977

[Colon carcinoma - duration of anamnesis and survival time (author's transl)].

In order to prove the hypothesis--short anamnesis; short survival time--the duration of the anamnesis and the period of survival of 230 patients with carcinoma of the colon were statistically mathematically and graphically investigated. No relationship in accordance with a rule was found between the duration of anamnesis and the time of survival. Curative surgery prolonged the period of survival significantly. The duration of the anamnesis depends on fortuitous factors and represents one of the stages of cancer. The delay after the first medical consultation is pointed out. It can be concluded that the resection of cancer in the early stage--early diagnosis--is for the survival decisive. The duration of the anamnesis is more important for the diagnosis than the surgical treatment and the prognosis.

Adult↗