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Biomedical subjects

J Willems

Publications and source records attributed to J Willems.

At least 91 records · Page 5Linked to original sources
PubMed1985

Chemiluminescence assay of phagocyte activity in mice bearing neuroblastoma: effect of in vitro culture of the tumor.

Phagocyte activity in mice bearing neuroblastoma (NB) has been assayed using a chemiluminescence (CL) technique and proves to be dependent on the pretreatment of the NB cells used to induce the tumor. Indeed, original NB C 1300 tumor, which is maintained by serial in vivo passages induces highly triggered peritoneal phagocytes, producing large amounts of reactive oxygen intermediates (ROI). On the contrary, C 1300 cells cultured in vitro for a few passages and established lines as well as clones derived from the original tumor fail to induce this triggering. However, this decreased phagocyte stimulation can be regained at full extent after a few in vivo passages of the tumor cells.

Animals↗
PubMed1985

Chondromyxoid fibroma. A review of the literature and a report on our own experience.

The present paper comprises a review of the literature on chondromyxoid fibroma (CMF) and a report on nine cases originally classified as CMF, found in a review of all curetted bone lesions at our department from 1955 to 1978. At histologic revaluation only two cases fulfilled the criteria for true CMF, whereas six were classified as other benign bone lesions and one proved to be a chondrosarcoma. The chondrosarcoma case after recurrence was subjected to more mutilating surgery than would have been necessary if correct diagnosis had been established initially. The other six benign cases were all well and without signs of recurrence 5-11 years after curettage. In one of the two true CMF cases, i.e. in a young boy, there were for 2 years postoperatively radiological signs of a progressive recurrence, which was left without treatment, since the patient was well. Interestingly, radiograms 2 and 11 years postoperatively essentially showed the same picture, indicating spontaneous cessation of the process. Chondromyxoid fibroma is an extremely rare lesion. Histologic misinterpretation is not uncommon. In sporadic cases this may have serious implications. It may be questioned whether surgical treatment of CMF in young patients, known to have a high recurrence rate, is mandatory.

Adult↗
PubMed1985

Pharmacological properties of the new potent diuretic torasemide in rats and dogs.

Torasemide, a pyridine-3-sulfonylurea derivative, has potent diuretic activity in rats and dogs. In both species urinary volume and electrolyte excretion increased linearly with the logarithm of the dose, thus resembling the profile of a high ceiling diuretic. The minimum effective dose by oral route was 0.2 mg/kg in the rat and less that 0.1 mg/kg in the dog. Maximal effect was obtained with about 10 mg/kg. Experiments by oral and i.v. routes in the rat indicated that torasemide was equally potent by both oral and parenteral administration. In both rats and dogs, urinary excretions induced by torasemide were similar to those obtained with furosemide. However, for the same natriuretic effect, potassium losses with torasemide were significantly less than with furosemide. On a weight basis, torasemide was 9-40 times more potent than furosemide in the rat and about 10 times in the dog. After oral administration the diuretic effects of torasemide started within 20 min and lasted approximately 2 h in the rat and more than 8 h in the dog. The activity of torasemide was not decreased after a repeated daily oral dose of 10 mg/kg for 15 days in the rat. Torasemide at a daily oral dose of 5 mg/kg for 12 days effectively reduced the arterial blood pressure in desoxycortone induced hypertension in the rat. Besides the diuretic and antihypertensive effects no other significant pharmacological effects were observed with torasemide in the different in vitro and in vivo experiments. Torasemide was practically fully absorbed by the gastrointestinal tract, its bioavailability by oral route ranged from 80 to 100%.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1984

Diastolic properties of the left ventricle in normal adults and in patients with third heart sounds.

To explore the pathogenesis of the third heart sound (S3), left ventricular hemodynamics in early diastole were studied during catheterization in normal adults without S3S (group I, n = 12) and in cardiac patients with S3S as the result of severe mitral regurgitation (group II, n = 11), dilated cardiomyopathy (group III, n = 24) or restricted left ventricular filling (group IV, n = 4). The height and steepness of the rise in left ventricular pressure after minimum diastolic pressure (the so-called rapid filling wave), maximum dV/dt, and the time constant of fall in isovolumetric pressure were measured. The completeness of relaxation was evaluated from the number of time constants elapsed at the time of minimum diastolic pressure. Pressure-volume data were fitted to simple elastic and viscoelastic models incorporating inflow rate into the equation. In all patients with S3S a significantly higher and steeper rapid filling wave was found than in normal adults. Maximum dV/dt was significantly greater in group II (1084.9 +/- 416 ml/sec; mean +/- SD) than in the other groups (463.9 +/- 177.1 ml/sec in group I, 448.8 +/- 134.0 ml/sec in group III, and 709.9 +/- 226.8 ml/sec in group IV). No significant differences in left ventricular chamber elastic properties in the different groups were found. However, intrapatient comparisons of the results of the use of elastic and viscoelastic equations revealed a significantly better curve fit (r = .930 vs .968, p less than .005) and a much higher viscous constant for group III. Similar results were found in group IV.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1984

Parathyroid carcinoma--problems in diagnosis and treatment.

Four patients with parathyroid carcinoma operated on at the Karolinska Hospital were reviewed. In three patients the parathyroid carcinoma was suspected at the primary operation and successfully treated with excision of the tumour and ipsilateral hemithyroidectomy. In one patient the diagnosis was made only after local recurrence of the tumour and the appearance of lung metastasis. Although removal of local recurrence and distant metastasis was not curative, the patient improved for a long period of time. When surgical resection did not successfully control the hypercalcemia, Mithramycin, 12.5 micrograms/kg intravenous daily was given for five days. With two days interruption the treatment was repeated. The hypercalcemia could in this manner be controlled for almost one and a half years. It is concluded that parathyroid carcinoma is a relatively rare endocrine tumour which may be cured by adequate initial operation. When surgery is not feasible to control hypercalcemia, Mithramycin seems to be the drug of choice even for long-term therapy.

Adult↗
PubMed1984

In vitro study of the influence of dopamine on rat and dog gastric fundus.

The effect of dopamine was studied in rat longitudinal fundus strips and in dog circular and longitudinal fundus strips. Contractions of similar amplitude were induced by transmural stimulation and by methacholine. In the rat, dopamine inhibits the electrically induced contractions partially by a post-junctional influence on the smooth muscle cells and partially by inhibiting the release of acetylcholine from the intramural cholinergic neurons. The latter effect is antagonized by phentolamine, while the former is antagonized by propranolol. Dopamine antagonists change the inhibitory effect of dopamine to a small degree but have a similar influence on the inhibitory effect of noradrenaline. The inhibitory effect of dopamine is largely indirect through the liberation of noradrenaline, since in the presence of cocaine or after reserpine-pretreatment the inhibition by dopamine is markedly reduced. In the presence of propranolol, cocaine and hydrocortisone, the inhibitory effect of dopamine is equally antagonized by the alpha 1-antagonist prazosin and the alpha 2-antagonist rauwolscine. In the dog, the inhibition of the electrically induced contractions by dopamine is mainly due to inhibition of the release of acetylcholine from the intramural cholinergic neurons. This effect is not influenced by the presence of cocaine and is completely antagonized by phentolamine and rauwolscine, while prazosin has no effect. From the dopamine antagonists tested, only metoclopramide had some antagonistic effect against dopamine but it antagonized to the same degree the inhibition by noradrenaline.

Animals↗
PubMed1983

Correlation between lymphocyte-mediated auto-tumor reactivities and clinical course. I. Evaluation of 46 patients with sarcoma.

T-cell-enriched blood lymphocyte populations from 24 osteosarcoma and 22 soft-tissue sarcoma patients were assayed at the time of surgery for proliferative response to, and/or cytotoxic potential against autologous tumor cells. Tumor-free period and survival of the patients were correlated with the results obtained in the in vitro tests. The observation time was between 18 and 118 months (mean 62) for the osteosarcoma patients and between 18 and 72 (mean 42) for the patients with soft-tissue sarcoma. In both groups tumor-free period and survival were longer for those individuals who had auto-tumor reactivity. In the non-reactive group, all patients died within 3 years. Almost all patients had cytotoxicity against K562.

Adolescent↗
PubMed1983

Correlation between lymphocyte-mediated auto-tumor reactivities and the clinical course. II. Evaluation of 69 patients with lung carcinoma.

T-cell-enriched lymphocyte populations of 69 lung carcinoma (44 squamous cell, 23 adeno-, and two large cell carcinoma) patients were investigated at the time of surgery for proliferative response to, and/or cytotoxic potential against, freshly separated autologous tumor cells. Tumor-free period and survival time of the patients were correlated with the reactivity obtained in the in vitro tests. The observation time varied between 20 and 78 months (mean 52). Tumor-free period and survival time were longer and survival rate higher in the group with lymphocyte reactivity toward their tumors. In the non-reactive group, all patients but one died within 3 years. Almost all patients had cytotoxic lymphocytes against K562, the three who did not belonging to the category with short survival time.

Adenocarcinoma↗
PubMed1983

Circulating immune complexes in murine neuroblastoma: quantification and shifts in immunoglobulin composition.

Circulating immune complexes (CIC) in sera obtained from neuroblastoma (NB)-bearing A/J mice were quantitated using a modified conglutinin (Kg) RIA technique which--in this case--gives very reproducible results. It shows that CIC levels in these sera increase almost linearly as a function of time after tumor challenge. Three weeks after inoculation values ranging from about 4 to up to 10 times those of normal sera are obtained, depending on the type of inoculum (NB tumor or established NB cell lines). However, when tumor is adapted to cell culture, these CIC levels, measured at a constant time interval after challenge, decrease on continued subcultivation in vitro. Furthermore, analyses of the immunoglobulin classes involved in the complexes show that this decrease is more pronounced for the IgG2a and IgG2b subclasses than for IgG1 and IgM, resulting in a shift of the ratio of immunoglobulin classes as a function of subcultivation of these tumor-derived cells.

Animals↗
PubMed1983

Nine years' experience with the Björk-Shiley prosthetic valve: early and late results of 932 valve replacements.

Between November, 1970, and December, 1977, 932 consecutive patients received the standard Björk-Shiley prosthesis. Operative mortality was 4.6% for aortic valve replacement (AVR; N = 364), 5.1% for mitral valve replacement (MVR; N = 313); 11.3% for multiple valve replacement (N = 194), and 13.7% for valve replacement combined with coronary artery bypass grafting (CABG; N = 51). Factors influencing hospital mortality included type of valve replacement, age at operation, whether the valve replacement was done as an emergency, and year of implantation. Complete follow-up (mean, 3.7 years) was achieved in 95% of the survivors. Actuarial survival was 82% for AVR patients at 8 years, 83% for MVR patients at 7 years, 72% for multiple valve replacement patients at 7 years, and 76% for those who had valve replacement with CABG at 3 years. No significant difference in late survival was found between patients with mitral insufficiency alone (p greater than 0.2) or aortic insufficiency alone (p greater than 0.9) and those with stenotic lesions only. Thromboembolic complications occurred at an incidence of 1.17% per patient-year, and Dicumarol-induced hemorrhages occurred at an incidence of 2.11% per patient-year. Twelve out of 13 patients survived operation for prosthetic valve thrombosis, indicating that this complication is not as catastrophic as many believe. The incidence of reoperation in anticoagulated patients was 0.63% per patient-year. All of these results are compared with data from the recent literature.

Aged↗
PubMed1983

Preoperative radiation therapy of high malignancy grade soft tissue sarcoma. A preliminary investigation.

Twenty-three patients with high malignancy grade soft tissue sarcoma received irradiation (about 40 Gy) followed by surgery. The follow-up time was 62 months or more in all patients. The local recurrence rate was 9 per cent (2/23). One of the patients was reoperated and is living free of disease, giving a local control rate of 95 per cent. Thirty per cent (7/23) of the cases developed distant metastases and died of the disease. Delayed wound healing was observed in 2 cases which was possibly due to the radiation therapy. Since surgery was regarded non-radical in 5 cases, the local control obtained by the combined radiation therapy and surgery is good and should be the subject for further investigations.

Adult↗
PubMed1980

Changes in pituitary responsiveness to luteinizing hormone-releasing hormone during an annual cycle in the domestic duck, Anas platyrhynchos L.

On four occasions during an annual cycle, 5--7 male domestic ducks were injected with two different doses (5 and 20 micrograms) of synthetic luteinizing hormone-releasing hormone (LHRH) to study the possible changes in responsiveness of the pituitary. The luteinizing hormone (LH) and the follicle-stimulating hormone (FSH) were measured in the plasma samples collected after these injections. The induced release of LH changes from one period of the year to another, being minimum in March at the height of the reproductive season. The LHRH injection also induces the release of some FSH but only in limited amounts. The changes in pituitary responsiveness to LHRH are negatively correlated to changes in the circulating LH level (it is high when the plasma LH is low and vice versa). This suggests that the hypothalamic synthesis and release of LHRH must also change during the year.

Animals↗
PubMed1979

Interferon therapy in multiple myeloma.

A woman with multiple myeloma relapsed after 6 years of satisfactory tumor control with melphalan therapy. When progression then occurred, she was given exogenous human leukocyte interferon, 3 x 10(6) reference units twice daily i.m., as the sole therapy. Side-effects of the interferon therapy consisted of fever reactions and thrombocytopenia. One month after the initiation of interferon therapy there was 1) improvement of general health with less pain and tiredness, 2) reduction of the M-component, IgG-lambda, in the serum, and 3) a reduced plasma cell concentration in the bone marrow. After 5 months of interferon therapy tumor progression occurred despite continuous interferon treatment. At the same time, the tumor cells were less sensitive to interferon in in vitro tests than prior to interferon therapy. It is suggested that interferon therapy should be given as initial treatment to a few patients with multiple myeloma in a phase I trial.

Aged↗