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Biomedical subjects

J Torhorst

Publications and source records attributed to J Torhorst.

At least 127 records · Page 7Linked to original sources
PubMed1980

Growth of human tumors in mice after short-term immunosuppression with procarbazine, cyclophosphamide, and antilymphocyte serum.

A simple combine treatment with immunosuppressive agents permitting the growth of human tumor xenografts in conventional mice is presented. It consists of two simultaneous applications of 90 mg of procarbazine (PCH) per kg and 30 mg of cyclophosphamide (CY) per kg, alternating with two doses of 0.15 ml/10 g of antilymphocyte serum (ALS) for 4 days before grafting. No postgraft treatment is used. With a take rate of 100%, at 60 days after subcutaneous transplantation into male C3H mice, fragments of a human colon adenocarcinoma had grown (on the average) into cherry-sized tumors. Two osteosarcomas, an Ewing sarcoma, and a bronchogenic carcinoma were also studied and grew similarly. Tumors could be established in the three tested mouse strains but grew better in male animals. Synergy of PCH and CY and ALS depends upon the alternating sequence of both drugs and ALS. The histology of the colon carcinoma and the Ewing sarcoma was unchanged as compared to the tumors growing in nude mice. In contrast, the osteosarcoma developed in a more differentiated fashion in the immunosuppressed mice. The presented model may serve as a screening system for anticancer drugs.

Adenocarcinoma↗
PubMed1980

Histological and cytological alterations in the skin of biotin-deficient chicks.

A basal diet with practically no natural biotin was supplemented with 10, 19, 34, 62, 111 or 200 microgram of biotin per kg. Chicks receiving these graded levels of biotin were used for histological investigations of skin samples of the foot pad and the under and upper side of the middle toe. Where there was biotin deficiency, epidermal hyperplasia, papillary growth, acanthosis and hyperkeratosis were observed on the foot pad and the under side of the toe. In the stratum spinosum, cells showed big nuclei and nucleoi, and the glycogen-containing nuclear and perinuclear vacuoles had disappeared. The alterations in the skin of the upper side of the toe were similar but far less pronounced. Cell proliferation measured by the labelling index was significantly increased in all three skin samples.

Animals↗
PubMed1979

The morphologic diagnosis of analgesic (phenacetin) abuse.

A number of different morphologic characteristics were examined to determine their relative values in establishing a purely morphologic diagnosis of phenacetin abuse. These included hyperpigmentation of the skin, the costal cartilages, the liver, and the renal tubules, and capillarosclerosis of the lower urinary tract. Hyperpigmentation of the skin, liver, and renal tubules cannot be used in the diagnosis of phenacetin abuse. Massive brown pigmentation of the costal cartilages in patients under 60 years of age suggests phenacetin abuse, but even this morphologic parameter, when used alone, is insufficient to establish a definite diagnosis. Capillarosclerosis in the lower urinary tract does, however, permit one to diagnose phenacetin abuse with certainty, as it is found exclusively in this condition.

Adolescent↗
PubMed1978

Capillarosclerosis of the lower urinary tract in analgesic (phenacetin) abuse. An electron-microscopic study.

The ultrastructural appearances in capillarosclerosis of the lower urinary tract in analgesic abuse are reported. The capillaries show thickened basement membranes consisting of numerous thin basement membrane lamellae. Between the newly formed basement membrane lamellae, masses of empty vacuoles (fat vacuoles) and a variety of membranous and vesicular structures are present. The pathogenesis of this alteration in the basement membrane is unknown. A common pathogenetic mechanism may be operative in the discoloration of renal papillae and mucous membranes of lower urinary tract on the one hand and capillarosclerosis on the other.

Arteriosclerosis↗
PubMed1978

Retinoic acid-binding protein in human breast cancer and dysplasia.

Seventy-five specimens of human breast tissue were checked for the presence of cellular retinoic acid-binding protein (cRABP). Fifty-two percent of the primary carcinomas and 43% of the dysplastic breast lesions (stage MII) contained detectable amounts of crabp, whereas no cRABP was found in normal tissue. Sucrose gradient centrifugation and electrophoresis on agarose were used for analysis of the presence of cRABP. The cRABP of human origin (normal uterus and neoplastic mammary tissue) differed in its mobility in agarose electrophoresis from that of rat testis cRABP.

Animals↗
PubMed1978

[Indication for subcutaneous mastectomy as carcinoma prevention].

The indication for subcutaneous mastectomy is analyzed. Prospective investigations seem to confirm that different morphological forms of breast dysplasia (grade I, II, III, PRECHTEL [10]) do not implicate differences in risk for development of invasive breast cancer. Only if these forms of breast dysplasia are associated to high risk factors such as family history of breast cancer, should subcutaneous mastectomy be considered as a cancer prophylaxis.

Breast↗
PubMed1977

Prevention of postoperative thromboembolism by dextran 40, low doses of heparin, or xantinol nicotinate.

The efficacy of dextran-40 infusions or low-dose heparin or xantinol-nicotinate administration in preventing postoperative thromboembolic complications has been investigated in a prospective, controlled, randomised trial as part of an international multicentre trial. 382 patients over the age of forty years undergoing elective major general surgery were investigated; 100 had a complete protocol in the control, 94 in the heparin, 92 in the dextran, and 32 in the xantinol-nicotinate group. 31 patients died: 13 in the control group, 10 in the heparin group, 6 in the dextran group, and 2 in the xantinol-nicotinate group. In 4 controls, 6 in the heparin group, and 1 in the dextran group the cause of death was acute pulmonary embolism. 4 further controls, 1 in the heparin group, and 2 in the dextran group had emboli found at necropsy, which either contributed to the deaths or were incidental findings. The distribution of pulmonary emboli in this study did not show the difference between the control and the heparin group reported in the multicentre trial. The 125I-fibrinogen test was done in all patients. The frequency of isotopic deep-vein thrombosis was 36-0% in the controls, 12-8% in the heparin group, 21-7% in the dextran group, and 40-6% in the xantinol-nicotinate group. The difference between the controls and the heparin groups was highly significant and between the control and the dextran group, probably significant. There were significantly more side-effects in the heparin group than in the dextran group.

Administration, Oral↗
PubMed1977

Autoradiographic and histopathologic studies on the mode of action of an aromatic retinoid (Ro 10-9359) on chemically induced epithelial tumors in Swiss mice.

The mode of action of an aromatic analogue of retinoic acid, ethyl all-trans-9-(4-methoxy-2,3,6-trimethyl-phenyl)-3,7-dimethyl-2,4,6,8-nonatetraenoate (Ro 10-9359), a compound known to possess a considerable prophylactic and therapeutic effect on skin papillomas and carcinomas, was investigated with autoradiographic and histopathologic methods. The ip application of a single dose of 1,000 mg Ro 10-9359/kg to female Swiss mice with chemically induced skin papillomas caused a 29% regression of the mean tumor diameter after 3 days and a 51% regression after 7 days. In the tumors, the number of DNA-synthesizing cells [measured by the labeling index (LI)] and the length of the cell cycle were not affected by the retinoid; thus a mode of action at the level of cell proliferation can be excluded. In the normal skin, an increase in the LI of about 30% was observed. A small effect on the cell loss was observed; however, it was not sufficient to explain quantitatively the regression of the tumors. When measured histometrically, it appeared that the loss of the horn and the formation of necroses, 3-10 times larger than in the placebo groups, were mainly responsible for the tumor regressions caused by the retinoid. After 7 days, the proportion of stroma in the tumors was increased, and dilation of the vessels and edema in the stroma proximal to the necroses were frequent.

9,10-Dimethyl-1,2-benzanthracene↗
PubMed1977

[Prognostic significance of histological and cytological parameters in biopsies].

In cancer and precancerous conditions, cytologic and histologic investigation of biopsies can serve to establish prognosis as well as for diagnosis. All prognostic factors must be taken into account in modifying a particular tumor therapy. Additional determination of biochemical parameters on the basis of biopsy material makes it possible to characterize the biology of tumor cells with greater precision. Transplant of tumor fragments into nude mice offers a further means of investigating tumor cell properties more closely in vivo.

Animals↗