Biomedical subjects

D Jacobovitz

Publications and source records attributed to D Jacobovitz.

30 records · Page 2Linked to original sources

PubMed1988

Immunohistochemical detection of c-Ha-ras oncogene p21 product in pre-neoplastic and neoplastic lesions during hepatocarcinogenesis in rats.

An immunohistochemical study of c-Ha-ras expression was performed on preneoplastic and neoplastic stages of diethylnitrosamine (DENA)-induced hepatocarcinogenesis in rats, using an antibody raised against a peptide sequence of the Ha-ras p21 product. Moderate to high immunostaining intensity was observed in the following hepatocytic lesions: (1) hepatocellular carcinomas (14/14) and associated neoplastic nodules (8/8) and foci of phenotypic alterations (35/40) (after 13-20 months of treatment); (2) neoplastic nodules (6/6) and associated foci (42/50) (after 5-9 months); (3) foci (10/10) (after 2 months); and (4) small, slowly growing foci (26/40) found 9 months after treatment with DENA without prior partial hepatectomy, resulting in low number of nodules and no tumor even after 15 months. No c-Ha-ras p21 was detected immunohistochemically in normal nor in regenerating rat liver. Our results indicate that increased Ha-ras expression is an early and stable event in liver lesions associated with hepatocarcinogenesis. They also imply that increased Ha-ras expression is insufficient (if at all implicated) for inducing fully malignant hepatocyte transformation. It might be indicative of cell populations at an increased transformation risk.

Animals↗

PubMed1987

Subrenal capsule assay for fresh human tumors in immunocompetent mice; an inappropriate technique for non-small cell lung cancer.

The subrenal capsule assay (SRA) seems to present some difficulties for the evaluation of the chemosensitivity of antineoplastic agents against fresh tumor xenografts. A study was therefore carried out to verify whether two different xenografts would behave in a similar way. Tumors such as melanoma provided adequate homogeneous material for this technique, while non-small cell lung carcinoma (NSCLC) were heterogeneous since the 1 mm3 specimen grafted under the renal capsule usually contained diffuse areas of necrosis and of infection. Furthermore, a large proportion of the grafted specimens, 257 out of 298, did not contain any tumor at all on microscopic examination even when they showed macroscopic growth. Added to these discrepancies, a random microscopic analysis of 180 adjacent fragments of NSCLC and melanomas demonstrated that the variability of heterogeneous tumors precludes any meaningful comparison between homologous tumor tissues designed to be grafted on treated and on control mice. The anti-inflammatory effect of chemotherapeutic drugs on the host's reaction to the graft is probably responsible for the differences between the macroscopic growth results observed in pieces grafted to both treated and control mice: however, it could not be simulated by hydrocortisone (HC) under our experimental conditions. This allows us to conclude that fresh tumors from NSCLC cannot be used in SRA.

Animals↗

PubMed1986

Subrenal capsule assay of fresh human tumors: problems and pitfalls.

The 6 day subrenal capsule (SRC) assay was performed in normal mice using 20 fresh human non-small cell lung cancers and nine fresh ovarian cancers. Different multi-agent chemotherapy regimens administered intravenously on days 2 + 3 of the assay were evaluated for activity against these two tumor types. Macroscopic results measured via an ocular microscope showed high activity for some combinations as well as for single agents. However, when subjected to microscopic examination, the SRC implants in the untreated control animals did not show viable tumor growth on day 6. Detailed histologic evaluation of over 800 SRC grafts reveals an intense inflammatory and fibrotic reaction in the majority of the grafts. These results indicate that drug sensitivity patterns obtained with this assay using only macroscopic criteria do not correlate with actual tumor regression. Microscopic analysis of the grafts prior to transplant shows absence or only minimal presence of tumor in many cases which also contributes to the poor growth observed in these two tumors.

Animals↗

PubMed1978

Morel's laminar sclerosis.

A 49-year-old alcoholic woman was admitted for convulsions. She died after a 4-week clinical course characterized by a persistent coma with diffuse muscular hypertonia. Post-mortem examination of the brain demonstrated a spongy degeneration and gliosis of the cerebral cortex, limited to the 3rd and the 4th layers. No other pathological lesion of the central nervous system could be objectivated. This is the first reported case in which Morel's laminar sclerosis was the only manifestation of 'alcoholic encephalopathy'. Morel's syndrome should be considered as a pathological entity separate from the Marchiafava-Bignami disease.

Alcoholism↗

PubMed1975

[Toxi-infectious shock pneumopathy. A morphological study (author's transl)].

The lungs of 68 septicaemic patients have been systematically studied and compared. The observed lesions include a whole range if alterations usually described in routine sampling of lungs in cases of deaths from diverse diseases. One lesion however appears more frequent and intense: infection of the pulmonary oedema. Inflammatory reactions are associated to acute arteritis at different stages of evolution which, in these patients, was more frequent in cases of shock.

Adult↗

PubMed1974