Effects of hypothyroidism on the DNA, carbohydrate, soluble protein and sialic acid contents of rat submandibular glands

Submandibular glands are a target organ of thyroid hormones. This study examined the effects of hypothyroidism on the biochemical characteristics of these glands in the nil. There were no effects on the neutral sugar and DNA contents. However, soluble protein concentrations (μg/mg wet weight) were significantly decreased and sialic acid concentrations (μg/mg soluble protein) were significantly elevated.     

Angiogenesis factor in endometrial carcinoma: A new prognostic indicator?

OBJECTIVE: Tumor angiogenesis is believed to be a prognostic indicator associated with tumor growth and metastasis. Studies of angiogenesis in breast, prostate, and lung cancer, as well as melanoma, have shown that neovascularization correlates with the likelihood of metastasis and recurrences. The purpose of this study was to evaluate microvessel density as a prognostic factor in endometrial cancer. METHODS: Between 1980 and 1991 the tumor registry identified 25 patients with a diagnosis of recurrent endometrial cancer. These patients were matched with 25 patients with nonrecurrent disease for age, stage, grade, and treatment. The histologic slides of the 50 patients were reviewed. The paraffin blocks were obtained, and the area of the deepest myometrial invasion was selected for staining. The microvessels within the invasive cancer were highlighted by means of immunocytochemical staining to detect factor VIII - related antigen. Microvessels were counted by two investigators who were blinded to the patients' clinical status. Survival data were analyzed with Kaplan-Meier survival curves. RESULTS: Microvessel count was related to likelihood of recurrence, although this trend did not reach statistical significance. Patients with tumors of low capillary density had a mean survival time of 123 months. Patients with tumors of high capillary density had a mean survival time of 75 months (p = 002). Among patients with recurrent disease, those with a low capillary count survived a mean of 64 months. Patients with recurrent disease with tumors of high capillary density survived a mean of 45 months (p = 0.002). CONCLUSION: Angiogenesis factor correlates with survival in endometrial carcinoma. (Am J Obstet Gynecol 1996;174:1879-84.)     

Killing of rat glial cells by complement: Deficiency of the rat analogue of CD59 is the cause of oligodendrocyte susceptibility to lysis

In an effort to understand the mechanisms of complement-mediated injury of the myelin/oligodendrocyte complex in demyelinating disease, we have examined the lytic susceptibility of rat glial cells in culture. It is known that rat oligodendrocytes are extremely sensitive to the lytic action of autologous complement, whereas other cells in the same culture system, including type II astrocytes which derive from the same progenitor cell, are relatively insensitive. Here we demonstrate that the complement sensitivity of oligodendrocytes is associated with a lack of expression of a complement-regulatory protein, the rat homologue of human CD59, and that complement resistance can be restored by the incorporation of purified rat CD59 into the cell membrane. Furthermore, neutralisation of rat CD59 on complement-resistant astrocytes renders them susceptible to lysis. Immature oligodendrocytes were resistant to complement attack yet did not express CD59, suggesting that a complement-activating factor appears on the membrane during oligodendrocyte maturation.     

Effects of X-ray contrast media and radiation on human vascular endothelial cellsin vitro

We have used cell culture techniques to study the effects of 16 contrast agents on human vascular endothelial cells (HUVEC)in vitro, where both the dose and duration of exposure are precisely known. Our results demonstrate that 1) exposure of HUVEC to radiographic contrast media can produce dose and time-dependent inhibition of the incorporation of [³H]leucine, [³H]thymidine, or [³H] uridine into marcromolecules; 2) thymidine incorporation is the most affected; 3) the inhibition is not primarily due to osmotic effects; and 4) concomitant exposure to X-irradiation does not sensitize HUVEC to contrast agents. Where marked inhibition occurred, it was accompanied by changes in cell morphology and later, by loss of the cytoplasmic marker lactate dehydrogenase, indicating that under the conditions of our experiments the effects were cytotoxic, and not merely cytostatic.     

Isozyme phenotypes of polyoma virus tumors in mice

Isozyme profiles for 32 enzyme systems were studied in tumors induced by two strains of polyoma virus (2PTA and LID1), in two conventional mouse strains (C3H/BiDa and NIH), and in athymic (nude) mice of two genetic backgrounds (C3H/Hes nu/nu and NIH nu/nu). Tumors studied were: primary and transplant passages of salivary gland tumors (127); primary thymic epithelial tumors (12); primary subcutaneous sarcomas (6); primary hair follicle tumors (5); primary and transplant passages of mammary tumors (18); primary ameloblastomas (3); and primary renal medullary sarcomas (3). Regardless of mouse strain or virus strain, the isozyme arrays were highly constant and unique for each tumor histotype with the exception of salivary and mammary tumors, which shared a single profile differing from that of each of the other histotype-associated profiles. Other tumor types could be distinguished from each other and from the salivary-mammary tumor pair by as few as five isozymes: glycerol-3-phosphate dehydrogenase; glyceraldehydephosphate dehydrogenase; lactate dehydrogenase; sorbitol dehydrogenase; and alkaline phosphatase. Twelve nonpolyoma mammary tumors and their passages from mouse mammary tumor virus-expressed C3H/Hes nu/+ mice were analyzed for the same enzymes; variations in activity and isozyme profiles were found for ten enzyme systems. Three spontaneous salivary myoepitheliomas in BALB/c mice were also analyzed; two different lactate dehydrogenase profiles were observed, and all three tumors lacked the placental alkaline phosphatase present in polyoma virus-induced salivary tumors. Uniformity of isozyme phenotype may be characteristic of DNA virus transformation of cells in a particular differentiative state. This uniformity does not appear to occur in mouse mammary tumor virus-associated tumors, spontaneous tumors, and, according to the literature, chemically induced tumors.