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Biomedical subjects

L R Hegstrand

Publications and source records attributed to L R Hegstrand.

13 recordsLinked to original sources

An unusual presentation of metastatic squamous cell carcinoma of the vulva.

Recurrent squamous cell cancer of the vulva metastasized via regional lymphatics. Hematogenous spread is late and unusual. A patient with metastatic disease presented with soft tissue mass in her thigh musculature. We believe this to be the first reported case of noncontiguous skeletal metastasis for this tumor.

Aged

Variations of brain histamine levels in germ-free and nephrectomized rats.

The influence of nephrectomy on brain and peripheral tissue histamine and on brain norepinephrine, dopamine, serotonin, and 5-hydroxyindoleacetic acid was studied in germ-free and conventionally housed rats. The conventional controls had higher levels of histamine in the hypothalamus than the germ-free control animals, but no differences existed for histamine in whole brain minus the hypothalamus or in peripheral tissues. Nephrectomy increased brain histamine and 5-hydroxyindoleacetic acid levels in both germ-free and conventional rats, but had no effect on norepinephrine, dopamine or serotonin. In contrast, the histamine level in the heart of the nephrectomized germ-free animals was lower than that for germ-free controls. There were no changes in the heart or liver histamine levels of the conventional nephrectomized rats.

Animals

Evidence for involvement of protein kinase in the activation by adenosine 3':5'-monophosphate of brain tyrosine 3-monooxygenase.

Addition of adenosine 3':5'-monophosphate (cAMP) to high speed supernatant preparations obtained from rat brain caused a 3- to 4-fold increase in tyrosine 3-monooxygenase (tyrosine hydroxylase) activity. The tyrosine 3-monooxygenase remained in an activated state upon removal of the cAMP by passing the enzyme through a Sephadex G-25 column. Substances which inhibit cAMP-dependent protein kinase, namely, EDTA, ADP, and adenosine, and protein kinase modulator, each antagonized the activation of tyrosine 3-monooxygenase produced by cAMP. Furthermore, addition of partially purified brain cAMP-dependent protein kinase caused a several-fold increase in tyrosin 3-monooxygenase activity. The activation of tyrosine 3-monooxygenase by added cAMP and protein kinase required the presence of ATP and Mg-2+. These data suggests that the cAMP activation of tyrosine 3-monooxygenase may be mediated by a cAMP-dependent protein kinase.

Adenosine

Effect of total parenteral nutrition on histamine in the rat brain and other tissues.

The effects of a constant infusion of total parenteral nutrition on the histamine content of the hypothalamus was studied in adult male rats. Histamine content of the stomach, kidney, liver, and heart was also determined. The relationship between tissue histamine levels and duration of the infusion was examined. Rats receiving intravenous infusions of total parenteral nutrition had significantly higher (p less than 0.001) histamine levels in the hypothalamus than did orally-fed control rats. No difference was observed in the histamine level in the remainder of the brain. Animals receiving parenterally infused nutrient solutions had a higher histamine content in the kidneys but lower histamine levels in the stomach than did the control rats. No changes in the histamine content of liver or heart were observed. It appears that increases in histamine levels in the kidney and hypothalamus of rats given total parenteral nutrition persist up to 5 days and 9 days, respectively. The mechanisms responsible for and the consequences of the alterations of histamine content of these tissues remain to be established.

Animals