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Biomedical subjects

M Lando

Publications and source records attributed to M Lando.

15 recordsLinked to original sources
PubMed1990

Modulation of intracellular cyclic adenosine monophosphate levels and the differentiation response of human neuroblastoma cells.

We have tested the ability of various compounds to raise intracellular cyclic AMP (cAMP) levels and, either alone or in combination with retinoic acid (RA), to promote differentiation of two "RA-resistant" sublines of LA-N-5 human neuroblastoma cells, designated LA-N-5HP and LA-N-5R9. Direct activation of adenylate cyclase by forskolin and cholera toxin increased intracellular cAMP levels over 10-fold in both cell lines after 1 h of treatment, after which the levels slowly declined for the next 16 to 24 h. After 5 days of continuous treatment, cAMP levels still remained 2- to 7-fold elevated above controls and were accompanied by a decrease in cell proliferation and an increase in neurite outgrowth. All these effects were exaggerated when the agents were combined with phosphodiesterase enzyme inhibitors. Increasing cAMP levels (up to 24-fold) with N6,O2'-dibutyryl cyclic AMP (dbcAMP) or 8-bromo-cAMP also resulted in decreased proliferation and an increase in morphological differentiation. Isoproterenol and epinephrine did not alter cAMP levels and had no discernible biological effects. Of the agents that raised cAMP levels, only dbcAMP caused an increase in acetylcholinesterase activity. This effect was duplicated with sodium butyrate and prostaglandin E1 in the absence of an increase in cAMP. RA promoted differentiation but also had little effect on cAMP levels. Combination treatment of cells with RA plus agents that raised cAMP levels resulted in greater degrees of differentiation than seen with single agent treatments. We conclude that: (a) the cAMP synthetic and degradative pathways are functional in LA-N-5HP and LA-N-5R9 cells; (b) elevation of cAMP is sufficient for inhibiting proliferation and promoting neurite outgrowth from these cells, but is not a necessary condition for inducing differentiation; and (c) elevation of intracellular cAMP potentiates the differentiation-inducing activity of RA.

Acetylcholinesterase↗
PubMed1988

Stabilization of hearing loss in Paget's disease with calcitonin and etidronate.

Paget's disease is a common skeletal disease characterized by abnormal bony resorption and deposition. Although the disease principally affects the axial skeleton, skull and temporal bone involvement occur. Affected individuals have significantly different rates of progression of hearing loss than normal persons. We describe two patients in whom this progressive hearing loss was halted and even reversed. These patients were treated with calcitonin and etidronate disodium and have been followed up for five and 3 1/2 years, respectively. Computed tomographic scans demonstrating extent of disease are included along with our treatment regimen and alkaline phosphatase response curves.

Aged↗
PubMedDate not supplied

25 ideas for maximizing board effectiveness.

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Attitude of Health Personnel↗
PubMedDate not supplied

Placental grade and pulmonary maturity in premature fetuses.

The correlation between the placental echographic appearances and pulmonary maturity was studied in 32 cases of normal pregnancy between the 29th and 33d weeks. The placental appearance was classified according to Grannum's criteria, and an amniocentesis was performed in each case. Both an L/S ratio and a foam stability (Clements') test were performed on the amniotic fluid. There were 10 cases of grade I and 22 cases of grade II placenta in the series. There was one mature L/S ratio in each placental grade; both had intermediate results with Clements' test. These findings differ significantly from those published in the literature on the subject, which are based on investigations in more mature fetal populations.

Female↗