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Biomedical subjects

M Leino

Publications and source records attributed to M Leino.

48 records · Page 3Linked to original sources
PubMed1986

Optic nerve injury after sudden traumatic rotation of the eye. A case report.

Optic nerve injury is regularly accompanied by signs of local facial or ocular injury, fractures or unconsciousness. The energy of the blow is thought to be delivered to the optic nerve directly by stretching and tearing and by shock wave forces and secondarily as sequelae of contusion. A case is described in which optic nerve injury is caused by a sudden traumatic duction of the eyeball, with all signs of local or systemic contusion missing. During observation the primarily healthy optic nerve head developed subtotal optic atrophy. This case strengthens the belief that the optic nerve is particularly vulnerable to stretching, tearing and torsion.

Blindness↗
PubMed1985

Methoxyindoles of the retina.

Melatonin and other 5-methoxyindoles are compounds usually associated with the pineal gland. Research is expanding from studies of pineal melatonin to studies of extrapineal organs and of other 5-methoxyindoles besides melatonin. Research in recent years has shown that the retina also contains and synthetises 5-methoxyindoles. The biochemical modes of action are still unclear. Nevertheless, they seem to have physiological roles in the pineal gland and the retina. These compounds are thought to participate in the regulation of the cyclic metabolism of the retina. Melatonin and other 5-methoxyindoles are often classified as neuromodulators.

5-Methoxytryptamine↗
PubMed1984

Effects of melatonin and 6-methoxy-tetrahydro-beta-carboline in light induced retinal damage: a computerized morphometric method.

The effects of melatonin and a related 5-methoxy-indole, 6-methoxy-1,2,3,4-tetrahydro-beta-carboline (6-MeO-THBC) were investigated in rats on the development of retinal degeneration in presence of high intensity illumination (HII). A morphometric method is used in which the degree of degeneration was evaluated by a computer-coupled graphical analyzer. Instead of measuring individual thicknesses of different retinal layers at various loci we measured large areas of retinal light microscopic sections. Thus the influence of sporadic artefactual and other fluctuations in the thickness of various layers of the retina can be essentially reduced. Continuous light produced significant degeneration of the retina and the degree of degeneration was further increased by both studied compounds and even more by 6-MeO-THBC. The role of melatonin and 6-MeO-THBC in retinal physiology is discussed.

Animals↗
PubMed1984

6-Methoxy-tetrahydro-beta-carboline and melatonin in the human retina.

The presence of two 5-methoxyindoles, 6-methoxy-1,2,3,4-tetrahydro-beta-carboline (6-MeO- THBC ) and melatonin was demonstrated in human retinae using a highly specific gas chromatographic mass spectrometric method from eyes affected with various ocular diseases. Both compounds were found to occur in similar quantities. 6-MeO- THBC is a newly-identified endogenously-occurring retinal compound possibly acting as a neuromodulator. The importance of 6-MeO- THBC and other beta-carbolines especially compared to other 5-methoxyindoles is discussed.

Adult↗
PubMed1984

Distribution of 1,2,3,4-tetrahydro-beta-carboline and 6-methoxy-1,2,3,4-tetrahydro-beta-carboline in mice.

The distribution of radioactivity after intravenous injection of 14C-labelled 1,2,3,4-tetrahydro-beta-carboline (THBC) and 6-methoxy-1,2,3,4-tetrahydro-beta-carboline (6-MeO-THBC) was studied on mice by whole-body autoradiography and by liquid scintillation counting (LSC). Following intravenous injection they rapidly distributed into different organs and were excreted into urine and the gut contents. A considerable uptake of the compounds was seen in the lungs, kidney, liver, bone marrow, urinary bladder, gastrointestinal tract and in various glands e.g. adrenal, Harderian and salivary glands. THBC moderately penetrated the blood-brain barrier and the placenta but 6-MeO-THBC seemed to penetrate poorly both. At early stages of the experiment the values of tissue radioactivity in LSC were generally much higher in the THBC group but 24 hours following injections the reverse was true with higher activities in the 6-MeO-THBC group. The initial excretion of 6-MeO-THBC seemed to be more rapid judged by the superfluous accumulation of activity in the bladder and a high accumulation of activity into the gut contents.

Animals↗
PubMed1984

Light microscopic autoradiography of rat retinae after intravitreal injection of [3H]6-methoxy-tetrahydro-beta-carboline.

Many beta-carbolines have recently been shown to occur in the human body and animals. beta-carbolines may act as neuromodulators although their physiological role is not known. We have studied the autoradiographic retinal distribution of intravitreally injected [3H]6-methoxy-tetrahydro-beta-carboline (6-MeO-THBC) in rats. The synaptic and ganglion cell layers accumulate pronounced radioactivity, as do some intra- and extracellular locations in the inner nuclear layer and the outer segments of the photoreceptors. The pigment epithelium gradually accumulates a very dense band of radioactivity. 6-MeO-THBC (pinoline, 5-methoxytryptoline, 6-methoxy-1,2,3,4-tetrahydronorharmane) has been shown to possess many important biochemical and pharmacological properties. It has been demonstrated to occur as a normal constituent in the retina of some animals. The relationship between 6-MeO-THBC, melatonin and other 5-methoxy-indoles is discussed.

Animals↗
PubMed1983

6-Methoxy-tetrahydro-beta-carboline in the retinae of rabbits and pigs.

beta-Carbolines are alkaloids found as normal constituents in many plants and animals. These compounds have many biochemical and pharmacological effects often related to a neuromodulator-like mode of action. We have demonstrated a beta-carboline derivative, 6-methoxy-1,2,3,4-tetrahydro-beta-carboline (6-MeO-THBC) as a normal constituent in the retina. The significance of beta-carbolines in the retina remains to be investigated.

Animals↗
PubMed1983

[14C]6-methoxy-1,2,3,4-tetrahydro-beta-carboline in retinal and other tissues after intravascular and intravitreal injections in mice and rats.

6-Methoxy-1,2,3,4-tetrahydro-beta-carboline (6-MeO-THBC) is a condensation product of 5-methoxytryptamine and formaldehyde. It possesses diverse biochemical and pharmacological properties and has been suggested to act as a neuromodulator. 6-MeO-THBC has been shown to occur in various tissues including the retina in animals and human beings. The present results show that the mouse and rat retina as well as other tissues take up 14C-labelled 6-MeO-THBC injected intravenously or intravitreally. The retinal concentrations show a prompt rise after the injection and significant levels are maintained after 2 days.

Animals↗
PubMed1980

Clinical trial of the topical use of disodium cromoglycate in vernal, allergic and chronic conjunctivitis.

Thirty-three patients were treated with disodium cromoglycate (DSCG). Of these 5 had vernal conjunctivitis, 18 had allergic conjunctivitis and 10 had mild chronic conjunctivitis in which the exact aetiology could not be determined. 70% of patients with DSCG as the only medication achieved at least some beneficial effect being almost exclusively in the groups of either vernal or allergic conjunctivitis. The basic trend seemed to indicate a reduction in severity during the treatment with DSCG in allergic diseases.

Chronic Disease↗