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Biomedical subjects

T Tervo

Publications and source records attributed to T Tervo.

At least 145 records · Page 8Linked to original sources

Innervation of the rabbit cornea. A histochemical and electron-microscopic study.

The innervation of the rabbit cornea was investigated histochemically and electron-microscopically with special reference to the autonomic nerves. Both formaldehyde- and glyoxylic-acid-induced fluorescence methods revealed adrenergic nerves in the stroma; a few fibres were also observed between the basal epithelial cells near the limbus. Acetylcholinesterase- (AChE-) positive nerves were found both in the stroma and in the epithelium, whereas nonspecific cholinesterase (NsChE) activity appeared only in the stromal nerves. Under the electron microscope, both AChE and NsChE activities were observed to be located in the axon membranes. A weak NsChE reaction also appeared in the Schwann cells. When the specimens fixed with KMnO4 were examined under the electron microscope, most nerve fibres did not contain any special axoplasmic structures, although several axons contained mitochondria. Moreover, two vesicle-containing axon types were found in the stromal nerves; axons with small granular vesicles and axons containing small agranular vesicles. In the epithelium, two types of fibres were observed; one type containing only mitochondria while the other showed both agranular vesicles and mitochondria.

Acetylcholinesterase↗

Consecutive demonstration of nerves containing catecholamine and acetylcholinesterase in the rat cornea.

The innervation of the cornea of newborn (two day old) and adult rats was investigated using glyoxylic-acid-induced fluorescence (GIF) for catacholamines and subsequent acetylcholinesterase reaction. Fluorescent nerve were observed around the limbal vessels and in the pericorneal nerve plexus, from which they branched towards the central parts of the cornea. The fluorescent corneal nerves were either nonvaricose or had varicosities at intervals of 10 micra. When the animals had been pretreated with nialamide, noradrenaline and propranolol, some fluorescent branching nerve terminals with numerous varicosities also appeared. All fluorescent nerves disappeared two days after ipsilateral superior cervical sympathectomy. When the acetylcholinesterase (AChE) reaction was performed subsequently to the GIF reaction the following nerve types could be identified: 1. nerves containing both catecholamine (CA) fluorescence and AChE, 2. Nerves containing only AChE.

Acetylcholinesterase↗

Transport adenosine triphosphatase activity in the rat cornea.

The sodium-potassium activated adenosine triphosphatase (NaKATPase) activity of the rat cornea was investigated histochemically using a Pb2+-precipitation technique in which adenosine triphosphate (ATP) is used as substrate and two methods for potassium-dependent para-nitrophenyl-phosphatase (K-NPPase) activity. With all the three techniques used it was demonstrated that the sodium-potassium-activated adenosine triphosphatase (NaK-ATPase) activity is localized in the cell membranes of the endothelium whereas a much weaker activity was observed in the epithelium. When the Pb2+-technique was used, the epithelial cell membranes showed a weaker reaction in the presence of ouabain. This activity was only Mg2+-dependent and was presumably due to an Mg2+-dependent ATPase. The validity of the histochemical techniques for NaK-ATPase activity is discussed. The results emphasize the importance of the endothelium as the main site of Na+ transport in the cornea. Small amounts of the enzyme are also present in the epithelium, which seems to be rich in Mg2+-ATPase. Provided that careful controls are performed, all the methods give consistent results in the cornea.

4-Nitrophenylphosphatase↗

Innervation of the rat Harderian gland by adrenergic and cholinergic nerve fibres.

The innervation of the rat Harderian gland was studied using histochemical methods for catecholamines and acetylcholinesterase (AChE). Selective denervations were performed to investigate the neural connections of this gland with various ganglia. Light microscopically the AChE-positive nerves seemed to run as thick bundles in the intertubular connective tissue. These bundles sent finer branches around the acini. The blood vessels, localized in the connective tissue septa, were surrounded by a dense plexus of AChE-containing fibres. By electron microscopy, the AChE-positive fibres were seen to terminate near the myoepithelial cells surrounding secretory cells. These fibres were also observed in contact with the blood vessels and occasionally close to the secretory cells. Fluorescent adrenergic nerves surrounded the blood vessels. Some fibres were also observed in the interlobular tissue. All the AChE-containing nerves degenerated after cutting the zygomatic nerve. On the other hand, removal of the ciliary ganglion or the superior cervical ganglion, or stereotactic coagulation of the ophthalmic nerve did not affect these nerves. The fluorescent adrenergic fibres disappeared following both removal of the superior cervical ganglion and coagulation of the ophthalmic nerve. These fibres were intact after removal of the ciliary ganglion.

Acetylcholinesterase↗

Catecholamines in shock.

The role of endogenous catecholamines in various clinical shock and stress states is reviewed; the effects, especially on the peripheral circulation, of catecholamine secretion are the same independent of the cause. Risks of using sympathomimetic agents in the treatment of shock are evaluated. A prolonged noradrenaline activity is to be expected in surgical stress states, e.g. multiple injuries, fat embolism syndrome, burns and infections; therapeutic approaches to minimize the sympathoadrenal activity are outlined.

Catecholamines↗

Histochemical demonstration of cholinesterase activity in the cornea of the rat and the effect of various denervations on the corneal nerves.

Cholinesterase (ChE) activities of the rat cornea were demonstrated histochemically by using both light and electron microscopes. Acetylcholinesterase (AChE) reaction was localized in the axolemma of the nerves in the corneal stroma. The epithelial cell membranes and the intraepithelial nerve endings also showed AChE reaction. Non-specific cholinesterase (NsChE) activity was observed only in the endothelial cell membranes. Cervical sympathectomy, ciliary ganglionectomy and stereotactic coagulation of the ophthalmic division of the trigeminal nerve were performed in order to study the routes of the AChE-containing nerves to the cornea. The disappearance of AChE-containing nerves was observed only after ophthalmic neurotomy. It is suggested that the AChE-containing nerves are distributed to the rat cornea exclusively via the ophthalamic nerve. They seem to be sensory nerves.

Acetylcholinesterase↗

Sympathetic nerves to the rat cornea.

The adrenergic innervation of the rat cornea was investigated by using the formaldehyde induced fluorescence (FIF) technique. The fluorescent nerves were observed mainly in the corneal stroma. Either cervical sympathectomy or pre-treatment with reserpine completely abolished the fluorescence of the adrenergic nerves of the cornea. After a stereotactic coagulation of the ophthalmic division of the trigeminal nerve, no adrenergic fibres were visible in the cornea and the number of the fluorescent iridic nerves was also reduced to a marked extent. On the other hand, ciliary ganglionectomy seemed to have no effect on the adrenergic fibres of the cornea. When the rats had been pre-treated with a monoamine oxidase inhibitors, nialamide, and noradrenaline, not only was there an increase in the intensity of the specific fluorescence, but also in the number of adrenergic nerves in the cornea. The epithelium was also shown to contain adrenergic nerves by administering high doses of nialamide combined with noradrenaline, both intravenously as well as topically on the cornea, under the protection of propranolol. It may be concluded that the rat cornea receives its adrenergic innervation along the posterior ciliary nerves. The short ciliary nerves do not appear to carry sympathetic nerves to the cornea.

Animals↗

Effects of denervations on the acetylcholinesterase-containing and fluorescent nerves of the rat iris.

The thiocholine method for the demonstration of AChE-containing fibres and the formaldehyde-induced fluorescence technique for the visualization of adrenergic fibres were employed to study the innervation of the albino rat iris. The following denervations were performed in order to verify the origins of different nerve types: (1) extirpation of the ciliary ganglion, (2) extirpation of the superior cervical ganglion, (3) stereotactic coagulation of the ophthalmic division of the trigeminal nerve, and (4) all possible combinations of the above-mentioned procedures. The denervations disclosed three main types of AChE-containing nerves in the iris: (1) nerve fibres degenerating after ciliary ganglionectomy, (2) thick nerve bundles in the dilator region disappearing after trigeminal neurotomy, and (3) fibres remaining intact after any type of denervation. Cervical sympathectomy had no effect on AChE-positive fibres. Under electron microscope AChE activity could be seen in the axolemma both in unmyelinated and in myelinated fibres. All fluorescent fibres vanished after ipsilateral cervical sympathectomy. Most of these fibres also disappeared after trigeminal neurotomy and the remaining fibres degenerated after subsequent ciliary ganglionectomy. On the basis of the present findings, the following conclusions can be drawn: (1) Most AChE-containing fibres of the rat iris originate in the ciliary ganglion. (2) The majority of the myelinated sensory fibres of the rat iris also contain AChE. (3) There is no AChE in the adrenergic fibres of the rat iris. (4) All adrenergic fibres of the rat iris originate in the ipsilateral superior cervical ganglion, and (5) these fibres enter the iris along with both the long and short ciliary nerves.

Acetylcholinesterase↗

[Serum enzymes in seriously injured patients].

In 45 patients with multiple injuries due to trauma, admitted consecutively to our clinic, the following enzyme activities were studied, beginning at the onset of treatment: SDH, GPT, GLDH, and acid phosphatase. The mean levels of SDH rose in all patients between 2 and 24 h after trauma. The mean values of GPT were above normal between 2 and 48 h after trauma; this rise was more pronounced and statistically significant in those patients who eventually died of trauma than in the less severely injured ones. Twenty-four hours after trauma, the levels of GLDH were 16 times higher in the first group of patients than in the less severely injured group. These results lead us to the conclusion that through serum level measurements of these enzymes particularly of GPT it is possible to evaluate the degree of tissue damage and the general state of this group of patients.

Acid Phosphatase↗

Plasma catecholamines in severely injured patients: a prospective study on 45 patients with multiple injuries.

Plasma catecholamine levels were studied in 45 severely injured patients for 8 days after the trauma. Sixteen of the patients were classified as critically injured and 29 as seriously injured. The total plasma catecholamine values of the whole group immediately after the injury were almost twice as high as the eighth day reference values and remained significantly higher than these values for 6 hours after the trauma. On admission both the plasma adrenaline and noradrenaline levels were elevated. The plasma adrenaline levels on admission correlated with the blood volume replacement which was required within the first 6 hours. The plasma noradrenaline levels in the critically injured group were significantly higher throughout the observation period than in the seriously injured group. A corresponding difference was observed in the plasma adrenaline concentrations only during the first 12 hours. The results showed that strong stimulation of the sympathetic nervous system occurs in severely injured patients. Factors stimulating the sympathetic nervous system apparently included hypovolaemia, tissue hypoxia, acidosis and the pain produced by the trauma and therapeutic measures.

Adult↗

Diagnostic laparocentesis and peritoneal lavage in patients with multiple blunt injuries.

A series of 53 patients with multiple injuries and suspected abdominal trauma were analysed to determine the accuracy of diagnostic laparocentesis and peritoneal lavage. Thirty-one positive findings resulted in immediate laparotomies. Fifteen patients with an otherwise strong suspicion of intra-abdominal injury were treated conservatively with an uneventful clinical course. All three false-negative findings were in patients who has previously been subjected to laparotomy. These 3 patients were laparotomized on the basis of other diagnostic evidence. Four positive and two false-positive findings resulted in unnecessary operations. Trocar laparocentesis combined with peritoneal lavage is a quick and safe aid in the diagnosis of blunt abdominal trauma. Trauma to the urinary tract, however, should be diagnosed without laparocentesis. The test does not replace other diagnostic methods, but it may shorten the preoperative delay in complicated situations.

Abdominal Injuries↗