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Biomedical subjects

T Tervo

Publications and source records attributed to T Tervo.

At least 127 records · Page 7Linked to original sources
PubMed1982

Ocular neuropeptides.

This article deals with the neuropeptides found in the eye and their actions. Substance P (SP) and VIP have been found in the anterior chamber of the eye. Here SP is localized in the sensory nerves of the sclera, cornea, iris, ciliary body and ciliary processes. It is supposed to be a sensory transmitter but can also be liberated by peripheral nerve endings as a response to various trauma. When this happens in the eye, for instance, after irritation of the Vth cranial nerve, SP causes an intense and long lasting miosis and may have some further actions as well. VIP has been demonstrated in nerves (probably cholinergic) of the posterior choroid and ciliary body. It is a potent vasodilator and may regulate choroideal blood flow. The retina is especially rich in different neuropeptides. SP, VIP, neurotensin, enkephalin, somatostatin, glucagon and gonadotropin-releasing hormone have all been demonstrated in the inner plexiform layer of the retina of various animal species. Specific information about the physiological role of retinal neuropeptides is still scarce but research is in progress. Considering the clinical significance of the new information about ocular neuropeptides, SP seems to be the most important substance. Recently a synthetic SP antagonist was reported to block the inflammatory response in the rabbit eye, which suggests a clinical use for this type of compounds.

Animals↗
PubMed1982

Substance P-immunoreactive nerves in the human cornea and iris.

Human corneas and irides obtained from corneal surgery or sector iridectomies were processed according to the indirect immunofluorescence technique for the demonstration of substance P (SP) immunofluorescence by means of a monoclonal SP antibody. SP immunofluorescence was observed in varicose fibers of the corneal epithelium and nerve trunks in the corneal stroma. SP-immunoreactive nerve fibers in the iris were detected mainly in the pupillary margin in both dilator and sphincter areas.

Cornea↗
PubMed1981

Immunoreactivity for substance P in the Gasserian ganglion, ophthalmic nerve and anterior segment of the rabbit eye.

The distribution of substance P (SP) immunofluorescence was investigated in the Gasserian ganglion, ophthalmic nerve and in the anterior segment of the rabbit eye. About one third of the nerve cell bodies in the Gasserian ganglion exhibited SP immunofluorescence, which was also observed in some nerve fibres of the ophthalmic nerve. In the cornea, some SP-positive nerves were found in the stroma and few of them were also observed in the epithelium. The iris contained numerous nerve fibres with SP immunofluorescence. In the sphincter area such fibres were circular, while the orientation of the SP fibres was radial in the dilator muscle. Both in the iris and in the ciliar body, the largest vessels are surrounded by nerves exhibiting SP immunofluorescence. A few nerve fibres also appeared in the stroma of the ciliary processes.

Animals↗
PubMed1981

Ruthenium red staining of blood-bubble interface in acute decompression sickness in rat.

The ultrastructure of the blood-bubble interface has been studied in rats decompressed experimentally. Subsequent to staining with ruthenium red there was detected by electron microscopy a continuous envelope like layer about 20 nm thick at the bubble-facing surface of the interface. The envelope like structure was visualized also by concanavalin A-ferritin, a glycosyl- and mannosyl residue-recognizing lectin coupled with an electron-dense probe, but the structure was not at all seen by the use of the conventional stains used in electron microscopy, uranyl acetate and lead citrate. No electron-dense layer was discernible on the application of only osmium tetroxide without further staining. The results indicate that material stainable by ruthenium red, and binding concanavalin A (probably a glycoprotein), is concentrated at the blood-bubble interface upon decompression. It is suggested that it plays a role in stabilization of the bubble and in the hematological alterations that are frequently observable in decompression sickness.

Animals↗
PubMed1981

Early pulmotoxic effects of oxygen on the rat alveolar type II epithelial cell.

Adult male rats were exposed to pure oxygen at atmospheric pressure for 12 and 24 h in order to examine the early pulmotoxic signs in alveolar type II epithelial cells. Lung specimens were processed for both light and electron microscopical examination. All changes were obvious, but less pronounced than in previous reports, and appeared only after 24 h of exposure. The type II cells showed dilation of the Golgi apparatus and changes in mitochondria. This experiment indicates that exposure to pure oxygen at atmospheric pressure for as short as 24 h, but not for 12 h, is adequate to induce subtle pulmotoxic changes in alveolar type II epithelial cells.

Animals↗
PubMed1980

Intertrochanteric osteotomy without displacement fixed with an AO blade plate in the treatment of osteoarthritis of the hip.

The results in 90 patients with osteoarthritis of the hip, treated by intertrochanteric osteotomy fixed with an AO blade plate, were analyzed 1-5 years after operation. The operation was performed without displacement of osteotomy, the aim being to produce bony union in the original position using the AO compression technique. With one exception, all osteotomies fused, but dislocation exceeding 0.5 cm resulted in four cases. The operation brought about relief from night pain in 88% of the patients and relief from weight-bearing pain in 41%. Abduction and adduction were the only movements that improved. The results were the same 1-2 and 4-5 years after the operation. Complications were rare, and the use of the compression method enabled the patients to get on by themselves the day after operation. This method is particularly well suited for young patients.

Adult↗
PubMed1980

Barrier properties of rat subcutaneous nerves to sodium fluorescein and fluorescein-labelled dextrans of various molecular weights.

Na-fluorescein and fluorescein-labelled dextrans of various molecular weights were injected i.v. to localize the blood-peripheral nerve barrier in rat subcutaneous nerves. Samples were taken from the subcutaneous fascia and skin 5 and 30 min after the injection. In the specimens taken 5 min after the injection, the fluorescence had diffused into the dermal tissue. The intraneural, epineural, and perineural blood vessels contained fluorescent material. The entry of fluorescent material from subcutaneous tissue into the nerves was prevented by the perineurium. The distribution of the tracer was uniform throughout molecular weight range tested (376-150,000). Both dermal and intravascular fluorescence were clearly weaker in the specimens taken 30 min following the injection, particularly if a tracer with a MW lower than 40,000 was used. After bilateral ligature of the renal blood vessels the fluorescence remained more intense, even after 30 min, and it was independent of the molecular diameter of the tracer injected. The location of the fluorescence was not changed by the operation and the intraneural capillaries remained intact. The results indicate that the intraneural capillaries are impermeable to the fluorescent tracers tested. In contrast, all the marker substances passed freely through cutaneous capillaries. The perineurium prevented the diffusion of fluorescent tracers from the surrounding tissue into the nerve.

Animals↗
PubMed1980

Permeability changes in cerebral, iridic, and retinal vessels during experimental decompression sickness in the rat.

An investigation has been made of the effect of acute decompression sickness upon the permeability of the cerebral, iridic, and retinal vessels of the rat, with sodium-fluorescein as intravenous tracer. No permeability changes were observable during the first 15 min subsequent to decompression, following exposure to 5.1 bar for 50 min. Focal leaky areas were found in the brain parenchyma after exposures to 5.1 bar for 120 min. Although sodium-fluorescein partially permeated the pial vessels in controls, the treatment in a hyperbaric chamber seems to increase the diffusion of the tracer from the pia into the cerebral cortex. Nevertheless, both the iridic and retinal vessels remained "tight." The factors which increase the permeability of microvasculature in brain and possible reasons for the negative results obtained with the iris and retina in decompression sickness are discussed.

Air Pressure↗
PubMed1979

Lumbosacral fusion by standing h-graft technique.

Fusion of the lumbosacral spine was carried out on 44 patients. A modification of the standing H-graft technique was used in 41 of the patients. The operative diagnosis was degeneration of the lumbosacral spine in nearly two-thirds of the cases and spondylolisthesis in about one-third. Operations for low back or sciatic pain had previously been performed on 17 patients. The duration of postoperative bed rest ranged from one to six weeks; a lumbosacral corset was used at least for six weeks postoperatively. The average stay in hospital was 52 days. Complications occurred in five cases. The operative results of 40 patients were evaluated on the basis of a follow-up examination performed on average 3.6 years after operation. Nearly half the patients with radiologically successful fusions had a good subjective improvement and about one-fourth had returned to their previous or corresponding occupations. The operative result was at least fair in about half the patients, assessed by a measure of the patients' subjective improvement and working capacity. In the non-fusion group (six cases) the operative results were exclusively poor. Age over 40 years, long-standing preoperative disability and previous back operations proved prognostic factors for poor results. Assessed from functional radiographs, 63% of two-segment fusions and 95% of one-segment fusions were successful. The operative technique appeared simple and suitable for fusions of one spinal segment, but the value of the lumbosacral fusion in the treatment of low back pain seemed doubtful because of the great proportion of poor clinical results even following technically successful fusions.

Adult↗
PubMed1979

The Putti-Platt operation in the treatment of recurrent anterior dislocation of the glenohumeral joint.

In this prospective follow-up investigation the results in 65 patients treated by the Putti-Platt operation for recurrent dislocation of the glenohumeral joint were analysed. The data was collected at follow-up examinations performed one year after operation and from the replies to a questionnaire distributed to the patients 2--6 years postoperatively. Analysis of the data showed that 95% of the patients considered the condition of the shoulder joint as good or at least as better than preoperatively. During the period of follow-up 23 redislocations occurred and 25% of the patients experienced postoperative pain in the operated shoulder joint. Postoperative limitation of movement of the joint was in general slight and did not hinder normal activities. Owing to the high frequency of redislocation the Putti-Platt operation is not recommended in any event for active sportsmen, since redislocation occurred to a statistically significant extent more often in this group than in other patients.

Adolescent↗
PubMed1978

Basal osteotomy of the first metatarsal bone in hallux valgus: experiences with the use of AO plate.

In young patients with hallux valgus, osteotomy with excision of the exostosis is frequently indicated. The basal, laterally based wedge osteotomy, is relatively seldom used. However this operation may produce a considerable reduction of the metatarsus primus varus. We modified the method by adding a small AO plate to ensure stabilization. The series consisted of 36 patients, in whom 52 feet were operated on. Pain was the most frequent indication for seeking treatment. A followup was performed an average of 1.5 years postoperatively. The subjective results were good in 41 cases, fair in nine, and poor in one. Objectively the results were good in 42 cases and fair in nine. The mean period of work was seven weeks. The metatarsus varus angle was reduced from 14.8 degrees to 9.3 degrees and the hallux valgus angle from 33.2 degrees to 17.7 degrees. The distance between the first and second metatarsal bones was reduced from 13. 7 mm to 10.2 mm. A good functional and cosmetic result was achieved in most of the cases.

Adult↗
PubMed1978

Pre- and postnatal development of catecholamine-containing and cholinesterase-positive nerves of the rat cornea and iris.

Glyoxylic acid-induced fluorescence technique and a copper thiocholine method were used to investigate the ontogenesis of the catecholamine-containing and cholinesterase-positive nerves of the rat iris and cornea. First fluorescent nerve fibres appeared in the iris on the 18th gestation day and in the cornea on the 19th day. A rapid increase in the density of the adrenergic nerve fibres of the iris continued to the age of three weeks, while the number of such fibres were small in the cornea. Acetylcholinesterase-positive fibres appeared both in the cornea and in the iris on the 19th gestation day. Their density increased more rapidly in the iris, especially in the sphincter muscle, than in the cornea. Non-specific cholinesterase activity was localized in the Schwann cells and the reaction was more intense during development than in the nerves of the cornea of adult rats.

Acetylcholinesterase↗
PubMed1978

Ultrastructure of the corneal nerves after fixation with potassium permanganate.

The innervation of the rat cornea was investigated electron microscopically after KMnO4 fixation. Myelinated nerve fibres were observed only in the limbal margin of the cornea, whereas the axons located in the stroma of the avascular cornea were surrounded by the Schwann cell cytoplasm. Axon profiles with small (300-500 A) granular vesicles and another type with agranular vesicles were seen among the non-vesiculated fibres in all parts of the cornea. After superior cervical ganglionectomy it was not possible to find any axons with small granular vesicles. On the other hand, sone degenerating axon profiles were observed in the stromal nerve trunks after ganglionectomy. In the epithelium-naked axons with an occasional mitochondrion and a few agranular vesicles penetrated between the epithelial cells. Moreover, axons filled with several mitochondria were rarely observed in the epithelium, but these were difficult to differentiate from the surrounding epithelial cells. The role of the different nerve types observed in the cornea is discussed. The results suggest that the rat cornea has a dual vegetative innervation.

Animals↗
PubMed1978

Catecholamine-containing and acetylcholinesterase-positive nerve fibres in the rabbit conjunctiva.

The innervation of the rabbit conjunctiva was investigated histochemically. Nerves containing acetylcholinesterase (AChE) were demonstrated using a copper thiocholine technique. Sympathetic nerve fibres were demonstrated using either the formaldehyde-induced fluorescence (FIF) or glyoxylic acid induced fluorescence (GIF) method. In addition, GIF and AChE-reactions were performed consecutively for the demonstration of fluorescent and AChE-positive nerves in the same specimen. The number of AChE-positive nerve fibres exceeded that of fluorescent fibres. Both fibre types were more numerous in the stroma of the limbal and tarsal conjunctiva than in the fornix. In the epithelium, only a few AChE-positive nerves were observed. These are assumed to be sensory. Most nerves seemed to contain both catecholamine-containing and AChE-positive fibres. However, nerves fibres containing only AChE-activity were also found. The blood vessels of the conjunctiva were innervated by both fluorescent and AChE-positive nerves, the distribution and number of which differed slightly.

Acetylcholinesterase↗