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Biomedical subjects

F Németh

Publications and source records attributed to F Németh.

At least 19 recordsLinked to original sources
PubMed1995

The fetlock tunnel syndrome: a macroscopic and microscopic study.

Chronic changes of several structures in around the fetlock tunnel can be a cause of the so-called fetlock tunnel syndrome (FTS) in the horse. Forty-nine annular ligaments (AL) from dead horses without a known history or clinical evidence of lameness and/or digital tendon sheath problems in these legs and 30 AL biopsies from horses suffering from FTS were studied macroscopically and microscopically. Macroscopically, the normal AL had a shiny white appearance, whereas the affected AL were often thicker and less white. Microscopically, the normal AL were about +/- 1 mm thick and were composed of undulating, parallel bundles of collagen. Small blood vessels with a diameter of 0.03-0.12 mm were found. The affected AL showed an increased thickness of collagen bundles, a changed direction of longitudinal axis of collagen bundles, and irregularly dispersed fibroblast nuclei. The number of blood vessels had increased, the external diameter of arteriolae could be up to 0.3 mm and arterial wall changes were observed. Possible relationships between the histological findings and the aetiology of the FTS are discussed.

Animals↗
PubMed1994

Effects of storage time and temperature on ionized calcium concentration in equine blood, plasma, and serum.

Stability of ionized calcium (Ca2+) concentrations and pH values in equine venous samples (n = 12 in each group) stored at 4 C for 3, 9, 24, and 48 hours (blood, plasma, and serum) or for 240 hours (plasma and serum), and at -20 C for 240 hours (plasma and serum), was studied. Storage of equine blood, plasma, and serum samples at 4 C for up to 48 hours and of serum samples at 4 C for up to 240 hours, despite appreciable pH changes, was associated with < 1.5% change in blood, plasma, and serum Ca2+ concentrations. Therefore, Ca2+ concentration in equine blood, plasma, and serum samples stored up to 48 hours and in serum samples stored up to 240 hours at 4 C is of diagnostic use.

Animals↗
PubMed1994

Effects of storage time and temperature on ionized calcium concentration in bovine and ovine blood, plasma, and serum.

Stability of ionized calcium (Ca2+) concentration and pH values in bovine and ovine venous samples (n = 12 in each group) stored at 4 C for 3, 9, 24, and 48 hours (blood, plasma, and serum) or for 240 hours (plasma and serum), and at -20 C for 240 hours (plasma and serum), was studied. Storage of bovine and ovine blood, plasma, and serum samples at 4 C for up to 48 hours and of ovine serum samples at 4 C for up to 240 hours, despite appreciable pH changes, was associated with < 2.0% change in blood, plasma, and serum Ca2+ concentrations. Therefore, Ca2+ concentration in bovine and ovine venous blood, plasma, and serum samples stored up to 48 hours, and in ovine serum samples stored up to 240 hours, at 4 C is of diagnostic use.

Animals↗
PubMed1994

Accessory carpal bone fractures in the horse.

The clinical signs, the radiographic appearance, and the treatment of two cases of fracture of the accessory carpal bone are described. The fractures were in the vertical plane. Surgical intervention consisted out of fixation of the fracture with two lag screws. Follow-up information revealed that one horse became sound and returned to complete athletic activity whereas the other horse remained lame. A brief literature review is given and the surgical treatment and the complications are discussed.

Animals↗
PubMed1994

Laboratory and clinical evaluation of a chromogenic endotoxin assay for horses with acute intestinal disorders.

In this study the laboratory and clinical performance of a chromogenic endotoxin assay for equine plasma was evaluated. The assay was sensitive (detection limit 3 ng LPS/L plasma), reproducible (within and between-assay CV at 50 ng LPS/L E. coli O111:B4 LPS standard addition was 5% and 7.5%, respectively), and not substantially affected by enhancement or inhibition phenomena (recovery of an in vitro spike was 75-125% in 80% of the samples). LPS added to whole blood was rapidly inactivated upon incubation at 37 degrees C but not at 0 degrees C. A recently developed blood collection tube for LPS testing was found suitable, i.e. LPS-free and providing non-contaminated samples. In 48 horses suffering from acute abdominal diseases requiring surgical treatment, LPS levels were significantly higher in platelet-rich plasma (PRP) than in platelet-poor plasma (PPP), and the proportional difference was related to the PRP platelet count (r = 0.52, p < 0.001, mean difference 48%, range 8-77%). LPS levels were also significantly higher in horses that died or were euthanized than in surviving horses (mean 16.5 and 7.1 ng/L PRP, respectively, p < 0.05). We conclude that LPS can be measured in equine plasma with picogram sensitivity and recommend the use of PRP instead of PPP for clinical LPS testing. For clinical use a decision limit for endotoxaemia of 5 ng LPS/L PRP appeared to be inadequate. Analysis at a higher cut-off level for endotoxaemia and the evaluation of clinical, pathological, and laboratory parameters would be more meaningful.

Acute Disease↗
PubMed1994

Nerve supply of the proximal sesamoid bone in the horse.

In chronical proximal sesamoid bone lameness it is difficult to localise the exact site of pain. A specific diagnostic analgesia is not available because of a deficiency of detailed information about the nerve supply to the proximal sesamoid bones and surrounding area. A macroscopic study of the nerve distribution to the proximal sesamoid bones of 10 foals and 5 adult horses revealed that these bones are innervated by two branches, in this study called the medial and lateral sesamoidean nerve, respectively, originating from the medial and lateral palmar nerve. Histology of the left forelimbs of two fetuses and one foal confirmed the macroscopic findings. Additionally, histology of ten proximal sesamoid bones of adult horses showed that myelinated nerve fibres are present in the nutrient foramina and in the trabecular bone, accompanying the larger arteries. This study provides possibilities for future diagnostics of proximal sesamoid bone lameness by specific local perineural analgesia.

Animals↗
PubMed1991

Bovine laminitis: clinical aspects, pathology and pathogenesis with reference to acute equine laminitis.

This review deals with the features of clinical and subclinical laminitis in cattle. Prominent clinical signs of acute laminitis are a tender gait and arched back. The sole horn reveals red and yellowish discolourations within five days. In subacute and chronic cases clinical signs are less severe. In chronic laminitis the shape of the claws is altered. Laminitis is frequently followed by sole ulceration and white zone lesions. Blood tests showed no significant changes for laminitic animals. Arteriographic studies of claws affected by laminitis indicated that blood vessels had narrowed lumens. Gross pathology revealed congestion of the corium and rotation of the distal phalanx. Histopathologic studies indicate that laminitis is associated with changes of the vasculature. Peripartum management and nutrition are important factors in its aetiology. It is hypothesised that laminitis is evoked by disturbed digital circulation. In the pathogenesis of acute laminitis three factors are considered important: the occurrence of thrombosis, haemodynamic aspects of the corium, and endotoxins which trigger these pathologic events.

Animals↗
PubMed1991

The use of the walking cast to repair fractures in horses and ponies.

The walking cast was used to repair 46 fractures of long bones (distal radius and tibia, metacarpus and metatarsus) and 10 fractures of first phalanx of 35 horses and 21 ponies. The walking cast proved to be highly effective. Even heavily comminuted and 'hopeless' fractures, which could not be treated with osteosynthesis, were treated successfully, because the weight of the animal, a common failure factor in large animal orthopaedics, was relieved from the injured leg. Immediate full weight bearing was possible post operatively. In five cases the walking cast was used in combination with osteosynthesis. Infection was the main complication that caused the walking cast to fail. Osteomyelitis may also be treated with a walking cast. Because of its success rate of 57 per cent, which is impressive, considering the type of fractures treated, we recommend the walking cast for international accreditation.

Animals↗
PubMed1990

[Chronic disease of the two sesamoid bones of the lower foot of the horse].

The aetiology and pathogenesis of navicular bone disease and sesamoidosis are discussed on the basis of findings reported in the literature and research. A marked similarity is found to be present between the clinical presentation, aetiology and pathogenesis of these two diseases. In addition, the intra and juxta-articular signs of degeneration as seen in these diseases are similar to those seen in various forms of arthrosis. Circulatory disturbances resulting from partial or complete arterial occlusion, caused by arteriosclerosis, are likely to play an important role in the cause of degeneration of various anatomical structures occurring in navicular bone disease and sesamoidosis. In contrast, it is unlikely that overloading is a major factor in the aetiology of navicular bone disease and sesamoidosis, although it may be of importance in its pathogenesis. For a full understanding of the cause of arteriosclerosis, far more fundamental research is required.

Animals↗
PubMed1989

Development of the navicular bone in foetal and young horses, including the arterial supply.

A macroscopic, arteriographic and histological study of the development and the arterial anatomy of the navicular bone of 33 foetuses and 55 young horses is described. After 125 days of gestation the blood supply consists of two routes: one situated in the superficial layer of the fibrocartilage and the other similar to the blood supply of the navicular bone of the normal mature horse. After 270 days gestation, the blood vessels in the fibrocartilage gradually regressed and retracted until they have disappeared at six months after birth. At two months after birth the first macroscopic thinning of the fibrocartilage was noticed. From seven months to one year about 45 per cent of the navicular bones showed a slight thinning of the fibrocartilage. A positive correlation was found between radiographic abnormalities (ie enlargement of the nutrient foramina) and the frequency of thinning of the fibrocartilage. Radiographic abnormalities were first recognised 14 days after birth, whereas the arteriogram showed the first changes such as fewer or no arteries entering distally at the distal extremities at 10 weeks after birth. At four weeks after birth the first arterial wall changes were found, ie intimal thickening with or without splitting of the internal elastic membrane. From that age onward, the number of navicular bones with arterial wall changes gradually increased. Starting at five months after birth only 6 to 20 per cent of the arteries in the navicular bones without radiographic abnormalities showed arterial wall changes. However, the navicular bones with radiographic abnormalities showed arterial wall changes in 25 to 80 per cent of the arteries.

Angiography↗
PubMed1989

The arterial supply of the navicular bone in adult horses with navicular disease.

A macroscopical, arteriographical and histological study was made of the arterial supply of the navicular bones of horses with clinical and/or radiographic signs of navicular disease. Based on the clinical and radiological findings the navicular bones of 40 Warmblood horses are divided into four different groups. In the pattern of the arteriogram obvious changes are noticed: an imbalance and a distal to proximal shift between the distal and proximal arterial supply occur, indicating a reduction of the distal blood supply with a compensatory reaction of the proximal, medial and lateral supply. The changes in the pattern of the arteriogram are histologically defined by arterio(lo) sclerosis and newly formed arteries. The presence of radiologically visible nutrient foramina is associated with a changed pattern in the arteriogram, increased bone remodelling and fibrosis. Ischaemia and increased pressure (hypertension and/or increased intra-articular pressure) are considered to be responsible for changes in form and number of radiologically visible nutrient foramina.

Angiography↗
PubMed1989

The effect of artificial occlusion of the Ramus navicularis and its branching arteries on the navicular bone in horses: an experimental study.

The clinical, radiographic, arteriographic, scintigraphic and histological effects of experimental occlusion of the Ramus navicularis (R. Navicularis) and its branching arteries are evaluated. Occlusion of the R. navicularis and its branching arteries creates changes, arteriographically and histologically, which resemble those of navicular disease. The increased bone remodelling, the shift in arterial pattern, the formation of collaterals and the increased connective tissue in the synovial membrane and nutrient foramina, as a reaction to the reduction of the distal arterial supply of the navicular bone, are also pathological features in the navicular bones of horses with navicular disease. The results of the present study support the theory that a reduced distal arterial supply of the navicular bone is important in the pathogenesis of navicular disease.

Angiography↗
PubMed1988

[Pathogenesis and drug therapy of acute laminitis in horses: a literature review].

Impairment of the microcirculation in the distal part of the foot is an important factor in the aetiology of equine laminitis. To prevent the development of chronic laminitis and the resulting complications, two new therapeutical principles were tested in the treatment of acute laminitis. Thrombosis which frequently occurs in the corium of the foot, could be controlled by administration of anticoagulants such as heparin. Alpha-receptor blocking agents such as phenoxybenzamine were used, to improve the peripheral blood flow. The use of these drugs and that of anti-inflammatory agents during the onset of acute laminitis is discussed in this review paper.

Animals↗
PubMed1988

Results of operative treatment of equine colic with special reference to surgery of the ileum.

This retrospective study presents the results of surgical treatment of obstructive colic in horses operated in the last decade (1976-1985). The overall short-term recovery rate (i.e. discharged from hospital) was 51% of cases presented for surgery, and 68% of cases which were considered to be amenable to surgical therapy. For long-term results (6 months-8 years follow up) these percentages must be reduced by about 15% due to mortality after discharge. Special attention has been given to surgery of the ileum, which is often involved in strangulation or obturation, and accounts for about 26% of gastrointestinal surgical disorders. The long-term recovery rate of ileal surgery was 54.3%, but ileocaecal intussusception and jejunocaecostomy with resection have a much poorer prognosis. The results of this study indicate that resection of the ileum should be avoided unless necrosis is present or threatening. The alternative is creation of a shunt between (distal) jejunum and caecum, thus bypassing the ileum and ileocaecal junction and preserving the original anatomical relationships.

Animals↗
PubMed1988

Detection of neurectomy by testing skin sensitivity using an electrical stimulus.

A method for detection of neurectomy by electrical stimulation of the skin, distal to the neurectomy site, was tested for accuracy and feasibility. An electrical stimulation device was designed and tested to find the minimum peak voltage that would elicit a response in normal horses. Twenty seven horses were then tested at regular intervals following neurectomy and their responses recorded. Immediately following neurectomy there was an area of insensitivity with sharply defined borders extending in an arc from the back of the pastern down towards the bulbs of the heels. In the months following neurectomy, re-innervation occurred and this area gradually reduced in size, although it was still possible to detect insensitive areas 14 months after neurectomy in all horses tested. The method proved to be safe, accurate and ethically acceptable.

Animals↗
PubMed1985

Lag screw fixation of sagittal navicular bone fractures in five horses.

A sagittal fracture of the navicular bone in five horses was treated by means of lag screw. Intra-operative radiographic monitoring and a specially developed guide apparatus was necessary to implant the screw precisely along the transverse axis of the navicular bone. Internal fixation resulted in progressive radiographic narrowing of the fracture zone. In all five patients the fracture healed (bony union) without superfluous callus formation.

Animals↗