Reperfusion strategy after regional ischaemia: comparative study of reperfusion conditions and compositions.

We investigated the effects of pressure, temperature and additives on aortic root reperfusion success. Cardiopulmonary bypass and heart arrest were initiated in mongrel dogs and sudden uncontrolled normothermic (group 1), pressure controlled substrate enriched normothermic (group 2a), pressure controlled unmodified normothermic (group 2b) and pressure controlled unmodified tepid (group 3) reperfusion compared. In group 1, the first cardiac rhythm was ventricular fibrillation, but dogs in the other groups showed spontaneous sinus rhythm. Recovery times were significantly longer and cardiac output levels significantly decreased in group 1 compared with the other groups. Prolonged lactate production and oxygen uptake failure were observed in group 1 compared with the other groups; oxidative stress markers and microscopic studies confirmed significant tissue injury in group 1. All parameters were similar between groups 2a, 2b and 3, indicating that low reperfusion pressure in the first 2 min is the most effective component of reperfusion.

Reperfusion strategy after regional ischaemia: simulation of emergency revascularization and effects of integrated cardioplegia on myocardial resuscitation.

We induced ischaemia in the left anterior descending artery of 16 dogs while the heart was beating, followed by cardiopulmonary bypass (CPB), aortic cross clamping and blood cardioplegia. Half of the dogs received integrated blood cardioplegia and sudden uncontrolled reperfusion (group A) while the others received the same cardioplegia followed by pressure-controlled tepid initial reperfusion (group B). The effects on myocardial cell metabolism, oxidative stress and ultrastructure were recorded. The recovery period was significantly longer and cardiac output levels after CPB significantly lower in group A compared with group B. Group A showed a failure to uptake and utilize oxygen during the recovery period and significant lipid peroxidation. Marked tissue oedema was seen in group A but mitochondrial and organelle integrity was almost normal in both groups. We conclude that integrated cardioplegia could partially resuscitate the myocardium in this model, and pressure controlled reperfusion during the first 2 min is needed as an adjunct procedure.

[The effects of application of rectal naproxen on postoperative analgesia, sedation and morphine use in heart surgery operations]. / Kalp cerrahisinde rektal naproksenin postoperatif analjezi, sedasyon ve morfin kullanimi üzerine etkileri.

In this study, effects and side effects of application of rectal naproxen, combined with patient controlled intravenous morphine analgesia, were investigated in the elective coronary bypass operations for postoperative pain control, sedation and opioid use. Following the ethical committee approval and individual patient self consent, 40 patients, who underwent coronary artery bypass surgery were included in the study. A double blind study was performed by administering rectal naproxen to group N (n = 20) and placebo to group P (n = 20), at the end of the operation. Doses were repeated at the 12th hour postoperatively. Patient controlled intravenous morphine analgesia was performed to all patients for postoperative 24 hours. Postoperative pain and sedation levels were assessed, the side effects were noted. There was no difference between two groups with respect to their demographic features duration of surgery, extubation time and side effects (p > 0.05). With respect to group P, decrease in opioid use, better sedation and decrease in pain scores during both resting and coughing was seen in group N (p < 0.05). In conclusion, analgesia applied by addition of rectal naproxen to opioids achieved better pain management in selected patients after cardiac surgery.

Human jejunal glutathione reductase: purification and evaluation of the NADPH- and glutathione-induced changes in redox state.

Human proximal jejunal glutathione reductase (EC 1.6.4.2) was purified to homogeneity by affinity chromatography on 2', 5'-ADP-Sepharose 4B. In most of its molecular and kinetic properties, the enzyme resembled glutathione reductase from other sources: The subunit mass was 56 kDa; the isoelectric point and pH optimum were 6.75 and 7.25, respectively; Michaelis constants, determined at pH 7.4, 37 degrees C, fell within the range of previously reported values [Km(NADPH) = 20 microM, Km(GSSG) = 80 microM]. The response of the enzyme to reducing conditions, on the other hand, had unique features: Preincubation with 1 mM NADPH resulted in 90% loss of activity which could be partially reversed by 2 mM GSSG, but not GSH. (Treatment with GSSG regenerated 68% of the original activity.) Reduction by GSH also caused inactivation which potentially amounted to greater than 80%. This inactivation could not be reversed by GSSG. The protective effect of GSSG against inactivation by GSH was studied. Except where [GSSG] far exceeded [GSH], the presence of GSSG in the preincubation medium decreased the extent of inhibition without affecting the rate constant for approach to equilibrium activity. At [GSSG] greater than [GSH] a decrease in the rate constant for inactivation was also observed. The results were interpreted in terms of a three-step mechanism: (1) preequilibrium reduction of Eox to Ered; (2) rate-limiting change in conformation from Ered to E'red, and (3) irreversible conversion to catalytically inferior products.

The mandibular joint: internal rearrangement.

Mandibular joint disorders have always aroused a great deal of controversy as to their nature, aetiology and treatment. Over the last decade, with the advent of sophisticated techniques for functional investigation, a measure of agreement has been reached among researchers and clinicians dealing with the problem. However there seems to have been an unfortunate spin-off in that there may be a tendency to overinvestigate, overcomplicate and overtreat the situation. Perhaps it is possible to regard the common disorders (pain-dysfunction, derangement, osteoarthrosis) as a single pathological entity, a traumatic condition, with associated degenerative factors. Arguments and evidence supporting this view are presented. It is suggested that there may be a common factor that explains the many and varied management regimes, and that is internal rearrangement of the mandibular joint.

Degenerative disease of the temporomandibular joint in young persons.

The majority of cases of temporomandibular joint pain that are referred to the consultant dental surgeon are diagnosed as pain-dysfunction syndrome, a term first suggested by Schwartz (1959) and now probably the most widely accepted. Another relatively common problem is degenerative disease or osteoarthrosis, and although this generally affects an older age group than pain-dysfunction syndrome, its occurance in the younger patient is by no means a rarity and is further evidence that the two conditions are expressions of the same problem, that is repetitive overloading of the joint. It is proposed that this should be termed mandibular stress syndrome.

Carcinoma of the dorsum of the tongue: a rarity or misdiagnosis.

Benign lesions occurring on the dorsum of the tongue have at times been diagnosed as carcinoma. A retrospective investigation into the problem is described and the clinical and histological difficulties that arise in the diagnosis of these lesions are discussed. It is concluded that the occurrence of primary carcinoma on the dorsum of the tongue is a rare entity. It may be erroneously diagnosed in cases of median rhomboid glossitis, granular cell myoblastoma and any other lesion associated with pseudoepitheliomatous hyperplasia. These conditions should always be considered when examining lesions in this location. Histological diagnosis, although difficult, is greatly facilitated by good biopsy technique but, above all, good liaison between surgeon, radiotherapist and pathologist is essential if these mistakes in diagnosis are to be avoided.

Rheumatoid arthritis of the temporomandibular joint.

An investigation into the involvement of the temporomandibular joint in rheumatoid arthritis is described. There is evidence to show that is is affected in two-thirds of all cases of the disease, and this figure agrees broadly with other recent studies. The clinical and radiographic presentation is discussed and its relationship to degenerative disease (osteoarthosis) of the temporomandibular joint is shown. The clinical course of this manifestation of rheumatoid arthritis is proposed and a line of treatment is suggested.