Biomedical subjects
Publications and source records attributed to M W Jones.
Mycobacterium marinum infections of the hand are very rare in the United Kingdom and we found only one case of involvement of deep structures (tenosynovitis) in the British literature. We report a case of septic arthritis due to the organism.
The early treatment of patients with bladder cancer reduces mortality. By arranging a pre-clinic intravenous urogram we reduced the time from receipt of the General Practitioner's referral letter to making a diagnosis from 85 to 67 days and saved on clinic time and resources. A further reduction to 52 days was made by not using any out-patient time at all. Significant saving of time and resources is possible without any disadvantage to the patient.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
A retrospective review of patients with a preoperative diagnosis of appendicitis or thought to have appendicitis at laparotomy showed a discrepancy between the surgeons' opinion of the macroscopic appearance of the appendix and the pathologist's opinion (which was assumed to be the most accurate) in 14.5% of cases. All cases were false positive diagnoses. Using the surgeons' descriptions of the appendix at appendicectomy, a sub-group can be identified with an 80% error rate. In this group, the terms used to describe the appendix were 'mild, early, slight or moderate inflammation'. This error rate is often ignored in studies on appendicitis. We recommend that only the terms 'normal' 'inflamed' or 'gangrenous or perforated' should be used to describe the appendix. If there is any doubt, it should be classed as normal. These recommendations will improve diagnostic accuracy at operation.
The locations of spinothalamic neurons and the funicular trajectories of their axons were studied in cats by retrograde transport of horseradish peroxidase (HRP). Five animals were used as controls to determine the cervical and lumbar laminar distributions of neurons contributing to the spinothalamic tract. An additional eight animals were used to determine the funicular trajectories of the spinothalamic axons of lumbar neurons by utilizing a series of thoracic spinal cord lesions in conjunction with retrograde transport of HRP from the sensory thalamus. Three of these animals underwent midthoracic ventral quadrant lesions, four animals underwent midthoracic dorsolateral funiculus lesions, and one animal underwent total spinal cord transection sparing the dorsal columns. The locations of the cells containing the HRP reaction product were then determined after a 3- to 5-day survival time, and the patterns of labeled cell locations of the lesion groups were compared to the control group patterns. In the lesioned animals, the cervical spinothalamic cell locations were used as a control to confirm the uniformity of the injection sites, transport and tissue processing. The major finding of this study is that there exist two distinct components of the spinothalamic tract. The dorsolateral spinothalamic tract (DSTT) is made up of axons originating in contralateral spinal cord lamina I and has negligible contribution from the deeper spinal cord laminae. The axons of lamina I cells cross segmentally and ascend exclusively in the dorsolateral funiculus (DLF). The DSTT comprises approximately 25% of the total spinothalamic input from the lumbar enlargement. The ventral spinothalamic tract (VSTT) is made up of axons originating in spinal cord laminae IV-V and VII-X. Very few lamina I cells contribute axons to the VSTT. This crossed pathway ascends in the ventrolateral and ventromedial portions of the spinal cord. No cells contributing to the spinothalamic tract were identified in spinal cord segments caudal to a dorsal column sparing lesion, indicating that there are no spinothalamic tract axons traveling in the dorsal columns. These results expand the classical concept of information processing by the spinothalamic tract. The DSTT is made up of lamina I cell axons. All lamina I spinothalamic cells respond exclusively to noxious peripheral stimuli. Hence the DSTT is a major nociceptive-specific ascending spinal pathway, yet lies outside the confines normally assigned to the spinothalamic tract.(ABSTRACT TRUNCATED AT 400 WORDS)
Dopaminergic terminals have been identified in the primary visual cortex with three techniques; immunocytochemistry with an anti-dopamine antiserum, retrograde axonal transport techniques using unconjugated wheat germ agglutinin and HPLC determination of catecholamines and metabolites in microdissected sub-regions of occipital cortex in the rat. The results demonstrate a specific dopaminergic innervation, arising from the ventral tegmental area, which is found mainly in laminae VI and V, but with minor innervation also in lamina I. Dopaminergic innervation to adjacent cortical regions is also described. Neurochemical data from post-mortem human material suggests that a similar innervation exists in man. An analysis of the distribution of dopaminergic fibres in relation to the known connections and possible functions of the deep laminae of visual cortex suggests that dopaminergic axons may participate in the corticofugal control of visual afferent pathways.
Dopamine (DA) utilisation has been assessed in the medial bank of the prefrontal cortex (FCx) and the agranular insular cortex (AgCx) of the rat in response to unilateral manipulations of the thalamic mediodorsal nucleus (MD). The ratios of 3,4-dihydroxyphenylacetic acid (DOPAC):DA and 4-hydroxy-3-methoxyphenylacetic acid (homovanillic acid, HVA):DA are used as indices of DA utilisation and were shown to increase in the ipsilateral FCx following electrical stimulation of lateral MD. A similar response was observed 1 hr after an infusion of the excitotoxin sodium ibotenate into lateral MD, although in this case the increase in DA utilisation in FCx was bilateral. Longer periods of recovery after ibotenate treatment (2 day and 1 week) produced DA utilisation ratios that had returned to near control values and by 1 week a significant decrease was detected in HVA:DA of the contralateral FCx. All treatments had little effect on DA utilisation in AgCx, although there was a tendency towards enhanced ratios after electrical stimulation and short-term ibotenate injection. These findings suggest that stimulation of MD neurones may tend to activate the DA system in their convergent terminal regions of cortex. It is argued that these influences result from interactions at the level of the DA terminal rather than at the cell bodies of mesocortical DA neurones.
Thirty-nine patients with neuralgic amyotrophy were reviewed. In addition to the clinical findings reported in the neurological literature, we commonly found pain throughout the upper limb, and diffuse involvement of the brachial plexus. Five patients had spinal accessory nerve lesions and five had glenohumeral instability. Sixty-four per cent of the patients had had an orthopaedic consultation during their acute illness. It is therefore important that orthopaedic surgeons are aware of this clinical syndrome and its management. The prognosis is excellent with non-invasive treatment.
Explore the source record for details and available documents.
Dopamine (DA) utilisation (expressed as homovanillic acid:DA) was compared in the medial prefrontal cortex (FCx), the agranular insular cortex (AgCx), the caudate-putamen (medial, CPM and lateral, CPL divisions) and the nucleus accumbens (NAc). DA utilisation in these regions decreased in the order AgCx greater than FCx greater than CPM, CPL, NAc, whilst the concentration of DA decreased in the reverse order. Thus, although fewer DA neurones appear to innervate AgCx compared with FCx, the rate of DA utilisation/release is much greater in AgCx. It is suggested that this apparently more marked activity in DA neurones innervating AgCx may reflect a relative lack of autoreceptor control.
We have investigated the role of the parafascicular-intralaminar thalamus in the regulation of dopaminergic function in the caudate-putamen by making unilateral injections of the excitotoxin, ibotenic acid, into the thalamus of the halothane-anaesthetized rat. Dopamine utilization was measured at 4 h, 18 h, and 7 days after operation in microdissected tissue from caudate-putamen, substantia nigra, and nucleus accumbens. High performance liquid chromatography with electrochemical detection was used to simultaneously determine dopamine, 3,4-dihydroxyphenylacetic acid and homovanillic acid. Dopamine utilization was recorded as a ratio of metabolite to its parent amine. At 4 h following injection large bilateral increases in dopamine utilization were recorded in both medial and lateral sectors of caudate-putamen. The percentage increases found for homovanillic acid-based ratios were larger than those found for 3,4-dihydroxyphenylacetic acid-based ratios. These results probably reflect increased dopamine release resulting from the acute effects of ibotenic acid. These changes were independent of dopamine utilization ratios recorded in the substantia nigra, which showed no change either ipsilateral or contralateral to the injection. In contrast to these findings, at 7 days following injection, dopamine utilization ratios were reduced both ipsilateral and contralateral to the injection, although only the ipsilateral reductions were significant. Again, no change was found for this survival time in the substantia nigra. At 18 h survival an intermediate pattern between the 4 h and 7 day result was found. In the nucleus accumbens, ibotenic acid injection produced similar results to those found in caudate-putamen, i.e. a bilateral increase in dopamine utilization at early time intervals and a unilateral ipsilateral decrease at long intervals following injection. These results show that dopamine release in the caudate-putamen is sensitive to experimentally induced changes in neural activity and lesions of its thalamic input. Since the effect of presumed stimulation is markedly greater than lesion, it would appear that, under the conditions employed in these experiments, the thalamus is relatively silent; a suggestion consistent with other evidence. Furthermore, since the changes found occurred in the absence of changes in utilization ratios in the substantia nigra, the mechanisms whereby thalamus regulates dopamine release may be exerted via a local circuit and/or a presynaptic mechanism in the region of dopamine terminals. The anatomical routes responsible for these effects are discussed.(ABSTRACT TRUNCATED AT 400 WORDS)
Dopamine receptor binding in the caudate-putamen was studied following bilateral lesions of the thalamostriatal pathway. Receptor binding was assayed using [3H]spiperone and defined with both (+)-butaclamol and S(-)-sulpiride. Radiofrequency lesions resulted in an increase in the Bmax of [3H]spiperone binding defined with both (+)-butaclamol and S(-)-sulpiride between 7 and 14 days following surgery. At longer survival times a fluctuating response was seen in which a decrease in receptor binding was observed at 28 days following lesion and a further rise again at 70 days. At no time point was significant change in Kd recorded. Further experiments were carried out to control for the possible effects of damage to fibres of passage and for inadvertent damage to habenula, as well as to define the receptor subtype involved. Ibotenic acid lesions resulted in similar effects to those reported with the radiofrequency method. Thus, 7 days following lesion, Bmax for (+)-butaclamol-defined [3H]spiperone binding increased by approximately 14-20% over that recorded in sham-lesioned animals. Using S(-)-sulpiride to define binding, Bmax was found to increase 13-17% in the same membrane preparations. Similar results were obtained in experiments at 14 days following ibotenic acid induced lesions. Again, no change in Kd was recorded. When radiofrequency lesions were made, which were largely restricted to habenula and associated fibres of passage, only small [(+)-butaclamol defined] or insignificant [S(-)-sulpiride defined] changes in Bmax were recorded. Combined radiofrequency lesions of habenula and ibotenic acid lesions of the thalamus resulted in a larger increase in Bmax for (+)-butaclamol defined binding than with S(-)-sulpiride defined binding. Our interpretation of these findings, in the light of the histology of the lesions, is that the predominant effect of removing thalamic input to the caudate-putamen is an increase in the number of D2 receptors, but without any change of affinity. A small component of the change in Bmax defined with (+)-butaclamol found with radiofrequency lesions may be due to a response at non-dopamine sites (possibly a 5-hydroxytryptamine receptor subtype) following damage to other caudate-putamen afferents which pass near the habenula or fasciculus retroflexus. Following unilateral ibotenic acid lesions of the thalamus, the number of high affinity uptake sites for dopamine was increased at long survival times.(ABSTRACT TRUNCATED AT 400 WORDS)
The application of a commercially available coulometric electrochemical detector to the automated HPLC analysis of some monoamines and their metabolites in microdissected areas of the rat nervous system is described. Apart from the stability and high sensitivity of the system, other appealing features of the technique are the facile sample preparation and long-term sample storage characteristics which show minimal analyte degradation. Basal values of some regional monoamine and metabolite concentration are listed together with a brief appendix that serves as a user's guide to the operation and maintenance of the detection system.
A spinothalamic tract that courses in the dorsolateral funiculus of the spinal cord and originates almost exclusively from spinal lamina I neurons has been demonstrated in the cat by retrograde transport of horseradish peroxidase. This tract is of special interest because the course of this predominantly lamina I, contralateral projection lies outside the classical course of the spinothalamic tract and because most lamina I cells contributing to the spinothalamic tract have been shown by other investigators to respond exclusively to somatic noxious stimuli. This newly described tract has important implications in the processing of noxious stimuli.
Cimetidine is an inhibitor of drug metabolism. We studied the effects of cimetidine (1,200 mg/d) on steady-state serum concentrations of carbamazepine and phenytoin in 11 epileptic volunteers. The mean serum carbamazepine concentration was unchanged after 7 days of cimetidine treatment. Five subjects were taking phenytoin concurrently; their mean serum phenytoin concentration was significantly increased after 7 and 10 days of cimetidine treatment and returned to baseline 2 weeks after cimetidine was discontinued. Cimetidine apparently inhibits the clearance of phenytoin but not of carbamazepine in adults on chronic therapy.
Explore the source record for details and available documents.