PubMed Health⌕ Search

Biomedical subjects

R D Evans

Publications and source records attributed to R D Evans.

At least 73 records · Page 4Linked to original sources
PubMed1998

Peripheral fat metabolism during infusion of an exogenous triacylglycerol emulsion.

OBJECTIVE: To test the hypothesis that intravenous infusion of lipid would bring about changes in adipose tissue metabolism, which would tend to spare net fat mobilization, and to attempt to identify the mediators of such responses. DESIGN: The triacylglycerol (TG) emulsion, Intralipid, was infused and metabolic changes in subcutaneous adipose tissue and forearm muscle were assessed by measurements of arterio-venous differences. SUBJECTS: Six normal male subjects aged 21-37 y, with body mass index (BMI) 23.0-25.9 kg/m2. RESULTS: Plasma TG and non-esterified fatty acid (NEFA) concentrations rose during infusion as expected. The rise in systemic plasma NEFA concentration occurred despite decreased NEFA release from adipose tissue. Intralipid infusion resulted in a suppression of intracellular lipolysis in adipose tissue, by mechanisms which are not clear. Plasma leptin concentrations, measured in a search for the regulator of lipolysis, showed consistent leptin release from adipose tissue which did not change significantly with time. CONCLUSION: The suppression of intracellular lipolysis in adipose tissue during Intralipid infusion is a new observation and may reflect a novel mechanism for regulation of fat storage.

3-Hydroxybutyric Acid↗
PubMed1998

Maxillary distraction osteogenesis in Pfeiffer's syndrome: urgent ocular protection by gradual midfacial skeletal advancement.

Distraction osteogenesis is increasingly recognised as a potentially useful technique to achieve the co-ordinated augmentation of craniofacial skeletal and soft tissue. A case is presented where bilateral maxillary distraction was successfully used to advance the midface in the treatment of recurrent ocular dislocation, in a 10-month-old boy with Pfeiffer's syndrome.

Acrocephalosyndactylia↗
PubMed1998

Functional occlusal relationships in a group of post-orthodontic patients: preliminary findings.

This study investigated features of the functional occlusion in a group of 37 patients immediately following two-arch fixed appliance treatment. Study casts were mounted in the retruded axis position on a semi-adjustable articulator and occlusal contacts were recorded with articulating paper in retruded and lateral mandibular positions. The magnitude of the slide between the retruded axis position and the intercuspal position was measured to the nearest 0.5 mm in the antero-posterior, vertical and lateral directions. The results revealed that the majority of subjects had a unilateral contact on initial closure in the retruded axis position, and a slide between this position and the intercuspal position. Most subjects demonstrated canine guidance on the working side in lateral positions. In addition, however, most subjects had contact between the second molars on the non-working side. Based on current concepts of functional occlusion, this group of post-orthodontic patients did not exhibit ideal occlusal relationships. The long-term implications of this finding are unclear, but may be associated with post-orthodontic instability, tooth wear and temporomandibular disorders. A long-term follow-up is planned to attempt to clarify some of these issues.

Dental Articulators↗
PubMed1998

Video versus lecture: effective alternatives for orthodontic auxiliary training.

Many studies have compared the relative effectiveness of visually-aided lectures and videotapes, but methodological flaws have prevented definitive comparison of the techniques. This study assessed the relative effectiveness of the two approaches for orthodontic auxiliary training. This study was a prospective, randomised trial, conducted at the Eastman Dental Hospital and Institute. Two groups of 16 dental auxiliaries, selected at random, studied identification and positioning of orthodontic brackets: one group attended a lecture accompanied by slides and the other viewed a video. Subjects bonded brackets onto acrylic teeth and the results were assessed by computerised image analysis. The subjects completed a questionnaire on their attitudes to the respective teaching methods. Results were assessed for accuracy of bracket placement and variations in type of auxiliary. There was no significant difference between the teaching methods except for bracket positioning where video was slightly better (P < 0.05). There was no significant difference between the types of auxiliary. Generally, video teaching and lecturing were equally effective, with video achieving slightly better results. Both methods were effective at teaching bracket placement, and dental nurses and student hygienists proved equally adept at bracket positioning.

Attitude of Health Personnel↗
PubMed1998

The feet in Pfeiffer's syndrome.

Broad toes are the classic clinical finding occurring in the feet in Pfeiffer's syndrome patients, but few cases undergo formal radiological assessment. However, the feet in other craniosynostosis syndromes resulting from mutations of the fibroblast growth factor receptor 2 gene have anomalies at many other sites within the feet, which raised the possibility that there may also be a wider range of anomalies other than broad big toes in the feet of those with Pfeiffer's syndrome. The object of this study was to assess prospectively the incidence and pattern of clinical and radiographic anomalies of the feet of patients with a confirmed diagnosis of Pfeiffer's syndrome. Twenty-two Pfeiffer's syndrome patients were examined both clinically and radiologically for anomalies of the feet. Clinical examination revealed broad big toes in 12 patients and syndactyly in 2. Radiographs of the feet were evaluated by a radiologist with an interest in skeletal dysplasia as well as by members of the Craniofacial team. A wider range of radiological than clinical anomalies involving the phalanges, metatarsals, and tarsals was seen. The severity of the anomalies observed ranged from normal to those resembling the feet of Apert's syndrome patients. Only 4 patients had radiologically normal feet. These radiographic findings suggest that there is a range of foot anomalies more extensive than the broad big toes, which are classically associated with Pfeiffer's syndrome.

Acrocephalosyndactylia↗
PubMed1998

The elbow in syndromic craniosynostosis.

Craniosynostosis may occur in conjunction with limb and visceral anomalies in more than 100 syndromes and may include anomalies of the elbow. Apert's, Pfeiffer's, Crouzon's, and Saethre-Chotzen syndrome have been linked with anomalies of the elbow, but the incidence and severity of such anomalies is unknown. A prospective radiographic study was undertaken to establish the types, incidence, and severity of elbow anomalies in patients with either Apert's, Pfeiffer's, Crouzon's, or Saethre-Chotzen syndrome attending the Craniofacial Centre at Great Ormond Street Hospital during a 12-month period. This study showed that elbow anomalies were very common in Apert's and Pfeiffer's syndrome, but less so in Crouzon's syndrome. The elbows in all patients with Saethre-Chotzen syndrome were normal. A range of anomalies was seen, with overlap between the syndromes. The severest anomaly seen in children with Crouzon's, Pfeiffer's, and Apert's syndrome was complete synostosis, which may require surgical intervention in due course. The results of this study suggest that the incidence of elbow anomalies in Apert's, Pfeiffer's, and Crouzon's syndrome is higher than the current literature suggests. Synostosis can be so severe that orthopedic review as part of the management of these children may be beneficial and may become increasingly important as more of these children survive into adulthood.

Acrocephalosyndactylia↗
PubMed1998

Alterations in myocardial lipid metabolism during lactation in the rat.

Metabolism of nonesterified fatty acid (palmitate, 1.1 mM) and triacylglycerol (TAG; triolein, 0.4 mM in the form of both rat chylomicrons and very low density lipoproteins) was studied in isolated perfused working hearts from fed nulliparous, lactating, and weaned rats. Hearts from virgin rats oxidized palmitate readily, but optimal cardiac mechanical performance occurred during perfusion with chylomicrons. In hearts from lactating dams, there was a significant increase in palmitate oxidation and a marked decrease in TAG oxidation from both chylomicrons and very low density lipoproteins compared with hearts from nulliparous animals. There was a concomitant decrease in lipoprotein lipase activity in hearts from lactating animals, and TAG in the absence of palmitate could not support optimal cardiac mechanical function. After litter removal, the changes in fatty acid and TAG metabolism observed in lactation returned to nulliparous values within 96 h. These results suggest that, during lactation, both exogenous and endogenous TAGs are directed away from heart and toward the lactating mammary gland; the heart, therefore, has to rely to a greater extent on nonesterified fatty acid for energy provision under these conditions.

Animals↗
PubMed1998

Review of the Dockery procedure for lateral ankle instability. A seven-year retrospective analysis.

This article presents a critical review of the Dockery procedure (autogenous peroneus longus free graft technique) for the treatment of lateral ankle instability. Those patients with gastrocnemius equinus were treated with gastrocnemius recession during surgery. The authors reviewed 33 stabilizations performed over a period of 7 years to analyze the effectiveness of the procedure with and without the addition of the gastrocnemius recession. Assessed were the type and length of conservative therapy, the time to return to regular activity, complications experienced, and the recurrence rate. The results show a reinjury rate of 3%. The complications included infection, prolonged healing, and occasional screw irritation requiring screw removal. In light of the low incidence of reinjury, this technique is a valid procedure for treating lateral ankle instability.

Adolescent↗
PubMed1997

The cervical spine in Crouzon syndrome.

STUDY DESIGN: All cervical spine radiographs of 44 patients with Crouzon syndrome treated at Great Ormond Street Hospital during the past 10 years were studied. OBJECTIVES: To assess the incidence and pattern of cervical spine abnormalities of patients with a confirmed diagnosis of Crouzon syndrome, but particularly regarding progressive fusion. SUMMARY OF BACKGROUND DATA: Previous studies into the cervical spine anomalies in those with Crouzon syndrome have shown an increased incidence of congenital abnormalities compared with the normal population. There is some suggestion from previous studies that cervical spine fusions are progressive in nature. METHODS: All radiographs were reviewed by the craniofacial team, along with a single pediatric radiologist with experience in assessment of skeletal dysplasias. RESULTS: Radiologic abnormalities included "butterfly" vertebrae and fusions of the bodies and the posterior elements. Evidence of fusion was present in eight of 44 (18%) of patients. C2-C3 and C5-C6 were almost equally affected. Block fusions involving multiple vertebrae were seen. Analysis of sequential studies in 16 patients showed evidence of progression in five. CONCLUSIONS: These results reveal an incidence of fusions that is lower than reported previously. There is radiologic evidence from serial studies that the fusions are progressive, and because these patients are children, the fusion process may not be complete, which may account for the lower incidence of fusions than in previous studies. The pattern of fusions is different from that in earlier studies, which may be a result of the method of diagnosis because this population is less likely to include atypical forms of other syndromes (which have a higher incidence of cervical fusions, particularly at C2-C3). Regarding other congenital anomalies, it appears that butterfly vertebrae are especially prevalent in association with Crouzon syndrome.

Cervical Vertebrae↗
PubMed1997

Effect of endotoxin and platelet-activating factor on lipid oxidation in the rat heart.

The effects of endotoxin and platelet-activating factor (PAF) administered in vivo and in vitro on lipid oxidation by isolated perfused working rat heart were investigated and compared. Endotoxin administered in vivo decreased oleate oxidation in perfused hearts and caused increased accumulation of lipid in myocardial tissue; this was accompanied by a dose-dependent inhibition of cardiac mechanical function. There was no effect on triolein (chylomicron) oxidation. By contrast, PAF administered in vivo caused a small (non-significant) increase in the oxidation rate of oleate and triolein, and also increased myocardial lipoprotein lipase activity. Cardiac mechanical function was not inhibited by PAF-indeed pretreatment of animals by PAF administered in vivo protected the heart from the decline in function associated with subsequent fatty acid perfusion. Administration of endotoxin during perfusion in vitro did not affect oleate or triolein oxidation and cardiac mechanical function was unchanged; PAF administered in vitro caused an early increase in oleate oxidation and a later increase in triolein oxidation. Administration of both endotoxin and PAF in vitro increased myocardial lipoprotein lipase activity. PAF is unlikely to be responsible for all of the effects of endotoxin on cardiac lipid metabolism.

Animals↗
PubMed1997

Hand anomalies in Crouzon syndrome.

OBJECTIVE: To review the hand radiographs of patients with Crouzon syndrome, to look for extracranial manifestations of the condition at this site. DESIGN: The hand radiographs of those with Crouzon syndrome attending the Craniofacial Service at Great Ormond Street between 1985 and 1996 were reviewed. RESULTS: Thirty-three patients underwent a total of 34 radiographs, one patient having had a serial study. This revealed a range of minor anomalies. Most striking was the presence of carpal fusions in four cases, a feature which has not previously been reported. CONCLUSION: The hands of Crouzon syndrome may have anomalies including carpal fusions, and these results are evidence that the condition may produce subtle effects on the hands.

Adolescent↗
PubMed1997

Effect of desferrioxamine cardioplegia on ischemia-reperfusion injury in isolated rat heart.

BACKGROUND: The protective effect of desferrioxamine against myocardial ischemia-reperfusion injury remains uncertain. In this study we examined a broad range of ischemia-reperfusion indices to determine the effect of desferrioxamine cardioplegia in a model that reflects surgical practice. METHODS: Isolated rat hearts were subjected to 90 minutes of ischemia with cold cardioplegia, with or without 0.5-mmol/L desferrioxamine. Left ventricular mechanical function and the levels of thiobarbituric acid-reactive substances and nonprotein thiol compounds were measured after reperfusion. Electron microscopic analysis of mitochondria was performed using diaminobenzidine staining, together with histochemical staining for glycogen and marker enzymes in left ventricular muscle and the atrioventricular node. RESULTS: The desferrioxamine group showed better preservation of diastolic function (chamber stiffness coefficient at 15 minutes and maximum rate of decrease of left ventricular pressure at 45 minutes of reperfusion). Histochemical analysis showed that mitochondria-specific succinate dehydrogenase and the nonspecific esterase of the atrioventricular node were better preserved in the desferrioxamine group. CONCLUSIONS: The findings from this study indicate that there is added protection against ischemia-reperfusion injury when desferrioxamine is added to the cardioplegic solution; however, the study also highlighted that, in this clinically applicable model, desferrioxamine is not universally protective against all aspects of ischemia-reperfusion injury.

Animals↗
PubMed1997

Craniosynostosis associated with FGFR3 pro250arg mutation results in a range of clinical presentations including unisutural sporadic craniosynostosis.

Several mutations involving the fibroblast growth factor receptor (FGFR) gene family have been identified in association with phenotypically distinct forms of craniosynostosis. One such point mutation, resulting in the substitution of proline by arginine in a critical region of the linker region between the first and second immunoglobulin-like domains, is associated with highly specific phenotypic consequences in that mutation at this point in FGFR1 results in Pfeiffer syndrome and analogous mutation in FGFR2 results in Apert syndrome. We now show that a much more variable clinical presentation accompanies analogous mutation in the FGFR3 gene. Specifically, mental retardation, apparently unrelated to the management of the craniosynostosis, appears to be a variable clinical consequence of this FGFR3 mutation.

Acrocephalosyndactylia↗
PubMed1997

The cervical spine in Saethre-Chotzen syndrome.

Twenty patients with a diagnosis of Saethre-Chotzen syndrome had their cervical spine radiographs reviewed. Radiologic abnormalities including vertebral fusion were present in 9 of the 20 patients. Fusion of both the vertebral bodies and the posterior elements was noted, although the latter site was more common. C2-3 was the level most commonly involved, although other levels were recorded. Analysis of sequential radiographs in nine patients revealed evidence of progression in seven patients. In those studies in children aged under 2 years, only 1 of 18 films showed evidence of fusion, while in those over 2 years of age, 10 of 12 showed evidence of fusion. These results reveal that the incidence of cervical anomalies in Saethre-Chotzen syndrome is greater than that in the general population. There is both direct and indirect evidence that the vertebral fusions are progressive during childhood.

Blepharoptosis↗