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Biomedical subjects

R J Newman

Publications and source records attributed to R J Newman.

At least 19 recordsLinked to original sources
PubMed2006

Behavioral and biochemical characterization of a mutant mouse strain lacking D-amino acid oxidase activity and its implications for schizophrenia.

D-amino acid oxidase (DAO) degrades D-serine, a co-agonist at the NMDA receptor (NMDAR). Hypofunction of the NMDAR has been suggested to contribute to the pathophysiology of schizophrenia. Intriguingly, DAO has been recently identified as a risk factor for schizophrenia through genetic association studies. A naturally occurring mouse strain (ddY/DAO-) has been identified which lacks DAO activity. We have characterized this strain both behaviorally and biochemically to evaluate DAO as a target for schizophrenia. We have confirmed that this strain lacks DAO activity and shown for the first time it has increased occupancy of the NMDAR glycine site due to elevated extracellular D-serine levels and has enhanced NMDAR function in vivo. Furthermore, the ddY/DAO- strain displays behaviors which suggest that it will be a useful tool for evaluation of the clinical benefit of DAO inhibition in schizophrenia.

Acoustic Stimulation↗
PubMed2004

Repair of acute rupture of the Achilles tendon: a new technique using polyester tape without external splintage.

INTRODUCTION: A new method of treating acute rupture of the Achilles tendon using polyester tape is reported. This requires no postoperative splintage, allows earlier mobilisation and prompt return to work and sport. PATIENTS AND METHODS: Thirty patients were reviewed prospectively and at a mean of 3 years from surgery. RESULTS: The average time of return to work, full weight-bearing and to driving was 40 days, 45 days and 49 days, respectively. The average time for return to sport was 122 days. Three patients required further surgery, two for infected wounds and one for scar release. There was one sural nerve injury. Twenty-two patients regained a normal range of ankle and subtalar movement, with the mean power of plantar flexion 84% of the opposite side. Of the 22 patients who played sport, 14 were still performing at the same or a higher level. There were no re-ruptures over this period. CONCLUSIONS: The technique is straightforward and avoids splintage. It also conveys other short- and long-term advantages over more established methods.

Achilles Tendon↗
PubMed2003

GABA(A) alpha 1 subunit knock-out mice do not show a hyperlocomotor response following amphetamine or cocaine treatment.

The GABA(A) receptor system provides the major inhibitory control in the CNS, with the alpha 1 beta 2 gamma 2 subunit combination being the most abundant and widely distributed form of the receptor. The alpha1 subunit knock-out (alpha1 KO) mice had a surprisingly mild overt phenotype, despite having lost approximately 60% of all GABA(A) receptors. The alpha1 KO mice had normal spontaneous locomotor activity, but were more sensitive to the sedating/ataxic effects of diazepam than wildtype (WT) mice. Pharmacological modulation of dopamine and N-methyl-D-aspartate (NMDA) receptors also produced altered responses in alpha1 KO mice compared with WT mice. As expected, the NMDA receptor antagonist MK801, amphetamine and cocaine increased locomotor activity in WT mice. Although MK801 increased locomotor activity in alpha1 KO mice, amphetamine and cocaine induced stereotypy not hyperlocomotion. Binding studies showed no gross changes in the total number of D1, D2 or NMDA receptors. Furthermore, pre-pulse inhibition of acoustic startle and the effects of cocaine in conditioned place preference were similar in both alpha1 KO and WT mice, indicating selective rather that global changes in response to dopaminergic agents. These data demonstrate subtle changes in behaviours mediated by neurotransmitters other than GABA in alpha1 KO mice and suggest that compensation may have occurred beyond the GABAergic system.

Amphetamine↗
PubMed2002

The Gotfried percutaneous compression plate compared with the conventional classic hip screw for the fixation of intertrochanteric fractures of the hip.

We performed a randomised, prospective trial in 111 patients with intertrochanteric fractures of the hip comparing the use of the Gotfried percutaneous compression plate (PCCP) with that of the classic hip screw (CHS). Blood loss and transfusion requirement were less in the PCCP group but the operating time was significantly longer. The complication rate after operation was similar in both groups, and at a minimum follow-up of six months there was no difference in the rates of fracture healing or implant failure. The PCCP gives results which are similar to those obtained with a conventional device. Its suggested advantages seem to be theoretical rather than practical and, being a fixed-angle implant, it is not universally applicable.

Aged↗
PubMed2000

Variations in the normal anatomy of the collateral ligaments of the human elbow joint.

The variations which occur in the medial and lateral ligament complexes of the elbow were investigated. These occurred frequently with the standard appearances occurring in no more than half the specimens on the medial side and one quarter of those on the lateral side. Surgeons who regularly perform elbow arthroplasty must be aware of these considerations, especially with the introduction of unconstrained prostheses which rely upon the ligament complex for their postoperative stability.

Aged↗
PubMed2000

Psychometric properties of the Halstead Category Test.

Using the Kuder-Richardson formula 20 (KR-20) corrected for item difficulty, the internal consistency reliability of the Halstead Category Test (HCT) was calculated for a sample (N = 398) of normal patients and volunteers, diffusely brain-damaged patients, and undiagnosed patients sent for neuropsychological assessment. The HCT Total Score reliability was.9716 and the subtest reliabilities ranged from.4587 to.9590. An item analysis found that most of the test items, except for those from Subtests I and II, were within established criteria for item difficulty and the discrimination index.

Adult↗
PubMed1999

Shoulder joint replacement for osteoarthrosis in association with thalidomide-induced phocomelia.

The natural history of thalidomide-induced phocomelia has not yet been established since only 35 years have elapsed since the problems associated with this drug became evident. This paper presents what is considered to be the first case of osteoarthrosis in such an individual treated by shoulder joint replacement. Joint arthoplasty is almost certainly going to become an integral part of the life-long rehabilitation process in such affected individuals.

Adult↗
PubMed1999

Complications of intra- and peri-articular steroid injections.

A prospective study was conducted to investigate the possible complications associated with intra- and peri-articular steroid injections. Data are presented on 1147 injections performed on 672 patients out of a total of 688 consecutive patients attending an orthopaedic outpatient setting. It was found to be a safe procedure, with a very low complication rate, if performed while taking adequate precautions. This should encourage general practitioners to offer these injections in their surgeries.

Adolescent↗
PubMed1998

Mennen paraskeletal plate fixation for fracture of the femoral shaft in association with ipsilateral hip arthroplasty.

We reviewed the results of Mennen paraskeletal plate fixation in 14 patients with fracture of the femoral shaft in association with a previously successful ipsilateral hip arthroplasty. Overall good results were obtained with undisplaced fractures but some of the results in those individuals with widely displaced and unstable fractures were disappointing leading to some serious complications including amputation. The paraskeletal plate appears then to be no more than an internal splint and caution needs to be exercised when this device is used in this situation.

Aged↗
PubMed1998

Primary tumors of the elbow: a review of the Leeds Regional Bone Tumour Registry.

A review of the Leeds Regional Bone Tumour Registry found that primary tumors of the elbow constituted 25 (1.2%) of the 2154 cases recorded between 1958 and 1992. Fifty percent occurred in the ulna, 20% in the radius, 20% in the humerus, and 10% in the soft tissues. Benign tumors were more common than malignant ones (19 versus 6). Malignant tumors occurred more frequently in older patients (mean age: 45 years) compared with patients with benign tumors (mean age: 17 years). The correct preoperative diagnosis was made on clinical or radiologic findings in only 16 patients, and the histologic diagnosis of the referring pathologist was changed by the Bone Tumour Registry panel in one case. In view of the difficulty of accurately diagnosing primary bone tumors, all such lesions should be referred to a regional bone tumor registry. Such registries can provide valuable information about these uncommon conditions for research, teaching, and education.

Adolescent↗
PubMed1994

Bad blood.

Explore the source record for details and available documents.

Blood Banks↗