Search PubMed⌕ Search

Biomedical subjects

M H Moore

Publications and source records attributed to M H Moore.

At least 55 records · Page 3Linked to original sources
PubMed1994

The high-resolution crystal structure of a parallel-stranded guanine tetraplex.

Repeat tracts of guanine bases found in DNA and RNA can form tetraplex structures in the presence of a variety of monovalent cations. Evidence suggests that guanine tetraplexes assume important functions within chromosomal telomeres, immunoglobulin switch regions, and the human immunodeficiency virus genome. The structure of a parallel-stranded tetraplex formed by the hexanucleotide d(TG4T) and stabilized by sodium cations was determined by x-ray crystallography to 1.2 angstroms resolution. Sharply resolved sodium cations were found between and within planes of hydrogen-bonded guanine quartets, and an ordered groove hydration was observed. Distinct intra- and intermolecular stacking arrangements were adopted by the guanine quartets. Thymine bases were exclusively involved in making extensive lattice contacts.

Computer Graphics↗
PubMed1994

Crystal structure of a suicidal DNA repair protein: the Ada O6-methylguanine-DNA methyltransferase from E. coli.

The mutagenic and carcinogenic effects of simple alkylating agents are mainly due to methylation at the O6 position of guanine in DNA. O6-methylguanine directs the incorporation of either thymine or cytosine without blocking DNA replication, resulting in GC to AT transition mutations. In prokaryotic and eukaryotic cells antimutagenic repair is effected by direct reversal of this DNA damage. A suicidal methyltransferase repair protein removes the methyl group from DNA to one of its own cysteine residues. The resulting self-methylation of the active site cysteine renders the protein inactive. Here we report the X-ray structure of the 19 kDa C-terminal domain of the Escherichia coli ada gene product, the prototype of these suicidal methyltransferases. In the crystal structure the active site cysteine is buried. We propose a model for the significant conformational change that the protein must undergo in order to bind DNA and effect methyl transfer.

Amino Acid Sequence↗
PubMed1994

Mandibular lengthening by distraction for airway obstruction in Treacher-Collins syndrome.

Mandibular lengthening by distraction was performed in a 6-year-old tracheostomy-dependent Treacher-Collins syndrome patient. Detailed preoperative imaging revealed an occluded retrotongue base pharyngeal airway, which, following mandibular distraction, became patent and permitted tracheostomy removal. Mandibular distraction as a technique must be targeted toward clinical problems--management of upper-airway obstruction may be one such scenario.

Airway Obstruction↗
PubMed1994

The frontal sinus in frontoethmoidal meningoencephaloceles.

We performed a review of all patients with frontoethmoidal meningoencephaloceles (FEME) in whom frontal sinus development would be expected to be complete. Frontal sinus absence is the predominant finding. The potential role of the FEME in producing a structural blockage to normal frontal sinus development is suggested. Surgical correction of the encephalocele should include augmentation of the glabella to compensate for the combined effects of the FEME and the surgical osteotomies in this region.

Adolescent↗
PubMed1994

Noncraniofacial manifestations of Crouzon's disease.

Although most interest centers on the craniofacial region in Crouzon's disease, noncraniofacial manifestations are important because they may complicate both diagnosis and management. A population of 59 patients with Crouzon's disease was reviewed to determine the frequency of these deformities. Stylohyoid ligament calcification (50%) and cervical spine (40%) and elbow (18%) abnormalities were the most common. Minor hand deformities (10%), other musculoskeletal deformities (7%), and visceral anomalies (7%) were also seen. Acanthosis nigricans was not present in this population. Recommendations are made for the assessment and management of Crouzon's disease with reference to these areas.

Acanthosis Nigricans↗
PubMed1994

Phenotypic variation in acrocephalosyndactyly syndromes: unusual findings in patient with features of Apert and Saethre-Chotzen syndromes.

The acrocephalosyndactyly syndromes have presented diagnostic challenges because of overlap in their clinical manifestations. We present a patient with features most suggestive of Apert syndrome, but with a pattern of syndactyly not previously described. In contrast to the complex syndactyly reported as a universal feature of this syndrome, this patient shows close to total simple syndactyly of the index through ring fingers of each hand. Differential diagnoses are discussed. Because the features are reminiscent of Apert syndrome, we suggest that a new classification of hand morphology should be added to include the pattern described here.

Acrocephalosyndactylia↗
PubMed1993

Upper airway obstruction in the syndromal craniosynostoses.

This series of consecutive cases details the prevalence and management of upper airway obstruction in the syndromal craniosynostoses (Crouzon, Apert and Pfeiffer syndromes). Upper airway obstruction presents more frequently in Crouzon and Pfeiffer syndrome when presenting early and during the intermediate years. Those patients with Apert syndrome appear relatively free of this problem. Management has been directed toward increasing the size of the nasopharyngeal space by soft tissue alterations (uvulopalatopharyngoplasty, soft palatal split and adenotonsillectomy) with success. Le Fort III advancement osteotomy has been reserved for those more extreme cases, again with objective airway improvement. These techniques have removed the necessity for the progression to tracheostomy in these cases.

Adenoidectomy↗
PubMed1993

Progressive hemifacial atrophy (Romberg's disease): skeletal involvement and treatment.

Progressive hemifacial atrophy (Romberg's disease) manifests variable involvement of the skin, soft tissue and underlying cranio-facial skeleton. Significant bony deformation has been identified in those patients with early onset disease, the result of factors both intrinsic to the disease process and secondary to the abnormal environment in which the skeleton develops (functional matrix). Treatment demands combined osteotomy and augmentation of the skeleton in concert with conventional approaches to soft tissue correction.

Adolescent↗
PubMed1993

Associated injuries in facial fractures: review of 839 patients.

Patients with facial trauma may have associated injuries requiring immediate or specialised attention. This paper reports the incidence and nature of significant associated neurosurgical, ocular, spinal, torso and extremity injuries in facial fracture patients treated by the Department of Plastic and Reconstructive Surgery from June 1989 to June 1992. Of 839 patients treated during the period, 95 patients (11.3%) sustained significant concomitant injuries outside the facial skeleton. There were 45 (5.4%) patients with associated neurosurgical injuries, 33 (3.9%) with ocular injuries, 8 (0.9%) with spinal injuries, 16 (1.9%) with injuries of the torso, and 62 (7.4%) with injuries of the extremities. The spectrum of the injuries is presented. Most neurosurgical injuries are a result of focal impact and the intervention required is related mainly to local fracture management and the repair of dural tears. The risk of significant ocular injury is highest when the fracture involves the orbit. Injuries of the spine, torso (chest, abdomen, pelvis), and limbs were seen mainly in road trauma patients.

Abdominal Injuries↗
PubMed1993

Basal encephalocoele: imaging and exposing the hernia.

Basal encephalocoeles are rarely reported anomalies. Eight cases seen by one unit manifested external facial features and internal cerebral anomalies characteristic of the individual encephalocoele subgroups. CT and MR imaging delineates the anatomy of the skeletal defect and the associated cerebral abnormalities. Such imaging of cases of median cleft face syndrome may identify previously unsuspected basal encephalocoeles. Transcranial correction with increased exposure, if needed, by the technique of facial bipartition has been performed in five cases.

Child↗
PubMed1993

Biointegrated hydroxylapatite-coated implant fixation of facial prostheses.

This pilot study reports the 2-year follow-up on hydroxylapatite-coated nonscrew titanium implants (Integral) used for fixation of auricular and orbital prostheses. Fifty-four implants have been inserted in a two-stage procedure for auricular reconstruction in 12 patients and orbital reconstruction in 2 patients. Clinically solid integration has occurred with 51 implants in 13 patients, three implants being lost in previously irradiated bone where soft tissue coverage was never adequate. Early soft tissue reaction occurred in those younger patients and where multiple previous surgery had occurred in the same area. Conservative local treatment produced resolution of this in all patients. Stable retention of cosmetically acceptable orbital prostheses was achieved with bar-clip assembly or magnet arrangements.

Durapatite↗
PubMed1993

Sports-related facial fractures: a review of 137 patients.

One hundred and thirty-seven patients with sports-related facial fractures were reviewed. These made up 16.3% of 839 patients with facial fractures seen at the Department of Plastic and Reconstructive Surgery, Royal Adelaide Hospital, between June 1989 and June 1992. Males made up 93.4% of patients and 89.1% were aged below 35 years. There was an intent to injure in 11%. Australian Rules football was the causative sport in 52.6%, all the injuries being the result of human contact. Orbitozygomatic fractures were the most frequently observed overall (62%) as well as in Australian Football (58.3%). Cricket contributed to 14.6%, the ball being the agent of injury in all but one of the patients. Horse-riding injuries were the most severe. 89.1% of the patients required surgery and hospital stays ranged from 0 to 18 days with an average stay of 4.7 days. Sports activities, although a significant source of enjoyment, are a significant cause of facial fractures with their attendant morbidity.

Adolescent↗
PubMed1993

Prolonged paralysis after neuromuscular junction blockade: case reports and electrodiagnostic findings.

Previous reports have described prolonged paralysis after treatment with neuromuscular junction (NMJ) blocking agents in critically ill patients. The purpose of this study was to describe the clinical and electrodiagnostic findings in 12 such patients. All patients developed prolonged and often profound weakness with no sensory loss after discontinuation of NMJ blockers. Nerve conduction studies generally showed decreased motor evoked response amplitudes with normal conduction velocities and normal sensory studies. Repetitive nerve stimulation demonstrated no decrement or increment in most patients, with a decrement to 3 Hz stimulation in one patient. Needle examination showed frequent fibrillation potentials and normal or low amplitude, short duration, polyphasic motor units. Physicians prescribing NMJ blockers in critically ill patients should be made aware of this potential complication and of the other agents (ie, corticosteroids) that may exacerbate the problem.

Adult↗
PubMed1993

The cloverleaf skull anomaly: managing extreme cranio-orbitofaciostenosis.

The cloverleaf skull anomaly represents the most manifestly extreme form of cranio-orbitofaciostenosis with hydrocephalus that has to date been associated with a uniformly poor outcome and frequent death in infancy. Assessment of the primary deformity and the approach to treatment in a consecutive series of 10 patients with the cloverleaf skull anomaly in the one unit are presented. Early predictable surgical correction of the cranio-stenosis is possible by fronto-orbital advancement and lambdoid craniectomy. Less satisfactory correction of hydrocephalus and orbitostenosis is possible with the attendant increased morbidity. Early survival and the potential for a satisfactory long-term outcome depend on the management of the faciostenosis and an airway that may be anomalous at multiple levels. The initial approach was routine tracheostomy, which provided short-term relief but with the morbidity associated with such airway maintenance in any environment other than the most sophisticated health services. More recently, upper airway surgery (uvulopalatopharyngoplasty, adenoidectomy, and soft palatal split) has ensured airway control and avoided the progression to tracheostomy. When utilized later (1 to 10 years), such surgery may alleviate the symptoms of upper airway obstruction and sleep apnea and permit delay of midfacial advancement.

Child↗
PubMed1992

Nonadjacent syndactyly in the congenital constriction band syndrome.

Hand anomalies in the amniotic band sequence are frequently both complex and difficult to explain in terms of our conventional understanding of limb embryogenesis. A case manifesting pseudosyndactyly between nonadjacent fingers confirms the role of an in utero disturbance after the seventh week, in concert with close apposition between nearby but not adjacent parts.

Amniotic Band Syndrome↗
PubMed1992

Influence of the maxillary canine on mandibular fracture.

The length of the root of the mandibular canine tooth has been considered by many authors as being a source of weakness in the mandible. It has also been suggested that a direct blow or a bending force around this tooth can result in traumatic injury. We advance a theory that implicates the maxillary canine tooth as directly contributing to the mandibular canine region fracture pattern.

Adolescent↗
PubMed1991

DNA-drug interactions. The crystal structures of d(TGTACA) and d(TGATCA) complexed with daunomycin.

The anticancer drug daunomycin has been co-crystallized with the hexanucleotide duplex sequences d(TGTACA) and d(TGATCA) and single crystal X-ray diffraction studies of these two complexes have been carried out. Structure solution of the d(TGTACA) and d(TGATCA) complexes to 1.6 and 1.7 Angstrom resolution, respectively, shows two daunomycin molecules bound to the DNA hexamer. Binding occurs via intercalation of the drug chromophore at the d(TpG) step, and hydrogen bonding interactions involving the drug, DNA and solvent molecules. The daunomycin sugar is located in the minor groove of the DNA hexamer and is stabilized by hydrogen bonds between the amino group of the sugar and functional groups on the floor of the groove. The amino sugar of the d(TGATCA) duplex interacts directly with the DNA sequence, while in the d(TGTACA) duplex, the interaction is via solvent molecules. Two other complexes d(CGTACG)-daunomycin and d(CGATCG)-daunomycin have previously been structurally characterized. Comparison of the four structures with daunomycin bound to the triplet sequences 5'TGT, 5'TGA, 5'CGT and 5'CGA reveals changes in the conformation of both the DNA hexamer and the daunomycin upon complexation, as well as the hydrogen bonding and van der Waals' interactions.

Binding Sites↗