Search PubMed⌕ Search

Biomedical subjects

D J Moore

Publications and source records attributed to D J Moore.

At least 91 records · Page 5Linked to original sources
PubMed1994

The evolutionary origin of the 35 kb circular DNA of Plasmodium falciparum: new evidence supports a possible rhodophyte ancestry.

In common with other Apicomplexan parasites, Plasmodium falciparum carries two extrachromosomal DNAs, one of which, the 6 kb element, is undoubtedly mitochondrial. The second, generally referred to as the 35 kb circle, is of unknown provenance, but the nature and organization of its genetic content makes a mitochondrial association unlikely and the molecule has features reminiscent of plastid genomes. We now report the occurrence on the circle of an open reading frame specifying a predicted 470 amino acid protein that shares more than 50% identity with a gene currently known only on the plastome of red algae. This high degree of conservation confirms the 35 kb circle's plastid ancestry, and we speculate that it may have originated from the rhodoplast of an ancient red algal endosymbiont in the progenitor of the Apicomplexa.

Amino Acid Sequence↗
PubMed1994

A diagnostic craniometric method for determining occlusal vertical dimension.

There is no precise scientific method for determining the correct edentulous occlusal vertical dimension. This study established the proportion between the ear-eye to chin-nose distance for determining reasonable occlusal vertical dimension. Two hundred white and 400 Asian men and women participated in this study. The ear-eye and chin-nose distances were measured with a modified craniometer. The results revealed that left ear-eye distance can be used to predict chin-nose distance with reasonable accuracy. However, the algorithm for making this prediction is not the same for combinations of sex and ethnic origin.

Adult↗
PubMed1994

Assessing shade differences in acrylic resin denture and natural teeth.

Four experiments in this study assess shade differences in acrylic resin denture and natural teeth. The first two examine the perceptual errors made by experienced dentists in their use of a manufacturer-provided shade guide for acrylic resin denture teeth. In the first of four experiments, dentists examine whether the numbering of a selected shade guide corresponds to the arrangement of the tabs from light to dark. In the second experiment, a visual discrimination task determines whether dentists can distinguish shade guide tabs from one another. The results from these two experiments revealed that the numbered progression of the shade tabs does not correspond to a light-to-dark order, that dentists have difficulty discriminating between several shade tabs, and that the shade tabs can be rearranged on an empirical basis. The third experiment demonstrated how the shade of natural teeth varies by age, gender, and complexion. The Biotone shade guide, rearranged in the manner suggested by the second experiment, was used to make these assessments. The fourth experiment examined whether the shades used for complete dentures were similar to shades found in natural teeth. The results from the last two experiments showed that shade selection can be facilitated by use of a rearranged set of shade guide tabs. The results also reveal that natural teeth significantly and clinically darken with age; however, selections made for denture teeth tend to be relatively constant in color, despite the age of the patient. Differences for gender and complexion do not appear to be clinically significant.

Acrylic Resins↗
PubMed1994

A matched cohort study of planned home and hospital births in Western Australia 1981-1987.

OBJECTIVE: to evaluate practice comparing planned home birth with planned hospital birth DESIGN: a retrospective analysis of a cohort who had planned to have a home birth compared with a matched hospital birth group SETTING: Western Australia (WA) PARTICIPANTS: all women (N = 976) who 'booked' to have a home birth 1981-1987 and 2928 matched women who had a planned hospital birth (singleton births only). MEASUREMENTS AND FINDINGS: women in the home birth group had a longer labour, were less likely to have had labour induced or to have had any sort of operative delivery. They were less likely overall to have had complications of labour, but more likely to have had a postpartum haemorrhage and more likely to have had a retained placenta. Babies in the home birth group were heavier and more likely to be post-term. They were less likely to have had an Apgar score below 8 at 5 minutes, to have taken more than 1 minute to establish respiration or to have received resuscitation. The crude odds ratio for planned home births for perinatal mortality was 1.25 (95% CI 0.44-3.55). Postneonatal mortality was more common in the hospital group. Planned home births were generally associated with less intervention than hospital births and with less maternal and neonatal morbidity, with the exception of third stage complications. Although not significant, the increase in perinatal mortality has been observed in other Australian studies of home births and requires continuing evaluation. KEY CONCLUSIONS: Planned home births in WA appear to be associated with less overall maternal and neonatal morbidity and less intervention than hospital births. IMPLICATIONS FOR PRACTICE: whether these observed differences in intervention and morbidity have any relationship to the small, non-significant increase in perinatal mortality could not be determined in this study. Continuing evaluation of home birth practice and outcome is essential.

Cohort Studies↗
PubMed1994

A comparative trial of magnesium citrate (Citramag) and Picolax for barium enema bowel preparation.

It has previously been suggested that a single dose of magnesium citrate produces adequate cleansing of the bowel for barium enema examination. To determine whether such a regimen has any advantage over the widely used two doses of Picolax, a prospective randomized blinded trial was performed with over 100 patients allocated to each of the bowel preparation regimens. Radiographs were assessed for quality of mucosal coating, faecal residue and overall quality of bowel preparation. Patient compliance was good with both regimens. Normal daily activities were inconvenienced significantly more by the Picolax (P < 0.001), whereas the magnesium citrate (Citramag) caused more interruption of sleep (P < 0.01). Mucosal coating was similar with both regimens. There was more faecal residue and poorer overall bowel preparation with Citramag (P < 0.001), although diagnostic accuracy was only infrequently felt to be compromised as a result. Citramag may offer an alternative to Picolax in patients where minimal disruption to daily activities is desirable and where the detection of polyps is not critical.

Activities of Daily Living↗
PubMed1994

The comparison of type of incision for transperitoneal abdominal aortic surgery based on postoperative respiratory complications and morbidity.

Equal access to the abdominal aorta can be attained through midline and transverse abdominal incisions. The surgical literature suggests that transverse incisions cause less postoperative pain and morbidity. Fifty patients (10 females and 40 males, mean age 67 years) undergoing abdominal aortic surgery were randomised to a midline (n = 25) or transverse (n = 25) incision. All patients were evaluated preoperatively and postoperatively for seven days. Changes in pulmonary function (FVC and FEV1), time to open and close the incision, analgesia used (morphine mg/kg/h), clinical or X-ray evidence of chest infection, and the duration of ICU stay were recorded. In the transverse group there was a reduction in the incidence of chest complications (20% vs. 28%, p = ns) and these incisions took longer to open (13.9 +/- 4.6 vs. 9.9 +/- 5.1, p < 0.05), but overall there was no significant difference between any other parameter in the two groups. Our results show no statistically significant difference in morbidity or analgesia consumption following transverse or midline abdominal incisions and we conclude that the type of incision used can be left to the surgeon's preference.

Aged↗
PubMed1994

Improved limb salvage and mobility following peroneal artery bypass.

During the 10-year period August 1981 to 1991, 92 consecutive patients underwent revascularisation to the peroneal artery (40 to the upper third, 30 to the mid and 22 to the distal third). The male/female ratio was 1.6:1 and the mean age was 72 years. Thirteen patients had independent mobility preoperatively while 58 had limited mobility and the remaining 18 were bed/housebound. Following surgery the patients were prospectively evaluated and mean follow-up was 25 months. The 1 and 3 year patency rates were 67 and 59% respectively and cumulative limb salvage rates were 75 and 71%. Forty-four patients returned to independent mobility while 36 had limited mobility and 11 remained housebound. Reconstruction to the peroneal artery is a valuable adjuvant for limb salvage providing satisfactory cumulative patency and facilitating improved mobility.

Aged↗
PubMed1994

Effectiveness of adjunctive irrigation in early periodontitis: multi-center evaluation.

The purpose of this study was to determine the effect of daily water irrigation versus regular oral hygiene alone on gingival and periodontal health in periodontitis patients receiving supportive periodontal treatment. The study also sought to determine if there are enhanced benefits from using an antiplaque zinc sulfate rinse as an irrigant. One hundred fifty-five patients who have had periodontitis and had been treated either surgically or non-surgically completed the 6-month multi-center multi-national study. Patients with at least two 5 mm sites demonstrating bleeding on probing were assigned to 3 equal groups by balanced randomization. In all centers Group A (n = 57) performed regular oral hygiene only, and Group B (n = 58) irrigated with 500 ml water once daily after regular oral hygiene. Group C (n = 40) patients irrigated with a total of 500 ml once daily; following irrigation with 300 ml water, the patients then irrigated with an additional 200 ml with a zinc sulfate solution. The irrigants were diluted to provide the manufacturer's recommended daily dosage. The supragingival irrigation was performed with a commercially available oral irrigator. Bacterial measurements at baseline, 3 months, and 6 months were taken to determine the effect of irrigation on the target organisms and will be reported elsewhere. Gingival index: irrigation with water (Group B) was significantly better than normal oral hygiene (Group A) and irrigation with zinc sulfate (Group C) (P < 0.05) in reducing gingival inflammation. Bleeding on probing: significant reductions in bleeding on probing occurred for water (Group B) compared to normal oral hygiene (Group A) (P < 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1994

The influence of supragingival plaque control on clinical and microbial outcomes following the use of antibiotics for the treatment of periodontitis.

Although supragingival plaque control is essential to successful periodontal therapy, the role of plaque control following systemic antibiotic use in periodontal disease has not been well defined. This study evaluated, following antibiotic use, which clinical and microbial parameters appeared to be influenced primarily by the antibiotics, independent of plaque control, and which outcomes appeared to be dependent on plaque control. Two hundred thirty-six patients (236) with moderate to severe periodontitis were clinically evaluated and microbial samples were taken by their private-practice periodontists. All patients were treated with scaling and root planing and a variety of systemic antibiotics, which were selected based on the microbial and clinical profile of the patient. Three months after therapy, patients were reevaluated and grouped by post-treatment plaque control, as either having very good oral hygiene (LoPl: N = 143; < or = 10% plaque-covered surfaces) or poor oral hygiene (HiPl: N = 93; > or = 25% plaque-covered surfaces). The two groups had different plaque and bleeding scores initially, but similar numbers of pockets probing > 5 mm and similar microbial patterns. Although the LoPl group had a significantly greater reduction in plaque than the HiPl group, bleeding scores and probing depths changed comparably in both groups after antibiotic therapy. Plaque control influenced outcomes significantly, but in a complex manner. The LoPl group exhibited a significantly greater reduction in certain bacteria, for example P. gingivalis. Interactions between plaque control and specific microbial parameters significantly affected clinical outcomes, although neither alone was sufficient to predict outcomes following antibiotic therapy.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1993

Quantitative IR studies of acyl chain conformational order in fatty acid homogeneous membranes of live cells of Acholeplasma laidlawii B.

Acholeplasma laidlawii B has been grown highly enriched in myristic, pentadecanoic, and palmitic acids. The conformational order in the acyl chains of living cell membranes has been compared with that in the membranes of lysed cells and the lipids extracted therefrom, using Fourier-transform infrared (FT-IR) spectroscopic techniques. A gel-liquid-crystal-phase transition (25-45 degrees C) was noted for both the live cells and the membranes. Surprisingly, CH2 wagging progressions, characteristic of coupled oscillators from acyl chains in the all-trans conformation, were detected in the live cells and in the cell membrane. A simple model suggested the presence of 1.7 gauche bonds/chain at the growth temperature (37 degrees C) in each case. Conformational order in the live cells and in the membranes was virtually identical over the range of cell viability (5-40 degrees C), as measured by the thermotropic responses of the k = 1 and k = 2 components of the wagging mode progression. This result was confirmed by studies of the thermotropic response of the symmetric CH2 stretching vibrations, a qualitative index of acyl chain order. In contrast, the membrane lipid extracts (i) show much more conformational disorder from 5 to 25 degrees C than either the live cells or the membranes, (ii) undergo a gel-liquid transition over a broader temperature range and with a reduced magnitude of change in the symmetric CH2 stretching frequency, and (iii) demonstrate a second transition centered at 50 degrees C, which is detected by a large increase in the localized CH2 wagging mode (1368 cm-1) that arises from conformationally disordered kink+gtg states.(ABSTRACT TRUNCATED AT 250 WORDS)

Acholeplasma laidlawii↗
PubMed1993

Sequence and organization of large subunit rRNA genes from the extrachromosomal 35 kb circular DNA of the malaria parasite Plasmodium falciparum.

The malaria parasite Plasmodium falciparum carries an extrachromosomal 35 kb circular DNA molecule of unknown provenance. A striking feature of the circle is a palindromic sequence of genes for subunit rRNAs and several tRNAs, spanning ca. 10.5 kb. The palindrome has an intriguing resemblance to the inverted repeat of plastid genomes, and the sequence and putative secondary structure of the malarial large subunit (LSU) rRNA described in this report were used as the basis of a phylogenetic study. The malarial rRNA was found to be highly divergent in comparison with a selected group of chloroplast LSU rRNAs but was more closely related to them than to mitochondrial LSU rRNA genes.

Animals↗
PubMed1993

High-performance liquid chromatographic assay for two rifamycin-derived hypocholesterolemic agents in liver and biological fluids.

CGP 43371 (compound I), a mono-pivaloyl oxazole derivative of a 3-piperazino-rifamycin, has been in clinical trials as a potential hypocholesterolemic agent. A reversed-phase high-performance liquid chromatographic (HPLC) assay was developed using a C18 column and a gradient solvent system of methanol-0.1 M sodium acetate, pH 4.5, at a flow-rate of 1 ml/min. The compound and internal standard (rifampicin) were detected by their ultraviolet absorption at 254 nm. Isolation of the compounds from plasma and liver homogenates was accomplished by precipitation of proteins with acetonitrile, followed by evaporation under nitrogen and reconstitution in methanol. Bile, lymph and urine were injected onto the HPLC column without pretreatment. Calibration curves were linear (r > 0.999) over the concentration range 0.25-20.0 micrograms/ml. The assay procedure was also applicable to other rifamycin derivatives and was able to distinguish between molecular species containing small differences in functionality.

Animals↗
PubMed1993

Prospective randomized comparison of in situ and reversed infrapopliteal vein grafts.

A three-centre prospective randomized trial was undertaken to compare the efficacy of in situ and reversed saphenous vein grafts for long bypasses to tibial and peroneal arteries. Of 162 patients entered into the study, 82 received an in situ graft and 80 a reversed vein graft. All operations were for limb salvage and the two groups of patients were well matched for age, sex, incidence of diabetes, smoking habits and coronary artery disease. At a maximum follow-up of 3 years there were 48 primary graft failures: 19 in the in situ group and 29 in the reversed vein group. Of these, three in situ grafts and seven reversed grafts were salvaged by secondary intervention. Secondary cumulative patency rates calculated at 3 years after operation were 68 and 66 per cent respectively for in situ and reversed grafts (P not significant). Cumulative limb salvage rates were 78 per cent for in situ grafts and 87 per cent for reversed grafts (P not significant). Separate analysis of a subgroup with small veins (< or = 3.5 mm minimum diameter) showed cumulative patency rates at 2 years of 74 per cent for in situ grafts and 60 per cent for reversed grafts (P not significant). These results indicate that for veins > 3.5 mm in diameter the in situ and reversed techniques for operation are equally effective. Some doubt remains about the best way of using smaller veins; a large number of such veins need to be studied to resolve this question.

Aged↗
PubMed1993

Uniparental inheritance of the mitochondrial gene cytochrome b in Plasmodium falciparum.

The inheritance of an extrachromosomal 6-kb element has been examined in the human malaria parasite Plasmodium falciparum. A single base pair difference in the cytochrome b gene from the 6-kb element of two different cloned lines of the parasite was identified, and used as a marker in a cross in the mosquito stage of the life cycle. Analysis of 59 individual hybrid oocysts resulting from this cross clearly demonstrated that inheritance of the cytochrome b gene was uniparental. This observation makes it possible to investigate the inheritance and evolution of cytoplasmic traits, including certain forms of drug resistance, in natural populations of this parasite.

Animals↗
PubMed1993

Epidermolysis bullosa and severe ulcerative colitis in an infant.

An infant with epidermolysis bullosa simplex had diarrhea at 3 weeks of age; severe ulcerative colitis was subsequently diagnosed. Epidermolysis bullosa simplex has not been associated with gastrointestinal disease except for buccal ulceration.

Colitis, Ulcerative↗
PubMed1993

Contralateral stenosis and stump pressures: parameters to identify the high risk patient undergoing carotid endarterectomy under local anaesthesia.

Carotid endarterectomy (CEA) under local anaesthesia (LA) enables the assessment of the two parameters of stump pressure and contralateral stenosis as predictors of neurological complications both intra- and postoperatively. Over a 7 year period, 175 carotid endarterectomies were performed under LA and of these, stump pressure measurements and angiographic findings were recorded on 99 patients. There were no deaths, two patients (2.0%) suffered a perioperative stroke (CVA) and one (1.0%) a transient ischaemic attack (TIA). An additional eight patients "obtunded" while the internal carotid artery was clamped, with complete resolution upon revascularisation in all but one patient who recovered fully within 24 h. Patients with contralateral occlusion or > or = 80% stenosis were more likely to develop complications (6/25 vs. 5/74 p < 0.03) and stump pressures were significantly lower in patients suffering an event (34.36 +/- 23.15 vs. 55.57 +/- 27.58, p < 0.02). By combining contralateral stenosis (> or = 80%) and stump pressure (< or = 35 mmHg), a "high risk" group of 42 patients in whom eight of the 11 events occurred, were identified. Contralateral stenosis and low stump pressures can be used in combination to identify high risk patients likely to develop neurological complications during or following CEA.

Aged↗