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Biomedical subjects

A Michael

Publications and source records attributed to A Michael.

At least 73 records · Page 4Linked to original sources
PubMed1997

UNIFOLIATA regulates leaf and flower morphogenesis in pea.

BACKGROUND: The vegetative phenotype of the pea mutant unifoliata (uni) is a simplification of the wild-type compound leaf to a single leaflet. Mutant uni plants are also self-sterile and the flowers resemble known floral meristem and organ identity mutants. In Antirrhinum and Arabidopsis, mutations in the floral meristem identity gene FLORICAULA/LEAFY (FLO/LFY) affect flower development alone, whereas the tobacco FLO/LFY homologue, NFL, is expressed in vegetative tissues, suggesting that NFL specifies determinacy in the progenitor cells for both flowers and leaves. In this paper, we characterised the pea homologue of FLO/LFY. RESULTS: The pea cDNA homologue of FLO/LFY, PEAFLO, mapped to the uni locus in recombinant-inbred mapping populations and markers based on PEAFLO cosegregated with uni in segregating sibling populations. The characterisation of two spontaneous uni mutant alleles, one containing a deletion and the other a point mutation in the PEAFLO coding sequences, predicted that PEAFLO corresponds to UNI and that the mutant vegetative phenotype was conferred by the defective PEAFLO gene. CONCLUSIONS: The uni mutant demonstrates that there are shared regulatory processes in the morphogenesis of leaves and flowers and that floral meristem identity genes have an extended role in plant development. Pleiotropic regulatory genes such as UNI support the hypothesis that leaves and flowers derive from a common ancestral sporophyll-like structure. The regulation of indeterminancy during leaf and flower morphogenesis by UNI may reflect a primitive function for the gene in the pre-angiosperm era.

Alleles↗
PubMed1997

Course of bone mineral content changes around cementless Zweymueller total hip arthroplasty. A 4-year follow-up study.

In this prospective study we followed the bone mineral content (BMC) changes over time in seven zones of interest around uncemented Zweymueller total hip arthroplasty (THA) components, using dual-energy X-ray absorptiometry (DEXA) combined with a radiographical analysis of the distal femoral cortices, close to the tip of the stem. In 36 women (average age 55 years) operated on for primary hip osteoarthritis, BMC of the hips was measured preoperatively and 2 weeks, 1 year and 4 years postoperatively. In particular, a significant decrease of the preoperative values (ranging from 35% to 42.53%; P = 0.05 to 0.01) was noted immediately postoperatively in zones 2-7. Thereafter, an additional significant increase of BMC was observed between the first and last observations at the greater (30%, P < 0.05) and lesser (35.48%, P < 0.01) trochanter. The BMC changes over time were not related to the age of the patients. The BMC reduction observed immediately after implantation of the Zweymueller THA is probably related to the intraoperatively removed bone from (1) the medial and distal inner surface of the acetabulum and (2) the inner femoral cortex. Thereafter, the BMC in zones 2, 6 and 7 remained practically unchanged. The fact that a significantly delayed BMC increase was found in the region of the greater and minor trochanter 4 years later may be due to an increasing, continuous bone turnover in the intertrochanteric area. Thus, the Zweymueller screw socket becomes definitively anchored immediately postoperatively in the medial and distal thirds of the acetabulum and remains stable over time, whereas the Zweymueller stem is mainly anchored within the distal femoral cortex as well as within the mass of the greater and minor trochanter, and was still stable at the 4-year follow-up.

Absorptiometry, Photon↗
PubMed1997

Three-level thoracic disc herniation: case report and review of the literature.

A rare case of three-level thoracic disc herniation with associated neurological impairment, including motor, sensor and urinary disturbances, is reported. The diagnosis and localization of the level of cord compression were mainly based on the clinical examination supported by the findings of magnetic resonance imaging and somatosensory evoked potentials. An anterolateral transthoracic approach at the upper-most affected level was selected for removal of all herniated discs, with the use of a surgical microscope; the resected rib was used for intervertebral fusion. An improvement in the patient's subjective and neurological condition was already apparent a few months after the operation, and solid fusion was roentgenographically found at all operated levels. The use of a surgical microscope allows complete removal of the herniated disc while avoiding wide vertebrectomy and associated iatrogenic damage to the spinal cord.

Adult↗
PubMed1997

Changes in bone mineral density around a stable uncemented total hip arthroplasty.

Changes in bone mineral density (BMD) around the components of the Zweymueller total hip arthroplasty were measured, using dual energy X-ray absorptiometry, in 36 women who were operated on for primary osteoarthritis. Seven regions of interest were studied. No changes occurred around the screw socket and the greater trochanter: but there was a significant reduction of BMD, only when measured immediately after the operation at the lesser trochanter and at the distal femoral cortex lateral and medial to the tip of the stem. These changes were not related to the age of the patients. The reduction of BMD in the femur was mostly associated with areas where bone had been removed at operation. The press-fit fixation of the Zweymueller stem and the maintenance of its fixation with time did not induce further bone turnover around it. The absence of changes in bone mineral density was due to the relatively small amount of subchondral removed and to the continued stable fixation of the socket.

Absorptiometry, Photon↗
PubMed1997

Reduced platelet aggregation after fluvastatin therapy is associated with altered platelet lipid composition and drug binding to the platelets.

AIMS: High plasma cholesterol concentration and increased platelet activity are two major risk factors for atherosclerosis. Lovastatin, the lipophilic drug was shown to inhibit platelet aggregation whereas pravastatin, the hydrophilic drug had no such effect. Analysis of the effect of fluvastatin which is both a lipophilic and hydrophilic drug, on platelet aggregation was the goal of the present study. METHODS: Fluvastatin 40 mg daily was administered to 25 patients with hypercholesterolaemia for up to 24 weeks. Normal subjects acted as controls. The influence of fluvastatin on plasma lipids and on platelet aggregation and fluidity was studied. The direct effect of fluvastatin on platelets was compared with that of other statins. RESULTS: Fluvastatin therapy (40 mg day (-1) for a period of 4 weeks) in hypercholesterolaemic patients resulted in a 23% and 29% reduction in plasma levels of total cholesterol and LDL-cholesterol respectively. Platelet cholesterol/phospholipids molar ratio was reduced by 26% and platelet aggregation was significantly (P<0.02) reduced by 10% after 4 weeks of fluvastatin treatment. On continuing fluvastatin therapy for additional 20 weeks, no further decrement in plasma LDL cholesterol levels or in platelet cholesterol/phospholipid ratio were noted. However, platelet aggregation was further significantly (P<0.01) reduced by up to 15%. Incubation of platelets with increasing concentrations of fluvastatin or lovastatin, demonstrated a dose-dependent reduction in platelet aggregation, whereas pravastatin showed no effect. This inhibitory effect of fluvastatin or lovastatin on platelet aggregation (up to 34% or 22% respectively at a concentration of 1 microg statin ml (-1) was found both in platelet rich plasma and in washed platelet suspensions. Fluvastatin and lovastatin (but not pravastatin), seem to share similar platelet binding sites, as non labelled fluvastatin or lovastatin were able to displace [3H]-labeled-fluvastatin from its binding sites on platelets. CONCLUSIONS: Fluvastatin therapy reduces platelet aggregation via a dual effect which involves its in vivo hypocholesterolaemic action on platelet cholesterol content, and also a direct effect of the drug binding to the platelets. The antiatherogenicity of fluvastatin may be related, in addition to its plasma cholesterol lowering ability, to its inhibitory effect on platelet activation.

Adult↗
PubMed1997

High rates of genital mycoplasma infection in the highlands of Papua New Guinea determined both by culture and by a commercial detection kit.

Duplicate vaginal swabs were collected from 100 women, and comparisons were made between an in-house broth-agar culture system and a commercially available kit, the Mycoplasma IST kit (bioMérieux), for the detection of Mycoplasma hominis and Ureaplasma urealyticum. There was good agreement between the two systems for detection of the genital mycoplasmas in terms of sensitivity, with values of > 92% being obtained. In terms of specificity, the mutual comparisons were less favorable, though specificity values of > 72% were obtained. Statistically there was no significant difference in the performance of the two tests (P < 0.1 for both M. hominis and U. urealyticum). While the broth-agar culture system was considerably less expensive than the kit, the Mycoplasma IST kit provided additional information on antibiotic susceptibilities and had the advantages of a shelf life of up to 12 months and not requiring the preparation of culture media. The prevalences of colonization obtained for M. hominis and U. urealyticum were extremely high in this randomly selected group of women from periurban and rural settlements in the Eastern Highlands of Papua New Guinea, being > or = 70% for M. hominis and > or = 78% for U. urealyticum. colonization with both genital mycoplasmas simultaneously was also very common, with > or = 60% of women being colonized by both M. hominis and U. urealyticum.

Adolescent↗
PubMed1996

Bisexual erotomania with polycystic ovary disease.

The case of a women with polycystic ovary disease and delusional disorder is reported. During the course of her paranoid illness she developed firstly "homosexual' erotomania and later "heterosexual' erotomania. We suggest that this is a rare presentation of delusional disorder.

Adult↗
PubMed1996

The application of EMLA and glyceryl trinitrate ointment prior to venepuncture.

The efficacy of EMLA cream combined with glyceryl trinitrate (GTN) ointment was assessed by a double-blind prospective study. Adult female patients were randomly allocated to receive either EMLA 1 ml or 2 ml combined with GTN 2 mg, or EMLA 2 ml only. The difference in pain scores between the three groups was not statistically significant. When GTN was used with EMLA, the quality of the veins was superior and aided intravenous cannulation. There were no significant side-effects. It is concluded that if GTN is used with EMLA, the dose of EMLA can be reduced and intravenous cannulation is technically easier compared with EMLA alone.

Adult↗