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Biomedical subjects

G Rea

Publications and source records attributed to G Rea.

At least 19 recordsLinked to original sources
PubMed2005

CSF shunt removal in children with hydrocephalus.

The possibility to remove a previously inserted CSF shunt device in hydrocephalic children is a well known though rare event for paediatric neurosurgeons. A retrospective analysis of our experience with a series of 850 children affected by non tumoral hydrocephalus shows that obvious shunt independence could be demonstrated in 3.2% of the patients (27 cases). The time interval between the CSF shunt insertion and removal ranged between 8 months and 12 years (mean: 8 years). Parameters analysed to search for any predictive elements were age at surgery, aetiology, type of prosthesis utilised, time interval between insertion and removal of the shunt, number of the possible revisions. The results of the study suggest that the highest incidence of shunt independence is reached in subjects operated on in early infancy, as 24 of 27 removed shunts were in patients operated on under 6 months of age, and the remaining in 2 children treated when less than 2 years old. Such a finding could be explained on the grounds of a delay in maturation of the CSF absorption mechanisms followed by a late normalisation in these patients. As regards to aetiology, 41% of the 27 patients considered in this series were affected by a post-haemorrhagic hydrocephalus, which was progressive, as demonstrated by serial neuroradiological examinations and echo-Doppler cerebral studies at the time of the surgical treatment. In six children the hydrocephalus was associated with myelomeningocele. Five patients had aqueduct stenosis and 2 communicating hydrocephalus. The types of CSF shunting system we utilised did not play any role in determining or facilitating shunt independence. No correlation was observed with the need and the number of shunt revisions. The role of the interval time between the insertion and the removal of the shunt was not analysable, because of the possible acquisition of the shunt independence prior to its demonstration at the moment of the surgical revision of the CSF shunt (elective lengthening because of the physiological body growth) or to the radiological demonstration of CSF shunt device disconnection. The same constraint prevents the evaluation of the actual overall incidence of shunt independence in shunted hydrocephalic children, as some of them could have harboured a non-functioning CSF shunt device, though unnoticed.

Age Factors↗
PubMed2005

Reproductive decision making before and after predictive testing for Huntington's disease: an Australian perspective.

A retrospective study examined both pre- and post-result reproductive decision making for 281 people at risk for Huntington's disease aged 18-45 years who had undergone predictive testing in one centre in Australia between 1990 and 2002. Forty-eight per cent of subjects had one or more pre-result pregnancies, and of these, three had prenatal linkage testing. One high-risk (50%) pregnancy was terminated. Four couples chose an alternative reproductive option. Following testing, data were available for 231 subjects, and no significant difference was found between mutation carriers and non-carriers in the occurrence of post-result pregnancies. This contrasts with the finding of a recent European study, although the outcome of the present study may have been influenced by loss of follow-up data for 50 subjects. Five carriers (17%) had a total of six prenatal tests. Four showed a carrier result and these pregnancies were terminated. Two carriers utilized an alternative reproductive option (donor insemination and pre-implantation genetic diagnosis). The results of this study confirm previous findings of a low uptake of prenatal testing and alternative reproductive options by people at risk for Huntington's disease undergoing predictive testing.

Abortion, Induced↗
PubMed2001

[MR imaging in the follow-up of ACL reconstruction: retrospective analysis of 54 patients].

PURPOSE: The authors evaluated the possible presence of lesions, in patients treated for anterior cruciate ligament (ACL) reconstruction. MATERIAL AND METHODS: MR examinations of the knee were performed in 54 patients previously surgically treated for an ACL lesion, with a patellar tendon graft. MR was performed in a period of time ranging from 10 to 36 months after surgery. The authors studied the new ligament, transosseous tunnel location, the patellar tendon, other possible articular lesions and the extent and signal of possible synovial fibrotic reaction. RESULTS: Lesions of the new ligament were found in 21 patients with the following patterns: atrophic reabsorption of the new-ACL (6 patients), and diffuse or focal alterations in morfology and signal (15 patients). In 15 patients the new ACL lesions were associated with incorrect positioning of tibial tunnels. All of the new ligament lesions diagnosed with MR were arthroscopically confirmed. In 12 patients the patellar tendon in 12 patients was involved with inflammatory-degenerative alterations. Other associated lesions were found involving menisci (18 patients), medial collateral ligament (MCL) (8 patients), osteochondral surfaces (12 patients). In patients with an intact new ACL, instability was correlated with meniscal lesions associated with MCL irregularities. In 4 patients a diffuse fibrotic synovial tissue was responsible for limited articular excursion. CONCLUSIONS: MR in post-ACL substitution has to panoramically investigate all articular compartments, with a complete evaluation of all articular lesions that can contribute to articular symptomatology in order to choose the correct therapeutic strategy.

Anterior Cruciate Ligament↗
PubMed2001

[Role of flowmetric analysis and of color-Doppler ultrasonography with contrast media in the different phases and follow-up of Graves' disease].

PURPOSE: The objectives of this study were: 1) to evaluate the role of color-Doppler ultrasonography (CDU) assessment of thyroid vascularity, measuring the peak systolic velocity (PSV) at the level of the inferior thyroid artery, and the intrathyroid vascularization in Graves' diseas; 2) to evaluate the role of contrast agent administration in predicting the relapse of hyperthyroidism or the biological activity of the disease after withdrawal of antithyroid drugs. PATIENTS AND METHOD: The study included 74 Graves' patients (59 F/ 15 M; mean age 45 years; range 23-71). Graves' disease was diagnosed according to the usual clinical and laboratory criteria. On the basis of the clinical and biochemical findings we divided Graves' patients into 4 different groups. Treatment was continued for at least 12 months, CDU examination was carried out after discontinuing therapy. Eight patients showed a relapse of hyperthyroidism within 5 months after suspension of therapy. In all cases the evaluation of intraparenchymal vascularization and PSV at the level of the inferior thyroid artery in basal conditions was followed by administration of contrast agent (Levovist, 300 mg/ml), with slow infusion (<2 ml/min) to avoid blooming artifact. Intraparenchymal vascularization was classified into 4 patterns according to Vitti et al. RESULTS: The value of the peak systolic velocity (PSV) at the level of the inferior thyroid artery was the best predictor of relapse. A value higher than 40 cm/sec was present in all the patients that showed relapse and only in two patients with stable remission. Administration of contrast agent is important to evaluate the biological activity of the disease. In the 5 patients exhibiting slightly increased vascularization after contrast agent administration we could assume the clinico-pathological recovery. CONCLUSIONS: CDU study of thyroid vascularization, based on the measurement of PSV at the level of the inferior thyroid artery and on the response to contrast agent administration is useful to distinguish three groups of patients: A) PSV >40 cm/sec with pattern III for at least 10 minutes from the beginning of the contrast agent administration (High risk of relapse); B) PSV <40 cm/sec with pattern II or III after contrast agent administration (Biological activity of the disease-Thyroiditis); C) PSV <40 cm/sec with Pattern I after contrast agent administration (Poor biological activity of the disease-recovery).

Adult↗
PubMed1998

Developmentally and wound-regulated expression of the gene encoding a cell wall copper amine oxidase in chickpea seedlings.

A chickpea cDNA encoding a cell wall copper amine oxidase (CuAO) was cloned and characterised. The 2010 bp open reading frame encodes a protein of 76.5 kDa which shares significant primary structure homology with other known CuAOs. Southern blot analysis indicates that in chickpea CuAO is encoded by a single gene or a small gene family. This cDNA was essential for studying the role of CuAO during seedling development and wound healing in chickpea seedlings. CuAO transcript level and activity were modulated during seedling development in parallel with cell maturation. Moreover, mechanical wounding induced a rapid increase of CuAO mRNA accumulation and enzyme activity which remained high during the wound-healing process. Aminoguanidine, a specific CuAO inhibitor, decreased the deposition of lignin-suberin barrier along the lesion. CuAO may be a limiting factor in H2O2 production in the cell wall of chickpea seedlings and its expression seems to integrate with the remodelling of plant cell wall occurring during ontogenesis and wound healing.

Amine Oxidase (Copper-Containing)↗
PubMed1998

Maize polyamine oxidase: primary structure from protein and cDNA sequencing.

The first complete amino acid sequence of a flavin-containing polyamine oxidase was solved by a combined approach of nucleotide and peptide sequence analysis. A cDNA of 1737 bp, isolated from maize seedlings by reverse transcription-polymerase chain reaction and rapid amplification of cDNA ends strategies, was cloned and its sequence determined. This cDNA contains information for a polypeptide chain of 500 amino acids. Its amino-terminal sequence shows the typical features of secretion signal peptides. The primary structure of the mature protein was independently confirmed by extensive amino acid sequencing. Structural relationships with flavin-containing monoamine oxidases are also discussed.

Amino Acid Sequence↗
PubMed1998

Competitive inhibition of Lens culinaris L. copper amine oxidase by amiloride, p-aminobenzamidine, clonidine, 4',6-diamidino-2-phenylindole and gabexate mesylate: a comparative study.

The competitive inhibition of Lens culinaris L. copper amine oxidase by amiloride (Ki = 4.1 x 10(-4) M), p-aminobenzamidine (Ki = 6.0 x 10(-4) M), clonidine (Ki = 5.0 x 10(-4) M), 4',6-diamidino-2-phenylindole (DAPI; Ki = 1.9 x 10(-5) M) and gabexate mesylate (Ki = 2.5 x 10(-4) M) has been investigated, at pH 7.0 and 25 degrees C. The affinity of p-aminobenzamidine, clonidine and DAPI for plant and mammalian copper amine oxidase is closely similar. However, values of Ki for amiloride and gabexate mesylate binding to swine kidney copper amine oxidase are lower than those observed for inhibitor binding to Lens culinaris L. cooper amine oxidase. Thus, amiloride and gabexate mesylate may represent useful model compounds for the development of selective inhibitors of mammalian copper amine oxidase, which may be important in view of the potential use of plant copper amine oxidase as drugs.

Amiloride↗
PubMed1996

Continuing investigation and controversy regarding risk of transmission of infection via dental handpieces.

Current epidemiologic evidence indicates that infectious diseases, specifically blood-borne pathogens such as hepatitis B, hepatitis C and HIV, are not transmitted from patient to patient via dental instruments. However, ongoing laboratory investigations suggest that potential pathogens may be retained within dental handpieces, creating a theoretical risk of cross infection. Controversy regarding certain laboratory study results and the clinical implications of these studies continues. Guidelines and regulations for infection control should be rational, and based on a realistic response to a documented risk. Dental professionals should be aware of continuing research focusing on these issues.

Blood-Borne Pathogens↗
PubMed1995

Assessing viral retention and elimination in rotary dental instruments.

The authors of this article used a laboratory model of herpes simplex virus infection to assess the potential for contamination of dental handpieces by a human viral pathogen. They found that although all the handpieces in the study were fitted with anti-retraction valves, it was not until the units were flushed internally and disinfected externally that the pathogens were eliminated.

Dental High-Speed Equipment↗
PubMed1992

The value of panoramic radiographic examination in patients with leukemia before medical management.

Panoramic radiographs were completed for patients with leukemia before the start of medical management. The radiographs were taken as part of the patient admission evaluation. Patients were examined and followed throughout the course of their medical management. Panoramic radiographs did not identify pathologic conditions that were not identified clinically or that required management during medical therapy. The radiograph evaluation was of value in correlation with clinical findings and was required before dental treatment. It is concluded that panoramic radiograph evaluation of patients with leukemia is not indicated as part of their routine evaluation and should not be used to screen patients for occult pathosis. The use of these radiographs should be based on history and examination findings.

Adolescent↗