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Biomedical subjects

R Ferner

Publications and source records attributed to R Ferner.

14 recordsLinked to original sources
PubMed2005

Management of the patient and family with neurofibromatosis 2: a consensus conference statement.

A consensus conference on neurofibromatosis 2 (NF2) was held in 2002 at the request of the United Kingdom (UK) Neurofibromatosis Association, with particular emphasis on vestibular schwannoma (VS) surgery. NF2 patients should be managed at specialty treatment centres, whose staff has extensive experience with the disease. All NF2 patients and their families should have access to genetic testing because presymptomatic diagnosis improves the clinical management of the disease. Some clinical manifestations of NF2, such as ocular abnormalities, can be detected in infancy; therefore, clinical screening for at-risk members of NF2 families can start at birth, with the first magnetic resonance (MRI) scan at 10-12 years of age. Minimal interference, maintenance of quality of life, and conservation of function or auditory rehabilitation are the cornerstones of NF2 management, and the decision points to achieve these goals for patients with different clinical presentations are discussed.

Adult↗
PubMed2003

Molecular analysis of astrocytomas presenting after age 10 in individuals with NF1.

BACKGROUND: Fifteen to 20% of children with neurofibromatosis type 1 (NF1) develop low-grade astrocytomas. Although brain tumors are less common in teenagers and adults with NF1, recent studies have suggested that patients with NF1 are at a significantly increased risk of developing astrocytomas. OBJECTIVE: S: To investigate the genetic basis for astrocytoma development in patients with NF1 beyond the first decade of life. METHODS: The authors performed molecular genetic analyses of 10 NF1-associated astrocytomas representing all World Health Organization (WHO) malignancy grades using fluorescence in situ hybridization, loss of heterozygosity, immunohistochemistry, and direct sequencing. RESULTS: Later-onset NF1-associated astrocytomas, unlike histologically identical sporadic astrocytomas, exhibit NF1 inactivation, supporting a direct association with NF1 rather than a chance occurrence. Furthermore, some of these astrocytomas have homozygous NF1 deletion. In addition, genetic changes observed in high-grade sporadic astrocytomas, including TP53 mutation and CDKN2A/p16 deletion, are also seen in NF1-associated high-grade astrocytomas. CONCLUSIONS: Neurofibromatosis type 1-associated astrocytomas occurring in patients older than 10 years exhibit genetic changes observed in sporadic high-grade astrocytomas. Patients with neurofibromatosis type 1 and germline NF1 deletions may be at risk for developing late-onset astrocytomas.

Adolescent↗
PubMed2000

A search for evidence of somatic mutations in the NF1 gene.

Neurofibromatosis type I (NF1) is an autosomal dominant disorder affecting 1 in 3000 people. The NF1 gene is located on chromosome 17q11.2, spans 350 kb of genomic DNA, and contains 60 exons. A major phenotypic feature of the disease is the widespread occurrence of benign dermal and plexiform neurofibromas. Genetic and biochemical data support the hypothesis that NF1 acts as a tumour suppressor gene. Molecular analysis of a number of NF1 specific tumours has shown the inactivation of both NF1 alleles during tumourigenesis, in accordance with Knudson's "two hit" hypothesis. We have studied 82 tumours from 45 NF1 patients. Two separate strategies were used in this study to search for the somatic changes involved in the formation of NF1 tumours. First, evidence of loss of heterozygosity (LOH) of the NF1 gene region was investigated, and, second, a screen for the presence of sequence alterations was conducted on a large panel of DNA derived from matched blood/tumour pairs. In this study, the largest of its kind to date, we found that 12% of the tumours (10/82) exhibited LOH; previous studies have detected LOH in 3-36% of the neurofibromas examined. In addition, an SSCP/HA mutation screen identified five novel NF1 germline and two somatic mutations. In a plexiform neurofibroma from an NF1 patient, mutations in both NF1 alleles have been characterised.

Chromosome Mapping↗
PubMed1999

Toxicity of mercury.

A ruling by the European Union heralds the demise of those useful clinical instruments, the mercury thermometer and the mercury sphygmomanometer. The new laws have been passed because of worries about mercury poisoning. Yet you can drink metallic mercury and come to no harm. What does it all mean? There are three forms of mercury from a toxicological point of view: inorganic mercury salts; organic mercury compounds; and metallic mercury. Inorganic mercury salts are water soluble, irritate the gut, and cause severe kidney damage. Organic mercury compounds, which are fat soluble, can cross the blood brain barrier and cause neurological damage. Mercury metal poses two dangers. It can be vaporised: the vapour pressure at room temperature is about 100 times the safe amount, so poisoning can occur if mercury metal is spilled into crevices or cracks in the floorboards. Dentists are occasionally poisoned this way. Mercury easily crosses into the brain, and causes tremor, depression, and behavioural disturbances. A second danger from metallic mercury is that it is biotransformed into organic mercury, by bacteria at the bottom of lakes. This can be passed along the food chain and eventually to man. It was this process that led to the Japanese tragedy at Minimata Bay in the late 1950s when over 800 people were poisoned. It is the need to reduce mercury contamination of the environment which should encourage us to cut the usage of metallic mercury. However, much more metallic mercury is spilled as waste by the chemical industry than is dropped on the floor in the clinic.

Animals↗
PubMed1996

Acute effects of beta blockade and exercise on mood and anxiety.

OBJECTIVE: To measure the previously reported beta blocker induced adverse changes in mood state and anxiety measures, and to determine if prolonged aerobic exercise attenuates such mood modifications. METHODS: After 4 days of drug treatment with comparable doses of propranolol (40 and 80 mg), metoprolol (50 and 100 mg), or placebo, mood (POMS) and anxiety states (STAI) were assessed in healthy volunteers, before and after 1 h of treadmill walking exercise at 50% maximum oxygen uptake. RESULTS: Compared to placebo, resting "tension", "depression", and "total mood disturbance" were significantly higher on propranolol 80 mg, but all were reduced with exercise. "Fatigue" and "confusion" were also higher on propranolol, and were unaffected by exercise. "Fatigue" was also higher than placebo after exercise on metoprolol 100 mg. "Anxiety" was unaffected by drug treatment or exercise. CONCLUSIONS: The evidence that beta blockers, and particularly propranolol, have adverse effects on mood was confirmed. It would be preferable to prescribe a beta blocker which does not adversely alter mood states. However, exercise significantly reduced the measures of "tension" and "depression" which were adversely increased by propranolol. Exercise prescription may therefore not only be compatible with beta blockade, but a highly desirable adjuvant therapy.

Adrenergic beta-Antagonists↗
PubMed1990

[Can ultrasound detect skeletal metastases?].

78 radiologically certified skeletal metastases--osteolytic as well as osteoplastic--were examined via sonography. A defect of the cortex could be seen in 82%, a periostal reaction in 28.2% and a concomitant soft tissue tumorous formation in 79.4%. In proving a soft part component sonography is superior to the conventional x-ray. Our study shows that osseous metastases can be verified by sonography.

Bone Neoplasms↗
PubMed1990

[Computed tomography of colonic diverticulitis].

33 patients with clinically suspected diverticulitis of the colon were studied prospectively by CT. The predictive value of symptoms, such as thickening of the colonic wall (86.6%), inflammatory changes of the pericolic fatty tissue (87.5%), the presence of diverticula (73.3%) and abscess formation (100%), were examined separately and their significance was evaluated. Our study was performed mainly on clinically less severe cases of diverticulitis. True positive results by CT were reached in 20/21 cases (sensitivity = 95.2%), true negative findings in 9/12 (specificity = 75.0%). The results of CT examinations were compared with those of contrast enemas (n = 24) and/or endoscopy (n = 6). The number of cases was too low to achieve statistic significance; the relatively high percentage of questionably positive results shows the difficulties inherent in these methods. Our study shows that CT is a good means to demonstrate even less severe forms of colonic diverticulitis with sufficient reliability.

Adult↗
PubMed1989

Relative efficacy of intravenous methylprednisolone and ACTH in the treatment of acute relapse in MS.

To compare the efficacy of high-dose intravenous methylprednisolone with intramuscular ACTH in the treatment of acute relapse in multiple sclerosis, we undertook a double-blind, randomized, controlled study involving 61 patients. There was a marked improvement in both groups in the course of the study, but no difference between them in either the rate of recovery or the final outcome. High-dose IV methylprednisolone is a safe alternative to ACTH in the management of acute relapse in MS.

Acute Disease↗
PubMed1987

Management of Guillain-Barré syndrome.

Guillain-Barré syndrome is a predominantly motor polyradiculoneuropathy in which neurological deficit reaches a peak within 1 month of onset. Seventy per cent of patients recover within 1 year, but 10% die and 20% have residual disability. Plasma exchange is advocated for severe cases early in the course of the disease but the role of steroids has yet to be determined.

Female↗
PubMed1983

Incidence and prognostic importance of jaundice after cardiopulmonary bypass surgery.

In a prospective study of 248 consecutive patients undergoing cardiopulmonary bypass surgery, early postoperative "post-pump" jaundice (PPJ) developed in 49 (20%). Development of PPJ was strongly associated with a bad outcome; 25% of jaundiced patients and 1% of non-jaundiced patients died in the postoperative period. The jaundice was a conjugated hyperbilirubinaemia, and was detectable in 48 out of 49 patients by postoperative day 2. Hypotension, hypoxia, and hypothermia ("shocked liver") were not associated with the development of PPJ, nor was evidence of haemolysis or heart-failure. Although PPJ was significantly associated with multiple valve replacement, higher transfusion requirements, and longer cardiopulmonary bypass time, it also occurred in patients undergoing uncomplicated operations. It is suggested that PPJ is caused by a defect in hepatic excretion of bilirubin.

Bilirubin↗
PubMed1981

ABC of ENT.

Explore the source record for details and available documents.

Adolescent↗
PubMedDate not supplied

The role of Se, Mo and Fe in the structure and function of carbon monoxide dehydrogenase.

CO dehydrogenase (EC 1.2.99.2) catalyzes the oxidation of CO according to the following equation: CO + H2O-->CO2 + 2 e- + 2 H+. It is a selenium-containing molybdo-iron-sulfur-flavoenzyme, which has been crystallized and structurally characterized in its oxidized state from the aerobic CO utilizing bacteria Oligotropha carboxidovorans and Hydrogenophaga pseudoflava. Both CO dehydrogenase structures show only minor differences, and the enzymes are dimers of two heterotrimers. Each heterotrimer is composed of a molybdoprotein, a flavoprotein, and an iron-sulfur protein. CO oxidation takes place at the molybdoprotein which contains a 1:1 mononuclear complex of molybdopterin-cytosine dinucleotide and a Mo-ion, along with a catalytically essential S-selanylcysteine. The latter is appropriately positioned in the SeMo-active site by a unique VAYRCSFR active site loop. In H. pseudoflava the arginine preceeding the cysteine in the active site loop is modified to a Cgamma-hydroxy arginine residue which has no obvious function. The substituents in the first coordination sphere of the Mo-ion are the enedithiolate sulfur atoms of the molybdopterin-cytosine dinucleotide, two oxo- and a sulfido-group. Extended X-ray absorption fine structure spectroscopy (EXAFS), along with the crystal structure of CO dehydrogenase (23.2 U mg(-1)) at 1.85 A resolution, have identified a sulfur atom at 2.3 A from the Mo-ion. The sulfur reacts with cyanide yielding thiocyanate. The corresponding inactive desulfo-CO dehydrogenase shows a typical desulfo inhibited-type of Mo-electron paramagnetic resonance (EPR) spectrum. Structural changes at the SeMo-site during catalysis are suggested by the Mo to Se distance of 3.7 A and the Mo-S-Se angle of 113 degrees in the oxidized enzyme which increase to 4.1 A, and 121 degrees, respectively, in the reduced enzyme. The intramolecular electron transport chain in CO dehydrogenase involves the following prosthetic groups and minimal distances: CO-->[Mo of the molybdenum cofactor] - 14.6 A - [2Fe-2S]I - 12.4 A - [2Fe-2S]II - 8.7 A - [FAD].

Aldehyde Oxidoreductases↗